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See detailIMPACT OF COVER CROP MANAGEMENT ON CROP PRODUCTION: A FIELD EXPERIMENT IN WALLONIA CONTEXT
Hiel, Marie-Pierre ULg; Bodson, Bernard ULg

Poster (2014, February)

Minimal soil tillage methods, crop rotation, cover crop and continuous plant residue cover are the main pillars of sustainable agriculture. Lower energy consumption, costs and time are some direct ... [more ▼]

Minimal soil tillage methods, crop rotation, cover crop and continuous plant residue cover are the main pillars of sustainable agriculture. Lower energy consumption, costs and time are some direct benefits in favor to the adaptation of this agriculture. This practices aims also directly at protecting the soil from wind and water erosion by covering the soil. Lower disruption of the soil aims at developping the micro- and macro-fauna activity that increases soil fertility and carbon and nitrogen sequestration in soils. Unfortunately, some of the great constraints to the adaptation of conservation agriculture remain weed management, fungal diseases and pest management, that has been shown to be a problem in non-ploughed fields. The aim of our study is to evaluate, on a same field (Wallonia context), contrasted tillage methods for managing the cover crop and the implantation of the main crop. The following measurements were taken: germination rate, root and shoot biomass development, root notation (size and shape), leaf area index and quality of harvested product. Preliminary results indicate that the different tillage methods did not have a significant impact on crop production or development. However changes in germination dynamics were observed, the reduced tillage inducing slower germination. Regarding weeds populations, some difference were observed in weed occurrences. Since a field exp [less ▲]

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See detailAnthropogenic effects on African Landscapes: Spatial Structure, Typologies, Ecological Impact
Vranken, Isabelle ULg

Poster (2014, February)

The problematique of anthropogenic disturbance on African landscapes is studied within the double framework of DPSIR (Drivers Pressures States Impact Response) and Pattern/Process Paradygm (Landscape ... [more ▼]

The problematique of anthropogenic disturbance on African landscapes is studied within the double framework of DPSIR (Drivers Pressures States Impact Response) and Pattern/Process Paradygm (Landscape Ecology). 20 landscae images from D.R. Congo, Ivory Coast and Benin were studied using indexes of spatial (compositional and configurational) heterogeneity and anthropogenic disturbance in order to highlight the relationship between spatial structure and disturbance intensity. The results show maximal heterogeneity at intermediate anthropogenic disturbances and fasten the triangular relationship between anthropogenic effect, biodiversity and spatial heterogeneity, that had been partially theoretised with the intermidiate disturbance and habitat heterogeneity hypotheses. [less ▲]

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See detailBayesian methods for predicting and modelling winter wheat biomass
Mansouri, Majdi ULg; Dumont, Benjamin ULg; Destain, Marie-France ULg

Poster (2014, February)

The objectives of this paper are threefold. The first objective is to propose to use an Improved Particle Filtering (IPF) based on minimizing Kullback-Leibler divergence for crop models' predictions. The ... [more ▼]

The objectives of this paper are threefold. The first objective is to propose to use an Improved Particle Filtering (IPF) based on minimizing Kullback-Leibler divergence for crop models' predictions. The performances of the proposed technique are compared with those of the conventional Particle Filtering (PF) for improving nonlinear crop model predictions. The main novelty of this task is to develop a Bayesian algorithm for nonlinear and non-Gaussian state and parameter estimation with better proposal distribution. The second objective is to investigate the effects of practical challenges on the performances of state estimation algorithms PF and IPF. Such practical challenges include (i) the effect of measurement noise on the estimation performances and (ii) the number of states and parameters to be estimated. The third objective is to use the state estimation techniques PF and IPF for updating prediction of nonlinear crop model in order to predict winter wheat biomass. PF and IPF are applied at a dynamic crop model with the aim to predict a state variable, namely the winter wheat biomass, and to estimate several model parameters. Furthermore, the effect of measurement noise (e.g., different signal-to-noise ratios) on the performances of PF and IPF is investigated. The results of the comparative studies show that the IPF provides a significant improvement over the PF because, unlike the PF which depends on the choice of sampling distribution used to estimate the posterior distribution, the IPF yields an optimum choice of the sampling distribution, which also accounts for the observed data. [less ▲]

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See detailImmunomodulatory effects of Rapamycin in xenogeneic GVHD
Ehx, Grégory ULg

Poster (2014, January 31)

Graft-versus-host disease (GVHD) remains a major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (HSCT). Several studies have shown that rapamycin (RAPA), an mTOR ... [more ▼]

Graft-versus-host disease (GVHD) remains a major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (HSCT). Several studies have shown that rapamycin (RAPA), an mTOR inhibitor with immunosuppressive properties, may reduce GVHD severity and mortality, notably by favoring regulatory T cells (Tregs) proliferation in vivo and in vitro. However, very few data have been reported about the global impact of this drug on the immune system in the context of GVHD. The present work investigates the cellular mechanisms by which RAPA delays death from xenogeneic GVHD induced by peripheral blood mononuclear cells infusion in NSG mice. Our results show that RAPA injections significantly delay death from xenogeneic GVHD and reduce disease severity. Flow cytometric analyses highlighted a strong reduction of human cells chimerism in mice together with higher CD4+/CD8+ T cells balance due to a lower proliferation of CD8+ T cells. In addition, the frequencies of naive CD4+ and CD8+ T cells were higher and the CD4+ T cells showed a reduced effector phenotype (CD45RO+CD27-). Tregs were positively affected as RAPA up-regulated their expression of Bcl-2 and Ki67 as well as their STAT5 phosphorylation level, leading to higher Treg frequency in treated mice. Altogether these data demonstrate that RAPA delays xenogeneic GVHD by lowering human chimerism and effector CD4+ frequency as well as promoting Tregs. [less ▲]

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See detailCryopreservation of embryos : a way to reduce the number of housed animals and the genetic drift.
Remy, Benoît ULg; Ectors, Fabien ULg; Drion, Pierre ULg

Poster (2014, January 27)

The GIGA Mouse facility platform has recently improved its mouse line cryopreservation technique. The method of embryo cryopreservation by rapid cooling also called aseptic vitrification has been selected ... [more ▼]

The GIGA Mouse facility platform has recently improved its mouse line cryopreservation technique. The method of embryo cryopreservation by rapid cooling also called aseptic vitrification has been selected. Vitrification media, key steps and timing have been optimized and validated. After a first partial exposition of the embryos to cryoprotective solutions, they are immersed in a vitrifying mixture of penetrating and non-penetrating cryoprotectants for a short time. The straw containing the embryos is immediately sealed before to be plunged in LN2, resulting in a brutal solidification in which crystallization does not have time to occur. [less ▲]

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See detailScikit-Learn: Machine Learning in the Python ecosystem
Joly, Arnaud ULg; Louppe, Gilles ULg

Poster (2014, January 27)

The scikit-learn project is an increasingly popular machine learning library written in Python. It is designed to be simple and efficient, useful to both experts and non-experts, and reusable in a variety ... [more ▼]

The scikit-learn project is an increasingly popular machine learning library written in Python. It is designed to be simple and efficient, useful to both experts and non-experts, and reusable in a variety of contexts. The primary aim of the project is to provide a compendium of efficient implementations of classic, well-established machine learning algorithms. Among other things, it includes classical supervised and unsupervised learning algorithms, tools for model evaluation and selection, as well as tools for data preprocessing and feature engineering. This presentation will illustrate the use of scikit-learn as a component of the larger scientific Python environment to solve complex data analysis tasks. Examples will include end-to-end workflows based on powerful and popular algorithms in the library. Among others, we will show how to use out-of-core learning with on-the-fly feature extraction to tackle very large natural language processing tasks, how to exploit an IPython cluster for distributed cross-validation, or how to build and use random forests to explore biological data. [less ▲]

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See detailKisspeptin and neuronal nitric oxide signaling are important in female sexual behavior
Hellier, Vincent ULg; Bakker, Julie

Poster (2014, January 27)

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See detailImmunomodulatory effects of Rapamycin in xenogeneic GVHD
Ehx, Grégory ULg; HANNON, Muriel ULg; DUBOIS, Sophie ULg et al

Poster (2014, January 27)

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See detailGIGA ANIMAL CARE : Mice & Zebrafish Animal Facility and Transgenesis
Remy, Benoît ULg; Ectors, Fabien ULg; Winandy, Marie ULg et al

Poster (2014, January 27)

In fundamental research, animal models allow to place molecular and cellular observations back into their physiological context. In applied research, these models still remain a mandatory step to evaluate ... [more ▼]

In fundamental research, animal models allow to place molecular and cellular observations back into their physiological context. In applied research, these models still remain a mandatory step to evaluate the efficiency and the toxicity of potential treatments, before going to clinical trials. Mouse and Zebrafish (Danio rerio) are two very interesting models because of a short live cycle and a high prolificacy. They require a limited space. Their genome is well known and shows a high homology with the human. Many tools are available to produce transgenic mice or zebrafishes. Many tests are validated using both these species. [less ▲]

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See detailL'oxydation des poudres: un défi pour l'avenir
Blecker, Christophe ULg

Poster (2014, January 27)

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See detailLe problème des protocoles longs au test de Rorschach
Dufour, Cristelle; Englebert, Jérôme ULg

Poster (2014, January 22)

Notre étude s’intéresse aux protocoles exceptionnellement longs (supérieurs à 50 réponses) fournis par cinq sujets au test du Rorschach administré et interprété selon la méthode du Système Intégré (Exner ... [more ▼]

Notre étude s’intéresse aux protocoles exceptionnellement longs (supérieurs à 50 réponses) fournis par cinq sujets au test du Rorschach administré et interprété selon la méthode du Système Intégré (Exner, 2003). Afin de mieux comprendre quelle attitude adopter face à ce type de protocole, nous avons effectué une réduction a posteriori du nombre de réponses en nous basant sur les recommandations d’Exner (1988, 1992, 2003). Nous avons ensuite réalisé une étude comparative entre l’interprétation clinique réalisée avec la totalité des réponses et avec seulement les cinq premières réponses par planche. Nous avons également reproduit cette méthodologie de réduction a posteriori du nombre de réponses avec quatre réponses par planche en nous inspirant des nouvelles recommandations du système R-PAS de Meyer et al. (2009). Selon ces propositions, un protocole de test de Rorschach serait valide lorsque le sujet fournit entre 20 et 40 réponses (entre 2 et 4 par planche). L’échantillon est composé de trois sujets tout-venant et deux sujets psychiatriques. Notre analyse a mis en évidence une stabilité de certaines variables (EB, Lambda, EA) mais d’importantes différences dans le profil psychologique des sujets après réduction. Nous avons observé une clarification des difficultés fondamentales chez les sujets psychiatriques et plutôt une neutralisation de ces difficultés pour les sujets tout-venant, avec notamment des stratégies défensives qui apparaissent plus adaptées. Selon les résultats obtenus à partir de notre échantillon, nous pouvons suggérer que la prise en compte de la totalité des réponses ou seulement du protocole partiel induit une différence dans l’interprétation clinique. En conséquence, toute réduction du nombre de réponses devrait se faire avec grande prudence. Notre étude permet de discuter des pratiques actuelles du test de Rorschach, en faisant dialoguer les contraintes inhérentes à la validité du test et les questions de la réduction de la complexité clinique propres à toute entreprise de standardisation. [less ▲]

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See detailLe Rorschach selon le Système Intégré et le TCI-R : comparaison et intégration
Rentmeister, Daniel; Englebert, Jérôme ULg; Blavier, Adelaïde ULg

Poster (2014, January 22)

Pour cette étude, un double objectif est recherché. Premièrement, nous comparons statistiquement le test de Rorschach selon le Système Intégré de J.E.Exner et le Temperament and Character Inventory – ... [more ▼]

Pour cette étude, un double objectif est recherché. Premièrement, nous comparons statistiquement le test de Rorschach selon le Système Intégré de J.E.Exner et le Temperament and Character Inventory – Revised de R. Cloninger afin de mettre en évidence leurs divergences et convergences. Deuxièmement, à l’aide de cas cliniques, nous discutons de la pertinence de l’intégration des résultats obtenus par ces deux outils en vue d’établir le profil psychologique complet et cohérent d’un individu. Pour la comparaison statistique, notre échantillon de 27 sujets tout-venant (M = 24,37 ans ; SD = 2,75) a d’abord été soumis au test de Rorschach. Directement après, chaque sujet a complété le TCI-R. Une analyse de corrélation (Rho de Pearson) a été calculée entre les indices et un ajustement de Bonferroni a été effectué. Pour l’analyse de cas, 3 sujets cliniques ont été recrutés. Une anamnèse a été réalisée et le test de Rorschach et TCI-R administré. Nos premiers résultats, qui sont à prendre avec prudence au vu du faible nombre de sujet de l’échantillon, sont à nuancer et discuter. À partir de 2016 comparaisons statistiques, nous sélectionnons les résultats les plus pertinents et discutons des différentes corrélations observées. Les analyses de cas nous montrent une concordance au niveau des relations sociales et de l’impulsivité ; et nous montrent que les informations propres à chaque test permettent de compléter le profil du sujet. Enfin, c’est en abordant les deux épistémologies différentes sur lesquelles reposent ces deux tests que nous pouvons expliquer au mieux les différences psychologiques mises en évidence à propos des mêmes individus. Nous concluons en suggérant que cette différence de résultats doit certainement être comprise selon une logique intégrative et souligne la complémentarité existant entre ces deux épreuves. [less ▲]

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See detailArt et schizophrénie : étude comparative de biographies d’artistes d’art brut et de sujets schizophrènes peintres
Moffarts, Aloïse; Englebert, Jérôme ULg

Poster (2014, January 22)

La psychopathologie phénoménologique explique la schizophrénie en termes de perte de l'évidence naturelle (Blankenburg, 1991/1971) ou de psychopathologie du sens commun (Stanghellini, 2000, 2004, 2007 ... [more ▼]

La psychopathologie phénoménologique explique la schizophrénie en termes de perte de l'évidence naturelle (Blankenburg, 1991/1971) ou de psychopathologie du sens commun (Stanghellini, 2000, 2004, 2007). Concernant les théories consacrées à l'art et la psychopathologie, nous nous penchons sur la théorie de la Gestaltung de Prinzhorn (1984), sur l’hypothèse de l’« l'art révolutionnaire » de Sass (1992 ; Spaniol, 2001) et analysons la classification de Jádi (Hulak, 1990). Enfin, à partir de ces travaux, nous avons établi trois types d'art qui peuvent se retrouver chez des artistes malades mentaux : art brut, art naïf et art de recherche. Notre méthodologie consiste à analyser la biographie de deux artistes peintres de la famille de « l'art brut » (Aloïse Cobraz et Adolf Wölfli) en les comparant aux biographies et analyses de cas de deux patients schizophrènes se considérant comme artistes peintres. Nous avons élaboré un questionnaire semi-structuré pour questionner les artistes sur leur parcours artistique et leur rapport à l’art. Après nos analyses et le croisement avec les théories existantes, nous émettons comme hypothèse que les schizophrènes artistes se distinguent des autres types d’artistes (pathologiques ou non) dans leur rapport à la créativité. Ceci est congruent avec le concept d’« art révolutionnaire » de Sass (1992). La classification de Jádi nous permet de suggérer qu’il n’est pas cohérent de parler d’un art des malades mentaux et que le trouble psychiatrique ne peut donc pas être considéré comme l’essence de l'art brut. Enfin, nous pouvons émettre l’hypothèse que l'art semble conférer aux schizophrènes artistes une forme d'adaptation sociale eu égard au sens commun « perdu ». [less ▲]

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See detailDendroecology and Dendroclimatology of a Tasmanian Bog Forest
Balanzategui, Daniel; Copenheaver, Carolyn; Frank, David et al

Poster (2014, January 14)

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See detailSelves Impairment in Bipolar Disorder through Self-Concept Clarity, Self-Defining Memories and Self-Esteem
Wagener, Aurélie ULg; Boulanger, Marie ULg; Van Limbergen, Coralie et al

Poster (2014, January 13)

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See detailDepression and autobiographical memory: which are the characteristics of depressed patients' self-defining memories?
Wagener, Aurélie ULg; Weigend, Alicia; Boulanger, Marie ULg et al

Poster (2014, January 13)

BACKGROUND. Depressed patients suffer from autobiographical memory deficits. Indeed, depressed patients present an overgeneralization and a mood congruence biases. Moreover, they seem to have difficulties ... [more ▼]

BACKGROUND. Depressed patients suffer from autobiographical memory deficits. Indeed, depressed patients present an overgeneralization and a mood congruence biases. Moreover, they seem to have difficulties to recall positive memories. Our aim is to focus on a specific kind of memories called “self-defining memories” (SDM) which are highly pertinent for self-building. Their characteristics (e.g. specificity, meaning making) were assessed and compared to those of healthy subjects. HYPOTHESES. Depressed patients relate less specific and meaning making events than control group. A mood congruence bias is observed. METHOD. 17 depressed patients and 18 healthy subjects fulfilled SDM exercises: subjects were asked to relate six important events that happened in their life. These SDM were assessed on several variables: specificity, impact, meaning making, contain. Moreover, subjects were assessed on depression severity and self-esteem (explicit and implicit). RESULTS. No difference between depressed patients and healthy subjects has been found for specificity. A marginal effect appeared for meaning making: control group seemed to relate more meaning making events than depressed patients. Depressed patients related more negative events than control group: this negative emotional valence was positively correlated with higher depression severity. Depressed subjects presented a lower explicit self-esteem than healthy subjects but no difference has been found for implicit self-esteem. Higher explicit self-esteem was positively correlated with positive emotional valence of SDM. DISCUSSION. Results partially support our hypotheses. Experimental and clinical implications of our results will be discussed. [less ▲]

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See detailMechanoreceptors in the anterior horn of the equine medial meniscus: an immunohistochemical approach.
Nemery, Elodie ULg; Gabriel, Annick ULg; Piret, Joëlle ULg et al

Poster (2014)

Mechanoreceptors are “encapsulated sensory end-organs” involved in proprioceptive function. Given the high incidence of meniscal injuries in horses, the clinical interest in these mechanoreceptors ... [more ▼]

Mechanoreceptors are “encapsulated sensory end-organs” involved in proprioceptive function. Given the high incidence of meniscal injuries in horses, the clinical interest in these mechanoreceptors, particularly in the meniscus, and the lack of information concerning them in equine menisci, our objective was to study these corpuscles in the anterior horn of the equine medial meniscus, which is the most common localization reported for equine meniscal injuries. An immunohistochemical approach to detect Schwann cells and nerve fibres allowed us to localize and identify these corpuscles within the meniscus. Three types of mechanoreceptors were identified and localized between the abaxial quarter and the abaxial third of the meniscus: the Ruffini, Pacini and Golgi corpuscles. In conclusion, from a purely fundamental point of view, our work highlights for the first time the presence of MCR at the level of the anterior horn of the equine medial meniscus and proposes a classification based on specific immunocytochemical techniques. This morphological approach could serve as a basis for clinical studies, in order to evaluate the impact of these corpuscles on the poor sportive prognosis in equine meniscal tears. [less ▲]

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See detailHow can long-term experimental plots can help us to understand the sustainability of different phosphorus inputs ?
Renneson, Malorie ULg; dufey, Joseph; Roisin, Christian et al

Poster (2014)

During the last twenty years, we observed a constant reduction of mineral fertilizer use, due to prices increase and environmental awareness, and an increase of crop removal, leading to a phosphorus (P ... [more ▼]

During the last twenty years, we observed a constant reduction of mineral fertilizer use, due to prices increase and environmental awareness, and an increase of crop removal, leading to a phosphorus (P) budget decrease. These changes are feared for a decrease of soil P content, which is already observed in some regions in Wallonia. However, P being an essential element for plant growth, is a such management compatible with yield maintaining? Are the current cropping systems sustainable? To answer to the questions, different studies are made. However, long-term data are rarely available to understand the influence of cropping systems on the soil behavior, leaching risks or to choose adequate indicators of P. To answer to these questions in our soils, 2 experimental plots of the Walloon Agricultural Research Center. These experimental plots were established in 1967 and 1959 in order to evaluate the effect of, respectively, 3 P and K input levels and different organic inputs on the production. Soils samples were taken in plots and analyzed in laboratory. So, different P indicators and edaphic parameters were determined. This study showed that all indicators are coherent with P levels and correlated with yields but no many differences can be shown between fertilizer types. Meanly, zero P-input engenders a decrease of yield of 7%, while a double input increases yield of 2% in comparison to plots with an input corresponding to crop export. So, financially, the zero P-input option is rarely profitable in the long-term and double input of P removed is never financially sustainable. Leaching into deeper soils levels was studied with analysis of deeper horizons which indicated any leaching , even in plots with double inputs. Indeed, soil P contents in depth were similar in these plots than those with no P-inputs or soils under forest cover. So, to conclude, these plots help to study the sustainability of cropping systems in real situations and to determine appropriate management of P. [less ▲]

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See detailPréservation de la thymopïèse dans le grand âge
RICOUR, Céline ULg; de saint hubert, Marie; Martens, Henri ULg et al

Poster (2014)

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See detailLignin as a raw material for industrial materials applications
Richel, Aurore ULg; Vanderghem, Caroline ULg; Jacquet, Nicolas ULg et al

Poster (2014)

Native lignin is an abundant biopolymer on earth and represents 15-30% by weight of the lignocellulosic biomass. Lignin is a heterogeneous cross-linked polymer composed of phenylpropane units (guaiacyl ... [more ▼]

Native lignin is an abundant biopolymer on earth and represents 15-30% by weight of the lignocellulosic biomass. Lignin is a heterogeneous cross-linked polymer composed of phenylpropane units (guaiacyl, syringyl or p-hydroxyphenyl) linked together by a panel of specific ether or carbon-carbon bonds.[1] Nowadays, large amounts of lignins and lignin-based wastes are available and originate either from the pulp and paper manufacturing or from the production of bioethanol from lignocellulose. [2] Typically, these lignins are dedicated to energetic purposes by combustion. In recent years however, novel axes for high added value applications have emerged and concern, notably, the use of lignin as performance products (e.g. polymer additives, binders) or specialty chemicals (e.g. surface-active agents) for materials applications.[3] Herein, several applications of lignin in materials sciences with industrial issues are presented. A correlation is established between the extraction processes from lignocellulosic materials and the chemical structure and physico-chemical properties of lignins.[4] Our research group has also developed new methodologies for the extraction of highly pure lignins from several starting materials, including food wastes, herbaceous raw materials and wood biomass. These methodologies include microwave-assisted extraction and two-step conventional pretreatment involving steam explosion. These methodologies are described in this presentation. [less ▲]

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See detailSpectroscopic analysis of the remorin-lipid interactions at the moleculaer level
Nasir, Mehmet Nail ULg; Perraki, Artemis; Mongrand, Sébastien et al

Poster (2014)

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See detailDoes the facultative bacteria Serratia symbiotica influence the foraging strategies of aphid parasitoids?
Attia, Sabrine; Louâpre, Philippe; Foray, Vincent et al

Poster (2014)

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See detailMetabolic cerebral correlates of conjunctive and relational memory in Alzheimer's disease
Bastin, Christine ULg; Bahri, Mohamed Ali ULg; Collette, Fabienne ULg et al

Poster (2014)

Introduction. Memory deficits are the clinical hallmark of typical Alzheimer’s disease. The precise nature of these deficits however remains to be fully characterized. In this study, we investigated ... [more ▼]

Introduction. Memory deficits are the clinical hallmark of typical Alzheimer’s disease. The precise nature of these deficits however remains to be fully characterized. In this study, we investigated binding in long-term episodic memory. Relational binding processes in memory create an associative link between independent items or between items and context into episodic memories (Cohen et al., 1999). An alternative process, conjunctive binding, allows associations to be encoded as a united representation of features into a single entity (O'Reilly and Rudy, 2001; Mayes et al., 2007). The current study (1) assessed whether Alzheimer’s disease disrupt both conjunctive and relational memory, and (2) related patients’ memory performance to cerebral metabolism. Methods. Thirty patients with mild Alzheimer’s disease and 24 healthy older adults performed a source memory task where items were associated to a background color (Diana et al., 2008, 2010). In one condition, relational binding was promoted by the instruction to associate the item with another object of the same color as the background. In the other condition, color had to be integrated as an item feature (conjunctive binding). Patients’ brain metabolic activity at rest (FDG-PET) was analysed with spatio-temporal Partial Least Squares (McIntosh et al., 1996) in order to assess the relation of behavioral performance and activity in functional cerebral networks. Results. Alzheimer’s disease patients had an impaired capacity to remember item-color associations, with deficits in both relational and conjunctive memory. However, performance in the two kinds of associative memory varied independently across patients. Partial least square analyses revealed a significant pattern of metabolic activity that correlated specifically with each condition (accounting for 76.48 % of the covariance in the data; p< .05). More specifically, poor conjunctive memory was related to hypometabolism in an anterior temporal-posterior fusiform brain network, whereas relational memory correlated with metabolism in regions of the default mode network. Conclusions. These findings support the hypothesis of distinct neural systems specialized in different types of associative memory and point to heterogeneous profiles of memory alteration in Alzheimer’s disease as a function of damage to the respective neural networks. [less ▲]

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See detailULTRASONIC WAVES THROUGH AGRICULTURAL SOILS TO DETERMINE THEIR COMPACTION AND POROSITY LEVEL 
Luong, Jeanne ULg; Mercatoris, Benoît ULg; Destain, Marie-France ULg

Poster (2014)

Compaction is one of the major causes of the physical degradation of agricultural soils. The traffic of more and more heavy machines leads to a decrease of the porosity at both the topsoil and subsoil ... [more ▼]

Compaction is one of the major causes of the physical degradation of agricultural soils. The traffic of more and more heavy machines leads to a decrease of the porosity at both the topsoil and subsoil levels. This has negative impacts in agricultural and environmental contexts such as the reduction of soil fertility and water infiltration. This project aims at characterizing in a fast and non-destructive way the state of compaction of an agricultural soil at a local scale using ultrasonic wave propagation. Acoustic signatures of soil samples will be correlated to their compaction level and their porosity distribution. This should allow a better comprehension of the compaction process and help to define critical threshold. As a result, this methodology could assist in taking restrictive measures such as load limitation of agricultural engines and implementing remedial methods. This poster presents the experimental protocol implement for this research. [less ▲]

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See detailGenetic parameters for individual birth weight, weaning weight and final weight of crossbred pigs from Piétrain boars
Dufrasne, Marie ULg; Wavreille, José; Piedboeuf, Maureen et al

Poster (2014)

Genetic parameters for birth weight (BWT), weaning weight (WWT), and final weight (BW) were estimated for crossbred pigs from Piétrain boars raised in test station. Estimates of direct heritability were ... [more ▼]

Genetic parameters for birth weight (BWT), weaning weight (WWT), and final weight (BW) were estimated for crossbred pigs from Piétrain boars raised in test station. Estimates of direct heritability were moderate (0.25 to 0.42), suggesting that genetic improvement of growth would be possible. Estimates of maternal heritability were 0.24 for BWT and WWT, and 0.05 for BW, indicating that the genetic influence of the dam on growth was not negligible until weaning. Genetic correlations between direct and maternal effects for BWT and WWT were moderate and unfavorable (-0.52 and -0.57 respectively). Direct genetic correlations were high and favorable between traits (0.40 to 0.75), suggesting that a high BWT is a good predictor to produce pigs with high final weight. Maternal genetic correlations between traits were low (0.01 to 0.03). Selection for higher BWT would increase final market weight but should be balanced with survival traits. [less ▲]

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See detailEvaluation of bio-based additives in architectural paints
Wenkin, M.; Delvaux, M.H.; de Lame, C. et al

Poster (2014)

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See detailMartian thermosphere scale height from SPICAM dayglow measurements
Stiepen, Arnaud ULg; Gérard, Jean-Claude; Bougher, Steve et al

Poster (2014)

We analyze the ultraviolet dayglow in the atmosphere of Mars through CO2+ and CO Cameron emissions. These emissions are accumulated on a large dataset of dayside grazing limb performed by the Spectroscopy ... [more ▼]

We analyze the ultraviolet dayglow in the atmosphere of Mars through CO2+ and CO Cameron emissions. These emissions are accumulated on a large dataset of dayside grazing limb performed by the Spectroscopy for Investigation of Characteristics of the Atmosphere of Mars (SPICAM) instrument on board the Mars Express spacecraft. The temperature of the Martian upper atmosphere can be retrieved from these limb emission profiles. We present discussion on the validity domain for such retrieval. We also show evidence for local (spatial and temporal) variability in the scale height of the atmosphere at the altitude of these emissions. [less ▲]

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See detailSituation and perspective of entomophagy in Kinshasa
Nsevolo, Papy; Caparros Megido, Rudy ULg; Blecker, Christophe ULg et al

Poster (2014)

Eating edible insects in Republic Democratic of Congo is a tradition for centuries but a lack of knowledge remains about an actualized inventory of species consumed in the country. Moreover, a rigorous ... [more ▼]

Eating edible insects in Republic Democratic of Congo is a tradition for centuries but a lack of knowledge remains about an actualized inventory of species consumed in the country. Moreover, a rigorous taxonomic matching of the used vernacular name of edible insects and a precise characterization of the sector of entomophagy are still needed. According to our studies focused on the city of Kinshasa, 14 edible species were inventoried as regularly consumed. They belong respectively and by degree of importance to the Lepidoptera (46.7%), Isoptera (18.6%), Orthoptera (17.6%), Coleoptera (9.7%) and Hymenoptera (3.7%) orders. Generally 80.0% of the Kinshasa population consumes at least one species of insects 5 days per month. The key peoples in the edible insect sector are mostly women. The incomes generated by this activity contribute to the well being of households, to reduce poverty and food insecurity in the capital Kinshasa. Future studies should focus on sustainable ways of harvesting wild populations, the use of improved conservation practices, the enhancement of cottage industries for farming insects and the development of economically feasible ways of mass-rearing edible species. [less ▲]

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See detailThe facultative bacterial symbiont Serratia symbiotica in Acyrtosiphon pisum confer resistance to Aphidius ervi
Attia, Sabrine; Foray, Vincent; Louâpres, Philippe et al

Poster (2014)

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See detailEtude de la durabilité des hydrofuges de surface pour la conservation du patrimoine en béton
Lucquiaud, Vincent ULg; Courard, Luc ULg

Poster (2014)

La protection du patrimoine historique en béton est un challenge pour les années futures. Un traitement hydrofuge retarde l’apparition de pathologies du béton et apporte une protection contre la ... [more ▼]

La protection du patrimoine historique en béton est un challenge pour les années futures. Un traitement hydrofuge retarde l’apparition de pathologies du béton et apporte une protection contre la pénétration de l’eau. Les produits existants - essentiellement du silane et siloxane base - ont été soumis à différents processus de vieillissement, tels que la carbonatation accélérée, des rayons UV, des cycles d'humidification, des chocs thermiques, et des cycles de gel-dégel. Leur efficacité a été évaluée suivant la mesure de l’angle de contact, leur perméabilité à la vapeur d’eau et aux chlorures et leur absorption capillaire. Les résultats de l’étude montre un bon comportement de ces produits aux les principaux vieillissements étudiés. [less ▲]

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See detailFunctional adaptations of the bacterial chaperone trigger factor to extreme environmental temperatures
Godin, Amandine ULg; Schmidpeter, P.; Schmid, F.X. et al

Poster (2014)

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See detailEstimation of dominance variance for growth traits with sire-dam subclass effects in a crossbred population of pigs
Dufrasne, Marie ULg; Faux, Pierre ULg; Piedboeuf, Maureen et al

Poster (2014)

Nonadditive genetic effects may be not negligible but are often ignored in genetic evaluations. The most important nonadditive effect is probably dominance. Prediction of dominance effects should allow a ... [more ▼]

Nonadditive genetic effects may be not negligible but are often ignored in genetic evaluations. The most important nonadditive effect is probably dominance. Prediction of dominance effects should allow a more precise estimation of the total genetic merit, particularly in populations that use specialized sire and dam lines, and with large number of full-sibs, like pigs. Computation of the inverted dominance relationship matrix, D-1, is difficult with large datasets. But, D-1 can be replaced by the inverted sire-dam subclass relationship matrix F-1, which represents the average dominance effect of full-sibs. The aim of this study was to estimate dominance variance for longitudinal measurements of body weight (BW) in a crossbred population of pigs The dataset consisted of 20,120 BW measurements recorded between 50 and 210 d of age on 2,341 crossbred pigs (Piétrain X Landrace). A random regression model was used to estimate variance components. Fixed effects were sex and date of recording. Random effects were additive genetic, permanent environment, parental dominance and residual. Dominance variance represented 7 to 9% of the total variance and 11 to 30% of additive variance. Those results showed that dominance variance exists for growth traits in pigs and may be relatively large. The estimation of dominance effects may be useful for mate selection program to maximize genetic merit of progeny. [less ▲]

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See detailA predictive battery of literacy acquisition for children in third year kindergarten
Gillet, Sophie ULg; Binamé, Florence ULg; Martinetti, Julie et al

Poster (2014)

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See detailOptimization of cricket breeding production system for human food in Ratanakiri province (Cambodia)
Caparros Megido, Rudy ULg; Alabi, Taofic ULg; Nieus, Clément et al

Poster (2014)

Despite many natural resources, Cambodia is considered as a relatively poor country with a Gross National Income per capita averaging about 880 USD in 2012. Annâdya project in the Ratanakiri province ... [more ▼]

Despite many natural resources, Cambodia is considered as a relatively poor country with a Gross National Income per capita averaging about 880 USD in 2012. Annâdya project in the Ratanakiri province (Cambodia) aims to improve the food security and nutrition of smallholder households by introducing and facilitating the adoption of productive and environmentally sustainable agricultural technologies. The main purpose of this work was to optimize a cheap cricket breeding production system for local farmers to contribute to the reduction of protein deficiency and to create new source of incomes. Cricket development, Teleogryllus testaceus (Walker), was compared between seven diets composed of different ratio of aerial parts of taro, young cassava leaves, young cashew leaves, brown rice flour (with or without the addition of banana slices) and between the traditionally used chicken feed diet. Cricket mortality was relatively low on all diets (<10 %) excepted on the two cashew-based diets where mortality achieves 90 %. Mean adult body mass of the cricket was significantly higher on control diet (chicken feed) and on the two cassava-based diet (80% of cassava leave flour, 20% of brown rice with or without banana slices) than on the other diets (F = 20.87, P<0.001). The nutritional analyzes of the seven diets shows that the ideal diet should contain 19% protein, 5-6% fat, and a percentage of carbohydrates as high as possible. While the cricket mass body gain seems to be proportional to the carbohydrate content of the diet, the use of older cassava leaves, more rich in carbohydrates than the younger ones, is an interesting solution to substitute relatively expensive brown rice and banana slices also consumed by local population. In the future, consideration should be given to the adjustment of cassava leave maturity in function of the cricket growth stage as it is already done with chicken feed in Thai cricket farms. [less ▲]

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See detailEfficient method for a controlled deposition of Pd nanoparticles on a glassy carbon electrode
Olu, Pierre-Yves; Chatenet, Marian; Job, Nathalie ULg

Poster (2014)

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See detailStudy of the Bacillus subtilis ATCC21332 pbpE-racX operon in relation with the formation or disassembly of biofilms
Vanden Broeck, Arnaud ULg; Van Der Heiden, Edwige ULg; Joris, Bernard ULg et al

Poster (2013, December 20)

Bacillus subtilis is a PGPR (Plant Growth Promoting Rhizobacterium) Gram positive bacterium and a model for studying the in vitro formation or disruption of biofilms. At the liquid/air interface of ... [more ▼]

Bacillus subtilis is a PGPR (Plant Growth Promoting Rhizobacterium) Gram positive bacterium and a model for studying the in vitro formation or disruption of biofilms. At the liquid/air interface of standing cultures, B. subtilis forms thick pellicles of limited lifetimes. Some D-amino acids have been reported among the factors playing a role in the disassembly of B. subtilis biofilms and ylmE or racX mutants (in which the racemases YlmE or RacX are absent) show a delay in pellicle disruption [I. Kolodkin et al. Science (2010) 328:627-629]. The racX encoding gene is part of a bicistronic operon in which the first gene (pbpE) codes for a Penicillin-Binding Protein, the PBP4* whose function is not characterized. Our studies aim to delete the complete pbpE-racX operon and compare the phenotypes of mutants and parental strains ATCC21332 or ATCC6051 in standing cultures. The substrate specificity of the purified RacX racemase is currently under investigation as well as the functional characterization of PBP4*, a protein possessing a lipocalin-like domain. [less ▲]

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See detailAssessing the influence of crop management strategies on the distribution of soil water content by ERT
Chelin, Marie ULg; Parvin, Nargish ULg; Hiel, Marie-Pierre ULg et al

Poster (2013, December 20)

Amongst other functions, cover crops are known to increase the stability of the soil structure. Commonly, their suppression is realized by using conventional tillage, but that it has been demonstrated to ... [more ▼]

Amongst other functions, cover crops are known to increase the stability of the soil structure. Commonly, their suppression is realized by using conventional tillage, but that it has been demonstrated to damage the soil structure, which directly impacts the soil water content. The proposed alternatives vary in terms of date, depth and type of tillage. As the soil water content is a major factor in agriculture, it is essential to better understand the influence of the cover crop management on its spatio-temporal distribution. Recent studies demonstrated the relevancy of the electrical resistivity tomography (ERT) to estimate the three-dimensional soil water content distribution. However, only a few of them were performed under field conditions. This study aims at (i) validating the use of the ERT method to estimate the soil water content distribution under field conditions (ii) quantifying the influence of cover crop management on the dynamic of soil water content along the growing season of a maize crop and on Belgian soil types. Three types of cover crop management content will be daily monitored: strip tillage, spring tillage and winter tillage. In order to assess the impact of plants on the soil water distribution, an additional plot will be burned after winter tillage. ERT will be used on a surface of 2 m² for each cover crop management. The validation of the average soil water content will be attended by using Time Domain Reflectrometers (TDR) and suction cups. The water stock obtained by ERT will be validated by using data from a weather station for the estimation of the evapotranspiration and rainfall and minirhizotrons for the assessment of the root water uptake. [less ▲]

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See detailExpansion urbaine et risques hydrologiques : cas de Butembo (RDC)
Sahani, Muhindo; Moeyersons, Jan; Ozer, Pierre ULg

Poster (2013, December 19)

Butembo constitue un cas typique de zone urbaine en région tropicale humide rencontrant une explosion démographique exceptionnelle. L’exode vers Butembo pour fuir l’insécurité dans la sous-région a ... [more ▼]

Butembo constitue un cas typique de zone urbaine en région tropicale humide rencontrant une explosion démographique exceptionnelle. L’exode vers Butembo pour fuir l’insécurité dans la sous-région a conduit à une rapide concentration spontanée des populations et à une urbanisation sans cesse croissante. L’imperméabilisation des vastes étendues de terres consécutive à cette expansion spatiale rapide de la ville a généré des problèmes environnementaux qui affectent la structure urbaine. A l’instar de nombreuses villes d’Afrique centrale, Butembo est actuellement confrontée à des risques hydrologiques diversifiés : ravinements progressifs et régressifs, inondations, et remobilisation d’anciens glissements de terrain. [less ▲]

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See detailLes acteurs non étatiques jouent un rôle déterminant dans le fonctionnement des services publics en territoires périurbains
Manzambi Kuwekita, Joseph ULg; Bruyère, Olivier ULg; REGINSTER, Jean-Yves ULg et al

Poster (2013, December 19)

Cette étude répertorie les acteurs étatiques et non étatiques qui offrent des services publics aux populations en territoire périurbain en vue d’améliorer leur intégration dans les politiques de ... [more ▼]

Cette étude répertorie les acteurs étatiques et non étatiques qui offrent des services publics aux populations en territoire périurbain en vue d’améliorer leur intégration dans les politiques de développement local de la commune périurbaine de Kisenso à Kinshasa, par des focus groups en juillet 2013. La question de recherche était : « quels sont les acteurs étatiques et non étatiques qui offrent les services publics en territoire périurbain, leurs rapports avec l’administration publique et comment envisager leur intégration dans les politiques de développement local » ? Les principaux résultats de cette étude montrent qu’à Kisenso, 5 acteurs étatiques et 75 acteurs non étatiques opèrent dans la commune de Kisenso, essentiellement dans les domaines suivants : santé, éducation, justice, social, environnement, énergie, PME, etc. en ce qui concerne les rapports qu’entretiennent les acteurs non étatiques avec l’Etat, (i) tous sont reconnus par la Commune car ils détiennent des autorisations délivrées par les instances de niveau national, (ii) ils ne rendent pas compte à la commune de leurs activités de manière formelle parce la loi ne les y oblige pas. 109 structures de santé sont fonctionnelles. Néanmoins, environ une trentaine d’ONGs transmettent leurs rapports d’activités à la Commune en fin d’année. De même, les acteurs non étatiques évoluant dans le secteur des soins de santé transmettent tous leurs rapports épidémiologiques, mais seulement 15/109 (soit 13,7%) rapportent sur les activités (SNIS). À la question de savoir pourquoi la population recourt aux services offerts par les différents acteurs, cette étude montre que les choix des populations pour un service ou un autre sont motivés essentiellement par la qualité de ces services, la compétence du personnel, l’efficacité, l’accueil, les coûts accessibles, l’accueil et la proximité du service avec le ménage. Quant à la manière d’intégrer les acteurs non étatiques dans les politiques de développement local, les acteurs ont proposé le processus suivant : (i) inventorier les structures et/ou les acteurs œuvrant dans la zone de santé et/ou la commune, (ii) faire les états des lieux pour identifier leur degré de fonctionnement, (iii) accorder les autorisations aux structures qui remplissent les conditions de fonctionnement, (iv) aider celles qui ne remplissent pas ces conditions à les remplir par la formation du personnel, la subvention des structures, etc.). Les résultats de cette recherche suggèrent que si l’on veut éviter que certains acteurs continuent à opérer dans la clandestinité pour des raisons d’ordre financier, à l’instar de tradipraticiens, ils devraient être exonérés de toutes taxes. Les résultats de cette recherche montrent que si l’on veut intégrer les acteurs non étatiques dans les politiques de développement local, les différentes autorités municipales devraient les associer, en amont, aux activités organisées telles la formation et la supervision, sans que cela ne leur soit facturé ; leur demander ensuite de rapporter sur leurs activités ne devrait plus entraîner de résistance. [less ▲]

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See detailLA DÉGRADATION D’UN ÉCOSYSTÈME FORESTIER PÉRI-URBAIN : QUELS SONT LES PRINCIPAUX FILTRES À SA RÉGÉNÉRATION ?
Hick, Aurélie ULg; Tooth, Martin; Hallin, Maud et al

Poster (2013, December 19)

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). Trois études ont été menées dans le but de caractériser les filtres écologiques et les filtres sociaux à la restauration de cet écosystème périurbaine. Les deux premières études ont pour objectif d’illustrer la diversité des communautés végétales du Miombo, leurs variations après dégradation le long d’un gradient forêt/savane sur les sols principaux de la plaine et les principaux filtres écologiques à sa régénération. 134 placettes forestières placées aléatoirement dans les derniers massifs forestiers présents dans un rayon de 50km autour de la ville ont été inventoriées. 53 placettes ont été placées sur trois sites choisis pour caractériser les communautés présentes le long du gradient de dégradation : forêts, forêts dégradées, savanes boisées, savanes arborées et savanes herbeuses. Au sein de ces placettes l’ensemble des espèces forestières ont été identifiées. Le sol a été caractérisé physiquement et chimiquement. La mesure de la biomasse herbacée a également été réalisée sur le gradient de dégradation. Les filtres sociaux ont été analysés aux travers de 35 enquêtes menées dans 4 villages de la plaine afin de comprendre leur mode d’agriculture, leur vision de l’arbre et la possibilité d’insérer un mode de culture de type agroforestier. Les grandes communautés caractéristiques de cet écosystème ont été mises en évidence, illustrant ainsi la richesse des dernières taches forestières présentes dans la plaine. Le type de sol est significativement corrélé à la répartition des communautés. Les essences présentes en savanes sont différentes de celles présentes en forêts pour un même type de sol. La biomasse herbacée est un filtre significatif à la régénération de la forêt favorisant la présence d’espèces tolérantes au feu. La modification des conditions chimiques du sol suite à la production de charbon de bois / agriculture n’est pas apparue comme un filtre majeur de la restauration. Les enquêtes nous ont permis de recenser une liste d’espèces utiles pour la production de charbon de bois, de bois de construction, etc d’après la vision des villageois. Néanmoins, les pratiques villageoises actuelles ne montrent pas d’intérêt à la préservation de ces espèces. Leur système de culture et leurs connaissances semblent tournés vers un mode culture de plus en plus intensif, mono-spécifique et tourné vers l’utilisation de fertilisants. Le problème majeur d’accès à la ressource en bois ne semble pas être dans la conscience de la population alors que la déforestation ne cesse de croitre. [less ▲]

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See detailImpact de l’érosion littorale dans les villes côtières africaines: de la procrastination des pouvoirs publics à la migration forcée des plus précaires. Cas de Cotonou, Bénin
Ozer, Pierre ULg; Hountondji, Yvon-Carmen; De Longueville, Florence ULg et al

Poster (2013, December 19)

Situé dans le Golfe de Guinée, le littoral béninois est soumis –sur certains tronçons– à une érosion assez rapide ces dernières décennies. Cette érosion côtière est principalement due actuellement aux ... [more ▼]

Situé dans le Golfe de Guinée, le littoral béninois est soumis –sur certains tronçons– à une érosion assez rapide ces dernières décennies. Cette érosion côtière est principalement due actuellement aux activités humaines parmi lesquelles les perturbations sédimentaires occasionnées par la construction de divers barrages dont celui de Nangbéto sur le fleuve Mono ; le blocage du transit littoral par les ouvrages portuaires de Cotonou ; les carrières de sable exploitées à même la plage ; et la diminution d’apports sédimentaires provenant de l’ouest suite à divers travaux de protection des côtes. En utilisant la fonction multi dates disponible dans Google Earth, cet article estime la superficie érodée à Cotonou entre 2002 et 2011 à l’est de l’exutoire du Lac Nokoué. En outre, il évalue le nombre de maisons détruites ainsi que le nombre de personnes contraintes à une migration forcée. Les figures sont importantes puisque de l’ordre de cent mètres de zone côtière ont totalement disparu en une décennie sur un tronçon de près de six kilomètres de long en pleine ville ou en proche périphérie. [less ▲]

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See detailUn contrat de rivière en zone périurbaine, la rivière Lukaya à Kinshasa, RDC.
Rosillon, Francis ULg; Jacmain, Céline

Poster (2013, December 19)

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See detailEtalement urbain des villes en Afrique subsaharienne et vulnérabilité croissante face au risque d’inondation : l’exemple de Nouakchott (Mauritanie)
Ozer, Pierre ULg; Ould Sidi Cheikh, Mohamed Ahmed; Ozer, André ULg

Poster (2013, December 19)

Après la sécheresse et la désertification qui ont fortement frappé la Mauritanie dans les années 1970 et 1980, la ville de Nouakchott a connu un développement démographique spectaculaire. En effet, la ... [more ▼]

Après la sécheresse et la désertification qui ont fortement frappé la Mauritanie dans les années 1970 et 1980, la ville de Nouakchott a connu un développement démographique spectaculaire. En effet, la population de la capitale mauritanienne est passée de 134 704 habitants en 1977 à 899 887 habitants recensés en mars 2013. Depuis 2000, Nouakchott voit sa population augmenter de 125 personnes par semaine ; une croissance absolue jamais atteinte par le passé. La ville s’est donc agrandie considérablement et les nouveaux arrivants ont construit leurs maisons dans des zones marginales sans aménagement préalable. Plusieurs quartiers se sont installés soit dans des zones dépressionnaires à sols salés sous forme de sebkha, soit dans des zones dunaires fortement ensablées. Sur base de l’analyse de la relation entre pluies et inondations, nous avons pu déterminer que ces dernières n’étaient plus dues à des événements pluviométriques extrêmes mais bien à un aménagement du territoire non contrôlé. [less ▲]

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See detailOxygen: a critical component of critically sized defects
Carlier, Aurélie ULg; Van Gastel, Nick; Geris, Liesbet ULg et al

Poster (2013, December 19)

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See detailLes villes d’Afrique Centrale balafrées par l’érosion ravinante : inventaire cartographique et impact socio-économique à Kinshasa (RDC)
Makanzu, Fils; Moeyersons, Jan; Vandecasteele, Ine et al

Poster (2013, December 19)

Kinshasa, la plus grande ville d’Afrique Centrale, a vu sa population passer de 404173 habitants en 1957 à près de 8 millions d’habitants en 2007, soit une augmentation d’environ 20 fois en 50 ans ... [more ▼]

Kinshasa, la plus grande ville d’Afrique Centrale, a vu sa population passer de 404173 habitants en 1957 à près de 8 millions d’habitants en 2007, soit une augmentation d’environ 20 fois en 50 ans seulement. La ville s’est entre-temps agrandie, s’étalant de 94 à 443 km² au cours de la même période. A l’aide de la télédétection et d’un SIG, les ravins d’au moins 5 mètres de large ont été cartographiés à partir d’un couple stéréoscopique SPOT 2006/2007 dans la haute ville de Kinshasa. Cet inventaire a permis la détermination de 308 ravins totalisant une longueur cumulée de 95 km qui occupent une superficie de 2 km² et dont la profondeur moyenne et la largeur moyenne sont respectivement de 7 et 21 mètres. La densité de ravinement est de 0,4 km/km². Sur le plan socio-économique, on déplore la destruction d’environ 95 habitations par an, ce qui cause des pertes estimées à 1,5 million d’USD annuellement. A cela s’ajoutent des tronçons de routes coupés, la rupture des tuyaux de raccordement en eau potable, la destruction des écoles, des centres de santé et des lieux de culte, ainsi que la chute des pylônes électriques. [less ▲]

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See detailContribution à l’optimisation de la localisation des zones adaptées au développement de l'agriculture périurbaine dans la commune de Parakou (Bénin) : étude des potentialités à partir des données multi sources (spatiales et socioéconomiques)
Hountondji, Yvon Carmen; De Longueville, Florence ULg; Ozer, Pierre ULg

Poster (2013, December 19)

Le présent document vise de façon globale à produire des bases techniques pour une mise en valeur rationnelle des zones adaptées au développement de l’agriculture d’appoint (produits de contre-saison) à ... [more ▼]

Le présent document vise de façon globale à produire des bases techniques pour une mise en valeur rationnelle des zones adaptées au développement de l’agriculture d’appoint (produits de contre-saison) à la périphérie de la ville de Parakou. Nous avons mis au point un outil technique pour appuyer la municipalité de Parakou (qui est en forte demande d’expertise) dans la gestion du foncier rural et urbain et à développer, autour de cette gestion foncière, des investissements à caractère économique et des actions de préservation des ressources naturelles. Sur base d’une approche systémique basée à la fois sur des données biophysiques (notamment spatiales) et socio-économiques, nous avons développé un outil de planification spatiale et d’aide à la décision pour l’ensemble des acteurs communaux investis sur la problématique du développement agricole local et de l’aménagement des espaces périurbains. [less ▲]

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See detailLE TRANSPORT SOLIDE DANS L’OUED EL-HACHEM ET SES EFFETS SUR LA RECHARGE DE LA NAPPE À PARTIR DES LACHERS DU BARRAGE DE BOUKOURDANE (Nord de l’Algérie)
Tadrist, Nassima ULg; Debauche, Olivier ULg

Poster (2013, December 18)

L’érosion hydrique et l’envasement des retenues des barrages en Algérie qui atteint des volumes élevés, causée par le transport solide (en suspension et par charriage) dans l'oued El-Hachem.L’étude ... [more ▼]

L’érosion hydrique et l’envasement des retenues des barrages en Algérie qui atteint des volumes élevés, causée par le transport solide (en suspension et par charriage) dans l'oued El-Hachem.L’étude consiste à étudier le transport de sédiments avant et après la réalisation du barrage de Boukourdane de façon à mettre en évidence la gravité de ce processus d’envasement sur la réduction du réservoir du barrage et sur l’hydraulique de l’oued à l’aval de l’ouvrage. Les résultats obtenus, montrent que le transport solide dans l’oued El-Hachem est relativement faible ; par conséquent la vitesse de sédimentation est lente dans la retenue. Cela se répercute sur la concentration dans les lâchers d’eau qui opèrent périodiquement par la vanne de fond du barrage qui devient très faible. Cette dernière n’a pas donc d’effet sur le colmatage du fond alluvionnaire de l’oued. L’étude de la recharge de la nappe à l’aval du barrage par ces lâchers confirme ce résultat. [less ▲]

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See detailAdult survival and reproduction in an Argentine bottlenose dolphin population: The science needed for its conservation
Vermeulen, Els ULg; Bräger, Stefan

Poster (2013, December 11)

Several small populations of bottlenose dolphins (Tursiops truncatus) are known to inhabit the Atlantic coast of Argentina, however, apparently with little exchange between them. The study population in ... [more ▼]

Several small populations of bottlenose dolphins (Tursiops truncatus) are known to inhabit the Atlantic coast of Argentina, however, apparently with little exchange between them. The study population in Bahia San Antonio (San Matías Gulf, province of Río Negro) appears to be one of the southernmost populations (42°S/65°W). Adult survival and calving rates are critical for the survival of this population. Boat-based photo-identification surveys between 2008 and 2011 were used for a mark-recapture analysis of the survival of 35 distinctly marked adults. Survey trips in September 2008 (n=9), August 2009 (n=10), September 2010 (n=6) and in September 2011 (n=6) were used as secondary periods for a Pollock’s Robust Design analysis within MARK. The population was assumed to be closed within the secondary periods, and model selection indicated random migrations (rather than Markovian or No migration) outside the secondary periods. Adult survival was very high. Calving interval was calculated for 14 reproductive females with 28 calves since 2006 with the average being 3.5 ± 1.03 years. Assuming a population size of approximately 100 individuals, the minimum annual birth rate is 4.7% per year. Of the 28 calves, 3 are presumed to have died within the first 2-3 years of life, whereas 14 are known to have survived that period. Although bottlenose dolphins occur further south along the Argentine coast, the study population appears to be the most southerly stable population after the neighboring Valdez population was recently reported to be vanishing. Interactions with fishing and contamination appear to be the most likely impacts on adult survival and reproduction. So far, our results indicate a relatively small population with apparently healthy birth and survival rates. [less ▲]

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See detailImpact of agricultural practices on soil microbial communities in Belgium
Degrune, Florine ULg; Taminiau, Bernard ULg; Dufrêne, Marc ULg et al

Poster (2013, December 11)

The use of fertilizers in agricultural soils is becoming a real environmental issue (an obvious example is eutrophication caused by leaching of phosphorus and nitrates). Much research has focused on ... [more ▼]

The use of fertilizers in agricultural soils is becoming a real environmental issue (an obvious example is eutrophication caused by leaching of phosphorus and nitrates). Much research has focused on finding ways to reduce the use of chemicals, and investigating microbial life may lead to solutions. We know that bacteria and fungi are deeply involved in nutrient cycles. Recently the emergence of massive parallel sequencing has enabled us to realize that microbial diversity is huger than we expected. With such a tool it should be possible to study how soil management practices affect the microbial diversity of agricultural soils. A few such studies have been conducted, most of them focusing on bacteria. For Belgium in particular, there is a lack of data on this topic. Here the aim was to see how residue management and tillage practices affect communities of both bacteria and fungi in Belgian agricultural soils. For this we used 454 pyrosequencing of 16S bacterial and 28S fungal rRNA genes. Soil samples came from an experiment in which faba beans were grown with four soil management practices (tillage and no tillage, with and without crop residues), each repeated four times in a Latin square. Several chemical and physical characteristics were measured on each sample. The results show that fungi and bacteria are both impacted by Tillage practices. The main soil drivers are Magnesium and Phosphorus for Fungi communities, and Phosphorus and Potassium for bacteria communities. Finally, the fungi variance observed between plots is explained at 38% by Tillage, Magnesium and phosphorus. And the bacteria variance is explained at 28% by Tillage, Phosphorus and Potassium. [less ▲]

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See detailValidation of ACE-FTS measurements of CFC-11, CFC-12 and HCFC-22 using ground-based FTIRs
Kolonjari, F; Walker, K A; Mahieu, Emmanuel ULg et al

Poster (2013, December 10)

Satellite data can be an effective global monitoring tool for long-lived compounds in the atmosphere. The Atmospheric Chemistry Experiment (ACE) is a mission onboard the Canadian satellite SCISAT. The ... [more ▼]

Satellite data can be an effective global monitoring tool for long-lived compounds in the atmosphere. The Atmospheric Chemistry Experiment (ACE) is a mission onboard the Canadian satellite SCISAT. The primary instrument on SCISAT is a high-resolution infrared Fourier transform spectrometer (ACE-FTS) which is capable of measuring a range of gases including key chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC) species. These families of species are of interest because of their significant contribution to anthropogenic ozone depletion and to global warming. To assess the quality of data derived from satellite measurements, validation using other data sources is critical. Ground-based Fourier transform infrared spectrometers (FTIRs) are particularly useful for this purpose. In this study, five FTIRs located at four sites around the world are used to validate the CFC-11 (CCl3F), CFC-12 (CCl2F2), and HCFC-22 (CHClF2) retrieved profiles from ACE-FTS measurements. These species are related because HCFC-22 was the primary replacement for CFC-11 and CFC-12 in refrigerant and propellant applications. The FTIRs used in this study record solar absorption spectra at Eureka (Canada), Jungfraujoch (Switzerland), Poker Flat (USA), and Toronto (Canada). The retrieval of CFC-11, CFC-12, and HCFC-22 are not standard products for many of these FTIRs, and as such, a harmonization of retrieval parameters between the sites has been conducted. The retrievals of these species from the FTIR spectra are sensitive from the surface to approximately 20 km, while the ACE-FTS profiles extend from 6 to 30 km. For each site, partial column comparisons between coincident measurements of the three species and a validation of the observed trends will be discussed. [less ▲]

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See detailThe 2-3 minutes periodicity in the polar aurora and the magnetosphere of Jupiter
Bonfond, Bertrand ULg; Grodent, Denis ULg; Gérard, Jean-Claude ULg et al

Poster (2013, December 10)

The main aurora at Jupiter is related to the middle magnetosphere and the corotation breakdown of the magnetospheric plasma. On the other hand, the polar regions either magnetically map to the outer ... [more ▼]

The main aurora at Jupiter is related to the middle magnetosphere and the corotation breakdown of the magnetospheric plasma. On the other hand, the polar regions either magnetically map to the outer magnetosphere or correspond to field lines open to the interplanetary medium and most of the auroral emissions from this region are still poorly understood. Among these polar auroral emissions are the flares, dramatic brightenings of several million square kilometers over a couple of minutes. Two previously reported observations of the southern hemisphere showed that these flares can be quasi-periodic with a re-occurrence time of 2-3 minutes. Here we report results from the Hubble Space Telescope campaign carried out in 2012-2013 with the STIS FUV instrument in time-tag mode (PI: D. Grodent). This campaign consisted in alternating observations of the two hemispheres. Based on the analysis of this dataset, we confirm that these quasi-periodic flares are ubiquitous and occur in both hemispheres. Moreover, in at least one case, these flares appear to occur in phase in both hemispheres. We compare the characteristics of these flares with those of the relativistic electron bursts observed by the Ulysses spacecraft with the HET instrument. We find that 2-3 minutes quasi-periodic burst are much more frequent than previously reported and that they magnetically map to the same auroral area as the flares. We conclude that these two phenomena are most probably related and arise from a common origin. [less ▲]

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See detailMagnetopause Boundary Normal Analysis at Jupiter and Saturn: Evidence of Kelvin Hemholtz Vorticies
Stauffer, Blake Hughes; Delamere, Peter A; Ma, Xuanye et al

Poster (2013, December 10)

Identification of surface waves and Kelvin Hemholtz (KH) vorticies at the magnetopause boundary at Jupiter and Saturn is critical to understanding interaction between the solar wind and their planetary ... [more ▼]

Identification of surface waves and Kelvin Hemholtz (KH) vorticies at the magnetopause boundary at Jupiter and Saturn is critical to understanding interaction between the solar wind and their planetary magnetospheres. The rapid rotation of those planets coincides with a co-rotating plasma that creates an asymmetry between the formation and evolution of surface waves on either side of the sub-solar point. Minimum variance analysis and other techniques are performed on hundreds of select crossings of Saturn's magnetopause from 2004 to 2012 by the Cassini spacecraft and 47 crossings at Jupiter's magnetopause by the Galileo spacecraft. It is compared to the boundary normals of a simple magnetopause model. The wide range in angular difference between the model and the analysis is evidence of the presence of KH instability vorticies at the magnetopause boundary. Furthermore, boundary crossings from the magnetosheath into the magnetosphere on the dusk flanks are dominated by shallower angles, consistent with MHD simulations of variable shear flows on the dayside magnetopause boundary. [less ▲]

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See detailInfluence of two breeds (Belgian Blue and Limousin) and previous storage time on pigment and lipid stability of high-oxygen atmosphere packaged beef
Didimo Imazaki, Pedro Henrique ULg; Tahiri, Assia ULg; Thimister, Jacqueline ULg et al

Poster (2013, December 10)

The aim of this study was to evaluate the effect of two breeds (Belgian Blue vs. Limousin) and previous storage time in vacuum conditions on color and lipid stability of meat packaged in high-oxygen ... [more ▼]

The aim of this study was to evaluate the effect of two breeds (Belgian Blue vs. Limousin) and previous storage time in vacuum conditions on color and lipid stability of meat packaged in high-oxygen atmosphere. Limousin meat samples of this study presented a higher sensitivity to myoglobin and lipid oxidation than Belgian Blue samples. The higher content of fat in those samples was one of the factors that could explain this higher sensitivity. Lipid oxidation and myoglobin oxidation appear to be linked, and further studies to understand the interaction between both processes are still needed. An understanding of the oxidative processes and their interaction would provide a basis for explaining quality deterioration in meat and also for developing strategies (e.g. antioxidant supplementation) to maintain sensory qualities. [less ▲]

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See detailHeat transfer characterization using heat and solute tracer tests in a shallow alluvial aquifer
Dassargues, Alain ULg; Wildemeersch, Samuel ULg; Jamin, Pierre ULg et al

Poster (2013, December 09)

Very low enthalpy geothermal systems are increasingly considered for heating or cooling using groundwater energy combined with heat pumps. The design and the impact of shallow geothermal systems are often ... [more ▼]

Very low enthalpy geothermal systems are increasingly considered for heating or cooling using groundwater energy combined with heat pumps. The design and the impact of shallow geothermal systems are often assessed in a semi-empirical way. It is accepted by most of the private partners but not by environmental authorities deploring a lack of rigorous evaluation of the mid- to long-term impact on groundwater. In view of a more rigorous methodology, heat and dye tracers are used for estimating simultaneously heat transfer and solute transport parameters in an alluvial aquifer. The experimental field site, is equipped with 21 piezometers drilled in alluvial deposits composed of a loam layer overlying a sand and gravel layer constituting the alluvial aquifer. The tracing experiment consisted in injecting simultaneously heated water and a dye tracer in a piezometer and monitoring evolution of groundwater temperature and tracer concentration in 3 control panels set perpendicularly to the main groundwater flow. Results showed drastic differences between heat transfer and solute transport due to the main influence of thermal capacity of the saturated porous medium. The tracing experiment was then simulated using a numerical model and the best estimation of heat transfer and solute transport parameters is obtained by calibrating this numerical model using inversion tools. The developed concepts and tests may lead to real projects of various extents that can be now optimized by the use of a rigorous and efficient methodology at the field scale. [less ▲]

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See detailIdentifying losses and expansions of selected gene families in incomplete genomic datasets
Di Franco, Arnaud ULg; Hanikenne, Marc ULg; Baurain, Denis ULg

Poster (2013, December 09)

Plantae (Archaeplastida) are a natural group of organisms with plastids of primary endosymbiotic origin. Within this group, members of the red algae show evidence of a reduction of their genomic content ... [more ▼]

Plantae (Archaeplastida) are a natural group of organisms with plastids of primary endosymbiotic origin. Within this group, members of the red algae show evidence of a reduction of their genomic content. In this work, we designed a bioinformatics approach to investigate the few, sometimes incomplete, genomic datasets available for red algae, with the purpose of pointing out possible gene family losses and expansions. Our pipeline first populates a relational database with precomputed orthology relationships between green plant genomes and red algal datasets and then efficiently queries the database for computing statistics of losses and expansions for a series of gene families of interest. [less ▲]

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

Poster (2013, December 08)

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See detailThe impact of the salience of fluency in recognition memory in Alzheimer’s disease
Simon, Jessica ULg; Bastin, Christine ULg; SALMON, Eric ULg et al

Poster (2013, December 06)

According to the dual-process models, recognition memory is supported by recollection and familiarity (Yonelinas, 2002). Familiarity is a complex function that depends on several processes. One of the ... [more ▼]

According to the dual-process models, recognition memory is supported by recollection and familiarity (Yonelinas, 2002). Familiarity is a complex function that depends on several processes. One of the most important mechanisms is the sense of familiarity driven by the fluency processing (Whittlesea, 1993). The fluency can be defined by the enhancement of processing speed and the ease of processing due to an earlier encounter with the stimulus. Our objective is to explore the effect on an increase of salience of fluency cues on the recognition memory performance of patients with Alzheimer disease (AD). Sixteen AD patients and sixteen healthy elderly controls (HC) performed two conditions of a memory task. In the study phase, 25 words were presented at a rate of one word every 1.5s. Participants were instructed to read the words aloud and to try and remember them. After a break of 5 minutes, participant performed a yes/no recognition task with 25 studied words and 25 new words. In the Non-Overlap condition, the 25 studied words were composed of a subset of letters of the alphabet and the 25 new words of the remaining letters. In the Overlap condition, the 50 words were based on the whole alphabet. The two recognition tasks were separated by a delay of 24h. The capacity to discriminate between old and new items was measured by the index d’. An ANOVA on d’ scores revealed that discrimination was poorer in the AD group than in the HC and also poorer in the Overlap condition than in the Non-Overlap condition. The current results showed that to increase salience of fluency at the level of letter by eliminating letter-overlap between old and new words increases the recognition performance to the same extent in both groups but the amplitude of AD memory deficit was not reduced (Bastin, Willems, Genon, & Salmon, 2013). [less ▲]

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See detailSoil infrastructure evolution and its effect on water transfer processes under contrasted tillage systems with preliminary results of soil moisture sensor calibration
Parvin, Nargish ULg; Degré, Aurore ULg; Garré, Sarah ULg et al

Poster (2013, December 05)

The heterogeneity of soil structure and porosity are highly influenced by external factors like tillage systems and other land management approaches. The aim of this project is to investigate the effect ... [more ▼]

The heterogeneity of soil structure and porosity are highly influenced by external factors like tillage systems and other land management approaches. The aim of this project is to investigate the effect of soil tillage along with residue management on the changing pattern of soil structure. This investigation will help to emphasize the different water flow dynamics especially the preferential flow processes through the soil that are influenced by the changes in structural distribution in the soil profile. Mostly the preferential flow of water is addressed by the apparent velocity through the soil but this study will focus on soil structure along with soil moisture dynamics at aggregate scale or more specifically at pedon scale. The experimentation has been started from June 2013 in the research field known as Solcouvert (objects: strip-till (ST) versus winter ploughing (WP)) and Solresidus (objects: no-till with organic matter restitution (NI) versus no-till without organic matter restitution (NO)). Soil profile description has been carried out in the four objects of land management. Soil sampling has been done in different depths of soil according to the soil profile description. Soil samples will be used for the measurement of water retention capacity, hydraulic conductivity and x-ray microtomography. In addition, there will be soil moisture sensors (Decagon 10HS, 5TM and ML3 Thetaprobe) in the field under four different trials. The soils from the different trials and also from different depths (0-15, 25-30 and 50-60 cm) were calibrated with the sensors. The calibration results were significantly (p<0.05) different between Solcouvert and Solresidus and there was also significant (p<0.05) difference among depths of same field especially between 0-15 and 50-60 cm. Soil bulk density and textural differences are the main reason for the differences of moisture content of different sites and depths measured by the moisture probes. In addition, the results were inconsistent along with overestimation of moisture content if the manufacturer based equation is used for the calibration. In our study, to capture the total soil moisture networks, the moisture sensors will be in the field in winter to spring and summer to autumn. All the experiments will be repeated twice a year. For the specific spatio-temporal comparison, the monitoring results from electrical resistance tomography will be available from the collaborated project of the same faculty. [less ▲]

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See detailEnhancement of thermophillic anaerobic digestion of methane by metal nanoparticles encapsulated in porous silica
Al-Ahmad, Alaa Eddin ULg; Hiligsmann, Serge ULg; Lambert, Stéphanie ULg et al

Poster (2013, December 05)

Increased demand and progressive depletion of fossil fuels, and worldwide concerns about greenhouse gas emissions have resulted in the development of promising technologies for renewable energy production ... [more ▼]

Increased demand and progressive depletion of fossil fuels, and worldwide concerns about greenhouse gas emissions have resulted in the development of promising technologies for renewable energy production. Therefore, potential alternatives for energy generation are intensively studied. One option is the use of biomass feedstock for the production of biogas through anaerobic digestion. This process is a biochemical technological process for the treatment of a wide range of feedstocks (e.g. organic fraction of municipal waste, animal manure and slurry, agricultural crops, etc.) to produce methane-rich biogas which can be used in replacement of fossil fuels in both heat and power generation and as a vehicle fuel. However, there are critical issues, which need to be addressed to make the production of bio-methane techno-economically viable and ecologically acceptable. One of the most important issues is the effect of trace metals addition on anaerobic digestion. These metals can be stimulatory, inhibitory, or even toxic for biochemical reactions, depending on their concentrations. As reported in literature, Ni, Co and Fe are all involved in the methane production biochemical process and serve as cofactors in enzymes which are involved in the biochemistry of methane formation (Zandvoort et al., 2006). Recently, enormous interest has been focused on biological applications of metal nanoparticles NPs due to their small size, high specified surface and their great potential in application to many science fields. The most studied process concerns zero valent palladium and iron NPs improving anaerobic biodegradation of chlorinated hydrocarbons (Windt et al., 2005). Moreover, investigation carried out in our lab showed that iron NPs encapsulated in silicate matrix may enhance hydrogen production by Clostridium butyricum (Beckers et al., 2013). Nevertheless the influences of metal NPs on methane producing anaerobic digestion have seldom been investigated. The present work investigates the enhancement effect of seven different metal NPs on methane production during the thermophilic anaerobic digestion. NPs of Cu, Pd, Pt, Ni, Co, Ag and Fe encapsulated in porous silica (SiO2) to prevent their coagulation and agglomeration, were added at concentration of 10-5mol/L in batch test (125ml serum bottles containing 70mL culture medium with 5g/L acetate monohydrate as the sole carbon substrate. Nickel, cobalt and iron NPs improved methane production from acetate. To confirm the previous results, the NPs were tested at different concentrations (10-4, 10-5, and 10-6 mol/L) with starch and glucose substrates. The results show that the impact increases with the increase of NPs concentrations up to 10-4 mol/L. The modified Gompertz equation was applied to describe the effect of NPs on anaerobic digestion. According to this model, the kinetic of methane production was particularly affected by nanoparticles addition. The values of the maximum methane production rate MPR (ml/day) was significantly higher 72.5% with nickel NPs at a concentration of 10-4 mol/L than the control without NPs. [less ▲]

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See detailSoil infrastructure evolution and its effect on water transfer processes under contrasted tillage systems
Parvin, Nargish; Degré, Aurore ULg; Garré, Sarah ULg et al

Poster (2013, December 05)

The heterogeneity of soil structure and porosity are highly influenced by external factors like tillage systems and other land management approaches. The aim of this project is to investigate the effect ... [more ▼]

The heterogeneity of soil structure and porosity are highly influenced by external factors like tillage systems and other land management approaches. The aim of this project is to investigate the effect of soil tillage along with residue management on the changing pattern of soil structure. This investigation will help to emphasize the different water flow dynamics especially the preferential flow processes through the soil that are influenced by the changes in structural distribution in the soil profile. Mostly the preferential flow of water is addressed by the apparent velocity through the soil but this study will focus on soil structure along with soil moisture dynamics at aggregate scale or more specifically at pedon scale. The experimentation has been started from June 2013 in the research field known as Solcouvert (objects: strip-till versus winter ploughing) and Solresidus (objects: no-till with organic matter restitution versus no-till without organic matter restitution). Soil profile description has been carried out in the four objects of land management. Soil sampling has been done in different depths of soil according to the soil profile description. Soil samples will be used for the measurement of water retention capacity, hydraulic conductivity and x-ray microtomography. In addition there will be soil moisture sensors (Decagon 10HS, 5TM and ML3 Thetaprobe) in the field under four different trials. The soils from the different trials and also from different depths (0-15, 25-30 and 50-60 cm) were calibrated with the sensors. The calibration results were significantly (p<0.05) different between Solcouvert and Solresidus and there was also significant (p<0.05) difference among depths of same field especially between 0-15 and 50-60 cm. Soil bulk density and textural differences are the main reason for the differences of moisture content of different sites and depths measured by the moisture probes. In addition, the results were inconsistent along with overestimation of moisture content if the manufacturer based equation is used for the calibration. We conclude that, site and depth wise calibration of low cost sensors is very essential for the interpretation of results. In our study, to capture the total soil moisture networks, the moisture sensors will be in the field during the crop season. All the experiments will be repeated twice a year. For the specific spatio-temporal comparison, the monitoring results from electrical resistance tomography will be available from the collaborated project of the same faculty. [less ▲]

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See detailDétermination de la teneur en équol dans les laits commercialisés en Wallonie (Belgique)
Daems, Frédéric ULg; Jasselette, Christophe; Franckson, Delphine et al

Poster (2013, December 04)

Detailed reference viewed: 37 (6 ULg)
See detailNumerical simulation of the electrical characteristics of CIGS/CdS/ZnO solar cell heterostructures
Amand, Julien ULg; Nguyen, Ngoc Duy ULg

Poster (2013, December 03)

The electrical characteristics of CIGS-based solar cell heterostructure have been simulated by numerically solving the basic semiconductor equations by means of a finite differences method based on a ... [more ▼]

The electrical characteristics of CIGS-based solar cell heterostructure have been simulated by numerically solving the basic semiconductor equations by means of a finite differences method based on a Scharfetter-Gummel discretization scheme. The electric potential, electric field, carrier concentrations, current densities and recombination rates are obtained as function of the space coordinate and the bias voltage. Starting with the analysis of a single absorber layer structure sandwiched between two metal electrodes, we subsequently studied the properties of the CIGS/ZnO pn heterojunction and the influence of the buffer layer thickness in the CIGS/CdS/ZnO on the cell electrical response. A special focus was also given to the influence of grain boundaries in the bulk of CIGS depending on the defects nature and concentration. Electrical measurements including admittance spectroscopy were performed on samples for comparison to be further lead. Motivations This research is part of the project IQuaReS (Innovative in-line Quality control for Renewable Solar solutions) that aims to develop an in-line quality control tool for manufactured CIGS-based solar cells, based on electrical and optoelectrical, preferably non-invasive measurement methods. Exploratory simulations aim to isolate signature patterns that could be sought in experimental measurements . [less ▲]

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See detailCT findings of an intra-abdominal metastatic sertoli cell tumor in a dog
Taylor, Olivia; Hamaide, Annick ULg; Mercier, Elise ULg et al

Poster (2013, December 01)

Detailed reference viewed: 21 (1 ULg)