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See detailLes semences non-industrielles : une hétérogénéité de pratiques mettant en cause le fixisme
Hecquet, Corentin ULg

in Les semences non-industrielles : une hétérogénéité de pratiques mettant en cause le fixisme (2013, November 20)

Les débats concernant les semences occupent depuis quelques années l’espace public. Se centrer sur cet objet permet de comprendre comment se construit une critique par des discours (dénonciation) et des ... [more ▼]

Les débats concernant les semences occupent depuis quelques années l’espace public. Se centrer sur cet objet permet de comprendre comment se construit une critique par des discours (dénonciation) et des pratiques (proposition). Ces enjeux scientifiques s’inscrivent dans une perspective agroécologique (Stassart, Baret et al. 2012). La critique porte sur le processus de désappropriation des semences et des connaissances et s’inscrit dans le paradigme productiviste (Bonneuil C. , Demeulenaere E. et al. 2006). Ma question de recherche au sujet des différentes constructions de qualification des semences non industrielles se fonde sur mes lectures reprises dans un état des lieux (partie 1). Par semences non industrielles j’entends celles qui ne sont pas inscrites dans une perspective productiviste. Afin de décrypter, j’utilise un cadre analytique constitué de trois catégories questions (la caractérisation ; les modes organisationnels et de circulation ; le positionnement juridico-politique). Ce cadre offre une lecture des tensions et synergies au sein de chacun des cas repris dans la deuxième partie (Kaol Kohz ; Kokopelli ; Semailles ; Bionatur). Leur hétérogénéité balise les cas d’étude. Ils offrent à comprendre les différentes stratégies développées par les pratiques des porteurs de projet, elles vont de l’utilisation du dispositif déployé par le régime semencier à la désobéissance en vue de qualifier leurs semences. Il est également nécessaire de comprendre comment chacun des projets parvient à chercher/maintenir sa proposition. Ce papier ambitionne non à présenter des résultats, mais plutôt comment produire des résultats sur cette question. [less ▲]

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See detailDesign of macroporous poly(ionic liquid)s by CO2/water emulsion templated polymerization
Boyère, Cédric ULg; Favrelle, Audrey; Boury, Frank et al

Poster (2013, November 20)

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See detailSwitching to the Dark Side: Repositioning of Polyglutamine Repeat Promotes Amyloid Fibril Formation by the Model Protein, β-Lactamase BlaP
Thorn, David ULg; Pain, Coralie ULg; Scarafone, Natacha et al

Conference (2013, November 20)

Background: The expansion of polyglutamine (polyQ) repeats is associated with an increased propensity of the protein to aggregate into amyloid fibrils. There are ten human proteins presently known within ... [more ▼]

Background: The expansion of polyglutamine (polyQ) repeats is associated with an increased propensity of the protein to aggregate into amyloid fibrils. There are ten human proteins presently known within which polyQ expansion above a threshold length, e.g. 35-50 residues, leads to ten distinct neurodegenerative disorders [1], the most well-known being Huntington’s disease. While repeat length, aggregation, and disease are well correlated, recent studies suggest the non-polyQ regions of these proteins can also play a significant role, both preventative and facilitative, in the aggregation process. With the aim of exploring this role in more detail, we have engineered chimeric proteins via the insertion of polyQ repeats of various length (23, 30, 55, 79 Q) into two sites of antibiotic resistance enzyme BlaP β-lactamase from Bacillus licheniformis 749/C [2]. Questions addressed: How does polyQ repeat position affect the structure, stability and aggregation of polyQ proteins? Methods: Aggregation kinetics determined by monitoring the decrease in soluble protein fraction over time. Aggregate morphology examined by transmission electron microscopy. Protein stability derived from thermal or chemical unfolding transitions monitored by far-UV CD and intrinsic fluorescence. Results and discussion: PolyQ insertion at either of the two positions led to a decrease in thermodynamic stability that was largely independent of polyQ length. Chimeras with polyQ insertions at position 216 were destabilised to a much greater extent than those with insertions at position 197. The reduced stability of the 216 chimeras was associated with an increased aggregation propensity: (i) the minimum polyQ length leading to aggregation was lower, and (ii) the aggregation rate was significantly higher than that observed by 197 chimeras with equivalent polyQ lengths. Remarkably, the two sites of polyQ insertion are indeed very similar, both residing within flexible loop regions between stable α-helices. Moreover, the 216 chimeras exhibited a higher aggregation propensity than their 197 counterparts even under denaturing conditions, suggesting the disparity between the two chimeras cannot be accounted for by structural differences alone. These findings highlight the strong and complex influence of the overall protein context on polyQ-mediated aggregation. The molecular basis for the observed changes in stability and aggregation propensity is the subject of on-going work. [less ▲]

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See detailRheological characterization of double thermo-responsive block copolymer hydrogels
Thomassin, Jean-Michel ULg; Mathieu, Kevin ULg; Kermagoret, Anthony ULg et al

Poster (2013, November 20)

The ability of double thermoresponsive block copolymers to form hydrogels has been thoroughly studied by rheology. These copolymers having two discrete LCSTs were synthesized following a one-pot strategy ... [more ▼]

The ability of double thermoresponsive block copolymers to form hydrogels has been thoroughly studied by rheology. These copolymers having two discrete LCSTs were synthesized following a one-pot strategy based on the sequential cobalt mediated radical polymeryzation of N-vinylcaprolactam (NVCL) followed by the copolymerization of N-vinylpyrrolidone (NVP) with the residual NVCL.Moreover, the very efficient cobalt mediated radical coupling of the growing chains was advantageously used to design triblock copolymers with similar morphological characteristics than the diblock copolymers (same external block length, copolymer ratio…) allowing direct comparison between their respective gels to be established. Different parameters have been compared such as the block length and the copolymer concentration. Temperature ramps were first performed to distinguish the different states, i.e., solubilized copolymers (below the two LCSTs), micelles (between the two LCSTs) and precipitated polymers (above the two LCSTs). [less ▲]

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See detailBio-inspired polymers for the functionalization of surfaces by green processes
Detrembleur, Christophe ULg

Conference (2013, November 20)

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See detailReversibly cross-linked polymer micelle as smart drug dellivery device
Lecomte, Philippe ULg; Riva, Raphaël ULg; Cajot, Sébastien et al

Conference (2013, November 20)

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See detailRelation entre anatomie du bois et traits fonctionnels chez 584 espèces d'Afrique tropicale
Morin-Rivat, Julie ULg; Fayolle, Adeline ULg; Doucet, Jean-Louis ULg et al

Poster (2013, November 19)

Les différences anatomiques observées dans le bois ont souvent été mises en relation avec des adaptations évolutives et environnementales. Toutefois, les liens entre structure du bois et contraintes ... [more ▼]

Les différences anatomiques observées dans le bois ont souvent été mises en relation avec des adaptations évolutives et environnementales. Toutefois, les liens entre structure du bois et contraintes écologiques restent peu connus. En effet, peu d’études ont combiné les approches anatomique et fonctionnelle. De plus, nos connaissances sont très limitées pour les biomes à grande diversité spécifique, en particulier l’Afrique tropicale. Les récents développements relatifs aux traits fonctionnels des espèces du Bassin du Congo poussent à tester de nouvelles hypothèses sur ces essences. Objectifs : Montrer dans quelle mesure les caractères anatomiques d’espèces de la zone guinéo-congolaise sont associés à plusieurs traits fonctionnels majeurs. Nous avons croisé plusieurs bases de données : 1) InsideWood : anatomie du bois, codage binaire (1/0) des descriptions : présence/absence des 163 caractères de la liste IAWA et 2) CoForTraits : traits fonctionnels de 1236 espèces, utilisation de 5 groupes de traits impliqués dans la croissance, la survie et la reproduction des plantes : a) la phénologie foliaire, b) le tempérament, c) la dispersion des graines, d) la forme de vie et e) la densité du bois. Analyse des pourcentages d’occurrence des caractères anatomiques pour les 584 espèces communes aux deux bases. Analyse factorielle des correspondances (AFC) entre les caractères anatomiques et les espèces. Analyse taxonomique enracinée pour évaluer les relations entre les caractères anatomiques et les traits fonctionnels. Tests de la variance. Résultats : 131 caractères anatomiques présents et 13 absents. Les caractères absents ou rares représentent soit des variables quantitatives soit des caractères typiques des régions tempérées. Les caractères très fréquents sont tropicaux et/ou africains. Plusieurs caractères sont très variables (ex. les cernes de croissance). Les 4 premiers axes de l’AFC représentent 15,23% de la variation anatomique. Parmi les caractères fréquents (ex. ponctuations ornées) et peu fréquents (ex. perforations scalariformes, cellules en tuile), plusieurs représentent un signal taxonomique soit au niveau de la famille (ex. Malvaceae, Fabaceae), soit au niveau du genre (ex. Strombosia spp.) Certains caractères proviennent d’un héritage écologique. Il existe en effet une divergence fonctionnelle et anatomique entre a) les grands arbres émergents et les arbustes de sous-bois. Ces éléments peuvent être mis en relation avec les stratégies de croissance en hauteur, de compétition pour accéder à la lumière, de durée de vie, d’efficacité vs de sécurité de la conduction hydrique, de résistance à la sécheresse et de colonisation de l’espace. Notre étude montre que les caractères anatomiques du bois sont dans une certaine mesure liés aux traits fonctionnels impliqués dans la croissance, la survie et la reproduction des plantes. Notre approche peut être utilisée pour évaluer les stratégies des plantes dans des milieux tropicaux à forte diversité spécifique. [less ▲]

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See detailLe rêve dans la Théorie du film ou l'épistémologie de l'exilé
Barbion, Sébastien ULg

Conference (2013, November 19)

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See detailOrganocatalyzed ring-opening polymerization of cyclic phosphate monomers
Clement, Benoît ULg; Vanslambrouck, Stéphanie ULg; Koole, Leo H. et al

Conference (2013, November 19)

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See detailA Management Control Perspective of Sustainability Reporting in Higher Education: In Search of a Holistic View
Ceulemans, Kim; Van Caillie, Didier ULg; Molderez, Ingrid et al

Conference (2013, November 18)

Higher education institutions have been actively attempting to integrate sustainability in their curricula, research, operations, and outreach activities over the last decades. Despite the efforts ... [more ▼]

Higher education institutions have been actively attempting to integrate sustainability in their curricula, research, operations, and outreach activities over the last decades. Despite the efforts undertaken, it is currently still challenging for their internal and external stakeholders to assess an institution’s sustainability-related activities and the extent of their implementation within the different activities of higher education. Since sustainability reporting in higher education is currently still in its early stages, and because a holistic view of sustainability integration in higher education on a management level is often lacking, this paper researches possible contributions of management control to sustainability reporting and the sustainability integration process in higher education. The paper adheres to a management control approach by applying Simons’ (1995) Levers of Control Framework to the field of sustainability in higher education, in search for a theoretical framework for reporting and integrating sustainability on a strategic level into higher education institutions. The research stresses the need for a holistic approach and for further in-depth study into certain aspects of the control framework, i.e., practical implementation of vision and mission statements, the concept of materiality, staff development, diagnostic indicator development, and the study of stakeholder engagement processes in higher education [less ▲]

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See detailLa vitamine D, état des lieux et recommandations
CAVALIER, Etienne ULg

Conference (2013, November 16)

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See detailStabilité et clarté du concept de soi : Comment se caractérise l'identité des patients dépressifs ?
Wagener, Aurélie ULg; Weigend, Alicia; Boulanger, Marie ULg et al

Poster (2013, November 16)

BACKGROUND. Depression is a psychopathology that affects many people (33.4 million every year in Europe). Depressed patients may demonstrate large variations in the evaluation of themselves (instability ... [more ▼]

BACKGROUND. Depression is a psychopathology that affects many people (33.4 million every year in Europe). Depressed patients may demonstrate large variations in the evaluation of themselves (instability of self-esteem and of self-efficacy). In addition, it has been demonstrated that, in the general population, negative feelings and emotions are positively correlated with the volatility of self-representations. However, no study has assessed the stability of personal identity in depressed patients. Some researchers have nevertheless shown that changes in personality traits are observable in the development of depressive disorder. HYPTHESES. Depressed patients’ description of their traits of personality varies depending on the mood phases crossings unlike that of control subjects who remained stable. METHOD. Depressed patients (N = 17, M age = 51) were compared to control subjects (N = 18, M age = 47). Severity of depressive symptoms (BDI -II), implicit (name - letter task) and explicit (CSR) self-esteem, stability of identity and self-concept clarity were assessed. RESULTS. Depressed patients have a self-perception less stable than control subjects and a lower clarity of identity. The severity of depressive symptoms was positively correlated with poorer clarity of identity. DISCUSSION. These results support our hypothesis. Experimental and clinical perspectives of these will be discussed. [less ▲]

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See detailL’Afrique et la science impériale britannique dans une phase de transition: une étude de cas de l’expédition au Congo en 1816 sous la direction de James Hingston Tuckey
Vandersmissen, Jan ULg

Conference (2013, November 16)

This paper fits in a broader research project funded by the Belgian F.R.S.-Fonds national de la Recherche scientifique. It is entitled: Africa in the “science policies” of France and Great Britain from ... [more ▼]

This paper fits in a broader research project funded by the Belgian F.R.S.-Fonds national de la Recherche scientifique. It is entitled: Africa in the “science policies” of France and Great Britain from the eighteenth to the mid- nineteenth century: the scholarly background of the Scramble. This general project aims at completing in an original way recent studies on the interactions between the “New Science” derived from the Scientific Revolution and the building of colonial empires in the Atlantic area from the Enlightenment to the apogee of the first Industrial Revolution. Its objective is to investigate how in this period Africa has become a scientific object in its own right for the colonial administrations of France and Great Britain. Botanical knowledge (industrial plants, food crops and medicinal herbs) that originated in Africa was first applied in the plantations of slave economies in the Caribbean and North America. It was increased with knowledge about the geography and natural history of the continent’s interior through a revival of exploration in Africa itself. The project aims to relate the increased interest from scholars for Africa to the intensification of economic and military competition between the powers. It also wants to demonstrate how a more precise knowledge of the African terrain influenced the ways in which the governments of both countries have integrated colonial expertise in a complex science policy adapted to the specific needs of the two states. In this paper I will focus on the British side of the spectrum. I will investigate the changing British attitude towards Africa in the early nineteenth century through a case study of an expedition to the River Congo organized in 1816. Although this expedition ended in disaster (a majority of the members died in the course of the undertaking), it offers a series of useful examples that help to illustrate the transformation of British science policies under the pressure of competition with the French. Thus, it is my aim to show how Great Britain in the face of state-oriented French science has abandoned its policy of informal relationships and started to encourage its administration and scientific institutions to intervene more directly in exploration. Crucial in this evolution was the way in which the Admiralty absorbed the scholarly input of a number of learned societies and institutions, such as the Royal Society, the British Museum or the so-called “African Association” – the latter combining both scientific and commercial objectives. Thus the expedition illustrates the transition from Late Enlightenment “Banksian” exploration, inspired by the omnipotent science organizer Sir Joseph Banks (1743-1820), towards a more thorough imperial design of exploration under the command of Sir John Barrow (1764-1848). Already since the French conquest of Egypt, “scientific” expeditions relied on the collaboration between learned networks and the military, an example that would be copied later in Algeria. At the British side, it was the Admiralty that strengthened its grip on exploration. Tuckey’s expedition illustrates very well the amplification of operations, the more direct intervention by the government, and the growing importance of the commercial agendas of science. I will focus here on the interaction between the Admiralty and the learned societies with regard to the composition of the instruction text given to the leader of the expedition on the eve of his departure, on the specific choice of the area he had to explore (related to the “Niger question”), on the practical organization (e.g. the development of special steam engines by the engineer Watt, the scientific equipment offered with the help of the British Museum, etc.), on the choice of the scientists who formed a real team of experts (e.g. Christen Smith, John Cranch, etc.), on the collection of scientific data and their integration in collections in Britain, on the presentation of the expedition’s results in a published report entitled Narrative of an expedition to explore the river Zaire, usually called the Congo, in South Africa, in 1816, under the direction of Captain J. K. Tuckey, R.N., (London, 1818), and finally, on the circulation of these results in the rest of Europe due to the translation of the report in Dutch and French. [less ▲]

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See detailQuelles activités pour nos seniors souffrant de maladie de la mémoire ?
Adam, Stéphane ULg

Conference (2013, November 16)

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See detailVitamine D et Allergie
GADISSEUR, Romy ULg

Conference (2013, November 16)

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See detailLe plomb atmosphérique enregistré dans les stalagmites de Han-sur-Lesse
Allan, Mouhamd ULg; Verheyden, sophie

Conference (2013, November 16)

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See detailLes aidants professionnels à domicile face à la démence: intérets d'une formation
Marquet, Manon ULg; Missotten, Pierre ULg; Charlot, Valentine ULg et al

Poster (2013, November 16)

Introduction : Des interventions non pharmacologiques peuvent réduire le risque que des aidants professionnels qui accompagnent des personnes âgées (atteintes ou non de démence) développent des attitudes ... [more ▼]

Introduction : Des interventions non pharmacologiques peuvent réduire le risque que des aidants professionnels qui accompagnent des personnes âgées (atteintes ou non de démence) développent des attitudes âgistes[1], un sentiment d’incompétence[2], une insatisfaction professionnelle[3,4] et un burnout[2]. Ces interventions sont néanmoins essentiellement destinées aux aidants en milieu institutionnel. Objectif : Évaluer, au niveau de différents paramètres (âgisme, connaissances sur la maladie d’Alzheimer, sentiment de compétence, satisfaction professionnelle, burnout, stratégies de coping), l’efficacité d’une formation destinée à des aidants professionnels à domicile. Méthodologie : 18 aides familiales ont bénéficié d’une formation de trois jours visant à améliorer leurs connaissances sur les démences et à les aider à mettre en place des stratégies de résolution de problèmes face aux difficultés rencontrées dans leur pratique, et ceci, afin de favoriser une vision moins stigmatisante de la maladie d’Alzheimer. Différents auto-questionnaires ont été complétés par les participantes avant et après l’intervention. Résultats : Les analyses statistiques indiquent que la formation permet de diminuer l’âgisme des aidantes, d’améliorer leurs connaissances sur la maladie d’Alzheimer et leur satisfaction vis-à-vis de leurs tâches professionnelles. Les stratégies de coping centrée sur la résolution de problème sont également considérées comme plus aidantes. Conclusion : L’intervention est efficace puisqu’elle atteint ses objectifs initiaux. Ces résultats encouragent non seulement la formation des aidants professionnels à domicile mais aussi l’évaluation de l’efficacité des interventions proposées, à la fois auprès des aidants professionnels, informels et des personnes accompagnées. En effet, sur base de la littérature[5,6], nous faisons l’hypothèse que l’amélioration des connaissances et la diminution de l’âgisme réduisent le risque d’induire des comportements de dépendance chez les personnes accompagnées. Ce constat est important compte tenu du rôle des aides familiales, à savoir aider les personnes âgées (atteintes ou non de démence) qui présentent des difficultés dans la réalisation des activités (instrumentales) de la vie quotidienne afin qu’elles restent le plus longtemps possible à leur domicile. Références : 1. Fritsch, T., et al. (2009). Gerontologist, 49, 117-127. 2. Mackenzie, C.S., et al. (2003). J Alzheimers Dis, 18, 291-299. 3. Vernooij-Dassen, M.J., et al. (2009). Aging Ment Health, 13, 383-390. 4. Coogle, C.L., et al. (2006). Educ Gerontol, 32, 611-631. 5. Avorn, J., et al. (1982). J Am Geriatr Soc, 30, 397-400. 6. Coudin, G., et al. (2010). Aging Ment Health, 14, 516-523. [less ▲]

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See detailUse of on-line flow cytometry for the characterization of physiological behavior in stress conditions during the bioprocess
Brognaux, Alison ULg; Han, Shanshan; Soren, Sorensen et al

Poster (2013, November 15)

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See detailDévéloppement intégré de matériaux hybrides photosynthétiques par encapsulation de micro-algues en vue de la production de méthabolites à haute valeur ajoutée (projet FOTOBIOMAT)
Duprez, Marie-Eve; Hantson, Anne-Lise; Thomas, Diane et al

Poster (2013, November 15)

La production de métabolites à haute valeur ajoutée tels que les caroténoïdes peut se faire au travers de la culture de micro-algues de type Dunaliella sp. notamment. La croissance de la biomasse en ... [more ▼]

La production de métabolites à haute valeur ajoutée tels que les caroténoïdes peut se faire au travers de la culture de micro-algues de type Dunaliella sp. notamment. La croissance de la biomasse en cellules libres a pour inconvénient majeur la destruction de la souche micro-algale lors des différentes étapes d’extraction des composés d’intérêt. Le projet FOTOBIOMAT (subsidié par le programme Greenomat de la Région wallonne) a pour but de développer un nouveau type de photobioréacteur dans lequel sont mises en oeuvre les micro-algues encapsulées dans des billes constituées d’un matériau hybride (alginate-silice). Les billes sont maintenues en suspension dans un lit fluidisé (mélange assez doux ne compromettant pas l’intégrité des billes). Ce type de mélange permet de renouveler les billes à la paroi du photobioréacteur, au contact de la source lumineuse. Le processus de photosynthèse est ainsi utilisé afin de convertir du CO2 en composé à haute valeur ajoutée (-carotène par exemple). La viabilité des micro-algues encapsulées doit être très importante (minimum 6 mois). Idéalement, le -carotène produit devrait être récupéré par une voie non polluante et ce, quasi en continu. Le projet est réalisé conjointement par quatre institutions universitaires (Université de Namur, Université Catholique de Louvain, Université de Liège et Université de Mons). Nous présentons ici différents résultats relatifs aux transferts gazeux et de matière au sein des billes, des billes vers une solution liquide ou de la solution vers les billes. L’oxygène produit par les micro-algues ainsi que le dioxyde de carbone consommé, preuves d’une bonne activité photosynthétique, doivent pouvoir migrer entre la matrice solide et le milieu de culture. La consommation de certains nutriments, les nitrates par exemple, essentiels à la croissance et à la survie de la souche micro-algale choisie peut également être suivie au cours du temps. Pour ce faire, différents types de sondes ont été utilisés avec plus ou moins de succès (Tableau 1). Les métabolites à haute valeur ajoutée produits (ici, le -carotène) doivent pouvoir être extraits des micro-algues et du matériau afin d’être récupérés dans la phase liquide. Des mesures de diffusion de composés tels que la rhodamine B (colorant) et de -carotène d’une solution agitée aux billes a été étudiée (Figures 1 et 2). Enfin, afin d’étudier leur capacité d’extraction du -carotène en-dehors des billes, différents solvants, dont la plupart sont connus pour leur capacité efficacité d’extraction de caroténoïdes hors des micro-algues, ont été testés. Il s’est avéré que si quelques solvants permettaient effectivement d’extraire du -carotène en-dehors des billes, ils étaient « agressifs » vis-à-vis du matériau (Tableau 2) ou de la biomasse. En outre, à l’heure actuelle, si aucun solvant « vert » et biocompatible n’a pu encore se dégager, l’huile de tournesol est en cours de test, tout en étudiant également l’action de procédés plus physiques (sonication, variations légères de température, …). [less ▲]

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See detailStéréotypes sur le vieillissement et sur la maladie d'Alzheimer : implications chez l'aidant familial
Bottard, Aude ULg; Adam, Stéphane ULg; Gilles, Christian et al

Poster (2013, November 15)

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See detailUse of Life Cycle Assessment to support in the Eco-Design of a glass-wool process
Gerbinet, Saïcha ULg; Renzoni, Roberto ULg; Briard, Vincent et al

Poster (2013, November 15)

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See detailCharacterisation of fengycin homologues produced by B. amyloliquefaciens (ET) strain isolated from a salt lake (Eastern Algeria)
Ait Kaki, Asma ULg; Noreddine, K.C.; Kara Ali, M. et al

Poster (2013, November 15)

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See detail« Product-oriented engineering » applied to the development of porous scaffolds for tissue engineering.
de Bien, Charlotte ULg; Ounally, Thameur; Collard, Valérie ULg et al

Poster (2013, November 15)

Ce travail vise à appliquer une approche « génie-orienté produit » à la fabrication de matrices poreuses synthétiques (scaffolds) susceptibles d’être utilisées en ingénierie tissulaire [1]. Parmi les ... [more ▼]

Ce travail vise à appliquer une approche « génie-orienté produit » à la fabrication de matrices poreuses synthétiques (scaffolds) susceptibles d’être utilisées en ingénierie tissulaire [1]. Parmi les différents polymères biosourcés et biodégradables déjà utilisés pour la fabrication de scaffolds, l’acide polylactique (PLA) a été choisi [2]. Des matrices poreuses ont été obtenues par un procédé de moussage par lyophilisation puis leur microstructure 2D/3D a été caractérisée par microtomographie à rayons X avant d’être mise en lien avec les conditions d’élaboration testées [3]. La diminution de la porosité ainsi que l’augmentation de l’épaisseur des parois avec l’augmentation de rapport polymère/solvant ont été confirmées. [less ▲]

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See detailProcédé de fabrication d'un matériau hybride photosynthétique obtenu par encapsulation de micro-algues en vue de sa mise en oeuvre dans un photobioréacteur à biomasse fixée
Lox, Frédéric ULg; Crine, Michel ULg; Toye, Dominique ULg et al

Poster (2013, November 15)

La méthode d’encapsulation a une grande influence sur la productivité et sur la viabilité des microalgues car elle conditionne leur environnement immédiat au sein du matériau hybride. Le contrôle de la ... [more ▼]

La méthode d’encapsulation a une grande influence sur la productivité et sur la viabilité des microalgues car elle conditionne leur environnement immédiat au sein du matériau hybride. Le contrôle de la porosité, de la composition chimique et la stabilité mécanique est fondamental. Cette étape de recherche consiste en la détermination des formulations chimiques idéales (densité cellulaire, compositions chimiques, porosité,…) et des conditions de synthèse (précurseurs chimiques, conditions d’encapsulation sol-gel) des matériaux hybrides photosynthétiques avec des microalgues sélectionnées; la géométrie (forme et dimensions) d’un matériau hybride donné (densité cellulaire, composition chimique, porosité) a une grande influence sur le transfert de matière (CO2, nutriments) et sur la transmission de la lumière jusqu’aux microalgues et donc sur l’activité métabolique et la viabilité de celles-ci. Le projet FOTOBIOMAT (subsidié par le programme Greenomat de la Région wallonne) est réalisé conjointement par quatre institutions universitaires Université de Namur (UNAMUR), Université Catholique de Louvain (UCL), Université de Liège (ULg) et Université de Mons UMONS)). La composition de départ du MHPS a été déterminée par UNAMUR. Nous aborderons ici les étapes de conception, construction et mise au point d’un dispositif de fabrication en continu de billes de matériau hybride photosynthétique contenant une microalgue du genre Dunaniella ainsi que l’adaptation du protocole de synthèse des billes en vue de permettre une production importante puis une production en continu qui ont été développées par le Laboratoire de Génie Chimique (LGC) de l’Université de Liège. Nous présenterons des études sur la caractérisation des MHPSs : -le transfert de lumière au sein du matériau et la diffusion de composés tels qu’un colorant (la rhodamine B), un pigment (le b-carotène) ou une protéine (l’hémoglobine) d’une solution agitée aux billes ont été réalisées ainsi que des tests d’extraction de b-carotène encapsulé directement dans les billes (UMONS) ; -la résistance, la distribution de la composition, la surface spécifique et la porosité de la couche La méthode d’encapsulation a une grande influence sur la productivité et sur la viabilité des microalgues car elle conditionne leur environnement immédiat au sein du matériau hybride. Le contrôle de la porosité, de la composition chimique et la stabilité mécanique est fondamental. Cette étape de recherche consiste en la détermination des formulations chimiques idéales (densité cellulaire, compositions chimiques, porosité,…) et des conditions de synthèse (précurseurs chimiques, conditions d’encapsulation sol-gel) des matériaux hybrides photosynthétiques avec des microalgues sélectionnées; la géométrie (forme et dimensions) d’un matériau hybride donné (densité cellulaire, composition chimique, porosité) a une grande influence sur le transfert de matière (CO2, nutriments) et sur la transmission de la lumière jusqu’aux microalgues et donc sur l’activité métabolique et la viabilité de celles-ci. Le projet FOTOBIOMAT (subsidié par le programme Greenomat de la Région wallonne) est réalisé conjointement par quatre institutions universitaires Université de Namur (UNAMUR), Université Catholique de Louvain (UCL), Université de Liège (ULg) et Université de Mons UMONS)). La composition de départ du MHPS a été déterminée par UNAMUR. Nous aborderons ici les étapes de conception, construction et mise au point d’un dispositif de fabrication en continu de billes de matériau hybride photosynthétique contenant une microalgue du genre Dunaniella ainsi que l’adaptation du protocole de synthèse des billes en vue de permettre une production importante puis une production en continu qui ont été développées par le Laboratoire de Génie Chimique (LGC) de l’Université de Liège. Nous présenterons des études sur la caractérisation des MHPSs : -le transfert de lumière au sein du matériau et la diffusion de composés tels qu’un colorant (la rhodamine B), un pigment (le b-carotène) ou une protéine (l’hémoglobine) d’une solution agitée aux billes ont été réalisées ainsi que des tests d’extraction de b-carotène encapsulé directement dans les billes (UMONS) ; -la résistance, la distribution de la composition, la surface spécifique et la porosité de la couche externe des MHPS (UNAMUR) ; -la répartition des dimensions et de la densité des billes obtenue en fonction du mode de production (ULg). [less ▲]

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See detailSynthesis of Pt/Carbon Xerogel Electrocatalysts for PEM Fuel Cells by the Multiple SEA Method
Zubiaur, Anthony ULg; Chatenet, Marian; Maillard, Frédéric et al

Poster (2013, November 15)

1. Introduction Proton exchange membrane fuel cell (PEMFC) catalysts are generally made of carbon black-supported Pt-based nanoparticles. However, carbon blacks do not display optimal properties for ... [more ▼]

1. Introduction Proton exchange membrane fuel cell (PEMFC) catalysts are generally made of carbon black-supported Pt-based nanoparticles. However, carbon blacks do not display optimal properties for electrocatalysis: they may contain high amount of chemical impurities, are essentially microporous, and the final structure of the electrodes is hardly tunable, which may cause diffusional limitations within the catalytic layer [1]. A possible solution to these drawbacks is the use of synthetic nanostructured materials with a controllable and reproducible texture and with a pure, known and constant chemical composition; carbon xerogels (CX) exhibit such properties [2]. In addition, high Pt weight percentages are necessary to achieve high electrical performance with thin electrodes. Highly dispersed CX-supported Pt nanoparticles catalysts (Pt/CX) can be prepared by the strong electrostatic adsorption (SEA) method [3,4]. This method consists in impregnating the CX support by a solution of metal precursor at an optimum pH measured beforehand (2.4-2.5 for the impregnation of CX with H2PtCl6 [5]). If the conditions of synthesis are well controlled, the coulombic interactions between the support and the metal precursor are maximized. Metal nanoparticles are obtained after filtration, drying and reduction under hydrogen. However, achieving high Pt weight percentages requires multiple “impregnation-drying-reduction” cycles [4]. The use of large volumes of fresh 1 gPt L-1 solution for each impregnation step induces inacceptable Pt losses. In order to improve the synthesis efficiency, efforts were targeted so as to re-use the same, highly loaded Pt solution for several impregnation steps. The present study is focused on the synthesis and the characterization of Pt/CX nanoparticles by the “multiple SEA method” in view of testing and using them as PEMFC electrocatalysts. 2. Experimental The support used in this work was a CX prepared by drying and pyrolysis of a resorcinol-formaldehyde aqueous gel [6]. The pore size distribution of this CX was centred at 80 nm. After pyrolysis, the CX was crushed and sieved between 75 and 250 μm. To synthesize Pt/CX catalysts, 1 g of CX powder was first mixed with 567 mL of an H2PtCl6 solution at 8.97 mmol L-1 (i.e. 1.75 gPt L-1) with an initial pH of 2.5. The surface loading (SL), i.e. the total area of CX surface in solution, was equal to 1000 m² L-1 and the concentration of H2PtCl6 was chosen high enough to re-use the solution five times. After 1 h of stirring, the mixture was filtered and the filtrate was kept for re-use in another impregnation step. The solid was dried in an oven at 333 K during 12 h. Then, the dried material was reduced at 473 K under H2 flow (0.04 mmol s-1) during 1 h to obtain carbon-supported Pt nanoparticles. In order to synthesize several catalysts with various Pt weight percentages, the complete procedure was repeated one to five times on the same support. After the last impregnation, each catalyst was reduced at 723 K under H2 (0.04 mmol s-1) during 5 h to clean the surface of the Pt particles from chlorine residues [4]. The five catalysts are labelled according to the number of “impregnation-drying-reduction” cycles (e.g. Pt-2 for the catalyst obtained after two cycles). The Pt weight percentage of the catalysts was measured by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The Pt particles were observed by transmission electron microscopy (TEM) and analysed by X-ray diffraction (XRD). The electro-active surface area of the Pt nanoparticles was measured by CO stripping voltammetry performed in 1 M sulphuric acid aqueous solution [7-9]. The specific activity of Pt particles for the Oxygen Reduction Reaction (ORR) was measured on a rotating disk electrode (RDE) in the same liquid electrolyte. 3. Results and discussion Table 1 summarizes some characteristics of the synthesized catalysts. The multiple SEA method leads to the synthesis of well dispersed Pt/CX catalysts with high Pt weight percentage, PtICP, which can be adjusted via the number of “impregnation-drying-reduction” cycles, and reaches 25 wt.% after five cycles. It is worth noting that the quantity of Pt deposited on the CX in one cycle, mPt, decreases after the first two cycles. This might be due to the successive impregnations in the acidic solution, the pH of which equals 2.4 - 2.5, and to the successive reduction steps: both procedures probably modify the surface chemistry of the CX, and leads to a shift of the optimal adsorption pH. This pH shift would induce a decrease in the amount of Pt deposited during the next cycles. This hypothesis remains under investigation. The analysis of TEM micrographs indicates that the five catalysts display the same mean Pt particle size, dTEM. This is corroborated by the comparison between the surface-averaged mean particle size, dS, and the CO equivalent diameter, dCO, or between the volume-averaged mean particle size, dV, and the average crystallite size calculated from XRD, dXRD. The values of the electroactive specific surface area of the Pt particles calculated from CO Journée scientifique GEPROC 2013 Procédés et Matériaux durables Université de Liège 15 novembre 2013 stripping, SCO, are the same for all the catalysts (ca. 95 m² gPt -1). The specific activity, SA, of the catalysts for the ORR is derived from the value of the Tafel plots and intercept. Fig. 1 shows that the Tafel plots are superimposed; as a result, the values of the specific activity at a given electrode potential are nearly identical for the five catalysts, and the Tafel slope, which is characteristic of the reaction mechanism, is almost constant as well (ca. -74 mV dec- 1). Since the specific activity depends on the average size of the Pt nanoparticles (the ORR is a structure-sensitive reaction), this result indicates that the number of impregnation sequences has no impact on the Pt nanoparticle size, and degree of agglomeration. 4. Conclusions The multiple SEA method allows obtaining well dispersed Pt/CX catalysts with high weight percentage up to 25 wt.%, and particle size close to ca. 2.5 nm. Studies are in progress to determine the maximum weight percentage that can be achieved without alteration of the metal dispersion. The multiple SEA method requires the use of less Pt than the SEA method from which it is inspired. Considering the synthesis of a 25 wt.% Pt/CX, the two methods require five “impregnation-drying-reduction” cycles but, for the SEA method, five solutions of 1gPt L-1 are used instead of only one solution of 1.75 gPt L-1, the latter being re-used in the case of multiple SEA. This difference leads to a nearly threefold decrease in the consumption of Pt. Further analyses will be performed so as to determine the optimal Pt weight percentage and the optimal thickness of the catalytic layer by modifying these two variables in a series of membrane-electrodes assemblies. [less ▲]

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See detailRole of non-polyQ regions on the different steps of amyloid fibril formation by polyQ proteins
Huynen, Céline ULg

Poster (2013, November 15)

Ten neurodegenerative diseases, referred to as polyglutamine (polyQ) diseases, are associated with the aggregation into amyloid fibrils of ten different proteins containing a polyQ expansion higher than a ... [more ▼]

Ten neurodegenerative diseases, referred to as polyglutamine (polyQ) diseases, are associated with the aggregation into amyloid fibrils of ten different proteins containing a polyQ expansion higher than a pathological threshold comprised between 35 to 45Q (1, 2). A large body of evidence indicate that the polyQ expansion is the critical determinant for the aggregation of these polyQ proteins. The aggregation process of polyQ proteins is, however, still not well understood. To better understand this mechanism at a molecular level, we have characterized model polyQ proteins made of the β-lactamase BlaP from Bacillus licheniformis 749/C and a polyQ tract of 0 to 79Q inserted either at position 197 or position 216 of BlaP. Those chimeras recapitulate the same aggregation behaviours than that of disease-associated polyQ proteins: there is a glutamine threshold for the aggregation into amyloid fibrils and the anticipation phenomenon. Most importantly, the threshold critically depends on the structural integrity of BlaP (3) which would impose some conformational and/or sterical constraints to the polyQ tract. Moreover the position of the polyQ insertion into BlaP modifies the aggregation propensity of BlaP chimeras. The present work aims to further investigate (i) how the protein context affects the different phases of the aggregation phenomenon (i.e. the nucleation and elongation phases) and (ii) the role of the oligomers formed during the early time of the aggregation process. The techniques used are mainly (1) quartz crystal microbalance (QCM) and atomic force microscopy (AFM) to study the elongation step of amyloid fibril formation and (2) dynamic light scattering (DLS) to study the evolution of the different populations formed during the aggregation time course. The results of these experiments indicate that the native conformation of BlaP197(Gln)55 interferes mainly with the nucleation but not with the elongation step of amyloid fibril formation. Moreover, these results demonstrate that the sequences flanking the polyQ tract significantly influence its propensity to elongate amyloid fibrils. [less ▲]

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See detailEpuration catalytique de biogaz
Claude, Vincent ULg; Lambert, Stéphanie ULg; Heinrichs, Benoît ULg et al

Poster (2013, November 15)

The poster presents the recent observations concerning the of Ni-Al2O3 catalysts synthesized in 2013. Particles size, surface areas and crystallinity of the samples are controlled thanks to the initial ... [more ▼]

The poster presents the recent observations concerning the of Ni-Al2O3 catalysts synthesized in 2013. Particles size, surface areas and crystallinity of the samples are controlled thanks to the initial reactives (surfactants, EDAS). [less ▲]

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See detailLaser-induced contamination and its impact on laser damage threshold
Schröder, H; Wagner, P; Kokkinos, Dimitrios ULg et al

in Laser-induced contamination and its impact on laser damage threshold (2013, November 14)

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See detailP.Vatic.Gr. inv. 11r : le "cadastre de Marmarique"
Ricciardetto, Antonio ULg

Conference (2013, November 14)

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See detailVulnérabilité du patient âgé (en partenariat avec le Professeur A. BENETOS)
Petermans, Jean ULg

Conference (2013, November 14)

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See detailDo recent West African rainfall variations really impact the livestock in the Sahel?
Ozer, Pierre ULg

Conference (2013, November 14)

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See detailFilamentous fungi in water distribution systems: what is the risk?
Hayette, Marie-Pierre ULg

Conference (2013, November 14)

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See detailObservations sur la forme, l'état du support et la mise en page du P.Vat.gr. 11
Carlig, Nathan ULg

Conference (2013, November 14)

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See detailLe dossier papyrologique de Favorinos d'Arles
Marganne, Marie-Hélène ULg

Conference (2013, November 14)

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See detailEUTHANASIE ET DEMENCE
Barthélemy, Nicole ULg; DAMAS, François ULg; ALLEPAERTS, Sophie ULg et al

Conference (2013, November 13)

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See detailEcology of mosquitoes (Diptera, Culicidae) potentially vectors of arboviruses according to the kinds of animal husbandry in Belgium
Boukraa, Slimane ULg; De la Grandière de Noronha Cotta, Maria Ana ULg; Bawin, Thomas ULg et al

Poster (2013, November 12)

Human activity, commercial exchanges and climate changes current and future, could favor the (re)-emergence of vector-borne diseases, by inducing changes on Culicidae populations. This study aims to ... [more ▼]

Human activity, commercial exchanges and climate changes current and future, could favor the (re)-emergence of vector-borne diseases, by inducing changes on Culicidae populations. This study aims to determine the potential importance of agricultural environments, especially cattle farms and equestrian, to welcome and favor the proliferation of some species of mosquito responsible for transmission of arboviruses. To better understand the structure of the Culicidae population and identify habitats favorable to the development of each species, a taxonomic inventory was conducted in 2008 (III, VI and X) and 2009 (V and IX) in ten cattle farms, and in 2011 (VI-X) and 2012 (VI-IX) in six equestrian farms located in Belgium. The harvest of mosquitoes is based on adult trapping by CO2-traps (Mosquito magnet) and on larval sampling at the level of 64 biotopes such as water troughs, used tires, abandoned utensils and temporary puddles or not. The morphotaxonomic of larvae and genitalia, and molecular study showed the presence of 15 species: Culiseta annulata Schrank, 1776; Cs. morsitans Theobald, 1901 Anopheles claviger s.s. Meigen, 1804; An. maculipennis s.s. Meigen, 1818; An. messeae Falleroni, 1926; An. plumbeus Stephens, 1828; Culex pipiens molestus Forskal, 1775; Cx. pipiens pipiens L., 1758; Cx. torrentium Martini, 1925; Cx. hortensis hortensis Ficalbi, 1889; Cx. territans Walker, 1856; Coquillettidia richiardii Ficalbi, 1889; Ochlerotatus geniculatus Olivier, 1791; Oc. cantans Meigen, 1818 and Aedes cinereus Meigen, 1818. Among the 57,680 individuals examined, Cx. pipiens s.l., Cx. torrentium and Cs. annulata are the dominants species and ubiquitous in all farms visited. The species of the genus Anopheles have strong ecological requirements and are therefore associated with some special habitats; other species however have a strong ability to adapt and therefore attend a wide variety of biotopes (Cx. pipiens s.l., Cx. torrentium and Cs. annulata). Water troughs, used tires and ponds are the most favorable habitats for larval development of Culicidae. The species potentially vectors of arboviruses that can cause problems in epidemiological farms are Cx. pipiens s.l., Cx. torrentium and Cq. richiardii. Therefore, despite the low diversity of mosquito observed within the livestock environments, they represent a significant risk for the reproduction of some potential vectors of arboviruses. In addition, some larval habitats constitute very favorable sites for proliferation of mosquito, causing a real problem of nuisance for animals of farms. [less ▲]

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See detailContribution to the description of the nitrogen cycle in Lake Kivu
Roland, Fleur ULg; Borges, Alberto ULg; Crowe, Sean et al

Poster (2013, November 12)

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See detailSAHBNET, An Accessible Surface-Based Elastic Network to Insert a Protein in a Complex Lipid Membrane
Dony, Nicolas ULg; Crowet, Jean-Marc ULg; Joris, Bernard ULg et al

Conference (2013, November 11)

Study of membrane proteins have become one of the most challenging fields in biology. Solving their structure is one important step toward the understanding of their physiological activity but despite the ... [more ▼]

Study of membrane proteins have become one of the most challenging fields in biology. Solving their structure is one important step toward the understanding of their physiological activity but despite the recent advances in membrane protein crystallization, it represents less than 1 % of the entries in the Protein Data Bank. Therefore, calculation methods to study membrane proteins are helpful to complement experimental studies and fill the gap between the information obtained from the sequence and/or structure, the experimental results and the biological activity. Molecular Dynamics is a method of choice for membrane simulations and the rising of coarse-grained forcefields has opened the way to longer simulations with reduced calculations times. However, these approaches have two main drawbacks, the preparation of complex systems and the preservation of the 3D protein structure, which is not trivial in coarse grained approach. To circumvent these problems, we propose to use a modified version of the Gromacs tool genbox to easily insert lipids and a network based on hydrogen bonds and accessible surface to maintain the protein 3D structure. This protocol is available through a website (gcgs.gembloux.ulg.ac.be). [less ▲]

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See detailInfinite Depth: du Movie Ride à la 3D relief, l'expérience de la profondeur.
Thonon, Jonathan ULg

Conference (2013, November 10)

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See detailTransient middle cerebral artery occlusion prevents habit formation in C57Bl/6J mice
Linden, Jérôme ULg; Plumier, Jean-Christophe ULg; Ferrara, André ULg et al

Poster (2013, November 10)

Pathologies affecting the striatum (e.g., Parkinson’s and Huntington’s disease) can result in impaired habit learning abilities. Likewise, such impairments have also been observed after stroke affecting ... [more ▼]

Pathologies affecting the striatum (e.g., Parkinson’s and Huntington’s disease) can result in impaired habit learning abilities. Likewise, such impairments have also been observed after stroke affecting the middle cerebral artery territory (encompassing the striatum). However, habit learning has never been investigated in animal stroke models, for which it could be a reliable measure of cognitive deficits. We thus assessed the ability to learn a habitual sequence of lever-presses using operant conditioning in mice after MCAO, one of the most common stroke models. C57Bl/6J mice underwent MCAO or sham surgery. Sensorimotor functioning was assessed using the vertical pole test, rotarod and amphetamine-induced rotation test. Habit learning was evaluated using the operant serial order learning (SOL) task: mice had to perform a series of two consecutive lever-presses (i.e., left then right) to obtain a food reward. Lesion extents were finally determined using anti-NeuN immunohistochemistry. MCAO mice were significantly impaired in both the rotarod and vertical pole test, and displayed a significantly greater number of ipsilateral rotations after amphetamine administration. In the operant SOL task, MCAO committed more errors than sham; moreover, they did not show any significant increase in performance along the sessions. Histological analysis showed consistent striatal and cortical infarctions. The lack of habit learning ability in MCAO mice is congruent with both the literature investigating the effect of striatal lesion in animals and the symptomatology observed in human stroke patients. Habit learning could thus be regarded as a reliable measure of functional outcome after MCAO, in combination with test assessing sensory and motor aspects. [less ▲]

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See detailM.G. Vassanji’s A Place Within: Thinking through India, Transnationally
Munos, Delphine ULg

Conference (2013, November 10)

In their groundbreaking collection, Minor Transnationalism, Françoise Lionnet and Shu-mei Shih advocate a new approach to transnationalism, which, by shifting the ground of analysis to “transversal” ... [more ▼]

In their groundbreaking collection, Minor Transnationalism, Françoise Lionnet and Shu-mei Shih advocate a new approach to transnationalism, which, by shifting the ground of analysis to “transversal” movements of culture, departs from existing theoretical frameworks and allows for the emergence of “minor-to-minor networks” (8) that have the potential to circumvent the major altogether. Lionnet’s and Shih’s understanding of transnationalism not in terms of vertical relations between center and margin, but in terms of cultural transversalism, is particularly apt in the context of MG Vassanji’s writings, notably because his books often complicate those hackneyed notions of hybridity constructing Western locales as the privileged sites of plurality. In this paper, my contention is that Lionnet’s and Shih’s concept of ‘minor transnationalism’ also proves useful to deconstruct the discourse of ‘dominant’ Western-based diasporas that style themselves as “the legitimate archive with which to explore diasporic subjectivities” (Vijay Mishra, 3) — such as the hyper-visible ‘new’ Indian diaspora of global capital. Taking its cue from Lionnet’s and Shih’s concept of minor transnationalism, this paper looks at A Place Within (2008), the memoir of Vassanji’s travels across the land of his ancestors over two decades, with a view to showing how the author’s positionality as a ‘minor’ transnational (i.e. as a Canadian writer of Indian descent born on East-African soil) gives a new twist to the now-classic ‘return to the Indian homeland’ narrative — a staple, indeed, of the enormously popular Indian diasporic literature. At stake is the contention that Vassanji’s own brand of ‘minor transnationalism’ allows for a unique descent into the messiness of India, the ‘slippery’ nature of its past — well beyond diaspora’s dubious politics of retrieval and its investment in purist readings of the Indian homeland [less ▲]

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See detailEstrogens control female sexual motivation and receptivity in quail.
de Bournonville, Catherine ULg; Ball, Gregory, F.; Balthazart, Jacques ULg et al

Poster (2013, November 10)

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See detailCoupes sombres (Martin Arnold et Walt Disney)
Belloi, Livio ULg

Conference (2013, November 09)

À partir de 2010, l'œuvre du cinéaste expérimental autrichien Martin Arnold a connu une mutation profonde. Alors que ses œuvres précédentes s'employaient à détourner des films de fiction hollywoodiens, le ... [more ▼]

À partir de 2010, l'œuvre du cinéaste expérimental autrichien Martin Arnold a connu une mutation profonde. Alors que ses œuvres précédentes s'employaient à détourner des films de fiction hollywoodiens, le travail contemporain d'Arnold vise, quant à lui, à retravailler des fragments de dessins animés issus de la production Disney. La présente communication se propose d'examiner ce corpus contemporain et d'en dégager les enjeux. Une attention toute particulière est réservée à "Shadow Cuts" (2010), film à l'occasion duquel Arnold renoue avec ses premières amours (le scratching visuel et sonore). [less ▲]

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See detailIncreased affinity of N-Methyl-AG525 stereoisomers for SK2 and SK3 channels
Liégeois, Jean-François ULg; Seutin, Vincent ULg; Dilly, Sébastien ULg

Poster (2013, November 09)

Small conductance calcium-activated potassium (SK, KCa2) channels represent interesting and challenging targets in medicinal chemistry. So far, the reference ligand is apamin, a peptide used in most ... [more ▼]

Small conductance calcium-activated potassium (SK, KCa2) channels represent interesting and challenging targets in medicinal chemistry. So far, the reference ligand is apamin, a peptide used in most published studies including the [125I] analog for binding studies. Nonpeptidic ligands with high affinity have been developed for several years. Currently, different questions remain to be solved. No selective and brain-penetrating agent is available. In addition, replacing [125I]apamin in binding experiments would be also interesting. We have developed different series of compounds initially derived from laudanosine (1). The quaternized derivative, N-methyl-laudanosine (NML), was found to be a weak SK blocker but highly reversible in electrophysiological experiments (2). Then, bis-charged derivatives were synthesized. Potentially brain-penetrating AG525 stereoisomers were obtained and tested for their affinity for SK channels (3). The affinity of one enantiomer, AG525E1, was found to be close to that of dequalinium (Ki ~ 200 nM) while the two other stereoisomers had a lower affinity. Following this study, quaternization of AG525 stereoisomers was carried out and the affinity of these compounds for SK channel subtypes was determined in comparison with that of parent compounds. We observed a significant increase of affinity for SK2 and SK3 channels for the bis-charged N-methyl derivatives as compared to the basic AG525 stereoisomers to. The ratio of selectivity was increased a little in the case of bis-charged N-methyl derivatives. In addition, the influence of stereochemistry was quite different between both groups. For basic AG525 stereoisomers, the S,S-enantiomer (AG525E1) was the most potent while, within bis-charged N-methyl analogues, both enantiomers had higher affinity. Further in silico approaches should permit to explain these results. References: (1) Graulich et al., Bioorg. Med. Chem. 2005, 13, 1201 (2) Scuvée-Moreau et al., J. Pharmacol. Exp. Ther. 2002, 302, 1176 (3) Graulich et al., Bioorg. Med. Chem. Lett., 2008, 18, 3440 [less ▲]

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See detailY avait-il vraiment des Gestalten dans L’analyse des sensations d’E. Mach ?
Zincq, Aurélien ULg

Conference (2013, November 08)

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See detailPINP in renal impaired patients: the assay matters
CAVALIER, Etienne ULg; DELANAYE, Pierre ULg

Poster (2013, November 08)

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See detailEculizumab (ECU) Inhibits Thrombotic Microangiopathy (TMA) and Improves Renal Function in Adult Atypical Hemolytic Uremic Syndrome (aHUS) Patients (Pts)
Fakhouri, Fadi; Hourmant, Maryvonne; Campistol, Josep et al

Poster (2013, November 08)

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See detailLibraries and their Role in Open Access: Challenges and Opportunities
Morse, Laura; Renaville, François ULg; Stohn, Christine

Conference (2013, November 08)

The open access movement gains momentum with an increasing number of institutions and funders adopting open access mandates for their funded research. Consequently, an increasing amount of material ... [more ▼]

The open access movement gains momentum with an increasing number of institutions and funders adopting open access mandates for their funded research. Consequently, an increasing amount of material becomes freely available, either from institutional repositories or from traditional or newly established journals. Libraries can play a dual role in supporting this movement: Firstly, they can provide services supporting the deposit of research output in their institutional repositories, including support for making it widely discoverable via indexes such as Google Scholar and library discovery systems. Secondly, libraries can make open access materials discoverable by their patrons through such indexes, thus expanding their collection to include materials that they would not necessarily license. This session will describe the experience of the University Libraries of Liège in Belgium and Harvard. University of Liège chose a top-down approach and made it compulsory for researchers to deposit their output in the institutional repository—ORBi. To support this mandate, the library offers services that help researchers deposit and disseminate their publications. Both libraries—Liège and Harvard—enable their students and faculty to discover open access content beyond their library’s acquired collection via their library discovery system. The session will also address challenges that arise from indexing open access publications and how index providers and libraries can deal with such publications, especially with articles that are deposited in different institutional repositories or published in so-called hybrid journals that contain a mix of open access and subscription articles. Finally, we will discuss with the audience how they see libraries’ role evolving in this area, what challenges they are currently facing, and the solutions and opportunities they have found. [less ▲]

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See detailInto the deep. La profondeur comme attraction dans les productions des Studios Disney
Tomasovic, Dick ULg

Conference (2013, November 08)

Depuis l’invention de la caméra multiplane en 1933 par l’ingénieur Bill Garity au sein des studios Disney, jusqu’à la création de la marque Disney Digital 3-D, en 2005, qui promeut le cinéma en relief ... [more ▼]

Depuis l’invention de la caméra multiplane en 1933 par l’ingénieur Bill Garity au sein des studios Disney, jusqu’à la création de la marque Disney Digital 3-D, en 2005, qui promeut le cinéma en relief stéréoscopique, les départements des effets spéciaux de la compagnie Disney se sont fortement investis dans la quête pour une restitution impressionnante, voire spectaculaire, de la profondeur de champ. Détaillant les illusions optiques de films aussi divers que The Old Mill (1937), Snow White and the Seven Dwarfs (1937), Bolt (2008), Alice in Wonderland (2010), ou Tron : Legacy (2011), cette intervention s’interroge également sur les présupposés idéologiques du simulacre de la profondeur chez Disney, qui se trouvent par ailleurs prolongés tant dans l’architecture des parcs à thèmes Disney que dans les dispositifs de nombre de leurs attractions. [less ▲]

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See detailLa redéfinition du premier ordre au début de la Renaissance : l'exemple du cardinal d'Amboise
Dumont, Jonathan ULg

in Dumont, Jonathan; Fagnart, Laure (Eds.) Georges Ier d'Amboise. 1460-1510. Une figure plurielle de la Renaissance. Actes du colloque tenu à l'Université de Liège les 2 et 3 décembre 2010 (2013, November 08)

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See detailHéritages et stimulants à la courte histoire de la PESD/PSDC
Dumoulin, André ULg

Conference (2013, November 08)

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See detailAu-delà des interdits. Religion islamique et pratiques culinaires marocaines en Italie.
Mescoli, Elsa ULg

Poster (2013, November 07)

In many discourses about the relationship between food and Islamic religion, attention is often devoted to normative aspects: Muslims food practices are ruled by the polarization between what is halal and ... [more ▼]

In many discourses about the relationship between food and Islamic religion, attention is often devoted to normative aspects: Muslims food practices are ruled by the polarization between what is halal and what is haram to eat. In this discursive context, even if negotiations with certain requirements can be taken into account, believers would primarily incorporate a food style determined by certain feed bans. My study, without neglecting these aspects, aims at demonstrating how the semantic field of the term halal not only includes all that is not forbidden for consumption by religious norms. This field opens indeed to many instructions, coming from Islamic sources, actively and positively guiding believers in their food choices. My doctoral research, focusing on culinary practices and objects of Moroccan women in migration context, made me reconsider the Islamic religion as having an affirmative role in eating behaviours and even in food preparation. The women protagonists of my ethnography show how the choice to use certain ingredients and to prepare some meals is dictated or supported by divine guidance. My presentation will focus on the materiality of these dynamics: through images collected during my ethnography, my intention is to recount the complexity and the concreteness of the relationship between eating habits and Islam. [less ▲]

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See detail"Climate change" and vulnerability analysis: poor will become poorer
Ozer, Pierre ULg

Conference (2013, November 07)

The recent Intergovernmental Panel on Climate Change’s Fifth Assessment Report (IPCC-AR5) considers new evidence of climate change based on many independent scientific analyses from observations of the ... [more ▼]

The recent Intergovernmental Panel on Climate Change’s Fifth Assessment Report (IPCC-AR5) considers new evidence of climate change based on many independent scientific analyses from observations of the climate system, paleoclimate archives, theoretical studies of climate processes and simulations using climate models. “Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia. The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, sea level has risen, and the concentrations of greenhouse gases have increased”. “Changes in many extreme weather and climate events have been observed since about 1950. It is very likely that the number of cold days and nights has decreased and the number of warm days and nights has increased on the global scale”. “It is likely that the frequency of heat waves has increased”. “There are likely more land regions where the number of heavy precipitation events has increased than where it has decreased”. “The frequency or intensity of heavy precipitation events has likely increased”. In the meantime, it is now well known that climate change consequences (increasing magnitude and frequency of droughts, floods, storms and/or coastal erosion) will mainly impact the most vulnerable. Although there are multiple ways to define vulnerability, we here define vulnerability as the exposure of individuals or collective groups to livelihood stress as a result of the impacts of such climate change and consecutive socioeconomic and environmental changes. In the context of this paper, we will focus on natural disasters induced by “climate change”. We will travel across developing countries to illustrate the increasing vulnerability of the poor and the way they –sometimes– develop effective adaptation responses. We conclude that, for many reasons (mainly the protection of individual, financial and/or political interests), the poor will become poorer. [less ▲]

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See detailStudying Vulnerability: Participation and Incident Reports
Rossignol, Nicolas ULg

Conference (2013, November 07)

Scholars in many fields of research have developed models, theories and concepts attempting to grasp and manage dangers that are often difficult to concretely imagine. Their final objective is to maintain ... [more ▼]

Scholars in many fields of research have developed models, theories and concepts attempting to grasp and manage dangers that are often difficult to concretely imagine. Their final objective is to maintain the safety of the system considered. Dealing with potential hazards, some researchers distinguish between the vulnerability approach and the risk approach. The risk based approach is focused on acquiring accurate probabilistic information about the events themselves. Yet, Sarewitz (2003: 806) reminds that “there are numerous cases in which accurate assessment of risk is impossible” and that “lack of experience with many phenomena and outcomes means that understanding the uncertainty of the uncertainty estimates is impossible”. Thus, beyond the risk-based approach, another perspective emerged: vulnerability analysis (VA). Vulnerability can be described as “the degree to which a system, subsystem, or system component is likely to experience harm due to exposure to a hazard” (Turner et al. 2003: 8074). VA seems capable of overcoming the shortcomings of risk analysis in situations where knowledge about both probabilities and outcomes is incomplete or insufficient (Sarewitz 2003). The vulnerability approach and the classical risk analysis approach are thus based on different premises (Gilbert 2006): while risk analysis focuses on the hazard, VA focuses on the system under threat. From that starting point, we realized in order to analyse the state-of-the art in the field of vulnerability analysis, with particular emphasis on participatory approaches. The aims were: i) to study how the concept of vulnerability has been defined and used in different fields of application (e.g. natural and industrial hazards) and ii) to analyse whether the theoretical claim that participatory approaches to vulnerability analysis have the potential for great scientific and political outputs has been actually demonstrated in practice. Based on this study we formulate a threefold critique: first, VA has been treated separately in natural and technological hazards fields. This separation is unproductive for a fine-grained understanding of what vulnerability can provide as a concept, as it prevents vulnerability to unleash the full range of its potential. Second, VA focused on assessment tools that are mainly quantitative, whereas qualitative appraisal is a key to assess vulnerability in a comprehensive way and to inform policy-making. Third, a systematic literature review on participatory VA case studies allows us to argue that participation has been important to address the above, but it remains too closed down in its approach and would rather benefit from embracing a more opened, encompassing perspective. Therefore, we suggest re-thinking participatory VA as one part of a dynamic process between opening-up and closing-down strategies, in order to support a reflexive vulnerability governance framework. Doing so is not exempt of challenges, though. Since analytical reflection on vulnerability is to be transferred into practices of risk and vulnerability governance, taking into account the context in which governance agents need to take appropriate decisions is of primary importance. Thus, based on the conclusion of this presentation, the practical ways of realizing a reflexive vulnerability governance should now be explored. [less ▲]

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See detailMeasuring the thermophysical properties of materials at high temperature - Application to the additive manufacturing of alloy Ti-6Al-4V and of stainless steel 316L
Mertens, Anne ULg; Paydas, Hakan ULg; Reginster, Sylvie ULg et al

Conference (2013, November 07)

In view of optimising the microstructures of metallic materials and obtaining the desired properties, the accurate characterisation of the thermophysical behaviour of these materials has long been ... [more ▼]

In view of optimising the microstructures of metallic materials and obtaining the desired properties, the accurate characterisation of the thermophysical behaviour of these materials has long been considered of paramount importance e.g. by allowing for the in-situ study of phase transformations, by providing data for numerical simulations and, essentially, by contributing to a better understanding of the fundamental mechanisms at play during processing. In the present work, the thermophysical behaviour of Ti-alloy Ti-6Al-4V and of stainless steel 316L has been characterised in details, in order to reach a better understanding of the phenomena controlling the microstructures and mechanical properties of parts made by additive manufacturing techniques that appear nowadays very promising in view of the economic production of near-net-shape, complex and (almost) fully dense parts from metallic materials. In particular, the thermal conductivity of Ti-alloy Ti-6Al-4V and of stainless steel 316L at high temperature has been determined by combining dilatometry, Differential Scanning Calorimetry (DSC) and laser flash diffusivimetry based on Laplace’s equation : k(T)=α(T)ρ(T)Cp(T) where k(T) is the thermal conductivity (W/m*K) α(T) is the thermal diffusivity (mm2/s) ρ(T) is the specific mass (g/cm3) Cp(T) is the specific heat capacity (J/g*K). Since Ti-alloy Ti-6Al-4V and stainless steel 316L exhibit quite different physical behaviours, their careful comparison is shown to shed more light into the role of phenomena such as epitaxial growth, out-of-equilibrium phase transformations and/or internal stresses in the additive manufacturing of metallic materials. [less ▲]

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See detailMeasuring feet trajectories: challenges and applications
Pierard, Sébastien ULg; Azrour, Samir ULg; Van Droogenbroeck, Marc ULg

Conference (2013, November 07)

Measuring reliable feet trajectories is needed in many applications. This paper provides the principles used in GAIMS, which is a non-intrusive system that measures feet trajectories based on multiple ... [more ▼]

Measuring reliable feet trajectories is needed in many applications. This paper provides the principles used in GAIMS, which is a non-intrusive system that measures feet trajectories based on multiple range laser scanners. We present the technical challenges that we had to address, as well as an overview of the implemented processing pipeline of GAIMS. [less ▲]

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See detailSEDIMENTARY DEVELOPMENT AND MAGNETIC SUSCEPTIBILITY OF THE FRASNIAN CARBONATE PLATFORM IN WESTERN BELGIUM (DINANT SYNCLINORIUM, LA THURE SECTION)
Pas, Damien ULg; Da Silva, Anne-Christine ULg; Labaye, Corentin et al

in 14 ième ASF 2013 (Association des Sédimentologistes Français) (2013, November 07)

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See detailUsing GAit Measuring System (GAIMS) to discriminate patients with multiple sclerosis from healthy person
Azrour, Samir ULg; Pierard, Sébastien ULg; Van Droogenbroeck, Marc ULg

Poster (2013, November 07)

Among voluntary movements, gait is the most affected by multiple sclerosis. Gait impairment is also a good indicator of the disease progression. However, measurement of gait character- istics made by ... [more ▼]

Among voluntary movements, gait is the most affected by multiple sclerosis. Gait impairment is also a good indicator of the disease progression. However, measurement of gait character- istics made by neurologists is usually limited to the use of a stopwatch. The GAit Measuring System (GAIMS), provides a wider range of measurements that allow the definition of several relevant gait descriptors. The work presented here shows the effectiveness of these gait descriptors and machine learning techniques to discriminate between healthy persons and patients with multiple sclerosis. [less ▲]

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See detailDe la paléoécologie à l'écologie actuelle : 2000 ans d'interaction homme-milieu dans le nord du Bassin du Congo
Morin-Rivat, Julie ULg; Bentaleb, Ilham; Biwole, Achille ULg et al

Poster (2013, November 06)

La forêt tropicale africaine a longtemps été considérée comme vierge du passage de l’homme. Cependant, plusieurs études récentes en paléoécologie et archéologie ont démontré la présence d’activités ... [more ▼]

La forêt tropicale africaine a longtemps été considérée comme vierge du passage de l’homme. Cependant, plusieurs études récentes en paléoécologie et archéologie ont démontré la présence d’activités humaines anciennes à partir d’indices paléoenvironnementaux (i.e. pollens de plantes anthropophiles) et d’artefacts (i.e. tessons de céramique). Ces études sont toutefois trop rares en raison de difficultés de terrain pour repérer et accéder aux sites archéologiques (couvert végétale dense, absence de pistes). De grandes zones à l’intérieur des terres demeurent donc inexplorées. Par ailleurs, peu d’études se sont penchées sur la question de l’impact de ces activités anthropiques passées sur la structure et la composition de la végétation actuelle. Grâce à une approche multidisciplinaire à la frontière entre sciences humaines et sciences de l’environnement (archéologie, pédoanthracologie : charbons de bois des sols, écologie forestière), notre objectif est d’identifier des indices d’activités humaines anciennes, lesquels sont été mis en relation avec les patrons actuels de végétation. Nos trois zones d’étude sont localisées en forêt tropicale humide de type guinéo-congolais et sont réparties dans le sud-ouest et sud-est du Cameroun et le nord de la République du Congo. Le long d’une vingtaine de transects de plusieurs kilomètres, nous avons appliqué un protocole systématique de récolte de matériel archéologique et archéobotanique dans des fosses situées sur des parcelles d’inventaire botanique. Ceci nous a permis de récolter plus d’un millier d’échantillons contenant des macrorestes végétaux carbonisés ainsi que des artefacts inédits pour la région (pierre taillée et polie, tessons de céramique, scories de métallurgie) et d’inventorier la végétation dans l’environnement immédiat des découvertes. L’analyse spatiale et temporelle (chronologie relative et par datation radiocarbone) des macrorestes a permis d’identifier des villages entourés de probables champs agricoles (agriculture itinérante sur brûlis). Les 68 datations radiocarbones et les types céramiques obtenus suivent une chronologie archéologique en deux phases : un âge du Fer ancien entre 2300 et 1300 BP et un âge du Fer récent se poursuivant jusqu’à la période subactuelle, entre 670 et 20 BP. Entre ces deux phases d’occupation, les traces d’activités anthropiques sont rares. La première phase d’activités serait à mettre en relation avec une fragmentation de la forêt dense à la suite d’un épisode climatique aride autour de 2500 BP, permettant ainsi aux populations de pénétrer la forêt. Un épisode plus humide à partir de 800 BP, avec un retour d’un couvert plus dense, aurait fait reculer les populations humaines. Leur rétablissement dans les forêts se serait produit conjointement à des conditions plus sèches. Ces trois phases rejoignent la chronologie générale établie à l’échelle de l’Afrique centrale. Les premiers taxons identifiés parmi les macrorestes végétaux carbonisés, graines et charbons de bois, démontrent l’utilisation ancienne du palmier à huile et d’arbres fruitiers sauvages. Les espèces ligneuses identifiées sont présentes dans le cortège floristique actuel. L’identification taxonomique des charbons de bois devrait nous permettre de reconstituer l’environnement végétal au cours des deux derniers millénaires. Les différences observées dans les couverts forestiers passé et actuel en termes de composition floristique ainsi que la structure des peuplements actuels sont de bons indicateurs d’impacts récents de l’homme sur son milieu. [less ▲]

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See detailPotential paleoseismological records in the Western Gulf of Corinth sediments (Greece) for the last 500 years
Beckers, Arnaud ULg; Mortier, Clément; Beck, Christian et al

Conference (2013, November 06)

Related to the Gulf of Corinth rifting, five earthquakes of magnitude greater than 5.8 occurred in the last 35 years. Consequently, the question of earthquake (EQ) hazard is particularly relevant. Onland ... [more ▼]

Related to the Gulf of Corinth rifting, five earthquakes of magnitude greater than 5.8 occurred in the last 35 years. Consequently, the question of earthquake (EQ) hazard is particularly relevant. Onland paleoseismological data are scarce and offshore data were absent before the present study. We investigated recent sediments bounding three well-defined major seismogenic faults: Aegion, Trizonia and Psathopyrgos faults. We retrieved 12 gravity cores from 50 to 85 cm long in three distinct sites: the southern shelf (40 to 50 m deep), a 180 m deep sub-basin, and a transect from the southern coast to the center of the gulf. Chronology is based on 137Cs (Atmospheric Nuclear Experiments) and 210Pb decay for two sites (Aegion and Trizonia). Considering sedimentation rates estimates in these areas, the longer cores record about 500 years of sedimentary archives. We performed granulometry, magnetic susceptibility, loss on ignition and geochemical (X-Ray Fluorescence) measurements on cores from each site. Some samples were observed with a binocular to identify the nature of the grains. We sought to identify layers potentially attributed to EQ-related processes like liquefaction and tsunamis for the sites on the shelves or mass transport and turbidity currents for the basins. In Aegion, 3 coarser layers have been identified at identical depth in 3 cores across the scarp. 210Pb decay show erosion just under the first event, that we attributed to the 1995 tsunami (backwash deposit) (figure). In the Trizonia Sub-Basin, among 3 clear grain-size peaks, two have been attributed to the 1817 Aegion EQ and the 1660 Galaxidi EQ. In Psathopyrgos, 10 “events” (grain-size and Zr/Rb peaks) have been identified in the deepest part of the transect and at least 2 on the shelf. Their analysis is in progress. [less ▲]

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See detailLe genre Guibourtia Benn: un modèle biologique idéal pour comprendre les mécanismes de spéciation
Tosso, Dji-ndé Félicien ULg; Daïnou, Kasso ULg; Hardy, Olivier et al

Poster (2013, November 06)

Les forêts denses tropicales humides se distinguent par leur grande diversité biologique qui leur confère un caractère complexe. Dans un tel contexte, comprendre le passé et l'histoire évolutive de la ... [more ▼]

Les forêts denses tropicales humides se distinguent par leur grande diversité biologique qui leur confère un caractère complexe. Dans un tel contexte, comprendre le passé et l'histoire évolutive de la dynamique de ces forêts, constitue un moyen efficace pour prédire leur dynamique future. De telles études qui traitent de la biologie évolutive (phylogénie et phylogéographie) sont rares en Afrique comparativement aux autres continents. Le présent travail ambitionne de contribuer, sur base d’un modèle biologique comportant plusieurs espèces sœurs, à la compréhension des mécanismes à l'origine de la diversité des écosystèmes forestiers tropicaux. Le modèle biologique choisi est le genre Guibourtia Benn daté de moins de 20.000 ans qui regroupe 13 espèces ligneuses africaines de grande importance socio-culturelle et économique. Ce modèle rassemble non seulement des espèces de formations végétales différentes (forêt et savane) mais aussi des espèces inféodées aux régions établies sur des sols variés (sableux, argilo-limoneux, calcaire, hydromorphe etc.). Spécifiquement, l’étude vise à (i) démêler les relations phylogénétiques au sein du genre Guibourtia sur la base de caractérisations physiologique et morphogénétique; (ii) inférer l'histoire évolutive au sein du genre Guibourtia grâce aux récents outils d'analyse phylogéographique et de datation moléculaire ; et (iii) examiner les possibilités de flux de gènes entre deux espèces morphologiquement semblables à savoir G. tessmannii (Harms) J. Léonard et G. pellegriniana J. Léonard à l’échelle du Gabon. Ce travail se distingue par son originalité du fait qu’il développe une approche qui combine la physiologie et la génétique. Les résultats contribueront à modéliser la distribution des différentes unités évolutives du genre Guibourtia avec un modèle dynamique de végétation (CARAIB) afin de conclure sur leur statut de conservation et déduire les stratégies de gestion durable appropriées. [less ▲]

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See detailLate Quaternay sedimentation and active faulting in the Western tip of the Gulf of Corinth, Greece
Hubert, Aurelia ULg; Beckers, Arnaud ULg; Beck, Christian et al

Poster (2013, November 06)

The Gulf of Corinth is one of the fastest-spreading intracontinental rifts on Earth. Present day kinematics (GPS data) indicates an opening direction oriented NNE-SSW and an opening rate increasing ... [more ▼]

The Gulf of Corinth is one of the fastest-spreading intracontinental rifts on Earth. Present day kinematics (GPS data) indicates an opening direction oriented NNE-SSW and an opening rate increasing westward from 11 mm y-1 in the central part to 16 mm y-1 in the westernmost part. A significant part of the deformation is localized offshore, where the fault geometry was not well known yet. The high extension rate would imply a high seismic hazard if faults are not creeping. We propose an accurate map of submarine faults in the western extremity of the Gulf of Corinth. The map is based on two high-resolution seismic reflection surveys (single channel sparker) performed aboard HCMR’s R/V ALKYON, within the frame of SISCOR ANR Project. About 600 km of seismic lines were acquired, with a 200 msTWTT maximum penetration down to what we infer to represent the MIS 5 discontinuity. Depocenters location is controlled by river deltas where up to 75m of post-LGM sediments are stored. Numerous, up to 15m thick, mass transport deposits fill the central and eastern parts. In the eastern part, the sedimentary infill is faulted by the known North Eratini, South Eratini and West Channel faults. At the longitude of the Trizonia Island, the seafloor in mainly horizontal and the only fault is the south dipping Trizonia fault. Between the Trizonia Island and the Mornos Delta, the shallower northern part of the gulf shows a diffuse pattern of deformation with faults striking mainly E-W and ESE-WNW. It shows south and north dipping normal faults, strike-slip faults, as well as an inherited basement relief. To the West, three young grabens have been identified, striking NE-SW and W-E. The northern, 6 km long, fault in this grabens system shows a clear strike-slip component (fig.1). [less ▲]

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See detailImpacts of past Human disturbances on present-day tree species assembly in a tropical forest of South-East Cameroon
Vleminckx, Jason; Doucet, Jean-Louis ULg; Daïnou, Kasso ULg et al

Poster (2013, November 06)

Many evidence have been found for intensive past Human presence in the forests of Central Africa, notably widespread charcoal occurrence in the soil. Forest clearing for slash-and-burn agriculture may ... [more ▼]

Many evidence have been found for intensive past Human presence in the forests of Central Africa, notably widespread charcoal occurrence in the soil. Forest clearing for slash-and-burn agriculture may have favored the competitiveness of light-demanding species (LD) to the detriment of shade-bearer species (SB). Hypothesis: Positive correlation between abundance of charcoal in the soil (proxy for past Human clearing) and abundance of LD.Mostly “young” charcoals were thought to reflect past Human disturbances that would have shaped present-day species assembly. However, CAI 0-20cm and CAI 20-100cm were highly correlated with each other (r-Pearson = 0.55; P<0.001) and both displayed positive correlations with Non-Pioneer LD abundance (significant with a classic test) and negative correlations with SB abundance. Although this observation is coherent with our hypothesis, significance disappeared when correcting for spatial autocorrelation [4], even after removing small-diameter trees potentially too young to be linked with last Human disturbances (not shown). Correlation of CAI between the two soil layers => Humans found appropriate conditions for settlement in the same area at different periods? Absence of significant correlation in ❸ (i) Last Human disturbances are too old to detect any signal on present-day tree species assembly. (ii) Human impact is weak compared to other factors (soil properties, dispersal limitation,…) (iii) Local scale heterogeneity of LD abundance is weak compared to landscape scale. Parallel large scale gradients in the abundance of Non-Pioneer LD and charcoal abundance (proxy for past slash-and-burn activities) were observed, but a causal link cannot be established so far. [less ▲]

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See detailCommunautés floristiques et paramètres édaphiques : comment se répartissent les forêts claires dans la plaine de Lubumbashi ?
Hick, Aurélie ULg; Hoffait, Nicolas; Kizila Wimana, Pacifique et al

Poster (2013, November 06)

Au sud de la République Démocratique du Congo, dans la province du Katanga, le redéveloppement des activités minières a entrainé un développement démographique exponentiel des principales villes minières ... [more ▼]

Au sud de la République Démocratique du Congo, dans la province du Katanga, le redéveloppement des activités minières a entrainé un développement démographique exponentiel des principales villes minières. La population de Lubumbashi, capitale du Katanga, est passée en 50 ans d’environ 100 000 habitants à plus d’1 million et demi (Munyemba Kankumbi, 2010). Cette évolution démographique a accentué la pression sur la forêt claire de type Miombo par l’augmentation des prélèvements, la pression immobilière et l’agriculture de subsistance (Malaisse, 1997). Dans la zone périurbaine de Lubumbashi, les surfaces de forêts claires qui occupaient 85 % du territoire en 1956 ont été réduites à moins de 12 % en 2009 (Munyemba Kankumbi, 2010). Afin de comprendre l’écosystème à restaurer, nous procédons à la caractérisation des communautés de Miombo dans la plaine de Lubumbashi en fonction des conditions édaphiques. Pour ce faire, 116 placettes forestières de 18m de rayon ont été placées aléatoirement dans les derniers massifs forestiers présents dans un rayon de 50km au nord de la ville. L’ensemble des arbres adultes de diamètre supérieur à 2cm de d.b.h ont été inventoriés. De plus, un second cercle de 5 mètres de rayon a été placé au centre de chaque placette de 18m afin de répertorier l’ensemble de la régénération forestière (< à 2cm de d.b.h). Un sondage descriptif de sol à la tarière a été réalisé dans chaque placette et un échantillon de sol composite a été prélevé pour les analyses chimiques de sol (C, N, pH KCl, K, Ca, Na, Mg, Mn). Les données floristiques ont subies une transformation de corde afin de pouvoir les traiter dans une analyse en composante principale (ACP). Une classification k-means a été réalisée sur les scores de l’ACP afin d’obtenir des groupes de communauté floristique. Chaque groupe a été caractérisé par leurs espèces indicatrices et dominantes. Ces analyses ont été menées sur le peuplement adulte et sur la régénération. Une analyse canonique des correspondances a permis de mettre en évidence le lien entre ces communautés et les paramètres édaphiques. Le miombo de la plaine de Lubumbashi est caractérisé par 6 communautés floristiques : une communauté à Uapaca nitida et Uapaca pilosa, une communauté à Brachystegia boehmii, une communauté à Marquesia macroura, une communauté à Julbernardia globiflora, une communauté à Uapaka kirkiana et pour finir une communauté à Diplorhynchus condylocarpon, Pseudolactnostylis maprouenifolia et Julbernardia paniculata. L’analyse nous révèle que ces communautés sont contraintes par les données édaphiques. Les communautés se différencient d’une part par la profondeur du sol, la charge caillouteuse, le carbone, l’azote et le potassium et d’autre part par le magnésium, le manganèse et le sodium. Dans une optique de restauration, il est donc essentiel de tenir compte du type de sol en place et de la communauté à restaurer. [less ▲]

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See detailNew tools for the dairy sector based on MIR and NIR spectroscopy
Grelet, Clément; Dehareng, Frédéric; Vanlierde, Amélie et al

Conference (2013, November 05)

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