Gravité de l'infection néonatale à GBS. Stratégies de prévention et Prise en charge du nouveau-né. Situation en Communauté Française.

Conference (2000, May 06)

Gravito-inertial and pressure modes detected in the B3 IV CoRoT target HD 43317

in Astronomy and Astrophysics (2012), 542

Context. OB stars are important building blocks of the Universe, but we have only a limited sample of them well understood enough from an asteroseismological point of view to provide feedback on the ... [more ▼]

Context. OB stars are important building blocks of the Universe, but we have only a limited sample of them well understood enough from an asteroseismological point of view to provide feedback on the current evolutionary models. Our study adds one special case to this sample, with more observational constraints than for most of these stars. <BR /> Aims: Our goal is to analyse and interpret the pulsational behaviour of the B3 IV star HD 43317 using the CoRoT light curve along with the ground-based spectroscopy gathered by the HARPS instrument. This way we continue our efforts to map the β Cep and SPB instability strips. <BR /> Methods: We used different techniques to reveal the abundances and fundamental stellar parameters from the newly-obtained high-resolution spectra. We used various time-series analysis tools to explore the nature of variations present in the light curve. We calculated the moments and used the pixel-by-pixel method to look for line profile variations in the high-resolution spectra. <BR /> Results: We find that HD 43317 is a single fast rotator (v[SUB]rot[/SUB] ≈ 50% v[SUB]crit[/SUB]) and hybrid SPB/β Cep-type pulsator with Solar metal abundances. We interpret the variations in photometry and spectroscopy as a result of rotational modulation connected to surface inhomogeneities, combined with the presence of both g and p mode pulsations. We detect a series of ten consecutive frequencies with an almost constant period spacing of 6339 s as well as a second shorter sequence consisting of seven frequencies with a spacing of 6380 s. The dominant frequencies fall in the regime of gravito-inertial modes. The CoRoT space mission was developed and is operated by the French space agency CNES, with participation of ESA's RSSD and Science Programmes, Austria, Belgium, Brazil, Germany, and Spain.Based on data gathered with HARPS installed on the 3.6 m ESO telescope (ESO Large Programme 182.D-0356) at La Silla, Chile.Table A.1 is only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via <A href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/542/A55">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/542/A55</A> [less ▲]

Gravity induced tectonics in the Rogaland anorthositic province, Southwest Norway

in Documents du BRGM (1999), 290

Gravity modes as a way to distinguish between hydrogen- and helium-burning red giant stars

in Nature (2011), 471

Red giants are evolved stars that have exhausted the supply of hydrogen in their cores and instead burn hydrogen in a surrounding shell. Once a red giant is sufficiently evolved, the helium in the core ... [more ▼]

Red giants are evolved stars that have exhausted the supply of hydrogen in their cores and instead burn hydrogen in a surrounding shell. Once a red giant is sufficiently evolved, the helium in the core also undergoes fusion. Outstanding issues in our understanding of red giants include uncertainties in the amount of mass lost at the surface before helium ignition and the amount of internal mixing from rotation and other processes. Progress is hampered by our inability to distinguish between red giants burning helium in the core and those still only burning hydrogen in a shell. Asteroseismology offers a way forward, being a powerful tool for probing the internal structures of stars using their natural oscillation frequencies. Here we report observations of gravity-mode period spacings in red giants that permit a distinction between evolutionary stages to be made. We use high-precision photometry obtained by the Kepler spacecraft over more than a year to measure oscillations in several hundred red giants. We find many stars whose dipole modes show sequences with approximately regular period spacings. These stars fall into two clear groups, allowing us to distinguish unambiguously between hydrogen-shell-burning stars (period spacing mostly ~50seconds) and those that are also burning helium (period spacing ~100 to 300 seconds). [less ▲]

La gravure à Liège au temps de Lambert Lombard

Scientific conference (2012, February 02)

Grazing by large river zooplankton: a key to summer potamoplankton decline? The case of the Meuse and Moselle rivers in 1994 and 1995

in Hydrobiologia (1998)

To explain summer declines in phytoplankton biomass in large rivers, we compared the effect of zooplankton grazing on the planktonic algae of two large European rivers, the Meuse and the Moselle. In situ ... [more ▼]

To explain summer declines in phytoplankton biomass in large rivers, we compared the effect of zooplankton grazing on the planktonic algae of two large European rivers, the Meuse and the Moselle. In situ grazing was measured during two years (1994 and 1995), using the Haney method. Total zooplankton community filtration rates recorded in the river Meuse ranged between 1 and 32% of the water volume filtered per day. A drastic algal decline was observed early July both years and may be explained by high densities of a rotiferdominated zooplankton community (500–700 ind. l􀀀1) with more than 75%of Brachionus calyciflorus. During the summer period in 1994, when grazingwas over 20%, edible algal biomasswas controlled by a diversified rotifer community (up to 2500 ind.l􀀀1), while a nonedible algal assemblage developed. In contrast, phytoplankton biomass remained comparatively lowin the Moselle throughout the lowflowperiod, as did zooplankton numbers duringmost of this time (fewer than 200 ind. l􀀀1 during the summer period). The proportion of crustaceans in this zooplanktonwas rather higher than in the Meuse, and they dominated at times, in biomass as well as in numbers. Nevertheless, measured in situ grazing rates (1–15%) could not explain the low summer algal biomass, even if low filtration rates may at times represent a significant carbon loss for phytoplankton, when and where net algal production was low. As a conclusion, the role of phytoplankton – zooplankton interactions in controlling algal biomass in large rivers is discussed. [less ▲]

Grazing incidence X-ray reflectometry studies of CdTe(1 1 1) surfaces and a-Si thin films

in Solar Energy Materials & Solar Cells (1998), 52

Chemically treated cadmium telluride (CdTe) surfaces and amorphous silicon (a-Si) thin films were characterized by X-ray reflectometry at grazing incidence. In the case of the surface of CdTe single ... [more ▼]

Chemically treated cadmium telluride (CdTe) surfaces and amorphous silicon (a-Si) thin films were characterized by X-ray reflectometry at grazing incidence. In the case of the surface of CdTe single crystal treated with an oxidizing agent (a solution of Br2 in CH3OH), the superficial layer was found to be less dense than its support with a profound alteration of CdTe in the volume. After rinsing in KOH solution, the properties of single-crystalline CdTe are obtained. In the case of a-Si thin layers, we show that the simulation of the reflectometry curves enables not only the determination of the layer thickness but also the detection of an ultrathin superficial oxide layer. [less ▲]

GRAZING OF BOSMINA LONGIROSTRIS ON TWO PLANKTONIC ALGAE: THE INFLUENCE OF SIZE AND TASTE.

Poster (1998, August 09)

The cladoceran Bosmina longirostris is a dominant species in the River Meuse (Belgium) especially during summer. Grazing of this small-sized cosmopolitan cladoceran on algae has been stated to be related ... [more ▼]

The cladoceran Bosmina longirostris is a dominant species in the River Meuse (Belgium) especially during summer. Grazing of this small-sized cosmopolitan cladoceran on algae has been stated to be related to the size of the grazed cells by some authors while other studies emphasised on the ability of bosminids to actively capture 'good tasting' particles. Grazing experiments were carried out in the laboratory with B. longirostris feeding on two algal species (Dictyosphaerium ehrenbergianum, 3-4 µm of diameter, and Chlamydomonas reinhardtii, 9-10 µm of diameter). Gut passage times and ingestion rates of the bosminids were determined with radioactively and fluorescently labelled algae. Although both algae have sizes reported to be actively grazed by B. longirostris, they were ingested at very different rates. The relative influence of cell size and cell 'taste' will be discussed. [less ▲]

GRB 061006: optical afterglow.

in GRB Coordinates Network (2006), 5718

Not Available

GRB 080315: optical observations.

E-print/Working paper (2008)

Not Available