Thermal transport in strongly correlated electron systems

Thermal conductivity and thermopower measurements in strongly correlated electron systems at low temperature

Rapidly Rotating Fermions in an Anisotropic Trap

We consider a cold gas of non-interacting fermions in a two dimensional harmonic trap with two different trapping frequencies $\omega_x \leq \omega_y$, and discuss the effect of rotation on the density profile. Depending on the rotation frequency $\Omega$ and the trap anisotropy $\omega_y/\omega_x$, the density profile assumes two qualitatively different shapes. For small anisotropy ($\omega_y/\omega_x \ll \sqrt{1+4 \Omega^2/\omega_x^2}$), the density consists of elliptical plateaus of constant density, corresponding to Landau levels and is well described by a two dimensional local density approximation. For large anisotropy ($\omega_y/\omega_x \gg \sqrt{1+4 \Omega^2/\omega_x^2}$), the density profile is Gaussian in the strong confining direction and semicircular with prominent Friedel oscillations in the weak direction. In this regime, a one dimensional local density approximation is well suited to describe the system. The crossover between the two regimes is smooth where the step structure between the Landau level edges turn into Friedel oscillations. Increasing the temperature causes the step structure or the Friedel oscillations to wash out leaving a Boltzmann gas density profile.Comment: 14 pages, 7 figure

Thermal transport in strongly correlated electron systems

Thermal conductivity and thermopower measurements in strongly correlated electron systems at low temperature

Flux flow in current driven mesoscopic superconductors: size effects

Flux-flow phenomena in a superconducting mesoscopic stripe submitted to an appliedcurrent and external magnetic field is studied. The time-dependent Ginzburg-Landauequations are solved numerically to obtain the electric and magnetic response of thesystem. It is shown that the I-V curves, for the wider strips, present a universalbehaviour. The dependence of the flux-flow resistivity on the magnetic field and widthallow us to propose a criterion characterizing, both, the macroscopic and mesoscopicregimes. The power spectrum of the average voltage permits identifying the effect ofsurface currents in vortices movement. Based on the maximum value of the power spectrumfirst harmonic we propose a geometric condition for matching between the sample dimensionsand the vortex lattice parameter.Fil: Sanchez Lotero, Pedro Nel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidade Federal de Pernambuco; BrasilFil: Domínguez, Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; ArgentinaFil: Albino Aguiar, J.. Universidade Federal de Pernambuco; Brasi

Un acercamiento a los dilemas bioéticos de la enfermedad y la muerte a partir de un ejercicio de análisis cinematográfico

Resumen En este artículo se presenta la perspectiva hermenéutica con relación a los dilemas bioéticos sobre la enfermedad y la muerte, tomando como referencia tres películas: Antes de partir (director: Rob Reiner), Mi vida sin mí (directora: Isabel Coixet), y La decisión más difícil (director: Nick Cassavetes). Se exponen aquí el análisis de las narraciones y aspectos semióticos encontrados en las obras, utilizando fichas recopilatorias de aspectos importantes de las películas y del seguimiento bibliográfico. Se encontró como los temas más retratados por los directores son el miedo a la muerte y a la enfermedad, el proceso de duelo y la angustia frente al futuro, aspectos muy existencialistas que fueron interpretados desde enfoques humanistas, éticos y psicosociales, demostrando la validez y vigencia del uso de los trabajos fílmicos como apoyo metódico para el estudio de estos temas de interés bioético

Risk factors associated with sexually transmitted infections and HIV among adolescents in a reference clinic in Madrid.

INTRODUCTION:Adolescents have a higher incidence of sexually transmitted infections (STIs) than persons of older age groups. The WHO emphasises the need to adopt specific and comprehensive prevention programmes aimed at this age group. The objective of this work was to analyse the prevalence of HIV/STIs among adolescents and to identify the sociodemographic, clinical and behavioural markers associated with these infections, in order to promote specific preventive strategies. METHODOLOGY:Retrospective descriptive study of adolescents, aged 10-19 years, who were attended to for the first consultation between 2016 and 2018 in a reference STI clinic in Madrid. All adolescents were given a structured epidemiological questionnaire where information on sociodemographic, clinical and behavioural characteristics was collected. They were screened for human inmmunodeficiency virus (HIV) and other sexually transmitted infections (STIs). The processing and analysis of the data was done using the STATA 15.0 statistical package. RESULTS:The frequency of HIV/STIs detected among all adolescents was: gonorrhoea 21.7%, chlamydia 17.1%, syphilis 4.8% and HIV 2.4%. After conducting a multivariate analysis, the independent and statistically significant variables related to the presence of an STI were having first sexual relations at a young age and having a history of STIs. Latin American origin was just below the level of statistical significance (p = 0.066). DISCUSSION/CONCLUSIONS:Adolescents who begin sexual relations at an early age or those who have a history of HIV/STIs are at higher risk of acquiring STIs. Comprehensive prevention programmes aimed specifically at adolescents should be implemented, especially before the age of 13 years