1,081 research outputs found

    The history of John Bowes & Partners up to 1914

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    CD4+ T cell hyporesponsiveness after repeated exposure to Schistosoma mansoni larvae is dependent upon interleukin-10

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    The effect that multiple percutaneous exposures to Schistosoma larvae has on the development of early CD4+ lymphocyte reactivity is unclear, yet it is important in the context of humans living in areas where schistosomiasis is endemic. In a murine model of multiple infections, we show that exposure of mice to repeated doses (4×) of Schistosoma mansoni cercariae, compared to a single dose (1×), results in CD4+ T cell hyporesponsiveness within the skin-draining lymph nodes (sdLN), manifested as reduced CD4+ cell proliferation and cytokine production. FoxP3+ CD4+ regulatory T cells were present in similar numbers in the sdLN of 4× and 1× mice and thus are unlikely to have a role in effecting hyporesponsiveness. Moreover, anergy of the CD4+ cell population from 4× mice was slight, as proliferation was only partly circumvented through the in vitro addition of exogenous interleukin-2 (IL-2), and the in vivo blockade of the regulatory molecule PD1 had a minimal effect on restoring responsiveness. In contrast, IL-10 was observed to be critical in mediating hyporesponsiveness, as CD4+ cells from the sdLN of 4× mice deficient for IL-10 were readily able to proliferate, unlike those from 4× wild-type cohorts. CD4+ cells from the sdLN of 4× mice exhibited higher levels of apoptosis and cell death, but in the absence of IL-10, there was significantly less cell death. Combined, our data show that IL-10 is a key factor in the development of CD4+ T cell hyporesponsiveness after repeated parasite exposure involving CD4+ cell apoptosis

    Supercriticality conditions for asymmetric zero-range process with sitewise disorder

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    We discuss necessary and sufficient conditions for the convergence of disordered asymmetric zero-range process to the critical invariant measures.Comment: 28 pages. arXiv admin note: text overlap with arXiv:1411.430

    Mapping topography and broad vegetation type to characterise the Boxford meadows SSSI (Unit 2)

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    Understanding the dynamic relationship between hydrology and ecology in a complex wetland setting should be considered integral to the sustainable management and conservation of wetland habitats and future water resource planning. Wetland hydrology can exhibit considerable spatial complexity as a result of sub surface and surface heterogeneity. The latter of which may be determined by the relationship between spatial topography variation and broad vegetation distribution. Any study to investigate such a relationship must be at a spatial resolution sufficient to identify patterns in surface topography and vegetation type. In this study state of the art survey technology was used to collect and record for subsequent mapping the topographic and vegetation characteristics of the Boxford lowland chalk groundwater dependent terrestrial ecosystem (GDTE). The resultant survey dataset successfully unveiled distinct patterns in topography and vegetation type. The analysis of the data in a Geographical Information System (GIS) desk confirmed for the first time the presence of paleo-channels and a braided fluvial system within the meadows. In addition the combined survey method gives some indication that the type of vegetation present appears to coincide with some of the more distinctive topographical features. The results demonstrate that combining the field survey campaign alongside desk based GIS analysis is an extremely useful and versatile tool and can provide valuable information to support the decision making process for both further scientific investigation and sustainable habitat management

    Intercomparison of carbonate chemistry measurements on a cruise in northwestern European shelf seas

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    Four carbonate system variables were measured in surface waters during a cruise aimed at investigating ocean acidification impacts traversing northwestern European shelf seas in the summer of 2011. High-resolution surface water data were collected for partial pressure of carbon dioxide (pCO2; using two independent instruments) and pH using the total pH scale (pHT), in addition to discrete measurements of total alkalinity and dissolved inorganic carbon. We thus overdetermined the carbonate system (four measured variables, two degrees of freedom), which allowed us to evaluate the level of agreement between the variables on a cruise whose main aim was not intercomparison, and thus where conditions were more representative of normal working conditions. Calculations of carbonate system variables from other measurements generally compared well with direct observations of the same variables (Pearson’s correlation coefficient always greater than or equal to 0.94; mean residuals were similar to the respective accuracies of the measurements). We therefore conclude that four of the independent data sets of carbonate chemistry variables were of high quality. A diurnal cycle with a maximum amplitude of 41 μatm was observed in the difference between the pCO2 values obtained by the two independent analytical pCO2 systems, and this was partly attributed to irregular seawater flows to the equilibrator and partly to biological activity inside the seawater supply and one of the equilibrators. We discuss how these issues can be addressed to improve carbonate chemistry data quality on future research cruises

    High-resolution proton nuclear magnetic resonance: application to the study of leukaemic lymphocytes.

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    Proton Nuclear Magnetic Resonance spectroscopy (1H NMR) is able to monitor the changes that develop at a molecular level when leukaemic cells proliferate in the thymus of AKR mice. Furthermore, cultured human lymphocyte cell lines are shown to differ in their 1H-NMR spectra. These spectral differences are attributable to changes in membrane fluidity and composition, which in turn reflect the stage of differentiation and the type of transformation of the lymphocyte lines, i.e. Epstein-Barr virus (EBV) or leukaemic transformation..

    1SXPS: A deep Swift X-ray Telescope point source catalog with light curves and spectra

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    We present the 1SXPS (Swift-XRT Point Source) catalog of 151,524 X-ray point-sources detected by the Swift-XRT in 8 years of operation. The catalog covers 1905 square degrees distributed approximately uniformly on the sky. We analyze the data in two ways. First we consider all observations individually, for which we have a typical sensitivity of ~3e-13 erg/cm2/s (0.3--10 keV). Then we co-add all data covering the same location on the sky: these images have a typical sensitivity of ~9e-14 erg/cm2/s (0.3--10 keV). Our sky coverage is nearly 2.5 times that of 3XMM-DR4, although the catalog is a factor of ~1.5 less sensitive. The median position error is 5.5" (90% confidence), including systematics. Our source detection method improves on that used in previous XRT catalogs and we report >68,000 new X-ray sources. The goals and observing strategy of the Swift satellite allow us to probe source variability on multiple timescales, and we find ~30,000 variable objects in our catalog. For every source we give positions, fluxes, time series (in four energy bands and two hardness ratios), estimates of the spectral properties, spectra and spectral fits for the brightest sources, and variability probabilities in multiple energy bands and timescales.Comment: 27 pages, 19 figures; accepted for publication in ApJS. The accompanying website, http://www.swift.ac.uk/1SXPS is live; the Vizier entry should be available shortl
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