926 research outputs found

    Characterization of the virulence, growth temperature and antibiotic resistance of the Campylobacter jejuni IAL 2383 strain isolated from humans

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    The objective of this study was to characterize the C. jejuni IAL2383 strain isolated from humans in Brazil. Transcripts for the racR, dnaJ and ciaB genes were found and flaA, plda and cadF genes were present in the genome and bacteria was sensitive to most of the important antimicrobials used to treat humans. C. jejuni IAL2383 is a good experimental model to analyze the interactions with cells

    Surface tension in the dilute Ising model. The Wulff construction

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    We study the surface tension and the phenomenon of phase coexistence for the Ising model on \mathbbm{Z}^d (d2d \geqslant 2) with ferromagnetic but random couplings. We prove the convergence in probability (with respect to random couplings) of surface tension and analyze its large deviations : upper deviations occur at volume order while lower deviations occur at surface order. We study the asymptotics of surface tension at low temperatures and relate the quenched value τq\tau^q of surface tension to maximal flows (first passage times if d=2d = 2). For a broad class of distributions of the couplings we show that the inequality τaτq\tau^a \leqslant \tau^q -- where τa\tau^a is the surface tension under the averaged Gibbs measure -- is strict at low temperatures. We also describe the phenomenon of phase coexistence in the dilute Ising model and discuss some of the consequences of the media randomness. All of our results hold as well for the dilute Potts and random cluster models

    Applying spatial reasoning to topographical data with a grounded geographical ontology

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    Grounding an ontology upon geographical data has been pro- posed as a method of handling the vagueness in the domain more effectively. In order to do this, we require methods of reasoning about the spatial relations between the regions within the data. This stage can be computationally expensive, as we require information on the location of points in relation to each other. This paper illustrates how using knowledge about regions allows us to reduce the computation required in an efficient and easy to understand manner. Further, we show how this system can be implemented in co-ordination with segmented data to reason abou

    Control of bovine brucellosis from persistently infected holdings using RB51 vaccination with test-and-slaughter : a comparative case report from a high incidence area in Portugal

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    Bovine brucellosis due to Brucella abortus infection causes significant reproduc-tive and production losses in cattle and is a major zoonosis. Eradication of this disease has proved difficult to achieve in Portugal where it still occurs in some regions despite an ongoing national eradication programme. In 2004, the Alent-ejo region, a major cattle producing area, reported one of the highest levels of bovine brucellosis in the country, especially in one divisional area. In that area, bovine brucellosis was particularly problematic in a holding of ten herds, the largest extensive cattle unit in the country, which remained infected despite an extensive test-and-slaughter programme and depopulation of five herds. A 5-year programme of RB51 vaccination with biannual test-and-slaughter was thus implemented in 2004. The apparent animal seroprevalence decreased from 19% (646/3,400) to 3% (88/2930) on the third herd-level test and remained below 0.8% (27/3324) after the fourth test. After the tenth test, the holding had a prevalence of 0.1% (2/2332) and only one herd remained positive with a within-herd prevalence of 1.1% (2/177). The results were compared to all other herds (n = 10) in the divisional area that were also persistently infected but were subject only to test-and-slaughter before being depopulated. In these herds, the strategy of test-andslaughter did not reduce the prevalence, which remained significantly higher than the vaccinated group (median = 0.48% and 8.5% in vaccinated versus non-vaccinated herds; Wilcoxon rank sum test; P < 0.01). The success of this pilot programme in continental Portugal pro-vided a valuable case study to the official veterinary services by illustrating the value of RB51 vaccination with parallel testing and improved biosecurity as a comprehensive and sustainable strategy for bovine brucellosis control in persis-tently infected herds.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1865-16822015-04-30hb201

    Quantitative Treatment of Decoherence

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    We outline different approaches to define and quantify decoherence. We argue that a measure based on a properly defined norm of deviation of the density matrix is appropriate for quantifying decoherence in quantum registers. For a semiconductor double quantum dot qubit, evaluation of this measure is reviewed. For a general class of decoherence processes, including those occurring in semiconductor qubits, we argue that this measure is additive: It scales linearly with the number of qubits.Comment: Revised version, 26 pages, in LaTeX, 3 EPS figure
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