382 research outputs found

    Host responses of different Triticeae to species of the cereal cyst nematode complex in relation to breeding resistant durum wheat

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    Vingt-huit lignées ou cultivars de #Triticum diploïdes (génomes A, D, S(I), U), tétraploïdes (génomes AB, D(V)M(V), UM, US(V)) et hexaploïdes (génome ABD) ont été étudiés pour leur capacité à permettre le développement de neuf populations d'#Heterodera avenae originaires de six pays (Algérie, France, Espagne, Australie, Israël et Inde), deux populations d'#Heterodera filipjevi provenant de Russie et de Bulgarie et une population d'#Heterodera latipons provenant d'Israël. Les tests ont été conduits dans des conditions artificielles selon une technique miniaturisée. Les résultats ont montré une résistance élevée à l'encontre des populations d'#H. avenae sensu stricto au sein des trois niveaux de ploïde et dans les différents génomes S(1) (#T. longissimum), D(V)M(V) (#T. ventricosum), UM (#T. ovatum), US(V) (#T. variabile) et ABD (#T. aestivum AUS 4930). Des sources de résistance complète ou partielle ont été trouvées dans le génome D (#T. tauschii CPI 110813 ou AUS 18913), mais leur expression dans les blés hexaploïdes synthétiques est incomplète. Il a été confirmé que le gène #Cre1 du blé cv. Loros est inefficace contre les populations d'#H. avenae d'Australie, d'Inde, et d'Israël, ainsi que contre les populations d'#H. filipjevi. La différenciation inter- et intraspécifique dans ce complexe de nématodes à kystes des céréales pour leur (a)virulence vis-à-vis de #Triticeae$ et leur capacité reproductive intrinsèque sont discutées, ainsi que l'utilisation de résistances complète et partielle dans les programmes de sélection. (Résumé d'auteur

    Efficient Pattern Matching in Python

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    Pattern matching is a powerful tool for symbolic computations. Applications include term rewriting systems, as well as the manipulation of symbolic expressions, abstract syntax trees, and XML and JSON data. It also allows for an intuitive description of algorithms in the form of rewrite rules. We present the open source Python module MatchPy, which offers functionality and expressiveness similar to the pattern matching in Mathematica. In particular, it includes syntactic pattern matching, as well as matching for commutative and/or associative functions, sequence variables, and matching with constraints. MatchPy uses new and improved algorithms to efficiently find matches for large pattern sets by exploiting similarities between patterns. The performance of MatchPy is investigated on several real-world problems

    Constraints on the Cosmic Infra-Red Background based on BeppoSAX and CAT spectra of Mkn 501

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    The TeV and X-ray data obtained by the imaging Cherenkov telescope CAT and X-ray satellite BeppoSAX during the remarkable flare of Mkn 501 in April 16, 1997 are used to constrain the flux of the Cosmic Infrared Background (CIB) using different CIB models. We show that a non-negligible absorption of gamma-rays due to the CIB could take place already in the low-energy (sub-TeV) domain of the spectrum of Mkn 501. This implies that the data of the low-energy threshold CAT telescope contain very important information about the CIB at short wavelengths, 0.4 mum <= lambda <= 3. mum. The analysis of almost simultaneous spectroscopic measurements of Mkn 501 in a high state by CAT and BeppoSAX in the framework of the standard homogeneous Synchrotron-Self-Compton (SSC) framework model leads to the conclusion that the density of the near-infrared background with typical ``starlight spectrum'' around 1 mum should be between 5 and 35 nW m^-2 sr^-1 (99 % CL), with most likely value around 20 nW m^-2 sr^-1. Also we argue that the CAT gamma-ray data alone allow rather robust upper limits on the CIB, lambda F_lambda <= 60 nW m^-2 sr^-1 at 1 mum, taking into account that for any reasonable scenario of gamma-ray production the differential intrinsic spectrum of gamma-ray hardly could be flatter than dN/dE == E^-1. This estimate agrees, within statistical and systematic uncertainties, with recent reports about tentative detections of the CIB at 2.2 and 3.5 mum by the Diffuse Infrared Background Experiment (DIRBE), as well as with the measurements of the background radiation at optical wavelengths from absolute photometry. We also discuss the impact of the intergalactic absorption effect in derivation of the SSC parameters for the jet in Mkn 501

    Comparison of simulated longitudinal profiles of hadronic air showers with MASS2 balloon data

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    The KASKADE and CORSIKA air shower generators are compared to the data collected by MASS2 balloon experiment in 1991. The test of longitudinal profile for proton, helium and muon flux production provide good constraints on these air shower generators. KASKADE and CORSIKA especially with the new simulator UrQMD for low energies are found to fit these data well. This study is limited to a comparison of longitudinal profiles and therefore does not provide constraints on the overall shower development.Comment: to be published in Astroparticle Physic

    Séries hypergéométriques multiples et polyzêtas

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    Genetic comparison of Campylobacter coli resulting from pigs and poultry with isolates resulting from human campylobacteriosis

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    133 isolates of Campylobacter coli isolated from Brittany in France and collected in 2003 were analysed by RFLP/PFGE. They came from pig (65), poultry (56) and human campylobacteriosis (12). No pulsotype common to the 3 origins could be detected but the analysis of the genetic similarity at 80% of the isolates made it possible to build 19 groups of similarity in 3 cases. Poultry isolates were found in groups containing human isolates. Neverthless, the pig isolates were always in groups different from the poultry isolates and the human ones. These results tend to indicate that the two animal productions would have their own genotype and that the campylobacters from pigs are rarely responsible of human campylobacteriosis

    Разработка метода количественного определения воды в сотовых панелях самолетов методом ИК термографии

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    Проведено моделирование и экспериментальные исследования по тепловому контролю воды в авиационных сотовых панелях. Рассмотрены случаи разного расположения воды внутри ячеек и разного количества воды. Показана возможность количественной оценки скрытой воды при двухстороннем и одностороннем доступе к объекту контроля. Разработан и реализован алгоритм количественной оценки массы воды для конкретной сотовой панели.Modelling and experimental activities of TNDT jf aviation honeycomb panels are conducted. The cases of various amount and location of water ingress are considered. The possibility of quantitative evaluation of hidden water with one and two side control is illustrated. The algoritm of quantitative evaluation of hidden water content is realized
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