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See detailInfluence of the convective flux perturbation on stellar oscillations: application to Delta Scuti and Gamma Doradus stars
Grigahcene, A.; Dupret, Marc-Antoine ULg; Garrido, R. et al

in Communications in Asteroseismology (2004), 145

We present a theory of convection-oscillation interaction. In our nonradial nonadiabatic pulsation code, the variation of the convective flux (radial and transversal components) is taken into account ... [more ▼]

We present a theory of convection-oscillation interaction. In our nonradial nonadiabatic pulsation code, the variation of the convective flux (radial and transversal components) is taken into account, following the theory of M. Gabriel, within the mixing length approach. We explore the influence of the convective flux variation on mode stability near the red-edge of the Delta Scuti instability strip and the excitation mechanisms of Gamma Doradus stars. [less ▲]

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See detailL'astronomie dans le monde
Manfroid, Jean ULg

Article for general public (2004)

Première image d'une planète extrasolaire?; Deux Jupiter chauds; Cycles stellaires; Le trou noir de M87; Un nouveau bras pour la Voie Lactée; L'étoile la plus massive jamais observée!

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See detailAll cases of word production are not created equal: Reply to Costa and Santesteban
French, R.; Jacquet, Maud ULg

in Trends in Cognitive Sciences (2004), 8(6), 254-254

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See detailFrames d'exponentielles
Charlier, Emilie ULg

Master's dissertation (2004)

Actuellement, la théorie des frames est utilisée principalement en analyse du signal. La découverte du lien entre les frames et les ondelelettes et les bases de Riesz a marqué le point de départ de ... [more ▼]

Actuellement, la théorie des frames est utilisée principalement en analyse du signal. La découverte du lien entre les frames et les ondelelettes et les bases de Riesz a marqué le point de départ de l’essor de la théorie des frames dans ce domaine. C’est dans le contexte de l’étude des séries nonharmoniques de Fourier que les frames ont été introduites par R.J. Duffin et A.C. Schaeffer en 1952 dans leur article intitulé "A class of nonharmonic Fourier series". Bien que la définition générale d’une frame sur un espace de Hilbert soit déjà donnée dans cet article et qu’une théorie des frames en elle-même y soit déjà développée, les auteurs, concernés surtout par l’analyse nonharmonique de Fourier, y développent essentiellement la notion de frames d’exponentielles dans l’espace L^2(I), où I est un intervalle borné de R. Le résultat principal obtenu par Duffin et Schaeffer est une condition suffisante pour qu’une suite de nombres complexes génère une frame d’exponentielles. Ce résultat est basé sur un résultat reliant les suites de densité uniforme et les fonctions entières de type exponentiel. Duffin et Schaeffer auteurs ne présentant qu’une condition suffisante, ils laissent donc là un problème ouvert : la caractérisation des frames d’exponentielles. Une résolution partielle de ce problème n’a été donnée que bien plus tard par Jaffard. En effet, en 1991, dans son article "A density criterion for frames of complex exponentials", Jaffard propose une condition nécessaire et suffisante pour qu’une suite réelle génère une frame d’exponentielles. Le but de ce mémoire est de présenter ces résultats. [less ▲]

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See detailSeconde campagne de mesure des odeurs sur le CET "Champ de Beaumont" à Monceau-sur-Sambre Estimation des nuisances olfactives
Nicolas, Jacques ULg; Denne, Pierre

Report (2004)

The study is made in the frame of a follow-up monitoring of all landfill sites in Wallonia, initiated by the Ministry of Environment and managed by ISSeP. The report concerns more particularly a second ... [more ▼]

The study is made in the frame of a follow-up monitoring of all landfill sites in Wallonia, initiated by the Ministry of Environment and managed by ISSeP. The report concerns more particularly a second measurement campaign on the landfill site of Monceau-sur-Sambre. Besides the usual field inspection technique, the research group used GC-MS analyses to evaluate the chemical composition of emissions and an atmospheric dispersion model to study the influence of local relief. [less ▲]

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See detailExtending the classification of bacterial transcription factors beyond the helix-turn-helix motif as an alternative approach to discover new cis/trans relationships
Rigali, Sébastien ULg; Schlicht, M.; Hoskisson, P. et al

in Nucleic Acids Research (2004), 32(11), 3418-3426

Transcription factors (TFs) of bacterial helix-turn-helix superfamilies exhibit different effector-binding domains (EBDs) fused to a DNA-binding domain with a common feature. In a previous study of the ... [more ▼]

Transcription factors (TFs) of bacterial helix-turn-helix superfamilies exhibit different effector-binding domains (EBDs) fused to a DNA-binding domain with a common feature. In a previous study of the GntR superfamily, we demonstrated that classifying members into subfamilies according to the EBD heterogeneity highlighted unsuspected and accurate TF-binding site signatures. In this work, we present how such in silico analysis can provide prediction tools to discover new cis/trans relationships. The TF-binding site consensus of the HutC/GntR subfamily was used to (i) predict target sites within the Streptomyces coelicolor genome, (ii) discover a new HutC/GntR regulon and (iii) discover its specific TF. By scanning the S.coelicolor genome we identified a presumed new HutC regulon that comprises genes of the phosphotransferase system (PTS) specific for the uptake of N-acetylglucosamine (PTSNag). A weight matrix was derived from the compilation of the predicted cis-acting elements upstream of each gene of the presumed regulon. Under the assumption that TFs are often subject to autoregulation, we used this matrix to scan the upstream region of the 24 HutC-like members of S.coelicolor. orf SCO5231 (dasR) was selected as the best candidate according to the high score of a 16 bp sequence identified in its upstream region. Our prediction that DasR regulates the PTSNag regulon was confirmed by in vivo and in vitro experiments. In conclusion, our in silico approach permitted to highlight the specific TF of a regulon out of the 673 orfs annotated as 'regulatory proteins' within the genome of S.coelicolor. [less ▲]

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See detailMembrane associated proteases and their inhibitors in tumour angiogenesis
Noël, Agnès ULg; Maillard, Catherine ULg; Rocks, Natacha ULg et al

in Journal of Clinical Pathology (2004), 57(6), 577-584

Cell surface proteolysis is an important mechanism for generating biologically active proteins that mediate a range of cellular functions and contribute to biological processes such as angiogenesis ... [more ▼]

Cell surface proteolysis is an important mechanism for generating biologically active proteins that mediate a range of cellular functions and contribute to biological processes such as angiogenesis. Although most studies have focused on the plasminogen system and matrix metalloproteinases ( MMPs), recently there has been an increase in the identification of membrane associated proteases, including serine proteases, ADAMs, and membrane-type MMPs (MT-MMPs). Normally, protease activity is tightly controlled by tissue inhibitors of MMPs (TIMPs) and plasminogen activator inhibitors (PAIs). The balance between active proteases and inhibitors is thought to determine the occurrence of proteolysis in vivo. High concentrations of proteolytic system components correlate with poor prognosis in many cancers. Paradoxically, high (not low) PAI-1 or TIMP concentrations predict poor survival in patients with various cancers. Recent observations indicate a much more complex role for protease inhibitors in tumour progression and angiogenesis than initially expected. As knowledge in the field of protease biology has improved, the unforeseen complexities of cell associated enzymes and their interaction with physiological inhibitors have emerged, often revealing unexpected mechanisms of action. [less ▲]

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See detailWR 20a: A massive cornerstone binary system comprising two extreme early-type stars
Rauw, Grégor ULg; De Becker, Michaël ULg; Nazé, Yaël ULg et al

in Astronomy and Astrophysics (2004), 420(2), 9-13

We analyse spectroscopic observations of WR20a revealing that this star is a massive early-type binary system with a most probable orbital period of similar to3.675 days. Our spectra indicate that both ... [more ▼]

We analyse spectroscopic observations of WR20a revealing that this star is a massive early-type binary system with a most probable orbital period of similar to3.675 days. Our spectra indicate that both components are most likely of WN6ha or 031f*/WN6ha spectral type. The orbital solution for a period of 3.675 days yields extremely large minimum masses of 70.7 +/- 4.0 and 68.8 +/- 3.8 M. for the two stars. These properties make WR 20a a cornerstone system for the study of massive star evolution. [less ▲]

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See detailDocumented spatial data set containing the subdivision of the basins into groundwater systems and subsystems, the selected locations per subsystem and a description of these sites, available data and projected additional measurements and equipment
Broers, Hans-Peter; Baran, Nicole; Batlle-Aguilar, Jordi et al

Report (2004)

The establishment of tools for trends analysis in groundwater is essential for the prediction and evaluation of measures taken within context of the Water Framework Directive and the draft Groundwater ... [more ▼]

The establishment of tools for trends analysis in groundwater is essential for the prediction and evaluation of measures taken within context of the Water Framework Directive and the draft Groundwater Directive. This report describes the spatial data sets which will be used for the purpose of detection, aggregation and extrapolation of temporal trends in groundwater quality. Trend analysis methods will be applied and tested at various scales and in various hydrogeological situations. The report contains a description of the studied sub-basins in TREND 2, including information on hydrogeology, land use and pressures, available data and projected additional measurements. Major differences between the sub-basins and the data sets are described to examine consequences for the work on trend detection. One of the challenges for TREND 2 is to define criteria for the application of various statistical and deterministic trend approaches for a range of hydrogeological conditions, spatial scales and types of groundwater monitoring. An overview of these conditions, scales and monitoring types is provided in the present report. [less ▲]

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See detailA randomised placebo controlled 12 week trial of budesonide and prednisolone in rheumatoid arthritis
Kirwan, J. R.; Hallgren, R.; Mielants, H. et al

in Annals of the Rheumatic Diseases (2004), 63(6), 688-695

Objectives: To compare budesonide, a locally acting glucocorticoid with minimal systemic exposure, with conventional glucocorticoid treatment and placebo in rheumatoid arthritis. Methods: A double blind ... [more ▼]

Objectives: To compare budesonide, a locally acting glucocorticoid with minimal systemic exposure, with conventional glucocorticoid treatment and placebo in rheumatoid arthritis. Methods: A double blind, randomised, controlled trial over 12 weeks in 143 patients with active rheumatoid arthritis, comparing budesonide 3 mg daily, budesonide 9 mg daily, prednisolone 7.5 mg daily, and placebo. Particular attention was paid to the pattern of clinical response and to changes in the four week period following discontinuation of treatment. Results: There were improvements in tender joint count and swollen joint count on budesonide 9 mg compared with placebo (28% for tender and 34% for swollen joint counts, p< 0.05). Prednisolone 7.5 mg gave similar results, while budesonide 3 mg was less effective. ACR20 response criteria were met by 25% of patients on placebo, 22% on budesonide 3 mg, 42% on budesonide 9 mg, and 56% on prednisolone 7.5 mg. A rapid and significant reduction in symptoms and signs in response to budesonide 9 mg and prednisolone 7.5 mg was evident by two weeks and maximal at eight weeks. There was no evidence that budesonide provided a different pattern of symptom control from prednisolone, or that symptoms became worse than placebo treatment levels after discontinuation of glucocorticoid treatment. Adverse effects attributable to glucocorticoids were equally common in all groups. Conclusions: The symptomatic benefits of budesonide 9 mg and prednisolone 7.5 mg are achieved within a short time of initiating treatment, are maintained for three months, and are not associated with any rebound in symptoms after stopping treatment. [less ▲]

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See detailEstradiol stimulation of Pulsatile gonadotropin-releasing hormone secretion in vitro: Correlation with perinatal exposure to sex steroids and induction of sexual precocity in vivo
Matagne, V.; Rasier, G.; LEBRETHON, Marie-Christine ULg et al

in Endocrinology (2004), 145(6), 2775-2783

Our aim was to study the effect of estradiol (E2) on pulsatile GnRH secretion in vitro in relation to sex and development. When hypothalamic explants obtained from 5- and 15-d-old female rats were exposed ... [more ▼]

Our aim was to study the effect of estradiol (E2) on pulsatile GnRH secretion in vitro in relation to sex and development. When hypothalamic explants obtained from 5- and 15-d-old female rats were exposed to E2 (10(-7) m), a reduction of GnRH interpulse interval (IPI) occurred but not at 25 and 50 d of age. This effect was prevented by the estrogen receptor antagonist ICI 182.780 and the AMPA/kainate receptor antagonist DNQX but not by the AMPA and N-methyl-D-aspartate receptor antagonists SYM 2206 and MK-801. E2 did not affect GnRH IPI in hypothalamic explants obtained from male rats. Therefore, the possible relation between the female-specific effects of E2 in vitro and perinatal sexual differentiation was investigated. When using explants obtained from female rats masculinized through testosterone injection on postnatal d 1, E2 was no longer effective in vitro at 5 and 15 d. In addition, with explants obtained from male rats demasculinized through perinatal aromatase inhibitor treatment, E2 became capable of decreasing GnRH IPI in vitro at 15 d. To study the possible pathophysiological significance of early hypothalamic E2 effects, female rats received a single E2 injection on postnatal d 10. This resulted in reduced GnRH IPI in vitro on d 15 as well as advancement in age at vaginal opening and first estrus. In conclusion, E2 decreases the GnRH IPI in the immature female hypothalamus in vitro through a mechanism that depends on perinatal brain sexual differentiation and that could be involved in some forms of female precocious puberty. [less ▲]

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See detailApplicability of Composite Sway Structures to Sway Frames
Demonceau, Jean-François ULg

Master of advanced studies dissertation (2004)

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See detailExploring Structure and Reformulations in Different Integer Programming Algorithms
Louveaux, Quentin ULg

Doctoral thesis (2004)

In this thesis we consider four topics all related to using problem reformulations in order to solve integer programs, i.e. optimization problems in which the decision variables must be integer. We first ... [more ▼]

In this thesis we consider four topics all related to using problem reformulations in order to solve integer programs, i.e. optimization problems in which the decision variables must be integer. We first consider the polyhedral approach. We start by addressing the ques- tion of lifting valid inequalities, i.e. finding a valid inequality for a set Y from the knowledge of a valid inequality for a lower-dimensional restriction X of Y . We simplify and clarify the presentation of the procedure. This allows us to derive conditions under which the computation of the lifting is tractable. The second topic is the study of valid inequalities for the single node flow set. The single node flow set is the problem obtained by considering one node of a fixed charge network flow problem. We derive valid inequalities for this set and various generalizations. Our approach is a systematic procedure using only basic tools of integer programming: fixing and complementing variables, mixed- integer rounding and lifting. The method allows us to explain and generate a large range of inequalities describing the convex hull of such sets. The last two topics are based on non-standard approaches for integer pro- gramming. We first show how the group relaxation approach can be used to provide reformulations for the integral basis method. This is based on a study of extended formulations for the group problem. We present four extended for- mulations and show that the projections of three of these formulations provide the convex hull of the original group problem. Initial computational tests of the approach are also reported. Finally we consider a problem that is difficult for the standard branch-and- bound approach even for small instances. A reformulation based on lattice basis reduction is known to be more effective. However the step to compute the re- duced basis is O(n4) and becomes a bottleneck for small to medium instances. By using the structure of the problem, we show that we can decompose the problem and obtain the basis by taking the kronecker product of two smaller bases easier to compute. Furthermore, if the two small bases are reduced, the kronecker product is also reduced up to a reordering of the vectors. Computa- tional results show the gain from such an approach. [less ▲]

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See detailProcessing and Characterization of Electrolytes Based on Doped Lanthanum Gallates for IT-SOFCs.
Traina, Karl ULg; Cloots, Rudi ULg

in Bossel, Ulf (Ed.) Sixth European Solid Oxide Fuel Cell Forum - Proceedings (2004, June)

Nowadays a huge interest exists towards the SOFC’s coming out on the large-scale market because of the variety of their advantageous applications. Clean conversion of chemical energy to electricity, co ... [more ▼]

Nowadays a huge interest exists towards the SOFC’s coming out on the large-scale market because of the variety of their advantageous applications. Clean conversion of chemical energy to electricity, co-generation of electricity and chemicals, low levels of noise and vibration, flexibility regarding the fuels used, high efhciency are evidences of this statement. One of the problems that still exist in this field concerns the effective and cost reasonable operation of SOFCs. In this context the lowering of the operation temperatures could be one of the solutions to this important issue. Because of their excellent oxide—ion conductivity and stability over a broad range of oxygen partial pressure, the appropriate doped lanthanum gallates are promising alternative electrolytes for intermediate temperature SOFCs (lT-SOFCs). The aim of this work is to present the experimental results, obtained in a close collaboration between the two Universities. The objects could be briefly outlined, as follows: to process planar electrolytes with different thicknesses, based on doped LaGaO3 via traditional ceramic techniques; to study the influence of the dopants type and their amount on the properties of electrolyte materials synthesized; to investigate the phase formation and phase composition in correlation with the phase diagrams, as well as the microstructure and elements distribution. A special emphasis was placed upon the electrochemical characterization in broad temperature range, using impedance spectroscopy. The results obtained have been discussed in details and conclusions have been drawn by common efforts of the two working groups. [less ▲]

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See detailA Microstructural Study of Doped-LaGaO3 (La0.9Sr0.1Ga0.8Mg0.2O2.85) Produced by an Autocombustion from a Gel-like Precursor
Traina, Karl ULg; Pirard, Jean-Paul; Rulmont, André ULg et al

in Bossel, Ulf (Ed.) Sixth European Solid Oxide Fuel Cell Forum - Proceedings (2004, June)

Polycrystalline dense samples of lanthanum gallate doped with strontium and magnesium (La0.9Sr0.1Ga0.8Mg0.2O2.85 or LSGM) was prepared using a novel gel precursor synthesis method. This consists in ... [more ▼]

Polycrystalline dense samples of lanthanum gallate doped with strontium and magnesium (La0.9Sr0.1Ga0.8Mg0.2O2.85 or LSGM) was prepared using a novel gel precursor synthesis method. This consists in preparing a LSGM precursor from a freeze-dried Agar-Agar gel. After the freeze-drying step, the dry residue is put in an oven at 120°C where autocombustion occurred. The as-produced powders are then calcined. Investigations are made to follow both structural and microstructural evolutions from the dry residue to the end product. The effect of the temperature evolution was examined by thermogravimetric analysis, X-ray diffraction, environmental scanning electron microscopy, and specific surface area analysis. Dilatometric curves and density measurements have been also performed on the sintered products. Advantages of this method are the ability to control size distribution and to obtain high density materials without any milling step thus avoiding any contamination coming from the grinding medium. [less ▲]

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See detailThe body we care for. Figures of anthropo-zoo-genesis
Despret, Vinciane ULg

in Body & society (2004), 10(2/3), 111-134

Clever Hans, the famous horse who was believed to be able to count, is generally cited as the paradigm of the influence of the observer. Psychologist Rosenthal has illustrated this phenomenon with his ... [more ▼]

Clever Hans, the famous horse who was believed to be able to count, is generally cited as the paradigm of the influence of the observer. Psychologist Rosenthal has illustrated this phenomenon with his well-known experiment about ‘bright’ and ‘dull’ maze rats. Hans, however, achieved something much more interesting. Hecould not only read human minds through their bodies: he could also influence his questioners to produce gestures he could read as cues for finding the answer. Hans could make human bodies be moved and be affected, and move and affect other beings and perform things without their owners’ knowledge. The question of ‘influence’ when we read this case becomes therefore far more complicated and interesting. It involves the question of the way bodies can attune, affect and transformeach other. We may follow carefully how scientists of ethological practices create access to the creatures they study, how they are moved by their subjects of interest, and how they give them a chance to be interesting andto articulate other responses. Doing so, we notice that the signs that define subject and object, what talks and what is talked about, subjectivity and objectivity, are redistributed in a new manner. These practices offer a new and pragmatic definition of the body, close to James’s theory of emotions: to have a body is to learn how to feel. [less ▲]

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See detailClinical utility of a pharmacostatistical model for ibandronate in osteoporosis
Gieschke, R.; Reginster, Jean-Yves ULg

in Annals of the Rheumatic Diseases (2004, June)

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See detailEtoricoxib demonstrates similar efficacy and improved gastrointestinal safety compared to naproxen in two 138-week randomized studies of osteoarthritis patients
Reginster, Jean-Yves ULg; Fischer, C. L.; Beualieu, A. et al

in Annals of the Rheumatic Diseases (2004, June)

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See detailA novel bisphosphonate dosing regimen: once-monthly oral ibandronate
Cooper, C.; Adami, Silvio; Stepan, J. J. et al

in Annals of the Rheumatic Diseases (2004, June)

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