4,584 research outputs found

    Screening tests, information, and the health-education gradient

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    The association between health outcomes and education - the health-education gradient - is widely documented but little is known about its source. Using microeconomic data on a sample of individuals aged 50+ in eight European countries, we find that education and cognitive skills (such as verbal fluency) are associated with a greater propensity for standard screening tests (mammography and colonoscopy). In order to study the role of information on the decision to screen, we test whether the health-education gradient varies with the quality of the information provided by the health care system, as proxied by the quality of the General Practitioner. Using an Instrumental Variable approach to control for the potential endogeneity of the GP quality score, we find evidence of a strong and significant complementarity between education and quality of primary care. We interpret this result as evidence that health-education gradient can be explained, at least in part, by the fact that better educated individuals are more able to process and internalize health related information as provided by GPs

    A Computing Method for Sound Propagation Through a Nonuniform Jet Stream

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    Understanding the principles of jet noise propagation is an essential ingredient of systematic noise reduction research. High speed computer methods offer a unique potential for dealing with complex real life physical systems whereas analytical solutions are restricted to sophisticated idealized models. The classical formulation of sound propagation through a jet flow was found to be inadequate for computer solutions and a more suitable approach was needed. Previous investigations selected the phase and amplitude of the acoustic pressure as dependent variables requiring the solution of a system of nonlinear algebraic equations. The nonlinearities complicated both the analysis and the computation. A reformulation of the convective wave equation in terms of a new set of dependent variables is developed with a special emphasis on its suitability for numerical solutions on fast computers. The technique is very attractive because the resulting equations are linear in nonwaving variables. The computer solution to such a linear system of algebraic equations may be obtained by well-defined and direct means which are conservative of computer time and storage space. Typical examples are illustrated and computational results are compared with available numerical and experimental data

    Integrated structure electromagnetic optimization of large space antenna reflectors

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    The requirements for extremely precise and powerful large space antenna reflectors have motivated the development of a procedure for shape control of the reflector surface. A mathematical optimization procedure has been developed which improves antenna performance while minimizing necessary shape correction effort. In contrast to previous work which proposed controlling the rms distortion error of the surface thereby indirectly improving antenna performance, the current work includes electromagnetic (EM) performance calculations as an integral of the control procedure. The application of the procedure to a radiometer design with a tetrahedral truss backup structure demonstrates the potential for significant improvement. The results indicate the benefit of including EM performance calculations in procedures for shape control of large space antenna reflectors

    Determination of Ganciclovir in Plasma of Newborns with Congenital CMV Infection

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    Infections caused by human cytomegalovirus are important causes of fetal and neonatal morbidity and mortality. Ganciclovir ([(9-(1,3-dihydroxy-2- propoxymethyl) guanine, GCV) is a synthetic acyclic nucleoside which has shown activity against Cytomegalovirus. GCV treatment has been associated with serious toxic hematological effects such as neutropenia and leukopenia, thus drug monitoring is needed, especially in the case of newborns. The aim of the work is to develop and validate an HPLC method for the quantification of GCV in plasm

    Phase-space density in heavy-ion collisions revisited

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    We derive the phase space density of bosons from a general boson interferometry formula. We find that the phase space density is connected with the two-particles and the single particle density distribution functions. If the boson density is large, the two particles density distribution function can not be expressed as a product of two single particle density distributions. However, if the boson density is so small that two particles density distribution function can be expressed as a product of two single particle density distributions, then Bertsch's formula is recovered. For a Gaussian model, the effects of multi-particles Bose-Einstein correlations on the mean phase space density are studied.Comment: 18 Pages, Four eps files, EPJC in Pres

    Small size boundary effects on two-pion interferometry

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    The Bose-Einstein correlations of two identically charged pions are derived when these particles, the most abundantly produced in relativistic heavy ion collisions, are confined in finite volumes. Boundary effects on single pion spectrum are also studied. Numerical results emphasize that conventional formulation usually adopted to describe two-pion interferometry should not be used when the source size is small, since this is the most sensitive case to boundary effects. Specific examples are considered for better illustration.Comment: more discussion on Figure4 and diffuse boundar

    The repayment of unsecured debt by European households

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    The existing literature that estimates the incidence of arrears relies on either household survey data or administrative data derived from the lender's records of their borrowers. But estimates based on these different sources will give different estimates of arrears. Moreover, the estimates are not useful for policy analysis or for a bank's lending decision, since they ignore the fact that some households do not borrow. The paper discusses the selection issues that are involved in using either source of data and is the first paper to bound the estimate of the household's underlying propensity to repay. To demonstrate the methodology, it uses data from the European Union Survey of Income and Living Conditions survey for 2008 to estimate the factors that affect repayment among Eurozone households
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