892 research outputs found

    Mycobacterium sp. as a possible cause of hypersensitivity pneumonitis in machine workers.

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    Hypersensitivity pneumonitis (HP) in workers exposed to metal removal fluids (MRFs) is increasing. This study supports the hypothesis that aerosolized mycobacteria colonizing the MRFs likely cause the disease. Three case studies of HP outbreaks among metal workers showed potentially high exposures to a rare and newly proposed Mycobacterium species. Retrospective review of samples submitted to our laboratory showed an association between presence of mycobacteria and HP

    Electrostatic boundary value problems in the Schwarzschild background

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    The electrostatic potential of any test charge distribution in Schwarzschild space with boundary values is derived. We calculate the Green's function, generalize the second Green's identity for p-forms and find the general solution. Boundary value problems are solved. With a multipole expansion the asymptotic property for the field of any charge distribution is derived. It is shown that one produces a Reissner--Nordstrom black hole if one lowers a test charge distribution slowly toward the horizon. The symmetry of the distribution is not important. All the multipole moments fade away except the monopole. A calculation of the gravitationally induced electrostatic self-force on a pointlike test charge distribution held stationary outside the black hole is presented.Comment: 18 pages, no figures, uses iopart.st

    Cosmological quantum entanglement

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    We review recent literature on the connection between quantum entanglement and cosmology, with an emphasis on the context of expanding universes. We discuss recent theoretical results reporting on the production of entanglement in quantum fields due to the expansion of the underlying spacetime. We explore how these results are affected by the statistics of the field (bosonic or fermionic), the type of expansion (de Sitter or asymptotically stationary), and the coupling to spacetime curvature (conformal or minimal). We then consider the extraction of entanglement from a quantum field by coupling to local detectors and how this procedure can be used to distinguish curvature from heating by their entanglement signature. We review the role played by quantum fluctuations in the early universe in nucleating the formation of galaxies and other cosmic structures through their conversion into classical density anisotropies during and after inflation. We report on current literature attempting to account for this transition in a rigorous way and discuss the importance of entanglement and decoherence in this process. We conclude with some prospects for further theoretical and experimental research in this area. These include extensions of current theoretical efforts, possible future observational pursuits, and experimental analogues that emulate these cosmic effects in a laboratory setting.Comment: 23 pages, 2 figures. v2 Added journal reference and minor changes to match the published versio

    The changing nature of labour regulation: the distinctiveness of the National Agreement for the Engineering Construction Industry

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    The article addresses the changing nature of labour regulation through analysis of the National Agreement for the Engineering Construction Industry, originating in 1981. It shows how multiple spatial regulatory scales, the changing coalitions of actors involved, employer and client engagement and labour agency have been critical to National Agreement for the Engineering Construction Industry's survival

    Electron Capture Strength for {60,62}Ni and {58,60,62,64}Ni(p,n){58,60,62,64}Cu reactions at 134.3 MeV

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    Background: The strength of electron capture for medium mass nuclei has a significant effect on the evolution of supernovae. There is insufficient knowledge of these strengths and very little data for important radioactive nuclei. Purpose: Determine whether it is feasible to obtain EC strength from studies of T_o+1 excitations in (p,n) reactions, and whether this might yield information for radioactive nuclei. Methods: Cross sections for the {58,60,62,64}Ni(p,n){58,60,62,64}Cu reactions were measured over the angular range of 0.3 deg to 11.6 deg at 134.3 MeV using the IUCF neutron time-of-flight facility. esults: The T_o+1 excitations in {60,62}Ni were identified by comparison with inelastic proton scattering spectra, their B(GT) were extracted, and the corresponding electron capture rates in supernovae were calculated. Data from the TRIUMF (n,p) experiments at 198 MeV were reanalyzed; the electron capture rates for the reanalyzed data are in moderately good agreement with the higher resolution (p,n) results, but differ in detail. The possibility of future measurements with radioactive nuclei was considered. Conclusions: It is possible to determine electron capturestrength from (p,n) experiments. This approach may make it possible to obtain electron capture strength for radioactive nuclei by studying (p,n) reactions in inverse kinematics.Comment: Submitted to Physical Review

    Theorems on shear-free perfect fluids with their Newtonian analogues

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    In this paper we provide fully covariant proofs of some theorems on shear-free perfect fluids. In particular, we explicitly show that any shear-free perfect fluid with the acceleration proportional to the vorticity vector (including the simpler case of vanishing acceleration) must be either non-expanding or non-rotating. We also show that these results are not necessarily true in the Newtonian case, and present an explicit comparison of shear-free dust in Newtonian and relativistic theories in order to see where and why the differences appear.Comment: 23 pages, LaTeX. Submitted to GR

    Classification of bicovariant differential calculi on the Jordanian quantum groups GL_{g,h}(2) and SL_{h}(2) and quantum Lie algebras

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    We classify all 4-dimensional first order bicovariant calculi on the Jordanian quantum group GL_{h,g}(2) and all 3-dimensional first order bicovariant calculi on the Jordanian quantum group SL_{h}(2). In both cases we assume that the bicovariant bimodules are generated as left modules by the differentials of the quantum group generators. It is found that there are 3 1-parameter families of 4-dimensional bicovariant first order calculi on GL_{h,g}(2) and that there is a single, unique, 3-dimensional bicovariant calculus on SL_{h}(2). This 3-dimensional calculus may be obtained through a classical-like reduction from any one of the three families of 4-dimensional calculi on GL_{h,g}(2). Details of the higher order calculi and also the quantum Lie algebras are presented for all calculi. The quantum Lie algebra obtained from the bicovariant calculus on SL_{h}(2) is shown to be isomorphic to the quantum Lie algebra we obtain as an ad-submodule within the Jordanian universal enveloping algebra U_{h}(sl(2)) and also through a consideration of the decomposition of the tensor product of two copies of the deformed adjoint module. We also obtain the quantum Killing form for this quantum Lie algebra.Comment: 33 pages, AMSLaTeX, misleading remark remove

    Uncertainty in On-The-Fly Epidemic Fitting

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    Abstract. The modern world features a plethora of social, technolog-ical and biological epidemic phenomena. These epidemics now spread at unprecedented rates thanks to advances in industrialisation, trans-port and telecommunications. Effective real-time decision making and management of modern epidemic outbreaks depends on the two factors: the ability to determine epidemic parameters as the epidemic unfolds, and the ability to characterise rigorously the uncertainties inherent in these parameters. This paper presents a generic maximum-likelihood-based methodology for online epidemic fitting of SIR models from a single trace which yields confidence intervals on parameter values. The method is fully automated and avoids the laborious manual efforts tra-ditionally deployed in the modelling of biological epidemics. We present case studies based on both synthetic and real data

    Nuclear Transparency to Intermediate-Energy Protons

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    Nuclear transparency in the (e,e'p) reaction for 135 < Tp < 800 MeV is investigated using the distorted wave approximation. Calculations using density-dependent effective interactions are compared with phenomenological optical potentials. Nuclear transparency is well correlated with proton absorption and neutron total cross sections. For Tp < 300 MeV there is considerable sensitivity to the choice of optical model, with the empirical effective interaction providing the best agreement with transparency data. For Tp > 300 MeV there is much less difference between optical models, but the calculations substantially underpredict transparency data and the discrepancy increases with A. The differences between Glauber and optical model calculations are related to their respective definitions of the semi-inclusive cross section. By using a more inclusive summation over final states the Glauber model emphasizes nucleon-nucleon inelasticity, whereas with a more restrictive summation the optical model emphasizes nucleon-nucleus inelasticity; experimental definitions of the semi-inclusive cross section lie between these extremes.Comment: uuencoded gz-compressed tar file containing revtex and bbl files and 5 postscript figures, totalling 31 pages. Uses psfi

    British industrial relations pluralism in the era of neoliberalism

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    This article provides a broad overview of the pluralist tradition in UK industrial relations scholarship, identifying its defining characteristics and mapping its evolution in recent decades. It deals in turn with the following: the appreciation of the relative interests of workers and employers that lies at the heart of the pluralist frame of reference, the research agenda that flows from this understanding, pluralist conceptions of context and agency within industrial relations, the standards that pluralists habitually use when assessing the employment relationship, the targets and modes of critique that pluralists direct against intellectual opponents, and the prescriptions that pluralists offer for industrial relations reform. Throughout the article there is a focus on change within the pluralist tradition and the manner in which it has adapted to the hegemony of neoliberalism in the realms of both ideas and policy
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