La visión del entrenador en la transición a través de deporte 2000

A través de las publicaciones especializadas en de la actividad física y el deporte que se editaron en el período que nos ocupa podemos conocer cuales eran las dificultades que tenían los entrenadores y los clubes e instituciones deportivas en las relaciones entre ambos en torno al ejercicio de la profesión de entrenador deportivo. Hemos comprobado que algunas de las circunstancias actuales que se dan en el entrenador no son nuevas y que ya se daban en este período aunque si bien algunas de estas parecen haberse cuando menos mejorado con el paso de los años: la formación del entrenador, el apoyo en otros profesionales especializados, el intrusismo de entrenadores sin titulación, la formalización contratos laborales que garanticen el cobro de emolumentos,.... Las investigaciones publicadas sobre el trabajo del entrenador en la transición son escasas, en la actualidad empiezan a sucederse corroborando así la importancia que tiene el entrenador como otro agente importante, al igual que deportistas, sistemas y métodos entrenamientos, medios e instalaciones,.... que intervienen en el proceso del entrenamiento

Codimension 4 singularities of reflectionally symmetryc planar vector fields

The paper deals with the topological classification of singularities of vector fields on the plane which are invariant under reflection with respect to a line. As it has been proved in previous papers, such a classification is necessary to determine the different topological types of singularities of vector fields on R3 whose linear part is invariant under rotations. To get the classification we use normal form theory and the blowing-up method

On the evolution of a large class of inhomogeneous scalar field cosmologies

The asymptotic behaviour of a family of inhomogeneous scalar field cosmologies with exponential potential is studied. By introducing new variables we can perform an almost complete analysis of the evolution of these cosmologies. Unlike the homogeneous case (Bianchi type solutions), when k^2<2 the models do not isotropize due to the presence of the inhomogeneitiesComment: 23 pages, 1 figure. Submitted to Classical and Quantum Gravit

Radio Emission from 3D Relativistic Hydrodynamic Jets: Observational Evidence of Jet Stratification

We present the first radio emission simulations from high resolution three dimensional relativistic hydrodynamic jets, which allow for a study of the observational implications of the interaction between the jet and external medium. This interaction gives rise to a stratification of the jet where a fast spine is surrounded by a slow high energy shear layer. The stratification, and in particular the large specific internal energy and slow flow in the shear layer largely determines the emission from the jet. If the magnetic field in the shear layer becomes helical (e.g., resulting from an initial toroidal field and an aligned field component generated by shear) the emission shows a cross section asymmetry, in which either the top or the bottom of the jet dominates the emission. This, as well as limb or spine brightening, is a function of the viewing angle and flow velocity, and the top/bottom jet emission predominance can be reversed if the jet changes direction with respect to the observer, or presents a change in velocity. The asymmetry is more prominent in the polarized flux, because of field cancellation (or amplification) along the line of sight. Recent observations of jet cross section emission asymmetries in the blazar 1055+018 can be explained assuming the existence of a shear layer with a helical magnetic field.Comment: 6 pages, 5 figures, 1 latex style file, ApJL accepte

Multiple Schr\"odinger pictures and dynamics in shortcuts to adiabaticity

A Schr\"odinger equation may be transformed by unitary operators into dynamical equations in different interaction pictures which share with it a common physical frame, i.e., the same underlying interactions, processes and dynamics. In contrast to this standard scenario, other relations are also possible, such as a common interaction-picture dynamical equation corresponding to several Schr\"odinger equations that represent different physics. This may enable us to design alternative and feasible experimental routes for operations that are a priori difficult or impossible to perform. The power of this concept is exemplified by engineering Hamiltonians that improve the performance or make realizable several shortcuts to adiabaticity

String-Unification, Universal One-Loop Corrections and Strongly Coupled Heterotic String Theory

We derive the universal threshold corrections in heterotic string theory including a continuous Wilson line. Unification of gauge and gravitational couplings is shown to be possible even within perturbative string theory. The relative importance of gauge group dependent and independent thresholds on unification is clarified. Equipped with these results we can then attempt an extrapolation to the strongly coupled heterotic string -- M-theory. We argue that such an extrapolation might be meaningful because of the holomorphic structure of the gauge coupling function and the close connection of the threshold corrections to the anomaly cancelation mechanism.Comment: 28 LaTex pages with 2 fig