707 research outputs found

    Transmission and quantification of verocytotoxin-producing Escherichia coli O157 in dairy cattle and calves

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    Data from a field study of 14 months duration in a naturally colonized dairy herd and data from an experiment with calves were used to quantify transmission of verocytotoxin-producing Escherichia coli (VTEC O157) in cattle. For the latter, two groups of 10 calves were randomly assigned and put out in one of two pastures. From each group, five animals were experimentally inoculated with 109 c.f.u. O157 VTEC and, considered infectious, put back in their group. Each of the susceptible contact calves became positive within 6 days of being reunited. The estimate of the basic reproduction ratio (R0) in the experiment was 7·3 (95% CI 3·92¿11·5), indicating that each infectious calf will infect seven other calves on average during an assumed infectious period of 28 days in a fully susceptible population. The R0 among dairy cows appeared to be about 10 times lower (0·70, 95% CI 0·48¿1·04). After the transmission experiment, six contact-infected animals that were shedding continuously during the experiment were housed in a tie stall during winter. After 40 days, all six tested negative for O157 VTEC. In June, after a period of 34 weeks in which the heifers remained negative, they were put out in a clean and isolated pasture to observe whether they started shedding again. On each pasture that was infected with O157 VTEC during the transmission experiment the previous summer, newly purchased susceptible calves were placed. None of the heifers or calves started shedding during 14 weeks, indicating that both the heifers and the previously contaminated pasture did not function as reservoir of O157 VTE

    Search for supersymmetry in multilepton events with the ATLAS detector

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    Роль международной мобильности ученых на разных этапах истории науки Украины

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    В статье освещается эволюция международного сотрудничества ученых Украины с зарубежными исследователями. Продемонстрировано огромное влияние стажировки отечественных ученых в крупнейших научных центрах мира, совместных исследований с зарубежными исследователями для становления науки в Украине, развития сети научных учреждений и высших учебных заведений. Охарактеризовано основные тенденции международного сотрудничества ученых Национальной академии наук и миграции научных работников в последние десятилетия.У статті висвітлюється еволюція міжнародного співробітництва вчених України з зарубіжними дослідниками. Продемонстровано величезний вплив стажування вітчизняних учених у найбільших наукових центрах світу, спільних досліджень із зарубіжними дослідниками для становлення науки в Україні, розвитку мережі наукових установ та вищих навчальних закладів. Охарактеризовано основні тенденції міжнародної співпраці вчених Національної академії наук України та міграції наукових працівників в останні десятиліття.Evolution of the international cooperation of Ukrainian scientists with foreign researchers is emphasized. The great impact from probation of national scientists at largest research centers across the globe, joint research with foreign partners on establishing the science system in Ukraine and building up the network of research institutions and higher education establishments is shown. Main tendencies in the international cooperation of scientists from the National Academy of Sciences of Ukraine and scientists’ migration in the latest decades

    Surveillance of zoonotic bacteria in finishing pigs in The Netherlands

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    In The Netherlands, from 1998 till 2002, a surveillance programme for zoonotic bacteria in finishing pigs was conducted at herd level. In 2000-2002, the prevalence of Salmonella spp. approximated 30%, while a significantly decreasing trend was observed when standardizing data for herdsize, age and quarter of sampling. Serotype discrimination showed the predominance of S. Typhimurium with an increasing role for phage type DT104. Prevalence estimates for Campylobacter spp. were 97% in 1998 (4th quarter only) and 45% in 1999. For STEC O157, prevalence estimates were 2% and 0% in 1998 and 1999, respectively. By using the samples from this study, a comparison study was conducted in which three different selective enrichment media, i.e. RV, MSRV and DIASALM, were compared for the isolation of Salmonella spp. from pig feces. Both MSRV and DIASALM scored significantly better compared to RV. By using logistic regression analysis of farm and herd specific data, potential risk factors for Salmonella spp. in finishing pig herds were identified and quantified

    Criminal procedures and cross-border cooperation in the EU area of criminal justice

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    This book examines to what extent differences between national and procedural criminal laws hinder the negotiations and the operation of cross-border cooperation instruments. It is based on a comparative analysis of a representative sample of Member States

    Transmission of MRSA ST398 between pigs during transport from farm to a slaughterhouse and during time spent in the holding area at the slaughterhouse

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    A distinct clone of MRSA, Multi Locus Sequence Type 398, was found in pigs and people in contact with pigs recently. In The Netherlands, a discrepancy is found between prevalences for MRSA ST398 in individual pigs on slaughterhouses and individual pigs on farms. Four batches of 30 slaughter pigs from 4 MRSA negative farms were selected and sampled before and after transport to the slaughterhouse and after resting time in the slaughterhouse to evaluate the possibility of pigs getting MRSA positive during this short-time period. Additional samples were taken from the environment, i.e. transport lorry and lairage. Pigs that stayed in a contaminated environment, either contaminated lorry or lairage or both, had a higher chance of becoming MRSA positive than pigs that stayed in areas that tested negative for MRSA. It was concluded that transmission of MRSA ST398 takes place in the short-time period of transport to the slaughterhouse and during time spent inlairages

    Longitudinal study on transmission of MRSA CC398 within pig herds

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    Background Since the detection of MRSA CC398 in pigs in 2004, it has emerged in livestock worldwide. MRSA CC398 has been found in people in contact with livestock and thus has become a public health issue. Data from a large-scale longitudinal study in two Danish and four Dutch pig herds were used to quantify MRSA CC398 transmission rates within pig herds and to identify factors affecting transmission between pigs. Results Sows and their offspring were sampled at varying intervals during a production cycle. Overall MRSA prevalence of sows increased from 33% before farrowing to 77% before weaning. Overall MRSA prevalence of piglets was > 60% during the entire study period. The recurrent finding of MRSA in the majority of individuals indicates true colonization or might be the result of contamination. Transmission rates were estimated using a Susceptible-Infectious-Susceptible (SIS-)model, which resulted in values of the reproduction ratio (R0) varying from 0.24 to 8.08. Transmission rates were higher in pigs treated with tetracyclins and ß-lactams compared to untreated pigs implying a selective advantage of MRSA CC398 when these antimicrobials are used. Furthermore, transmission rates were higher in pre-weaning pigs compared to post-weaning pigs which might be explained by an age-related susceptibility or the presence of the sow as a primary source of MRSA CC398. Finally, transmission rates increased with the relative increase of the infection pressure within the pen compared to the total infection pressure, implying that within-pen transmission is a more important route compared to between-pen transmission and transmission through environmental exposure. Conclusion Our results indicate that MRSA CC398 is able to spread and persist in pig herds, resulting in an endemic situation. Transmission rates are affected by the use of selective antimicrobials and by the age of pigs

    Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

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    A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

    Observation of associated near-side and away-side long-range correlations in √sNN=5.02  TeV proton-lead collisions with the ATLAS detector

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    Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02  TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1  μb-1 of data as a function of transverse momentum (pT) and the transverse energy (ΣETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∼0) correlation that grows rapidly with increasing ΣETPb. A long-range “away-side” (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos⁡2Δϕ modulation for all ΣETPb ranges and particle pT

    Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC

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    Measurements of inclusive jet suppression in heavy ion collisions at the LHC provide direct sensitivity to the physics of jet quenching. In a sample of lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the anti-kt algorithm with values for the distance parameter that determines the nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp. Jet production is found to be suppressed by approximately a factor of two in the 10% most central collisions relative to peripheral collisions. Rcp varies smoothly with centrality as characterized by the number of participating nucleons. The observed suppression is only weakly dependent on jet radius and transverse momentum. These results provide the first direct measurement of inclusive jet suppression in heavy ion collisions and complement previous measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables, submitted to Physics Letters B. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02
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