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See detailTowards a comprehensive C-budgeting approach of a coccolithophorid bloom in the Northern Bay of Biscay (June 2006)
Harlay, Jérôme ULg; Borges, Alberto ULg; De Bodt, Caroline et al

Poster (2009, January 25)

A biogeochemical multidisciplinary survey was carried out in the northern Bay of Biscay, in early June 2006, during which 14C-based primary production and calcification were determined as well as O2-based ... [more ▼]

A biogeochemical multidisciplinary survey was carried out in the northern Bay of Biscay, in early June 2006, during which 14C-based primary production and calcification were determined as well as O2-based community respiration. Contemporary remote sensing images showed several patches of high reflectance (HR) in the investigated area. Based on remote sensing and in situ measured biogeochemical parameters, the area exhibited varying coccolithophorid bloom stages from its early development to the post-bloom stages. The major HR patch, characterizing a post-stationary stage of the bloom, was located between 48°N and 49°N over the shelf along the continental margin. It was associated with moderate chlorophyll-a levels, never exceeding 1.0 µg L-1, dissolved phosphorus and silica depletion, and undersaturation of CO2 with respect to atmospheric equilibrium. Considered as the main drivers of the C cycle in this area, the CO2 fluxes associated with primary production, calcification and respiration were integrated in order to provide a comprehensive C budget in the area. [less ▲]

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See detailCell lysis during coccolithophorid blooms in the Northern Bay of Biscay
De Bodt, Caroline; Harlay, Jérôme ULg; Roevros, Nathalie et al

Poster (2009, January 25)

Phytoplankton cell lysis occurs in natural populations and is often associated with viral activity and zooplankton grazing. Cell lysis rates are expected to increase towards the decaying phase of the ... [more ▼]

Phytoplankton cell lysis occurs in natural populations and is often associated with viral activity and zooplankton grazing. Cell lysis rates are expected to increase towards the decaying phase of the bloom and may be associated with enhanced microbial activity and export of particulate matter to the seafloor. Their estimation was based on the measurement of esterase (a cytoplasmic enzyme) activity expected to appear in the water only after cell breakage. Field investigations, supported by remote sensing data, were conducted in recent years during late spring in the Northern Bay of Biscay, where frequent and recurrent coccolithophorid blooms are observed. Results on cell lysis rates determined in surface waters will be presented with relevant biogeochemical parameters (temperature, particulate organic and inorganic carbon, transparent exopolymer particles, nutrients, chlorophyll a) in order to investigate phytoplankton dynamics in relation to coccolithophorid development. The use of this parameter to characterize bloom termination, especially during coccolithophorid blooms will be discussed. [less ▲]

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See detailLe rôle du pharmacien clinicien dans un service de gériatrie
Van Hees, Thierry ULg

Conference given outside the academic context (2009)

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See detailElectrografting method for forming and regulating a strong adherent nanostructured polymer coating
Voccia, Samuel; Serwas, Harry ULg; Jérôme, Christine ULg et al

Patent (2009)

Electrografting method for forming and regulating a strongly adherent nanostructured polymer coating onto an electro-conductive surface profile characterized in that the surface profile is regulated by ... [more ▼]

Electrografting method for forming and regulating a strongly adherent nanostructured polymer coating onto an electro-conductive surface profile characterized in that the surface profile is regulated by electrodeposition of nanometre- and/or micrometre-scale nuclei onto the surface profile prior to or simultaneously to the formation of the polymer coating. [less ▲]

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See detailA Distributed Lattice Boltzmann-based Flow Simulator
Dethier, Gérard ULg

Conference (2009, January 22)

The use of Lattice Boltzmann (LB) methods is interesting to describe flows through complex geometries encountered in Chemical Engineering (porous media, packed beds, multi phase flows). However, flow ... [more ▼]

The use of Lattice Boltzmann (LB) methods is interesting to describe flows through complex geometries encountered in Chemical Engineering (porous media, packed beds, multi phase flows). However, flow simulations based on LB methods can require big amounts of memory. It is not always possible to run a simulation on a single machine. Distributed computing is a solution to this problem and also accelerates the execution of the flow simulation. In the context of dynamic heterogeneous clusters, the available machines can have different computational powers. The computational power of each machine can vary during a flow simulation (because of background load). Also, the number of available machines can change. These characteristics impose the use of special technics. Dynamic Load Balancing allows the optimal use of available machines. A fault occurs when one or several machines interrupt the execution of the distributed software component they were executing. Checkpointing makes the system fault tolerant. In order to obtain a scalable software and to suppress single points of failure, a special effort is made to decentralize as much as possible the software components of the simulator. Currently, fluid flows of 400³ points (more than 9 GBytes of data) are simulated using an heterogeneous cluster of 54 machines. [less ▲]

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See detailSynthesis of an universal linker to label oligonucleotides via Click Chemistry
Flagothier, Jessica ULg; Mercier, Frederic; Kaisin, Geoffroy ULg et al

Poster (2009, January 21)

For more than 3 decades, oligonucleotides have been used for therapies, imaging and diagnostics. They are known to hybridize specifically with RNA of a complementary sequence on tissue sections and more ... [more ▼]

For more than 3 decades, oligonucleotides have been used for therapies, imaging and diagnostics. They are known to hybridize specifically with RNA of a complementary sequence on tissue sections and more recently to block the expression of target mRNA when administered in vivo (1). Positron emission Tomography (PET) is a sensitive and non invasive imaging technique, and is the most advanced technology currently available for studying in vivo molecular interactions and therapeutic agents. It is a method of choice to assess the pharmacokinetics of new therapeutics agents such as modified oligonucleotides. Among positron-emitting nuclides, fluorine-18 (t1/2 = 109.8 min) appears to be the best candidate due to its favourable physical and nuclear properties. Several of the methods described in the literature to label oligonucleotides present a number of disadvantages (time of synthesis, low overall radiolabelling yield, non-universal). Due to the speed, selectiveness and the relatively mild experimentals conditions, “Click” chemistry seems a powerful technique. The most explored Click reaction is Huisgen 1,3 dipolar cycloaddition. In our case, this reaction occurs between an alkyne group presents on the oligonucleotide and an azide group on the 18F labelled prosthetic group. The originality of our strategy is the use of a universal linker diverted from the trans-4-hydroxy-proline directly connected to the oligonucleotide. This linker mimics a sugar of the oligonucleotide sequence and should improve their resistance to exonucleases. Synthesis of this compound will be presented. [less ▲]

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See detailL’appropriation par des futurs formateurs d’enseignants d’une démarche d’accompagnement réflexif : Analyse critique des critères d’évaluation.
Beckers, Jacqueline ULg; Van der Linden, Sylvie ULg

Conference (2009, January 21)

Cette communication portera sur une approche évaluative du développement professionnel de futurs formateurs d’enseignants (FF). Dans le cadre d’un module de formation du master en Sciences de l’Education ... [more ▼]

Cette communication portera sur une approche évaluative du développement professionnel de futurs formateurs d’enseignants (FF). Dans le cadre d’un module de formation du master en Sciences de l’Education de l’université de Liège (ULg – Belgique), ceux-ci sont préparés à accompagner professionnellement de futurs enseignants (FE) selon une démarche de « supervision réflexive » (Beckers, 2007) inspirée des travaux de Schön (1983) et de Vermersch (1994, 2004) et complétée par l’apport de la didactique professionnelle (Pastré 2005, 2008 ). Il s’agit à la fois de maximiser les occasions pour le FE de prendre conscience de son modèle opératif en situation professionnelle et d’augmenter l’adéquation de son action par meilleure appréhension de la structure conceptuelle de ces situations en regard des buts prioritaires du métier. Cette compétence est à la fois travaillée à l’ULg (en séances collectives, individuelles et en petits groupes) et sur le terrain où les FF accompagnent les FE en stage (cette année, en classes préscolaires). Le travail théorique et pratique de la démarche de supervision réflexive avec les futurs formateurs a débouché sur la clarification de critères de qualité de l’accompagnement visé. Ceux-ci sont appliqués par les formateurs ULg aux données brutes de l’ accompagnement mené par chaque FF (traces retranscrites des entretiens de régulation et rédaction du carnet de bord). Ils sont également utilisés en auto-évaluation par les FF à propos de leur accompagnement. Cette double démarche d’évaluation (hétéro-évaluation et auto-évaluation) alimente une partie de la séance de « confrontation herméneutique » qui réunit chaque FF et les deux formateurs ULg après lecture par ceux-ci de tous les documents (données brutes et rapports). Cette partie du travail permet d’approcher le degré d’appropriation de la compétence d’accompagnement par le FF (genèse instrumentale et conceptuelle – Pastré, 2005). Chaque FF produit également un rapport qui porte sur l’analyse de l’accompagnement qu’il a mené, en interaction avec les caractéristiques contextuelles, et sur l’évolution qu’il a pu observer chez son compagnon FE du point du développement de ses compétences professionnelles et de sa construction identitaire. La discussion de ces analyses alimente la deuxième partie de la « confrontation herméneutique » ; elle permet d’approcher davantage une éventuelle genèse identitaire (Pastré, 2005). L’analyse critique de ces multiples sources d’information et la triangulation des données alimentera la réflexion sur la pertinence des outils et des démarches d’évaluation de ces processus complexes que sont le développement des compétences et de l’identité professionnelles. [less ▲]

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See detailSolute transport modelling at the groundwater body scale: Nitrate trends assessment in the Geer basin (Belgium)
Orban, Philippe ULg

Doctoral thesis (2009)

Water resources management is now recognized as a multidisciplinary task that has to be performed in an integrated way, within the natural boundaries of the hydrological basin or of the aquifers. Policy ... [more ▼]

Water resources management is now recognized as a multidisciplinary task that has to be performed in an integrated way, within the natural boundaries of the hydrological basin or of the aquifers. Policy makers and water managers express a need to have tools able at this regional scale to help in the management of the water resources. Until now, few methodologies and tools were available to assess and model the fate of diffuse contaminants in groundwater at the regional scale. In this context, the objective of this research was to develop a pragmatic tool to assess and to model groundwater flow and solute transport at the regional scale. A general methodology including the acquisition and the management of data and a new flexible numerical approach was developed. This numerical approach called Hybrid Finite Element Mixing Cell (HFEMC) was implemented in the SUFT3D simulator developed by the Hydrogeology Group of the University of Liège. A first application of this methodology was performed on the Geer basin. The chalk aquifer of the Geer basin is an important resource of groundwater for the city of Liège and its suburbs. The quality of this groundwater resource is threatened by diffuse nitrate contamination mostly resulting from agricultural practices. New field investigations were performed in the basin to better understand the spatial distribution of the nitrate contamination. Samples were taken for environmental tracers (tritium, CFC’s and SF6) analysis. The spatial distribution of environmental tracers concentrations is in concordance with the spatial distribution of nitrates. This allows proposing a coherent interpretative schema of the groundwater flow and solute transport at the regional scale. These new data and the results of a statistical nitrate trend analysis were used to calibrate the groundwater model developed with the HFEMC approach. This groundwater flow and solute transport model was used to forecast the evolution of nitrate concentrations in groundwater under a realistic scenario of nitrate input for the period 2008-2058. According to the modelling results, upward nitrate trends observed in the basin will not be reversed for 2015 as prescribed by the EU Water Framework Directive. The regional scale groundwater solute transport model was subsequently used to compute nitrate concentrations in groundwater under different scenarios of nitrate input to feed a socio-economic analysis performed by BRGM. These computed concentrations were used to assess the benefit, for the users, linked to the reduction of contamination resulting from the changes in nitrate input. These benefits were compared to the costs associated to the implementation of the considered agri-environmental schemes that allow reducing the nitrate input to groundwater. [less ▲]

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See detailL'Enseignement militaire à l'épreuve de l'européanisation Adaptation de la Politique de l'enseignement pour l'Ecole Royale Militaire de Belgique aux évolutions de la PESD
Paile, Sylvain ULg

in Thématique du Centre des Sciences Sociales de la Défense (2009), 19

Publication made from the report of the research for the Belgian Federal Science Policy (SPF) "Adaptation of the education policy for the Royal Military Academy to the evolution of the Common European ... [more ▼]

Publication made from the report of the research for the Belgian Federal Science Policy (SPF) "Adaptation of the education policy for the Royal Military Academy to the evolution of the Common European Security and Defence Policy" (April 2007- March 2008). [less ▲]

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See detailVisual Backgound Extractor
Van Droogenbroeck, Marc ULg; Barnich, Olivier ULg

Patent (2009)

ViBe is a powerful pixel-based technique that detects the background in video sequences. Many experiments have shown that it performs better than the state-of-the-art techniques known in the scientific ... [more ▼]

ViBe is a powerful pixel-based technique that detects the background in video sequences. Many experiments have shown that it performs better than the state-of-the-art techniques known in the scientific literature. In addition the computational load is lower than simple background techniques implemented in commercial products. ViBe is the perfect solution for both softwares and hardware implementations. [less ▲]

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See detailSynthesis and pH-dependent micellization of diblock copolymer mixtures
Van Butsele, Kathy ULg; Sibret, Pierre ULg; Fustin, Charles-André et al

in Journal of Colloid & Interface Science (2009), 329(2), 235-243

This work focused on the preparation and the aqueous solution properties of hybrid polymeric micelles consisting of a hydrophobic poly(ε-caprolactone) (PCL) core and a mixed shell of hydrophilic poly ... [more ▼]

This work focused on the preparation and the aqueous solution properties of hybrid polymeric micelles consisting of a hydrophobic poly(ε-caprolactone) (PCL) core and a mixed shell of hydrophilic poly(ethylene oxide) (PEO) and pH-sensitive poly(2-vinylpyridine) (P2VP). The hybrid micelles were successfully prepared by the rapid addition of acidic water to a binary solution of PCL34-b-PEO114 and PCL32-b-P2VP52 diblock copolymers in N,N-dimethylformamide. These micelles were pH-responsive as result of the pH-dependent ionization of the P2VP block. The impact of pH on the self-assembly of the binary mixture of diblocks—thus on the composition, shape, size and surface properties of the micelles—was studied by a variety of experimental techniques, i.e., dynamic and static light scattering, transmission electron microscopy, Zeta potential, fluorescence spectroscopy and complement hemolytic 50 test. [less ▲]

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See detailPerspectives pour une sémantique des objets discursifs
Stienon, Valérie ULg

in Fabula (2009), 10(1),

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See detailLa réforme du Fonds des Communes
Husson, Jean-François ULg

Conference given outside the academic context (2009)

Conférence pour des décideurs publics et privés intéressés par le développement de la région namuroise portant sur la réforme du Fonds des communes (dispositif de transfert destiné aux financement général ... [more ▼]

Conférence pour des décideurs publics et privés intéressés par le développement de la région namuroise portant sur la réforme du Fonds des communes (dispositif de transfert destiné aux financement général des communes wallonnes) et ses conséquences. [less ▲]

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See detailGroundwater flow modelling in the central zone of Hanoi, Vietnam
Jusseret, Simon; Vu, Thanh Tam; Dassargues, Alain ULg

in Hydrogeology Journal (2009), 17(4), 915-934

On the basis of a review of the Quaternary sedimentary architecture in the area of Hanoi city (Vietnam), a numerical, deterministic and three-dimensional groundwater flow model has been built for a ... [more ▼]

On the basis of a review of the Quaternary sedimentary architecture in the area of Hanoi city (Vietnam), a numerical, deterministic and three-dimensional groundwater flow model has been built for a simulation between 1995 and 2004. The sedimentary architecture has been constructed on the basis of the data from 32 drillings covering the entire Quaternary sequence (but with little sedimentological detail), as well as hydrographical and hydrogeological data. Both steady- and transient-state conditions were tested. Results calculated by the model seem to indicate that the conceptual hypotheses adopted are reasonable for the modelled domain and period. The simulation allows for calculation of the regional groundwater flow trends. It is also used for assessing the relative importance of the various recharge sources of the shallow aquifer system in Hanoi, and for estimating the interactions between groundwater and the Red River. [less ▲]

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See detailSur le concept de "valeur pure"
Sofia, Estanislao ULg

in Letras & Letras (2009), 25(1), 13-38

The concept of « value », in Saussure’s theory, could receive many interpretations, all of them legitimately based on manuscripts. This paper takes but one of those possible lectures: the one which ... [more ▼]

The concept of « value », in Saussure’s theory, could receive many interpretations, all of them legitimately based on manuscripts. This paper takes but one of those possible lectures: the one which pretends that the notion of “value” is theoretically equivalent to [?] the notion of “pure difference”. The aim is to analyze such formulas in order to seize their conceptual scope, then to measure the possible articulations. We will see how this formula (this conception of “value”) bears some difficulties and goes against others saussurians positions, even concerning that same concept of “value”. [less ▲]

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See detailNouvelles relations entre scientifiques et communautés locales dans la gestion des aires protégées
Escobar Jimenez, Kelly ULg

Poster (2009, January 09)

L'exploration de nouvelles relations entre communautés locales et milieux scientifique se concentre sur: un processus: la prise de décisions sur les limites, les espèces et les communautés responsables ou ... [more ▼]

L'exploration de nouvelles relations entre communautés locales et milieux scientifique se concentre sur: un processus: la prise de décisions sur les limites, les espèces et les communautés responsables ou “bénéficiaires” des aires protégées en Amazonie Équatorienne; sur une autorité: les concepts techniques et scientifiques sur les caractéristiques et la gestion des aires protégées en AL, notamment en Amazonie Équatorienne; et sur des relations: la gestion des aires protégées constitue-t-elle un scénario de nouvelles relations entre scientifiques et communautés locales, vu les démarches participatives généralisées en Amérique latine ? [less ▲]

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See detailPopovic (Pierre), Imaginaire social et folie littéraire. Le second Empire de Paulin Gagne
Sindaco, Sarah ULg

in COnTEXTES : Revue de Sociologie de la Littérature (2009)

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See detailPaclitaxel-loaded PEGylated PLGA-based nanoparticles: in vitro and in vivo evaluation
Danhier, Fabienne; Lecouturier, Nathalie; Vroman, Benoît et al

in Journal of Controlled Release (2009), 133(1), 11-17

The incorporation efficiency of PTX was higher with the nanoprecipitation technique. The release behavior of PTX exhibited a biphasic pattern characterized by an initial burst release followed by a slower ... [more ▼]

The incorporation efficiency of PTX was higher with the nanoprecipitation technique. The release behavior of PTX exhibited a biphasic pattern characterized by an initial burst release followed by a slower and continuous release. The in vitro anti-tumoral activity was assessed using the Human Cervix Carcinoma cells (HeLa) by the MTT test and was compared to the commercial formulation Taxol® and to Cremophor® EL. When exposed to 25 µg/ml of PTX, the cell viability was lower for PTX-loaded nanoparticles than for Taxol® (IC50 5.5 vs 15.5 µg/ml). Flow cytometry studies showed that the cellular uptake of PTX-loaded nanoparticles was concentration and time dependent. Exposure of HeLa cells to Taxol® and PTX-loaded nanoparticles induced the same percentage of apoptotic cells. PTX-loaded nanoparticles showed greater tumor growth inhibition effect in vivo on TLT tumor, compared with Taxol®. Therefore, PTX-loaded nanoparticles may be considered as an effective anticancer drug delivery system for cancer chemotherapy. [less ▲]

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See detailLimnological variability and pelagic fish abundance (Stolothrissa tanganicae and Lates stappersii) in Lake Tanganyika
Plisnier, P. D.; Mgana, H.; Kimirei, I. et al

in Hydrobiologia (2009), 625(1), 117-134

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See detailNew light on the driving mechanism in roAp stars. I. Effects of metallicity
Théado, S.; Dupret, Marc-Antoine ULg; Noels-Grötsch, Arlette ULg et al

in Astronomy and Astrophysics (2009), 493

Context: Observations suggest that a relationship exists between the driving mechanism of roAp star pulsations and the heavy element distribution in these stars. Aims: We attempt to study the effects of ... [more ▼]

Context: Observations suggest that a relationship exists between the driving mechanism of roAp star pulsations and the heavy element distribution in these stars. Aims: We attempt to study the effects of local and global metallicity variations on the excitation mechanism of high order p-modes in A star models. Methods: We developed stellar evolutionary models to describe magnetic A stars with different global metallicity or local metal accumulation profiles. These models were computed with CLES (``Code Liègeois d'évolution stellaire''), and the stability of our models was assessed with the non-adiabatic oscillation code MAD. Results: Our models reproduce the blue edge of the roAp star instability strip, but generate a red edge hotter than the observed one, regardless of metallicity. Surprisingly, we find that an increase in opacity inside the driving region can produce a lower amount of driving, which we refer to as the ``inverse kappa-mechanism''. [less ▲]

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