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See detailImpacts de la mise en service d'une microcentrale hydroélectrique sur les populations de poissons de la Lhomme à Poix Saint-Hubert
Ovidio, Michaël ULg; Philippart, Jean-Claude ULg; Paquer, Frédéric ULg et al

Report (2006)

Ce rapport présente une partie des résultats des recherches menées dans le cadre d’une convention d’études 2005-2007 entre le Ministère de la Région Wallonne (Division de l’Eau, Direction des Cours d’Eau ... [more ▼]

Ce rapport présente une partie des résultats des recherches menées dans le cadre d’une convention d’études 2005-2007 entre le Ministère de la Région Wallonne (Division de l’Eau, Direction des Cours d’Eau Non Navigables) et l’Université de Liège (Laboratoire de Démographie des Poissons et d’Hydroécologie, Unité de Biologie du Comportement). L’objet particulier de la recherche évoquée est le suivi biologique de la population piscicole de la Lhomme à Poix Saint-Hubert après la construction et la mise en service en fin 2002 d’une microcentrale hydroélectrique par la société S.A. Hydroval. La réalisation de cette étude correspond à une étude d’impact a posteriori, dont la réalisation conditionnait l’octroi du permis d’exploitation. Cette recherche très ciblée est une composante d’une convention d’études générale intitulée « Définition de bases biologiques et éco-hydrauliques pour la libre circulation des poissons dans les cours d'eau non navigables de Wallonie ». [less ▲]

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See detailIFFT-equivariant quantizations
Boniver, Fabien; Mathonet, Pierre ULg

in Journal of Geometry and Physics (2006), 56(4), 712-730

The existence and uniqueness of quantizations that are equivariant with respect to conformal and projective Lie algebras of vector fields were recently obtained by Duval, Lecomte and Ovsienko. In order to ... [more ▼]

The existence and uniqueness of quantizations that are equivariant with respect to conformal and projective Lie algebras of vector fields were recently obtained by Duval, Lecomte and Ovsienko. In order to do so, they computed spectra of some Casimir operators. We give an explicit formula for those spectra in the general framework of IFFT-algebras classified by Kobayashi and Nagano. We also define tree-like subsets of eigenspaces of those operators in which eigenvalues can be compared to show the existence of IFFT-equivariant quantizations. We apply our results to prove the existence and uniqueness of quantizations that are equivariant with respect to the infinitesimal action of the symplectic (resp. pseudo-orhogonal) group on the symplectic (resp. pseudo-orthogonal) Grassmann manifold. [less ▲]

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See detailProgramme d'action sur le lien entre santé et alimentation auprès des usagers des maisons médicales liégeoises
Lachaussée, Christine; Legrève, Christian; Miermans, Marie-Christine ULg

in Santé Conjuguée (2006), (36), 25-34

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See detailFasciites nécrosantes: stratégie diagnostique et thérapeutique
Smeets, Laurent ULg; Bous, Aurélie ULg; Lecoq, Jean-Pierre ULg et al

in Revue Médicale de Liège (2006), 61(4), 240-244

The necrotizing fasciitis is a medico-surgical emergency, characterized by the rapid speard of the infection in the subcutaneous tissue, involving fascia superficialis. Peaucity of cutaneous findings ... [more ▼]

The necrotizing fasciitis is a medico-surgical emergency, characterized by the rapid speard of the infection in the subcutaneous tissue, involving fascia superficialis. Peaucity of cutaneous findings early in the course of the disease makes diagnosis a challenge for physician. Pain out of proportion to clinical findings, fever and signs of systemic toxicity are the keys in identification of necrotizing fasciitis. Delayed diagnosis lead to sepsis syndrom and/or multiple organ failure and correlate with poor oucome. Radiolographs, CT-scan or MRI are main radiologic studies, but such procedures should never delay surgical intervention. Intravenous antibiotics, fluid and electrolyte management and analgesia are needed in addition to radical debridment. Clindamycin, hyperbaric oxygen therapy and intravenous immunoglobulins are discussed treatments. Only prompt recognition and immediat care warrant a lower mortality and morbidity for this life-threatening infection. [less ▲]

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See detailL'image du mois. Un cas inhabituel d'insuffisance aortique aigue
Quaniers, Janine ULg; Legrand, V.; Limet, Raymond ULg

in Revue Médicale de Liège (2006), 61(4), 211

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See detailOffline persistence of memory-related cerebral activity during active wakefulness
Peigneux, Philippe ULg; Orban, Pierre ULg; Balteau, Evelyne ULg et al

in PLoS Biology (2006), 4(4), 100

Much remains to be discovered about the fate of recent memories in the human brain. Several studies have reported the reactivation of learning-related cerebral activity during post-training sleep ... [more ▼]

Much remains to be discovered about the fate of recent memories in the human brain. Several studies have reported the reactivation of learning-related cerebral activity during post-training sleep, suggesting that sleep plays a role in the offline processing and consolidation of memory. However, little is known about how new information is maintained and processed during post-training wakefulness before sleep, while the brain is actively engaged in other cognitive activities. We show, using functional magnetic resonance imaging, that brain activity elicited during a new learning episode modulates brain responses to an unrelated cognitive task, during the waking period following the end of training. This post-training activity evolves in learning-related cerebral structures, in which functional connections with other brain regions are gradually established or reinforced. It also correlates with behavioral performance. These processes follow a different time course for hippocampus-dependent and hippocampus-independent memories. Our experimental approach allowed the characterization of the offline evolution of the cerebral correlates of recent memories, without the confounding effect of concurrent practice of the learned material. Results indicate that the human brain has already extensively processed recent memories during the first hours of post-training wakefulness, even when simultaneously coping with unrelated cognitive demands. [less ▲]

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See detailNouvelles frontières de l’entreprise et gestion de l’emploi, le cas des centres d’appels
Rorive, Brigitte; Naedenoen, Frédéric ULg

Conference (2006, April)

To understand the link between new corporate boundaries and employment management, we must take the heterogeneity of the call centers industry and its companies into account. Often described for the ... [more ▼]

To understand the link between new corporate boundaries and employment management, we must take the heterogeneity of the call centers industry and its companies into account. Often described for the degradation of the employment and work conditions that it creates, the call center industry is nevertheless far to response to an unique logic of job management. Through four case studies, diversified according to 2 axes: the level of added value offered by the call centers and its organizational complexity, let emerge different kind of logics, influenced by the position of the studied company on these two axes. They show the existence of a link between the configuration of inter-organizational relationship and the internal politics of human resources and employment management. This link has an effect on the extreme difficulty to conciliate the worker’s and the organizations’s interests, particularly when the client heavily intervene in the call center internal management , or influence strongly its operations by contractual requirements. [less ▲]

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See detailINTEGRAL detection of hard X-rays from NGC 6334: nonthermal emission from colliding winds or an AGN?
Bykov, A. M.; Krassilchtchikov, A. M.; Uvarov, Y. A. et al

in Astronomy and Astrophysics (2006), 449(3), 917-923

Aims. We report the detection of hard X-ray emission from the field of the star-forming region NGC 6334 with the International Gamma-Ray Astrophysics Laboratory INTEGRAL. Methods. The JEM-X monitor and ... [more ▼]

Aims. We report the detection of hard X-ray emission from the field of the star-forming region NGC 6334 with the International Gamma-Ray Astrophysics Laboratory INTEGRAL. Methods. The JEM-X monitor and ISGRI imager aboard INTEGRAL and Chandra ACIS imager were used to construct 3-80 keV images and spectra of NGC 6334. Results. The 3-10 keV and 10-35 keV images made with JEM-X show a complex structure of extended emission from NGC 6334. The ISGRI source detected in the energy ranges 20-40 keV, 40-80 keV, and 20-60 keV coincides with the NGC 6334 ridge. The 20-60 keV flux from the source is (1.8 +/- 0.37) x 10(-11) erg cm(-2) s(-1). Spectral analysis of the source revealed a hard power-law component with a photon index about 1. The observed X-ray fluxes are in agreement with extrapolations of X-ray imaging observations of NGC 6334 by Chandra ACIS and ASCAGIS. Conclusions. The X-ray data are consistent with two very different physical models. A probable scenario is emission from a heavily absorbed, compact and hard Chandra source that is associated with the AGN candidate radio source NGC 6334B. Another possible model is the extended Chandra source of nonthermal emission from NGC 6334 that can also account for the hard X-ray emission observed by INTEGRAL. The origin of the emission in this scenario is due to electron acceleration in energetic outflows from massive early type stars. The possibility of emission from a young supernova remnant, as suggested by earlier infrared observations of NGC 6334, is constrained by the non-detection of Ti-44 lines. [less ▲]

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See detailImportance of risk stratification models in cardiac surgery
Kolh, Philippe ULg

in European Heart Journal (2006), 27(7), 768-769

This editorial refers to 'Comparison of 19 pre-operative risk strati. cation models in open-heart surgery'dagger by J. Nilsson et al., on page 867.

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See detailLes céphalées par abus d'antalgiques et d'anti-migraineux
Fumal, Arnaud ULg; Magis, Delphine ULg; Schoenen, Jean ULg

in Revue Médicale de Liège (2006), 61(4), 217-22

Medication overuse headache (MOH) insidiously evolves from episodic migraine or tension-type headache because of overconsumption of analgesics, ergotamine or triptans. It affects 1-2% of the general ... [more ▼]

Medication overuse headache (MOH) insidiously evolves from episodic migraine or tension-type headache because of overconsumption of analgesics, ergotamine or triptans. It affects 1-2% of the general population, but 15-20% of patients attending specialized headache centers. The precise neurobiologic mechanisms underlying this complication of episodic headaches are not well understood. Abnormalities of central monoaminergic systems have been suggested and substance dependence is more frequent in personal and family histories of affected subjects. In a recent FDG-PET study of 16 migraineurs with MOH before and after analgesics withdrawal we found a persistent hypometabolism of the medial orbitofrontal cortex, comparable to the one described after withdrawal in substance abuse. The orbitofrontal cortex plays a pivotal role in drive, decision-making and drug dependence. We postulate that its hypoactivity predisposes certain migraineurs to MOH and to relapse after withdrawal. There is no unique management strategy for these patients, but medication withdrawal is a prerequisite for the effectiveness of preventive treatments and headache improvement. [less ▲]

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See detailExtremely randomized trees
Geurts, Pierre ULg; Ernst, Damien ULg; Wehenkel, Louis ULg

in Machine Learning (2006), 63(1), 3-42

This paper proposes anew tree-based ensemble method for supervised classification and regression problems. It essentially consists of randomizing strongly both attribute and cut-point choice while ... [more ▼]

This paper proposes anew tree-based ensemble method for supervised classification and regression problems. It essentially consists of randomizing strongly both attribute and cut-point choice while splitting a tree node. In the extreme case, it builds totally randomized trees whose structures are independent of the output values of the learning sample. The strength of the randomization can be tuned to problem specifics by the appropriate choice of a parameter. We evaluate the robustness of the default choice of this parameter, and we also provide insight on how to adjust it in particular situations. Besides accuracy, the main strength of the resulting algorithm is computational efficiency. A bias/variance analysis of the Extra-Trees algorithm is also provided as well as a geometrical and a kernel characterization of the models induced. [less ▲]

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See detailAllégorie et langue peuple. De Rictus à Mallarmé
Durand, Pascal ULg

in Bon-A-Tirer : Revue Littéraire en Ligne (2006), 44

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See detailQuatre maisons d'architecte à Liège
Charlier, Sébastien ULg

in Nouvelles du Patrimoine (Les) (2006), 112

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See detailCombining classification techniques with Kalman filters for aircraft engine diagnostics
Dewallef, Pierre ULg; Romessis, C.; Léonard, Olivier ULg et al

in Journal of Engineering for Gas Turbines & Power (2006), 128(2), 281-287

A diagnostic method consisting of a combination of Kalman filters and Bayesian Belief Network (BBN) is presented. A soft-constrained Kalman filter uses a priori information derived by a BBN at each time ... [more ▼]

A diagnostic method consisting of a combination of Kalman filters and Bayesian Belief Network (BBN) is presented. A soft-constrained Kalman filter uses a priori information derived by a BBN at each time step, to derive estimations of the unknown health parameters. The resulting algorithm hers improved identification capability in comparison to the stand-alone Kalman filter. The paper focuses on a way of combining the information produced by the BBN with the Kalman filter. An extensive set of fault cases is used to test the method on a typical civil turbofan layout. The effectiveness of the method is thus demonstrated, and its advantages over individual constituent methods are presented. [less ▲]

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See detailImportance of the creatinine calibration in the estimation of GFR by MDRD equation
Delanaye, Pierre ULg; Cavalier, Etienne ULg; Chapelle, Jean-Paul ULg et al

in Nephrology Dialysis Transplantation (2006), 21(4), 1130-1130

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See detailLiMn2-xTixO4 spinel-type compounds (x <= 1): Structural, electrical and magnetic properties
Krins, Natasha ULg; Hatert, Frédéric ULg; Traina, Karl ULg et al

in Solid State Ionics (2006), 177(11-12), 1033-1040

LiMn2-xTixO4 compounds with 0.5 =<x =< 1 were prepared by solid state reaction and Pechini technique. Powder X-ray diffraction showed that all samples crystallize with the spinel crystal structure (S.G ... [more ▼]

LiMn2-xTixO4 compounds with 0.5 =<x =< 1 were prepared by solid state reaction and Pechini technique. Powder X-ray diffraction showed that all samples crystallize with the spinel crystal structure (S.G. Fd3m). The cubic unit-cell parameter increases with the Ti content. The influence of the Ti content and cationic distribution on the magnetic properties of the compounds was studied by measuring the temperature and magnetic field dependences of the magnetization: substitution by non-magnetic d(0) Ti4+ ions appeared to weaken the magnetic interactions between the manganese ions. The electrical properties of LiMnTiO4 were studied by AC impedance spectroscopy and DC polarisation measurements, which revealed the electronic character of the conduction process. (c) 2006 Elsevier B.V. All rights reserved. [less ▲]

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See detailL'osteodensitometrie dans le depistage de l'osteoporose: le paradoxe Belge
Neuprez, A.; Gillet, Philippe ULg; Collette, C. et al

in Revue Médicale de Liège (2006), 61(4), 249-55

Osteoporosis is considered as a major Public Health issue, in most developed countries. Bone mineral density assessment is the single best predictor of the future fracture risk for an individual. Belgium ... [more ▼]

Osteoporosis is considered as a major Public Health issue, in most developed countries. Bone mineral density assessment is the single best predictor of the future fracture risk for an individual. Belgium has the highest number of bone densitometers, per million habitants, in Europe. However, densitometry is not yet reimbursed in Belgium. This situation is rather paradoxical since the demonstration of a prevalent vertebral fracture or of a low bone mineral density is requested to obtain the reimbursement of drugs to be used for the management of osteoporosis. Hopefully, Belgium will soon be online with the requirement s of the European Commission, suggesting to make bone densitometry accessible, through reimbursement. [less ▲]

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See detailTOTEM: A Toolbox for Traffic Engineering Methods
Lepropre, Jean; Balon, Simon ULg; Leduc, Guy ULg

Poster (2006, April)

In this document, we propose a demonstration of TOTEM, a TOolbox for Traffic Engineering Methods. This toolbox integrates a series of tools for intra-domain and inter-domain traffic engineering of IP and ... [more ▼]

In this document, we propose a demonstration of TOTEM, a TOolbox for Traffic Engineering Methods. This toolbox integrates a series of tools for intra-domain and inter-domain traffic engineering of IP and MPLS networks. It provides an open source software that allows an operator to test methods coming from the academic research. A researcher can also use the toolbox to compare and promote new TE algorithms. The toolbox is designed to be deployed either as an on-line tool in an operational network, or as an off-line traffic engineering simulator. [less ▲]

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See detailBegian Surveillance Plans to Assess Changes in Salmonella Prevalence in Meat Production Stages.
Ghafir, Yasmine; China, Bernard; Korsak Koulagenko, Nicolas ULg et al

Article for general public (2006)

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