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See detailEffects of geographic origin on growth and food intake in Eurasian perch (Perca fluviatilis L.) juveniles under intensive culture conditions
Mandiki, S. N. M.; Blanchard, G.; Mélard, Charles ULg et al

in Aquaculture (2004), 229(1-4), 117-128

Survival, growth, and food intake of Eurasian perch (Perca fluviatilis) juveniles from different stocks originating from various geographic regions of Europe were compared under the same conditions of ... [more ▼]

Survival, growth, and food intake of Eurasian perch (Perca fluviatilis) juveniles from different stocks originating from various geographic regions of Europe were compared under the same conditions of laboratory-scale intensive culture. In Experiment 1, four stocks originating from Italy (1), southwest (SF) and northwest (NF) France, and Belgium (B) were examined at larval and early juvenile (initial body weight, IBW = 0.53 g) stages. In Experiment 2, B stock was compared to a Finnish (F) one in two trials, including small (IBW = 1.26 g) and large (IBW = 32 g) juveniles. In Experiment 3, small (IBW = 1.29 g) and large (IBW = 7.33 g) juveniles from Polish (P), F, and B stocks were examined. In Experiment 1, body weight means at hatching and survival at the end of the larval stage were significantly lower in the I and SF stocks than in the B and NF stocks. In the early juvenile stage, survival and growth rates were significantly lower in the I and SF stocks than in the B and NF ones. In Experiment 2, {early juvenile stage} survival in the F stock was significantly lower than in the B stock, partly due to a higher incidence of cannibalism. During this stage, growth rates and food intake or feed efficiency in the F and B stocks were comparable, but at the end of the juvenile stage, the F stock outperformed the B one. In Experiment 3, survival in all the three stocks was comparable both in small and large juveniles. In contrast to the higher performance of F juveniles in Experiment 2, growth rates were comparable between the B and F stocks, and fish from the P stock had the highest growth rates. The results indicate a high level of variation within and between hatchery stocks in survival rates, growth rates, and food intake. These variations depended on the geographic origin of the fish, with the lowest survival and growth potentials being in the stocks originating from the southern regions. These findings highlight the interest in evaluating growth and food consumption of different Eurasian perch stocks. Such evaluation is a necessary tool for genetic selection in improving performance in perch aquaculture. (C) 2004 Elsevier Science B.V. All rights reserved. [less ▲]

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See detailL'édition à l'heure des trous noirs
Durand, Pascal ULg

in Acrimed (2004)

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See detailThe maximum deviation just-in-time scheduling problem
Brauner, Nadia; Crama, Yves ULg

in Discrete Applied Mathematics (2004), 134(1-3), 25-50

This note revisits the maximum deviation just-in-time (MDJIT) scheduling problem previously investigated by Steiner and Yeomans. Its main result is a set of algebraic necessary and sufficient conditions ... [more ▼]

This note revisits the maximum deviation just-in-time (MDJIT) scheduling problem previously investigated by Steiner and Yeomans. Its main result is a set of algebraic necessary and sufficient conditions for the existence of a MDJIT schedule with a given objective function value. These conditions are used to provide a finer analysis of the complexity of the MDJIT problem. The note also investigates various special cases of the MDJIT problem and suggests several questions for further investigation. (C) 2003 Elsevier B.V. All rights reserved. [less ▲]

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See detailA new process for the synthesis of alkoxyamines active in controlled radical polymerization
Detrembleur, Christophe ULg; Gross, Thomas; Meyer, Rolf-Volker

Patent (2004)

The present invention relates to a new process for the preparation of alkoxyamine initiators and to a process of radical polymerization using the alkoxyamine initiators as intermediates.

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See detailOne-pot process for the preparation of functionalized alkoxyamines
Detrembleur, Christophe ULg; Gross, Thomas; Meyer, Rolf-Volker

Patent (2004)

The present invention relates to a new one-pot process for the preparation of functionalized alkoxyamine initiators of the formula (I) <CHEM> from amines of the formula (II) <CHEM> and to a process of ... [more ▼]

The present invention relates to a new one-pot process for the preparation of functionalized alkoxyamine initiators of the formula (I) <CHEM> from amines of the formula (II) <CHEM> and to a process of controlled radical polymerization using the functionalized alkoxyamine as initiators. In the above formulae, R<1>-R<5> have the meanings given in the description. [less ▲]

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See detailMolecular basis of the amylose-like polymer formation catalyzed by Neisseria polysaccharea amylosucrase
Albenne, C.; Skov, L. K.; Mirza, O. et al

in Journal of Biological Chemistry (2004), 279(1), 726-734

Amylosucrase from Neisseria polysaccharea is a remarkable transglucosidase from family 13 of the glycosidehydrolases that synthesizes an insoluble amylose-like polymer from sucrose in the absence of any ... [more ▼]

Amylosucrase from Neisseria polysaccharea is a remarkable transglucosidase from family 13 of the glycosidehydrolases that synthesizes an insoluble amylose-like polymer from sucrose in the absence of any primer. Amylosucrase shares strong structural similarities with alpha-amylases. Exactly how this enzyme catalyzes the formation of alpha-1,4-glucan and which structural features are involved in this unique functionality existing in family 13 are important questions still not fully answered. Here, we provide evidence that amylosucrase initializes polymer formation by releasing, through sucrose hydrolysis, a glucose molecule that is subsequently used as the first acceptor molecule. Maltooligosaccharides of increasing size were produced and successively elongated at their nonreducing ends until they reached a critical size and concentration, causing precipitation. The ability of amylosucrase to bind and to elongate maltooligosaccharides is notably due to the presence of key residues at the OB1 acceptor binding site that contribute strongly to the guidance ( Arg(415), subsite +4) and the correct positioning (Asp(394) and Arg(446), subsite +1) of acceptor molecules. On the other hand, Arg(226) (subsites +2/+3) limits the binding of maltooligosaccharides, resulting in the accumulation of small products (G to G3) in the medium. A remarkable mutant (R226A), activated by the products it forms, was generated. It yields twice as much insoluble glucan as the wild-type enzyme and leads to the production of lower quantities of by-products. [less ▲]

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See detailSynthesis and evaluation of N1/C4-substituted beta-lactams as PPE and HLE inhibitors
Gérard, Stéphane; Galleni, Moreno ULg; Dive, Georges ULg et al

in Bioorganic & Medicinal Chemistry (2004), 12(1), 129-138

4-(Alkylamino)carbonyl-1-(alkoxy)carbonyl-2-azetidinones (9-11) have been prepared in five steps from 4-(benzyloxy)carbonyl-1-(t-butyidimethyl)silyl-2-azetidinone (1). The P-lactam reactivity of 9 has ... [more ▼]

4-(Alkylamino)carbonyl-1-(alkoxy)carbonyl-2-azetidinones (9-11) have been prepared in five steps from 4-(benzyloxy)carbonyl-1-(t-butyidimethyl)silyl-2-azetidinone (1). The P-lactam reactivity of 9 has been established by H-1 NMR experiment. Compound 11 was a good reversible inhibitor of PPE and HLE. Based on theoretical design, series of 2-azetidinones (12-17) and 4(alkoxy)carbonyl-2-azetidinones (18-21) bearing various carbonyl (ester, thiolester, amide) and thiocarbonyl (thioamide) functionalities at position N1 were similarly prepared. In the absence of C4-substituent, the compounds were inactive against elastases. On the other hand, 4-(benzyloxy)carbonyl-1-(ethylthioxy)carbonyl-2-azetidinone (19) and 4-(benzyloxy)carbonyl-1-(benzylamino)-thiocarbonyl-2-azetidinone (21) were both good reversible inhibitors, but acting most probably via different mechanisms (enzymic processing of the exocyclic ester function or beta-lactam ring opening). (C) 2003 Elsevier Ltd. All rights reserved. [less ▲]

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See detailProcess for the synthesis for alkoxy amines and their use in controlled radical polymerization
Detrembleur, Christophe ULg; Gross, Thomas; Meyer, Rolf-Volker

Patent (2004)

A one-pot process for the preparation of alkoxyamines conforming to formulae (I) or (II), preferably (I) is disclosed. The process entails (1) reacting of an oxidizing agent (A) with a sterically hindered ... [more ▼]

A one-pot process for the preparation of alkoxyamines conforming to formulae (I) or (II), preferably (I) is disclosed. The process entails (1) reacting of an oxidizing agent (A) with a sterically hindered secondary amine of the general formula (III), in a water-containing medium to form a reaction product and an aqueous phase, (2) removing of the aqueous phase, and (3) (adding to the reaction product a free-radical initiator (B) under conditions that promote the decomposition of the initiator to generate free radicals. Also disclosed is a process for polymerizing monomers, the process using the alkoxyamine prepared by the inventive process. [less ▲]

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See detailTheoretical instability strips for delta Scuti and gamma Doradus stars
Dupret, Marc-Antoine ULg; Grigahcène, A.; Garrido, R. et al

in Astronomy and Astrophysics (2004), 414

New theoretical instability strips for delta Sct and gamma Dor stars are presented. These results have been obtained taking into account the perturbation of the convective flux following the treatment of ... [more ▼]

New theoretical instability strips for delta Sct and gamma Dor stars are presented. These results have been obtained taking into account the perturbation of the convective flux following the treatment of Gabriel (\cite{Gabriel1996}). For the first time, the red edge of the delta Sct instability strip for non-radial modes is obtained. The influence of this time-dependent convection (TDC) on the driving of the gamma Dor gravity modes is investigated. The results obtained for different values of the mixing-length parameter alpha are compared for the gamma Dor models. A good agreement with observations is found for models with alpha between 1.8 and 2.0. [less ▲]

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See detailNon-adiabatic pulsations in delta Scuti stars
Moya, A.; Garrido, R.; Dupret, Marc-Antoine ULg

in Stellar Structure and Habitable Planet Finding (2004, January 01)

For delta Scuti stars, phase differences and amplitude ratios between the relative effective temperature variation and the relative radial displacement can be derived from multicolor photometric ... [more ▼]

For delta Scuti stars, phase differences and amplitude ratios between the relative effective temperature variation and the relative radial displacement can be derived from multicolor photometric observations. The same quantities can be also calculated from theoretical non-adiabatic pulsation models. We present here these theoretical results, which indicate that non-adiabatic quantities depend on the mixing length parameter alpha used to treat the convection in the standard Mixing Length Theory (MLT). This dependence can be used to test and to constrain, through multicolor observations, the way MLT describes convection in the outermost layers of the star. We will use the equilibrium models provided by the CESAM evolutionary code. The pulsational observables are calculated by using a non-adiabatic pulsation code developed by R. Garridon and A. Moya. In the evolutionary and pulsation codes, a complete reconstruction of the non-grey atmosphere (Kurucz models) is included. The interaction between pulsation and atmosphere, as described by Dupret et al. (2002), is also included in the code. [less ▲]

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See detailMutational analysis of the catalytic centre of the Citrobacter freundii AmpD N-acetylmuramyl-L-alanine amidase
Genereux, Catherine ULg; Dehareng, Dominique ULg; Devreese, Bart et al

in Biochemical Journal (2004), 377(Pt 1), 111-120

Citrobacter freundii AmpD is an intracellular 1,6-anhydro-N-acetylmuramyl-L-alanine amidase involved in both peptidoglycan recycling and beta-lactamase induction. AmpD exhibits a strict specificity for 1 ... [more ▼]

Citrobacter freundii AmpD is an intracellular 1,6-anhydro-N-acetylmuramyl-L-alanine amidase involved in both peptidoglycan recycling and beta-lactamase induction. AmpD exhibits a strict specificity for 1,6-anhydromuropeptides and requires zinc for enzymic activity. The AmpD three-dimensional structure exhibits a fold similar to that of another Zn2+ N-acetylmuramyl-L-alanine amidase, the T7 lysozyme, and these two enzymes define a new family of Zn-amidases which can be related to the eukaryotic PGRP (peptidoglycan-recognition protein) domains. In an attempt to assign the different zinc ligands and to probe the catalytic mechanism of AmpD amidase, molecular modelling based on the NMR structure and site-directed mutagenesis were performed. Mutation of the two residues presumed to act as zinc ligands into alanine (H34A and D164A) yielded inactive proteins which had also lost their ability to bind zinc. By contrast, the active H154N mutant retained the capacity to bind the metal ion. Three other residues which could be involved in the AmpD catalytic mechanism have been mutated (Y63F, E116A, K162H and K162Q). The E116A mutant was inactive, but on the basis of the molecular modelling this residue is not directly involved in the catalytic mechanism, but rather in the binding of the zinc by contributing to the correct orientation of His-34. The K162H and K162Q mutants retained very low activity (0.7 and 0.2% of the wildtype activity respectively), whereas the Y63F mutant showed 16% of the wild-type activity. These three latter mutants exhibited a good affinity for Zn ions and the substituted residues are probably involved in the binding of the substrate. We also describe a new method for generating the N-acetylglucosaminyl-1,6-anhydro-N-acetylmuramyl-tripeptide AmpD substrate from purified peptidoglycan by the combined action of two hydrolytic enzymes. [less ▲]

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See detailAdditional science potential for COROT
Weiss, W. W.; Aerts, C.; Aigrain, S. et al

in Favata, F.; Aigrain, S.; Wilson, A. (Eds.) Stellar Structure and Habitable Planet Finding (2004, January 01)

Space experiments which are aiming towards asteroseismology and the detection of exoplanets, like COROT or MOST, Eddington and Kepler, are designed to deliver high precision photometric data. Obviously ... [more ▼]

Space experiments which are aiming towards asteroseismology and the detection of exoplanets, like COROT or MOST, Eddington and Kepler, are designed to deliver high precision photometric data. Obviously, they can be used also for other purposes than the primary science goals and in addition many other targets can or will be automatically observed simultaneously with the primary targets. As a consequence, fascinating possibilities for additional (parallel, secondary) science projects emerge. For COROT a dedicated working group was thus established with the goal to contribute any useful information which may optimize the scientific output of the mission. [less ▲]

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See detailOverexpression of TIMP-1 under the MMP-9 promoter interferes with wound healing in transgenic mice
Salonurmi, T.; Parikka, M.; Kontusaari, S. et al

in Cell & Tissue Research (2004), 315(1), 27-37

We have generated transgenic mice harboring the murine matrix metalloproteinase 9 (MMP-9) promoter cloned in front of human TIMP-1 cDNA. The transgenic mice were viable and fertile and exhibited normal ... [more ▼]

We have generated transgenic mice harboring the murine matrix metalloproteinase 9 (MMP-9) promoter cloned in front of human TIMP-1 cDNA. The transgenic mice were viable and fertile and exhibited normal growth and general development. During wound healing the mice were shown to express human TIMP-1 in keratinocytes that normally express MMP-9. However, the healing of skin wounds was significantly retarded with slow migration of keratinocytes over the wound in transgenic mice. In situ zymography carried out on wound tissues revealed total blockage of gelatinolytic activity (i.e., MMP-9 and MMP-2). The results confirm studies with MMP-9 knockout mice showing that MMP-9 is not essential for general development, but they also demonstrate an important role of keratinocyte MMP-9, as well that of other keratinocyte MMPs that are inhibited by TIMP-1, in wound healing. The transgenic mice generated in this study provide a model for the role of MMPs in MMP-9-producing cells in other challenging situations such as bone fracture recovery and cancer invasion. [less ▲]

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See detailEffect of a novel thromboxane A(2) inhibitor on right ventricular-arterial coupling in endotoxic shock
Lambermont, Bernard ULg; Kolh, Philippe ULg; Ghuysen, Alexandre ULg et al

in Shock (2004), 21(1), 45-51

We investigated the effects of a dual thromboxane (TX)A(2) synthase inhibitor and TXA(2) receptor antagonist (BM-573) on right ventricular-arterial coupling in a porcine model of endotoxic shock. Thirty ... [more ▼]

We investigated the effects of a dual thromboxane (TX)A(2) synthase inhibitor and TXA(2) receptor antagonist (BM-573) on right ventricular-arterial coupling in a porcine model of endotoxic shock. Thirty minutes before the onset of 0.5 mg/kg endotoxin infusion, six pigs (Endo group) received an infusion with a placebo solution, and six other pigs (Anta group) with BM-573. Right ventricular pressure-volume loops were obtained by the conductance catheter technique. The slope (E-es) of the end-systolic pressure-volume relationship and its volume intercept at 25 mmHg were calculated as measures of right ventricular systolic function. RV afterload was quantified by pulmonary arterial elastance (E-a), and E-es/E-a ratio represented right ventricular-arterial coupling. Mechanical efficiency was defined as the ratio of stroke work and pressure-volume area. In this model of endotoxic shock, BM-573 blunted the early phase of pulmonary hypertension, improved arterial oxygenation, and prevented a decrease in right ventricular myocardial efficiency and right ventricular dilatation. However, the drug could not prevent the loss of homeometric regulation and alterations in right ventricular-arterial coupling. In conclusion, dual TXA(2) synthase inhibitor and receptor antagonists such as BM-573 have potential therapeutic applications, improving right ventricular efficiency and arterial oxygenation in endotoxic shock. [less ▲]

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See detailEtat de l'art de l'holographie dynamique : systèmes appliqués à la métrologie et au contrôle non destructif
Georges, Marc ULg; Thizy, Cédric ULg; Ryhon, Sébastien et al

Conference (2004, January)

Dans ce papier, nous présentons le résultat de plus de dix années de recherche et développement au Centre Spatial de Liège (CSL) concernant une caméra holographique (utilisant la technique de l ... [more ▼]

Dans ce papier, nous présentons le résultat de plus de dix années de recherche et développement au Centre Spatial de Liège (CSL) concernant une caméra holographique (utilisant la technique de l'interférométrie holographique) capable d'effectuer des mesures, sans contact et sur un grand champ, de déplacements dans la gamme des microns et submicrons. Les principales applications montrées sont la recherche de défauts, l'identification de modes de vibration et la métrologie de déplacements. [less ▲]

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See detailDynamic holography for fringerprints detection
Lemaire, Philippe; Georges, Marc ULg

Conference (2004, January)

Fingerprint detection method is generally based on optical contrast technique. We present a special case of holographic interferometry use, that envisages fingerprint visualisation on base of their relief ... [more ▼]

Fingerprint detection method is generally based on optical contrast technique. We present a special case of holographic interferometry use, that envisages fingerprint visualisation on base of their relief. Background of the algorithm is first presented and discussed. We finish by practical application. [less ▲]

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See detailGranular size segregation in underwater sand ripples
Rousseaux, G.; Caps, Hervé ULg; Wesfreid, J. E.

in European Physical Journal E -- Soft Matter (2004), 13(2), 213-219

We report an experimental study of a binary sand bed under an oscillating water flow. The formation and evolution of ripples is observed. The appearance of a granular segregation is shown to strongly ... [more ▼]

We report an experimental study of a binary sand bed under an oscillating water flow. The formation and evolution of ripples is observed. The appearance of a granular segregation is shown to strongly depend on the sand bed preparation. The initial wavelength of the mixture is measured. In the final steady state, a segregation in volume is observed instead of a segregation at the surface as reported before. The correlation between this phenomenon and the fluid flow is emphasised. Finally, different "exotic" patterns and their geophysical implications are presented. [less ▲]

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See detailEffects of silicon addition on the electrical and magnetic properties of copper-doped (La,Ca)MnO3 compounds
Vertruyen, Bénédicte ULg; Rulmont, André ULg; Cloots, Rudi ULg et al

in Journal of Magnetism and Magnetic Materials (2004), 268(3), 364-373

In this paper we report about the electrical properties of La0.7Ca0.3MnO3 compounds substituted by copper on the manganese site and/or deliberately contaminated by SiO2 in the reactant mixture. Several ... [more ▼]

In this paper we report about the electrical properties of La0.7Ca0.3MnO3 compounds substituted by copper on the manganese site and/or deliberately contaminated by SiO2 in the reactant mixture. Several phenomena have been observed and discussed. SiO2 addition leads to the formation of an apatite-like secondary phase that affects the electrical conduction through the percolation of the charge carriers. On the other hand, depending on the relative amounts of copper and silicon, the temperature dependence of the electrical resistivity can be noticeably modified: our results enable us to compare the effects of crystallographic vacancies on the A and B sites of the perovskite with the influence of the copper ions substituted on the manganese site. The most original result occurs for the compounds with a small ratio Si/Cu, which display double-peaked resistivity vs. temperature curves. (C) 2003 Elsevier B.V. All rights reserved. [less ▲]

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See detailFour extended formulations of the corner polyhedron
Louveaux, Quentin ULg

Conference (2004, January)

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