201 research outputs found

    Household transmission of invasive group A Streptococcus infections in England: a population-based study, 2009, 2011 to 13

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    Invasive group A s treptococcal infection has a 15% case fatality rate and a risk of secondary transmission. This retrospective study us ed two national data sources from England ; enhanced surveillance ( 2009) and a case management system ( 2011 - 13) to identify clusters of sever e group A streptococcal disease . 2 4 household pairs were identified. The median onset interval between cases was 2 days (range 0 - 28) with simultaneous onset in 8 pairs . The attack rate during the 30 days after first exposure to a primary case was 4 52 0 per 100000 person - years at risk (95% CI 2 900 - 673 0 ) a 19 40 ( 12 40 - 28 80 ) fold elevation over the background incidence . The theoretical number needed to treat ( NNT ) to prevent one secondary case using antibiotic prophylaxis was 2 71 ( 194 - 454 ) overall, 50 for mother - neonate pairs ( 2 7 - 3 93 ) and 8 2 for couples aged 75 years and over ( 46 - 417 ). Whilst a dramatic increased risk of infection was noted in all household contacts, increased ris k was greatest for mother - neonate pairs and couples aged 75 and over , suggesting targeted prophylaxis c ould be considered. Offering prophylaxis is challenging due to the short time interval between cases emphasising the importance of immediate notification and assessment of contacts

    Textile-based non-invasive lithium drug monitoring: A proof-of-concept study for wearable sensing

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    Flexible wearable chemical sensors are emerging tools which target diagnosis and monitoring of medical conditions. One of the potential applications of wearable chemical sensors is therapeutic drug monitoring for drugs that have a narrow therapeutic range such as lithium. We have investigated the possibility of developing a fibre-based device for non-invasive lithium drug monitoring in interstitial fluid. A flexible cotton-based lithium sensor was coupled with a carbon fibre-based reference electrode to obtain a potentiometric device. In vitro reverse iontophoresis experiments were performed to extract Li+ from under porcine skin by applying a current density of 0.4 mA cm-2 via two electrodes. Carbon fibre-based reverse iontophoresis electrodes were fabricated and used instead of a conventional silver wire-based version and comparable results were obtained. The fibre-based Li+ sensor and reference electrodes were capable of determining the Li+ concentration in samples collected via reverse iontophoresis and the results compared well to those obtained by ion chromatography. Additionally, biocompatibility of the used materials have been tested. Promising results were obtained which confirm the possibility of monitoring lithium in interstitial fluid using a wearable sensor

    Domain Growth in a 1-D Driven Diffusive System

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    The low-temperature coarsening dynamics of a one-dimensional Ising model, with conserved magnetisation and subject to a small external driving force, is studied analytically in the limit where the volume fraction \mu of the minority phase is small, and numerically for general \mu. The mean domain size L(t) grows as t^{1/2} in all cases, and the domain-size distribution for domains of one sign is very well described by the form P_l(l) \propto (l/L^3)\exp[-\lambda(\mu)(l^2/L^2)], which is exact for small \mu (and possibly for all \mu). The persistence exponent for the minority phase has the value 3/2 for \mu \to 0.Comment: 8 pages, REVTeX, 7 Postscript figures, uses multicol.sty and epsf.sty. Submitted to Phys. Rev.

    The future of public sector accounting research. A polyphonic debate

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    PurposeThe purpose of this polyphonic paper is to report on interdisciplinary discussions on the state-of-the-art and future of public sector accounting research (PSAR). The authors hope to enliven the debates of the past and future developments in terms of context, themes, theories, methods and impacts in the field of PSAR by the exchanges they include here. Design/methodology/approachThis polyphonic paper adopts an interdisciplinary approach. It brings into conversation ideas, views and approaches of several scholars on the actual and future developments of PSAR in various contexts, and explores potential implications. FindingsThis paper has brought together scholars from a plurality of disciplines, research methods and geographical areas, showing at the same time several points of convergence on important future themes (such as accounting as a mean for public, accounting, hybridity and value pluralism) and enabling conditions (accounting capabilities, profession and digitalisation) for PSA scholarship and practice, and the richness of looking at them from a plurality of perspectives. Research limitations/implicationsExploring these past and future developments opens up the potential for interesting theoretical insights. A much greater theoretical and practical reconsideration of PSAR will be fostered by the exchanges included here. Originality/valueIn setting out a future research agenda, this paper fosters theoretical and methodological pluralism in the interdisciplinary research community interested in PSAR in various contexts. The discussion perspectives presented in this paper constitute not only a basis for further research in this relevant accounting area on the role, status and developments of PSAR but also creative potential for practitioners to be more reflective on their practices and also intended and united outcomes of such practices

    From urn models to zero-range processes: statics and dynamics

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    The aim of these lecture notes is a description of the statics and dynamics of zero-range processes and related models. After revisiting some conceptual aspects of the subject, emphasis is then put on the study of the class of zero-range processes for which a condensation transition arises.Comment: Lecture notes for the Luxembourg Summer School 200

    NGO accounting and accountability: past, present and future

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    The main aim of this paper is to introduce key themes of NGO accounting and accountability and provide an overview of the papers included in this special issue. These papers deal with formal reporting issues related to the regulatory requirements as well as various alternative forms of informal accountability mechanisms which are more related with the core social purpose of the organisation. This special issue contributes not only to the scholarly debates on NGO accounting and accountability but also to the various issues facing policy makers and NGO practitioners. We have provided a robust research agenda for future researchers. HIGHLIGHTS We define the term ‘NGO’ for the purposes of this issue, concluding that NGOs’ social purposes and the constraint on distribution of surpluses are the two common characteristics. This definition encourages researchers to cast their net wider when considering contexts in which to undertake their NGO study. NGO accountability discharge is broadening to a wider range of stakeholders. There are many NGO accounting and accountability issues that warrant further research

    Anomalous self-diffusion in the ferromagnetic Ising chain with Kawasaki dynamics

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    We investigate the motion of a tagged spin in a ferromagnetic Ising chain evolving under Kawasaki dynamics. At equilibrium, the displacement is Gaussian, with a variance growing as At1/2A t^{1/2}. The temperature dependence of the prefactor AA is derived exactly. At low temperature, where the static correlation length ξ\xi is large, the mean square displacement grows as (t/ξ2)2/3(t/\xi^2)^{2/3} in the coarsening regime, i.e., as a finite fraction of the mean square domain length. The case of totally asymmetric dynamics, where (+)(+) (resp. ()(-)) spins move only to the right (resp. to the left), is also considered. In the steady state, the displacement variance grows as Bt2/3B t^{2/3}. The temperature dependence of the prefactor BB is derived exactly, using the Kardar-Parisi-Zhang theory. At low temperature, the displacement variance grows as t/ξ2t/\xi^2 in the coarsening regime, again proportionally to the mean square domain length.Comment: 22 pages, 8 figures. A few minor changes and update

    New Dynamic Monte Carlo Renormalization Group Method

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    The dynamical critical exponent of the two-dimensional spin-flip Ising model is evaluated by a Monte Carlo renormalization group method involving a transformation in time. The results agree very well with a finite-size scaling analysis performed on the same data. The value of z=2.13±0.01z = 2.13 \pm 0.01 is obtained, which is consistent with most recent estimates

    Transverse-field Ising spin chain with inhomogeneous disorder

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    We consider the critical and off-critical properties at the boundary of the random transverse-field Ising spin chain when the distribution of the couplings and/or transverse fields, at a distance ll from the surface, deviates from its uniform bulk value by terms of order lκl^{-\kappa} with an amplitude AA. Exact results are obtained using a correspondence between the surface magnetization of the model and the surviving probability of a random walk with time-dependent absorbing boundary conditions. For slow enough decay, κ<1/2\kappa<1/2, the inhomogeneity is relevant: Either the surface stays ordered at the bulk critical point or the average surface magnetization displays an essential singularity, depending on the sign of AA. In the marginal situation, κ=1/2\kappa=1/2, the average surface magnetization decays as a power law with a continuously varying, AA-dependent, critical exponent which is obtained analytically. The behavior of the critical and off-critical autocorrelation functions as well as the scaling form of the probability distributions for the surface magnetization and the first gaps are determined through a phenomenological scaling theory. In the Griffiths phase, the properties of the Griffiths-McCoy singularities are not affected by the inhomogeneity. The various results are checked using numerical methods based on a mapping to free fermions.Comment: 11 pages (Revtex), 11 figure
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