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See detailEffet de l'addition des tannins de châtaigniers sur la rétention azotée et la digestibilité chez les ruminants ingérant des produits herbagers.
Kriaa, Samia; Thewis, André ULg

in Tropicultura (1999), 16/17(1), 26-28

The use of chestnut tannin (CT) (hydrolysable tannins), added at a low concentration (4 g CT/100 g of total nitrogen (TN) = 0,8 g cT/kg of DM distribute) to a grass forage for growing sheep, improves the ... [more ▼]

The use of chestnut tannin (CT) (hydrolysable tannins), added at a low concentration (4 g CT/100 g of total nitrogen (TN) = 0,8 g cT/kg of DM distribute) to a grass forage for growing sheep, improves the N retention (P0,01). The improvement of N retention is explained by the decrease of nitrogen in the urine, indicating a better use of absorbed nitrogen. Moreover, the addition at these low concentrations of CT to fresh grass does not alter neither the digestibility of its constituents (OM, TN, ADF) nor the rate of ingestion. [less ▲]

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See detailFirst-principles characterization of the four phases of barium titanate
Ghosez, Philippe ULg; Gonze, X.; Michenaud, J. P.

in Ferroelectrics (1999), 220(1-2), 1-15

Using a first-principles approach, the four phases of perovskite barium titanate are studied. We determine the lattice parameter, the bulk modulus and the cohesive energy of the cubic phase; the relaxed ... [more ▼]

Using a first-principles approach, the four phases of perovskite barium titanate are studied. We determine the lattice parameter, the bulk modulus and the cohesive energy of the cubic phase; the relaxed atomic positions in the three ferroelectric structures; and the evolution of the electronic properties from one phase to the other. The role of electronic exchange-correlation energy in the stabilization of the different phases is also investigated. [less ▲]

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See detailFormation documentaire et projets pédagogiques
Pochet, Bernard ULg; Thirion, Paul ULg

in Bulletin des Bibliothèques de France (1999), 44(1), 16-22

This article is the fruit of a reflective study carried out over ten years by the group Formation des utilisateurs de l'Association belge de documentation. After a description of «the informational space» ... [more ▼]

This article is the fruit of a reflective study carried out over ten years by the group Formation des utilisateurs de l'Association belge de documentation. After a description of «the informational space» offered by this group and without forgetting the place of the Internet, it offers an outline proposal on general documentation training, largely methodological and integrated in pedagogical projects. Information literacy includes aspects as varied as taking account and expression of information needs, the knowledge of the space of information, the criticism and evaluation of information, and its exploitation... It concludes with the need to construct a solid pedagogical project and with a call to all documentation professionals. [less ▲]

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See detailAnionic synthesis of [1,4-poly(diene)-b-syndiotactic poly(methyl methacrylate)] diblock copolymers: 7Li NMR study of the intermediate reaction of lithium poly(diene) anion with 1,1-diphenylethylene
Zune, Catherine; Dubois, Philippe ULg; Jérôme, Robert ULg et al

in Macromolecular Chemistry and Physics (1999), 200(2), 460-467

The end-capping with 1,1-diphenylethylene (DPE) of living 1,4-poly(diene) lithiated anions prepared in cyclohexane (Chx) and toluene is a major but poorly controlled step in the synthesis of syndiotactic ... [more ▼]

The end-capping with 1,1-diphenylethylene (DPE) of living 1,4-poly(diene) lithiated anions prepared in cyclohexane (Chx) and toluene is a major but poorly controlled step in the synthesis of syndiotactic poly(methyl methacrylate) (sPMMA) containing block copolymers. The kinetics of the reaction have been studied by means of 7Li NMR not only in Chx and toluene but also in their mixtures with polar solvents, since the solvent polarity must be increased for MMA to be predominantly converted into sPMMA. Although the addition of a polar solvent (tetrahydrofuran (THF), diethyl ether) to Chx and toluene is known to increase the reactivity of living polymeric anions, contaminating lithium salts, such as lithium hydroxide, slow down the end-capping reaction even when 10 vol.-% polar solvent is added. Moreover, the polymeric diphenylalkyllithium anions are unstable in 1/9 (v/v) THF/Chx mixture, as a result of the nucleophilic attack of THF. On the basis of all these observations, new experimental conditions are proposed for improving the control of the anionic block copolymerization of 1,3-dienes and MMA to yield 1,4-poly(diene) and sPMMA containing block copolymers. [less ▲]

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See detailAnalysing financial returns using regression models based on non-symmetric stable distributions
Lambert, Philippe ULg; Lindsey, James ULg

in Journal of the Royal Statistical Society : Series C (Applied Statistics) (1999), 48

The daily evolution of the price of Abbey National shares over a 10-week period is analysed by using regression models based on possibly non-symmetric stable distributions. These distributions, which are ... [more ▼]

The daily evolution of the price of Abbey National shares over a 10-week period is analysed by using regression models based on possibly non-symmetric stable distributions. These distributions, which are only known through their characteristic function, can be used in practice for interactive modelling of heavy-tailed processes. A regression model for the location parameter is proposed and shown to induce a similar model for the mode. Finally, regression models for the other three parameters of the stable distribution are introduced. The model found to fit best allows the skewness of the distribution, rather than the location or scale parameters, to vary over time. The most likely share return is thus changing over time although the region where most returns are observed is stationary. [less ▲]

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See detailIntragranular and intergranular superconducting properties of bulk melt-textured YBCO
Vanderbemden, Philippe ULg; Cloots, Rudi ULg; Ausloos, Marcel ULg et al

in IEEE Transactions on Applied Superconductivity (1999), 9(2), 2308-2311

We have investigated the superconducting properties of bulk melt-processed YBCO using different experimental techniques. First, single domain materials (i.e. containing no grain boundaries) have been ... [more ▼]

We have investigated the superconducting properties of bulk melt-processed YBCO using different experimental techniques. First, single domain materials (i.e. containing no grain boundaries) have been studied. Electrical resistivity, current-voltage characteristics, M-H loops, and A,C. susceptibility. have been measured for different field and current directions. The intragranular properties are characteristic of high-quality melt-processed YBCO material,,vith a critical current density J(c)(T=77K, B=1T//c) > 10(4) A/cm(2). The anisotropy ratio J(c)(ab)/ J(c)(c) is found to be close to 3. Both magnetic and transport measurements show that defects in the microstructure do not significantly impede the current flow inside the single domain. These results were compared to those measured on samples containing one "natural" single grain boundary which sometimes appears during the grain growth process. The intergranular properties show a much stronger current and magnetic field dependence than that measured within the grain and these differences are discussed. [less ▲]

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See detailThe X-ray emission spectra of multicharged xenon ions in a gas puff laser-produced plasma
Yu Skobelev, I.; Dyakin, V. M.; Ya Faenov, A. et al

in Journal of Physics : B Atomic Molecular & Optical Physics (1999), 32

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See detailMatrix-metalloproteinases in bronchopulmonary carcinomas.
Martinella-Catusse, C.; Nawrocki, B.; Gilles, Christine ULg et al

in Histology and Histopathology (1999), 14(3), 839-43

Matrix metalloproteinases (MMPs) represent a group of enzymes involved in the degradation of most of the components of the extracellular matrix and therefore participate in tumoural invasion. MMPs ... [more ▼]

Matrix metalloproteinases (MMPs) represent a group of enzymes involved in the degradation of most of the components of the extracellular matrix and therefore participate in tumoural invasion. MMPs, especially gelatinases A and B, MT1-MMP, the activator of gelatinase A, and stromelysin-3 were found overexpressed in many cancers including bronchopulmonary carcinomas. In vivo observations revealed that fibroblasts are the principal source of production of MMPs. Some of these enzymes such as MT1-MMP and stromelysin 3, displayed a focal stromal localisation near preinvasive and invasive tumour clusters. Furthermore, some tumour cell lines were shown to stimulate the expression of MT1-MMP by fibroblasts. All these in vivo and in vitro results suggest that certain tumour cells produce diffusible factors which could influence the MMP stromal expression. Among these factors, the TCSF (Tumor Collagenase Stimulatory Factor) which is known to upregulate some MMPs in vitro could be a good candidate for this stromal regulation, since it is produced by bronchial tumour cells in vivo. In this review, we address such a cooperation between tumour and stromal cells for the production of MMPs and emphasize their necessity for tumoural progression in bronchopulmonary carcinomas [less ▲]

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See detailAn imprinted QTL with major effect on muscle mass and fat deposition maps to the IgfII locus in pigs
Nezer, C.; Moreau, L.; Brouwers, B. et al

in Nature Genetics (1999), 21

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See detailAtteintes physiopathologiques liees a la circulation extracorporelle. Pathogenies et modes de prevention
Defraigne, Jean-Olivier ULg

in Bulletin et Mémoires de l'Académie Royale de Médecine de Belgique (1999), 154(10-12), 381-91392-5

During heart surgery, several humoral cascades (coagulation, complement, kallicrein-kinin, cytokines, fibrinolysis) and several cell systems (platelets, neutrophils, endothelial cells, ...) are activated ... [more ▼]

During heart surgery, several humoral cascades (coagulation, complement, kallicrein-kinin, cytokines, fibrinolysis) and several cell systems (platelets, neutrophils, endothelial cells, ...) are activated. Numerous contributing factors have been reported: blood contact with foreign surfaces of the extracorporeal circuits, blood-air interface, lung and myocardial ischemia-reperfusion after unclamping, hypothermia, shear stresses, ... A post-perfusion syndrome may develop which include miscellaneous symptoms: coagulation disturbances and bleeding, neurological alterations, inflammatory syndrome, and, in extreme cases, multisystemic organ failure. Even if the present mortality of cardiac surgery is low, several approaches have been proposed to reduce such activations. They are based on changing in the circuit design, or in the composition of the luminal surfaces of the tubing and oxygenator, on improvement of the operative technique, and on modifications of the perfusion technique. Pharmacological agents are also used (anti-inflammatory drugs, corticoids, serine proteases inhibitor (aprotinin, ...). Nevertheless, the development of more biocompatible surfaces seems a promising goal. [less ▲]

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See detailInvariant bidifferential operators on tensor densities over a contact manifold
Mathonet, Pierre ULg

in Letters in Mathematical Physics (1999), 48(3), 251-261

The spaces of tensor densities over a manifold M are modules over the Lie algebra Vect (M) of vector fields over the manifold. When M is a contact manifold, one can consider the algebra C(M) of vector ... [more ▼]

The spaces of tensor densities over a manifold M are modules over the Lie algebra Vect (M) of vector fields over the manifold. When M is a contact manifold, one can consider the algebra C(M) of vector fields which preserves the contact structure. If the manifold is endowed with a contact projective structure, there is an embedding of the linear symplectic algebra sp (2n+2,R) in C(M). In this Letter, we determine the C(M)- and the sp(2n+2,R)-invariant bidifferential operators on tensor densities. [less ▲]

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See detailPregnancy-Associated Glycoprotein and progesterone profiles during pregnancy and postpartum in native goats from north-east of Brazil.
Melo de Sousa, Noelita ULg; Garbayo, J. M.; Figueiredo, J. R. et al

in Small Ruminant Research (1999), 32

Pregnancy diagnosis is a critical procedure for monitoring goat reproductive performance. In the present investigation, pregnancy-associated glycoprotein (PAG) profiles during pregnancy and first month ... [more ▼]

Pregnancy diagnosis is a critical procedure for monitoring goat reproductive performance. In the present investigation, pregnancy-associated glycoprotein (PAG) profiles during pregnancy and first month postpartum, as well as progesterone (P4) concentrations throughout pregnancy, were determined in native goats from the north-east of Brazil. A total of 30 goats (Moxoto, n = 19 and Caninde, n = 11) were used. Peripheral blood was collected on days 0 (Day 0 = AI), 11, 16, 18, 20, 24 and 30 after AI. Samples were subsequently collected every 2 weeks until day 145, and weekly during the first month postpartum. The levels of PAG and P4 were determined by radioimmunoassay (RIA). The profiles of PAG were not different between the breeds throughout pregnancy. However, a significant effect of the week of pregnancy (p < 0.01) and the number of fetuses (p < 0.05) in PAG concentrations were found. Lower concentrations of PAG were observed during weeks 1 and 3, compared to the rest of the gestation. Thereafter, there was a significant (p < 0.05) increase in PAG concentrations from week 5 to 7 and a significant decrease (p < 0.05) in week 9. The PAG concentrations remained relatively constant until week 17, and finally decreased slowly until parturition. After parturition, PAG concentrations decreased rapidly, and continued to decrease until week 4. During pregnancy, mean P4 concentrations had weekly variations among the animals (p < 0.01) and the period of pregnancy (p < 0.01), but P4 was not affected by the breed or number of fetuses. These results indicate that PAG and P4 concentrations were similar for Caninde and Moxoto goats and that, for both the breeds, the stage of pregnancy and the number of fetuses could influence PAG production. [less ▲]

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See detailChanges in mediobasal hypothalamic gonadotropin-releasing hormone messenger ribonucleic acid levels induced by mating or ovariectomy in a reflex ovulator, the ferret.
Bakker, Julie ULg; Rubin, B. S.; Baum, M. J.

in Endocrinology (1999), 140(2), 595-602

The ferret is a reflex-ovulating species in which receipt of an intromission induces a prolonged (+/- 12 h) preovulatory LH surge in the estrous female. This LH surge is probably stimulated by a large ... [more ▼]

The ferret is a reflex-ovulating species in which receipt of an intromission induces a prolonged (+/- 12 h) preovulatory LH surge in the estrous female. This LH surge is probably stimulated by a large release of GnRH from the mediobasal hypothalamus (MBH). In Exp 1 we asked whether GnRH messenger RNA (mRNA) levels increase in response to mating so as to replenish the MBH GnRH stores needed to sustain the preovulatory LH surge. Estrous females were killed 0, 0.25, 0.5, 1, 3, 6, 14, or 24 h after the onset of a 10-min intromission from a male. Coronal brain sections ranging from the rostral preoptic area caudally to the posterior hypothalamus were processed for in situ hybridization using a 35S-labeled oligoprobe complementary to the human GnRH-coding region. We found no evidence of increased MBH GnRH mRNA levels during the ferret's mating-induced preovulatory LH surge. Instead, the number of GnRH mRNA-expressing cells dropped significantly in the arcuate region beginning 6 h after onset of intromission and remained low thereafter. Furthermore, cellular GnRH mRNA levels decreased in the arcuate region toward the end of the preovulatory LH surge. In Exp 2 we asked whether ovarian hormones regulate MBH GnRH mRNA levels in the female ferret. Ovariectomy of estrous females significantly reduced the number of GnRH mRNA-expressing cells in the arcuate region. This decrease was probably not due to the absence of circulating estradiol. Gonadally intact anestrous females had levels of MBH GnRH mRNA similar to those in estrous females even though plasma estradiol levels were equally low in anestrous females and ovariectomized females. Ovarian hormones other than estradiol may stimulate MBH GnRH mRNA levels in anestrous and estrous females. [less ▲]

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See detailCyanobacterial sequences retrieved directly from the Great Sippewissett Salt Marsh, MA, USA
Dillon, Jesse; Wilmotte, Annick ULg

in Bulletin de l'Institut Océanographique. Numéro spécial (1999), 19

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See detailCapital humain, emploi et revenus du travail: Belgique, 1992
Docquier, Frédéric; Laurent, Sébastien; Perelman, Sergio ULg

in Cahiers Economiques de Bruxelles (1999), (161), 77-103

L’objet de ce papier est de mettre en évidence, pour un échantillon de travailleurs salariés masculins, le rôle de l’éducation et, de façon plus large, du capital humain sur l’emploi et la formation des ... [more ▼]

L’objet de ce papier est de mettre en évidence, pour un échantillon de travailleurs salariés masculins, le rôle de l’éducation et, de façon plus large, du capital humain sur l’emploi et la formation des salaires en Belgique. A partir de données individuelles, on estime économétriquement les relations entre d’une part, le diplôme obtenu et, d’autre part, le fait d’avoir un emploi ainsi que le niveau de rémunération correspondant. Les résultats obtenus confirment de manière statistiquement significative ces relations en mettant en évidence non seulement le rôle du niveau des études mais également celui du type d’enseignement (général, technique, professionnel) poursuivie sur le rendement en capital humain. On montre aussi que la dimension régionale a une importance non négligeable sur le taux d’occupation; par contre, elle s’avère être totalement inopérante sur la formation des salaires. [less ▲]

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See detailAutour du chat de Cheshire et de son sourire: Approche phylogénétique du rire et du sourire humains
Servais, Véronique ULg

in Homme (L') : Revue Française d'Anthropologie (1999), volume 39 N° 150(avril-juin), 157-176

The paper offers an original synthesis of the hypothesis of primatologists about the origins of human smile and laughter.

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See detailLes troubles cognitifs consécutifs à un trauma crânien léger chez l'enfant
Closset, Annette; Van der Linden, Martial ULg; Misson, Jean-Paul ULg

in Percentile (1999), 4

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See detailLe comportement social des urodèles
Denoël, Mathieu ULg

in Cahiers d'Ethologie (1999), 19

It could be misleading to consider that the social behaviour of newts and salamanders is simple and can be generalized. Indeed, individuals are faced with external and internal conditions which are ... [more ▼]

It could be misleading to consider that the social behaviour of newts and salamanders is simple and can be generalized. Indeed, individuals are faced with external and internal conditions which are extremely variable. In response to these factors, they may respond in a particular way. The behavioural variations, called alternative tactics, allow individuals to improve their fitness, i.e. to ensure the survival of their genes. They can be exhibited in reaction to a large range of factors such as the mere presence or density of competitors, the operational sex-ratio, the behaviour and kinship of the other individuals, the abiotic characteristics of the environment, the experience of the individuals involved. These alternative tactics are favoured in urodeles. Indeed, although the main process of fertilization is internal, they breed by means of a spermatophore deposited in the external environment. Each species of newts and salamanders exhibits specific behavioural patterns as they developed and evolved in particular environments which have exerted selective pressures on the individuals and in this way on the species. As a consequence, the understanding of patterns of behaviour requires that we know the environment in which they appeared. The main occurrence of parental care and territoriality in terrestrial environments may be explained by the features of these habitats in which eggs could not survive without protection, and in which adults may defend areas of particular interest and communicate by means of pheromones. All of these characteristics show that we have to study the behaviour of individuals of different species under several conditions. Without such an analysis, it would be difficult to understand biodiversity. [less ▲]

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See detailDiverticulosis and Diverticulitis in the Immunocompromised Patients
Detry, Olivier ULg; Honore, Pierre ULg; Meurisse, Michel ULg et al

in Acta Chirurgica Belgica (1999), 99(3, May-Jun), 100-2

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See detailSocioeconomic and psychosocial conditions of parents and cardiovascular risk factors in their children: the Belgian Luxembourg Child Study III.
Guillaume, Michèle ULg; Lapidus, L.; Lambert, A. et al

in Acta Paediatrica (1999), 88(8), 866-73

Socioeconomic and psychosocial handicaps are often associated with disease. There is a large body of information on adults on such relationships, but data are sparse on children. In a cohort of 1028 boys ... [more ▼]

Socioeconomic and psychosocial handicaps are often associated with disease. There is a large body of information on adults on such relationships, but data are sparse on children. In a cohort of 1028 boys and girls, selected at random from school classes in Province de Luxembourg, a mainly rural area of Belgium, these problems were analysed in age strata of 6-8, 8-10, 10-12 years. Participation rate was 71%. Information was collected from questionnaires,. Anthropometric variables, blood pressure and glucose as well as cholesterol, triglycerides and insulin were measured in the children and related to the psychosocial and socioeconomic factors, organized into rural, psychosocial, socioeconomic and alcohol/smoking clusters of observations. Rural: Duration of living in the area of the child and parents correlated with diastolic blood pressure, particularly in boys (p < 0.01). Psychosocial: Housewives (p = 0.002) and their children (p = 0.002) had higher body mass indexes (BMI) than other mothers and their children. Sons of housewives also had higher blood pressure (systolic, p = 0.0007, diastolic, p = 0.007). Socioeconomic: Socioeconomic factors of parents (profession, unemployment) played relatively minor roles. Alcohol/smoking: Alcohol consumption was related to skinfold thickness in boys (p = 0.022), but not in girls. Girls, but not boys, with smoking parents had higher BMI (p=0.014). Multiple regression analyses suggested that psychosocial factors, such as housewives as mothers of large families, may be important for associations with cardiovascular risk factors in their children. There were apparent differences in the findings between girls and boys, suggesting that boys are more vulnerable to the impacts of the factors analysed. [less ▲]

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See detailA new observed pre-copulatory behaviour of the lesser-spotted dogfish, scyliorhinus canicula, in captivity
Domi, Nadège; Poncin, Pascal ULg; Voss, Jacques

in Société française d'Ichtyologie (1999)

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See detailAnalyse du comportement des structures métalliques en cas d'incendie
Franssen, Jean-Marc ULg; Dhima, Dhionis

in Construction Métallique (1999), 3

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See detailDefining obesity in childhood: current practice.
Guillaume, Michèle ULg

in American Journal of Clinical Nutrition (1999), 70(1), 126-30

A survey of information from 26 countries was performed to examine the methods, cutoff points, and reference materials used to define obesity in childhood and adolescence. The body mass index (in kg/m2 ... [more ▼]

A survey of information from 26 countries was performed to examine the methods, cutoff points, and reference materials used to define obesity in childhood and adolescence. The body mass index (in kg/m2) was used frequently, as well as several other methods. Reference materials used were often based on national surveys, although reference data from other countries were sometimes used. The data presented was often insufficient to judge the representativeness of the reference material. Cutoff points varied considerably. Available data allow neither a meaningful international estimation of the prevalence of obesity nor international comparisons. Although associated with considerable problems, this situation can be improved with an international consensus which, by necessity, will be riddled with uncertainties and compromises. [less ▲]

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See detailSpreadsheet based teaching aids in chemical engineering education
Heyen, Georges ULg; Kalitventzeff, Boris ULg

in Computers & Chemical Engineering (1999), 23(Suppl. S), 629-632

Modern spreadsheet programs offer a wide range of calculation, charting and dialog options, allowing the development of effective teaching aids. Examples of worksheet illustrating numerical analysis ... [more ▼]

Modern spreadsheet programs offer a wide range of calculation, charting and dialog options, allowing the development of effective teaching aids. Examples of worksheet illustrating numerical analysis, thermodynamics and unit operations are shown. All offer complete interaction between the problem statement and the presentation of results. [less ▲]

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See detailComment on "physical reality of light-induced atomic states"
Schlagheck, Peter ULg; Hornberger, K.; Buchleitner, A.

in Physical Review Letters (1999), 82(3), 664-664

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See detailLa vaccination contre le virus respiratoire syncytial bovin
Thiry, Etienne ULg; Pastoret, Paul-Pierre ULg; Valarcher, J. F. et al

in Bulletin des Groupements Techniques Vétérinaires (1999), 5

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See detailInvolvement of indole-3-acetic acid in the circadian growth of the first internode of Arabidopsis
Jouve, Laurent; Gaspar, Thomas ULg; Kevers, Claire ULg et al

in Planta (1999), 209(1), 136-142

The extension rate of the first inflorescence node of Arabidopsis was measured during light/dark or continuous light exposure and was found to exhibit oscillations which showed a circadian rhythmicity ... [more ▼]

The extension rate of the first inflorescence node of Arabidopsis was measured during light/dark or continuous light exposure and was found to exhibit oscillations which showed a circadian rhythmicity. Decapitation induced a strong inhibition of stem extension. Subsequent application of IAA restored growth and the associated extension-rate oscillations. In addition, IAA treatments, after decapitation, re-established the circadian rhythmicity visible in the intact plants during free run. This indicates that the upper zone of the inflorescence has a major influence on the extension rate of floral stems and implies a role for auxin. Application of N-(1-naphthyl)phthalamic acid, an IAA transport inhibitor, to an intact floral stem inhibited growth and the rhythmicity in the extension rate oscillations, indicating that IAA polar transport may play a role in the dynamics of stem elongation. Furthermore, IAA-aspartate application, after decapitation, did not restore growth and rhythmicity. Nevertheless, biochemical analysis of IAA and IAA-aspartate demonstrated circadian fluctuations of the endogenous levels of both compounds. These observations suggest that IAA metabolism is an essential factor in the regulation of the circadian growth rhythm of Arabidopsis floral stems. [less ▲]

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See detailModelling the butterfat crystallisation process
Heyen, Georges ULg; Alleman, Xavier; Kalitventzeff, Boris ULg et al

in Computers & Chemical Engineering (1999), 23(Suppl. S), 819-822

Milk fat exhibits seasonal variations in composition and properties which are undesirable for many subsequent applications. Thus techniques are sought to process dairy products in order to achieve a ... [more ▼]

Milk fat exhibits seasonal variations in composition and properties which are undesirable for many subsequent applications. Thus techniques are sought to process dairy products in order to achieve a consistent quality. A brief introduction to milk fat presents its most important particularities, especially composition, seasonal variations, solid fat content, crystalisation and polymorphism. The differential scanning calorimetry (DSC) analysis allows to estimate the solid fat content. Different methods have been developed to estimate more and more precisely the solid fat content which is certainly an important parameter in the description of the textural properties of butterfat. The industrial crystallisation process is modelled on the basis of pilot plant data. That model allows to approach the particular temperature profile in the scraped surface heat exchangers and to give a first explanation of the involved phenomena. [less ▲]

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See detailCardiorespiratory measurements and indices of oxidative stress in exercising COPD horses
Art, Tatiana ULg; Kirschvink, Nathalie; Smith, Nicola et al

in Equine Veterinary Journal. Supplement (1999), 30

The effect of a COPD crisis on arterial blood gases, heart rate, lactate and indices of oxidative stress were investigated before, during and 1 h after a 'run up to fatigue' in 6 COPD horses. They were ... [more ▼]

The effect of a COPD crisis on arterial blood gases, heart rate, lactate and indices of oxidative stress were investigated before, during and 1 h after a 'run up to fatigue' in 6 COPD horses. They were investigated twice, randomly: once in acute crisis (C) and once in clinical remission (R). Arterial and mixed venous blood samples were collected and analysed for partial pressures in O2 and CO2. The mixed venous blood was also analysed for plasma lactate (LA) and packed cell volume (PCV), as well as for indices of oxidative stress, i.e. reduced glutathione, glutathione disulphide, glutathione redox ratio (GRR) and lipid hydroperoxides (LPH). The exercise test was an effort of increasing intensity on a treadmill at 0% slope, which was stopped when the horses showed signs of exhaustion. Their performance was evaluated by the number of steps and the running time in the last step. Heart rate was monitored continuously during the test. Blood sampling was performed before, just after and 1 h after the end of the test. The COPD crisis significantly reduced the time to fatigue. However, despite the fact that the exercise intensity and length were lower, peak HR and peak LA were similar in C and R, while arterial hypoxaemia and hypercapnia, and PCV were significantly higher in C, indicating a higher physiological stress in this condition. By contrast, the oxidative stress seemed to be higher in R than in C as suggested by the fact that, 1 h after exercise, GRR and LPH were significantly increased with regards to their pre-exercise values in R and not in C. The fact that exercise did not induce an oxidative stress in C could be partly related to (1) the lower exercise intensity reached by the horses, and (2) to the more severe hypoxaemia experienced in this condition. In conclusion, COPD horses in acute crisis show a significant decrease in performance. The reasons for this exercise intolerance remain unclear, but do not appear to be related to any increase of the oxidative stress in C. [less ▲]

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See detailDesigned combination of chiral selectors for adjustment of enantioseparation selectivity in capillary electrophoresis.
Fillet, Marianne ULg; Chankvetadze, Bezhan; Crommen, Jacques ULg et al

in Electrophoresis (1999), 20(13), 2691-7

In this study an attempt has been made to explain the reasons for changing the enantioseparation selectivity in some dual cyclodextrin (CD) systems compared to the use of single chiral selectors in ... [more ▼]

In this study an attempt has been made to explain the reasons for changing the enantioseparation selectivity in some dual cyclodextrin (CD) systems compared to the use of single chiral selectors in capillary electrophoresis (CE). An explanation for selectivity changes is proposed based on the effect of the chiral selector on the mobility of the analyte. In order to support the proposed mechanism, several dual systems were designed on the basis of the known recognition pattern of enantiomers for individual CDs. In most cases the separation selectivity could be adjusted in a designed way. There was no experimental evidence for simultaneous binding of a given chiral analyte with both chiral selectors or of chiral recognition of an analyte complex with one CD by another CD. [less ▲]

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See detailElimination of adsorption effects in the analysis of water-soluble vitamins in pharmaceutical formulations by capillary electrophoresis.
Fotsing, Lucas; Fillet, Marianne ULg; Chiap, Patrice ULg et al

in Journal of Chromatography. A (1999), 853(1-2), 391-401

A tendency to an increase in migration times was observed when different water-soluble vitamins were analysed repeatedly in pharmaceutical preparations by capillary electrophoresis. In order to better ... [more ▼]

A tendency to an increase in migration times was observed when different water-soluble vitamins were analysed repeatedly in pharmaceutical preparations by capillary electrophoresis. In order to better understand the origin of this effect, the influence of the vitamins and the excipients, such as cellulose derivatives, was investigated. These studies indicated that the increase in analyte migration times was most probably due to the adsorption of different kinds of constituents to the capillary wall. Different rinsing procedures were tested in order to eliminate these unfavourable effects. A rinse of the capillary with a 25 mM sodium dodecyl sulfate (SDS) solution in the running buffer between successive runs was found to be particularly effective when the analysis was performed by free solution capillary zone electrophoresis (CZE). When the vitamins were determined by micellar electrokinetic chromatography (MEKC) using SDS as surfactant, a short capillary rinse with the running buffer was sufficient to obtain reproducible migration times. The CZE and MEKC methods developed were validated and compared. Both methods could be applied to the determination of water-soluble vitamins in different multivitamin formulations. [less ▲]

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See detailLes biotechnologies vegetales appropriees dans le contexte du dialogue Nord-Sud.
Lepoivre, Philippe ULg

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (1999), 3(1),

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See detailL'esthéticien
Steinmetz, Rudy ULg

in Art&Fact (1999)

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See detailPCAM: a multi-user facility-based protein crystallization apparatus for microgravity
Carter, Daniel; Wright, Brenda; Miller, Teresa et al

in Journal of Crystal Growth (1999), 196

A facility-based protein crystallization apparatus for microgravity (PCAM) has been constructed and flown on a series of Space Shuttle Missions. The hardware development was undertaken largely because of ... [more ▼]

A facility-based protein crystallization apparatus for microgravity (PCAM) has been constructed and flown on a series of Space Shuttle Missions. The hardware development was undertaken largely because of the many important examples of quality improvements gained from crystal growth in the diffusion-limited environment in space. The concept was based on the adaptation for microgravity of a commonly available crystallization tray to increase sample density, to facilitate co-investigator participation and to improve flight logistics and handling. A co-investigator group representing scientists from industry, academia, and government laboratories has been established. Microgravity applications of the hardware have produced improvements in a number of structure-based crystallographic studies and include examples of enabling research. Additionally, the facility has been used to support fundamental research in protein crystal growth which has delineated factors contributing to the effect of microgravity on the growth and quality of protein crystals. [less ▲]

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See detailLa leçon des choses. Robinson ou la répétition
Durand, Pascal ULg

in Etudes Françaises (1999), 35/1

Roman à ce point connu qu'il n'est plus guère lu, texte tronqué parce que trop réécrit, Robinson Crusoe tire peut-être bien de tout ce que Rousseau appelait son « fatras » l'essentiel de sa signification ... [more ▼]

Roman à ce point connu qu'il n'est plus guère lu, texte tronqué parce que trop réécrit, Robinson Crusoe tire peut-être bien de tout ce que Rousseau appelait son « fatras » l'essentiel de sa signification. Actes rituels, besognes et constructions, plaintes et méditations, prières et prêchi-prêcha font de ce texte un roman de la répétition dans lequel un héros calculateur soumet les objets divers qui l'environnent à une comptabilité compulsive. La leçon des choses est trompeuse : le principe d'utilité qu'elles proclament masque assez mal qu'elles restent prises, aux yeux de Robinson, dans la logique marchande qu'elles semblaient suspendre. [less ▲]

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See detailEffective resolution of racemic pirlindole at the preparative scale
De Tullio, Pascal ULg; Ceccato, A.; Liégeois, Jean-François ULg et al

in Chirality (1999), 11

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See detailConfirmation and disconfirmation : Their social advantages
Leyens, J. P.; Dardenne, Benoît ULg; Yzerbyt, V. et al

in European Review of Social Psychology (1999)

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See detailYeast species for biocontrol of apple postharvest diseases: an encouraging case of study for practical use
Jijakli, Haissam ULg; Grevesse, Cathy; Lepoivre, Philippe ULg

in biotechnological approaches in biocontrol of plant pathogens (1999)

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See detailMolecular and Clinicopathological Diagnosis of Non-Wildebeest Associated Malignant Catarrhal Fever in Belgium
Desmecht, Daniel ULg; Cassart, Dominique ULg; Rollin, Frédéric ULg et al

in Veterinary Record : Journal of the British Veterinary Association (1999), 144(14), 388

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See detailOn the use of the Cowan's code for atomic structure calculations in singly ionized lanthanides
Quinet, Pascal ULg; Palmeri, P.; Biémont, Emile ULg

in Journal of Quantitative Spectroscopy & Radiative Transfer (1999), 62

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See detailThe crustal tongue melting model and the origin of massive anorthosites
Duchesne, Jean-Clair ULg; Liégeois, Jean-Paul ULg; Vander Auwera, Jacqueline ULg et al

in Terra Nova (1999), 11

Recent detailed field studies in several anorthosite complexes have shown that anorthosites are frequently linked with weakness zones in the crust which favour their emplacement at mid-crust levels ... [more ▼]

Recent detailed field studies in several anorthosite complexes have shown that anorthosites are frequently linked with weakness zones in the crust which favour their emplacement at mid-crust levels. Recent experimental data have also shown that the parent magma compositions of various anorthosite massifs lie on thermal highs in the relevant phase diagrams, indicating that these magmas cannot be derived by fractionation of peridotitic mantle melts but rather are produced by melting of gabbronoritic sources. In the Sveconorwegian province terrane boundaries have been traced in deep seismic profiles to Moho offsets or to tongues of lower crustal material underthrust to depths of 40-50 km. We therefore suggest that the parent magmas of anorthosite massifs are produced by melting of gabbronoritic rocks from the lower crust that had been thrust into the mantle by collision of terranes. [less ▲]

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See detailGoverning biodiversity
Mougenot, Catherine ULg; Mormont, Marc ULg

in International Journal of Environment and Pollution (1999), 12(4), 78-99

he hypothesis of this paper is that the value conferred on nature designates both the ''objects of nature'' that are the subject of consideration, and the human beings for whom they are intended or who ... [more ▼]

he hypothesis of this paper is that the value conferred on nature designates both the ''objects of nature'' that are the subject of consideration, and the human beings for whom they are intended or who are responsible for them. These designation processes are dynamic and linked, but also interdependent. In order to examine these processes more closely, we make use of the concept of network, which integrates the action of different players in their specific world, as well as ''objects'' that can be as different as scientific nomenclatures, available sites, management plans, funds, etc. In other words, protection practices link up different universes, scientific models and practices, institutional practices, nature conservation practices and, finally, the evolution of species and natural sites that are not passive entities. The fact that we speak of ''socio-natural'' networks indicates that nature conservation is ''based'' on chains of equivalences that integrate these different players and universes. The processes are dynamic ones. The paper therefore examines how they can be stabilised or expanded, and also how they can be transformed in a much more radical manner. The study is applied to the Walloon Region (in Belgium). The paper first looks at what could be considered as the ''classical nature conservation network'', and then examines how it is called to evolve. The fact is that contemporary situations lead us to take account of different types of networks for conserving and maintaining nature. These are compared, and the paper examines how each of them attempts to take account of the increasingly complex and also increasingly open concept of biodiversity. This perspective of networking also leads us to conclude that none of these networks (scientific, economic, legislative, institutional, etc.) that go to make up nature conservation is capable on its own of giving value to nature. This is acquired - or not - only by building a hybrid chain that cuts across or integrates these different worlds. [less ▲]

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See detailLe controle thérapeutique des médicaments antidépresseurs
Charlier, Corinne ULg; Ansseau, Marc ULg; Pinto, Emmanuel ULg et al

in Annales de Biologie Clinique (1999), 57(4, Jul-Aug), 463-8

Depression is a pathology frequently observed in general medicine (10%). Treatment of depression makes great use of drugs from different pharmacological classes. The optimal posology is difficult to ... [more ▼]

Depression is a pathology frequently observed in general medicine (10%). Treatment of depression makes great use of drugs from different pharmacological classes. The optimal posology is difficult to establish, and clinicians prefer to avoid side effects by prescribing low regimen. This study is related to an evaluation of seric antidepressant concentrations in comparison with the daily doses in a large psychiatric population. Side effects of drugs are appreciated by enzymatic determinations. [less ▲]

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See detailDendrimer-like star block and amphiphilic copolymers by combination of ring opening and atom transfer radical polymerization
Hedrick, James L.; Trollsas, Mikael; Hawker, Craig Jon et al

in Macromolecules (1998), 31(25), 8691-8705

A new type of macromolecular architecture, denoted as dendrimer-like star block copolymers, is reported. These block copolymers are described by a radial geometry where the different generations or layers ... [more ▼]

A new type of macromolecular architecture, denoted as dendrimer-like star block copolymers, is reported. These block copolymers are described by a radial geometry where the different generations or layers are comprised of high molecular weight polymer emanating from a central core. A hexahydroxyl functional core was used as an initiator for the “living” ring opening polymerization (ROP) of ε-caprolactone producing a hydroxyl terminated six arm star polymer with controlled molecular weight and narrow polydispersities (PD < 1.1). Capping these chain ends with dendrons containing activated bromide moieties produced “macro-initiators” for atom transfer radical polymerization (ATRP). Methyl methacrylate was polymerized from these “macro-initiators” in the presence of an organometallic promoter to produce the requisite dendrimer-like star polymers. High molecular weight was obtained with low polydispersities (<1.2). Alternatively, amphiphilic character could be introduced by designing the different layers or generations to be either hydrophobic or hydrophilic. For example, methyl methacrylate (MMA) with either hydroxyethyl methacrylate (HEMA) or methacrylate functional ethylene oxide macromonomers (EO) were polymerized from these “macro-initiators” to provide a hydrophilic outer layer. The use of macromolecular building blocks allows rapid attainment of high polymer in a limited number of steps with purification between transformation requiring only polymer precipitation. [less ▲]

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See detailLa résistance bactérienne aux antibiotiques, un modèle exemplaire d'évolution moléculaire dirigée
Ghuysen, Jean-Marie ULg

in Verhandelingen - Koninklijke Academie voor Geneeskunde van Belgie (1998), 60(4), 287-294

The simplest conceivable event that can occur at the gene level can result in the development of efficacious resistance tot antibiotics. The bacterial world behaves as an enormous organism whose cells can ... [more ▼]

The simplest conceivable event that can occur at the gene level can result in the development of efficacious resistance tot antibiotics. The bacterial world behaves as an enormous organism whose cells can exchange their genes very easily. Accordingly, oppotunities for the exhcange of genetic material in nature are probably unlimited. This knowledge cannot be ignored. It leads to the important conclusion that the antibiotics are societal drugs. A resistance gene which has appeared somewhere in the world can travel far and fast. [less ▲]

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See detailTransport of arginine and ornithine into isolated mitochondria of Saccharomyces cerevisiae.
Soetens, Oriane; Crabeel, Marjolaine; Elmoualij, Benaïssa ULg et al

in European Journal of Biochemistry (1998), 258(2), 702-9

In this work we have characterised the transport of L-arginine and L-ornithine into mitochondria isolated from a wild-type Saccharomyces cerevisiae strain and an isogenic arg11 knock-out mutant. The Arg11 ... [more ▼]

In this work we have characterised the transport of L-arginine and L-ornithine into mitochondria isolated from a wild-type Saccharomyces cerevisiae strain and an isogenic arg11 knock-out mutant. The Arg11 protein (Arg11p) is a mitochondrial carrier required for arginine biosynthesis [Crabeel, M., Soetens, O., De Rijcke, M., Pratiwi, R. & Pankiewicz, R. (1996) J. Biol. Chem. 271, 25011-25019]. Reconstitution experiments have confirmed that it is an L-ornithine carrier also transporting L-arginine and L-lysine by order of decreasing affinity, but not L-histidine [Palmieri, L., De Marco, V., Iacobazzi, V., Palmieri, F., Runswick, M. & Walker, J. (1997) FEBS Lett. 410, 447-451]. Evidence is presented here that the mitochondrial inner membrane contains an L-arginine and L-ornithine transporting system distinct from Arg11p, in keeping with the arginine leaky phenotype of arg11 knock-out mutants. The newly characterised carrier, which we propose to name Bac1p (basic amino acid carrier), behaves as an antiporter catalysing the electroneutral exchange of the basic amino acids L-arginine, L-lysine, L-ornithine and L-histidine and displays the highest affinity for L-arginine (Km of 30 microM). L-Arginine uptake has a pH optimum in the range of 7.5-9 and is inhibited by several sulphydryl reagents, by pyridoxal 5'-phosphate and by cations [less ▲]

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See detailObservations of Coronal Structures Above an Active Region by EIT and Implications for Coronal Energy Deposition
Neupert, W. M.; Newmark, J.; Delaboudinière, J.-P. et al

in Solar Physics (1998), 183

Solar EUV images recorded by the EUV Imaging Telescope (EIT) on SOHO have been used to evaluate temperature and density as a function of position in two largescale features in the corona observed in the ... [more ▼]

Solar EUV images recorded by the EUV Imaging Telescope (EIT) on SOHO have been used to evaluate temperature and density as a function of position in two largescale features in the corona observed in the temperature range of 1.0-2.0MK. Such observations permit estimates of longitudinal temperature gradients (if present) in the corona and, consequently, estimates of thermal conduction and radiative losses as a function of position in the features. We examine two relatively cool features as recorded in EIT's Feix/x (171Å) and Fexii (195Å) bands in a decaying active region. The first is a long-lived loop-like feature with one leg, ending in the active region, much more prominent than one or more distant footpoints assumed to be rooted in regions of weakly enhanced field. The other is a near-radial feature, observed at the West limb, which may be either the base of a very high loop or the base of a helmet streamer. We evaluate energy requirements to support a steady-state energy balance in these features and find in both instances that downward thermal conductive losses (at heights above the transition region) are inadequate to support local radiative losses, which are the predominant loss mechanism. The requirement that a coronal energy deposition rate proportional to the square of the ambient electron density (or pressure) is present in these cool coronal features provides an additional constraint on coronal heating mechanisms. [less ▲]

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See detailPolarization properties of a sample of broad absorption line and gravitationally lensed quasars
Hutsemekers, Damien ULg; Lamy, H.; Remy, M.

in Astronomy and Astrophysics (1998), 340

New broad-band linear polarization measurements have been obtained for a sample of 42 optically selected QSOs including 29 broad absorption line (BAL) QSOs. The polarization properties of different sub ... [more ▼]

New broad-band linear polarization measurements have been obtained for a sample of 42 optically selected QSOs including 29 broad absorption line (BAL) QSOs. The polarization properties of different sub-classes have been compared, and possible correlations with various spectral indices searched for. The main results of our study are: (1) Nearly all highly polarized QSOs of our sample belong to the sub-class of BAL QSOs with low-ionization absorption features (LIBAL QSOs). (2) The range of polarization is significantly larger for LIBAL QSOs than for high-ionization (HI) BAL QSOs and non-BAL QSOs. (3) There is some indication that HIBAL QSOs as a class may be more polarized than non-BAL QSOs and therefore intermediate between LIBAL and non-BAL QSOs, but the statistics are not compelling from the sample surveyed thus far. (4) For LIBAL QSOs, the continuum polarization appears significantly correlated with the line profile detachment index, in the sense that LIBAL QSOs with P Cygni-type profiles are more polarized. No correlation was found with the strength of the low- or the high-ionization absorption features, nor with the strength or the width of the emission lines. These results are consistent with a scenario in which LIBAL QSOs constitute a different class of radio-quiet QSOs with more absorbing material and more dust. Higher maximum polarization can therefore be reached, while the actually measured polarization depends on the geometry and orientation of the system as do the line profiles. The observed correlation is interpreted within the framework of recent ``wind-from-disk'' models. Tables~2 and 3 are also available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.html}\fnmsep\thanks{Based on observations collected at the European Southern Observatory (ESO, La Silla) [less ▲]

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See detailPhase behavior of diblock copolymers between styrene and n-alkyl methacrylates
Ruzette, A. V. G.; Banerjee, P.; Mayes, A. M. et al

in Macromolecules (1998), 31(24), 8509-8516

In contrast to most diblock copolymers which exhibit the classical upper critical ordering transition (UCOT), polystyrene-b-poly n-butyl methacrylatePS-b-PBMAhas been shown to undergo ordering upon ... [more ▼]

In contrast to most diblock copolymers which exhibit the classical upper critical ordering transition (UCOT), polystyrene-b-poly n-butyl methacrylatePS-b-PBMAhas been shown to undergo ordering upon heating through a lower critical ordering transition (LCOT). Here we report the phase behavior of a family of diblock copolymers formed from styrene and a homologous series of n-alkyl methacrylates, as determined by combined dynamic rheological testing and small-angle neutron scattering (SANS). It is shown that the shortest side chain methacrylates, with the exception of methyl methacrylate, exhibit the LCOT, while for side chains longer than n-butyl, the copolymers exhibit the classical UCOT behavior. Combined group contribution/lattice fluid model calculations of the solubility parameter and specific volume of the corresponding homopolymers qualitatively support these observations. The same calculations were further employed to molecularly design LCOT behavior into a new diblock material consisting of styrene and a random copolymer of methyl and lauryl methacrylate, denoted PS-b-P(MMA-r-LMA). The success of this approach suggests a simple semiquantitative method for predicting and designing the phase behavior of weakly interacting polymer pairs. [less ▲]

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See detailVariabilite cyclique d'etoiles Wolf-Rayet apparemment isolees.
Morel, Thierry ULg; St-Louis, N.

in Journal of the Royal Astronomical Society of Canada (1998), 92

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See detailSpontaneous Apamin-Sensitive Hyperpolarizations in Dopaminergic Neurons of Neonatal Rats
Seutin, Vincent ULg; Massotte, Laurent ULg; Scuvée-Moreau, Jacqueline ULg et al

in Journal of Neurophysiology (1998), 80(6), 3361-4

Spontaneous apamin-sensitive hyperpolarizations in dopaminergic neurons of neonatal rats. J. Neurophysiol. 80: 3361-3364, 1998. Intracellular recordings from substantia nigra slices revealed the existence ... [more ▼]

Spontaneous apamin-sensitive hyperpolarizations in dopaminergic neurons of neonatal rats. J. Neurophysiol. 80: 3361-3364, 1998. Intracellular recordings from substantia nigra slices revealed the existence of spontaneous hyperpolarizations (amplitude 2-8 mV, duration 100-400 ms) at -60 mV in most dopaminergic neurons of neonatal (9-15 days) but not adult rats. These events were blocked by apamin (300 nM) and bicuculline methochloride (100-300 microM), which blocks apamin-sensitive currents. They were unaffected by the selective gamma-aminobutyric acid-A (GABAA) antagonists SR95531 (100 microM) and picrotoxin (30-50 microM), the GABAB antagonist CGP35348 (300 microM), the D2 antagonist haloperidol (1 microM), and the metabotropic antagonist MCPG (1 mM). The hyperpolarizations were strongly attenuated or abolished when recording electrodes contained 200 mM 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid. They were resistant to tetrodotoxin in the majority of the cells. They had some voltage dependency and were in some cases transiently potentiated when cells were briefly depolarized by current injection. We conclude that dopaminergic neurons have developmentally regulated physiological properties. These spontaneous hyperpolarizations might affect the firing rate of these cells, which was found to be lower in neonates than in adults. [less ▲]

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See detailEnantiomeric Separation of Pirlindole by Liquid Chromatography Using Different Types of Chiral Stationary Phases
Ceccato, Attilio ULg; Hubert, Philippe ULg; De Tullio, Pascal ULg et al

in Journal of Pharmaceutical & Biomedical Analysis (1998), 18(4-5), 605-14

The enantioseparation of pirlindole by liquid chromatography (LC) was investigated using three different chiral stationary phases (CSPs) containing either cellulose tris-(3,5-dimethylphenylcarbamate ... [more ▼]

The enantioseparation of pirlindole by liquid chromatography (LC) was investigated using three different chiral stationary phases (CSPs) containing either cellulose tris-(3,5-dimethylphenylcarbamate) (Chiralcel OD-R), ovomucoid (OVM) or beta-cyclodextrin (beta-CD). The effects of the mobile phase pH on retention, enantioselectivity and resolution were studied. Methanol and acetonitrile were tested as organic modifiers while the influence of the addition to the mobile phase of sodium alkanesulfonates or sodium perchlorate was also investigated. Sodium perchlorate was only used on the Chiralcel OD-R column while sodium alkanesulfonates were tested as mobile phase additives on the three kinds of CSPs. The enantioseparation of pirlindole could be obtained on all CSPs tested, the best results with respect to chiral resolution being achieved on the Chiralcel OD-R and the OVM columns. The use of sodium octanesulfonate (NaOS) was found to improve the enantioseparation of pirlindole on the OVM column while enantioselectivity was considerably enhanced by addition of sodium perchlorate on the Chiralcel OD-R column. [less ▲]

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See detailStereocomplexation of sPMMA-PBD-sPMMA triblock copolymers with isotactic PMMA. II: Effect of molecular weight
Yu, Jian Ming; Jérôme, Robert ULg

in Polymer (1998), 39(25), 6567-6575

Thermoplastic elastomers consisting of triblock copolymers (MBM) with outer syndiotactic poly(methyl methacrylate) (sPMMA) blocks associated to an inner polybutadiene (PBD) block have been modified by ... [more ▼]

Thermoplastic elastomers consisting of triblock copolymers (MBM) with outer syndiotactic poly(methyl methacrylate) (sPMMA) blocks associated to an inner polybutadiene (PBD) block have been modified by stereocomplexation with isotactic PMMA (iPMMA) at a constant 2/1 sPMMA/iPMMA (or s/i) mixing ratio. Toluene cast films of these stereocomplexes have been studied by thermal analysis as a function of molecular weight of the sPMMA blocks and the iPMMA homopolymer. Although the melting temperature of the stereocomplex (Tm) is independent of molecular weight of the sPMMA blocks ( sPMMA) in the studied range from 7000 to 46 000, the melting enthalpy increases with increasing sPMMA. This effect is, however, erased by the sample annealing at 140°C for 15 h, and a melting enthalpy of cα. 33 J/g total PMMA is then observed whatever the copolymer composition. One melting endotherm is observed in case of low sPMMA. although two melting endotherms are reported for higher sPMMA depending, however, on the heating rate. Two endotherms are indeed observed at small sPMMA as the heating rate is low. Molecular weight of iPMMA has no significant effect on either the melting temperature or the melting enthalpy of the stereocomplexes. Dynamic mechanical analysis has confirmed the phase separation of the complexed triblock copolymers. At constant molecular weight of PBD and iPMMA, stereocomplexation increases the tensile strength of MBM copolymers containing small sPMMA blocks, whereas the opposite effect is observed for longer sPMMA blocks. When the same MBM copolymer is complexed by iPMMA, the tensile properties are independent of the molecular weight of iPMMA at least in the range from 5000 to 74 000. [less ▲]

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See detailElectrochemically synthesized polypyrrole nanotubules : effects of different experimental conditions
Demoustier-Champagne, Sophie; Ferain, Etienne; Jérôme, Christine ULg et al

in European Polymer Journal (1998), 34(12), 1767-1774

Nanotubules of polypyrrole (PPy) were electrochemically synthesized using the pores of nanoporous polycarbonate (PC) particle track-etched membranes (PTM) as templates. The influence of some conditions of ... [more ▼]

Nanotubules of polypyrrole (PPy) were electrochemically synthesized using the pores of nanoporous polycarbonate (PC) particle track-etched membranes (PTM) as templates. The influence of some conditions of electrosynthesis (electrochemical method, monomer concentration, electrolyte concentration and nature) on the kinetics of pyrrole electropolymerization and on the morphology of the obtained nanomaterials has been investigated. In particular, the empirical kinetics of the electrochemical generation of polypyrrole-perchlorate (PPy-ClO4) from aqueous solution, at 0.8 V (vs SCE) was followed by electrical charges measurement. The orders with respect to pyrrole and LiClO4 are 0.34 and 0.70 respectively. The electrogeneration of polypyrrole-polystyrenesulfonate (PPy-PSS) was also followed and shows that an increase of the electrolyte concentration increases the polymerization rate at constant potential. Finally, the morphology of PPy nanotubules doped with LiClO4 and NaPSS has been studied by high resolution emission SEM and by TEM. [less ▲]

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See detailChlorophyll Synthesis in Dark-Grown Pine Primary Needles
Schoefs, B.; Franck, Fabrice ULg

in Plant Physiology (1998), 118(4), 1159-68

The pigment content of dark-grown primary needles of Pinus jeffreyi L. and Pinus sylvestris L. was determined by high-performance liquid chromatography. The state of protochlorophyllide a and of ... [more ▼]

The pigment content of dark-grown primary needles of Pinus jeffreyi L. and Pinus sylvestris L. was determined by high-performance liquid chromatography. The state of protochlorophyllide a and of chlorophylls during dark growth were analyzed by in situ 77 K fluorescence spectroscopy. Both measurements unambiguously demonstrated that pine primary needles are able to synthesize chlorophyll in the dark. Norflurazon strongly inhibited both carotenoid and chlorophyll synthesis. Needles of plants treated with this inhibitor had low chlorophyll content, contained only traces of xanthophylls, and accumulated carotenoid precursors. The first form of chlorophyll detected in young pine needles grown in darkness had an emission maximum at 678 nm. Chlorophyll-protein complexes with in situ spectroscopic properties similar to those of fully green needles (685, 695, and 735 nm) later accumulated in untreated plants, whereas in norflurazon-treated plants the photosystem I emission at 735 nm was completely lacking. To better characterize the light-dependent chlorophyll biosynthetic pathway in pine needles, the 77 K fluorescence properties of in situ protochlorophyllide a spectral forms were studied. Photoactive and nonphotoactive protochlorophyllide a forms with emission properties similar to those reported for dark-grown angiosperms were found, but excitation spectra were substantially red shifted. Because of their lower chlorophyll content, norflurazon-treated plants were used to study the protochlorophyllide a photoreduction process triggered by one light flash. The first stable chlorophyllide photoproduct was a chlorophyllide a form emitting at 688 nm as in angiosperms. Further chlorophyllide a shifts usually observed in angiosperms were not detected. The rapid regeneration of photoactive protochlorophyllide a from nonphotoactive protochlorophyllide after one flash was demonstrated. [less ▲]

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See detailSuivi du patient traité par amiodarone
LANCELLOTTI, Patrizio ULg; Melon, Pierre ULg; Kulbertus, Henri ULg

in Revue Médicale de Liège (1998), 53(12), 762-5

Amiodarone is a highly effective antiarrhythmic agent. Its iodine content and tissue accumulation are however responsible for various side effects. In this article, we review the various amiodarone ... [more ▼]

Amiodarone is a highly effective antiarrhythmic agent. Its iodine content and tissue accumulation are however responsible for various side effects. In this article, we review the various amiodarone related side effects and propose a monitoring chart for patients treated by this specific agent. [less ▲]

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See detailLe cinéma documentaire en Belgique francophone aujourd'hui
Van Cauwenberge, Geneviève ULg

in Revue Nouvelle (1998), 12

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See detailMultimodular Penicillin-Binding Proteins: An Enigmatic Family of Orthologs and Paralogs
Goffin, Colette ULg; Ghuysen, Jean-Marie ULg

in Microbiology & Molecular Biology Reviews (1998), 62(4), 1079-1093

The monofunctional penicillin-binding DD-peptidases and penicillin-hydrolyzing serine beta-lactamases diverged from a common ancestor by the acquisition of structural changes in the polypeptide chain ... [more ▼]

The monofunctional penicillin-binding DD-peptidases and penicillin-hydrolyzing serine beta-lactamases diverged from a common ancestor by the acquisition of structural changes in the polypeptide chain while retaining the same folding, three-motif amino acid sequence signature, serine-assisted catalytic mechanism, and active-site topology. Fusion events gave rise to multimodular penicillin-binding proteins (PBPs). The acyl serine transferase penicillin-binding (PB) module possesses the three active-site defining motifs of the superfamily; it is linked to the carboxy end of a non-penicillin-binding (n-PB) module through a conserved fusion site; the two modules form a single polypeptide chain which folds on the exterior of the plasma membrane and is anchored by a transmembrane spanner; and the full-size PBPs cluster into two classes, A and B. In the class A PBPs, the n-PB modules are a continuum of diverging sequences; they possess a five-motif amino acid sequence signature, and conserved dicarboxylic amino acid residues are probably elements of the glycosyl transferase catalytic center. The PB modules fall into five subclasses: A1 and A2 in gram-negative bacteria and A3, A4, and A5 in gram-positive bacteria. The full-size class A PBPs combine the required enzymatic activities for peptidoglycan assembly from lipid-transported disaccharide-peptide units and almost certainly prescribe different, PB-module specific traits in peptidoglycan cross-linking. In the class B PBPs, the PB and n-PB modules cluster in a concerted manner. A PB module of subclass B2 or B3 is linked to an n-PB module of subclass B2 or B3 in gram-negative bacteria, and a PB module of subclass B1, B4, or B5 is linked to an n-PB module of subclass B1, B4, or B5 in gram-positive bacteria. Class B PBPs are involved in cell morphogenesis. The three motifs borne by the n-PB modules are probably sites for module-module interaction and the polypeptide stretches which extend between motifs 1 and 2 are sites for protein-protein interaction. The full-size class B PBPs are an assortment of orthologs and paralogs, which prescribe traits as complex as wall expansion and septum formation. PBPs of subclass B1 are unique to gram-positive bacteria. They are not essential, but they represent an important mechanism of resistance to penicillin among the enterococci and staphylococci. Natural evolution and PBP- and beta-lactamase-mediated resistance show that the ability of the catalytic centers to adapt their properties to new situations is limitless. Studies of the reaction pathways by using the methods of quantum chemistry suggest that resistance to penicillin is a road of no return. [less ▲]

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See detailA propos des prothèses mammaires. L'examen senologique conventionnel
Lifrange, Eric ULg; Colin, Claude ULg

in Revue Médicale de Liège (1998), 53(12), 746-9

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See detailTransplantation hépatique: expérience et résultats du programme de l'Université de Liège
Honore, Pierre ULg; Detry, Olivier ULg; Meurisse, Michel ULg et al

in Revue Médicale de Liège (1998), 53(12), 735-7

The orthotopic liver transplantation (OLT) program of the University of Liege was initiated in 1986. Between 1986 and December 1998, 150 adult OLT have been performed in our institution, including 18 ... [more ▼]

The orthotopic liver transplantation (OLT) program of the University of Liege was initiated in 1986. Between 1986 and December 1998, 150 adult OLT have been performed in our institution, including 18 liver retransplantations, 1 combined heart and liver transplantation and 3 combined liver and kidney transplantations. The aim of this study was to report the last 3 years of our experience. From January 1996 to November 1998, we performed 50 OLT on 49 patients. Three were retransplantations and two were combined liver and kidney transplantations. Fourty-three patients were transplanted for chronic liver disease and 6 for acute or subacute hepatopathy. Mean waiting time on the list was 4 weeks. Immunosuppression was based on triple therapy (cyclosporin A/tacrolimus, steroids, azathioprine), with steroid and azathioprine withdrawal in most of the patients after 3 months. In the chronic liver disease group, operative (< 30 days) survival was 95% (peroperative myocardial infarction in 2 patients). In the acute liver disease group, postoperative survival was 66%. No perioperative death occurred in 1997 and 1998. Actuarial one year survival was 87%. In our experience, OLT has become a safe procedure. [less ▲]

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See detailManagement of Fulminant Hepatic Failure
Detry, Olivier ULg; Honore, Pierre ULg; Meurisse, Michel ULg et al

in Acta Chirurgica Belgica (1998), 98(6), 235-40

Fulminant hepatic failure is an infrequent but dreadful disease, occurring usually in young patients. Despite fulminant hepatic failure is reversible in most of the cases, some patients develop brain ... [more ▼]

Fulminant hepatic failure is an infrequent but dreadful disease, occurring usually in young patients. Despite fulminant hepatic failure is reversible in most of the cases, some patients develop brain edema and intracranial hypertension, which are the most common cause of death in these patients. Liver transplantation significantly improves the prognosis of selected patients in who precise criteria predict a low chance of survival. This review summarizes the modern standard of care of patients with fulminant hepatic failure, with particular underlining of the management of brain oedema and intracranial hypertension. [less ▲]

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See detailJeunesse et violence à l'école: approche sociologique
Robert, Jocelyne ULg

in Education-Formation (1998), 252(hiver),

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See detailEffects of Regular Insulin or Insulin Lispro on Glucose Metabolism after an Oral Glucose Load in Patients with Type 2 Diabetes Mellitus
Paquot, Nicolas ULg; Roulin, D.; Schneiter, P. et al

in Diabètes & Métabolism (1998), 24(6), 523-8

Seven obese Type 2 diabetic patients were studied for two 4-h periods after ingestion of a glucose load to determine the effects of preprandial subcutaneous injection of Insulin Lispro (5 min before the ... [more ▼]

Seven obese Type 2 diabetic patients were studied for two 4-h periods after ingestion of a glucose load to determine the effects of preprandial subcutaneous injection of Insulin Lispro (5 min before the meal) or regular insulin (20 min before the meal) on glucose metabolism. Glucose production and utilisation were measured using a dual isotope method. After Lispro, the mean postprandial increase in plasma glucose was 29% lower and the increase in insulin concentration 25% higher than after regular insulin (p < 0.05). Suppression of endogenous glucose production was similar with both types of insulin. Thus, preprandial injection of Lispro reduced postprandial glucose increments in Type 2 diabetic patients as compared to regular insulin. This effect is best explained by the increased postprandial bioavailability of Lispro. [less ▲]

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See detailInternal functionalization in hyperbranched polyesters
Trollsas, Michaël; Hedrick, James L.; Mecerreyes, David et al

in Journal of Polymer Science. Part A, Polymer Chemistry (1998), 35(17), 3187-3192

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See detailPurification and Characterization of a 315 Kda Keratinolytic Subtilisin-Like Serine Protease from Microsporum Canis and Evidence of Its Secretion in Naturally Infected Cats
Mignon, Bernard ULg; Swinnen, M.; Bouchara, J. P. et al

in Medical Mycology (1998), 36(6), 395-404

A keratinolytic protease, secreted as the major component by a feline clinical isolate of Microsporum canis cultivated in a minimal medium containing cat keratin, was purified by affinity chromatography ... [more ▼]

A keratinolytic protease, secreted as the major component by a feline clinical isolate of Microsporum canis cultivated in a minimal medium containing cat keratin, was purified by affinity chromatography on bacitracin agarose and gel filtration. The apparent molecular mass of the enzyme was 31.5 kDa and the pI was 11.8. The enzyme was not glycosylated and its first 15 N-terminal amino acids showed numerous similarities with other fungal subtilisins. The optimum pH was around 9 while inactivation of the enzyme was reversible at pH 4, but not at pH 11. The enzyme was stable at 37 degrees C with an apparent optimum temperature around 55 degrees C. PMSF, soybean trypsin inhibitor (SBTI) and chymostatin strongly inhibited the proteinase. The highest affinity (Km of 0.37 mM) and physiological efficiency (k(cat)/Km) were obtained for the synthetic substrate N-Suc-Ala-Ala-Pro-Phe-p-nitroanilide. These results indicate that the keratinase belongs to the subtilisin-like serine protease family. Purified rabbit immunoglobulins G prepared against the keratinase and used in an immunohistochemical test allowed the detection of the keratinase produced by the fungus invading hair structures in naturally infected cats. The in vitro keratinolytic activity of the enzyme and its production in vivo suggest that it may contribute to pathogenicity. [less ▲]

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See detailManagement of Recipients of Hepatic Allografts Harvested from Donors with Malignancy Diagnosed Shortly after Transplantation
Detry, Olivier ULg; Honore, Pierre ULg; Jacquet, Nicolas et al

in Clinical Transplantation (1998), 12(6), 579-81

Transmission of undiagnosed malignancy with the graft is a dramatic complication of liver transplantation. Alternatives in the management of the recipients of livers, harvested from donors with malignancy ... [more ▼]

Transmission of undiagnosed malignancy with the graft is a dramatic complication of liver transplantation. Alternatives in the management of the recipients of livers, harvested from donors with malignancy diagnosed shortly after transplantation, are either early re-transplantation or close follow-up without re-operation. We reported 4 cases of liver recipients whose allografts were harvested from donors who were diagnosed with malignancy shortly after the liver transplantation. One recipient underwent re-transplantation, and the three other allografts were not removed. No recipient developed recurrence in the follow-up. While graft removal may be the only way to avoid tumor recurrence in recipients of liver graft harvested from donor with malignancy, close follow-up without re-operation may also be considered. The risk of tumor transferral may depend on the histopathological aggressiveness and metastatic potential of the donor tumor, and may be low for low-grade, local tumors. This risk should be evaluated by analyzing large series, using databases of Eurotransplant or United Network for Organ Sharing. [less ▲]

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See detailEuropean multicentre evaluation of the Super Aution SA-4220 urinalysis analyser
Galimany, R.; Arambarri, M.; Biosca et al

in Clinical Chemistry & Laboratory Medicine (1998), 36(12), 947-58

A multicentre evaluation of the urine test strip analyser Super Aution-4220 was carried out in six laboratories. The analytical performance of the instrument with regard to imprecision, linearity ... [more ▼]

A multicentre evaluation of the urine test strip analyser Super Aution-4220 was carried out in six laboratories. The analytical performance of the instrument with regard to imprecision, linearity, detection limit, drift, carry-over and method comparison was studied. Using the Aution stick 8 test strip the pH, glucose, protein, ketones, bilirubin, blood, urobilinogen and leukocyte esterase were analysed. Specific gravity measurements were performed by refractive index method. Within-run and between-run imprecision determined at three levels of analyte were good. No carry-over was observed. Obtained results were linear through all the described analytical range. No significant drift was detected. Method comparison with some quantitative methods was performed and showed a good correlation with most of the analytes. The study of interferences showed minor interferences by common therapeutic drugs with the measurement of some analytes. During the assessment period of about 6 months no breakdown occurred in any laboratory. The Super Aution urine analyser appeared to be a highly automated analyser of urinary test strips. The operation was simple and the maintenance required only a few minutes a day. [less ▲]

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See detailPatterns of the Immunohistochemical Expression of Melanoma-Associated Antigens and Density of Cd45r0+ Activated T Lymphocytes and L1-Protein Positive Macrophages in Primary Cutaneous Melanomas
Pierard-Franchimont, Claudine ULg; Letawe, C.; Nikkels, Arjen ULg et al

in International Journal of Molecular Medicine (1998), 2(6), 721-724

There is ample evidence for spontaneous antimelanoma immune reactivity mediated by melanocyte-differentiation-antigens (MDAs). Our aim was to determine whether MDA immunoreactivity is associated with ... [more ▼]

There is ample evidence for spontaneous antimelanoma immune reactivity mediated by melanocyte-differentiation-antigens (MDAs). Our aim was to determine whether MDA immunoreactivity is associated with increased tumour-infiltrating lymphocytes (TIL) and macrophages (TIM). A retrospective study was conducted in 30 medium and high grade primary cutaneous melanomas (PCM) as identified by CART-analysis. All of the cases had developed clinical evidence for metastasis within 3 years following surgical excision of the PCM. We used immunohistochemistry and computerized image analysis to quantify MDAs positive cells (Melan A/MART-1, gp100/Pmel 17/HMB45, tyrosinase), CD45R0-positive TIL and LI-protein-positive TIM. A stochastic relationship was present between the MDA immuno-reactivities and the densities in TIL and TIM. An inverse relationship was yielded between TIL and TIM. No specific pattern of PCM immunoreactivity for MDAs, TIL and TIM was found to predict metastases. [less ▲]

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See detailHystéroscopie opératoire ou hystérectomie dans le traitement des lésions utérines bénignes. Que choisir en 1998?
Herman, Philippe ULg; Gaspard, Ulysse ULg; Foidart, Jean-Michel ULg

in Revue Médicale de Liège (1998), 53(12), 756-61

In the past, the treatment of benign uterine lesions required, in many instances, a hysterectomy. These days, most cases can be successfully treated by hysteroscopy. To be reliable, this technique must ... [more ▼]

In the past, the treatment of benign uterine lesions required, in many instances, a hysterectomy. These days, most cases can be successfully treated by hysteroscopy. To be reliable, this technique must lead to a significant reduction in the number of hysterectomies performed for benign uterine lesions. The electroresection technique is preferred to that using the Nd-YAG laser because of its lower cost and its equivalent efficacy. By using the uterine perfusion pump device, the risk of resorption syndrome can be reduced to its minimum. Submucosal myomas < 1 cm, benign endometrial hyperplasia and adenomyosis are the commonest benign lesions treated. Dysfunctional uterine bleeding can also be treated by an endometrectomy. A preoperative workup includes a transvaginal ultrasound and a biopsy. This ensures that only benign lesions that are accessible to a hysteroscopy will be submitted to this technique and that no cases of endometrial cancer or atypical hyperplasia would be ignored. This study presents 270 cases of operative hysteroscopy with a follow-up to 4 years. 82.8% of myomatous lesions were treated with success. The results for patients with benign endometrial polyps or benign endometrial hyperplasia are also excellent with only 4.6% and 5.6% rate of secondary surgery respectively. Adenomyosis does not appear to be a good indication for hysteroscopy as only 37% of patients did not need a definitive hysterectomy. Rates of operative complications (post-operative bleeding, uterine perforation, resorption syndrome and difficulty of access) are acceptable and get less frequent as the surgeon experience increases. [less ▲]

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See detailDe quelques complexes, obsessions et refoulements en didactique du français langue étrangère et seconde
Defays, Jean-Marc ULg

in Langage et l'Homme (Le) : Recherches Pluridisciplinaires sur le Langage (1998), XXXIII(4), 451-463

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See detailRecent developments in anionic polymerization
Jérôme, Robert ULg; Tong, Jiangdong

in Current Opinion in Solid State and Materials Science (1998), 3(6), 573-578

The past year witnessed very significant advances in the living anionic polymerization of (meth)acrylate monomers, particularly in hydrocarbons at or below 0°C. Block polymerization of alkyl methacrylates ... [more ▼]

The past year witnessed very significant advances in the living anionic polymerization of (meth)acrylate monomers, particularly in hydrocarbons at or below 0°C. Block polymerization of alkyl methacrylates with primary alkyl acrylates, although somewhat improved, remains a challenge. Anionic polymerization of styrene, diene and its derivatives was carried out with the aim of synthesizing functional polymers and block copolymers of various architectures. There has been a trend towards combining different living techniques in order to design polymers of unique architectures and properties. [less ▲]

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See detailSuspension de l'exécution d'un permis d'urbanisme : conditions
Delnoy, Michel ULg

in Immobilier (1998), 20

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See detailRelative Reproductive success of males in polyandrous crosses of Barbus meridionalis (Cyprinidae) revealed by microsatellite genotyping
Chenuil, A.; Cattaneo-Berrebi, G.; Binda et al

in Folia Zoologica (1998), 47

Using microsatellite genotyping in Barbus meridionalis, we tried to assess the identity of fathers of progeny produced during four experimental polyandrous crosses involving the same four males and one or ... [more ▼]

Using microsatellite genotyping in Barbus meridionalis, we tried to assess the identity of fathers of progeny produced during four experimental polyandrous crosses involving the same four males and one or two females. The pooled analysis revealed that males had significantly different reproductive successes. We found no conspicuous causes explaining differential reproductive success in the behavioural data or in the physical characteristics of the males but a genetic determinism is the most parsimonious hypothesis to account for this variability. We argue that this conclusion is compatible with the hypothesis that the reproductive strategy of barbels, which involves large aggregations of males, is a result of sexual selection. This study provides guidelines for future interspecific crosses and constitutes the preliminary experiment of an investigation of the origin of a hybrid zone between Barbus barbus and Barbus meridionalis. [less ▲]

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See detailThree photometric methods tested on ground-based data of Q 2237+0305
Burud, I.; Stabell, R.; Magain, Pierre ULg et al

in Astronomy and Astrophysics (1998), 339

The Einstein Cross, Q 2237+0305, has been photometrically observed in four bands on two successive nights at NOT (La Palma, Spain) in October 1995. Three independent algorithms have been used to analyse ... [more ▼]

The Einstein Cross, Q 2237+0305, has been photometrically observed in four bands on two successive nights at NOT (La Palma, Spain) in October 1995. Three independent algorithms have been used to analyse the data: an automatic image decomposition technique, a CLEAN algorithm and the new MCS deconvolution code. The photometric and astrometric results obtained with the three methods are presented. No photometric variations were found in the four quasar images. Comparison of the photometry from the three techniques shows that both systematic and random errors affect each method. When the seeing is worse than 1farcs0 , the errors from the automatic image decomposition technique and the Clean algorithm tend to be large (0.04-0.1 magnitudes) while the deconvolution code still gives accurate results (1sigma error below 0.04) even for frames with seeing as bad as 1farcs7 . Reddening is observed in the quasar images and is found to be compatible with either extinction from the lensing galaxy or colour dependent microlensing. The photometric accuracy depends on the light distribution used to model the lensing galaxy. In particular, using a numerical galaxy model, as done with the MCS algorithm, makes the method less seeing dependent. Another advantage of using a numerical model is that eventual non-homogeneous structures in the galaxy can be modeled. Finally, we propose an observational strategy for a future photometric monitoring of the Einstein Cross. Based on observations obtained at NOT, La Palma. [less ▲]

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See detailShape signifiers for throttle control of a low-order compressor model
Sepulchre, Rodolphe ULg; Kokotovic, Petar

in IEEE Transactions on Automatic Control (1998), 43(11), 1643-1648

Rotating stall and surge, two instability mechanisms limiting the performance of aeroengines compressors, are studied on the third-order Moore–Greitzer model. The skewness of the compressor characteristic ... [more ▼]

Rotating stall and surge, two instability mechanisms limiting the performance of aeroengines compressors, are studied on the third-order Moore–Greitzer model. The skewness of the compressor characteristic, a single parameter shape signifier, is shown to determine the key qualitative properties of feedback control. [less ▲]

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See detailTransplantation d'un rein prélevé laparoscopiquement chez un donneur vivant apparente
Detry, Olivier ULg; Defechereux, Thierry ULg; Hamoir, Etienne ULg et al

in Revue Médicale de Liège (1998), 53(11), 657-9

Transplantation of kidney grafts harvested in living donors has demonstrated better results than grafts harvested from brain dead donors. Recently, laparoscopic live donor nephrectomy has been introduced ... [more ▼]

Transplantation of kidney grafts harvested in living donors has demonstrated better results than grafts harvested from brain dead donors. Recently, laparoscopic live donor nephrectomy has been introduced to reduce the live procurement morbidity. [less ▲]

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See detailCultured Oligodendrocyte Progenitors Derived from Cerebral Cortex Express a Glycine Receptor Which Is Pharmacologically Distinct from the Neuronal Isoform
Belachew, Shibeshih ULg; Rogister, Bernard ULg; Rigo, Jean-Michel et al

in European Journal of Neuroscience (1998), 10(11), 3556-64

Using the whole-cell patch-clamp technique, we demonstrate glycine-induced currents in oligosphere-derived oligodendrocyte progenitors cultured from newborn rats. Similar inward currents are also ... [more ▼]

Using the whole-cell patch-clamp technique, we demonstrate glycine-induced currents in oligosphere-derived oligodendrocyte progenitors cultured from newborn rats. Similar inward currents are also triggered by beta-alanine and taurine, two established glycine receptor agonists. In our recording conditions, glycine-gated currents in oligodendrocyte progenitors reverse about 0 mV and are reversibly inhibited by the glycine competitive antagonist strychnine, the Cl- channel blocker picrotoxinin and the non-competitive antagonist cyanotriphenylborate. The oligodendrocyte progenitors glycine receptor (GlyR) differs from the corresponding neuronal receptor: [3H]strychnine binding data and the strychnine inhibition curve of glycine-induced currents in oligodendrocyte progenitor cultures suggest the existence of two strychnine binding sites on the oligodendroglial GlyR. Using total RNA isolated from oligodendrocyte progenitors cultures, reverse transcription-polymerase chain reaction analysis of glycine receptor subunit expression shows the presence of alpha2 and beta subunits and immunocytochemical stainings confirm that this GlyR contains an alpha subunit which is not alpha1. The molecular structure of the oligodendroglial GlyR could be either homopentameric alpha2 or heteromeric alpha2beta but in both cases, the sequence of the alpha2 or beta subunits have to be different from the known neuronal sequences in order to explain, respectively, the cyanotriphenylborate (alpha2) and picrotoxinin (beta) sensitivities. This work thus demonstrates that GlyR are expressed by oligodendrocytes obtained not only from spinal cord but also from supraspinal structures. The pharmacological properties and presumably the molecular structure of oligodendroglial GlyR are original. The physiological meaning of the presence of such receptors on developing and mature oligodendrocytes remains unknown. [less ▲]

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See detailEvaluation of a Diphenylphosphorylazide-Crosslinked Collagen Membrane for Guided Bone Regeneration in Mandibular Defects in Rats
Zahedi, Sharam ULg; Legrand, Roman ULg; Brunel, G. et al

in Journal of Periodontology (1998), 69(11), 1238-46

In the present study, the potential of a diphenylphosphorylazide-crosslinked type I bovine collagen membrane was evaluated in the healing of mandibular bone defects applying the biological concept of ... [more ▼]

In the present study, the potential of a diphenylphosphorylazide-crosslinked type I bovine collagen membrane was evaluated in the healing of mandibular bone defects applying the biological concept of guided bone regeneration. The experiment was carried out on 25 Wistar rats. After exposing the mandibular ramus bilaterally, 5 mm diameter full-thickness circular bone defects were surgically created. While the defect on one side was covered by the membrane (experimental), the defect on the other side was left uncovered (control) before closure of the overlying soft tissues. The rats were sacrificed in groups of 5 after 7, 15, 30, 90, and 180 days of healing. Although at early stages of healing similar amounts of bone formation were observed in the experimental and control defects, after 1 month of healing, most of the experimental defects were completely closed with new bone, while in the control defects, only limited amounts of new bone were observed at the rims and in the lingual aspect of the lesions. In the 90- and 180-day animals, all experimental defects were completely closed, while in the control defects, no statistically significant increase in bone regeneration was observed. The increase in percentage of bone regeneration in the experimental defects was statistically significant between the 15-day specimens as compared with the 7-day specimens (P < 0.01) and likewise between 30-day and 15-day specimens (P < 0.001). It can be concluded that a DPPA-crosslinked collagen membrane yields biocompatibility, ad hoc mechanical hindrance, and handling characteristics suitable for guided bone regeneration applications in this experimental model. [less ▲]

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See detailLes effets de l'induction du travail sur le déroulement de l'accouchement
Gucciardo, L.; Thoumsin, H.; Foidart, Jean-Michel ULg

in Revue Médicale de Liège (1998), 53(11), 665-8

Labour induction has become a common practice. Given the significant number of induced deliveries carried out each year, it is important to know the consequences of this induction policy. The effects of ... [more ▼]

Labour induction has become a common practice. Given the significant number of induced deliveries carried out each year, it is important to know the consequences of this induction policy. The effects of labour induction on the childbirth are still the subject of considerable controversy. The increase of the caesarean and instrumental extraction rates has already been emphasized in previous studies. This article is based on an analysis of 10,045 deliveries carried out in the CHR Obstetrical Clinic of La Citadelle, between 1991 and 1997. The conclusions are instructive. Thus a departmental policy of setting an induction level of 35% will allocate 2/3 of the workload between 8:00 AM and 8:00 PM during the week, with a preponderance on Friday. The Caesarean rate is not increased but peridurals and recourse to instrumental extraction are more frequent. [less ▲]

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See detailJuvenile Rheumatoid Arthritis and Del(22q11) Syndrome: A Non-Random Association
Verloes, Alain ULg; Curry, C.; Jamar, Michelle ULg et al

in Journal of Medical Genetics (1998), 35(11), 943-7

Del(22q11) is a common microdeletion syndrome with an extremely variable phenotype. Besides classical manifestations, such as velocardiofacial (Shprintzen) or DiGeorge syndromes, del(22q11) syndrome may ... [more ▼]

Del(22q11) is a common microdeletion syndrome with an extremely variable phenotype. Besides classical manifestations, such as velocardiofacial (Shprintzen) or DiGeorge syndromes, del(22q11) syndrome may be associated with unusual but probably causally related anomalies that expand its phenotype and complicate its recognition. We report here three children with the deletion and a chronic, erosive polyarthritis resembling idiopathic cases of juvenile rheumatoid arthritis (JRA). Patient 1, born in 1983, initially presented with developmental delay, facial dysmorphism, velopharyngeal insufficiency, and severe gastro-oesophageal reflux requiring G tube feeding. From the age of 3 years, he developed JRA, which resulted in severe restrictive joint disease, osteopenia, and platyspondyly. Patient 2, born in 1976, had tetralogy of Fallot and peripheral pulmonary artery stenosis. She developed slowly, had mild dysmorphic facial features, an abnormal voice, and borderline intelligence. JRA was diagnosed at the age of 5 years. The disorder followed a subacute course, with relatively mild inflammatory phenomena, but an extremely severe skeletal involvement with major osteopenia, restrictive joint disease (bilateral hip replacement), and almost complete osteolysis of the carpal and tarsal bones with phalangeal synostoses, leading to major motor impairment and confinement to a wheelchair. Patient 3, born in 1990, has VSD, right embryo-toxon, bifid uvula, and facial dysmorphism. She developed JRA at the age of 1 year. She is not mentally retarded but has major speech delay secondary to congenital deafness inherited from her mother. In the three patients, a del(22q11) was shown by FISH analysis. These observations, and five other recently published cases, indicate that a JRA-like syndrome is a component of the del(22q11) spectrum. The deletion may be overlooked in those children with severe, chronic inflammatory disorder. [less ▲]

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See detailVaricella-zoster virus IE63, a virion component expressed during latency and acute infection, elicits humoral and cellular immunity
Sadzot-Delvaux, Catherine ULg; Arvin, Ann M.; Rentier, Bernard ULg

in Journal of Infectious Diseases (1998), 178(Suppl. 1), 43-47

Varicella-zoster virus (VZV) latency in human dorsal root ganglia is characterized by the transcription of large regions of its genome and by the expression of large amounts of some polypeptides, which ... [more ▼]

Varicella-zoster virus (VZV) latency in human dorsal root ganglia is characterized by the transcription of large regions of its genome and by the expression of large amounts of some polypeptides, which are also expressed during lytic cycles. The immediate early 63 protein (IE63) is a virion component expressed very early in cutaneous lesions and the first viral protein detected during latency. Immune response against IE63 has been evaluated among naturally immune adults with a history of chickenpox: Specific antibodies were detected in serum, and most subjects who had a T cell proliferation with unfractionated VZV antigens had T cell recognition of purified IE63. The cytotoxic T cell (CTL) response to IE63 was equivalent to CTL recognition of IE62, the major tegument component of VZV, whose immunogenicity has been previously described. T cell recognition of IE63 and other VZV proteins is one of the likely mechanisms involved in controlling VZV reactivation from latency. [less ▲]

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See detailMethod Development Strategies for the Enantioseparation of Drugs by Capillary Electrophoresis Using Cyclodextrins as Chiral Additives
Fillet, Marianne ULg; Hubert, Philippe ULg; Crommen, Jacques ULg

in Electrophoresis (1998), 19(16-17), 2834-40

General strategies for the development of capillary electrophoretic methods for the enantiomeric separation of basic, acidic or neutral drugs were developed. For all kinds of compounds, the use of a ... [more ▼]

General strategies for the development of capillary electrophoretic methods for the enantiomeric separation of basic, acidic or neutral drugs were developed. For all kinds of compounds, the use of a buffer made of 100 mM phosphoric acid adjusted to pH 3 with triethanolamine and containing anionic and/or uncharged cyclodextrin (CD) derivatives as chiral selectors was recommended. Two different optimization schemes depending on the acidic or basic character of the analytes, were elaborated. For most basic compounds present in cationic form at pH 3, enantiomeric separation could be achieved in the normal polarity mode. Different beta-cyclodextrin derivatives were first tested at a given concentration. Five derivatives were found to be particularly useful for enantioseparations in capillary electrophoresis (CE): the anionic carboxymethyl-beta-CD (CMCD) and sulfobutyl-beta-CD (SBCD) and the neutral dimethyl-beta-CD (DMCD), trimethyl-beta-CD (TMCD) and hydroxypropyl-beta-CD (HPCD). After selection of the most suitable CD, its concentration was optimized with respect to chiral resolution. If necessary, a further improvement in resolution could often be obtained for the enantiomers of cationic solutes by increasing the buffer pH from 3 to 5 using CMCD as chiral additive. Another possible alternative for enhancement in chiral resolution was the addition of metharlol or cyclohexanol to the buffer. For acidic drugs, essentially present in uncharged form at pH 3, and for neutral solutes, anionic CD derivatives such as SBCD or CMCD were first tested at a given concentration in the reversed polarity mode. Dual systems, based on the simultaneous addition of a charged CD (SBCD or CMCD) and a neutral CD (TMCD or DMCD), could then be investigated for resolution improvement. After optimization of the CD concentrations, the use of dual systems with CMCD at pH 5 could also be tested if necessary, especially for very weak acidic and neutral drugs. By applying these optimization strategies, 48 of the 50 drugs examined as model compounds could be fully enantioseparated by CE in short analysis times (usually less than 10 min). [less ▲]

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See detailLaminar difference in GABA uptake and GAT-1 expression in rat CA1
Engel, Dominique ULg; Schmitz, D; Gloveli, T et al

in Journal of Physiology (1998), 512(Pt3), 643-649

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See detailMorphometric Study of the Equine Navicular Bone: Variations with Breeds and Types of Horse and Influence of Exercise
Gabriel, Annick ULg; Jolly, Sandra ULg; Detilleux, Johann ULg et al

in Journal of Anatomy (1998), 193((Pt 4)), 535-49

Navicular bones from the 4 limbs of 95 horses, classified in 9 categories, were studied. The anatomical bases were established for the morphometry of the navicular bone and its variations according to the ... [more ▼]

Navicular bones from the 4 limbs of 95 horses, classified in 9 categories, were studied. The anatomical bases were established for the morphometry of the navicular bone and its variations according to the category of horse, after corrections were made for front or rear limb, sex, weight, size and age. In ponies, navicular bone measurements were smallest for light ponies and regularly increased with body size, but in horses, navicular bone dimensions were smallest for the athletic halfbred, intermediate for draft horse, thoroughbreds and sedentary halfbreds and largest for heavy halfbreds. The athletic halfbred thus showed reduced bone dimensions when compared with other horse types. Navicular bones from 61 horses were studied histomorphometrically. Light horses and ponies possessed larger amounts of cancellous bone and less cortical bone. Draft horses and heavy ponies showed marked thickening of cortical bone with minimum intracortical porosity, and a decrease in marrow spaces associated with more trabecular bone. Two distinct zones were observed for the flexor surface cortex: an external zone composed mainly of poorly remodelled lamellar bone, disposed in a distoproximal oblique direction, and an internal zone composed mainly of secondary bone, with a lateromedial direction for haversian canals. Flexor cortex external zone tended to be smaller for heavy ponies than for the light ponies. It was the opposite for horses, with the largest amount of external zone registered for draft horses. In athletic horses, we observed an increase in the amount of cortical bone at the expense of cancellous bone which could be the result of reduced resorption and increased formation at the corticoendosteal junction. Cancellous bone was reduced for the athletic horses but the number of trabeculae and their specific surfaces were larger. Increased bone formation and reduced resorption could also account for these differences. [less ▲]

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See detailElectrografting of acrylic and methacrylic monomers onto metals: influence of the relative polarity and donor-acceptor properties of the monomer and the solvent
Baute, Noëlle; Teyssié, Philippe; Martinot, Lucien et al

in European Journal of Inorganic Chemistry (1998), 1998(11), 1711-1720

The possibility of grafting a series of alkyl polyacrylates and polymethacrylates onto a nickel cathode by electropoly-merization of the parent monomers has been investigated and has emphasized the ... [more ▼]

The possibility of grafting a series of alkyl polyacrylates and polymethacrylates onto a nickel cathode by electropoly-merization of the parent monomers has been investigated and has emphasized the critical importance of the solvent used. Indeed, the intensity of the inhibition peak, which is the electrochemical mark of the cathode passivation as result of the polymer grafting, clearly depends on both the polarity and the donor-acceptor properties of the solvent. The Gutmann concept is used to account for these experimental results. An increase in the donicity of the solvent used for the electrochemical medium has allowed, for the very first time, several polyacrylates and polymethacrylates [such as poly(ethyl acrylate), poly(methyl methacrylate), and poly(2-trimethylsilyloxyethyl methacrylate)] to be electrografted onto Ni. This observation is consistent with a competition process between the monomer and the solvent for being adsorbed on the cathode and amassing in its very close vicinity. The outcome of this competition is controlled by the relative polarity (in case of low donicity) and the relative donor-acceptor properties (when the difference is high enough) of the monomer/solvent pair, and by the monomer concentration (in case of weak competition). A semiquantitative relationship has also been observed between the monomer ability to be electrografted and the electron-accepting character of the vinyl β-carbon atom as measured by 13C NMR. [less ▲]

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See detailCrossing of two mobile averages: A method for measuring the roughness exponent
Vandewalle, Nicolas ULg; Ausloos, Marcel ULg

in Physical Review. E : Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics (1998), 58(5), 6832-6834

Self-affine signals characterized by a defined Hurst (roughness) exponent H can be investigated through mobile averages. The density rho of crossing points between any two moving averages is a measure of ... [more ▼]

Self-affine signals characterized by a defined Hurst (roughness) exponent H can be investigated through mobile averages. The density rho of crossing points between any two moving averages is a measure of long-range power-law correlations in the signal. The method is compared to the detrended fluctuation analysis. We rake advantage of our findings in order to propose a practically powerful and accurate technique for determining H and apply it right away to cases with persistent or antipersistent correlations. [less ▲]

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See detail“Sainte” : le double procès du texte
Durand, Pascal ULg

in Op. Cit. : Revue de Littératures Française et Comparée (1998), 11

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See detailFgf-3 and Fgf-4 Elicit Distinct Oncogenic Properties in Mouse Mammary Myoepithelial Cells
Hajitou, Amin; Baramova, Eugénia; Bajou, Khalid ULg et al

in Oncogene (1998), 17(16), 2059-71

Fibroblast Growth Factors 3 (FGF-3) and 4 (FGF-4) were compared for the effects they each exert on EF43 mouse cells. This non-transformed mammary cell line appears to be myoepithelial mainly because it ... [more ▼]

Fibroblast Growth Factors 3 (FGF-3) and 4 (FGF-4) were compared for the effects they each exert on EF43 mouse cells. This non-transformed mammary cell line appears to be myoepithelial mainly because it expresses alpha-smooth muscle actin. The EF43 cells were infected with similar vectors that carry either the short fgf-3 sequence (the product of which goes into the secretory pathway), fgf-4 or the selection gene only as control. In syngeneic animals, EF43.fgf-3 cells were tumorigenic only when orthotopically implanted whereas EF43.fgf-4 cells invariably gave rise to aggressive tumors. However, both tumor types were metastatic as evidenced by the blue micrometastases observed when the implanted cells expressed lacZ. In vitro, the FGF-3 producing cells were strongly invasive in matrigel coated chambers whereas the EF43.fgf-4 cells only were invasive in type I-collagen gels. Interestingly, FGF-3 production greatly stimulated the synthesis of pro-MMP-9 (Matrix Metalloprotease-9) and, to a lesser extent, that of pro-MMP-2. FGF-3 also up-regulated the production of plasminogen activators. In contrast, FGF-4 had no effect on these secretions and the medium conditioned by the EF43.fgf-4 cells displayed the largest plasminogen activator-inhibitor activity. These results show that FGF-3 and FGF-4 have distinct mechanisms of action on myoepithelial cells. [less ▲]

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See detailTransmission and confocal fluorescence microscopy and time-resolved fluorescence spectroscopy combined with a laser trap: investigation of optically trapped block copolymer micelles
Gensch, Thomas; Hofkens, Johan; van Stam, Jan et al

in Journal of Physical Chemistry B (1998), 102(43), 8440-8451

Optical trapping was combined with transmission microscopy (TM), confocal and nonconfocal fluorescence scanning microscopy (CFSM and FSM, respectively), and confocal and nonconfocal time-resolved ... [more ▼]

Optical trapping was combined with transmission microscopy (TM), confocal and nonconfocal fluorescence scanning microscopy (CFSM and FSM, respectively), and confocal and nonconfocal time-resolved fluorescence spectroscopy (CTRFS and TRFS, respectively) to study latex particles and block copolymer micelles. Dye-labeled latex particles of various size, in polymer composite films as well as optically trapped in solution, were studied with CFSM to characterize the limits of the setup. CFSM revealed that the resolution in the x- and y-directions was near the theoretical limit, i.e., 200−250 nm. CTRFS on the labeled latex particles revealed that the decay time of the label was not influenced by the polymer matrix nor the optical trap. Poly(tert-butylstyrene-block-sodium methacrylate) micelles (diameter approximately 30−40 nm) in deuterated aqueous solutions could be optically trapped, this region of high copolymer micelle concentration being referred to as a trapped cluster. In the transmission images, trapped clusters of 1.5−2 μm diameter were detected. Fluorescence images were obtained using perylene as a fluorophore that is specifically dissolved within the block copolymer micelles. The size of the trapped cluster, estimated from TM and FSM images, increases with increasing irradiation time and power, respectively. In the TM images, the trapped cluster appears as a dark spot (low transmission) with a bright (high transmission) corona-like ring around it. The appearance of the corona is explained as a light deflection phenomenon; i.e., the trapped cluster acts as lens due to a lateral refractive index gradient. When the corona is taken into account when the diameter of the trapped clusters is calculated, a very good agreement is found between TM and FSM. Long irradiation times lead to the formation of large trapped clusters, which are stable for about 10 s, with diameters of several hundred nanometers, while, for short irradiation times, the trapped cluster is smaller and disappears within a time less than 1 s. With CFSM it could be shown that the trapped particle has a spot size of approximately 1.7 μm in the region of the IR laser focus, while the diameter extends up to 5 μm without using the confocal imaging capability. The reason for this is that the conditions for optical trapping are fulfilled not only in but also above and below the focal region. Due to the high numerical aperture, a dumbbell-like shape of the trapped cluster results. [less ▲]

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See detailInvestigation of methyl methacrylate and vinyl acetate polymerization promoted by Al(iBu)3/2,2'-bipyridine and Al(iBu)3/2,2'-bipyridine/TEMPO complexes
Granel, Claude; Jérôme, Robert ULg; Teyssié, Philippe et al

in Macromolecules (1998), 31(21), 7133-7141

Results of methyl methacrylate (MMA) and vinyl acetate (VOAc) polymerization using the Al(iBu)3/2,2‘-bipyridine/TEMPO initiating system at room temperature failed to confirm the “living” radical mechanism ... [more ▼]

Results of methyl methacrylate (MMA) and vinyl acetate (VOAc) polymerization using the Al(iBu)3/2,2‘-bipyridine/TEMPO initiating system at room temperature failed to confirm the “living” radical mechanism reported earlier. Several species apparently propagate without control in a normal free radical process and only above a critical initiator concentration. No evidence was found for the penta- and hexacoordinated aluminum species previously suggested, but high conversion to an alkoxyamine was observed. Additionally, mixing Al(iBu)3 and BIPY promotes a variety of reactions involving alkyl and hydride transfers to the aromatic rings forming reduced BIPY products, along with a persistent organoaluminum radical. All these results illustrate that the process is considerably more complicated than postulated before. Conversely, at −78 °C, a single active species excluding the participation of TEMPO has been put in evidence, displaying some “living” characteristics. Several experiments support its anionic nature, as previously suggested by Ikeda. [less ▲]

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See detailTnf-Alpha and Ifn-Gamma Down-Regulate the Expression of the Metastasis-Associated Bi-Functional 37lrp/P40 Gene and Protein in Transformed Keratinocytes
Clausse, Nathalie; van den Brûle, Frédéric; Delvenne, Philippe ULg et al

in Biochemical and Biophysical Research Communications (1998), 251(2), 564-9

The 37 LRP/p40 molecule is a bi-functional protein in which expression is increased in a large variety of cancers in association with their metastatic phenotype. Here we present the first data concerning ... [more ▼]

The 37 LRP/p40 molecule is a bi-functional protein in which expression is increased in a large variety of cancers in association with their metastatic phenotype. Here we present the first data concerning the 37 LRP/p40 gene promoter activity and show that it is very active in a cervix carcinoma cell line. Interestingly, despite hallmarks of a housekeeping gene, we show that the 37 LRP/p40 gene promoter can be down-regulated by two potentially anticancerous cytokines, TNF-alpha and IFN-gamma. In addition, the dual fate of the protein, i.e., being intracellularly involved in the cell translation machinery and incorporated into a 67-kDa cell surface protein functioning as a laminin receptor (67LR), is differentially affected by the treatment. Our data suggest multiple regulation levels in the control of the 67LR/37LRP/p40 molecule expression and uncover new clues for the understanding of both the control of expression of this metastasis-associated molecule and the IFN-gamma and TNF-alpha anticancerous action. [less ▲]

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See detailCarbon Dioxide Emission from European Estuaries
Frankignoulle, Michel; Abril, Gwenaël; Borges, Alberto ULg et al

in Science (1998), 282(5388), 434-6

The partial pressure of carbon dioxide (pCO2) in surface waters and related atmospheric exchanges were measured in nine European estuaries. Averaged fluxes over the entire estuaries are usually in the ... [more ▼]

The partial pressure of carbon dioxide (pCO2) in surface waters and related atmospheric exchanges were measured in nine European estuaries. Averaged fluxes over the entire estuaries are usually in the range of 0.1 to 0.5 mole of CO2 per square meter per day. For wide estuaries, net daily fluxes to the atmosphere amount to several hundred tons of carbon (up to 790 tons of carbon per day in the Scheldt estuary). European estuaries emit between 30 and 60 million tons of carbon per year to the atmosphere, representing 5 to 10% of present anthropogenic CO2 emissions for Western Europe. [less ▲]

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See detailPositive parity pentaquarks in a Goldstone boson exchange model
Stancu, Floarea ULg

in Physical Review. D : Particles and Fields (1998), D58

We study the stability of the pentaquarks $uudd\overline{Q}$, $uuds\overline{Q}$ and $udss\overline{Q}$ ($Q = c$ or $b$) of positive parity in a constituent quark model based on Goldstone boson exchange ... [more ▼]

We study the stability of the pentaquarks $uudd\overline{Q}$, $uuds\overline{Q}$ and $udss\overline{Q}$ ($Q = c$ or $b$) of positive parity in a constituent quark model based on Goldstone boson exchange interaction between quarks. The pentaquark parity is the antiquark parity times that of a quark excited to a p-shell. We show that the Goldstone boson exchange interaction favors these pentaquarks much more than the negative parity ones of the same flavour content but all quarks in the ground state. We find that the nonstrange pentaquarks are stable against strong decays. [less ▲]

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See detailX-ray analysis of the NMC-A beta-lactamase at 1.64-A resolution, a class A carbapenemase with broad substrate specificity
Swaren, Peter; Maveyraud, Laurent; Raquet, Xavier et al

in Journal of Biological Chemistry (1998), 273(41), 26714-26721

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See detailAcromegalie : Onderzoeken
Beckers, Albert ULg; Stevenaert, Achille ULg

in Medical News (1998), 51

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See detailAcromégalie : Examens complémentaires
Beckers, Albert ULg; Stevenaert, Achille ULg

in Medical News (1998), 51

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