8,438 research outputs found

    Correlation between genetic polymorphisms and stroke recovery: analysis of the GAIN Americas and GAIN International Studies

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    BACKGROUND AND PURPOSE: Recovery after stroke occurs on the basis of specific molecular events. Genetic polymorphisms associated with impaired neural repair or plasticity might reduce recovery from stroke and might also account for some of the intersubject variability in stroke recovery. This study hypothesized that the ApoE epsilon4 polymorphism and the val(66) met polymorphism for brain-derived neurotrophic factor (BDNF) are each associated with poorer outcome after stroke. Associations with mitochondrial genotype were also explored. METHODS: Genotypes were determined in 255 stroke patients who also received behavioral evaluations in the Glycine Antagonist In Neuroprotection (GAIN) clinical trials. The primary outcome measure was recovery during the first month post-stroke, as this is the time when neural repair is at a maximum and so when genetic influences might have their largest impact. Two secondary outcome measures at 3 months post-stroke were also examined. RESULTS: Genotype groups were similar acutely post-stroke. Presence of the ApoE epsilon4 polymorphism was associated with significantly poorer recovery over the first month post-stroke (P = 0.023) and with a lower proportion of subjects with minimal or no disability (modified Rankin score 0-1, P = 0.01) at 3 months post-stroke. Indeed, those with this polymorphism were approximately half as likely to achieve minimal or no disability (18.2%) versus those with polymorphism absent (35.5%). Findings were confirmed in multivariate models. Results suggested possible effects from the val(66) met BDNF polymorphism and from the R0 mitochondrial DNA haplotype. CONCLUSIONS: Genetic factors, particularly the ApoE epsilon4 polymorphism, might contribute to variability in outcomes after stroke

    IMPACT OF PESTICIDE REGULATORY POLICIES ON U.S. RICE PRODUCTION

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    This paper examines the costs and benefits of pesticide regulations on US rice production. Benefit - cost analysis of FIFRA (The Federal Insecticide, Fungicide, and Rodenticide Act) has been done taking into consideration the externality costs associated with the Endangered Species Act and the Worker Protection Standard, for which compliance under FIFRA has become mandatory since 1990.Pesticide regulation, Agricultural and Food Policy, Environmental Economics and Policy,

    Understanding Eating Behaviors of New Dehli\u27s Youth

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    This qualitative study documents perceived benefits of and barriers to engaging in healthy eating behaviors among adolescents in New Delhi, India. Researchers explored factors that influenced the consumption of breakfast, fruits and vegetables, and soft drinks in this population and adolescents’ ideas about how to intervene to encourage or discourage, respectively, these behaviors. Students (n=151 6th and 8th graders) from five private schools participated in focus group discussions. Findings showed that the majority of youth eat breakfast that may consist of traditional and Western choices. Despite sound knowledge of the benefits of fruits and vegetables consumption, adolescents do not eat the recommended daily servings due to flavor preferences. Soft drink consumption was, reportedly, universal. Several factors influenced these decisions and details are herein provided. The paucity of studies on this subject provides researchers with the opportunity to explore how eating patterns of Indian youth might be shaping the health and disease landscape of India in the upcoming decades. The study adds to the slim body of literature on the subject and could be used to inform future nutrition interventions in India

    A quantum central limit theorem for non-equilibrium systems: Exact local relaxation of correlated states

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    We prove that quantum many-body systems on a one-dimensional lattice locally relax to Gaussian states under non-equilibrium dynamics generated by a bosonic quadratic Hamiltonian. This is true for a large class of initial states - pure or mixed - which have to satisfy merely weak conditions concerning the decay of correlations. The considered setting is a proven instance of a situation where dynamically evolving closed quantum systems locally appear as if they had truly relaxed, to maximum entropy states for fixed second moments. This furthers the understanding of relaxation in suddenly quenched quantum many-body systems. The proof features a non-commutative central limit theorem for non-i.i.d. random variables, showing convergence to Gaussian characteristic functions, giving rise to trace-norm closeness. We briefly relate our findings to ideas of typicality and concentration of measure.Comment: 27 pages, final versio

    The thermal and two-particle stress-energy must be ill-defined on the 2-d Misner space chronology horizon

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    We show that an analogue of the (four dimensional) image sum method can be used to reproduce the results, due to Krasnikov, that for the model of a real massless scalar field on the initial globally hyperbolic region IGH of two-dimensional Misner space there exist two-particle and thermal Hadamard states (built on the conformal vacuum) such that the (expectation value of the renormalised) stress-energy tensor in these states vanishes on IGH. However, we shall prove that the conclusions of a general theorem by Kay, Radzikowski and Wald still apply for these states. That is, in any of these states, for any point b on the Cauchy horizon and any neighbourhood N of b, there exists at least one pair of non-null related points (x,x'), with x and x' in the intersection of IGH with N, such that (a suitably differentiated form of) its two-point function is singular. (We prove this by showing that the two-point functions of these states share the same singularities as the conformal vacuum on which they are built.) In other words, the stress-energy tensor in any of these states is necessarily ill-defined on the Cauchy horizon.Comment: 6 pages, LaTeX, RevTeX, no figure

    Parametric instability in dark molecular clouds

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    The present work investigates the parametric instability of parallel propagating circularly polarized Alfven(pump) waves in a weakly ionized molecular cloud. It is shown that the relative drift between the plasma particles gives rise to the Hall effect resulting in the modified pump wave characteristics. Although the linearized fluid equations with periodic coefficients are difficult to solve analytically, it is shown that a linear transformation can remove the periodic dependence. The resulting linearized equations with constant coefficients are used to derive an algebraic dispersion relation. The growth rate of the parametric instability is a sensitive function of the amplitude of the pump wave as well as to the ratio of the pump and the modified dust-cyclotron frequencies. The instability is insensitive to the plasma-beta The results are applied to the molecular clouds.Comment: 27 page, 5 figures, accepted in Ap

    Chosen-ciphertext security from subset sum

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    We construct a public-key encryption (PKE) scheme whose security is polynomial-time equivalent to the hardness of the Subset Sum problem. Our scheme achieves the standard notion of indistinguishability against chosen-ciphertext attacks (IND-CCA) and can be used to encrypt messages of arbitrary polynomial length, improving upon a previous construction by Lyubashevsky, Palacio, and Segev (TCC 2010) which achieved only the weaker notion of semantic security (IND-CPA) and whose concrete security decreases with the length of the message being encrypted. At the core of our construction is a trapdoor technique which originates in the work of Micciancio and Peikert (Eurocrypt 2012

    CARDIAC TRANSPLANTATION IN THE RAT

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