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

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

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

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

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

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

Bolide summer: The Paleocene/Eocene thermal maximum as a response to an extraterrestrial trigger

The standard paradigm that the Paleocene/Eocene thermal maximum (PETM) represents a threshold event intrinsic to Earth's climate and connected in some way with long-term warming has influenced interpretations of the geochemical, climate, and biological perturbations that occurred at this event. As recent high-resolution data have demonstrated that the onset of the event was geologically instantaneous, attempts to account for the event solely through endogenous mechanisms have become increasingly strained. The rapid onset of the event indicates that it was triggered by a catastrophic event which we suggest was most likely a bolide impact. We discuss features of the PETM that require explanation and argue that mechanisms that have previously been proposed either cannot explain all of these features or would require some sort of high-energy trigger. A bolide impact could provide such a trigger and, in the event of a comet impact, could contribute directly to the shape of the carbon isotope curve. We introduce a carbon cycle model that would explain the PETM by global warming following a bolide impact, leading to the oxidation of terrestrial organic carbon stores built up during the late Paleocene. Our intention is to encourage other researchers to seriously consider an impact trigger for the PETM, especially in the absence of plausible alternative mechanisms

Parametric instabilities in magnetized multicomponent plasmas

This paper investigates the excitation of various natural modes in a magnetized bi-ion or dusty plasma. The excitation is provided by parametrically pumping the magnetic field. Here two ion-like species are allowed to be fully mobile. This generalizes our previous work where the second heavy species was taken to be stationary. Their collection of charge from the background neutral plasma modifies the dispersion properties of the pump and excited waves. The introduction of an extra mobile species adds extra modes to both these types of waves. We firstly investigate the pump wave in detail, in the case where the background magnetic field is perpendicular to the direction of propagation of the pump wave. Then we derive the dispersion equation relating the pump to the excited wave for modes propagating parallel to the background magnetic field. It is found that there are a total of twelve resonant interactions allowed, whose various growth rates are calculated and discussed.Comment: Published in May 2004; this is a late submission to the archive. 14 pages, 8 figure