On the Localization of the Personalized PageRank of Complex Networks

In this paper new results on personalized PageRank are shown. We consider directed graphs that may contain dangling nodes. The main result presented gives an analytical characterization of all the possible values of the personalized PageRank for any node.We use this result to give a theoretical justification of a recent model that uses the personalized PageRank to classify users of Social Networks Sites. We introduce new concepts concerning competitivity and leadership in complex networks. We also present some theoretical techniques to locate leaders and competitors which are valid for any personalization vector and by using only information related to the adjacency matrix of the graph and the distribution of its dangling nodes

Comparing univariate and multivariate models to forecast portfolio value-at-risk

This article addresses the problem of forecasting portfolio value-at-risk (VaR) with multivariate GARCH models vis-à-vis univariate models. Existing literature has tried to answer this question by analyzing only small portfolios and using a testing framework not appropriate for ranking VaR models. In this work we provide a more comprehensive look at the problem of portfolio VaR forecasting by using more appropriate statistical tests of comparative predictive ability. Moreover, we compare univariate vs. multivariate VaR models in the context of diversified portfolios containing a large number of assets and also provide evidence based on Monte Carlo experiments. We conclude that, if the sample size is moderately large, multivariate models outperform univariate counterparts on an out-of-sample basis.Market risk, Backtesting, Conditional predictive ability, GARCH, Volatility, Capital requirements, Basel II

El proceso de asentamiento de la migración México-Estados Unidos

Existe un proceso de reconfiguración en la migración mexicana a Estados Unidos. En la actualidad la población migrante es de 11 millones de personas y equivale a 11 por ciento del total de la población mexicana. Los centros de expulsión siguen siendo los de origen rural del bajío mexicano, pero se han sumado los de tipo urbano y particularmente del sur sureste del país, con población indígena. En cuanto al género, éste es balanceado, 56 por ciento masculino y 44 por ciento femenino. Respecto a los destinos en Estados Unidos, Texas, California, Arizona, Nuevo México e Indiana siguen siendo importantes, pero ahora los migrantes mexicanos son mayoría en 43 Estados. Los cruces tradicionales han perdido importancia y han surgido otros como Altar Sonora (Sásabe-Sasabe, Sonoyta, Agua Prieta y Cd. Juárez) cuya principal característica es la peligrosidad para la vida del migrante y la utilización de coyotes para atravesar la frontera

Performing an Environmental Tax Reform in a Regional Economy. A Computable General Equilibrium Approach

We use a Computable General Equilibrium model to simulate the effects of an Environmental Tax Reform in a regional economy (Andalusia, Spain). The reform involves imposing a tax on CO2 or SO2 emissions and reducing either the Income Tax or the payroll tax of employers to Social Security, and eventually keeping public deficit unchanged. This approach enables us to test the so-called double dividend hypothesis, which states that this kind of reform is likely to improve both environmental and non-environmental welfare. In the economy under analysis, an employment double dividend arises when the payroll tax is reduced and, if CO2 emissions are selected as environmental target, a (limited) strong double could also be obtained. No double dividend appears when Income Tax is reduced to compensate the environmental tax.environmental tax reform, computable general equilibrium, double dividend.

Pilot Study of a Clinical Pathway Implementation in Rectal Cancer

Background Rectal cancer is a highly prevalent disease which needs a multidisciplinary approach to be treated. The absence of specific protocols implies a significant and unjustifiable variability among the different professionals involved in this disease. The purpose is to develop a clinical pathway based on the analysis process and aims to reduce this variability and to reduce unnecessary costs. Methods We created a multidisciplinary team with contributors from every clinical area involved in the diagnosis and treatment in this disease. We held periodic meetings to agree on a protocol based on the best available clinical practice guidelines. Once we had agreed on the protocol, we implemented its use as a standard in our institution. Every patient older than 18 years who was diagnosed with rectal cancer was considered a candidate to be treated via the pathway. Results We evaluated 48 patients during the course of this study. Every parameter measured was improved after the implementation of the pathway, except the proportion of patients with 12 nodes or more analysed. The perception that our patients had about this project was very good. Conclusions Clinical pathways are needed to improve the quality of health care. This kind of project helps reduce hospital costs and optimizes the use of limited resources. On the other hand, unexplained variability is also reduced, with consequent benefits for the patients

Sign language in Spanish television. Study on reception

Este artículo analiza las preferencias de las personas sordas signantes usuarias del servicio de interpretación a lengua de signos y las características con que los canales prestan este servicio en la televisión de difusión estatal en España. El objetivo es conocer si el modo en que se ofrece este servicio de accesibilidad se aproxima o difiere de las preferencias de sus usuarios. Se ha recogido la opinión sobre este servicio de personas sordas que utilizan como primera lengua para la comunicación la lengua de signos española. También se ha realizado un estudio de los programas signados emitidos durante una semana (10-16/marzo/2014). Los principales datos resultantes revelan que las personas sordas están insatisfechas con el horario de emisión de estos programas, demandan espacios informativos con lengua de signos, reclaman la presencia de signantes sordos y prefieren al intérprete como imagen principal. Con respecto al análisis de los programas, el estudio apunta que la mayoría de los programas signados se emiten durante la madrugada, están dirigidos al entretenimiento, los intérpretes son signantes oyentes y su figura se sitúa en una esquina de la pantalla.The present article analyses the preferences of the deaf who use sign language and are users of the TV interpretation service to sign language, as well as the characteristics with which TV channels provide that service in television in Spain. The objective is to establish whether the way in which the aforementioned accessibility service is provided matches the preferences of users or differ from them. The analysis presents the opinion on this service of the deaf that use the Spanish sign language as their first language for communication. A study has also been conducted on the programmes broadcast with sign language during week 10-16/03/2014. The main data collected reveal that the deaf are dissatisfied with broadcasting times. They ask for news programmes with sign language, they would rather have the interpretation carried out by deaf people who use sign language and they prefer that the interpreter is the main image on screen. Concerning the analysis of the programmes broadcast, the study shows that the majority of programmes with sign language are broadcast at night, they are entertainment programmes, the interpretation is carried out by hearing people who use sign language and that their image is displayed in a corner of the screen

Cultural diversity, sign language and televisión in Spain

Este artículo analiza la televisión en relación con la lengua de signos en España durante los años 2010-2012. Para ello se ha partido de los datos publicados sobre la presencia de la lengua de signos en la televisión estatal desde que la Ley General de la Comunicación Audiovisual impuso a los operadores las obligaciones de emisión, en 2010. La mayoría de los canales ha incorporado la lengua de signos siguiendo las directrices de la legislación nacional e internacional. ¿Cuáles son las motivaciones que han inspirado estos desarrollos legislativos y cuáles son las estrategias de las empresas de televisión que las implantan? Se trata de favorecer la accesibilidad a la televisión a las personas sordas que utilizan la lengua de signos. Pero también alrededor de esta lengua se articula la identidad cultural de la comunidad sorda. El objetivo del estudio ha sido evaluar en qué medida la televisión en lengua de signos constituye una expresión cultural de la comunidad sorda. Este análisis pone de manifiesto que mayoritariamente la incorporación de la lengua de signos que hacen los canales se ha planteado como práctica que favorece la accesibilidad alejándose de la perspectiva socioculturalThis article analyses television in connection with sign language in Spain during years 2010-2012. It is based on published data on the use of sign language in state television after the General Law on Audiovisual Communication imposed obligations on broadcasters in 2010. Most television channels have included sign language in their broadcasts as guided by national and international legislation. What has inspired such legal developments and what strategies have been put in place by complying companies? The aim is to encourage television accessibility for the deaf who use sign language. But sign language also articulates the cultural identity of the deaf community. The objective of the research is to assess the extent to which sign language in television is a cultural expression of the deaf community. This analysis highlights that the inclusion of sign language in television channels has been mostly envisaged as a practice that enhances accessibility letting the sociocultural approach aside.Ministerio de Economí

La modelación. Un eje para la red de desarrollo de usos

El escrito muestra un panorama general de una investigación que constituyó una categoría de modelación para la matemática escolar. Dicha categoría provoca el desarrollo de red de uso de conocimiento matemático, develado en las herramientas de variación local, global y su articulación para caracterizar comportamientos o tendencias. Se exhibe una breve descripción teórica del eje de la categoría, mismo que sustenta diseños de situación desenvueltos en tres momentos: transformación, variación y aproximación, caracterizados por el tipo de usos de lo gráfico, lo numérico o lo analítico que emergen como justificación funcional de los estudiantes ante los diseños de modelación escolar

Nuevas aportaciones a la flora de Andalucía: Sierra de Gádor (Almería)

New floristic records for Andalusian: Sierra de Gódor (Almería).Palabras clave. Flora, corologia, fitosociologia, Almería, Andalucía.Key words. Flora, corology, fitosociology, Almería, Andalusian