References of "2003"
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See detailAnalysis of peer interaction among children in a tutoring situation pertaining to mathematical problems of the multiplying type
Crahay, Marcel ULg; Hindryckx, Geneviève ULg; Lebe, Martine

in De Corte, E. (Ed.) Powerful learning environments : unravelling basic components and dimensions (2003)

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See detail(Ex)communication
Dumortier, Jean-Louis ULg

in Lettre de la DLFM (2003), 32

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See detailCultures maraîchères et insectes utiles
Francis, Frédéric ULg; Colignon, Pierre; Haubruge, Eric ULg

in Le Canard déchaîné du Kauwberg (2003), 46

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See detailA conceptual framework to design and support self-directed learning in a blended learning program. A case-stydy: the DES-TEF
Denis, Brigitte ULg

in Journal of Educational Media (2003), 28(2-3), 115-127

This paper relates different strategies developed in order to support the learning process in a blended learning programme involving adults from different backgrounds who are interested in the use of ... [more ▼]

This paper relates different strategies developed in order to support the learning process in a blended learning programme involving adults from different backgrounds who are interested in the use of Information and Communication Technologies for Education (ICTE). Referring to Carré & Pearn’s model of the seven pillars of self-learning, the author describes some principles, tools and resources that have been developed within the framework of a postgraduate diploma and that could be extended to similar adult training programmes. [less ▲]

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See detailMise au point d’une procédure de caractérisation quantitative des surfaces démolies en béton en vue de travaux de réfection
Bélair, Normand; Bissonnette, Benoît; Courard, Luc ULg

in Progression de la recherche québécoise sur les ouvrages d'art (2003)

Cet article présente l’état d’avancement d’un projet visant le développement et la validation d’une technique permettant de caractériser de façon quantitative l’intégrité mécanique d’une surface en béton ... [more ▼]

Cet article présente l’état d’avancement d’un projet visant le développement et la validation d’une technique permettant de caractériser de façon quantitative l’intégrité mécanique d’une surface en béton préparée (démolie) aux fins de travaux de réfections superficielles. Dans un premier temps, une étude de l’influence des variables de base (taille des pastilles métalliques, profondeur de forage, nature de l’adhésif, etc.) relatives à l’essai d’arrachement sur la cohésion du béton a été réalisée afin d’optimiser la procédure expérimentale. De plus, les performances comparatives de deux dispositifs d’essai disponibles commercialement ont été évaluées afin d’identifier l’appareil le mieux adapté (facilité et rapidité d’exécution, efficacité, reproductibilité, coût, etc.). Afin de valider le protocole expérimental retenu et d’évaluer quantitativement les effets du mode de démolition, des essais d’arrachement ont été réalisés en laboratoire sur une série d’éléments en béton dont la surface a été préparée au moyen de différentes méthodes de préparation, notamment le marteau pneumatique, la scarification, le jet de sable et le jet d’eau. Une technique de caractérisation quantitative de la rugosité de surface a également été élaborée. Sur la base de ces essais, il est possible d’établir l’influence du mode de démolition sur l’intégrité mécanique de la surface obtenue et d’émettre des recommandations préliminaires. [less ▲]

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See detailDevelopment of pure prolactin receptor antagonists
Bernichtein, Sophie; Kayser, Christine; Dillner, Karin et al

in Journal of Biological Chemistry (2003), 278(38), 35988-99

Prolactin (PRL) promotes tumor growth in various experimental models and leads to prostate hyperplasia and mammary neoplasia in PRL transgenic mice. Increasing experimental evidence argues for the ... [more ▼]

Prolactin (PRL) promotes tumor growth in various experimental models and leads to prostate hyperplasia and mammary neoplasia in PRL transgenic mice. Increasing experimental evidence argues for the involvement of autocrine PRL in this process. PRL receptor antagonists have been developed to counteract these undesired proliferative actions of PRL. However, all forms of PRL receptor antagonists obtained to date exhibit partial agonism, preventing their therapeutic use as full antagonists. In the present study, we describe the development of new human PRL antagonists devoid of agonistic properties and therefore able to act as pure antagonists. This was demonstrated using several in vitro bioassays, including highly sensitive assays able to detect extremely low levels of receptor activation. These new compounds also act as pure antagonists in vivo, as assessed by analyzing their ability to competitively inhibit PRL-triggered signaling cascades in various target tissues (liver, mammary gland, and prostate). Finally, by using transgenic mice expressing PRL specifically in the prostate, which exhibit constitutively activated signaling cascades paralleling hyperplasia, we show that these new PRL analogs are able to completely revert PRL-activated events. These second generation human PRL antagonists are good candidates to be used as inhibitors of growth-promoting actions of PRL. [less ▲]

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See detailNumerical shear tests for different elasto-plastic laws
de Montleau, P.; Duchene, Laurent ULg; Flores, Paulo et al

in Onate, E.; Owen, D. R. J. (Eds.) Proceedings of the VII International Conference on Computational Plasticity (COMPLAS 2003) (2003)

This paper presents the numerical simulation of a cyclic simple shear test. The blank tested is a high strength steel sheet for which we use three different constitutive plastic laws derived from Teodosiu ... [more ▼]

This paper presents the numerical simulation of a cyclic simple shear test. The blank tested is a high strength steel sheet for which we use three different constitutive plastic laws derived from Teodosiu's model. These laws take into account respectively isotropic, kinematic and mixed isotropic-kinematic hardening. The goal of the paper is to provide a first numerical idea of the stress-strain path in the center of an experimental test sample. [less ▲]

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See detailPrévenir le mal
Strivay, Lucienne ULg

in Lempereur, Françoise; Neuberg, André (Eds.) Guérisseurs d'hier et d'aujourd'hui (2003)

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See detailSpinal mechanisms contribute to analgesia produced by epidural sufentanil combined with bupivacaine for postoperative analgesia
Joris, Jean ULg; Jacob, Eric; Sessler, Daniel et al

in Anesthesia and Analgesia (2003), 97

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See detailDes Fleurs de saints à l'odeur de sainteté. L'hagiographie en terres wallonnes,
George, Philippe ULg; Raschevitch, Sonia ULg

in Dumortier, Jean-Louis; George, Philippe (Eds.) Regards sur le XVIIe siècle. Feuillets de la Cathédrale de Liège. (2003)

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See detailDiagnosis and monitoring of pregnancy in sheep: reality and perspectives
El Amiri, Bouchra; Karen, Aly; Cognié, Yves et al

in Productions Animales (2003), 16(2), 79-90

The present review aims at presenting different methods for pregnancy diagnosis. Since these methods are to be used in the herds, precocity, sensitivity, specificity, accuracy to predict pregnant and non ... [more ▼]

The present review aims at presenting different methods for pregnancy diagnosis. Since these methods are to be used in the herds, precocity, sensitivity, specificity, accuracy to predict pregnant and non-pregnant ewes, and the possibility to determine fetal numbers are carefully analysed. The progesterone assay is accurate as early as day 17th after fecundation; but the fertilization day must be precisely known. The pregnancy specific or associated glycoproteins (PSPB/PAG) assay is highly sensitive and specific at day 22 in blood and at day 32 in milk samples. However, this assay does not allow to predict the fetal number. The ultrasonography B-mode used on 30 days of gestation gives very good or excellent performance in terms of sensitivity and specificity depending on the practitioner. The method is also able to predict the real time fetal number. [less ▲]

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See detailRedefining the role of psr in beta-lactam resistance and cell autolysis of Enterococcus hirae.
Sapunaric, Frédéric ULg; Franssen, Christine; Stefanic, Patrick et al

in Journal of Bacteriology (2003), 185(20), 5925-35

The contribution of penicillin-binding protein 5 (PBP5) and the PBP5 synthesis repressor (Psr) to the beta-lactam resistance, growth, and cell autolysis of wild-type strain ATCC 9790 and resistant strain ... [more ▼]

The contribution of penicillin-binding protein 5 (PBP5) and the PBP5 synthesis repressor (Psr) to the beta-lactam resistance, growth, and cell autolysis of wild-type strain ATCC 9790 and resistant strain R40 of Enterococcus hirae was investigated by disruption or substitution of the corresponding pbp5 and psr genes by Campbell-type recombination. The resulting modifications were confirmed by hybridization and PCR. The low susceptibility of E. hirae to beta-lactams was confirmed to be largely dependent on the presence of PBP5. However, against all expectations, inactivation of psr in ATCC 9790 or complementation of R40 cells with psr did not modify the susceptibility to benzylpenicillin or the growth and cell autolysis rates. These results indicated that the psr gene does not seem to be involved in the regulation of PBP5 synthesis and consequently in beta-lactam resistance or in the regulation of cell autolysis in E. hirae. [less ▲]

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See detailMons/Maisières : les occupations paléolithiques de "l'Atelier de Taille de la Berge Nord-Est" à Maisières-Canal
Miller, Rebecca ULg; Guillaume, Alain; Otte, Marcel ULg

in Chronique de l'Archéologie Wallonne (2003), 11

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See detailAvantages sélectifs d'un phénotype hétérochronique. Eco-éthologie des populations pédomorphiques du Triton alpestre, Triturus alpestris (Amphibia, Caudata)
Denoël, Mathieu ULg

Book published by Cahiers d'Ethologie (2003)

Facultative paedomorphosis is a polyphenism that has important evolutionary implications in promoting morphological differentiation and habitat use variation, and has occurred in several urodele species ... [more ▼]

Facultative paedomorphosis is a polyphenism that has important evolutionary implications in promoting morphological differentiation and habitat use variation, and has occurred in several urodele species throughout the world. Several hypotheses based on life-history theory have been proposed to explain the wide range of habitats where facultative paedomorphosis occurs, suggesting multiple causes. In populations experiencing facultative paedomorphosis, some individuals metamorphose and mature (metamorphs), while others attain sexual maturity while still retaining traits of larval somatic morphology (paedomorphs). The paedomorphic process by which the development of somatic and reproductive organs is shifted between related individuals is assumed to significantly contribute to macro-evolutionary processes. Indeed, it implies large phenotypic variations in the absence of deep genetic changes. A way to explain the importance of these developmental heterochronies is to show their adaptive value in the micro-evolutive stage. The aim of this thesis is to determine the advantages gained by an individual that adopts a paedomorphic developmental pathway rather than a metamorphic one. To do this, we studied five factors: habitat use; resource partitioning; age and size structures; sexual compatibility; and the effect of environmental factors. The ecological and ethological characteristics of several mixed populations (composed of both paedomorphic and metamorphic individuals) of the Alpine newt Triturus alpestris (Amphibia, Salamandridae) were investigated from 1997 to 2000. These populations were located in France, Italy and Greece. The habitats occupied by dimorphic populations of the Alpine newt are highly variable. We have found the two morphs in syntopy in deep permanent lakes, and in small shallow and temporary ponds. Aquatic habitats were surrounded by various terrestrial habitats. As a result, it was not possible to correlate any particular environment type with the maintenance of the polymorphism in natural populations. The only common trait of the paedomorphic populations was that they were located at the southern margin of the range of the species (Italy, the Balkan peninsula, and southeastern France). Such a restriction of the distributional range of paedomorphosis suggests that this trait is maintained by genes which are shared only by these populations. Such a restriction may be due to Holocene colonizations from Pleistocene refugia, in which case paedomorphosis may have appeared in these refugia during the last glaciations. Nevertheless, as long as the phylogeny of the group remains uncertain, we cannot reject the possibility of an earlier origin of paedomorphosis. The two morphs primarily differed in space use and feeding habits. These differences were particularly marked in deep alpine aquatic habitats, where the paedomorphs occupy deep waters devoid of competitors, such as fish. In such waters, the paedomorphs were more abundant on the bottom and in the water column, whereas the metamorphs mainly occupied the water surface and shore. The paedomorphs primarily ingested plankton, while the metamorphs mainly foraged on terrestrial prey that had fallen on the water surface. Although these feeding habits depend on newt habitats - plankton being more abundant in the water column, and terrestrial prey at the water surface - the trophic spectrum in each habitat still differed. While the energetic values of the prey eaten by the two morphs strongly differed, by ingesting a large number of planktonic organisms, the paedomorphs attained similar or even larger caloric intake rates than metamorphs. The paedomorphs' superior body condition suggests that they may have higher long-term success than the metamorphs. Differences in body condition may also reflect the terrestrial life habit of the metamorphs, since metamorphosed individuals are able to avoid competition with reproductive adults and larvae by leaving the water. In the paedomorphic populations, several size-structured cohorts of larvae coexist, and competition among these cohorts is lowered by size-selective predation, since small larvae catch smaller prey than larger larvae and paedomorphs. Although this difference in diet was in part due to gape-size limitation, the gilled individuals also size-selected prey among a range of catchable items. Resource partitioning then favoured the coexistence of the two adult morphs, and their gilled descendants, which coexist with them. The two morphs also differed in feeding performance. Whereas the paedomorphs were better predators than metamorphs on water fleas, metamorphs were more adept at capturing large terrestrial invertebrates (flies). These differences in feeding performances were caused by the morphological particularities of the two morphs. Paedomorphs had a fish-like feeding structure with a unidirectional water flow passing through the oral cavity, and then being expelled through gill slits on the posterior side of the head. In contrast, metamorphs had a smaller oral cavity and a bidirectional water flow due to closed gill slits. Although the metamorphic structure produces less suction, it allows for catching bigger prey because of a larger gape-size (biting rather than sucking). Our measures of feeding performances confirmed the data from natural populations, with each of the morphs preferentially eating their predicted prey. The particular use of micro-habitats by the two morphs is also in agreement with optimality models predicting predation in the more profitable patches. In the Alpine newt, paedomorphosis can be produced by two main processes: neoteny and progenesis. In some populations, the two morphs reached sexual maturity at the same age (neoteny); in other populations, sexual maturity was reached earlier by paedomorphs (progenesis). Progenesis was observed in unstable water habitats. Pond drying suppressed the possibility of late maturation, which is characteristic of a neotenic developmental pathway. On the other hand, the precocious sexual maturation of paedomorphs favoured the fast colonization of new habitats, owing to a high intrinsic rate of natural increase. Neoteny was typical of permanent waters with harsh constraints on growth. By forgoing metamorphosis, larvae also avoid the cost of changing of structure (decrease in body weight in our experiments). Progenetic paedomorphosis appears then as a major trait that can be selected due to the advantages of earlier maturation. The two morphs are sexually compatible; thus, metamorphs can "exchange" genes with paedomorphs at each generation. While the two morphs markedly differ in their secondary sexual characteristics, females did not show any preference related to these characteristics. The absence of sexual isolation between the morphs shows that they are not involved in a sympatric speciation process. The maintenance of the polymorphism is more advantageous than the formation of two isolated species. Paedomorphosis occurs in aquatic habitats where total drying can occur, and where the maintenance of facultative paedomorphosis is maintained by metamorphs that have paedomorphic genes but do not (permanently) express them. In such habitats, the sexual isolation of the two morphs would lead to the extinction of paedomorphosis in the event of pond drying or similar catastrophe. Because the environment can modify the ontogenetic pathway, paedomorphosis in the Alpine newt can be considered a polyphenism. Indeed, restricting the amount of water or food available induces paedomorphs to metamorphose. The marking of individual paedomorphs in a natural population proved that metamorphosis also occurs in the field. However, salamander density and progressive drying of aquaria did not have any apparent effect on paedomorph metamorphosis. When the possibility of a short migration across dry land was given, paedomorphs moved towards an available water basin and maintained their larval somatic characters during the migrations. By being able to migrate on land towards permanent water, paedomorphs are able to retain a feeding morphology that favors them in microhabitats where plankton is abundant. Facultative paedomorphosis in the Alpine newt allows populations to cope with environmental variability, and is adaptive in allowing precocious maturation or a larger use of resources in spatially heterogeneous environments. Thus, it is not surprising that paedomorphosis can evolve in such dissimilar environments as lowland temporary ponds and highland deep lakes. In such places, paedomorphosis appears to be the best solution as long as fish predation is relaxed. The introduction of fish throughout Europe is thus a serious problem, and has resulted in the extinction of several large paedomorphic populations. If this trend is not stopped rapidly, paedomorphosis in the Alpine newt - and in other species - will belong to the past. [less ▲]

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See detailNF-κB transcription factor induces drug resistance through MDR1 expression in cancer cells
Bentires-Alj, Mohamed; Barbu, Véronique; Fillet, Marianne ULg et al

in Oncogene (2003), 22

The ubiquitous NF-kappaB transcription factor has been reported to inhibit apoptosis and to induce drug resistance in cancer cells. Drug resistance is the major reason for cancer therapy failure and ... [more ▼]

The ubiquitous NF-kappaB transcription factor has been reported to inhibit apoptosis and to induce drug resistance in cancer cells. Drug resistance is the major reason for cancer therapy failure and neoplastic cells often develop multiple mechanisms of drug resistance during tumor progression. We observed that NF-kappaB or P-glycoprotein inhibition in the HCT15 colon cancer cells led to increased apoptotic cell death in response to daunomycin treatment. Interestingly, NF-kappaB inhibition through transfection of a plasmid coding for a mutated IkappaB-alpha inhibitor increased daunomycin cell uptake. Indeed, the inhibition of NF-kappaB reduced mdr1 mRNA and P-glycoprotein expression in HCT15 cells. We identified a consensus NF-kappaB binding site in the first intron of the human mdr1 gene and demonstrated that NF-kappaB complexes could bind with this intronic site. Moreover, NF-kappaB transactivates an mdr1 promoter luciferase construct. Our data thus demonstrate a role for NF-kappaB in the regulation of the mdr1 gene expression in cancer cells and in drug resistance. [less ▲]

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See detailFestina lente: evidences for fast and slow learning processes and a role for sleep in human motor skill learning.
Maquet, Pierre ULg; Laureys, Steven ULg; Perrin, Fabien et al

in Learning & Memory (Cold Spring Harbor, N.Y.) (2003), 10(4), 237-9

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