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See detailLaboratoire et allergologie : nouvelles applications
Gadisseur, Romy ULiege; Cavalier, Etienne ULiege

Conference (2010, February 04)

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See detailEffects of eythropoietin administration on mitral regurgitation and left ventricular remodeling in heart failure patients.
Cosyns, B.; Velez-Roa, S.; Droogmans, S. et al

in International Journal of Cardiology (2010), 138(3), 306-307

The effects of erythropoietin administration on mitral regurgitation in patients with congestive heart failure have not yet been examined. After 2 months, erythropoietin treatment results in a significant ... [more ▼]

The effects of erythropoietin administration on mitral regurgitation in patients with congestive heart failure have not yet been examined. After 2 months, erythropoietin treatment results in a significant reduction in left ventricular volumes and mitral regurgitation severity and improves hemodynamics. [less ▲]

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See detailEnsemble perturbation smoother for optimizing tidal boundary conditions by assimilation of High-Frequency radar surface currents - application to the German Bight
Barth, Alexander ULiege; Alvera Azcarate, Aïda ULiege; Gurgel, Klaus-Werner et al

in Ocean Science (2010), 6(1), 161-178

High-Frequency (HF) radars measure the ocean surface currents at various spatial and temporal scales. These include tidal currents, wind-driven circulation, density-driven circulation and Stokes drift ... [more ▼]

High-Frequency (HF) radars measure the ocean surface currents at various spatial and temporal scales. These include tidal currents, wind-driven circulation, density-driven circulation and Stokes drift. Sequential assimilation methods updating the model state have been proven successful to correct the density-driven currents by assimilation of observations such as sea surface height, sea surface temperature and in-situ profiles. However, the situation is different for tides in coastal models since these are not generated within the domain, but are rather propagated inside the domain through the boundary conditions. For improving the modeled tidal variability it is therefore not sufficient to update the model state via data assimilation without updating the boundary conditions. The optimization of boundary conditions to match observations inside the domain is traditionally achieved through variational assimilation methods. In this work we present an ensemble smoother to improve the tidal boundary values so that the model represents more closely the observed currents. To create an ensemble of dynamically realistic boundary conditions, a cost function is formulated which is directly related to the probability of each boundary condition perturbation. This cost function ensures that the boundary condition perturbations are spatially smooth and that the structure of the perturbations satisfies approximately the harmonic linearized shallow water equations. Based on those perturbations an ensemble simulation is carried out using the full three-dimensional General Estuarine Ocean Model (GETM). Optimized boundary values are obtained by assimilating all observations using the covariances of the ensemble simulation. [less ▲]

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See detailPretreatments and enzymatic hydrolysis of Miscanthus x giganteus for oligosaccharides production: delignification degree and characterisation of the hydrolysis products
Vanderghem, Caroline ULiege; Jacquet, Nicolas ULiege; Blecker, Christophe ULiege et al

Poster (2010, February 04)

The aim of the present study is to compare two delignification methods (formic/acetic acid1 and soaking in aqueous ammonia) on Miscanthus x giganteus and to assess the suitability to produce cellobiose ... [more ▼]

The aim of the present study is to compare two delignification methods (formic/acetic acid1 and soaking in aqueous ammonia) on Miscanthus x giganteus and to assess the suitability to produce cellobiose and other oligosaccharides after enzymatic hydrolysis. Oligosaccharides have recently gotten attention for their health benefits. Two methods were compared in order to quantify lignin: the acid detergent lignin method (procedure of Van Soest most commonly employed by animal scientist and agronomists for analysis of forages) and the Klason lignin procedure. Lignin concentrations in raw material determined by both methods were different; Klason lignin value (23.5%) was greater than the acid detergent lignin concentration (12.9%). Possible reasons of these results will be discussed. Pretreatment by the formic/acid mixture showed a better deliginification rate compared to the soaking in aqueous ammonia method. Results were based on Klason lignin. Analysis of the structural carbohydrates revealed that untreated miscanthus was mainly composed of glucose and xylose. Extracted pulps by both delignification methods were hydrolysed by commercial cellulases and hemicellulases. A major challenge is the characterisation of complex mixtures of lignocellulosic hydrolysates. In this study, the hydrolysis products were separated and quantified by highperformance anion exchange chromatography with pulsed amperometric detection (HPAECPAD). This method was successfully applied to the quantitative analysis of monosaccharides (glucose and xylose) and disaccharides (cellobiose and xylobiose) formed by the enzymatic hydrolysis of pretreated miscanthus. The influence of the pretreatments on the oligosaccharides yields will be presented. [less ▲]

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See detailEvaluation logopédique des enfants d’âge scolaire (7-12 ans) : la nouvelle batterie L2MA-2
Maillart, Christelle ULiege; Chevrie-Muller, Claude

Conference given outside the academic context (2010)

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See detailL’interférométrie au service de l’astronomie
Defrere, Denis ULiege

Conference given outside the academic context (2010)

General public talk given by Denis Defrere on the role of interferometry in astronomy.

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See detailSpinoza, l'inexistence du mal
Krtolica, Igor ULiege

Conference (2010, February 02)

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See detailLe droit romain après les Romains
Gerkens, Jean-François ULiege

Conference (2010, February 02)

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See detailLa sémiotique visuelle entre principes généraux et spécificités. A partir du Groupe µ
Dondero, Maria Giulia ULiege

in Nouveaux Actes Sémiotiques (2010, February 02)

Cette étude vise à examiner les raisons pour lesquelles la sémiotique a toujours éprouvé de grandes difficultés à élaborer une théorie des mécanismes généraux de la signification — la transversalité du ... [more ▼]

Cette étude vise à examiner les raisons pour lesquelles la sémiotique a toujours éprouvé de grandes difficultés à élaborer une théorie des mécanismes généraux de la signification — la transversalité du sens par rapport aux différents médias est un de plus grands défis qu’elle s’est donnés — qui, en même temps, rende les énoncés analysables (en effet, le sens de ces derniers ne peut être établi que si on prend en compte la spécificité des substances de leur expression et de leur fonctionnement des culturel). D’un côté, les dernières décennies ont vu surgir des « théories de champ » (théorie de la peinture, de la photographie, du cinéma, etc.) mettant en avant la spécificité des différentes formes expressives ; de l’autre la sémiotique a produit des théories de la signification si générales qu’elles sont impuissantes à mener l’analyse de ces formes expressives (ce qui l’a amené à étudier les organisations discursives indépendamment du parcours génératif de l’expression). Les travaux du Groupe μ démontrent la possibilité de dépasser cette contradiction. S’ils y arrivent, c’est parce qu’ils affrontent la question générale de la perception — manifestation matérielle des signifiants des énoncés textuels — et la question pratique de la production du signe, sans pour autant réifier la spécificité matérielle des énoncés. [less ▲]

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See detailLife cycle environmental performance of using substitution fuels in cement production
Belboom, Sandra ULiege; Halleux, Hubert; Léonard, Angélique ULiege et al

Poster (2010, February 01)

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See detailA life-cycle assessment of injectable drug primary packaging : comparing the traditional process in glass vials with the new Closed Vial technology (polymer vials)
Belboom, Sandra ULiege; Renzoni, Roberto ULiege; Verjans, Benoît et al

Poster (2010, February 01)

This study based on the life cycle assessment methodology compares environmental impacts of two packaging alternatives used for injectable drugs: the traditional method based on glass vials and the new ... [more ▼]

This study based on the life cycle assessment methodology compares environmental impacts of two packaging alternatives used for injectable drugs: the traditional method based on glass vials and the new method developed by Aseptic Technologies based on polymer vials. [less ▲]

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See detailNkx6.1 and nkx6.2 regulate alpha- and beta-cell formation in zebrafish by acting on pancreatic endocrine progenitor cells.
Binot, Anne-Catherine; Manfroid, Isabelle ULiege; Flasse, Lydie ULiege et al

in Developmental Biology (2010), 340(2), 397-407

In mice, the Nkx6 genes are crucial to alpha- and beta-cell differentiation, but the molecular mechanisms by which they regulate pancreatic subtype specification remain elusive. Here it is shown that in ... [more ▼]

In mice, the Nkx6 genes are crucial to alpha- and beta-cell differentiation, but the molecular mechanisms by which they regulate pancreatic subtype specification remain elusive. Here it is shown that in zebrafish, nkx6.1 and nkx6.2 are co-expressed at early stages in the first pancreatic endocrine progenitors, but that their expression domains gradually segregate into different layers, nkx6.1 being expressed ventrally with respect to the forming islet while nkx6.2 is expressed mainly in beta-cells. Knockdown of nkx6.2 or nkx6.1 expression leads to nearly complete loss of alpha-cells but has no effect on beta-, delta-, or epsilon-cells. In contrast, nkx6.1/nkx6.2 double knockdown leads additionally to a drastic reduction of beta-cells. Synergy between the effects of nkx6.1 and nkx6.2 knockdown on both beta- and alpha-cell differentiation suggests that nkx6.1 and nkx6.2 have the same biological activity, the required total nkx6 threshold being higher for alpha-cell than for beta-cell differentiation. Finally, we demonstrate that the nkx6 act on the establishment of the pancreatic endocrine progenitor pool whose size is correlated with the total nkx6 expression level. On the basis of our data, we propose a model in which nkx6.1 and nkx6.2, by allowing the establishment of the endocrine progenitor pool, control alpha- and beta-cell differentiation. [less ▲]

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See detailProjet 3WSA : Rapport d'évaluation Les Modèles Hydrologiques face aux "risques Industriels"
MAGERMANS, POL ULiege; Everbecq, Etienne ULiege; Grard, Aline ULiege et al

Report (2010)

Dans le cadre de l'élaboration d'une plateforme dédicacée aux risques industriels, nous avons mené une revue des modèles hydrologiques disponibles à l'Aquapôle de l'Université de Liège. Après avoir décrit ... [more ▼]

Dans le cadre de l'élaboration d'une plateforme dédicacée aux risques industriels, nous avons mené une revue des modèles hydrologiques disponibles à l'Aquapôle de l'Université de Liège. Après avoir décrit les potentialités de ces modèles, nous décrivons 4 modèles conceptuels dédicacés aux rejets accidentels de polluants, d'une architecture logicielle simple à un couplage complexe de plusieurs de modèles, basés sur des extensions des modèles existant. [less ▲]

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See detailThe thermal emission of the young and massive planet CoRoT-2b at 4.5 and 8 μm
Gillon, Michaël ULiege; Lanotte, Audrey ULiege; Barman, T. et al

in Astronomy and Astrophysics (2010), 511

We report measurements of the thermal emission of the young and massive planet CoRoT-2b at 4.5 and 8 microns with the Spitzer Infrared Array Camera (IRAC). Our measured occultation depths are 0.510 +- 0 ... [more ▼]

We report measurements of the thermal emission of the young and massive planet CoRoT-2b at 4.5 and 8 microns with the Spitzer Infrared Array Camera (IRAC). Our measured occultation depths are 0.510 +- 0.042 % and 0.41 +- 0.11 % at 4.5 and 8 microns, respectively. In addition to the CoRoT optical measurements, these planet/star flux ratios indicate a poor heat distribution to the night side of the planet and are in better agreement with an atmosphere free of temperature inversion layer. Still, the presence of such an inversion is not definitely ruled out by the observations and a larger wavelength coverage is required to remove the current ambiguity. Our global analysis of CoRoT, Spitzer and ground-based data confirms the large mass and size of the planet with slightly revised values (Mp = 3.47 +- 0.22 Mjup, Rp = 1.466 +- 0.044 Rjup). We find a small but significant offset in the timing of the occultation when compared to a purely circular orbital solution, leading to e cos(omega) = -0.00291 +- 0.00063 where e is the orbital eccentricity and omega is the argument of periastron. Constraining the age of the system to be at most of a few hundreds of Myr and assuming that the non-zero orbital eccentricity is not due to a third undetected body, we model the coupled orbital-tidal evolution of the system with various tidal Q values, core sizes and initial orbital parameters. For log(Q_s') = 5 - 6, our modelling is able to explain the large radius of CoRoT-2b if log(Q_p') <= 5.5 through a transient tidal circularization and corresponding planet tidal heating event. Under this model, the planet will reach its Roche limit within 20 Myr at most. [less ▲]

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See detailHot and cool: two emission-line stars with constrasting behaviours in the same XMM-Newton field
Nazé, Yaël ULiege; Rauw, Grégor ULiege; Ud-Doula, A.

in Astronomy and Astrophysics (2010), 510

High-energy emissions are good indicators of peculiar behaviours in stars. We have therefore obtained an XMM-Newton observation of HD 155806 and 1RXS J171502.4-333344, and derived their spectral ... [more ▼]

High-energy emissions are good indicators of peculiar behaviours in stars. We have therefore obtained an XMM-Newton observation of HD 155806 and 1RXS J171502.4-333344, and derived their spectral properties for the first time. The X-ray spectrum of HD 155806 appears soft, even slightly softer than usual for O-type stars (as shown by a comparison with the O9 star HD 155889 in the same XMM-Newton field). It is well-fitted with a two-component thermal model with low temperatures (0.2 and 0.6 keV), and it shows no overluminosity (log[L_X/L_BOL] = -6.75). The high-resolution spectrum, though noisy, reveals a few broad, symmetric X-ray lines (FWHMË 2500 km s[SUP]-1[/SUP]). The X-ray emission is compatible with the wind-shock model and therefore appears unaffected by the putative dense equatorial regions at the origin of the Oe classification. 1RXS J171502.4-333344 is a nearby flaring source of moderate X-ray luminosity (log[L_X/L_BOL] = -3), with a soft thermal spectrum composed of narrow lines and presenting a larger abundance of elements (e.g. Ne) with a high first ionization potential (FIP) compared to lower-FIP elements. All the evidence indicates a coronal origin for the X-ray emission, in agreement with the dMe classification of this source. Based on observations collected with XMM-Newton, an ESA Science Mission with instruments and contributions directly funded by ESA Member States and the USA (NASA).Research Associate FNRS. [less ▲]

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See detailThe CORALIE survey for southern extrasolar planets. XVI. Discovery of a planetary system around HD 147018 and of two long period and massive planets orbiting HD 171238 and HD 204313
Segransan, D.; Udry, S.; Mayor, M. et al

in Astronomy and Astrophysics (2010), 511

We report the detection of a double planetary system around HD 140718 as well as the discovery of two long period and massive planets orbiting HD 171238 and HD 204313. Those discoveries were made with the ... [more ▼]

We report the detection of a double planetary system around HD 140718 as well as the discovery of two long period and massive planets orbiting HD 171238 and HD 204313. Those discoveries were made with the CORALIE Echelle spectrograph mounted on the 1.2-m Euler Swiss telescope located at La Silla Observatory, Chile. The planetary system orbiting the nearby G9 dwarf HD 147018 is composed of an eccentric inner planet (e = 0.47) with twice the mass of Jupiter (2.1 MJup) and with an orbital period of 44.24 days. The outer planet is even more massive (6.6 MJup) with a slightly eccentric orbit (e = 0.13) and a period of 1008 days. The planet orbiting HD 171238 has a minimum mass of 2.6 MJup, a period of 1523 days and an eccentricity of 0.40. It orbits a G8 dwarfs at 2.5 AU. The last planet, <ASTROBJ>HD 204313</ASTROBJ> b, is a 4.0 M[SUB]Jup[/SUB]-planet with a period of 5.3 years and has a low eccentricity (e = 0.13). It orbits a G5 dwarfs at 3.1 AU. The three parent stars are metal rich, which further strengthens the case that massive planets tend to form around metal rich stars. [less ▲]

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See detailDynamical evolution of titanium, strontium, and yttrium spots on the surface of the HgMn star HD 11753
Briquet, Maryline ULiege; Korhonen, H.; González, J. F. et al

in Astronomy and Astrophysics (2010), 511

<BR /> Aims: We gathered about 100 high-resolution spectra of three typical HgMn (mercury-manganese) stars, <ASTROBJ>HD 11753</ASTROBJ>, <ASTROBJ>HD 53244</ASTROBJ>, and <ASTROBJ>HD 221507</ASTROBJ>, to ... [more ▼]

<BR /> Aims: We gathered about 100 high-resolution spectra of three typical HgMn (mercury-manganese) stars, <ASTROBJ>HD 11753</ASTROBJ>, <ASTROBJ>HD 53244</ASTROBJ>, and <ASTROBJ>HD 221507</ASTROBJ>, to search for slowly pulsating B-like pulsations and surface inhomogeneous distribution of various chemical elements. <BR /> Methods: Classical frequency analysis methods were used to detect line profile variability and to determine the variation period. Doppler imaging reconstruction was performed to obtain abundance maps of chemical elements on the stellar surface. <BR /> Results: For <ASTROBJ>HD 11753</ASTROBJ>, which is the star with the most pronounced variability, distinct spectral line profile changes were detected for Ti, Sr, Y, Zr, and Hg, whereas for <ASTROBJ>HD 53244</ASTROBJ> and <ASTROBJ>HD 221507</ASTROBJ> the most variable line profiles belong to the elements Hg and Y, respectively. We derived rotation periods for all three stars from the variations of radial velocities and equivalent widths of spectral lines belonging to inhomogeneously distributed elements: P[SUB]rot[/SUB] (<ASTROBJ>HD 11753</ASTROBJ>) = 9.54 d, P[SUB]rot[/SUB] (<ASTROBJ>HD 53244</ASTROBJ>) = 6.16 d, and P[SUB]rot[/SUB] (<ASTROBJ>HD 221507</ASTROBJ>) = 1.93 d. For <ASTROBJ>HD 11753</ASTROBJ> the Doppler imaging technique was applied to derive the distribution of the most variable elements Ti, Sr, and Y using two datasets separated by ~65 days. Results of Doppler imaging reconstruction revealed noticeable changes in the surface distributions of Ti II, Sr II, and Y II between the datasets, indicating the hitherto not well understood physical processes in stars with radiative envelopes that cause a rather fast dynamical chemical spot evolution. Based on observations obtained with the CORALIE Echelle Spectrograph on the 1.2-m Euler Swiss telescope, situated at La Silla, Chile.Postdoctoral Fellow of the Fund for Scientific Research, Flanders. [less ▲]

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See detailGravitational settling in pulsating subdwarf B stars and their progenitors
Hu, Haili; Glebbeek, E.; Thoul, Anne ULiege et al

in Astronomy and Astrophysics (2010), 511

Context. Diffusion of atoms can be important during quiescent phases of stellar evolution. Particularly in the very thin inert envelopes of subdwarf B stars, diffusive movements will considerably change ... [more ▼]

Context. Diffusion of atoms can be important during quiescent phases of stellar evolution. Particularly in the very thin inert envelopes of subdwarf B stars, diffusive movements will considerably change the envelope structure and the surface abundances on a short timescale. Also, the subdwarfs will inherit the effects of diffusion in their direct progenitors, namely giants near the tip of the red giant branch. This will influence the global evolution and the pulsational properties of subdwarf B stars. <BR /> Aims: We investigate the impact of gravitational settling, thermal diffusion and concentration diffusion on the evolution and pulsations of subdwarf B stars. Although radiative levitation is not explicitly calculated, we evaluate its effect by approximating the resulting iron accumulation in the driving region. This allows us to study the excitation of the pulsation modes, albeit in a parametric fashion. Our diffusive stellar models are compared with models evolved without diffusion. <BR /> Methods: We use a detailed stellar evolution code to solve simultaneously the equations of stellar structure and evolution, including the composition changes due to diffusion. The diffusion calculations are performed for a multicomponent fluid using diffusion coefficients derived from a screened Coulomb potential. We constructed subdwarf B models with a mass of 0.465 M[SUB]ȯ[/SUB] from a 1 M[SUB]ȯ[/SUB] and 3 M[SUB]ȯ[/SUB] zero-age main sequence progenitor. The low mass star ignited helium in an energetic flash, while the intermediate mass star started helium fusion gently. For each progenitor type we computed series with and without atomic diffusion. <BR /> Results: Atomic diffusion in red giants causes the helium core mass at the onset of helium ignition to be larger. We find an increase of 0.0015 M[SUB]ȯ[/SUB] for the 1 M[SUB]ȯ[/SUB] model and 0.0036 M[SUB]ȯ[/SUB] for the 3 M[SUB]ȯ[/SUB] model. The effects on the red giant surface abundances are small after the first dredge up. The evolutionary tracks of the diffusive subdwarf B models are shifted to lower surface gravities and effective temperatures due to outward diffusion of hydrogen. This affects both the frequencies of the excited modes and the overall frequency spectrum. Especially the structure and pulsations of the post-non-degenerate sdB star are drastically altered, proving that atomic diffusion cannot be ignored in these stars. Sinking of metals could to some extent increase the gravities and temperatures due to the associated decrease in the stellar opacity. However, this effect should be limited as it is counteracted by radiative levitation. [less ▲]

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See detailA photometric and spectroscopic investigation of star formation in the very young open cluster NGC 6383
Rauw, Grégor ULiege; Manfroid, Jean ULiege; De Becker, Michaël ULiege

in Astronomy and Astrophysics (2010), 511

Context. The very young open cluster NGC 6383 centered on the O-star binary HD 159176 is an interesting place for studying the impact of early-type stars with strong radiation fields and powerful winds on ... [more ▼]

Context. The very young open cluster NGC 6383 centered on the O-star binary HD 159176 is an interesting place for studying the impact of early-type stars with strong radiation fields and powerful winds on the formation processes of low-mass stars. <BR /> Aims: To investigate this process, it is necessary to determine the characteristics (age, presence, or absence of circumstellar material) of the population of low-mass pre-main-sequence (PMS) stars in the cluster. <BR /> Methods: We obtained deep UBV(RI)[SUB]c[/SUB] Hα photometric data of the entire cluster as well as medium-resolution optical spectroscopy of a subsample of X-ray selected objects. <BR /> Results: Our spectroscopic data reveal only very weak Hα emission lines in a few X-ray selected PMS candidates. We photometrically identify a number of Hα emission candidates but their cluster membership is uncertain. We find that the fainter objects in the field of view have a wide range of extinction (up to A[SUB]V[/SUB] = 20), one X-ray selected OB star having A[SUB]V[/SUB] â 8. <BR /> Conclusions: Our investigation uncovers a population of PMS stars in NGC 6383 that are probably coeval with HD 159176. In addition, we detect a population of reddened objects that are probably located at different depths within the natal molecular cloud of the cluster. Finally, we identify a rather complex spatial distribution of Hα emitters, which is probably indicative of a severe contamination by foreground and background stars. Based on observations collected at the European Southern Observatory (ESO, La Silla, Chile).Table 2 is only available in electronic form at the CDS via anonymous ftp cdsarc.u-strasbg.fr (130.79.128.5) or via <A href="http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/511/A25">http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/511/A25</A> [less ▲]

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