References of "2007"
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See detailLa politique de sûreté dans les organisations
Eggermont, Gilbert; Zwetkoff, Catherine ULg; Brunet, Sébastien ULg et al

(2007)

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See detailSYNOVIOCYTES, NOT CHONDROCYTES, RELEASE FREE RADICALS AFTER CYCLES OF ANOXIA/RE-OXYGENATION
Schneider, Nicole ULg; Mouithys-Mickalad, Ange ULg; Lejeune, Jean-Philippe ULg et al

Poster (2007)

Introduction : An oxidant activity has been implicated in the onset of equine osteoarthritis. Most of the studies have been done on articular chondrocytes, but little is known about the role of ... [more ▼]

Introduction : An oxidant activity has been implicated in the onset of equine osteoarthritis. Most of the studies have been done on articular chondrocytes, but little is known about the role of synoviocytes. Objective : Our aim was to investigate if equine articular chondrocytes, primary synoviocytes or synoviocytes of a continuous cell line are able to produce free radicals after exposure to anoxia and re-oxygenation. Methods : By oxymetry and electron paramagnetic resonance (EPR), we investigated the effects of repeated anoxia/re-oxygenation (A/R) periods on the respiration and production of free radicals by synoviocytes (rabbit HIG-82 cell line and primary equine synoviocytes) and equine articular chondrocytes. Three periods of 20 min anoxia followed by re-oxygenation were applied to 10exp7 cells; O2 consumption was measured before anoxia and after each re-oxygenation. After the last A/R, cellular free radical formation was investigated by EPR spectroscopy with spin trapping technique (n = 3 for each cell line). Results : Both types of synoviocytes showed a high O2 consumption, which was slower after anoxia. By EPR with the spin trap POBN, we proved a free radical formation. Results were similar for equine and rabbit synoviocytes. For chondrocytes, we observed a low O2 consumption, unchanged by anoxia, and no free radical production. Conclusion : These observations suggest an oxidant activity of synoviocytes, potentially important for the onset of osteoarthritis. [less ▲]

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See detailHCCI engine modeling and experimental investigations - Part 1: The reduction, composition and validation of a n-heptane/iso-octane mechanism
Machrafi, Hatim ULg; Guibert, P.; Cavadias, S. et al

in Combustion Science And Technology (2007), 179(12), 2561-2580

A certain possible approach for the control of HCCI chemistry is to use kinetic chemistry mechanisms. This opens a field of interest that lead to the composition of a validated reduced PRF chemistry ... [more ▼]

A certain possible approach for the control of HCCI chemistry is to use kinetic chemistry mechanisms. This opens a field of interest that lead to the composition of a validated reduced PRF chemistry mechanism. For this purpose a skeletal chemical reaction mechanism for n-heptane and for iso-octane are constructed from a detailed n-heptane and iso-octane mechanism of the Chalmers University of Technology. Subsequently these two mechanisms are forged into one reduced chemical reaction mechanism for mixtures of n-heptane and isooctane (39 species and 47 reactions). This mechanism is numerically validated against the Chalmers mechanisms, respecting the HCCI application range. The reduced mechanism is also successfully numerically validated against another more detailed mechanism provided by LLNL. Engine experiments are performed validating this mixture mechanism with respect to the fuel composition containing n-heptane and iso-octane. The influence of the compression ratio and the equivalence ratio is also studied and used to validate the reduced PRF mechanism. [less ▲]

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See detailDevelopment of an absolute quantification method targeting growth hormone biomarkers using liquid chromatography coupled to isotope dilution mass spectrometry.
Kirsch, Stéphanie ULg; Widart, Joëlle ULg; Louette, Joel et al

in Journal of Chromatography. A (2007), 1153(1-2), 300-6

A method to perform absolute quantification of two biomarkers (IGF-1 and IGFBP-3) of growth hormone abuse has been developed. Isotope dilution is used with synthetically labelled peptides as internal ... [more ▼]

A method to perform absolute quantification of two biomarkers (IGF-1 and IGFBP-3) of growth hormone abuse has been developed. Isotope dilution is used with synthetically labelled peptides as internal standards. Peptide selection and multiple reaction monitoring design are discussed. A simple sample preparation based on the reduction and alkylation of cysteine residues followed by tryptic digestion provides a sufficient digestion of proteins. Serum samples fortified with increasing amounts of target proteins are analysed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) on a triple quadrupole mass spectrometer. Specificity is ensured by the selection of sequences with no homology in BLAST, as well as retention time deviation check, and ion ratio monitoring. Linearity is studied in terms of calibration curves. These curves for IGFBP-3 and IGF-1 are generated with mean slopes of 0.055 and 0.065, intercepts of 0.107 and -0.011, and with coefficients of correlation of 0.95 and 0.98, respectively. These curves result from the addition of proteins to the serum. Risks of variations related to potential matrix effects are therefore reduced, as well as probable variations related to the digestion steps. The working concentration ranges are 4-10 ng/microl for IGFBP-3 and 2-8 ng/microl for IGF-1. Preliminary data regarding repeatability show that relative standard deviations (RSDs) range between 13 and 32% for IGFBP-3 and between 7 and 29% for IGF-1. [less ▲]

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See detailInfluence of progesterone concentrations on secretory functions of trophoblast and pituitary during the first trimester of pregnancy in dairy cattle
Ayad, A.; Melo de Sousa, Noelita ULg; Sulon, Joseph ULg et al

in Theriogenology (2007), 67(9), 1503-1511

The essential role played by progesterone in the maintenance of pregnancy is unequivocal; however, the effects of progesterone on the secretory patterns of placental and pituitary molecules during the ... [more ▼]

The essential role played by progesterone in the maintenance of pregnancy is unequivocal; however, the effects of progesterone on the secretory patterns of placental and pituitary molecules during the gestation period are not well defined. The objective of this study was to describe pregnancy-associated glycoprotein (PAG) concentrations (measured by RIA-497 and RIA-Pool) in pregnant females with progesterone concentrations lower (low-P4 group, n = 20) or higher (high-P4 group, n = 17) than the mean of 8.74 ng/mL on Day 21 (AI = Day 0). Luteinizing hormone (LH) and prolactin concentrations were also measured in both groups. Throughout the study period, blood samples were collected on Days 0, 21, 45, 60, and 80 from 37 females that were confirmed to be pregnant. PAG concentrations measured by both RIA-497 and RIA-Pool tended to be higher in high-P4 group than in low-P4 group from Day 30 until Day 80. On Day 80, plasma PAG concentrations that were measured using RIA-497 were observed to be higher (P < 0.05) in the high-P4 group than in the low-P4 group (10.2 +/- 8.7 ng/mL versus 6.9 +/- 13.8 ng/mL). Concentrations of LH on Day 60 and prolactin on Day 80 were observed to be significantly lower (P < 0.05) in the high-P4 group. There was a tendency for the concentrations of LH (Days 45 and 80) and prolactin (Days 30, 45, and 60) to be lower in cows in the high-P4 group than in the low-P4 group. Our results suggest the existence of a relationship among the concentration levels of progesterone, PAG, LH, and prolactin during early pregnancy. (C) 2007 Elsevier Inc. All rights reserved. [less ▲]

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See detailHypogonadisme par déficience de LH.
Beckers, Albert ULg

in Bulletin et Mémoires de l'Académie Royale de Médecine de Belgique (2007), 162(5-6), 291-7298

A 30-year-old man was investigated for delayed puberty and infertility. These investigations showed a complete absence of circulating luteinizing hormone (LH). Genetic studies revealed a missense mutation ... [more ▼]

A 30-year-old man was investigated for delayed puberty and infertility. These investigations showed a complete absence of circulating luteinizing hormone (LH). Genetic studies revealed a missense mutation in the LHbeta gene (G36D). This mutation disrupts a vital cystine knot motif and abrogates the heterodimerization and secretion of LH. Treatment with hCG was instituted, which led to arise in testosterone and improvement in spermatogenesis. After in vitro fertilization the patient had a son who was heterozygous for the G36D mutation. A second patient with similar clinical and biological presentation has been explored. A non-frame shift deletion of 3 base-pairs was discovered at position 20 which led to the deletion of a lysine residue. The proband and his prepubescent brother were homozygotic for this mutation. These cases illustrate the important physiological role of LH in male sexual maturation and fertility. [less ▲]

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See detailField induced metastabilities in U(Ru0.96Rh0.04)(2)Si-2
Silhanek, Alejandro ULg; Jaime, M.; Harrison, N. et al

in Physica C: Superconductivity (2007), 460(Part 1), 682-683

U(Ru0.96Rh0.04)(2)Si-2 is an anisotropic itinerant 5f heavy electron system which exhibits a single field induced magnetic phase concealing a quantum critical point. We show that the boundary of this ... [more ▼]

U(Ru0.96Rh0.04)(2)Si-2 is an anisotropic itinerant 5f heavy electron system which exhibits a single field induced magnetic phase concealing a quantum critical point. We show that the boundary of this phase corresponds to a first order transition as revealed by (1) a large and symmetric specific heat anomaly, (2) an asymmetric magnetocaloric effect on entering and exiting this phase, and (3) a clear history and time-dependent specific heat. We explore the thermodynamic similarities with the mixed valence compound YbInCu4 and show that the out-of-equilibrium properties are analogous to those depicted by the critical state model for hard superconductors. (C) 2007 Elsevier B.V. All rights reserved. [less ▲]

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See detailLes antidépresseurs.
Ansseau, Marc ULg; Pitchot, William ULg

in Guelfi, J. D.; Rouillon, F. (Eds.) Manuel de Psychiatrie (2007)

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See detailNeuroimaging of REM sleep and dreaming
Dang Vu, Thien Thanh ULg; Schabus, Manuel; Desseilles, Martin ULg et al

in McNamara, Patrick; Barrett, Deirdre (Eds.) The New Science of Dreaming (2007)

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See detailDes images et des récits qui disent le changement, des questions, des impasses et des possibles
Stassart, Pierre M ULg; Lecomte, Nadége

in Regards croisés (2007)

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See detailTherapeutic use of high-frequency repetitive transcranial magnetic stimulation in stroke.
Hotermans, Christophe; Peigneux, Philippe ULg; Moonen, Gustave ULg et al

in Stroke (2007), 38(2), 253254

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See detailSingle-mode microwave-assisted atom transfer radical polymerization catalyzed by [RuCl2(p-cymene)(PCy3)]
Delfosse, Sebastien; Borguet, Yannick ULg; Delaude, Lionel ULg et al

in Macromolecular Rapid Communications (2007), 28(4), 492-503

In the atom transfer radical polymerization (ATRP) of methyl methacrylate in the presence of [RuCl2(p-cymene)(PCy3)] (p-cymene=4-isopropyltoluene, PCy3=tricyclohexylphosphine), a microwave effect is noted ... [more ▼]

In the atom transfer radical polymerization (ATRP) of methyl methacrylate in the presence of [RuCl2(p-cymene)(PCy3)] (p-cymene=4-isopropyltoluene, PCy3=tricyclohexylphosphine), a microwave effect is noted which strikingly depends on both the temperature and the method used (conventional microwave synthesis (CMS, i.e., without simultaneous cooling) or enhanced microwave synthesis (EMS, with simultaneous cooling)). Thus, between 85 and 120 degrees C under CMS conditions, microwave-assisted polymerizations take place in a controlled fashion, and at 120 degrees C the microwave-assisted polymerization is three times faster than the conventionally heated protocol. However, from 130 degrees C, microwave irradiation has a deleterious effect and the polymerizations are no longer controlled. Likewise, using the EMS method in the temperature range of 85-120 degrees C results in uncontrolled processes, as indicated by the unsuccessful resumption of the polymerizations. These failures might be attributed to a significantly high concentration of radical species, which results in enhanced propagation and termination - mostly disproportionation - rates. [less ▲]

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See detailField penetration into hard type-II superconducting tubes: effects of a cap, a non-superconducting joint, and non-uniform superconducting properties
Denis, Samuel ULg; Dirickx, Michel ULg; Vanderbemden, Philippe ULg et al

in Superconductor Science and Technology (2007), 20(5), 418-427

Using the numerical method of Brandt (1998 Phys. Rev. B 58 6506), we study the penetration of a uniform magnetic field that is gradually applied parallel to the axis of finite type-II superconducting ... [more ▼]

Using the numerical method of Brandt (1998 Phys. Rev. B 58 6506), we study the penetration of a uniform magnetic field that is gradually applied parallel to the axis of finite type-II superconducting tubular samples with strong pinning. This study is carried out in view of designing low-frequency magnetic shields by exploiting the diamagnetic properties of type-II superconductors. First, we compare the field penetration into open and closed tubes. For long tubes (length larger than three times the outer diameter), we show that a cap weakly affects the maximum magnetic induction that can be shielded, but greatly increases the region over which the field is nearly uniform. When the length of the tube is shorter, both the maximum shieldable magnetic induction and the uniformity of the field attenuation are enhanced by closing the tube. We also show that making a hole in the cap, which is often necessary for applications, does not greatly affect the shielding properties provided the diameter of the hole is small compared to that of the tube (hole diameter smaller than a quarter of the outer tube diameter). In view of designing large size magnetic shields, superconducting tubes of finite size need to be joined together. We therefore examine in a second part how the presence of a non-superconducting joint between the tubes affects the shielding efficiency. It is shown that the effect of a joint depends upon its position along the tube axis and strongly increases with its size. Third, we study how non-uniform superconducting properties affect the shielding capabilities. [less ▲]

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See detailEffects of the stage of maturation and varieties on the chemical composition of banana and plantain peels
Happi Emaga, Thomas ULg; Andrianaivo, Rado; Wathelet, Bernard ULg et al

in Food Chemistry (2007), 103(2), 590-600

A study of the chemical composition of six varieties of fruit peels of the banana and plantain: dessert banana (Musa AAA), plantain (Musa AAB) cooking banana (Musa ABB) and hybrid (Musa AAAB) at three ... [more ▼]

A study of the chemical composition of six varieties of fruit peels of the banana and plantain: dessert banana (Musa AAA), plantain (Musa AAB) cooking banana (Musa ABB) and hybrid (Musa AAAB) at three stages of ripeness, was carried out in order to explore their potential applications. The varieties did not affect chemical constituents in a consistent manner. Peel of the six varieties was rich in total dietary fibre (TDF) (40-50%). The protein content in peel of the banana and plantain was 8-11%. Leucine, valine, phenylalanine and threonine were essential amino acids in significant quantities: Lysine was the limiting amino acid. The content of lipid varied from 2.2% to 10.9% and was rich in polyunsaturated fatty acids, particularly linoleic acid and alpha-linolenic acid. Potassium was the most significant mineral element. Peel of plantain was richer in starch than were the banana peels. Maturation of fruits involved increase in soluble sugar content and, at the same time, decrease in starch. The degradation of the starch under the action of the endogenous enzymes, may explain the increase in the soluble sugar content. Further investigations on the composition and the physiological functions (using animal-feeding experiments) of these dietary fibres must be considered. (c) 2006 Elsevier Ltd. All rights reserved. [less ▲]

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See detailRésumé C.E. n°170.233, du 19 avril 2007, Hollander et csrts
Delnoy, Michel ULg

in Aménagement - Environnement (2007), 4

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See detailLe trouble de l’attention avec hyperactivité : un trouble spécifique de l’inhibition ?
Catale, Corinne ULg; Meulemans, Thierry ULg

Poster (2007)

Unité de Neuropsychologie, Université de Liège (Belgique) Introduction Le trouble d’attention avec hyperactivité (ou ADHD, Attention Deficit/Hyperactivity Disorder) se caractérise par [1] un trouble ... [more ▼]

Unité de Neuropsychologie, Université de Liège (Belgique) Introduction Le trouble d’attention avec hyperactivité (ou ADHD, Attention Deficit/Hyperactivity Disorder) se caractérise par [1] un trouble d’attention, [2] une importante agitation motrice et [3] une impulsivité motrice. Ce trouble présente une prévalence estimée à 5 à 10% de la population prépubère, avec une nette prédominance masculine. Les conséquences de l’ADHD sont importantes : échec scolaire, difficultés d’apprentissages, mauvaise intégration sociale… En neuropsychologie, l’approche de l’ADHD vise à mieux comprendre les difficultés cognitives – et en particulier exécutives – que présentent ces enfants. Ainsi, s’il apparaît qu’un grand nombre de processus exécutifs sont altérés (voir Willcutt et al., 2005), plusieurs auteurs soulignent qu’un déficit de l’inhibition constituerait l’élément-clé qui rendrait compte des manifestations cognitives et cliniques de ce syndrome (Barkley, 1997). De nombreuses recherches ont toutefois suggéré que l’inhibition ne renvoie pas à un processus unitaire mais implique au contraire plusieurs sous-composants (inhibition verbale, motrice, perceptive ; voir par exemple Nassauer & Halperin, 2003). L’objectif de cette étude consiste à déterminer dans quelle mesure les troubles de l’inhibition présentés par les enfants ADHD sont sous-tendus par un déficit généralisé des processus inhibiteurs ou au contraire par une atteinte spécifique d’un de ces processus. Méthode Nous avons administré à 13 enfants ADHD âgé de 6 à 12 ans et 13 enfants de contrôle (appariés sur base de l’âge et du sexe) des tâches d’inhibition évaluant les capacités d’inhibition verbale (test de Stroop), motrice (épreuves de la Statue et du Go/No Go) et perceptive (Nassauer & Halperin, 2003), et une épreuve de raisonnement (Matrices de Raven Colorées). Résultats Les analyses de comparaison de moyennes indiquent que les enfants ADHD présentent des performances inférieures à celles des enfants de contrôle pour l’ensemble des épreuves d’inhibition : inhibition verbale (p<.05), motrice (p<.001) et perceptive (p<.01). Toutefois, des analyses de covariance montrent que lorsque l’on contrôle le niveau de raisonnement, les différences entre nos deux groupes disparaissent pour toutes les tâches, à l’exception de l’épreuve d’inhibition motrice « Statue ». Discussion Ces résultats préliminaires suggèrent que les enfants ADHD ne présentent pas un déficit généralisé des processus inhibiteurs, et que les troubles de l’inhibition motrice constituent probablement un élément-clé caractérisant le profil cognitif de ces enfants. Ces données confirment par ailleurs l’idée selon laquelle le concept d’inhibition recouvre des processus différents susceptibles d’être affectés de façon spécifique dans l’ADHD. [less ▲]

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See detailLe roman pour adolescents
Delbrassine, Daniel ULg

in Enjeux: Revue de formation continuée et de didactique du français (2007), 68(Printemps), 7-27

L'article est construit en deux temps: une approche du statut littéraire du roman contemporain adressé aux adolescents, et une analyse de son rôle dans la formation à la "lecture littéraire".

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See detailLong-Term Feeding Ecology and Habitat Use in Harbour Porpoises Phocoena Phocoena from Scandinavian Waters Inferred from Trace Elements and Stable Isotopes
Fontaine, Michael ULg; Tolley, K. A.; Siebert, U. et al

in BMC Ecology (2007), 7

BACKGROUND: We investigated the feeding ecology and habitat use of 32 harbour porpoises by-caught in 4 localities along the Scandinavian coast from the North Sea to the Barents Sea using time-integrative ... [more ▼]

BACKGROUND: We investigated the feeding ecology and habitat use of 32 harbour porpoises by-caught in 4 localities along the Scandinavian coast from the North Sea to the Barents Sea using time-integrative markers: stable isotopes (delta13C, delta15N) and trace elements (Zn, Cu, Fe, Se, total Hg and Cd), in relation to habitat characteristics (bathymetry) and geographic position (latitude). RESULTS: Among the trace elements analysed, only Cd, with an oceanic specific food origin, was found to be useful as an ecological tracer. All other trace elements studied were not useful, most likely because of physiological regulation and/or few specific sources in the food web. The delta13C, delta15N signatures and Cd levels were highly correlated with each other, as well as with local bathymetry and geographic position (latitude). Variation in the isotopic ratios indicated a shift in harbour porpoise's feeding habits from pelagic prey species in deep northern waters to more coastal and/or demersal prey in the relatively shallow North Sea and Skagerrak waters. This result is consistent with stomach content analyses found in the literature. This shift was associated with a northward Cd-enrichment which provides further support to the Cd 'anomaly' previously reported in polar waters and suggests that porpoises in deep northern waters include Cd-contaminated prey in their diet, such as oceanic cephalopods. CONCLUSION: As stable isotopes and Cd provide information in the medium and the long term respectively, the spatial variation found, shows that harbour porpoises experience different ecological regimes during the year along the Scandinavian coasts, adapting their feeding habits to local oceanographic conditions, without performing extensive migration. [less ▲]

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