A real variable characterization of Gromov hyperbolicity of flute surfaces

23 pages, 1 figure.-- MSC2000 codes: 41A10, 46E35, 46G10.-- ArXiv pre-print available at: http://arxiv.org/abs/0806.0093Previously presented as Communication at International Congress of Mathematicians 2006 (ICM2006, Madrid, Spain, Aug 22-30, 2006).Preaccepted for publication at: Osaka Journal of MathematicsIn this paper we give a characterization of the Gromov hyperbolicity of trains (a large class of Denjoy domains which contains the flute surfaces) in terms of the behavior of a real function. This function describes somehow the distances between some remarkable geodesics in the train. This theorem has several consequences; in particular, it allows to deduce a result about stability of hyperbolicity, even though the original surface and the modified one are not quasi-isometric.Research partially supported by three grants from M.E.C. (MTM 2006-11976, MTM 2006-13000-C03-02 and MTM 2007-30904-E), Spain.No publicad

The role of funnels and punctures in the Gromov hyperbolicity of Riemann surfaces

27 pages, no figures.-- MSC2000 codes: 30F20, 30F45.MR#: MR2243795 (2007e:30063)Zbl#: Zbl 1108.30031We prove results on geodesic metric spaces which guarantee that some spaces are not hyperbolic in the Gromov sense. We use these theorems in order to study the hyperbolicity of Riemann surfaces. We obtain a criterion on the genus of a surface which implies non-hyperbolicity. We also include a characterization of the hyperbolicity of a Riemann surface S* obtained by deleting a closed set from one original surface S. In the particular case when the closed set is a union of continua and isolated points, the results clarify the role of punctures and funnels (and other more general ends) in the hyperbolicity of Riemann surfaces.Research by all three authors partially supported by a grant from DGI (BFM 2003-04870), Spain. In addition, research by third author (Eva Tourís) was partially supported by a grant from DGI (BFM 2000-0022), Spain.Publicad

El subtitulado para sordos : estado de la cuestión en España

El objetivo de este artículo es exponer la realidad del subtitulado para sordos en España. Describiremos, siguiendo diversos criterios, los tipos de subtítulos para personas con déficit auditivo que se registran en el panorama del estado español; haremos un breve recorrido histórico desde el momento en el que nace esta modalidad de trasvase hasta nuestros días, destacando las propuestas, leyes y normas que contribuyen a eliminar las barreras con las que se encuentra la comunidad sorda en su acceso a los productos audiovisuales que inundan nuestro mercado y sociedad y, finalmente, nos centraremos sobre todo en las cadenas de televisión, principales productoras de subtítulos en nuestro país, y analizaremos el estado de la cuestión que nos ocupa tanto en aquellas de ámbito estatal como en las autonómicas.The aim of this article is to portray the state of subtitling for the deaf in Spain. A description of the different types of subtitles used in Spain for persons with hearing impairment will be undertaken following different criteria. A historical perspective will be provided right from the time such a transmission method was developed up to the present time. Proposals, norms and laws that contribute to barrier elimination for the deaf community (while attempting to access audiovisual products that flood our market and society) will be covered. Lastly, this paper will focus on the TV channels, which are the principal producers of subtitles in Spain and will further provide an analysis of the current state both at the national and regional levels

A propósito de los métodos de estudio de la Historia económica de la Antigüedad

El trabajo es una reflexión acerca de los métodos de estudio de la Historia Económica de la Antigüedad utilizados desde el nacimiento de ésta como disciplina autónoma a finales del siglo XIX; también sobre las aportaciones de la economía al conocimiento de otras dimensiones de la sociedad romana de la Antigüedad. A partir de esta reflexión, el artículo implica, asimismo, plantearse una vez más la cuestión de la oportunidad de los estudios de naturaleza interdisciplinar en la investigación del historiador del Derecho y el romanista.This work is an overview about Ancient Economic History study methods used since its birth as a discipline at the end of 19th century. At the same time, this work will also show Economy contributions to the knowledge of another ancient roman society dimensions. From this point, the article raises once again the matter of interdisciplinary studies for the Law and Roman Law researcher.Le travail est une réflexion sur les méthodes d’étude de l’Histoire Économique de l’Antiquité utilisées depuis la naissance de celle-ci comme discipline autonome à la fin du XIXème siècle; aussi sur les contributions de l’économie à la connaissance d’autres dimensions de la société romaine de l’Antiquité. À partir de cette réflexion, l’article implique, de même, se poser une fois de plus la question de l’occasion des études de nature interdisciplinaire dans la recherche de l’historien du Droit et de l’historien romaniste. En alemán: Die Arbeit bringt Gedanken zu Untersuchungsmethoden der antiken Wirtschafts-geschichte, die seit ihrer Entstehung als eigenständiges Fach zu Ende des 19. Jahrhunderts angewandt wurden. Thematisiert wird der Beitrag der Wirtschaft zur Erschließung anderer Bereiche der römischen Gesellschaft in der Antike. Ausgehend von dieser Überlegung will der Artikel erneut aufzeigen, wie günstig sich die Interdisziplinarität von Untersuchungen auf die Forschungen von Rechtshistorikern und Romanisten auswirkt

Activated sludge response to detergent spill in sewage

Motivation: The aim of this study is to determine the response of activated sludge microorganisms to detergent spill events that occurs sporadically in the Wastewater Treatment Plants (WWTPs). This detergent spill can cause loss of floccular structures and the disappearance of part of the microbiota constituent of the mixed liquor. Methods: The pilot plant used for the study consists of four series-connected lagoons, with aeration systems in three of them, and a feed tank of 25L. The lagoon stabilization process allows the generation and maturation of activated sludge necessary for wastewater treatment. The mixed liquor was sampled to identify its functional groups present in the water allowing a later comparative after applying detergent. Four spills in total, based on Sodium Dodecyl Sulfate (SDS) were carried out and its effects studied. Results: Observations showed the existence of floccular structures of remarkable resistance of as well as the presence of  many functional groups of microorganisms in the detergent spills up to 37,5mg/l. Higher spills from 60mg/l to 120mg/l increase floccular damages and microbiota mortality. It was observed a proliferation of filamentous bacteria Beggiatoa on the surface of activated sludge after spills, as well as Paramecium association to it. Conclusions: Lagooning system seems to respond well to detergent discharges lower than 40mg / l SDS, keeping floccular structures very compacts and the presence of groups of microorganisms. Discharges of 60mg / l to 120mg / l significantly increase the mortality rate of activated sludge microbiota and the loss of structure at the floc, especially in the first two ponds. The system seems to cushion the spills in the first ponds reducing further damage in rear lagoons. The third lagoon had the highest average number of individuals per milliliter that can be due to a lower impact by detergent spills and the contribution of aeration system. Beggiatoa proliferation could be motivated by an oxygen descent in lagoons associated to detergent discharges

Assessing social engagement practices in unstable environments: An examination of collective action and community participation in Mexico

El estudio que se presenta utiliza la teoría de Capital Social, explora los efectos del capital social, la violencia, y el compromiso político en dos observables: acción colectiva y voluntad de ayuda a la comunidad en México. Se utiliza una encuesta recabada en 2011 (N=7,416) y procedimientos estadísticos (correlaciones y análisis de regresión usando mínimos cuadrados ordinarios (MCO) con modelos anidados). Los resultados muestran que los factores contextuales y políticos, particularmente el miedo y la violencia, influyen en la mobillización en acción colectiva. Se indican algunas implicaciones para las interacciones sociales en escenarios de conflicto prolongado e inestabilidad, en particular, para México

Isoperimetric inequalities in graphs and surfaces

Let M be the set of metric spaces that are either graphs with bounded degree or Riemannian manifolds with bounded geometry. Kanai proved the quasi-isometric stability of several geometric properties (in particular, of isoperimetric inequalities) for the spaces in M. Kanai proves directly these results for graphs with bounded degree; in order to prove the general case, he uses a graph (an ?-net) associated to a Riemannian manifold with bounded geometry. This paper studies the stability of isoperimetric inequalities under quasi-isometries between non-exceptional Riemann surfaces (endowed with their Poincare metrics). The present work proves the stability of the linear isoperimetric inequality for planar surfaces (genus zero surfaces) without the condition on bounded geometry. It is also shown the stability of any non-linear isoperimetric inequality

Ressenyes

Obra ressenyada: Jeremy MUNDAY, Introducing Translation Studies. Londres y Nueva York: Routledge, 2000

The multiplication operator, zero location and asymptotic for non-diagonal Sobolev norms

14 pages, no figures.-- Online version published Jul 9, 2009.Article in press.In this paper we are going to study the zero location and asymptotic behavior of extremal polynomials with respect to a generalized non-diagonal Sobolev norm in which the product of the function and its derivative appears. The orthogonal polynomials with respect to this Sobolev norm are a particular case of those extremal polynomials. The multiplication operator by the independent variable is the main tool in order to obtain our results.Supported in part by three grants from M.E.C. (MTM 2006-13000-C03-02, MTM 2006-11976 and MTM 2007-30904-E) and by a grant from U.C.III M./C.A.M. (CCG07-UC3M/ESP-3339), Spain.Publicad