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See detailModelling weathering processes at the catchment scale: The WITCH numerical model
Godderis, Y.; François, Louis ULg; Probst, A. et al

in Geochimica et Cosmochimica Acta (2006), 70(5), 1128-1147

A numerical model of chemical weathering in soil horizons and underlying bedrock (WITCH) has been coupled to a numerical model of water and carbon cycles in forest ecosystems (ASPECTS) to simulate the ... [more ▼]

A numerical model of chemical weathering in soil horizons and underlying bedrock (WITCH) has been coupled to a numerical model of water and carbon cycles in forest ecosystems (ASPECTS) to simulate the concentration of major species within the soil horizons and the stream of the Strengbach granitic watershed, located in the Vosges Mountains (France). For the first time, simulations of solute concentrations in soil layers and in the catchment river have been performed on a seasonal basis. The model is able to reproduce the concentrations of most major species within the soil horizons, as well as catching the first-order seasonal fluctuations of aqueous calcium, magnesium and silica concentrations. However, the WITCH model underestimates concentrations of Mg2+ and silica at the spring of the catchment stream, and significantly underestimates Ca2+ concentration. The deficit in calculated calcium can be compensated for by dissolution of trace apatite disseminated in the bedrock. However, the resulting increased Ca2+ release yields important smectite precipitation in the deepest model layer (in contact with the bedrock) and subsequent removal of large amount of silica and magnesium from solution. In contrast, the model accurately accounts for the concentrations of major species (Ca, Mg and silica) measured in the catchment stream when precipitation of clay minerals is not allowed. The model underestimation of Mg2+ and H4SiO4 concentrations when precipitation of well crystallized smectites is allowed strongly suggests that precipitation of well crystallized clay minerals is overestimated and that more soluble poorly crystallized and amorphous materials may be forming. In agreement with observations on other watersheds draining granitic rocks, this study indicates that highly soluble trace calcic phases control the aqueous calcium budget in the Strengbach watershed. (c) 2005 Elsevier Inc. All rights reserved. [less ▲]

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See detailEtude écopathologique des facteurs de risque des mammites dans les élevages laitiers en Wallonie
Delfosse, C.; Froidmont, E.; Curnel, Y. et al

Poster (2006)

La mammite a de multiples origines et est souvent de type subclinique, rendant contrôle et surveillance difficiles. La majorité des études relatives aux mammites se caractérise par une approche ... [more ▼]

La mammite a de multiples origines et est souvent de type subclinique, rendant contrôle et surveillance difficiles. La majorité des études relatives aux mammites se caractérise par une approche individuelle. Le cadre expérimental restreint de celles-ci ne permet pas une interprétation précise des observations, à la suite du nombre limité de facteurs étudiés. L’approche choisie pour cette étude se veut globale et implique un grand nombre d’exploitations. Elle a pour objectifs d’identifier et de hiérarchiser, au travers d’une enquête, les caractéristiques générales de traite et les conditions environnementales des élevages laitiers influençant le statut sanitaire du pis [less ▲]

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See detailParasites and the island syndrome: the colonization of the western Mediterranean islands by Heligmosomoides polygyrus (Dujardin, 1845)
Nieberding, Caroline M. ULg; Morand, S.; Libois, Roland ULg et al

in Journal of Biogeography (2006), 33(7), 1212-1222

Aim Populations of free-living vertebrates on islands frequently differ from their mainland counterparts by a series of changes in morphometric, life-history, behavioural, physiological and genetic traits ... [more ▼]

Aim Populations of free-living vertebrates on islands frequently differ from their mainland counterparts by a series of changes in morphometric, life-history, behavioural, physiological and genetic traits, collectively referred to as the 'island syndrome'. It is not known, however, whether the 'island syndrome' also affects parasitic organisms. The present study establishes the colonization pattern of the Mediterranean islands by the nematode Heligmosomoides polygyrus, a direct and specific parasite of rodent hosts of the Apodemus genus, and evaluates the effects of island colonization by this species on two components of the island syndrome: the loss of genetic diversity and the enlargement of the ecological niche. Location Heligmosomoides polygyrus was sampled on seven western Mediterranean islands - Corsica, Crete, Elba, Majorca, Minorca, Sardinia and Sicily - as well as in 20 continental locations covering the Mediterranean basin. Methods The mitochondrial cytochrome b gene (690 base pairs) was sequenced in 166 adult H. polygyrus individuals sampled in the 27 continental and island locations. Phylogenetic reconstructions in distance, parsimony, maximum likelihood and Bayesian posterior probabilities were carried out on the whole cytochrome b gene data set. The levels of nucleotide, haplotype and genetic divergence (Kimura two-parameter distance estimator) diversities were estimated in each island population and in the various continental lineages. Results Phylogenetic reconstructions show that the mainland origins of H. polygyrus were continental Spain for the Balearic Islands (Majorca, Minorca), northern Italy for the Tyrrhenian Islands (Corsica, Sardinia, Elba), southern Italy for Sicily, and the Balkan region for Crete. A comparison of island H. polygyrus populations with their mainland source populations revealed two characteristic components of the island syndrome in this parasite. First, island H. polygyrus populations display a significant loss of genetic diversity, which is related (r(2) = 0.73) to the distance separating the island from the mainland source region. Second, H. polygyrus exhibits a niche enlargement following insularization. Indeed, H. polygyrus in Corsica is present in both A. sylvaticus and Mus musculus domesticus, while mainland H. polygyrus populations are present exclusively in Apodemus hosts. Main conclusions Our results show that H. polygyrus has undergone a loss of genetic diversity and a niche (host) enlargement following colonization of the western Mediterranean islands. To our knowledge, this study provides the first evidence for components of the 'island syndrome' in a parasitic nematode species. [less ▲]

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See detailInAs with wurtzite crystal structure: full-potential and psedopotential ab-initio calculations
Zanolli, Zeila ULg; von Barth, Ulf

in Luitz, Joachim; Hebert, Cecile; Weinmeier, Kerstin (Eds.) et al DFTEM2006 - bringing together two communities (2006)

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See detailA Principal-Agent Theory Approach to Public Expenditure Management Systems in Developing Countries
Leruth, Luc ULg; Paul, Elisabeth ULg

in IMF Working Paper (2006), 06/204

A well-functioning public expenditure management (PEM) system is considered a critical pillar of government efficiency, on par with a low-distortion tax system and efficient tax administration. The paper ... [more ▼]

A well-functioning public expenditure management (PEM) system is considered a critical pillar of government efficiency, on par with a low-distortion tax system and efficient tax administration. The paper discusses PEM systems in developing countries using an analytical framework based on principal-agent theory. This simple model can be applied to various PEM systems, and allows for comparisons between institutional settings. To illustrate this, we analyze the benefits derived from the use by the Ministry of Finance (MoF) of two control instruments; ex post audits and ex ante controls, and assess their value in terms of their ability to deter cheating. We derive a set of possible “control regimes” which can be used by the MoF. Although we illustrate the use of the model using developing countries, it is also relevant to developed economies. [less ▲]

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See detailSTRATEGY FOR THE QUALITATIVE AND QUANTITATIVE ANALYSIS OF CROP SYRUP CONTAINING ISOMALTOOLIGOSACCHARIDES KNOWN AS EMERGING PREBIOTICS
Goffin, Dorothée ULg

Conference (2006)

Isomaltooligosaccharides (IMOs) are non-digestible oligosaccharides, considered as prebiotics and therefore aim to selectively feed probiotics indigenous to the human colon. Recent data obtained in human ... [more ▼]

Isomaltooligosaccharides (IMOs) are non-digestible oligosaccharides, considered as prebiotics and therefore aim to selectively feed probiotics indigenous to the human colon. Recent data obtained in human subjects, support the involvement of dietary oligosaccharides in physiological processes in the different intestinal cell type and also outside the gastrointestinal tract (e.g. hormone production, lipid and carbohydrate metabolism). IMOs consists of glucose monomers linked by at least one α-1-6, or in a lower proportion α -1-3 (nigerose family) or α -1-2 (kojibiose family) glucosidic linkages. In our case they are produced enzymatically from corn starch. It results in a very complex mixture with molecules characterized at the same time by their DP value (from 2 to ~20), linkages types (α-1-2, 3 or 6) and the proportion and position of each type of linkage (only α -1-6 or combined types). The challenge of this study was to find a qualitative and quantitative method to characterize the syrups. In a subsequent study, every unidentified peak could be determined by NMR or Mass spectrometry. Three different chromatographic methods have been tested and compared over their selectivity, sensibility, robustness, applicability and their quantitative power. The HPLC-RID (Refractive Index Detector) used with a Prevail Carbohydrate column (Alltech), adapted for carbohydrates with a certain value of DP, appear to be poorly selective due to the obligation of working in isocratic conditions. The HPLC-ELSD (Evaporating Light Scattering Detector) used with the same column gave a very good separation upon the DP as the Prevail accepts a wide range of solvant changing and even a separation of the different DP 2 molecules. The sensibility was also improved due to the stability of the baseline. The quantitative analysis is a bit more awkward due to the relatively limited linear portion of the calibration curve. High-performance Anion Exchange Chromatography coupled with Pulsed Amperometric Detection (HPAEC-PAD) appeared to deserve a special mention, since it provides selective separation and sensitive detection. In fact, this technique is the only chromatographic one to separate with effectiveness homologue molecules having a difference only in their DP (up to high DPs) or linkage types. This is due to the separation mode based on the difference in ionic force of the sugars in alkaline conditions (mainly due to the DP and the structure of the molecule). However, during the detection, the electrochemical behavior of carbohydrates can be affected by molecular weight as well as by structural differences giving rise to different response factors; as a consequence, HPAEC-PAD is not generally considered as suitable for quantitative studies of complex mixtures of oligosaccharides. In this work a methodological approach is presented in order to get a quantitative response through a rigorous methodology for our IMOs. It also opens the way to the theoretical determination of the response factor for the homologue molecules in relation with their structure and DP. [less ▲]

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See detailHistone deacetylase 7 is involved in the control of angiogenesis by regulating platelet-derived growth factor-β
Mottet, Denis; Bellahcene, Akeila ULg; Deroanne, Christophe et al

Conference (2006)

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See detailThe antitrypanosomal drug melarsoprol competitively inhibits thiamin uptake in mouse neuroblastoma cells
Szyniarowski, Piotr; Bettendorff, Lucien ULg; Schweingruber, M. E.

in Cell Biology and Toxicology (2006), 22(3), 183-187

Melarsoprol is the main drug used for the treatment of late-stage sleeping sickness, although it causes severe side-effects such as encephalopathy and polyneuropathy leading to death in some patients ... [more ▼]

Melarsoprol is the main drug used for the treatment of late-stage sleeping sickness, although it causes severe side-effects such as encephalopathy and polyneuropathy leading to death in some patients. Recent data suggest that melarsoprol and its active metabolite melarsenoxide interfere with thiamin transport and metabolism in E. coli and yeast, but there are no data concerning their possible effects on thiamin metabolism in mammalian cells. We tested both drugs on thiamin transport in cultured mouse neuroblastoma cells using C-14-labeled thiamin. Melarsoprol, competitively inhibits high-affinity thiamin transport in mouse neuroblastoma cells with a K-i of 44 mu mol/L. However, the active compound melarsenoxide has no inhibitory effect. This suggests that the side effects of melarsoprol treatment are unlikely to be due to inhibition of thiamin transport by melarsenoxide, its main metabolite in the brain. [less ▲]

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See detailCannulation of bovine fetuses for a long period blood collection: the chirurgical approach
Touati, Kamal ULg; Melo de Sousa, Noelita ULg; Van der Weijden, G. C. et al

in Proceedings: 24th World Buiatrics Congress (2006)

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See detailLa politique industrielle sous les tirs croisés de la mondialisation et du droit communautaire de la concurrence
Petit, Nicolas ULg

in Mondialisation politique industrielle et droit comm de la concurrence (2006)

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See detailContribution à l’étude du rayonnement solaire à la station météorologique du Mont Rigi. Transparence de l’atmosphère et albédo
Dury, Marie ULg

Master's dissertation (2006)

Notre mémoire s’est centré sur le rayonnement solaire au Mont Rigi à partir de la grande quantité de paramètres météorologiques engrangés par la nouvelle station météorologique automatique de l’I.R.M ... [more ▼]

Notre mémoire s’est centré sur le rayonnement solaire au Mont Rigi à partir de la grande quantité de paramètres météorologiques engrangés par la nouvelle station météorologique automatique de l’I.R.M. (2001). Jusqu’à ce jour, aucune étude systématique n’avait encore été consacrée à ce beau sujet. Dans la première partie, nous présentons la station et les appareils de mesure en étant surtout soucieuse d’évoquer et d’illustrer les perturbations dont peuvent souffrir les mesures suite aux conditions météorologiques parfois rudes dans les Hautes-Fagnes telles qu’on n’en rencontre pas dans les autres stations automatiques du pays et qui ne sont pas toujours compatibles avec des enregistrements automatiques. La deuxième partie, point central de notre travail, porte sur l’étude de la transparence de l’atmosphère au Mont Rigi avec pour objectif de mettre en évidence les particularités de la composition de l’air de la région et de quantifier son influence sur le rayonnement solaire. Nous avons utilisé les paramètres à notre disposition: la hauteur du soleil, la teneur en vapeur d’eau de l’air (caractérisée par la hauteur d’eau condensable) et la couverture nuageuse. La troisième partie s’intéresse à la variation de l’albédo de la surface sous le pyranomètre, caractérisée par une végétation herbacée et hétérogène, composée d’espèces courantes dans les Hautes-Fagnes (épilobes en épis, myrtille, callune,…). Cette question n'a pas constitué le point central de notre recherche mais étant donné que nous possédions deux ans et demi de mesures en continu d’albédo, il était intéressant d’apporter de nouvelles observations à l’étude de ce paramètre. [less ▲]

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See detailPolitiques de l'autobiographie chez Sartre
Denis, Benoît ULg

in Temps Modernes (Les) (2006), (641), 149-167

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See detailBiodiversity of cucurbits consumed as sauce thickener in Ivory Coast : a capital resource for the economic prosperity of rural women
Zoro Bi, I.; Koffi, K. K.; Dje, Y. et al

in Tropical Biodiversity : Science, Date, Conservation (2006)

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