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See detailMulti-wavelength observations of Jupiter's aurora coordinated with Hisaki and other space telescopes
Kimura, Tomoki; Badman, Sarah; Tao, Chihiro et al

Conference (2014, December 15)

From January to April 2014, two observing campaigns by multi-wavelength remote sensing from X-ray to radio were performed to uncover energy transport process in Jupiter’s plasma environment using space ... [more ▼]

From January to April 2014, two observing campaigns by multi-wavelength remote sensing from X-ray to radio were performed to uncover energy transport process in Jupiter’s plasma environment using space telescopes and ground-based facilities. These campaigns were triggered by the new Hisaki spacecraft launched in September 2013, which is an extremely ultraviolet (EUV) space telescope of JAXA designed for planetary observations. In the first campaign in January, Hubble Space Telescope (HST) made imaging of far ultraviolet (FUV) aurora with a high special resolution (0.08”) through two weeks while Hisaki continuously monitored aurora and plasma torus emissions in EUV wavelength with a high temporal resolution (1 min<). We discovered new magnetospheric activities from the campaign data: e.g., internally-driven type auroral brightening associated with hot plasma injection, and plasma and electromagnetic filed modulations in the inner magnetosphere externally driven by the solar wind modulation. The second campaign in April was performed by Chandra X-ray Observatory (CXO), XMM newton, and Suzaku satellite simultaneously with Hisaki. Relativistic auroral accelerations in the polar region and hot plasma in the inner magnetosphere were captured by the X-ray space telescopes simultaneously with EUV monitoring of aurora and plasma torus. Auroral intensity in EUV indicated a clear periodicity of 45 minutes whereas the periodicity was not evident in X-ray intensity although previous observations by CXO indicated clear 40-minute periodicity in the polar cap X-ray aurora. In this presentation, we show remarkable scientific results obtained these campaigns. [less ▲]

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See detailModélisation des processus physiques et biologiques dans des fosses septiques et voies de valorisation des boues de vidange:Application à Bujumbura-Burundi
Nsavyimana, Gaston ULg

Doctoral thesis (2014)

Dans les pays en développement (PED) en général et au Burundi en particulier, la problématique de gestion des eaux usées et des déchets solides constitue un enjeu majeur pour les spécialistes et les ... [more ▼]

Dans les pays en développement (PED) en général et au Burundi en particulier, la problématique de gestion des eaux usées et des déchets solides constitue un enjeu majeur pour les spécialistes et les autorités locales. En effet, suite à un manque des stations d'épuration collectives au Burundi, les fosses septiques sont les plus utilisées pour gérer les eaux usées produites. Cependant, les processus qui s'y déroulent ne sont pas encore maîtrisés et la gestion des boues de vidange lorsque ces installations sont remplies, constitue une problématique qui mérite d'être abordée afin de trouver des solutions adaptées, à court et à long terme. Et, suite à une absence des technologies appropriées en matière de gestion des déchets solides, ils sont jetés de manière inadmissible (dans les caniveaux, rivières, places publiques, etc.), et cela peut engendrer à court ou à long terme des nuisances graves, tant pour la santé et l'hygiène publique que pour l'environnement. C’est dans l’optique de contribuer: (i) à l'amélioration de la qualité environnementale; (ii) et à la réduction des risques sanitaires associés à la gestion des déchets liquides et solides à Bujumbura (Burundi), que s’inscrit ce travail de recherche qui porte sur la "Modélisation des processus physiques et biologiques dans des fosses septiques et voies de valorisation des boues de vidange: Application à Bujumbura-Burundi". Différents axes ont ainsi été abordés pour répondre a cet objectif général : (1) la quantification des processus physico-chimiques dans des fosses septiques; (2) la modélisation stœchiométrique, cinétique et mathématique des processus biochimiques; et (3) l'étude des voies de valorisation énergétique des boues de vidange, soit seules (en digestion anaérobie) ou combinées avec des déchets solides fermentescibles (en co-digestion anaérobie). L'étude de quantification des processus physico-chimiques, matérialisables par le phénomène de décantation des particules solides a permis de dégager deux résultats principaux: (i) les effluents d'entrée dans les fosses septiques présentent une bonne décantabilité; (ii) les effluents de sortie de ces ouvrages (107 mg MES/L) ne respectent pas les normes de rejets (30 mg MES/L: cas de la norme Belge). Des dispositifs appropriés pour le traitement des effluents de sortie des fosses septiques (lit filtrant drainé/ou non à flux vertical sur un massif de sable, lit filtrant drainé/ou non à flux vertical sur un massif de zéolithe, lit filtrant horizontal drainé, tertre d’infiltration, tranchée d'épandage ou lit bactérien percolateur) ont été proposés pour palier les insuffisances des puits perdants couramment utilisés au Burundi. L'étude de caractérisation des flux entrant dans des fosses septiques était indispensable pour les modélisations ultérieures (stœchiométrique, cinétique et mathématique) des processus biochimiques et a permis de quantifier, de manière revisitée, la notion d' un équivalent habitant. Ainsi, un équivalent habitant (EH) a été déterminé pour la Belgique et le Burundi en termes de la demande chimique en oxygène (DCO), soit 138,75 ± 20,09 gDCO/EH/j et 117,08 ± 10,09 gDCO/EH/j respectivement. De plus, cette étude a permis de caractériser, par rapport à un équivalent habitant, différents composés chimiques importants contenus dans les flux entrant dans les fosses septiques. Les résultats variaient entre 0,37 ± 0,18 g/EH/j (pour les acides aminés urinaires ) et 43,44 ± 4,35 g/EH/j ( pour glucides), avec des valeurs de 5,00 ± 0,3; 10,15 ± 1,96; 10,6 ± 3,27; 14,7 ± 0,4 et 14,99 ± 1,57 g/EH/j respectivement pour les savons de bain/douche, lipides, azote total, détergent pour lave-linge et protéines. Ces résultats ont contribué à l'élaboration d'une formule "de biomole de substrat complexe" (C23 H49O9N) représentant les eaux usées, utile pour simplifier la modélisation mathématique de fonctionnement des fosses septiques en réduisant le nombre de processus, de variables d’état, d’équations cinétiques associées et des paramètres qui en découlent. La modélisation stœchiométrique des processus biochimiques qui se déroulent dans les fosses septiques, après avoir vérifié que le métabolisme est bien anaérobie, même si des eaux usées éventuellement saturées en O2 entrent quotidiennement dans ce type de dispositifs, a permis de mettre en place un système d’équations qui décrit la stœchiométrie de fonctionnement des fosses septiques. Par ailleurs, dans les pays en développement comme le Burundi, les laboratoires sont moins équipés et ont un accès très limité aux équipements modernes d'analyse usuels (ex., GC ou HPLC ), pour le dosage des acides gras volatils (AGV). A cet effet, nous avons développé et vérifié une nouvelle méthode de dosage des AGV par titrage, efficace et proche de la méthode chromatographique en phase gazeuse. A 99% d'intervalle de confiance, les résultats obtenus à l'aide de cette nouvelle méthode, sont comparables à ceux de la chromatographie en phase gazeuse. La modélisation cinétique a permis de mettre en exergue un modèle de dégradation de la biomole du substrat complexe, qui s'est révélé comparable au modèle cinétique de Monod. Les constantes cinétiques découlant du traitement des données sont dans le cas présent: (i) le taux maximum de croissance spécifique (µmax) égal à 0,0065 j-1; (ii) la constante de demi-saturation de ce substrat combiné synthétique égale à 9,18 g DCO/l ou 4,26 g/l; et (iii) le taux de mortalité égal à 0,0001 j-1. Ces données sont très utiles pour les simulations de fonctionnement des fosses septiques à l'aide d'un logiciel de gestion des ouvrages de traitement des eaux usées (WEST®). Ce travail a également permis de développer un modèle global de fonctionnement des fosses septiques (MFS/DDA ), qui par ailleurs a été présenté suivant le formalisme matriciel de Petersen. Une étude préliminaire de caractérisation détaillée des boues de vidange a montré qu'elles sont presque stabilisées, du point de vue valorisation énergétique. Lorsqu'elles sont digérées seules, elles présentent un faible potentiel méthanogène, soit 2,09 m3 biogaz/m3 de boues fraîches (après deux mois de digestion). Ce biogaz est composé de 71% de CH4 contre 29% de CO2. Ce travail a montré un intérêt de co-digestion anaérobie des boues de vidange avec les déchets solides fermentescibles. A cet effet, un rapport MVSFS/MOVdéchets égal à 0,3 (MOVdéchets étant exprimées en poids sec de déchets et MVSFS en poids sec des boues de vidange) s’est révélé optimal , pour leur meilleure valorisation énergétique, avec une production cumulée maximale de biogaz égal à 12,14 m3biogaz/m3 de mélange gadoues-déchets. La composition moyenne de ce biogaz était de 65,6% en CH4 contre 34,4% en CO2. Mots Clés: Burundi; Assainissement; Fosses septiques; Eaux noires; Eaux grises; Equivalent habitant; Décantation; Digestion anaérobie; Substrat combiné; Acides gras volatils; Modèle stœchiométrique; Modèle cinétique; Matrice de Petersen; Simulations avec WEST®; Boues de vidange; Potentiel méthanogène; Co-digestion anaérobie; Déchets solides fermentescibles. [less ▲]

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See detailFirst monitoring results of three straw bale buildings in Belgium
Evrard, Arnaud; Dubois, Samuel ULg; Louis, Arnaud et al

Conference (2014, December 13)

Straw bale use in buildings may be an interesting way to decrease our energy needs and our impact on environment. The present paper describes an experimental set up to monitor three straw bale buildings ... [more ▼]

Straw bale use in buildings may be an interesting way to decrease our energy needs and our impact on environment. The present paper describes an experimental set up to monitor three straw bale buildings recently built in Belgium. For each building, results on temperature and relative humidity, inside and outside, are analyzed, as well as internal evolution of temperature and humidity distribution in the walls. The first building is an office building where two finishing are compared. Measurements also provide additional data on CO2 levels and electric consumption. The two other buildings are dwellings where live one single family. In the first one, a wall in the bedroom and a retaining wall are analyzed. In the second one, a wall in the bedroom and a wall in the bathroom are analyzed. Their hygrothermal behavior is discussed based on simulation results obtained with WUFI Pro and WUFI Plus software. The criterion for the validation of wall behavior is based on water content distribution through the walls. The paper confirms the great potential of this type of building technology and helps to identify how to assess and validate their effective hygrothermal behavior. [less ▲]

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See detailL’antithèse de la psychopathologie : à propos d’un inexistant
Englebert, Jérôme ULg

Scientific conference (2014, December 12)

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See detailParticulate soils adherence and surface cleanability: influence of biomacromolecules at interfaces and of substrate hydrophobicity
Toure, Yetioman ULg

Doctoral thesis (2014)

Cleaning of particulate soils is an important issue in food and pharmaceutical production. Understanding the adherence of these soils is a fundamental requirement for improving surfaces cleanability. The ... [more ▼]

Cleaning of particulate soils is an important issue in food and pharmaceutical production. Understanding the adherence of these soils is a fundamental requirement for improving surfaces cleanability. The combination of particles and macromolecules substances appears in many processes. Adsorbed compounds from these mixtures may influence interactions at interfaces and thus fouling and cleaning. This thesis deals with a deeper understanding of the physico-chemical mechanisms affecting soiling and cleanability of open substrates in the presence of biomacromolecules (dextran, bovine serum albumin – BSA, beta-lactoglobulin – β-LGB). Model substrates were chosen according to their hydrophobicity. The influence of macromolecules was examined by introducing them in the quartz suspension taken as a model of hard hydrophilic soil used for soiling, or by conditioning the substrate prior to soiling. The substrates were pretreated with ethanol (-Eth.), piranha or UV-Ozone (-UVO); soiled by spraying the quartz suspensions, then dried, before cleaning assessment. The removal of the soiling particles was evaluated after exposure to water in a radial flow chamber (RFC). Auxiliary characterizations were surface tension and contact angle measurements, surface analysis of the substrate by X-ray photoelectron spectroscopy (XPS) and Scanning electron microscopy (SEM). The interpretation of XPS data allowed the complexity due to the ubiquitous presence of organic contaminants to be coped with, and the surface composition to be expressed in terms of both the amount of adlayer and the mass concentration of adlayer constituents. The contact of substrates with proteins led to their adsorption, which dominated the composition of the organic layer with respect to contaminants initially present, and was not markedly desorbed upon rinsing. Dextran was easily removed in presence of water, independently on the substrate nature. Surface hydrophobicity was shown to influence the morphology of the aggregates resulting from drying. The rounder aggregates formed on polystyrene when soiling was performed with suspension in pure water are more sensitive to wall shear stress than flatter ones formed on more hydrophilic substrate. This is the result of the competing processes of droplet rolling and coalescing, on the one hand, and droplet spreading, on the other hand. It affects the shape and compactness of the adhering aggregates, the efficiency of shear forces upon cleaning and finally, the adherence of soiling particles. The presence of proteins (either native or denatured) at the interface improved strongly the cleanability of more hydrophilic substrate (glass, StSteel-UVO). This is attributed to the lower surface tension. The dependence of cleanability on capillary forces, and in particular on the liquid surface tension, is predominant as compared with its dependence on the size and shape of the soiling aggregates, which influence the efficiency of shear forces exerted by the flowing water upon cleaning. The cleanability of less hydrophilic substrate (stainless steel only pre-cleaned with ethanol) did not change markedly in the presence of proteins; this may be due to a more complex interaction between surface tension and contact angle, on one hand, and a more complex interaction between proteins and contaminants, on the other hand. The presence of dextran did not affect the cleanability, as neither the liquid surface tension nor the contact angle was appreciably affected. [less ▲]

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See detailEvolutionary history of the wood mouse (Apodemus sylvaticus) in the Palearctic region, with emphasis on the colonization of the Orkney Islands and Iceland
Durieu, Benoit ULg; Michaux, Johan ULg

Poster (2014, December 12)

To improve our knowledge concerning the hypothesis of northern refugia during the last glaciation for European species, we have focused our study on the evolutionary history of the wood mouse (Apodemus ... [more ▼]

To improve our knowledge concerning the hypothesis of northern refugia during the last glaciation for European species, we have focused our study on the evolutionary history of the wood mouse (Apodemus sylvaticus) throughout its Palearctic distribution. In addition, we also studied the wood mice populations from Orkney Islands and Iceland in order to understand their ways of colonization in the Atlantic islands. We used different molecular markers (cytb mitochondrial gene and a mitochondrial pseudogene). A geometric morphometric analysis using a morphological marker (mandible) was also used. This work highlights the potential existence of new wood mice lineages in Western Europe. These would be genetically differentiated, probably due to a geographical separation of an ancestral population in different refugia situated in the Iberian Peninsula during the last glacial maximum. Morphological differences also exist between the wood mice lineages. However, the study did not bring any evidence concerning the existence of Nordic refugia for this species. Concerning the insular populations, our results seem to show that populations from Orkney Islands and Iceland are genetically close to the Great Britain populations. They would have been introduced in these islands by Vikings or by earlier human populations. Additional sampling in Western Europe and in the Atlantic islands will clarify the origins of these populations. [less ▲]

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See detailHoney bee colony strength - Assessing accuracy of the Liebefeld estimation method
Leclercq, Gil ULg; Gengler, Nicolas ULg; Francis, Frédéric ULg et al

Poster (2014, December 12)

Honey bee colony strength (number of adult bees in a colony) is a crucial character used for both breeding and research. In breeding programs a rough estimate is usually sufficient to select strong ... [more ▼]

Honey bee colony strength (number of adult bees in a colony) is a crucial character used for both breeding and research. In breeding programs a rough estimate is usually sufficient to select strong colonies. On the other hand, the accuracy of this character can deeply affect the quality of several studies in both fundamental and applied research. For example these studies are related to the assessment of low demographic variations following a stress, or the estimate of a host-parasite ratio (e.g. involving the mite Varroa destructor Anderson & Trueman). The “Liebefeld estimation method” is extensively used in these studies while its accuracy remains weakly documented. Our goal is to provide more information on the accuracy of this method. [less ▲]

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See detailFrom Bad Models to Good Policies: an Intertwined Story about Energy and Reinforcement Learning
Fonteneau, Raphaël ULg

Speech/Talk (2014)

Batch mode reinforcement learning is a subclass of reinforcement learning for which the decision making problem has to be addressed without model, using trajectories only (no model, nor simulator nor ... [more ▼]

Batch mode reinforcement learning is a subclass of reinforcement learning for which the decision making problem has to be addressed without model, using trajectories only (no model, nor simulator nor additional interactions with the actual system). In this setting, we propose a discussion about a minmax approach to generalization for deterministic problems with continuous state space. This approach aims at computing robust policies considering the fact that the sample of trajectories may be arbitrarily bad. This discussion will be intertwined with the description of a fascinating batch mode reinforcement learning-type problem with trajectories of societies as input, and for which crucial good decisions have to be taken: the energy transition. [less ▲]

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See detailImpact of goldfish on terrestrial and aquatic microhabitat use in the palmate newt
Darnet, Elodie; Winandy, Laurane ULg; Denoël, Mathieu ULg

Poster (2014, December 12)

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See detailImpact of triclosan on behaviour and neural development of Cyprinodon variegatus
Benichou, Farida; Rahmouni, Chahrazed; Denoël, Mathieu ULg et al

Poster (2014, December 12)

The study focussed on the effects of triclosan (TCS) exposure on mobility and hearing capacities of Cyprinodon variegatus larvae. TCS is an omnipresent antimicrobial and contaminant of aquatic ecosystems ... [more ▼]

The study focussed on the effects of triclosan (TCS) exposure on mobility and hearing capacities of Cyprinodon variegatus larvae. TCS is an omnipresent antimicrobial and contaminant of aquatic ecosystems, which can act as endocrine disruptor, mainly by modifying thyroid functioning. Larval stages are particularly vulnerable to deleterious effects of endocrine disrupters because of potential impairment of fish development and behaviour. Exposure to TCS was conducted at fertilization of eggs at concentrations likely to be found in the environment: 20, 50 and 100 μg.l-1. The analysis of growth parameters of C. variegatus showed no effect of TCS on the fertility of eggs, survival and larval weight. Subsequently, THs concentrations were measured on 15 days post hatching larvae. THs are initially produced as T4 (thyroxine) cells and then converted in the bioactive form of T3 (triiodothyronine) cells. The observed increase of T4 and T3 cells in larvae exposed to 50 and 100 μg.l-1 suggests an increase in THs synthesis as a consequence of TCS exposure. Auditory thresholds of larvae were determined using ABR (Auditory Brainstem Response) technique, and finally larval mobility was measured. For both parameters no significant differences were observed among the three different treatments. Audiograms showed that the auditory system is not yet completely established at 30 days post hatching. However, these results allowed us to consider C. variegatus as an “hearing generalist” because this species have a hearing sensitivity lower than 2000 Hz. Regarding locomotion, our result summarized short time experiences targeting only swimming speed, distance and degree of mobility. It would be interesting to expand the behavioural aspects on other parameters of locomotion and integrate Cyprinodon reaction to different stress (light or touch). In conclusion, our results require an extensive long-term study on the full life cycle of C. variegatus, in order to evaluate the impact of triclosan on neural function and behaviour through several generations. [less ▲]

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See detailFunambulisme, prudence et ruse. Analyse du contexte de travail des directeurs de prison en Belgique
Dubois, Christophe ULg

Scientific conference (2014, December 12)

Cette contribution à l’analyse sociologique du travail des directeurs de prison éclaire tout d’abord le fondement de ce métier : la gestion de la détention. Présentée comme "individualisée ... [more ▼]

Cette contribution à l’analyse sociologique du travail des directeurs de prison éclaire tout d’abord le fondement de ce métier : la gestion de la détention. Présentée comme "individualisée/individualisante" dans les discours politique, la gestion de la détention s'exerce toutefois dans des contextes de travail bureaucratisés (que l'on pense à la gestion du personnel, à la gestion logistique, à la gestion comptable ou à la gestion stratégique), composés de diverses scènes d’interaction (organisationnelle, politique, associative, administrative, judiciaire, interministérielle) et marqués par les « référentiels » (Muller, 2000) de judiciarisation et de managérialisation du secteur public. L’étude du travail des directeurs de prison met ensuite en lumière trois mécanismes de régulation des établissements pénitentiaires : le pouvoir des [chefs] surveillants au centre d’une « régulation autonome » (Reynaud, 1988) ; la multi-dépendance inter-organisationnelle des prisons éprouvée quotidiennement par les directeurs au centre d’une « régulation croisée » (Crozier et Thoenig, 1975) ; l’articulation ponctuelle et « prudente » (Champy, 2012), par les directeurs, des contraintes et des opportunités inhérentes aux différentes scènes sur lesquelles ils interagissent. L'analyse de certaines situations concrètes révèle enfin que le travail des directeurs n’est pas seulement technique (sur les plans juridiques et administratifs) mais aussi politique: il requiert une hiérarchisation des valeurs ou des finalités poursuivies dans leur activité. [less ▲]

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See detailRapid morphological change of barbels (Cyprinidae) after the dry-up of Sahara
Brahimi, Amina; Tarai, Nacer; Libois, Roland ULg

Poster (2014, December 12)

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See detailLa chance du malentendu : conflit, créativité et communication "réussie"
Servais, Christine ULg

Conference (2014, December 12)

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See detailAnalphabétisme secondaire, raison cynique et la culture pour tous.
Hamers, Jérémy ULg

Conference (2014, December 12)

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See detailRGD surface functionalization of the hydrophilic acrylic intraocular lens material to control posterior capsular opacification
Huang, Yi-Shiang ULg; Bertrand, Virginie ULg; Bozukova, Dimitriya et al

in PLoS ONE (2014), 9(12), 32

Posterior Capsular Opacification (PCO) is the capsule fibrosis developed on implanted IntraOcular Lens (IOL) by the de-differentiation of Lens Epithelial Cells (LECs) undergoing Epithelial Mesenchymal ... [more ▼]

Posterior Capsular Opacification (PCO) is the capsule fibrosis developed on implanted IntraOcular Lens (IOL) by the de-differentiation of Lens Epithelial Cells (LECs) undergoing Epithelial Mesenchymal Transition (EMT). Literature has shown that the incidence of PCO is multifactorial including the patient’s age or disease, surgical technique, and IOL design and material. Reports comparing hydrophilic and hydrophobic acrylic IOLs have shown that the former has more severe PCO. On the other hand, we have previously demonstrated that the adhesion of LECs is favored on hydrophobic compared to hydrophilic materials. By combining these two facts and contemporary knowledge in PCO development via the EMT pathway, we propose a biomimetically inspired strategy to promote LEC adhesion without de-differentiation to reduce the risk of PCO development. By surface grafting of a cell adhesion molecule (RGD peptide) onto the conventional hydrophilic acrylic IOL material, the surface-functionalized IOL can be used to reconstitute a capsule-LEC-IOL sandwich structure, which has been considered to prevent PCO formation in literature. Our results show that the innovative biomaterial improves LEC adhesion, while also exhibiting similar optical (light transmittance, optical bench) and mechanical (haptic compression force, IOL injection force) properties compared to the starting material. In addition, compared to the hydrophobic IOL material, our bioactive biomaterial exhibits similar abilities in LEC adhesion, morphology maintenance, and EMT biomarker expression, which is the crucial pathway to induce PCO. The in vitro assays suggest that this biomaterial has the potential to reduce the risk factor of PCO development. [less ▲]

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