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Sainte-Foy-les-Lyon, France

Among global changes induced by human activities, association of breakdown of geographical barriers and impoverishered biodiversity of agroecosystems may have a strong evolutionary impact on pest species. As a consequence of trade networks' expansion, secondary contacts between incipient species, if hybrid incompatibility is not yet reached, may result in hybrid swarms, even more when empty niches are available as usual in crop fields and farms. By providing important sources of genetic novelty for organisms to adapt in changing environments, hybridization may be strongly involved in the emergence of invasive populations. Because national and international trade networks offered multiple hybridization opportunities during the previous and current centuries, population structure of many pest species is expected to be the most intricate and its inference often blurred when using fast-evolving markers. Here we show that mito-nuclear sequence datasets may be the most helpful in disentangling successive layers of admixture in the composition of pest populations. As a model we used D. gallinae s. l., a mesostigmatid mite complex of two species primarily parasitizing birds, namely D. gallinae L1 and D. gallinae s. str. The latter is a pest species, considered invading layer farms in Brazil. The structure of the pest as represented by isolates from both wild and domestic birds, from European (with a focus on France), Australian and Brazilian farms, revealed past hybridization events and very recent contact between deeply divergent lineages. The role of wild birds in the dissemination of mites appears to be null in European and Australian farms, but not in Brazilian ones. In French farms, some recent secondary contact is obviously consecutive to trade flows. Scenarios of populations' history were established, showing five different combinations of more or less dramatic bottlenecks and founder events, nearly interspecific hybridizations and recent population mixing within D. gallinae s. str. © 2011 Roy, Buronfosse. Source

Shiga toxin-producing Escherichia coli (STEC) is an important cause of food-borne illness. The public health implication of the presence of STEC in dairy products remains unclear. Knowledge of STEC behavior in cheeses would help to evaluate the human health risk. The aim of our study was to observe the growth and survival of experimentally inoculated STEC strains in raw-milk cheeses manufactured and ripened according to five technological schemes: blue-type cheese, uncooked pressed cheese with long ripening and with short ripening steps, cooked cheese, and lactic cheese. Cheeses were contaminated with different STEC serotypes (O157:H7, O26:H11, O103:H2, and O145:H28) at the milk preparation stage. STEC growth and survival were monitored on selective media during the entire manufacturing process. STEC grew (2 to 3 log(10) CFU · g(-1)) in blue-type cheese and the two uncooked pressed cheeses during the first 24 h of cheese making. Then, STEC levels progressively decreased in cheeses that were ripened for more than 6 months. In cooked cheese and in lactic cheese with a long acidic coagulation step (pH < 4.5), STEC did not grow. Their levels decreased after the cooking step in the cooked cheese and after the coagulation step in the lactic cheese, but STEC was still detectable at the end of ripening and storage. A serotype effect was found: in all cheeses studied, serotype O157:H7 grew less strongly and was less persistent than the others serotypes. This study improves knowledge of the behavior of different STEC serotypes in various raw-milk cheeses. Source

The disclosure relates to a system for preparing an opening created on an organic wall, comprising: a supporting body defining a longitudinal axis and having a proximal portion and a distal portion adapted for insertion through the opening; external clamping elements deployable in an outwardly flaring arrangement relative to the supporting body and able to cover portions of an annular surface of said wall; andbiasing elements arranged to tighten and juxtapose said external clamping elements on said body in order to progressively deform said annular surface so as to shape on said wall a tubular portion extending along the longitudinal axis and form an anchoring clamp consisting of said external clamping elements.

The invention relates to a system for performing an anastomosis between an organic wall having an opening and an organic hollow tube, comprising:

Delignette-Muller M.L.,VetAgro Sup | Dutang C.,University of Strasbourg
Journal of Statistical Software | Year: 2015

The package ftdistrplus provides functions for tting univariate distributions to different types of data (continuous censored or non-censored data and discrete data) and allowing different estimation methods (maximum likelihood, moment matching, quantile matching and maximum goodness-of-fit estimation). Outputs of fitdist and fitdistcens functions are S3 objects, for which speci c methods are provided, including summary, plot and quantile. This package also provides various functions to compare the fit of several distributions to the same data set and can handle to bootstrap parameter estimates. Detailed examples are given in food risk assessment, ecotoxicology and insurance contexts. © 2015, American Statistical Association. All rights reserved. Source

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