Le caracal (felis caracal, Schreber 1776) (synthèse bibliographique)

Dans une première partie, l'auteur situe le caracal (felis caracal) parmi les félidés avec une discussion sur sa classification au sein de l'un des genres suivants : lynx, felis, profelis ou caracal. Puis une description physique détaillée conclut cette présentation zoologique. La deuxième partie est consacrée à l'étude de sa biologie en milieu naturel. Dans la dernière partie, un point est fait sur son statut actuel : le caracal est abondant en Afrique australe, alors qu'il est rare et menacé en Afrique du nord, au Moyen-Orient et en Asie du Sud-ouest. Divers aspects de ses relations avec les hommes sont décrits. Enfin, l'auteur expose quelques éléments du maintien de ce félin en captivité.NANTES-Ecole Nat.Vétérinaire (441092302) / SudocSudocFranceF

Development of variable emissivity coatings for thermal radiator

International audienceFor years the use of variable emissivity devices and coatings has been envisaged by the academic and industrials space actors. The aim is to overcome the drawback specific to constant thermo-optical coatings with regard to the variation of heat load during the mission and so to maximize the heat rejection capacity and to minimize the heating power budget. The most promising of these coatings are based on thermochromic(TCH) and electrochromic (ECH) materials. Thermochromic materials can be adjusted to behave as poor emitters at low temperature, and good emitters at high temperature. As such, they are proposed as smart elements capable of supporting thermal control on board of spacecraft, without the need of any electronic feedback or electromechanical actuation, and, therefore, at zero power costs. The solutions proposed for TCH smart radiators are pretty heterogeneous, and range from sintered tiles, to sol-gel paints, to vacuum thin-films. Another promising approach is based on electrochromic devices. Common ECHs work in the visible spectrum and modulate transmitted or reflected light intensities upon application of voltage. The advantage of ECH for space application is achieved by adapting the infrared emissivity of a surface by application of a low power electrical potential. In an ongoing R&D activity funded by ESA and CNES the TCH multilayer tiles are based on VO2 technology developed with industrial means and ECH devices are based on encapsulated conducting polymers. By now ECH and TCH emissivity contrast between cold and hot case has been measured up to 0.3 and 0.4 respectively, within a variation range as narrow as 20°C for thermochromic. In this presentation the various approaches in order to design, manufacture and test TCH and ECH materials as well as variable emissivity radiator breadboards will be discussed. Prototypes and final test results for both technologies will be presented

Early combination therapy with hydroxychloroquine and azithromycin reduces mortality in 10,429 COVID-19 outpatients

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Outcomes of 3,737 COVID-19 patients treated with hydroxychloroquine/azithromycin and other regimens in Marseille, France: A retrospective analysis

International audienceElsevier has created a COVID-19 resource centre with free information in English and Mandarin on the novel coronavirus COVID-19. The COVID-19 resource centre is hosted on Elsevier Connect, the company's public news and information website. Elsevier hereby grants permission to make all its COVID-19-related research that is available on the COVID-19 resource centre-including this research content-immediately available in PubMed Central and other publicly funded repositories, such as the WHO COVID database with rights for unrestricted research re-use and analyses in any form or by any means with acknowledgement of the original source. These permissions are granted for free by Elsevier for as long as the COVID-19 resource centre remains active

A highly virulent variant of HIV-1 circulating in the Netherlands

We discovered a highly virulent variant of subtype-B HIV-1 in the Netherlands. One hundred nine individuals with this variant had a 0.54 to 0.74 log10 increase (i.e., a ~3.5-fold to 5.5-fold increase) in viral load compared with, and exhibited CD4 cell decline twice as fast as, 6604 individuals with other subtype-B strains. Without treatment, advanced HIV-CD4 cell counts below 350 cells per cubic millimeter, with long-term clinical consequences-is expected to be reached, on average, 9 months after diagnosis for individuals in their thirties with this variant. Age, sex, suspected mode of transmission, and place of birth for the aforementioned 109 individuals were typical for HIV-positive people in the Netherlands, which suggests that the increased virulence is attributable to the viral strain. Genetic sequence analysis suggests that this variant arose in the 1990s from de novo mutation, not recombination, with increased transmissibility and an unfamiliar molecular mechanism of virulence