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 References of "Doctoral thesis"      in Complete repository Arts & humanities   Archaeology   Art & art history   Classical & oriental studies   History   Languages & linguistics   Literature   Performing arts   Philosophy & ethics   Religion & theology   Multidisciplinary, general & others Business & economic sciences   Accounting & auditing   Production, distribution & supply chain management   Finance   General management & organizational theory   Human resources management   Management information systems   Marketing   Strategy & innovation   Quantitative methods in economics & management   General economics & history of economic thought   International economics   Macroeconomics & monetary economics   Microeconomics   Economic systems & public economics   Social economics   Special economic topics (health, labor, transportation…)   Multidisciplinary, general & others Engineering, computing & technology   Aerospace & aeronautics engineering   Architecture   Chemical engineering   Civil engineering   Computer science   Electrical & electronics engineering   Energy   Geological, petroleum & mining engineering   Materials science & engineering   Mechanical engineering   Multidisciplinary, general & others Human health sciences   Alternative medicine   Anesthesia & intensive care   Cardiovascular & respiratory systems   Dentistry & oral medicine   Dermatology   Endocrinology, metabolism & nutrition   Forensic medicine   Gastroenterology & hepatology   General & internal medicine   Geriatrics   Hematology   Immunology & infectious disease   Laboratory medicine & medical technology   Neurology   Oncology   Ophthalmology   Orthopedics, rehabilitation & sports medicine   Otolaryngology   Pediatrics   Pharmacy, pharmacology & toxicology   Psychiatry   Public health, health care sciences & services   Radiology, nuclear medicine & imaging   Reproductive medicine (gynecology, andrology, obstetrics)   Rheumatology   Surgery   Urology & nephrology   Multidisciplinary, general & others Law, criminology & political science   Civil law   Criminal law & procedure   Criminology   Economic & commercial law   European & international law   Judicial law   Metalaw, Roman law, history of law & comparative law   Political science, public administration & international relations   Public law   Social law   Tax law   Multidisciplinary, general & others Life sciences   Agriculture & agronomy   Anatomy (cytology, histology, embryology...) & physiology   Animal production & animal husbandry   Aquatic sciences & oceanology   Biochemistry, biophysics & molecular biology   Biotechnology   Entomology & pest control   Environmental sciences & ecology   Food science   Genetics & genetic processes   Microbiology   Phytobiology (plant sciences, forestry, mycology...)   Veterinary medicine & animal health   Zoology   Multidisciplinary, general & others Physical, chemical, mathematical & earth Sciences   Chemistry   Earth sciences & physical geography   Mathematics   Physics   Space science, astronomy & astrophysics   Multidisciplinary, general & others Social & behavioral sciences, psychology   Animal psychology, ethology & psychobiology   Anthropology   Communication & mass media   Education & instruction   Human geography & demography   Library & information sciences   Neurosciences & behavior   Regional & inter-regional studies   Social work & social policy   Sociology & social sciences   Social, industrial & organizational psychology   Theoretical & cognitive psychology   Treatment & clinical psychology   Multidisciplinary, general & others     Showing results 501 to 600 of 1406     1 2 3 4 5 6 7 8 9 10 11     Direct imaging, photometry and spectroscopy of gravitationally lensed quasarsRicci, Davide Doctoral thesis (2012)Detailed reference viewed: 21 (3 ULg) Biosynthèse des dérivés triphosphorylés de la thiamine chez E. coliGigliobianco, Tiziana Doctoral thesis (2012)Detailed reference viewed: 25 (12 ULg) L'évaluation des compétences : de la méthodologie de la réflexivité garante de la transférabilité aux perspectives ouvertes par la didactique professionnelleChenu, Florent Doctoral thesis (2012)Detailed reference viewed: 97 (14 ULg) Évaluation de l’impact de l’extrapolation de bioréacteur sur la physiologie de Yarrowia lipolytica pour la production de lipaseKar, Tambi Doctoral thesis (2012)Les travaux entrepris au cours de cette thèse visent à mettre en place une méthodologie globale d’extrapolation de bioréacteurs. Le procédé de production de lipase par Yarrowia lipolytica a été plus ... [more ▼]Les travaux entrepris au cours de cette thèse visent à mettre en place une méthodologie globale d’extrapolation de bioréacteurs. Le procédé de production de lipase par Yarrowia lipolytica a été plus particulièrement investigué, compte tenu de la complexité du système biologique et des paramètres physico-chimiques mis en œuvre. En effet, ce procédé met en œuvre une levure dite non conventionnelle dans un réacteur multiphasique G-L-L comprenant un substrat hydrophobe (le méthyloléate étant utilisé comme source de carbone renouvelable). Du fait du caractère strictement aérobie de ce type de levure, le transfert d’oxygène est un paramètre critique pour ce procédé. Dans un premier temps, l’ensemble des paramètres physico-chimiques clés du procédé ont été investigués (c’est-à-dire la dispersion du méthyloléate, les fluctuations en oxygène dissous et en pH). Cette évaluation a été menée en se basant sur des paramètres physico-chimiques (mélange du réacteur, transfert d’oxygène,…), mais également sur base de paramètres biologiques (synthèse et excrétion de la lipase, activation du gène lip2,…). Cette première étude a démontré que le paramètre critique était la fluctuation de l’oxygène dissous, ce paramètre menant à une réduction du rendement spécifique en lipase, liée à une atténuation de l’activité du gène lip2 codant pour la lipase extracellulaire de Y. lipolytica. Ce paramètre est d’autant plus important que les amplitudes des fluctuations en oxygène dissous sont amplifiées lors du processus de montée en échelle pour l’extrapolation du procédé. L’efficacité de dispersion du substrat hydrophobe (méthyloléate) au sein du milieu aqueux ne semble pas avoir d’impact sur l’efficacité du procédé, la levure sécrétant un biosurfactant permettant de stabiliser la dispersion. Les fluctuations en pH ont également peu d’impact sur le rendement de production de lipase, mais des observations au microscope ont révélé un début de dimorphisme cellulaire. Cette observation démontre la complexité de la réponse du système biologique face aux conditions de procédé. L’impact des fluctuations en oxygène dissous sur l’activité du gène lip2 a été confirmé par des analyses plus poussées en PCR quantitative (RT-qPCR). La deuxième partie du travail a donc été focalisée sur l’optimisation du transfert d’oxygène. Cette optimisation n’est pas triviale si on considère le phénomène de formation de mousse important lorsque la dispersion G-L au sein du réacteur est trop fine. Deux stratégies antimousse ont donc été envisagées : l’une mettant en œuvre l’ajout d’antimousse chimique et l’autre l’emploi d’un briseur de mousse mécanique. Cette dernière méthode s’est révélée inefficace du fait de la formation d’une couche de mousse persistante entre la surface du liquide et la turbine du briseur de mousse. Des analyses en cytométrie en flux ont permis d’observer un phénomène de dimorphisme qui semble lié au passage des cellules microbiennes au travers de cette couche de mousse, ce qui diminue le rendement en lipase. L’ajout d’antimousse chimique a donc été retenu et le transfert d’oxygène a pu être optimisé en fonction de contraintes de formation de mousse en considérant un enrichissement progressif de l’air d’entrée en oxygène pur. La dernière partie du travail a consisté à estimer l’extrapolation du procédé en prenant en compte à la fois les contraintes physico-chimiques du système (optimisation du transfert d’oxygène et limitation de la formation de mousse), ainsi que les contraintes biologiques. Cette extrapolation a tout d’abord été estimée au niveau de réacteurs scale-down permettant de reproduire les défauts d’écoulement généralement rencontrés au niveau industriel. De manière surprenante, cette étude a démontré que suite à l’adaptation physiologique des micro-organismes aux conditions d’écoulement, les problèmes de formation de mousse étaient de moins en moins marqués au cours de la montée en échelle du procédé. Cette observation va à l’encontre des calculs du génie chimique qui prédisent une augmentation du volume de mousse généré suite à la montée en volume des bioréacteurs et a été validée au niveau d’un bioréacteur pilote de 500L. Cela nous mène à conclure que la présence d’hétérogénéités au sein du volume réactionnel ne doit pas forcément être considérée comme un facteur négatif et pourrait au contraire être exploitée afin d’améliorer les performances des procédés et le design des bioréacteurs. [less ▲]Detailed reference viewed: 101 (26 ULg) Contribution à l’optimalisation du support nutritionnel et de la croissance des prématurés de très faible poids à la naissanceSENTERRE, Thibault Doctoral thesis (2012)Detailed reference viewed: 29 (3 ULg) Structuration de la diversité génétique du genre Milicia: taxonomie, phylogéographie, dynamique des populationsDaïnou, Kasso Doctoral thesis (2012)Characterizing population genetic structure using phylogeographic approach contributes to understanding of evolutionary processes that affect plant populations. The present study investigated how past ... [more ▼]Characterizing population genetic structure using phylogeographic approach contributes to understanding of evolutionary processes that affect plant populations. The present study investigated how past environmental variations can shape the spatial genetic diversity of an African timber tree species, Milicia excelsa (Welw) C.C. Berg. Given that plant responses to disturbances are closely linked to life history traits, this research also aimed to describe relationships between the reproductive traits of M. excelsa and its population genetic structure. Phylogeographic analyses were performed throughout the range of M. excelsa using nuclear and chloroplastic markers. Ecological characterization was conducted for a single population located in south-East Cameroon. Since M. excelsa is similar to the other species of its genus, M. regia (A. Chev) C.C. Berg, we first performed a morphogenetic comparison of these two taxa. The results confirmed an important morphological similarity between the two species with very rare discriminating criteria. In fact Bayesian assignment methods and reproductive isolation patterns suggest the occurrence of interspecific hybridization, which appeared to be unidirectional: hybrids displayed the M. regia morphotype. Because M. regia is known to be more adapted to humid tropical forests, one may expect it to occur in the Congo basin zone. However, its range is restricted to the western part of West Africa while M. excelsa occurs from Guinea-Conakry to Zimbabwe. Interestingly, in the case of M. excelsa, Central and West African specimens had no shared haplotype. This result was unexpected because long gene dispersal distances were found in Cameroonian populations, as expected from the behaviours of the main dispersal animals we identified, the bat Eidolon helvum and the parrots Psittacus erithacus and Agapornis swindernianus. In general, despite the likelihood for long distance seed dispersal, distinct genetic clusters were identified over West and Central Africa and their location may support the forest refugia hypothesis. In addition a phylogeographical signal was detected in chloroplast DNA indicating a prolonged separation between West and Central Africa populations with an accumulation of new mutations. At a smaller spatial scale, patterns of genetic structure also seemed to be weakly influenced by divergent reproduction times among sympatric individuals. The level of genetic diversity in the study populations falls within the range of values calculated for other tropical tree species. If phylogeography helps to infer population history, it also requires ecological or biological information to confirm some uncertainties. Such detailed data were often lacking to completely interpret numerous of our results. The present study raised new questions and led to new perspectives for further investigation both in phylogeography and botany. [less ▲]Detailed reference viewed: 150 (36 ULg) Isolation and identification of antioxidant phytochemicals from Cuban species of the genera Erythroxylum P. Browne and Pluchea CassPerera Cordova, Wilmer Doctoral thesis (2012)Phytochemicals showing antioxidant properties are largely recognized as beneficial to human health and disease prevention. Cuba is well known for having a rich flora with a high percentage of endemic ... [more ▼]Phytochemicals showing antioxidant properties are largely recognized as beneficial to human health and disease prevention. Cuba is well known for having a rich flora with a high percentage of endemic species; it is considered as an interesting source of plant species for searching bioactive metabolites. Polar and non-polar extracts were prepared by fractionation from macerations in ethanol: H2O (7:3 v/v) from several Cuban plant species. The antioxidant capacity and the concentration in phenolic compounds were assayed in these extracts. The native species Pluchea carolinensis (Jacq.) G. Don., Pluchea odorata (L.) Cass. and Pluchea rosea Godfrey were identified as the most promising sources of antioxidants. The n-butanol extracts obtained by reflux from endemic Erythroxylum alaternifolium A. Rich. var. alaternifolium, var. parvifolium and suborbiculare also displayed high antioxidant capacity and high levels in phenolic compounds. The antioxidant capacity and the phenolic content of hydroalcoholic macerations from leaves, inflorescences, stems and roots of species of the genus Pluchea were also compared. Leaf extracts followed by inflorescence extracts showed the highest values of antioxidant capacity. The species P. carolinensis was used as a model to evaluate the antioxidant capacity in two locations and two phenological stages and also for monitoring the antioxidant capacity over some months. Natural adult specimens presented a higher phenolic content, as well as higher antioxidant capacity than young and cultivated specimens. Maximal antioxidant capacity and concentrations in phenolics were recorded in January, September and December; over the blooming stage (March), the antioxidant capacity was minimal. Two different solvents of extraction and two methods were also screened for extracting the maximal concentrations in antioxidants. Hydroalcoholic extractions showed higher antioxidant capacity than ethanolic ones. However, no difference in antioxidant capacity were measured between the two methods of extraction. The antioxidant capacity of P. carolinensis was also measured in leaves of plantlets micro-propagated on three different in vitro culture media and it was compared with leaves of young specimens grown ex-vitro. The inclusion of a cytokinin in culture media increased the antioxidant capacity of the leaf extracts of plantlets grown in vitro. However, the antioxidant capacity of plantlets grown in vitro was lower than that of young specimens grown ex-vitro. Additionally, several phenolic compounds were isolated from the species studied. Two flavonol glycosides were isolated from n-butanol leaf extract of Erythroxylum alaternifolium var. alaternifolium. Moreover, 22 phenolic compounds (including 9 phenolic acids and 13 flavonoids) were also identified from leaf, inflorescence and stem extracts of the three Pluchea species. All of them are reported for the first time in Cuban Pluchea species. In addition, rosmarinic acid, ferulic acid, quercetagetin, herbacetin, quercitrin, eupalitin and 3-methyl-quercetagetin were described for the first time in the genus Pluchea. The antioxidant capacity of each of these compounds was evaluated. The results suggested that most of these phytochemicals have an important contribution to the antioxidant capacity found in plant extracts. [less ▲]Detailed reference viewed: 163 (10 ULg) Etude de l'autofloculation dans un Chenal Algal à Haut Rendement (CAHR)Baya, Dehenould Guy Doctoral thesis (2012)Dans la technique du Chenal Algal à Haut Rendement (CAHR), l’effluent récupéré est très riche en microalgues. Les caractéristiques particulières de ce système (faible profondeur, faible temps de séjour ... [more ▼]Dans la technique du Chenal Algal à Haut Rendement (CAHR), l’effluent récupéré est très riche en microalgues. Les caractéristiques particulières de ce système (faible profondeur, faible temps de séjour, agitation mécanique) combinées avec la présence d’ions inorganiques dans l’effluent sont les principaux éléments qui favorisent le développement intensif d’algues. Le rejet d’un tel effluent sans récupération préalable des microalgues est nuisible aux ressources biologiques terrestres et aquatiques et, plus généralement à l’ensemble des écosystèmes naturels. Par ailleurs, les microalgues peuvent être valorisées à des fins alimentaires ou d’extraction de sous-produits à valeur ajoutée. De plus, la récupération de la biomasse algale permettrait la réutilisation possible de la fraction liquide en irrigation notamment. Dans ce contexte, la récolte de la biomasse algale issue du CAHR constitue un enjeu majeur. Cependant, la petite taille des microalgues, la faible densité et les concentrations limitées rencontrées dans le CAHR comparées à celles de bioréacteurs industriels soulèvent un problème de rentabilité économique pour leur récupération en raison des énormes volumes d’eau à traiter. Les techniques usuelles de récupération de ces biomasses (en particulier par centrifugation) ont des coûts prohibitifs vis-à-vis de la valeur des produits récupérés. Dans ce cadre l’autofloculation qui est définie comme la formation et le rassemblement spontané de microalgues se présente comme une alternative aux problèmes rencontrés par les techniques conventionnelles de récupération des algues. C’est dans cette dynamique de recherche de s’inscrit cette thèse dont l’objectif est de déterminer les mécanismes impliqués dans l’autofloculation ainsi que les conditions optimales nécessaires à la réalisation de ce phénomène. Ce document est divisé en six grands chapitres : Les deux premiers chapitres sont consacrés à une revue des connaissances sur CAHR et la biomasse algale se développant dans ce système d’épuration. Également, un état de l’art concernant les méthodes de récolte de la biomasse algale notamment l’autofloculation est réalisé. Les simulations réalisées dans le chapitre III grâce à notre modèle thermodynamique de calcul de l’indice de saturation (IS) de différents composés mettent en évidence que les phosphates de calcium et formes substituées (Octacalcium phosphate, Ca4H(PO4)3; phosphate de calcium amorphe, Ca3(PO4)2; Hydroxyapatite, Ca5(PO4)3(OH); fluoroapatite, Ca5(PO4)3F et chloroapatite, Ca5(PO4)3Cl) sont les principaux composés inorganiques susceptibles d’être impliqués dans l’autofloculation. Le chapitre IV est consacré à la caractérisation des charges de surface, du potentiel zêta et des points isoélectriques de quelques phosphates de calcium et de la biomasse algale qui se développe dans le CAHR. Ces trois caractéristiques ont été déterminées respectivement par titrage colloïdal, par la méthode électrophorétique et par la méthode de Park et Regalbuto (1995) (détermination du pH d’équilibre à charge élevée). Cette étude a permis de conclure que la neutralisation des charges de surface des algues par les phosphates de calcium est probablement un moteur de l’autofloculation. Dans le chapitre V, des essais d’autofloculation simulée sur une biomasse provenant du CAHR et d’un milieu de culture ont été réalisés. Cette étude a essentiellement porté sur la détermination des concentrations optimales en ions calciums et orthophosphates, mais également sur la détermination des rapports de masse et de charge optimum entre les phosphates de calcium et algues pour une floculation maximale de la biomasse. Les résultats obtenus démontrent que les rendements d’autofloculation simulée sont très sensibles aux variations des concentrations en Ca2+ et PO43- et qu’il est indispensable de déterminer les concentrations optimales en ions calciums et orthophosphates pour obtenir les rendements maximums. En outre, les résultats permettent également de conclure que la neutralisation des charges des algues par les phosphates de calcium (purs ou substitués) se fait avec une stœchiométrie 1:1. Les doses de floculant nécessaires sont donc liées à la charge et peuvent être déterminées a priori sur cette base. Enfin, le chapitre VI porte sur le suivi expérimental de l’évolution de la biomasse algale dans une installation pilote et une installation réelle de traitement d’effluents par culture de microalgues installées au campus d’Arlon (eaux usées synthétiques) et Marrakech (eaux usées domestiques prétraitées). Les paramètres physiques, chimiques et biologiques ont été investigués, suivant les variations des conditions du milieu. Les résultats obtenus démontrent que l’installation de l’autofloculation entraine une déstabilisation du CAHR et une réduction de l’activité photosynthétique des algues. Ainsi, nous avons à notre disposition pour une eau de composition donnée, les outils pour prévoir la quantité d’algues qui pourra être récupérée sans ajouts de réactifs, encore faut il pouvoir gérer le réacteur pour atteindre ces conditions dans un délai court. [less ▲]Detailed reference viewed: 106 (16 ULg) Etude des mécanismes cellulaires et moléculaires à l'origine du phénomène des DOMS (Delayed-Onset Muscle Soreness) consécutif à l'exercice excentrique.Hody, Stéphanie Doctoral thesis (2012)Tous, nous avons déjà ressenti diverses sensations de courbatures après avoir réalisé un exercice musculaire intense et/ou inhabituel. Ces douleurs musculaires d’apparition retardée et d’intensité ... [more ▼]Tous, nous avons déjà ressenti diverses sensations de courbatures après avoir réalisé un exercice musculaire intense et/ou inhabituel. Ces douleurs musculaires d’apparition retardée et d’intensité variable sont désignées scientifiquement par l’acronyme « DOMS » pour « Delayed-Onset Muscle Soreness ». Le rôle particulier du mode de contraction excentrique dans la survenue des DOMS est largement accepté. Rappelons que l’exercice excentrique est caractérisé par l’association paradoxale des phénomènes opposés d’allongement musculo-tendineux et de développement tensionnel. Dès lors, les contraintes mécaniques accompagnant les contractions excentriques peuvent entraîner diverses altérations de l’ultrastructure musculaire qui se manifestent par une série de symptômes cliniques rendant les DOMS invalidants sur le plan fonctionnel. Or, le caractère discriminant de l’évaluation excentrique et l’efficacité rééducative de l’exercice excentrique dans plusieurs types de pathologies de l’appareil locomoteur ont formellement été démontrées. Dans ces conditions et bien qu’elles disparaissent spontanément après quelques jours de récupération, les DOMS retardent fréquemment la mise en route de programmes de réadaptation ou d’entraînement sportif. Actuellement, à l’analyse de la littérature, on ne peut que constater l’absence de solution thérapeutique susceptible d’atténuer significativement l’intensité des DOMS et de leurs conséquences fonctionnelles associées. Paradoxalement, l’exercice excentrique lui-même, lorsqu’il est proposé en conditions sous-maximales progressivement intensifiées, semble constituer la seule prévention réellement efficace, capable de prévenir l’apparition des DOMS. Malgré la littérature abondante consacrée à la description du phénomène des DOMS, aucune théorie unifiée n’est actuellement disponible pour expliquer la survenue différée des sensations douloureuses et les signes associés. L’efficacité d’un entraînement spécifique dans la prévention des DOMS a été confirmée par de nombreux travaux mais la nature de cet effet protecteur reste sujette à conjectures. Ce travail vise à une meilleure connaissance des mécanismes cellulaires et moléculaires impliqués dans le phénomène des DOMS survenant après la réalisation d’un exercice excentrique. Au cours de ce travail, nous avons donc tenté de contribuer à répondre aux questions suivantes : (1) Quels sont les corrélats biochimiques correspondants à l’apparition des DOMS suite à l’exécution d’exercices excentriques ? (2) Quels sont les mécanismes responsables de la variabilité interindividuelle des réponses à l’exercice excentrique ? (3) Quelles sont les adaptations induites par l’entraînement excentrique permettant de prévenir l’apparition des DOMS ? L’originalité de notre travail réside dans la mise au point d’un protocole expérimental chez l’humain associant la provocation de DOMS au moyen d’un dynamomètre isocinétique, le prélèvement de tissus musculaires humains par biopsie à l’aiguille et l’analyse protéomique comparative de ceux-ci par la méthode du 2D-DIGE. Nos travaux suggèrent qu’une plus grande sensibilité aux microlésions induites par l’exercice excentrique s’expliquerait par une prédominance de fibres rapides de type glycolytique et qu’un entraînement excentrique visant à prévenir les DOMS induirait une transition des fibres rapides de type glycolytique vers des fibres plus oxydatives. Le modèle humain, utilisé dans ce travail, nous a également permis de définir des indices de fatigue permettant de prédire l’ampleur de la réponse de la CK et de suggérer l’existence d’un effet protecteur controlatéral. Toutefois, les limites de l’expérimentation humaine ne nous permettent pas d’envisager une « manipulation » du système expérimental. Si on veut dépasser le stade expérimental d’observation encore possible chez l’humain et aborder le stade de stimulation et/ou d’invalidation par exemple, le recours à un modèle animal s’impose de lui-même. [less ▲]Detailed reference viewed: 56 (21 ULg) Total Electron Content reconstruction using triple frequency GNSS signalsSpits, Justine Doctoral thesis (2012)Nowadays, Global Navigation Satellite System (GNSS) provide accurate three dimensional positioning and navigation anywhere and anytime on the Earth’s surface and are being utilized in numerous civilian ... [more ▼]Nowadays, Global Navigation Satellite System (GNSS) provide accurate three dimensional positioning and navigation anywhere and anytime on the Earth’s surface and are being utilized in numerous civilian and military applications. The US Global Positioning System (GPS) is currently being modernized to transmit radio signals on an additional third frequency, while the European Galileo is a newly developed system which will transmit on three civil frequency bands. One of the major error sources affecting GNSS is the delay caused when the signals pass through the ionosphere on their way to the Earth’s surface. This delay is inversely proportional to the square of the carrier frequency, and directly proportional to the Total Electron Content (TEC) of the ionosphere. In the last 20 years, several techniques using dual frequency GNSS measurements have been developed to estimate the TEC. With these techniques, systematic errors are confined to at least - 2.5 and 2.5 TECU for a mid-latitude site, and to at least - 5.5 and 5 TECU for a low-latitude location. In the last decades, knowledge about the ionosphere has grown considerably thanks to the use of GNSS measurements, and in turn the GNSS have highly benefited from this improved knowledge. Nowadays the availability of triple frequency GNSS signals enables the development of new processing techniques. We have therefore dedicated this work to developing a TEC reconstruction methodology based on triple frequency GNSS measurements and aimed at improving the accuracy of the final TEC values with regards to existing techniques. The structure of this study is as follows. Firstly, we provide information about GNSS, focusing on concepts, definitions and assumptions which will be used throughout this study. Then, we introduce the concepts of ionospheric propagation of radio signals and give a review of the literature on existing techniques used to extract the TEC with dual frequency GNSS measurements. We further present the complete design of the triple frequency TEC reconstruction methodology. We start by giving the set of combinations which allows us to resolve the original integer ambiguities, then we address the principles of TEC reconstruction, and finally we give an accuracy assessment of the computed TEC values. We also present an innovative technique to calibrate the satellite and receiver code hardware delays. We continue with testing the features developed on a simulated GPS and Galileo observation dataset, as well as on a real GIOVE observation dataset. Finally, we conclude this work by providing a critical overview of our investigations and suggesting various improvements of the current limitations. [less ▲]Detailed reference viewed: 141 (8 ULg) Chemical ecology in earthyworms: food foraging strategy and intra-specific interactions in Eisenia fetida (Savigny, 1826) and potential applications in vermicompostingZirbes, Lara Doctoral thesis (2012)Detailed reference viewed: 108 (29 ULg) Identification of Pythium species inducing common bean (Phaseolus vulgaris L.) root rot symptoms and development of backcrosses to improve the level of varietal resistance to this diseaseNzungize Rusagara, John Doctoral thesis (2012)The common bean (Phaseolus vulgaris L.) is the most important food legume grown worldwide. It is a prioritary crop in various countries of East Africa and is grown mainly by small farmers for home ... [more ▼]The common bean (Phaseolus vulgaris L.) is the most important food legume grown worldwide. It is a prioritary crop in various countries of East Africa and is grown mainly by small farmers for home consumption, the excess being sold in markets. Important yield losses of common bean induced by root rot diseases have been identified in several countries in East Africa including Rwanda. This is partly explained by the intensification of the cultivation of beans, the absence of rotations, the practice of continuous cultivation of this legume, and decline in soil fertility. Although bean root rot symptoms are caused by a number of soil borne pathogens depending on environmental conditions, Pythium spp. are the fungal pathogens most frequently associated with severe epidemics in eastern Africa. Studies on root rot have indicated that continuous cropping of beans, a common practice in eastern Africa, exacerbates the problem. This work was undertaken to improve the varietal resistance of common bean to limit the damages caused by Pythium in Rwanda. An analysis of the diversity of Pythium species associated with root rot was conducted through collect of samples of common bean plants throughout the country and through the characterization of the Pythium species causing root rot. The collected samples were used to isolate 96 typical Pythium colonies which were classified into 16 Pythium species according to their respective molecular sequences of the ribosomal ITS fragments. Molecular characterization using the ITS-DNA sequences was also carried out on samples isolated on infected beans roots. The study of the distribution of each species identified within the samples analyzed, revealed that Pythium vexans is the most widespread taxon in the different common bean producing areas in Rwanda. Pathogenicity tests of the 16 identified Pythium species were performed on a set of 10 common bean varieties. The results showed that all identified Pythium species were pathogenic to common bean: they all induce symptoms of root rot under controlled conditions. However, the common bean varieties used in this investigation showed differences in their reaction to inoculation with the 16 Pythium species. At the end of this work of the characterization of Pythium species isolated in Rwanda, a scheme for improving varietal resistance has been implemented. It is based on a backcross protocol assisted by molecular marker (PYAA 19800). Recurrent parents are composed of three common bean varieties traditionally grown in Rwanda while the two donor parents are a resistant variety of the Mesoamerican gene pool and a resistant variety of Andean pool. The progeny obtained after the backcrossing program was subjected to the pathogenicity trials by inoculating with a strain of Pythium ultimum in controlled conditions in order to verify the effectiveness of this improvement protocol. These trials have shown that in the offspring all the individuals showing the presence of the marker gene were also resistant to Pythium with very low levels of severity at the end of inoculation tests. [less ▲]Detailed reference viewed: 102 (7 ULg) Gouverner la maternité au Bénin. Les difficiles conditions d'application des politiques sanitaires dans le territoire de la PendjariSambiéni, N'Koué Emmanuel Doctoral thesis (2012)La Zone Sanitaire de Tanguiéta, partie intégrante du système de santé au Bénin, expérimente, depuis la décentralisation de ce système, la gestion autonome de l’offre de soins de santé moderne dans toutes ... [more ▼]La Zone Sanitaire de Tanguiéta, partie intégrante du système de santé au Bénin, expérimente, depuis la décentralisation de ce système, la gestion autonome de l’offre de soins de santé moderne dans toutes ses dimensions. Elle est particulièrement ingénieuse dans la production d’initiatives de soins au profit des mères engagées dans l’enfantement, avec le soutien de l’Etat et des partenaires du secteur de la santé. Cet engagement est justifié officiellement par la situation critique des indicateurs de Santé Maternelle traduisant une morbidité et une mortalité élevées. La ZST est tout d’abord un espace socioculturel d’une particularité remarquable, comparée au reste du pays, du fait même de sa position géographique, de son identité culturelle pendjarienne et de son histoire sociopolitique. C’est de son identité socioculturelle et sociopolitique qu’elle revendique son autonomie technico-administrative dans la fourniture des soins de santé. La curiosité intellectuelle de cette recherche socioanthropologique est de comprendre comment la demande et les soins aux femmes qui « veulent donner la vie » sont véritablement « structurés » et « gouvernés » dans cet espace socioculturel et médical. « Habitus maternel » et « gouvernementalité» sont utilisés à la fois comme concepts et comme postures méthodologiques et épistémologiques afin de décrypter et d’analyser « l’ordre » et « le progrès » dans ces logiques et pratiques obstétricales. Suivant une méthodologie essentiellement qualitative, la recherche a duré quatre ans, avec une longue présence sur le terrain, consistant en des observations dans les maternités et dans les familles ainsi que des entretiens avec les différents acteurs participant aux soins. Cette recherche nous apprend que dans l’ordre traditionnel, l’enfantement a été historiquement et socialement géré par des institutions laissant une place assez faible à l’expression de l’individu, qu’il soit le père ou la mère de l’enfant en construction bio-sociale. A l’heure actuelle, les maternités modernes ont toujours du mal à prendre le pas sur ces institutions dans le contrôle des soins avant, pendant et après l’accouchement. Malheureusement, affaiblies par les différentes influences sociales, ces institutions apparaissent socialement et techniquement incapables de contenir et de régler le mal de la grossesse et de l’accouchement. La maternité, tant dans son état traditionnel que moderne, demeure encore morbide et mortelle. L’Etat et ses institutions d’encadrement et d’offre de soins maternels, peu connectés aux réalités socioculturelles, s’avèrent constamment dépendants des agences des Nations Unies et des autres partenaires privés, producteurs de stratégies le plus souvent d’ordre idéologique et militant. La Stratégie Nationale de Réduction de la Mortalité Maternelle et Néonatale et l’Initiative Femme pour Femme, respectivement élaborées au Ministère de la Santé et au niveau de la Zone Sanitaire, révèlent le rendez-vous manqué dans la rencontre programmée entre usagers des maternités et offre de soins dans la planification sanitaire. La maternité, avec ses multiples acteurs en négociation permanente sans consensus, est conflictuelle et souvent détournée de sa mission. Elle empile régulièrement des stratégies tout en chassant constamment ses premiers bénéficiaires et en mettant les enjeux sanitaires en arrière-plan. Pour une « Maternité Sans Risques » dans les espaces traditionnel et moderne, il faudra chercher et comprendre comment, dans la nébuleuse des institutions qui les gèrent dans ces deux registres, les femmes peuvent renforcer leurs positions légitimes dans la négociation pour l’orientation des soins obstétricaux essentiels et d’urgence. Il conviendra enfin d’étudier les conditions pour une lecture effective du risque obstétrical dans l’environnement social des femmes. [less ▲]Detailed reference viewed: 56 (1 ULg) Machine learning-based feature ranking: Statistical interpretation and gene network inferenceHuynh-Thu, Vân Anh Doctoral thesis (2012)Machine learning techniques, and in particular supervised learning methods, are nowadays widely used in bioinformatics. Two prominent applications that we target specifically in this thesis are biomarker ... [more ▼]Machine learning techniques, and in particular supervised learning methods, are nowadays widely used in bioinformatics. Two prominent applications that we target specifically in this thesis are biomarker discovery and regulatory network inference. These two problems are commonly addressed through the use of feature ranking methods that order the input features of a supervised learning problem from the most to the less relevant for predicting the output. This thesis presents, on the one hand, methodological contributions around machine learning-based feature ranking techniques and on the other hand, more applicative contributions on gene regulatory network inference. Our methodological contributions focus on the problem of selecting truly relevant features from machine learning-based feature rankings. Unlike the p-values returned by univariate tests, relevance scores derived from machine learning techniques to rank the features are usually not statistically interpretable. This lack of interpretability makes the identification of the truly relevant features among the top-ranked ones a very difficult task and hence prevents the wide adoption of these methods by practitioners. Our first contribution in this field concerns a procedure, based on permutation tests, that estimates for each subset of top-ranked features the probability for that subset to contain at least one irrelevant feature (called CER for "conditional error rate"). As a second contribution, we performed a large-scale evaluation of several, existing or novel, procedures, including our CER method, that all replace the original relevance scores with measures that can be interpreted in a statistical way. These procedures, which were assessed on several artificial and real datasets, differ greatly in terms of computing times and the tradeoff they achieve in terms of false positives and false negatives. Our experiments also clearly highlight that using model performance as a criterion for feature selection is often counter-productive. The problem of gene regulatory network inference can be formulated as several feature selection problems, each one aiming at discovering the regulators of one target gene. Within this family of methods, we developed the GENIE3 algorithm that exploits feature rankings derived from tree-based ensemble methods to infer gene networks from steady-state gene expression data. In a second step, we derived two extensions of GENIE3 that aim to infer regulatory networks from other types of data. The first extension exploits expression data provided by time course experiments, while the second extension is related to genetical genomics datasets, which contain expression data together with information about genetic markers. GENIE3 was best performer in the DREAM4 In Silico Multifactorial challenge in 2009 and in the DREAM5 Network Inference challenge in 2010, and its extensions perform very well compared to other methods on several artificial datasets. [less ▲]Detailed reference viewed: 418 (39 ULg) Dynamique associative et réduction de la pauvreté rurale: une étude comparative de villages inégalement couverts par des Organisations Non Gouvernementales dans la province du Bandundu et dans l’hinterland de Kinshasa.Nganda Afumba, Jean Pierre Doctoral thesis (2012)Comme bon nombre de pays en développement, la République Démocratique du Congo observe, depuis le début des années 90, un développement sans précédent du mouvement associatif, particulièrement des ... [more ▼]Comme bon nombre de pays en développement, la République Démocratique du Congo observe, depuis le début des années 90, un développement sans précédent du mouvement associatif, particulièrement des organisations non gouvernementales de développement. Dans un environnement où les pouvoirs publics sont quasi inexistants, ces dernières sont considérées par certains comme des instruments efficaces de réduction de la pauvreté, et par d’autres comme des opportunistes évoluant aux dépens de la misère des gens. La présente recherche se propose de faire une étude comparative entre, d’une part, des ménages de deux villages de l’hinterland de Kinshasa largement couverts par des ONG, et d’autre part, des ménages de deux autres villages dans le Bandundu ne bénéficiant d’aucune intervention d’ONG. Cette étude a pour but la compréhension, l’analyse et l’appréciation empirique de la pertinence de la stratégie de développement et de réduction de la pauvreté rurale orientée vers la promotion des organisations associatives du type ONG, et in fine suggère un outil susceptible d’améliorer les interventions visant la réduction de la pauvreté rurale. [less ▲]Detailed reference viewed: 126 (22 ULg) Numerical schemes for tracer studies in shallow shelf seasMercier, Christophe Doctoral thesis (2012)Nowadays, tracers have revealed to be an invaluable integrated tool to investigate the different thematics related to coastal areas, shallow shelf seas or estuaries. In this work, they are used in ... [more ▼]Nowadays, tracers have revealed to be an invaluable integrated tool to investigate the different thematics related to coastal areas, shallow shelf seas or estuaries. In this work, they are used in combination with a parallel scalable Fortran90 implementation of a 3D hydrodynamic model to study the transport of mud within the Belgian Coastal Zone. The results obtained illustrate the need for tools to understand the interactions between such highly energetic coastal areas and the sediment dynamics. The Constituent Age and Residence time Theory (CART), originally applied to passive tracers, is therefore extended to describe the sediments and used to quantify their rates of resuspension and horizontal transport. This application reveals some numerical issues that may degrade the reliability of the results. The different numerical parameterizations are thus revisited starting with the use of advection schemes, and especially, the Total Variation Diminishing (TVD) schemes built along the line defined by Harten. It is shown that the blind application of the usual TVD schemes and associated flux limiters can lead to non-TVD solutions when applied to complex geometries. Spatial and/or temporal variations of the bathymetry can indeed break the TVD property. Hopefully, really TVD schemes can be recovered by taking these variations into account in the formulation of the flux limiters. Even if its Eulerian formulation eases the implementation of CART into existing models, it is shown that CART's computation procedure lacks a numerical framework for a robust application. To address this, we enforce the consistency, defined as the requirement that the integration scheme does not introduce errors in the age field when aging is the only active process. Unfortunately, this does not guarantee the absence of overshootings. While it does not seem feasible to ensure a TVD behavior of the age field, appropriate modifications of the flux/slope limiters are derived here to prevent the occurrence of age values outside the physically acceptable range. On the bases of the solutions obtained after the advection of any numbers of tracers using high-order non-linear schemes, several control or global variables can be built. Even if the independent advection schemes used are specifically built to produce profiles free from the numerical artifacts that can spoil the physical meaning of the results, such global/control variables can exhibit these unwanted behaviors. This problematic is firstly treated with regard to the TVD schemes built from Harten's theorem. But guaranteeing the TVD property is not always feasible. Alternatively, appropriate modifications of the flux/slope limiters are implemented here to enforce a maximum principle for any global/control variable built as first-order homographic function of its components. [less ▲]Detailed reference viewed: 53 (17 ULg) Développement d'un dispositif d'analyses par faisceaux d'ions de haute énergie et application en archéométrieDupuis, Thomas Doctoral thesis (2012)Detailed reference viewed: 60 (6 ULg) Essays on the complex relationships between Innovation and Performance in service firms, with particular reference to financial services: An intellectual capital perspectiveMention, Anne-Laure Doctoral thesis (2012)Service sector firms have long been neglected in innovation studies despite their increasing importance for economy. However, recent research has revealed that service firms do innovate although they ... [more ▼]Service sector firms have long been neglected in innovation studies despite their increasing importance for economy. However, recent research has revealed that service firms do innovate although they follow distinct paths and reach different outcomes than those of the manufacturing sector. Measuring the effects of innovation on performance has thus become an essential concern for both policy‐makers and business leaders. This dissertation specifically contributes to the current debate on the effects of innovation on performance at firm‐level in the service sector by shedding more light on the characteristics of these complex relationships and by defining its underlying mechanisms. For these purposes, an intellectual capital perspective is adopted. This dissertation first takes a broad sector approach to services, focusing on potentially innovative core service activities, and relying on the concept of relational capital, it explores the most commonly reported feature of innovation in services, which is the openness of the innovation process. As prior research indicates that there is a diversity of innovation patterns in services, the dissertation then concentrates on financial service firms. Besides their own significance, financial firms play a critical role in the proper functioning of the entire economy. Focusing on this specific industry, the dissertation further delineates the innovation process into its constitutive elements, referring to human, structural and relational capital concepts. The setting for most of the empirical studies is Luxembourg, which allows benefitting from the peculiarities of this small, open, international but highly innovative economy dominated by service firms. This dissertation mainly concludes that adopting an open strategy for innovation activities brings differentiated results according to the partners involved, with some contrast observed between market, science and competitor co‐operation. When examining how resources mobilized in the innovation process interact to affect performance in financial services, the dominant role of relational capital emerges. Furthermore, the examination unveils the interaction effects between the constitutive elements of intellectual capital and confirms the importance of the orientation towards innovation, in its various facets, in financial firms. Overall, this dissertation shows that adopting an intellectual capital perspective to understand the innovation process, to reveal its main ingredients and to disentangle its effects on performance can be insightful. [less ▲]Detailed reference viewed: 36 (7 ULg) Diversity and endemism of Murinae rodents in Thai limestone karsts: a genetic approachLatinne, Alice Doctoral thesis (2012)Limestone karsts are characterized by an important species richness and high levels of endemic species of plants, vertebrates and invertebrates adapted to this extreme environment. However, in Southeast ... [more ▼]Limestone karsts are characterized by an important species richness and high levels of endemic species of plants, vertebrates and invertebrates adapted to this extreme environment. However, in Southeast Asia, karst ecosystems suffer from a considerable lack of scientific data and remain widely unknown despite their high biological importance. Combining field investigations with phylogeographic and phylogenetic analyses based on several kinds of molecular markers, this thesis aims at exploring the diversity and endemism of Murinae rodents in limestone karsts of Thailand. Thai limestone karsts host two endemic Murinae rodent species, Leopoldamys neilli and Niviventer hinpoon. This thesis reveals that L. neilli is more largely distributed in Thailand than indicated by previous records available in the literature. The species has been recorded in numerous limestone karsts of Thailand with the exception of its peninsular area. L. neilli has also been discovered in central Laos. Moreover our niche modeling study indicates that large tracts of suitable habitat for this species may also occur in several regions of Indochina. L. neilli populations are highly fragmented and a deep genealogical divergence among its lineages is observed. Both mitochondrial and nuclear markers support a large-scale population structure of four main groups (west, centre, north and northeast) and a strong finer structure within each of these groups. These results indicate that L. neilli populations are isolated on karsts such as on islands and that migrations among them are reduced. Our findings also suggest that the current phylogeographic pattern of this species results from the fragmentation of a widespread ancestral population and that vicariance has played a significant role in the evolutionary history of L. neilli. These deep vicariant events that occurred during Plio-Pleistocene are related to the formation of the Central Plain of Thailand. Moreover, the western populations of L. neilli are genetically and morphologically highly divergent from the other populations and could represent a separate species. This strong phylogeographic pattern is not observed for other Murinae species with lower levels of ecological specialization such as Leopoldamys edwardsi and Rattus tanezumi. Finally, this thesis provides preliminary information about the diet of L. neilli and indicates that plants of the Solanaceae family constitute an important part of its diet. The phylogeographic structure of N. hinpoon is not similar to the one of L. neilli. In contrast to L. neilli, N. hinpoon is confined to central Thailand and mitochondrial markers used in this study indicated that this species is genetically homogenous and characterized by a single mitochondrial lineage. Valuable data to refine the conservation status of L. neilli and N. hinpoon, two species currently listed as Data Deficient on the IUCN Red List have been gathered during this study. Three main threats to the long-term subsistence of L. neilli have been identified: (1) the high fragmentation of its population, (2) the large-scale destruction of limestone karsts in Southeast Asia, and (3) the intense trapping of this species for human consumption in northeastern Thailand. Therefore we propose to consider L. neilli as “Near threatened” on the IUCN Red List. However, if the western lineage of L. neilli represents a separate species, it should be listed as “Vulnerable”. Due to its small distribution range and the high threats that its habitat is facing in central Thailand, N. hinpoon would also be qualified as “Vulnerable” on the IUCN Red List. In addition to karst endemic species, this thesis reveals that Thai limestone karsts host high levels of Murinae rodent diversity. A sequence-based species delimitation method completed by the analysis of the level of genetic divergence was used to define species boundaries within our rodent samples collected in limestone karsts. A total of 12 described Murinae species, corresponding to 17 putative species based on our genetic criteria, were encountered in limestone karsts of Thailand. Most of these species are associated to forest ecosystems. Therefore this study suggests that limestone karsts could play a key role in the preservation of the rodent biodiversity by providing refuges for the forest-dwelling Murinae rodents in deforested regions. An important cryptic diversity has been detected within the traditionally recognized species Maxomys surifer and Berylmys bowersi. They could be considered as species complex and require further taxonomic work. The potential distribution of Leopoldamys edwardsi and Leopoldamys sabanus, two species also distributed in Thailand, has been investigated using niche modeling techniques. The predicted distribution ranges of these two species suggest a clear geographical separation between them, with the potential distribution of L. edwardsi being limited to the northern part of Indochina while L. sabanus is mainly distributed in the Sundaic region. Our findings also suggest that these two species could have survived in large areas of Southeast Asia during Quaternary ice ages without large scale extinction and that no drastic modification of the distribution of these species will occur in the future due to climate changes. In conclusion, using various genetic approaches, this work gains important insights into the Murinae rodent diversity of Thai limestone karsts and represents the first detailed study of karst endemic rodent species in Southeast Asia. [less ▲]Detailed reference viewed: 85 (11 ULg) Practicing local culture as a vehicle of integration? Creative collaborations and Brussels’ Zinneke Parade.Costanzo, Joseph Doctoral thesis (2012)Immigrant integration, and socio-economic cohesion more broadly, continue to be top priorities at many levels of governance in Europe and are long-standing fixtures of scholarly, political and public ... [more ▼]Immigrant integration, and socio-economic cohesion more broadly, continue to be top priorities at many levels of governance in Europe and are long-standing fixtures of scholarly, political and public debate across Europe and North America. Although integration and culture have been dominant themes in contemporary European and American social science and humanities literatures, their intersections—particularly involving immigrant participation in local arts and cultural activities—remain understudied. Through the use of mixed-methods research, my doctoral thesis addresses how participating in such creative activities serves as a vehicle for integration. This topic is examined within the context of the European capital city-region of Brussels, and provokes further inquiry into the role of place in integration and identity-making particularly within a context in which there is no universal or normative local identity. With the onsite support of local experts, artistic and cultural actors and the public at large, I examine the ‘creative collaboration’ of Zinneke Parade 2010—a biennial socio-cultural and urban project with origins in the Brussels 2000 European Capital of Culture Programme (ECoC). Though politicians and community organizers frequently cite Zinneke as an exemplary project of the Brussels-Capital Region, to date, no formal study has been conducted neither into its role in bridging many of the city’s socio-linguistic, spatial and economic divides nor into its role as a source for building local networks, social, cultural, economic or otherwise. Finally, this work is unique in its treatment of migrant and ethnic minority identity representations in an explicitly non-ethno-cultural event. In its biennial parade, Zinneke purposefully does not re-present separate ethno-cultural pasts, but instead reflects the identities of collective and creative efforts of today’s local Bruxellois. Fielded throughout 2010 and early 2011, in-depth interviews, combined with short as well as detailed questionnaires, form the basis of data which I have collected to answer the question: Does practicing local culture facilitate integration? [less ▲]Detailed reference viewed: 146 (4 ULg) Identification et caractérisation fonctionnelle de nouveaux single nucleotide polymorphisms dans le gène anti-myxovirus MxA humainTran Thi Duc, Tam Doctoral thesis (2012)Detailed reference viewed: 23 (5 ULg) Etude de l’implication du microARN miR-146a dansHalkein, Julie Doctoral thesis (2012)La cardiomyopathie du péripartum (PPCM) est une maladie mortelle qui touche certaines femmes entre le dernier mois de la grossesse et jusqu’à 5 mois après l’accouchement. Ces femmes présentent des ... [more ▼]La cardiomyopathie du péripartum (PPCM) est une maladie mortelle qui touche certaines femmes entre le dernier mois de la grossesse et jusqu’à 5 mois après l’accouchement. Ces femmes présentent des symptômes d’hypertension et un dysfonctionnemment du ventricule gauche. A la fois l’endothélium et les cardiomyocytes sont affectés dans le cœur des patientes atteintes de la PPCM et il a été récemment montré que le fragment de 16 kDa de la prolactine (PRL 16K) était un facteur majeur dans la pathophysiologie de la maladie. Dans notre laboratoire, nous travaillons depuis des années sur les mécanismes d’action de la PRL 16K. Nous nous intéressons également aux microARN (miARN), ces régulateurs de l’expression des gènes décrits pour être impliqués dans la plupart des processus physiologiques et pathologiques tels que l’angiogenèse ou les maladies cardiovasculaires. Ils sont également décrits depuis peu pour pouvoir être sécrétés par une cellule productrice et transférés à une cellule receveuse, via des microvésicules, afin d’y jouer un rôle. Au cours de ce travail, nous avons mis en évidence que la PRL 16K est capable d’induire l’expression de miR-146a au sein des cellules endothéliales via l’activation de NF-B et d’induire son transfert via des microvésicules appelées exosomes. Ces exosomes endothéliaux sont capable d’interagir avec les cardiomyocytes et le contenu en miR-146a y est transféré. Au sein des cellules endothéliales, miR-146a possède des propriétés anti-angiogènes. Il réprime la prolifération et favorise l’apoptose des cellules endothéliales. Parmi ses gènes cibles potentiels, nous validons NRAS via lequel miR-146a pourrait médier une partie de ses effets. Au sein des cardiomyocytes, nous avons mis en évidence un rôle de miR-146a dans la répression du métabolisme corrélé à une diminution de l’expression d’ErbB4. Nous avons ensuite montré le rôle central tenu par miR-146a dans un modèle murin de souris développant la PPCM. On retrouve dans le cœur de ces souris un niveau augmenté de miR-146a et un niveau diminué d’ErbB4 et de NRAS. De plus, l’inhibition de miR-146a dans ces souris PPCM, via l’injection d’oligonucléotides anti-sens, permet de restaurer le phénotype sain des souris PPCM. On observe une restauration de l’activité cardiaque ainsi qu’une normalisation des niveaux d’expression de miR-146a et de ses gènes cibles. Chez la femme présentant une PPCM, les niveaux cardiaques de miR-146a et d’ErbB4 sont également dérégulés. Ces résultats suggèrent que miR-146a tient un rôle central dans la pathophysiologie de la PPCM et permet d’expliquer la dualité d’action de la PRL 16K sur les cellules endothéliales et les cardiomyocytes. Enfin, les miARN extracellulaires présents dans le plasma constituent des biomarqueurs de choix pour le diagnostic d’un grand nombre de pathologies. Ainsi, nous avons mis en évidence un niveau d’expression plasmatique significativement plus élevé chez les patientes atteintes d’une PPCM comparé à celui de femmes saines ainsi que de patientes présentant également de l’insuffisance cardiaque dû à une cardiomyopathie dilatée. En conclusion, en plus d’être un facteur impliqué de façon centrale dans la pathophysiologie de la PPCM et constituant dès lors une cible thérapeutique intéressante, miR-146a permet un diagnostic spécifique de la maladie. [less ▲]Detailed reference viewed: 87 (5 ULg) Assessing the impacts of technical and structure choices on groundwater model performance using a complex synthetic caseWildemeersch, Samuel Doctoral thesis (2012)According to the European Water Framework Directive (2000/60/EC) and the specific Groundwater Directive (2006/188/EC), Member States have to manage groundwater at the groundwater body scale and in an ... [more ▼]According to the European Water Framework Directive (2000/60/EC) and the specific Groundwater Directive (2006/188/EC), Member States have to manage groundwater at the groundwater body scale and in an integrated way. Given the objectives of “good quantitative and qualitative status” of groundwater for 2015 stated by the Directive, end-users want to know the quantitative and qualitative evolution of groundwater for several scenarios. Physically-based and spatially-distributed groundwater flow and transport models constitute useful management tools in this context since they take explicitely into account the heterogeneity and the physical processes occuring in the subsurface for predicting system responses to future stress factors. However, at such a scale, groundwater flow and transport modelling is challenging due to (1) the complexity of geological and hydrogeological contexts, (2) the uneven level of characterisation knowledge, and (3) the representativity of measured parameters. Furthermore, such models require long execution times. As a consequence, a series of choices and simplifications are made for dealing with these issues. Therefore, the outstanding question is to know whether endusers’expectations can be met in spite of such choices and simplifications. This work focuses on choices and simplifications related to spatial discretisation and saturation–pressure relations in the unsaturated one. The influence of stress factor time resolution is also tested. Considering this general context, the objective of the present work is to evaluate the influence of some model technical (spatial discretisation) and structure (saturation–pressure relations) uncertainties on model results, parameter sensitivities, and optimisation performance in order to provide guidelines for model development. This is performed using a synthetic case inspired by typical groundwater bodies of Wallonia (Belgium). This synthetic case is used for obtaining reference observations in terms of flow rates and hydraulic heads. These reference observations are then compared with their simulated equivalent produced by simplified models differing by their spatial discretisation, their saturation–pressure relations in the unsaturated zone, or the time resolution of their stress factors. The simplified models are then ranked using several performance criteria measuring the discrepancies between reference observations and their simulated equivalent. This ranking leads to guidelines for large-scale groundwater flow model development with respect to typical end-users’ expectations. Whatever the time resolution of stress factors, the quantitative and qualitative analyses performed indicate that coarsening horizontal spatial discretisation deteriorates mainly the simulation of flow rates, coarsening vertical spatial discretisation deteriorates mainly the simulation of hydraulic heads, and (over)simplifying saturation–pressure relations in the unsaturated zone significantly impair the simulation of both flow rates and hydraulic heads. Although optimisation can compensate for errors induced by model technical and structure uncertainties, the improvement of model fit is limited, especially for the coarsest models. Furthermore, with respect to end-users’ expectations, the weighted least-square objective function is not always the most relevant criteria for optimising models. Therefore, it is essential to use specific performance criteria for evaluating model performance depending on the objectives of the study. The ideal would be to develop an end-users objective function for including such performance criteria in the optimisation process and stop the optimisation process once performance criteria would have reached the values specified by the end-users with respect to the objectives of the study. [less ▲]Detailed reference viewed: 79 (26 ULg) Experimental and Numerical Investigations of the Aeroelastic Stability of Bluff StructuresAndrianne, Thomas Doctoral thesis (2012)The study of the dynamic interactions between the wind and civil engineering structures has become increasingly important over the last few decades. Most of these structures are aerodynamically "bluff ... [more ▼]The study of the dynamic interactions between the wind and civil engineering structures has become increasingly important over the last few decades. Most of these structures are aerodynamically "bluff" and are becoming more flexible. Bluff-body aeroelasticity is a very challenging research area due to the unsteadiness and nonlinearity of the aerodynamic loading. This thesis presents the investigation of three aeroelastic phenomena affecting bluff-bodies: Vortex Induced Vibration (VIV), Galloping and Torsional Flutter. For each instability, extensive experimental studies are carried out in the wind tunnel. Innovative analysis, based on the Common-base Proper Orthogonal Decomposition (CPOD) method is used to study the flow visualization data. The VIV phenomenon is studied on a flexible tube with a circular cross-section, supported from its midpoint. A CPOD-based input-output model is developed to describe the system. The galloping instability is studied on a generic bridge section. A complete analysis of the aeroelastic behaviour of the structure is presented and a new polynomial empirical model is developed, which reflects accurately the nonlinear nature of the system. The torsional flutter phenomenon is extensively studied for two different structures: a generic bridge deck and a rectangular cylinder. The Motion Induced Vortex is identified as the fundamental cause of this aeroelastic phenomenon, on the basis of the analysis of the flow around the oscillating rectangle. In addition, it is demonstrated that the quasi-steady theory is not adapted to estimate the onset velocity of torsional flutter. Finally, a 2D aeroelastic simulation code, based on the Discrete Vortex Method (DVM) is developed. The non-linear aerodynamics around the body are well reproduced, allowing the simulation of all the aeroelastic instabilities investigated experimentally. [less ▲]Detailed reference viewed: 204 (65 ULg) Role of NF-κB p65 subunit phosphorylation by ATM in DNA damage-regulated gene expressionSabatel, Hélène Doctoral thesis (2012)DNA damage, induced by several genotoxic agents, challenge genome integrity. Among the different types of DNA lesions, DNA double-strand breaks (DSB) are the most deleterious. Indeed, if not correctly ... [more ▼]DNA damage, induced by several genotoxic agents, challenge genome integrity. Among the different types of DNA lesions, DNA double-strand breaks (DSB) are the most deleterious. Indeed, if not correctly repaired, they can lead to cell death or carcinogenesis. Upon DSB, cells activate a complex signaling network, the DNA damage response (DDR), to counteract those threats. The DDR coordinates DSB repair, checkpoint activation, apoptosis and transcription factors regulation, including NF-κB.   NF-κB family is composed of 5 proteins (RelA/p65, RelB, c-Rel, p105/p50 and p100/p52) which assemble in dimers to form active NF-κB transcription factor. In resting cells, NF-κB complexes are bound to inhibitor proteins such as IκBα, and maintained inactive in the cytoplasm. Classical NF-κB activation requires activation of IκB kinase (IKK) complex, which phosphorylates IκBα, finally leading to its degradation. NF-κB transcription factor is then free to translocate to the nucleus where it regulates a wide array of target genes. NF-κB is an important regulator of diverse cellular processes, including immune response, inflammation, cell survival, proliferation, differentiation, adhesion and apoptosis. NF-κB activation is associated to several pathogenesis and especially contributes to the growth and malignancy of cancer cells. NF-κB also affects the tumor response to many types of chemotherapy and ionizing radiation. Therefore the understanding of the regulation mechanisms of this transcription factor represent a major concern.   This work was interested in the regulation mechanism of DSB-induced NF-κB via the direct phosphorylation of the NF-κB subunit p65 by ATM kinase, the main mediator protein of the DDR. Indeed, rapidly activated in response to DSB, this kinase phosporylates a huge amount of substrates involved in different cellular functions. It had been previously shown that ATM was required for DSB-induced NF-κB activation by acting at two levels. On the one hand, activated ATM phosphorylates the IKK regulatory subunit NEMO. On the other hand, ATM is important for TAK1 activation and TRAF6 poly-ubiquitination, two steps necessary for full IKK complex activation too. The present work therefore highlighted a third ATM-mediated NF-κB regulation mechanism. This study showed that following DNA damage, the phosphorylation of p65 on Ser547 by ATM lead to the lower expression of a set of specific genes mainly involved in inflammation. Phosphorylated p65 was shown to interact with the co-repressor HDAC1, leading to specific promoter deacetylation and subsequent decreased gene expression.   In a second time, we also showed for the first time the requirement of MDC1 protein in DNA damage-induced NF-κB activation. MDC1 protein is mainly described as playing an important role in DSB-induced nuclear foci, which consist in large protein structures that assemble at the site of the DSB. Nevertheless, it appeared in this study that the role of MDC1 in NF-κB activation pathway is foci-independent. [less ▲]Detailed reference viewed: 89 (38 ULg) Spatial and temporal responses of marine gastropods and biofilms to urban wastewater pollution in a Mediterranean coastal areaVermeulen, Simon Doctoral thesis (2012)The increasing human pressure exerted along coastlines and the subsequent increase in the delivery of pollutants at sea is a matter of concern worldwide. Urban wastewaters contain a variety of pollutants ... [more ▼]The increasing human pressure exerted along coastlines and the subsequent increase in the delivery of pollutants at sea is a matter of concern worldwide. Urban wastewaters contain a variety of pollutants (mainly N, P, and trace elements) which can be involved in the launching of eutrophication. This complex process is able to fundamentally alter the integrity of coastal ecosystems thereby impairing the sustainability of economic activities and involving health risks for human through the consumption of sea products. Eutrophication is considered for more than 40 years as a pervasive process and a priority issue for the preservation of the health status of coastal ecosystems. The Mediterranean Sea supports high economic pressures in relation with the continuously increasing number of inhabitants and tourists in coastal areas. The physico-chemical (e.g. oligotrophy, microtidal regime) features of waters make them sensitive to eutrophication and several heavily urbanized areas have been experiencing adverse effects of this process for decades (e.g. biodiversity losses, Harmful Algal Blooms, fishes’ kills,…etc). Nowadays, smaller localities discharging insufficiently treated or raw wastewaters at sea also begin to report eutrophication problems especially during summer months when the number of tourists considerably increases the resident populations. National monitoring programs generally focus on priority areas by using either toxicological (e.g. trace metals in molluscs) and / or structural (e.g. phytoplankton biomasses) parameters to follow the evolution of already impacted water bodies. However, if the most deleterious effects of eutrophication are well known, little information is actually available regarding the early symptoms of the process. The identification of time- and cost-efficient indicators along with analytical procedures that would deliver early warning signals of pollution is therefore required to assist local authorities in the implementation of environmental policies. This research aimed at implementing some easy-to-use and efficient tools to detect the impact of urban wastewater pollution in Mediterranean coastal areas. A new set of potential early bioindicators has been identified. The gastropods Patella caerulea and Monodonta turbinata inhabiting the Mediterranean rocky midlittoral zone and epilithic biofilms were selected as good candidates for monitoring purpose. Biofilms which are microbenthic communities mainly composed of microalgae have been used for decades in freshwater systems as early indicators of pollution. In contrast, marine biofilms have largely been neglected and little is known regarding their composition, their physiology, and the way they react to wastewater pollution. We focused our studies on the Calvi Bay (NW Mediterranean, France) which is, regarding the anthropogenic pressure exerted on its coastal fringe, representative of other moderately urbanized areas of the Mediterranean basin. The Calvi Bay area is indeed among the preferred summer destinations by tourists in Corsica and is influenced by a single point source of pollution which is secondary-treated urban wastewater. A control vs. impacted sites approach has been used to assess the responses of the selected bioindicators to wastewater pollution. Our first task was to characterize the nature and amounts of the main pollutants (nutrients, trace elements) discharged in the Calvi Bay. Since nutrient measurements are commonly used to infer into the trophic status of water bodies, we assessed whether this parameter was reliable to detect the influence of wastewater discharge in the study area. The main pollutants discharged at sea were ammonium, phosphorus and iron. Amounts considerably increased during summer months (July and August) which was related to the high frequentation of the Calvi Bay area by tourists. Measurements of nutrient concentrations in seawater samples from controls and impacted sites did not allow evidencing the influence of wastewater inputs. In contrast, the high spatial and temporal resolution achieved through a small scale sampling design conducted in a small harbour impacted by wastewater discharges showed large spatial variability in the dispersion of effluents and hourly variations in the amounts of pollutants. The extrapolation of these results at the scale of the Calvi Bay may have explained our failure to detect the pollution by using samples collected punctually in space and time. These results suggested that the use of bioindicators that integrate the variable influence of nutrient pulses was required to evidence pollution. We focused our second study on a toxicological approach to detect the bioavailability of anthropogenically-derived nutrients in the midlittoral zone of the Calvi Bay and of the Marseille harbour. Multi-spatial scales and seasonal dual C and N stable isotope analyses were performed on the limpet Patella caerulea, the snail Monodonta turbinata, epilithic biofilms, and the macroalga Rissoella verruculosa. All bioindicators exhibited strongly elevated δ15N values at impacted sites compared to pristine ones, which revealed the influence of wastewater pollution in the midlittoral zone and the biological availability of anthropogenically-derived nitrogen at the base of the food web. Gastropods provided a time-integrated response reflecting the control vs. impacted status of sites. Results indicated that one sampling campaign per year should be sufficient to evidence wastewater pollution likely because of the slow turnover rate of gastropods’ muscles. Macroalgae showed a reliable but less consistent signal of wastewater pollution compared to other indicators. Only epilithic biofilms tended to show the occurrence of nutrient pulses during the tourist season which suggested that wastewater discharges may have influenced the composition and / or the physiology of communities. However the sampling of biofilms developed on natural rocky substrates was destructive and did not allow investigating the fine biological structure of communities and thus to fully understand the output of community scale parameters such as stable isotopes. We therefore recommended using biofilms grown on artificial substrates to circumvent this problem. We then allowed biofilms to develop on glass slides which are the most currently used artificial substrates in freshwater systems. Our task was to find out the most suitable technique to isolate and identify benthic diatoms which are common colonizers on newly available substrates. The species-specific tolerance to pollution of diatoms has been used for decades in the assessment of the health status of freshwater bodies. However, little is known on their marine counterparts and on their ability to evidence wastewater pollution. A specific and time-cost-efficient technique was implemented for the processing of lightly silicified benthic marine diatoms from Mediterranean oligotrophic areas. This was achieved through the multiple comparisons of existing protocols used either in sea- or fresh-waters. We finally investigated, by means of mesocosm deployed in situ and field experiments, the responses of biofilms developed on glass slides to a range of urban wastewater exposures. Colonization experiments lasted for 24 days in summer conditions. A multi-parametric assessment was conducted using a combination of toxicological and structural approaches applied to different biological scales. Toxicological parameters such as C-N stable isotopes, C:N:P ratios, and Trace Elements were measured at the community scale while the structural parameters were considered at the community (standing crops), assemblage (densities of the main autotroph and heterotroph organisms), and the genus (diatoms) scales. The mesocosm experiments were highly efficient to demonstrate the good potential of biofilms as early indicators of wastewater pollution. The impact of wastewater pollution was mainly identified at the community and the genus (diatoms) scales. Standing crops and the C-N stable isotopes were the most useful parameters showing respectively a stimulation of microalgal biomasses (i.e. eutrophication) and the bioavailability of wastewater-derived nitrogen even at low pollution levels. At the genus scale, the composition of diatoms’ assemblages changed markedly especially in the most polluted mesocosms. Results notably highlighted the proliferation of the small-sized individuals of Entomoneis which was thought to outcompete the larger diatoms belonging to the genus Mastogloia for nutrient uptake. The responses of biofilms to pollution largely differed between mesocosm and field experiments. Nevertheless, standing crop parameters corroborated results obtained in mesocosms allowing to assume an influence of wastewater pollution in the Calvi Bay. Field samples were generally characterized by the presence of well developed hydrozoan colonies which were only seldom reported at mesocosm sites. The presumably impacted site also exhibited the highest densities in other heterotrophic eukaryote groups (e.g. nematodes, polychaetes, foraminifers) and primary producers. We interpreted these results either as a top-down effect or as an increase in habitat complexity. The genus scale determination of diatoms’ assemblages showed a decrease in the relative abundances of Mastogloia at the impacted site which was in accordance with results from the mesocosm experiments. The highest density values were also observed for Cylindrotheca at impacted site. The last part of this research gathers the multiple spatial and temporal responses provided by the selected bioindicators to urban wastewater pollution in order to validate their future routine use in the context of monitoring programs. The occurrence of potential confusion sources in the interpretation of data was critically reviewed. The time-cost-efficiency of the tested parameters was then evaluated in order to assist environmental managers in their choices of biofilm-based techniques for detecting wastewater pollution. Finally since biofilms exhibited some strong accumulations of toxic elements, ecological hypotheses dealing with the trophic role of biofilms and the transfer of pollutants through the food webs are provided. [less ▲]Detailed reference viewed: 153 (31 ULg) Real-time Simultaneous Modelling and Tracking of Articulated ObjectsDeclercq, Arnaud Doctoral thesis (2012)In terms of capability, there is still a huge gap between the human visual system and existing computer vision algorithms. To achieve results of su cient quality, these algorithms are generally extremely ... [more ▼]In terms of capability, there is still a huge gap between the human visual system and existing computer vision algorithms. To achieve results of su cient quality, these algorithms are generally extremely specialised in the task they have been designed for. All the knowledge available during their implementation is used to bias the output result and/or facilitate the initialisation of the system. This leads to increased robustness but a lower reusability of the code. In most cases, it also majorly limits the freedom of the user by constraining him to a limited set of possible interactions. In this thesis, we propose to go in the opposite direction by developing a general framework capable of both tracking and learning objects as complex as articulated objects. The robustness will be achieved by using one task to assist the other. The method should be completely unsupervised with no prior knowledge about the appearance or shape of the objects encountered (although, we decided to focus on rigid and articulated objects). With this framework, we hope to provide directions for a more di cult and distant goal: that of completely eliminating the time consuming prior design of object models in computer vision applications. This long term target will allow the reduction of the time and cost of implementing computer vision applications. It will also provide a larger freedom in the range of objects that can be used by the program. Our research focuses on three main aspects of this framework. The rst one is to create an object description e ective on a wide variety of complex objects and able to assist the object tracking while being learnt. The second is to provide both tracking and learning methods that can be executed simultaneously in real-time. This is particularly challenging for tracking when a large number of features are involved. Finally, our most challenging task and the core of this thesis, is to design robust tracking and learning solutions able to assist each other without creating counter-productive bias when one of them fails. [less ▲]Detailed reference viewed: 20 (6 ULg) Experimental study of the hydraulic behaviour of Piano Key WeirsMachiels, Olivier Doctoral thesis (2012)Detailed reference viewed: 97 (27 ULg) Vers un nouveau biosubstitut pour l'ingénierie tissulaire du ligament croisé antérieur: approche biomécaniqueLaurent, Cédric Doctoral thesis (2012)Detailed reference viewed: 29 (2 ULg) Identification d'effecteurs de la signalisation Delta/Notch dans la différenciation des cellules endocrines du système digestifFlasse, Lydie Doctoral thesis (2012)Les cellules endocrines du système digestif incluent les cellules pancréatiques, regroupées en ilots de Langherhans et les cellules entéroendocrines, disséminées tout le long de l’épithélium du tube ... [more ▼]Les cellules endocrines du système digestif incluent les cellules pancréatiques, regroupées en ilots de Langherhans et les cellules entéroendocrines, disséminées tout le long de l’épithélium du tube digestif. Un disfonctionnement de ces cellules peut être à l’origine de graves maladies, en conséquence les cellules endocrine du tractus digestif font l’objet de nombreuses études. Une connaissance précise du mode de fonctionnement mais aussi du développement et de la différenciation de ces cellules est requise afin de pouvoir élaborer de nouveaux traitements. Bien que ces deux populations de cellules endocrines soient situées dans des organes distincts, elles présentent de nombreuses similarités. Ces similitudes se retrouvent au niveau des hormones produites mais également au niveau des facteurs de transcription et des voies de signalisation impliquées dans le développement de ces cellules. La signalisation Notch joue un rôle primordial dans le contrôle de la différenciation des cellules endocrines pancréatiques et intestinales, chez la souris et le zebrafish. L’objectif de ce travail consiste à mieux comprendre les étapes précoces de la différenciation endocrine en recherchant des effecteurs de type ARP/ASCL de la voie de signalisation Delta/Notch, impliqués dans le développement endocrine du tractus digestif. Dans le pancréas, nous montrons que le facteur ascl1b est le premier marqueur pancréatique endocrine à apparaître. Ce facteur qui appartient à la famille des ASCL, est requis pour initier la différenciation de la lignée endocrine. Le facteur neurod1, appartenant à la famille des ARP, agit plus tardivement dans le développement de cette lignée afin de permettre le maintien du programme de différenciation endocrine. Nous démontrons que ces deux facteurs agissent séquentiellement dans les précurseurs endocrines pour promouvoir leur différenciation. La perte simultanée de ces deux facteurs conduit à l’absence totale de cellules endocrine. Dans le tractus gastro-intestinal, nous montrons que la signalisation Delta/Notch réprime le destin sécréteur en inhibant l’expression du facteur ascl1a. La présence de ce facteur est absolument requise pour la différenciation de l’ensemble des cellules sécrétrice. ascl1a est à la base de la cascade de facteur de transcription contrôlant la différenciation des cellules entéroendocrines. Nous montrons également que, dans cet organe, neurod1 régule la différenciation de certains types de cellules entéroendocrines. Parallèlement à cette étude des facteurs ARP/ASCL, nous avons mis en évidence la fonction d’un nouveau régulateur de la différenciation endocrine pancréatique: rfx6. Ce facteur est exclusivement exprimé dans la lignée endocrine chez le zebrafish. En l’absence de rfx6, les précurseurs endocrine sont bloqués dans leur différenciation et s’accumulent. Ce facteur est donc requis pour la différenciation terminale des précurseurs endocrines. [less ▲]Detailed reference viewed: 53 (14 ULg) Contribution à l’identification de l’agent étiologique de l’entéropathie épizootique du lapinHuybens, Nathalie Doctoral thesis (2012)Epizootic rabbit enteropathy (ERE) is a pathology of the digestive system inducing economic loss in rabbit husbandry throughout Europe. The aetiological agent is unknown at the present time but a ... [more ▼]Epizootic rabbit enteropathy (ERE) is a pathology of the digestive system inducing economic loss in rabbit husbandry throughout Europe. The aetiological agent is unknown at the present time but a reference inoculum (TEC4) reproduces the pathology. This inoculum contains an extremely rich bacterial flora. Several methods were used to reduce this bacterial flora while retaining virulence: centrifugation on discontinuous sucrose gradient, cellular adherence and treatment with chloroform/ethanol, antibiotics and an acid buffer. The flora of the obtained fractions were analyzed using traditional bacteriological techniques: identification of cultivable species, counting of colony forming units (CFU) and direct bacterioscopic exam after Gram coloration. Then, molecular biology was used to compare inocula, fractions and negative control. Three methods were used to find sequences present in virulent inocula and absent from non virulent inocula and negative controls. Twenty-two restriction enzymes were used to compare the 16SrDNA restriction profile (Amplified Ribosomal DNA Restriction Analysis or ARDRA). Hypervariable regions V3 and V6 to V8 were studied by Denaturating Gradient Gel Electrophoresis (DGGE). Finally, Random Amplification of Polymorphic DNA (RAPD) was used on the inocula, fractions and negative controls. Only the RAPD allow the obtainment of sequences specific to virulent inoculum. Unfortunately, a study on field samples did not confirm the link between the sequences and ERE. For one of the two identified sequences, a bacterial strain carrier was isolated. The strain was inoculated into rabbits but no clinical signs of ERE were observed. Samples of stools, blood and serum were collected during an experimental ERE infection. The evolution of fecal bacterial flora was studied using DGGE to follow the evolution of flora over the course of the disease. Unfortunately, neither specific bands nor specific band patterns appeared to be linked to the disease. Seven bacterial species were detected in the blood samples of three inoculated rabbits at day two post inoculation, confirming the hypothesis that bacteriemia occurs early on ERE infection. Finally, six fractions were analysed by pyrosequencing of the 16SrDNA gene. The aim was to find one or several species present in the virulent inocula but absent or less numerous in the nonvirulent inocula and control. The richness and diversity of all the inocula is equal or superior to human feces. As expected, the flora identified by pyrosequencing was different from the cultivable flora. However, no genera or species was specifically linked to the virulent inocula. The resolution of this technique was inadequate to identify the aetiological agent of ERE. A higher number of samples and sequences could at best restrain the identification to one genus. [less ▲]Detailed reference viewed: 35 (5 ULg) Evaluation of the superficie of asphaltic mixes: Texture and acoustics absorption related to tire/ road noise.Luong, Jeanne Doctoral thesis (2012)Detailed reference viewed: 11 (1 ULg) Effets des paramètres stellaires et de larotation modérée sur les propriétés sismiques des étoiles gamma DoradusBouabid, Mehdi Doctoral thesis (2011)Detailed reference viewed: 32 (15 ULg) Développement d’un procédé biotechnologique de production de molécules à note verte à partir de feuilles de betteraveGigot, Cédric Doctoral thesis (2011)La grande richesse des feuilles de betterave en 13-HPL (entre 10 et 12 UE1/g de poids frais), une enzyme produisant le (3Z)-hexénol, le (2E)-hexénal et le n-hexanal, fait de ce substrat un candidat ... [more ▼]La grande richesse des feuilles de betterave en 13-HPL (entre 10 et 12 UE1/g de poids frais), une enzyme produisant le (3Z)-hexénol, le (2E)-hexénal et le n-hexanal, fait de ce substrat un candidat potentiel pour le développement d’un procédé biotechnologique de production d’arômes alimentaires. Maillon essentiel du système de défense des plantes, l’enzyme 13-HPL est inductible par des stimuli externes et son expression dépend de l’âge et de l’état physiologique de la plante. Au cours de ce travail, l’optimisation de l’expression de cette enzyme au sein du végétal a été étudiée préalablement au développement d’un procédé industriel visant à exploiter ce substrat. Ce procédé comprend successivement quatre opérations chimiques : une hydrolyse d’huile végétale riche en acides gras insaturés, une oxydation de ces acides, un clivage par les 13-HPLs et une purification des aldéhydes et des alcools synthétisés. Selon nos résultats, l’étape limitante de ce procédé est la synthèse d’aldéhydes qui présente, dans des conditions optimales de réaction, une capacité de production maximale de 0,502mM à l’échelle pilote (100L). L’inhibition suicide par le substrat et l’instabilité combinée de l’enzyme et de ces produits de réaction réduisent le taux de clivage des aldéhydes. La mise au point d’un système d’extraction des arômes volatils par flux gazeux et d’une alimentation fedbatch en substrat permet de réduire l’impact limitant de ces facteurs et d’accroître la capacité de production à 1,37mM. Afin de mieux comprendre les mécanismes réactionnels, l’enzyme 13-HPL de la betterave a été séquencée et clonée dans un vecteur procaryote permettant de disposer d’une source d’activité enzymatique indépendante des contraintes du milieu extérieur. L’utilisation de ces techniques a permis de développer un procédé bivalent (à la fois de source microbienne et végétale) de production d’arôme exploitable au sein de l’industrie alimentaire. [less ▲]Detailed reference viewed: 96 (19 ULg) Évaluation du niveau de stress du cheval en compétition et en milieu hospitalier : Mesures comportementales, physiologiques et appréciation du tempéramentPeeters, Marie Doctoral thesis (2011)Both in humans and in animals, stress is sometimes considered as useful for the accomplishment of certain tasks. But it might also have a negative influence on health, welfare or safety. We often impose ... [more ▼]Both in humans and in animals, stress is sometimes considered as useful for the accomplishment of certain tasks. But it might also have a negative influence on health, welfare or safety. We often impose on our domestic horses a lifestyle very different from their natural one. As soon as we interact with this animal, either during manipulations or in competition, we face him to various stressors. This stress can affect their health, their well-being as well as their sportive performances. Horses’ stress might also lead to a lack of safety for people handling them (horsemen, riders, breeders, veterinarian,...). Stress can be assessed by various indirect ways. Among all responses possibly shown by horses submitted to a stressor, we mainly focused on behavioural responses and on a physiological response: changes in cortisol secretion. Our first goal was to validate the use of saliva for free cortisol level determination. Secondly, we used this technique to assess stress level of both horses and riders during equestrian competitions. We compared riders’ and horses’ stress levels and we examined the potential relationship between the stress levels and the competition performances. The results showed that cortisol levels significantly increased during competition, both in horses and riders. The best performances were achieved by riders with the smallest increase in cortisol during competition. And, more surprisingly, the best performances were achieved by horses with highest cortisol increase. In this study, stress of both partners seems to have an opposite influence on their performances during competition: positive effects for horses (‘eustress’) but negative effects for riders (‘distress’). It would be interesting to test these measurements under other competition conditions. We also have tested the relationship between the horse’s temperament (scored by the owner), the stress levels in competition and the obtained performances. It came out that a higher increase in cortisol is more related to some ‘excitement’ rather than anxiety, and was mainly found in curious, motivated and active horses. This stress follow-up in competition should improve the welfare of the horse and his rider, and should probably also enhance performances achieved by the pair. In clinical settings, we identified the stress-related behaviours, that use to lead to a low ‘easiness of manipulation’. We also tested the relationship between temperament assessed by the owners, by the clinic staff and the stress-related behaviours. More particularly, we observed a predictive effect of a simple test (weigh scale test) on the appearance of these stress-related behaviours. This test would allow clinicians to anticipate potential difficulties during examinations and to prevent deriving injuries. Improving the stress measurement techniques and horses’ temperament assessment is essential for domestic horse welfare studies, as they occur in hospital, during competition, or in other stressful situations. Using physiological stress measurements, as salivary cortisol, is very useful and more reliable if they are used in conjunction with ethological methods.  [less ▲]Detailed reference viewed: 110 (23 ULg) Les pestivirus à l'interface faune sauvage-faune domestique: pathogénie chez l'isard gestant et épidémiologie dans la région Provence-Alpes-Côte d'AzurMartin, Claire Doctoral thesis (2011)Dans les Alpes du Sud de la France, des diminutions de populations de chamois (Rupicapra rupicapra) ont été rapportées. Or, depuis une dizaine d’année, des pestivirus ont causé de fortes mortalités dans ... [more ▼]Dans les Alpes du Sud de la France, des diminutions de populations de chamois (Rupicapra rupicapra) ont été rapportées. Or, depuis une dizaine d’année, des pestivirus ont causé de fortes mortalités dans des populations d’isards des Pyrénées (Rupicapra pyrenaica). Bien que les signes cliniques associés à cette infection aient été caractérisés chez cette espèce, la pathogénie chez les animaux gestants est peu étudiée. De plus, des transmissions inter-espèces ont régulièrement été incriminées dans l’épidémiologie des pestiviroses ; ceci particulièrement au niveau des alpages où des contacts fréquents sont décrits entre ruminants sauvages et domestiques. Les objectifs de ce travail de thèse ont donc été, dans un premier temps, d’étudier la pathogénie de l’infection à pestivirus chez des isards et plus particulièrement ses effets sur la gestation. Dans un second temps, nous avons étudié l’épidémiologie de l’infection dans différentes zones de la région Provence-Alpes-Côte d’Azur (PACA), tout d’abord chez des ruminants sauvages, puis à l’interface entre les ruminants sauvages et domestiques partageant les mêmes alpages (...). [less ▲]Detailed reference viewed: 43 (9 ULg) Déconvolution aveugle d'images mono- et multicanales par méthodes variationnelles - Application à l'imagerie aérienneHammer, Alexandre Doctoral thesis (2011)Detailed reference viewed: 50 (6 ULg) Processus d'externalisation graphique dans les activités cognitives complexes : le cas de l’esquisse numérique en conception architecturale individuelle et collectiveSafin, Stéphane Doctoral thesis (2011)This thesis investigates the modalities of creating external representations in complex cognitive activities, especially graphical representations: the explanatory diagrams, annotations of documents or ... [more ▼]This thesis investigates the modalities of creating external representations in complex cognitive activities, especially graphical representations: the explanatory diagrams, annotations of documents or drawings make it possible to formulate ideas, to synthesize information, to communicate and to reason. This work seeks to understand in depth the processes involved in graphic expression, and the impact of representation supports on this activity. For this purpose, it addresses the original concept of digital sketch in the field of architectural design. This concept aims to allow the architect to draw freehand sketches, in an entirely digital environment, but in a «natural» way, as with its traditional tools. The idea is to take advantage of the ease of use of the pen, while exploiting the capabilities of simulation or representation of the digital medium. The freehand sketch is indeed known as an essential tool for the design: thanks to its fluidity, its immediacy and the freedom it allows, it supports efficiently the creative phases of ideation. It is also a powerful tool for document annotation in collaborative design and project review. This work analyzes the interest and the contribution of digital sketching in architectural design, but also stresses the constraints it vehicles as an instrument of individual and collective thought. It also seeks to identify the impact of electronic pen as a mode of interaction on the cognitive and graphical activities in design tasks. This thesis is based on three original empirical studies on the use of digital sketching environments. It describes the logic of graphical externalization, compares the characteristics of digital and traditional sketches, identifies the cognitive functions of representations transformations and makes explicit the role of the graphical modality in collaborative remote design. [less ▲]Detailed reference viewed: 182 (16 ULg) First-principles study of multiferroic materials : BiFeO3 and Bi2FeCrO6Goffinet, Marco Doctoral thesis (2011)The present work is devoted to an ab-initio characterization, using planewave and localized basis sets, of multiferroic and magnetoelectric materials. After a general description of the underlying ... [more ▼]The present work is devoted to an ab-initio characterization, using planewave and localized basis sets, of multiferroic and magnetoelectric materials. After a general description of the underlying concepts and computational techniques, we focus on BiFeO3, which is probably the most intensively studied multiferroic. We start our investigation by comparing the ability of different exchange-correlation functionals (LSDA(+U), GGA and hybrid) to accurately describe the most fundamental properties of BiFeO3 (crystallographic structure, electronic band structure, magnetism, phonons at Gamma, Born effective charges). Next we present infrared reflectivity and Raman spectra obtained from first-principles and compare them to experimental data. We then extend the study of the dynamical properties of BiFeO3 to the whole Brillouin zone by analyzing the phonon band structure, density of states and interatomic force constants. We also use combined Einstein and Debye models to fit the specific heat as obtained from first-principles and compare it to experimental data. The final part of this thesis is devoted to the investigation of pressure driven spin phase transitions in Bi2FeCrO6 . [less ▲]Detailed reference viewed: 156 (16 ULg) Land conversion for industrialization and its impacts on household livelihood strategies in Hung Yen province, northern VietnamNguyen, Thi Dien Doctoral thesis (2011)This thesis is about the impact of land conversion for industrialization on household livelihood strategies in Hung Yen province, northern Vietnam. The study shows that land conversion is generating a ... [more ▼]This thesis is about the impact of land conversion for industrialization on household livelihood strategies in Hung Yen province, northern Vietnam. The study shows that land conversion is generating a household landholdings decline while boosting the land market. After land conversion, 16% of laborers in the surveyed households find employment in industrial factories while 52% find jobs in the informal sector. Because of land conversion, rather than being net food producers, peasant households have become net food purchasers. Meantime, food safety in industrial areas is threatened by increasing environmental pollution. The findings also demonstrate that 51.9% of the surveyed households choose diversification as a livelihood strategy while 35.6% of them shift entirely to non-farm strategies. Among the affected peasant groups, households with a non-farm background that lost less than 50% of their agricultural land are likely to be in a better position to engage in lucrative non-farm jobs. Land conversion is causing a complex agrarian transformation in Vietnam. On the one hand, it generates a mechanism of social differentiation which is determined by land alteration and capital accumulation from high earning non-farm activities. On the other hand, peasant livelihood strategies, thanks to adaptation and innovation, have mitigated the impacts of land conversion and reveal the persistence of a peasant economy. [less ▲]Detailed reference viewed: 65 (13 ULg) La médiation par les objets en design industriel - Perspectives pour l'ingénierie de conceptionElsen, Catherine Doctoral thesis (2011)The preliminary ideation phase, determining more than 70 % of a project’s total costs, is a crucial part of the design process. It usually gathers several actors around the innovative solving process of a ... [more ▼]The preliminary ideation phase, determining more than 70 % of a project’s total costs, is a crucial part of the design process. It usually gathers several actors around the innovative solving process of a complex problem : it merges their complementary expertise, the use of mediating objects as well as a mysterious part of creativity in order to reach a solution if not innovative, at least satisfactory. With the introduction of always more powerful Computer Aided Design tools, industrial design sees its every-day practices drastically evolving : these software still not support designers during their preliminary design phases and free-hand sketches, on the other hand, encounter increasing difficulties to meet today time-to-market pressures. This thesis analyzes free-hand sketches’ and CAD tools’ respective and complementary strengths as supports to preliminary design phases. Advanced design engineering concepts, nurturing the study of the particular articulation existing between both mediating objects, are associated with dedicated Human Factors methodologies for the analysis of every-day professional practices. The research project draws its main qualitative and quantitative results from three field studies and two experimentations, bringing together more than forty professional designers and three design companies. Its multi-disciplinary approach leads to models and recommendations that directly nurture the definition of a new design support system. The specifications tend to respect, augment or, on the contrary, reject some aspects of these mediating objects and aim at supporting a design process always in respect with designers’ constraints and real needs. Beyond the concepts of our support system, we discuss some results that are of interest for communities of design engineering and human-computer interaction. Among these results are : - the extension of the preliminary design phase’s boarders ; - the non-dichotomous approach of rough and detailed mediating objects ; - the coexistence of two design moves : in addition to Schön’s «see-transform-see» theory, the externalization of a strong mental image or a strong pre-inventive form explains the early uses of CAD tools ; - the study of tool’s uses and misuses and graphic and semantic contents of external representations all along the design process, reintroduced in a simplified four-steps model ; the study of shifts occurring between 2D and 3D representations and their implications for the system’s automatization ; - and, at the strokes’ scale, the study of the exploitable key-features and the strokes’ cycles and their implications for the temporality of assistance. The thesis also discusses the added-value of its theoretical and methodological background for the materialization of a design-engineering community that articulates designer, mediating objects, design process and end-users in a coherent system, sound basis for the specification of adapted and adopted design support systems. [less ▲]Detailed reference viewed: 127 (23 ULg) Astrophysical parameters and multiplicity of massive stars: a mathematical approachMahy, Laurent Doctoral thesis (2011)Often quoted for their crucial role in the ecology of galaxies, massive stars remain mysterious. The exact process leading to their formation, their stability or their stellar winds are so many questions ... [more ▼]Often quoted for their crucial role in the ecology of galaxies, massive stars remain mysterious. The exact process leading to their formation, their stability or their stellar winds are so many questions which are still unanswered. Since the lifetime of these objects is too short to allow them to move far away from their birth places, the large majority of massive stars are located in young open clusters or in OB associations. The observations of massive stars in these locations thus provide with promising information on their formation mechanisms. One of the most interesting properties, in this context, is their multiplicity. Indeed, the proportion of multiple systems, the values of orbital periods, of eccentricities, or of mass ratios are parameters directly linked to the formation mechanism and to the dynamical interactions occurring during the earliest stages of their existence. Moreover, constraining this multiplicity with a sufficient accuracy allows to obtain a better determination of the nature and physical parameters of massive stars. The present work is devoted to the study of the O star populations located in the young open cluster NGC2244 and in the surrounding Mon OB2 association as well as in several OB associations of the Cygnus complex. We establish not only the multiplicity of about thirty stars but also their fundamental parameters such as their masses or their N content. However, the complexity of observed spectra of multiple systems makes these objects difficult to investigate. Their analysis thus requires the development and the utilization of mathematical tools such as the "disentangling" which allows to separate the spectra of the components from the observed ones or such as the Doppler tomography which aims at mapping the wind interactions seen in some binary systems. The first part of this dissertation is dedicated to the development and to the characterization of these mathematical methods whilst the second part focuses on the study of populations of massive stars. We refine the orbital and physical parameters of systems already known as multiple. In this context, the analysis of the two components of LZ Cep system reveals modified abundances for the secondary star, confirming a mass transfer from the secondary towards to primary. We also detect for the first time a third star in the HD150136 system. This object, composed of an O3, an O5.5 and an O6.5, constitutes a new test to apply these mathematical methods and thus to better constrain the physical properties of the system as well as those of each component. Moreover, we find, in the population of NGC2244, of Mon OB2 and of the Cygnus OB associations, six new binary systems and derive the orbital solutions for five of them. These results show that NGC2244 hosts only one long-period binary and none with a short period whilst four short-period and no long-period systems are detected in the Cygnus complex. This obvious lack of short-period system in NGC2244 contrasts with the O star populations in other young open clusters such as NGC6231 or IC 2944. Besides the multiplicity, the fundamental parameters such as the N content also allows us to, notably, adapt the so-called Hunter-diagram to galactic O stars. Moreover, we have obtained photometric data for six O-type stars in NGC2244 and Mon OB2 with the CoRoT satellite. These data of unprecedented quality allow us to detect the presence, in the O star light curves, of red noise which is supposed to originate from either the sub-surface convection zone, the granulation or an onset of clumping in the winds of the stars. We also highlight the existence of non-radial pulsations in the light curve of Plaskett’s Star as well as a hot spot located between the two components of that system. In addition, numerous frequencies, extracted from the CoRoT light curves, reveal, for some of the observed stars, solar-like oscillations or beta Cephei-like pulsations. This analysis thus gives a first observational constraint on the bright end of the massive star instability strip. [less ▲]Detailed reference viewed: 25 (13 ULg) Beef cattle systems in the context of sustainable agriculture in Bac Kan province, the Northern Mountainous Region of VietnamHoang, Thi Huong Tra Doctoral thesis (2011)Among livestock types, beef cattle production is ranked as a very important sub-sector in the extremely harsh natural conditions characterising the northern uplands of Vietnam, where ethnic minorities are ... [more ▼]Among livestock types, beef cattle production is ranked as a very important sub-sector in the extremely harsh natural conditions characterising the northern uplands of Vietnam, where ethnic minorities are often concentrated on land resources which are not hospitable to crops. To help local people to escape from poverty, many organisations have initiated development projects featuring beef cattle production, but it still remains under-developed, hence the generally high level of poverty faced by farmers.

Thus, the study aims to assess the characteristics and appropriateness of beef cattle feeding systems, which are compared from the point of view of sustainability.

Stratified sampling was used to select 97 households within free-range, part-time grazing, and cut-and-carry feeding systems, which were surveyed in Bac Kan province between 2007 and 2009. The collection of field data was implemented using various survey instruments such as structured questionnaires and interview guides. Data processing consisted in descriptive statistics, correlations between the variables, and the calculation of socio-economic indicators. Based on the sample surveyed, the differences between the three systems of cattle management were highlighted.

Access to grazing land and its topography, the ethnicity of the communities, the relative importance of agricultural and forest production, and opportunities for off-farm employment were all factors influencing the cattle systems. Those using the “cut-and-carry” fodder system are practicing the most efficient husbandry style among the systems from both the social and economic points of view, except for lack of proper management and use of cattle manure. Manure use for cultivation in this system was limited because of the predominantly steep slope lands and the habits of the indigenous peoples. Animal manure utility was evaluated as less important in the cut-and-carry system compared to other systems practiced in the lowlands.

However, good prospects are seen to improve conditions in the rural uplands in the future. Thus, different strategies should be implemented to fill the gap and improve the position of farmers. The study derives helpful recommendations for farmers keeping beef cattle to strongly develop their production, alleviate poverty, and improve their livelihoods. [less ▲]Detailed reference viewed: 106 (27 ULg) auditory sensitivity in birds: sex differences and noise impactsNoirot, Isabelle Doctoral thesis (2011)Detailed reference viewed: 21 (7 ULg) Synthèse, mise en forme et frittage de céramiques thermoélectriques de formulation In2-xGexO3Combe, Emmanuel Doctoral thesis (2011)Ce travail de thèse porte sur l’étude des relations procédé, micro/nanostructures et propriétés thermoélectriques de composés oxydes de formulation In2-xGexO3. Dans ce contexte, des techniques de synthèse ... [more ▼]Ce travail de thèse porte sur l’étude des relations procédé, micro/nanostructures et propriétés thermoélectriques de composés oxydes de formulation In2-xGexO3. Dans ce contexte, des techniques de synthèse des poudres par chimie douce (procédé citrate), de mise en forme en milieu liquide (coulage en moule poreux) et de frittage non conventionnel des céramiques (frittage micro-ondes) ont été développées. Par comparaison à des procédés d’élaboration classiques, le développement du procédé citrate a permis la préparation de microstructures homogènes permettant d’optimiser les propriétés de transport. La figure de mérite ZT des composés In2-xGexO3 atteint ainsi des valeurs supérieures à 0,3 à 1000 K. Afin de mieux contrôler la densification pendant le frittage, l’utilisation d’une technique de mise en forme par coulage en moule poreux a été expérimentée et des densités après frittage proches de la densité théorique ont pu être obtenues grâce à une mise en ordre optimisée des particules dans les composés crus. Le développement du frittage micro-ondes à ce type de matériau a par ailleurs permis d’obtenir des microstructures très fines (taille de grains inferieure à 500 nm). Un dispositif thermoélectrique (surface de 35 × 40 mm², 56 jambes) de formulations Ca3Co4O9 et In1.994Sn0.006O3 a été également réalisé. Celui-ci délivre une puissance de 480 mW pour un gradient de température de 550 K. Ces différentes études ouvrent des perspectives intéressantes dans l’élaboration de composés et de dispositifs thermoélectriques à base d’éléments oxydes présentant des performances accrues. [less ▲]Detailed reference viewed: 83 (10 ULg) Analytical strategies for the detection of counterfeit erectile dysfunction drugsSacré, Pierre-Yves Doctoral thesis (2011)Since the late eighties, when it was first mentioned, the worldwide phenomenon of pharmaceutical counterfeiting is growing. Belgian customs often encounter presumed counterfeited medical products in ... [more ▼]Since the late eighties, when it was first mentioned, the worldwide phenomenon of pharmaceutical counterfeiting is growing. Belgian customs often encounter presumed counterfeited medical products in Belgian airports and ports because of their central position in Europe and their importance in the transit of goods. Further and deeper analyses are required to assess the counterfeit character of these goods and to provide a scientific basis for the eventual legal procedure. As reference laboratory for the federal agency for medicines and health products (FAMHP), the Scientific Institute of Public Health (IPH) frequently analyses illegal and counterfeit pharmaceutical preparations. The present research project was started with the objective of evaluating several existing methods and developing new analytical methods to detect counterfeit erectile dysfunction drugs. This thesis is focused on the analysis of illegal samples of phosphodiesterase type 5 inhibitors (PDE5-i) containing drugs because these are the most counterfeited pharmaceutical specialities in Belgium. The research was divided into a spectroscopic and a chromatographic part: Infrared based spectroscopies have already demonstrated their ability to detect counterfeit drugs. The first part of the study evaluates the capacity of each technique (mid-infrared (mid-IR), near-infrared (NIR) and Raman spectroscopy) separately and their combinations to discriminate genuine from illegal tablets. Then, the Classification And Regression Trees (CART) algorithm has been used to classify the different samples following the classification system of the Dutch National Institute for Public Health and the Environment (RIVM). The second spectroscopic approach used Raman microspectroscopy mapping to detect counterfeited Viagra®. This technique allows the detection of different compounds according to their Raman spectrum but also the study of the distribution of a selected ingredient among the core of a tablet. The chromatographic part consists of the development and validation of a new Ultra High Pressure Liquid Chromatography method coupled with a UV diode array detector (UHPLC-DAD) and compatible with mass spectrometry (MS) to detect and quantify the three authorised phosphodiesterase type 5 inhibitors (sildenafil, tadalafil and vardenafil) and five of their analogues in illegal pharmaceutical preparations. This method has been validated between +/- 5% acceptance limits using the total error approach and has been compared to the official Viagra® assay method. The ability of HPLC-UV impurity fingerprints to detect illegal samples and to predict whether a new unknown sample is genuine has also been evaluated. The developed analytical methods may be included in a general approach to detect counterfeit drugs containing PDE5-i. This generic approach may also be used to detect other types of counterfeited drugs but should therefore be adapted for each type of medicine. [less ▲]Detailed reference viewed: 109 (7 ULg) Etude des propriétés physico-chimiques et technofonctionnelles des crèmes végétales en relation avec les conditions de reconstitutionAnihouvi, Prudent Placide Doctoral thesis (2011)In this work, an integrated approach was adopted to study vegetal creams in order to have a global understanding of their properties. This approach included: (i) the influence of fat and other ingredients ... [more ▼]In this work, an integrated approach was adopted to study vegetal creams in order to have a global understanding of their properties. This approach included: (i) the influence of fat and other ingredients of the formulation, particularly a low molecular weight surfactant, Tween 60 (ii) and the manufacturing process implemented for their preparation. The effect of fat was investigated by adopting an original approach that consisted in studying both the thermal and structural behavior of the non-emulsified fat (NEF) and the emulsified fat (EF). This clearly demonstrated the impact of the physicochemical characteristics of fat on the physicochemical and technofunctional properties of creams. It well established that small differences in the composition of fats may have great effects on the technofunctional behavior of creams. The influence of fat on the final properties of creams was mainly marked through the crystallization and melting behaviors of fat, and through the crystalline varieties formed during maturation. The effect of temperature on the stability of creams based on the physical evolution of the fat was also highlighted. The addition of tween 60 to the formulation significantly improved the properties of particle size, rheology, stability and whipping of creams. This improvement was the result of not only synergistic effect of surfactant molecules of buttermilk and tween 60 during emulsification but also desorption of proteins from the drop surfaces and modification of crystallization of the EF. The study of the influence of the process showed that the choice of the emulsification method and operating parameters are important considerations in the reconstitution of creams. It was shown that it was possible to modulate the properties of creams by only modifying the process. [less ▲]Detailed reference viewed: 56 (11 ULg) Introduction à la démarche spirituelle des moines errants de l'Egypte copte (250-451). Une étude fondée sur la "Mission de Paphnuce" et les principales sources littéraires du monachisme errant de l'époque concernéeMalevez, Marc Doctoral thesis (2011)Having given the definition of the words "monks" and "wanderer", the thesis try to demonstrate that the spiritual step as it is presented by Evagrius Ponticus corresponding to the reality that was in the ... [more ▼]Having given the definition of the words "monks" and "wanderer", the thesis try to demonstrate that the spiritual step as it is presented by Evagrius Ponticus corresponding to the reality that was in the spirit of the wanderer monks in Coptic Egypt and not a philosophical construction, based mainly on his experience outside Egypt. We will reconstitute and put in order the essential anachoristic monastic step, since the renouncement of marriage and fatherhood until the final getting of the Charism of the perfect and a saint on earth, as it appears from the main literary sources of that era. The thesis is also based on three Coptic manuscripts, three Arabic Manuscripts and five Ethiopian Manuscripts of the "Mission of Paphnutius", a travel story written in the fourth century. The thesis demonstrates also the characteristic idiorrhytmic and without doubt essentially reasonable of the step of the monks. [less ▲]Detailed reference viewed: 49 (9 ULg) Utilisation des composts de biodéchets ménagers pour l'amélioration de la fertilité des sols acides de la province de Kinshasa (République Démocratique du Congo)Mulaji Kyela, Crispin Doctoral thesis (2011)This work is part of the research for appropriate methods for sustainable management of the sandy soils of the province of Kinshasa (Democratic Republic of Congo), in order to ensure and guarantee the ... [more ▼]This work is part of the research for appropriate methods for sustainable management of the sandy soils of the province of Kinshasa (Democratic Republic of Congo), in order to ensure and guarantee the adequate food security. It consists of a scientic research of the use of composts produced from household organic waste in improving the quality of sandy soils to the province of Kinshasa. The general objective pursued in this work is to evaluate the impact of four repeated applications of organic matter from bio-waste compost on chemical and biochemical parameters dynamics in acid sandy soils and their productivity. A pilot composting on a small scale has been installed for the production of composts from municipal solid waste and characterization of composts obtained has revealed the agronomic potential that presents this material. The diagnosis of the condition agropedological soils revealed that soils of the three study sites are sandy classified as rubics arenoferrasols (dystrics), have excellent physical conditions for drainage, air circulation and root penetration possess variables charges colloids, show an acid reaction, low organic matter and low nutrient minerals contents. In addition, their water and nutrients retentions capacity are very limited, and are the main soil constraints to agricultural productivity of these soils. After four growing seasons in real environments, the study of the reaction with the soil organic amendments (20, 40, 60 t.ha-1 MB) gave satisfactory results. The provision of continuous additions of organic composts significantly increased the values of pH, TOC, CEC, SB eff and reduced the rate of exchangeable Al saturation in the three sites. With the highest dose T3 (60 t.ha-1 MB), the pH increased at least 0.8 units and the carbon content multiplied by 2.5 to 3 on the three sites. CEC values increased from 3.3 to 5.02 cmol(+)mg.kg-1 and the toxic aluminum saturation decreased more effective than 90%. Regarding biochemical parameters (microbial carbon & nitrogen, RB, RIS, APA, Unt, Ut), compost treatments induced a significant improvement in function and doses applied throughout the experiment. These contributions have induced microbial activity which contributed to the increase in soil nutrients (N, P, ...) by microbiological activities. The availability of nutrients and fourniture of carbon by the composts explain these increases. In addition, yields on different test plants (Glycine max L. Merr, Arachis hypogaea L. and Hibiscus sabbariffa L.) were positively influenced by the treatments of organic composts household wastes. Compared with mineral fertilizers, their fertilizing potential is not negligible. According to the results observed, doses ≥ 40 t.ha MB-1 should be to keep and maintain an acceptable level of fertility and yields potentiel of crops. But low doses were more efficient than high doses of agronomic point of view. Doses ≤ 20 t.ha-1 MB are recommended in annual crop and regular. Phosphorus was found to be the most limiting element to agricultural production of soil sites studied whatever of the types of amendments and cultures used. Finally, the study indicates that for reasons of efficiency, availability and funds increased production may be obtained through synergy between the composts used in small quantities and fertilizer mineral supplements. [less ▲]Detailed reference viewed: 134 (11 ULg) Contribution of cobalt-mediated radical polymerization to macromolecular engineering and photodynamic therapyHurtgen, Marie Doctoral thesis (2011)Cobalt-mediated radical polymerization (CMRP) is an emerging class of controlled radical polymerization technique based on the reversible deactivation of the propagating radicals by a cobalt complex. This ... [more ▼]Cobalt-mediated radical polymerization (CMRP) is an emerging class of controlled radical polymerization technique based on the reversible deactivation of the propagating radicals by a cobalt complex. This thesis aims at broadening the nature, the structure, the properties and the end-use of (co)polymers accessible by CMRP. The first part of this work is devoted to the synthesis of novel statistical, graft and block copolymers by CMRP. First, the statistical copolymerization of conjugated (n-butyl acrylate) with a non-conjugated one (vinyl acetate) has been successfully controlled by bis(acetylacetonato)cobalt(II). The optimal experimental conditions were then implemented to the copolymerization of vinyl acetate with poly(ethylene glycol) acrylate, which yielded (quasi-)diblock amphiphilic graft copolymers for potential biomedical applications in one step. CMRP also revealed successful for the synthesis of well-defined thermo-responsive copolymers based on poly(N-vinylcaprolactam), either amphiphilic or double-hydrophilic at room temperature. In the second part of this thesis, we investigated the potential of CMRP for the synthesis of new agents for cancer photodynamic therapy. The synthesis of such photosensitizers relied on the chain-end functionalization by [60]fullerene of water-soluble (co)polymers (or precursors) prepared by CMRP. The photodynamic activity of poly(vinyl alcohol)/C60, poly(N-vinylpyrrolidone-co-vinyl acetate)/C60 and poly(PEG acrylate-co-vinyl acetate)/C60 nanohybrids were assessed through photophysical and in vitro experiments. Also, the ability of the nanohybrids to avoid recognition by the immune system was evaluated by a protein adsorption test. Finally, some hints on how to improve the synthesis of the nanohybrids - and therefore, their photodynamic activity - were provided by a mechanistic study of the grafting onto C60 of macroradicals released by cobalt end-capped polymers [less ▲]Detailed reference viewed: 120 (84 ULg) Une expérience critique de la pensée. Essai sur les kantismes de Foucault (1961-1969/1978-1984)Bolmain, Thomas Doctoral thesis (2011)Ma thèse se propose de démontrer les points suivants : 1. La pensée de Foucault doit être rapportée comme à sa condition de possibilité philosophique à l’émergence historique de la pensée critique telle ... [more ▼]Ma thèse se propose de démontrer les points suivants : 1. La pensée de Foucault doit être rapportée comme à sa condition de possibilité philosophique à l’émergence historique de la pensée critique telle qu’elle est associée au nom de Kant : j'ai étudié, dans leurs modalités diverses, « les kantismes de Foucault » ; 2. Pour le comprendre, il est de première importance de se concentrer sur les deux extrêmes de son parcours philosophique (1961-1969 et 1978-1984) ; 3. Ce postulat en implique un autre, de nature méthodologique : le choix de privilégier une reconstruction conceptuelle plutôt que chronologique de l’œuvre de Foucault ; ainsi peut-on mettre en évidence la cohérence très forte qui anime son parcours, sous les discontinuités évidentes qui l’affectent ; 4. La cohérence philosophique de la pensée de Foucault est liée à trois éléments : - l’unité d’une méthode, d’une certaine attitude de la pensée (nominalisme matérialiste réalisé dans la forme d’une archéo-généalogie) ; - l’insistance d’une question toujours posée dans le cadre de l’interrogation critique et d’une reprise partielle des motifs du transcendantal et surtout de la finitude ; cette question se résume du passage de la critique de la question anthropologique classique (Qu’est-ce que l’homme ?) à une enquête portant sur les modes d’être historiques du sujet (Que sommes-nous aujourd’hui ?) ; - la reprise constante de trois concepts qui font le cœur de la conceptualité philosophique moderne et qui forment chez Foucault un réseau à la relative systématicité : ceux d’expérience, de pensée et de critique ; 5. Le concept d’expérience est la pierre de touche de toute l’œuvre de Foucault : seule sa reconstruction patiente permet de saisir, de décrire et d’élaborer de manière satisfaisante la manière de penser qui est la sienne, dans son rapport critique à la pensée de Kant. Une fois rapportée à sa condition historique de possibilité, l'oeuvre de Kant, on comprend à la fois la nécessité conceptuelle de la proposition philosophique de Foucault mais aussi, par suite, les limites de sa proposition éthico-politique. C'est ce que j'ai nommé le nihilisme achevé ou positif de Foucault, la pure exigence d'une transformation micro-politique indéterminée et non-fondée de l'état de choses donné. Aller plus loin que celle-ci supposerait de reprendre la question philosophique directrice de Foucault - comment la transformation du sujet dans l’histoire vers un surcroît d’autonomie s’articule-t-elle à sa finitude radicale ? - aux abords de la dialectique, et en particulier en fonction de concepts critiqués par l'auteur, ceux de négativité et de totalité. [less ▲]Detailed reference viewed: 101 (24 ULg) Nanostructuration induced by self-organization of polystyrene nanospheres as a template for the controlled growth of functional materialsColson, Pierre Doctoral thesis (2011)In the last few years, nanosphere lithography emerged as an inexpensive, material specific and high-output nanostructure fabrication process to manufacture arrays of periodic structures. The goal of this ... [more ▼]In the last few years, nanosphere lithography emerged as an inexpensive, material specific and high-output nanostructure fabrication process to manufacture arrays of periodic structures. The goal of this thesis was centered on both parts of the nanosphere lithography process, namely first the optimization of monolayer colloidal masks prepared by spin coating of monodisperse polystyrene (PS) nanospheres and secondly the use of these masks to develop new attractive applications in various fields. In order to assess the quality of the manufactured colloidal crystal masks, we developed a computerized image analysis procedure (Matlab) based on SEM micrographs. We successfully performed the different stages of the image analysis in such a way to discriminate and identify each nanosphere. As a quantification of order in the self-organized nanospheres, we chose to determine the percentage of hexacoordinated nanospheres by computing the distances between each of them. We applied experimental design to spin coating to evaluate the efficiency of this method to extract and model the relationships between the experimental parameters and the degree of ordering in the particles monolayers. We identified adequate spin coating parameters to synthesize large defect-free domains, reaching up to 200 μm2, which is the highest value ever reported for samples prepared by spin coating. Statistical analysis highlighted that rapid substrate acceleration and high rotation rates are necessary to get large, well-ordered areas. We also studied the surfactant concentration usually added to the beads suspension or the use of reactive ion etching (RIE) process to modify the masks. By using PS nanosphere templates (490 nm or 250 nm diameter), we successfully manufactured large arrays of L10-Fe50Pt50 and Co nanotriangles with uniform sizes. In addition to crystallographic and microstructural characterizations, we evaluated the magnetic properties of the nanostructures both from a qualitative (MFM) and quantitative (SQUID) point of view. The magnetic stability of the single-domain FePt nanodots was evidenced by focused MOKE analysis. This is of major importance for further use in magnetic storage applications and has never been reported yet. The soft magnetic Co nanodots displayed either single domain or vortex domains states, depending on the magnetization direction. The MOKE hysteresis loops revealed an increased coercive field compared with thin films. This is probably due to a specific magnetization reversal process caused by the shape of the nanodots. Oxide nanostructures were then manufactured. The polystyrene templates (490 nm diameter) were used for the guided hydrothermal growth of well-aligned ZnO nanowires. The control of the spacing between the nanowires combined with high c-axis preferred orientation led to higher dye loading values compared with continuous unpatterned films. This was undoubtedly attributed to an increased accessible surface area due to the patterning. Moreover, the increased roughness due to the patterning induced a higher water contact angle compared with an unpatterned ZnO nanowire array. Reversible superhydrophylicity to hydrophobicity was observed and controlled by successive UV illumination and O2 annealing. The achievements attained in this work have brought a significant contribution to the field of nano- and microfabrication. New pathways were opened for interesting future work with respect to continued fundamental and applied research. [less ▲]Detailed reference viewed: 285 (59 ULg) Experimental and numerical study of the factors influencing the performances of magnetic screens made of high temperature superconductorsFagnard, Jean-François Doctoral thesis (2011)In this thesis, we investigate in details the magnetic shielding processes in high temperature superconductors. We aim at predicting and measuring the influence of the parameters governing the ... [more ▼]In this thesis, we investigate in details the magnetic shielding processes in high temperature superconductors. We aim at predicting and measuring the influence of the parameters governing the superconducting behaviour (e.g., the critical current density Jc and its field dependence) on the magnetic flux penetration inside hollow cylinders. Three objectives are pursued. The first objective is to characterize the performances of cylindrical magnetic shields made of various high temperature superconductors (Bi-2223, Bi-2212, Y-123) for several external parameters that can be directly controlled in the experiments. These include the temperature, the geometry of the magnetic screen, the amplitude of the applied magnetic field, its orientation (H // or ⊥ cylinder axis) and its frequency (in the case of an AC excitation). The focus has been put on the effect of the sweep rate of the applied magnetic field, dBapp/dt, on the threshold magnetic flux density, Blim, above which the magnetic shielding is no longer efficient. We show that the curve of dBapp/dt vs. Blim can be directly related to the E(J) constitutive law and we explain how the field dependence of the critical current density affects the relationship between both curves. A wide range of electric field levels is investigated in this thesis thanks to the use of a number of experimental techniques. The experimental set-ups required for these investigations are described in a separate chapter where the performances and limitations of each set-up is put forward. The second objective of the thesis is to confront experimental data and numerical simulations using models of increasing complexity. We present two numerical models that take into account the strongly non-linear E(J) relationship characterizing the superconducting behaviour. The first numerical model is based on the Brandt algorithm. This model is able to describe magnetic shielding experiments which involve time-varying magnetic fields on (i) infinite samples subjected to transverse magnetic fields or on (ii) samples of finite size in axisymmetric geometries subjected to axial magnetic fields. The second model is based on a finite element method (using the GetDP software). This model can be used for both axisymmetric 2D modelling and full 3D modelling. In the latter case, it provides extremely useful information for understanding configurations where the applied magnetic field and the hollow cylinder do not present a particular symmetry. Both 2D and 3D models are able to provide current and field distributions in the superconductor. The confrontation between experimental and modelling results allows us to better understand how physical properties (critical temperature Tc, critical current density Jc, ...) and geometry affect the magnetic shielding performances (shielding factor SF, threshold induction Blim). Conversely, we present three different practical procedures using either the analytical Bean model or a 2D numerical model in order to determine the constitutive law parameters of the superconducting materials from data measured on hollow cylinders. As a third objective, we aim at investigating how the different types of HTS magnetic screens of moderate dimensions (a few cubic centimetres) could be scaled up in order to provide larger shielded volumes. Three methods are explored. The first method to build larger magnetic screens (typically ten(s) of centimetres) is to find means to assemble several (pieces of) superconducting hollow cylinders to obtain a large shielding enclosure. Experiments are carried out on superconducting cylinders cut either along or perpendicular to their axis. The influence of the cut width and the angle of the applied magnetic field with respect to the cut plane are studied. Modellings are carried out on shorter cylinders in order to understand how the presence of the cut modifies the current distribution and thus the magnetic shielding properties. The second method consist in characterizing the magnetic shielding of several hollow cylinders made with the same superconducting material but having different sizes. This helps us in determining whether the manufacturing process is able to provide large cylinders with good magnetic shielding performances. In a last method, we investigate an architecture of superconducting magnetic screens that differs from those based on bulk hollow cylinders. The idea is to exploit the high Jc-performances of superconducting tapes (based on thin film technology) to build magnetic shielding structures which can be easily scalable. The measurement results obtained on such structures are promising as the actual limitation seems to be geometrical. Using more superconducting tapes in order to achieve a higher aspect ratio should give magnetic shields which are as efficient as bulk cylinders. [less ▲]Detailed reference viewed: 52 (14 ULg) Le contexte urbain et climatique des risques hydrologiques de la ville de Butembo (Nord Kivu/RDC)Muhindo, Sahani Doctoral thesis (2011)Butembo, a small town in the humid tropical region, is a typical case of, a city with an exceptionally rapid population growth. The spontaneous concentration of populations due to uncontrolled migration ... [more ▼]Butembo, a small town in the humid tropical region, is a typical case of, a city with an exceptionally rapid population growth. The spontaneous concentration of populations due to uncontrolled migration on a relatively small territory has led to urban sprawl. Soil sealing of large areas caused by a rapid spatial expansion of the town has generated environmental problems that affect the urban structure. The city is facing diverse hydrological risks. Progressive and regressive gully development accelerates and increasingly affects water availability. In recent years, the urban area faces floods, perceived locally as exceptional. The remobilization of old landslides locally causes damage. Since its inception, Butembo has never had an objective reference map. The only ones which are available are manually drawn. It is known that land use planning can fight effectively against most major risks in so far as the elements that govern their occurrence are known and that the areas at risk can be located and defined on the basis of objective and scientific criteria. The main goal of this thesis is to produce a map of and for the city of Butembo which can help to support decision making or at least to understand the reasons of the environmental degradation in the urban area. In that direction, this thesis leads to editing a map of hydrological risks. It is based on approaches combining remote sensing and terrain activities. A detailed analysis of rainfall events is made to see if the rains did influence the environmental problems in the town of Butembo. The results reveal an exceptional urban expansion. The urban sprawl of Butembo increased from 2,39 km² in 1957 to 85,83 km² in 2008, approximately 54 % of 158,95 km². This increase in urban area is the result of exceptional population growth in the town. Indeed, the population rose from 9 653 in 1957 to 581 449 inhabitants in 2008. This urbanization has resulted in a new land use with all the consequences on the urban landscape. Since 1957 valley and hillslope gullying remained all the time confined spatially within the diachronic urbanized expansions. Urbanization precedes the development of gullies and these are confined to areas where the runoff coefficient increased by urbanization. For the time being, there is not yet fusion between progressive and regressive gullies. In the future, flooding threats all the flat valley bottoms in the case nothing is done. Landslides are active and are in the creep phase. 11 of the 16 landslides inventoried are partially co-triggered by seismic. Finally, the damage to the urban structure cannot be ascribed to changes in the rainfall pattern over the 30 last years. All the rains of recent years are normal for the city as their recurrence time is under 6 years. The main cause of environmental problems within the city is urbanization. Remediation methods require intervention not only in the field of runoff evacuation. The problems must also be tackled upstream, on the slopes, using all the techniques that can prevent or reduce the generation of runoff. [less ▲]Detailed reference viewed: 125 (16 ULg) Identification et caractérisation de bactériocines produites par deux bactéries lactiques (Enterococcus faecium CWBI-B1430 et Enterococcus mundtii CWBI-B1431) isolées à partir de fromages frais artisanaux péruviensAguilar Galvez, Ana Consuelo Doctoral thesis (2011)A screening of lactic acid bacteria (LAB) with bacteriocin-like inhibitory activity against Listeria monocytogenes was performed. The screening was conducted in 27 traditional artisanal-produced cheeses ... [more ▼]A screening of lactic acid bacteria (LAB) with bacteriocin-like inhibitory activity against Listeria monocytogenes was performed. The screening was conducted in 27 traditional artisanal-produced cheeses obtained from different Peruvian regions. Two thousand two hundred and seventy seven strains (2277) were isolated, of which 20 exhibited bacteriocin-like inhibitory activity, two strains stand out for having higher activity against listeria, as well as stability at pH value of 2-11 and a thermal stability. The two strains were identified using 16 S ribosomal DNA method, and were registered in the GenBank database of NCBI (National Center for Biotechnology Information). These were Enterococcus faecium CWBI-B1430 (accession number EF591817) and Enterococcus mundtii CWBI-B1431 (accession number EF591816). Two of the major factors concerned in a potential health risk associated with the genus Enterococcus were evaluated, and it was demonstrated that they were sensitive to vancomycin and showed no hemolytic activity. Genetic studies showed the presence of four putative bacteriocin genes in both strains, these were enterocin A, enterocin B, enterocin P, and mundticin KS. The reverse transcription-PCR analysis was realized, the expression of the bacteriocin genes enterocin A, enterocin B, and mundticin KS in CWBI-B1430 was showed, while bacteriocin genes enterocin P and mundticin KS was demonstrated in CWBI-B1431. These results are the first report of the expression of mundticin KS in E. faecium and enterocin P in E. mundtii. Also, the expression was studied at different temperatures, unlike the enterocin P, where only a positive signal was obtained at 12 and 37°C. All other enterocin showed positive signal at 12, 30, 37 and 42°C. The production of bacteriocins on a small scale, in both strains was studied. It was investigate the influence of initial pH (4.5, 5.0, 5.5, 6.0, 6.5 and 7.0), temperature (25, 30 and 37°C) and oxygen level (anaerobic, microaerobic and aerobic). The conditions for maximizing the production of bacteriocins are : initial pH of 7.0, at 37 °C, and microaerobic conditions for CWBI-B1430 strain; initial pH of 6.5, at 37 °C, and an aerobic condition for CWBI-B1431. The influence of the source of carbon and nitrogen, as well as their concentration in the bacteriocin production, was studied. The study of the production of short-chain fatty acids by these strains of multiproducing bacteriocins, showed the propionic acid as the most important. The purification study confirmed that the two bacteria in question are multi-producing of bacteriocins, as shown by the obtained chromatograms, showing different molecular weights, different charge and hydrophobicity level. The results of in situ application of the two selected strains or their supernatant does not show the same efficiency as those obtained in vitro. Factors such as temperature and food composition may be the origin of these results. Therefore, we propose the use of both strains in the food industry, for being multi-producing bacteriocins, have broad spectrum of inhibition and because the substances that produce have functional properties that are useful in the food industry. [less ▲]Detailed reference viewed: 271 (17 ULg) Power Line Conductors, a Contribution to the Analysis of their Dynamic BehaviourGuérard, Suzanne Doctoral thesis (2011)Detailed reference viewed: 48 (7 ULg) THE ROLE OF CUSTOMER PERCEIVED EMPLOYEE EMOTIONAL COMPETENCE IN SERVICE ENCOUNTERSDelcourt, Cécile Doctoral thesis (2011)The present dissertation is based on three studies, sharing one common theme: employee emotional competence (EEC). The overall aim of this dissertation is to examine the effect of customer perceptions of ... [more ▼]The present dissertation is based on three studies, sharing one common theme: employee emotional competence (EEC). The overall aim of this dissertation is to examine the effect of customer perceptions of employee emotional competence on their evaluations of critical service encounters. To achieve this goal, each study builds a theoretical framework and presents empirical assessments of aspects of the issue under consideration. While psychology scholars have conceptualized, measured, and evaluated the impact of EEC in work-related relationships (i.e., internal perspective of EEC), the role of EEC in customer-related relationships (i.e., service encounters) has received little attention by marketing scholars. We argue in this dissertation that a customer perspective of EEC is necessary to examine EEC in such context. Recent studies in the service literature have suggested that EEC could be valuable in service encounters–especially in critical service encounters since customers want employees to recognize the uniqueness of their personal experience (Price et al., 1995b). Given the potential influential role of EEC in a marketing context, researchers have called for further investigation (Kidwell et al., 2011; Verbeke et al., 2008). Therefore, this dissertation approaches the concept of EEC by first focusing on emotional competence (i.e., the actual demonstration of emotionally competent behaviors by the employee) instead of emotional intelligence (i.e., the potential one employee has to demonstrate emotionally competent behaviors). In this respect, we examine customer perceptions–rather than employee perceptions or supervisor perceptions of EEC–since these last measures are subject to important biases and since only customers can evaluate if the employee has actually displayed emotionally competent behaviors during the service encounter. More specifically, the focus is on the exploration of EEC and its effects on customer outcomes. Based on a review of the literature from various disciplines and research streams, comprehensive models are constructed, summarizing theoretical propositions and hypotheses. The first study examines in a field study the impact of customer perceptions of EEC on customer satisfaction and loyalty in high-contact services. The mediating role of rapport is examined. We found that EEC influence both customer satisfaction and loyalty. Rapport mediates both relationships. The second study aims to conceptualize EEC in service encounters and to develop a short, valid, and reliable measure based on that conceptualization. By using a rigorous scale development procedure, we define EEC as customer perceptions of employees’ abilities to perceive, understand, and regulate customer emotions in a service encounter to ensure harmonious encounters. This measure of EEC is strongly related to key customer outcomes such as customer satisfaction. The third study aims to understand in an experimental design the role of EEC compared to employee technical competence (ETC) in emotionally charged service encounters. We found that EEC moderates the relationship between ETC and customer outcomes such as negative customer emotions, rapport, and service encounter satisfaction. When EEC is low, the impact of ETC on those variables is low or even non significant. When EEC is high, ETC strongly influences those customer outcomes. Together, the three studies provide rich insights on the impact of EEC on customer outcomes in a service encounter context. To improve the customer’s experience in service encounters, managers should encourage their contact employees to display emotionally competent behaviors by perceiving, understanding, and regulating customer emotions. When employees have high EEC, the impact of ETC on customers is the highest. Rapport mediates the relationship between EEC and key customer outcomes such as customer satisfaction and loyalty. [less ▲]Detailed reference viewed: 138 (11 ULg) Entre Union européenne et Région wallonne : multiplicité des échelons de pouvoir et subsidiarité territoriale Analyse de la subsidiarité territoriale au travers des directives Seveso, IPPC, responsabilité environnementale et de leurs mesures de transposition en Région wallonne.Hanson, Sophie Doctoral thesis (2011)La Région wallonne s’inscrit dans un contexte organisationnel particulier. D’une part, elle constitue une composante d’un État membre de l’Union européenne. D’autre part, elle fait partie d’un État à ... [more ▼]La Région wallonne s’inscrit dans un contexte organisationnel particulier. D’une part, elle constitue une composante d’un État membre de l’Union européenne. D’autre part, elle fait partie d’un État à structure fédérale comportant une entité fédérale, des entités fédérées et des collectivités locales (provinces, communes). Il est permis de s'interroger, dans ce contexte, sur la nature des relations que peut entretenir la Région wallonne avec les entités gravitant autour d’elle. Le principe de subsidiarité, dans sa fonction territoriale, peut constituer une clé de lecture dans la mesure où il est indissociable des systèmes institutionnels multi-niveaux. Il implique que ce soit l’échelon qui est le plus proche des citoyens qui soit privilégié afin de remplir une tâche. Si toutefois, il ne parvient pas à rencontrer un objectif déterminé, l’échelon supérieur peut intervenir s’il peut satisfaire ce dernier de manière plus efficace. La question centrale qui a guidé la recherche a donc été de savoir, au travers de l’exemple de la Région wallonne, si les rapports entre les échelons de pouvoir, de la commune à l’Union européenne s’effectuent en application du principe de subsidiarité, dans sa fonction territoriale. Trois directives européennes importantes ressortissant au domaine de l'environnement (Seveso, IPPC et responsabilité environnementale) ainsi que leurs mesures de transposition en Région wallonne ont été examinées à l'aune de ce principe. [less ▲]Detailed reference viewed: 68 (16 ULg) Des projets aux réseaux: la construction d'un compromisVandenborne, Emilie Doctoral thesis (2011)Cette thèse étudie la construction en réseaux des projets. Elle a pour objet une sociologie de l’action en réseaux appuyée d’une sociologie des normes et d’une sociologie de l’acteur-réseau. Elle ... [more ▼]Cette thèse étudie la construction en réseaux des projets. Elle a pour objet une sociologie de l’action en réseaux appuyée d’une sociologie des normes et d’une sociologie de l’acteur-réseau. Elle interroge les comportements collectifs autour de projets au sein du secteur biotechnologique. La question centrale qui se pose est celle de l’apparition de nouvelles formes de gouvernance réticulaire à partir d’une configuration par projets. [less ▲]Detailed reference viewed: 96 (30 ULg) Avant Hergé. Etude des premières apparitions de bande dessinée en Belgique francophone (1830-1914).Paques, Frédéric Doctoral thesis (2011)Detailed reference viewed: 84 (12 ULg) Le Dictionnaire au second degré. Socio-logiques d'un détournement générique.Saint-Amand, Denis Doctoral thesis (2011)Detailed reference viewed: 50 (12 ULg) Conception et synthèse de nouveaux complexes de ruthénium pour la formation catalytique de liaisons C–CBorguet, Yannick Doctoral thesis (2011)During the last decade, catalytic methods enabling the formation of single and multiple C–C bonds have sparked a major interest from the Chemists community. Among them, olefin metathesis has emerged as a ... [more ▼]During the last decade, catalytic methods enabling the formation of single and multiple C–C bonds have sparked a major interest from the Chemists community. Among them, olefin metathesis has emerged as a powerful tool, opening unique routes to synthesize organic compounds and polymers. This is mainly due to the advent of well-defined ruthenium–benzylidene complexes first developed by Grubbs and co-workers in the early 1990’s. Since then, countless structural alterations have been made to these archetypal compounds in order to tailor their activity, stability, solubility, . . . However, the synthesis of these derivatives may be tedious and costly since it almost systematically requires the use of the Grubbs 1st generation catalyst as a starting material. Therefore, non-proprietary catalysts with high activity are still eagerly sought. This thesis is mainly focused on the design of straightforward and reliable syntheses of new complexes derived from the homobimetallic molecular scaffold (I) first reported by Severin in 2005. Our first aim was to enhance the catalytic activity of such compounds in olefin metathesis and in controlled radical reactions. [less ▲]Detailed reference viewed: 94 (19 ULg) Rôle des moustiques Culicidae, de leurs communautés microbiennes et des réservoirs vertébrés, dans la transmission des arbovirus à MadagascarRaharimalala, Fara Nantenaina Doctoral thesis (2011)These last ten years, Indian Ocean islands have been the theatre of severe epidemics of arboviroses. However, little information was available about the local dynamics of the virus transmission and ... [more ▼]These last ten years, Indian Ocean islands have been the theatre of severe epidemics of arboviroses. However, little information was available about the local dynamics of the virus transmission and identity of the vector species and vertebrates réservoirs involved. Madagascar island was chosen for its high endemic biodiversity, contrasting climatic conditions and drastic changes in habitats due to an increase anthropic pressure. These factors increase the epidemiological risks of infectious diseases. In this context, our objective was to characterize the role of Culicidae as major vectors, the associated microbial communities, and wild vertebrates (lémurs) as potential réservoirs in the transmission arboviroses. Molecular techniques allowed udpdating the biogeography of Aedes and showed the dominance of Aedes albopictus competent to chikungunya virus. Other mosquitoes captured belonged to Culex antennatus, Culex decens, Culex quinquefasciatus et Mansonia uniformis. The bacterium Wolbachia was detected in most mosquito especies,but Culex antennatus. Searching of arboviruses by qRT‐PCR revealed infection of Culex antennatus and lemurs (Lepilemur edwardsi et Eulemur rufus) by the rift valley fever virus. [less ▲]Detailed reference viewed: 35 (5 ULg) Contribution to the epidemiology of bovine tuberculosis in northern EcuadorProaño Perez, Freddy Doctoral thesis (2011)See attached document, page viiDetailed reference viewed: 23 (3 ULg) Impact des facteurs de contexte sur le design des systèmes de contrôle de gestion dans les collectivités locales béninoises: Une approche contingenteTogodo Azon, Degodo Aimé Doctoral thesis (2011)Très peu d’études empiriques ont analysé les facteurs qui influencent le design des systèmes de contrôle de gestion dans les collectivités locales de l’Afrique au Sud du Sahara. La présente recherche, qui ... [more ▼]Très peu d’études empiriques ont analysé les facteurs qui influencent le design des systèmes de contrôle de gestion dans les collectivités locales de l’Afrique au Sud du Sahara. La présente recherche, qui prend pour cadre le Bénin, explore les facteurs qui influencent le design des systèmes de contrôle de gestion dans les communes béninoises. Pour ce faire, nous avons développé six chapitres complémentaires articulés en trois parties. Dans une première partie, nous avons fait un état de la littérature qui aboutit à un modèle conceptuel. Ce modèle présente les différents outils de contrôle de gestion et les facteurs organisationnels et extra-organisationnels susceptibles d’influencer le choix des outils. La deuxième partie est une étude empirique hypothético-déductive à base de questionnaires sur soixante-dix communes béninoises. Dans cette partie, nous avons présenté les caractéristiques des systèmes de contrôle de gestion utilisés dans les communes béninoises et identifié les facteurs institutionnels et socioculturels qui influencent la configuration organisationnelle et le design des systèmes de contrôle de gestion dans les collectivités locales béninoises. La troisième partie est une étude empirique inductive qui présente trois études de cas. Ces études de cas, utilisées en complément et en approfondissement de l’analyse quantitative, ont révélé le rôle capital que joue le style de management adopté par les autorités locales dans la gestion du changement organisationnel et dans la maitrise des pressions politiques locales. Enfin, la recherche s’achève en dégageant les principales implications de notre modélisation sur l’introduction de la Nouvelle Gestion Publique en Afrique sub-saharienne et sur le type de décentralisation choisi par le Bénin. [less ▲]Detailed reference viewed: 103 (13 ULg) Etudes sur le syntagme nominal en néo-égyptien: l'article zéro, la possession attributive et le changement de genreNéven, Laurence Doctoral thesis (2011)Le syntagme nominal offre de nombreuses possibilités de recherches. Les études peuvent se concentrer sur des syntagmes nominaux simples ou complexes et s’intéresser aux différents éléments qui les ... [more ▼]Le syntagme nominal offre de nombreuses possibilités de recherches. Les études peuvent se concentrer sur des syntagmes nominaux simples ou complexes et s’intéresser aux différents éléments qui les composent. De même, les relations syntaxiques entre deux ou plusieurs syntagmes nominaux peuvent faire l’objet d’une attention particulière et les recherches peuvent se focaliser sur une langue ou un état de langue spécifique, ou, au contraire, s’envisager dans une perspective typologique prenant en compte un nombre plus ou moins élevé de langues. Dans le cadre de ma thèse de doctorat, j’ai décidé de me concentrer sur le néo-égyptien et d’étudier trois points essentiels qui sont la détermination, la possession et le genre. Le premier chapitre de ce travail s’est intéressé à la détermination des substantifs et plus particulièrement aux articles. L’originalité de cette partie réside dans le fait de proposer et de montrer l’existence d’un article zéro qui peut être intégré au paradigme des articles. Celui-ci se distingue dès lors d’une absence d’article. L’opposition entre ces deux concepts repose sur certains critères fondamentaux. Il faut ainsi que le syntagme nominal précédé de zéro puisse commuter avec un syntagme nominal précédé d’un article défini et/ou indéfini. Il doit également se trouver dans un environnement syntaxique similaire et offrir à l’ensemble une signification particulière. J’ai constaté qu’il existait des alternances entre l’article défini, indéfini et zéro (apposition, générique et vocatif). Si ce n’est dans le cas du générique, l’usage d’un zéro n’est pas significatif. J’ai également étudié l’emploi des déterminants au sein de certaines constructions spécifiques et de catégories de noms (abstraits, collectifs, comptables, de fonction, massifs et propres). Seuls les noms abstraits, comptables et massifs font usage d’un zéro significatif. L’article défini sert à spécifier l’entité ou à référer à une entité connue à la fois du locuteur et de l’interlocuteur. L’article indéfini réfère également à une entité particulière, mais spécifique ou non. Enfin, l’article zéro est utilisé lorsque l’on veut référer à une entité homogène et dénote une non-quantification absolue. L’opposition à deux membres, c’est-à-dire entre l’article défini et zéro s’est révélée pertinente dans le cas des noms abstraits et des noms comptables ; et l’opposition à trois membres, c’est-à-dire entre l’article défini, l’article indéfini et zéro s’est révélée pertinente avec les noms massifs. Il semble donc que la présence d’un article zéro soit principalement liée à certaines catégories de substantifs et ne réponde pas à des critères syntaxiques selon sa présence dans telle ou telle construction. L’objectif de mon chapitre II était d’offrir une classification des divers procédés permettant d’exprimer la possession attributive en néo-égyptien. L’examen de ces moyens formels s’est réalisé en se fondant sur trois points principaux : l’environnement syntaxique et sémantique, l’influence du genre littéraire et/ou du registre de texte et l’évolution diachronique. L’opposition entre l’article possessif et le pronom suffixe est principalement une opposition de registre textuel, mais elle peut également être d’ordre syntaxique ou sémantique. L’opposition entre l’article possessif et le pronom indépendant concerne la définition des possédés. Le pronom indépendant est employé lorsque le substantif est indéfini ou précédé du démonstratif. La préposition m-di prendra le relais du pronom indépendant dans l’expression de la possession attributive, mais les prémices de ce remplacement fonctionnel ne sont pas perceptibles avant la fin de la 20e dynastie. En revanche, l’opposition entre le génitif direct et le génitif indirect est quasi inexistante. En effet, le génitif direct n’est guère plus productif et se limite pour la majeure partie aux titres de fonctions. L’objectif de mon dernier chapitre était de montrer qu’ont existé en égyptien ancien des changements ou des variations de genre. Cette étude ne pouvait se prétendre exhaustive en regard du corpus délimité. J’ai donc voulu poser les premiers jalons et proposer des hypothèses qui expliqueraient certains de ces changements ou de ces flottements. En me fondant principalement sur la contribution de Michel Roché, concernant les variations du genre en langue française, j’ai établi cinq schémas prenant en compte les différentes possibilités. Les principaux arguments qui m’ont été utiles pour l’analyse du genre sont les articles ou leurs substituts et l’accord du pseudo-participe et du pronom de rappel (pronom suffixe). Cela m’a permis de mettre en exergue plusieurs mots qui ont connu un flottement dans l’attribution du genre avec un retour au genre originel (principalement des parties du corps), ainsi que des substantifs qui ont changé de genre entre le néo-égyptien et le démotique (AH.t et btA). Le mot dmi « ville », quant à lui, correspond peut-être à un dédoublement de genre dans lequel le nouveau lexème dmi.t se spécifie sémantiquement. Enfin, l’emprunt de mots sémitiques a également provoqué des confusions dans le genre des noms et plus spécifiquement parmi les substantifs qui originellement se terminent par un –t appartenant au radical. J’ai proposé plusieurs hypothèses pour expliquer ces changements ou flottements de genre. Il s’agit de l’absence ou la rareté du déterminant, des changements phonétiques, de la proximité formelle et sémantique de deux substantifs et de l’emprunt à des langues étrangères. [less ▲]Detailed reference viewed: 47 (14 ULg) Génétique de la neuropathie laryngée récurrente chez le chevalDupuis, Marie-Capucine Doctoral thesis (2011)Recurrent laryngeal neuropathy (RLN), known as « roaring » or « whistling », has been considered as the most important equine airway disease of the horse. It can cause abnormal respiratory noise during ... [more ▼]Recurrent laryngeal neuropathy (RLN), known as « roaring » or « whistling », has been considered as the most important equine airway disease of the horse. It can cause abnormal respiratory noise during fast exercise, secondary to a reduced abduction of the left arytenoid cartilage, which may impair performance. Despite significant research into the disease, some aspects, such as etiology and pathogenesis, remain unknown. Several papers suggest a genetic basis but molecular studies have never been reported. Using the EquineSNP50 Beadchip, we genotyped 234 cases (196 Warmbloods, 20 Trotters, 14 Thoroughbreds and 4 Draft Horses), 228 breed-matched controls and 69 parents. Linkage disequilibrium and population structure were quantified before performing single marker and haplotype-based association studies, as well as family-based linkage analyses. Two genome-wide suggestive loci were identified on chromosomes 21 and 31, driven by the enrichment of a “protective” haplotype in controls compared to cases. Our study indicates that predisposition to RLN has a complex determinism, probably involving a high number of genes, of which the candidates on chromosome 21 and 31 may have the largest effects. We performed a copy-number variants analysis on the same data. After characterization of the regions harbouring these variants, an association study with RLN was conducted. A duplication on chromosome 10 was identified in ten affected horses and two unphenotyped parents that were sharing a long haplotype. This work provides novel insights in the genetic determinism of NLR and opens new field of research. If the genuine nature of these loci is confirmed in independent cohorts, identifying the causative genes may increase our understanding of RLN pathogenesis. Assuming that RLN is very polygenic, predictive diagnosis and selection may be more effective using a genomic selection type of approach. [less ▲]Detailed reference viewed: 39 (13 ULg) Studii privind perfectionarea managementului strategic in dezvoltarea rurala durabila din Depresiunea Jijia-BahluiPaveliuc Olariu, Codrin Doctoral thesis (2011)This paper addresses one of the most current and important problem of the Romanian rural space, whose study is absolutely necessary for the uniformous performance of the different types of socio-economic ... [more ▼]This paper addresses one of the most current and important problem of the Romanian rural space, whose study is absolutely necessary for the uniformous performance of the different types of socio-economic activities at rural communities level, namely sustainable rural development. The motivation behind this PhD thesis is constituted by the relevance of the scientific and practical importance of the role that a formal proces of strategic management in sustainable rural development holds at rural communities level both from their development options point of view and, also, in its whole. Extremely important for the strategic management of sustainable rural development are the analysis of the linkages that exist between rural communities and urban centres and their evaluation because, through this areas specificity, both constitute environments that can easily influence development at individual and society level in case a way of harnessing them doesnt exist. Thus, the implementation of the strategic management concept becomes necessary whose role is to manage and evaluate the previously mentioned phenomenon. From this point of view, strategic management can be defined as a set of rigurously established and organized activities which, starting from local existing conditions, analyze the needs and development potential of the rural community in a development vision in view of filtering and minimizing the negative effect of rural-urban linkages. By choosing the “Studies regarding the improvement of strategic management in sustainable rural development in the Jijia-Bahlui Depression” theme I followed to highlight a problem by understanding which you can explain the causes of the socio-economic success or failure of rural communities. Choosing the research team regarding strategic management in sustainable rural development can be justified through the ever growing interest manifested at public level through the development of rural space and rural development support policies. The main principle of the PhD thesis is constituted by offering a conceptual framework for analyzing and identifying the needs and the development potential of rura l communities that are the basis of the strategic process. The key words of the paper are: strategy, rural, urban, rurbanization, rural-urban lonkages, strategic management, development, rural space, rural environment, rurality, quality of life, community, inhabitant, decision, decision making process, decision factor, needs, potential. Synthesis of the main parts in the PhD thesis First part, „BIBLIOGRAPHIC STUDY REGARDING SUSTAINABLE RURAL DEVELOPMENT OF LOCAL COMMUNITIES” consists of 2 chapters that hold theoretical aspects regarding sustainable rural development, rurbanization, quality of life and strategic management. Part II, „OWN RESEARCHED, RESULTS AND THEIR INTERPRETATION” is composed of 6 chapters that underline own ressearches carried out along side the results and their interpretations. The first chapter of the PhD thesis „STUDIES REGARDING THE SUSTAINABLE RURAL DEVELOPMENT CONCEPT” is an introductory, explicatory one, realizing a general analysis of the basic concepts specific to the sustainable rural development process in local communities. In its evolution, chapter I presents a few theoretical aspects regarding the dimesions of sustainable rural development, also observing the functions and interdependencies that arrise at its level. Also, the first chapter refers to the evolution and state of knowledge regarding quality of life. The quality of life analysis in this cahpte starts from presenting the concept in different forms, then continuing with its manifestations under the form of the poverty concept. Also, the quality of life indicators utilized at world level are presented, a plurality of approached being noticed not just in regards to concept, but also from the phenomenon practicality point of view. CHAPTER II – „RESEARCH REGARDING LOCAL ENVIRONMENT INFLUENCES ON THE SUSTAINABLE RURAL DEVELOPMENT PROCESS” defines the idea that, at local community level, there are influences of the internal and external environment on the socio - economic development on individual and society level. Harnessing these influences through adopting some strategies by the local public administration in this sense assmues the indetification and their evaluation with great accuracy and, in their support comes strategic management which becomes an indispensable guide for management critical situations in the local socio-economic development. The importance of this chapte derives from the fact that strategic management, as an essential tool in local public administration, holds as a purpose to streamline the local development process in order to realize the set objectives with maximum efficiency. Strategic management implies the establishment by local public authorities of the vision that is willing to assume and, also, concrete establishing of the strategic development objectives following a deep analysis of locally existing needs,and,also, of the individual and society potential. Also, rurbanization has been defined, beed identified key decision factors at local level, with a focus on public institutions representatives with a role in developing and implementing public policies. CHAPTER III „PURPOSE, OBJECTIVES AND RESEARCH METHOD” reveals the main scientific purpose of the paper. The needs and development potential of rural communities and, also, or rural-urban interactions evaluation constitutes the main scientific purpose of the paper. the main objective of the thesis is represented by the identification and evaluation and, also, of interactions that exist between rural communities and urban centres and adopting the adequate measures to adapt these to the specific of the local community. The specific objective of the paper resides in applying the strategic management process in sustainable rural development at the Belcesti commune level through the prism of the two components: analysis on the basis of the needs and development potential of the rural community and strategic management through rural-urban linkages and rural-rural flows. Overcoming the answers formulation difficulties assumes adopting decisions to the resources allocation method, optimizing local development strategies and, also, the ways of attracting at local level the positive rural-urban and rural-rural flows. CHAPTER IV, named „THE ANALYSIS OF THE BELCESTI COMMUNE LOCAL ENVIRONMENT” presents a few aspects regarding the definition of the Jijia-Bahlui Depression rural environment, natural resources, human resources, economic resources, local economy, performances, risks and recent accomplishments of agriculture and, also, the agriculture market of Belcesti commune. In this chapter the research area has been delimited, the analysis being oriented towards studying the way in which strategic management is done at local level, the main problems of local development, respectively infrastructure development, cultura and social cohesion. CHAPTER V – „ANALZA NEVOILOR ŞI POTENŢIALULUI DE DEZVOLTARE A COMUNEI BELCEŞTI, JUDEŢUL IAŞI” is dedicated to the case study done in Belcesti commune, Iasi county. Belcesti commune corespunde to the demands regarding a complex and rigurous approach as constituted by the present paper. The paper offers the theoretical-methodological framework necessary to the scientific and operational substantiation of the strategic management at commune level. The reasoning that substantiated this approach needed, on one side, the conceptual identification of the necessary methodology for evaluating the needs and development potential at local community level in five areas of activity proven of special importance for Belcesti commune. The principle that stands at the basis of the Belcesti commune development is the continuous improvement of the local environment through the growth of the administrative capacity of the local public authorities, these trying to give citizens trust in the decision making process. This chapter is dedicated to the evaluation of the needs and development potential of the community through the working groups methods as a response to the risk associated to the existing development discrepancies at this time in the North-East Development Region. The general local development strategies that presently exist in Romanian communes depend on the criterias used. Depending on the frequency and impact of the utilized analysis you can choose as response measures between prevention, avoidance and decisions transfer. A sustainable rural development process must constitute a major component of any decision making process having an important role in accomplishing foreseen at its initiation. The presented indicators have a relative common evolution tendency, the interactions between areas of activitities and their areas of expertise being major influence factor. CHAPTER VI – „THE ANALYSIS OF RURAL-URBAN LINKAGES AND OF THE RURBANIZATION EFFECT ON THE SOCIO-ECONOMIC DEVELOPMENT OF THE LOCAL COMMUNITY – BELCESTI COMMUNE, IASI COUNTY” presents the importance of evaluating the existing rural-urban linkage between rural communities and neighboring urban centers. These interactions present at local communities’ level influence both the individual and society in general, their impact being analyzed through different methods. The isolation degree of a locality is the most direct way to evaluate it, the peripherality index and the distance-time one revealing the type of access to different types of services at local level and, also, the level of interaction between the analyzed commune and the surrounding localities. In the case of Belcesti commune, the peripherality index has a value of 1.15 with a low to average degree of interaction with surrounding cities, respectively Harlau and Podu Iloaiei, being instead affected from an access to services point of view as the distance-time index analysis shows us. CHAPTER VII – „SCENARIOS FOR THE SUSTAINABLE RURAL DEVELOPMENT OF THE LOCA COMMUNITY – BELCESTI COMMUNE, IASI COUNTY” summarizes the results of the realized analysis, conceiving, according to some prognosis of the effect of the evolution in three directions of the peripherality and distance-time indexes, 3 development scenarios for Belcesti commune. The existence of such a prognosis reveals the fact that, due to a well substantiated analysis, different development visions of the rural community can be realized. In the realistic scenario, this vision present the implication framework of local public authorities in the diversification and growth of the local economy by supporting entrepreneurial initiatives of different types, key areas being agriculture and tourism. These scenarios were substantiated on the basis of opinions survey done on citizens and public institutions representatives, their opinions regarding the development visions of Belcesti commune being able to influence decisively its direction. CAPITOLUL VIII – „CONCLUSIONS AND RECOMMENDATIONS” resumes the hyphoteses from which we started, underlining own interpretations and their importance at rural community level. The end of the paper is constituted in a set of conclusiond regarding the impact of the strategic management process in sustainable rural development, the evolution of some socio - economic indicators, as a result of its action in the rural space and, also, the manifestation of different components of this (individual, decision group, society, public environment, private environment etc.) to the influence of rural-urban linkages. The conclusions set out the personal contribution to solutioning problems generated by the sustainable rural development process and, indirectly, by rural-urban linkages, resorting to their utilization through filtering and recirculation in a positive manner. BIBLIOGRAPHY – is composed from a number of 79 titles from the national and international literature and, also, from Internet research. [less ▲]Detailed reference viewed: 14 (0 ULg) Contribution to the study of waste heat recovery systems on commercial truck diesel engines.Espinosa, Nicolas Doctoral thesis (2011)Detailed reference viewed: 120 (17 ULg) SEISMICALLY RETROFITTING AND UPGRADING RC-MRF BY USING EXPANDED METAL PANELSPhung Ngoc, Dung Doctoral thesis (2011)Reinforced concrete moment resisting frames (RC-MRFs) have been widely used as the main structural resisting systems for over 30 years based on their capacity in resisting both gravity loads and lateral ... [more ▼]Reinforced concrete moment resisting frames (RC-MRFs) have been widely used as the main structural resisting systems for over 30 years based on their capacity in resisting both gravity loads and lateral forces like winds or earthquakes and on low cost of construction. However, there have been still many existing RC-MRFs not designed according to any modern seismic code. This may lead to some undesired failures under a rather low intensity earthquake. There are several existing retrofitting systems available for seismically retrofitting RC-MRFs, such as steel braces, steel plate or RC shear walls, base isolators…In those, some are able to increase the stiffness, strength, deformation and energy absorbing capacity of the structures and some are able to reduce the influence of the seismic actions on the structure. Despite having advantage in increasing the stiffness and strength for the buildings, the use of bulky systems like RC shear walls to retrofit buildings under seismic actions becomes more limited due to its complication in erection and high costs for foundation. The use of lighter retrofitting systems such as steel braces or shear walls made from steel or aluminium… has been becoming more favourable. Made from sheet steel or various alloys by cutting and simultaneous stretching cold, expanded metal is considered as a macro-foam material. An expanded metal panel (EMP) with rectangular dimensions of 1.25m x 2.5m having many rhomb shape stitches with different geometrical sizes is the popular product. Currently it is employed primarily in the areas of protection (fencing, gates) and architecture. The final goal of this study is to consider a new application different in the field of civil engineering and more specifically that of the earthquake resistance of buildings. The work plan includes two main parts. This first part will set the EMP over existing techniques and see if its use is justified in the context of earthquake resistance. In addition, a more detailed description of the EMP is considered. In this way, the different data required for modelling the new resistance system are known and analyzes, tests and comparisons can be made in order to validate the use of EMP in the context of earthquake resistance. A complete study on pure shear behaviour of EMP under monotonic and quasi-static cyclic loading has been developed including experimental, theoretical and numerical investigations. To apply EMP in seismically retrofitting RC-MRFs, thirty two RC-MRFs have been designed according to two codes EC2 and EC8. The seismic performance of the studied frames has been evaluated using Pushover and NLTH analyses. For the frames designed according to EC2 or EC8 with low ductility, some prominent deficiencies are found, such as incomplete load path or the soft-story failure. Based on the knowledge of deficiencies of the existing frames, many attempts to exploit EMP to seismically retrofit the existing frames have been made. All frames designed according to EC2 and EC8 with Low Ductility Class need to retrofit because they cannot reach the target displacements due to premature failure of beam-column joints. To seismically retrofit them by using EMP, a design procedure based on Direct Displacement Based Design (DDBD) has been proposed. The design is an iterative procedure, starting with the selection of the target displacements at the top based on the results from Pushover analysis. They are usually less than the limit displacements at which RC frames collapse due to crushing of the concrete at beam-column joints. These displacements are also the target ones for the retrofitted frames. The results from design procedure proposed are significantly affected by some typical factors such as selected target displacements and capacity of the existing frames contributing to overall resistance of the retrofitted frames, equivalent viscous damping of the EMP and MRFs as well as geometrical dimensions of the existing frames. The retrofitted design results, assessed by Pushover and NLTH analyses, have indicated that DDDB is a useful tool to design EMP to seismically retrofit the existing frames. With EMP, all retrofitted frames can reach target displacements under design earthquakes without any brittle failure, not like the original frames. However, EMP cannot improve the behaviour of the beam-column joints. Under the earthquakes greater than design ones, failure of the nodes is still observed in all retrofitted frames. The comparison of the seismic performance of the frames before and after being retrofitted has shown that EMP is able to reduce the influence of the earthquake on the original frames by increasing their strength and stiffness and by absorbing the seismic energy. Proposed design procedure of connection between EMP and the frame elements is applicable. This was verified in the experiments when connecting EMP with the steel testing frames. The design approach for the connection is based on Capacity Design, all starting with the maximum resistance of the bars in a rhomb-shape stitch of the EMP and the tension field action developed in the EMP during shear loading. However, it is necessary to perform tests on the connections between EMP and the RC beams and columns. Also, improved practical details can be developed. [less ▲]Detailed reference viewed: 104 (9 ULg) Contribution to Entanglement Theory, Applications in Atomic Systems and Cavity QEDGillet, Jérémie Doctoral thesis (2011)We introduce in this thesis two entanglement detection criteria, the Schrödinger-Robertson partial transpose inequality, which can be implemented experimentally in a variety of systems and generalized N ... [more ▼]We introduce in this thesis two entanglement detection criteria, the Schrödinger-Robertson partial transpose inequality, which can be implemented experimentally in a variety of systems and generalized N-qubit concurrences, which can be used to evaluate multipartite entanglement in N-qubit mixed states. Then, we investigate ways to experimentally produce entanglement by giving a theoretical model which successfully describes the dipole blockade effect. We study its possible applications in systems of two and three two-level atoms as well as its relations with the EITeffect in systems of two three-level atoms. Finally, we show the possibility of two-photon processes in a system of two two-level atoms embedded in a cavity by using perturbation theory and a full master equation approach. We unveil interesting features of blockade and transparency in such cavity QED systems. [less ▲]Detailed reference viewed: 54 (12 ULg) Etude des protéines régulées par le froid chez une bactérie antarctique : approche protéomique et biochimique de la psychrophiliePiette, Florence Doctoral thesis (2011)Detailed reference viewed: 39 (11 ULg) Implication des cellules Natural Killer (NK) dans le développement des lésions associées à l'infection par les papillomavirus humains (HPV)Renoux, Virginie Doctoral thesis (2011)Persistent infections with high-risk papillomavirus (HPV) are associated with more than 25% of cancers induced by infectious agents. Nevertheless, the two vaccines preventing HPV infection have no ... [more ▼]Persistent infections with high-risk papillomavirus (HPV) are associated with more than 25% of cancers induced by infectious agents. Nevertheless, the two vaccines preventing HPV infection have no therapeutic efficacy and it has been estimated that there will be no measurable decline of HPV-associated tumours before 2040. The immune system is able to control, at least partially, HPV infection and subsequent tumour development. Around 90% of HPV-infected women will clear the virus within two years, but the immune effectors responsible for this viral clearance are unknown. Hence, the aim of this study was to determine if Natural Killer (NK) cells could play a role in the immune response against HPV infection and related cancers. The first part of this work was focused on the in vitro interaction of NK cells with L1 and L1L2 Virus Like Particles (VLP) of HPV16. We observed that, in the presence of HPV-VLP, NK cells displayed a higher cytotoxic activity against HPV+ cells by increasing the exocytosis of their cytotoxic granules and by secreting TNF-α and IFN-γ. NK cell activation was correlated with a fast entry of HPV-VLP by macropinocytosis and we determined that cell surface CD16 expression was necessary for HPV internalization, but also for degranulation and cytokine production. In the second part, to understand the molecular mechanisms of HPV-VLP stimulation, we investigated the signalling pathways operating in NK cells to trigger their cytotoxic activity in the presence of viral particles. We observed that the MAP kinases ERK and p38 were phosphorylated in the presence of both L1 and L1L2 HPV-VLP. Using specific inhibitors, we demonstrated that phosphorylation of these MAPK was required for degranulation and cytokine secretion by NK cells in the presence of VLP. In conclusion, NK cell activity could be an important player in the immune response contributing to viral clearance and to regression of HPV-induced cervical lesions. [less ▲]Detailed reference viewed: 65 (17 ULg) Modélisation spatialement distribuée et physiquement basée d’écoulements hydrologiques et hydrodynamiques pour l’aide à la gestion d’ouvrages hydrauliquesKhuat Duy, Bruno Doctoral thesis (2011)La gestion des ressources en eau constitue une préoccupation qui prend une place de plus en plus importante dans nos sociétés. Les événements climatiques extrêmes subis ces dernières années (pluies ... [more ▼]La gestion des ressources en eau constitue une préoccupation qui prend une place de plus en plus importante dans nos sociétés. Les événements climatiques extrêmes subis ces dernières années (pluies diluviennes mais également sécheresses) montrent toute la nécessité d’une meilleure compréhension des phénomènes en cause afin de mettre en place une gestion efficace des ressources. Ces études passent notamment par le développement de logiciels de simulation basés sur des modèles hydrologiques et hydrodynamiques fiables capables de représenter correctement les phénomènes réels mis en jeu. Cette thèse contribue à la mise en place d’un outil de modélisation spatialement distribuée et physiquement basée d’écoulements hydrologiques et hydrodynamiques, destiné notamment à fournir une aide précieuse pour la gestion d’ouvrages hydrauliques. Chaque composante de modélisation du circuit hydrologique, depuis la pluie jusqu’à l’exutoire de la rivière, est examinée. Des améliorations ou développements plus fondamentaux sont alors proposés pour améliorer la qualité de modélisation. Entre autres, cette thèse aborde en profondeur des sujets tels que la prise en compte de la microtopographie dans la représentation des phénomènes de surface (stockage dans les dépressions, écoulement en ruisselets, relations hauteurs-section-volume…), le calcul de l’infiltration (modèle à fronts multiples, effet de l’occupation du sol…) ou l’écoulement dans la couche hypodermique (écoulement saturé/non saturé, mise en pression…). Les recherches et développements portent également sur l’écoulement dans les axes de concentration (création d’un réseau de rivières cohérent à la fois avec le modèle numérique de terrain et les levés précis sur site, exploitation adéquate des données de section, modélisation efficace des ouvrages en charge ou non…). La modélisation des surfaces imperméables (avec séparation des zones égouttées ou non) est également abordée de façon détaillée, dans le cadre d’une application sur un bassin versant instrumenté de 130 km². Cette application envisage aussi bien la modélisation d’un événement ponctuel que des simulations à long terme. Enfin, l’étude d’un bassin peu instrumenté permet de montrer la large applicabilité et sa capacité à servir de support efficace dans la gestion des rivières et des ouvrages hydrauliques associés. [less ▲]Detailed reference viewed: 43 (5 ULg) Mathematical modeling of biogeochemical processes associated to a coccolithophorid (Emiliania huxleyi) bloom - Study of the seasonal and long-term variability of biogeochemical properties in the Black Sea using a Data Interpolating Variational Analysis (DIVA)Joassin, Pascal Doctoral thesis (2011)A OD biogeochemical model has been developed to represent coccolithophorid physiological features concerned by carbon export (primary production, active DOC excretion, TEP formation, and calcification ... [more ▼]A OD biogeochemical model has been developed to represent coccolithophorid physiological features concerned by carbon export (primary production, active DOC excretion, TEP formation, and calcification) and susceptible to be sensitive to varying pCO2. The model is initially calibrated and validated using a large set of biogeochemical data monitored during Emiliania huxleyi blooms induced in a mesocosm experiment, under present-day pCO2 conditions. Afterwards, impacts of varying pCO2 conditions on Emiliania huxleyi physiology are investigated using biogeochemical variables monitored in mesocosms under low and high pCO2 conditions. The methodology promotes a double approach: the recalibration model parameters’ that optimizes the representation of observations from low and high pCO2 treatments, and the utilization of a RM ANOVA procedure to indicate significant differences between biogeochemical variables monitored during blooms induced in low and high pCO2 treatments. Since the early 1970’s, the Black Sea ecosystem has suffered significant ecological alterations, essentially caused by anthropogenic impacts. Dam constructions on the Danube River in combination with heavy nutrients discharge via the riverine run-off lead to strong modifications of its physical and biogeochemical properties, with final consequences consisting in an enhancement of the typical anoxic state of the deep waters. The long-term evolution of key biogeochemical variables (oxygen, hydrogen sulfide, and chlorophyll) has been studied through the reconstruction of horizontal fields, using long time data series and the DIVA interpolating tool. In addition, the examination during the best sampled period (1986-1993) of these biogeochemical variables’ fields, completed with nitrates and phosphates fields, highlighted seasonal and horizontal variability within typical sections of their profiles. [less ▲]Detailed reference viewed: 41 (7 ULg) Optimization Methods for the design and production of Naval StructuresBay, Maud Doctoral thesis (2011)In the past decades the marine industry has undergone significant evolution and the production of large passenger ships faced dramatic changes. The size, the complexity and the security standards of the ... [more ▼]In the past decades the marine industry has undergone significant evolution and the production of large passenger ships faced dramatic changes. The size, the complexity and the security standards of the ships have increased and the ship-owners have become less and less willing to wait once the order is placed. In the meantime, due to growing intense competition, the shipyards have had to improve their efficiency and master their production costs: they progressively moved from manufacture to automated production processes. As a consequence, the shipyards have now to meet this difficult challenge: produce more complex ships, cheaper and faster. In the first part of the thesis we consider the structural optimization problem that arises in the early design phase of a project. Given a vessel overall dimensions and form, structural optimization consists in defining the scantling of the structure’s constitutive elements so as to minimize its total weight or cost, while taking weight, robustness and security issues into account. Designers have to make the most adequate choices within a very short period of time. The decisions made during the design phase have a major impact on the final structure and on its production cost. We propose new algorithms to compute near-optimal solutions of the discrete structural optimization problem. In the second part of the thesis, we turn to the building process of large ships and we present new methods to improve production facility management of shipyards. The ship building process requires the production and the assembly of tens, or even hundreds of thousands of steel elements. We define a space and time allocation problem that arises in assembly halls producing large building blocks and we develop algorithms for its solution. A successful implementation of a flexible and robust application is nowadays in use at a shipyard. [less ▲]Detailed reference viewed: 55 (7 ULg) Etude comparée de l’écologie de deux espèces jumelles de Chiroptères (Mammalia : Chiroptera ) en Belgique: l’oreillard roux (Plecotus auritus) (Linn., 1758) et l’oreillard gris (Plecotus austriacus ) (Fischer, 1829).Motte, Gregory Doctoral thesis (2011)Introduction The purpose of this study is to verify one of the principal rules of ecology: the principle of exclusive competition, by using the sibling species of long-eared bats present in Belgium as a ... [more ▼]Introduction The purpose of this study is to verify one of the principal rules of ecology: the principle of exclusive competition, by using the sibling species of long-eared bats present in Belgium as a model: the brown long-eared bat (Plecotus auritus) and the grey long-eared bat (Plecotus austriacus). Two similar species present in the same region and, what is more, share the same roost, must differ according to certain aspects of their ecological niche in order to be able to co-exist (MacNab 1971). In order to determine the resource sharing mechanisms between the two species, we have compared the three important dimensions of their ecological requirements: the use of trophic resources by means of faecal analysis and the use of space and time by radio-tracking. Trophic resources One hundred and thirty samples (4688 droppings, 6388 occurrences) taken from 5 single-species colonies of P. austriacus, 5 single-species colonies of P. auritus and from a mixed colony have been taken into account in the analysis of the summer diet. With the help of a first model constructed with the aid of generalized linear regressions, we have shown that, independently of the cohabitation conditions (single-species and mixed colonies), the two species have similar dietary requirements. Qualitatively, the same types of prey are consumed : Lepidoptera, Diptera (Craneflies, Cyclorrhapha and others Diptera), Coleoptera, Arachnids and Dermaptera. Small quantitative differences of between 3% to 8%, were seen to exist : P. austriacus consumes slightly more Coleoptera and Lepidoptera and fewer Craneflies than P. auritus. With the help of a second model enabling interspecific comparison of the diet according to whether the animal belonged to the single-species colonies or the mixed colony, we were able to show that the differences were more marked. When P. austriacus belong to single-species colonies, with reference to single-species colonies of P. auritus, predicted value indicate that they consume more Coleoptera (+ 5,0 %, p = 0,001) Lepidoptera (+ 14,4 %, p < 0,0005) and fewer Arachnids (- 8,3 %, p < 0,0005), Dermaptera (- 8,8%, p < 0,0005) and Craneflies (- 9,5 %, p = 0,009). This leads us to believe that the proportion of non-flying or diurnal prey gleaned by P. auritus is 2,5 times greater than that of P. austriacus. On the other hand, when P. austriacus belongs to the mixed colony, in reference to the P. austriacus single-species colonies, it changed its feeding behaviour. The predicted consumption of Arachnids and Dermaptera is higher, 14,5 % (p < 0,0005) and 11,3 % (p < 0,0005) respectively, while the consumption of Lepidoptera is much less (- 25,6 %, p < 0,0005). The syntopic P. austriacus also consume more craneflies (+ 7,9 %, p = 0,034) but fewer Coleoptera (-11,1 %, p = 0,009). This shows that P. austriacus posesses surprising adaptation abilities. The diet of the P. auritus of the mixed colony in relation to the single-species P. auritus, only showed slight variations on the other hand : - 7% (p = 0,006) for the Cyclorrhapha and - 4% (p = 0,002) for the Dermaptera. In syntopy, the study of seasonal variations has shown that the quantitative differences were significant at the end of gestation and lactation when the energy requirement is at its highest. In June, P. austriacus consumes more Arachnids (p = 0,046), in July, more Arachnids (p = 0,020) and fewer Lepidoptera (p = 0,020). In August, they consume more Dermaptera (p = 0.019), fewer Coleoptera (p = 0.032) and Lepidoptera (p = 0.034). Winter trophic ecology Our study has also led to the discovery of a little-known aspect of the ecology of chiroptera: winter trophic ecology. The results have shown that long-eared bats consume at least 70% of their prey which they capture by gleaning (Spiders, Dermaptera, Cyclorrhapha). These results have made it possible to confirm that the two species possess the ability to glean their prey. Spatial and temporal resources Twenty-two Plecotus were used for the analysis : seven P. auritus in Gozin, six P. austriacus in Gembes, five P. auritus and four P. austriacus in Pondrome (mixed colony). Eighty-four nights of monitoring corresponding to the discovery of 111 hunting grounds were used for the analyses. The results show that the use of space by P. auritus and P. austriacus contain similarities. The distance of the hunting grounds, the number of grounds visited per night, the duration of their use, their surface and the individual area of daily activity are similar. In the same way, contrary to what the literature suggests, it seems that P. auritus possesses the ability to exploit the open or semi-open areas like the meadows surrounded by linear woodland elements, while P. austriacus possesses the ability to exploit equally well the closed areas such as woods. In syntopy, the two species showed a different selection of habitats (grasslands, leafy woods,, gardens, edges for P. auritus and leafy or coniferous woods, gardens and edges for P. austriacus), P. auritus spending 64% of hunting time above the grassland against 83% in the woods for P. austriacus. On the other hand, in comparison with the two single-species colonies, the division of hunting time around the roost is more spread out in terms of space and the number of hunting grounds visited by night is more important. No difference in the exploitation of temporal resources was detected; the later departures from the Gozin colony were attributed to the presence of artificial lighting placed in front of the roost. The mechanisms allowing resources partitioning In the case of single-species colonies we have shown the existence of trophic resources partitioning. In fact, P. austriacus showed a diet less rich in Arachnids, Dermaptera, Craneflies and richer in Coeloptera and Lepidoptera than P. auritus. However, in syntopy, P. austriacus clearly modified its diet by consuming more Arachnids and Dermaptera to the detriment of Coleoptera and Lepidoptera. The consumption in Arachnids and Dermaptera remains higher than those of single-species P. auritus. Whether for single-species colonies or mixed colonies, trophic resources partitioning is quite evident. As requirements in terms of syntopy were modified, the results lead us to assume that inter-specific competition exists between this sibling species. The differences observed in the diet are probably dictated by a different use of the habitats. Indeed, in relation with the ecology of prey, the results of habitats use have made it possible to show that habitat partitioning occurs between the two species of long-eared bat. Our results therefore constitute a good illustration of the principle of competitive exclusion. Whether in the case of single-species colonies or mixed colonies, the two species share the trophic and spatial resources which allow them to co-exist. Recommendations for the conservation of the species To satisfy the requirements of the summer diet, it is necessary to maintain a network of diverse habitats composed of gardens, meadowlands, humid zones, hedges, bushes, tree alignments, leafy or mixed woodlands, preferably hygrophilous, allowing for the development of undergrowth and clearings. The results of the selection of surface habitats have globally confirmed the importance of these habitats used as hunting grounds. The selection of linear habitats such as tree-lines, hedges, bushes and edges also show the importance of ecological networks and the potentially damaging effects of the fragmentation of habitats on the bat population. In order to integrate the spatial requirements of P. austriacus, we recommend the establishment of a minimum protection perimeter of 3500 metres around the nest. With regard to P. auritus, it would be judicious to protect a minimum perimeter of a radius of 2000 metres. [less ▲]Detailed reference viewed: 64 (10 ULg) Financement de l'entrepreneuriat rural dans la Région du Centre au CamerounAhouissou, Brice Anicet Doctoral thesis (2011)L’une des principales contraintes des micros entrepreneurs ruraux est l’absence de structures de financement adaptées susceptibles de favoriser leur accès au financement à moindre coût avec des conditions ... [more ▼]L’une des principales contraintes des micros entrepreneurs ruraux est l’absence de structures de financement adaptées susceptibles de favoriser leur accès au financement à moindre coût avec des conditions moins contraignantes. Face à ce problème, il convient de se demander s’il n’est pas possible de développer des stratégies de financement adaptées aux micros entrepreneurs ruraux. C’est la réponse à cette question qui a servi de fil conducteur à ce travail. L’objectif global de la recherche est d’apporter une contribution à l’identification et à la réduction des principales contraintes auxquelles les entrepreneurs ruraux sont confrontés dans le financement de leurs activités. La méthodologie mise en œuvre s’est appuyée sur le suivi mensuel de 50 micros entrepreneurs pendant une année. Une enquête de validation a été organisée à la fin du suivi auprès de 141 micros entreprises, 19 usuriers et 21 Etablissements de microfinance (EMF). La mauvaise estimation des besoins de trésorerie, les taux d’intérêts élevés des crédits octroyés, les délais courts des remboursements, les faibles montants des emprunts sont les principales contraintes des micros entrepreneurs ruraux dans l’accès au financement mises en exergue dans cette recherche. Ces difficultés des micros entreprises sont, entre autres, dues à l’offre inadéquate des structures de financement formelles. En conclusion, il est proposé la mise en place d’un fonds de refinancement des EMF et la mise en œuvre d’un modèle de financement adapté à l’entrepreneuriat rural dans la région du Centre. [less ▲]Detailed reference viewed: 137 (27 ULg) Sustainable energy conversion through the use of Organic Rankine Cycles for waste heat recovery and solar applicationsQuoilin, Sylvain Doctoral thesis (2011)This thesis contributes to the knowledge and the characterization of small-scale Organic Rankine Cycles (ORC). It is based on experimental data, thermodynamic models and case studies. The experimental ... [more ▼]This thesis contributes to the knowledge and the characterization of small-scale Organic Rankine Cycles (ORC). It is based on experimental data, thermodynamic models and case studies. The experimental studies include: 1. A prototype of small-scale waste heat recovery ORC using an open-drive oil-free scroll expander, declined in two successive versions with major improvements. 2. A prototype of hermetic scroll expander tested on vapor test rig designed for that purpose. The achieved performance are promising, with expander overall isentropic effectivenesses higher than 70% and cycle efficiencies comparable or higher than the typical efficiencies reported in the scientific literature for the considered temperature range. New steady-state semi-empirical models of each component are developed and validated with the experimental data. The global model of the ORC prototype allows predicting its performance with a good accuracy and can be exploited to simulate possible improvements or alternative cycle configurations. Dynamic models of the cycle are also developed for the purpose of evaluating the system's reaction to transient conditions. These models are used to define and compare different control strategies. The issues of cycle optimization and fluid selection are treated using the steady-state semi-empirical models. The thermodynamic optimization of such cycles is first demonstrated by practical examples. Furthermore, three different methods for fluid selection are proposed, investigated and compared. Their respective advantages and fields of application are described. Finally, two prospective studies of small-scale ORC systems are proposed. The first one is a solar ORC designed for the rural electrification of remote regions in Africa. This prototype aims at competing with the photovoltaic technology, with the advantage of generating hot water as by-product. The second prospective study deals with the recovery of highly transient heat sources. Advanced regulation strategies are proposed to address the practical issues inherent to such systems. These strategies are compared with the state-of-the-art strategies and show a non-negligible potential of performance improvement. [less ▲]Detailed reference viewed: 3570 (84 ULg) Contribution au développement d'un dispositif expérimental d'atomes froids de fer et spectroscopie à ultra-haute résolution de cet atomeKrins, Stéphanie Doctoral thesis (2011)Le présent travail est dédié à la conception, la modélisation et l'implémentation d'un dispositif expérimental visant, pour la toute première fois, à piéger et à refroidir par laser des atomes de fer ... [more ▼]Le présent travail est dédié à la conception, la modélisation et l'implémentation d'un dispositif expérimental visant, pour la toute première fois, à piéger et à refroidir par laser des atomes de fer. Dans ce cadre, une contribution majeure au développement de ce dispositif est rapportée ici. Cette contribution comprend notamment la mise en place de dispositifs de stabilisation laser sub-MHz adaptés aux transitions spécifiques de l'atome de fer à 372 et 358 nm, ainsi que l'implémentation d'un ralentisseur Zeeman sur des faisceaux de ces atomes issus d'un four à haute température. Par ailleurs, des déterminations à ultra-haute résolution de grandeurs spectroscopiques fondamentales liées aux effets isotopiques et de structure hyperfine des transitions à 372 nm et 373.7 nm du fer sont rapportées pour la toute première fois. Une comparaison extrêmement précise de la position de la raie du fer à 358 nm par rapport à la raie de l'iode moléculaire R(90)3-10 à 13957.8542 cm-1 est également présentée. Cette comparaison met à disposition avec la précision requise la dernière donnée spectroscopique qui était inconnue dans la littérature scientifique pour une mise au point optimale du refroidissement laser d'atomes de fer. Elle ouvre la voie à l'implémentation finale du dispositif présenté dans ce travail. [less ▲]Detailed reference viewed: 36 (8 ULg) Compétitivité des filières rizicoles burundaises: le riz de l'Imbo et le riz des maraisGahiro, Léonidas Doctoral thesis (2011)Le riz est une culture récente, pratiquée surtout dans la plaine de l'Imbo et dans les marais de moyenne altitude du Burundi. D'une part, les ressources disponibles et les technologies de production ... [more ▼]Le riz est une culture récente, pratiquée surtout dans la plaine de l'Imbo et dans les marais de moyenne altitude du Burundi. D'une part, les ressources disponibles et les technologies de production rendent le riz de l'Imbo plus compétitif que le riz des marais. D'autre part, la majorité des qualités locales s'avèrent moins compétitives que celles importées de l'Asie et la Tanzanie. [less ▲]Detailed reference viewed: 154 (27 ULg) Residual Stress in Veneering CeramicMAINJOT, Amélie Doctoral thesis (2011)Detailed reference viewed: 4 (0 ULg) On the dichotomic collective behaviors of large populations of pulse-coupled firing oscillatorsMauroy, Alexandre Doctoral thesis (2011)The study of populations of pulse-coupled firing oscillators is a general and simple paradigm to investigate a wealth of natural phenomena, including the collective behaviors of neurons, the ... [more ▼]The study of populations of pulse-coupled firing oscillators is a general and simple paradigm to investigate a wealth of natural phenomena, including the collective behaviors of neurons, the synchronization of cardiac pacemaker cells, or the dynamics of earthquakes. In this framework, the oscillators of the network interact through an instantaneous impulsive coupling: whenever an oscillator fires, it sends out a pulse which instantaneously increments the state of the other oscillators by a constant value. There is an extensive literature on the subject, which investigates various model extensions, but only in the case of leaky integrate-and-fire oscillators. In contrast, the present dissertation addresses the study of other integrate-and-fire dynamics: general monotone integrate-and-fire dynamics and quadratic integrate-and-fire dynamics. The main contribution of the thesis highlights that the populations of oscillators exhibit a dichotomic collective behavior: either the oscillators achieve perfect synchrony (slow firing frequency) or the oscillators converge toward a phase-locked clustering configuration (fast firing frequency). The dichotomic behavior is established both for finite and infinite populations of oscillators, drawing a strong parallel between discrete-time systems in finite-dimensional spaces and continuous-time systems in infinite-dimensional spaces. The first part of the dissertation is dedicated to the study of monotone integrate-and-fire dynamics. We show that the dichotomic behavior of the oscillators results from the monotonicity property of the dynamics: the monotonicity property induces a global contraction property of the network, that forces the dichotomic behavior. Interestingly, the analysis emphasizes that the contraction property is captured through a 1-norm, instead of a (more common) quadratic norm. In the second part of the dissertation, we investigate the collective behavior of quadratic integrate-and-fire oscillators. Although the dynamics is not monotone, an “average” monotonicity property ensures that the collective behavior is still dichotomic. However, a global analysis of the dichotomic behavior is elusive and leads to a standing conjecture. A local stability analysis circumvents this issue and proves the dichotomic behavior in particular situations (small networks, weak coupling, etc.). Surprisingly, the local stability analysis shows that specific integrate-and-fire oscillators exhibit a non-dichotomic behavior, thereby suggesting that the dichotomic behavior is not a general feature of every network of pulse-coupled oscillators. The present thesis investigates the remarkable dichotomic behavior that emerges from networks of pulse-coupled integrate-and-fire oscillators, putting emphasis on the stability properties of these particular networks and developing theoretical results for the analysis of the corresponding dynamical systems. [less ▲]Detailed reference viewed: 111 (17 ULg) L'influence des pairs sur le développement des comportements normatifs et antisociaux chez l'adolescent délinquantMathys, Cécile Doctoral thesis (2011)Detailed reference viewed: 36 (7 ULg) Io's interaction with Jupiter's magnetosphereDols, Vincent Doctoral thesis (2011)Io, the innermost Galilean moon of Jupiter, is the most volcanic body of the solar system. This volcanism is responsible for a tenuous atmosphere composed mainly of S, O and SO2. This atmosphere is ... [more ▼]Io, the innermost Galilean moon of Jupiter, is the most volcanic body of the solar system. This volcanism is responsible for a tenuous atmosphere composed mainly of S, O and SO2. This atmosphere is constantly bombarded by the plasma that co-rotates with the magnetic field of Jupiter, producing new ions and perturbing locally the magnetic field. This local perturbation is responsible for auroral emissions in the atmosphere of Jupiter, at the foot of Io’s flux tube. The spacecraft Galileo made five flybys of Io between 1995 and 2001 at very low altitude (~100’s km) and made plasma and magnetic field measurements that reveal the complexity of Io’s interaction with Jupiter. Past studies have tackled the modeling of this interaction using different complementary approaches, each shedding a new light on the issue but each involving some simplifications. The MHD models (Linker et al., 1998) are based on an a priori parameterization of the ionization in the atmosphere, generally assuming spherical symmetry and a single atmospheric and plasma species (representative of O and S). They ignore the important effect of the cooling of electrons as well as the multi-species composition of both the plasma and the atmosphere. The two-fluid approach (Saur et al., 1999) computes precisely the ionization and collisions in the atmosphere of Io but make the assumption of a constant magnetic field, limiting the self-consistency of the model and potentially introducing large quantitative errors. We combine a multi-species chemistry model of the interaction that includes atomic and molecular species with a self-consistent Hall-MHD calculation of the flow and magnetic perturbation to model as self-consistently as possible the plasma variables along the different flybys of Io by the Galileo probe. [less ▲]Detailed reference viewed: 26 (4 ULg) Study of the ecology, population structure and dynamic of the macroalgae Codium elisabethae in Faial (Azores) with underwater visible imagery.Sirjacobs, Damien Doctoral thesis (2011)Codium elisabethae O.C. Schmidt is a dark green globose macroalgae isolating an internal sea water volume in a lumen. Codium elisabethae is endemic to the Macaronesian region and is very similar to Codium ... [more ▼]Codium elisabethae O.C. Schmidt is a dark green globose macroalgae isolating an internal sea water volume in a lumen. Codium elisabethae is endemic to the Macaronesian region and is very similar to Codium bursa C. Agardh whose distribution range spans the West-European, North-Western African and Mediterranean coasts and which was proposed as a potential indicator of coastal environmental changes based on the study of its ecology, revealing its long lifespan. Until recently, relatively little was known on Codium elisabethae as compared to the more widespread Codium bursa. To fill this gap, the present research aimed at producing an accurate description of the ecology and population dynamics of Codium elisabethae occupying the rocky shores of the Monte da Guia Special Area of Conservation (SAC)/Natura 2000 network (Faial, Azores). To achieve this, two reference sites were selected for long term monitoring: a sheltered no-go reserve exhibiting a dense Codium elisabethae population (Caldeirinhas), and a location experiencing more exposed conditions holding a sparser population (Ponta Furada). First, environmental conditions experimented by benthic organisms were extensively quantified and interpretated in regard to topographical particularities of each site. The study of reproduction dynamics showed a persistent summer fertility and an important vegetative reproduction. Important nutrient concentration ratio was found between the Codium elisabethae lumen water and surrounding sea water (mean ratios: nitrates: 5.7; ammonium: 3.4; phosphates: 3.1). In situ counting’s and size measurements revealed much higher densities of young recruits in the site of the Caldeirinhas (order of 20 ind/m²) than in the one of Ponta Furada (order of 1/m), for both summer and winter. Secondly, underwater visible imagery was exploited as an efficient and non-invasive alternative to classical in situ population estimation. Between August 2003 and November 2005, fifteen seabed photo coverages were collected by scuba-divers. Subsequent image processing consisted in mosaicing, interactive identification, and automatic change detection methods. This allowed quantifying the seasonal fluctuations of population structures (density, percentage cover and biomass) and of population dynamics (growth, recruitment, mortality and primary production). Chi-square tests of image-derived estimates and in situ measurements confirmed the validity of a centimeter precision for the estimation of population structure of individuals above 4 cm diameter. Important variability of population structure and density was observed within the sites at small spatial scales. Significant differences of population structure and dynamics parameters are demonstrated between two close-by but contrasting coastal habitats. Population density showed a sharp reduction in autumn 2003 and did not recover fully in spring and summer 2004. During the following year, population of the protected site maintained density and biomass, while at the exposed site population density dropped. In contrast with conclusions from earlier studies on the Azorian Codium elisabethae and on the Mediterranean Codium bursa, the present study revealed higher biomass (34 - 730 g dry wt.m-²), growth rates (up to 2.5 cm/month in summer) and primary production (0.53 – 11.5 g dry wt.m-².day-1), and demonstrated the seasonal fluctuations of these parameters for the studied Azorian Codium elisabethae population. The lifespan of Codium elisabethae was estimated to reach at least 7 years in the SAC of Monte da Guia based on an integration of average seasonal growth rates measured by imagery on extended population samples. This study demonstrates the high potential of registered underwater photomosaics time-series for long term surveys of macroalgae populations. This work provides also a strong framework to further developments and applicability to other species, which should be helpful to strengthen our current understanding of benthic ecosystem processes. [less ▲]Detailed reference viewed: 143 (40 ULg) La résilience des banques libanaises : analyse de certains aspects de la gestion des risques dans le cadre de l'accord de BâleEl Khoury, Ghada Doctoral thesis (2011)Located in an environment of high uncertainty, supervisors in Lebanon have decided to comply with regulations issued by the Basel Accords and to monitor the new Basel Committee prudential framework. This ... [more ▼]Located in an environment of high uncertainty, supervisors in Lebanon have decided to comply with regulations issued by the Basel Accords and to monitor the new Basel Committee prudential framework. This thesis focuses on the Lebanese banking sector and on Basel II specific aspects in the Lebanese context. Four research areas are covered : 1. Evaluation of the capitalization level of Lebanese banks as required by Basel II prudential standards. 2. Lebanese sovereign risk analysis and its impact on the sustainability of banks through the measurement of probability of default of the Lebanese state on its Eurobonds denominated in U.S. dollars. 3. Examining the question of bank balance sheet procyclicality generated by the accounting and prudential framework, and by contextual factors specific to the resilience of the Lebanese banking sector. 4. Evaluation of the adaptation level of the Lebanese banking sector to new risk management approaches by estimating the probability that banks will well manage their risks. From a comparative analysis of the regulatory and economic capital, we found that 14 banks have a high economic capital relative to regulatory capital under Basel II in 2005. We also observed that the risks faced by Lebanese banks are primarily related to credit risk and sovereign risk in particular. Applying the valuation model of default risk, developed by Merrick (2001), and based on a review of scientific literature, we proposed a synthetic measure of credit risk of the Lebanese US dollar denominated Eurobonds. The results show that changes in the probability of default and recovery rates are explained by the trust vis-à-vis the market and state. Based on a review of the scientific literature, we have developed theories of economic fluctuations and financial instability. The analyses of procyclicality in the Lebanese context have shown that the factors leading to a balance sheet procyclicality in the Lebanese banking sector are atypical. We have also shown the resilience of the Lebanese banking sector to recent shocks and crises. Through a survey conducted between November 2009 and February 2010, we assessed the level of adaptation of the Lebanese banking sector to new risk management approaches. The results show that some banks have become more aware of the importance of developing proper risk management practices. Therefore, other banks remain in a precarious stage. [less ▲]Detailed reference viewed: 179 (9 ULg) MODELISATION DE L’ACTIVITE DES BACTERIES DU SOUFRE EN LAGUNAGEHarerimana, Casimir Doctoral thesis (2011)Detailed reference viewed: 69 (11 ULg) Signal transduction in photodynamic therapy-mediated cell deathCoupienne, Isabelle Doctoral thesis (2011)Les glioblastomes sont des tumeurs du cerveau comptant parmi les plus fréquentes et les plus agressives. En effet, l’espérance de vie médiane des patients est d’environ quinze mois après diagnostic ... [more ▼]Les glioblastomes sont des tumeurs du cerveau comptant parmi les plus fréquentes et les plus agressives. En effet, l’espérance de vie médiane des patients est d’environ quinze mois après diagnostic. Malgré d’intenses recherches et l’utilisation de traitements combinant la chirurgie, la radiothérapie et la chimiothérapie, le pronostic des patients n’a guère évolué depuis une vingtaine d’années. Ces tumeurs sont caractérisées par la présence de diverses altérations génétiques et, généralement, par une activation constitutive du facteur de transcription NF-κB. Étant un régulateur majeur de l’apoptose et de la survie cellulaire, ce facteur pourrait jour un rôle central dans la résistance des glioblastomes aux diverses thérapies. Au cours de ce travail, nous avons étudié les effets de l’inhibition du NF-κB sur la mort cellulaire des glioblastomes induite en réponse à un traitement par PDT, dont l’efficacité repose sur la production d’espèces réactives de l’oxygène suite à la présence simultanée d’un photosensibilisateur, de lumière et d’oxygène. Ainsi, nos résultats montrent que les cellules dans lesquelles le NF-κB est inhibé présentent une sensibilité accrue au traitement par rapport aux cellules non-inhibées. De plus, cette augmentation de mort cellulaire est majoritairement due à de la nécrose. Le traitement par PDT conduit également à l’apparition d’autophagie cytoprotectrice dont l’inhibition améliore l’efficacité du traitement. Nous nous sommes ensuite focalisés sur la mort par nécrose et avons démontré l’implication de la kinase RIP3 dans la mort nécrotique induite par PDT. Il est apparu que l’oxygène singulet produit au cours du traitement était à l’origine de la nécrose RIP3-dépendante. Cependant, les intermédiaires transductionnels et la manière dont le NF-κB exerce ses effets anti-nécrotiques demeurent encore inconnus. Enfin, afin de mieux comprendre le rôle joué par RIP3 dans la mort induite par PDT, nous avons utilisé la lignée d’ostéosarcome U2OS, déficiente en cette protéine, et au sein de laquelle nous en avons restauré l’expression. De manière surprenante, les cellules sauvages se sont révélées plus sensibles au traitement que les U2OS exprimant RIP3. De plus, la lignée RIP3-U2OS montre un taux d’apoptose supérieur à celui de son homologue sauvage. Cette divergence peut en partie s’expliquer par une induction d’autophagie plus importante au sein des RIP3-U2OS. Celle-ci, pouvant être un mécanisme pro-survie, peut leur conférer une protection contre la mort cellulaire en facilitant l’élimination des organelles endommagés. Enfin, nous avons déterminé que les cellules sauvages présentent un taux de nécrose plus important que les cellules RIP3-U2OS en réponse au traitement. Nos résultats ont dont permis de prouver (i) que l’inhibition du NF-κB améliorait la sensibilité des glioblastomes à la mort cellulaire induite par un traitement par 5-ALA-PDT, (ii) que celle-ci était, dans ce cas, majoritairement de la nécrose RIP3-dépendante et (iii) de mettre au jour un rôle pour RIP3 dans la régulation de l’apoptose et de l’autophagie induites par PDT. [less ▲]Detailed reference viewed: 30 (16 ULg) Extension of the Liège Intranuclear Cascade Model to the 2-15 GeV Incident Energy RangePedoux, Sophie Doctoral thesis (2011)The Liège Intra-Nuclear Cascade model (INCL4) has been shown to be quite successful for the description of spallation reactions. However its validity domain is limited to an upper incident energy of ~2 ... [more ▼]The Liège Intra-Nuclear Cascade model (INCL4) has been shown to be quite successful for the description of spallation reactions. However its validity domain is limited to an upper incident energy of ~2 GeV, because inelastic elementary processes are restricted to the excitation and de-excitation of the Delta resonance. In this thesis, the INCL4 model is extended to higher incident energy. This is realised by including other inelastic elementary collisions, direct multipion production in elementary nucleon-nucleon and pion-nucleon collisions. This is somehow opposite to the usual extension to high energy of such models, as it is usually realised by including excitation of heavier baryonic resonances. Experimental data and isospin symmetry have been exploited in the implementation of multipion channels, but we could not avoid to introduce specific models for the energy-momentum and charge repartition on the final pions. The predictions of the modified model for production of protons, neutrons and charged pions by proton and pion beams off nuclei are compared with experimental data. A short study on nuclear fragmentation is also presented. [less ▲]Detailed reference viewed: 40 (6 ULg) Bouncing droplets, the role of deformationsTerwagne, Denis Doctoral thesis (2011)Nowadays, innovative applications such as "lab-on-a-chip", micro-reactors or biological chips are developed for industry, biology or medicine. Capillary issues are encountered which are not yet fully ... [more ▼]Nowadays, innovative applications such as "lab-on-a-chip", micro-reactors or biological chips are developed for industry, biology or medicine. Capillary issues are encountered which are not yet fully understood. It is therefore essential to open up ways to manipulate tiny amounts of liquid in order to mix them, encapsulate them or to create emulsions. The bouncing droplets on an oscillating liquid interface allow their manipulation. Indeed, under certain conditions, droplets can bounce indefinitely on a bath surface as long as the squeezed air film which separates the drop from the bath is renewed at each bounce. We chose to study deformable droplets on a non-deformable bath. The droplets are deformable because they are large or made of a low viscous oil, the liquid of the bath being highly viscous silicone oil. We investigated how the deforma- tions, the stability and the trajectories of the droplets depends on the forcing parameters such as the frequency and the amplitude of the oscillation. We also studied the possibility of mixing and emulsifying droplets on the bath. Finally, we showed the effect of the deformation of the bath on these bouncing droplets and studied the trajectories of walking droplets [1] which are used as a model for quantum-like particles [2-5]. In this manuscript, we reported an exploration of the droplets behavior as a function of the ability of the bath and/or the droplet to deform. Depending on the forcing frequency, specific deformation modes are excited on the bouncing droplets. We used these modes to rationalize their bouncing stability and to create double emulsions in a compound droplet. Then, we determined numerically the complex bifurcation diagrams of the trajectories of a bouncing droplet thanks to a model based on a spring. On a low viscous bath, we evidenced the importance of its deformation. We showed that a walker exists as soon as the droplet experiences, once every two oscillation periods, a jump high enough to trigger a Faraday wave. As a consequence, we have to take the bouncing droplets into account when looking for an alternative way to manipulate them or as a model of quantum-like particles. The bouncing droplets still exhibit lots of intriguing behaviors which have yet to be explained. They can therefore remain the focus of future works. [less ▲]Detailed reference viewed: 112 (20 ULg) Impact des oiseaux granivores sur les céréales les plus cultivées au Burundi: cas du rizNasasagare, Régine Pacis Doctoral thesis (2011)Detailed reference viewed: 48 (5 ULg) Application de la spectroscopie Raman à l’analyse de colorants sur fibres de coton dans le contexte de la criminalistiqueLepot, Laurent Doctoral thesis (2011)Forensic examination of textile fibres is based on fibre morphology and on fibre material and dyes characterization. Cotton is the most frequently used fibre in textiles but also the most encountered in ... [more ▼]Forensic examination of textile fibres is based on fibre morphology and on fibre material and dyes characterization. Cotton is the most frequently used fibre in textiles but also the most encountered in casework. While man-made fibres show various morphologies and materials, cotton is a natural cellulosic fibre with constant morphology. Cotton fibres examination can consequently be summarized in the characterization of fibre dyes. However forensic needs require non-destructive, fast and sensitive techniques. For fibres microspectrophotometry (MSP) is the commonly used technique and the obtained UV-Vis absorption spectrum reflects dyes used to colour the fibre. Any other technique suitable for dye characterization is thus helpful to reinforce MSP results on cotton fibres. Raman spectroscopy is a fast non-destructive technique, easy to integrate into the fibre analytical sequence without any additional sample preparation. Moreover it provides specific molecular information and seems convenient for the study of coloured molecules. This work allowed to demonstrate the potential of the technique in dyed cotton fibres examination through the characterization of pure dyes but also the ability to detect different components in dye mixtures. In order to help dye identification spectral databases were built using Raman spectra collected in the present work. Unfortunately such a database will never be exhaustive and the identification of an unknown dye would be compromised. An interesting option is to identify the general chemical class of the unknown dye, especially to evaluate its rarity. The recognition of some dye chemical classes has been made by the mean of characteristic peaks but this method remains somewhat subjective. This subjectivity can be bypassed using chemometric techniques; they are able to predict chemical class membership on the basis of Raman specific information. Some experiments have been performed on Raman spectra using PCA models and the SIMCA classification tool. [less ▲]Detailed reference viewed: 180 (29 ULg) Study of the Cape Ghir upwelling filament using variational data analysis and regional numerical modelTroupin, Charles Doctoral thesis (2011)Aim: Upwelling filaments are shallow, elongated structures of cool waters often visible in the regions of coastal upwelling. The present thesis aims to improve our knowledge on the mechanisms responsible ... [more ▼]Aim: Upwelling filaments are shallow, elongated structures of cool waters often visible in the regions of coastal upwelling. The present thesis aims to improve our knowledge on the mechanisms responsible for the generation of filaments. Location: the study is centered on the Canary Current Upwelling system, located off northwest Africa, in particular around Cape Ghir (30°38'N, 9°53'W), where these filaments are frequently observed. Methods: - We compiled historical in situ data to build a high-resolution climatology of temperature and salinity in the region of interest using the Data Interpolating Variational Analysis (\diva) method. - We ran the experiments with the numerical model ROMS to investigate the processes responsible for the filament generation. - We collected in situ measurements during a cruise in August-September 2009, in the frame of the CAIBEX project, in the filament area and analyzed them to get a detailed description of the Cape Ghir filament, its variability and its biogeochemical characteristics. - We computed anomalies of several variables with respect to a long-term mean to examine the time-evolution of the Canary Current Upwelling system. Results: The climatology showed improvements with respect to existing products, especially in the coastal area, and was a valuable asset to provide initial and boundary conditions for the numerical model. The results of the simulations underlined the role of the wind in the filament generation and confirmed our assumption of a mechanism based on the potential vorticity balance. Preliminary analysis of the cruise data allowed us to characterize the filament physical and biological properties, in particular we observed the signal of a subsurface (at a depth of 300~m) anticyclonic eddy on the northern flank of the filament, also present in the numerical model outputs. Anomalies for the year 2010 revealed a widespread warming over the tropical and subtropical Atlantic Ocean and a diminution of the upwelling activity. We attributed these anomalies to a weakening of the winds, itself related to a strongly negative North Atlantic Oscillation (NAO) index. [less ▲]Detailed reference viewed: 100 (28 ULg) Impacts des changements climatiques passés et présents sur la génétique et la démographie du Cincle plongeur (Cinclus cinclus)Hourlay, Frederic Doctoral thesis (2011)Climate change is emerging as the greatest threat to natural communities in many, if not most, of the world’s ecosystems in coming decades. Numerous studies have revealed present and probable future ... [more ▼]Climate change is emerging as the greatest threat to natural communities in many, if not most, of the world’s ecosystems in coming decades. Numerous studies have revealed present and probable future consequences that climate change will have on many animal and vegetal species. According to these studies, birds could be affected, mostly negatively, in various ways : distribution, abundance, phenology, ethology ... The purpose of this work is to determine how the White-throated Dipper (Cinclus cinclus), a Palearctic, temperate, passerine bird that is exclusively associated with flowing water, reacted to the climate changes that occurred during the Pleistocene, and how climate change currently affects this species : - For this purpose, we conducted a phylogeographic study : we analysed three fragments of mtDNA (i.e. fragments coding for cytochrome b, ND2 and domains II and III of the controle region) from 106 tissue samples originating from 24 dipper populations, mostly located in the Western Palearctic. - The second part of this work consisted in analysing ringing recoveries and nest-boxes frequentation from a dippers population settled on the river Syre and its tributaries (Luxemburg) and followed from 1979 to 2001. Populations census were also conducted on different water courses in Luxemburg, in order to determine dipper habitat preferences. 1. Phylogeography of the dipper in the Western Palearctic region In spite of a low genetic variability, the results of our phylogeographic study reveal a complex phylogeographic structure for this species with at least five distinct lineages for the Western Palearctic region. As for many species of the Western Palearctic fauna and flora, this genetic structure is probably linked to the isolation of populations in different southern refuges during glacial periods. Furthermore, the isolation of populations in Scandinavia and/or Eastern regions, but also in Morocco and probably in Corsica, was accentuated by ecological and biogeographic barriers during Quaternary interglacial periods. During glacial periods, Italy, Sicily and the Balkano-Carpathian region acted as major refuge zones for the dipper. At the end of the last ice age, Western Europe was repopulated by dippers from a refuge located in Italy and, probably, South-East France, while Eastern Europe was recolonised by Balkano-Carpathian birds. A large contact zone between these two lineages was evidenced and extends from Luxembourg to Hungary. Finally, our results indicate the need to clarify the taxonomic status of the dipper, especially concerning the European subspecies whose validity appears uncertain. 2. Dipper demography – Influence of climate change and other anthropic pertubations Results obtained from the analysis of demographic and morphologic variables of the Luxemburger population are in agreement with results obtained from other European populations. Differences observed between these populations are mostly due to climate and habitat quality differences. However, other factors could also partly explain these differences. As for other places in Europe, nest boxes installation dramatically increased dippers population size on the river Syre. Our results also suggest that the installation of nest boxes could influence some demographic and morphologic variables, probably as a result of population increase. But, above all, our results show how temperatures and precipitations affect these variables, and particularly laying dates. Climatic changes that occurred during the last decades provoked earlier laying dates. Whereas clutch size and nest size remained unchanged, the Luxemburger population size decreased during the same period, as observed for other European populations. The main cause to this decrease should be an increase of environmental instability inducing notably a decrease of food ressources for dippers. As a result, we observed a significant decrease of females body weight during this period. Climate change will also probably have a serious impact on dipper genetic diversity, leading to the disappearance of the most southern populations and eventually of certain genetic clades. The results obtained concerning the taxonomic status of the dipper and its demography could be useful in the framework of a conservation program, if necessary. In this perspective, the development of habitat suitability prediction tools, as the one we developed, could also be very helpful. [less ▲]Detailed reference viewed: 53 (12 ULg) Unveiling the internal structure and evolution of massive stars through their pulsation modesGodart, Mélanie Doctoral thesis (2011)Stars in the night sky are not as quiet as they seem. A human being wandering on Earth few billions years ago would have seen a different night sky, with different stars forming different constellations ... [more ▼]Stars in the night sky are not as quiet as they seem. A human being wandering on Earth few billions years ago would have seen a different night sky, with different stars forming different constellations. Moving forward in time, he would have been the witness of stellar evolution as some stars would have suddenly shined while others disappeared forever. Hard to realize at a time scale of human life, stars are born, evolve, and die in a limited lifetime which can last only a few million years for the most massive to trillion years for the less massive. Fortunately, it is not necessary to wait that long to study the formation and evolution of stars. Stellar evolution can be studied on shorter time scales, on thousands of stars, at various evolutionary stages. This is of great importance as stars shape the Universe and produce the chemical elements at the origin of life. Probing the internal structure of stars is however very challenging due to the opacity barrier of their superficial layers. One way to get around this issue is to study and interpret stellar pulsations. As seismologists extract information about Earth interior trough the study of earthquakes, asteroseismologists can study the internal structure of stars by studying their oscillations. In this thesis, this technique is used to study the internal structure and evolution of massive stars which are at least eight times more massive than our Sun and which have a spectral type between O and B. The first part of this work is devoted to the determination of the $\kappa$-mechanism instability domains for massive stars. In order to extend the computations to the post-main sequence phase of evolution, we develop a numerical technique in which the non-adiabatic computations for the stellar core are made, independently than for the envelope, within the quasi-adiabatic and the asymptotic treatment. In a second step, we investigate the pulsations modes in O main sequence stars and in B post-main sequence stars. The presence of g-modes in post-main sequence stars is closely related to the internal structure of the star and we study the effects of several physical factors on the occurrence of these modes. Finally, the last part of this work is dedicated to the characterization of strange mode pulsations. In particular, we focus on strange modes having an adiabatic counterpart, which are trapped into a superficial cavity. The effect of the model atmosphere on the excitation is investigated in addition to the characterization of their eigenfunctions. [less ▲]Detailed reference viewed: 44 (17 ULg) Caractérisation des effets de température dans la zone endommagée autour de tunnels de stockage de déchets nucléaires dans des roches argileusesDizier, Arnaud Doctoral thesis (2011)La solution du stockage des déchets nucléaires de haute activité et de longue durée de vie dans les couches argileuses profondes comporte de nombreuses incertitudes. Pour combler celles-ci de nombreux ... [more ▼]La solution du stockage des déchets nucléaires de haute activité et de longue durée de vie dans les couches argileuses profondes comporte de nombreuses incertitudes. Pour combler celles-ci de nombreux projets européens sont réalisés de façon à les minimiser. Le projet TIMODAZ (Thermal Impact On the Damaged Zone Around a Radioactive Waste Disposal in Clay Host Rocks) étudie l'influence de la température sur la zone endommagée. Cette zone correspond à une zone soumise à la redistribution des contraintes lors de l'excavation constituant un lieu de développement de micro et macro fractures. Cet endommagement mécanique est complété par un endommagement thermique lors de la pose des canisters qui vont émettre de la chaleur durant des milliers d'années et donc provoquer une augmentation de la température du massif argileux. Cette élévation de température de l'argile peut faire apparaitre des déformations plastiques thermiques de contraction. Cette nouvelle plasticité peut contribuer au développement de la zone endommagée. L'objectif de ce travail est donc de caractériser la zone endommagée autour des tunnels souterrains, construits dans l'Argile de Boom, soumis à des élévations de température induites par les déchets nucléaires. Durant ce travail, une loi de comportement thermo-mécanique est implémentée. Celle-ci se base sur un "modèle à chapeau" étendu à la thermo-plasticité. Ce modèle comprend la combinaison d'un modèle à frottement interne, d'un critère Cam-Clay et d'un critère de rupture à la traction. Ce modèle est étendu à la température et en particulier à la thermo-plasticité en considérant les travaux de Sultan. Les paramètres thermo-hydro-mécaniques de l'Argile de Boom sont identifiés et servent à la modélisation d'expériences de laboratoire et in situ. Ces expériences consistent en outres en un cylindre creux, en l'expérience de chauffage ATLASIII et en l'expérience à grande échelle PRACLAY. Ces trois expériences ont pour objectif d'étudier l'Argile de Boom d'une petite échelle à une plus grande représentative du massif argileux. L'étude du comportement dans la zone élastique et plastique est également prise en compte via ces différentes expériences. Les résultats, avec différentes lois de comportement, montrent que l'influence de la thermo-plasticité est faible mais non négligeable vis-à-vis des déformations déviatoriques engendrées par l'excavation. [less ▲]Detailed reference viewed: 90 (10 ULg) InSAR Applied to the Study of Active Volcanic and Seismic Areas in AfricaWauthier, Christelle Doctoral thesis (2011)Two active volcanic areas situated in immature portions of the East African Rift System (EARS): the Lake Kivu (Dem. Rep. of Congo) and Lake Natron (Tanzania) regions, which are located in the western and ... [more ▼]Two active volcanic areas situated in immature portions of the East African Rift System (EARS): the Lake Kivu (Dem. Rep. of Congo) and Lake Natron (Tanzania) regions, which are located in the western and eastern branch, respectively, are still poorly known. Both areas indeed lack of ground-based networks, due to security problems or difficult field accessibility. The Lake Kivu area includes two volcanoes erupting frequently: the Nyamulagira and Nyiragongo volcanoes. The SAR database covering these volcanoes in- cludes data from JERS, ERS-1&2, ENVISAT, ALOS, RADARSAT-1&2 satellites back from year 1996. SAR Interferometry (InSAR) is thus applied to study the ground de- formations. MT-InSAR approaches, such as the ”‘StaMPS”’ method, are used to give us new complementary information to better constrain the previous established eruption models, or gain new insights on eruptions missed by the conventional InSAR, as well as on magmatic and tectonic activity. When enough constrains are available, the ground displacements are modeled using a 3D-Mixed Boundary Elements Method combined with a neighborhood algorithm. Hence, the 1996, 2002, 2004 and 2010 eruptions of Nyamu- lagira are modeled. The modeling results, coupled with the StaMPS MT-InSAR results, bring new insights concerning the magma plumbing system of this poorly known volcano and its eruptive mechanisms. The collapse of the eastern flank of Nyamulagira, along the NNW-trend fractures network linking Nyamulagira and Nyiragongo volcanoes, can also be identified. InSAR also captures the ground displacements associated with the January 2002 Nyiragongo eruption. The modeling of this major event evidences a deep magma intrusion beneath the Lake Kivu. Such intrusions should be taken into account for hazard assessment. The magma could indeed finds its way to the Lake Kivu floor, as evidenced by the presence of several old phreato-magmatic cones, and causes a lake overturn. The low dikes overpressures found in the North Kivu and Lake Natron areas indicate that, although the rift is considered as immature, the rift extension is driven by the supply of magma from depth, rather than by the tectonics. A new criterion to identify the rifting stage is found to be the stress state. In the southern part of the rift, tectonic activity dominates, indicating that the tectonics is probably driving the rift opening there. [less ▲]Detailed reference viewed: 87 (7 ULg) Dynamique des transactions foncières et vulnérabilité rurale au Niger : cas des communes rurales de Tchadoua et YaouriLawali Mani, Sitou Doctoral thesis (2011)Summary In Niger, agriculture is the principal activity of the rural populations. Unfortunately the access to the land becomes very difficult to the farmers in the center-south of the country. This area ... [more ▼]Summary In Niger, agriculture is the principal activity of the rural populations. Unfortunately the access to the land becomes very difficult to the farmers in the center-south of the country. This area is confronted to the space saturation and the emergence of the land transactions whose causes, process and impacts on the agricultural households are little known. The study undertaken in the rural municipality of Tchadoua and Yaouri aimed at analyzing the dynamics of the land transactions in bond with the rural vulnerability in terms of the stakes of access and management of the grounds, but also their securisation. The problems were studied with a multidisciplinary approach. The analyses (quantitative and qualitative) were carried out on the basis of the data collected in the village areas of Maijanguero and Gomba through cards of investigations and semi-structured interviews with a sample of 30% of the households. We also used participatory observations of agricultural practices and consultation of different sources of documentation. Administration and others authorities have been also interviewed aswel as members of the land commissions and the intermediaries of the transactions. The results obtained show that the problem of access and management of the land in these agricultural areas is an important concern for rural producers. The land blocking due to the strong demographic pressure and the increase of economic stakes (crop rent) influence the excessive parceling out of the grounds and the individualization of the farms. This individualization supports consequently, the emergence of the commercial land speculations for the profit of the economic operators installed from now in logic of monopolization of grounds. The purchase, the pledge and the lease constitute the principal access modes to the ground instead of old forms of solidarity (gift, loan). Also, the new agrarian initiatives of assistance appear and take part in the improvement of the socio-economic conditions of the rural households. The results also made it possible to highlight a diversity of trajectories of the exploitations. The land ‘’monetarisation’’ influenced strongly the land management and reinforced the exclusion of the vulnerable groups. The strong changes of technical transformation and farming system are observed. It as revealed as the land accumulation or ‘’décapitalisation’’ depends of the type of farm, its strategy and its revenue. Indeed, three tendencies become apparent from the trajectories: great manufacturing units with dominant commercial accumulate land, use the hired labor work and araw cash crop (souchet); a strong land ‘’decapitalisation’’ at the extremely vulnerable and without viable strategy of adaptation in the long term. Lastly, the small farm witch made a diversification and a strong intensification, and there resist to the multiple attempts of land spoliation. These last constitute a model of stable and durable farm whose strategy is based primarily on the agricultural intensification through effective and less expensive agroforestry practices to increase their production and their land capital. The informel and discrete character of land transactions and the networks of intermediation by which are negotiated the land sales accentuate the land insecurity and contribute to increase the land prices. The analysis of the securisation practices of the land rights proves that legal formalization though timid, reduced considerably the frequency of the rural conflicts and offers agricultural opportunities of investments. However, the land commissions encounter difficulties which, slow down the generalization of the legal formalization of transactions. All things considered, the land problem remains a central stake of development thus, the securisation of the land rights of the rural poor must be a priority of the priorities to reach a durable food safety. It is thus urgent to make the land commissions more operational in their giving the means of operation in order to ensure a broad diffusion of the procedures of formalization for more impact and also encouraging the producers through small subsidies to practice the carrying agri-environmental measurements. [less ▲]Detailed reference viewed: 97 (21 ULg) Le Caire : carrefour des ambassades. Étude historique et diplomatique de la correspondance échangée entre les sultans mamlouks circassiens et les souverains timourides et turcomans (Qara Qoyunlu-Qaramanides) au XVes. d’après le BnF ms.ar. 4440.Dekkiche, Malika Doctoral thesis (2011)Pendant près de 250 ans, les sultans Mamlouks d’Égypte (1250) et de Syrie (1260) furent les représentants suprêmes de l’Islam aussi bien aux yeux des Musulmans que des Chrétiens d’Occident. Leur capitale ... [more ▼]Pendant près de 250 ans, les sultans Mamlouks d’Égypte (1250) et de Syrie (1260) furent les représentants suprêmes de l’Islam aussi bien aux yeux des Musulmans que des Chrétiens d’Occident. Leur capitale, Le Caire, s’érigea en véritable carrefour des ambassades venues des quatre coins du monde connu alors. Cependant, presque rien des archives de cette dynastie ne nous est parvenu sous sa forme originale. Heureusement, les secrétaires de chancellerie de cette époque nous ont laissé un nombre non négligeable d’ouvrages, manuels de chancellerie et Formulaires, dans lesquelles ils nous révèlent les pratiques de chancellerie en cours alors et nous présentent de nombreuses copies de lettres qui furent échangées entre les sultans mamlouks et d’autres dynasties, musulmanes, chrétiennes ou autres. La présente thèse de doctorat se fonde sur l’un de ces formulaires, conservé sous sa forme manuscrite à la Bibliothèque Nationale de France, Paris, sous la cote ms. ar. 4440. Nous avons extrait de ce manuscrit un corpus de 19 lettres échangées entre les sultans mamlouks et trois autres dynasties musulmanes du XVes. régnant sur un territoire allant de l’Anatolie à l’Iran en passant par l’Iraq: les Timourides, les Qara Qoyunlu et les Qaramanides. Après l’édition critique de ce corpus, nous nous sommes concentrée sur l’étude historique et diplomatique de celui-ci. La première partie de la thèse concerne l’étude historique du corpus et de ce que nous avons appelé « la réalité de l’ambassade ». Le protocole de réception des ambassades au Caire par les sultans mamlouks, est assez bien renseigné à travers les chroniques des historiens de l’époque. Il est important de bien connaître ces règles afin de mesurer l’importance que le souverain accordait à son correspondant. Après énonciation de ces règles protocolaires, nous proposons, pour chaque dynastie en question, un aperçu de l’état des relations qui étaient établies entre elles et les sultans mamlouks, avant de nous atteler à l’étude historique du corpus proprement dite. Pour ce faire, nous avons dépouillé années après années les chroniques mamloukes et tenté de remettre chacune des lettres du corpus dans le contexte de l’ambassade qui lui était propre. Enfin, nous nous sommes concentrée sur le contenu des messages de ces lettres et avons analysé les raisons qui étaient à l’origine de l’envoi de l’ambassade. Nous nous sommes rendue compte de l’importance que ces lettres possèdent en tant que sources historiques de la période couverte, car elles nous révèlent un grand nombre de détails omis par les historiens contemporains des faits, ce qui nous permet de réévaluer avec plus de précision le rôle que la dynastie mamlouke jouait encore à cette époque notamment en tant que représentant suprême de la communauté musulmane et ce malgré les affronts subis par les différents pouvoirs montants, comme les Timourides. Nous avons grâce à l’analyse du protocole de cérémonie et du contenu des messages deux grilles de lecture nous permettant d’évaluer l’état des relations établies entre les Mamlouks et les trois autres dynasties, mais pour que l’étude soit complète, il est une troisième grille qui doit être prise en compte. Elle nous est fournie par la diplomatique et elle fait l’objet de la seconde partie de notre thèse. Dans cette partie, nous nous sommes concentrée, outre sur notre corpus, sur l’étude des manuels de chancellerie de l’époque mamlouke et nous avons tenté, grâce à eux, de reconstituer les règles de chancellerie propres à la rédaction de la correspondance entre les sultans mamlouks et les souverains musulmans afin de mesurer de façon certaine les liens qui sous-tendaient les relations établies entre les différents correspondants. Une telle étude vient à point lorsque l’on sait le retard que la discipline diplomatique a pris dans le cadre des études arabo-musulmanes. Enfin, la mise en parallèle de cette partie avec la première nous permet de dresser un tableau assez complet de la perception que les Mamlouks avaient des autres dynasties avec lesquelles ils étaient en contact. [less ▲]Detailed reference viewed: 114 (13 ULg)