Avis d'expert sur la détermination des caractéristiques d'inflammabilité du chanvre

International audienceDes dépôts de chanvre de faible épaisseur (de l'ordre de quelques mm) sont sensibles au phénomène d'auto-échauffement avec amorçage d'une combustion retardée dans l'ensemble du dépôt. Le contact de points chauds peut amorcer localement un phénomène identique de combustion lente qui, à terme, va s'étendre à la totalité du dépôt. Sur la base du retour d'expérience mettant en oeuvre des travaux de meulage et de tronçonnage en présence de solide combustible pulvérulent, ainsi que des valeurs expérimentales des caractéristiques d'inflammabilité du chanvre, l'INERIS a démontré que le chanvre est un matériau susceptible de s'auto-échauffer en présence de points chauds tels que des travaux de meulage et de tronçonnage. On ne peut que rappeler les risques particuliers engendrés par les travaux par point chaud et la nécessité de les prévenir par la mise en oeuvre rigoureuse de mesures techniques et organisationnelles adaptées. Une "analyse des risques" préalable, une transposition écrite des règles à respecter, la sensibilisation des opérateurs salariés ou sous-traitants, un nettoyage soigné dans un rayon de 11 m autour de la zone de travail et le contrôle des travaux après la fin des travaux sont des actions indispensables pour garantir la sécurité

Morphological variation of the spermatheca in the garden snail Cantareus aspersus - article in French with an abridged English version

articleSpermathecal morphology is known to play an important role in postcopulatory sexual selection of many invertebrates. In helicid land snails, the spermatheca is subdivided into tubules, whose number is sometimes subject to a strong inter-individual variation. Significance of this variation for postcopulatory sexual selection is unknown, but it might be related to cryptic female choice. In the present work, we have investigated the fine multi-tubular structure of the sperm storage organ in Cantareus aspersus. We found between 3 and 13 tubules per individual in a single population, which represents a degree of variation rarely observed in helicid land snails

‘Good-genes' and ‘compatible-genes' effects in an Alpine whitefish and the information content of breeding tubercles over the course of the spawning season

Some models of sexual selection predict that individuals vary in their genetic quality and reveal some of this variation in their secondary sexual characteristics. Alpine whitefish (Coregonus sp.) develop breeding tubercles shortly before their spawning season. These tubercles are epidermal structures that are distributed regularly along the body sides of both males and females. There is still much unexplained variation in the size of breeding tubercles within both sexes and with much overlap between the sexes. It has been suggested that breeding tubercles function to maintain body contact between the mating partners during spawning, act as weapons for defence of spawning territories, or are sexual signals that reveal aspects of genetic quality. We took two samples of whitefish from their spawning place, one at the beginning and one around the peak of spawning season. We found that females have on average smaller breeding tubercles than males, and that tubercle size partly reveals the stage of gonad maturation. Two independent full-factorial breeding experiments revealed that embryo mortality was significantly influenced by male and female effects. This finding demonstrates that the males differed in their genetic quality (because offspring get nothing but genes from their fathers). Tubercle size was negatively linked to some aspects of embryo mortality in the first breeding experiment but not significantly so in the second. This lack of consistency adds to inconsistent results that were reported before and suggests that (i) some aspects of genetic quality are not revealed in breeding tubercles while others are, or (ii) individuals vary in their signaling strategies and the information content of breeding tubercles is not always reliable. Moreover, the fact that female whitefish have breeding tubercles of significant size while males seem to have few reasons to be choosy suggests that the tubercles might also serve some functions that are not linked to sexual signalin

Evaluation des risques sanitaires liés à l'injection de biogaz épure dans un réseau de gaz naturel

National audienceCe document reprend l'avis de l'Agence Française de Sécurité Sanitaire de l'Environnement et du Travail (Afsset) émis à la suite de l'expertise collective menée pour l'évaluation de risques sanitaires liés à l'injection de biogaz dans le réseau de gaz naturel. L'intégralité de cette expertise est publiée et disponible sur le site internet de l'Agence, seuls les grands axes sont présentés dans ce document. Suite aux recommandations émises par l'Afsset, des travaux ont été initiés afin de recueillir et analyser des données de composition sur le biogaz issus de boues de STEP. L'INERIS est en charge de ce projet. Par la suite, les données seront utilisées afin d'évaluer les risques accidentels (consécutifs à la valorisation du biogaz, au transport par canalisation et à la valorisation énergétique, industrielle et domestique) ; ainsi que les risques sanitaires pour les utilisateurs (consécutifs à l'injection dans le réseau de gaz naturel)

Total Synthesis of the Diterpenoid (+)â Harringtonolide

Described herein is the first asymmetric total synthesis of (+)â harringtonolide, a natural diterpenoid with an unusual tropone imbedded in a cagelike framework. The key transformations include an intramolecular Dielsâ Alder reaction and a rhodiumâ complexâ catalyzed intramolecular [3+2] cycloaddition to install the tetracyclic core as well as a highly efficient tropone formation.Ever more rings: The first asymmetric total synthesis of the diterpenoid (+)â harringtonolide is described. The key features include an asymmetric transfer hydrogenation, an intramolecular Dielsâ Alder reaction, chemoselective functionalization of an olefin in the presence of an acetylenic group, a rhodiumâ catalyzed intramolecular [3+2] cycloaddition, and efficient formation of the tropone.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137303/1/anie201605879-sup-0001-misc_information.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137303/2/anie201605879_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137303/3/anie201605879.pd

European wildcat populations are subdivided into five main biogeographic groups: consequences of Pleistocene climate changes or recent anthropogenic fragmentation?

Extant populations of the European wildcat are fragmented across the continent, the likely consequence of recent extirpations due to habitat loss and over-hunting. However, their underlying phylogeographic history has never been reconstructed. For testing the hypothesis that the European wildcat survived the Ice Age fragmented in Mediterranean refuges, we assayed the genetic variation at 31 microsatellites in 668 presumptive European wildcats sampled in 15 European countries. Moreover, to evaluate the extent of subspecies/population divergence and identify eventual wild × domestic cat hybrids, we genotyped 26 African wildcats from Sardinia and North Africa and 294 random-bred domestic cats. Results of multivariate analyses and Bayesian clustering confirmed that the European wild and the domestic cats (plus the African wildcats) belong to two well-differentiated clusters (average Ф ST = 0.159, r st = 0.392, P > 0.001; Analysis of molecular variance [AMOVA]). We identified from c. 5% to 10% cryptic hybrids in southern and central European populations. In contrast, wild-living cats in Hungary and Scotland showed deep signatures of genetic admixture and introgression with domestic cats. The European wildcats are subdivided into five main genetic clusters (average Ф ST = 0.103, r st = 0.143, P > 0.001; AMOVA) corresponding to five biogeographic groups, respectively, distributed in the Iberian Peninsula, central Europe, central Germany, Italian Peninsula and the island of Sicily, and in north-eastern Italy and northern Balkan regions (Dinaric Alps). Approximate Bayesian Computation simulations supported late Pleistocene-early Holocene population splittings (from c. 60 k to 10 k years ago), contemporary to the last Ice Age climatic changes. These results provide evidences for wildcat Mediterranean refuges in southwestern Europe, but the evolution history of eastern wildcat populations remains to be clarified. Historical genetic subdivisions suggest conservation strategies aimed at enhancing gene flow through the restoration of ecological corridors within each biogeographic units. Concomitantly, the risk of hybridization with free-ranging domestic cats along corridor edges should be carefully monitored

Male dominance linked to size and age, but not to 'good genes' in brown trout (Salmo trutta)

BACKGROUND: Males that are successful in intra-sexual competition are often assumed to be of superior quality. In the mating system of most salmonid species, intensive dominance fights are common and the winners monopolise most mates and sire most offspring. We drew a random sample of mature male brown trout (Salmo trutta) from two wild populations and determined their dominance hierarchy or traits linked to dominance. The fish were then stripped and their sperm was used for in vitro fertilisations in two full-factorial breeding designs. We recorded embryo viability until hatching in both experiments, and juvenile survival during 20 months after release into a natural streamlet in the second experiment. Since offspring of brown trout get only genes from their fathers, we used offspring survival as a quality measure to test (i) whether males differ in their genetic quality, and if so, (ii) whether dominance or traits linked to dominance reveal 'good genes'. RESULTS: We found significant additive genetic variance on embryo survival, i.e. males differed in their genetic quality. Older, heavier and larger males were more successful in intra-sexual selection. However, neither dominance nor dominance indicators like body length, weight or age were significantly linked to genetic quality measured as embryo or juvenile survival. CONCLUSION: We found no evidence that females can improve their offspring's genetic viability by mating with large and dominant males. If there still were advantages of mating with dominant males, they may be linked to non-genetic benefits or to genetic advantages that are context dependent and therefore possibly not revealed under our experimental conditions - even if we found significant additive genetic variation for embryo viability under such conditions

An integrated 4249 marker FISH/RH map of the canine genome

BACKGROUND: The 156 breeds of dog recognized by the American Kennel Club offer a unique opportunity to map genes important in genetic variation. Each breed features a defining constellation of morphological and behavioral traits, often generated by deliberate crossing of closely related individuals, leading to a high rate of genetic disease in many breeds. Understanding the genetic basis of both phenotypic variation and disease susceptibility in the dog provides new ways in which to dissect the genetics of human health and biology. RESULTS: To facilitate both genetic mapping and cloning efforts, we have constructed an integrated canine genome map that is both dense and accurate. The resulting resource encompasses 4249 markers, and was constructed using the RHDF5000-2 whole genome radiation hybrid panel. The radiation hybrid (RH) map features a density of one marker every 900 Kb and contains 1760 bacterial artificial chromosome clones (BACs) localized to 1423 unique positions, 851 of which have also been mapped by fluorescence in situ hybridization (FISH). The two data sets show excellent concordance. Excluding the Y chromosome, the map features an RH/FISH mapped BAC every 3.5 Mb and an RH mapped BAC-end, on average, every 2 Mb. For 2233 markers, the orthologous human genes have been established, allowing the identification of 79 conserved segments (CS) between the dog and human genomes, dramatically extending the length of most previously described CS. CONCLUSIONS: These results provide a necessary resource for the canine genome mapping community to undertake positional cloning experiments and provide new insights into the comparative canine-human genome maps