Protein variability in cereal cyst nematodes from different geographic regions assessed by two-dimensional gel electrophoresis

La variabilité protéique de douze populations de nématodes à kyste des céréales provenant de sept pays (quatre continents) a été étudiée à partir de trois échantillons par population, chacun constitué de 40 femelles blanches âgées de 50 jours, produites sur le même blé, #Triticum aestivum cv. Arminda, en conditions contrôlées. La pathogénie de chaque isolat est précisée par référence à la littérature ou/et à des tests d'hôtes complémentaires. Trois électrophorèses sont réalisées par échantillon protéique avec de légères modifications apportées aux techniques de migration (O'Farrell, 1975) et de coloration (Oakley et al., 1980). 320 polypeptides sont détectés sur l'ensemble des populations. Les profils protéiques sont comparés par analyse d'images informatisée à l'aide d'une station Vax (4000.60), d'un scanner (Eikonix, Kodak) et du logiciel Kepler (L.S.B. Corporation). Différents degrès de sévérité dans l'acceptation de la détection des spots ont été établis selon leur volume et/ou une gamme d'amplitudes. Les indices de similarité (F) et les distances génétiques (D = 1-F) sont calculés à partir des spots homologues. Les dendrogrammes correspondants sont construits selon la méthode UPGMA. Les résultats montrent une grande variabilité protéique entre populations et une séparation nette entre le groupe #Heterodera avenae sensu stricto et le groupe Gotland. Dans le groupe #H. avenae$ sensu stricto, les deux populations françaises et un isolat d'Australie du sud sont fortement apparentés. Des protéines spécifiques des deux pathotypes français Ha12 et Ha12/FR2 sont caractérisées. La comparaison des profils protéiques par analyse d'images informatisée est discutée. (Résumé d'auteur

A New Platform for Editing Digital Multimedia : the eTalks

The eTalks are a new digital multimedia editing plaform developed at the University of Lausanne: their application is implemented via an easy-to-use editor interface, designed for the use of researchers themselves, to create and edit original eTalks. This permits the linking together of images, sounds and textual materials with hyperlinks, enriching it with relevant information. The final release of eTalks allows complete ‘citability’ of its contents: each and every portion of the researchers' talks can be precisely referred to and thus cited with a specific identifier, just like any traditional, paper-based scientific publication but with all the potential for plural literacies. It is openly accessible and the code is open source, including guidelines to install the eTalks. It contributes to the development of multiliteracies in the digital academic production of knowledge

Efficient Pattern Matching in Python

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

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

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

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

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

An Euler-type formula for β(2n)\beta(2n) and closed-form expressions for a class of zeta series

In a recent work, Dancs and He found an Euler-type formula for $\,\zeta{(2\,n+1)}$, $\,n\,$ being a positive integer, which contains a series they could not reduce to a finite closed-form. This open problem reveals a greater complexity in comparison to $\zeta(2n)$, which is a rational multiple of $\pi^{2n}$. For the Dirichlet beta function, the things are `inverse': $\beta(2n+1)$ is a rational multiple of $\pi^{2n+1}$ and no closed-form expression is known for $\beta(2n)$. Here in this work, I modify the Dancs-He approach in order to derive an Euler-type formula for $\,\beta{(2n)}$, including $\,\beta{(2)} = G$, the Catalan's constant. I also convert the resulting series into zeta series, which yields new exact closed-form expressions for a class of zeta series involving $\,\beta{(2n)}$ and a finite number of odd zeta values. A closed-form expression for a certain zeta series is also conjectured.Comment: 11 pages, no figures. A few small corrections. ACCEPTED for publication in: Integral Transf. Special Functions (09/11/2011

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

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

Polynucleotide phosphorylase has an impact on cell biology of Campylobacter jejuni

Polynucleotide phosphorylase (PNPase), encoded by the pnp gene, is known to degrade mRNA, mediating post-transcriptional regulation and may affect cellular functions. The role of PNPase is pleiotropic. As orthologs of the two major ribonucleases (RNase E and RNase II) of Escherichia coli are missing in the Campylobacter jejuni genome, in the current study the focus has been on the C. jejuni ortholog of PNPase. The effect of PNPase mutation on C. jejuni phenotypes and proteome was investigated. The inactivation of the pnp gene reduced significantly the ability of C. jejuni to adhere and to invade Ht-29 cells. Moreover, the pnp mutant strain exhibited a decrease in C. jejuni swimming ability and chick colonization. To explain effects of PNPase on C. jejuni 81-176 phenotype, the proteome of the pnp mutant and parental strains were compared. Overall, little variation in protein production was observed. Despite the predicted role of PNPase in mRNA regulation, the pnp mutation did not induce profound proteomic changes suggesting that other ribonucleases in C. jejuni might ensure this biological function in the absence of PNPase. Nevertheless, synthesis of proteins which are involved in virulence (LuxS, PEB3), motility (N-acetylneuraminic acid synthetase), stress-response (KatA, DnaK, Hsp90), and translation system (EF-Tu, EF-G) were modified in the pnp mutant strain suggesting a more specific role of PNPase in C. jejuni. In conclusion, PNPase deficiency induces limited but important consequences on C. jejuni biology that could explain swimming limitation, chick colonization delay, and the decrease of cell adhesion/invasion ability

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

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

Resistance to the cereal cyst nematode (Heterodera avenae) transferred from the wild grass Aegilops ventricosa to hexaploid wheat by a "stepping-stone" procedure

Transfer of resistance toHeterodera avenae, the cereal cyst nematode (CCN), by a stepping-stoneprocedure from the wild grassAegilops ventricosa to hexaploid wheat has been demonstrated. The number of nematodes per plant was lower, and reached a plateau much earlier, in the resistant introgression line H93-8 (1–2 nematodes per plant) than in the recipient H10-15 wheat (14–16 nematodes per plant). Necrosis (hypersensitive reaction) near the nematode, little cell fusion, and few, often degraded syncytia were observed in infested H93-8 roots, while abundant, well-formed syncytia were present in the susceptible H10-15 wheat. Line H93-8 was highly resistant to the two Spanish populations tested, as well as the four French races (Fr1-Fr4), and the British pathotype Hall, but was susceptible to the Swedish pathotypes HgI and HgIII. Resistance was inherited as though determined by a single quasi-dominant factor in the F2 generations resulting from crosses of H93-8 with H10-15 and with Loros, a resistant wheat carrying the geneCre1 (syn.Ccn1). The resistance gene in H93-8 (Cre2 orCcn2) is not allelic with respect to that in Loros. RFLPs and other markers, together with the cytogenetical evidence, indicate that theCre2 gene has been integrated into a wheat chromosome without affecting its meiotic pairing ability. Introduction ofCre2 by backcrossing into a commercial wheat backgroud increases grain yield when under challenge by the nematode and is not detrimental in the absence of infestation