1,045 research outputs found
How Histone Deacetylases Control Myelination
Myelinated axons are a beautiful example of symbiotic interactions between two cell types: Myelinating glial cells organize axonal membranes and build their myelin sheaths to allow fast action potential conduction, while axons regulate myelination and enhance the survival of myelinating cells. Axonal demyelination, occurring in neurodegenerative diseases or after a nerve injury, results in severe motor and/or mental disabilities. Thus, understanding how the myelination process is induced, regulated, and maintained is crucial to develop new therapeutic strategies for regeneration in the nervous system. Epigenetic regulation has recently been recognized as a fundamental contributing player. In this review, we focus on the central mechanisms of gene regulation mediated by histone deacetylation and other key functions of histone deacetylases in Schwann cells and oligodendrocytes, the myelinating glia of the peripheral and central nervous system
Atmospheric corrections of low altitude thermal infrared airborne images acquired over a tropical cropped area
Corrections atmosphériques d'images thermiques de cultures tropicales acquises à basse altitude. / Accurate corrections of atmospheric effects on thermal infrared remote sensing data are an essential pre-requisite for the development of thermal infrared airborne-derived crop water stress indices. These corrections can be performed using ground surface temperature measurements, which are time consuming and expensive. Atmospheric effects can also be corrected using radiative transfer models that require knowledge of atmospheric status. The latter can be accurately characterized from radiosoundings, but these are usually unavailable. It can also be derived from meteorological model simulations, but spatial and temporal resolution are often too coarse. This study proposes performing atmospheric corrections by using temperature and relative humidity profiles acquired in flight from onboard sensors during data collection. Such measurements are used to document the atmospheric radiative transfer model MATISSE. First results from an experimentation over a tropical cropped area show that corrections are made with a 1.46 °K accuracy
Anisotropic growth of the thiophene-based layer on Si(111)-B
International audienceThe formation of large assemblies on the Si(111)-B surface is discussed with the help of STM simulations and DFT calculations. Although highly regular assemblies of DTB10B along the Si row direction are observed, the existence of two herringbone isomers introduces a lower periodicity within the 2D molecular network. The formation of herringbone units is explained by weak intermolecular interactions while the 1D assembling depends mainly on the interactions of the C10 side chains with the Si(111)-B surface
New Prospects for Research on Manipulation of Insect Vectors by Pathogens
International audienc
The Fermi view of gamma-ray bursts
Since its successful launch in June 2008, the {\it Fermi} Gamma-ray Space
Telescope has made important breakthroughs in the understanding of the
Gamma-Ray Burst (GRB) phenomemon. The combination of the GBM and the LAT
instruments onboard the {\it Fermi} observatory has provided a wealth of
information from its observations of GRBs over seven decades in energy. We
present brief descriptions of the {\it Fermi} instruments and their
capabilities for GRB science, and report highlights from {\it Fermi}
observations of high-energy prompt and extended GRB emission. The main physical
implications of these results are discussed, along with open questions
regarding GRB modelling. We emphasize future synergies with ground-based
\v{C}erenkov telescopes at the time of the SVOM mission.Comment: 10 pages, 10 figures -- Published in a special issue of Comptes
Rendus Physique "GRB studies in the SVOM era", Eds. F. Daigne, G. Dubu
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