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See detailQuantitative and qualitative hydrogeological study of the alluvial aquifer of Somes-Szamos (RO-HU) NATO SfP Project 973684 SQUASH
Dassargues, Alain ULg; Lenart, Laszlo; Drobot, Radu

in Hidrotehnica (2004), 49(9-10), 3-7

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See detailCrystal structure of the C47S mutant of human peroxiredoxin 5
Evrard, Christine ULg; Smeets, Aude; Knoops, Bernard et al

in Journal of Chemical Crystallography (2004), 34

In the crystal structure of the reduced form of the wild-type human peroxiredoxin 5, the presence of a benzoate ion in direct interaction with the peroxidatic cysteine (Cys 47) appeared as a rather ... [more ▼]

In the crystal structure of the reduced form of the wild-type human peroxiredoxin 5, the presence of a benzoate ion in direct interaction with the peroxidatic cysteine (Cys 47) appeared as a rather intriguing feature since it is known that the benzoate ion can play the role of a specific hydroxyl radical scavenger. The crystal structure of the C47S mutant of the same enzyme has been crystallized in the tetragonal system, space group P41212, with a = 65.65 Å, c = 122.04 Å. It confirms the presence of this benzoate ion in spite of the mutation into a serine of the Cys 47 residue to which the benzoate ion was directly linked in the wild-type structure. The benzoate ion seems to be stabilized by hydrophobic contacts on both sides of the aromatic ring. In this matter, the α5 helix, which is specific to peroxiredoxin 5 among mammalian peroxiredoxins, plays an important role. These hydrophobic contacts also allow to suggest why the benzoate ion disappears when the molecule is oxidized. [less ▲]

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See detailCrystal structure of a dimeric oxidized form of human peroxiredoxin 5
Evrard, Christine ULg; Capron, Arnaud; Marchand, Cécile et al

in Journal of Molecular Biology (2004), 337

Peroxiredoxin 5 is the last discovered mammalian member of an ubiquitous family of peroxidases widely distributed among prokaryotes and eukaryotes. Mammalian peroxiredoxin 5 has been recently classified ... [more ▼]

Peroxiredoxin 5 is the last discovered mammalian member of an ubiquitous family of peroxidases widely distributed among prokaryotes and eukaryotes. Mammalian peroxiredoxin 5 has been recently classified as an atypical 2-Cys peroxiredoxin due to the presence of a conserved peroxidatic N-terminal cysteine (Cys47) and an unconserved resolving C-terminal cysteine residue (Cys151) forming an intramolecular disulfide intermediate in the oxidized enzyme. We have recently reported the crystal structure of human peroxiredoxin 5 in its reduced form. Here, a new crystal form of human peroxiredoxin 5 is described at 2.0 Ǻ resolution. The asymmetric unit contains three polypeptide chains. Surprisingly, beside two reduced chains, the third one is oxidized although the enzyme was crystallized under initial reducing conditions in presence of 1 mM 1,4-dithio-DL-threitol. The oxidized polypeptide chain forms an homodimer with a symmetry related one through intermolecular disulfide bonds between Cys47 and Cys151. The formation of these disulfide bonds is accompanied by the partial unwinding of the N-terminal parts of the a2 helix, which in the reduced form, contains the peroxidatic Cys47 and the α6 helix, which is sequentially close to the resolving residue Cys151. In each monomer of the oxidized chain, the C-terminal part including the α6 helix is completely reorganized and is isolated from the rest of the protein on an extended arm. In the oxidized dimer, the arm belonging to the first monomer now appears at the surface of the second subunit and vice versa. [less ▲]

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See detailDrying up of a natural spring for ensuring stability of an artificial slope: is it sustainable development ?
Dachy, Marie; Sage, Sandrine; Dassargues, Alain ULg

in Hack, R.; Azzam, R.; Charlier, Robert (Eds.) Engineering geology for infrastructure planning in Europe (2004)

Near a small city of the Belgian ‘Ardennes’ (East of Belgium), modification of a natural slope for extension of industrial activities has required an extensive drainage in a weathered zone composed of ... [more ▼]

Near a small city of the Belgian ‘Ardennes’ (East of Belgium), modification of a natural slope for extension of industrial activities has required an extensive drainage in a weathered zone composed of colluvium and weathered claystones and quartzites. After a few days, the drain at the foot of the artificial slope was producing about 1000 m3/day while a natural spring located at a 200 m distance on the hillside was completely dried up. This spring was used for drinking water by the local community. A shallow geophysical prospection by refraction seismics and 2D geoelectrical tomography, associated to geological, morphostructural and hydrogeological observations have lead to a clear understanding of (1) the spring occurrence; (2) the feeding conditions of the spring and consequently (3) the ‘lateral’ hydraulic impact of the drain. In the hill, the bedrock is changing from quartzites (uphill) to claystones (downhill) inducing changes in hydraulic conductivity and thickness of the overlying weathered zone. On the basis of these hydrogeological conditions, associated to the specific topographic conditions, different possible remediation schemas have been proposed to the decision makers. Unfortunately, the full restoration of the natural spring appears to be one of the most technically and financially difficult option …while it is surely the most suitable in the name of a sustainable development. [less ▲]

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See detailMycosis fungoides progression and chronic solvent exposure
Nikkels, Arjen ULg; Quatresooz, Pascale ULg; Delvenne, Philippe ULg et al

in Dermatology : International Journal for Clinical & Investigative Dermatology (2004), 208(2), 171-173

The effect of repeated exposure to specific chemicals on the initiation or progression of mycosis fungoides (MF) remains unsettled. A patient with low-grade patch stage MF progressively developed MF ... [more ▼]

The effect of repeated exposure to specific chemicals on the initiation or progression of mycosis fungoides (MF) remains unsettled. A patient with low-grade patch stage MF progressively developed MF plaques restricted to his arms, and a tumour on his right thigh. These areas were subject to repeated exposure to solvents. His thigh was indeed in close contact with his trousers pocket where he used to store a wiping rag drenched into white spirit and cellulosic thinner. Immunophenotyping these lesions revealed a dense LCA+, CD2+, CD3+, CD4+, CD5+, CD7+, CD45+, CD45RO+ T-cell infiltrate admixed with many factor XIIIa+ dendrocytes. T-cell receptor rearrangement analysis identified a monoclonal T-cell infiltrate. An internal work-up remained negative. Stopping further solvent exposure failed to improve his condition. Oral corticotherapy combined with low-dose interferon-alpha2a halted disease progression. This observation suggests that long-term solvent exposure may trigger MF and hasten its progression from the patch stage to the plaque and tumour stages. Copyright (C) 2004 S. Karger AG, Basel. [less ▲]

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See detailField campaigns: pumping tests and tracer tests
Brouyère, Serge ULg; Bretotean, Mihai; Minciuna, Marin-Nelu et al

in Hidrotehnica (2004), 49(9-10), 36-50

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See detailLa Belgique et le Groupe des Quatre en matière de défense
Dumoulin, André ULg

in Courrier hebdomadaire du CRISP (2004), 1862-1863

En avril 2003, quatre pays (Belgique, France, Allemagne, Luxembourg) avaient proposé d’approfondir les questions de sécurité et de défense au profit de l’Union européenne et de l’OTAN. Cette initiative ... [more ▼]

En avril 2003, quatre pays (Belgique, France, Allemagne, Luxembourg) avaient proposé d’approfondir les questions de sécurité et de défense au profit de l’Union européenne et de l’OTAN. Cette initiative, d’origine belge, se heurta aux réticences des Etats-Unis et des pays européens les plus anglophiles dans la mesure où elle fut présentée au beau milieu de la crise transatlantique et intra-européenne à propos de la guerre en Irak. Mais derrière les propositions du « groupe des chocolatiers » comme on les surnomma avec dédain, se profilaient des propositions audacieuses de renforcement de la politique européenne de sécurité et de défense. Pour l’essentiel, toutes les propositions du Groupe des Quatre furent adoptées par le Conseil de l’Union européenne, les capitales et sont même, pour la plupart, inscrites dans le traité de Lisbonne : cellule civilo-militaire de planification, Agence européenne de l’armement, coopération structurée permanente en matière de défense, clause d’assistance, extension des missions de l’Union européenne, Académie européenne de sécurité et de défense, etc. [less ▲]

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See detailMaintien et stratégies de renforcement de la motivation des étudiants dans l'enseignement à distance
Mignon, Jacques ULg; Closset, Jean-Louis ULg

in Actes du 21e congrès de l’Association internationale de pédagogie universitaire (AIPU) (2004)

L'exploitation des nouvelles technologies dans la mise sur pied d'un enseignement à distance s'accompagne nécessairement d'une réflexion pédagogique structurée. Cette réflexion fait souvent fi de la mise ... [more ▼]

L'exploitation des nouvelles technologies dans la mise sur pied d'un enseignement à distance s'accompagne nécessairement d'une réflexion pédagogique structurée. Cette réflexion fait souvent fi de la mise en oeuvre de véritables stratégies motivationnelles. Pourtant, lorsqu'on demande à un enseignant pourquoi il souhaite mettre un cours en ligne, il invoque souvent le fait de chercher à motiver ses étudiants. Nous distinguerons ici le maintien de la motivation, du renforcement de la motivation des étudiants. Les risques de démotivation et d'abandon sont très nombreux dans l'enseignement à distance, même avec le soutien des nouvelles technologies. Il est donc essentiel de veiller à maintenir constamment la motivation initiale de l'apprenant. Si le maintien de cette motivation fait appel à des moyens, des trucs, des recettes de tutorat, il n'en va pas de même du renforcement de la motivation. En effet, il s'agit ici de mettre au point, dès la phase de conception du cours, de véritables stratégies motivationnelles. Quels sont les risques de démotivation des étudiants ? Comment les éviter ? Quelles bases théoriques peuvent nous guider dans notre mise au point des stratégies motivationnelles ? Quelles pistes motivationnelles le concepteur peut-il emprunter, et dans quelles perspectives ? Sur base des théories de la motivation, notre recension des données bibliographiques vise à préciser les questions que doivent se poser les concepteurs de cours à distance. De même, elle débouche, pour chaque question, sur des pistes concrètes à explorer. [less ▲]

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See detailAstronomes célèbres et astronomes moins connus ... (5) Hubble
Biémont, Emile ULg

in Galactée (2004), 43

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See detailAstronomes célèbres et astronomes moins connus ... (4) Bailly
Biémont, Emile ULg

in Galactée (2004), 40

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See detailStructural investigations of HSS rolls for hot strip mill
Lecomte-Beckers, Jacqueline ULg; Tchuindjang, Jérôme Tchoufack ULg; Ernst, R. et al

in Proceedings of the 41st Rolling Seminar Processes, Rolled and Coated Product (2004)

High Speed Steel (HSS) cast rolls are used in front finishing stands of hot strip mills (HSM). Good wear resistance and hardness at high temperatures, are defining features of HSS. Previous experience has ... [more ▼]

High Speed Steel (HSS) cast rolls are used in front finishing stands of hot strip mills (HSM). Good wear resistance and hardness at high temperatures, are defining features of HSS. Previous experience has shown that HSS rolls containing mainly hard MC carbides have a high friction coefficient, which is detrimental for the rolling power consumption and for the strip surface quality. On the other hand, HSS rolls containing eutectic rod shaped carbides are brittle and more susceptible to spalling. To overcome these problems, a suitable grade, called HSS7, that gives the best compromise between a low friction coefficient and a high crack propagation and wear resistance was developed. That alloy contains well-dispersed hard VC carbides improving wear, and non-interconnected eutectic carbides of the M2C and M7C3 type, hindering crack propagation. All the metallurgical factors affecting the performance and damage of under rolling condition in front finishing stands are reviewed: wear resistance, friction coefficient, resistance to rolling incident, and oxide film formation. The effect of nature, morphology and amount was for each of the carbides studied and connected to the factor affecting the behaviour of the new grade developed. Different techniques are used such as: differential thermal analysis, optical and electron scanning microscopy and image analysis. A correlation with mechanical properties was also performed. [less ▲]

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See detailMelting and crystallisation behaviour of multi-component Fe-C-Cr-X alloys : microstructural aspects
Tchuindjang, Jérôme Tchoufack ULg; Lecomte-Beckers, Jacqueline ULg

in Proceedings of the 13th European Microscopy Congress (2004)

Studied materials are of the Fe-C-Cr-X multi-component system where X represents a group of strong carbides formers as Mo, V, or Nb. These alloys are used for wear components. Differential Thermal ... [more ▼]

Studied materials are of the Fe-C-Cr-X multi-component system where X represents a group of strong carbides formers as Mo, V, or Nb. These alloys are used for wear components. Differential Thermal Analysis (DTA) was used to determine the melting and solidification behaviour of these materials. Raw material has a thermomecanical history that involved casting, heat treating and hot forming, which could be investigated by the melting sequence of the DTA trial. [less ▲]

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See detailMesoscopic model of intergranular cracks in low carbon steel during cooling of continuous casting
Castagne, S.; Pascon, Frédéric ULg; Lecomte-Beckers, Jacqueline ULg et al

in Lamberigts, M. (Ed.) Proceedings of the 2nd international conference of thermomechanical processing of steels (TMP 2004) (2004)

This paper addresses the problem of transverse cracking during the continuous casting of low carbon steel. The damage mechanisms occurring at high temperature during this process are identified and a ... [more ▼]

This paper addresses the problem of transverse cracking during the continuous casting of low carbon steel. The damage mechanisms occurring at high temperature during this process are identified and a numerical approach for the modelling of these phenomena at the grain scale is proposed. Experiments allowing the identification of the model’s parameters are described. Finally, the first results obtained with the model are presented. [less ▲]

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See detailEtiologies et exploration electrophysiologique des paralysies diaphragmatiques.
MAERTENS DE NOORDHOUT, Alain ULg

in Revue Neurologique (2004), 160(12), 1239-44

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