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See detailHydrogeological investigations at the Membach station, Belgium, and application to correct long periodic gravity variations
Van Camp, Michel; Vanclooster, Marnik; Crommen, O. et al

in Journal of Geophysical Research (2006), 111(B10),

A comprehensive hydrogeological investigation regarding the influence of variations in local and regional water mass on superconducting gravity measurements is presented for observations taken near the ... [more ▼]

A comprehensive hydrogeological investigation regarding the influence of variations in local and regional water mass on superconducting gravity measurements is presented for observations taken near the geodynamic station of Membach, Belgium. Applying a regional water storage model, the gravity contribution due to the elastic deformation of the Earth was derived. In addition, the Newtonian gravity effect induced by the local water mass variations was calculated, using soil moisture observations taken at the ground surface (about 48 m above the gravimeters). The computation of the gravimetric effect is based on a digital elevation model with spatially discretized rectangular prisms. The obtained results are compared with the observations of a superconducting gravimeter (SG). We find that the seasonal variations can be reasonably well predicted with the regional water storage model and the local Newtonian effects. Shorter-period effects depend on the local changes in hydrology. This result shows the sensitivity of SG observations to very local water storage changes. [less ▲]

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See detailStochastic analysis of the effect of spatial variability of diffusion parameters on radionuclide transport in a low permeability clay layer
Huysmans, Marijke; Dassargues, Alain ULg

in Hydrogeology Journal (2006), 14(7), 1094-1106

Most studies that incorporate subsurface heterogeneity in groundwater flow and transport models only analyze and simulate the spatial variability of hydraulic conductivity. Heterogeneity of the other flow ... [more ▼]

Most studies that incorporate subsurface heterogeneity in groundwater flow and transport models only analyze and simulate the spatial variability of hydraulic conductivity. Heterogeneity of the other flow and transport parameters are usually neglected. This approach is often justified, but there are, however, cases in which disregarding the heterogeneity of the other flow and transport parameters can be questionable. In low permeability media, for instance, diffusion is often the dominant transport mechanism. It therefore seems logical to incorporate the spatial variability of the diffusion parameters in the transport model. This study therefore analyses and simulates the spatial variability of the effective diffusion coefficient and the diffusion accessible porosity with geostatistical techniques and incorporates their heterogeneity in the transport model of a low permeability formation. The formation studied was Boom clay (Belgium), a candidate host rock for the deep geological disposal of high-level radioactive waste. The calculated output radionuclide fluxes of this model are compared with the fluxes calculated with a homogeneous model and a model with a heterogeneous hydraulic conductivity distribution. This analysis shows that the heterogeneity of the diffusion parameters has a much larger effect on the calculated output radionuclide fluxes than the heterogeneity of hydraulic conductivity in the low permeability medium under study. [less ▲]

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See detailStochastic analysis of the effect of spatial variability of diffusion parameters on radionuclide transport in low permeability clay layer
Huysmans, Marijke; Dassargues, Alain ULg

in Calibration and Reliability in Groundwater Modelling: From Uncertainty to Decision Making (2006)

Most studies that incorporate subsurface heterogeneity in groundwater flow and transport models only analyze and simulate the spatial variability of hydraulic conductivity. Heterogeneity of the other flow ... [more ▼]

Most studies that incorporate subsurface heterogeneity in groundwater flow and transport models only analyze and simulate the spatial variability of hydraulic conductivity. Heterogeneity of the other flow and transport parameters is usually neglected. This approach is often justified, but there are however cases in which disregarding the heterogeneity of the other flow and transport parameters can be questionable. In low permeability media, for instance, diffusion is often the dominant transport mechanism. It therefore seems logical to incorporate the spatial variability of the diffusion parameters in the transport model. This study therefore analyzes and simulates the spatial variability of the effective diffusion coefficient and the diffusion accessible porosity with geostatistical techniques and incorporates their heterogeneity in the transport model of a low permeability formation. The calculated output radionuclide fluxes of this model are compared with the fluxes calculated with a homogeneous model and a model with a heterogeneous hydraulic conductivity distribution. This analysis shows that the heterogeneity of the diffusion parameters has a much larger effect on the calculated output radionuclide fluxes than the heterogeneity of hydraulic conductivity. [less ▲]

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See detailHydrogeological modeling of radionuclide transport in heterogeneous low-permeability media: a comparison between Boom Clay and Ieper Clay
Huysmans, Marijke; Dassargues, Alain ULg

in Soares, A.; Pereira, M. J.; Dimitrakopoulos, R. (Eds.) GeoENV VI: Geostatistics for Environmental Applications (2006)

Deep low-permeability clay layers are considered as possible suitable environments for disposal of high-level radioactive waste. In Belgium, the Boom Clay is the reference host formation and the Ieper ... [more ▼]

Deep low-permeability clay layers are considered as possible suitable environments for disposal of high-level radioactive waste. In Belgium, the Boom Clay is the reference host formation and the Ieper Clay an alternative host formation for research and safety and feasibility assessment of deep disposal of nuclear waste. In this study, two hydrogeological models are built to calculate the radionuclide fluxes that would migrate from a potential repository through these two clay formations. Transport parameters heterogeneity is incorporated in the models using stochastic sequential simulation of hydraulic conductivity, diffusion coefficient and diffusion accessible porosity, using primary information and several types of secondary information, i.e. resistivity, gamma ray and grain size. The calculated radionuclide fluxes in the two clay formations are compared. Results show that in the Ieper Clay larger differences between the fluxes through the lower and the upper clay boundary occur, larger total output radionuclide amounts are calculated, and a larger effect of parameter heterogeneity on the calculated fluxes is observed, compared to the Boom Clay. [less ▲]

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See detailCharacterisation of fissured aquifers in the semi-arid region of the mid-Atlas plateau (Oulmès, Morocco)
Orban, Philippe ULg; Ruthy, Ingrid ULg; Elbatloussi, D. et al

in GIRE3D: International Congress on Integrated Water Resources management and Challenges of the Sustainable Development (2006)

The Oulmès plateau (mid-Atlas in Morocco) is known for its groundwater resources in this semi-arid region. In the studied zone (approximately 80 km2), the mineral water of ‘Sidi Ali’ is exploited as well ... [more ▼]

The Oulmès plateau (mid-Atlas in Morocco) is known for its groundwater resources in this semi-arid region. In the studied zone (approximately 80 km2), the mineral water of ‘Sidi Ali’ is exploited as well as the naturally semi-sparkling ‘mineral water of Oulmès’ which are main mineral waters marketed in Morocco. Their sources are located at less than four kilometers from each other. In the same time, the drinking water supply to the local rural populations is far from being sufficient, and even in some places non-existent. In addition the plateau is also the place where many fruit-bearing cultures have been undertaken for a few years. Irrigation and the use of pesticide and herbicide compounds as well as fertilizers could constitute threats for the groundwater quantity and quality and unpleasant consequences are expected for all dependent groundwater end-users. Thus, in this semi-arid zone, an acute problem of sustainable development arises in terms of groundwater quantity and quality. An extended study has involved data collection, measurement campaigns (piezometric levels, sampling & analysis of groundwater), shallow geophysical prospecting, pumping tests, building of a data base, estimation of the recharge spatial distribution and hydrogeological mapping. On the basis of this study, a better understanding is possible about the state and the particular hydrodynamic behaviour of groundwater in the fissured hard-rocks of this plateau. Results are expressed in maps providing explicit and useful information allowing future decisions which can be taken for the welfare of everyone and particularly for the local populations. [less ▲]

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See detailProteomics in Myzus persicae: effect of aphid host plant switch.
Francis, Frédéric ULg; Gerkens, Pascal; Harmel, Nicolas ULg et al

in Insect Biochemistry and Molecular Biology (2006), 36(3), 219-27

Chemical ecology is the study of how particular chemicals are involved in interactions of organisms with each other and with their surroundings. In order to reduce insect attack, plants have evolved a ... [more ▼]

Chemical ecology is the study of how particular chemicals are involved in interactions of organisms with each other and with their surroundings. In order to reduce insect attack, plants have evolved a variety of defence mechanisms, both constitutive and inducible, while insects have evolved strategies to overcome these plant defences (such as detoxification enzymes). A major determinant of the influence of evolutionary arms races is the strategy of the insect: generalist insect herbivores, such as Myzus persicae aphid, need more complex adaptive mechanisms since they need to respond to a large array of different plant defensive chemicals. Here we studied the chemical ecology of M. persicae associated with different plant species, from Brassicaceae and Solanaceae families. To identify the involved adaptation systems to cope with the plant secondary substances and to assess the differential expression of these systems, a proteomic approach was developed. A non-restrictive approach was developed to identify all the potential adaptation systems toward the secondary metabolites from host plants. The complex protein mixtures were separated by two-dimensional electrophoresis methods and the related spots of proteins significantly varying were selected and identified by mass spectrometry (ESI MS/MS) coupled with data bank investigations. Fourteen aphid proteins were found to vary according to host plant switch; ten of them were down regulated (proteins involved in glycolysis, TCA cycle, protein and lipid synthesis) while four others were overexpressed (mainly related to the cytoskeleton). These techniques are very reliable to describe the proteome from organisms such as insects in response to particular environmental change such as host plant species of herbivores. [less ▲]

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See detailLitterature review on the redistributive effects of pension systems
Grammenos, S.; Lefèbvre, Mathieu; Pestieau, Pierre ULg et al

Report (2006)

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See detailLe système anglais présagerait-il de l'avenir en matière de qualité de l'enseignement universitaire en Communauté française de Belgique ?
Vandeweerd, Jean-Michel ULg; Mignon, Jacques ULg; Reggers, Thérèse ULg

in Actes du 22e congrès de l’Association internationale de pédagogie universitaire (AIPU) (2006)

Issues du monde industriel, les démarches d'amélioration de la qualité se sont rapidement étendues aux autres secteurs. Elles faisaient cependant défaut au niveau de l'enseignement supérieur en Communauté ... [more ▼]

Issues du monde industriel, les démarches d'amélioration de la qualité se sont rapidement étendues aux autres secteurs. Elles faisaient cependant défaut au niveau de l'enseignement supérieur en Communauté française de Belgique. Comblant cette lacune, celle-ci vient de se doter d'un outil de gestion de la qualité de son enseignement. L’Agence d’Evaluation de la Qualité de l'Enseignement Supérieur (AEQES) a été constituée au premier janvier 2003. La première réunion s'est tenue un an plus tard (23 janvier 2004). Elle doit permettre de répondre aux recommandations européennes déjà arrêtées en la matière, d’assurer la représentation de la Communauté française de Belgique dans les instances concernées, mais surtout de doter cette communauté d'une structure organisant l'évaluation de la qualité de l'enseignement au sein des établissements. Dans ce contexte, il est peu probable d’échapper à un courant d’inspiration anglo-saxonne en matière de qualité de l’enseignement supérieur dans lequel le processus qualité est considéré comme un ROI (Return On Investment) ou un processus d'amélioration continue dépendant des moyens (humains, technologiques, financiers, …) qui lui sont consacrés. Le cas qui suit concerne le travail de réflexion d’une trentaine de professionnels autour de la démarche qualité dans l’enseignement supérieur en Communauté française de Belgique. [less ▲]

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See detailFormer à l'information : Pourquoi ? Comment ?
Pochet, Bernard ULg

in FADBEN (Ed.) 7è congrès des enseignants documentalistes de l'Educaton nationale - Information et démocratie. Formons nos citoyens (2006)

Force est de constater qu'il n'existe pas de capacité innée de repérage et d'exploitation de l'information. Ce sont des compétences qui s'acquièrent et pour lesquelles l'enseignement, l'école, a un rôle ... [more ▼]

Force est de constater qu'il n'existe pas de capacité innée de repérage et d'exploitation de l'information. Ce sont des compétences qui s'acquièrent et pour lesquelles l'enseignement, l'école, a un rôle essentiel à jouer. Il s'agit de compétences fondamentales donnant les moyens à l'individu, l'élève, l'étudiant, le travailleur, d'accéder à d'autres compétences et d'être un citoyen responsable à même de juger de la valeur réelle d’une information et d’avoir vis-à-vis d’elle une attitude critique lui permettant d’agir efficacement sur son environnement. La simplification apparente de l'accès à l'information amène à entendre un discours politique particulièrement simplificateur, davantage inquiet des aspects techniques de l'accès à « des informations » que du réel problème posé par la formation des utilisateurs. Il faut bien constater que souvent, il n'y a aucune volonté politique vis-à-vis du problème de la formation documentaire, comme il y en a si peu, en Belgique en tout cas, vis-à-vis du livre et de la documentation en général. Au cours de cette communication, nous tenterons de répondre aux questions posées ci-dessus, à la lumière de la réalité de l'enseignement supérieur en Communauté française de Belgique et de notre expérience au sein du groupe EduDOC. [less ▲]

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See detailMesures d’impact des régulations dans la construction d’un enseignement à distance (EAD) en initiation à l’entomologie
Mignon, Jacques ULg; Reggers, Thérèse ULg

in Revue Internationale des Technologies en Pédagogie Universitaire (2006), 3(1-2), 8-18

The course “Introduction to entomology” at Gembloux Agricultural University (Belgium) integrates both distance learning and laboratories. Its progressive development permits a precise description of the ... [more ▼]

The course “Introduction to entomology” at Gembloux Agricultural University (Belgium) integrates both distance learning and laboratories. Its progressive development permits a precise description of the experimentation influence and regulation steps on course’s parameters. The course has been evaluated by students and the results were compared with other indicators. The results showed a positive but insufficient progression. This confirms the difficulty to set up a distance learning with rapidity and effectiveness. Furthermore, this underscores the evolution of students’ needs and the importance of the permanent spiral of “experimentation-regulation and post-regulation”. [less ▲]

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See detailConflagrations. La mosaïque du Coup de dés
Durand, Pascal ULg

in Belloi, Livio; Delville, Michel (Eds.) L’Œuvre en morceaux. Esthétiques de la mosaïque (2006)

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See detailChromosomal patterns of gene expression from microarray data: methodology, validation and clinical relevance in gliomas.
Turkheimer, Federico E; Roncaroli, Federico; Hennuy, Benoît ULg et al

in BMC Bioinformatics (2006), 7

BACKGROUND: Expression microarrays represent a powerful technique for the simultaneous investigation of thousands of genes. The evidence that genes are not randomly distributed in the genome and that ... [more ▼]

BACKGROUND: Expression microarrays represent a powerful technique for the simultaneous investigation of thousands of genes. The evidence that genes are not randomly distributed in the genome and that their coordinated expression depends on their position on chromosomes has highlighted the need for mathematical approaches to exploit this dependency for the analysis of expression data-sets. RESULTS: We have devised a novel mathematical technique (CHROMOWAVE) based on the Haar wavelet transform and applied it to a dataset obtained with the Affymetrix HG-U133_Plus_2 array in 27 gliomas. CHROMOWAVE generated multi-chromosomal pattern featuring low expression in chromosomes 1p, 4, 9q, 13, 18, and 19q. This pattern was not only statistically robust but also clinically relevant as it was predictive of favourable outcome. This finding was replicated on a data-set independently acquired by another laboratory. FISH analysis indicated that monosomy 1p and 19q was a frequent feature of tumours displaying the CHROMOWAVE pattern but that allelic loss on chromosomes 4, 9q, 13 and 18 was much less common. CONCLUSION: The ability to detect expression changes of spatially related genes and to map their position on chromosomes makes CHROMOWAVE a valuable screening method for the identification and display of regional gene expression changes of clinical relevance. In this study, FISH data showed that monosomy was frequently associated with diffuse low gene expression on chromosome 1p and 19q but not on chromosomes 4, 9q, 13 and 18. Comparative genomic hybridisation, allelic polymorphism analysis and methylation studies are in progress in order to identify the various mechanisms involved in this multi-chromosomal expression pattern. [less ▲]

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See detailPhonon band structure and electron-phonon interactions in metallic nanowires
Verstraete, Matthieu ULg; Gonze, Xavier

in Physical Review. B : Condensed Matter (2006), 74

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See detailDu Résume Infirmier Minimum aux Données Infirmières du Résumé Hospitalier Minimal … évolution ou révolution ?
THONON, Olivier ULg; MANNA, Mirella

in GILSON, Patrick; LONGE, Patrick (Eds.) Mémento de l'Art Infirmier 2006/2007 (2006)

Detailed reference viewed: 14 (5 ULg)