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See detailConceptual model uncertainty in groundwater modeling: Combining generalized likelihood uncertainty estimation and Bayesian model averaging
Rojas, Rodrigo; Feyen, Luc; Dassargues, Alain ULg

in Water Resources Research (2008), 44

Uncertainty assessments in groundwater modeling applications typically attribute all sources of uncertainty to errors in parameters and inputs, neglecting what may be the primary source of uncertainty ... [more ▼]

Uncertainty assessments in groundwater modeling applications typically attribute all sources of uncertainty to errors in parameters and inputs, neglecting what may be the primary source of uncertainty, namely, errors in the conceptualization of the system.Confining the set of plausible system representations to a single model leads to underdispersive and prone-to-bias predictions. In this work, we present a general and flexible approach that combines generalized likelihood uncertainty estimation (GLUE) and Bayesian model averaging (BMA) to assess uncertainty in model predictions that arise from errors in model structure, inputs, and parameters. In a prior analysis, a set of plausible models is selected, and the joint prior input and parameter space is sampled to form potential simulators of the system. For each model, the likelihood measures of acceptable simulators, assigned to thembased on their ability to reproduce observed systembehavior, are integrated over the joint input and parameter space to obtain the integrated model likelihood. The latter is used to weight the predictions of the respective model in the BMA ensemble predictions. For illustrative purposes, we applied the methodology to a three-dimensional hypothetical setup. Results showed that predictions of groundwater budget terms varied considerably among competing models; despite this, a set of 16 head observations used for conditioning did not allow differentiating between the models. BMA provided average predictions that were more conservative than individual predictions obtained for individual models. Conceptual model uncertainty contributed up to 30% of the total uncertainty. The results clearly indicate the need to consider alternative conceptualizations to account for model uncertainty. [less ▲]

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See detailCentral Exclusive Dijet Production
Dechambre, Alice ULg; Cudell, Jean-René ULg; Ivanov, Igor ULg et al

in AIP Conference Proceedings (2008), 1038

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See detailWerner Rolevinck, Fasciculus temporum
Adam, Renaud ULg

in De Schepper, Marcus; Kelders, Ann; Pauwels, Jan (Eds.) Les seigneurs du livre. Les grands collectionneurs du XIXème siècle à la Bibliothèque royale de Belgique (2008)

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See detailJean de Saint-Laurent, Postillae evangeliorum totius anni et aliquorum festorum
Adam, Renaud ULg

in De Schepper, Marcus; Kelders, Ann; Pauwels, Jan (Eds.) Les seigneurs du livre. Les grands collectionneurs du XIXème siècle à la Bibliothèque royale de Belgique (2008)

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See detailJohannes de Sancto Laurentio, Postillae evangeliorum totius anni et aliquorum festorum
Adam, Renaud ULg

in De Schepper, Marcus; Kelders, Ann; Pauwels, Jan (Eds.) In de ban van boeken. Grote verzamelaars uit de negentiende eeuw in de Koninklijke Bibliotheek van België (2008)

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See detailLa sociologie critique de Pierre Bourdieu : le dernier structuralisme
Frère, Bruno ULg

in Jacquemain, Marc; Frère, Bruno (Eds.) Epistémologie de la sociologie (2008)

Pierre Bourdieu, décédé en 2002, a laissé derrière lui une œuvre riche d’une quarantaine d’ouvrages et de centaines d’articles1. L’école « critique » qu’il a forgée fait autorité depuis les années 70 pour ... [more ▼]

Pierre Bourdieu, décédé en 2002, a laissé derrière lui une œuvre riche d’une quarantaine d’ouvrages et de centaines d’articles1. L’école « critique » qu’il a forgée fait autorité depuis les années 70 pour toute une génération de sociologues à travers le monde. Aux innombrables traductions et commentaires accessibles dans toutes les langues s’ajoutent aujourd’hui des hommages dont il y a fort à parier que le nombre aura doublé d’ici la publication du présent texte. Mais des critiques, dès les années 80 se sont également présentées, non souvent sans une véritable pertinence (Boudon, Boltanski, Latour). Nous montrerons à ce titre qu'il est devenu impossible de les contourner depuis le point de vue critique, lequel n'est fonctionnel que sur certains terrains. Il peut donc apparaître très audacieux de prétendre, en quelques pages, à la fois résumer une œuvre aussi dense que complexe, déjà décortiquée par de nombreux spécialistes à maintes reprises et en présenter les principaux déficits. Pour nous aider dans cette tâche, nous nous armerons, en plus, des principaux textes de l’intéressé, des synthèses exhaustives de son oeuvre qui font actuellement autorité comme celles de Pinto (1998), de Mounier (2001), de Corcuff (2003a) et surtout celle Accardo sur laquelle nous nous appuierons principalement (1997) ainsi que des principaux ouvrages ayant engagé la discussion critique. En abordant les différents concepts clefs (habitus, champ, hexis, illusio) depuis ces derniers nous verrons en quoi cette sociologie, malgré son succès, peut continuer à être considérée sinon comme déterministe, en tout cas comme structuraliste. Il existe un ensemble de réalités sociales qu'elle ne permet pas d'éclairer et qui implique de se tourner vers d'autres paradigmes [less ▲]

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See detailRobustness of a thixoforming production line
Pierret, Jean-Christophe ULg; Rassili, Ahmed ULg; Vaneetveld, Grégory ULg et al

in Solid State Phenomena (2008), 141-143

The development of the thixoforming process made great progress since its beginning. But whereas thixoforming of aluminium and other low melting point alloys is now an industrial reality, thixoforming of ... [more ▼]

The development of the thixoforming process made great progress since its beginning. But whereas thixoforming of aluminium and other low melting point alloys is now an industrial reality, thixoforming of high melting point alloys, as steel, is still at the research level. High temperature issues, die wearing and production rate are problems that must be solved and are more and more investigated. This work is a study of the robustness of a complete thixoforming unit dealing with steel. This flexible unit allows parts of various shapes be formed in conditions close to industrial ones. The study focus on the heating strategy, heat exchanges between the slug and the tool, the feeding and the cycle time. In this work, modelling has been used to simulate heating and feeding. In parallel, experiments have been made to obtain the needed parameters, to validate the modelling and to evaluate the capacities of such a line. [less ▲]

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See detailOptimization of the formulation and post-treatment of stainless steel for rapid manufacturing
Vaneetveld, Grégory ULg; Clarinval, A. M.; Dormal, T. et al

in Journal of Materials Processing Technology (2008), 196(1-3), 160-164

Rapid prototyping process called Optoform shapes functional parts from a photocurable paste. This paste contains metal powder, resin, UV photoinitiator and wetting agent. After processing on the Optoform ... [more ▼]

Rapid prototyping process called Optoform shapes functional parts from a photocurable paste. This paste contains metal powder, resin, UV photoinitiator and wetting agent. After processing on the Optoform machine, a post-treatment is applied (debinding+sintering). During the post-treatment, the residual carbon coming from the resin modifies the composition of the metal and its melting point. This modification affects densification mechanisms, which leads to a residual porosity that lowers mechanical characteristics. We will present theoretical consideration leading to the optimization of the formulation. To improve the process, bimodal powder is used and thermal treatment is adapted. (c) 2007 Elsevier B.V. All rights reserved. [less ▲]

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See detailPrairies traditionnelles d'Ardenne
Philippe, Anne; Rouxhet, Serge ULg; Lambert, Jean et al

Book published by Région Wallonne (2008)

Les prairies traditionnelles, issues de pratiques agricoles traditionnelles et extensives, constituent en Région wallonne, comme sur l'ensemble de l'Europe occidentale, un des milieux les plus riches en ... [more ▼]

Les prairies traditionnelles, issues de pratiques agricoles traditionnelles et extensives, constituent en Région wallonne, comme sur l'ensemble de l'Europe occidentale, un des milieux les plus riches en espèces. Quatre types de prairies caractéristiques de cette région sont présentées avec quelques-unes de leurs plantes diagnostiques. [less ▲]

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See detailAn ac susceptometer for the characterization of large, bulk superconducting samples
Laurent, Philippe ULg; Fagnard, Jean-François ULg; Vanderheyden, Benoît ULg et al

in Measurement Science & Technology (2008), 19(8), 085705

The main purpose of this work was to design, develop and construct a simple, low-cost ac susceptometer to measure large, bulk superconducting samples (up to 32 mm in diameter) in the temperature range ... [more ▼]

The main purpose of this work was to design, develop and construct a simple, low-cost ac susceptometer to measure large, bulk superconducting samples (up to 32 mm in diameter) in the temperature range 78–120 K. The design incorporates a double heating system that enables a high heating rate (25 K h−1) while maintaining a small temperature gradient (<0.2 K) across the sample. The apparatus can be calibrated precisely using a copper coil connected in series with the primary coil. The system has been used successfully to measure the temperature dependence of the ac magnetic properties of entire RE–Ba–Cu–O [(RE)BCO] bulk superconducting domains. A typical ac susceptibility measurement run from 78 K to 95 K takes about 2 h, with excellent temperature resolution (temperature step ∼ 4 mK) around the critical temperature, in particular. [less ▲]

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See detailDirected forgetting and aging: the role of retrieval processes, processing speed, and proactive interference.
Hogge, Michaël; Adam, Stéphane ULg; Collette, Fabienne ULg

in Neuropsychology, Development, and Cognition. Section B, Aging, Neuropsychology and Cognition (2008), 15(4), 471-91

The directed forgetting effect obtained with the item method is supposed to depend on both selective rehearsal of to-be-remembered (TBR) items and attentional inhibition of to-be-forgotten (TBF) items. In ... [more ▼]

The directed forgetting effect obtained with the item method is supposed to depend on both selective rehearsal of to-be-remembered (TBR) items and attentional inhibition of to-be-forgotten (TBF) items. In this study, we investigated the locus of the directed forgetting deficit in older adults by exploring the influence of recollection and familiarity-based retrieval processes on age-related differences in directed forgetting. Moreover, we explored the influence of processing speed, short-term memory capacity, thought suppression tendencies, and sensitivity to proactive interference on performance. The results indicated that older adults' directed forgetting difficulties are due to decreased recollection of TBR items, associated with increased automatic retrieval of TBF items. Moreover, processing speed and proactive interference appeared to be responsible for the decreased recall of TBR items. [less ▲]

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See detailAsthme réfractaire : mécanismes sous-jacents, diagnostics et nouvelles approches thérapeutiques.
Manise, Maïté ULg; Louis, Renaud ULg

in Revue Médicale de Liège (2008), 63(7-8), 494-499

There has been a recent increase in the prevalence of asthma worldwide. Most cases can be satisfactorily managed with a combination of inhaled corticoids and bronchodilators. However, some 10% of patients ... [more ▼]

There has been a recent increase in the prevalence of asthma worldwide. Most cases can be satisfactorily managed with a combination of inhaled corticoids and bronchodilators. However, some 10% of patients remain symptomatic despite high doses of inhaled corticosteroids and long-acting β-2 agonists. They represent a heterogeneous group consisting of those who are either undertreated, or really refractory to current available treatment. [less ▲]

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See detailCahier des Charges Boeuf des Prairies Gaumaises
Hanus, Hélène; Roussel, Laurence; Stassart, Pierre M ULg et al

Learning material (2008)

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See detailL'intérêt botanique des anciennes exploitations de phyllades ardoisiers de Vielsalm Ardoise et coticule en Terre de Salm
Rouxhet, Serge ULg; Sérusiaux, Emmanuël ULg; Clesse, Joseph

in Goemaere, Eric (Ed.) Ardoise et coticule en Terre de Salm (2008)

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See detailCan laboratory tests help to define the profile of desensitised patients or patients at high risk of severe reaction ?
Gadisseur, Romy ULg; Collard, Ludivine; Cataldo, Didier ULg et al

in Allergy (2008), 63(Suppl. 88), 1773

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See detailCystatin C or Creatinine for Detection of Stage 3 Chronic Kidney Disease in Anorexia Nervosa.
Delanaye, Pierre ULg; Cavalier, Etienne ULg; Radermecker, Régis ULg et al

in Nephron. Clinical Practice (2008), 110(3), 158-163

Background: Patients with anorexia nervosa (AN) are at a high risk of renal failure. Chronic kidney disease (CKD) is often missed in these patients because the serum creatinine is a poor marker of kidney ... [more ▼]

Background: Patients with anorexia nervosa (AN) are at a high risk of renal failure. Chronic kidney disease (CKD) is often missed in these patients because the serum creatinine is a poor marker of kidney function. We studied the utility of cystatin C to detect renal failure in this population. Method: Twenty-seven AN patients were studied. Glomerular filtration rates (GFR) were measured with the chromium-51- ethylenediaminetetraacetate ((51)Cr-EDTA) method. We compared the ability of creatinine and cystatin C to detect stage 3 CKD (GFR below 60 ml/min) by ROC curve analysis. Results: In this cohort, there is no correlation between GFR and serum creatinine, but there is a significant correlation between cystatin C and GFR. By ROC analysis, the cystatin C concentration is better than the serum creatinine concentration for the detection of stage 3 CKD (area under the curve of 0.86 vs. 0.61, p = 0.05). Conclusion: Plasma cystatin C is better than serum creatinine in detecting stage 3 CKD in patients with AN. [less ▲]

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See detailNew data on the intraindividual variation of cystatin C.
Delanaye, Pierre ULg; Cavalier, Etienne ULg; Depas, Gisèle ULg et al

in Nephron. Clinical Practice (2008), 108(4), 246-8

BACKGROUND: Cystatin C is a new interesting marker of glomerular filtration rate (GFR). However, data regarding its biological variance are scarce and conflicting. The ability of cystatin C to ... [more ▼]

BACKGROUND: Cystatin C is a new interesting marker of glomerular filtration rate (GFR). However, data regarding its biological variance are scarce and conflicting. The ability of cystatin C to longitudinally follow renal function in patients therefore remains questionable. METHODS: 12 healthy subjects (6 men and 6 women) were included in the final statistical analysis. Serum creatinine, plasma cystatin C and GFR were measured twice after a 1-week interval on the same day, at the same time, and under the same preanalytical and analytical conditions. GFR was measured with an iohexol method. Serum creatinine was measured with a compensated Jaffe and an enzymatic method. Plasma cystatin C was measured by a particle-enhanced immunonephelometric method. Analytical (CV(A)) and within-subject (CV(I)) variances were classically calculated. RESULTS: CV(A) for creatinine (Jaffe and enzymatic methods) and cystatin C was 2.5, 0.97 and 1.29%, respectively. CV(I) was 5.8, 5 and 4.5% for the Jaffe creatinine, enzymatic creatinine and cystatin C determinations, respectively. CONCLUSION: Our study confirms that intraindividual variation of cystatin C and creatinine are similar. Therefore, from a biological point of view, cystatin C seems as accurate as creatinine for the longitudinal follow-up of renal function in daily clinical practice. [less ▲]

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See detailAre the IKKs and IKK-related kinases TBK1 and IKK-ε similarly activated ?
Chau, Tieu-Lan ULg; Gioia, Romain ULg; GATOT, Jean-Stéphane ULg et al

in Trends in Biochemical Sciences - Regular Edition (2008), 33

The IKKs, IKKa and IKKb, and the IKK-related kinases TBK1 and IKKe, play essential roles in innate immunity through signal-induced activation of NF-κB and IRF3/7, respectively. Although the signaling ... [more ▼]

The IKKs, IKKa and IKKb, and the IKK-related kinases TBK1 and IKKe, play essential roles in innate immunity through signal-induced activation of NF-κB and IRF3/7, respectively. Although the signaling events within these pathways have been extensively studied, the mechanisms of IKK and IKK-related complex assembly and activation remain poorly defined. Recent data provide insight into the requirement for scaffold proteins in complex assembly; NEMO coordinates some IKK complexes, whereas TANK, NAP1 or SINTBAD assemble TBK1 and IKKe complexes. The different scaffold proteins undergo similar post-translational modifications, including phosphorylation and non-degradative polyubiquitylation. Moreover, increasing evidence suggests that distinct scaffold proteins assemble IKK and potentially TBK1 and IKKε sub-complexes in a stimulus-specific manner, which might be a mechanism to achieve specificity. [less ▲]

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See detailAnalytical study of three cystatin C assays and their impact on cystatin C-based GFR-prediction equations.
Delanaye, Pierre ULg; Pieroni, Laurence; Abshoff, Christelle et al

in Clinica Chimica Acta (2008), 398(1-2), 118-24

BACKGROUND: Cystatin C-based equations are used to estimate GFR. However, three cystatin C immunoassays are on the market. Difference in cystatin C assays could have strong consequences on the accuracy ... [more ▼]

BACKGROUND: Cystatin C-based equations are used to estimate GFR. However, three cystatin C immunoassays are on the market. Difference in cystatin C assays could have strong consequences on the accuracy and precision of cystatin C-based equations. We have performed an analytical study of these three assays and studied potential differences between assays on the precision of cystatin C-based equations. METHODS: We have studied imprecision, recovery, linearity and interferences of the three immunoassays (nephelometric assay from Siemens and turbidimetric assays from Dako and Gentian). The impact of differences in cystatin C assays has been studied for the equations published by Levey (Siemens assay) and Grubb (Dako assay). RESULTS: Analytical performance of the Dako assay is slightly less high. For cystatin C values below 2.5 mg/L, no statistical difference is found between results given by the Dako and the Gentian assays. So, both assays can be used in the Grubb equation. Cystatin C results are different with the Siemens assay. The Levey equation, built with the Siemens assay, can only be used with cystatin C values measured with this assay. Using the Dako or Gentian assay results in the Levey equation can lead to differences in estimating GFR up to 6 mL/min/1.73 m2. Differences can reach 9.5 mL/min/1.73 m2 if the Siemens assay is used in the Grubb equation. CONCLUSION: The Siemens and Gentian assays seem analytically more valid than the Dako assay for cystatin C determination. Differences in cystatin C assays can lead to significant differences in cystatin C-based equations. However, these differences seem less important than the differences observed with creatinine and creatinine-based equations. [less ▲]

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