169 research outputs found

    Impacto del Síndrome de Burnout Académico en el Bajo Rendimiento y la Salud Mental en Estudiantes Universitarios

    Get PDF
    El articulo reflexiona sobre la influencia del síndrome de burnout académico y su impacto en el promedio académico y la salud mental de un grupo de estudiantes de Ciencias de la Salud de una Universidad Privada del Caribe Colombiano. La población fueron estudiantes de Medicina, Odontología y Enfermería de una Universidad Privada de la ciudad de Santa Marta, Colombia, los Resultados evidenciaron que el 68% de los estudiantes presentaron promedio académico alto, el 25% medio y el 18% excelente. Se concluye que el síndrome de burnout académico, en particular el alto nivel de agotamiento emocional presente en los estudiantes, no afecta el promedio académico de los participantes, pero si puede alterar su salud mental

    A Possible Crypto-Superconducting Structure in a Superconducting Ferromagnet

    Full text link
    We have measured the dc and ac electrical and magnetic properties in various magnetic fields of the recently reported superconducting ferromagnet RuSr2GdCu2O8. Our reversible magnetization measurements demonstrate the absence of a bulk Meissner state in the compound below the superconducting transition temperature. Several scenarios that might account for the absence of a bulk Meissner state, including the possible presence of a sponge-like non-uniform superconducting or a crypto-superconducting structure in the chemically uniform Ru-1212, have been proposed and discussed.Comment: 8 pages, 5 PNG figures, submitted to Proceedings of the 9th Japan-US Workshop on High-Tc Superconductors, Yamanashi, Japan, October 13-15, 1999; accepted for publication in Physica C (December 24, 1999

    Effect of structural defects on anomalous ultrasound propagation in solids during second-order phase transitions

    Full text link
    The effect of structural defects on the critical ultrasound attenuation and ultrasound velocity dispersion in Ising-like three-dimensional systems is studied. A field-theoretical description of the dynamic effects of acoustic-wave propagation in solids during phase transitions is performed with allowance for both fluctuation and relaxation attenuation mechanisms. The temperature and frequency dependences of the scaling functions of the attenuation coefficient and the ultrasound velocity dispersion are calculated in a two-loop approximation for pure and structurally disordered systems, and their asymptotic behavior in hydrodynamic and critical regions is separated. As compared to a pure system, the presence of structural defects in it is shown to cause a stronger increase in the sound attenuation coefficient and the sound velocity dispersion even in the hydrodynamic region as the critical temperature is reached. As compared to pure analogs, structurally disordered systems should exhibit stronger temperature and frequency dependences of the acoustic characteristics in the critical region.Comment: 7 RevTeX pages, 4 figure

    Connecting

    Get PDF
    Helen Walker - More Apt, Connected Title Sheryl Lain - Hey, Teach! Do You Love Me? Matthew B. Ittig - Ask Me Tomorrow Laurence Musgrove - Writing Program Julie O’Connell - The Power of a Slave Narrative Leslie A. Werden - Embracing Chaos Donna Souder-Hodge - Teaching Dachau Tanya R. Cochran, Rasha Diab, Thomas Ferrel, & Beth Godbee - Hanging Out: Cultivating Life-Giving Writing Groups Onlin

    Anomalous fluctuations of the condensate in interacting Bose gases

    Full text link
    We find that the fluctuations of the condensate in a weakly interacting Bose gas confined in a box of volume VV follow the law V4/3\sim V^{4/3}. This anomalous behaviour arises from the occurrence of infrared divergencies due to phonon excitations and holds also for strongly correlated Bose superfluids. The analysis is extended to an interacting Bose gas confined in a harmonic trap where the fluctuations are found to exhibit a similar anomaly.Comment: 4 pages, RevTe

    Analysis of Stochastic Strategies in Bacterial Competence: A Master Equation Approach

    Get PDF
    Competence is a transiently differentiated state that certain bacterial cells reach when faced with a stressful environment. Entrance into competence can be attributed to the excitability of the dynamics governing the genetic circuit that regulates this cellular behavior. Like many biological behaviors, entrance into competence is a stochastic event. In this case cellular noise is responsible for driving the cell from a vegetative state into competence and back. In this work we present a novel numerical method for the analysis of stochastic biochemical events and use it to study the excitable dynamics responsible for competence in Bacillus subtilis. Starting with a Finite State Projection (FSP) solution of the chemical master equation (CME), we develop efficient numerical tools for accurately computing competence probability. Additionally, we propose a new approach for the sensitivity analysis of stochastic events and utilize it to elucidate the robustness properties of the competence regulatory genetic circuit. We also propose and implement a numerical method to calculate the expected time it takes a cell to return from competence. Although this study is focused on an example of cell-differentiation in Bacillus subtilis, our approach can be applied to a wide range of stochastic phenomena in biological systems

    Critical behavior of the three-dimensional XY universality class

    Full text link
    We improve the theoretical estimates of the critical exponents for the three-dimensional XY universality class. We find alpha=-0.0146(8), gamma=1.3177(5), nu=0.67155(27), eta=0.0380(4), beta=0.3485(2), and delta=4.780(2). We observe a discrepancy with the most recent experimental estimate of alpha; this discrepancy calls for further theoretical and experimental investigations. Our results are obtained by combining Monte Carlo simulations based on finite-size scaling methods, and high-temperature expansions. Two improved models (with suppressed leading scaling corrections) are selected by Monte Carlo computation. The critical exponents are computed from high-temperature expansions specialized to these improved models. By the same technique we determine the coefficients of the small-magnetization expansion of the equation of state. This expansion is extended analytically by means of approximate parametric representations, obtaining the equation of state in the whole critical region. We also determine the specific-heat amplitude ratio.Comment: 61 pages, 3 figures, RevTe

    High Magnetic Shear Gain in a Liquid Sodium Stable Couette Flow Experiment; A Prelude to an alpha-Omega Dynamo

    Full text link
    The Ω\Omega-phase of the liquid sodium α\alpha-Ω\Omega dynamo experiment at NMIMT in cooperation with LANL has successfully demonstrated the production of a high toroidal field, Bϕ8×BrB_{\phi} \simeq 8\times B_r from the radial component of an applied poloidal magnetic field, BrB_r. This enhanced toroidal field is produced by rotational shear in stable Couette flow within liquid sodium at Rm120Rm \simeq 120. The small turbulence in stable Taylor-Couette flow is caused by Ekman flow where (δv/v)2103 (\delta v/v)^2 \sim 10^{-3} . This high Ω\Omega-gain in low turbulence flow contrasts with a smaller Ω\Omega-gain in higher turbulence, Helmholtz-unstable shear flows. This result supports the ansatz that large scale astrophysical magnetic fields are created within semi-coherent large scale motions in which turbulence plays only a smaller diffusive role that enables magnetic flux linkage.Comment: 5 pages, 5 figures, submitted PRL revised version: add one author, minor typo'

    Analytic structure factors and pair-correlation functions for the unpolarized homogeneous electron gas

    Full text link
    We propose a simple and accurate model for the electron static structure factors (and corresponding pair-correlation functions) of the 3D unpolarized homogeneous electron gas. Our spin-resolved pair-correlation function is built up with a combination of analytic constraints and fitting procedures to quantum Monte Carlo data, and, in comparison to previous attempts (i) fulfills more known integral and differential properties of the exact pair-correlation function, (ii) is analytic both in real and in reciprocal space, and (iii) accurately interpolates the newest, extensive diffusion-Monte Carlo data of Ortiz, Harris and Ballone [Phys. Rev. Lett. 82, 5317 (1999)]. This can be of interest for the study of electron correlations of real materials and for the construction of new exchange and correlation energy density functionals.Comment: 14 pages, 5 figures, submitted to Phys. Rev.

    Improved high-temperature expansion and critical equation of state of three-dimensional Ising-like systems

    Full text link
    High-temperature series are computed for a generalized 3d3d Ising model with arbitrary potential. Two specific ``improved'' potentials (suppressing leading scaling corrections) are selected by Monte Carlo computation. Critical exponents are extracted from high-temperature series specialized to improved potentials, achieving high accuracy; our best estimates are: γ=1.2371(4)\gamma=1.2371(4), ν=0.63002(23)\nu=0.63002(23), α=0.1099(7)\alpha=0.1099(7), η=0.0364(4)\eta=0.0364(4), β=0.32648(18)\beta=0.32648(18). By the same technique, the coefficients of the small-field expansion for the effective potential (Helmholtz free energy) are computed. These results are applied to the construction of parametric representations of the critical equation of state. A systematic approximation scheme, based on a global stationarity condition, is introduced (the lowest-order approximation reproduces the linear parametric model). This scheme is used for an accurate determination of universal ratios of amplitudes. A comparison with other theoretical and experimental determinations of universal quantities is presented.Comment: 65 pages, 1 figure, revtex. New Monte Carlo data by Hasenbusch enabled us to improve the determination of the critical exponents and of the equation of state. The discussion of several topics was improved and the bibliography was update
    corecore