519 research outputs found

    Security oriented e-infrastructures supporting neurological research and clinical trials

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    The neurological and wider clinical domains stand to gain greatly from the vision of the grid in providing seamless yet secure access to distributed, heterogeneous computational resources and data sets. Whilst a wealth of clinical data exists within local, regional and national healthcare boundaries, access to and usage of these data sets demands that fine grained security is supported and subsequently enforced. This paper explores the security challenges of the e-health domain, focusing in particular on authorization. The context of these explorations is the MRC funded VOTES (Virtual Organisations for Trials and Epidemiological Studies) and the JISC funded GLASS (Glasgow early adoption of Shibboleth project) which are developing Grid infrastructures for clinical trials with case studies in the brain trauma domain

    Grid infrastructures for secure access to and use of bioinformatics data: experiences from the BRIDGES project

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    The BRIDGES project was funded by the UK Department of Trade and Industry (DTI) to address the needs of cardiovascular research scientists investigating the genetic causes of hypertension as part of the Wellcome Trust funded (£4.34M) cardiovascular functional genomics (CFG) project. Security was at the heart of the BRIDGES project and an advanced data and compute grid infrastructure incorporating latest grid authorisation technologies was developed and delivered to the scientists. We outline these grid infrastructures and describe the perceived security requirements at the project start including data classifications and how these evolved throughout the lifetime of the project. The uptake and adoption of the project results are also presented along with the challenges that must be overcome to support the secure exchange of life science data sets. We also present how we will use the BRIDGES experiences in future projects at the National e-Science Centre

    Long wavelength structural anomalies in jammed systems

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    The structural properties of static, jammed packings of monodisperse spheres in the vicinity of the jamming transition are investigated using large-scale computer simulations. At small wavenumber kk, we argue that the anomalous behavior in the static structure factor, S(k)kS(k) \sim k, is consequential of an excess of low-frequency, collective excitations seen in the vibrational spectrum. This anomalous feature becomes more pronounced closest to the jamming transition, such that S(0)0S(0) \to 0 at the transition point. We introduce an appropriate dispersion relation that accounts for these phenomena that leads us to relate these structural features to characteristic length scales associated with the low-frequency vibrational modes of these systems. When the particles are frictional, this anomalous behavior is suppressed providing yet more evidence that jamming transitions of frictional spheres lie at lower packing fractions that that for frictionless spheres. These results suggest that the mechanical properties of jammed and glassy media may therefore be inferred from measurements of both the static and dynamical structure factors.Comment: 8 pages, 6 figure captions. Completely revised version to appear in Phys. Rev.

    Ordered Information Systems and Graph Granulation

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    The concept of an Information System, as used in Rough Set theory, is extended to the case of a partially ordered universe equipped with a set of order preserving attributes. These information systems give rise to partitions of the universe where the set of equivalence classes is partially ordered. Such ordered partitions correspond to relations on the universe which are reflexive and transitive. This correspondence allows the definition of approximation operators for an ordered information system by using the concepts of opening and closing from mathematical morphology. A special case of partial orders are graphs and hypergraphs and these provide motivation for the need to consider approximations on partial orders

    Exact factorization of correlation functions in 2-D critical percolation

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    By use of conformal field theory, we discover several exact factorizations of higher-order density correlation functions in critical two-dimensional percolation. Our formulas are valid in the upper half-plane, or any conformally equivalent region. We find excellent agreement of our results with high-precision computer simulations. There are indications that our formulas hold more generally.Comment: 6 pages, 3 figures. Oral presentation given at STATPHYS 23. V2: Minor additions and corrections, figures improve

    The density functional theory of classical fluids revisited

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    We reconsider the density functional theory of nonuniform classical fluids from the point of view of convex analysis. From the observation that the logarithm of the grand-partition function logΞ[ϕ]\log \Xi [\phi] is a convex functional of the external potential ϕ\phi it is shown that the Kohn-Sham free energy A[ρ]{\cal A}[\rho] is a convex functional of the density ρ\rho. logΞ[ϕ]\log \Xi [\phi] and A[ρ]{\cal A}[\rho] constitute a pair of Legendre transforms and each of these functionals can therefore be obtained as the solution of a variational principle. The convexity ensures the unicity of the solution in both cases. The variational principle which gives logΞ[ϕ]\log \Xi [\phi] as the maximum of a functional of ρ\rho is precisely that considered in the density functional theory while the dual principle, which gives A[ρ]{\cal A}[\rho] as the maximum of a functional of ϕ\phi seems to be a new result.Comment: 10 page

    Owner perceptions of their cat's quality of life when treated with a modified University of Wisconsin-Madison protocol for lymphoma

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    The objectives of this study were to assess owner perceptions of their cat’s quality of life during treatment for lymphoma with a doxorubicin-containing multi-agent chemotherapy protocol, whether various health-related parameters correlated with quality of life scores, and to assess owner satisfaction with the protocol

    Critical behavior of a fluid in a disordered porous matrix: An Ornstein-Zernike approach

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    Using a liquid-state approach based on Ornstein-Zernike equations, we study the behavior of a fluid inside a porous disordered matrix near the liquid-gas critical point.The results obtained within various standard approximation schemes such as lowest-order γ\gamma-ordering and the mean-spherical approximation suggest that the critical behavior is closely related to that of the random-field Ising model (RFIM).Comment: 10 pages, revtex, to appear in Physical Review Letter

    Prevalence and risk factors for mast cell tumours in dogs in England

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    BACKGROUND: Mast cell tumour (MCT) appears to be a frequent tumour type in dogs, though there is little published in relation to its frequency in dogs in the UK. The current study aimed to investigate prevalence and risk factors for MCTs in dogs attending English primary-care veterinary practices. METHODS: Electronic patient records from practices participating in the VetCompass animal surveillance project between July 2007 and June 2013 were searched for MCT diagnosis. Various search terms and standard diagnostic terms (VeNom codes) identified records containing MCT diagnoses, which were evaluated against clinical criteria for inclusion to the study. MCT prevalence for the entire dataset and specific breed types were calculated. Descriptive statistics characterised MCT cases and multivariable logistic regression methods evaluated risk factors for association with MCT (P < 0.05). RESULTS: Within a population of 168,636 dogs, 453 had MCT, yielding a prevalence of 0.27% (95% confidence interval (CI) 0.24% - 0.29%). The highest breed type specific prevalences were for the Boxer at 1.95% (95% CI 1.40% - 2.51%), Golden Retriever at 1.39% (0.98% - 1.81%) and Weimaraner at 0.85% (95% CI 0.17% to 1.53%). Age, insurance status, neuter status, weight and breed type were associated with MCT diagnosis. Of dogs of specific breed type, the Boxer, Pug and Staffordshire Bull Terrier showed greater odds of MCT diagnosis compared with crossbred dogs. Conversely, the German Shepherd Dog, Border Collie, West Highland White Terrier, Springer Spaniel and Cocker Spaniel had reduced odds of MCT diagnosis compared with crossbred dogs. No association was found between MCT diagnosis and sex. CLINICAL SIGNIFICANCE: This study highlights a clinically significant prevalence of MCT and identifies specific breed types with predisposition to MCT, potentially aiding veterinarian awareness and facilitating diagnosis
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