Publications ORBi OA
Bookmark and Share    
Full Text
Peer Reviewed
See detailLearned material content and acquisition level modulate cerebral reactivation during posttraining rapid-eye-movements sleep
Peigneux, Philippe ULg; Laureys, Steven ULg; Fuchs, Sonia et al

in NeuroImage (2003), 20(1), 125-134

We have previously shown that several brain areas are activated both during sequence learning at wake and during subsequent rapid-eye-movements (REM) sleep (Nat. Neurosci. 3 (2000) 831-836), suggesting ... [more ▼]

We have previously shown that several brain areas are activated both during sequence learning at wake and during subsequent rapid-eye-movements (REM) sleep (Nat. Neurosci. 3 (2000) 831-836), suggesting that REM sleep participates in the reprocessing of recent memory traces in humans. However, the nature of the reprocessed information remains open. Here, we show that regional cerebral reactivation during posttraining REM sleep is not merely related to the acquisition of basic visuomotor skills during prior practice of the serial reaction time task, but rather to the implicit acquisition of the probabilistic rules that defined stimulus sequences. Moreover, functional connections between the reactivated cuneus and the striatum-the latter being critical for implicit sequence learning-are reinforced during REM sleep after practice on a probabilistic rather than on a random sequence of stimuli. Our results therefore support the hypothesis that REM sleep is deeply involved in the reprocessing and optimization of the high-order information contained in the material to be learned. In addition, we show that the level of acquisition of probabilistic rules attained prior to sleep is correlated to the increase in regional cerebral blood flow during subsequent REM sleep. This suggests that posttraining cerebral reactivation is modulated by the strength of the memory traces developed during the learning episode. Our data provide the first experimental evidence for a link between behavioral performance and cerebral reactivation during REM sleep. (C) 2003 Elsevier Inc. All rights reserved. [less ▲]

Detailed reference viewed: 35 (4 ULg)
Full Text
See detailConférence citoyenne sur les tests génétiques "Lire dans mes gènes" - Rapport d'évaluation
Mormont, Marc ULg; Melard, François ULg

Report (2003)

Rapport d'évaluation sur la première conférence citoyenne nationale en Belgique (FRB). Le rapport présente les implications méthodologiques liées au fonctionnement de la conférence citoyenne.

Detailed reference viewed: 26 (5 ULg)
Full Text
Peer Reviewed
See detailDurability of mortars modified with metakaolin
Courard, Luc ULg; Darimont, Anne ULg; Schouterden, M. et al

in Cement & Concrete Research (2003), 33(9), 1473-1479

Results of an investigation to determine the effects of metakaolin additions on transport properties of mortars are reported. Comparisons are made to ordinary Portland cement (OPC) to determine the ... [more ▼]

Results of an investigation to determine the effects of metakaolin additions on transport properties of mortars are reported. Comparisons are made to ordinary Portland cement (OPC) to determine the influence of addition and replacement percentage. Cement is replaced on a mass basis of 5-20% for metakaolin. A mixture with natural kaolin is also studied. The transport properties and chemical behaviors are analyzed by means of chloride diffusion tests and sulfate immersion. Obserdvations after more than 100 days are used to prescribe mixtures that reduce the rate of chloride diffusion and sulfate degradation. For metakaolin, the optimum seems to be between 10% and 15% with regard to inhibition effect on chloride diffusion and sulfate attack. (C) 2003 Elsevier Ltd. All rights reserved. [less ▲]

Detailed reference viewed: 91 (10 ULg)
Full Text
Peer Reviewed
See detailA tool to design steel elements submitted to compartment fires - OZone V2. Part 2: Methodology and application
Cadorin, Jean-François; Pintea, Dan; Dotreppe, Jean-Claude ULg et al

in Fire Safety Journal (2003), 38(5), 429-451

The methodology implemented in the tool OZone V2 to design steel elements submitted to compartment fires is presented. Input needed to define a fire compartment are first quoted. The procedure to define ... [more ▼]

The methodology implemented in the tool OZone V2 to design steel elements submitted to compartment fires is presented. Input needed to define a fire compartment are first quoted. The procedure to define the design fire is then explained. This procedure enables to take into account the benefits of active measures on the fire safety. The combined use of a two- and a one-zone model is then presented. A particular attention is given to the criteria of choice of the model and to the different scenarios that can occur. The calculation of steel element temperature is then explained. The proposed procedure takes into account the localised effect of a fire with the help of Hasemi's model. The fire resistance is then calculated with the EUROCODE 3 methods. An application is finally presented. (C) 2003 Elsevier Science Ltd. All rights reserved. [less ▲]

Detailed reference viewed: 301 (7 ULg)
Full Text
Peer Reviewed
See detailEarly onset neonatal sepsis and meningitis in Belgium: a decade review
MELIN, Pierrette ULg; Maquet, Julie; Ducoffre, Geneviève et al

in American Society of Microbiology (Ed.) Program and Abstracts of the 43rd Intersciences Conference on Antimicrobial Agents and Chemotherapy (2003, September)

Background: In the late 1990s, Belgium has reached the era of “group B streptococcal (GBS) prevention” and after 1996, some institutions, but not the majority, had implemented intrapartum ... [more ▼]

Background: In the late 1990s, Belgium has reached the era of “group B streptococcal (GBS) prevention” and after 1996, some institutions, but not the majority, had implemented intrapartum antibioprophylaxis for GBS prevention. Concern exists that one unintended consequence of GBS prevention efforts through chemoprophylaxis may be an increase in the rate of serious neonatal infections due to Gram negative bacteria (GNB). To monitor trends, continued surveillance of neonatal sepsis is needed. Methods: On a weekly basis, laboratories of the Belgian sentinel network notified each case of neonatal bacteremia or meningitis occurring within 28 days after birth. We reviewed on a year-base data collected from 1991-2001 for early–onset diseases (EOD; < 5 days). Results: A yearly mean of 47 cases (24-90) were notified by 28 (16-35) laboratories. Overall GBS remained the leading cause and represented annually 37.9% (25-54.7%) of EOD and did not show significant change. It was followed by E.coli 11.4%, coagulase negative staphylococci (CNS) 11.9%, S.aureus 9.9%, Listeria sp 3.9%, S.pyogenes (GAS) 2.5%, S.pneumoniae 2.7%, H.influenzae 2.7% and others. During the decade, whereas a significant reduction in the rate of E.coli and other GNB EOD occurred (p <0.01), significant increases in the rate of EOD due to GAS (p <0.001), S.aureus (p <0.001), and CNS (p <0.01), were found. For CNS, we did not have data to distinguish definite or possible infections from contaminations. Conclusions: 1) During the last decade, GBS has remained the leading cause of neonatal EOD. 2) A decline in the rate of E.coli and other GNB infections occurred. 3) In the late 1990s, S.aureus and CNS were more frequently reported. 4) An increase in GAS occurrence was found 5) Potential change in pathogens overtime requires confirmation by ongoing surveillance. [less ▲]

Detailed reference viewed: 59 (2 ULg)
Full Text
Peer Reviewed
See detailAntimicrobial Susceptibilities of recent clinical isolates of group B streptococci agalactiae from Belgium
MELIN, Pierrette ULg; Maquet, Julie; Rodriguez Cuns, Grisel et al

in American Society of Microbiology (Ed.) Program and Abstracts of the 43rd Intersciences Conference on Antimicrobial Agents and Chemotherapy (2003, September)

Background: : GBS cause severe infections in neonates, pregnant women and other adults. Empiric therapy is usually started before susceptibility results are available. Early neonatal diseases can be ... [more ▼]

Background: : GBS cause severe infections in neonates, pregnant women and other adults. Empiric therapy is usually started before susceptibility results are available. Early neonatal diseases can be prevented with intrapartum antibiotic prophylaxis based on accurate susceptibility surveillance data. A previous Belgian study showed an increase of 3 to 10 % R to erythromycin (EM) through the 1990s. Methods: 187 GBS isolates consecutively received at the reference laboratory between 2001 to March 2003 were from 73 neonates (52 early-onset and 21 late-onset diseases), 52 adults and 62 from pregnant women’s vagina. MICs of penicillin (PG), EM, clindamycin (CM) and gentamicin (GM) were determined with Etest. PG MBCs were also determined by inactivating the drug in MIC plates using betalactamase. EM resistant (R) isolates were tested by the CM + EM double disk to determine macrolide R phenotypes. Results: All strains were susceptible (S) to PG and no tolerance was observed with MBCs falling within 2 dilutions of MICs. 19.2% of isolates were R to EM, with significantly more R isolates from adults (30.8%; p <0.01) and serotype V (46.8%; p <0,001). 80% had the MLSB phenotype (R to EM and CM), 16 were constitutive and 12 inducible. The M phenotype (R to EM and S to CM) was seen in 7 (20%) of isolates. Less than 10% of isolates were inhibited by GM MIC of <=64 mg/L, 83.6% by 128-256 mg/L and 2.9% by >/=512 mg/L. Non typable strains were more R to GM (p <0.01). Conclusions: 1) PG remained active against all isolates and no tolerance was seen. 2) Prevalence of R to macrolides had increased since 1999, particularly in adult isolates and serotype V. 3) Intermediate to high level R to GM was seen and potential synergy of PG + GM should be investigated. 4) R surveillance is mandatory to guide prophylaxis and treatment of serious GBS infections. [less ▲]

Detailed reference viewed: 18 (1 ULg)
Full Text
Peer Reviewed
See detailIncreased Mrna Expression of Decorin in the Prolapsing Posterior Leaflet of the Mitral Valve
Radermecker, M. A.; Limet, Raymond ULg; Lapiere, C. M. et al

in Interactive Cardiovascular and Thoracic Surgery (2003), 2(3), 389-94

To improve our understanding of myxomatous degeneration of the valvar tissue as seen in mitral valve prolapse, we have compared the biosynthetic phenotype of the connective tissue cells in myxomatous ... [more ▼]

To improve our understanding of myxomatous degeneration of the valvar tissue as seen in mitral valve prolapse, we have compared the biosynthetic phenotype of the connective tissue cells in myxomatous segments (n=4) resected during surgery with that of homologous segments of normal valves (n=4) harvested in age-matched organ donors. The steady-state level of mRNA for selected extracellular matrix macromolecules and metalloproteinases was assessed by quantitative (internal standard controlled) reverse transcriptase-polymerase chain reaction (RT-PCR). Among the investigated gene products, the decorin mRNA expression was significantly increased in degenerative valve compared with normal tissue (211+/-48 vs. 100+/-70, p<0.02). The level of fibrillin 2 also tended to be increased (194+/-88 vs. 100+/-81, p=0.08). These results suggest that myxomatous valvar tissue is characterized by an overexpression of mRNA for decorin. Owing to the role of this small leucine-rich proteoglycan in the regulation of fibril assembly and stability, this alteration may account for or is a result of a defective organization of the collagen and elastic fibers in this disease and contribute to the intrinsic distensibility and fragility of the myxomatous tissue. [less ▲]

Detailed reference viewed: 27 (7 ULg)
Full Text
Peer Reviewed
See detailComparative study of different lipases acting on milk fat globule membrane monolayers.
Danthine, Sabine ULg; Blecker, Christophe ULg; Deroanne, Claude

Poster (2003, September)

Detailed reference viewed: 5 (1 ULg)
Full Text
Peer Reviewed
See detailEffect of the inclusion time of extruded linseed supplementation before slaughter on n-3 fatty acids enrichment of chicken meat.
Rondia, P.; Delmotte, Charles; Maene, D. et al

Poster (2003, September)

Detailed reference viewed: 6 (1 ULg)
Full Text
Peer Reviewed
See detailThe use of simulators as training tools
Nyssen, Anne-Sophie ULg

in Current Medical Anesthesiology (2003)

Detailed reference viewed: 16 (2 ULg)
Full Text
Peer Reviewed
See detailA tool to design steel elements submitted to compartment fires - OZone V2. Part 1: pre- and post-flashover compartment fire model
Cadorin, Jean-François; Franssen, Jean-Marc ULg

in Fire Safety Journal (2003), 38(5), 395-427

The computer code OZone V2 has been developed to help engineers in designing structural elements submitted to compartment fires. The code is based on several recent developments, in compartment fire ... [more ▼]

The computer code OZone V2 has been developed to help engineers in designing structural elements submitted to compartment fires. The code is based on several recent developments, in compartment fire modelling on one hand and on the effect of localised fires on structures on the other hand. It includes a single compartment fire model that combines a two-zone model and a one-zone model. In this paper, the description of this compartment fire model is given. The main model is first presented. It consists of the usual zone model equations fully coupled with the partition model equations. The partitions are modelled by the finite element method. The switch from the two-zone to the one-zone model is then explained. The vertical, horizontal and forced vent sub-models are presented, followed by the fire source and the combustion models. A comparison between this code and another compartment fire model NAT is made. The OZone calculations are then compared to full scale fire tests. Considerations as to how this model is used for the design of steel elements will be presented in a companion paper (Fire Saf. J., this issue). (C) 2003 Elsevier Science Ltd. All rights reserved. [less ▲]

Detailed reference viewed: 399 (8 ULg)
Full Text
Peer Reviewed
See detailCyanobacterial diversity in natural and artificial microbial mats of Lake Fryxell (McMurdo dry valleys, Antarctica): A morphological and molecular approach
Taton, A.; Grubisic, Stana ULg; Brambilla, E. et al

in Applied and Environmental Microbiology (2003), 69(9), 5157-5169

Currently, there is no consensus concerning the geographic distribution and extent of endemism in Antarctic cyanobacteria. In this paper we describe the phenotypic and genotypic diversity of cyanobacteria ... [more ▼]

Currently, there is no consensus concerning the geographic distribution and extent of endemism in Antarctic cyanobacteria. In this paper we describe the phenotypic and genotypic diversity of cyanobacteria in a field microbial mat sample from Lake Fryxell and in an artificial cold-adapted sample cultured in a benthic gradient chamber (BGC) by using an inoculum from the same mat. Light microscopy and molecular tools, including 16S rRNA gene clone libraries, denaturing gradient gel electrophoresis, and sequencing, were used. For the first time in the study of cyanobacterial diversity of environmental samples, internal transcribed spacer (ITS) sequences were retrieved and analyzed to complement the information obtained from the 16S rRNA gene. Microscopy allowed eight morphotypes to be identified, only one of which is likely to be an Antarctic endemic morphotype. Molecular analysis, however, revealed an entirely different pattern. A much higher number of phylotypes (15 phylotypes) was found, but no sequences from Nodularia and Hydrocoryne, as observed by microscopy, were retrieved. The 16S rRNA gene sequences determined in this study were distributed in 11 phylogenetic lineages, 3 of which were exclusively Antarctic and 2 of which were novel. Collectively, these Antarctic sequences together with all the other polar sequences were distributed in 22 lineages, 9 of which were exclusively Antarctic, including the 2 novel lineages observed in this study. The cultured BGC mat had lower diversity than the field mat. However, the two samples shared three morphotypes and three phylotypes. Moreover, the BGC mat allowed enrichment of one additional phylotype. ITS sequence analysis revealed a complex signal that was difficult to interpret. Finally, this study provided evidence of molecular diversity of cyanobacteria in Antarctica that is much greater than the diversity currently known based on traditional microscopic analysis. Furthermore, Antarctic endemic species were more abundant than was estimated on the basis of morphological features. Decisive arguments concerning the global geographic distribution of cyanobacteria should therefore incorporate data obtained with the molecular tools described here. [less ▲]

Detailed reference viewed: 55 (6 ULg)
Full Text
Peer Reviewed
See detailAn XMM-Newton observation of the very young open cluster NGC 6383
Rauw, Grégor ULg; De Becker, Michaël ULg; Gosset, Eric ULg et al

in Astronomy and Astrophysics (2003), 407(3), 925-15

We report the detection of a number of X-ray sources associated with the very young open cluster NGC6383. About two thirds of these objects are correlated with a rather faint optical source and all but ... [more ▼]

We report the detection of a number of X-ray sources associated with the very young open cluster NGC6383. About two thirds of these objects are correlated with a rather faint optical source and all but one have at least one infrared counterpart within a correlation radius of 8 arcsec. Although NGC6383 is not associated with a prominent star forming region, the overall properties of many of the X-ray sources suggest that they may be candidates for low-mass pre-main sequence stars. The number of X-ray sources increases towards the cluster center suggesting that there exists a close relation between the massive O-star binary system HD159176 in the cluster core and the population of X-ray bright low-mass objects in NGC 6383. [less ▲]

Detailed reference viewed: 47 (8 ULg)
Full Text
Peer Reviewed
See detailBody contour 180 degrees pinhole SPET with or without tilted detector: a phantom study
Seret, Alain ULg; Flérès, David; Firket, Olivier et al

in European Journal of Nuclear Medicine and Molecular Imaging (2003), 30(9), 1205-1210

This study investigated the feasibility of ordered subsets expectation maximisation (OS-EM) reconstruction of 180 degrees pinhole single-photon emission tomography (SPET) acquired in body contour mode ... [more ▼]

This study investigated the feasibility of ordered subsets expectation maximisation (OS-EM) reconstruction of 180 degrees pinhole single-photon emission tomography (SPET) acquired in body contour mode (variable distance between the detector and the axis of rotation for each projection) with or without a tilted detector head. Four non-circular orbits were designed bearing in mind the rotation radius and tilt angle values of previous pinhole SPET acquisitions in patients with circular orbits. The reconstructions were performed using a dedicated OS-EM algorithm. Reconstructed images of line and uniformity phantoms showed that the spatial and uniformity characteristics of the radioactive objects were preserved. In comparison with the circular orbits, the non-circular orbits allowed only a moderate gain (maximum 10%) in resolution. However, body contour pinhole SPET would significantly facilitate the camera set-up and in this way should decrease the camera set-up time, which is an important parameter in patient studies. [less ▲]

Detailed reference viewed: 52 (2 ULg)
Full Text
Peer Reviewed
See detailThe use of degrees of certainty to evaluate knowledge
Brutomesso, Daniela; Gagnayre, Remi; Leclercq, Dieudonné ULg et al

in Patient Education & Counseling (2003), 51(1), 29-37

In patients with chronic diseases education should improve knowledge about the disease and increase certainty in knowledge. We present here a technique to measure changes in certainty after an educational ... [more ▼]

In patients with chronic diseases education should improve knowledge about the disease and increase certainty in knowledge. We present here a technique to measure changes in certainty after an educational intervention. For this purpose, before and after a course, patients answer a questionnaire in which answers are accompanied by an estimate of the degree of certainty. Answers are then assigned to areas of knowledge defined a priori: mastered (certainty greater than or equal to90%, correctness greater than or equal to90%), hazardous (certainty greater than or equal to90%, correctness less than or equal to50%), uncertain (certainty less than or equal to50%, correctness greater than or equal to90%) and residual. Finally differences in the distribution of answers among different areas are analysed statistically. Using this technique in a group of patients with type I diabetes who followed a course on insulin use, we found significant changes in the distribution of answers among different areas of knowledge. Thus changes in certainty can be analysed quantitatively and used to evaluate better the effect of therapeutic education. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved. [less ▲]

Detailed reference viewed: 133 (14 ULg)
Full Text
Peer Reviewed
See detailNouvelles directives americaines et europeennes en 2003 pour la prise en charge de l'hypertension arterielle
Krzesinski, Jean-Marie ULg

in Revue Médicale de Liège (2003), 58(9), 563-571

New American and European guidelines have been released in 2003, the purpose of which is to improve the management of arterial hypertension. The decision to treat high blood pressure now mainly relies on ... [more ▼]

New American and European guidelines have been released in 2003, the purpose of which is to improve the management of arterial hypertension. The decision to treat high blood pressure now mainly relies on the individual cardiovascular risk rather than on the sole blood pressure level. Thus, antihypertensive drugs could be proposed even to normotensive individuals, provided they have a high cardiovascular risk (> 20% at 10 years). On the other hand, grade 1 or 2 hypertensive patients, if their baseline cardiovascular risk is low, will be prescribed antihypertensive drugs only after 3 to 6 months of follow-up. In all cases, individualized non pharmacological means must always be proposed and their use stimulated. The target blood pressure under treatment will be < 140/90 mmHg when the cardiovascular risk is low or moderate, but < 130/80 mmHg when high risk exists. To reach this target, a drug combination is very often necessary, and it frequently includes a low dose of diuretic. To-day, the option of using a low dose biotherapy as an alternative to monotherapy is even proposed as first step antihypertensive treatment. After initiation of treatment, the patient must be regularly followed up and stimulated to decrease his cardiovascular risk to the lowest possible level, following an inclusive approach. [less ▲]

Detailed reference viewed: 193 (5 ULg)
Full Text
Peer Reviewed
See detailPotentiation of tumor necrosis factor-induced NF-kappa B activation by deacetylase inhibitors is associated with a delayed cytoplasmic reappearance of I kappa B alpha
Adam, Emmanuelle; Quivy, Vincent; Bex, Françoise et al

in Molecular and Cellular Biology (2003), 23(17), 6200-6209

Previous studies have implicated acetylases and deacetylases in regulating the transcriptional activity of NF-kappaB. Here, we show that inhibitors of deacetylases such as trichostatin A (TSA) and sodium ... [more ▼]

Previous studies have implicated acetylases and deacetylases in regulating the transcriptional activity of NF-kappaB. Here, we show that inhibitors of deacetylases such as trichostatin A (TSA) and sodium butyrate (NaBut) potentiated TNF-induced expression of several natural NF-kappaB-driven promoters. This transcriptional synergism observed between TNF and TSA (or NaBut) required intact kappaB sites in all promoters tested and was biologically relevant as demonstrated by RNase protection on two instances of endogenous NF-kappaB-regulated gene transcription. Importantly, TSA prolonged both TNF-induced DNA-binding activity and the presence of NF-kappaKB in the nucleus. We showed that the p65 subunit of NF-kappaB was acetylated in vivo. However, this acetylation was weak, suggesting that other mechanisms could be implicated in the potentiated binding and transactivation activities of NF-kappaB after TNF plus TSA versus TNF treatment. Western blot and immunofluorescence confocal microscopy experiments revealed a delay in the cytoplasmic reappearance of the IkappaBalpha inhibitor that correlated temporally with the prolonged intranuclear binding and presence of NF-kappaB. This delay was due neither to a defect in IkappaBalpha mRNA production nor to a nuclear retention of IkappaBalpha but was rather due to a persistent proteasome-mediated degradation of IkappaBalpha. A prolongation of IkappaB kinase activity could explain, at least partially, the delayed IkappaBalpha cytoplasmic reappearance observed in presence of TNF plus TSA. [less ▲]

Detailed reference viewed: 38 (4 ULg)
Full Text
Peer Reviewed
See detailWR bubbles and HeII emission
Nazé, Yaël ULg; Rauw, Grégor ULg; Manfroid, Jean ULg et al

in Astronomy and Astrophysics (2003), 408(1), 171-186

We present the very first high quality images of the He II lambda4686 emission in three high excitation nebulae of the Magellanic Clouds. A fourth high excitation nebula, situated around the WR star BAT99 ... [more ▼]

We present the very first high quality images of the He II lambda4686 emission in three high excitation nebulae of the Magellanic Clouds. A fourth high excitation nebula, situated around the WR star BAT99-2, was analysed in a previous letter. Using VLT FORS data, we investigate the morphology of the ring nebulae around the early-type WN stars BAT99-49 [less ▲]

Detailed reference viewed: 18 (2 ULg)