El programa nuclear de Corea del Norte y las perspectivas de reunificación peninsular

La revelación oficial por Corea del Norte de su programa nuclear (de enriquecimiento de uranio) no ha supuesto grandes sorpresas, pero sí ha despertado varios interrogantes. En primer término, por qué Pyongyang ha decidido admitir, aunque de forma ambigua, su programa nuclear, que contradice los acuerdos KEDO de 1994 y, en segundo lugar, por qué lo ha hecho precisamente ahora, cuando la guerra contra Irak, otro de los integrantes del club del "eje del mal", sigue siendo posible. Igualmente, la nueva situación creada tras esa admisión afecta seriamente al proceso de reunificación de la península coreana, que se encuentra en un momento complicado debido a la conjunción de varios factores, como son el ocaso de la sunshine policy, o "política de mano tendida", las elecciones presidenciales en Corea del Sur en diciembre de 2002, el acercamiento de Japón a Pyongyang, el cambio de liderazgo en China y la nueva postura de Washington respecto a Corea del Norte. La incertidumbre vuelve a presidir el proceso intercoreano y, sobre todo, recupera la tensión y la amenaza de un conflicto armado en la zona

Translation surfaces of linear Weingarten type

We give a relatively simple proof that a translation surface in Euclidean space that satisfies a relation of type $aH+bK=c$, for some real numbers $a,b,c$, where $H$ and $K$ are the mean curvature and the Gauss curvature of the surface, respectively, must have $a=0$ or $b=0$, and thus, $K$ is constant or $H$ is constant. Our method of proof extends to the Lorentzian ambient space

The Militarization of Emergencies: Is the Spanish Model an Example to Be Followed by the Multitasking Armies of Latin America?

The role of the armed forces in Latin America is characterized by their participation in multiple internal missions. These range from security functions to the provision of social, educational, and public services, among others; their role also involves providing emergency relief. However, some of the armed forces involved in this type of mission do not have specialized units or corps. This poses obvious problems not only from a technical and operational point of view, but also from the perspective of civil-military relations and the definition of the roles of armies. Some Latin American countries have looked to the Emergency Military Unit in Spain as an example to follow for the implementation of a civil defense model based on specialized military resources. The aim of this paper is therefore twofold. First, it seeks to explain that the militarization of emergencies does not involve expanding the use of force but that it can become a 'wildcard' policy tool instead. Second, it intends to show how the apparent success of the Spanish Emergency Military Unit resulted from some¿not always positive¿lessons that can be replicated in the armed forces in Latin America

Radial solutions for equations of Weingarten type

In this paper we study the linear Weingarten equation defined by the fully non-linear PDE adivDu/root 1+|Du|(2)+bdetD(2)u/(1+|Du|(2))(2)=?(1/root 1+|Du|(2)) in a domain omega subset of R-2, where ?is an element of C-1([-1,1]) and a,b is an element of R. We approach the existence of radial solutions when omega is a disk of small radius, giving an affirmative answer when the PDE is of elliptic type. In the hyperbolic case we show that no radial solution exists, while in the parabolic case we find explicitly all the solutions. In the elliptic case we prove uniqueness and symmetry results concerning the Dirichlet problem of such equation

Scattering Polarization and Hanle Effect in Stellar Atmospheres with Horizontal Inhomogeneities

Scattering of light from an anisotropic source produces linear polarization in spectral lines and the continuum. In the outer layers of a stellar atmosphere the anisotropy of the radiation field is typically dominated by the radiation escaping away, but local horizontal fluctuations of the physical conditions may also contribute, distorting the illumination and hence, the polarization pattern. Additionally, a magnetic field may perturb and modify the line scattering polarization signals through the Hanle effect. Here, we study such symmetry-breaking effects. We develop a method to solve the transfer of polarized radiation in a scattering atmosphere with weak horizontal fluctuations of the opacity and source functions. It comprises linearization (small opacity fluctuations are assumed), reduction to a quasi-planeparallel problem through harmonic analysis, and numerical solution by generalized standard techniques. We apply this method to study scattering polarization in atmospheres with horizontal fluctuations in the Planck function and opacity. We derive several very general results and constraints from considerations on the symmetries and dimensionality of the problem, and we give explicit solutions of a few illustrative problems of especial interest. For example, we show (a) how the amplitudes of the fractional linear polarization signals change when considering increasingly smaller horizontal atmospheric inhomogeneities, (b) that in the presence of such inhomogeneities even a vertical magnetic field may modify the scattering line polarization, and (c) that forward scattering polarization may be produced without the need of an inclined magnetic field. These results are important to understand the physics of the problem and as benchmarks for multidimensional radiative transfer codes.Comment: 27 pages, 13 figures, to appear in Ap

Engagement y productividad en las empresas

El presente trabajo pretende mostrar algunos avances en el término “engagement”, y como puede ser implementado en las organizaciones, teniendo en cuenta los diferentes factores que intervienen, para que los trabajadores se sientan “engaged” dentro de la organización. Además busca relacionar las diferentes habilidades y tipos de liderazgo que los altos mandos utilizan con sus empleados y como éste afecta la productividad de los trabajadores en las organizaciones. Para esto, se realizó una investigación de las clases de liderazgo y los comportamientos de los altos mandos, que pueden afectar positiva y negativamente el vínculo y sentido de pertenencia que tienen los trabajadores con la empresa en la que trabajan. Considerando importante las habilidades del liderazgo transformacional, para lograr desarrollar algún grado de engagement en los trabajadores, lo cual genera a su vez, un alza en la productividad de sus resultados dentro de la organización.This work seeks to expose some studies of “engagement”, and how it can be useful at different organizations, having into account all the factors that may influence for workers feel “engaged” inside theirs work. Also, wants to link all types of leaderships and attitudes that head coaches implement with theirs workers, and how they may affect the productivity in the organization. For this, we realized an investigation about types of leadership and behavior of heads coaches, that may affect positive and negatively sense of belonging that workers has whit their companies. Considering important the abilities and features of the transformational leadership, to achieve the development of “engagement” in workers, which also causes, a rise in productivity of results insides the organization

Depolarizing collisions with hydrogen: neutral and singly ionized alkaline earths

Depolarizing collisions are elastic or quasielastic collisions that equalize the populations and destroy the coherence between the magnetic sublevels of atomic levels. In astrophysical plasmas, the main depolarizing collider is neutral hydrogen. We consider depolarizing rates on the lowest levels of neutral and singly ionized alkaly-earths Mg I, Sr I, Ba I, Mg II, Ca II, and Ba II, due to collisions with H. We compute ab initio potential curves of the atom-H system and solve the quantum mechanical dynamics. From the scattering amplitudes we calculate the depolarizing rates for Maxwellian distributions of colliders at temperatures T <10000 K. A comparative analysis of our results and previous calculations in the literature is done. We discuss the effect of these rates on the formation of scattering polarization patterns of resonant lines of alkali-earths in the solar atmosphere, and their effect on Hanle effect diagnostics of solar magnetic fields.Comment: 18 pages, 3 figures. Summitted to ApJ (2014