Entity

Time filter

Source Type

Belgium

Rixhon G.,University of Liege | Juvigne E.,FRS FNRS
Geologica Belgica | Year: 2010

Located in the northern part of the Ardenne massif, the Ninglinspo catchment shows morphologic features (valley floor benches, slope dissymmetry, river superimposition, etc) which constitute the likely heritage of periglacial processes. Here, we consider chiefly the geomorphic meaning of the valley floor benches. Assuming that bench deposits resulted at least partially from periglacial processes during the last glacial means that, during the Holocene warming, the river was unable to evacuate them totally. Reasoning in the same way for previous glacial and interglacial episodes (e.g. with a river unable to transport during warm periods the entirety of the materials provided by periglacial slope processes), implies that a polygenic genesis of these benches should be considered. In this study, we try to bring to the fore this polygenic origin using different various techniques, including geophysical surveying and tephrochronology. Finally, catchment denudation rates by periglacial slope processes ranging from 0.45 to 2 mm/ka have been inferred since the last glacial. Source


Delvigne F.,University of Liege | brognaux A.,University of Liege | Gorret N.,French National Institute for Agricultural Research | Neubauer P.,TU Berlin | And 7 more authors.
Biochemical Engineering Journal | Year: 2011

The dynamics of microbial stress response in intensive cultivation conditions remains not completely understood. In this work, two green fluorescent protein (GFP) transcriptional reporters have been used as biosensors of the heterogeneities generated in a two-compartment scale-down reactor. The stress promoters have been chosen for their responsiveness to carbon limitation corresponding to the global substrate profiles encountered in intensive fed-batch cultures. From our results, it can be concluded that the exposure of microbial cells to substrates heterogeneities tends to decrease the GFP expression level in fed-batch mode. Fluorescence intensities have been monitored at the single cell level by using flow cytometry. During the course of the fed-batch culture, a drop at the level of the intracellular GFP content has been observed for the two scale-down operating conditions and for the two promoters sensitive to substrate limitation (rpoS and csiE). The fluorescence drop can be attributed to the repression of these promoters but also to the release of GFP to the extracellular medium according to the increase of the fluorescence level of the supernatant. This leakage has been observed for all the operating conditions, i.e. the scale-down reactors and the culture operating in the normal mode, i.e. in a well-mixed bioreactor. Interestingly, GFP leakage is more pronounced in the case of the cultures operated in the normal mode. Indeed, staining by propidium iodide tends to be more elevated for the microbial cells cultured under the normal mode by comparison with those cultured in scale-down conditions, indicating a higher permeability of the membrane. These results suggest that GFP microbial biosensors could be used to detect simultaneously mixing imperfections and their impact on the viability of microorganisms. © 2011 Elsevier B.V. Source


Halbwachs J.-L.,University of Strasbourg | Boffin H.M.J.,ESO | Le Bouquin J.-B.,CNRS Grenoble Institute for Particle Astrophysics and Cosmology Laboratory | Kiefer F.,Tel Aviv University | And 17 more authors.
Monthly Notices of the Royal Astronomical Society | Year: 2016

In anticipation of the Gaia astrometric mission, a sample of spectroscopic binaries is being observed since 2010 with the Spectrograph pour l'Observation des PHénomènes des Intérieurs stellaires et des Exoplanètes (SOPHIE) spectrograph at the Haute-Provence Observatory. Our aim is to derive the orbital elements of double-lined spectroscopic binaries (SB2s) with an accuracy sufficient to finally obtain the masses of the components with relative errors as small as 1 per cent when combined with Gaia astrometric measurements. In order to validate the masses derived from Gaia, interferometric observations are obtained for three SB2s in our sample with F-K components: HIP 14157, HIP 20601 and HIP 117186. The masses of the six stellar components are derived. Due to its edge-on orientation, HIP 14157 is probably an eclipsing binary. We note that almost all the derived masses are a few per cent larger than the expectations from the standard spectral type-mass calibration and mass-luminosity relation. Our calculation also leads to accurate parallaxes for the three binaries, and the Hipparcos parallaxes are confirmed. © 2015 The Authors. Source


Meyfroidt P.,FRS FNRS | Meyfroidt P.,Catholic University of Louvain
Human Ecology | Year: 2013

Forest transition - i.e., the shift from decreasing to expanding forest cover - in the northern mountains of Vietnam was analyzed at the local scale in four villages from the 1970s to 2007-2008 to understand feedbacks from local environmental degradation on land uses, the conditions under which such feedbacks occur, and their possible roles in the transition. Remote sensing data were combined with field surveys including interviews, group discussions, mental and participatory mapping, observations and secondary sources. The feedbacks from environmental degradation and changes in the provision of ecosystem services to land practices via environmental cognitions were analyzed. The case studies showed that forest scarcity was perceived, interpreted and evaluated before possibly affecting land use practices. © 2013 Springer Science+Business Media New York. Source


In this article, we report the 2011 European guidelines on the management of cardiovascular diseases during pregnancy, with particular attention to the management of hypertension as hypertensive disorders are the most frequent cardiovascular complications in pregnancy. Source

Discover hidden collaborations