References of "1990"
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See detailImpact des biotechnologies en santé animale
Pastoret, Paul-Pierre ULg; Thiry, Etienne ULg; Brochier, B. et al

Report (1990)

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See detailRole of the Conserved Amino Acids of the 'Sdn' Loop (Ser130, Asp131 and Asn132) in a Class a Beta-Lactamase Studied by Site-Directed Mutagenesis
Jacob, Françoise; Joris, Bernard ULg; Lepage, Sophie et al

in Biochemical Journal (1990), 271(2), 399-406

Ser130, Asp131 and Asn132 ('SDN') are highly conserved residues in class A beta-lactamases forming one wall of the active-site cavity. All three residues of the SDN loop in Streptomyces albus G beta ... [more ▼]

Ser130, Asp131 and Asn132 ('SDN') are highly conserved residues in class A beta-lactamases forming one wall of the active-site cavity. All three residues of the SDN loop in Streptomyces albus G beta-lactamase were modified by site-directed mutagenesis. The mutant proteins were expressed in Streptomyces lividans, purified from culture supernatants and their kinetic parameters were determined for several substrates. Ser130 was substituted by Asn, Ala and Gly. The first modification yielded an almost totally inactive protein, whereas the smaller-side-chain mutants (A and G) retained some activity, but were less stable than the wild-type enzyme. Ser130 might thus be involved in maintaining the structure of the active-site cavity. Mutations of Asp131 into Glu and Gly proved to be highly detrimental to enzyme stability, reflecting significant structural perturbations. Mutation of Asn132 into Ala resulted in a dramatically decreased enzymic activity (more than 100-fold) especially toward cephalosporin substrates, kcat. being the most affected parameter, which would indicate a role of Asn132 in transition-state stabilization rather than in ground-state binding. Comparison of the N132A and the previously described N132S mutant enzymes underline the importance of an H-bond-forming residue at position 132 for the catalytic process. [less ▲]

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See detailDe la géodésie au centimètre près avec GPS ?
Warnant, René ULg

Conference given outside the academic context (1990)

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See detailHeat transport in dielectric crystals at low temperature: A variational formulation based on extended irreversible thermodynamics
Lebon, Georgy ULg; Dauby, Pierre ULg

in Physical Review (1990), 42

We propose a variational principle applicable to the heat-transport equations derived some years ago by Guyer and Krumhansl [Phys. Rev. 133, 1411 (1964); 148, 766 (1966); 148, 778 (1966)] to describe heat ... [more ▼]

We propose a variational principle applicable to the heat-transport equations derived some years ago by Guyer and Krumhansl [Phys. Rev. 133, 1411 (1964); 148, 766 (1966); 148, 778 (1966)] to describe heat-wave propagation in dielectric crystals at low temperature. The variational principle appears as a generalization of Prigogine's minimum-entropy production criterion. The analysis is based on extended irreversible thermodynamics, which is used to derive the Guyer-Krumhansl equations from macroscopic arguments. [less ▲]

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See detailLes étudiants en Droit: études et projets d'insertion professionnelle
Robert, Jocelyne ULg

in Annales de Droit de Liège (1990), 6-7

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See detailBasal and postexercise CK 2 concentrations in a group of well trained athletes evaluated by chemiluminescent assay
Ordonez, J.; Chapelle, Jean-Paul ULg; Serra, J. R. et al

Poster (1990, October)

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See detailEngineering a Novel β-Lactamase by a Single Point Mutation
Jacob, F.; Joris, Bernard ULg; Dideberg, O. et al

in Protein Engineering (1990), 4(1), 79-86

beta-Lactamases are widespread and efficient bacterial enzymes which play a major role in bacterial resistance to penicillins and cephalosporins. In order to elucidate the role of the residues lying in a ... [more ▼]

beta-Lactamases are widespread and efficient bacterial enzymes which play a major role in bacterial resistance to penicillins and cephalosporins. In order to elucidate the role of the residues lying in a conserved loop of the enzymatic cavity of the active-site serine Streptomyces albus G beta-lactamase, modified proteins were produced by oligo-directed mutagenesis. Mutation of Asn116, which lies on one side of the active site cavity pointing to the substrate-binding site, into a serine residue resulted in spectacular modifications of the specificity profile of the enzyme. That replacement yielded an enzyme with a nearly unchanged activity towards good penicillin substrates. In sharp contrast its efficiency in hydrolysing cephalosporins was drastically reduced, the best substrates suffering the largest decrease in the second-order rate constant for serine acylation. In fact that single mutation generated a truly new enzyme behaving exclusively as a penicillinase, a situation which is never encountered to the same degree in any of the numerous naturally occurring variants of class A beta-lactamases. [less ▲]

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See detailFormation of P Cygni line profiles in relativistically expanding atmospheres
Hutsemekers, Damien ULg; Surdej, Jean ULg

in Astrophysical Journal (1990), 361

The probabilistic approach of Surdej (1979) is followed to generalize the Sobolev (1958) formalism to the case of special relativity, in order to interpret accurately the P Cygni line profiles observed in ... [more ▼]

The probabilistic approach of Surdej (1979) is followed to generalize the Sobolev (1958) formalism to the case of special relativity, in order to interpret accurately the P Cygni line profiles observed in the spectrum of broad absorption-line quasars and supernovae. The expressions of the source function and of the line profile are derived, and it is shown that the relativistic P Cygni line profiles are significantly different from those computed in the framework of the classical theory. Thus, for increasing values of the terminal wind velocity, the red emission wing becomes definitely narrower than the blue one, while the line center emission increases. This is no longer symmetrical in accordance with the relativistic expression of the Doppler effect. [less ▲]

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See detailDetection of Chloroplast DNA by Using Fluorescent Monoclonal Anti-Bromodeoxyuridine Antibody and Analysis of Its Fate During Zygote Formation in Chlamydomonas Reinhardtii
Munaut, Carine ULg; Dombrowicz, D.; Matagne, René-Fernand ULg

in Current Genetics (1990), 18(3), 259-63

A monoclonal anti-bromodeoxyuridine antibody conjugated to fluorescein was used to detect the chloroplast nucleoids after specific incorporation of bromodeoxyuridine (BUdR) into the chloroplast DNA of ... [more ▼]

A monoclonal anti-bromodeoxyuridine antibody conjugated to fluorescein was used to detect the chloroplast nucleoids after specific incorporation of bromodeoxyuridine (BUdR) into the chloroplast DNA of Chlamydomonas reinhardtii. The incorporation of BUdR was enhanced by simultaneous treatment with fluorodeoxyuridine (FUdR). The method was applied to analyze the fate of chloroplast DNA in zygotes resulting from mating between BUdR-treated gametes (mt+ or mt-) and untreated gametes of opposite mating-type. In crosses between wild-type strains, the nucleoids of mt+ origin remained in the large majority of zygotes whereas those of mt- origin most often disappeared within the first hours following copulation. In crosses of the type mat-3 mt+ x wild-type mt- (the mat-3 mutation permits a high transmission of chloroplast genes from the mt- parent), the nucleoids of mt- origin were generally not eliminated which indicates that the mat-3 mutation prevents the selective destruction of paternal chloroplast DNA in the zygote. [less ▲]

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See detailLa prévention des faillites au sein des Petites et Moyennes Entreprises : application de modèles statistiques simples au cas belge
Van Caillie, Didier ULg

in La Vie au Bureau (1990)

Après avoir rappelé l'importance du phénomène de la faillite et la manière dont de nombreuses PME entrent insidieusement dans un processus de faillite et de défaillance, cet article présente quelques ... [more ▼]

Après avoir rappelé l'importance du phénomène de la faillite et la manière dont de nombreuses PME entrent insidieusement dans un processus de faillite et de défaillance, cet article présente quelques modèles statistiques simples qui s'avèrent à la fois utiles et calculables dans le contexte belge du début des années '90. [less ▲]

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See detailAnalytical and clinical performances of a new automated immunoassay for measuring CK-MB in serum
Chapelle, Jean-Paul ULg; El Allaf, M.

Conference (1990, October)

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See detailRotational analysis of the a3Πr-X1Σ+ transition of AlI
Mahieu, Emmanuel ULg; DUBOIS, I.; BREDOHL, H.

in Journal of Molecular Spectroscopy (1990), 143(2), 359-365

The a3Πr-X1Σ+ transition of Al I has been analyzed for the first time. Accurate rotational and vibrational constants are given for the a3Πr electronic state.

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See detailTropomyosin from the Striated Muscles of Carp (Cyprinus Carpio) and of Icefish (Channichthys Rhinoceratus)
Feller, Georges ULg; D'Haese, J.; Gerday, Charles ULg

in Archives Internationales de Physiologie et de Biochimie (1990), 98(5), 297-305

Tropomyosin of fast-twitch, slow-twitch and cardiac muscles of carp and icefish has been isolated by hydroxyapatite chromatography. The subunit distribution has been investigated by polyacrylamide gel ... [more ▼]

Tropomyosin of fast-twitch, slow-twitch and cardiac muscles of carp and icefish has been isolated by hydroxyapatite chromatography. The subunit distribution has been investigated by polyacrylamide gel electrophoresis and by peptide mapping. The purified skeletal muscle tropomyosins all belong to the alpha family and differ from higher vertebrate tropomyosin by the lack of beta subunits. Specific alpha isotypes are however encountered in fast-twitch fibres (alpha w subunit) and slow-twitch or intermediate (pink) fibres (alpha and alpha w subunits). The amino acid compositions and the paracrystals formed by the carp alpha w alpha w and alpha alpha w tropomyosins do not differ markedly from that of rabbit alpha alpha chains. They differ however by their capability to inhibit the ATPase activity of rabbit skeletal muscle acto-HMM system. A beta-like subunit is found in carp cardiac tropomyosin, in the proportion of 25% of the native protein, but not in icefish heart. [less ▲]

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See detailMembrane Topology, Structure, and Functions of the Penicillin-Interactive Proteins
Ghuysen, Jean-Marie ULg

in Biotechnology & Applied Biochemistry (1990, October), 12(5), 468-472

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See detailVariational Metric and Exponential Penalization
Mouallif, Khalil; Tossings, Patricia ULg

in Journal of Optimization Theory & Applications (1990), 67(1), 185-192

Attouch and Wets have introduced recently a variational metric between closed proper convex functions. The aim of this note is to give an estimation of this metric in the case of the exponential penalties ... [more ▼]

Attouch and Wets have introduced recently a variational metric between closed proper convex functions. The aim of this note is to give an estimation of this metric in the case of the exponential penalties. We can therefore recover some convergence results for the exponential penalty method. [less ▲]

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See detailPrinciples and Evaluation of an Experimental Target Recognition System for Laser-Radar Imagery
Verly, Jacques ULg; Delanoy, Richard L.; Dudgeon, Dan E.

Conference (1990, October)

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See detailStrategic Relocatable Target (SRT) Detection and Identification: Applications of Machine Intelligence Techniques
Delanoy, Richard L.; Verly, Jacques ULg; Dudgeon, Dan E.

Conference (1990, October)

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See detailResults in contour-texture coding
Lemaire, Pierre; Van Droogenbroeck, Marc ULg

Report (1990)

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See detailLes Cajuns de Louisiane
Sacré, Robert ULg

in Prologue (1990), (232), 43-45

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