82 research outputs found

    Does limited virucidal activity of biocides include duck hepatitis B virucidal action?

    Get PDF
    BACKGROUND: There is agreement that the infectivity assay with the duck hepatitis B virus (DHBV) is a suitable surrogate test to validate disinfectants for hepatitis B virucidal activity. However, since this test is not widely used, information is necessary whether disinfectants with limited virucidal activity also inactivate DHBV. In general, disinfectants with limited virucidal activity are used for skin and sensitive surfaces while agents with full activity are more aggressive. The present study compares the activity of five different biocides against DHBV and the classical test virus for limited virucidal activity, the vaccinia virus strain Lister Elstree (VACV) or the modified vaccinia Ankara strain (MVA). METHODS: Virucidal assay was performed as suspension test according to the German DVV/RKI guideline. Duck hepatitis B virus obtained from congenitally infected Peking ducks was propagated in primary duck embryonic hepatocytes and was detected by indirect immunofluorescent antigen staining. RESULTS: The DHBV was inactivated by the use of 40% ethanol within 1-min and 30% isopropanol within 2-min exposure. In comparison, 40% ethanol within 2-min and 40% isopropanol within 1-min exposure were effective against VACV/MVA. These alcohols only have limited virucidal activity, while the following agents have full activity. 0.01% peracetic acid inactivated DHBV within 2 min and a concentration of 0.005% had virucidal efficacy against VACV/MVA within 1 min. After 2-min exposure, 0.05% glutardialdehyde showed a comparable activity against DHBV and VACV/MVA. This is also the case for 0.7% formaldehyde after a contact time of 30 min. CONCLUSIONS: Duck hepatitis B virus is at least as sensitive to limited virucidal activity as VACV/MVA. Peracetic acid is less effective against DHBV, while the alcohols are less effective against VACV/MVA. It can be expected that in absence of more direct tests the results may be extrapolated to HBV

    Recordings in an integrating central neuron provide a quick way for identifying appropriate anaesthetic use in fish

    Get PDF
    Abstract In animal husbandry, livestock industry and research facilities, anaesthetic agents are frequently used to moderate stressful intervention. For mammals and birds, procedures have been established to fine-tune anaesthesia according to the intervention. In ectothermic vertebrates, however, and despite changes in legislation and growing evidence on their cognitive abilities, the presently available information is insufficient to make similarly informed decisions. Here we suggest a straightforward way for rapidly filling this gap. By recording from a command neuron in the brain of fish whose crucial role requires it to integrate and process information from all sensory systems and to relay it to motor output pathways, the specific effects of candidate anaesthesia on central processing of sensory information can directly and efficiently be probed. Our approach allows a rapid and reliable way of deciding if and at which concentration a given anaesthetic affects the central nervous system and sensory processing. We employ our method to four anaesthetics commonly used in fish and demonstrate that our method quickly and with small numbers of animals provides the critical data for informed decisions on anaesthetic use

    Transverse Polarization of Top Quark Pairs at the Tevatron and the Large Hadron Collider

    Full text link
    We investigate the prospects to observe effects of transverse polarization of top quarks in pp,ppˉttˉXpp,p\bar{p}\to t\bar{t}X. QCD absorptive parts generate a polarization of top quarks and antiquarks transverse to the production plane in the partonic processes qqˉttˉq\bar{q}\to t\bar{t} and ggttˉgg\to t\bar{t}, which reaches values of a few percent. These perturbative QCD effects are decreased at the hadronic level. A measurement through momentum correlations among the tt and tˉ\bar{t} decay products will be difficult both at an upgraded Tevatron and at the LHC.Comment: 14 pages, LaTeX; 8 uuencoded, tar-compressed figures added separatel

    Epidemiology and immunogenetic background of islet cell antibody - positive nondiabetic schoolchildren : Ulm-Frankfurt population study

    Get PDF
    Islet cell antibodies (ICAs) were determined in a large cohort of white nondiabetic schoolchildren (n = 4287) from a homogenous population in southern Germany. The prevalence of ICA levels greater than or equal to 5 Juvenile Diabetes Foundation (JDF) U was 1.05% (95% confidence interval 0.8-1.4%). Analysis of HLA-DR beta and -DQ beta alleles revealed that the specificities found to be increased in insulin-dependent (type I) diabetic subjects with the same ethnic background were also associated with ICA positivity in the nondiabetic schoolchildren. HLA-DR3 (P less than 0.01) and -DR4 (P less than 0.01) phenotypes and absence of Asp residue (P less than 0.01) at codon 57 of the HLA-DQ beta-chain were significantly increased in ICA+ compared with control subjects. High levels of ICAs, which were categorized as either greater than or equal to 17 or greater than or equal to 30 JDF U, were found to be associated with amino acids other than Asp at position 57 of the HLA-DQ beta-chain. No association of ICA level was found for HLA-DR phenotypes

    A Poincare-Covariant Parton Cascade Model for Ultrarelativistic Heavy-Ion Reactions

    Get PDF
    We present a new cascade-type microscopic simulation of nucleus-nucleus collisions at RHIC energies. The basic elements are partons (quarks and gluons) moving in 8N-dimensional phase space according to Poincare-covariant dynamics. The parton-parton scattering cross sections used in the model are computed within perturbative QCD in the tree-level approximation. The Q^2 dependence of the structure functions is included by an implementation of the DGLAP mechanism suitable for a cascade, so that the number of partons is not static, but varies in space and time as the collision of two nuclei evolves. The resulting parton distributions are presented, and meaningful comparisons with experimental data are discussed.Comment: 30 pages. 11 figures. Submitted to Phys.Rev.

    J/ψ+c+cˉJ/\psi + c + \bar{c} Photoproduction in e+ee^+ e^- Scattering

    Full text link
    We investigate the J/ψJ/\psi + c + cˉ\bar{c} photoproduction in e+ee^+ e^- collision at the LEP II energy. The physical motivations for this study are: 1) such next-to-leading order(NLO) process was not considered in previous investigations of J/ψJ/\psi photoproduction in e+ee^+ e^- interaction, and it is worthwhile to do so in order to make sound predictions for experimental comparison; 2) from recent Belle experiment results, the process with same final states at the BB factory has a theoretically yet unexplainable large fraction; hence it is interesting to see what may happen at other colliders; 3) the existing LEP data are marginal in observing such process, and at the planed Linear Colliders(LCs) this process can be measured with high accuracy; 4) it is necessary to take this process into consideration in the aim of elucidating the quarkonium production mechanism, especially in testing the universality of NRQCD nonperturbative matrix elements via J/ψJ/\psi photoproduction in electron-position collisions.Comment: 15 pages, 3 figure

    Networks of Depression and Anxiety Symptoms Across Development.

    Get PDF
    OBJECTIVE: Frequent co-occurrence and bidirectional longitudinal associations have led some researchers to question the boundaries between depression and anxiety. A longitudinal investigation of the interconnected symptom structure of these constructs may help determine the extent to which they are distinct, and whether this changes over development. Therefore, the present study used network analysis to examine these symptom−symptom associations developmentally from early childhood to mid-adolescence. METHOD: We analyzed data from the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development (N = 1,147). Depression and anxiety symptoms were assessed on 7 occasions between ages 5 and 14 years using maternal reports. Regularized partial correlation networks were constructed at each time point, and diagnostic boundaries were explored using empirical tests of network modularity (ie, clustering of symptom nodes). Nonparametric permutation tests were used to determine whether symptoms became more associated over development, and network centrality was examined to identify developmental changes in the overall importance of specific symptoms. RESULTS: Symptoms formed highly interconnected networks, as evidenced by strong associations between depression and anxiety symptoms and a lack of distinct clustering. There was some evidence of an increase in overall connectivity as children aged. Feeling “anxious/fearful” and “unhappy/sad” were consistently the most central symptoms over development. CONCLUSION: Minimal clustering of nodes indicated no separation of depression and anxiety symptoms from early childhood through mid-adolescence. An increase in connectivity over development suggests that symptoms may reinforce each other, potentially contributing to the high levels of lifetime continuity of these disorders

    Introduction: building the history of language learning and teaching (HoLLT)

    Get PDF
    The papers presented in this issue are the result of a workshop held at the University of Nottingham in December 2012 as part of an Arts and Humanities Research Council research network Towards a History of Modern Foreign Language Teaching and Learning (2012–14) intended to stimulate historical research into language teaching and learning. This, the first workshop in the programme, focused on exchanging information on the history of language learning and teaching (HoLLT) across the different language traditions, for it had become clear to us that scholars working within their own language disciplines were often relatively unaware of work outside these. We hope that this special issue — with overview articles on the history of English, French, German, and Spanish as second/foreign languages — will help overcome that lack of awareness and facilitate further research collaboration. Charting the history of language teaching and learning will, in turn, make us all better informed in facing challenges and changes to policy and practice now and in the future. It is instructive in the current climate, for example, to realize that grave doubts were held about whether second foreign languages could survive alongside French in British schools in the early twentieth century (McLelland, forthcoming), or to look back at earlier attempts to establish foreign languages in primary schools (Bayley, 1989; Burstall et al., 1974; Hoy, 1977). As we write, language learning in England is undergoing yet more radical change. Language teaching for all children from the age of seven is being made compulsory in primary schools from 2014, while at Key Stage 3 (up to age 16), where a foreign language has not been compulsory since 2002, the most recent programme of study for England has virtually abandoned the recent focus on intercultural competence and now requires learners to ‘read great literature in the original language’,1 a radical change in emphasis compared to the previous half-century, which seems to reflect a very different view of what language learning is for. We seem to be little closer in 2014 than we were at the dawn of the twentieth century to answering with any certainty the questions that lie at the very foundations of language teaching: who should learn a foreign language, why learners learn, what they need to learn, and what we want to teach them — answers that we need before we can consider how we want to teach. The research programme begun under our research network is intended to help us to take ‘the long view’ on such questions
    corecore