824 research outputs found

    Formalisation and Implementation of the XACML Access Control Mechanism

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    We propose a formal account of XACML, an OASIS standard adhering to the Policy Based Access Control model for the specifica- tion and enforcement of access control policies. To clarify all ambiguous and intricate aspects of XACML, we provide it with a more manageable alternative syntax and with a solid semantic ground. This lays the basis for developing tools and methodologies which allow software engineers to easily and precisely regulate access to resources using policies. To demonstrate feasibility and effectiveness of our approach, we provide a software tool, supporting the specification and evaluation of policies and access requests, whose implementation fully relies on our formal development

    Targeted nasal vaccination provides antibody-independent protection against Staphylococcus aureus.

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    Despite showing promise in preclinical models, anti-Staphylococcus aureus vaccines have failed in clinical trials. To date, approaches have focused on neutralizing/opsonizing antibodies; however, vaccines exclusively inducing cellular immunity have not been studied to formally test whether a cellular-only response can protect against infection. We demonstrate that nasal vaccination with targeted nanoparticles loaded with Staphylococcus aureus antigen protects against acute systemic S. aureus infection in the absence of any antigen-specific antibodies. These findings can help inform future developments in staphylococcal vaccine development and studies into the requirements for protective immunity against S. aureus

    Towards a synthesized critique of neoliberal biodiversity conservation

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    During the last three decades, the arena of biodiversity conservation has largely aligned itself with the globally dominant political ideology of neoliberalism and associated governmentalities. Schemes such as payments for ecological services are promoted to reach the multiple ‘wins’ so desired: improved biodiversity conservation, economic development, (international) cooperation and poverty alleviation, amongst others. While critical scholarship with respect to understanding the linkages between neoliberalism, capitalism and the environment has a long tradition, a synthesized critique of neoliberal conservation - the ideology (and related practices) that the salvation of nature requires capitalist expansion - remains lacking. This paper aims to provide such a critique. We commence with the assertion that there has been a conflation between ‘economics’ and neoliberal ideology in conservation thinking and implementation. As a result, we argue, it becomes easier to distinguish the main problems that neoliberal win-win models pose for biodiversity conservation. These are framed around three points: the stimulation of contradictions; appropriation and misrepresentation and the disciplining of dissent. Inspired by Bruno Latour’s recent ‘compositionist manifesto’, the conclusion outlines some ideas for moving beyond critique

    Anti-staphylococcal humoral immune response in persistent nasal carriers and noncarriers of Staphylococcus aureus

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    BACKGROUND. Persistent carriers have a higher risk of Staphylococcus aureus infections than noncarriers but a lower risk of bacteremia-related death. Here, the role played by anti-staphylococcal antibodies was studied. METHODS. Serum samples from 15 persistent carriers and 19 noncarriers were analyzed for immunoglobulin (Ig) G, IgA, and IgM binding to 19 S. aureus antigens, by means of Luminex technology. Nasal secretions and serum samples obtained after 6 months were also analyzed. RESULTS. Median serum IgG levels were significantly higher in persistent carriers than in noncarriers for toxic shock syndrome toxin (TSST)-1 (median fluorescence intensity [MFI] value, 11,554 vs. 4291; P < .001) and staphylococcal enterotoxin (SE) A (742 vs. 218; P < .05); median IgA levels were higher for TSST-1 (P < .01), SEA, and clumping factor (Clf) A and B (P < .05). The in vitro neutralizing capacity of anti-TSST-1 antibodies was correlated with the MFI value (R(2) = 0.93) and was higher in persistent carriers (90.6% vs. 70.6%; P < .05). Antibody levels were stable over time and correlated with levels in nasal secretions (for IgG, R(2) = 0.87; for IgA, R(2) = 0.77). CONCLUSIONS. Antibodies to TSST-1 ha

    SRAO CO Observation of 11 Supernova Remnants in l = 70 to 190 deg

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    We present the results of 12CO J = 1-0 line observations of eleven Galactic supernova remnants (SNRs) obtained using the Seoul Radio Astronomy Observatory (SRAO) 6-m radio telescope. The observation was made as a part of the SRAO CO survey of SNRs between l = 70 and 190 deg, which is intended to identify SNRs interacting with molecular clouds. The mapping areas for the individual SNRs are determined to cover their full extent in the radio continuum. We used halfbeam grid spacing (60") for 9 SNRs and full-beam grid spacing (120") for the rest. We detected CO emission towards most of the remnants. In six SNRs, molecular clouds showed a good spatial relation with their radio morphology, although no direct evidence for the interaction was detected. Two SNRs are particularly interesting: G85.4+0.7, where there is a filamentary molecular cloud along the radio shell, and 3C434.1, where a large molecular cloud appears to block the western half of the remnant. We briefly summarize the results obtained for individual SNRs.Comment: Accepted for publication in Astrophysics & Space Science. 12 pages, 12 figures, and 3 table

    Dynamical downscaling for the southwest of Western Australia using the WRF modelling system

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    The southwest of Western Australia (SWWA) is a region of significant cereal production, with the main crops being winter grown wheat and barley. The most important factors influencing wheat growth and production are temperature extremes and precipitation, and hence, it is critical to have an understanding of how these environmental factors have changed in the past, and how they are likely to change in the future. One method of addressing this important research question is by using regional climate models (RCMs) to dynamically downscale re-analysis products and/or output form Global Circulation Models to a fine resolution. One tool which is being increasingly used for this purpose is the Weather Research and Forecasting Model (WRF) Advanced Research (ARW). However, like any modeling system, WRF-ARW requires thorough testing before it is implemented to carry out long-term climate runs. This paper examines the influence of different input data sources, as well as model physics options on simulated precipitation and maximum and minimum temperatures in SWWA by comparing the simulations against an observational gridded dataset. It is found that running WRF3.3 with the 1.0 × 1.0 degree National Center for Environmental Prediction Final analysis (NCEP-FNL), as compared to the 2.5 × 2.5 degree NCEP / National Center for Atmospheric Research (NCEP/NCAR or NNRP) results in much improved simulations of precipitation and temperatures. Using the National Oceanic and Atmospheric Administration 1.0 × 1.0 degree resolution sea surface temperature (SST) dataset does not result in markedly different results as compared to using the NNRP surface skin temperatures as SSTs. Using the Betts-Miller-Jajic (BMJ) scheme for cumulus/convection parameterisation rather than the more widely used Kain Fritsch (KF) scheme results in slightly higher errors for precipitation, and no marked change in temperatures. The latest version of the Rapid Radiative Transfer Model (RRTMG) is found to result in improved simulations of maximum and minimum temperatures, as compared to the RRTM, Community Atmosphere Model (CAM) 3.0, and Dudhia schemes. Use of the Asymmetric Convective Model as the planetary boundary-layer scheme rather than the more widely used Yonsei University scheme results in over-prediction of maximum and minimum temperatures

    Aesthetics of self-scaling: parallaxed transregionalism and Kutluğ Ataman's art practice

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    This article examines relations of ethnography, contemporary art-practice, globalisation and scalar geopolitics with particular reference to Kutluğ Ataman’s artworks. Having been shortlisted for the Turner Prize at the Tate and awarded the prestigious international Carnegie Prize in 2004 with his forty-screen video installation Küba (2004), Ataman became an extremely well-known, globally acclaimed artist and filmmaker. Self-conscious of their global travel and critically attentive to the contemporary ethnographic turn in the visual arts scene, Ataman’s video-works perform a conscientious failure of representing cultural alterity as indigeneity. Concentrating on the artist’s engagement with ethnography, this article contains three main parts. Analyses of the selection of videos in each part will give an account of different scalar aspects of Ataman’s artworks. It will first revisit a previous study (Çakirlar 2011) on the artist’s earlier work of video-portraits including Never My Soul! (2002) and Women Who Wear Wigs (1999). A detailed discussion of Küba follows, which may be taken as the ‘hinge - work’ in Ataman’s oeuvre that marks a scalar transition in his critical focus - from body and identity to community and geopolitics. The discussion will then move to a brief analysis of the series Mesopotamian Dramaturgies, including the screen-based sculptures Dome (2009), Column (2009), Frame (2009), English as a Second Language (2009), and The Complete Works of William Shakespeare (2009). Rather than addressing scale as a differential concept, this article aims to demonstrate the ways in which Ataman’s art-practice produces self-scaling, self-regioning subjects that unsettle the hierarchical constructions of scale and facilitates a critique of the scalar normativity within the global art world’s regionalisms and internationalisms

    Measurement of D*+/- meson production in jets from pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

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    This paper reports a measurement of D*+/- meson production in jets from proton-proton collisions at a center-of-mass energy of sqrt(s) = 7 TeV at the CERN Large Hadron Collider. The measurement is based on a data sample recorded with the ATLAS detector with an integrated luminosity of 0.30 pb^-1 for jets with transverse momentum between 25 and 70 GeV in the pseudorapidity range |eta| < 2.5. D*+/- mesons found in jets are fully reconstructed in the decay chain: D*+ -> D0pi+, D0 -> K-pi+, and its charge conjugate. The production rate is found to be N(D*+/-)/N(jet) = 0.025 +/- 0.001(stat.) +/- 0.004(syst.) for D*+/- mesons that carry a fraction z of the jet momentum in the range 0.3 < z < 1. Monte Carlo predictions fail to describe the data at small values of z, and this is most marked at low jet transverse momentum.Comment: 10 pages plus author list (22 pages total), 5 figures, 1 table, matches published version in Physical Review

    The influence of charge on the multiple thermal transitions observed in xanthan

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    Helix-coil transitions in xanthans occur at lower temperatures when the pyruvate group is charged, destabilising the polymer chains. Increasing salt content increases the transition temperature by reducing the effective charge on the pyruvate. A simple equivalent mass action model predicts how transition temperatures change as a function of salt concentration. The functional form of the change in transition temperature (1/T) versus natural log (salt concentration) is approximately linear and similar to more traditional polyelectrolyte theories. Transition temperatures in xanthans containing nominally homogeneous pyruvate contents show biphasic transitions, this is because the phases contain different pyruvate levels, however the transitions approach one another in temperature and eventually merge as salt content is increased. It is proposed that pyruvate groups, despite being present at a lower concentration relative to glucuronic acid, dominate the charge interactions due to their location on the outside of the helices

    Memory Th1 Cells Are Protective in Invasive Staphylococcus aureus Infection

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    Mechanisms of protective immunity to Staphylococcus aureus infection in humans remain elusive. While the importance of cellular immunity has been shown in mice, T cell responses in humans have not been characterised. Using a murine model of recurrent S. aureus peritonitis, we demonstrated that prior exposure to S. aureus enhanced IFNγ responses upon subsequent infection, while adoptive transfer of S. aureus antigen-specific Th1 cells was protective in naïve mice. Translating these findings, we found that S. aureus antigen-specific Th1 cells were also significantly expanded during human S. aureus bloodstream infection (BSI). These Th1 cells were CD45RO+, indicative of a memory phenotype. Thus, exposure to S. aureus induces memory Th1 cells in mice and humans, identifying Th1 cells as potential S. aureus vaccine targets. Consequently, we developed a model vaccine comprising staphylococcal clumping factor A, which we demonstrate to be an effective human T cell antigen, combined with the Th1-driving adjuvant CpG. This novel Th1-inducing vaccine conferred significant protection during S. aureus infection in mice. This study notably advances our understanding of S. aureus cellular immunity, and demonstrates for the first time that a correlate of S. aureus protective immunity identified in mice may be relevant in humans
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