663 research outputs found

    Universality of quantum Brownian motion

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    Are Markovian master equations for quantum Brownian motion independent of model assumptions used in the derivation and, thus, universal? With the aim of answering this question, we use a random band-matrix model for the system-bath interaction to derive Markovian master equations for the time evolution of one-dimensional quantum systems weakly coupled to a heat bath. We study in detail two simple systems, the harmonic oscillator and the two-level system. Our results are in complete agreement with those of earlier models, like the Caldeira-Legget model and, in the large-band limit, with the Agarwal equations (both with and without rotating-wave approximation). This proves the universality of these master equations.Comment: 24 page

    The Q223R polymorphism of the leptin receptor gene as a predictor of weight gain in childhood obesity and the identification of possible factors involved

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    Childhood rapid weight gain during development has been postulated as a predictor of obesity. The objective of this study was to investigate the effect of single nucleotide polymorphisms (SNPs) on the annual weight gain and height growth, as well as identifying possible lifestyle factors involved. (2) Methods: As part of the GENYAL study, 221 children (6–8 years old) of Madrid (Spain) were enrolled. A total of 11 SNPs associated with high childhood body mass indexes (BMIs) were assessed. Anthropometric measurements, dietary and physical activity data, were collected in 2017 and 2018. Bonferroni-corrected linear models were used to fit the data. (3) Results: A significant association between the Q223R LEPR and the weight growth was found, showing a different behavior between GA and GG genotypes (p = 0.001). Regarding lifestyle factors, an interaction between Q223R genotypes and total active weekly hours/week to predict the weight growth (kg/year) was observed (p = 0.023). In all the genotypes, a beneficial effect against rapid weight growth was observed, but the effect size of the interaction was much more significant in homozygous (GG) minor homozygous (β = −0.61 (−0.95, −0.26) versus heterozygous (AG) and wild-type homozygous (AA) genotypes (β = −0.07 (−0.24, 0.09) and β = −0.12 (−0.32, 0.08), respectively). (4) Conclusions: These results may contribute to more personalized recommendations to prevent childhood obesit

    The women professors in the Schoo lof Law Universidad de Buenos Aires

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    Este capítulo describe la situación actual de las mujeres profesoras de Derecho de la Facultad de Derecho de la Universidad de Buenos Aires (UBA). Concluye que, si bien, el avance experimentado por las mujeres de la academia jurídica dentro de la institución resulta significativo, es aún insuficiente para lograr la igualdad de género en el plantel docente. Esto no resulta sorprendente ya que refleja las características generales de la participación femenina en la esfera pública, a la que las mujeres se han incorporado en grandes proporciones pero aún encuentran grandes dificultades para alcanzar los cargos más altos.This chapter describes the current situation of women teaching Lawat the University of Buenos Aires (UBA) Law School and concludes that,however important, the progress experienced by women legal academicsfrom the University of Buenos Aires (UBA) Law School has proved in-sufficient to bring about gender equality.Fil: Kohen, Beatriz. Durham University; Reino Unido. Universidad de Palermo. Facultad de Derecho; ArgentinaFil: Ariza Navarrete, Sonia. Centro de Estudios de Estado y Sociedad; Argentina. Instituto Universitario Europeo en Derecho Comparado; EspañaFil: Ramallo, María de Los Ángeles. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Palermo. Facultad de Derecho; Argentina. Universidad de Buenos Aires. Facultad de Derecho. Instituto de Investigaciones Jurídicas y Sociales "Dr. Ambrosio L. Gioja"; Argentin

    Polymorphism of CLOCK gene rs3749474 as a modulator of the circadian evening carbohydrate intake impact on nutritional status in an adult sample

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    The aim of this study was to evaluate the distribution of energy intake and macronutrients consumption throughout the day, and how its effect on nutritional status can be modulated by the presence of the rs3749474 polymorphism of the CLOCK gene in the Cantoblanco Platform for Nutritional Genomics (“GENYAL Platform”). This cross-sectional study was carried out on 898 volunteers between 18 and 69 years old (65.5% women). Anthropometric measurements, social issues and health, dietary, biochemical, genetic, and physical activity data were collected. Subsequently, 21 statistical interaction models were designed to predict the body mass index (BMI) considering seven dietary variables analyzed by three genetic models (adjusted by age, sex, and physical activity). The average BMI was 26.9 ± 4.65 kg/m2, 62.14% presented an excess weight (BMI > 25 kg/m2). A significant interaction was observed between the presence of the rs3749474 polymorphism and the evening carbohydrate intake (% of the total daily energy intake [%TEI]) (adjusted p = 0.046), when predicting the BMI. Participants carrying TT/CT genotype showed a positive association between the evening carbohydrate intake (%TEI) and BMI (β = 0.3379, 95% CI = (0.1689,0.5080)) and (β = 0.1529, 95% CI = (−0.0164,0.3227)), respectively, whereas the wild type allele (CC) showed a negative association (β = −0.0321, 95% CI = (−0.1505,0.0862)). No significant interaction with the remaining model variables was identified. New dietary strategies may be implemented to schedule the circadian distribution of macronutrients according to the genotyp

    Asymmetric Inflationary Reheating and the Nature of Mirror Universe

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    The existence of a shadow world (or mirror universe) with matter and forces identical to that of the visible world but interacting with the latter only via gravity can be motivated by superstring theories as well as by recent attempts to understand the nature of a sterile neutrino needed if all known neutrino data are to be consistent with each other. A simple way to reconcile the constraints of big bang nucleosynthesis in such a theory is to postulate that the reheating temperature after inflation in the mirror universe is lower than that in the visible one. We have constructed explicit models that realize this proposal and have shown that the asymmetric reheating can be related to a difference of the electroweak symmetry breaking scales in the two sectors, which is needed for a solution of the neutrino puzzles in this picture. Cosmological implications of the mirror matter are also discussed.Comment: 13 pages, LATEX, no figures (slight textual changes, few references added

    Polymorphic appetite effects on waist circumference depend on rs3749474 CLOCK gene variant

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    Chronobiological aspects controlled by CLOCK genes may influence obesity incidence. Although there are studies that show an association between the expression of these genes and energy intake, waist circumference or abdominal obesity phenotypes, interactions with appetite have been insufficiently investigated in relation to chrononutrition. The objective was to identify interactions between CLOCK genetic variants involved in appetite status. A total of 442 subjects (329 women, 113 men; aged 18 to 65 years) were recruited. Anthropometric, dietary and lifestyle data were collected by trained nutritionists. Participants were classified according to their appetite feelings with a Likert scale. Multiple linear regression models were used to examine associations of the type genotype x appetite status on adiposity-related variables. p values were corrected by the Bonferroni method. A significant influence was found concerning the effects of appetite on waist circumference with respect to rs3749474 CLOCK polymorphism (p < 0.001). An additive model analysis (adjusted by age, gender, exercise and energy intake) showed that risk allele carriers, increased the waist circumference around 14 cm (β = 14.1, CI = 6.3–22.0) by each increment in the level of appetite. The effects of appetite on waist circumference may be partly modulated by the rs3749474 CLOCK polymorphism

    Test Particle in a Quantum Gas

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    A master equation with a Lindblad structure is derived, which describes the interaction of a test particle with a macroscopic system and is expressed in terms of the operator valued dynamic structure factor of the system. In the case of a free Fermi or Bose gas the result is evaluated in the Brownian limit, thus obtaining a single generator master equation for the description of quantum Brownian motion in which the correction due to quantum statistics is explicitly calculated. The friction coefficients for Boltzmann and Bose or Fermi statistics are compared.Comment: 9 pages, revtex, no figure

    Visual hallucinations associated with varenicline: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Varenicline is widely used for smoking cessation. It has shown efficacy over placebo and bupropion in manufacturer-sponsored trials. Those with mental illness were excluded from these trials. There are case reports of exacerbation of mental illness and development of psychiatric symptoms with varenicline use.</p> <p>Case presentation</p> <p>A 61-year-old male Caucasian being treated for post-traumatic stress disorder, depression not otherwise specified and alcohol dependence, was prescribed varenicline while he was in a post-traumatic stress disorder/alcohol dual diagnosis treatment program. He developed visual hallucinations, which became worse with titration of the medication. These symptoms resolved upon discontinuation of varenicline.</p> <p>Conclusion</p> <p>Patients with mental illness have a higher incidence of nicotine dependence, and attempts should be made for smoking cessation. Varenicline has not been widely tested in this population. There are reports of exacerbation of mental illness, and probable causation of psychiatric symptoms in the mentally ill. Providers should be aware of this possibility and advise their patients appropriately.</p

    Spin-polarized proximity effect in superconducting junctions

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    We study spin dependent phonomena in superconducting junctions in both ballistic and diffusive regimes. For ballistic junctions we study both ferromagnet / ss- and d-wave superconductor junctions and two dimensional electron gas / s-wave superconductor junctions with Rashba spin-orbit coupling. It is shown that the exchange field alway suppresses the conductance while the Rashba spin-orbit coupling can enhance it. In the latter part of the article we study the diffusive ferromagnet / insulator / ss- and d-wave superconductor junctions, where the proximity effect can be enhanced by the exchange field in contrast to common belief. It is shown that the resonant proximity effect originating from the exchange field strongly influences the tunneling conductance and density of states.Comment: 14 pages, 7 figures, submitted to Comptes Rendus de l'Acadeacute;mie des Sciences (Comptes Rendus Physique) Special Issue " Magnetism and Superconductivity Coexistence". Figures 4-7 are modified in v
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