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See detailNew insights into the nature of the peculiar star theta Carinae
Hubrig, S.; Briquet, Maryline ULg; Morel, Thierry ULg et al

in Astronomy and Astrophysics (2008), 488

Context: θ Carinae belongs to a group of peculiar early-type stars (OBN) with enhanced nitrogen and carbon deficiency. It is also known as a binary system, but it is not clear yet whether the chemical ... [more ▼]

Context: θ Carinae belongs to a group of peculiar early-type stars (OBN) with enhanced nitrogen and carbon deficiency. It is also known as a binary system, but it is not clear yet whether the chemical anomalies can be explained by mass transfer between the two components. On the basis of the previously reported spectral variability of a few metal lines it may be expected that θ Car possesses a weak magnetic field. <BR />Aims: A study of the physical nature of this hot massive binary which is furthermore a well-known blue straggler lying ~2 mag above the turnoff of the young open cluster IC 2602 is important to understand the origin of its strong chemical anomalies. <BR />Methods: We acquired high resolution spectroscopic and low resolution spectropolarimetric observations to achieve the following goals: a) to improve the orbital parameters to allow a more in-depth discussion on the possibility of mass transfer in the binary system; b) to carry out a non-local thermodynamic equilibrium (NLTE) abundance analysis; and c) to search for the presence of a magnetic field. <BR />Results: The study of the radial velocities using CORALIE spectra allowed us to significantly improve the orbital parameters. A comparative NLTE abundance analysis was undertaken for θ Car and two other early B-type stars with recently detected magnetic fields, Ï Sco and ξ[SUP]1[/SUP] CMa. The analysis revealed significantly different abundance patterns: a one-order-of-magnitude nitrogen overabundance and carbon depletion was found in θ Car, while the oxygen abundance is roughly solar. For the stars ξ[SUP]1[/SUP] CMa and Ï Sco the carbon abundance is solar and, while an N excess is also detected, it is of much smaller amplitude (0.4-0.6 dex). Such an N overabundance is typical of the values already found for other slowly-rotating (magnetic) B-type dwarfs. For θ Car, we attribute instead the chemical peculiarities to a past episode of mass transfer between the two binary components. The results of the search for a magnetic field using FORS 1 at the VLT consisting of 26 measurements over a time span of ~1.2 h are rather inconclusive: only few measurements have a significance level of 3Ï . Although we detect a periodicity of the order of ~8.8 min in the dataset involving the measurements on all hydrogen Balmer lines with the exception of the Hα and Hβ lines, these results have to be confirmed by additional time-resolved magnetic field observations. Based on observations collected with the CORALIE spectrograph attached to the Euler Telescope of the Geneva Observatory located at La Silla (Chile), at the European Southern Observatory, Paranal, Chile (ESO programmes 67.D-0239(A), 072.D-0377(A), 078.D-0080(A) and 278.D-5056(A)), and at the Complejo Astronómico El Leoncito (CASLEO), Argentina. [less ▲]

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See detailNew insights into the nature of the SMC WR/LBV binary HD 5980
Foellmi, C.; Koenigsberger, G.; Georgiev, L. et al

in Revista Mexicana de Astronomía y Astrofísica (2008), 44(1), 3-27

We present the results of optical wavelength observations of the unusual SMC eclipsing binary system HD 5980 obtained in 1999 and 2004-2005. Radial velocity curves for the erupting LBV/WR object (star A ... [more ▼]

We present the results of optical wavelength observations of the unusual SMC eclipsing binary system HD 5980 obtained in 1999 and 2004-2005. Radial velocity curves for the erupting LBV/WR object (star A) and its close WR-like companion (star B) are obtained by deblending the variable emission-line profiles of NIV and NV lines. The derived masses M-A = 58 - 79 M-circle dot and M-B = 51 - 67 M-circle dot, are more consistent with the the stars' location near the top of the HRD than previous estimates. The presence of a wind-wind interaction region is inferred from the orbital phase-dependent behavior of He I P Cygni absorption components. The emission-line intensities continued with the declining trend previously seen in UV spectra. The behavior of the photospheric absorption lines is consistent with the results of Schweickhardt (2000) who concludes that the third object in the combined spectrum, star C, is also a binary system with P-starC similar to 96.5 days, e=0.83. [less ▲]

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See detailNew Insights into the Quasar Type 1/Type 2 Dichotomy from Correlations between Quasar Host Orientation and Polarization
Borguet, Benoît ULg; Hutsemekers, Damien ULg; Letawe, Géraldine ULg et al

in Bastien, Pierre (Ed.) Astronomical Polarimetry 2008: Science from Small to Large Telescopes. ASPC 449 (2011, November 01)

We investigate correlations between the direction of the optical linear polarization and the orientation of the host galaxy/extended emission for type 1 and type 2 radio-loud and radio-quiet quasars. We ... [more ▼]

We investigate correlations between the direction of the optical linear polarization and the orientation of the host galaxy/extended emission for type 1 and type 2 radio-loud and radio-quiet quasars. We have used high resolution Hubble Space Telescope data and a deconvolution process to obtain a good determination of the host galaxy/extended emission (EE) position angle. With these new measurements and a compilation of data from the literature, we find a significant correlation, different for type 1 and type 2 objects, between the linear polarization position angle and the orientation of the EE, suggesting scattering by an extended UV/blue region in both types of objects. Our observations support the extension of the Unification Model to the higher luminosity AGNs like the quasars, assuming a two component scattering model. [less ▲]

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See detailNew Insights into the Regulation and Function of Brain Estrogen Synthase (Aromatase)
Balthazart, Jacques ULg; Ball, G. F.

in Trends in Neurosciences (1998), 21(6), 243-9

In the brain, conversion of androgens into estrogens by the enzyme aromatase (estrogen synthase) is a key mechanism by which testosterone regulates many physiological and behavioral processes, including ... [more ▼]

In the brain, conversion of androgens into estrogens by the enzyme aromatase (estrogen synthase) is a key mechanism by which testosterone regulates many physiological and behavioral processes, including the activation of male sexual behavior, brain sexual differentiation and negative feedback effects of steroid hormones on gonadotropin secretion. Studies on the distribution and regulation of brain aromatase have led to a new perspective on the control and function of this enzyme. A growing body of evidence indicates that the estrogen regulation of aromatase is, at least in part, trans-synaptic. Afferent catecholamine pathways appear to regulate aromatase activity in some brain areas and thereby provide a way for environmental cues to modulate this enzyme.The localization of aromatase in pre-synaptic boutons suggests possible roles for estrogens at the synapse. [less ▲]

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See detailNew insights into the transformation of carbohydrates into platform chemicals
Richel, Aurore ULg; Wathelet, Jean-Paul ULg; Paquot, Michel ULg

Poster (2010, October 14)

The synthesis of furanic compounds from carbohydrates has become exciting in chemistry and in catalysis studies, because it represents one of the major routes for achieving sustainable energy supply and ... [more ▼]

The synthesis of furanic compounds from carbohydrates has become exciting in chemistry and in catalysis studies, because it represents one of the major routes for achieving sustainable energy supply and chemicals production.1 In particular, 5-hydroxymethylfurfural (5-HMF) and 2-furfural (2-F) occupy a pivotal place and are recognised as versatile and multi-functional starting points for the synthesis of a panel of precursors. Microwaves have readily appeared as a powerfull technique for accelerating reaction rates and increasing selectivities in the field of carbohydrate chemistry.3 In particular, their involvment in combination with heterogeneous catalysts have opened new vistas in the production of bio-oxygenated platform chemicals. The state of the art and main outlook of this strategy are reported here. [less ▲]

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See detailNew Insights into Thymus Physiology
Geenen, Vincent ULg

Scientific conference (2013, November 08)

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See detailNew insights on the role of root radial conductivity on the overall uptake dynamics
Lobet, Guillaume ULg; Javaux, M.; Couvreur, V. et al

Conference (2011)

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See detailNew insights on the role of root radial hydraulic conductivity in the overall water uptake process
Lobet, Guillaume ULg; Draye, X.

in Communications in Agricultural and Applied Biological Sciences (2012), 77(1), 117--122

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See detailNew insights to the pathogenesis of acute pulmonary edema in patients with ischaemic left ventricular dysfunction: role of dynamic mitral regurgitation
Lancellotti, Patrizio ULg; Bauer, C.; Stainier, P. Y. et al

in European Heart Journal (2004), 25(Suppl. S), 589

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See detailNew institutional economic theories of non-profits and cooperatives: a critique from an evolutionary perspective
Bauwens, Thomas ULg

E-print/Working paper (2013)

Traditional economic theories of social enterprises rely on new institutional economics. Although these theories have an undeniable explanatory power, they display a series of non-negligible flaws ... [more ▼]

Traditional economic theories of social enterprises rely on new institutional economics. Although these theories have an undeniable explanatory power, they display a series of non-negligible flaws. Evolutionary and complexity approaches in economics may help overcome these limits. The object of this article is, in a first time, to review the different new institutional theories applied to non-profits and cooperatives and, in a second time, to present some criticisms addressed to new institutional economics. We concentrate on two controversial aspects of the latter: on the one hand, its underlying hypotheses about individuals and, in particular, bounded rationality and opportunism; on the other hand, its neglect of the emergent and evolving nature of economic phenomena and of the importance of history and the environment in agents’ institutional choices. For each criticism, we make proposals, mainly inspired by evolutionary and complexity approaches in economics, in order to overcome these limits. [less ▲]

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See detailNew INTEGRAL Observations of η Carinae Close to Periastron
Leyder, J.-C.; Walter, R.; Rauw, Grégor ULg

in Astronomical Society of the Pacific Conference Series (2013, January 01)

The soft X-ray thermal emission of η Carinae varies strongly around the periastron, following the orbital period of 5.5 yr. We studied the hard X-ray non-thermal emission of η Car using new INTEGRAL ... [more ▼]

The soft X-ray thermal emission of η Carinae varies strongly around the periastron, following the orbital period of 5.5 yr. We studied the hard X-ray non-thermal emission of η Car using new INTEGRAL observations taken close to periastron. We showed that the hard X-ray emission is very likely to be associated with η Car, and not with any other source found within the INTEGRAL error circle. We also showed that the 3-σ detection during the soft X-ray minimum is consistent with a hydrogen column density that does not exceed 6×10[SUP]23[/SUP] cm[SUP]-2[/SUP]. [less ▲]

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See detailThe new integrated hydrological model MOHISE: construction, implementation and results
Carabin, G.; Brouyère, Serge ULg; Dassargues, Alain ULg et al

in Book of abstracts of the International Workshop on Catchment Scale Hydrologic Modeling and Data Assimilation (2001)

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See detailNew Integrated Tools to Improve the Traffic and the Port Planning
Rigo, Philippe ULg; Rodriguez, S.

in 29th PIANC International Congress (1999)

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See detailNew integrative method to generate Bacillus subtilis recombinant strains free of selection markers
Brans, Alain ULg; Filée, Patrice ULg; Chevigné, Andy ULg et al

in Applied and Environmental Microbiology (2004), 70(12), 7241-7250

The novel method described in this paper combines the use of blaI, which encodes a repressor involved in Bacillus licheniformis BlaP beta-lactamase regulation, an antibiotic resistance gene, and a B ... [more ▼]

The novel method described in this paper combines the use of blaI, which encodes a repressor involved in Bacillus licheniformis BlaP beta-lactamase regulation, an antibiotic resistance gene, and a B. subtilis strain (BS1541) that is conditionally auxotrophic for lysine. We constructed a BlaI cassette containing blaI and the spectinomycin resistance genes and two short direct repeat DNA sequences, one at each extremity of the cassette. The BS1541 strain was obtained by replacing the B. subtilis P(lysA) promoter with that of the P(blaP) beta-lactamase promoter. In the resulting strain, the cloning of the blaI repressor gene confers lysine auxotrophy to BS1541. After integration of the BlaI cassette into the chromosome of a conditionally lys-auxotrophic (BS1541) strain by homologous recombination and positive selection for spectinomycin resistance, the eviction of the BlaI cassette was achieved by single crossover between the two short direct repeat sequences. This strategy was successfully used to inactivate a single gene and to introduce a gene of interest in the Bacillus chromosome. In both cases the resulting strains are free of selection marker. This allows the use of the BlaI cassette to repeatedly further modify the Bacillus chromosome. [less ▲]

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See detailNew interaction formulae for beam-columns in Eurocode 3: the French Belgian approach
Jaspart, Jean-Pierre ULg; Cerfontaine, F.

in Proceedings of the Third European Conference on Steel Structures (EUROSTEEL) (2002)

Detailed reference viewed: 38 (1 ULg)