1,295 research outputs found

    Quantum Correlations from the Conditional Statistics of Incomplete Data

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    We study, in theory and experiment, the quantum properties of correlated light fields measured with click-counting detectors providing incomplete information on the photon statistics. We establish a correlation parameter for the conditional statistics, and we derive the corresponding nonclassicality criteria for detecting conditional quantum correlations. Classical bounds for Pearson's correlation parameter are formulated that allow us, once they are violated, to determine nonclassical correlations via the joint statistics. On the one hand, we demonstrate nonclassical correlations in terms of the joint click statistics of light produced by a parametric down conversion source. On the other hand, we verify quantum correlations of a heralded, split single-photon state via the conditional click statistics together with a generalization to higher-order moments. We discuss the performance of the presented nonclassicality criteria to successfully discern joint and conditional quantum correlations. Remarkably, our results are obtained without making any assumptions on the response function, quantum efficiency, and dark-count rate of the photodetectors

    Fit for work? Health, employability and challenges for the UK welfare reform agenda

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    This article introduces a special issue of Policy Studies entitled “Fit for work? Health, employability and challenges for the UK welfare reform agenda”. Growing from a shared concern over the need to expand the evidence base around the processes that led to large numbers of people claiming disability benefits in the UK, it brings together contributions from leading labour market and social policy researchers providing evidence and commentary on major reforms to Incapacity Benefit (IB) in the UK. This special issue address three key questions: what are the main causes of the long-term rise in the number of people claiming IBs; what will reduce the number of claimants; and what is likely to deliver policy effectively and efficiently? This introduction first explains and examines the challenges to reforms to IB in the UK, and then, in conclusion, highlights the answers to the previous three questions – first, labour market restructuring and marginalisation have driven the rise in numbers claiming IBs. Second, economic regeneration in the Britain’s less prosperous areas coupled with intensive and sustained supply-side support measures will bring numbers down. Third, delivery need to be flexible and tailored to individual needs and needs to be able to access local and expert knowledge in a range of organisations, including Job Centre Plus, the NHS as well as the private and voluntary sectors

    The effect of storage on enzyme activities in tissues

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    A comparative study of the effects of four treatment regimes on ivermectin efficacy, body weight and pasture contamination in lambs naturally infected with gastrointestinal nematodes in Scotland

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    AbstractRefugia-based drenching regimes have been widely recommended to slow development of anthelmintic resistance but there are few comparisons between different treatment approaches in the UK. The impact of four ivermectin treatment regimes on drug efficacy, lamb body weight and nematode contamination during a 154 day grazing season were evaluated in a consecutive five year field study. Regimes were whole-flock treatment every 4weeks (NST), targeted selective treatment (TST) based on individual performance, strategic whole-flock treatments at pre-determined times (SPT) or whole-flock treatment when clinical signs were apparent (MT). Mean numbers of ivermectin drenches administered per season were 4.0, 1.8, 2.0 and 1.4 for NST, TST, SPT and MT groups, respectively. The mean anthelmintic efficacy (AE) for each treatment group was based on faecal egg count reduction post-treatment employing a bootstrap sampling based algorithm. Mean AE was 95–98% for all groups in 2006 and mean AE (95% confidence limits) for NST declined to 62% (55%, 68%) in 2010. In comparison, AE for TST, SPT and MT in 2010 were 86% (81%, 92%), 86% (83%, 90%) and 83% (78%, 88%), respectively. Body weight in TST and SPT was similar to NST in all years (p>0.05), however MT lambs were lighter than NST in 2006–2008 (p⩽0.04). Tracer lamb worm burdens was lowest in NST but was not significantly different between other groups. Overall, both the TST and SPT regimes appeared to maintain animal performance and conserve anthelmintic efficacy compared with a neo-suppressive anthelmintic treatment regime

    Modification of plant cell walls with hydroxycinnamic acids by BAHD acyltransferases

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    In the last decade it has become clear that enzymes in the "BAHD" family of acyl-CoA transferases play important roles in the addition of phenolic acids to form ester-linked moieties on cell wall polymers. We focus here on the addition of two such phenolics-the hydroxycinnamates, ferulate and p-coumarate-to two cell wall polymers, glucuronoarabinoxylan and to lignin. The resulting ester-linked feruloyl and p-coumaroyl moities are key features of the cell walls of grasses and other commelinid monocots. The capacity of ferulate to participate in radical oxidative coupling means that its addition to glucuronoarabinoxylan or to lignin has profound implications for the properties of the cell wall - allowing respectively oxidative crosslinking to glucuronoarabinoxylan chains or introducing ester bonds into lignin polymers. A subclade of similar to 10 BAHD genes in grasses is now known to (1) contain genes strongly implicated in addition of p-coumarate or ferulate to glucuronoarabinoxylan (2) encode enzymes that add p-coumarate or ferulate to lignin precursors. Here, we review the evidence for functions of these genes and the biotechnological applications of manipulating them, discuss our understanding of mechanisms involved, and highlight outstanding questions for future research

    Increased Toxoplasma gondii positivity relative to age in 125 Scottish sheep flocks; evidence of frequent acquired infection

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    Toxoplasma gondii seroprevalence was determined in 3333 sheep sera from 125 distinct sheep flocks in Scotland, with the majority of flocks being represented by 27 samples, which were collected between July 2006 and August 2008. The selected farms give a representative sample of 14 400 sheep holdings identified in the Scottish Government census data from 2004. Overall T. gondii seroprevalence, at individual sheep level, was determined to be 56.6%; each flock tested, had at least a single positive animal and in four flocks all ewes tested positive. The seroprevalence of sheep increased from 37.7% in one year old stock to 73.8% in ewes that were older than six years, showing that acquired infections during the life of the animals is frequent and that environmental contamination by T. gondii oocysts must be significant. The median within-flock seroprevalence varied significantly across Scotland, with the lowest seroprevalence of 42.3% in the South and the highest seroprevalence of 69.2% in the far North of Scotland and the Scottish Islands, while the central part of Scotland had a seroprevalence of 57.7%. This distribution disequilibrium may be due to the spread and survival of oocysts on pasture and lambing areas. A questionnaire accompanying sampling of flocks identified farms that used Toxovax®, a commercial vaccine that protects sheep from abortion due to T. gondii infection. Only 24.7% of farmers used the vaccine and the vaccine did not significantly affect the within flock seroprevalence for T. gondii. The implications for food safety and human infection are discussed

    Phenotypic characterisation of the cellular immune infiltrate in placentas of cattle following experimental inoculation with Neospora caninum in late gestation

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    Abstract Despite Neospora caninum being a major cause of bovine abortion worldwide, its pathogenesis is not completely understood. Neospora infection stimulates host cell-mediated immune responses, which may be responsible for the placental damage leading to abortion. The aim of the current study was to characterize the placental immune response following an experimental inoculation of pregnant cattle with N. caninum tachyzoites at day 210 of gestation. Cows were culled at 14, 28, 42 and 56 days post inoculation (dpi). Placentomes were examined by immunohistochemistry using antibodies against macrophages, T-cell subsets (CD4, CD8 and γδ), NK cells and B cells. Macrophages were detected mainly at 14 days post inoculation. Inflammation was generally mild and mainly characterized by CD3+, CD4+ and γδ T-cells; whereas CD8+ and NK cells were less numerous. The immune cell repertoire observed in this study was similar to those seen in pregnant cattle challenged with N. caninum at early gestation. However, cellular infiltrates were less severe than those seen during first trimester Neospora infections. This may explain the milder clinical outcome observed when animals are infected late in gestation.The authors acknowledge the Scottish Government’s Rural and Environment Science and Analytical Services Division (RESAS), UK, and Instituto Nacional de Tecnología Agropecuaria (INTA), Argentina, for funding this study and Dr Alex Schock from Animal Health and Veterinary Laboratories Agency and Prof. Gary Entrican from Moredun Research Institute for useful and constructive discussion.Peer Reviewe

    Characterization of the immune cell response in the placentas from cattle following experimental inoculation with Neospora caninum throughout pregnancy

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    Trabajo presentado al 2nd International Meeting on Apicomplexan Parasites in Farm Animals (Kusadasi, Turquía, 31 octubre al 2 noviembre, 2013).Despite Neospora caninum (NC) being a major cause of bovine abortion worldwide, its pathogenesis is not completely understood. Evidence of immune mediated placental pathology has been reported as being responsible for compromising pregnancy probably due to the adverse effect of an exacerbated Th1 response at the maternal-foetal interface. Different clinical outcomes are known to follow experimental infections at different stages of gestation, with foetal death being the most common finding during early gestation infections, and the birth of live congenitally infected calves upon infection at mid or late gestation. The aim of our studies was to characterise placental immune responses following experimental infection during pregnancy. Cows were infected with NC tachyzoites at day 70, 140 and 210 of pregnancy and culled at 14, 28, 42 and 56 days post inoculation. Placentomes were examined by immunohistochemistry using antibodies against macrophages, T-cells (CD3, CD4, CD8, ¿¿TCR), NK and B cells and by in situ hybridization to characterize cytokine expression (IL-12, IFN-¿, TNF-¿ and IL-4). Inflammation was mainly characterised by the presence of CD3+, CD4+ and ¿¿ T-cells during the three time points. In early gestation inflammation was generally moderate to severe and mainly characterized by infiltration of IL-12, IFN-¿ and TNF-¿ expressing cells. This infiltration was more pronounced in the samples of placentome collected from dams carrying a dead foetus or one that had aborted, compared with the mothers carrying live foetuses at the time of sampling. In contrast, the infiltration of CD3+, CD4+, CD8+ and ¿¿ T-cells and Th1 cytokine expressing-cells was less evident following NC infection at mid gestation and scarce during infection at late gestation. These findings may partially explain the milder clinical outcome observed when animals are infected with NC at mid or late gestation.Peer Reviewe
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