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See detailClimate change : Impacts of shoreline erosion in developing countries
Ozer, Pierre ULg; Lemena, Kidja Hermann

Conference (2015, March 11)

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See detailElastic and inelastic transmission in guided atom lasers: A truncated Wigner approach
Dujardin, Julien ULg; Argüelles, Arturo; Schlagheck, Peter ULg

in Physical Review A (2015), 91

We study the transport properties of a Bose-Einstein condensate formed by an ultracold gas of bosonic atoms that is coupled from a magnetic trap into a one-dimensional waveguide. Our theoretical approach ... [more ▼]

We study the transport properties of a Bose-Einstein condensate formed by an ultracold gas of bosonic atoms that is coupled from a magnetic trap into a one-dimensional waveguide. Our theoretical approach to tackling this problem is based on the truncated Wigner method for which we assume the system to consist of two semi-infinite noninteracting leads and a finite interacting scattering region with two constrictions modeling an atomic quantum dot. The transmission is computed in the steady-state regime and we find a good agreement between truncated Wigner and matrix-product state calculations. We also identify clear signatures of inelastic resonant scattering by analyzing the distribution of energy in the transmitted atomic-matter wave beam. [less ▲]

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See detailThe Role of Government in Path- Dependent Development of SME Sector in Ukraine
Shutyak, Yuliya; Van Caillie, Didier ULg

in Journal of East-West Business (2015), 21(1), 67-90

This article studies evolution of governmental support for SME development from the times of Perestroika until 2013. Guided by institutional theory, the article revises SME development in Ukraine and ... [more ▼]

This article studies evolution of governmental support for SME development from the times of Perestroika until 2013. Guided by institutional theory, the article revises SME development in Ukraine and explains government actions through the prism of path dependence. The analysis is conducted within a matrix logic resuming the data by several periods of time corresponding to changes in the Ukrainian government and being juxtaposed to the main stages of the path dependence analytical framework. The study reveals main trends in governmental support for small business and main challenges remaining nowadays. [less ▲]

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See detailLa dette wallonne: développements récents
Piron, Damien ULg; Bayenet, Benoît ULg

Conference (2015, March 11)

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See detailEtude Quatuor
Tostivint, Isabelle; Castiglione, Vincent ULg

Conference (2015, March 11)

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See detailGreen strategies applied to the synthesis of polymer particles for protein delivery
Alaimo, David ULg

Doctoral thesis (2015)

With the recent progresses in biotechnology that enable the production of various peptides and proteins, there is a growing interest for their use as therapeutic agents. Indeed, since the introduction of ... [more ▼]

With the recent progresses in biotechnology that enable the production of various peptides and proteins, there is a growing interest for their use as therapeutic agents. Indeed, since the introduction of the first recombinant therapeutic protein, human insulin, 30 years ago, the interest for pharmaceutical proteins have increased remarkably for various therapeutic purposes. Nevertheless, several challenges still remain such as the preservation of the quite fragile complex protein structure of these proteins to warrant their therapeutic activity after storage and administration into the body. Protecting them against chemical/enzymatic degradation from the environment is a prerequisite to efficiency. To reach this goal and prolong/trigger the release of therapeutic proteins in the body, different carriers were developed and investigated. Among them, polymer nanogels and microcpasules appear as quite promising systems. The thesis focuses on the preparation of novel carriers for protein delivery while using “green” strategies. More precisely, protein carriers are produced by two approaches. The first one investigates the preparation of hydrophilic nanogels by free radical dispersion polymerization of hydroxyethyl methacrylate (HEMA) in supercritical carbon dioxide. The development of dedicated stabilizers efficient in this green medium is thus first considered particularly focussing on the study of the influence of the stabilizer architecture. Then, the optimized candidate is used for the size- controlled nanogels preparation. A strategy allowing the removal of the hydrophobic component of the stabilizer is then investigated based on the synthesis of a photocleavable copolymer. The performances of these as-obtained novel nanogels to load and release proteins is then investigated. In a second approach, the synthesis of protein-loaded microcapsules offering a tunable permeability in response to the external glucose concentration is investigated. For that purpose, the layer-by-layer assembly of dedicated copolymer polyelectrolytes including glucose-sensitive diol/boronic acid bonds was performed on the surface of protein-loaded calcium carbonate particles. After dissolution of the calcium salt, microcapsules able to tune the release of the encapsulated protein in response to glucose concentration are obtained. [less ▲]

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See detailFamilles de tâches en langues modernes : pistes de réflexion et propositions d'outils
Simons, Germain ULg; Pagnoul, Pierre ULg

Conference (2015, March 10)

Cette communication aborde la notion de "familles de tâches" en langues modernes, qui est centrale à l'approche communicative et à l'approche actionnelle préconisée par le CECRL. Dans cette communication ... [more ▼]

Cette communication aborde la notion de "familles de tâches" en langues modernes, qui est centrale à l'approche communicative et à l'approche actionnelle préconisée par le CECRL. Dans cette communication, nous montrons en quoi le document "Familles de tâches en langues modernes" proposé en FWB est important et novateur, mais aussi perfectible. Après avoir présenté le document et une nouvelle modélisation de celui-ci, nous proposons deux dimensions supplémentaires susceptibles d'optimiser le regroupement de tâches complexes en "familles". Nous présentons ensuite des outils d'observation et d'évaluation d'une tâche complexe portant sur un débat de société régulé en anglais/langue étrangère. Des extraits vidéo d'une séquence didactique expérimentale sont présentés et analysés. [less ▲]

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See detail“Rhizoponics”: a novel hydroponic rhizotron for root system analyses on mature Arabidopsis thaliana plants
Mathieu, Laura ULg; Lobet, Guillaume ULg; Tocquin, Pierre ULg et al

Poster (2015, March 10)

Well-developed and functional roots are critical to support plant life and reach high crop yields. Their study however, is hampered by their underground growth and characterizing complex root system ... [more ▼]

Well-developed and functional roots are critical to support plant life and reach high crop yields. Their study however, is hampered by their underground growth and characterizing complex root system architecture therefore remains a challenge. In the model plant Arabidopsis thaliana, in vitro culture remains the easiest and preferred method to study root development, which limits the analyses to young seedlings. We present here an innovative design of hydroponic rhizotron (rhizoponics) designed for the root system analysis of adult plants of Arabidopsis thaliana. [less ▲]

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See detailMicrobiological quality of surface water treated with Moringa oleifera seeds or cakes during the storage : case study of water reservoirs of Loumbila, Ziga and Ouaga 3 Dams in Burkina Faso.
Kabore, Aminata; Savadogo, Boubacar; Otoidobiga, Harmonie C. et al

in Journal of Water Resource and Protection (2015), 7

Water purification with Moringa oleifera seeds has received a lot of attention because it reduces water turbidity and pathogenic microorganisms. However, it is important to define the optimum conditions ... [more ▼]

Water purification with Moringa oleifera seeds has received a lot of attention because it reduces water turbidity and pathogenic microorganisms. However, it is important to define the optimum conditions of storage to preserve the treated water quality. The study aims to investigate microbial quality of water treated with Moringa oleifera seeds or cake coagulants inrelation to the storage temperature and shelf life in order to define the optimum conditions of storage. A total of 45 water samples from 3 water reservoirs of Loumbila, Ziga and Ouaga 3 dams were collected in sterile glass bottles and treated in triplicate with Moringa oleifera seeds or defatted cakes coagulants. Treated water samples obtained at optimum conditions were stored at room temperature (25°C - 30°C) and at 4°C. Fecal bacteria pollution indicators (Escherichia coli, fecal coliforms and fecal streptococcus) and parasites were monitored every 24 hours during three (3) days abased on laboratory standard methods. Data were analyzed using the Student's t-test and XLSTAT 7.5.2 statiscal software. From the results obtained, bacterial indicators increased significantly with storage temperature (p < 0.0001) and shelf life (p < 0.0001). However, for all water samples bacterial growth was more important in samples treated with Moringa oleifera cakes than seeds (p < 0.0001). For water samples treated with Moringa oleifera seeds and stored at room temperature, bacterial increase after 72 hours was 57 - 80, 42 - 50 and 22 - 47 CFU/100 ml for fecal coliforms, E. coli and fecal streptococcus, respectively. With Moringa oleifera cake's treatment, the increase was 63 - 104, 57 - 82 and 28 - 52 for the same indicators, respectively. Bacterial growth was also more important at room temperature than at 4°C. Thus, microbiological quality of water treated with Moringa oleifera seeds was better than cakes whatever storage temperature and shelf life. Overall, water treated with Moringa oleifera seeds should be stored at low temperature and consumed within 24 hours. [less ▲]

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See detailModelling the dynamics of European ecosystems from the early Holocene to the end of the 21st century with the CARAIB dynamic vegetation model
Dury, Marie ULg

Doctoral thesis (2015)

With the current climate change as background, we worked with the dynamic vegetation model CARAIB (CARbon Assimilation In the Biosphere) to study the functioning and dynamics of European ecosystems under ... [more ▼]

With the current climate change as background, we worked with the dynamic vegetation model CARAIB (CARbon Assimilation In the Biosphere) to study the functioning and dynamics of European ecosystems under changing climatic conditions from the beginning of the Holocene to the end of the 21st century. Originally designed to study the role of vegetation in the global carbon cycle and to reconstruct steady state vegetation distributions under current, past and future climatic conditions, we adapt the CARAIB model to perform transient simulations in order to assess vegetation response to changing climate. For this, we improved the demographic processes represented in the model: the conditions for plant establishment, the response to stresses, the competition between species, the species migration, etc. This new version of the model is first described and its main outputs are evaluated using site-based observations, but primarily remote sensing products. The first study carried out with the new version of CARAIB assessed the response of European forest ecosystems to 21st century climate. The classification of the European vegetation in Bioclimatic Affinity Groups (BAGs, Laurent et al., 2008), based on species traits and climatic tolerances and requirements, as well as the fire module recently implemented were for the first time used in future transient projections. The model was first driven by the ARPEGE/Climate model to illustrate and analyse the potential impacts of climate change on forest productivity and distribution as well as fire intensity over Europe under forcing from different IPCC emission scenarios (B1, A1B and A2). The vegetation model projects for the future more frequent and severe droughts in southern Europe. In these areas, the model indicates that interannual variability of net primary productivity might strongly increase as well as wildfire frequency and intensity, which may have large impacts on vegetation density and distribution. In northern Europe and in the Alps, with reduced temperature variability and positive soil water anomalies, NPP variability tends to decrease. The potential CO2 fertilizing effect was studied assuming constant and increasing atmospheric CO2 concentration in the vegetation model. To quantify the uncertainties in the climate projections and in their potential impacts on ecosystems, the vegetation model was also driven by three regional climate models (KNMI-RACMO2, DMI-HIRHAM5 and HC-HadRM3Q0 RCMs) from the European Union project ENSEMBLES. We continued further the analysis representing the European vegetation at the scale of individual species. A set of 99 species (47 herbs, 12 shrubs and 40 trees) have been prepared in such a way that each BAG of plants used in the first part of this work is represented by several of these species. This ensures to provide a full set of species with the major ecosystem functions represented. Like for the BAGs, the bioclimatic limits of the species were obtained by overlapping species distribution from the Atlas Florae Europaeae (AFE) with climatic data. Since the first study highlighted the importance of climatic variability on plant functioning, we used here a 30-yr time series (and not average climate as usually) to determine species establishment and survival conditions. The comparison between the modelled distributions obtained with new climatic thresholds and observed species distribution reveals that taking a longer climatic time series into account improves the predictions of species spatial pattern. Using this improved representation of current species requirements, we projected potential shifts in species distributions for the end of the century. We spatially evaluated the suitability for species establishment and stresses conditions as well as the disappearance and the potential appearance of species. 18% of tree species and 22% of herb and shrub species (respectively 30% and 64% if the CO2 fertilization effect on species is not taken into account) might experience a loss of 30% or more of their current distribution. Finally we combined different model outputs in an original index evaluating the risk of ecosystem disruption to assess the vulnerability of species and ecosystems to future climate change. The highest values of the index are found in southern Europe indicating that the amplitude of the expected ecosystem changes largely exceeds current interannual variability in this area. If climate is one of the main drivers of species dynamics, rapid climate changes as projected for the 21st century might prevent species to track suitable climatic conditions and fill their potential ranges impeded by dispersal capacity. To assess the actual response of vegetation to climate change, we introduced a species migration module in the dynamic vegetation model. Its calibration and evaluation have been performed on the Holocene period considered as an interesting homologue to current climate change, even if the change rate must have been lower. With the module, we studied the postglacial re-colonization of Europe by two tree species Fagus sylvatica and Picea abies. Using maximum potential migration rates (381 and 450 m yr-1 for beech and spruce) calculated by a species distribution model dealing with demographic and dispersal traits, we evaluated with the dynamic vegetation model the involvement of inter-specific competition but also of high climatic variability on species spatio-temporal dynamics. Considering these abiotic and biotic variables in the migration processes resulted in mean migration rates of 91 (± 38) and 131 (± 73) m yr-1 respectively for Fagus sylvatica and Picea abies. If the comparison with palaeorecords demonstrates the ability of such an approach to reasonably replicate the regional features of the species spatio- temporal progressions, the objective was not to reproduce accurately postglacial species history (still not well known and understood) but rather to determine the relative role of some environmental variables on the migration of the two species through different migration scenarii. It appeared that Holocene beech migration might have been strongly affected by interspecific competition while it is climatic conditions and their variability that might have conditioned the spruce migration. With the different scenarios, we showed that mono-causal explanations cannot however explain the observed timing and pattern at the European scale and we rather give preference to a combination of climate, dispersal and competitive factors, the potential role of anthropogenic disturbances being not studied here. [less ▲]

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See detailLes génériques d’antibiotiques : une fausse bonne idée ?
Van Hees, Thierry ULg

Scientific conference (2015, March 10)

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See detailUn collectif en construction : le cas du CRISdoc
Bastard, Joséphine ULg; Beuker, Laura ULg; Colemans, Julie ULg et al

Conference (2015, March 10)

Cette communication vise à s’interroger sur la construction de l’identité professionnelle du chercheur en sciences humaines et sociales à travers la construction d’un collectif spontané émanant de jeunes ... [more ▼]

Cette communication vise à s’interroger sur la construction de l’identité professionnelle du chercheur en sciences humaines et sociales à travers la construction d’un collectif spontané émanant de jeunes chercheurs : le CRISdoc. Le Centre de Recherche et d’Interventions Sociologiques (CRIS) est un laboratoire rattaché à l’Institut des Sciences Humaines et Sociales de l’Université de Liège (Belgique). Créé dans le courant des années 1990, le CRIS s’est développé au départ d’un petit groupe de chercheurs mus par une même conception de la sociologie ; héritage de leurs liens étroits avec le Centre de Sociologie des Organisations (CSO). Ce laboratoire s’est progressivement étendu et diversifié en intégrant notamment des chercheurs en criminologie. Il est composé aujourd’hui de six académiques, deux chercheurs post-doctoraux, trois assistants et douze doctorants, ainsi que d’une multitude de chercheurs associés. Au sein du laboratoire, un groupe de travail baptisé « CRISdoc » a récemment vu le jour. Il est composé d’une dizaine de chercheurs (doctorants et post-doctorants). Il s’agit de comprendre les raisons d’être d’un tel collectif, de décrire les caractéristiques de ses membres et les objectifs inhérents à cette démarche. Le métier de chercheur, et particulièrement le processus doctoral, est un travail essentiellement solitaire. A l’exception des interactions avec son promoteur, au cours desquelles les lignes directrice de la thèse s’élaborent progressivement, le doctorant réalise son terrain seul, et traite seul de son objet de recherche. Notre lieu de travail nous rapproche cependant. Quoique nous soyons rarement tous présents, étant donné les impératifs de notre travail de terrain, nous partageons un même couloir. Celui-ci est le point de départ d’autres rencontres informelles Bien qu’étant rarement présents tous au même moment, du fait de nos impératifs empiriques et du fonctionnement relativement informel du service, nous entretenons des relations interpersonnelles régulières, à travers des activités au contenu professionnelles (séminaires, formations) mais surtout extraprofessionnelles (temps de midi, repas organisés par l’institution ou par nos soins, apéritifs improvisés, etc.). Ces échanges sont la preuve que nous ne sommes pas seuls. Pour autant, ils n’offrent que de rares occasions de procéder à de réels échanges de fond structurés. Depuis plusieurs mois, de nombreuses discussions informelles ont traité de cet aspect, et du fait qu’au-delà de nos différences apparentes, nous vivons en partie les mêmes expériences, questionnements, ou obstacles. En outre, nous partageons régulièrement, sans forcément y penser ou en parler, des cadres théoriques ou des méthodes de travail similaires. Peu à peu, l’idée de se réunir autour de ces différents sujets a commencé à germer. Le premier défi auquel nous devions faire face était étroitement lié à l’hétérogénéité du collectif. Nos profils sont, en effet, contrastés et de nombreuses caractéristiques sont à prendre en compte : l’âge (de 24 à 35 ans), la formation (sociologie, gestion des ressources humaines, sciences du travail, sciences politiques, langues romanes, histoire, droit, gestion de projets), le promoteur (cinq différents, avec leurs propres sensibilités théoriques), le type de recherche (fondamentale ou commanditée), le financement (FNRS, FRFC, ARC, PAI, BRAIN, assistanat), le champ de recherche (police, justice, enseignement, santé, emploi), l’expérience (début/milieu/fin de thèse, post-doctorat, contrats de recherche antérieurs), etc. Comment dès lors parvenir à créer un espace commun de travail et de réflexion ? Notre première réunion formelle était destinée à délimiter les contours et les objectifs de réunions futures. Malgré cette diversité, notre première rencontre a permis de distinguer une série de thématiques communes et de fixer un calendrier afin d’échanger sur différents sujets tels que l’organisation du travail empirique, l’articulation entre les apports théoriques et empiriques, la rupture épistémologique et le retour aux acteurs concernés, ou encore la distanciation par rapport au projet initial et au promoteur. À raison d’une rencontre par mois environ, réparties sur la présente année académique, nous procédons à un partage de connaissances, d’expériences et de conseils. Le séminaire « CRISdoc » est né. Reste la question des objectifs poursuivis, individuels et collectifs, explicites et implicites, d’une telle démarche. Tout d’abord, nous aspirons pour la plupart à partager nos questionnements, nos expériences afin de surmonter les obstacles rencontrés ou plus simplement de parfaire notre apprentissage du métier de chercheur. Nous considérons notre hétérogénéité comme une richesse dont chacun peut se nourrir individuellement : les plus expérimentés partageant leur vécu, les plus jeunes apportant un regard neuf. Ensuite, le CRISdoc remplit une série de fonctions secondaires, mais non moins importantes car il permet de partager ses doutes, craintes, déceptions, impasses, de relativiser ou démystifier la recherche, le tout dans une ambiance conviviale, peu contraignante et en dehors de toute pression ou jugement hiérarchique. Enfin, la question du collectif en lui-même reste ouverte : au-delà de la rencontre de nos intérêts individuels, la démarche participe-t-elle à l’émergence d’un véritable collectif, d’une identité « doctorant » au sein du service ? Ou ce partage n’est-il qu’une occasion supplémentaire de renforcer le caractère individuel de notre métier ? S’il est actuellement difficile d’y répondre de façon précise, ces interrogations conservent toute notre attention. Dès lors, cette communication vise à s’interroger de manière descriptive et réflexive sur ce processus de construction de l’identité professionnelle à un niveau individuel et collectif. [less ▲]

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See detailBaryon resonances in large Nc QCD
Matagne, Nicolas; Stancu, Floarea ULg

in Reviews of Modern Physics (2015), 87

We review the current status and present open challenges of large $N_c$ QCD baryon spectroscopy. After introducing the $1/N_c$ expansion method we first shortly revisit the latest achievements for the ... [more ▼]

We review the current status and present open challenges of large $N_c$ QCD baryon spectroscopy. After introducing the $1/N_c$ expansion method we first shortly revisit the latest achievements for the ground state properties. Next we discuss the applicability of this method to excited states, presenting two different approaches with their advantages and disadvantages. Selected results for the spectrum and strong and electromagnetic decays are described. We also present further developments for the applicability of the method to excited states, based on the qualitative compatibility between the quark excitation picture and the meson-nucleon scattering picture. We show that a quantitative comparison between results obtained from the mass formula of the $1/N_c$ expansion method and quark models brings convincing support to quark models and shortly discuss the implications of different large $N_c$ limits. We stress that the SU(6) spin-flavor structure of large $N_c$ baryon allows a convenient classification of highly excited resonances into SU(3) multiplets and predicts mass ranges for the missing partners. [less ▲]

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