1,774 research outputs found

    Towards a novel carbon device for the treatment of sepsis

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    Sepsis is a systemic inflammatory response to infection in which the balance of pro- andanti-inflammatory mediators, which normally isolate and eliminate infection, is disrupted[1]. Gram negative sepsis is initiated by bacterial endotoxin release which activatesmacrophages and circulating monocytes to release TNF and IL-1ÎČ followed by IL-6 andother inflammatory cytokines [2]. As the disease progresses, an unregulatedinflammatory response results in, tissue injury, haematological dysfunction and organdysfunction. Severe sepsis, involving organ hypoperfusion may be further complicatedby hypotension that is unresponsive to adequate fluid replacement, resulting in septicshock and finally death [3].Despite improvements in anti-microbial and supportive therapies, sepsis remains asignificant cause of morbidity and mortality in ICUs worldwide [4]. The complexity ofprocesses mediating the progression of sepsis suggests that an extracorporeal devicecombining blood filtration with adsorption of a wide range of toxins, and inflammatorymediators offers the most comprehensive treatment strategy. However, no such deviceexists at present. A novel, uncoated, polymer pyrolysed synthetic carbon device isproposed which combines the superior adsorption properties of uncoated activatedcarbons with the capacity to manipulate porous structure for controlled adsorption oftarget plasma proteins and polypeptides [5]. Preliminary haemocompatibility andadsorptive capacity was assessed using a carbon matrix prototype

    On The Problem of Particle Production in c=1 Matrix Model

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    We reconsider and analyze in detail the problem of particle production in the time dependent background of c=1c=1 matrix model where the Fermi sea drains away at late time. In addition to the moving mirror method, which has already been discussed in hep-th/0403169 and hep-th/0403275, we describe yet another method of computing the Bogolubov coefficients which gives the same result. We emphasize that these Bogolubov coefficients are approximately correct for small value of the deformation parameter. We also study the time evolution of the collective field theory stress-tensor with a special point-splitting regularization. Our computations go beyond the approximation of the previous treatments and are valid at large coordinate distances from the boundary at a finite time and up-to a finite coordinate distance from the boundary at late time. In this region of validity our regularization produces a certain singular term that is precisely canceled by the collective field theory counter term in the present background. The energy and momentum densities fall off exponentially at large distance from the boundary to the values corresponding to the static background. This clearly shows that the radiated energy reaches the asymptotic region signaling the space-time decay.Comment: 37 pages, 5 figures. Section 6 is modified to clarify main accomplishments of the paper including a discussion comparing stress-tensor analysis with those preexisted in literature. Other modifications include minor changes in the text and addition of one reference. Version accepted for publication in JHE

    The problem with Kappa

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    It is becoming clear that traditional evaluation measures used in Computational Linguistics (including Error Rates, Accuracy, Recall, Precision and F-measure) are of limited value for unbiased evaluation of systems, and are not meaningful for comparison of algorithms unless both the dataset and algorithm parameters are strictly controlled for skew (Prevalence and Bias). The use of techniques originally designed for other purposes, in particular Receiver Operating Characteristics Area Under Curve, plus variants of Kappa, have been proposed to fill the void. This paper aims to clear up some of the confusion relating to evaluation, by demonstrating that the usefulness of each evaluation method is highly dependent on the assumptions made about the distributions of the dataset and the underlying populations. The behaviour of a number of evaluation measures is compared under common assumptions. Deploying a system in a context which has the opposite skew from its validation set can be expected to approximately negate Fleiss Kappa and halve Cohen Kappa but leave Powers Kappa unchanged. For most performance evaluation purposes, the latter is thus most appropriate, whilst for comparison of behaviour, Matthews Correlation is recommended

    New results on cut-off effects in spectroscopy with the fixed point action

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    Our study on the cut-off effects in quenched light hadron spectroscopy and pion scattering length with the fixed point action is extended by results obtained at a lattice spacing a=0.102 fm in a box of size L=1.8 fm. The cut-off effects are small, but clearly seen as the resolution is increased from a=0.153 fm to a=0.102 fm. In the quark mass region where the errors are small and under control, our results on the APE plot lie close to the extrapolated numbers of the CP-PACS Collaboration.Comment: 15 pages, 11 figures, reference correcte

    Influence of shear flow on vesicles near a wall: a numerical study

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    We describe the dynamics of three-dimensional fluid vesicles in steady shear flow in the vicinity of a wall. This is analyzed numerically at low Reynolds numbers using a boundary element method. The area-incompressible vesicle exhibits bending elasticity. Forces due to adhesion or gravity oppose the hydrodynamic lift force driving the vesicle away from a wall. We investigate three cases. First, a neutrally buoyant vesicle is placed in the vicinity of a wall which acts only as a geometrical constraint. We find that the lift velocity is linearly proportional to shear rate and decreases with increasing distance between the vesicle and the wall. Second, with a vesicle filled with a denser fluid, we find a stationary hovering state. We present an estimate of the viscous lift force which seems to agree with recent experiments of Lorz et al. [Europhys. Lett., vol. 51, 468 (2000)]. Third, if the wall exerts an additional adhesive force, we investigate the dynamical unbinding transition which occurs at an adhesion strength linearly proportional to the shear rate.Comment: 17 pages (incl. 10 figures), RevTeX (figures in PostScript

    Staggered versus overlap fermions: a study in the Schwinger model with Nf=0,1,2N_f=0,1,2

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    We study the scalar condensate and the topological susceptibility for a continuous range of quark masses in the Schwinger model with Nf=0,1,2N_f=0,1,2 dynamical flavors, using both the overlap and the staggered discretization. At finite lattice spacing the differences between the two formulations become rather dramatic near the chiral limit, but they get severely reduced, at the coupling considered, after a few smearing steps.Comment: 15 pages, 7 figures, v2: 1 ref corrected, minor change

    A rapid review of variation in the use of dental general anaesthetics in children

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    Introduction: The use of dental general anaesthetics (DGAs) remains a cause for concern due to additional strains placed on health services. There are numerous factors influencing the prevalence and use of DGAs, and understanding these is an important first step in addressing the issue. Aim: Conduct a rapid review of current peer-reviewed and grey literature on the variation in the use of DGAs in children. Methods: Electronic searching using Medline via Ovid covering DGA articles from 1998 onwards, written in English. Publication types included primary and secondary sources from peer-reviewed journals and reports, as well as grey literature. Results: From 935 results, 171 articles were included in the final review. Themes emerging from the literature included discussions of DGA variation, variations in standards of service provision by health services, and the socio-demographic and geographical characteristics of children. Prominent socio-demographic and geographical characteristics included age, other health conditions, ethnic and cultural background, socioeconomic status and deprivation, and geographical location. Conclusions: This review identified numerous variations in the patterns associated with DGA provision and uptake at both a health service and individual level. The findings demonstrate the complicated and multifaceted nature of DGA practices worldwide

    The celebrity entrepreneur on television: profile, politics and power

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    This article examines the rise of the ‘celebrity entrepreneur’ on television through the emergence of the ‘business entertainment format’ and considers the ways in which regular television exposure can be converted into political influence. Within television studies there has been a preoccupation in recent years with how lifestyle and reality formats work to transform ‘ordinary’ people into celebrities. As a result, the contribution of vocationally skilled business professionals to factual entertainment programming has gone almost unnoticed. This article draws on interviews with key media industry professionals and begins by looking at the construction of entrepreneurs as different types of television personalities and how discourses of work, skill and knowledge function in business shows. It then outlines how entrepreneurs can utilize their newly acquired televisual skills to cultivate a wider media profile and secure various forms of political access and influence. Integral to this is the centrality of public relations and media management agencies in shaping media discourses and developing the individual as a ‘brand identity’ that can be used to endorse a range of products or ideas. This has led to policy makers and politicians attempting to mobilize the media profile of celebrity entrepreneurs to reach out and connect with the public on business and enterprise-related issues
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