43 research outputs found

    The local power of the gradient test

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    The asymptotic expansion of the distribution of the gradient test statistic is derived for a composite hypothesis under a sequence of Pitman alternative hypotheses converging to the null hypothesis at rate n−1/2n^{-1/2}, nn being the sample size. Comparisons of the local powers of the gradient, likelihood ratio, Wald and score tests reveal no uniform superiority property. The power performance of all four criteria in one-parameter exponential family is examined.Comment: To appear in the Annals of the Institute of Statistical Mathematics, this http://www.ism.ac.jp/editsec/aism-e.htm

    Search for resonances in the mass distribution of jet pairs with one or two jets identified as b-jets in proton–proton collisions at √s=13TeV with the ATLAS detector

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    Searches for high-mass resonances in the dijet invariant mass spectrum with one or two jets identi-fied as b-jets are performed using an integrated luminosity of 3.2fb−1of proton–proton collisions with a centre-of-mass energy of √s=13TeVrecorded by the ATLAS detector at the Large Hadron Collider. Noevidence of anomalous phenomena is observed in the data, which are used to exclude, at 95%credibility level, excited b∗quarks with masses from 1.1TeVto 2.1TeVand leptophobic Z bosons with masses from 1.1TeVto 1.5TeV. Contributions of a Gaussian signal shape with effective cross sections ranging from approximately 0.4 to 0.001pb are also excluded in the mass range 1.5–5.0TeV

    Study of the rare B-s(0) and B-0 decays into the pi(+) pi(-) mu(+) mu(-) final state

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    A search for the rare decays Bs0→π+π−Ό+Ό−B_s^0 \to \pi^+\pi^-\mu^+\mu^- and B0→π+π−Ό+Ό−B^0 \to \pi^+\pi^-\mu^+\mu^- is performed in a data set corresponding to an integrated luminosity of 3.0 fb−1^{-1} collected by the LHCb detector in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV. Decay candidates with pion pairs that have invariant mass in the range 0.5-1.3 GeV/c2c^2 and with muon pairs that do not originate from a resonance are considered. The first observation of the decay Bs0→π+π−Ό+Ό−B_s^0 \to \pi^+\pi^-\mu^+\mu^- and the first evidence of the decay B0→π+π−Ό+Ό−B^0 \to \pi^+\pi^-\mu^+\mu^- are obtained and the branching fractions, restricted to the dipion-mass range considered, are measured to be B(Bs0→π+π−Ό+Ό−)=(8.6±1.5 (stat)±0.7 (syst)±0.7 (norm))×10−8\mathcal{B}(B_s^0 \to \pi^+\pi^-\mu^+\mu^-)=(8.6\pm 1.5\,({\rm stat}) \pm 0.7\,({\rm syst})\pm 0.7\,({\rm norm}))\times 10^{-8} and B(B0→π+π−Ό+Ό−)=(2.11±0.51 (stat)±0.15 (syst)±0.16 (norm))×10−8\mathcal{B}(B^0 \to \pi^+\pi^-\mu^+\mu^-)=(2.11\pm 0.51\,({\rm stat}) \pm 0.15\,({\rm syst})\pm 0.16\,({\rm norm}) )\times 10^{-8}, where the third uncertainty is due to the branching fraction of the decay B0→J/ψ(→Ό+Ό−)K∗(890)0(→K+π−)B^0\to J/\psi(\to \mu^+\mu^-)K^*(890)^0(\to K^+\pi^-), used as a normalisation.Comment: 21 pages, 3 figures, 2 Table

    Observation of ηc(2S)→ppˉ\eta_{c}(2S) \to p \bar p and search for X(3872)→ppˉX(3872) \to p \bar p decays

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    The first observation of the decay ηc(2S)→ppˉ\eta_{c}(2S) \to p \bar p is reported using proton-proton collision data corresponding to an integrated luminosity of 3.0 fb−13.0\rm \, fb^{-1} recorded by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. The ηc(2S)\eta_{c}(2S) resonance is produced in the decay B+→[ccˉ]K+B^{+} \to [c\bar c] K^{+}. The product of branching fractions normalised to that for the J/ψJ/\psi intermediate state, Rηc(2S){\cal R}_{\eta_{c}(2S)}, is measured to be \begin{align*} {\cal R}_{\eta_{c}(2S)}\equiv\frac{{\mathcal B}(B^{+} \to \eta_{c}(2S) K^{+}) \times {\mathcal B}(\eta_{c}(2S) \to p \bar p)}{{\mathcal B}(B^{+} \to J/\psi K^{+}) \times {\mathcal B}(J/\psi\to p \bar p)} =~& (1.58 \pm 0.33 \pm 0.09)\times 10^{-2}, \end{align*} where the first uncertainty is statistical and the second systematic. No signals for the decays B+→X(3872)(→ppˉ)K+B^{+} \to X(3872) (\to p \bar p) K^{+} and B+→ψ(3770)(→ppˉ)K+B^{+} \to \psi(3770) (\to p \bar p) K^{+} are seen, and the 95\% confidence level upper limits on their relative branching ratios are % found to be RX(3872)<0.25×10−2{\cal R}_{X(3872)}<0.25\times10^{-2} and Rψ(3770))<0.10{\cal R}_{\psi(3770))}<0.10. In addition, the mass differences between the ηc(1S)\eta_{c}(1S) and the J/ψJ/\psi states, between the ηc(2S)\eta_{c}(2S) and the ψ(2S)\psi(2S) states, and the natural width of the ηc(1S)\eta_{c}(1S) are measured as \begin{align*} M_{J/\psi} - M_{\eta_{c}(1S)} =~& 110.2 \pm 0.5 \pm 0.9 \rm \, MeV, M_{\psi(2S)} -M_{\eta_{c}(2S)} =~ & 52.5 \pm 1.7 \pm 0.6 \rm \, MeV, \Gamma_{\eta_{c}(1S)} =~& 34.0 \pm 1.9 \pm 1.3 \rm \, MeV. \end{align*}Comment: 16 pages, 2 figures All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2016-016.htm

    First observation of forward Z→bbˉZ \rightarrow b \bar{b} production in pppp collisions at s=8\sqrt{s}=8 TeV

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    The decay Z→bb¯ is reconstructed in pp collision data, corresponding to 2 fb −1 of integrated luminosity, collected by the LHCb experiment at a centre-of-mass energy of s=8 TeV. The product of the Z production cross-section and the Z→bb¯ branching fraction is measured for candidates in the fiducial region defined by two particle-level b -quark jets with pseudorapidities in the range 2.220 GeV and dijet invariant mass in the range 4520GeVanddijetinvariantmassintherange GeV and dijet invariant mass in the range 45 < m_{jj} < 165GeV.Fromasignalyieldof GeV. From a signal yield of 5462 \pm 763 Z \rightarrow b \bar{b}events,wheretheuncertaintyisstatistical,aproductioncross−sectiontimesbranchingfractionof events, where the uncertainty is statistical, a production cross-section times branching fraction of 332 \pm 46 \pm 59pbisobtained,wherethefirstuncertaintyisstatisticalandthesecondsystematic.Themeasuredsignificanceofthesignalyieldis6.0standarddeviations.Thismeasurementrepresentsthefirstobservationofthe pb is obtained, where the first uncertainty is statistical and the second systematic. The measured significance of the signal yield is 6.0 standard deviations. This measurement represents the first observation of the Z \rightarrow b \bar{b}productionintheforwardregionof production in the forward region of pp$ collisions

    Essential veterinary education in the virology of domestic animals, wild animals and birds: diagnosis and pathogenesis of viral infections

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    An education in veterinary virology should establish a basis for life-long learning and enable veterinary graduates to address professionally the control and eradication of viral diseases, both locally and globally. It is therefore more important that the curriculum focuses on a sound understanding of the nature and behaviour of viruses and their interactions with animal hosts, rather than imparting detailed information on an ever-increasing number of individual viral diseases in a widening range of animal species. Graduate veterinarians should be prepared with a comprehensive knowledge of the nature of viruses and their close dependence on the hosts that they infect, as well as a good understanding of pathogenesis, immunology, epidemiology, diagnostic approaches and control options. All these are necessary if the profession is successfully to meet familiar and new challenges in viral diseases in a wide range of host species, under different management conditions, in various geographic areas of the world

    Integrating the issues of global and veterinary public health into the veterinary education curriculum: an Australian perspective

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    This article discusses the integration of global and veterinary public health issues into the Australian veterinary curriculum. Formal veterinary education in Australia has a history of over 100 years and veterinarians have played a major role in the control of zoonotic and transboundary diseases for an even longer period. Australia is the largest exporter of red meat and live animals in the world. Therefore, educating veterinarians to promote and ensure food safety and animal welfare is prominent in Australian veterinary curricula. Veterinary degrees are accredited to allow Australian graduates to work professionally overseas, including in the United Kingdom and United States of America, and, in recent years, globalisation of the student body at Australian veterinary schools has occurred. For this reason, an appropriately broad curriculum is required to produce graduates who are able to address challenges in veterinary public health throughout the world. A Public Health University Network has been established to harmonise the veterinary public health curricula at the various veterinary schools and to develop the 'Australian veterinary public health philosophy', with its links to global issues and the 'One World, One Health' concept. Finally, conclusions are drawn on the implications of veterinary public health teaching in Australia and the preparation of Australian graduates for the global profession

    Transfer of maternal antibody against group A rotavirus from sows to piglets and serological responses following natural infection

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    An enzyme-linked immunosorbent assay (ELISA) was developed for the measurement of antirotaviral antibody in sera and faeces from pigs and used to study the dynamics of antirotaviral antibody responses in three cohorts of pigs. Piglets acquired antirotaviral antibody by sucking their dams soon after birth. Antirotaviral antibodies of IgA and IgG classes were detected in both colostrum and milk of all sows tested but IgM class antibodies were not. The antibody levels in colostrum were eight to 32 times higher than those in milk which was collected 18 days post partum. The levels of antibody in piglets' sera were comparable to those in colostrum but declined quickly to low levels by one month old. Maternal antibody was also detected in the faeces of piglets up to 18 days old. Natural rotavirus infection occurred in each of these cohorts when the geometric mean ELISA titres of maternal antibody in their sera declined to 1/1600 (by days 21, 25 and 30 for cohorts 1, 2 and 3, respectively). However, a positive correlation was not obtained between the levels of antirotaviral antibody and protection in individual litters within each of the cohort groups. In each of the cohorts, rotavirus infection usually occurred in one or two piglets first and then spread to other piglets in the same cohort. It is therefore suggested that maternally derived antibody is protective against rotavirus infection in piglets only for the first one or two weeks. Following natural infection with rotavirus, increases in serum antibodies were detected in two of the three cohorts by 20 to 30 days after the average time of onset of faecal shedding of virus

    Development and evaluation of a rapid immunomagnetic bead assay for the detection of classical swine fever virus antigen

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    Classical swine fever (CSF) is a highly contagious and severe viral disease of swine resulting in substantial production losses in different farming systems in many regions of the world. The accurate and rapid detection of CSF outbreaks is reliant on sensitive and specific laboratory testing and is a key component of disease control. Specific detection of CSF virus can be achieved by virus isolation in tissue culture, antigen capture or the detection of viral RNA using molecular techniques. In order to reduce the time taken to achieve a diagnostic result and simplify testing methods, an antigen capture ELISA using immunomagnetic beads (IMB) as the solid phase was developed and compared to a microplate-based antigen capture (AC)-ELISA. The IMB-ELISA has up to 64-fold greater analytical sensitivity than the AC-ELISA and initial estimates of diagnostic sensitivity and specificity are 100%. The IMB-ELISA has a highly robust, rapid and stable test format and is simpler to perform than the AC-ELISA. The IMB-ELISA has the added advantage that a result can be sensitively and specifically determined by eye, lending it to the possibility of adaptation to a near-to-field test with minimal equipment or expertise needed
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