Understanding and characterizing nestedness in mutualistic bipartite networks

In this work we present a dynamical model that succesfully describes the organization of mutualistic ecological systems. The main characteristic of these systems is the nested structure of the bipartite adjacency matrix describing their interactions. We introduce a nestedness coefficient, as an alternative to the Atmar and Patterson temperature, commonly used to measure the nestedness degree of the network. This coefficient has the advantage of being based on the robustness of the ecological system and it is not only describing the ordering of the bipartite matrix but it is also able to tell the difference, if any, between the degree of organization of each guild.Comment: oral talk in Computer Physics Conference CCP2008, Brazi

A result concerning controllability for the Navier-Stokes equations

The main goal of this paper is to present a new result concerning controllability of the time-dependent Navier-Stokes equations. Here, the control variable is the trace of the velocity field on a "small" part of the boundary. The main result states that the linear space spanned by final states is dense in the L space of admissible fields. For the proof, one uses a duality argument that is suggested by the linear theory. This reduces the task to an existence/regularity result for a nonlinear problem

Automatic mesh generation processor for 3-D parabolic boundary discretization

An automatic Mesh Generation Preprocessor for BE Programs with a considerable of capabilities has been developed. This program allows almost any kind of geometry and tipology to be defined with a small amount of external data, and with an important approximation of the boundary geometry. Also the error checking possibility is very important for a fast comprobation of the results

Analysis and Assembling of Network Structure in Mutualistic Systems

It has been observed that mutualistic bipartite networks have a nested structure of interactions. In addition, the degree distributions associated with the two guilds involved in such networks (e.g. plants & pollinators or plants & seed dispersers) approximately follow a truncated power law. We show that nestedness and truncated power law distributions are intimately linked, and that any biological reasons for such truncation are superimposed to finite size effects . We further explore the internal organization of bipartite networks by developing a self-organizing network model (SNM) that reproduces empirical observations of pollination systems of widely different sizes. Since the only inputs to the SNM are numbers of plant and animal species, and their interactions (i.e., no data on local abundance of the interacting species are needed), we suggest that the well-known association between species frequency of interaction and species degree is a consequence rather than a cause, of the observed network structure.Comment: J. of. Theor. Biology, in pres

Diseño de controles internos para la gestión de existencias en Grifo Tobi EIRL, periodo 2017-2018

Las MYPES no suelen implementar controles internos, razón por la cual llegan a sufrir de robos por parte de sus trabajadores o pérdidas reiteradas, las cuales llegan a ser descubiertas cuando ya hay un gran perjuicio en la empresa. Por este motivo la presente investigación buscó diseñar controles internos para la gestión de existencias en la empresa Grifo Tobi EIRL. La presente investigación es de tipo aplicada, de nivel descriptivo y explicativo y enfoque cualitativo, con un diseño no experimental. A través de cuestionarios a los empleados y de la elaboración de 2 flujogramas se pudo averiguar el nivel de confiabilidad de los controles internos de la empresa, tanto en la gestión de compras como en la de ventas, de lo que se pudo concluir que eran prácticamente inexistentes los controles internos, corriendo así grandes riesgos la empresa en cuanto a la posesión de sus existencias. Finalmente en base a las evidencias y el marco teórico, se diseñaron controles internos para la gestión de existencias, además de un manual de funciones organizacionales y un organigrama; concluyendo que es de suma importancia que todo sea implementado en la mayor prontitud posible, porque hay grandes probabilidades de que la empresa pueda estar viéndose afectada

La despersonalización de la conciencia como presupuesto de la libertad: una aproximación desde la fenomenología existencial de Jean-Paul Sartre

This article will examine the ways in which de-personalization of consciousness constitutes an unavoidable reading clue in order to understand the existential phenomenological conception of human freedom championed by Jean-Paul Sartre. Thus, the study of The Transcendence of the Ego, and of Being and Nothingness, among a few other of Sartre’s writings from the thirties, will allow the reader to discover that the cons­ciousness as an impersonal transcendental field is built as an onto-phenomenological foundation for the full assertion of human freedom. Man is only free, by definition, when he is capable of exiling the ego from consciousness.En este artículo se examina cómo la despersonalización de la conciencia constituye una pista de lectura ineludible a efectos de comprender la concepción fenomenológico-existencial de la libertad humana defendida por Jean-Paul Sartre. Así, el estudio de La trascendencia del Ego, de El ser y la nada, entre otros escritos sartrianos del treinta, nos permitirá descubrir que la construcción de la conciencia como campo trascen­dental impersonal se erige a manera de fundamento onto-fenomenológico para la afirmación plena de la libertad humana. Exilando al yo de la conciencia, el hombre es, por definición, libre