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See detailDe la prairie à votre verre de lait, sur les traces des isoflavones...
Daems, Frédéric ULg

Scientific conference (2016, March 16)

présentation du sujet de thèse en 3 minutes (Exercice de vulgarisation).

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See detailIntercomparison of in-situ NDIR and column FTIR measurements of CO2 at Jungfraujoch
Schibig, M. F.; Mahieu, Emmanuel ULg; Henne, S. et al

in Atmospheric Chemistry & Physics Discussions (2016), 2016

We compare two CO2 time series measured at the High Alpine Research Station Jungfraujoch (3580 m a.s.l., Switzerland) in the period from 2005 to 2013 with an in-situ surface measurement system using a ... [more ▼]

We compare two CO2 time series measured at the High Alpine Research Station Jungfraujoch (3580 m a.s.l., Switzerland) in the period from 2005 to 2013 with an in-situ surface measurement system using a nondispersive infrared analyzer (NDIR) and a ground-based remote sensing system using solar absorption Fourier Transform Infrared spectrometry (FTIR). Although the two data sets show an absolute shift of about 13 ppm, the slopes of the annual CO2 increase are in good agreement within their uncertainties. They are 2.04 ± 0.07 ppm yr-1 and 1.97 ± 0.05 ppm yr-1 for the FTIR and the NDIR system, respectively. The seasonality of the FTIR and the NDIR system is 4.46 ± 1.11 ppm and 10.10 ± 0.73 ppm, respectively. The difference is caused by a dampening of the CO2 signal with increasing altitude due to mixing processes. While the minima of both data series occur in the middle of August, the maxima of the two datasets differ by about ten weeks, the maximum of the FTIR measurements is in middle of January, whereas the maximum of the NDIR measurements is found at the end of March. Sensitivity analyses revealed that the air masses measured by the NDIR system at the surface of Jungfraujoch are mainly influenced by central Europe, whereas the air masses measured by the FTIR system in the column above Jungfraujoch are influenced by regions as far west as the Caribbean and the United States. [less ▲]

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See detailCharacterization of the impact of tillage and nitrogen fertilization on the root development of a winter wheat crop by use of NIR hyperspectral imaging combined to chemometrics
Fraipont, Guillaume ULg; Eylenbosch, Damien ULg; Fernández Pierna, Juan Antonio et al

Poster (2016, March 16)

The objective of this study is to characterize the impact of tillage management and nitrogen fertilization on the root system development of a winter wheat crop. To reach this objective, an innovative ... [more ▼]

The objective of this study is to characterize the impact of tillage management and nitrogen fertilization on the root system development of a winter wheat crop. To reach this objective, an innovative root quantification method that combines NIR hyperspectral imaging (NIR-HSI) and chemometric tools will be applied. [less ▲]

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See detailChoisir le sexe de son veau. Est-ce possible et comment ?
Hanzen, Christian ULg

Conference given outside the academic context (2016)

Le but de ces deux heures de formation continue pour les vétérinaires est de(1) énoncer les facteurs propres à l’animal et à l’environnement susceptibles d’influencer le sexe ratio, (2) d’en expliquer les ... [more ▼]

Le but de ces deux heures de formation continue pour les vétérinaires est de(1) énoncer les facteurs propres à l’animal et à l’environnement susceptibles d’influencer le sexe ratio, (2) d’en expliquer les mécanismes d’effet et (3) de recommander une utilisation raisonnée du sperme sexé. [less ▲]

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See detailEvaluation results of ECHAM-HAMMOZ
Schultz, Martin; Taraborrelli, Domenico; Franco, Bruno ULg et al

Conference (2016, March 16)

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See detailFrom commensalism to parasitism in Carapidae (Ophidiiformes): heterochronic modes of development?
Parmentier, Eric ULg; Lanterbecq, Déborah; Eeckhaut, Igor

in PeerJ (2016), 4

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See detailL’œuvre-exposition. Entre signe artistique, dispositif scénographie et pratique curatoriale
Bawin, Julie ULg

Scientific conference (2016, March 16)

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See detailLangue française, littérature et culture francophones en Belgique
Defays, Jean-Marc ULg

Scientific conference (2016, March 16)

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

Doctoral thesis (2016)

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

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

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See detailDepressive symptomatology and the influence of the behavioral avoidance and activation: A gender-specific investigation
Wagener, Aurélie ULg; Baeyens, Céline; Blairy, Sylvie ULg

in Journal of Affective Disorders (2016), 193

BACKGROUNG: Depression is a highly prevalent disorder which is usually considered as differentially experienced depending on gender. Behavioral theories of depression pinpoint the importance of the ... [more ▼]

BACKGROUNG: Depression is a highly prevalent disorder which is usually considered as differentially experienced depending on gender. Behavioral theories of depression pinpoint the importance of the behavioral avoidance in the maintenance of depression. However, little is known about the specific impact of the behavioral avoidance and activation on each depressive symptom as well as on gender differences on the behavioral features of depression. METHODS: This study’s aim was two-fold: (1) to assess the presence of gender differences on the BDI-II; (2) to investigate the respective predictive value of behavioral avoidance and of behavioral activation on each depressive symptom assessed by the BDI-II depending on gender. Community adults and adults attending mental healthcare composed the sample. RESULTS: Results showed differences in symptomatology profiles depending on gender (e.g. higher scores of sadness, self-criticalness in women, higher scores of past failure and loss of pleasure in men). Behavioral avoidance positively predicted almost all depressive symptoms in women and in men while behavioral activation negatively predicted almost all symptoms in both gender. Nevertheless, the strengths of these relationships were different for some symptoms (e.g. pessimism). LIMITATIONS: The use of self-report instruments; the lack of assessment of causal or precipitating factors of the depressive symptomatology; the higher number of women in the sample. CONCLUSIONS: Results are discussed with respect to previous findings and present clinical implications: (1) to underline the relevance of the combination of gender-specific assessment tools; (2) to highlight the need of tailored psychological intervention. [less ▲]

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See detailFoot identification from digital 3D models of lion tracks and paws
Marchal, Antoine ULg; Lejeune, Philippe ULg; De Bruyn, Nico

Conference (2016, March 15)

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See detailStructural basis for recognition of histone H3K36me3 nucleosome by human de novo DNA methyltransferases 3A and 3B
Rondelet, Grégoire; Dal Maso, Thomas; Willems, Luc ULg et al

in Journal of Structural Biology (2016), 194

DNA methylation is an important epigenetic modification involved in chromatin organization and gene expression. The function of DNA methylation depends on cell context and is correlated with histone ... [more ▼]

DNA methylation is an important epigenetic modification involved in chromatin organization and gene expression. The function of DNA methylation depends on cell context and is correlated with histone modification patterns. In particular, trimethylation of Lys36 on histone H3 tail (H3K36me3) is associated with DNA methylation and elongation phase of transcription. PWWP domains of the de novo DNA methyltransferases DNMT3A and DNMT3B read this epigenetic mark to guide DNA methylation. Here we report the first crystal structure of the DNMT3B PWWP domain–H3K36me3 complex. Based on this structure, we propose a model of the DNMT3A PWWP domain–H3K36me3 complex and build a model of DNMT3A (PWWP-ADD-CD) in a nucleosomal context. The trimethylated side chain of Lys36 (H3K36me3) is inserted into an aromatic cage similar to the ‘‘Royal” superfamily domains known to bind methylated histones. A key interaction between trimethylated Lys36 and a conserved water molecule stabilized by Ser270 explains the lack of affinity of mutated DNMT3B (S270P) for the H3K36me3 epigenetic mark in the ICF (Immunodeficiency, Centromeric instability and Facial abnormalities) syndrome. The model of the DNMT3A-DNMT3L heterotetramer in complex with a dinucleosome highlights the mechanism for recognition of nucleosome by DNMT3s and explains the periodicity of de novo DNA methylation. [less ▲]

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

Doctoral thesis (2016)

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

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

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See detailThe transition to conservation agriculture : an insularization process towards sustainability
Vankeerberghen, Audrey ULg; Stassart, Pierre M ULg

in International Journal of Agricultural Sustainability (2016)

Part of the Sustainability Transition Studies, this work addresses the question of the relationship between niches and regimes by examining the transition to conservation agriculture. It seeks to ... [more ▼]

Part of the Sustainability Transition Studies, this work addresses the question of the relationship between niches and regimes by examining the transition to conservation agriculture. It seeks to understand how farmers' transition to conservation agriculture can contribute to a better understanding of the transition of agro-food systems towards sustainability. Based on an analysis of farmers' trajectories in the Walloon region in Belgium, the paper develops the notion of insularization in order to characterize the emergence of conservation agriculture as a niche that is a dynamic process, growing from within and progressively detaching itself from the conventional agricultural regime. The analysis of farmers' transition shows how, after an initial phase of destabilization of the conventional ploughing regime, learning and experiencing processes can lead to a transformation in soil and soil quality management perceptions. Our hypothesis is that this cognitive transformation constitutes a tipping point in the insularization process because of its effects on agricultural practices, which increase the detachment of conservation agriculture from the regime and thus embed the irreversibility and sustainability of the transition. The term insularization is used to describe an ecologization pathway of agricultural practices endogenous to the regime that can not only lead to adaptive changes on the periphery of the system, but might also induce a deep and systemic transformation of conventional agricultural practices. [less ▲]

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See detailC'est la faute à l'Europe !
Grandjean, Geoffrey ULg

Conference given outside the academic context (2016)

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See detailGel Beads to Investigate Sedimentation
Leleu, David ULg; Pfennig, Andreas ULg

Scientific conference (2016, March 14)

Separation of liquid-liquid dispersions with multiple phases involves different interactions between the different dispersed species present in the system, which makes it difficult to predict e.g. the ... [more ▼]

Separation of liquid-liquid dispersions with multiple phases involves different interactions between the different dispersed species present in the system, which makes it difficult to predict e.g. the separation behaviour. Nevertheless such systems are relevant in chemical engineering e.g. for systems involving gas bubbles and simultaneously solid particles like in a fermentation broth. Models for describing the sedimentation behaviour as a basis for settler design are available in principle but have not been systematically validated for variation in size-distribution and e.g. density differences between the various species in the system. Thus, to design technical separation equipment, the separation process has to be better understood, which requires the study of the sedimentation as a first step. This project is focused on the interactions which may occur between each species during the sedimentation e.g. the effect on sedimentation of descending particles when they meet ascending drops. However, a proper study of the sedimentation with fluid phases is difficult due to other phenomena occurring simultaneously, e.g. coalescence. To overcome this issue, the use of gel beads is proposed, which due to their solid interface cannot coalesce. In addition, it is easy to define their parameters which are the density, the hardness and the size distribution. Besides, they can also be preserved during an extended period of time, experiments can thus be reproduced many times with identical beads. During the project, gel beads are designed with different particle size distributions and with different densities. Different batches of the produced gel beads will be mixed to simulate systems with different dispersed phases discriminated via density and different size distributions. With these multiple dispersed phases Experiments will be performed in a settling cell in order to evaluate the overall sedimentation velocity at certain hold up. Simultaneously a new method for measurement of local hold-up profile in the dispersion is tested, which allows hold-up measurement even in opaque systems. Finally sedimentation models found in the literature are compared and adapted to experimental results for predict the sedimentation of systems which involve different dispersed phases. In the presentation the new hold-up measurement will be presented together with an error analysis, experiments on the sedimentation of multiple dispersed phases and the model evaluation will be presented. [less ▲]

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

Doctoral thesis (2016)

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

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

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