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See detail2. “La Parure“ di Maupassant. Strategie conclusive ed echi flaubertiani
Benzoni, Pietro ULg

in Strumenti Critici (2003), 103(3), 417-438

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See detail2. Implantation des cultures
Eylenbosch, Damien ULg; Hiel, Marie-Pierre ULg; Meza Morales, Walter ULg et al

in Bodson, Bernard; Destain, Jean-Pierre (Eds.) Livre Blanc Céréales (2014, February 26)

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See detail2. Implantation des cultures
Eylenbosch, Damien ULg; Pierreux, Jérome ULg; Dufranne, Delphine et al

in Bodson, Bernard; Destain, Jean-Pierre (Eds.) Livre Blanc - Céréales (2013, February 27)

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See detail2. Implantation des cultures
Bodson, Bernard ULg; Roisin, Christian; Vancutsem, Françoise ULg et al

in Livre Blanc: Céréales - Gembloux (2011, February 23)

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See detail2. Variétés - 1. Froment d'hiver
Seutin, Benoit ULg; Jacquemin, Guillaume; Vancutsem, Françoise ULg et al

in Destain, Jean-Pierre; Bodson, Bernard (Eds.) Livre Blanc - Céréales - Gembloux (2012, September 06)

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See detail2. Variétés - 1. Froment d'hiver
Seutin, Benoit ULg; Vancutsem, Françoise ULg; Couvreur, Luc et al

in Livre blanc: Céréales-Gembloux - Informations avant les semis (2011, September 08)

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See detail2. Variétés - 2. Escourgeon et orge d’hiver fourragers
Monfort, Bruno; Couvreur, Luc; Jacquemin, Guillaume et al

in Livre Blanc: Céréales-Gembloux - Informations avant les semis (2011, September 08)

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See detail2. Variétés - 2. Escourgeon et orge d'hiver fourragers
Monfort, Bruno; Couvreur, Luc; Jacquemin, Guillaume et al

in Destain, Jean-Pierre; Bodson, Bernard (Eds.) Livre Blanc - Céréales - Gembloux (2012, September 06)

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See detail2.2.1. Evolution de l'utilisation des engrais et des amendements
Lebailly, Philippe ULg; Barthelemy, P.-A.; Burny, Philippe ULg

in Hallet, C.; Ledent, A. (Eds.) Etat de l'Environnement wallon 1995, tome 2 : Agriculture (1996)

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See detailA 2.3 Day Periodic Variability in the Apparently Single Wolf-Rayet Star WR 134: Collapsed Companion or Rotational Modulation?
Morel, Thierry ULg; Marchenko, Sergey V; Eenens, Philippe R J et al

in Astrophysical Journal (1999), 518

The apparently single WN 6 type star WR 134 (HD 191765) is distinguished among the Wolf-Rayet star population by its strong, presumably cyclical (P~2.3 day) spectral variations. A true periodicity-which ... [more ▼]

The apparently single WN 6 type star WR 134 (HD 191765) is distinguished among the Wolf-Rayet star population by its strong, presumably cyclical (P~2.3 day) spectral variations. A true periodicity-which is still very much debated-would render WR 134 a prime candidate for harboring either a collapsed companion or a rotating, large-scale, inhomogeneous outflow. We have carried out an intensive campaign of spectroscopic and photometric monitoring of WR 134 from 1989 to 1997 in an attempt to reveal the true nature of this object. This unprecedentedly large data set allows us to confirm unambiguously the existence of a coherent 2.25+/-0.05 day periodicity in the line-profile changes of He II lambda4686, although the global pattern of variability is different from one epoch to another. This period is only marginally detected in the photometric data set. Assuming the 2.25 day periodic variability to be induced by orbital motion of a collapsed companion, we develop a simple model that aims to investigate (1) the effect of this strongly ionizing, accreting companion on the Wolf-Rayet wind structure, and (2) the expected emergent X-ray luminosity. We argue that the predicted and observed X-ray fluxes can only be matched if the accretion on the collapsed star is significantly inhibited. Additionally, we performed simulations of line-profile variations caused by the orbital revolution of a localized, strongly ionized wind cavity surrounding the X-ray source. A reasonable fit is achieved between the observed and modeled phase-dependent line profiles of He II lambda4686. However, the derived size of the photoionized zone substantially exceeds our expectations, given the observed low-level X-ray flux. Alternatively, we explore rotational modulation of a persistent, largely anisotropic outflow as the origin of the observed cyclical variability. Although qualitative, this hypothesis leads to greater consistency with the observations. [less ▲]

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See detailThe 2.35 year itch of Cyg OB2 #9. II. Radio monitoring
Blomme, R.; Nazé, Yaël ULg; Volpi, D. et al

in Astronomy and Astrophysics (2013), 550

Cyg OB2 #9 is one of a small set of non-thermal radio emitting massive O-star binaries. The non-thermal radiation is due to synchrotron emission in the colliding-wind region. Cyg OB2 #9 was only recently ... [more ▼]

Cyg OB2 #9 is one of a small set of non-thermal radio emitting massive O-star binaries. The non-thermal radiation is due to synchrotron emission in the colliding-wind region. Cyg OB2 #9 was only recently discovered to be a binary system and a multiwavelength campaign was organized to study its 2011 periastron passage. We want to better determine the parameters of this system and model the wind-wind collision. This will lead to a better understanding of the Fermi mechanism that accelerates electrons up to relativistic speeds in shocks, and its occurrence in colliding-wind binaries. We report here on the results of the radio observations obtained in the monitoring campaign and present a simple model to interpret the data. We used the Expanded Very Large Array (EVLA) radio interferometer to obtain 6 and 20 cm continuum fluxes during the Cyg OB2 #9 periastron passage in 2011. We introduce a simple model to solve the radiative transfer in the stellar winds and the colliding-wind region, and thus determine the expected behaviour of the radio light curve. The observed radio light curve shows a steep drop in flux sometime before periastron. The fluxes drop to a level that is comparable to the expected free-free emission from the stellar winds, suggesting that the non-thermal emitting region is completely hidden at that time. After periastron passage, the fluxes slowly increase. We use the asymmetry of the light curve to show that the primary has the stronger wind. This is somewhat unexpected if we use the astrophysical parameters based on theoretical calibrations. But it becomes entirely feasible if we take into account that a given spectral type – luminosity class combination covers a range of astrophysical parameters. The colliding-wind region also contributes to the free-free emission, which can help to explain the high values of the spectral index seen after periastron passage. Combining our data with older Very Large Array (VLA) data allows us to derive a period P = 860:0 3:7 days for this system. With this period, we update the orbital parameters that were derived in the first paper of this series. A simple model introduced to explain only the radio data already allows some constraints to be put on the parameters of this binary system. Future, more sophisticated, modelling that will also include optical, X-ray and interferometric information will provide even better constraints. [less ▲]

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See detailThe 2.35 year itch of Cygnus OB2 #9. I. Optical and X-ray monitoring
Nazé, Yaël ULg; Mahy, Laurent ULg; Damerdji, Yassine ULg et al

in Astronomy and Astrophysics (2012), 546

Context. Nonthermal radio emission in massive stars is expected to arise in wind-wind collisions occurring inside a binary system. One such case, the O-type star Cyg OB2 #9, was proven to be a binary only ... [more ▼]

Context. Nonthermal radio emission in massive stars is expected to arise in wind-wind collisions occurring inside a binary system. One such case, the O-type star Cyg OB2 #9, was proven to be a binary only four years ago, but the orbital parameters remained uncertain. The periastron passage of 2011 was the first one to be observable under good conditions since the discovery of binarity. <BR /> Aims: In this context, we have organized a large monitoring campaign to refine the orbital solution and to study the wind-wind collision. <BR /> Methods: This paper presents the analysis of optical spectroscopic data, as well as of a dedicated X-ray monitoring performed with Swift and XMM-Newton. <BR /> Results: In light of our refined orbital solution, Cyg OB2 #9 appears as a massive O+O binary with a long period and high eccentricity; its components (O5-5.5I for the primary and O3-4III for the secondary) have similar masses and similar luminosities. The new data also provide the first evidence that a wind-wind collision is present in the system. In the optical domain, the broad Hα line varies, displaying enhanced absorption and emission components at periastron. X-ray observations yield the unambiguous signature of an adiabatic collision, because as the stars approach periastron, the X-ray luminosity closely follows the 1/D variation expected in that case. The X-ray spectrum appears, however, slightly softer at periastron, which is probably related to winds colliding at slightly lower speeds at that time. <BR /> Conclusions: It is the first time that such a variation has been detected in O+O systems, and the first case where the wind-wind collision is found to remain adiabatic even at periastron passage. [less ▲]

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See detailThe 2.4-A crystal structure of the penicillin-resistant penicillin-binding protein PBP5fm from Enterococcus faecium in complex with benzylpenicillin.
Sauvage, Eric ULg; Kerff, Frédéric ULg; Fonze, E. et al

in Cellular and Molecular Life Sciences : CMLS (2002), 59(7), 1223-32

Penicillin-binding proteins (PBPs) are membrane proteins involved in the final stages of peptidoglycan synthesis and represent the targets of beta-lactam antibiotics. Enterococci are naturally resistant ... [more ▼]

Penicillin-binding proteins (PBPs) are membrane proteins involved in the final stages of peptidoglycan synthesis and represent the targets of beta-lactam antibiotics. Enterococci are naturally resistant to these antibiotics because they produce a PBP, named PBP5fm in Enterococcus faecium, with low-level affinity for beta-lactams. We report here the crystal structure of the acyl-enzyme complex of PBP5fm with benzylpenicillin at a resolution of 2.4 A. A characteristic of the active site, which distinguishes PBP5fm from other PBPs of known structure, is the topology of the loop 451-465 defining the left edge of the cavity. The residue Arg464, involved in a salt bridge with the residue Asp481, confers a greater rigidity to the PBP5fm active site. In addition, the presence of the Val465 residue, which points into the active site, reducing its accessibility, could account for the low affinity of PBP5fm for beta-lactam. This loop is common to PBPs of low affinity, such as PBP2a from Staphylococcus aureus and PBP3 from Bacillus subtilis. Moreover, the insertion of a serine after residue 466 in the most resistant strains underlines even more the determining role of this loop in the recognition of the substrates. [less ▲]

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See detailA 2.5 D finite element model for bending and straightening in continuous casting of steel slabs
Pascon, Frédéric ULg; Cescotto, Serge ULg; Habraken, Anne ULg

in International Journal for Numerical Methods in Engineering (2006), (68), 125-149

This paper presents a bi-dimensional slice model of the continuous casting process developed to focus on the risk of transverse cracking during bending and straightening of steel slabs. The model is based ... [more ▼]

This paper presents a bi-dimensional slice model of the continuous casting process developed to focus on the risk of transverse cracking during bending and straightening of steel slabs. The model is based on the finite element method and it integrates both thermal and mechanical aspects: temperature evolution, solidification, stress and strain developments. Generalized plain strain conditions are applied in the casting direction, allowing taking account of the extraction force applied to the slab as well as strains in this direction. The model also includes an original solution to counteract the generally wrong modelling of slab bulging with such slice models. The model has been applied to an industrial case of slab casting. Some numerical results illustrate the accuracy of the model compared to results of other models, measurements and observations on the caster. Transverse cracks are predicted to be the most likely to occur at the edge on the upper face, at the end of straightening of the slab. This is due to the combination of low ductility of the material with tensile stress and elongation in the casting direction in the straightening zone. This conclusion has been confirmed by the examination of slabs that present transverse cracks. [less ▲]

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See detailA 2.5-Mb contig constructed from Angus, Longhorn and horned Hereford DNA spanning the polled interval on bovine chromosome 1
Wunderlich, K. R.; Abbey, C. A.; Clayton, D. R. et al

in Animal Genetics (2006), 37(6), 592-594

The polled locus has been mapped by genetic linkage analysis to the proximal region of bovine chromosome 1. As an intermediate step in our efforts to identify the polled locus and the underlying causative ... [more ▼]

The polled locus has been mapped by genetic linkage analysis to the proximal region of bovine chromosome 1. As an intermediate step in our efforts to identify the polled locus and the underlying causative mutation for the polled phenotype, we have constructed a BAC-based physical map of the interval containing the polled locus. Clones containing genes and markers in the critical interval were isolated from the TAMBT (constructed from Angus and Longhorn genomic DNA) and CHORI-240 (constructed from horned Hereford genomic DNA) BAC libraries and ordered based on fingerprinting and the presence or absence of 80 STS markers. A single contig spanning 2.5 Mb was assembled. Comparison of the physical order of STSs to the corresponding region of human chromosome 21 revealed the same order of genes within the polled critical interval. This contig of overlapping BAC clones from horned and polled breeds is a useful resource for SNP discovery and characterization of positional candidate genes. [less ▲]

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See detail2.8-A Structure of penicillin-sensitive D-alanyl carboxypeptidase-transpeptidase from Streptomyces R61 and complexes with beta-lactams
Kelly, Judith A; Knox, James R; Moews, Paul C et al

in Journal of Biological Chemistry (1985), 260(10), 6449-6458

The crystallographic structure of the penicillin-sensitive D-alanyl carboxypeptidase-transpeptidase from Streptomyces R61 has been solved to 2.8-A resolution. The 38,000-dalton serine peptidase has two ... [more ▼]

The crystallographic structure of the penicillin-sensitive D-alanyl carboxypeptidase-transpeptidase from Streptomyces R61 has been solved to 2.8-A resolution. The 38,000-dalton serine peptidase has two regions of secondary structure, an alpha/beta cluster, and a region which contains five helical segments. The beta sheet is composed of five beta strands. The tertiary structure has no homology with the classic serine proteases or with the zinc carboxypeptidases. The binding at a common site of three types of beta-lactam (a penicillin, a cephalosporin, a monocyclic beta-lactam) and a desazacyclobutanone has been observed in Fourier difference maps. The binding site sequence is Val-Gly-Ser-Val-Thr-Lys. The beta-lactam ring lies near the enzyme's catalytic serine at position 37, and the C3 substituent of a cephalosporin falls near lysine 40. [less ▲]

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See detail20 ans d'études dans 2 bassins versants boisés en Ardenne
Guillaume, Patricia; Bosman, Bernard ULg; Bazgir, Masoud et al

Diverse speeche and writing (2011)

En Région wallonne, de nombreux sols forestiers se caractérisent par un pH faible et une pauvreté en Ca, P et surtout Mg. Depuis 1991, dans le cadre d’études sur le dépérissement forestier et l’impact de ... [more ▼]

En Région wallonne, de nombreux sols forestiers se caractérisent par un pH faible et une pauvreté en Ca, P et surtout Mg. Depuis 1991, dans le cadre d’études sur le dépérissement forestier et l’impact de mesures de gestion forestière, le laboratoire d’Ecologie Végétale et Microbienne (ULg) étudie l’évolution des concentrations et des flux en éléments minéraux dans les principaux compartiments de deux bassins versants. Ce triptyque résume une partie de ces recherches. [less ▲]

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See detail20 ans de formation ! et demain ?
Morant, Michel ULg

Conference (2011, June 08)

La présentation met en évidence les besoins nouveaux dans les compétences requises pour un gestionnaire de transfert de technologie ou agent de valorisation

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