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See detail"Favorites of the Gods". The Seleucid Kings coping with the divine. A qualitative and quantitative approach of the numismatic evidence attesting the "discreet" divinization of the Seleucids"
Iossif, Panagiotis ULg

Doctoral thesis (2016)

Les Séleucides ont hérité de la plus grande partie du territoire légué par Alexandre le Grand. Leur empire, dans son extension maximale, s’étendait de la Chersonèse de Thrace à l’ouest jusqu’à la ... [more ▼]

Les Séleucides ont hérité de la plus grande partie du territoire légué par Alexandre le Grand. Leur empire, dans son extension maximale, s’étendait de la Chersonèse de Thrace à l’ouest jusqu’à la Bactriane à l’est. Des études récentes ont montré que la population de l’empire a pu atteindre un maximum de 30 millions d’habitants appartenant à différents groupes ethniques et culturels. L’administration de ce vaste territoire multiethnique constituait un véritable défi pour les Séleucides. Il ne fait pas de doute que l’essentiel de leur structure administrative la plus grande part de leur structure administrative provenait directement des Achéménides, mais d’autres aspects plus innovants étaient des créations ad hoc visant à résoudre des problèmes particuliers de la Cour royale et de l’administration. Les deux premiers Séleucides, Séleucos Ier et Antiochos Ier, développèrent une politique coloniale intensive en fondant de nouvelles cités dans l’ensemble des territoires nouvellement conquis. Les nouvelles colonies visaient à marquer physiquement et idéologiquement le territoire et les populations indigènes. Certaines de ces nouvelles fondations devinrent des cités importantes de l’empire, tandis que d’autres restèrent simplement des postes militaires protégeant des zones sensibles. Parmi les premières, Séleucie du Tigre et Antioche devinrent d’importants centres urbains et sont souvent, bien que de manière incorrecte, qualifiées de « capitales ». OBJECTIFS DE LA RECHERCHE La ligne idéologique reliant les différents territoires, populations et groupes ethniques de ce vaste empire n’était autre que le roi lui-même et sa dynastie. Dans cet état de la recherche, nous avons considéré que la figure du roi séleucide était sous-étudiée et relativement marginalisée. Les récentes études ont rarement (voire jamais) posé la question du rôle de la personne royale elle-même en tant que constituant idéologique de l’empire. Son rôle vis-à-vis de et avec le divin est virtuellement ignoré, et le culte royal séleucide n’a jamais fait l’objet d’une étude approfondie. L’analyse iconographique des représentations des rois séleucides n’est jamais allée au-delà de la simple description. Pour ces raisons, dans notre thèse nous avons tenté de répondre aux questions suivantes : quel est le rôle du roi (et de la famille royale en général) dans la création idéologique de ce que nous appelons l’empire séleucide ? Comment ces rois ont-ils envisagé leur relation avec le divin ? Quels dieux ont-ils privilégiés et pour quelles raisons ? Ont-ils jamais tenté de devenir eux-mêmes des dieux, ainsi qu’on peut parfois le lire dans des manuels généraux d’histoire et d’art hellénistiques ? Quels médias les rois (et leur administration) ont-ils de préférence utilisés pour communiquer leur image ? Quels étaient les publics visés ? LA MÉTHODOLOGIE Cette étude est avant tout numismatique, iconographique et religieuse. Cela ne signifie pas que d’autres sources soient exclues de l’analyse, et nous utilisons un large éventail de données archéologiques, épigraphiques et philologiques. La méthode que nous avons adoptée pour répondre aux questions ci-dessus est simple et directe: une analyse exhaustive des données numismatiques établissant un lien entre les rois et le divin et témoignant de la position particulière de la hiérarchie entre les hommes et les dieux. Ces sources numismatiques sont analysées à la fois « quantitativement » et « qualitativement ». Dans un premier temps, nous proposons une analyse détaillée d’une série de questions numismatiques liée à la position des rois en relation avec le divin et/ou leur volonté d’établir une idéologie royale commune. L’impact de ces analyses est ensuite évalué quantitativement à partir de deux bases de données qui ont été établies spécifiquement en vue de cette recherche et se trouve in extenso dans les annexes de la thèse. La première, la « Seleucid Hoard Database » (SHD), réunit virtuellement tous les trésors séleucides, c’est-à-dire tous les trésors contenant au moins une monnaie séleucide. Les données/pièces de monnaie sont étudiées dans les moindres détails afin de permettre à la SHD d’être utilisée pour examiner un large éventail de questions telles que la « quantité relative » de monnaies portant les types d’Apollon ou de Zeus, ou celles présentant le roi avec des attributs divins. La seconde base de données, la « Seleucid Excavations Database » (SED), rassemble le matériel numismatique provenant de fouilles archéologiques et de trouvailles isolées, c’est-à-dire les monnaies trouvées dans des fouilles mais aussi celles qui sont rapportées sans contexte archéologique précis. La structure des deux bases de données est comparable et permet d’obtenir une image représentative de la production monétaire originelle des rois. Ceci dit, nous nous sommes appliqué à démontrer méthodologiquement et statistiquement la représentativité des deux bases de données. Dans ce but, nous avons essayé d’aller au-delà de la simple réunion du « maximum de données possible » afin d’obtenir un échantillon fiable. En ce sens, cette étude s’inspire de la numismatique romaine, et tout particulièrement des analyses proposées par des spécialistes de la (Grande-) Bretagne romaine STRUCTURE DE LA THÈSE La thèse est divisée en quatre parties. Dans la première, nous analysons ce que nous appelons le « contexte du culte royal », c’est-à-dire les sources archéologiques et épigraphiques témoignant d’un culte royal et/ou des relations des Séleucides avec le divin. Le premier chapitre examine les données archéologiques liées au culte royal des Séleucides: naoi (temples), temenoi (enceintes consacrées), autels ou statues des rois. Notre analyse se concentre sur les cultes offerts aux rois par les cités grecques, principalement en Asie Mineure. Le second chapitre analyse les témoignages épigraphiques du prétendu culte « étatique », c’est-à-dire de la façon dont les rois (et leur Cour) se conféraient à eux-mêmes des τιμαὶ (honneurs). Nous examinons en détail le cadre méthodologique des études antérieures concernant la distinction entre culte « civique » et « étatique » avant de nous concentrer sur les fameux prostagmata (ordonnances) de 193 av. n. è. instaurant le culte de la reine Laodicée dans les satrapies du royaume. Le dernier chapitre de la première partie propose une analyse nouvelle de la documentation babylonienne relative au culte du roi et de sa famille. Cette analyse témoigne de l’influence des pratiques grecques sur les rituels locaux en Babylonie et explique pourquoi les rois séleucides participaient activement (et parfois en personne) au festival de l’Akitu. La conclusion de cette première partie introductive est que l’association des Séleucides au divin reste discrète, tant dans les contextes grecs que dans les contextes indigènes. La seconde partie de la thèse introduit l’analyse numismatique et iconographique des données. Il faut toutefois noter que les monnaies ne sont que le point de départ d’analyses plus approfondies dès lors que l’ensemble de données disponibles sont mises à contribution. Dans cette partie nous testons notre thèse principale quant à la « discrétion » des Séleucides lorsqu’ils traitaient avec le divin. Cette thèse est mise à l’épreuve des données visuelles tout en étant discutée à la lumière d’autres sources d’information relatives au rôle du roi séleucide. L’ordre des chapitres est à la fois chronologique et thématique: le premier chapitre examine les toutes premières émissions monétaires de Séleucos Ier portant des attributs divins, i. e. les monnaies de Suse que l’on appelle communément « au trophée ». L’étude de ce monnayage produit par le fondateur de la dynastie dans un atelier monétaire important mais périphérique introduit une série de questions qui seront posées à travers la thèse : pour quelle raison les représentations du roi comportaient-elles des attributs divins ? Quelles étaient la signification et l’importance de ces attributs dans l’idéologie royale ? Comment le roi se positionnait-il en relation avec le divin au moyen de ses représentations numismatiques ? Une grande attention est portée aux détails (par exemple l’episemon du bouclier macédonien au revers, la clef pour comprendre ce monnayage), mais le problème est également envisagé sur le long terme en comparant les données des bases de données SHD et SED. Le second chapitre reste dans le domaine des cornes et introduit la politique taurine et cornue des Séleucides. Nous examinons toutes les données disponibles et arrivons, une fois de plus, à la « discrète » des Séleucides. La même conclusion est obtenue suite à l’analyse d’une petite émission d’un atelier incertain sous Séleucos Ier qui va élargir l’imagerie dionysiaque de la numismatique séleucide. Le chapitre suivant s’intéresse à la signification de l’association du roi avec la représentation d’Apollon assis sur l’omphalos, une image généralement considérée comme la marque déposée de la dynastie. Ce chapitre joue un rôle central dans notre démonstration car il se concentre sur l’ancêtre divin de la dynastie, son archégète, et sur les moyens par lesquels les Séleucides introduisirent et envisagèrent cette filiation au travers de différents médias. Même si une filiation divine semble impressionnante, les rois (et leur administration) s’en servirent d’une façon plutôt « discrète », à la fois dans les sources visuelles et épigraphiques, ce qui suggère que les implications de cette filiation divine étaient discrètes dans l’idéologie royale. Les rois apparaissent comme les « favoris » des dieux, ils sont eusebès (pieux) et jouissent de l’eunoia (bienveillance) divine; ceci est également démontré dans le chapitre suivant où nous focalisons sur un détail un peu marginal : une barbe apparaissant temporairement sur les portraits de certaines émissions monétaires. Ces séries sont liées à des vœux faits par les rois ; une fois de plus, le roi s’associe et se rattache au divin d’une façon « discrète », que nous osons aussi dire « personnelle ». Cette discrétion est aussi discutée lorsque nous considérons une série de monnaies montrant le buste royal drapé. Les chapitres précédents ont insisté sur le caractère subtil de l’association de Séleucos Ier et Antiochos II avec le divin. L’analyse de l’imagerie céleste d’Antiochos IV et de ses successeurs démontre que la situation change sous le règne de l’Epiphane. Antiochos IV s’associe en effet avec le divin d’une manière plus flagrante, usant (et abusant)des attributs divins sur ses portraits. La suite de l’étude suggère cependant que sa politique était beaucoup plus nuancée par rapport à ce qu’affirment certaines études. L’analyse de la circulation et du volume des émissions monétaires nous permettent en effet de réévaluer la politique d’Antiochos IV, et de comprendre que le roi n’était pas, après tout, moins « discret » que ses progonoi, mais qu’il tentait simplement de s’adapter au problème critique de son époque, c’est-à-dire l’arrivée d’un nouveau et important compétiteur en Méditerranée orientale, Rome. Le dernier chapitre de la seconde partie de notre thèse examine la relation des reines avec le divin au travers de l’analyse d’une émission de petits bronzes frappés dans l’est et l’ouest de l’empire. Il apparait que les reines séleucides étaient associées de manière préférentielle avec la déesse Aphrodite, une divinité autrement marginale parmi les types monétaires séleucides. Le chapitre suivant introduit la troisième partie de la thèse, laquelle correspond à l’analyse quantitative des données numismatiques (et sigillographiques). Notre analyse offre une démonstration méthodologique de la fiabilité, de l’utilité et des perspectives futures des bases de données SED et SHD. Les analyses de ces deux bases de données sont les plus détaillées possibles, car il s’agit d’une toute nouvelle méthode en numismatique grecque. C’est pourquoi les bases de données sont testées au moyen de méthodes statistiques. Cela mène l’analyse à quelques conclusions surprenantes concernant, par exemple, le volume des productions monétaires et le niveau de monétarisation des Séleucides et des Ptolémées, ou le rapport étroit observé en comparant la SED et la SHD aux plus grandes collections numismatiques du monde. En vue de ces études comparatives, plus de 25.000 pièces de monnaie appartenant à cinq collections majeures ont été examinées, ce qui donne à nos bases de données et à leur usage dans le futur un poids supplémentaire. Après la démonstration de la fiabilité des bases de données, les trois chapitres suivants se concentrent sur la question principale de la thèse: à quel point la relation des Séleucides avec le divin était-elle « discrète » ? Nous y répondons d’abord en analysant les monnaies appelées « divines », c’est-à-dire les pièces où le roi est décrit portant un ou plusieurs attributs divins. Le résultat est surprenant : pas plus de 30 pourcents des monnaies séleucides portent un type divin. Ce pourcentage est même plus faible lorsque l’on prend en considération les paramètres du métal, de la circulation et de la chronologie. En tout cas, une fois de plus, nous constatons que les Séleucides hésitèrent à s’associer au divin de manière plus ostentatoire. Ce résultat, un simple nombre, a des conséquences importantes pour la compréhension de l’idéologie royale et religieuse, et pour déterminer les publics visés par ces médias visuels. L’analyse comparative des données numismatiques et des données sigillographiques de Séleucie du Tigre sert d’étude de cas pour identifier les différentes audiences visées par les différents types de communication visuelle. Dans tous ces cas, il est évident que les rois séleucides n’affirmèrent jamais réellement un statut divin ; ils restèrent des rois eusebès, les « favoris des dieux », voulant simplement afficher soit leur piété, soit la faveur divine dont ils bénéficiaient, plutôt que leur (supposé) statut divin. L’étude comparative et diachronique des représentations d’Apollon et de Zeus montre également que les monnaies, en tant que documents officiels, étaient l’expression de politiques précises, déterminées et ciblées. L’évolution de l’iconographie numismatique de Zeus à Apollon et puis de nouveau à Zeus ne fut pas une question de goût personnel, mais l’expression visuelle de la naissance d’une dynastie et des luttes internes de cette dynastie, tout particulièrement après la défaite de Magnésie du Méandre en 189 av. n. è. Le court chapitre suivant vise à démontrer les possibilités offertes par les bases de données SED et SHD. Dans cette optique, nous avons choisi, d’une manière assez provocante, de comparer la vitesse de circulation de la monnaie dans la zone Euro et l’empire séleucide. Le résultat est surprenant mais montre clairement les nombreuses perspectives offertes par la création de grandes bases de données. Le chapitre de conclusion est consacré à ce que nous considérons comme la scène idéale pour l’étalage de la magnificence royale séleucide: la procession de Daphné organisée par Antiochos IV. L’analyse de ce cortège met en évidence la manière dont ce roi voulait être perçu par ses sujets et par les représentants étrangers (les theoroi) et désirait se positionner dans la dichotomie entre l’humain et le divin. En conclusion, dans cette thèse, nous examinons le roi séleucide face au divin en nous concentrant sur les expressions visuelles des médias produits par le roi lui-même (et son administration). C’est la démarche du sommet vers la base (top-to-bottom) qui nous intéresse. Le roi et sa Cour mirent en scène une idéologie et une politique communes : la façon dont le roi doit être vu et perçu par ses sujets et les dynasties hellénistiques rivales. Au cours de ce processus, le roi (et sa Cour et son administration) restèrent très prudents ; ils ne franchirent jamais la ligne rouge séparant les sphères humaine et divine. Ils préférèrent toujours mettre en valeur leur piété envers le divin plutôt que leur hypothétique nature divine. Les rois préférèrent afficher leur position en tant que favoris des dieux plutôt que prétendre être des dieux eux-mêmes. Il leur importait plutôt de revendiquer leur victoire (espérée ou obtenue) en exprimant leur position unique de « favoris des dieux ». C’est cela que les données numismatiques donnent à voir et c’est ce qu’Antiochos IV mit en scène lors de la procession de Daphné. La thèse porte le titre parlant de « Favoris des dieux ». La raison en est simple: être les préférés des dieux était la seule position que revendiquaient les rois séleucides. Ils étaient les fils d’Apollon, mais par-dessus tout, ils exprimaient leur piété envers le divin ; et comme ils étaient des rois pieux, ils pouvaient être les favoris des dieux. C’est là le message politique, idéologique et religieux qu’ils élaborèrent et communiquèrent. On peut observer que c’était un message plutôt subtil, discret et efficace, puisque la piété est une valeur commune à toutes les religions et que pour cette raison elle devait être comprise par les différents sujets de leur immense empire. Nous avons soutenu la thèse que le roi séleucide n’est pas dieu, que jamais il n’a souhaité exprimer sa propre divinité et/ou ne s’est présenté comme tel. Il se servait des attributs divins comme de marqueurs visuels de son eusebia, sa piété, et pour afficher sa position de « favori des dieux ». [less ▲]

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See detailL'ENSEIGNEMENT DU FRANÇAIS AUX ANGLOPHONES AU CAMEROUN : ANALYSE ET PROPOSITIONS DIDACTIQUES
Mouto Betoko, Christiane ULg

Doctoral thesis (2016)

Au Cameroun, l’école est la garante de la politique du bilinguisme officiel qui vise à faire de tous les citoyens camerounais des individus parfaitement bilingues, afin de garantir leur intégration sur ... [more ▼]

Au Cameroun, l’école est la garante de la politique du bilinguisme officiel qui vise à faire de tous les citoyens camerounais des individus parfaitement bilingues, afin de garantir leur intégration sur l’ensemble du territoire national. Les élèves anglophones apprennent donc le français, leur deuxième langue officielle (LO2), comme toutes les autres disciplines, tout au long de leur cursus secondaire. En classes terminales, l’un des objectifs prioritaires de l’enseignement de la LO2 (French) est de préparer les élèves à intégrer les milieux universitaires et/ou socioprofessionnels majoritairement implantés en zone francophone. Néanmoins, dans ce contexte, l’atteinte des objectifs scolaires du bilinguisme constitue une problématique imputable à de nombreuses inadéquations inhérentes au sous-système éducatif anglophone. C’est dans cette optique que nous nous sommes demandé comment allier « objectifs scolaires du bilinguisme » et « méthodologie de l’enseignement du French» pour une préparation effective de notre public cible à son intégration dans son milieu de vie au sortir du secondaire. Ainsi, nous avons inscrit cette étude dans le champ épistémologique de la didactique du français langue étrangère, domaine disciplinaire qui fait de la connaissance des publics le point de départ de tout projet de formation en langues étrangères. Ceci dit, nous défendons la thèse selon laquelle la prise en compte des besoins réels des principaux acteurs devrait constituer l’étape préalable à la mise au point des projets de réforme tels la réforme du système éducatif et par ricochet, des programmes de formation que connaît actuellement l’éducation au Cameroun. Ayant constaté que l’environnement sociolinguistique où se déroulent l’enseignement et l’apprentissage du French n’est pas sans conséquence directe sur la mise en application du bilinguisme scolaire, nous avons jugé nécessaire de comprendre les politiques linguistique et éducative du milieu d’étude. Ainsi, dans la première partie de ce travail, il convenait de s’interroger sur le mode d’emploi réel des langues officielles, particulièrement en ce qui concerne l’usage de la langue française dans la société camerounaise ; de comprendre la problématique de la formation bilingue au Cameroun ; de questionner la place des langues maternelles à l’école ; d’analyser les failles du sous-système éducatif anglophone en matière d’enseignements des langues officielles ; et enfin, de mener une réflexion didactique sur les programmes de français II. Dans la deuxième partie de ce travail, nous avons mis en exergue l’importance de la prise en compte des caractéristiques des principaux acteurs de la salle de classe dans l’élaboration des programmes de formation. Les profils de ces acteurs étant absents des directives institutionnelles, nous les avons questionnés pour mettre leurs caractéristiques au grand jour. Pour ce faire, nous avons mené une enquête de terrain dans les deux régions qui constituent la zone anglophone (Nord-Ouest et Sud-Ouest) et, dans une région de la zone francophone (Centre). La récolte des données s’est faite par le biais de deux questionnaires (un pour les enseignants et un pour les élèves en classes terminales) et d’une grille d’observation des pratiques de classe. La méthode utilisée est l’analyse quantitative et descriptive des données statistiques. À travers la discussion des résultats obtenus sur la terrain d’enquête, nous avons validé l’hypothèse générale émise au départ, stipulant qu’il y a actuellement une inadéquation entre les objectifs scolaires du bilinguisme et la méthodologie mise en œuvre pour les atteindre en classes terminales du sous-système éducatif anglophone. À travers cette démonstration, nous avons tout simplement touché du doigt la réalité selon laquelle l’atteinte des objectifs visés dans le cadre du bilinguisme ne peut se faire sans avoir établie, au préalable, les besoins réels des principaux acteurs de la salle de classe. [less ▲]

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See detail"Saisir l'État". Les conflits d’héritage, la justice et la place du droit à Cotonou.
Andreetta, Sophie ULg

Doctoral thesis (2016)

Tout comme de nombreux autres États sur le continent africain, le Bénin a entrepris, à partir des années 1990, une large réforme de ses services publics dans laquelle la justice occupe une place centrale ... [more ▼]

Tout comme de nombreux autres États sur le continent africain, le Bénin a entrepris, à partir des années 1990, une large réforme de ses services publics dans laquelle la justice occupe une place centrale. Parmi les premiers textes à faire l’objet d’une révision figure le Code des personnes et de la famille, censé promouvoir l’égalité des sexes, contrairement au droit « coutumier » jusque-là applicable à la majorité des familles. Avec les conflits d’héritage comme porte d’entrée, cette recherche avait pour objectif de réfléchir à l’appropriation de ce nouveau texte par différents types d’acteurs. En effet, les questions liées à la gestion et à la répartition de l’héritage sont fréquemment source de conflits à Cotonou et dans les localités voisines. De nombreuses familles saisissent les cours et tribunaux. Dans un contexte où les services publics sont souvent associés à la corruption et aux pratiques informelles, cette thèse envisage les spécificités du système judicaire béninois, la question de la place du droit pour les citoyens, dans le travail des juges et le fonctionnement des tribunaux, démontrant ainsi que les règles officielles sont loin d’être systématiquement contournées dans les administrations africaines. [less ▲]

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See detailOn Generalized Hölder-Zygmund Spaces
Kreit, Damien ULg

Doctoral thesis (2016)

To study the regularity of functions, many functional spaces have been introduced during the 20th century. Among them, let us mention the Hölder-Zygmund spaces \Lambda^{\alpha}(\R^{d}) and the Besov ... [more ▼]

To study the regularity of functions, many functional spaces have been introduced during the 20th century. Among them, let us mention the Hölder-Zygmund spaces \Lambda^{\alpha}(\R^{d}) and the Besov spaces B_{p,q}^{\alpha}(\R^{d}) where \alpha>0 somehow indicates the regularity of their elements (p,q\in ]0,+\infty]). The Hölder-Zygmund spaces are particular cases of Besov spaces in the sense that \Lambda^{\alpha}(\R^{d})=B_{\infty,\infty}^{\alpha}(\R^{d}). A generalization of Besov spaces has been introduced in the middle of the seventies and is still studied nowadays. This new type of space allows a deepest study of the regularity of functions. In this thesis, we start from this generalization in order to introduce a generalization of Hölder-Zygmund spaces. The first aim of this thesis is to show that most classical properties of Hölder-Zygmund spaces can be transposed to their generalized version. Among others, a complete characterization of these spaces in terms of wavelet coefficients is proved, which opens their use in the context of the signal analysis. The second aim of this thesis is to introduce a generalized version of the pointwise Hölder spaces similarly to their global version. We then show that most properties of the global spaces can be transposed to their generalized pointwise version. Finally, we study the regularity of some financial stochastic processes. [less ▲]

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See detailInsect pathogenic Aspergillus species in mosquito (Diptera: Culicidae) control compared to Metarhizium anisopliae
Bawin, Thomas ULg

Doctoral thesis (2016)

Many mosquito (Diptera: Culicidae) species are vectors responsible for the transmission of infectious diseases of medical and veterinary importance. Risk for infection considerably increased during the ... [more ▼]

Many mosquito (Diptera: Culicidae) species are vectors responsible for the transmission of infectious diseases of medical and veterinary importance. Risk for infection considerably increased during the last decades due to climate changes and increasing global trade. Vector control is essential for public health management. Integrated pest management is now promoted due to harmful side effects of the chemical insecticides classically used for mosquito control and insect resistance development. This PhD thesis takes part in the selection process of insect pathogenic fungi. Three biological models (Aspergillus clavatus Desmazieres, Aspergillus flavus Link, and Metarhizium anisopliae (Metschnikoff) Sorokin) were selected and investigated regarding their spore insecticidal activity, mode of action, and selectivity. Throughout this scheme, the use of agricultural materials and derivatives in fermentation processes was emphasized. Production methods and insecticidal potential of the fungi were first investigated. On the one hand, the two Aspergillus species were compared to M. anisopliae regarding their spore production when cultured on agro-industrial substrates (white rice and wheat bran) and their insecticidal effect on larvae of the southern house mosquito, Culex quinquefasciatus Say. Our results showed that both substrates are suitable to culture the three insect pathogenic fungal species; but wheat bran-based media increased from 3 to 7-fold the spore yields in solid-state compared to white rice-based media. Also, insect pathogenic Aspergillus species were suggested to yield in similar spore levels in such conditions (in a range of 10^9 spores per g of substrate) and be as virulent against mosquito larvae compared to M. anisopliae. On the other hand, a bioreactor design intended to support large-scale production on agricultural materials by combining the technological advantages of submerged and solid-state fermentations was implemented using A. clavatus. This system allowed facility in recuperation and purification of spores (confined on a packed solid substrate) that retained virulence against mosquito larvae; but also metabolites (contained in a circulating liquid medium) that showed insecticidal effect. The mechanisms responsible for the insecticidal effects of the spores, and their selectivity were then investigated. On the one hand, the invasion routes of A. clavatus spores on mosquito larvae were investigated by light and electron microscopy. Histological observations suggest that toxins secreted by active germinating spores of A. clavatus in the digestive tract altered the larval tissues, leading to necrosis and causing larval death. Fungal proliferation and sporulation then occurred during a saprophytic phase. Such action mode also probably occurred in the case of the two other species. On the other hand, the insecticidal activity of the fungi was assessed against the pea aphid, Acyrthosiphon pisum Linnaeus. Adult A. pisum aphids were susceptible (increased mortality and decreased reproductive potential) to the three fungal species. As a consequence, these fungi would probably be able to infect a broad spectrum of insect hosts (whatever terrestrial or aquatic) once released in the environment. The implications of the results for mosquito control and application strategies are finally discussed, and perspectives for future works proposed. [less ▲]

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See detailETUDE DE LA DYNAMIQUE DE LA DESERTIFICATION DANS LE BASSIN VERSANT DE LA MOULOUYA EN INTEGRANT LES DONNEES ISSUES DE LA TELEDETECTION ET LES DONNEES SOCIO-ECONOMIQUES
Mokhtari, Noureddine ULg

Doctoral thesis (2016)

La recherche sur la désertification et la dégradation de l’environnement est très complexe et vise la mise en relation entre les ressources de l’environnement, leurs limites de durabilité et des usages ... [more ▼]

La recherche sur la désertification et la dégradation de l’environnement est très complexe et vise la mise en relation entre les ressources de l’environnement, leurs limites de durabilité et des usages qui se font de ces ressources par l’homme en tant qu’agent économique qui vise à améliorer son bien-être. Dans le bassin versant de la Moulouya caractérisé par un climat essentiellement aride à semi-aride, une augmentation sensible de la population et une forte hausse de la demande en ressources naturelles, le problème de la désertification se pose en termes d’adaptation des besoins de la population aux contraintes du milieu en vue de maintenir la durabilité des ressources. Dans ce sens, le challenge consiste en un double objectif, premièrement l’évaluation de la désertification à travers l’analyse de l’état de dégradation du milieu et deuxièmement, l’étude des causes de cette dégradation moyennant des enquêtes axées sur les pratiques agricoles et la formulation de propositions d’actions à entreprendre pouvant être utilisés de manière opérationnelle par les acteurs locaux et les pouvoirs publics. Ainsi, le suivi de la dynamique des phénomènes biophysiques liés à la désertification s’est fait essentiellement à travers l’étude de l’évolution du climat et de la qualité de la végétation à l’échelle de l’ensemble de la zone étudiée (NDVI) et au niveau d’une zone d’intérêt pour la recherche (occupation du sol). Pour la végétation, le suivi spatio-temporel de la végétation a montré pour les trois sources de données à basse résolution utilisées (GIMMS, MEDOKADS et SPOT) des évolutions similaires de l’indice de végétation NDVI. Malgré les différences entre les amplitudes de variation du NDVI, liées essentiellement aux spécificités des algorithmes de traitement, les trois séries données conservent la même tendance stationnaire au cours du temps. D’une manière générale, les fluctuations du NDVI mises en évidence à l’aide des données NDVI à basse résolution reflètent principalement les variations spatio-temporelles en quantité et en qualité des précipitations d’une année par rapport à une autre et ne montrent aucune tendance particulière concernant la qualité de la végétation. L’identification des zones sensibles à la désertification, réalisée sur la base de l’approche MEDALUS, a montré que les zones fragiles et critiques totalisent 61% de la superficie du bassin versant, soit une superficie d’environ 3,25 millions d’Ha. Spatialement, les zones sensibles à la dégradation se trouvent aussi bien dans la Basse Moulouya que dans les Hauts Plateaux et la vallée de Missour constitués essentiellement de parcours steppiques. L’analyse de la dynamique d’occupation du sol à travers l’utilisation des images satellites (LANDSAT) pour la commune de Tissaf, choisie comme zone d’intérêt pour la recherche, a révélé une dégradation qualitative de la végétation. En effet, de grandes superficies d’Alfa dense à très dense (végétation climacique) se sont dégradées pour se retrouver dans la classe d’Alfa faiblement dense, soit une diminution de l’ordre de 16.199 Ha sur 20 ans. L’analyse des causes de la dégradation des parcours au niveau de la commune de Tissaf à travers l’étude de la productivité des parcours et du système d’élevage pastoral a révélé que le capital, en tant que facteur de production, joue un rôle important dans les stratégies d’utilisation des ressources fourragères « gratuites » issues des parcours collectifs. Ainsi, les grands éleveurs sédentaires ou semi-nomades disposant d’importants fonds propres et grâce à une utilisation plus opportuniste des parcours collectifs paraissent profiter davantage de ces ressources (46.478,15 UF) par rapport aux petits éleveurs sédentaires et transhumants (5.148,70 UF et 18.714,40 UF). Les petits éleveurs qui adaptent l’effectif de leur cheptel en fonction des conditions du milieu (décapitalisation en période de sécheresse) semblent profiter moins en quantité et en qualité des ressources pastorales disponibles. En guise de conclusion, la thèse propose des scénarios d’adaptation des systèmes de production agricoles qui peuvent être utilisés d’une manière opérationnelle par les acteurs locaux et les pouvoirs publics en vue d’orienter les stratégies de développement et d’investissement vers les secteurs rentables économiquement et qui respectent en même temps l’environnement. [less ▲]

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See detailGestion des stupéfiants au bloc opératoire
LOMMEL, Isabelle ULg

Master of advanced studies dissertation (2016)

La gestion des stupéfiants est une obligation légale. Dans le travail quotidien de l’infirmier de salle d’opération, la redondance d’écritures et le manque de disponibilités entrainent une banalisation de ... [more ▼]

La gestion des stupéfiants est une obligation légale. Dans le travail quotidien de l’infirmier de salle d’opération, la redondance d’écritures et le manque de disponibilités entrainent une banalisation de cette obligation. On oublie que ce médicament ‘différent’ est source de danger, d’addiction, de deal et qu’il peut être mortel. Ce travail est le résultat d’une analyse de la situation existante et de son adéquation avec la loi et la littérature scientifique. Sa conclusion permet de mettre en évidence que les participants au flux des stupéfiants doivent être conscientisés que leurs actions doivent être guidées par une logique. Cette logique de processus doit être institutionnelle. La philosophie Lean est d’application dans ce travail. Par la publication d’une synthèse des pistes de perfectionnement sous forme de délivrable ‘A3’, cette étude sera remise aux dirigeants du bloc opératoire Selon cette philosophie, il faut impérativement implémenter des méthodes de brainstorming consistant à mettre en évidence, entre collègues, les raisons de mal-fonctionnement. C’est également en équipe que des moyens d’amélioration de la situation doivent être élaborés, ce sans bouleversement majeur, c’est la méthode des petits pas. L’équipe du bloc doit mettre en place: 1. Un descriptif de la situation existante. 2. La pose en groupe d’indicateurs de bon fonctionnement. 3. L’étude collégiale de méthodes d’optimalisation des processus existants via des standards de travail. 4. Le suivi des indicateurs pour constater les améliorations et les amplifier par ajustement des processus. 5. Le bénéfice doit être visible tant au niveau de la sécurité du patient et du personnel que du stress ambiant. Cette philosophie doit perdurer dans le temps et s’intégrer dans le LEAN institutionnel. [less ▲]

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See detailRhodococcus erythropolis T902.1 as a bioaugmentation starter: mechanisms, constrains and potentialities for the hydrocarbon degradation
Masy, Thibaut ULg

Doctoral thesis (2016)

Since the advent of the industrial revolution in the 19th century, anthropogenic activities and lack of environmental concern gave birth to numerous contaminated areas. Amongst released pollutants ... [more ▼]

Since the advent of the industrial revolution in the 19th century, anthropogenic activities and lack of environmental concern gave birth to numerous contaminated areas. Amongst released pollutants, hydrocarbons (HC) are the most widespread in the environment but they can also constitute a carbon source for numerous microorganisms. Therefore, bioremediation (i.e. the use of microorganisms to degrade pollutants) appears as an ecologically- and cost-effective technique compared to chemical or physical treatments. This biotreatment technology often relies either on stimulating indigenous microorganisms already present in soil (biostimulation) or on adding specific microbial degraders (bioaugmentation) to enhance the natural attenuation of contaminants. However, there is a need for improved understanding of the causes that can lead to its failure or its low efficiency, such as diverse environmental constraints or poor adaptation ability of laboratory-cultivated microorganisms. Amongst bacteria studied, Rhodococcus sp. has been previously described as a potential candidate for bioaugmentation due to its ability to degrade a broad range of organic pollutants, to produce biosurfactants, which improves pollutant bioavailability, and to rapidly adapt to many environmental stresses (e.g. desiccation, low temperature, high salinity). The main objective of this work is thus to assess the potentiality and limitations in the use of a specific strain, Rhodococcus erythropolis T902.1, to degrade HC (from simple n-alkanes to polyaromatic) in diverse field conditions. The factors limiting such a process have to be identified and, as much as possible, overcome. A first bioaugmentation experiment in microcosms aimed at identifying these constrains in carbon and clay-rich soils contaminated with heating oil. This treatment was successful in strongly polluted soil, since the addition of the strain T902.1 helped in redirecting the limited quantity of available oxygen towards a higher HC degradation and also correlated with a higher proportion of degrading genes in bioaugmented soils, compared to biostimulated and control ones. However, this effect decreased with time as T902.1 development was curtailed by competition and potentially predation from the endogenous flora. In addition, HC were heterogeneously distributed and this hampered the detection of a real degradation in lowest polluted soils. As a result, inoculation should be targeted to highly polluted areas (e.g. contaminant source zones), but it requires controlling soil heterogeneity.   We thus resorted to electrical resistivity tomography (ERT), to describe this heterogeneity and to monitor bacterial HC degradation activity. This geophysical tool could discriminate lithological heterogeneities that were artificially introduced in a 2 m³ pilot. Compared to a first insufficient biostimulation phase, the introduction of R. erythropolis T902.1 in this pilot led to a HC depletion of almost 80% (6900 to 1600 ppm) in 3 months in the injection zone, where pollutants were less bioavailable. Simultaneously, HC mineralization and biosurfactant production were deduced from the monitoring of ERT, biological and physicochemical parameters. In another study, R. erythropolis T902.1 could form stable biofilms on the materials constituting draining pavement structures, which allowed its long-term survival in a real parking lot and improved the decontamination of runoff water drained through this structure during pollution tests carried out at a pilot scale. This indicates that the strain could be widely used in other decontaminating systems and not only in soil. Furthermore, this biofilm formation could be triggered by an appropriate pre-adaptation of the cells before their injection in the polluted environment, to ensure a higher ecological robustness of the inoculum, compared to the one observed in the microcosm experiment. A third constrain is the poor or slow degrading activity toward some recalcitrant compounds, such as polyaromatic HC (PAH). Metallic nanoparticles synthesized by a sol-gel process were considered as potential catalysts for the improvement of degradation kinetics. Iron nanoparticles boosted the bacterial catalytic activity of the strain T902.1 in liquid cultures containing biphenyl as the sole carbon source. Following results suggested that the iron encapsulated in the porous silica matrix, was progressively attracted by siderophores (heterobactins) produced by the strain. However, this hypothesis has still to be confirmed by further analyses. From these experiments, R. erythropolis T902.1 globally proved to compete and improve degradation rates in highly polluted soils compared to biostimulation, even under low oxygen and nutrient contents. Notably, the production of trehalolipidic biosurfactants enhances HC bioavailability for their further uptake by the strain and surrounding microorganisms. Furthermore, this strain forms stable biofilms on several supports, which increases its lifespan and paves the way for many applications in bioremediation systems. Finally, it can also be used in synergy with sol-gel iron nanoparticles to treat recalcitrant compounds such as PAH and some chlorinated aromatics, but this combination needs to be further tested in more complex media, such as soil or waste water. [less ▲]

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See detailLa question urbaine revisitée. Analyse socio-politique comparée de la régulation publique des inégalités environnementales
Lejeune, Zoé ULg

Doctoral thesis (2016)

Les inégalités environnementales forment un relatif « impensé » de la plupart des politiques publiques qui sont aujourd’hui mises en place dans nos villes. S’il apparaît qu’il y a une sous-estimation de ... [more ▼]

Les inégalités environnementales forment un relatif « impensé » de la plupart des politiques publiques qui sont aujourd’hui mises en place dans nos villes. S’il apparaît qu’il y a une sous-estimation de cet enjeu de la part des autorités politiques au sens large, il nous a semblé utile de mieux comprendre les processus socio-politiques à l’œuvre. C’est un double mouvement que nous interrogeons dans la thèse. D’une part, quels sont les processus « sociétaux », collectifs qui contribuent à la production de phénomènes inégalitaires en matière environnementale ? D’autre part, quels sont les dispositifs socio-politiques qui se dessinent afin d’y trouver une solution collective et politique ? La première approche privilégiée pose la question des conditions sociétales de la formation et de l’émergence des inégalités environnementales : distribution des charges environnementales, inégale participation dans la vie publique et collective et inégalités socio-spatiales. Cette première question nous a conduit à mobiliser les données du Baromètre social de la Wallonie 2012 et son module de questions sur l’environnement. La seconde grande question interroge les modalités de la gestion collective et publique des inégalités environnementales, à savoir les solutions mises en place aujourd’hui pour y faire face. Cette analyse se propose dès lors d’étudier les modalités de la régulation publique des inégalités environnementales dans une perspective comparative internationale face à la transformation de l’action collective et publique urbaine. Pour ce faire, nous avons réalisé des enquêtes de terrain qualitatives (entretiens semi-dirigés) dans plusieurs villes, en Angleterre (Sheffield) et en Belgique (Liège). Celles-ci nous ont conduit à proposer un modèle conceptuel de lecture de la régulation publique des inégalités environnementales en milieu urbain. [less ▲]

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See detailAn efficient and flexible software tool for genome-wide association interaction studies
Van Lishout, François ULg

Doctoral thesis (2016)

Humans are made up of approximately 3.2 billion base pairs, out of which about 62 million can vary from one individual to another. These particular base pairs are called single nucleotide polymorphisms ... [more ▼]

Humans are made up of approximately 3.2 billion base pairs, out of which about 62 million can vary from one individual to another. These particular base pairs are called single nucleotide polymorphisms (SNPs). It is well known that some particular combination of SNP values increase dramatically the risk of contracting certain type of disease, like Crohn's disease, Alzheimer, diabetes and cancer, just to name a few. However, there are still a lot of new discoveries to make and specialized software is required for this task. It has been shown that individual SNPs cannot account for much of the heritability on their own. Therefore, this PhD thesis is dedicated to interaction studies, the purpose of which is to identify pairs of SNPs and/or environmental factors that might regulate the susceptibility to the disease under investigation. Model-Based Multifactor Dimensionality Reduction (MB-MDR) is a powerful and flexible methodology to perform interaction analysis, while minimizing the amount of false discoveries. Before this thesis, the only available implementation was an R-package taking days to analyze a dataset composed of just hundred of SNPs. However, a typical dataset contains hundreds of thousands or millions of SNPs, even after data cleaning and quality control. The aim of this thesis is to write a software able to analyze such datasets within a few days with the MB-MDR methodology. In other words, the goal is to get 10^8 times faster than the R-package, while still remaining powerful, flexible and keeping the amount of false discoveries low. Several contributions were needed to reach this goal and are presented in this thesis. First, a new software was written from scratch in C++, in order to be able to optimize every single computation, instead of relying on too generic functions as was the case for the R-package. Second, the methodology itself was improved, irrespective of the programming language. Indeed, MB-MDR is based on the maxT algorithm (introduced by Westfall&Young in 1993) to assess significance of the results and it can be customized for interaction analysis. A first major contribution of this PhD work, called Van Lishout's implementation of maxT, was introduced in 2011. The parallel version of this algorithm enables to analyze a dataset composed of hundred thousands of SNPs within a few days. The most important contribution of this thesis, called the gammaMAXT algorithm, was introduced in 2014. The parallel version enables to analyze a dataset composed of one million SNPs within one day. In this thesis, we also propose a new viewpoint to handle population stratification and correct for covariates. Many simulated and real-life data analysis are provided, to highlight the flexibility of the software and its ability to find interesting results from a biological point of view. The latest version, called mbmdr-4.4.1.out, can be downloaded freely at http://www.statgen.ulg.ac.be with the corresponding documentation. [less ▲]

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See detail“The Sweet Smell of Chemistry” - Characterization of volatile mixtures from Life Sciences
Stefanuto, Pierre-Hugues ULg

Doctoral thesis (2016)

From a Separation Science standpoint, Life Sciences represent a broad source of complex compound mixtures that require powerful analytical strategies to be considered when characterization is aimed. The ... [more ▼]

From a Separation Science standpoint, Life Sciences represent a broad source of complex compound mixtures that require powerful analytical strategies to be considered when characterization is aimed. The depiction of the complex volatile organic compound (VOC) component of these mixtures is an important part of such characterization. The aim of this doctoral work was to develop a versatile analytical approach to resolve such VOC samples. For the characterization of complex VOC mixtures, comprehensive two-dimensional gas chromatography (GC×GC) is the method of choice. The combination of two GC separation columns offers higher peak capacity than single dimension GC (1D GC). Moreover, the hyphenation of GC×GC to a mass spectrometer provides an extra dimension of identification, especially when high-resolution (HR) time-of-flight mass spectrometers (TOFMS) is used. However, the optimization of the GC×GC conditions is not straightforward. Currently, there are no defined strategies to obtain the best capabilities these instruments, not only in terms of the optimization of the separation itself, but also mainly in terms of data processing efficiency. The first section of this work was devoted to the evaluation of theoretical aspects and the definition of a specific optimization strategy for GC×GC separation. The first part dealt with the heavily debated concept of ‘orthogonality’ was specifically investigated by means of a metric calculation, the Orthogonality Index (OI), linked to a new nomenclature describing the separation space usage. The second part was focused on the development of an optimization strategy for the sampling and the chromatographic separation of VOCs, as well as the processing of large sets of GC×GC data. This was conducted on complex beer aroma headspace replicates for sampling method selection, peak dispersion optimization, and robust multivariate statistical treatment. The third part of this theoretical investigation relied on the implementation of fast-GC conditions for GC×GC separation. The idea was to evaluate the effect of combining short columns, fast modulation, high temperature ramping, and high flow on GC×GC efficiency for explosive headspace analyses. In the second section, the focus was directed to challenging applications in the area of thanatochemistry, i.e. the chemistry of death, especially considering the volatile fraction of cadaveric decomposition, a complex chemical process releasing numerous VOCs. In this context, soil surrounding decomposing remains, headspace of cadavers, and more “specific” matrices (i.e. synthetic solutions and internal gas from decomposition) were analyzed by GC×GC TOFMS. Major attention was dedicated to the development of an analytical and data mining procedures for these complex VOC samples with emphasis on the study of the impact of different parameters on the cadaveric decomposition process. [less ▲]

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See detailDe l'activation des politiques d'emploi à l'agitation des chômeurs
Beuker, Laura ULg

Doctoral thesis (2016)

• Ce travail de thèse a pour objet la traduction et la mise en œuvre concrète du Plan d’accompagnement et de suivi des demandeurs d’emploi par les conseillers emploi (FOREm et Actiris) et par les ... [more ▼]

• Ce travail de thèse a pour objet la traduction et la mise en œuvre concrète du Plan d’accompagnement et de suivi des demandeurs d’emploi par les conseillers emploi (FOREm et Actiris) et par les facilitateurs (ONEm) en Belgique francophone. Ceux-ci sont effectivement situés en première ligne dans la mise en « actes » et en « mots » de cette mesure d’activation. Notre entrée dans les pratiques d’accompagnement et de suivi des demandeurs d’emploi repose sur une démarche empirique foncièrement qualitative. Le travail de terrain s’est déroulé entre janvier 2013 et février 2014. Il repose sur une immersion au sein de huit sites, et articule la réalisation d’entretiens semi-directifs, la récolte de documents internes et l’observation d’entretiens. Prenant appui sur les apports de l’Economie des conventions, de la Nouvelle sociologie économique et de la Sociologie des groupes professionnels, ce travail met en exergue l’idée selon laquelle plutôt que « d’activer » les demandeurs d’emploi, il est question « d’agiter » ces derniers… [less ▲]

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See detailNumerical Modeling and Experimental Identification of Mistuned Multi-Stage Bladed Assemblies
Nyssen, Florence ULg

Doctoral thesis (2016)

In turbomachinery, low pressure compressors are composed of a succession of bladed disks. To reduce the mass and increase the performance of the aircraft engines, one-piece multi-stage units of bladed ... [more ▼]

In turbomachinery, low pressure compressors are composed of a succession of bladed disks. To reduce the mass and increase the performance of the aircraft engines, one-piece multi-stage units of bladed disks have been recently developed. But these one-piece technologies are challenging for the mechanical design due to exacerbated effects of mistuning (i.e., mode localization and forced response amplification). In the thesis, an experimental method for the identification of mistuning in multi-stage bladed structures is proposed and validated. Numerical modeling methods are proposed to reduce computational times for the statistical predictions of the forced response amplification. A characterization of the interstage coupling is performed and a criterion is proposed to predict in advance if a multi-stage analysis is necessary. [less ▲]

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See detailSolid-supported synthesis of peptidoglycan fragments and their biological evaluation
Simon, Justine ULg

Doctoral thesis (2016)

In this work, a new methodology for the synthesis of peptidoglycan fragments containing (2S,6R)-A2pm is proposed. Thanks to a solid phase platform, cross metathesis was achieved between two easily ... [more ▼]

In this work, a new methodology for the synthesis of peptidoglycan fragments containing (2S,6R)-A2pm is proposed. Thanks to a solid phase platform, cross metathesis was achieved between two easily manufactured chiral synthons, allylglycine anchored to a resin and vinylglycine derivatives. Due to the need of fragments for the study of the peptidoglycan recycling, this modular efficient platform could be useful to synthesize diverse derivatives of other peptides and muropeptides containing (2S,6R)-A2pm. In the framework of this project, (S)-Ala-γ-(R)-Glu-(2S,6R)-A2pm-(R)-Ala and γ-(R)-Glu-(2S,6R)-A2pm were synthesized. Their interactions with the R39 peptidase were studied by X-ray diffraction. According to the crystallographic results, (S)-Ala-γ-(R)-Glu-(2S,6R)-A2pm-(R)-Ala 1 is a reversible covalent binding inhibitor of R39. These data are supported by an enzymatic study using the thioesterase activity of the R39 peptidase on (R)-S2d. Because of the specific affinity for the R enantiomer of thioesters, the enantioselective synthesis of (R)-S2d is described that makes use of the coupling agent T3P. A chromatographic method is proposed to evaluate the degree of thioester racemization. The kinetics of the interaction between the thioester and different PBPs were studied and a protocol for microtiter plate-based assays is developed allowing the screening of compound libraries for inhibitors of PBPs. In the future, the synthesized peptidoglycan fragments will be used as reference compounds in the framework of the NetRBI project. [less ▲]

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See detailCharacterization, dynamics and trophic ecology of macrofauna associated to seagrass macrophytodetritus accumulations (Calvi Bay, Mediterranean Sea)
Remy, François ULg

Doctoral thesis (2016)

Posidonia oceanica meadows are a major coastal Mediterranean ecosystem. Although highly productive this Mediterranean marine flower plant is not much consumed by herbivore organisms. During autumnal ... [more ▼]

Posidonia oceanica meadows are a major coastal Mediterranean ecosystem. Although highly productive this Mediterranean marine flower plant is not much consumed by herbivore organisms. During autumnal senescence, most (up to 90%) of the foliar primary production of P. oceanica ends in the “detrital compartment”. These dead leaves, also called “macrophytodetritus”, begin to degrade immediately inside the meadow, but a large amount will be rapidly exported to adjacent unvegetated accumulation zones, such as bare sand patches. Associated to drift macroalgae, living detached P. oceanica shoots, micro-organisms and fine sediment, these macrophytoderitus form what we call “exported P. oceanica litter”. This exported litter is a highly dynamic habitat for a whole community of invertebrates: meiofauna (38µm < size < 500µm) and macrofauna (size ≥ 500µm) on which we focused on. This dynamic nature of exported litter could play a major structuring role in terms of abundance, diversity and trophic ecology of this vagile macrofauna community at a seasonal, annual or spatial scale, but also during stochastic, brief and very strong perturbations: resource pulses. In this context, this PhD Thesis had 7 main objectives: i. Characterize for the first time exhaustively the macrofauna community. ii. Evaluate the spatiotemporal changes occurring at two different time scales in the detritus themselves and in the macrofauna community. iii. Relating these variations with measured environmental parameters. iv. Experimentally demonstrate the stratification occurring in a stable P. oceanica litter accumulation and the impact of this stratification on environmental conditions and on the macrofauna. v. Experimentally demonstrate the impact of resource pulses on the exported P. oceanica litter macrofauna community. vi. Unravel for the first time the global P. oceanica litter macrofauna food web using gut contents examinations and stable isotopes (C and N). vii. Evaluate the spatiotemporal changes of diet preferences of this community and determine if the observed changes are really synonym of true diet changes. This PhD Thesis demonstrated that exported P. oceanica litter was mainly composed of dead P. oceanica leaves (70-80%). It followed the natural annual cycle of P. oceanica and presented a maximum abundance in autumn just after leaves senescence. Measured environmental parameters also showed important variations linked to different factors such as force and direction of the wind, litter abundance and probably temperature. The continuous presence of the vagile macrofauna community throughout the year was demonstrated as well. This community was composed of 115 species and largely dominated by arthropods (77%), followed by annelids (12%) and mollusks (7%), while other taxa were much more anecdotal. Even if diversity is quite important, only a few species dominate largely the community. Indeed, 19 species represent more than 90% of the total abundance. One species to keep in mind: Gammarella fucicola, the most typical dominant and abundant amphipod species, representing 40-50% of the total abundance. In addition to this general pattern, litter vagile macrofauna presented important seasonal and annual variations. In the case of several species, these variations could be linked to some measured environmental parameters, but we had to recognize that most species did not seem to be influenced by environmental parameters measured during this PhD. However, oxygen concentration was the most important environmental parameter, potentially influencing 7 of the 19 most dominant and abundant species. The experimentally demonstrated physico-chemical stratification occurring inside litter accumulations was strongly related to this oxygen parameter. Indeed we demonstrated that several species were distributed in the different layers of a litter accumulation according to oxygen concentration and to a lesser extent, to nutrients concentration (mostly NH4). Besides, smaller time scale sampling allowed the identification of several stormy events corresponding to the definition of resource pulses. These pulses were demonstrated to play a potentially important role on the structure of the macrofauna community, favoring importantly the detritivore species and hypoxia tolerant species. It was also demonstrated that resource pulses could induce diet switching increasing the consumption of dead P. oceanica leaves just after the events, potentially increasing the litter decomposition by the macrofauna. The trophic web described in this PhD Thesis was composed of several trophic levels, from the primary herbivore/detritivore consumer, to second order carnivore predators. Different dietary preferences were highlighted, but major information was that dead P. oceanica leaves were ingested by a majority (85%) of the sampled species. Moreover, stable isotope analysis confirmed that P. oceanica litter was assimilated by most primary consumers and this “detrital signal” could be identified to the upper trophic levels, which is an argument in favor of the importance of macrofauna as major dead P. oceanica leaves decomposers. This also highlighted their potential role in terms of organic matter transfer from the P. oceanica meadow itself to the Mediterranean coastal food webs. Seasonal variations were observed in terms of trophic niches, and SIAR mixing model confirmed that this variability was sometimes caused by real diet modifications, potentially linked to the variable availability of food sources. This PhD Thesis, combining standardized sampling at two different time scales, trophic web analysis (gut contents and stable isotopes) and original experimentation allowed us to describe a diverse and abundant macrofauna community associated to P. oceanica exported litter, its temporal variations, potential responses to resource pulses as well as the link existing between some species and measured environmental parameters. This PhD also described the food web of this community and demonstrated the importance of dead P. oceanica leaves as food source for many invertebrates composing this community. These invertebrates thus seemed to play an important role in both litter decomposition and organic matter flux from the P. oceanica meadow to the Mediterranean coastal food webs. [less ▲]

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See detailLa gestion des ressources humaines au sein des ONG internationales: les relations siège-filiale dans un contexte instable (le cas du Burundi)
Hakizumukama, Alexis ULg

Doctoral thesis (2016)

Executive summary Applied to different contexts, the approach to management and HRM practices initially operative, considered by some as the essential and universal key to organizational success, may face ... [more ▼]

Executive summary Applied to different contexts, the approach to management and HRM practices initially operative, considered by some as the essential and universal key to organizational success, may face some contextual constraints and lead to conflicting results. Now, the local context brings to the subsidiary of international organizations little or no opportunities for the Headquarters. At the same time, the local context adds specific constraints. The consideration of these opportunities and constraints by the officials of the subsidiary is a real managerial challenge for them. This implies much more than a simple transfer of what has always worked well elsewhere. This questioning of the success of the universalist perspective pushes us to diagnose other possible ways to suggest for the approach to management and HRM practices that could better accommodate the local management. Our study is particularly concerned with international NGOs operating in sub-Saharan Africa and Burundi in particular. Our theoretical argument mobilizes universalist, culturalist and institutionalist approaches. Our study concerns only the subsidiaries of international NGOs and not their Headquarters. Note that throughout our work, the word "Siège" means the Headquarters and not the local management of the subsidiary. To mark this distinction, we opt to write it with a capital "S". Based on a contextualist analysis of five case studies of subsidiaries of international NGOs, we find that, upon their arrival or within the first years of implementation of the subsidiary, the leaders of these international subsidiaries almost always opt for a relational or even paternalistic model of management. Indeed, this model allows a gain in confidence and the establishement of strong relationships between the expats and the locals, and between volunteers and employees. The latter model also helps to react or deal with the complexity of an unstable local context (civil war, hatred and ethnic conflicts, distrust versus foreigners, oral tradition culture, lack of separation between work and family life, lack of some skills in the labor market and poverty of the population). Beyond the local constraints, pressure from the Headquarters, and the donors' requirements often result in the evolution of the business model implemented during the establishment period. But toward what model is moving the subsidiary, why, how and what are the implications for HRM practices? This is the series of questions we try to answer throughout this work. To get there, we pay special attention to the power games, the identification of the most influential players, the relationships, the mechanisms of prevention and / or of conflict management and the mobilization around the common goal. Our study shows that the managers of subsidiaries have two possible choices of a position: control logic or adaptation logic. The results of our research argue for the second option to be the most favorable to take into consideration the local context and to contribute to the emergence of consistent and very innovative HRM practices. Our work shows that the model based on the adaptation logic is more effective when the appropriation of the Headquarters rule by the members of the subsidiary is dominated by joint regulation mechanisms, and when the management of the subsidiary is polyphonic for what concerns managing the evolution of contextual factors. In fact, the latter mechanisms lead to the organization, in due time, to a genuine process of organizational change. The polyphonic style is generally characterized by flexibility, autonomy, accountability, collaboration, cooperation within teams and the search for compromise to satisfy the essential interests of the different stakeholders, including those at Headquarters. However, we note that some managers, guided by rational mimicry derived from the culture of their country of origin and their experience elsewhere, tried control-based management resulting in the domination of regulatory mechanisms either autonomous or controlled. Our observation is that the control-based management model leads the subsidiary in a logic of submission or circumvention of the rules and practices developed by the parent company. This management model quickly faces major resistance from certain groups of stakeholders who feel that their interests are threatened. For example, internal conflicts occur in these subsidiaries at the expense of the cooperation and the achievement of desired results. Highlighting the importance of the local context and the relationships Headquarters- subsidiaries together with the role of the management style in the evolution of HRM practices in the local management of international NGOs working in unstable and specific context (land and sector insufficiently studied up to now), this study brings a great contribution to international management and intercultural management theory in general and sub-Saharan Africa in particular. [less ▲]

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See detailLe passé en France au XVIIe siècle. Représentations, usages et transferts des savoirs historiques
Saal, Caroline ULg

Doctoral thesis (2016)

La majeure partie des études sur le passé au XVIIe siècle se porte sur l’historiographie, sur la théorie de l’histoire et sur son écriture à cette époque. Grâce au développement de l’histoire des idées et ... [more ▼]

La majeure partie des études sur le passé au XVIIe siècle se porte sur l’historiographie, sur la théorie de l’histoire et sur son écriture à cette époque. Grâce au développement de l’histoire des idées et de l’histoire culturelle, de nouvelles approches ont émergé. Pour l’histoire moderne française, elles prennent essentiellement la forme d’études de figures souvenirs et de leur prégnance dans une culture donnée. Mais deux postulats m’ont invitée à travailler autrement, hors des pratiques historiennes et sans choisir a priori de figures-souvenirs. Le premier tient à l’acquisition des savoirs historiques. La connaissance que possède une personne sur le passé de la communauté humaine résulte d’une multitude de vecteurs et de médias, de nature et d’objectifs divers, et, plus encore, elle résulte de leur croisement. Le second postulat provient des innovations en histoire des savoirs de ces dernières années : une société ancienne repose sur un système de pensée et sur une configuration des savoirs distincte de la nôtre. Pour travailler sur les savoirs sous l’Ancien Régime, il faut appréhender l’altérité d’un ancien régime des savoirs et, plutôt que de rechercher la généalogie de disciplines, regarder à l’œuvre ces savoirs mixtes, aux nombreuses ramifications, la manière de les créer, de se les approprier et de les utiliser. Certes, Reinhart Koselleck et Kristof Pomian avaient déjà produit d’importants enseignements sur les processus. On a longtemps considéré qu’ils avaient probablement tout dit. Il fallait pourtant vérifier la percolation de ces enseignements au-delà des génies créateurs et des penseurs institués. Cette thèse étudie ces processus dans des opérations d’appropriation des savoirs historiques au sein des publics alphabétisés et la compréhension de ces savoirs en société : les pamphlets « historiés » de la Fronde, les conférences du Bureau d’Adresse de Théophraste Renaudot et des estampes ludiques – jeux de carte et jeux de l’oie historiques. Elle démontre le rôle de ces imprimés de forme brève comme lieux d’acculturation des savoirs historiques, mettant à disposition un prêt-à-penser sur le passé. S’inspirant des grilles de lecture des théories de la pensée complexe, développée entre autres par Edgar Morin, elle éclaire la pluralité des questions que se posaient les hommes de l’époque moderne sur leur passé, et les liens entre ces questions, leur lieu social d’émergence, les pratiques de la connaissance et les paradigmes culturels. [less ▲]

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See detailImproving probiotic viability and functionality by bioreactors engineering
Nguyen, Huu Thanh ULg

Doctoral thesis (2016)

There is a growing market for probiotic bacteria, but their production is still the subject to technical limitations, i.e. susceptibility to the stress conditions found during upstream and downstream ... [more ▼]

There is a growing market for probiotic bacteria, but their production is still the subject to technical limitations, i.e. susceptibility to the stress conditions found during upstream and downstream operations. In this work, we have investigated the effect of cultivation and drying conditions on Bifidobacterium bifidum MG 25628, a probiotic bacteria being particularly sensitive to bioprocessing conditions. Previous results have shown that microbial physiology, and the ability of microbes to cope with stress, is dependent of the growth rate and the growth phase. It is also known that the preliminary exposure of microbial cells to sub-lethal stress enhance its robustness. Accordingly, the effect of the exposure of B. bifidum in a two-compartment reactor designed in order to expose the strain to different temperature conditions was investigated. We found that the exposure of B. bifidum at 42°C for 1h at the onset of the stationary phase enhanced significantly survival after freeze-drying. It appeared that the increase in cell survival was attributed to the induction of the synthesis and an exopolysaccharide layer surrounding the cells. The method involving the exposure of the strain to sub-lethal temperature stress was further successfully scaled-up to a bioreactor volume of 2000 L. EPS synthesis can also be stimulated by sparing the bioreactor with carbon dioxide. In this context, we investigated the EPS yield in two specific bioreactor designs for the intensification of the CO2 gas-liquid mass transfer, i.e. a trickle bed and a falling-film microreactor. Depending of the operating conditions, these two bioreactor configurations led to a significant improvement in EPS synthesis (around 21 g/L). Extensive comparative proteomic analysis confirmed the impact on CO2 mass transfer on cell physiology, notably by enhancing the intracellular concentration of two key enzymes implied in carbonate uptake, i.e. phosphoenolpyruvate carboxylase and carbamoyl phosphate synthase. Taken altogether, these results point out that biochemical engineering parameters can be used as a very efficient strategy for improving probiotic robustness. Additionally, this non-GMO approach is more suited to the consumer expectations. [less ▲]

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See detailLa portabilité du statut personnel dans l’espace européen : De l’émergence d’un droit fondamental à l’élaboration d’une méthode de la reconnaissance
Pfeiff, Silvia ULg

Doctoral thesis (2016)

Opposer un refus de reconnaissance au statut personnel d’un individu revient à renier une partie de son identité. Le fait que des citoyens européens puissent subir les inconvénients liés à la survenance ... [more ▼]

Opposer un refus de reconnaissance au statut personnel d’un individu revient à renier une partie de son identité. Le fait que des citoyens européens puissent subir les inconvénients liés à la survenance d’un statut ‘boiteux’ lors de l’exercice de leur liberté de circulation est-il compatible avec les droits et libertés garantis par la Convention européenne des droits de l’homme et les Traités européens ? Cette question était à l’origine de notre recherche doctorale. Celle-ci nous a menés à nous interroger sur l’étendue des droits et libertés européens, tels qu’ils découlent de la jurisprudence de la Cour européenne des droits de l’homme et de la Cour de justice de l’Union européenne, et à explorer les pistes de solutions que recèle aujourd’hui le droit européen en tant que cadre supranational pour l’ensemble des États membres. Sous l’impulsion motrice de la Cour européenne des droits de l’homme et de la Cour de justice de l’Union européenne, la protection de la portabilité du statut personnel a connu ces dernières années des développements sans précédent. Il s’imposait dès lors de dégager les lignes directrices de cette importante œuvre prétorienne. Celles-ci s’imposent, de lege lata, aux États membres dès lors qu’ils envisagent de refuser de reconnaître le statut personnel d’un citoyen européen cristallisé dans un autre État membre. Il peut, à notre sens, être déduit de cette jurisprudence qu’un refus de reconnaissance du statut personnel constitue une ingérence dans le droit à la vie privée et familiale, lorsque la personne concernée nourrissait une confiance légitime en la permanence de son statut. Un tel refus risque également, par ricochet, de priver la personne de certains droits patrimoniaux liés à son statut, tel un droit successoral ou une créance alimentaire. La reconnaissance pourrait alors devenir un préalable nécessaire au respect de ses biens et, par conséquent, son refus constituer une ingérence à ce droit fondamental. Dans certaines circonstances, le refus de reconnaissance peut également porter atteinte au principe d’égalité ainsi qu’au droit à un procès équitable, pour autant que le statut personnel découle d’une décision judiciaire. Enfin, la discontinuité du statut personnel peut constituer une entrave à la liberté de circulation et porter atteinte à la citoyenneté européenne. Dès lors, l’existence d’un droit fondamental du citoyen européen à la permanence de son statut personnel acquis dans un État membre nous paraît s’inscrire dans la droite ligne des principes fixés par les deux Hautes juridictions européennes. Ce droit n’est cependant pas absolu. La jurisprudence tant strasbourgeoise que luxembourgeoise admet – dans des mesures comparables au demeurant – que l’État d’accueil puisse refuser de reconnaître le statut personnel acquis à l’étranger, pour autant que cela s’avère nécessaire à la protection de son intérêt légitime. Ces considérations nous ont amenés à conclure que les motifs abstraits de refus de reconnaissance traditionnellement retenus en droit international privé ne devraient plus permettre de justifier, à eux seuls, un refus de reconnaissance dans le contexte intra-européen. Ainsi, nous pensons que l’État d’accueil ne devrait plus pouvoir refuser de reconnaître un statut cristallisé dans un autre État membre pour le seul motif qu’il n’a pas été établi conformément à la loi désignée par sa règle de conflit, ou que l’État membre d’origine ne pré-sente pas de liens jugés suffisants avec la personne concernée. Si le refus de reconnaissance ne s’appuie pas, en outre, sur la volonté de protéger un intérêt légitime du for, il ne répondrait pas aux critères fixés par la jurisprudence européenne. En effet, le respect d’une règle abstraite de conflit de lois ou d’une exigence de liens suffisants ne paraît pas constituer un objectif légitime suffisant aux yeux des deux Cours européennes. La protection de ces règles abstraites ne semble, au demeurant, pas proportionnée à l’atteinte portée au droit à la permanence du statut personnel. De lege lata, nous estimons que seules l’exception de fraude, entendue très étroitement, et l’exception d’ordre public pourraient justifier, à elles seules, un refus de reconnaissance. Le cadre général ainsi posé, nous nous sommes consacrés dans la seconde partie de notre recherche – que nous avons voulue créative – à tenter de tracer, à la lumière de la jurisprudence européenne, les contours d’une méthode européenne de la reconnaissance. Cette méthode est une variante de ce qu’il est communément admis d’appeler la, ou les méthode(s) de la reconnaissance. La variante que nous préconisons est construite sur le principe selon lequel, afin d’assurer la portabilité du statut personnel au sein de l’Union européenne, la reconnaissance du statut cristallisé dans un État membre doit être la règle et les refus de reconnaissance l’exception, qu’il appartient à l’État d’accueil de justifier. En application de la méthode européenne de la reconnaissance, l’autorité d’accueil doit reconnaître le statut personnel d’une personne dès que celui-ci a été cristallisé dans un acte émanant d’une autorité publique d’un État membre, matériellement compétente pour ce faire, sans devoir vérifier au préalable sa validité. Elle peut cependant refuser de reconnaître le statut étranger si, et seulement si, ce refus apparaît nécessaire à la sauvegarde d’un intérêt fondamental de l’État d’accueil. Ce refus de reconnaissance prend alors la forme d’une exception européenne d’ordre public. Celle-ci systématise la mise en balance entre l’atteinte portée au droit à la permanence du statut personnel et l’intérêt légitime de l’État d’accueil poursuivi par le refus de reconnaissance. De surcroît, si l’État d’accueil est internationalement compétent pour ce faire, il peut annuler le statut étranger dans les mêmes conditions que l’État d’origine. Dans le cadre du contentieux de l’annulation, la validité du statut étranger est alors appréciée au regard des règles applicables dans l’ordre juridique d’origine, en tenant tout particulièrement compte des motifs de couverture éventuelle des nullités et de la titularité des personnes autorisées à soulever celle-ci. La méthode proposée pourrait, à notre sens, être traduite dans un Règlement européen, ce qui faciliterait incontestablement sa mise en œuvre. Afin de vérifier la faisabilité de la méthode européenne proposée, nous avons testé son application sur les situations potentiellement boiteuses épinglées lors d’un examen de droit comparé portant sur la circulation de quatre éléments du statut personnel au sein de quatre États membres. Les éléments du statut personnel sélectionnés étaient le nom de fa-mille, le mariage, le partenariat enregistré et le lien de filiation biologique. L’examen a porté sur les droits belge, français, allemand et anglais. Il a permis de mettre en évidence quelques-uns des atouts et faiblesses de la méthode proposée, que nous avons exposés dans le dernier chapitre de notre thèse et que nous résumons ci-dessous. La méthode européenne de la reconnaissance présente l’avantage d’offrir une réponse unique à la question de la portabilité du statut personnel. La distinction méthodologique traditionnellement retenue en fonction de la nature judiciaire ou non de l’acte à reconnaître est abandonnée. Elle permet d’éviter une grande partie des situations potentiellement boiteuses épinglées lors de notre examen de droit comparé, notamment en écartant le contrôle conflictuel et les autres motifs abstraits de refus de reconnaissance. La question de la qualification du statut établi à l’étranger se pose par conséquent avec moins d’acuité. Par ailleurs, elle met un terme à plusieurs débats actuels référencés au cours de nos travaux et apporte une réponse à des situations de vide juridique. Le postulat de la reconnaissance simplifie la circulation du statut personnel, puisque ce n’est qu’en cas de doute sur la compatibilité de l’accueil avec l’ordre public du for que l’autorité saisie procèdera à un examen plus approfondi de la situation qui lui est présentée. Dans la grande majorité des situations, le statut personnel circulera sans aucun réel contrôle au fond. L’approche concrète promue par la méthode proposée suscite cependant une difficulté particulière, qui n’existe pas, ou seulement dans une moindre mesure, dans l’application des règles abstraites de droit international privé étudiées. Il s’agit de la résolution des statuts inconciliables. Les approches traditionnelles, consistant à donner priorité au statut cristallisé dans l’ordre juridique d’accueil ou à appliquer un critère temporel, sont en effet écartées en faveur d’une approche concrète mettant en balance tous les intérêts en cause. S’agissant d’une méthode classiquement utilisée pour résoudre les conflits de droits fondamentaux, on connaît les difficultés et critiques auxquelles elle s’expose. De manière plus générale, la méthode européenne de la reconnaissance impose aux autorités nationales d’intégrer la logique européenne dans leur raisonnement, lorsqu’elles sont saisies de la question de la reconnaissance d’un élément du statut personnel cristallisé à l’intervention d’une autorité publique d’un État membre. Ce faisant, elle devrait réduire la survenance de statuts personnels boiteux et contribuer ainsi à faciliter la circulation des citoyens européens. Cette recherche s’inscrit dès lors à la croisée du droit de la famille, du droit international privé, du droit européen et des droits fondamentaux. [less ▲]

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See detailOn Vulnerability and Vulnerabilities of Incident Reporting
Rossignol, Nicolas ULg

Doctoral thesis (2016)

This PhD thesis – composed of a series of five papers tied together by an introduction and conclusions – explores the functioning of an Incident Reporting System used in a high-risk organization. It aims ... [more ▼]

This PhD thesis – composed of a series of five papers tied together by an introduction and conclusions – explores the functioning of an Incident Reporting System used in a high-risk organization. It aims at understanding how safety is actually constructed by and through this reporting system and what it actually does to the meaning of safety when it prescribes a set of sociotechnical practices. From a conceptual point of view, this PhD thesis departs from classical risk or vulnerability analyses which tend to measure factors in order to produce what are supposed to be “objective” results and “manageable” recommendations for decision makers. By relying on a constructivist understanding of vulnerability, this research explores and characterizes situations and events the consequences of which are ambiguous and the probabilities of which are uncertain. It thus broadens the scope of classical risk or vulnerability analyses and complements it with a qualitative and discourse-based attention to organizational, cultural and ethical questions. [less ▲]

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See detailModeling in Air Transportation: Cargo Loading and Itinerary Choice
Lurkin, Virginie ULg

Doctoral thesis (2016)

We examine two problems as part of this dissertation. The first is a cargo loading problem. The aim is to load a set of containers and pallets into a cargo aircraft that serves multiple airports. Our work ... [more ▼]

We examine two problems as part of this dissertation. The first is a cargo loading problem. The aim is to load a set of containers and pallets into a cargo aircraft that serves multiple airports. Our work is the first to model cargo transport as a series of trips consisting of several legs at the end of which pickup and delivery operations might occur. This problem is crucial for airlines because in an attempt to reduce their costs, most airlines prefer to load as many containers as possible, even if all the loaded containers do not have the same final destination. Our results demonstrate that it is possible to quickly find near optimal or excellent feasible loading plans, and that our approach leads to substantial savings with respect to typical manual approaches currently used in practice. The second problem we examine involves the estimation of itinerary choice models that include price variables and correct for price endogeneity using a control function that uses several types of instrumental variables. The motivation for developing these models is to demonstrate the importance of accounting for price endogeneity and to estimate different price sensitivities as a function of advance purchase periods. This is important as the airline industry can use our results to incorporate different customer segments as revealed through high-yield and low-yield booking curves when evaluating the profitability of airline schedules. Results based on Continental U.S. markets for May 2013 departures showed that models that fail to account for price endogeneity overestimate customers' value of time and result in biased price estimates and incorrect pricing recommendations. The advanced models estimated (nested logit and ordered generalized extreme value (OGEV) models) are shown to outperform the baseline multinomial logit model with regard to statistical tests and behavioral interpretations. Additionally, results show that price sensitivities vary as a function of advance purchase periods, with those purchasing high-yield products being less price sensitive than those purchasing low-yield products (across any advance purchase periods) and those purchasing closer to departure being less price sensitive. Results also indicate that inter-alternative competition is strong for itineraries that share similar departure times. Finally, as part of the itinerary choice model developed in this dissertation, we estimate highly refined departure time of day preferences. Results are intuitive and show that departure time of day preferences vary across many dimensions including the length of haul, direction of travel, number of time zones crossed, departure day of week, and itinerary type (i.e., outbound, inbound, and one-way itineraries). To the best of our knowledge, these curves represent the most refined publicly-available estimates of airline passengers' time of day preferences. [less ▲]

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See detailImpact de l'incertitude sur la gouvernance des institutions de microfinance: cas de coopératives burundaises
Niyungeko, Thadée ULg

Doctoral thesis (2016)

The microfinance sector has attracted increasing attention particularly in literature and in political circles in recent years. Microfinance is seen as a key means for the poors to access to financial ... [more ▼]

The microfinance sector has attracted increasing attention particularly in literature and in political circles in recent years. Microfinance is seen as a key means for the poors to access to financial services. Nevertheless, one of the challenges of microfinance institutions lies in their governance. To study the governance of microfinance institutions, many authors recommend to consider not only their diversity related to their natures and their missions, but also the context of the country in which they operate. However, existing works have not fully taken into account the contextual factors in the study of the governance of MFIs. This thesis contributes to bridge these gaps. It is in this sense of a specific and suitable approach to microfinance institutions. It analyzes the impact of the uncertainty related to an internal armed conflict in Burundi cooperatives. This research shows that face of uncertainty, policymakers are faced with the decision-making problems in compliance with the rules. Conflicts of interest arise, the paradoxes in the roles of directors or in inter-organizational relationships are observed. The results of this research also show the limits of volunteer principle in cooperative organizations in times of uncertainty. To cope with uncertainty, cooperatives undertaking various coping strategies despite their organizational similarities. They further develop inter-organizational relationships in search of legitimacy and scope of expression. Belonging to the network and the pressures of supervisor push these organizations to adopt isomorphic structures and practices. This thesis is a first milestone in the studies on the governance of cooperatives under uncertainty. It goes beyond the Burundian context by formulating hypotheses to be tested in future studies and in other places. [less ▲]

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See detailSexual attraction in lady beetles: fundamentals and applications
Fassotte, Bérénice ULg

Doctoral thesis (2016)

Sustainable agriculture relies on the development of environmentally friendly methods of crop production. Therefore, alternative solutions are required to decrease insecticide use and to promote the ... [more ▼]

Sustainable agriculture relies on the development of environmentally friendly methods of crop production. Therefore, alternative solutions are required to decrease insecticide use and to promote the efficacy of natural enemies against insect pests. Investigating the sexual behavior of lady beetles is of practical relevance, because these insects could be used to reduce plant-feeding insect populations in crop fields by taking advantage of their predatory behavior. In this context, the objective of this PhD thesis was twofold: (1) a fundamental research that focuses on the identification of the sex pheromone of Harmonia axyridis (Pallas) and (2) an applied approach aimed at elaborating semiochemicals slow-release dispensers with these compounds, in order to attract individuals in cultivated fields. We have demonstrated that virgin females of H. axyridis display a typical male-calling behavior in presence of prey, which is associated with the release of a pheromonal blend that is highly attractive for conspecific males. Dynamic headspace sampling and subsequent chemical analyses allowed the characterization of this sex pheromone. Finally, we focused on the development of a formulation releasing a combination of semiochemicals that attract aphid predators. The formulation, composed of alginate beads, was optimized under laboratory conditions. The release rate of the formulation was assessed by dynamic headspace sampling coupled with adsorbent trapping. The formulation was efficient at attracting two natural enemies of aphids. All these results are discussed in the context of sustainable agriculture, with the use of semiochemicals, and especially pheromones, as potential tools to enhance current cropping systems. In near future, the application of such molecules, based on strong knowledge of insect olfaction, is expected to increase considerably with the development of new methods aimed at attracting predators and/or parasitoids. In addition, improvements of experimental devices, such as the elaboration of slow release dispensers, are suggested in the last chapter of this PhD thesis. [less ▲]

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See detailLe billonnage cloisonné en agriculture des montagnes: évaluation et facteurs d'acceptation. Cas des Hauts Plateaux de l'Ouest-Cameroun
Djoukeng, Henri Grisseur ULg

Doctoral thesis (2016)

In the Western Highlands of Cameroon as in all other regions of the world where mountain agriculture is practiced, erosion and runoff pose a real threat to the sustainable preservation of natural ... [more ▼]

In the Western Highlands of Cameroon as in all other regions of the world where mountain agriculture is practiced, erosion and runoff pose a real threat to the sustainable preservation of natural resources. Generally, plots located on the slopes of the mountains in the Western Highlands have either become less productive or totally unproductive; this situation is exasperated by the scarcity of arable land which is largely attributed to cultural practices that do not take into account soil and water conservation methods. To better quantify the impacts of erosion and runoff on the different functions assigned to agriculture and agricultural holdings, this thesis has implemented tied ridging which is an unused soil and water conservation technique. We have thus compared the effectiveness of the existing soil preparation methods (ridging along the steepest slopes and flatbed cultivation) with tied ridging on two operating slopes namely 11% and 29%. The results showed a significant difference between the current practice (flatbed and ridging along the steepest slopes) and tied ridging in terms of soil loss (p = 0.003), yields (p = 0.003), and runoff water (p < 0.001). Under sole cropping of potato on a hectare of land, the tied ridging led to: (i) increase in populations of cultivated plants by 7%, (ii) significant reduction of runoff (lowered by a factor of seven) and soil loss (lowered by a factor of five), (iii) increase in yields by 80%, (iv) increase in farmer’s profitability by approximately 908388 FCFA.ha-1. The tied ridging needed 41% extra work regardless the slope of the land on which it was practiced. The tied ridging showed undeniable advantages: the stress of additional work was offset by the gain in yields for producer; additional work created additional job opportunities for the community; and tied ridging improved the conservation of soil and water for a healthy environment. Although the technique has several advantages, the provision of financial means for its implementation could be a negative point, because family labor supply is generally insufficient for its realization and the hired labor is expensive. Further work was dedicated to measuring the rate of adoption of the tied ridging technique and analysis of the determinants for adoption. The study showed that exploiting land ownership by farmers is a key factor in the implementation of soil conservation techniques. The results showed tied ridging adoption rates of 93% and 62% for dignitaries and other farmers respectively. Overall, access to land, operating slopes, and adoption of soil and water conservation techniques were significantly influenced by agronomic potentials of plots and socio-economic situation of farmers (p <0.05). Finally, in order to quantify the overall impact of tied ridging on the quality of surface water, we measured the proportion of sediments migrating from plots under the three soil preparation methods and entering to the river’s bed. The collected and measured sediments consisted of soil, plant residues, and other wastes (chemical packages, plastic casing used for irrigation, and food packages). The results showed that tied ridging cultivation method significantly reduced siltation of the Méloh River (p<0.05). Compared to 2012 and 2013, quantities of sediment decreased by 66% in 2014, the year in which the tied ridging technique was adopted on 75% of the plots. Thus the flatbed and ridging along the steepest slopes soil preparation methods are the principal cause of siltation and pollution of the Méloh River. The results of this research led to the following prospective approaches for improvement: (i) test the tied ridging technique with other crops and with different inter mounds’ spacing, (ii) study the facilitation of access to credit and creating farmer's organizations for promoting the adoption of tied ridging, (iii) test other soil and water conservation techniques such as live hedges, direct-sowing mulch-based crop (agroecology), and agroforestry, and (iv) conduct general limnologic studies of watersheds. The general limnology studies the surface waters according to their seasonal variations, and their physico-chemical and biological aspects. [less ▲]

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See detailLes femmes entrepreneures au Maroc : Quels sont les facteurs individuels et contextuels qui influencent leur activité ? Une étude comparative entre trois profils de femmes entrepreneures
Salman, Noura ULg

Doctoral thesis (2016)

L’entrepreneuriat féminin, en tant que vecteur de croissance et d’emploi suscite l’intérêt des décideurs politiques, économiques et académiques (De Bruin et al. 2007 ; Arasti, 2008 ; Lebègue, 2010 ... [more ▼]

L’entrepreneuriat féminin, en tant que vecteur de croissance et d’emploi suscite l’intérêt des décideurs politiques, économiques et académiques (De Bruin et al. 2007 ; Arasti, 2008 ; Lebègue, 2010 ; Hugues et al. 2012). Dans cette perspective, notre thèse a comme objectif d’identifier les principaux facteurs individuels/personnels et contextuels susceptibles d’influencer l’activité entrepreneuriale des femmes marocaine. A partir d’une étude comparative entre trois profils de femmes entrepreneures : les femmes chefs d’entreprises, les femmes en professions libérales et les femmes coopératrices, nous avons cherché à comprendre comment un ensemble de facteurs peuvent être favorable ou défavorable à l’activité entrepreneuriale des femmes marocaines. Dans ce cadre, une série d’interviewés qualitatives (60 interviews) ont été réalisées entre 2011 et 2013. Pour réaliser cette enquête nous nous somme appuyés sur un ensemble de propositions de recherches élaborées à partir de notre cadre théorique. En s’inscrivant dans une perspective féministe, notre analyse s’appuie essentiellement sur l’analyse du genre. Cinq groupes de facteurs ont été retenus pour notre recherche, à savoir : les facteurs personnels, les facteurs familiaux, les facteurs institutionnels, les facteurs professionnels ainsi que les facteurs socioculturels. Notre analyse permet à la fois d’appréhender l’influence des facteurs ci-dessus sur l’activité entrepreneuriale des femmes dans le contexte marocain mais, aussi, la particularité de leur expérience via une lecture en termes de genre. Nous résultats indiquent, que des facteurs personnels, en particulier les motivations personnelles, et les facteurs familiaux (le soutien du conjoint et le réseau familial) constituent les principaux leviers pour les femmes entrepreneures marocaines. Par contre les facteurs institutionnels (l’administration et le financement externe), les facteurs professionnels notamment les clients et enfin les facteurs socioculturels sont les principaux freins pour les femmes entrepreneures marocaines. Nous résultats indiquent ainsi, des caractéristiques similaires aux trois groupes de femmes entrepreneures. Mais également, des différences importantes entre les trois catégories. Cela témoigne de la réalité plurielle de l’entrepreneuriat féminin au Maroc, qui peut susciter un intérêt auprès des praticiens et des théoriciens de ce phénomène. [less ▲]

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See detailSTUDY AND CHARACTERIZATION OF MAGNETIC AND MULTIFERROIC MATERIALS BY FIRST-PRINCIPLES CALCULATIONS
Garcia Castro, Andrés Camilo ULg

Doctoral thesis (2016)

In the last fifteen years, multifunctional materials, and more specifically, multi- functional oxides have been widely studied due to its wide range of properties. Properties that go from ... [more ▼]

In the last fifteen years, multifunctional materials, and more specifically, multi- functional oxides have been widely studied due to its wide range of properties. Properties that go from superconductivity to ferroelectricity passing through mag- netism and multiferroism have been reported. Nonetheless, the fluoride family was left aside and little information is known about its possible ferroelectricity or mul- tiferroism. In this Ph.D thesis, we explored the electronic, vibrational, structural and magnetic properties of fluoride perovskite-based compounds. To such pur- poses, We performed ab-initio calculations based in the density-functional theory (DFT) as implemented in VASP and CRYSTAL codes. Our first step was to perform vibrational analyses in a large set of fluoroper- ovskites ABF3. Based on the results, we proposed a model that establishes an A-site geometrically driven ferroelectric vibrational instability in fluorides. Our studies reveal a different behavior as a function of isotropic pressure for NaBF3 with respect to oxides (e.g. BaTiO3) with B = Ca, V, Mn, and Zn. For these compounds we found an increase of the ferroelectric instability as a function of hydrostatic pressure. This probably due to the “transformation” of eigendisplace- ments responsible for the mode that creates the corresponding instability. In particular, an increase of ionic A-site radii present a strong influence in FE-polar instability. We also have shown, based on our first-principles calculations and symmetry theory analysis that all post-perovskites ABX3 with an active magnetic B-site cation can exhibit a noncollinear magnetic configuration, which happens to be allowed by symmetry. With these findings, the magnetic properties found exper- imentally were clarified for this particular high-pressure phase perovskite found at the Earth’s mantle. Additionally, We have predicted that NaMnF3 suffers a structural phase transition under pressure to a post-perovskite phase, where non- collinear ferromagnetism and large magnetic moment components are obtained within this high-pressure phase.. Going beyond, We have shown that it is possible to achieve multiferroic-induced state in NaMnF3 under epitaxial strain at compressive or tensile strain. We found a nonlinear behavior of the ferroelectric instability as well as a non-linear piezo- electric response as a function of epitaxial strain. The later completely different as the one found in oxide perovskites. Similarly, an out-of-plane polarization was observed, a property that has not been observed in oxides. We observed a Na + Mn sites cooperative ferroelectric ordering for compressive strain against a pure A-site geometrically driven ferroelectricity at tensile values of the ac-strain. Magnetic ordering reveals a non-collinear ground state with the GzAxFy repre- sentation. Even more interesting, and non-linear magnetoelectric coupling was found under the strained Pna1 ground state becoming the first known multifer- roic/magnetoelectric perovskite fluoride. Later, in order to go further, We studied the electronic and structural proper- ties of novel heterostructures based on oxyfluorides (KTaO3)n/(KBF3)l B = Zn and Ni interfaces. We found that the orbital levels splitting at the interfaces is strongly modified by the O–B–F coordination. The polar catastrophe phenomena also takes place in the oxyfluoride interfaces similarly to oxide heterostructure, however, we found that less number of layers are needed in order to achieve the insulator-to-metal transition when comparing to SrTiO3/LaAlO3 superlat- tices. We observed that the magnetism in the KTaO3/KNiF3 exhibits a moment magnitude modulations. Nevertheless, the magnetic structure keeps the G-type antiferromagnetism such as in the bulk former compound. Surprisingly, we ob- served a large k3-Rashba type splitting in at the oxyfluoride interfaces, at least four times larger than the one reported in SrTiO3/LaAlO3 interface and twice of the KTaO3-based transistor. In conclusion, we observed that fluorides-perovskites are good prototypes for multifunctional properties as oxides. Therefore, based on the results reported in this thesis, we expect that experimentalist and theoreticians can be motivated in characterization of fluorides, which can lead to a new set of unexplored materials with potential novel applications in electronics. [less ▲]

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See detailDocteur
Poskin, Antoine ULg

Doctoral thesis (2016)

During summer 2011, cattle presented severe hyperthermia combined with dropped milk yield and diarrhoea from unknown origin. In October 2011, blood was collected from cattle presenting these clinical ... [more ▼]

During summer 2011, cattle presented severe hyperthermia combined with dropped milk yield and diarrhoea from unknown origin. In October 2011, blood was collected from cattle presenting these clinical signs in Schmallenberg, a small city in West Germany. A new Orthobunyavirus, responsible for these unspecific clinical signs was identified and named Schmallenberg virus (SBV). Upon November 2011, an epizootic outbreak of abortion, stillbirths and malformed new-born was observed in bovine, ovine and caprine herds in Europe due to transplacental transmission of SBV to the foetus. The SBV vectors are small hematophagous midges of the gender Culicoides. This work contributed to estimate the impact of the SBV epidemic in Belgium (Study 1). On the basis of farmer’s observations, between 0.5% and 4% of calves were aborted, stillborn or malformed due to SBV in 2011-2012. Abortions and stillbirths were not clear consequences of the SBV outbreak in cattle. In sheep, between 11% and 19% of lambs were aborted, stillborn or malformed due to SBV in 2011-2012. Deformed animal was the most important finding of SBV outbreak at herd level and an essential condition for the farmer to send suspected samples to the National Reference Laboratory (NRL) for SBV analysis. The results gathered from the study indicate that SBV surveillance and monitoring should be implemented by SBV RNA detection with rRT-PCR in organs collected from stillborn and deformed calves and lambs born in big herds. The high impact of SBV highlighted in the Study 1 was putatively explained by unknown host supporting the SBV activity. In this respect, the role of pigs had never been evaluated. This was essential considering the suggested role of the domestic pigs in the life- cycle of the SBV-closely related Akabane virus (AKAV) (Huang et al., 2003). The absence of RNAemia after experimental infection of piglets with SBV realized in the Study 2 of the i thesis suggests the absence of obvious role of domestic pigs in SBV life-cycle. The absence of RNAemia is indeed a strong indication that further spread of SBV from the pigs to the Culicoides during a blood meal of the vector is not likely to occur, therefore making impossible an SBV transmission. The limited and temporary seroconversion observed after SBV inoculation in only half of the inoculated piglets and the absence of seroconversion reported in a limited number of field collected samples support this consideration. To prevent SBV progression, it was crucial to further study the pathogenesis of SBV. The Study 1 proved that the most important clinical impact of SBV was the consequence of the malformed new-born; hereto it was particularly crucial to improve the knowledge on the development of the SBV-related teratogenic effects. In this respect, experimental infection of pregnant sheep with SBV constituted an appropriate research approach. An experimental model was therefore essential to standardize. This thesis contributed to the standardization of in vivo experiments (in collaboration with another working group) by determining the minimum infectious dose of an SBV infectious inoculum. This reference infectious serum must contain approximately 20 TCID50 to induce a homogeneous effective infection in sheep. This dose is rather low and could be inoculated by a single Culicoides under natural conditions. Beyond this minimum infectious dose, no dose dependent effect was observed in productively inoculated ewes, either in the duration of the RNAemia, the quantity of SBV RNA detected by rRT–PCR in the blood, or in the number of SBV RNA copies present in the organs collected at necropsy. The experimental model developed (partly) in the Study 3 was used to inoculate pregnant ewes at day 45 and 60 of gestation, and increase the knowledge on SBV transplacental transmission. The inoculation induced the persistence of SBV RNA in placental organs until birth. Schmallenberg virus RNA was recovered from the organs collected at birth from the lambs of both groups. However, the chance to obtain SBV RNA positive placental ii organs was significantly higher when the infectious inoculum was inoculated at day 60 of gestation. Positive organs in lambs included CNS and muscle, but no malformation was observed in new-born lambs. This absence of malformations suggests that SBV inoculation must occur earlier than the day 45 of gestation to produce teratogenic effects in sheep. Also, the persistence of SBV RNA in the foetal envelope is indicative of a putative mean for SBV overwintering. The Study 4 highlighted a 6 month persistent seroconversion in the absence of SBV surinfection. In the meantime, SBV circulation drastically dropped on the field and the absence of SBV circulation could induce the sheep to become seronegative under natural conditions. In the Study 5, the experimental model developed in the Study 3 was used to demonstrate that one single SBV inoculation can induce a protective immunity in sheep that persists during a minimum period of 15 months. This experiment highlights that 2 successive periods of SBV circulation, spared of one year, is not likely to induce malformations on the field the second year. Based on the experience gathered with the closely related AKAV, recurrent outbreaks of congenital events can be expected for a long period. Vaccination of seronegative animals could be used to prevent the deleterious effects of SBV in case of SBV re-emergence. During this epidemic, different surveillance approaches including syndromic surveillance, sentinel herd surveillance, cross-sectional seroprevalence studies and pathogen surveillance in vectors have proven their utility and complementarity and should be considered to continue in the future in order to monitor the SBV dynamic. [less ▲]

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See detailDevelopment and validation of analytical methods based on GC-MS/MC Triple Quadrupole instrument for the analysis of POPs in food and feed matrices
Calaprice, Chiara ULg

Doctoral thesis (2016)

This thesis focused on the development and validation of analytical methods for the de-tection and quantification of Persistent Organic Pollutants (POPs) in biological matrices, namely food and feed ... [more ▼]

This thesis focused on the development and validation of analytical methods for the de-tection and quantification of Persistent Organic Pollutants (POPs) in biological matrices, namely food and feed samples. POPs are a group of chemical compounds listed after the Stockholm Convention in 2001, with demonstrated toxicity and dangerousness for envi-ronment, animals and humans. In this work of thesis, special attention was reserved to some selected POPs: polychlo-rodibenzo-p-dioxins (PCDDs), polychlorodibenzofurans (PCDFs), usually referred to as “dioxins”, and polychlorinated biphenyls (PCBs), as there is a big concern about these contaminants in Taranto, a city in the Southern Italy very close to Bari, my home town. Taranto, indeed, is characterized by a large industrial area with a steel mill, several incin-erators and a refinery in few kilometre radius (Di Leo et al., 2014). This work has been done in collaboration with the University of Liège (Belgium) where a consolidated exper-tise in the field of POP measurements was available, especially in terms of dioxin anal-yses. In Chapter 1 the main steps, from sample preparation to data elaboration, of a validated confirmatory method for dioxin and PCB detection in food and feed using gas chromatog-raphy coupled to tandem mass spectrometry Triple Quad instrument (GC-MS/MS Triple Quad) have been described. This method was developed at the University of Liège in the framework of the last updates of the EU Regulation that in 2014 allowed confirmatory quantitative analysis of dioxins with Triple Quad. This method was the starting point of this work of thesis, because it was used for all dioxin and PCB quantifications. In Chapter 2 and chapter 3 alternative clean-up approaches for dioxin analysis in fatty food matrices have been developed using different automated systems. These works have been done in the framework of solvent and time saving for high throughput analytical methods in dioxin analysis. In chapter 2, an already existing automated system, DEXTechTM from LCTech GmbH (LCTech GmbH, Bahnweg 41, 84405 Dorfen, Germany) was used for sample clean-up, but a completely new clean-up approach was developed with this. GC-MS/MS Triple Quad instrument, as well as Magnetic Sector High Resolution Mass Spectrometry (HRMS) instrument were employed for final quantification, to demonstrate the suitability of our newly developed clean-up approaches whatever the instrumental detection. In Chapter 3 PowerPrepTM automated system from Fluid Management System (FMS Inc., 580 Pleasant Street, Watertown, MA 02472, USA) was used and our routine sample clean-up approach was modified in order to enhance the efficiency and to reduce cost and solvent consumption of the analysis. In Chapter 4 the main method for dioxin analysis was adapted for the integration of Dechloranes in the list of the analytes targeted in the regular control for dioxins in food and feed. Dechloranes are a family of 6 organo-chlorinated compounds with structure similar to Mirex, also called Dechlorane, a POP listed in the Stockholm convention. Dechloranes have been found in human blood of people from Europe (Brasseur et al., 2014) and in this work an analytical method for Dechlorane detection was developed and validated to investigate food as a possible route of exposure for humans in Europe, where no production plant has been identified so far. The analytical method was used to analyse 88 food and feed real sample and to give an idea of Dechlorane daily dietary intake. [less ▲]

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See detailStudy of the genetic structure of the African buffalo populations (Syncerus caffer): Impact of its high mobility and of the population fragmentation on its distribution and its interactions with humans
Smitz, Nathalie ULg

Doctoral thesis (2016)

The African continent still hosts a unique diversified megafaunal community. However, phylogeographical patterns of African species have not yet been largely studied, as compared to the North American and ... [more ▼]

The African continent still hosts a unique diversified megafaunal community. However, phylogeographical patterns of African species have not yet been largely studied, as compared to the North American and European species. Moreover, nowadays, the African ecosystems suffer of considerable anthropogenic pressures and of severe climatic modifications. Wildlife population fragmentation resulting from habitat loss, drought, poaching and diseases is currently threatening many African species survivals. The present thesis aimed at investigating the phylogeography and the population genetic structure of the African buffalo (Syncerus caffer) at different spatio-temporal scales (phylogeographical scale vs demographic scale), based on different molecular markers (mtDNA D-Loop region, 17 microsatellites and a large set of ‘Single Nucleotide Polymorphisms’ (SNPs)). The African buffalo is an emblematic key species and provides a powerful model to enhance our understanding of the African biogeography and the species conservation requirements. The aim of the first part of the present work was to reconstruct the evolutionary history of the African buffalo based on the study of the mtDNA D-Loop hypervariable region. More particularly, we aimed at studying the impact of the Quaternary climatic fluctuations on the species distribution (i.e. phylogeographical scale). Moreover, one of our purposes was also to investigate the taxonomic controversies linked to the extreme within species morphological variability, using molecular tools. From a sample set including all four morphologically recognized subspecies roaming the sub-Saharan African continent (hereafter called ecophenotypes), two taxonomic units were supported by genetics. The genetic discontinuity was located between the West-Central (S. c. nanus, S. c. brachyceros and S. c. aequinoctialis) and the South-Eastern populations (S. c. caffer). The low amount of genetic differentiation within each of these two units, or lineages, was attributed to a recent (in evolutionary term) Pleistocene expansion in both lineages, with rapid adaptation to a variety of habitats. Using both microsatellites and a large set of SNPs, the second part of the present thesis aimed at investigating the impact of human activities and recent climatic changes on the population structure of the species (i.e. demographic scale). While mtDNA did not allowed to distinguish finer sub-structuration within the two identified lineages, suggesting high female gene flow at an evolutionary timescale, these last molecular markers allowed to identify eight different populations at the continental level: two in West-Central Africa, three in Eastern and three in Southern Africa. Both ancient (Neolithic revolution) and recent anthropogenic activities were proposed to have shaped the demographic population structure observed in Southern and Eastern Africa. Recently, two of these populations were shown to be under significant genetic drift, following severe demographic bottlenecks. In these two cases, the sharp reduction in the size of the populations was proposed to be linked to disease eradication campaigns and to overharvesting during civil wars. Nevertheless, they did not display a significant loss in heterozygosity, indicating that they are still genetically healthy. Interestingly, at the contact region between the S. c. caffer and the S. c. aequinoctialis savanna ecophenotypes, a population displaying a shared genetic pool was also identified, corroborating the existence of hybrids between the different forms (intermediate morphological characteristics). In conclusion, using various genetic approaches and molecular markers, the present work gained insights into the taxonomy and the evolutionary history of the African buffalo, as well as in its conservation management requirements. [less ▲]

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See detailDéveloppement de procédés sol-gel de fabrication de matériaux de batterie
Eskenazi, David ULg

Doctoral thesis (2016)

Différents procédés, installations et moyens d'analyse ont été développés pour la fabrication de matériaux de batterie Li-ion par procédé sol-gel. Leur objectif est de faciliter l'utilisation industrielle ... [more ▼]

Différents procédés, installations et moyens d'analyse ont été développés pour la fabrication de matériaux de batterie Li-ion par procédé sol-gel. Leur objectif est de faciliter l'utilisation industrielle de ces matériaux. Il s'agit d'un réacteur continu de fabrication de xérogels de carbone sous forme de billes, d'un réacteur de nitruration de phosphates, et d'une technique d'analyse thermique couplée à de la spectrométrie de masse. [less ▲]

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See detailModel-Based Prediction of the Response to Vascular Filling Therapy
Pironet, Antoine ULg

Doctoral thesis (2016)

Vascular filling is one of the most frequent interventions in intensive care units. Its expected effect is to increase cardiac output. However, this increase is only observed in approximately 50 % of ... [more ▼]

Vascular filling is one of the most frequent interventions in intensive care units. Its expected effect is to increase cardiac output. However, this increase is only observed in approximately 50 % of cases. In addition, excessive vascular filling can lead to deleterious effects, such as pulmonary oedema, which increase length of ventilation, stay, mortality and cost. Clinicians are thus looking for indices to provide a priori knowledge of the effect of vascular filling. This thesis focuses on a mathematical model-based approach to predict the response to vascular filling. Mathematical models are sets of equations representing the behaviour of a given system as, for instance, the cardiovascular system. To understand the concept of vascular filling, basic elements of cardio-vascular anatomy and physiology are presented in the first part of this thesis. Then, fur- ther details about vascular filling therapy are given, as well as the current indices used by clinicians to predict its effects. The static indices are easy to obtain, but do not perform well. The dynamic indices, based on cardio-pulmonary interac- tions, perform better, but are difficult and highly invasive to implement clinically. A new index, total stressed blood volume, also seems to perform well, but is not easy to obtain clinically. This work develops and then uses models of the cardio- vascular system to make this parameter available to clinicians. Building on the elements of physiology provided in the first part, the second part of this thesis describes ways to model the components of the cardio-vascular system as lumped elements, such as chambers, valves and resistances. Two mod- els of the cardio-vascular system, comprising respectively three and six cham- bers, are built from such elements. These two models involve a small number of parameters, including the total stressed volume in the model. The third part of this thesis describes the potential and methods to identify the parameters of the two cardio-vascular system models. Parameter identifica- tion aims at finding the parameter values that make model simulations as close as possible to measured data. The available data is thus first described, accord- ing to whether it is collected in an experimental laboratory or an intensive care unit. Then, it is mathematically demonstrated that all model parameters can the- oretically be identified from data available in an intensive care unit. However, practically speaking, some parameters are difficult to identify, because they have little influence on the simulations, or have the same effect as other parameters. Fi- nally, computational methods to perform parameter identification are presented and compared. The last part of this thesis presents two applications of the cardio-vascular system models to experimental data. First, all parameters of the six-chamber cardio-vascular system model are identified from data recorded during a preload reduction experiment. This result provides the first quantitative validation of the six-chamber model in transient conditions. Second, all parameters of the three-chamber cardio-vascular system model, including total stressed volume, are identified from data recorded during vascular filling experiments. The total stressed volume parameter is shown to be systematically related to the change in cardiac output after vascular filling. This last index thus provides, for the first time, a model-based means of predicting the response to vascular filling. [less ▲]

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See detailTherapy of Adult T-cell Leukemia by inhibition of the DNA repair mechanisms
Carpentier, Alexandre ULg

Doctoral thesis (2016)

The Tax oncoprotein plays a central role in viral persistence and pathogenesis of human T-cell leukemia virus type 1 (HTLV-1). Indeed, Tax transforms primary cells and induces tumors in transgenic mouse ... [more ▼]

The Tax oncoprotein plays a central role in viral persistence and pathogenesis of human T-cell leukemia virus type 1 (HTLV-1). Indeed, Tax transforms primary cells and induces tumors in transgenic mouse models. Mechanistically, Tax accelerates the S phase of the cell cycle by firing late replication origins. This modification of the replication timing program induces an oncogenic stress that generates DNA damage such as double-strand breaks. Tax thus provides a selective advantage that promotes proliferation but also exposes host cells to potentially harmful clastogenic damage. How Tax-expressing cells handle this oncogenic stress is currently unknown. In this thesis, we show that Tax-expressing cells activate the DNA Damage Response (DDR). We quantified the repair efficiencies of DNA double-strand breaks. We demonstrate that Tax induces the recruitment of DNA repair core proteins (Ku70, RAD51 and RAD52) on chromatin. We further show that the efficiency of homologous recombination (HR) is inhibited by Tax. In contrast, non-homologous end joining (NHEJ) and single-strand annealing (SSA) are activated in the presence of Tax. Taking advantage of the addiction of Tax-expressing cells on improved DNA repair, we show that pharmacological inhibition of these pathways in HTLV-1 infected lymphocytes leads to an accumulation of DNA damage and apoptosis. We propose a novel therapeutic approach for the treatment of ATL based on the use of inhibitors targeting DNA repair pathways. [less ▲]

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See detailApplication de l’échographie à l’étude de la dynamique folliculaire lors de l’oestrus induit chez la vache Azawak au Niger
Moussa Garba, Mahamadou ULg

Doctoral thesis (2016)

Le Niger dispose d’énormes potentialités en matière d’élevage bovin notamment. Mieux exploitées et gérées, elles pourraient améliorer de manière très significative les performances des races locales. Les ... [more ▼]

Le Niger dispose d’énormes potentialités en matière d’élevage bovin notamment. Mieux exploitées et gérées, elles pourraient améliorer de manière très significative les performances des races locales. Les faibles performances de production et de reproduction qui caractérisent le bétail nigérien sont imputables à plusieurs facteurs, notamment les déficiences alimentaires, le mauvais état sanitaire et le faible potentiel génétique des races locales. L’alimentation du cheptel dont dépendent les productions, reste largement tributaire du régime des pluies dont les faibles quantités généralement enregistrées rendent aléatoire la production fourragère. De même, le faible taux de couverture sanitaire entraine la persistance de certaines maladies (PPCB, pasteurellose, tuberculose, parasitoses, mammites..) contribuant ainsi à la baisse des performances de production et de reproduction. La race bovine Azawak, la meilleure laitière produit à peine 7 à 8 litres de lait par jour. Au cours de ces dernières décennies, plusieurs stratégies et programmes de développement ont été élaborés et mis en oeuvre en vue de valoriser les productions animales. Cependant, la mise en oeuvre de ces stratégies et programmes de développement n’a pas permis d’améliorer la performance du secteur de l’élevage et certains indicateurs comme la consommation de viande et de lait par habitant ont diminué de manière drastique. En dépit d’un cheptel bovin numériquement important (+ de 11 millions de têtes), le Niger enregistre un déficit laitier important. La production locale est loin de couvrir les besoins de la population. La présente étude est une contribution visant à terme à augmenter la production laitière par le recours à l’insémination artificielle dont il restait cependant à : - faire le point sur les caractéristiques et performances de reproduction de Bos indicus ; - évaluer les caractéristiques physiologiques et pathologiques du tractus génital de la femelle Bos indicus ; - décrire par échographie les caractéristiques de la croissance folliculaire et de l’ovulation chez des femelles Azawak dont l’oestrus a été induit par une PGF2α ou par des progestagènes. La documentation sur les caractéristiques et performances de reproduction des zébus africains est peu nombreuse. Ainsi, une synthèse a été réalisée pour dresser l’état des lieux des connaissances dans le domaine de la reproduction de Bos indicus. Compte tenu des faibles performances de reproduction de Bos indicus, et pour recourir à l’insémination artificielle, divers traitements hormonaux sont envisagés. Ce travail a également actualisé les résultats potentiels offerts par l’insémination artificielle réalisée sur chaleurs naturelles ou induites. L’infécondité est une des caractéristiques de l’élevage bovin en Afrique se traduisant par un allongement de l’âge du premier vêlage et de l’intervalle entre vêlage. Elle limite le progrès génétique et la rentabilité des élevages de Bos indicus. Pour comprendre si les pathologies du tractus reproducteur constituent un facteur de risque d’infécondité dans le bétail nigérien, une étude a été conduite à l’abattoir de Niamey au Niger. Elle a concerné 500 tractus génitaux de 500 femelles zébus (Bos indicus) appartenant à quatre races bovines (Azawak, Bororo, Djelli, Goudali). Ces vaches et génisses, âgées en moyenne de 8 ± 2,5 ans, ont eu une note d’état corporel moyenne de 1,6 ± 0,6 et un poids moyen de carcasse de 113 ± 21 kg. Aucune différence significative n’a été observée entre les races étudiées en ce qui concerne le diamètre du col (3,4 ± 1,1 cm), la longueur du col (8,1 ±2,5 cm) et des cornes (21,6 ± 5,2 cm), le diamètre des cornes (1,6 ± 0,5 cm), la longueur et la largeur de l’ovaire droit (19,8 ± 4,4 mm et 11,2 ± 3,8 mm) et de l’ovaire gauche (18,8 ± 4,5 mm et 10,2 ± 3,3mm) et le poids des ovaires gauche et droit (2,5 ± 1,6 et 2,9 g ± 1,8 g respectivement). Ces données sont d’une manière générale, inférieures à celles classiquement rapportées pour le genre Bos taurus. Diverses pathologies de l’appareil génital (kystes, infections utérines, free-martinisme, pyomètre) ont été observées sur 10,4 % des tractus génitaux. La fréquence observée des pathologies donne à penser qu’elles ne constituent pas un facteur de risque majeur de l’infécondité. Ce résultat à amener à étudier l’effet des traitements hormonaux sur la croissance folliculaire et l’ovulation. En effet, la croissance folliculaire jusqu’à l’ovulation après synchronisation et induction des chaleurs au moyen de PGF2α et de progestagènes a été appréciée par échographie chez 42 vaches en lactation de race Azawak. Ces animaux issus de la station de Toukounous ont été ensuite inséminés deux fois (à 12 heures et à 24 heures) 5 après la détection de l’oestrus sur respectivement 16 et 11 femelles traitées à la PGF2α et aux progestagènes. Cette investigation à permis de noter les constats suivants : Les taux moyens d’induction ont été de 81 % dans les deux traitements. Le délai moyen d’apparition de l’oestrus est apparu significativement plus long après injection d’une PGF2α (84,8 ± 26,0 heures) qu’après retrait du PRID (59,2 ± 5,8 heures). La durée moyenne de l’oestrus a été plus courte après son induction au moyen de la PGF2α (12,6 ± 2,6 heures) que du progestagène (22,9 ± 2,7 heures) ; Le délai d’ovulation à partir des chaleurs n’a pas été significativement différent chez les animaux traités à la PGF2α (30,3 heures) et aux progestagènes (28,4 heures) ; Le taux de gestation après une injection de PGF2α (31,2 %) a été inférieur à celui obtenu après utilisation du protocole à base de progestagènes associé à une injection de PGF2α et d’eCG (54,5 %). Les intervalles observés entre les traitements et l’oestrus et l’ovulation permettent de préconiser une insémination plus précoce des animaux traités au moyen de progestagènes qu’avec une PGF2α. [less ▲]

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See detailRégulation de la transcription du virus T-lymphotrope humain de type I (HTLV-1) par le complexe MiniChromosome Maintenance 2-7 (MCM2-7)
Barez, Pierre-Yves ULg

Doctoral thesis (2016)

First oncogenic retrovirus discovered, the human T-lymphotropic virus type 1 (HTLV-1) infects approximately 5 to 10 millions of individuals worldwide. HTLV-1 is the etiological agent of adult T-cell ... [more ▼]

First oncogenic retrovirus discovered, the human T-lymphotropic virus type 1 (HTLV-1) infects approximately 5 to 10 millions of individuals worldwide. HTLV-1 is the etiological agent of adult T-cell leukemia and a neurodegenerative disorder called HAM/TSP (HTLV-1 associated myelopathy/Tropical spastic paraparesis). The HTLV-1 Tax protein interacts with the minichromosome maintenance MCM2-7 helicase, through the amino-terminal part of MCM3. This interaction accelerates firing of late DNA replication origins (ORI) in infected cells. Since Tax acts on the long terminal repeat (LTR), we hypothesized that the MCM2-7 complex could also be recruited to the viral promoter. Using chromatin immunoprecipitation, we show that MCM2-7 indeed interacts with LTR sequences. However, loading of the MCM complex does not fire DNA replication in an autonomous plasmid replication assay. In contrast, MCM2-7 activates viral transcription in luciferase reporter assays and in the context of a proviral clone. Short hairpin RNA interference of MCM2-7 inhibits LTR-driven Tax transactivation in lymphocytes. Finally, siRNAs targeting MCM3 reduce viral transcription in HTLV-1 infected cell lines. Together, our data thus indicate that the presence of the MCM2-7 complex on the HTLV-1 promoter is involved in viral transcription. [less ▲]

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See detailExpression des propriétés biologiques des substances humiques de lixiviats sur le développement racinaire de ligneux
Tahiri, Abdelghani ULg

Doctoral thesis (2016)

Humic substances (HS) are a dark-colored heterogeneous organic compounds originated from microbial decomposition and chemical degradation of organic matter. The exact structure and composition of HS ... [more ▼]

Humic substances (HS) are a dark-colored heterogeneous organic compounds originated from microbial decomposition and chemical degradation of organic matter. The exact structure and composition of HS macromolecules are not totally elucidated due to their complexity and their structural heterogeneity. They have long been recognized as plant growth promoting substances, particularly with regard to influencing nutrient uptake, root growth and architecture and by improving soil structure. However, the molecular mechanisms through which HS influence plant physiology are not well understood and must be deepened. The aim of this doctoral thesis is to obtain deeper understanding of the biological activity exerted by HS extracted from landfill leachates in comparaison to a commercial formulation extracted from leonardite on roots growth of woody plants in relation to their chemical characterization and mechanisms of action. Three experimental approach have been carried out. The first one concerns a comparative chemical characterization of total HS and derived fractions, separated in function of their solubility and molecular weight, was performed using elemental analysis, UV-vis, FT-IR and 1H NMR spectroscopy and MALDI-TOF mass spectrometry. Obtained results indicate that HS of both origins were basically similar regarding the presence of their chemical structures but, differ mainly in their relative abundance. The second, concerns the development of an in vitro culture model to study the biological activity of HS on the development of root system of two woody pioneer species. The data obtained showed that the effect of HS depends on plant species, concertation, mode of application and source of HS. If the high molecular weight fraction (HA) was effective at promoting root development, the lower ones (FA and OM) inhibit it in function of the concentration used. Finally, a molecular approach was investigated to study some molecular mechanisms that plant act in response to HS comparing the expression of four genes (ABCB1, ABCB19, GS and ADH) implicated respectively in auxin, nitrogen and carbon metabolisms. Obtained data show that HS and their HA fractions influence root growth and development apparently by influencing different mechanism of regulation associated with polar auxin transport, the incorporation of inorganic nitrogen as glutamate, carbon metabolism and abiotic stress responses. Results presented in this thesis showed that landfill leachates HS especially their HA fraction can be valued as bio-stimulant of plant growth. [less ▲]

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See detailDEVELOPMENT OF PHARMACOLOGICAL TOOLS FOR THE IDENTIFICATION OF G PROTEIN-COUPLED RECEPTORS LIGANDS
Gilissen, Julie ULg

Doctoral thesis (2016)

G protein-coupled receptors (GPCRs) represent the protein family most successfully targeted for treating human diseases. They couple to G proteins to mobilize second messenger pathways that lead to ... [more ▼]

G protein-coupled receptors (GPCRs) represent the protein family most successfully targeted for treating human diseases. They couple to G proteins to mobilize second messenger pathways that lead to cellular responses and ultimately to physiological changes. However many are poorly characterized with few ligands reported or remain completely orphans. Therefore, there is a growing need for screening-compatible and sensitive assays in order to identify new ligands. The present project aims at developing pharmacological tools to characterize the pharmacology and physiology of GPCRs. Our approach rely on i) development of receptor models and assays for the identification of ligands, ii) screening of chemical and virtual small molecules libraries and iii) analysis of structure-activity relationships study of active molecules. The project has been divided in two parts. To set-up assays for the evaluation of GPCRs activation, we selected the understudied succinate receptor 1 (SUCNR1) that is proposed to affect cellular metabolism and pathophysiology of diseases in multiple organs. Nevertheless the receptor has never been validated as a drug target because very few ligands have been described. So, developing pharmacological tools for SUCNR1 remains of great interest in therapeutic drug discovery. First, we have started by examining SUCNR1 signaling pathways in HEK293 cells. Our investigations have highlighted the efficient coupling to Gαi and thus the negative modulation of intracellular cAMP levels. Consequently we have implemented an assay sensitive to cAMP variations to identify ligands able to induce SUCNR1 activation. However, an important drawback to track agonists for Gαi-coupled receptors is the mandatory stimulation of cAMP levels. Inducers such as forskolin must be used and are sources of variations and errors. In order to avoid these artifacts we have set-up and validated a cAMP-inducer free method based on the GloSensor biosensor. This real time assay was amenable to high-throughput screening for the detection of Gαi-coupled receptors agonists. The strategy monitoring basal cAMP levels compared to the stimulated cAMP levels allowed to decrease recording time and artifcats from forskolin use, leading to the identification of fewer false positives and unidentified false negatives. Although both methods found agonists in the chemical library screened, no active new scaffolds on SUCNR1 were discovered. We infer that this method could facilitate the study and screening of Gαi-coupled receptors for active ligands. Secondly, given the interesting potential of SUCNR1 for promising therapeutic advances, we have carried out the study of the receptor interaction with its natural ligand, succinate. We have optimized the previous three-dimensional model for SUCNR1 binding pocket by means of more detailed structure-activity relationships study of succinate related molecules. The study of structure-activity relationships performed by Pierre Geubelle, in parallel to this work, allowed the deduction of the structural elements required to be active on SUCNR1. Thus we have defined a pharmacophore for activity on the receptor and subsequently evaluated various cycloalkanes. With our cAMP assay, Pierre Geubelle has highlighted the (1R, 2S)-1,2-cyclopropanedicarboxylate to be able to activate SUCNR1. We confirmed the activity of this compound on SUCNR1 capacity to recruit arrestin 3 and determined the pharmacological properties of this new ligand as SUCNR1 agonist, in vitro and in vivo. To confirm our in vitro results, we have also assessed the hypertensive properties of this cyclic analogue. Intravenous addition at the dose of 0.1 mg.kg-1 in rats has been demonstrated to increase blood pressure in the same range as succinate. Consequently we have demonstrated that (1R, 2S)-1,2-cyclopropanedicarboxylate could be regarded as an original synthetic full agonist for SUCNR1. In addition, the pharmacophore for SUCNR1 should help to generate synthetic compounds characterized by an increased potency and/or efficacy compared to succinate. [less ▲]

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See detailẾtude de l’émergence des organisations pastorales et de leur rôle dans les processus de gestion partagée de la vallée de la Tarka dans les départements de Bermo et Dakoro (Centre sud du Niger)
IBRAHIM, Habibou

Doctoral thesis (2016)

Cette thèse vise à analyser les organisations pastorales et leurs rôles dans la gestion des conflits fonciers. En Afrique subsaharienne et particulièrement au Niger, le foncier est au centre des enjeux de ... [more ▼]

Cette thèse vise à analyser les organisations pastorales et leurs rôles dans la gestion des conflits fonciers. En Afrique subsaharienne et particulièrement au Niger, le foncier est au centre des enjeux de l’agro-pastoralisme. La sécurisation des droits d’accès aux ressources et des systèmes de tenure foncière sont essentiels pour la gestion et la résolution des conflits fonciers (Herrea et al., 2007). La région de Maradi constitue la zone de contact entre le Nord pastoral et le Sud agricole. Dans cette partie centrale où la pression foncière, aggravée par la croissance démographique, se pose avec acuité, le spectre des conflits fonciers est malheureusement devenu un phénomène chronique, une donnée permanente (GADO., 2000). La pluralité des normes et plusieurs sources de droit contribuent à complexifier le règlement des litiges fonciers entre acteurs dans les départements de Dakoro et Guidan Roumdji (Moutari., 2001). Or la dynamique globale des systèmes d’élevage est déterminée par la complémentarité des espaces agro-pastoraux. Cette complémentarité est remise en cause par ces pressions foncières et suscite des changements organisationnels dans les communautés du centre Sud du Niger (Yamba., 2004 ; 2000). C’est le rôle des associations pastorales à Dakoro et Bermo qui est l’objet de cette recherche. En effet les organisations paysannes en Afrique Subsaharienne et au Niger en particulier jouent un rôle important dans la définition des politiques agricoles et deviennent des conditions indiscutables de la réussite des actions à promouvoir à l’échelle locale (Courade et Deveze., 2006 ; Mercoiret, 2006 ; Mercoiret et al. 2004). La méthodologie de travail relève de l’approche ethnographique. Les outils et instruments d’enquête sont les questionnaires et les entretiens ouverts avec les acteurs locaux sur les dynamiques territoriales, les modes d’action des associations pastorales et les conflits fonciers. Les résultats viennent aussi des travaux et des documents des projets, des ONG et des rapports des services techniques de l’Etat. Pour un souci de fiabilité des données, nous avons tenu à réaliser des séances de restitution des données et de triangulations pour confronter les informations de diverses sources. Au total 104 personnes sont enquêtées dont 30 % auprès des associations. Ces investigations ont concerné aussi les secrétaires des commissions foncières, les préfets, les agents des projets et des ONG et le président du tribunal de Dakoro ainsi que les leaders pastoraux, les transhumants, les agriculteurs et associations pastorales. [less ▲]

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See detailCaractérisation et tests de traitement des déchets ménagers et boues de vidange par voie anaérobie et compostage pour la ville de Kinshas
Mindele Ukondalemba, Léonard ULg

Doctoral thesis (2016)

Dans les pays en développement (PED) en général et en République Démocratique du Congo en particulier, la problématique de l’assainissement (eaux usées et des déchets solides) constitue un enjeu majeur ... [more ▼]

Dans les pays en développement (PED) en général et en République Démocratique du Congo en particulier, la problématique de l’assainissement (eaux usées et des déchets solides) constitue un enjeu majeur pour les spécialistes et les autorités locales. Cette thèse a comme objectif général de faire une évaluation de l’état des lieux et de dégager des pistes possibles de traitements des déchets solides et liquides en vue de protéger les populations et de s’orienter vers des traitements qui respectent au mieux les principes du développement durable. Pour réaliser cet objectif, il a été question de caractériser les déchets municipaux solides, spécialement des déchets ménagers, par une méthode de caractérisation rapide, simple et peu couteuse. Pour ce qui concerne la gestion des eaux usées, spécialement les boues de vidange provenant de l’assainissement non collectif (ANC), par une méthode sociologique mobilisant des techniques d'enquêtes et d'observation sur site, qui a permis de bien comprendre les pratiques d'assainissement non collectif sur terrain dans le contexte de la République démocratique du Congo ; enfin d’un essai de traitement par une digestion anaérobie (ou co-digestion anaérobie) des déchets suivi du compostage (ou co-compostage).Parmi les modes de traitement de déchets, la digestion anaérobie paraît être une option attrayante pour la dégradation des déchets ménagers fermentescibles en produits utiles tels que le biogaz et le compost de haute qualité. De ce fait, nous avons mené une étude expérimentale comparative entre la digestion anaérobie des déchets ménagers fermentescibles uniquement et la co-digestion anaérobie des déchets ménagers fermentescibles et de boues de vidange de fosse septique. L’expérience a été conduite dans deux cuves de 80 litres. La digestion et la co-digestion anaérobies se sont déroulées à la température de 25°C et en deux étapes, de sorte que la première étape dans la cuve de 80 L, s’arrête à l'acidogenèse et que la deuxième étape se passe dans un autre digesteur de 10 L allant de l’acétogenèse à la méthanogenèse. Les résultats ont montré que 1,3 Nm3 de méthane sont produits à partir de la digestion anaérobie des déchets uniquement et 1,8 Nm3 de méthane sont produits à partir de la co-digestion des déchets et des boues de vidange, confirmant l’intérêt de la co-digestion.Les résultats préliminaires trouvés sont encourageants, notamment en matière de gain detemps dans la durée du processus. Le procédé a entre autres avantages de limiter la manipulation du déchet en cours de traitement et de fournir à la fin deux produits directement valorisables : le compost et le méthane. Bien entendu ces résultats préliminaires devront être validés par des essais à une échelle un peu plus grande avant de proposer de passer à des projets en vraie grandeur. Ainsi nous espérons que ce travail pourra contribuer à la relance des digesteurs anaérobies pour favoriser les énergies renouvelables tels que prôné ce dernier temps par la COP21 et ainsi éviter la déforestation intempestives des nos forets. Mots clés : assainissement non collectif, déchets solides fermentescibles, boue de vidange, co-digestion anaérobie, indicateur d'assainissement, digestion anaérobie, compost. [less ▲]

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See detailPrincipal static wind loads within a rigorous methodology to the envelope reconstruction problem
Blaise, Nicolas ULg

Doctoral thesis (2016)

Static wind loads are being used for the design of large civil structures such as high-rise buildings, large roofs and long-span bridges. Once static wind loads are known, they are used through the ... [more ▼]

Static wind loads are being used for the design of large civil structures such as high-rise buildings, large roofs and long-span bridges. Once static wind loads are known, they are used through the iterative design process without repeating cumbersome dynamical analyses. In this framework, structural engineers can effectively focus on the structural sizing since static analyses are straightforward. No codified wind loads, however, exist for those large structures with unique shapes and there is no consensual view on how to formally derived them. For each new major project, the challenge consists therefore in deriving a relevant set of static wind loads. Obviously, these loads must provide the actual envelope values of structural responses of interest. This states the objective of the envelope reconstruction problem and constitutes the core of this thesis. The proposed developments to solve this problem are relevant for structures responding with a linear dynamic behavior to the buffeting action of synoptic winds in a stationary framework. The pioneering concept of Equivalent Static Wind Load is normally considered for the design. An extensive review points out two main limitations of the current formulations. They have been originally established in a Gaussian context, are associated with either a nodal or nodal-modal basis and do not have a formal definition. The proposed Conditional Expected Load method overcomes the three drawbacks by defining a Conditional Expected Static Wind Load. This novel approach presents a general rigorous formulation for linear structural behavior, irrespective of the basis used for the analysis and relevant in a non-Gaussian context. The method is particularized for a certain class of non-Gaussian processes through a bicubic translation model. This model covers a large range of non-Gaussianity in the random processes and therefore paves the way for the formal establishment of “non-Gaussian” static wind loads with a physical interpretation. Other kinds of static loads such as the covariance proper transformation loading modes and the modal inertial loads are additionally studied. Unfortunately, both sets of loads are simply relevant for two limit structural behaviors, quasi-static and resonant, respectively. Moreover, they do not adapt to the set of structural responses of interest. From both points of view, one key result from our study is the innovative concept of Principal Static Wind Load as a sound solution for the envelope reconstruction problem. The concept relies upon a robust mathematical foundation. These loads are determined by the singular value decomposition of a large set of equivalent static wind loads. This decomposition can be seen as a way to rank the most relevant load patterns for the envelope reconstruction problem. The principal static wind loads have also the added distinctive advantage to be flexible. They are, indeed, able to naturally adapt to the set of structural responses of interest. Finally, a complete methodology to solve the envelope reconstruction problem irrespective of the structure, its load-bearing system and its susceptibility to vibrations in a Gaussian or non-Gaussian context is rigorously conceptualized. The intrinsic controllability of a set of pertinent parameters provides a smart balance between over and underestimation of the actual envelope. Moreover, combinations of static wind loads are computed to speed-up the reconstruction of the envelope values. The problem of determining these combination coefficients is formulated as a constrained nonlinear optimization. Equivalent and principal static wind loads, covariance proper transformation loading modes and modal inertial loads are implemented within the proposed methodology. Three examples: a four-span bridge, a real-life large stadium roof and a low-rise building demonstrate that the envelope reconstruction accuracy is considerably improved with principal static wind loads and with combinations thereof. [less ▲]

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See detailEvaluation des charges polluantes (domestiques et industrielles) arrivant au lac Kivu dans la ville de Bukavu, RD. Congo
Lina Aleke, Alex ULg

Doctoral thesis (2016)

Dans les pays en développement (PED) en général, et plus particulièrement en République Démocratique du Congo (RDC), le développement des villes et l'augmentation des populations urbaines se font avec une ... [more ▼]

Dans les pays en développement (PED) en général, et plus particulièrement en République Démocratique du Congo (RDC), le développement des villes et l'augmentation des populations urbaines se font avec une rapidité telle que l'accessibilité à l'eau potable et à l'assainissement de basepose un problème croissant de sante publique et de bien-être des populations. Le manque d'expertise et des moyens techniques et/ou financiers ne permet pas de mettre en place des programmes cohérents et adaptés aux réalités et défis que connaissent ces pays. C'est dans cette optique que la présente étude qui porte sur la caractérisation des eaux résiduaires domestiques et industrielles générées dans la ville de Bukavu, a été menée en vue d'évaluer les flux des pollutions arrivant dans le lac Kivu. Différents axes de recherche ont été ainsi exploités pour répondre a cet objectif. Ce sont :l'évaluation de l'assainissement non collectif (ANC),la caractérisation des flux polluants générés par les activités domestiques et industrielles, etl'analyse critique des atouts naturels (physiques, géologiques, hydrogéologiques, etc.) de la ville de Bukavu en vue de mettre sur pied des filières permettant un assainissement correctet la protection du lac Kivu. L'évaluation de l'assainissement a été basée sur une démarche sociologique faisant appel à des techniques d'enquêtes et d'observation deterrain. Une approche d’évaluation par un indicateur découlant de la combinaison des indicateurs mis en place au prorata des trois maillons composants une filière d’ANC (amont, intermédiaire et aval) a été utilisée. Les résultats obtenus montrent un faible niveau d'accès à l'eau potable et à l'assainissement de base qui serait lié à des facteurs historiques, physiques, politiques, et socio-économiques. De plus, un effort considérable reste à faire pour la gestion du maillon aval car la gestion des boues produites se fait pour le moment de manière non conforme. Par ailleurs, la densité de la population, en pleine croissance, nécessite une politique de construction de logements bien appropriée. Réalisée au niveau des émissaires domestiques (ITFM, Rukumbuka, PIR, Nyamugo et Bagira) et des rivières (Bwindi, Tshula, Wesha et Kahwa) qui traversent Bukavu, la caractérisation des flux de pollutions domestiques a été menéeau travers des méthodes physicochimiques et microbiologiques. Elle a permisd'apprécier l'importance des risques sanitaires qu'encourent les habitants de Bukavu dans leur quotidien, ainsi que l'ampleur des pressions que subit le lac qui en est le réceptacle. De la même manière, notre étude s'est intéressée aux flux produits des pollutions industrielles brassicoles et pharmaceutiques, suivant une approche physicochimique. Il ressort de ces analyses que les émissaires domestiques constituent le cadre de premier choix adopté par les habitants pour le rejet de leurs déchets. Ce faisant, les rivières de la ville font l'objet d'importantes pollutions engendrées par les activités domestiques, et constituent des égouts à ciel ouvert. Les flux évacués et arrivant quotidiennement dans le lac vont de 2165 kg (rivière Bwindi) à 5974 kg DBO5 (riviere Kahwa) en saison sèche, et de 5303 kg (rivière Bwindi) à 14270 kgDBO5 (rivière Kahwa) en saison de pluie, correspondant aux charges totales respectives de 7468 kg DBO5 et 20244 kg DBO5. Les flux des pollutions microbiologiques ont été évalués a 2,3.109 UFC/EH DBO5 pour la rivière Bwindi et 6.109 UFC/EH DBO5 pour la rivière Kahwa en ce qui concerne les coliformes fécaux, et 2800 œufs/EH DBO5 (rivière Bwindi) et 4185 œufs/EH DBO5 (rivièreKahwa) pour les parasites.En outre, 11 taxons de parasites ont été identifiés. Ce sont : Entamoeba coli, Giardia lamblia, Entamoeba histolytica, Ascaris sp. (taxon le plus distribué), Ankylostoma sp., Strongyloides sp., Trichuris trichiura, Hymenolepis nana, Hymenolepis diminuta, Taenia saginata et Schistosoma mansoni. Recevant les eaux de 4 de 5 émissaires domestiques étudiés, la rivière Kahwa s'est avérée comme la plus polluée des rivières de Bukavu. Concernant les pollutions industrielles, pour chaque litre de boisson (bières et boissons gazeuses confondues), la société brassicole Bralima utilise entre 4,7 et 5,7 l d'eau, avec une moyenne de 5,1 l.Les pollutions spécifiques s'établissent entre 1,2 et 1,6 kg DCO/hl, et 0,2 et 0,4 kg MES/hl de produits finis, avec unecharge globale évaluée 194,1 kgDCO par jour, avant traitement. L'abattement des pollutions dans la station d'épuration de cette société brassicole devrait être amélioré en vue de réduire ses pressions sur le lac et les risques sanitaires auxquels sont exposées les populations. Quant à la Pharmakina, la charge globale des pollutions, évaluée à 1229,2 kgDCO par jour, arrive dans le lac Kivu sans aucun traitement préalable, constituant ainsi de graves menaces environnementales et écologiques imputables à sa responsabilité. [less ▲]

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See detailPerturbations of interactome networks in acute lymphoblastic leukaemia: identification of EXT1 tumor suppressor as a Notch pathway regulator
Daakour, Sarah ULg

Doctoral thesis (2016)

Whole genome sequencing technologies have enabled the identification of mutations implicated in diseases including cancer. Recently, research efforts to compare and categorize mutations, genes expression ... [more ▼]

Whole genome sequencing technologies have enabled the identification of mutations implicated in diseases including cancer. Recently, research efforts to compare and categorize mutations, genes expression and genomic characteristics helped generating literature-curation databases. A large number of databases were developed to address data integration and standardization for human cancers, such as Catalogue Of Somatic Mutations In Cancer (COSMIC), The Cancer Genome Atlas (TCGA), International Cancer Genome Consortium, Integrative Onco Genomics (IntOGen). Although the identification of these mutations highlights “cancer causative genes”, it does not give a detailed explanation of molecular mechanisms leading to the development of cancer. Though, understanding mechanisms leading to cancer development and progression remains a challenge that requires further investigations. The great majority of mutated genes are found in liquid tumors such as leukemia and lymphomas. In the first part of this study, we reasoned that leukemia associated genes could be extended to additional candidates identified using interactomic approaches. We used protein-protein interaction (PPI) mapping strategies to explore information on cancer genes frequently mutated in Acute lymphoblastic leukemia (ALL). We first extracted mutational data associated to ALL, and used interactome mapping analysis for literature-curated interactions and yeast two-hybrid experimental data in order to identify potential novel target genes associated with ALL. We highlighted mutated hub proteins interconnected in an ALL-cancer gene products network and identified novel interacting partners that link key ALL-cancer driver gene products. We identified EXT1 tumor suppressor gene as a novel common interactor for NOTCH1 and FBXW7. In the second part of this study, we experimentally validated EXT1, as a novel player in the regulation of the Notch pathway. Our study thus provides a proof-of-concept on how systematic interactome approaches could allow identification of novel targeted genes and pathways associated to human cancer. [less ▲]

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See detailEpidemiological Study of Canine Leishmaniasis in Algeria and its Impact on the Human Visceral Leishmaniasis
Adel, Amal ULg

Doctoral thesis (2016)

Zoonotic visceral leishmaniasis (VL), caused by Leishmania infantum is a vector-borne disease, transmitted to humans by the bite of infected female phlebotomine sand flies. In absence of treatment the ... [more ▼]

Zoonotic visceral leishmaniasis (VL), caused by Leishmania infantum is a vector-borne disease, transmitted to humans by the bite of infected female phlebotomine sand flies. In absence of treatment the outcome is death. The disease is characterised by irregular fever bouts, loss of weight, hepatosplenomegaly and anaemia. It is endemic in the Indian sub-continent and in East Africa. In the Mediterranean region, it is present in rural areas, in villages, in mountain areas, but also in certain peri-urban zones, where the parasites survive in dogs and other mammals. In fact, domestic dogs are the principal reservoir of human VL and they also can develop a more generalised and fatal form of the disease, although more than half of the dogs remain asymptomatic, the individual outcome depending on both cellular and humoral immune responses. Both symptomatic and asymptomatic dogs can infect the phlebotomine vectors, thereby enabling the transmission to other dogs or to people. This is the main reason why early detection and treatment of infected animals is the best way to reduce the risk of infection and, as such, forms an essential component in the prevention and control of the human disease. Ideally, a so-called “gold standard” test is required to reliably and correctly determine the infectious status of an individual and/or the infection prevalence in a population in a certain region at a certain point in time. A gold-standard test provides an error-free classification of individuals as infected or infection-free. The discriminative power of a real-life test is quantified by measures of precision, more specifically the sensitivity and the specificity of the test. They vary in function of characteristics of the population studied. In the majority of cases, a gold standard test does not exist. In order to overcome this lack, use is made of reference tests. The latter are often imperfect (sensitivity and specificity below one) and they allow estimation of a so-called apparent prevalence rather than the actual true prevalence. A statistical solution to the problem of lack of gold standard test consists of a Bayesian approach, which allows us to combine data of a study with external (prior, independent) information, such as results from previous studies or expert opinion. This approach yields an estimate of the true prevalence, as well as estimates of the sensitivity and specificity of the tests used. This thesis attempts to contribute towards a better understanding of the epidemiology of visceral leishmaniasis in Algeria. More specifically, our general objective (Chapter 3) was to estimate the true prevalence of canine leishmaniasis, in a situation where a diagnostic gold standard test was unavailable, and to describe the epidemiological curve and profile of visceral leishmaniasis in the country. With this in mind, the work is organised in nine chapters. The first chapter outlines the importance of leishmaniasis (respectively visceral and canine) in terms of public health and veterinary public health and provides an overview of the current knowledge base on canine leishmaniasis. The second chapter is devoted to a description of the epidemiological methodology available for the estimation of the true prevalence and the test characteristics in the absence of gold standard test. Chapter 4 describes an epidemiological study conducted in the capital city Algiers, comprising 462 dogs subdivided in four groups according to their function (stray dogs, guard dogs, farm dogs and pet dogs). A Bayesian approach was used to estimate the true prevalence of canine leishmaniasis in the four groups and to evaluate three serological tests: an indirect immunofluorescence test (IFAT), a direct agglutination test (DAT) and a commercial rapid test on gel, based on the protein rK39 (PaGIA). We were able to demonstrate variability in the test performance characteristics in the different groups, and this in terms of sensitivity and specificity. IFAT, although it is an imperfect test, is nevertheless the test of choice when the dog population targeted consists of stray dogs, but its specificity drops to a unsatisfactory 65.2% (IC: 60.2-73.5%) when applied to farm dogs: the fact of living together with other animals may induce cross-reactions. Stray dogs also yielded the highest estimate for the true prevalence (11.7%), probably a consequence of their constant living outside, which increases the risk of exposure to infected phlebotomine vectors. Using the above results, a large-scale transversal survey was mounted in six towns of the littoral zone of Algeria (Chapter 5). Thus, a total of 2,184 farm dogs and guard dogs were sampled in two distinct periods using two serological tests: before and after the main vector season, using IFAT and DAT. Serial and parallel interpretation of the combined tests were compared to various other statistical methods in order to estimate the true prevalence and the sensitivity and specificity of the two tests. The latent class model of Hui and Walter based on conditional independence between the diagnostic tests was compared to a Bayesian model, which made it possible to include conditional dependency between tests, if required. The best-adjusted model estimated canine leishmaniasis prevalence between 11% and 38% with an increasing trend from west to east. IFAT sensitivity varied between 86% and 88% in the different localities, whereas specificity ranged between 65% and 87%. DAT was invariably less sensitive than IFAT, but had a better specificity: between 80% and 95% in function of locality and season. The results highlighted once more the danger of considering IFAT to be a gold standard test for canine leishmaniasis. Chapter 6 draws up an epidemiological profile of human zoonotic visceral leishmaniasis in Algeria, based on cases notified to the National Public Health Institute between 1998 and 2008. A total of 1,562 were found for this period. This translates into an incidence rate of 0.45 cases per 100,000 inhabitants, of which 81.4% were children between zero and four years of age. Splenomegaly, fever, pallor and pancytopenia were the principal clinical and biochemical signs. Antimonies are the first-line treatment drugs in paediatric wards and amphotericin B injections are the treatment of choice in adults. Severe under-declaration (less than one case in ten notified) was demonstrated thanks to a survey carried out in the paediatric, internal medicine and infectious diseases departments of the five university hospital centres in Algiers, which had an influx of patients from all four corners of the country. Results of both Chapter 5 and Chapter 6 revealed a concordance between human visceral leishmaniasis incidence rates and true prevalence of canine leishmaniasis, providing extra support for the hypothesis that dogs are the main reservoir of the disease. Motivated by the results of the two surveys (Chapters 4 and 5), Chapter 7 describes a literature review of the performance of IFAT when used to estimate the canine leishmaniasis prevalence in the Mediterranean basin. Chapters 8 and 9 present the general discussion and conclusions and recommendations of the overall contribution of this research effort. Even though this work only represent a small addition to knowledge body on visceral leishmaniasis, it allowed us to better describe and understand the epidemiology of visceral leishmaniasis in Algeria and to obtain true prevalence estimates of canine leishmaniasis in various towns in the littoral zone of the country. It showed us the importance of correctly identifying and defining the target population of surveys to obtain the best possible posterior estimates and to optimise control measures. This work also showed the efficacy of the application of appropriate statistical models in a Bayesian framework when confronted with the absence of a gold standard test. Chapter 10 summarizes all references cited in the thesis. [less ▲]

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See detailFlexibility services in the electrical system
Mathieu, Sébastien ULg

Doctoral thesis (2016)

The work presented in this thesis considers the electrical flexibility from the electric load to its usage as a commodity. The conception of the European electrical system has led to a large amount of ... [more ▼]

The work presented in this thesis considers the electrical flexibility from the electric load to its usage as a commodity. The conception of the European electrical system has led to a large amount of actors that are impacted by flexibility exchanges. This thesis proposes approaches to assess the impact of exchanging flexibility in the electrical system and analyzes the complex interactions resulting from these exchanges. The modeling techniques used to carry the analysis are optimization, game theory and agent-based modeling. The impacts on different parts of the electrical system are presented: the day-ahead energy market, the secondary reserve and the distribution system. Since flexibility is the base block of this thesis, two methods to obtain flexibility from actual consumption processes are broached: direct control of the loads and dynamic pricing. One chapter provides an example of how flexibility can be obtained by the direct control of a portfolio of heat pumps and another chapter studies the control of electric heaters and boilers via the use of a simple price signal. [less ▲]

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See detailStratégies innovantes d’adaptation à la variabilité et au changement climatiques au Sahel : cas de l’irrigation de complément et de l’information climatique dans les exploitations agricoles du Burkina Faso
Zongo, Bétéo ULg

Doctoral thesis (2016)

The Sahelian farmers, the scientific community, government and development partners are actively looking for new farming practices to mitigate the consequences of dry spells probably exacerbated by ... [more ▼]

The Sahelian farmers, the scientific community, government and development partners are actively looking for new farming practices to mitigate the consequences of dry spells probably exacerbated by climate changes. To contribute for this challenge, this research examines the issue of agricultural innovations’ adoption in the Sahelian and Sudano-Sahelian zones of Burkina Faso. Among promoting agricultural innovation, the study explored the possibilities to popularize the practice of supplemental irrigation from individual basins (ICBI) and the use of climate information (CI) in the farms. The approach developed is threefold. Data were collected from farm households through surveys and conducting experimentation of ICBI and use of CI in rainfed agriculture. In addition to the usual descriptive statistics, analysis of variance, the multinomial logit model was used to analyze the determinants of the agricultural innovations dissemination. Determining factors of farmers’ willingness to adopt ICBI were identified using a logistic model. The criteria for partial budgeting were used as tools for assessing the economic viability of ICBI. The Heckman model associated with the contingent valuation approach was used to analyze famers’ willingness to use CI. Simulations were made from a bio-economic model to test some policy instruments for the adoption of these new practices. After four decades of diffusion (1974-2013), the adoption rate is estimated at 69.3% for stone bunds, 49.1% for zaï, 26.2% for grass strips and less than 10% for half-moons, bunds land and mulching. The low level of farmers’ organization and access to agricultural services were the major constraints to their adoption. Over 65% of the farmers believe that ICBI is an effective way to mitigate the adverse effects of dry spells on crop yields. After three years, the experiments showed that this innovation in family farms increases maize yield by 1.08T/ha (88.3%). Maize production surplus achieved with ICBI can fill the monthly cereal requirements of 17 people on average and increases the gross margin by F 178,483 CFA compared to the situation without irrigation. The review of the net present value, internal rate of return and the net benefits increase ratio showed that the profitability to practice supplemental irrigation depends on the types of basins. From the sampled farmers, 93% of them required CI to guide their decision in planning agricultural activities. About 64% of the farmers are willing to pay for CI. The experiments reveal that the surplus of maize and sorghum yield obtained with the use of CI meets the monthly cereal requirement of 7 persons on average compared to traditional seasonal forecasts. The simulations indicate that the ICBI in middle year increases the expected income of 26.5% (F 133 030 CFA) compared to the situation without irrigation. The tested policies include six types of grant and the establishment of a system for granting credit to farm households to finance the supplementary irrigation device. The implementation of these policies should facilitate the adoption of ICBI at a larger scale. The researchers and development actors should pursue the experimentation on the combination of ICBI and CI. [less ▲]

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See detailMultiscale approach of spray retention on superhydrophobic plant surfaces
Massinon, Mathieu ULg

Doctoral thesis (2016)

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See detailIndirect quadrangular mesh generation and validation of curved finite elements
Johnen, Amaury ULg

Doctoral thesis (2016)

Among the different types of 3D finite element meshes, hexahedral meshes present properties that can be highly desirable, such as alignment with physical features or a lower computational cost. For this ... [more ▼]

Among the different types of 3D finite element meshes, hexahedral meshes present properties that can be highly desirable, such as alignment with physical features or a lower computational cost. For this reason and despite the maturity of the tetrahedral mesh generators, hexahedral mesh generation has always been a prolific research domain. Yet, there exists currently no robust algorithm capable of generating conformal all-hexahedral meshes with prescribed input size field on any arbitrary geometry. One difficulty that remains is that there exists no method to robustly assert that a hexahedron is valid. Indeed, linear hexahedra can be folded (tangled) in the same way than curvilinear tetrahedra. This thesis addresses two subjects. First, two original quadrangular mesh generation techniques are investigated, with the aim to generalize them to 3D. Both are indirect methods and thus consider the problem of combining pairs of triangles of an initial input triangular mesh. The first technique, called Blossom-Quad, computes the optimal solution of this problem with respect to a given quality criterion. As for any indirect method, the quality of the solution strongly depends on the location of the nodes in the initial triangular mesh. The generalization to 3D is however unclear and a second technique is investigated. This one aims at computing a near-optimal solution by using a look-ahead tree technique. The corresponding algorithm allows tuning the quality of the final mesh by choosing the depth of the tree as a parameter. This technique gives a promising way forward, especially as it is directly applicable in 3D. The second subject concerns the development of a method that permits to compute, with respect to any prescribed tolerance, the extrema of Jacobian-based quantities defined on finite elements of any order and type. Applied to the Jacobian determinant, this method allows to assert the validity of any (curvi-)linear finite element. This method is also applied to a quality measure that quantifies the pointwise anisotropy of the elements. Besides being very attractive for hexahedral mesh generation, this method is especially useful for the analysis of curvilinear finite element meshes. It can moreover be an important component of optimization techniques for achieving robustness. [less ▲]

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See detailLower Carboniferous shallow marine sequences from the Central Alborz Basin, Iran (north-eastern margin of Gondwana): sedimentology, biostratigraphy and rock– magnetic studies
Sardar Abadi, Mehrdad ULg

Doctoral thesis (2016)

The Lower Carboniferous Mobarak Formation records the development of a carbonate platform on the southern Paleo-Tethyan passive margin. This pervasive carbonate factory was deposited following the opening ... [more ▼]

The Lower Carboniferous Mobarak Formation records the development of a carbonate platform on the southern Paleo-Tethyan passive margin. This pervasive carbonate factory was deposited following the opening of the Paleo-Tethys Ocean into the Alborz Basin along the northern margin of Gondwana. The depositional facies range from the most proximal to the most distal and include coastal environments, inner ramp peritidal facies, peloidal to crinoidal shoals, storm to fair-weather influenced mid-ramps, proximal to distal shell beds and low energy outer ramps. Storms clearly played a dominant role in the distribution of skeletal and non-skeletal shoals on the carbonate ramp. Sedimentological analyses complemented with foraminiferal biostratigraphy reveal four events which are interpreted to represent the principal factors controlling carbonate platform evolution in the Alborz Basin during the Lower Carboniferous: 1) A transgression linked to global temperature rise in the Early Tournaisian (Middle Hastarain) resulted in the formation of thick-bedded argillaceous limestones. 2) the Hastarian–Ivorian boundary glaciation phase, 3) Upper Ivorian–Lower Viséan? tectonic block faulting. 4) the Viséan- Serpukhovian glaciation phase. The three foraminiferal assemblages encountered in the Tournaisian interval of the Mobarak Formation are restricted to specific periods within the Ivorian. The occurrence of specific foraminiferal taxa in Alborz is tightly governed by transgressions and migration of North Paleo–Tethyan biotic elements as response to the thermal period. We also combined proxies for ambient paleothermometry in addition to the indications for arid conditions and arid conditions and the presence of foraminiferal taxa with a North Paleo-Tethyan affinity in the Lower Carboniferous Mobarak Formation to suggest a paleo-position for the Alborz Basin at lower latitudes than approximately 45  –50  southern paleolatitude reported thus far. Magnetic susceptibility ( in ) was measured and compared with facies from the same sample. There is a clear link between  in and facies, and the average  in values are higher for distal facies than for proximal ones. The  in profile of Lower Carboniferous carbonate sequence reflects stratigraphic variations in response to relative sea level changes and detrital input. In the context of the sequence stratigraphic framework, the average  in values for lowstand and transgressive system tracts deposits are higher than for the highstand system tracts deposits. The clear link between  in and facies points to at least partly preserved primary  in signal, related to detrital inputs. In respect to the hysteresis measurements the in signal is mainly carried by low coercivity ferromagnetic minerals such as magnetite, with a mixture of relatively coarse grains (detrital fraction) and ultra-fine grains (probably formed during diagenesis). [less ▲]

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See detailCoating of crystallized Yttrium Orthoferrite (o-YFeO3) by wet deposition methods
Stevens, Frédéric ULg

Doctoral thesis (2016)

L’objectif de cette thèse est d’obtenir un dépôt d’orthoferrite d’yttrium orthorhombique sur substrat conducteur. Ceci, en vue de d’étudier de nouveaux catalyseurs potentiels pour le clivage ... [more ▼]

L’objectif de cette thèse est d’obtenir un dépôt d’orthoferrite d’yttrium orthorhombique sur substrat conducteur. Ceci, en vue de d’étudier de nouveaux catalyseurs potentiels pour le clivage photoélectrochimique de l’eau. Le clivage photoélectrochomique de l’eau produit dudihydrogène et du dioxygène grâce à l’énergie solaire et un catalyseur. Le dihydrogène et le dioxygène sont les combustibles d’une réaction exothermique. Transformer l’eau en ces deux composés est donc une méthode de stockage de l’énergie. Plusieurs semiconducteurs sont étudiés comme catalyseurs pour ce clivage. Cette thèse se concentre sur l’étude de l’un d’eux : l’orthoferrite d’yttrium orthorhombique (o-YFeO3), et sur deux méthodes de dépôt de ce matériau sur substrat conducteur : la méthode de déposition par plongée (dip-coating) et la pyrolyse d’une vaporisation ultrasoniquement générée (USP). Dans un premier temps, deux méthodes de synthèse del’o-YFeO3, sous forme de poudre, ont été envisagées : l’une basée sur des chlorures de fer et d’yttrium, l’autre basée sur les nitrates de ces mêmes métaux. Les éventuels problèmes de proportion ou de précipitations successives ont été respectivement dissipés par une étude de masse et une analyse de l’évolution du pH. Ces poudres, issues des chlorures ou des nitrates, ont permis de caractériser la proportion et la pureté des phases cristallines en fonction de la température de calcination par l’étude de la diffraction des rayons X (XRD) ; de caractériser l’énergie de la bande interdite (band gap optique) par la spectroscopie de réflectance diffuse (DRS) et d’en observer leur morphologie par les microscopies électroniques à balayage (SEM) ou en transmission (TEM). Toutes ces analyses nous ont poussés à continuer notre étude en nous focalisant sur la synthèse basée sur les nitrates et d’utiliser une température de calcination de 850°C. Ensuite, ces mêmes analyses (pH, XRD, DRS) ont permis d’estimer l’influence de l’ajout de différents composés organiques en cours de synthèsesur la cristallinité, la pureté, la température de calcination et l’énergie de la bande interdite de ces poudres. Cette thèse a montré que l’additif qui améliore au maximum ces propriétés est l’acide citrique. Dans le cas des poudres, dès 450°C – soit 400°C de moins que la même synthèse sans acide citrique – l’o-YFeO3est cristallisé. Les solutions qui seront utilisées pour les méthodes dedéposition seront donc composées à partir, entre autre, de nitrate de fer, de nitrate d’yttrium et d’acide citrique. La méthode dite du « dip-coating » consiste à plonger le substrat qu’on compte recouvrir dans une solution de précurseurs – composée, entre autre, des nitrates métalliques et d’acide citrique – de le ressortir recouvert d’un film mince de cette solution pour ensuite le chauffer et ainsi obtenir un dépôt du matériau désiré. De nombreux problèmes d’adhérence, de stabilité de solution, de quantité de matière, d’homogénéité de dépôt et de cristallisation de composé ont eu raison de nos efforts pour la mise au point de tels dépôts par cette technique. L’autre méthode de déposition utilisée durant cettethèse est l’«USP ». Cette technique vaporise une solution de précurseurs au moyen de vibrations ultrasoniques. Le brouillard ainsi généré est propulsé vers le substrat par du gaz sous pression. Le substrat, pendant ce processus, est placé sur une plaque chauffante. La solution vaporisée chauffera au fur et à mesure qu’elle se rapprochera du substrat. Cette technique implique l’ajustement de plusieurs paramètres qui définissent le type de composés qui atteindront le substrat. Cette thèse a abouti à la mise au point de ces différents paramètres qui ont permis d’obtenir un dépôt d’orthoferrite d’yttrium orthorhombique sur un substrat conducteur. Ce dépôt présente une activité photoélectrochimique en tant qu’anode pour le clivage de l’eau, mais ses performances ne permettent pas, dans son état actuel, de concurrencer les semiconducteurs précédement décrit par d’autres chercheurs. Une poursuite des travaux dans ce domaine devraient se focaliser sur le dopage et/ou la structuration contrôlée de l’orthoferrite d’yttrium. [less ▲]

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See detailContribution à l'amélioration de la production laitière et de la reproduction des vaches Ankole et croisées Ankole x Frisonne en territoire de Beni, République Démocratique du Congo
Katungu Kibwana, Denise ULg

Doctoral thesis (2016)

Eastern Democratic Republic of the Congo, especially Kivu, is a large pastoral region but the cattle numbers of which considerably decreased following the conflicts that the country underwent over the ... [more ▼]

Eastern Democratic Republic of the Congo, especially Kivu, is a large pastoral region but the cattle numbers of which considerably decreased following the conflicts that the country underwent over the past two decades, with important losses in breeding skills. Cattle breeding currently practiced in Kivu may be described as "great unknown". Data available in literature relate to old studies and focuse on peripheral areas from Kivu. This study aimed, at first, to establish a diagnosis on dairy cattle breeding inhabits in the east of the Democratic Republic of the Congo, especially in the provinces of North Kivu. This diagnosis based on the choices adopted by breeders according to animal genetic, constraints related to feeding, animal housing and the main reproductive characteristics of females. The other objective of the study was to test an improved farming method taking into account the perceived constraints highlighted with the diagnostic investigation. The proposal took into account the realities of the south, and thus was characterized by simplicity and speed of implementation, in the emergency context that the population lives daily in the region. 1. Breeding cattle and milk production in tropical environments: Case of eastern region of the Democratic Republic of the Congo. Inventory and perspectives. In East of Democratic Republic of the Congo, cattle breeding is based on exploitation of non-selected dairy cattle raised in extensive unimproved rearing system. Extensive breeding of traditional type is the bulk of the pastoral activities in the region and the country. The main factors limiting cattle breeding in this area of D.R. of the Congo, as in most tropical environments, consist in: (i) low genetic potential of African cattle with low level of production and (ii) poor farming conditions due to low feed quality and health coverage, precarious livestock housing, poor management of reproduction and animal genetic resources, and low breeders’ technicity. These factors affect productive and reproductive performance of animals. Low milk production arising does not allow breeders to provide their needs and cover milk needs of the population, thus leading to importation of large amounts of milk and its derived products. 2. Extensive farming practices and cattle performances of the local breed and crossed with exotic dairy breeds in the Democratic Republic of the Congo The study was conducted in Beni, Democratic Republic of the Congo. It aimed to highlight the breeding cattle system and dairy production levels of both local cows and cows crossed with exotic dairy breeds raised in the environment, and reproductive parameters (age at first calving, interval calving and fertility) as well as mortality rate of animals. The data, obtained from 8464 animals, including 4805 cows (2309 local vs 2496 crossed with Sahiwal and exotic dairy breeds - Friesian, Brown Swiss and Jersey considered ameliorative) were analyzed by chi-square test for categorical data, by generalized linear model based on the genetic type, forage quality and type of supplementation for continuous data, and by Anova-One-way for to test the effect of the degree of specialization and professionalism of breeders. Non-parametric data were analyzed by Spearman correlation test. All factors studied had a significant influence on milk production (P <0.001); calving interval, meanwhile, was significantly influenced by breed (P <0.002) and the type of supplementation (P= 0.011), age at first calving was only influenced by the breed (P <0.001). Milk production, age at first calving, calving interval, fecundity rate and mortality rates of local cattle were respectively 2.6 ± 0.17 l/d, 41.1 ± 1.02 mo, 22.6 ± 0.73 mo, 53.0% and 4.8% between 0 and 1 year and 3.6% between 1 and 2 years vs 6.1 ± 0.21 l/d, 32.5 ± 1.21 mo, 19.1 ± 0.87 mo, 44.8%, 6.7% between 0 and 1 year and 4.4% between 1 and 2 years, respectively, in crossed type. Forage supplementation had a significant effect on milk production compared to the situation with natural forage (1.6 l/d more, P <0.001), and by-products supplementation associated or not to mineral permitted an increase of 0.9 liter of milk production compared to the situation without supplementation (P= 0.041). Increased supplementation with or without the mineral reduced calving interval by 3.6 mo compared to the situation without supplementation, and by 2.5 mo compared to the simple supplementation (P= 0.011). The type of forage had no significant effect on calving interval. The mortality rate was significantly influenced by breed (P= 0.017). A significant interaction between the genetic type and forage type was observed on milk production (P <0.001). Some parameters studied were also influenced by degree of specialization of the breeders - calving interval (P= 0.04 in crossbred type and P <0.001 in local bred) - age of first calving in local bred (P= 0.015); and by degree of professionalization - age of first calving in local bred (P= 0.04) - calving interval (P= 0.08) and milk production in crossbred type (P= 0.04). 3. Effect of improved feeding and housing, and of Friesian blood level on milk production of Ankole x Friesian crossbred cows The study was carried out at the Vitolu/Misugho farm extension, in Beni territory, Democratic Republic of Congo. The objective of this study was to quantify the effects of rearing conditions (feeding and housing in stall of night), and of Friesian blood level on milk production of Ankole x Friesian crossbreds cows. Data were obtained from 30 cows. The birth weights of calves were compared between groups using a Student test. Using the SAS software (Statistical Analysis System, version 9.1.3), data on average daily milk production were analyzed using a mixed model (proc mixed), including the effects of treatment group, Friesian blood level, day in milk, and the simple interactions between these effects. Day in milk within animal was included as a repeated measurement, and a type 1 autoregressive covariance structure was associated to. Differences were considered significant at P <0.05. The indicators of variation were expressed as standard deviation. The experimental unit was the cow. All factors affected significantly daily milk production (P <0.001). The results of these analyzes show that average milk production was higher group offered the improved feed and housed in the stable (6.8 ± 0.31 l/d vs 5.2 ± 0.31 l/d in the control group cows housed in kraal at night, P <0.001). The pic of milk production was observed around the 79th and 96th days respectively in IG and CoG. In both groups, cows adapted their milk production for the rainfall regime and milk production was significantly higher during the rainy season. Lactation curve was very dependent on rainfall regime and did not follow the shape of a normal curve. Improved milk production and highest values were observed with >25% of Friesian blood level (5.3 ± 0.31 l/d to 6.6 ± 0.23 l/d, from 25 to 44%, P <0.001). Interactions between treatment (improved feed and housing) and Friesian blood level were also observed (P <0.001). The IG cows showed the highest milk production compared to the control group (milk productions of 5.8 ± 0.50; 7.0 ± 0.66 and 7.8 ± 0.70 l/d were obtained with 25, 38 and 44% of blood Friesian, respectively, in the treated group vs. 4.8 ± 0.23; 5.5 ± 0.23 and 5.4 ± 0.16 l/d in the control group, P <0.001). [less ▲]

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See detailRankine cycle based waste heat recovery system applied to heavy duty vehicles: topological optimization and model based control
Grelet, Vincent ULg

Doctoral thesis (2016)

standards force the original engine manufacturers to search for innovative solutions in order to reduce oil consumption. As an important part of the energy contained in the primary carrier (the fuel) is ... [more ▼]

standards force the original engine manufacturers to search for innovative solutions in order to reduce oil consumption. As an important part of the energy contained in the primary carrier (the fuel) is lost to the ambient through heat, it seems convenient to recover a part of this thermal energy and to turn it into fuel consumption reduction. Thermodynamic bottoming cycle such as the Rankine cycle could be used to meet this objective. Its popular use throughout the world for electricity generation makes it a natural candidate for on-board implementation in vehicles. However, a certain number of hurdles are still present before the system can be efficiently applied to heavy-duty trucks. In the last thirty years, numerous studies heave been carried out to evaluate the real potential of that kind of system on a vehicle but nothing has yet been commercialized. The heat sources to recover from, the constraints relative to the on-board application and the long and frequent transient behavior of the vehicle mean both the system architecture and its control strategy need to be optimized. The system optimization leads to a choice in terms of working fluid, heat sources and sinks, and components sizing in order to maximize power recovery and hence the fuel saving. The control plays a major role by using the capability of such a system to ensure an efficient and safe operation and limiting the interactions with the other vehicle sub-systems. In this thesis, a system design methodology is introduced to optimize the system architecture using complete model-based vehicle simulation. The constraints relative to the mobile application are taken into consideration to evaluate the potential of such a system. Modelbased control strategies for on controlled variable, namely the superheat level, are developed. Constrained by the implementation platform, different control frameworks ranging from PID to model predictive controllers or observer based controllers are developed to fit into a normal automotive electronic control unit. Most of these novel strategies were experimentally validated on a test rig developed during the thesis. [less ▲]

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See detailDynamique des flux de carbone entre l'atmosphère et des écosystèmes ouest-africains: cas des forêts et savanes sous climat soudanien au Bénin
Ago, Expédit Evariste ULg

Doctoral thesis (2016)

In West Africa as elsewhere in other parts of the world, natural and anthropogenic ecosystems are the main sources for energy, building poles and livestock fodder. They probably behave like some nets ... [more ▼]

In West Africa as elsewhere in other parts of the world, natural and anthropogenic ecosystems are the main sources for energy, building poles and livestock fodder. They probably behave like some nets carbon sinks, but there are only few studies that have focused on their carbon exchanges with the atmosphere. Preserving terrestrial ecosystems has proven essential to any emissions mitigation policy of green house gases, notably CO2. This thesis focuses on the analysis of the CO2 fluxes in three contrasting types of the ecosystem under a Sudanian climate in Benin. Specifically, it was a cultivated forest, a protected forest and a cultivated savannah. Turbulent CO2 fluxes were measured by an eddy-covariance system placed above the ecosystems. The measurements were made during variable periods of 17 months (cultivated forest), 18 months (protected forest) and 29 months (cultivated savannah). The three studied sites have been equipped by the hydro-meteorological observatory AMMA-CATCH and the national project Ouémé 2025. The CO2 fluxes data were completed by some meteorological measurements and by an inventory of dominating species the three sites. Fluxes were examined on the basis of the two main seasons imposed by the cycle of West African Monsoon. The spatial (local and regional) and temporal (hour, seasonal, annual and inter-annual) scales were considered according to the sites. Water was the main factor controlling the dynamic of the terrestrial West African ecosystems. At the daily scales, the radiation was the main driving variable of the net CO2 fluxes. Besides that radiation control, a clear relationship was observed between the net CO2 fluxes and the canopy conductance. A limited impact of saturation deficit was observed, notably during the afternoon. The soil moisture was the main factor governing the ecosystem respiration. However, no clear dependency of the ecosystem respiration on the temperature was observed at hourly scale. After long dry periods, the ecosystem respiration increased immediately in response to the first significant rains. The CO2 fluxes and the characteristics of the protected forest were always higher than those of the cultivated savannah at the daily and seasonal scales. At the annual scale, while the protected forest (Bellefoungou) and cultivated savannah (Nalohou) sequestered an average of 640 ± 50 and 232 ± 27 g C m-2, respectively considering the period of the measurements, the cultivated forest was in equilibrium with 29 ± 16 g C m-2. Overall, the three studied ecosystems were more efficient during morning and wet season than during afternoon and dry season. Finally, this study revealed that the inter-annual variability of the carbon sequestration by the cultivated savannah was mainly controlled by the ecosystem respiration variability in relation to the soil water content variation. [less ▲]

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See detailDe la magie au magique. Conscience, réalité-humaine et être-dans-le-monde chez Sartre (1927-1948)
Dassonneville, Gautier ULg

Doctoral thesis (2016)

This research deals with Sartre's early existential philosophy by resituating it in the field of French post-Comtian philosophy in the early twentieth century and by re-establishing an anthropological ... [more ▼]

This research deals with Sartre's early existential philosophy by resituating it in the field of French post-Comtian philosophy in the early twentieth century and by re-establishing an anthropological moment in which the issue of magic is explored in the psychological and social sciences. Following the different paths of the conceptual exchange through which the notion of magic becomes that the magical in Sartre's view, we study three poles of sartrian phenomenological ontology : intentional consciousness, human reality and being-in-the-world. The hypothesis advanced by this thesis is that the magical, according to different modes ranging from topicalization through obliteration, plays a determining role in the elaboration of existentialism whose genesis is traced here from Sartre's very first writings in 1927.  Faced with the legacy of a positivist anthropology in terms of an analytical methodology, Sartre privileges a synthetic approach and conceives consciousness in its affective and irrational aspects. Images of magical thought are called upon for rethinking openness to the world of consciousness and its relationship to itself and to Others. Returning to Sartrian anthropology, we question how consciousness can be grasped as an irreflexive and absolute spontaneity and how human reality is interpreted through its attitudes and behaviours; in particular through the way it faces its own freedom which is fundamentally and irremediably exposed to contradiction. This structure of human reality as existential project leads Sartre to reconsider being-in-the-world as based in originary dispossession through which ontology is brought back to the magical. [less ▲]

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See detailAspects socio-économiques et technique de la conservation du mouton Koundoum au Niger
Hamadou, Issa ULg

Doctoral thesis (2016)

Résumé Le mouton Koundoum représente le principal mouton à laine du Niger et est exclusivement élevé dans les îles et sur les bords du fleuve Niger, depuis la frontière du Mali jusqu’à Niamey. Il ... [more ▼]

Résumé Le mouton Koundoum représente le principal mouton à laine du Niger et est exclusivement élevé dans les îles et sur les bords du fleuve Niger, depuis la frontière du Mali jusqu’à Niamey. Il constitue une source de nourriture et de revenus pour les agriculteurs ruraux de cette zone. Cette race est reconnue pour sa production de laine et sa remarquable adaptation à l’humidité dans la vallée du fleuve Niger. Peu d’informations sont disponibles sur les caractéristiques de cette race alors qu’on assiste à une régression drastique de son effectif. La documentation des caractéristiques d’une race est importante pour son utilisation et sa conservation. Cette étude a été entreprise pour documenter (i) le système de production et les caractéristiques morphobiométriques du mouton Koundoum, (ii) les préférences des éleveurs et leur disposition à payer ou à recevoir une compensation pour les caractéristiques des ovins, (iii) les caractéristiques de reproduction du mouton Koundoum et (iv) les points de vue des parties prenantes potentielles susceptibles de contribuer à la réussite de la gestion et la conservation de la biodiversité des animaux d'élevage au Niger. Ainsi, pour caractériser la race et comprendre son contexte de production, une enquête a été menée auprès de 104 ménages dans quatre communes le long du fleuve Niger (Kollo, Tillabéry, Say et Tera) pendant la période d’août à décembre 2011. Neuf mesures corporelles, comprenant le poids vif, ont été prises sur 180 moutons Koundoum (101 femelles et 79 mâles). L’effectif des troupeaux de moutons varie de 2 à 60 têtes, avec une taille moyenne de huit animaux et les deux tiers des troupeaux comptant moins de 10 animaux. Principalement alimentés sur les pâturages naturels, 85,6% des troupeaux reçoivent des résidus de récolte en supplément. Seul l'accouplement naturel est pratiqué par les éleveurs et les soins vétérinaires sont limités aux anti-helminthiques et à une pharmacopée traditionnelle. L'affiliation fréquente des éleveurs à des associations professionnelles apparait comme un facteur favorable à la mise en œuvre d'un programme collectif de conservation. Le mouton Koundoum est de robe blanche ou noire, avec une fréquence plus élevée pour la couleur noire (75,6%). Les pendeloques sont présentes dans les deux sexes à des fréquences similaires, d’environ 14 %. Toutes les variables biométriques sont positivement et significativement corrélées entre elles. Le périmètre thoracique montre la meilleure corrélation avec le poids vif, tant chez les mâles que chez les femelles. Trois variables ont été sélectionnées pour la prédiction du poids vif: le périmètre thoracique, la hauteur au garrot et la longueur de la croupe. Il ressort de cette étude que la conservation in situ de la race Koundoum s’annonce comme très problématique, du fait du manque d’opportunités de marché pour la laine et de disposition des petits éleveurs à élever le mouton Koundoum en race pure. Dans le but d’objectiver ce dernier frein, la seconde étude, conduite dans la même zone de septembre 2012 à février 2013, caractérise les préférences des éleveurs pour les béliers reproducteurs et aborde leur disposition à contribuer au programme de conservation du mouton Koundoum à travers leur appréciation quantifiée des principales caractéristiques phénotypiques de la race. L'outil de l'empilement proportionnel est utilisé d'abord dans 11 groupes de discussion focalisée réunissant des éleveurs autour de la question des principaux critères de sélection de béliers reproducteurs. La méthode d'analyse conjointe multi-attributs est ensuite appliquée avec 168 propriétaires de moutons. L'estimation économétrique de la fonction d'utilité des éleveurs est réalisée avec un modèle logit conditionnel et la disposition à payer est calculée par le rapport entre chaque coefficient d’utilité des caractères et de l’attribut monétaire. Les résultats révèlent un fort rejet par les éleveurs des caractéristiques comme la laine et la robe noire et montre ainsi la faible acceptabilité d'un programme de conservation in situ. Quelques éleveurs avec une préoccupation particulière pour la conservation de la race, pour des motifs culturels, peuvent néanmoins adhérer à un tel programme de conservation, qui devrait être principalement fondé sur des stratégies ex situ. En vue de ces stratégies ex situ, il est nécessaire d’étudier les caractéristiques de reproduction chez le mouton Koundoum. La troisième étude a ainsi été conduite en station, à la ferme expérimentale et de recherche de la Faculté d’Agronomie de l’Université Abdou Moumouni de Niamey (Niger) pendant la période de décembre 2013 à avril 2014. L’étude a plus précisément déterminé les caractéristiques du cycle œstral de la brebis et quelques caractéristiques spermatiques du bélier de la race Koundoum du Niger. Ainsi, seize brebis et huit béliers Koundoum ont été utilisés pour cette étude. Les brebis ont été soumises à une observation biquotidienne de leur comportement sexuel en vue de détecter les œstrus, à l’aide de béliers boute-en-train. Les échantillons de sperme ont été recueillis à l’aide d’un vagin artificiel chez les béliers pendant les périodes d’œstrus des brebis. La motilité du sperme a été déterminée à l’aide d’un microscope et sa concentration à l’aide d’un spectrophotomètre. Sur les 16 brebis, 13 ont manifesté au moins une fois des comportements d’œstrus ayant une durée moyenne de 37,8 ± 5,8 heures avec une durée moyenne de cycle œstral de 18,1 ± 1,1 jours. La collecte de semence a pu être réalisée sur 4 béliers sur les 8 inclus dans le protocole. Les éjaculats collectés ont présenté un volume moyen de 1,03 ± 0,3 ml, une motilité de 3,4, et une concentration de 1322 ± 544 millions/ ml. La connaissance de la durée du cycle et de l’œstrus est un élément de base pour la maîtrise de la fonction sexuelle des brebis. La difficulté de collecte de la semence de béliers Koundoum devra être prise en compte dans les plans de conservation par cryogénisation de paillettes. Les informations obtenues à travers cette étude sont une base permettant de poser les premiers jalons du programme de conservation et d’amélioration de cette race. Enfin, une quatrième et dernière étude a été conduite de mars à avril 2014 pour examiner les points de vue des parties prenantes potentielles susceptibles de contribuer à la réussite de la gestion et la conservation de la biodiversité des animaux d'élevage au Niger. La recherche applique la méthodologie Q afin de révéler des discours consensuels et divergents. Après le développement de l'ensemble des affirmations sur le thème de la biodiversité (échantillon Q), les arrangements des affirmations ont été réalisées par les répondants à travers une échelle de Likert à 7 niveaux, de -3 à +3. L'analyse des données (les arrangements Q) avec le package qmethod sous le logiciel R a révélé trois points de vue distincts des parties prenantes sur l'importance de la biodiversité dans l'agriculture et l'élevage, l'équilibre entre le progrès et la conservation et les différentes méthodes de conservation. L'étude montre un consensus apparent sur l'importance de la biodiversité, qui est évidemment un sujet promu dans le pays. Derrière le consensus, différents discours sont définis qui semblent tous divisés par le même dilemme entre la conservation et le développement économique. Comprendre les différentes réponses et poids attribués à chacun des composants du dilemme guidera des campagnes de sensibilisation et aidera à identifier les intérêts divergents des parties prenantes. [less ▲]

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See detailA Feasibility Study of Direct Injection Spraying Technology for Small Scale Farms: Modeling and Design of A Process Control System
El Aissaoui, Abdellah ULg

Doctoral thesis (2016)

El Aissaoui Abdellah (2015). A feasibility study of direct injection spraying technology for Small Scale Farming: Modeling and design of a process control system. University of Liege-Gembloux Agro-Bio ... [more ▼]

El Aissaoui Abdellah (2015). A feasibility study of direct injection spraying technology for Small Scale Farming: Modeling and design of a process control system. University of Liege-Gembloux Agro-Bio Tech. Belgium. 176p., 11 tabl., 75 fig. The study aims to develop a process controller of direct injection spraying system (DIS) that can fit to carry out precise chemical application using variable rate application based on speed sensing in the context of small scale farming. It has the specific objectives of studying the feasibility of DIS by optimizing the hydraulic system and the process control designs as the main requirements for the best system reactivity and performance. The final design of DIS assessed to implement hydraulic system (hardware) and process controller (software) of a sprayer framework mounted on a rolling chariot propelled by walker operator. A logical approach is used of reviewing the state of art and formulating a specification book to develop a cost effective prototype to eventually adapt DIS expertise to the context of small scale farming. The demarche consists on giving low cost solution of variable rate technology to solve the technical problems related to usage and inefficiency of pesticide application mainly done by portable sprayers. The state of art gives a light on the development process of direct injection spraying technology (DIS) within the scope of precision agriculture progress. It also deals with technical options, advantages and problems related to DIS and control engineering solutions developed for improving spraying application efficiency and safety measures for human and environment. After that we have specified requirements of the researched DIS prototype by referring to existing art of DIS technologies and by diagnosing problems of chemical application in the context of small scale farming. It concerns specifically the technical requirements, setting values and performance of DIS process controller according to the working conditions of intensive cropping in small farming. The materials and methods consist on presenting the approach used for modeling the DIS prototype (splitting the problematic to the two main design aspects of hydraulic system and process control system) and evaluating it in laboratory conditions using simulated velocity data input. The data acquisition system is implemented for assessing the performance of DIS hydraulic and process controller performances. After that, the process controller is implemented in a cost effective electronic kit (box) to be mounted on a small sprayer framework propelled by worker. The hydraulic modeling of DIS served for optimizing the lag transport task as main problem of system reactivity performance and concentration process change. An algorithm is implemented in VB program to assess effect of hydraulic serial boom design (diameter and number of mounted nozzles in serial scheme) on flow dynamic to find compromise between lag transport, mixing ability (turbulence) and friction loss tasks that yield lateral and longitudinal uniformities application of standard boom layout. The modeling results showed lag transport and uniformity of respectively 2 s and 96 % for optimal conventional boom of 6 mm inner diameter having ten tip nozzles (ISO11003, 1.2 L/min~3bars). To solve systematic problem of lateral miss uniformity of serial boom layout (standard scheme), improved parallel boom layout (equidistant tubing lines of 4 mm diameter) is adopted for obtaining an even lag transport between nozzles. The test of parallel boom layout showed even lag transport approximating 1.5 s for ten mounted nozzles. The total response time of DIS is optimally improved to be within 2.5 s by installing electrical pumps close to boom and injecting chemical in suction side to the carrier pump assumed to perform online mixing without use of static mixer. The PID feedback controller is modeled in MATLABTM software. The process is considered as a first order process having a time constant of 0.2 s and a delay transport less than 2 s. Two control strategies of constant carrier flow control (CCFC) and total flow control (TFC) are modeled and implemented for test in laboratory conditions. Both strategies were tested and evaluated on the basis of different solicitations of variable speed input within the range of 0 - 2 m/s as a field working condition of walker operating a rolling sprayer chariot. Finally, on the basis of the results of modeling and experimental assessment, an affordable kit of PLC process controller and PWM modules for actuating carrier pump and metering pump is performed in compact electronic box for potential usage on small sprayer framework to be propelled by walker operator in agricultural field. The controller is based on a PLC microcontroller implemented for carrying out a constant carrier flow rate and a variable chemical injection rate proportionally to the operating speed. The prototype is tested for applying variable rate application using simulated step solicitations within the range of the operator working conditions of 0 - 2 m/s. The study showed the feasibility of implementing a cost effective process controller design for applying variable rate chemical in small farming context. The controller is adaptable for sprayer mounted on wheeled chariot to be propelled by worker assumed to walk at variable velocity. [less ▲]

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See detailAerothermodynamics of Pre-Flight and In-Flight Testing Methodologies for Atmospheric Entry Probes
Sakraker, Isil ULg

Doctoral thesis (2016)

Spacecraft, returning back to Earth, experience a very harsh environment during the encounter with the particles of the atmosphere. One of the major issues of the atmospheric entry is the extreme ... [more ▼]

Spacecraft, returning back to Earth, experience a very harsh environment during the encounter with the particles of the atmosphere. One of the major issues of the atmospheric entry is the extreme aerodynamic heating and the exothermic chemical reactions due to the gas-surface interaction at hypersonic free stream velocities. There is a constant effort by the space agencies to increase the understanding of the re-entry flight dynamics to optimize the spacecraft and especially its thermal protection system design. During the design process, ground tests and numerical tools are extensively used for their low cost and controlled environment abilities. However, real flight tests are indispensable for ground test and numerical tools validation. Due to high costs, such missions are rarely launched and thus there is an increasing interest in small affordable entry probes. Such platforms, once matured enough, may serve as an easily accessible tool to produce experimental data. It is the aim of this dissertation to propose tools to improve ground test capabilities and on the other hand to present the design, and using the developed tools, the testing of aerothermodynamic experimental payloads to collect flight data with a small entry probe. QARMAN (QubeSat for Aerothermodynamic Research and Measurements on AblatioN) is a triple unit CubeSat with ablative and ceramic thermal protection systems. It will perform an atmospheric entry with 7.7 km/s and a peak heat flux of 1.7 MW/m2. The aim of the in-flight experiments is to retrieve real flight data on ablator efficiency (temperature, pressure, recession) and temperature-pressure measurements for transition on the side panels. The peculiar squared geometry of QARMAN led to the development of a Flight-to-Ground Duplication methodology accounting for spacecraft geometries. It allows duplicating fully the stagnation region of a spacecraft with an arbitrary geometry in subsonic plasma wind tunnels. As a requirement of this methodology, free stream characterization techniques, specifically enthalpy measurement techniques are introduced. Experimental and numerical databases are built. A thorough ablation characterization campaign in VKI Plasmatron is conducted to provide input for building material response models. The cork P50 ablator is studied in terms of surface and sub-surface temperatures, emissivity, mass loss, char-pyrolysis layers, outgassing species and recession and swelling profiles. Similar in-flight experiments are proposed for QARMAN flight for in-depth temperature and pressure. Methods to build models for advanced data treatment are proposed. A full picture of post-flight analysis strategy is described for each study to relate the ground tools and flight data. [less ▲]

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See detailExperimental and Numerical Characterization of Damage and Application to Incremental Forming
Guzmán Inostroza, Carlos Felipe ULg

Doctoral thesis (2016)

Nowadays, product manufacturing can be divided into two groups: relatively simple products produced in a large production chain and complex (specialized) components produced in reduced batches. Within the ... [more ▼]

Nowadays, product manufacturing can be divided into two groups: relatively simple products produced in a large production chain and complex (specialized) components produced in reduced batches. Within the second group, prototyping through incremental sheet forming (ISF) has been subject of several studies. ISF refers to processes where the plastic deformation occurs by repeated contact with a relatively small tool. A crucial aspect in the ISF processes is that the final shape is determined only by the tool movement. The focus of this research is the single point incremental forming (SPIF) process variant, where a clamped sheet metal is deformed by using a relatively small spherical tool. SPIF has several advantages over traditional forming, such as the high formability attainable by the material. Different hypothesis haven been proposed to explain this behavior, but there is still not a clear and definitive understanding of the relation between the particular stress and strain state induced in the material during SPIF and the material degradation leading to localization or fracture. In this thesis, a fundamental research is proposed using the finite element (FE) code LAGAMINE, developed within the University of Liège. Numerical implementation and validation of the Gurson-Tvergaard-Needleman (GTN) damage model into this FE code is performed. An experimental test campaign is developed to characterize plastic and damage behavior and to validate the damage model for the DC01 steel grade. Finally, this damage model is applied to simulate the SPIF process in order to verify if it is capable to predict failure. The thesis discusses the material parameter identification for classical plasticity models, describing the anisotropy and hardening behavior of the sheet metal. The derivation of the equations of the numerical damage model and the efficiency of the implementation is presented in great detail. A methodology for the numerical parameter identification of the damage model is proposed, including microscopic measurements by optical microscopy and strain and displacement field measurements by digital image correlation (DIC). The identified Gurson model is applied to simulate standard SPIF geometries, like the line, cone and pyramid tests. The simulations are performed using the solid-shell element formulation and validated in terms of shape and force prediction. Literature reviews of the Gurson model and the SPIF process are also included. The experimental results show that the selected material (DC01 steel sheet) exhibits a slight anisotropic behavior and work-hardening stagnation on cyclic tests. The performed microscopic measurements are not representative of the actual damage, but they give a qualitative estimation of the physical mechanism of fracture. The initial porosity of the material was determined using optical microscopy measurements in the base material. The numerical implementation of the model is developed with all variables integrated in an implicit way, based on the backward Euler scheme. Nucleation, coalescence and shear extensions implementations are validated by results obtained from the literature. The macroscopic campaign allowed to identify the parameters for nucleation, coalescence and shear. An unique set of results matching all experiments was not possible to obtain, so different sets of parameters are retrieved following an approach that includes inverse modeling and sensitivity analysis. A numerical-experimental comparison of strain values in the loading direction shows that the model is able to correctly predict the strain distribution except during localization of the strain. Globally, the obtained set of material parameters is in good agreement with the experimental results. For SPIF FE simulations, the results of the shape prediction are in good agreement with the experimental results, both for the line and pyramid test. Nevertheless, the force prediction is too high compared to reference values. On the other hand, the GTN model is capable to detect failure in a pyramid and a cone, but the prediction is too premature compared to the experimental failure angle for the same material and geometry. An accurate prediction of failure for the SPIF process was not possible to achieve. The GTN model extended to shear presents inherent flaws that prevent an accurate prediction of the failure angle for the SPIF process. Hence, an extensive research on the damage mechanisms leading to fracture for SPIF cannot rely (only) on the GTN model. The classical coalescence model of the GTN model is insufficient to correctly predict failure. Hence, it is recommended that further analysis concentrates on the description of this particular stage of damage evolution. During the development of this thesis, a robust implementation of the GTN model into the FE code LAGAMINE was done, including an extensive experimental database of microscopic and macroscopic measurements for the DC01 steel sheet. Other phenomena can be explored thanks to this model. [less ▲]

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See detailCo-simulation of Electromagnetic Transients and Phasor Models of Electric Power Systems
Plumier, Frédéric ULg

Doctoral thesis (2016)

This study investigates and improves methods used for the combination of phasor and electromagnetic transients time domain simulations of power systems. It involves the study of the protocols of ... [more ▼]

This study investigates and improves methods used for the combination of phasor and electromagnetic transients time domain simulations of power systems. It involves the study of the protocols of computation, the comparison of the different kinds of boundary conditions used to represent one sub-system when simulating the other, and the interfacing of phasor and electromagnetic transients models. The Nordic system has been used to realize the tests. Illustrative simulation results are reported for the case of a single and of multiple boundary buses between the sub-systems. [less ▲]

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See detailSynthesis and Physical Properties of Helical Nanosized Quinoline-based Foldamers: Structure, dynamics and photoinduced electron transport
Li, Xuesong ULg

Doctoral thesis (2016)

Herein, synthesis, characterization and application (photoinduced electron transport) of nanosized quinoline-based foldamers have been explored. With double segment strategy, a variety of helical ... [more ▼]

Herein, synthesis, characterization and application (photoinduced electron transport) of nanosized quinoline-based foldamers have been explored. With double segment strategy, a variety of helical nanosized foldamers (up to 96 quinoline units) were successfully prepared based on 8-aminoquinoline-2-carboxylic acid monomer. The dynamic properties in gas phase and solution were investigated. Ion mobility mass spectrometry afforded access to the conformation state of foldamers in gas phase; DOSY and fluorescence anisotropy assessed the diffusion (translational and rotational, respectively) of foldamers in solution. All of these techniques revealed that quinoline-based foldamers are rigid and that helical conformation is conserved. Photoinduced electron transport through nanosized foldamer was also studied and the mechanism and the transport ratios were revealed. [less ▲]

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See detailEfficient methods for large-scale time-harmonic wave simulations
Marsic, Nicolas ULg

Doctoral thesis (2016)

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See detailCARRIÈRES MIGRATOIRES ET POLITIQUE D’INTÉGRATION DANS LA RÉGION DE MADRID. L’EXEMPLE DES MIGRANTS ADULTES DANS LA VILLE DE PARLA (2007-2012)
Brey, Elisa ULg

Doctoral thesis (2016)

This dissertation analyses the migratory carreers of adult migrants settled in the urban outskirts of Madrid, in Spain, during the first years of the economic crisis (2007-2012). The aim is to understand ... [more ▼]

This dissertation analyses the migratory carreers of adult migrants settled in the urban outskirts of Madrid, in Spain, during the first years of the economic crisis (2007-2012). The aim is to understand the dynamics of migratory carreers through the access to a residence permit, the labour and the housing market. To achieve this goal, semi-structured interviews have been conducted with migrants from Morocco, Romania, countries of Subsaharan Africa and the Andean Community (Ecuador, Colombia, Bolivia and Peru). Interviews and observations have also been conducted with leaders of local associations and representatives of municipal services to which migrants have access. A typology is proposed, considering that migratory carreers can adopt regular or informal dynamics, following the characteristics of a community or a society. [less ▲]

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See detailBeyond the Line: Murray Bail's Spatial Poetics
Herbillon, Marie ULg

Doctoral thesis (2016)

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See detailLa justice pénale internationale à l'épreuve des droits humains : étude de la privation de liberté devant la Cour pénale internationale
Deprez, Christophe ULg

Doctoral thesis (2016)

Entre instrument de protection des libertés fondamentales et menace à l'égard de ces mêmes libertés, l'activité pénale est un phénomène cerné de paradoxes. Les règles de protection des droits humains ont ... [more ▼]

Entre instrument de protection des libertés fondamentales et menace à l'égard de ces mêmes libertés, l'activité pénale est un phénomène cerné de paradoxes. Les règles de protection des droits humains ont notamment pour ambition de contenir ces paradoxes : en encadrant le pouvoir de contrainte que l'autorité répressive peut exercer sur les individus, ces normes essentielles doivent permettre de garantir une justice pénale qui demeure fidèle aux principes qu'elle entend défendre. Mais quelle peut bien être l'emprise des droits humains sur l'action du juge pénal international ? Dès lors que le droit international des droits de l'homme a été pensé et conçu pour circonscrire l'autorité des États, qu'en reste-t-il lorsqu'on cherche à l'appliquer – en particulier – à la Cour pénale internationale ? Dans quelle mesure et sur la base de quel(s) fondement(s) juridique(s) cet acteur répressif d'un genre nouveau est-il tenu au respect de règles auxquelles il n'a pas expressément souscrit ? Les spécificités de la justice pénale internationale – et, singulièrement, la gravité des crimes ayant favorisé son émergence – réclament-elles une adaptation du niveau de protection accordé aux suspects et accusés internationaux ? Quel accueil le Statut de la Cour pénale internationale et les règlements qui l'accompagnent réservent-ils aux standards pertinents, en particulier en matière de privation de liberté ? La jurisprudence de la Cour révèle-t-elle une pratique conforme à ces standards ? Le projet de recherche vise à apporter un éclairage sur l'ensemble de ces questions et, ainsi, à mettre la justice pénale internationale à l'épreuve des droits humains. [less ▲]

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See detailDiagnostic préalable à un contrat d'axe sur la ligne SNCB 40 Liège-Guillemins - Visé. Etude du potentiel de l'outil contrat d'axe en Wallonie et de la densification des gares de la ligne 40
Wilmotte, Pierre-François ULg

Master's dissertation (2016)

Le travail vise à alimenter la réflexion menée par le consortium Pluris - Trame - B. Bianchet à propos de l'élaboration d'un Schéma de Développement Territorial (SDT) pour l'arrondissement de Liège : d ... [more ▼]

Le travail vise à alimenter la réflexion menée par le consortium Pluris - Trame - B. Bianchet à propos de l'élaboration d'un Schéma de Développement Territorial (SDT) pour l'arrondissement de Liège : d'une part, étudier le potentiel des quartiers de gare en région liégeoise et, d'autre part, à voir si l'outil des "Contrats d'axe", développés en France, pourrait être pertinent dans le cadre wallon. La recherche a été appliquée à un axe ferroviaire de la région de Liège. [less ▲]

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See detailLa disponibilité et le prix du foncier à vocation économique: quel impact sur le développement économique en Wallonie?
Vandermeer, Marie-Caroline ULg

Doctoral thesis (2016)

This doctoral dissertation concerns the policy of land production related to economic land in Wallonia. This policy corresponds to the development of economic estates by public authorities, through ... [more ▼]

This doctoral dissertation concerns the policy of land production related to economic land in Wallonia. This policy corresponds to the development of economic estates by public authorities, through economic development agencies, to accommodate businesses. It is based on the argument according to which the availability of land – cheap if possible – is an essential factor in territorial attractiveness and competitiveness. The reflections presented in this dissertation originate from the discrepancy between this argument and the scientific literature devoted to regional development. Indeed, unlike elected representatives and economic development agencies, scholars active in the field of regional sciences only very rarely refer to the impact of the land markets on levels of development. Rather than focusing on the theme of land prices and land availability, regional scientists underline the importance of intangible factors such as innovation, education, integration into networks, territorial identity, strategic management or governance. In view of this difference, it seems appropriate to assess the spatial and economic effectiveness of the Walloon policy of land production. To do this, our wish is to objectify the real role of the availability and the price of economic land on territorial development. The first part of the dissertation develops a reflection on the literature dedicated to the relationships between land and property markets and regional development. It leads to highlight the need to develop knowledge on the impact of land and property markets on business competitiveness, regional attractiveness and economic development. The second part is devoted to the study of the availability of economic land and aims to assess the spatial effectiveness and the economic effectiveness of policies which offer an important quantity of economic land. To do this, statistical analyses were conducted on two study areas: the Northwest Europe and Belgium. As regards spatial effectiveness, the results underline significant national differentials in terms of land consumption on the one hand, while highlighting the economic sprawl that characterises France and Belgium on the other hand. As regards economic effectiveness, our results show that the impact of the development of economic estates on growth depends largely on regional contexts. Our analyses identified three regional profiles. First, urban regions, where land availability only plays a marginal role, most likely owing to the presence of numerous activities that are not very extensive spatially, yet very productive in terms of added value. Secondly, intermediate regions, where the availability of economic land has a real impact on development. However, it would appear that the profile of these regions is adapted to the presence of activities which, like logistics, generate a limited amount of jobs and added value per surface unit. Thirdly, rural regions, where the opening of land to urbanisation does not deliver the desired results. In these regions, the availability of land is not a sufficient condition for economic growth and job creation. However, we have to precise that the Belgian rural regions are rather similar to intermediate regions, probably thanks to their good connectivity. The third part concerns the study of the economic land prices. It tends to assess the impact of these prices on company property costs. The developed statistical analysis is based on annual accounts of companies with one reporting unit localised in Walloon economic estates. Results suggest that property costs are rather low. On average, they represent 1.4% of all their operational costs and 5.4% of their added-values. By contrast, labour costs are eight times higher. In addition, our analyses suggest that an increase in land prices would have a limited impact on property costs. These results tend to invalidate the hypothesis that low land prices are a key determinant of regional development. Although, property costs are highly dependent on the business sector and the size of firms. For instance, for logistic companies and small firms, property costs represent more than 10% of their added-values and 2% to 5% of their operational costs. These results tend to highlight the fact that high land prices can have a negative impact on the development of these companies. As a final point, our conclusion discusses the recommendation that economic land supply policies must be adapted according to both, the profile of the territories and the profile of the firms. Indeed, in urban regions, land supply policies aiming to supply an important land supply at low price is probably inefficient from an economic standpoint. By contrast, economic development can be expected in intermediate regions with active land policies dedicated to land-intensive activities. Moreover, a specific attention should be paid to small companies. [less ▲]

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See detailStimuli-responsive self-assembled macromolecular systems with potential drug delivery applications: structural characterization by Small-Angle Neutron Scattering
Joset, Arnaud ULg

Doctoral thesis (2016)

Colloids are known since the early 19th century but they have mainly sparked interest since the last few decades thanks to their use in biomedical applications or in the design of new materials. The aim ... [more ▼]

Colloids are known since the early 19th century but they have mainly sparked interest since the last few decades thanks to their use in biomedical applications or in the design of new materials. The aim of this thesis is the study of stimuli-responsive colloids by Small-Angle Neutron Scattering (SANS). The stimuli may be the pH, the temperature, the addition of a ligand or of metallic ions or a combination of them. SANS is a useful technique which provides information about the internal structure of nano-objects but also, if appropriate conditions are met, about the organization of the objects in solution. Several samples built from the auto-assembly of block copolymers and liposomes have been prepared. The macroscopic cross sections have been modeled with the aim to infer the main structural parameters of the samples: the global size, the polydispersity, the structure and volume occupied by the hydrophilic and hydrophobic components inside the nano-objects. The SANS measurements have been performed as a function of the intensity of the stimulus, in order to quantify the evolution of the structural parameters. The first experimental part focuses on micellar samples built from sequenced block copolymers. The blocks may be biodegradable (e.g., poly(ε-caprolactone)), biocompatible (e.g., poly(ethylene oxide)), pH-sensitive (e.g., poly(2 vinylpyridine), poly(acrylic acid)) or temperature-sensitive (e.g., poly(N-isopropylacrylamide)). The influence of the concentration and the formation of bridges between micelles have been investigated through the analysis of metallo-supramolecular micellar gels resulting from the self-assembling of polystyrene-block-poly(tert-butylacrylate) PS-b-PtBA-tpy (tpy stands for terpyridine) block copolymers in the presence of transition metal ions. The second part focuses on the analysis of liposomes interacting with an increasing concentration of Randomly Methylated β-cyclodextrins (RAMEB). This part is divided into two chapters. The first one deals with liposomes mainly composed of dimyristoylphosphatidylcholine (DMPC) and the second one investigates the effects of cholesterol doping on the same DMPC liposomes interacting with RAMEB. [less ▲]

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See detailPerformance and Robustness of Nonlinear Systems Using Bifurcation Analysis
Detroux, Thibaut ULg

Doctoral thesis (2016)

Nonlinear vibrations can be frequently encountered in engineering applications, and take their origin from different sources including contact, friction or large displacements. Other manifestations of ... [more ▼]

Nonlinear vibrations can be frequently encountered in engineering applications, and take their origin from different sources including contact, friction or large displacements. Other manifestations of nonlinearities are peculiar phenomena such as amplitude jumps, quasi-periodic oscillations and isolated response curves. These phenomena are closely related to the presence of bifurcations in the frequency response, which dictate the system's dynamics. While recent progress has been achieved to develop tools for nonlinear modal analysis of industrial applications, bifurcation analysis was still limited to reduced models and academic case studies. Along with the lack of an efficient algorithm to detect and study bifurcations, bifurcation analysis for design purposes also remained unexplored. The fundamental contribution of this doctoral thesis is the development of a new methodology for the detection, characterization and tracking of bifurcations of large-scale mechanical systems. To this end, an extension of the harmonic balance (HB) method is proposed. Taking advantage of the efficiency of the HB method for the continuation of nonlinear normal modes and frequency responses, this extension allows for robust computation of bifurcation curves in the system's parameter space. A validation of the methodology is performed on the strongly nonlinear model of an Airbus Defence & Space spacecraft, which possesses an impact-type nonlinear device consisting of multiple mechanical stops limiting the motion of an inertia wheel mounted on an elastomeric interface. The second main contribution is the development of a new vibration absorber, the nonlinear tuned vibration absorber (NLTVA), which generalizes Den Hartog's equal-peak method to nonlinear systems. The absorber is demonstrated to exhibit unprecedented performance for the mitigation of nonlinear resonances. In a second step, the HB-based bifurcation methodology is utilized to characterize the performance regions of the NLTVA, and to ensure its robustness with respect to parameter uncertainties. [less ▲]

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See detailPour une sociologie de la littérature en milieu minoritaire. Analyse des discours (méta)littéraires associés à la littérature acadienne
Nicaise, Nicolas ULg

Doctoral thesis (2016)

Plus qu’un objet stabilisé, notre parti-pris est d’étudier, dans cette thèse, le phénomène de la littérature en milieu minoritaire en cherchant à montrer, par une approche systémique, comment la ... [more ▼]

Plus qu’un objet stabilisé, notre parti-pris est d’étudier, dans cette thèse, le phénomène de la littérature en milieu minoritaire en cherchant à montrer, par une approche systémique, comment la littérature acadienne se structure et s’institutionnalise. C’est à partir de l’étude d’un réseau d’acteurs et d’instances ainsi que des pratiques discursives littéraires et (méta)littéraires qui construisent cette littérature qu’il nous apparaît possible d’interroger – aux croisements de multiples courants théoriques empruntés à la sociologie de la littérature –, les relations complexes entre textes et contexte. L’objectif n’est donc pas seulement de modéliser un milieu littéraire, mais de dégager, à partir des textes de multiples acteurs du milieu, les configurations poétiques, les représentations discursives comme les conditions et les paramètres de fonctionnement du milieu. Pour autant, il ne s’agit pas d’isoler un milieu littéraire, mais d’observer comment celui-ci émerge et intègre un système plus vaste en questionnant nos représentations du littéraire. [less ▲]

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See detailFunction-based Analyses of Bacterial Symbionts Associated with the Brown Alga Ascophyllum nodosum and Identification of Novel Bacterial Hydrolytic Enzyme Genes
Martin, Marjolaine ULg

Doctoral thesis (2016)

Marine macroalgae are highly colonized by microorganisms, with which they maintain a close relationship characterized by both beneficial and detrimental interactions. Alga-associated bacteria have notably ... [more ▼]

Marine macroalgae are highly colonized by microorganisms, with which they maintain a close relationship characterized by both beneficial and detrimental interactions. Alga-associated bacteria have notably developed a range of enzymes enabling them to colonize the host surface and to use algal biomass as a carbon source. The hydrolytic potential of these bacteria, however, has been investigated almost solely at individual scale. Studies have shown the ability of some seaweed-associated bacterial strains to hydrolyze lipids, algal-cell-wall polysaccharides, and other sugars. In this work we aimed to investigate the hydrolytic potential of the bacterial microbiota associated with the brown alga Ascophyllum nodosum. For this we employed two complementary function-based approaches: functional metagenomics applied to this microbiota and functional analysis of the cultivable fraction thereof. By functional metagenomics, we identified numerous esterase genes, a beta-glucosidase gene, and an endocellulase gene. The cellulase was purified and biochemically characterized, showing interesting biotechnological features such as halotolerance and activity at low temperature. Furthermore, we assigned tentative origins to the identified genes, thus getting a glimpse of the bacterial taxa associated with the studied alga. Secondly, we investigated the cultivable surface microbiota associated with three A. nodosum samples. More than 300 bacteria were isolated, assigned to a bacterial taxon and screened for algal-polysaccharide-degrading enzymes (agarase, iota-carrageenase, kappa-carrageenase, and alginate lyases). This allowed the identification of several polysaccharolytic isolates, some of them likely to be new strains or novel species, belonging to two classes: the Flavobacteriia and the Gammaproteobacteria. Subsequently, we constructed and screened two plurigenomic libraries, each produced with the genomes of five representative isolates of each class, and identified several functional genes. With this work we highlight the presence of A. nodosum-associated bacterial taxa likely to entertain a privileged relation with seaweeds and having developed a range of hydrolytic activities assumed to enable them to associate with algae. We also provide information (taxa, abundances, genomic potential) on macroalgal-polysaccharide-degrading bacteria, in which interest has grown over the last ten years. [less ▲]

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See detailÉtude des anthocyanes de l’Hibiscus sp
Beye, Cheikh ULg

Doctoral thesis (2016)

Très répandues dans le règne végétal, les anthocyanes sont le sujet d'un grand nombre d'études. Celles-ci abordent en général les aspects concernant leur instabilité vis-à-vis des conditions dans ... [more ▼]

Très répandues dans le règne végétal, les anthocyanes sont le sujet d'un grand nombre d'études. Celles-ci abordent en général les aspects concernant leur instabilité vis-à-vis des conditions dans lesquelles elles sont employées ou l'effet bénéfique de leur consommation sur certaines pathologies chroniques. Provenant de nombreux types de fruits et légumes comestibles, elles sont extraites en vue de leur utilisation comme colorant alimentaire naturel. C'est ce dernier aspect qui a été le sujet principal de ce travail dont l'objectif était de montrer que les calices d’Hibiscus sabdariffa (H. sabdariffa) pouvaient être utilisés comme matière première pour la fabrication de colorant. Les deux principaux cultivars provenant du Sénégal présentent des différences significatives du point de vue de leur contenu en anthocyanes sur le plan qualitatif et quantitatif. L'influence des conditions de culture sur la concentration en anthocyanes a été mise en évidence. Une technique chromatographique a été utilisée pour concentrer les anthocyanes. Les résultats provenant d'expériences faites en batch agité avec une résine macroporeuse ont permis de déterminer les paramètres tels que le temps de contact nécessaire à l'atteinte de l'équilibre, la capacité d'adsorption maximale et de conclure que la résine utilisée avait une capacité d'adsorption élevée pour les anthocyanes. Suite à la fabrication du colorant, une partie importante de la masse de calices restait inutilisée alors qu'elle contenait encore des substances valorisables. Leur caractérisation a permis de montrer que les résidus des calices d'H. sabdariffa pourraient être valorisés par la production de pectines destinées au marché des additifs alimentaires, d'oligosaccharides à effet prébiotique ou de biocarburants. [less ▲]

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See detailẾtude de l’émergence des organisations pastorales et de leur rôle dans les processus de gestion partagée de la vallée de la Tarka dans les départements de Bermo et Dakoro (Centre sud du Niger)
Ibrahim, Habibou ULg

Doctoral thesis (2016)

Cette thèse vise à analyser les organisations pastorales et leurs rôles dans la gestion des conflits fonciers. En Afrique subsaharienne et particulièrement au Niger, le foncier est au centre des enjeux de ... [more ▼]

Cette thèse vise à analyser les organisations pastorales et leurs rôles dans la gestion des conflits fonciers. En Afrique subsaharienne et particulièrement au Niger, le foncier est au centre des enjeux de l’agro-pastoralisme. La sécurisation des droits d’accès aux ressources et des systèmes de tenure foncière sont essentiels pour la gestion et la résolution des conflits fonciers (Herrea et al., 2007). La région de Maradi constitue la zone de contact entre le Nord pastoral et le Sud agricole. Dans cette partie centrale où la pression foncière, aggravée par la croissance démographique, se pose avec acuité, le spectre des conflits fonciers est malheureusement devenu un phénomène chronique, une donnée permanente (GADO., 2000). La pluralité des normes et plusieurs sources de droit contribuent à complexifier le règlement des litiges fonciers entre acteurs dans les départements de Dakoro et Guidan Roumdji (Moutari., 2001). Or la dynamique globale des systèmes d’élevage est déterminée par la complémentarité des espaces agro-pastoraux. Cette complémentarité est remise en cause par ces pressions foncières et suscite des changements organisationnels dans les communautés du centre Sud du Niger (Yamba., 2004 ; 2000). C’est le rôle des associations pastorales à Dakoro et Bermo qui est l’objet de cette recherche. En effet les organisations paysannes en Afrique Subsaharienne et au Niger en particulier jouent un rôle important dans la définition des politiques agricoles et deviennent des conditions indiscutables de la réussite des actions à promouvoir à l’échelle locale (Courade et Deveze., 2006 ; Mercoiret, 2006 ; Mercoiret et al. 2004). La méthodologie de travail relève de l’approche ethnographique. Les outils et instruments d’enquête sont les questionnaires et les entretiens ouverts avec les acteurs locaux sur les dynamiques territoriales, les modes d’action des associations pastorales et les conflits fonciers. Les résultats viennent aussi des travaux et des documents des projets, des ONG et des rapports des services techniques de l’Etat. Pour un souci de fiabilité des données, nous avons tenu à réaliser des séances de restitution des données et de triangulations pour confronter les informations de diverses sources. Au total 104 personnes sont enquêtées dont 30 % auprès des associations. Ces investigations ont concerné aussi les secrétaires des commissions foncières, les préfets, les agents des projets et des ONG et le président du tribunal de Dakoro ainsi que les leaders pastoraux, les transhumants, les agriculteurs et associations pastorales. [less ▲]

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See detailCaractérisation de la niche édaphique des espèces cupro-cobalticoles du katanga (R.D. Congo) en vue de leur conservation et de leur valorisation dans des stratégies de phytostabilisation
Boisson, Sylvain ULg

Doctoral thesis (2016)

Natural metalliferous habitats represent unique study cases for scientific research as geopedology, biology and eco-evolution of metallophytes. Southeastern Democratic Republic of Congo hosts among the ... [more ▼]

Natural metalliferous habitats represent unique study cases for scientific research as geopedology, biology and eco-evolution of metallophytes. Southeastern Democratic Republic of Congo hosts among the most important copper and cobalt deposits of the world, having a high economic value. Copper and cobalt outcroups have been formed during billion years by geological successions. More than one hundred hills are now scattered in an area of 300 km long and 50 km large in vegetation matrix consisting on an open forest called Miombo. This area is called Katangan Copperbelt. At the top of hills, the close proximity between the deposit and the soil surface lead to a high concentration of bioavailable copper and cobalt in soil solution exceeding the tolerance threshold of most of plants. More than 550 taxa including 10 % are identified as endemics and compose two distinct herbaceous plant formations: the steppic savanna is found on the lowest minralised soils and the steppe occurs in the highest mineralized soils at the top of hills. Mining activities have dramatic consequences on environement and public health, leading to the destruction of natural meatlliferous habitats and to the creation of anthropogenic polluted sites. Considering the threat on endemic plant species of the Katangan Copperbelt, several in situ and ex situ conservation strategies have been implemented for the last ten years in collaboration with several institutions. Furthermore, metallophytes constitute remarkable resources for the biotechnologies such as phytoremediation due to their metal tolerance or their accumulation ability. Anthropogenic metalliferous sites of the Katangan Copperbelt could be considered for the conservation of metallophyte with a perspective of remediation of polluted soils. Both challenges require the characterization of the environmental factors determining the distribution of plant species in natural sites and their performance in anthropogenic sites. This thesis aims at characterising the edaphic niche of metallophytes from the Katangan Copperbelt in order to propose actions combining the conservation of metallophyte and the phytostabilisation of polluted soils. The first axis focused on the study of two fundamental concepts in ecology, the theory of ecological niche and the concept of edaphic endemism, in order to understand the plant-soil relationships. Threatened endemic species were chosen as study case to determine the cause of the restricted distributions of metallophytes on metalliferous soils. The second axis tested the success of the establishment of endemic metallophytes in phytostabilisation strategies using the grass Microchloa altera. An assessment of the potential of other grasses was performed based on the specific criterions needed in phytostabilisation in order to identify candidate species for conservation–phystabilisation strategies. [less ▲]

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See detailMarket Dynamics in the Financial Industry - Essays on Interdependence and Market Timing
Biell, Elisabeth ULg

Doctoral thesis (2016)

The global financial crisis and the subsequent sovereign crisis are painful reminders of how the standards of financial markets are profoundly challenged in times of crisis. The main lesson is that the ... [more ▼]

The global financial crisis and the subsequent sovereign crisis are painful reminders of how the standards of financial markets are profoundly challenged in times of crisis. The main lesson is that the structural changes and the increased risk of shock transmissions require a more accurate risk assessment that captures the complexity of market dynamics. Based on an empirical approach, this thesis aims at loosening a priori assumptions common in literature in order to develop new methodologies that are more robust and more flexible to the dynamics of changing market conditions. The first aspect of market dynamics addressed in this thesis is the dependence structure of financial markets. The connectedness of the banking and sovereign sectors is dynamically assessed on the basis of daily CDS spreads using complex networks. We turn away from the traditional linear correlation measures and use copula theory to account for extreme events and tail dependence, which is crucial when studying credit and default risk. Through the calculation of minimum spanning trees, our methodology evaluates the transmission pattern of shocks over time and their propagation across geopolitical borders. Going beyond the analysis of simple interdependence, we apply a structural break analysis to measure a contagion index that captures increased co-movements in the network. This thesis tackles a second aspect of market dynamics which relates to major events in the life of a company affecting a company’s market value. By means of operational loss events and cross-listing decisions, we illustrate our refined event study technique that overcomes the drawback of a priori assumptions about the event date. In addition to the reaction magnitude, our approach investigates the point in time when most of the market reaction takes place by highlighting two variables: the start and the length of stock markets' responses. [less ▲]

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See detailUrban megaprojects-based approach in urban planning: from isolated objects to shaping the city:The case of Dubai
Aoun, Oula ULg

Doctoral thesis (2016)

Urban megaprojects are at the core of cities’ re-imaging and marketing. As large-scale development projects, they are considered as a globalization product, marked by a search for spectacle and visibility ... [more ▼]

Urban megaprojects are at the core of cities’ re-imaging and marketing. As large-scale development projects, they are considered as a globalization product, marked by a search for spectacle and visibility. In Dubai, UMPs have constituted in recent years the main tool in drawing a city image that aims to compete with the world global cities. Through UMPs, an economy based on spectacle and fascination is being deployed, within a complex system of governance that encompasses family ties, business logic and individualist visions. UMPS are not exceptions or isolated developments, they are in Dubai, a mean through which the city is expanding and being managed. UMPs are here the backbone public planning instrument to what we can call a UMPs-based approach to planning and development. Paradoxically, it is these very large projects, usually associated to urban fragmentation that allow, through their form and processes, the emergence of forms of regulation that articulate actors, institutions, interests, resources, spaces and scales. These adaptations and negotiations are orchestrated in a strategic pilotage manner, through informal, often unveiled ad hoc regulatory spaces. The ultimate goal is to ensure a certain synchronization between temporalities and project through a continuous logic of complementarity and competitiveness. [less ▲]

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See detailContribution à l’étude de la morphologie et du développement de l’encéphale, en particulier du cervelet, chez le mouton
Salouci, Moustafa ULg

Doctoral thesis (2016)

De nombreuses maladies virales émergentes chez le mouton génèrent des anomalies congénitales au niveau du système nerveux central (SNC), or, peu d'informations sont disponibles dans la littérature sur ... [more ▼]

De nombreuses maladies virales émergentes chez le mouton génèrent des anomalies congénitales au niveau du système nerveux central (SNC), or, peu d'informations sont disponibles dans la littérature sur l’anatomie et le développement du cerveau du mouton, en particulier en ce qui concerne le cervelet. Par ailleurs, il s’avère que le mouton pourrait représenter un bon modèle expérimental animal pour l’étude de certaines pathologies survenant pendant le développement embryonnaire de l’encéphale. Au cours de cette thèse, nous avons présenté les résultats d’une série de dissections de l’encéphale du mouton afin de confronter nos résultats aux descriptions d’anatomie classique et de comparer ces résultats avec le bovin qui est souvent considéré comme animal de référence quand on parle de « ruminants ». Ensuite, nous nous sommes intéressés au développement de deux types de cellules au sein du cervelet, qui sont très peu connues chez le mouton. Ce travail a été réalisé en deux phases. La première a consisté à étudier le développement des cellules de Purkinje dans des coupes de cervelet de fœtus à différents âges de gestation et colorées à l'hématoxyline-éosine, violet de crésyl ou Klüver-Barrera. Au cours de cette étude, nous avons observé les cellules de Purkinje dès le 100ème jour de gestation. Des degrés variables de développement des cellules de Purkinje ont été observés dans différentes zones du cervelet. Nos résultats suggèrent que le développement des cellules de Purkinje débute dans les régions caudales du cervelet et dans le vermis avant de concerner les hémisphères cérébelleux. L'alignement des cellules de Purkinje était très régulier dans les régions caudales du cervelet. Une absence partielle des cellules de Purkinje dans les régions rostrales du cervelet a été observée chez les fœtus et l'adulte. Dans la première semaine après la naissance, certaines cellules de Purkinje ectopiques ont été observées dans la substance blanche du cervelet. Au cours de la seconde partie de notre thèse. Nous avons étudié le développement des astrocytes qui constituent la plus grande population de cellules gliales dans le cerveau et jouent des rôles très importants dans le développement du système nerveux central. Cette étude a été réalisée au moyen d’une technique immunohistochimique. L'utilisation du marqueur de la GFAP (protéine acide glio-fibrillaire) a montré plusieurs variations dans le degré de développement des astrocytes dans les différentes zones du cervelet du mouton pendant la vie fœtale. Au cours du 60ème jour de gestation, les astrocytes se trouvent au niveau du toit du quatrième ventricule. Pendant leur développement, les cellules radiales se transforment en astrocytes (cellules de Bergman) à partir du 100ème jour de gestation. Nos observations suggèrent que le développement des astrocytes débute au niveau de la substance blanche des zones ventrales des parties caudales du cervelet. Ceux-ci se distribuent ensuite dans les régions les plus rostrales du cervelet. Ce développement commence dans le vermis avant d’atteindre les hémisphères cérébelleux. Certaines similitudes ont été confirmées pour de nombreux aspects développementaux entre l’homme et le mouton dans le cadre de l’utilisation du mouton en tant que modèle animal. Les résultats obtenus durant cette thèse ont permis de mieux comprendre le développement normal des cellules de Purkinje et des astrocytes. Ils permettent de compléter les connaissances déjà acquises sur le développement du cervelet et d’établir des bases importantes pour de futures études portant sur les fonctions et la physiologie des astrocytes et des cellules de Purkinje ainsi que les modifications pouvant survenir lors de pathologie tant chez l’homme que chez le mouton. [less ▲]

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See detailContribution to the study of african swine fever in the Democratic Republic of Congo: epidemiological and virological approaches
Mulumba Mfumu Kazadi, Léopold ULg

Doctoral thesis (2015)

Les résultats de cette thèse sont présentés sous la forme d’un ensemble cohérent de quatre études. 1. – Caractérisation moléculaire des souches du virus de la peste porcine africaine (PPA) impliquées dans ... [more ▼]

Les résultats de cette thèse sont présentés sous la forme d’un ensemble cohérent de quatre études. 1. – Caractérisation moléculaire des souches du virus de la peste porcine africaine (PPA) impliquées dans la persistance de l’infection en Afrique centrale (République Démocratique du Congo, RDC). Entre 1997 et 2000, sur 350 prélèvements de sang et organes provenant des porcs apparemment sains, 73 porcs (20,8%) avaient les anticorps dirigés contre la peste porcine africaine (PPA). Au cours de la même enquête, des organes prélevés sur les carcasses des porcs provenant d’une ferme familiale avec des mortalités constatées ont permis la détection de l’ADN du virus de la PPA. La caractérisation du virus a permis d’établir une similarité génétique avec des souches d’Afrique de l’Ouest, notamment du Nigeria et du Ghana. 2. – Estimation de la prévalence de la peste porcine africaine en République Démocratique du Congo et évaluation de la sensibilité et de la spécificité de trois tests ELISA en condition de terrain. Une étude a été menée sur 495 porcs domestiques apparemment en bonne santé de la RDC afin de déterminer le niveau d’exposition au virus de la PPA sur la base de 3 tests ELISA utilisant respectivement comme antigène la protéine VP72 soit sous forme brute (CP72) ou soit sous forme recombinante (rp72) et la protéine p30 recombinante (rp30). En outre, une PCR ciblant la région conservée du gène B646L codant pour la protéine de capside VP72 a été utilisée afin de déterminer l'exposition en fonction du stade de l'infection virus de la PPA. La prévalence apparente (PA) calculée avec les tests ELISA variait de 10% (48/482) avec la RP30 à 22,3% (79/354) avec la rp72. Basé sur des résultats positifs reproduits au moins par deux tests de diagnostic, la PA globale a été estimé à 17% (55/328). Parmi 495 animaux testés par PCR, l’ADN du virus de la PPA a été détecté chez 7 animaux (1,4%), dont 5 porcs séropositifs. En outre, en considérant le test ELISA CP72 comme référence, la sensibilité et la spécificité relatives des tests ELISA rp72 et rp30 ont été estimées sur un sous-ensemble de 328 porcs pour lesquels les résultats à tous les tests étaient disponibles. Le test ELISA rp72 avait une sensibilité relative de 93,5% (IC à 95%: 82,1 à 98,6) et une spécificité relative de 88,0% (IC à 95%: 83,6 à 91,5). Le test ELISA rp30 avait une sensibilité relative de 34,8% (IC à 95%: 21,3 à 50,2) et une spécificité relative de 93,7% (IC à 95%: 89,7 à 95,9). La combinaison globale de la PCR et des trois tests ELISA a révélé que 62% des cas positifs avaient au moins un de leur résultat confirmé par un autre test. Le test ELISA rp72 peut être recommandé dans le dépistage à grande échelle de la maladie dans les zones endémiques de PPA en Afrique comme une alternative au test ELISA de CP72. En outre, le test ELISA de rp30 peut être recommandé pour la confirmation à tout stade de l'infection, y compris dans les plus précoces en parallèle avec la PCR. 3 – La caractérisation génétique des isolats du virus de la PPA impliquées dans les foyers en République Démocratique du Congo, entre 2005 et 2012, révèle une co-circulation de trois Génotypes : I, IX et XIV et 16 variants du virus. L’étude a portée sur 62 pièces anatomiques de rates, ganglions hépato-gastriques, reins, cœurs, poumons, foies et estomacs provenant des 57 carcasses des porcs dont 54 provenant de foyers et 3 provenant des points d’abattage des marchés. L’ensemble représente 25 foyers au total. Ces foyers concernent 5 Provinces de la RDC, dont notamment l’Equateur, le Bas-Congo, le Katanga et Kinshasa. L’étude a révélé la co-circulation de 3 génotypes (I, IX et XIV) et 16 variants du virus. 4 - Immunisation des porcs des races Africaines avec le virus OURT88/3 du Génotype I induit une protection contre l’infection avec deux souches virulentes du Génotype I. La souche atténuée OURT88/3 du virus de la PPA, de genotype I, a déjà démontré son pouvoir protecteur chez les porcs domestiques de races européennes envers les isolats virulents du virus de la PPA. Pour déterminer si les réponses immunitaires protectrices pourraient également être induites chez des porcs de races indigènes de de la région Kinshassa en République démocratique du Congo, nous avons immunisé un groupe de 8 porcs avec la souche atténuée OURT88/3 et infecté les porcs 21 jours plus tard avec la souche virulente OURT88/1 du même génotype. Parmi les 8 porcs, 4 ont été protégés contre l’infection. Trois des 8 porcs sont morts du virus de la PPA et un 4ième est mort de cause inconnue. Les 4 porcs restants ont survécu à une seconde infection avec une souche virulente RDC 085/10 du virus de la PPA, de même génotype. Deux groupes contrôles de porcs non immunisés ont été infectés par la souche OURT88/1 ou la souche RDC 085/10 et ont développé des signes cliniques aigus de la PPA. Ils avaient des niveaux élevés de génome viral dans le sang. [less ▲]

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See detailEstimation of diet digestibility and intake by grazing ruminants through near infrared reflectance spectroscopy analysis of faeces. Application in various contexts of livestock production
Decruyenaere, Virginie ULg

Doctoral thesis (2015)

Grazing is the most economical feeding scheme for ruminants. Grazing management, however, is often difficult for breeders, particularly because of a lack of knowledge about grass availability and quality ... [more ▼]

Grazing is the most economical feeding scheme for ruminants. Grazing management, however, is often difficult for breeders, particularly because of a lack of knowledge about grass availability and quality. There are methods for assessing the quantitative and qualitative characteristics of grass, but they are difficult to apply in the case of grazing ruminants. Near infrared reflectance spectroscopy (NIRS) is based on the absorption of infrared light by organic matters to provide NIRS spectra. These NIRS spectra can be correlated with the chemical or biological composition of samples in order to develop calibrations that can be used as predictive models. The primary objective of this PhD thesis was to study the potential of NIRS applied to faeces (FNIRS) in order to predict the characteristics of the diets of grazing herbivores. The particular focus was on the in vivo organic matter digestibility, voluntary intake and botanical composition of ingested diets. The main results of the study show that FNIRS has great portential for estimating in vivo digestibility and voluntary intake by grazing ruminants and that faeces are a good indicator of ingested diets. Based on both large or small and varied databases, the results suggest that FNIRS spectral libraries could be developed for characterising ruminant feed intake. The accuracy of the FNIRS models in estimating in vivo digestibility and voluntary intake is similar to or better than that of other methods usually used to assess these parameters. FNIRS could also be used to predict ruminants’ diet composition in terms of plant species. These predictions should be used only for ranking, however, because of the current lack of accurate procedures for determining diet selection individually. NIRS applied to faeces can be used to predict the in vivo characteristics of forage with sufficient accuracy. The prediction error of NIRS calibrations depends on the accuracy and precision of the reference data. The prediction of in vivo digestibility and intake is sufficiently repeatable compared with the procedure using the reference method. Intake is more difficult to predict with sufficient precision and is more closely linked to animal variability and to uncertainty of the FNIRS models. The major difficulty in using this method lies in generating the diet-faecal pairs as reliably as possible. FNIRS calibrations for predicting in vivo diet characteristics are derivative calibrations. The sample analysed for reference values (diet samples) differs from the samples submitted to NIRS analyses (faeces). With regard to research on forages, in vivo trials with animals confined in pens or digestibility crates appears to be the best reference method for generating FNIRS calibrations. Future work will involve developing FNIRS calibrations for predicting independent datasets and using them to create decision-support tools for improving diverse grazing management schemes. The major focus should be to compare different feeding strategies rather than to obtain an exact estimate of feed intake values. As a low-cost and rapid prediction technique, FNIRS could contribute significantly to the development of a methodology that would help improve our knowledge of forage and animal variability. [less ▲]

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See detailTranscriptomic analysis of pancreatic cells in zebrafish
Tarifeño Saldivia, Estefanía ULg

Doctoral thesis (2015)

Pancreas is a mixed gland composed of endocrine and exocrine tissues and plays a crucial role in the metabolism of all vertebrates. The endocrine cells are mainly grouped into the islets of Langerhans and ... [more ▼]

Pancreas is a mixed gland composed of endocrine and exocrine tissues and plays a crucial role in the metabolism of all vertebrates. The endocrine cells are mainly grouped into the islets of Langerhans and secrete distinct hormones, such as glucagon (α-cell), insulin (β-cell), somatostatin (δ-cell) and ghrelin (ε-cell). Diabetes occurs when insulin production by the β-cells is unable to counteract increase of glycemia. The goal of the first part of my thesis was to determine the transcriptomic signatures of each pancreatic cell type in zebrafish in order to identify novel cell type-specific regulatory genes that might be crucial for their differentiation and/or physiology. Pancreatic acinar cells, ductal cells as well as the endocrine α-, β- and δ-cells were isolated from different transgenic adult zebrafish using FACS and RNA-seq was performed from these highly purified cell types. Comparison between the RNA-seq datasets allowed us to highlight all genes (protein coding and non-coding genes) with enriched expression in each cell type and to identify new markers of the mature pancreatic cells in zebrafish. In order to establish the expression blueprint of pancreatic endocrine and exocrine cells conserved from fish to mammals, we compared the pancreatic transcriptomes from zebrafish, mouse and human. Using pancreatic RNA-seq data available in databases, we determined the set of genes displaying enriched expression in endocrine and exocrine cells of human and mouse. Comparison of these data with the zebrafish pancreatic endocrine and exocrine data revealed the genes with conserved expression among vertebrates. Most of the transcription factors previously known to be important for pancreatic cell differentiation are included in this set of conserved genes. This interspecies comparative analysis highlighted genes with evolutionary conserved expression whose pancreatic function is still unknown, but also revealed striking differences in gene expression patterns between species. The goal of the second part of my thesis was to understand the global transcriptional change produced by the loss-of-function of pax6b in pancreatic endocrine cells during pancreas development in zebrafish. We performed RNA-seq from purified pancreatic endocrine cells from wild-type and mutant (pax6b sa0086 null allele) zebrafish embryos at 27 hpf. By comparing the transcriptome of wild-type and mutant endocrine cells, we identified thousands of genes differentially expressed. Notably, we observed that the expression level of the pancreatic hormones was affected as it was reported in murine models. These analyses have revealed the transcriptional network regulated by pax6b in endocrine cells during differentiation. These analyses highlighted many unknown pax6b targets and novel regulators possibly involved in pancreatic function. Future functional analyses will be needed to further investigate the function of the novel regulators identified by this study. [less ▲]

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See detailEcologie et connaissances ethnozoologiques de quelques espèces d'oiseaux gibiers menaces des ecosytèmes du Sud du Bénin
Lougbegnon, Olou Toussaint ULg

Doctoral thesis (2015)

The natural areas of the south of Benin under subequatorial climate are diversified in resident birds’ species as well as migratory one. Some of them are hunted for food and therapeutic purposes by ... [more ▼]

The natural areas of the south of Benin under subequatorial climate are diversified in resident birds’ species as well as migratory one. Some of them are hunted for food and therapeutic purposes by grassroots communities. The most used are Guttera pucherani, Dendrocygna viduata, Egretta alba, Egretta ardesiaca, Porphyrio alleni et Porphyrio porphyrio. In order to reduce pressure on biodiversity in this part of Benin and to implement the sustainable conservation of birds’ species, this study on ecology and ethno-zoological knowledge of hunted bird species was carried out in the forest areas and the Ramsar sites 1017 and 1018. Field prospections were conducted from 2009 to 2012. The birds’ inventory method used was based on listening point techniques of 15 minutes. Data analysis were analyzed through the computation of bird species abundances, the establishment of maps distribution of the species, the habitat description and the modeling of the climatic niche of these species under climatic models CCCMA (Canadian Centre for Climate Modeling and Analysis) and CSIRO (Commonwealth Scientific and Industrial Research Organization) using MAXENT3.3.2. The ethno-zoological knowledge of the birds species were assessed through individual and groups survey and allowed to calculate the use values of the different part of the birds’ species according to the socio-cultural groups, sex and age. Moreover a logistic binary regression was carried out to determine the socio-economic factors which affect bird species exploitation by the grassroots communities. Results of modeling showed that among the variables selected for the prediction of the climatic models, distance from river, altitude appeared as the environmental variable which more contributed to the prediction of the models (with an average of 74.32 % and 12.94%). Projection under CCCMA and CSIRO in 2050, showed a progression of the favorable areas to Dendrocygna viduata, Porphyrio alleni, Porphyrio alleni, Egretta ardesiaca while it showed a regression of the favorable areas to Egretta alba. The estimated uses values showed that the ethno-zoological knowledge on the bird species differed according to the ethnic groups. Birds are used for food, medicinal and magico-mystics purposes. The magico-mystics and food were the most frequent used categories. Homogeneity of knowledge was found among the informants regarding the ethnic group as well as for the sex with respectively 0.66 and 0.7 for the use diversity value (ID) and use equitability value (IE). No significant difference was found between the informant for the use diversity value (ID) and use equitability value (IE). This study helps to build a database on 6 birds’ species and can be used for bird game ranching and game farming in Benin. [less ▲]

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