7,952 research outputs found

    Shuttle extravehicular activity signal processor pulse amplitude modulation decommutator

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    To provide data with long-term stability and accuracy, the pulse amplitude modulation (PAM) decommutator was synchronized to the PAM-return to zero wavetrain, and each channel was sampled with a common sample and hold circuit and digitized sequentially. The digital value of each channel was then scaled by the digital value of the calibration channels. The corrected digital value of each channel was stored for one complete frame and then transferred to the multiplexer-demultiplexer at a high rate in one block of serial digital data. A test model was built to demonstrate this design approach taken for the PAM decom and performance data was provided. The accuracies obtained with various signal to noise ratios are shown

    Trading places : worklessness dynamics in Greater Manchester

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    As part of the Local Economic Assessment process, a number of additional research projects were proposed by Greater Manchester (GM) local authorities into areas where data gaps exist or a greater understanding and analysis of a particular issue is required. One such area was the dynamics of the workless population in deprived neighbourhoods. There are neighbourhoods across GM where worklessness rates are persistently high. It has been suggested that in some areas this is partly the result of individuals moving out of deprived neighbourhoods to ‘better’ areas having found employment and then being replaced by workless individuals moving into the neighbourhood. Thus, people experience positive individual level employment outcomes whilst living in a neighbourhood, but the area may change little over time and may appear unresponsive to initiatives aimed at reducing worklessness. The analysis in this report breaks new ground in using individual level data on employment transitions and geographical movements taken from Department for Work and Pensions (DWP) and Her Majesty’s Revenue and Customs (HMRC) records to shed light on neighbourhood level population dynamics

    Understanding the worklessness dynamics and characteristics of deprived areas

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    Research was commissioned to use individual level data from the Work and Pensions Longitudinal Study (WPLS) to try to shed light on some unanswered questions about the dynamics of worklessness in deprived areas. It has been suggested that in certain deprived neighbourhoods individuals make the transition from worklessness into employment and move away to less deprived areas. As these people move away they are replaced by inflows of other workless people who may themselves find employment and move on in a similar way. Therefore, although people experience positive individual level employment outcomes whilst living in a neighbourhood, the area may change little over time and may appear unresponsive to initiatives aimed at reducing worklessness. This research examines this issue and the associated policy implications. The research classifies deprived areas according to whether they were an ‘improver’ or ‘non-improver’ area, over the period 2004 to 2007, as well as identifying ‘transition’ areas (a subset of ‘non-improver’ areas characterised by high population churn). We have published a full list of these classifications for each Lower Super Output Area in Great Britain, to enable local partners to conduct their own follow-up research into the issues locally. This has been simultaneously published alongside this report

    Small animal disease surveillance: respiratory disease 2017

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    This report focuses on surveillance for respiratory disease in companion animals. It begins with an analysis of data from 392 veterinary practices contributing to the Small Animal Veterinary Surveillance Network (SAVSNET) between January and December 2017. The following section describes canine respiratory coronavirus infections in dogs, presenting results from laboratory-confirmed cases across the country between January 2010 and December 2017. This is followed by an update on the temporal trends of three important syndromes in companion animals, namely gastroenteritis, pruritus and respiratory disease, from 2014 to 2017. A fourth section presents a brief update on Streptococcus equi subspecies zooepidemicus in companion animals. The final section summarises some recent developments pertinent to companion animal health, namely eyeworm (Thelazzia callipaeda) infestations in dogs imported to the UK and canine influenza virus in the USA and Canada

    Dynamical response of the Hodgkin-Huxley model in the high-input regime

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    The response of the Hodgkin-Huxley neuronal model subjected to stochastic uncorrelated spike trains originating from a large number of inhibitory and excitatory post-synaptic potentials is analyzed in detail. The model is examined in its three fundamental dynamical regimes: silence, bistability and repetitive firing. Its response is characterized in terms of statistical indicators (interspike-interval distributions and their first moments) as well as of dynamical indicators (autocorrelation functions and conditional entropies). In the silent regime, the coexistence of two different coherence resonances is revealed: one occurs at quite low noise and is related to the stimulation of subthreshold oscillations around the rest state; the second one (at intermediate noise variance) is associated with the regularization of the sequence of spikes emitted by the neuron. Bistability in the low noise limit can be interpreted in terms of jumping processes across barriers activated by stochastic fluctuations. In the repetitive firing regime a maximization of incoherence is observed at finite noise variance. Finally, the mechanisms responsible for spike triggering in the various regimes are clearly identified.Comment: 14 pages, 24 figures in eps, submitted to Physical Review

    English indices of deprivation 2010 : technical report

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    The English indices of deprivation 2010 is the third release in a series of statistics produced to measure multiple forms of deprivation at the small spatial scale. It updates the indices of deprivation 2007 and 2004, retaining broadly the same methodology, domains and indicators. This report outlines the conceptualisation underpinning the model of multiple deprivation used and describes the indicators and domains that make up the indices

    A natural histone H2A variant lacking the Bub1 phosphorylation site and regulated depletion of centromeric histone CENP-A foster evolvability in Candida albicans.

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    Eukaryotes have evolved elaborate mechanisms to ensure that chromosomes segregate with high fidelity during mitosis and meiosis, and yet specific aneuploidies can be adaptive during environmental stress. Here, we identify a chromatin-based system required for inducible aneuploidy in a human pathogen. Candida albicans utilizes chromosome missegregation to acquire tolerance to antifungal drugs and for nonmeiotic ploidy reduction after mating. We discovered that the ancestor of C. albicans and 2 related pathogens evolved a variant of histone 2A (H2A) that lacks the conserved phosphorylation site for kinetochore-associated Bub1 kinase, a key regulator of chromosome segregation. Using engineered strains, we show that the relative gene dosage of this variant versus canonical H2A controls the fidelity of chromosome segregation and the rate of acquisition of tolerance to antifungal drugs via aneuploidy. Furthermore, whole-genome chromatin precipitation analysis reveals that Centromere Protein A/ Centromeric Histone H3-like Protein (CENP-A/Cse4), a centromeric histone H3 variant that forms the platform of the eukaryotic kinetochore, is depleted from tetraploid-mating products relative to diploid parents and is virtually eliminated from cells exposed to aneuploidy-promoting cues. We conclude that genetically programmed and environmentally induced changes in chromatin can confer the capacity for enhanced evolvability via chromosome missegregation

    Approaching the event horizon: 1.3mm VLBI of SgrA*

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    Advances in VLBI instrumentation now allow wideband recording that significantly increases the sensitivity of short wavelength VLBI observations. Observations of the super-massive black hole candidate at the center of the Milky Way, SgrA*, with short wavelength VLBI reduces the scattering effects of the intervening interstellar medium, allowing observations with angular resolution comparable to the apparent size of the event horizon of the putative black hole. Observations in April 2007 at a wavelength of 1.3mm on a three station VLBI array have now confirmed structure in SgrA* on scales of just a few Schwarzschild radii. When modeled as a circular Gaussian, the fitted diameter of SgrA* is 37 micro arcsec (+16,-10; 3-sigma), which is smaller than the expected apparent size of the event horizon of the Galactic Center black hole. These observations demonstrate that mm/sub-mm VLBI is poised to open a new window onto the study of black hole physics via high angular resolution observations of the Galactic Center.Comment: 6 pages, 4 figures, Proceedings for "The Universe under the Microscope" (AHAR 2008), held in Bad Honnef (Germany) in April 2008, to be published in Journal of Physics: Conference Series by Institute of Physics Publishing, R. Schoedel, A. Eckart, S. Pfalzner, and E. Ros (eds.
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