References of "2003"
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See detailRésistances bactériennes aux antibiotiques : le cas des pathogènes respiratoires du bovin
Mainil, Jacques ULg

Scientific conference (2003, December)

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See detailOverproduction of lipase by Yarrowia lipolytica mutants
Fickers, Patrick ULg; Nicaud, J. M.; Destain, Jacqueline ULg et al

in Applied Microbiology & Biotechnology (2003), 63(2), 136-142

Non-genetically modified mutants with increased capacities of extracellular lipase production were obtained from Yarrowia lipolytica strain CBS6303 by chemical mutagenesis. Of the 400 mutants isolated ... [more ▼]

Non-genetically modified mutants with increased capacities of extracellular lipase production were obtained from Yarrowia lipolytica strain CBS6303 by chemical mutagenesis. Of the 400 mutants isolated, LgX64.81 had the highest potential for the development of an industrial lipase production process. This mutant exhibits lipase production uncoupled from catabolite repression by glucose, and a 10-fold increased productivity upon addition of oleic acid. Using a LIP2-LacZ reporter gene, we demonstrate that the mutant phenotype originates from a trans-acting mutation. The glucose uptake capacity of LgX64.81 is reduced 2.5-fold compared to the wild-type-strain, and it exhibits high lipase production on glucose medium. A trans-acting mutation in a gene involved in glucose transport could thus explain this mutant phenotype. [less ▲]

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See detailPsychrophilic enzymes: Hot topics in cold adaptation
Feller, Georges ULg; Gerday, Charles ULg

in Nature Reviews Microbiology (2003), 1(3), 200-208

More than three-quarters of the Earth's surface is occupied by cold ecosystems, including the ocean depths, and polar and alpine regions. These permanently cold environments have been successfully ... [more ▼]

More than three-quarters of the Earth's surface is occupied by cold ecosystems, including the ocean depths, and polar and alpine regions. These permanently cold environments have been successfully colonized by a class of extremophilic microorganisms that are known as psychrophiles (which literally means cold-loving). The ability to thrive at temperatures that are close to, or below, the freezing point of water requires a vast array of adaptations to maintain the metabolic rates and sustained growth compatible with life in these severe environmental conditions. [less ▲]

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See detailQuantitative analysis of strychnine and brucine in Strychnos nux-vomica using H-1-NMR
Frederich, Michel ULg; Choi, Y. H.; Verpoorte, R.

in Planta Medica (2003), 69(12), 1169-1171

A quantitative analysis using H-1-NMR (Q-NMR) has been developed for the determination of strychnine and brucine in Strychnos nux-vomica seeds and stems. The advantages of the method are that no reference ... [more ▼]

A quantitative analysis using H-1-NMR (Q-NMR) has been developed for the determination of strychnine and brucine in Strychnos nux-vomica seeds and stems. The advantages of the method are that no reference alkaloids are needed for calibration curves, the quantification could be directly realized on a crude extract, strychnine and brucine could easily be distinguished, an overall profile of the preparation (including non alkaloid compounds) could be directly obtained, and a very significant time-gain could be achieved, in comparison to conventional HPLC methods, for instance. [less ▲]

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See detailIdentification of specific biomarkers related to the effects of pollutants on the immune system of marine mammals
Brenez, Cécile; Gerkens, Pascal; Jauniaux, Thierry ULg et al

Poster (2003, December)

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See detailRise and survival of bovine herpesvirus 1 recombinants after primary infection and reactivation from latency
Schynts, F.; Meurens, F.; Detry, Bruno et al

in Journal of Virology (2003), 77(23), 12535-12542

Recombination is thought to be an important source of genetic variation in herpesviruses. Several studies, performed in vitro or in vivo, detected recombinant viruses after the coinoculation of two ... [more ▼]

Recombination is thought to be an important source of genetic variation in herpesviruses. Several studies, performed in vitro or in vivo, detected recombinant viruses after the coinoculation of two distinguishable strains of the same herpesvirus species. However, none of these studies investigated the evolution of the relative proportions of parental versus recombinant progeny populations after coinoculation of the natural host, both during the excretion and the reexcretion period. In the present study, we address this by studying the infection of cattle with bovine herpesvirus 1 (BoHV-1). The recombination of two BoHV-1 mutants lacking either glycoprotein C (gC(-)/gE(+)) or E (gC(+)/gE(-)) was investigated after inoculation of cattle by the natural route of infection. The results demonstrated that (i) recombination is a frequent event in vivo since recombinants (gC(+)/gE(+) and gC(-)/gE(-)) were detected in all coinoculated calves, (ii) relative proportions of progeny populations evolved during the excretion period toward a situation where two populations (gC(+)/gE(+) and gC(-)/gE(+)) predominated without fully outcompeting the presence of the two other detected populations (gC(+)/gE(-) and gC(-)/gE(-)), and (iii) after reactivation from latency, no gC(+)/gE(-) and gC(-)/gE(-) progeny viruses were detected, although gC(+)/gE(-) mutants, when inoculated alone, were detected after reactivation treatment. In view of these data, the importance of gE in the biology of BoHV-1 infection and the role of recombination in herpesvirus evolution are discussed. [less ▲]

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See detailRight lobe living-related liver transplantation in a Jehovah's Witness
Detry, Olivier ULg; De Roover, Arnaud ULg; Kaba, Abdourahmane ULg et al

in Transplant International (2003), 16(12), 895-896

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See detailThe aromatase knockout (ArKO) mouse provides new evidence that estrogens are required for the development of the female brain
Bakker, Julie ULg; Honda, S.; Harada, N. et al

in Annals of the New York Academy of Sciences (2003), 1007

The classic view of sexual differentiation is that the male brain develops under the influence of testicular secretions, whereas the female brain develops in the absence of any hormonal stimulation ... [more ▼]

The classic view of sexual differentiation is that the male brain develops under the influence of testicular secretions, whereas the female brain develops in the absence of any hormonal stimulation. However, several studies have suggested a possible role of estradiol in female neural development, although they did not provide unequivocal evidence that estradiol is indispensable for the development of the female brain and behavior. As a result, the hypothesis subsequently languished because of the lack of a suitable animal model to test estrogen's possible contribution to female differentiation. The recent introduction of the aromatase knockout (ArKO) mouse, which is deficient in aromatase activity because of a targeted mutation in the CYP19 gene and therefore cannot aromatize androgen to estrogen, has provided a new opportunity to reopen the debate of whether estradiol contributes to the development of the female brain. Female ArKO mice showed reduced levels of lordosis behavior after adult treatment with estradiol and progesterone, suggesting that estradiol is required for the development of the neural mechanisms controlling this behavior in female mice. The neural systems affected may include the olfactory systems in that ArKO females also showed impairments in olfactory investigation of odors from conspecifics. Thus, the classic view of sexual differentiation, that is, the female brain develops in the absence of any hormonal secretion, needs to be re-examined. [less ▲]

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See detailTowards a consistant safety format of steel beam-columns: application of the new interaction formulae for ambient temperature to elevated temperatures
Vila Real, Paulo; Lopes, Nuno; da Silva, Luis et al

in Steel & Composite Structures (2003), 3(6), 383-401

Two new formulae for the design of beam-columns at room temperature have been proposed into Eurocode 3, prEN 1993-1-1 (2002), and are the result of great efforts made by two working groups that followed ... [more ▼]

Two new formulae for the design of beam-columns at room temperature have been proposed into Eurocode 3, prEN 1993-1-1 (2002), and are the result of great efforts made by two working groups that followed different approaches, a French-Belgian team and an Austrian-German one. Under fire conditions the prEN 1993-1-2 (structural fire design) presents formulae, for the design of beam-columns based on the prENV 1993-1-1 (1992). In order to study the possibility of having, in part 1-1 and part 1-2 of the Eurocode 3, the same approach, a numerical research was made using the finite element program SAFIR, developed at the University of Liege for the study 4 structures subjected to fire. [less ▲]

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See detailTrajectoires professionnelles féminines : flexibilités et enjeux de genre
Gavray, Claire ULg

Doctoral thesis (2003)

Professional positions and transitions, and the capacities of autonomy which result from it, vary very significantly according to three articulated variables: the gender group, the level of certification ... [more ▼]

Professional positions and transitions, and the capacities of autonomy which result from it, vary very significantly according to three articulated variables: the gender group, the level of certification and the life course development. The gendered social hierarchisation present in every field of social insertion -although different according to generation- occupies a significant position in the construction of this course. It's important to understand objective and subjective factors (through values, choices, rôles, plans, opportunities and constraints) influencing professional paths within each gender group . These comparisons are essential. Neglecting the gender perspective and theory forbids the comprehension of the work and labor offer but also of the distribution of places on labour market. Decompartmentalization of `employment, formation, family, social capital' is also more than ever necessary to analyse individual trajectories and to imagine fieldeffective and nondiscriminating policies. For exemple, time -and its value- seems a crucial issue for the families, the citizens, the democratic society in change. [less ▲]

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See detailProtochlorophyllide reduction: Mechanisms and evolution
Schoefs, B.; Franck, Fabrice ULg

in Photochemistry and Photobiology (2003), 78(6), 543-557

Protochlorophyllide (Pchlide) reductases are key enzymes in the process of chlorophyll biosynthesis. In this review, current knowledge on the molecular organization, substrate specificity and assembly of ... [more ▼]

Protochlorophyllide (Pchlide) reductases are key enzymes in the process of chlorophyll biosynthesis. In this review, current knowledge on the molecular organization, substrate specificity and assembly of the light-dependent reduced nicotinamide adenine dinucleotide phosphate:Pchlide oxidoreductases are discussed. Characteristics of light-independent enzymes are also described briefly, and the possible reasons for the selection of light-dependent enzymes during the course of evolution are discussed. [less ▲]

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See detailPhotosynthesis and state transitions in mitochondrial mutants of Chlamydomonas reinhardtii affected in respiration
Cardol, Pierre ULg; Gloire, Geoffrey ULg; Havaux, M. et al

in Plant Physiology (2003), 133(4), 2010-2020

Photosynthetic activities were analyzed in Chlamydomonas reinhardtii mitochondrial mutants affected in different complexes (I, III, IV, I + III, and I + IV) of the respiratory chain. Oxygen evolution ... [more ▼]

Photosynthetic activities were analyzed in Chlamydomonas reinhardtii mitochondrial mutants affected in different complexes (I, III, IV, I + III, and I + IV) of the respiratory chain. Oxygen evolution curves showed a positive relationship between the apparent yield of photosynthetic linear electron transport and the number of active proton-pumping sites in mitochondria. Although no significant alterations of the quantitative relationships between major photosynthetic complexes were found in the mutants, 77 K fluorescence spectra showed a preferential excitation of photosystem I (PSI) compared with wild type, which was indicative of a shift toward state 2. This effect was correlated with high levels of phosphorylation of light-harvesting complex II polypeptides, indicating the preferential association of light-harvesting complex II with PSI. The transition to state 1 occurred in untreated wild-type cells exposed to PSI light or in 3-(3,4-dichlorophenyl)-1,1-dimethylurea-treated cells exposed to white light. In mutants of the cytochrome pathway and in double mutants, this transition was only observed in white light in the presence of 3-(3,4-dichlorophenyl)-1,1-dimethylurea. This suggests higher rates of non-photochemical plastoquinone reduction through the chlororespiratory pathway, which was confirmed by measurements of the complementary area above the fluorescence induction curve in dark-adapted cells. Photo-acoustic measurements of energy storage by PSI showed a stimulation of PSI-driven cyclic electron flow in the most affected mutants. The present results demonstrate that in C. reinhardtii mutants, permanent defects in the mitochondrial electron transport chain stabilize state 2, which favors cyclic over linear electron transport in the chloroplast. [less ▲]

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See detailPolymorphisms in the CYP 2D6 gene: Association with plasma concentrations of fluoxetine and paroxetine
Charlier, Corinne ULg; Broly, Franck; Pinto, Emmanuel ULg et al

in Therapeutic Drug Monitoring (2003), 25(6), 738-742

Most antidepressants are metabolized by cytochrome P450 (CYP) 2D6, and it is well known that there may be significant interindividual variation in the capacity to metabolize xenobiotics. About 7 to 10% of ... [more ▼]

Most antidepressants are metabolized by cytochrome P450 (CYP) 2D6, and it is well known that there may be significant interindividual variation in the capacity to metabolize xenobiotics. About 7 to 10% of whites are poor metabolisers (PM), and, on the contrary, about 5% are ultrarapid metabolizers (UM), inducing very different rates in the transformation of antidepressants extensively metabolized by CYP 2D6. CYP 2D6 polymorphism can be a potential risk factor for the development of side effects or a reason for the poor efficacy of the treatment. Various probe drugs may be used for phenotyping CYP 2D6, but genotyping is now available using leukocyte DNA and is independent of concomitant drug use. in this study, we used PCR-based methods for the identification of CYP 2D6 genotypes in 49 patients receiving standard doses of fluoxetine or paroxetine and found that plasma concentration of the antidepressant drugs was significantly correlated with genetic status. In one patient who displayed CYP 2D6 gene duplication (UM), paroxetine plasma concentration was extremely low. in PM fluoxetine-treated patients, drug plasma concentration was significantly higher than that seen in extensive metabolizers. [less ▲]

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See detailThe influence of an acid-base-equilibrium on the adsorption behaviour of a weak polyampholyte
Mahltig, Boris; Jérôme, Robert ULg; Stamm, Manfred

in Journal of Polymer Research (2003), 10(4), 219-223

A weak diblock polyampholyte PMAA-b-PDMAEMA, poly(methacrylic acid)-block-poly((dimethylamino)ethyl methacrylate), was investigated as a model system for the influence of an acid-base-equilibrium of a ... [more ▼]

A weak diblock polyampholyte PMAA-b-PDMAEMA, poly(methacrylic acid)-block-poly((dimethylamino)ethyl methacrylate), was investigated as a model system for the influence of an acid-base-equilibrium of a phthalic acid buffer system on the polyelectrolyte adsorption behaviour. The adsorption of polyampholyte from aqueous solution onto silicon surfaces is known to be strongly influenced by the parameters of the polymer solution and the properties of the polyampholyte itself like block ratio or molecular weight. In the case of the investigated polyampholytes, the main parameter with the most significant influence on the adsorption is the pH. The big influence of pH on adsorption results from the charges of the polymer chains and the substrate, which are determined by the pH. Therefore, it should be useful to investigate the influence of a buffer system on the polyampholyte adsorption. On the one hand the buffer system enables to determine the pH of the aqueous polyampholyte solution more precisely. On the other hand the concentrations of different phthalic species like the phthalic acid, the hydrogen phthalate and the phthalate are strongly influenced by pH. These different species were observed to have a strong influence on the adsorption behaviour of the polyampholyte, so the adsorption as function of pH was observed to be also determined by the acid-base-equilibrium of the buffer system. The adsorbed amount of polyampholyte dried after the adsorption process was determined using ellipsometry, while the surface topography of these adsorbed layers were characterized by atomic force microscopy (AFM). [less ▲]

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See detailLes fondations belges d'utilité publique : entre permanence et changements
Pirotte, Gautier ULg; Heuschen, Laurence

Report (2003)

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See detailErreurs de classification dans les tables de contingence
Magis, David ULg

Scientific conference (2003, December)

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See detailEOF calculations and data filling from incomplete oceanographic datasets
Beckers, Jean-Marie ULg; Rixen, M.

in Journal of Atmospheric and Oceanic Technology (2003), 20(12), 1839-1856

The paper presents a new self-consistent method to infer missing data from oceanographic data series and to extract the relevant empirical orthogonal functions. As a by-product, the new method allows for ... [more ▼]

The paper presents a new self-consistent method to infer missing data from oceanographic data series and to extract the relevant empirical orthogonal functions. As a by-product, the new method allows for the detection of the number of statistically significant EOFs by a cross-validation procedure for a complete or incomplete dataset, as well as the noise level and interpolation error. Since the proposed filling and analysis method does not need a priori information about the error covariance structure, the method is self-consistent and parameter free. [less ▲]

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