Absence of squirt singularities for the multi-phase Muskat problem

In this paper we study the evolution of multiple fluids with different constant densities in porous media. This physical scenario is known as the Muskat and the (multi-phase) Hele-Shaw problems. In this context we prove that the fluids do not develop squirt singularities.Comment: 16 page

The current financial crisis: what should we learn from the great depressions of the Twentieth Century?

Studying the experience of countries that have experienced great depressions during the twentieth century teaches us that massive public interventions in the economy to maintain employment and investment during a financial crisis can, if they distort incentives enough, lead to a great depression.

Evaluación de variedades de caña de azúcar (Saccharum spp.) para la producción de panela en linares departamento de Nariño

Con el fin de mejorar la producción de panela, en el municipio de Linares, Nariño (01º 21’ 22.4”Norte y 77º 31’ 77.5”Oeste), se evaluó el comportamiento agronómico y agroindustrial de siete variedades de caña de azúcar. Se empleó un diseño estadístico de bloques completos al azar con siete tratamientos y tres repeticiones. Los resultados mostraron que las variedades CC 84-75, CC 85-92, CC 85-47 y RD 75-11, presentaron bajo volcamiento, las cuales pueden ser consideradas promisorias para la producción de panela. Las seis variedades de caña y el testigo presentaron buen comportamiento fitosanitario ante la presencia de las enfermedades Bipolaris sacchari (mancha de ojo) y Leptosphaeria sacchari (mancha de anillo) y por tanto se clasifica como resistente bajo condiciones naturales de infección. Las seis variedades introducidas mostraron comportamiento similar al testigo en incidencia de daño por el barrenador Diatraea spp. y rendimiento de panela el cual osciló entre 10.77 t.ha-1 y 16.15 t.ha-1 sin diferencias significativas entre tratamientos (p > 0.05)

La rauda del Alcázar de Córdoba

The aims of this study are to review the types of information which can be potentially obtained in the research of the populational dynamic on Xth century in Cordoba, based on an anthropological sample proceeding from an islamic cemetery. Preservation introduces a multitude of confounding factors to give a false appearance to the osteological samples, pointing to the paleopathological aspects as the more conditioned.El objetivo de este estudio es mostrar las diferentes informaciones que pueden ser obtenidas potencialmente en la investigación de la dinámica de poblaciones en el siglo X en Córdoba, basada en una muestra antropológica procedente de una necrópolis islámica. La preservación aporta múltiples factores que enmascaran las muestras osteológicas, con los aspectos paleopatológicos como los más condicionados

Nonexistence of self-similar singularities for the 3D incompressible Euler equations

We prove that there exists no self-similar finite time blowing up solution to the 3D incompressible Euler equations. By similar method we also show nonexistence of self-similar blowing up solutions to the divergence-free transport equation in $\Bbb R^n$. This result has direct applications to the density dependent Euler equations, the Boussinesq system, and the quasi-geostrophic equations, for which we also show nonexistence of self-similar blowing up solutions.Comment: This version refines the previous one by relaxing the condition of compact support for the vorticit

On the noncommutative eikonal

We study the eikonal approximation to quantum mechanics on the Moyal plane. Instead of using a star product, the analysis is carried out in terms of operator-valued wavefunctions depending on noncommuting, operator-valued coordinates.Comment: 18 page

Automation on the generation of genome scale metabolic models

Background: Nowadays, the reconstruction of genome scale metabolic models is a non-automatized and interactive process based on decision taking. This lengthy process usually requires a full year of one person's work in order to satisfactory collect, analyze and validate the list of all metabolic reactions present in a specific organism. In order to write this list, one manually has to go through a huge amount of genomic, metabolomic and physiological information. Currently, there is no optimal algorithm that allows one to automatically go through all this information and generate the models taking into account probabilistic criteria of unicity and completeness that a biologist would consider. Results: This work presents the automation of a methodology for the reconstruction of genome scale metabolic models for any organism. The methodology that follows is the automatized version of the steps implemented manually for the reconstruction of the genome scale metabolic model of a photosynthetic organism, {\it Synechocystis sp. PCC6803}. The steps for the reconstruction are implemented in a computational platform (COPABI) that generates the models from the probabilistic algorithms that have been developed. Conclusions: For validation of the developed algorithm robustness, the metabolic models of several organisms generated by the platform have been studied together with published models that have been manually curated. Network properties of the models like connectivity and average shortest mean path of the different models have been compared and analyzed.Comment: 24 pages, 2 figures, 2 table

Public and private sector wages interactions in a general equilibrium model

This paper develops a dynamic general equilibrium model in which the public and the private sector interact in the labor market. Previous studies that analyze the labor market effects of public sector employment and wages have mostly assumed exogenous rules for public wage and public employment. We show that theories that equalize wages with marginal products in the private sector can rationalize the interaction of public and private sector wages when extended to accommodate a non-trivial government sector/public sector union that endogenously determines public employment and wages. Our model suggests a positive correlation between public and private sector wages. Any increase in tax revenues, coupled with the existence of a positive public-private sector wage gap, makes working in the public sector an attractive option. Thus, a positive neutral productivity shock increases public and private sector wages. More interestingly, even a private-sector specific productivity shock spills-over to the public sector, increasing public wages. These facts lend some support to the wage leading role of the private sector. Nevertheless, at the same time, a positive shock to public sector wages would lead to an increase in private sector wages, via the flow of workers from the private to the public sector. JEL Classification: C32, J30, J51, J52, E62, E63, H50Labor market, public employment, public wages, Trade Unions