References of "2003"
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See detailLa Motivation. Comprendre et agir.
Chenu, Florent ULg; Crepin, Françoise ULg; Jehin, Monique ULg

Learning material (2003)

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See detailModèles expérimentaux in vitro des HPV
Delvenne, Philippe ULg; Hubert, Pascale ULg; Havard, Laurence et al

in Aubin, F.; Pretet, J. F.; Mougin, C. (Eds.) Papillomavirus Humains (2003)

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See detailOntogenesis of behavioral sensitization and conditioned place preference induced by psychostimulants in laboratory rodents
Tirelli, Ezio ULg; Laviola, Giovanni; Adriani, Walter

in Neuroscience & Biobehavioral Reviews (2003), 27(1-2), 163-178

The present review deals mainly with the ontogenesis of two important phenomena involved in vulnerability to several neuropsychiatric disorders, namely with drug-induced sensitization (both contextual and ... [more ▼]

The present review deals mainly with the ontogenesis of two important phenomena involved in vulnerability to several neuropsychiatric disorders, namely with drug-induced sensitization (both contextual and non-contextual) and with conditioned place preference. The term 'infancy' covers the first three postnatal weeks during development in rats and mice. Conversely, the term 'adolescence' may cover the whole postnatal period ranging from weaning (PND 21) to adulthood (at least PND 60) or specifically the period around the onset of puberty (animals aged 33-44 days). Recent studies in rats demonstrated that the establishment of a context-dependent sensitization appears during the first (for repeated drug administration) or during the second (for a single drug administration) postnatal week. However, the memory of drug-context association is transient in developing pups (lasting one or two days following the drug pretreatment). The long-term retention of drug-context associations matures progressively, and is complete by the third week of postnatal life. Finally, those mechanisms responsible for an adult-like profile of context-independent pharmacological sensitization appear later during ontogenesis, being mature by the fourth week of postnatal life. Another set of experiments extended this ontogenetic characterization by comparing adolescent and adult mice. When compared to the latter, the former subjects exhibit a greater amphetamine-induced locomotor sensitization, almost no sensitization of aversive stereotyped behaviors, and a less marked place conditioning. The strength of the drug-induced place conditioning was also directly compared with the unconditioned novelty-seeking drive. In conclusion, neonatal rats are able to show a relatively short-lasting retention of sensitized drug effects (short-term sensitization), whereas the ability to exhibit relatively long-lasting sensitized effects matures progressively during infancy (long-term sensitization). On the other hand, adolescent mice show a reduced sensitization of drug-induced psychotic symptoms, together with a more marked sensitization of arousing and euphorigenic properties of the drug and a reduced incentive memory of its hedonic effects. These age-related changes do imply very different degrees of vulnerability to drug addiction and several other neuropsychiatric disorders. (C) 2003 Elsevier Science Ltd. All rights reserved. [less ▲]

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See detailGuided vortex motion in superconductors with a square antidot array
Silhanek, Alejandro ULg; Van Look, L.; Raedts, S. et al

in Physical Review. B : Condensed Matter (2003), 68(21),

We have measured the in-plane anisotropy of the vortex mobility in a thin Pb film with a square array of antidots. The Lorentz force, acting on the vortices, was rotated by adding two perpendicular ... [more ▼]

We have measured the in-plane anisotropy of the vortex mobility in a thin Pb film with a square array of antidots. The Lorentz force, acting on the vortices, was rotated by adding two perpendicular currents and keeping the amplitude of the net current constant. One set of voltage probes was used to detect the vortex motion. We show that the pinning landscape provided by the square antidot lattice influences the vortex motion in two different ways. First, the modulus of the vortex velocity becomes angular dependent with a lower mobility along the diagonals of the pinning array. Second, the vortex displacement is preferentially parallel to the principal axes of the underlying pinning lattice, giving rise to a misalignment between the vortex velocity and the applied Lorentz force. We show that this anisotropic vortex motion is temperature dependent and progressively fades out when approaching the normal state. [less ▲]

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See detailChronique de la 55ème Session de la SIHDA à Rotterdam (18-22 Septembre 2001)
Gerkens, Jean-François ULg

in Revue Internationale des Droits de l'Antiquité (2003), L

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See detailTowards a more versatile alpha-glucan biosynthesis in plants
Jacon, Géraldine ULg

in Journal of Plant Physiology (2003)

During the last 10 years, the increased need for starches with novel properties has occupied the research community, and many efforts were concentrated on unraveling the starch bio- synthesis pathways ... [more ▼]

During the last 10 years, the increased need for starches with novel properties has occupied the research community, and many efforts were concentrated on unraveling the starch bio- synthesis pathways. The knowledge generated in these investigations was subsequently used to produce tailor-made starches in higher plants using recombinant DNA technology. Examples of starches with new functionalities are those with a modified degree of branching (Schwall et al. 2000, Shewma- ker et al. 1994, Kortstee et al. 1996) and the amylose-free starch (Visser et al. 1991a, Kuipers et al.1994), some of which hold potential for applications in the paper-, textile-, plastics-, food and pharmaceutical industry. The accumulation of more starch has also been an objective, but this will not be dis- cussed further here, (see: Slattery et al. 2000). In our laboratory, we have embarked on two generic tech- nologies with a very wide range of applicability: (i) introduction of new linkages types and structural elements using glu- cansucrases, and (ii) engineering granule-boundness by using microbial starch-binding domains (SBDs). It is expected that these technologies will contribute substantially to the biosynthesis of more versatile α-glucans in the near future, leading to starches with altered functionalities that cannot be obtained by conventional breeding. In this study recent developments in starch modification using heterologous expression of microbial genes will be reviewed, with emphasis on the potato plant. [less ▲]

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See detailAnalyse sensorielle : principes de base.
Blecker, Christophe ULg

in Cours d'analyse sensorielle du beurre et du lait en poudre. (2003)

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See detailLes partis et la politique de défense
Dumoulin, André ULg

in Courrier hebdomadaire du CRISP (2003), 1798

Le présent Courrier hebdomadaire a pour objet l’analyse de l’intégration des questions de défense nationale et européenne au sein des préoccupations des partis politiques belges. Cette analyse comprend ... [more ▼]

Le présent Courrier hebdomadaire a pour objet l’analyse de l’intégration des questions de défense nationale et européenne au sein des préoccupations des partis politiques belges. Cette analyse comprend deux volets. Le premier examine les activités parlementaires en rapport avec les affaires militaires belges et européennes. Nous procéderons, plus précisément, à l’analyse des travaux conduits par la commission de la Défense nationale de la Chambre au cours de la dernière législature. Le second repose sur un examen des propositions relatives à la défense belge et européenne (politique européenne de sécurité et de défense) au sein des programmes politiques des partis représentés au Parlement fédéral dans la perspective des élections législatives du 18 mai 2003. L’objet de cette étude est de déceler les lieux de convergences et de divergences entre les formations politiques du pays (mise à l’agenda politique des partis, définition des priorités, visions prospectives, etc.). Il s’est agi, plus exactement, de relever les principales thématiques abordées par les partis en matière de défense nationale et européenne. En effet, à l’instar d’un grand nombre de compétences régaliennes, le secteur de la défense constitue un lieu d’intersection de multiples problématiques de type économique, social, budgétaire, environnemental et politique au sens propre du terme. En outre, le concept même de défense peut être décliné en une variété de sous-thèmes qui lui sont constitutifs (structure de forces, choix des systèmes d’armes et des matériels, définition des tâches et missions, statut du personnel, intégration au sein des enceintes multilatérales, spécialisation,…). Il est, enfin, utile de préciser que cette étude ne prend en compte ni les divers documents internes (à diffusion publique ou restreinte), ni les notes de travail produites par les partis, ni les études spécialisées sur la place de la Belgique en matière de sécurité européenne. Ce choix a été opéré à dessein. Il s’agit, en effet, de s’intéresser aux seules dispositions programmatiques spécifiquement adressées à l’ensemble des concitoyens dans le cadre de travaux parlementaires et d’un choix électoral donné. Aussi, cette étude ne peut être assimilée à un bilan exhaustif des positions et conceptions des partis en la matière ; il est plutôt un indicateur des messages que les formations politiques entendent transmettre aux citoyens [less ▲]

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See detailL'interférence virale chez les Alphaherpesvirinae
Meurens, François; Muylkens, Benoît ULg; Schynts, Frédéric et al

in Virologie (2003), 7

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See detailShortened irradiation scheme, continuous infusion of 5-fluorouracil and fractionation of mitomycin C in locally advanced anal carcinomas. Results of a phase II study of the European Organization for Research and Treatment of Cancer. Radiotherapy and Gastrointestinal Cooperative Groups
Bosset, J. F.; Roelofsen, F.; Morgan, D. A. L. et al

in European Journal of Cancer (2003), 39

Abstract The European Organization for Research and Treatment of Cancer (EORTC) 22861 randomised trial established that combined radiochemotherapy is the standard treatment for locally advanced anal ... [more ▼]

Abstract The European Organization for Research and Treatment of Cancer (EORTC) 22861 randomised trial established that combined radiochemotherapy is the standard treatment for locally advanced anal cancer. This EORTC phase II study (#22953) tests the feasibility of reducing the gap between sequences to 2 weeks, to deliver Mitomycin C (MMC) in each radiotherapy sequence and 5-FU continuously during the treatment. The first sequence consisted of 36 Gy over 4 weeks. 5-FU 200 mg/m2/days 1–26, MMC 10 mg/m2/day 1 gap 16 days. Then a second sequence of 23.4 Gy over 17 days, 5-FU 200 mg/m2/days 1–17 and, MMC 10 mg/m2/day 1 was given. 43 patients with a World Health Organization (WHO) status of 0 (n=27) or 1 (n=16) and with T2-T4, N0-3 tumours were included. Compliance with the planned treatment, doses and duration was 93%. The complete response rate was 90.7%. Grade 3 toxicities of 28, 12 and 2% were observed for skin, diarrhoea and haematological toxicities, respectively. The 3-year estimated rates for trials 22861 and 22953 are: 68 and 88% for local control; 72 and 81% for colostomy-free interval, 62 and 84% for severe late toxicity-free interval, and 70 and 81% for survival, respectively. The 22953 scheme is feasible and the results are promising. This is now considered as the new standard scheme by the EORTC. [less ▲]

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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 detailHow Daphnia copes with excess carbon in its food
Darchambeau, François ULg; Faerovig, P. J.; Hessen, D. O.

in Oecologia (2003), 136(3), 336-346

Animals that maintain near homeostatic elemental ratios may get rid of excess ingested elements from their food in different ways. C regulation was studied in juveniles of Daphnia magna feeding on two ... [more ▼]

Animals that maintain near homeostatic elemental ratios may get rid of excess ingested elements from their food in different ways. C regulation was studied in juveniles of Daphnia magna feeding on two Selenastrum capricornutum cultures contrasting in P content (400 and 80 C:P atomic ratios). Both cultures were labelled with C-14 in order to measure Daphnia ingestion and assimilation rates. No significant difference in ingestion rates was observed between P-low and P-rich food, whereas the net assimilation of C-14 was higher in the treatment with P-rich algae. Some Daphnia were also homogeneously labelled over 5 days on radioactive algae to estimate respiration rates and excretion rates of dissolved organic C (DOC). The respiration rate for Daphnia fed with high C:P algae (38.7% of body C day(-1)) was significantly higher than for those feeding on low C:P algae (25.3% of body C day(-1)). The DOC excretion rate was also higher when animals were fed on P-low algae (13.4% of body C day(-1)) than on P-rich algae (5.7% of body C day(-1)) . When corrected for respiratory losses, total assimilation of C did not differ significantly between treatments (around 60% of body C day(-1)). Judging from these experiments, D. magna can maintain its stoichiometric balance when feeding on unbalanced diets (high C:P) primarily by disposing of excess dietary C via respiration and excretion of DOC. [less ▲]

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See detailEchographie abdominale du chien et du chat
Busoni, Valeria ULg

Learning material (2003)

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See detail‘De kanker van een diepgewortelde droom’. Over Marcel van Maele
Spinoy, Erik ULg

in Van Maele, Marcel (Ed.) Scherpschuttersfeest (2003)

This is a general introduction to the work of the Flemish novelist and poet Marcel van Maele.

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See detailThe neuroendocrinology of reproductive behavior in Japanese quail
Balthazart, Jacques ULg; Baillien, Michelle; Charlier, Thierry ULg et al

in Domestic Animal Endocrinology (2003), 25

Sex steroid hormones such as testosterone have widespread effects on brain physiology and function but one of their best characterized effects arguably involves the activation of male sexual behavior ... [more ▼]

Sex steroid hormones such as testosterone have widespread effects on brain physiology and function but one of their best characterized effects arguably involves the activation of male sexual behavior. During the past 20 years we have investigated the testosterone control of male sexual behavior in an avian species, the Japanese quail (Coturnix japonica).We briefly reviewhere the main features and advantages of this species relating to the investigation of fundamental questions in the field of behavioral neuroendocrinology, a field that studies inter-relationship among hormones, brain and behavior. Special attention is given to the intracellular metabolism of testosterone, in particular its aromatization into an estrogen, which plays a critical limiting role in the mediation of the behavioral effects of testosterone. Brain aromatase activity is controlled by steroids which increase the transcription of the enzyme, but afferent inputs that affect the intraneuronal concentrations of calcium also appear to have a pronounced effect on the enzyme activity through rapid changes in its phosphorylation status. The physiological significance of these slowgenomic and rapid, presumably non-genomic, changes in brain aromatase activity are also briefly discussed. [less ▲]

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See detailChemistry of silica at different concentrations of non-ionic surfactant solutions: Effect of pH of the synthesis gel on the preparation of mesoporous silicas
Léonard, Alexandre ULg; Blin, J. L.; Jacobs, P. A. et al

in Microporous and Mesoporous Materials (2003), 63(1-3), 59-73

Ordered and disordered mesoporous silicas have been synthesized through an assembly of non-ionic decaoxyethylene cetyl ether [C 16(EO) 10] and a tetramethoxysilane silica source by variation of the pH ... [more ▼]

Ordered and disordered mesoporous silicas have been synthesized through an assembly of non-ionic decaoxyethylene cetyl ether [C 16(EO) 10] and a tetramethoxysilane silica source by variation of the pH value of the synthesis gel. The structure, texture and morphology of the mesoporous silicas, synthesized with concentrated and diluted surfactant solutions, have been discussed from the perspective of silica's chemistry upon a variation of pH values of the synthesis gel (micellar solution). With concentrated surfactant solutions (50 wt%), disordered compounds are obtained in a range of pH from 2.0 to 7.0 (micellar solution). As the pH increases, however, the pore size distributions (PSD) become broader and bimodality appears due to the micelle-templated silica (MTS) mesopores and openings arising from silica dissolution-reprecipitation processes. Also, the MTS pores expand due to a change in conformation of the surfactant hydrophilic head upon pH increase. On the other hand, diluted surfactant solutions (10 wt%) lead to ordered materials in a pH range from 2.0 to 7.0 (synthesis gel). The PSD remain very narrow but interparticular porosity appears and the morphologies undergo deep changes from toroids, gyroids and ropes to aggregates of very small particles with increasing pH. © 2003 Elsevier Inc. All rights reserved. [less ▲]

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