Experiencia de evaluación externa de las Universidades

Este artículo se propone analizar la evaluación externa de la enseñanza, la investigación y los servicios académicos de las titulaciones en el contexto del Plan Nacional de Evaluación de la Calidad de las Universidades (Consejo de Universidades, 1995) y del Programa de Evaluación de la Calidad de la Enseñanza Superior de la Universitat de Barcelona (1995). Los procedimientos e instrumentos para cada fase de evaluación son presentados en otros artículos del número 315 de esta Revista (Rodríguez, 1998). Por lo tanto, tras una breve contextualización nos centraremos en el análisis de las condiciones previas, del desarrollo del proceso y de los resultados de la experiencia de la evaluación externa

Explicit coercivity estimates for the linearized Boltzmann and Landau operators

We prove explicit coercivity estimates for the linearized Boltzmann and Landau operators, for a general class of interactions including any inverse-power law interactions, and hard spheres. The functional spaces of these coercivity estimates depend on the collision kernel of these operators. They cover the spectral gap estimates for the linearized Boltzmann operator with Maxwell molecules, improve these estimates for hard potentials, and are the first explicit coercivity estimates for soft potentials (including in particular the case of Coulombian interactions). We also prove a regularity property for the linearized Boltzmann operator with non locally integrable collision kernels, and we deduce from it a new proof of the compactness of its resolvent for hard potentials without angular cutoff.Comment: 32 page

Blow-up of the hyperbolic Burgers equation

The memory effects on microscopic kinetic systems have been sometimes modelled by means of the introduction of second order time derivatives in the macroscopic hydrodynamic equations. One prototypical example is the hyperbolic modification of the Burgers equation, that has been introduced to clarify the interplay of hyperbolicity and nonlinear hydrodynamic evolution. Previous studies suggested the finite time blow-up of this equation, and here we present a rigorous proof of this fact

Strong Shock Waves and Nonequilibrium Response in a One-dimensional Gas: a Boltzmann Equation Approach

We investigate the nonequilibrium behavior of a one-dimensional binary fluid on the basis of Boltzmann equation, using an infinitely strong shock wave as probe. Density, velocity and temperature profiles are obtained as a function of the mixture mass ratio \mu. We show that temperature overshoots near the shock layer, and that heavy particles are denser, slower and cooler than light particles in the strong nonequilibrium region around the shock. The shock width w(\mu), which characterizes the size of this region, decreases as w(\mu) ~ \mu^{1/3} for \mu-->0. In this limit, two very different length scales control the fluid structure, with heavy particles equilibrating much faster than light ones. Hydrodynamic fields relax exponentially toward equilibrium, \phi(x) ~ exp[-x/\lambda]. The scale separation is also apparent here, with two typical scales, \lambda_1 and \lambda_2, such that \lambda_1 ~ \mu^{1/2} as \mu-->0$, while \lambda_2, which is the slow scale controlling the fluid's asymptotic relaxation, increases to a constant value in this limit. These results are discussed at the light of recent numerical studies on the nonequilibrium behavior of similar 1d binary fluids.Comment: 9 pages, 8 figs, published versio

Detection of the glucocorticoid receptors in brain protein extracts by SDS-PAGE

Uncorrected proofGlucocorticoids are steroid hormones vital for organ system homeostasis and for the maintenance of essential biological processes. A significant part of these actions are mediated through glucocorticoid receptor (GR) that belongs to the nuclear receptor superfamily. To cover such variety of processes the different glucocorticoids act through different GR isoforms that are originated due to posttranscriptional and posttranslational mechanisms. For this reason when evaluating the levels of GRs we should preferentially determine protein levels instead of gene expression. Here, we describe the detection by Western blotting of the GR (a and ß isoforms) protein, using macrodissected brain tissue

Relativistic Dissipative Hydrodynamics: A Minimal Causal Theory

We present a new formalism for the theory of relativistic dissipative hydrodynamics. Here, we look for the minimal structure of such a theory which satisfies the covariance and causality by introducing the memory effect in irreversible currents. Our theory has a much simpler structure and thus has several advantages for practical purposes compared to the Israel-Stewart theory (IS). It can readily be applied to the full three-dimensional hydrodynamical calculations. We apply our formalism to the Bjorken model and the results are shown to be analogous to the IS.Comment: 25 pages, 2 figures, Phys. Rev. C in pres

A causal statistical family of dissipative divergence type fluids

In this paper we investigate some properties, including causality, of a particular class of relativistic dissipative fluid theories of divergence type. This set is defined as those theories coming from a statistical description of matter, in the sense that the three tensor fields appearing in the theory can be expressed as the three first momenta of a suitable distribution function. In this set of theories the causality condition for the resulting system of hyperbolic partial differential equations is very simple and allow to identify a subclass of manifestly causal theories, which are so for all states outside equilibrium for which the theory preserves this statistical interpretation condition. This subclass includes the usual equilibrium distributions, namely Boltzmann, Bose or Fermi distributions, according to the statistics used, suitably generalized outside equilibrium. Therefore this gives a simple proof that they are causal in a neighborhood of equilibrium. We also find a bigger set of dissipative divergence type theories which are only pseudo-statistical, in the sense that the third rank tensor of the fluid theory has the symmetry and trace properties of a third momentum of an statistical distribution, but the energy-momentum tensor, while having the form of a second momentum distribution, it is so for a different distribution function. This set also contains a subclass (including the one already mentioned) of manifestly causal theories.Comment: LaTex, documentstyle{article