Recent changes and tendencies in precipitation in Andalusia

La cuantificación y el conocimiento de los cambios climáticos a escala regional es una de las tematicas más relevantes en el debate del cambio global. Poder entender los cambios a nivel regional y sus impactos es avanzar en el conocimiento de las características de variabilidad natural (Lionello et al. 2006). Se presentan en este trabajo los resultados del análisis de numerosas series de precipitación de Andalucía durante el periodo 1931-2007 de observatorios localizados en los principales sistemas montañosos de la región. Estas zonas son especialmente sensibles a las variaciones climáticas, ya que en ellas se localizan la mayor parte de los espacios naturales protegidos e infraestructuras hidráulicas. Las cantidades más importantes de precipitación se registran en estas zonas donde se acumulan los principales recursos hídricos de la región. Por ello, la existencia de cambios en las precipitaciones en estas áreas puede tener considerables impactos medioambientales y socio-económicos. Desde los años sesenta hasta los años noventa del siglo pasado, el cambio más destacable en las series de precipitación, es una tendencia decreciente en marzo, que ha sido constatada por diversos autores para la vertiente occidental de la Península Ibérica. En este artículo ampliamos la dimensión temporal de este fenómeno, evaluando su magnitud con una perspectiva histórica (comienzos del siglo XIX), y extendiéndolo hasta el presente. Además, si examinamos las variaciones espaciales que se registran en todo el sur peninsular. El análisis del fenómeno a una escala plurisecular pone de manifiesto la singularidad de este comportamiento en las precipitaciones a lo largo de las últimas décadas del siglo XX. Por último, hemos puesto en relación los resultados obtenidos, con las previsiones de cambio climático y con estudios recientes sobre variaciones en los patrones de circulación atmosférica en el Atlántico norte.Quantifying and understanding climatic changes at a regional scale is one of the most important and uncertain issues within the global change debate. An important step towards the understanding of regional climatic changes and impacts is the assesment of natural climate variability (Lionello et al. 2006). The analysis of a numerous precipitation monthly series over the period 1931-2007 located in the main mountanious ranges of Andalusia region (South of Spain) is presented. These areas are especially sensitive to climate changes due to the fact that most natural protected ecosystem and reservoirs are placed there, where most of the regional precipitation amounts fall and the main water volumes of the region are stored. Therefore, the occurence of changes in the averages of the pluviometric contributions in these mountains will have important environmental and socio-economic impacts. The mosts relevant and significant changes is found in March when precipitation in the central and western regions of the Iberian Peinsula presents a clear continuous decline of 50% from the 60’s onwards documented by several authors. In this paper we describe this phenomenon up to 2007 evaluating, on the one hand, its magnitude and evolution from a historical perspective and, on the other hand, the spatial variations of precipitation in the study area. Despite the similarities with other periods when considering various centuries of data, these last decades of the 20th century present different characteristics. The results of this study are related to climate change predictions and to recent studies reporting atmospheric circulation changes in the North Atlantic area

Visibilidad en las editoriales universitarias : el encuentro con el lector

Hace una década, el panorama de la edición universitaria era, si no sombrío, desalentador. Esto mostraba Leandro de Sagastizábal, a quien debemos buena parte, por no decir toda, de la información, discusión y estado de las cosas en este campo en nuestro país: en 2001 señalaba este desaliento en la ausencia de políticas consistentes en la mayoría de los espacios editoriales universitarios, presupuestos inexistentes, equipos sui generis y falta de capacitación. En una extensa y completa investigación posterior, de Sagastizábal concluye que salvo excepciones, la edición universitaria en estas regiones se gestiona con poca autonomía, recursos escasos y con estructuras débiles y poco profesionales.Instituto de Investigaciones en Humanidades y Ciencias Sociale

Ingeniería de Calidad de Servicio en redes IP

Los servicios multimedia (vídeo bajo demanda, audioconferencia...) tienen requisitos de calidad de servicio (QoS en inglés). Es necesario garantizar unos niveles de QoS (limitar la pérdida de paquetes, asegurar un ancho de banda mínimo, limitar el retardo máximo...) requeridos por el usuario. En esta charla aprenderemos conceptos básicos relacionados con la provisión de la calidad de servicio en redes de conmutación de paquetes como Internet. Veremos qué componentes son necesarios para conseguir QoS: control de admisión, reserva de recursos, clasificación de paquetes, algoritmos de gestión de las colas, algoritmos de control de la congestión. Finalmente, daremos un vistazo a cómo queda la calidad de experiencia del usuario final.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Mean waiting time in the M/H2/s queue: application to mobile communications Systems

In this paper a procedure to approximately calculate the mean waiting time in the M/H2/s queue is presented. The approximation is heuristic although based in the intuitive symmetry between the deterministic and balanced hyperexponential-2 distributions. The three parameters which fully describe the H2 distribution are considered, so the approximation can also be used for the M/G/s queue when the first three moments are known. If only the first two moments of the holding time distribution are known, the estimation can also be applied accepting a lesser accuracy. The estimation proposed is a closed formula extremely easy to compute and the results are very accurate. This features makes it helpful in the design of mobile telecommunication systems with more than one channel and queueing allowed (like trunking Private Mobile Radio PMR systems), where holding time distributions with coefficients of variation higher than one may appear. As a second stage, the possibility of calls owning a certain level of priority is studied. Two service classes are considered according to a non-preemtive priority scheme (also known as Head Of the Line or HOL). This priority feature is often required in mobile telecommunications systems to improve the access delay of some special calls by degrading the delay suffered by the rest. If the proportion of calls owning priority is kept low, the degradation is shared by many calls and then kept small. In this paper a procedure to estimate the mean waiting time in queue for each priority class is presented. This procedure is also very easy to compute. The environment for which the results of this paper are intended suggests medium or heavy overall load and light priority load (priority proportion is kept low). This is the situation under which the accuracy of the proposed method is checked. Although simulations are necessary in the final phase of the design, the procedure presented here is helpful as a first quick insight into the system performance.Peer ReviewedPostprint (published version

Assessing the governance capacity to implement resource-oriented sanitation and waste management systems in urban areas of Latin America and the Caribbean

Sustainable approaches for waste management and sanitation are key to deal with the environmental and health challenges that growing urbanization is creating around the world. Implementing systems that allow to reuse resources contained in the organic waste streams (OWS) is an approach that can bring many benefits, especially in low-medium income areas as the Latin American and Caribbean region, where excreta, wastewater, and waste are not properly managed. The transformation towards these systems requires not only technological changes, but also changes in the way that urban waste and wastewater are governed. The aim of this study was to assess the capacity of the town of Chía (Colombia) to govern the transition towards resource-oriented sanitation and waste management systems. The Governance Capacity Framework (GCF) was used as a method to evaluate the governance capacity of the town to implement these systems. The assessment revealed that the capacity of Chía to govern the implementation of resource-oriented sanitation and waste management systems was low. Furthermore, governance factors that could be hindering the implementation of these systems were identified. Low level of knowledge of resource recovery from OWS in the public spheres, insufficient collaboration and communication across sectors and institutions that had competences on waste management and sanitation, short-term vision within the local decision-making processes and insufficient incentives to support local entrepreneurship on circular economy. Despite these challenges, analysis also revealed the existence of public-private partnerships and entrepreneurs working in successful initiatives linked with resource-oriented systems in Chía and other towns of Cundinamarca county. The study concluded that in Chía there was a gap between local initiatives of resource recovery from OWS that brought environmental, economic, and social benefits at small scale and its inclusion in the local and regional governance systems. Findings of this study touches upon many governance aspects such as knowledge, legislation, financing and even culture. Further research is needed to look closer to each of those and make concrete, feasible and effective proposals that bring change with a long-term sustainability vision. Finally, when analysing the results of the evaluation and making future proposals, strengths, and shortcomings of applying the GCF as an analytical tool for a specific case study like Chía need to be considered

La influencia de la presión atmosférica y el viento en la variabilidad del nivel del mar en el mareógrafo de Bonanza (Cádiz)

En esta comunicación se analiza la influencia de la presión atmosférica y el viento en la variabilidad del nivel del mar en el mareógrafo de Bonanza (Cádiz) mediante modelos de regresión lineal con el objeto de caracterizar y cuantificar el peso de las variables climáticas sobre los valores y la variabilidad del nivel del mar.This paper analyses the influence of air pressure and wind on sea level trough the data provided by tidal gauge of Bonanza (Cádiz) by means of linear regression analysis. The aim of the study is to characterize and quantify the importance of the climatic variables on the values and variability on sea level for this area

Análisis de índices extremos de temperatura máxima del Grupo de Expertos para la Detección del Cambio Climático e Índices en Andalucía (1961-2014)

Se realiza un análisis de índices de extremos térmicos de temperatura máxima para la región de Andalucía, una de las zonas más vulnerables de Europa al cambio climático. Los datos empleados proceden de la base de datos del European Climate Assessment & Dataset vinculada al ENSEMBLES Project y gestionada por el Koninklijk Nederlands Meteorologisch Instituut. Se han escogido 9 estaciones meteorológicas distribuidas espacialmente de forma representativa por la región para el periodo 1961-2014. Se ha analizado en cada una de ellas el comportamiento de las series de 4 índices del Expert Team on Climate Change Detection and Indices (días cálidos, días de verano, rachas cálidas y máximo mensual de las máximas diarias), disponibles en la página web del ECA&D (http://www.ecad.eu/download/). Éstos permitirán evaluar muchos aspectos del cambio climático global, el cual incluye cambios en la intensidad, frecuencia, y duración de la temperatura máxima. Según los test de tendencia de Mann-Kendall y Spearman y t de Student, existen tendencias estadísticamente significativas al incremento de la temperatura máxima asociada en los 4 índices analizados, siendo especialmente destacables los cambios detectados en las estaciones de primavera y verano. Los resultados se comparan con trabajos procedentes para Andalucía a fin de proporcionar una visión conjunta y actualizada de los cambios en las temperaturas máximas en Andalucía

G-3MRP: a game-theoretical multimedia multimetric map-aware routing1 protocol for vehicular ad hoc networks

© 2022 Elsevier. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/The particular requirements and special features of vehicular ad hoc networks (VANETs) (e.g., special mo8 bility patterns, short link lifetimes, rapid topology changes) involve challenges for the research community. 9 One of these challenges is the development of new routing protocols specially designed for VANETs. In 10 this paper, we present a novel game-theoretical approach of a multimetric geographical routing protocol for 11 VANETs to forward video-reporting messages in smart cities. Game theory is considered a very interesting 12 theoretical framework to analyze and optimize resource allocation problems in digital communication sce13 narios. Our contribution has shown to enhance the overall performance of VANETs in urban scenarios, in 14 terms of percentage of packet losses, average end-to-end packet delay and peak signal to noise ratio (PSNR).This work was supported by the Spanish Government under research project “Enhancing Communication Protocols with Machine Learning while Protecting Sensitive Data (COMPROMISE)” PID2020-113795RB-C31, funded by MCIN/AEI/10.13039/501100011033. Ahmad M. Mezher holds a McCain Postdoctoral Fellowship in Innovation with the Electrical and Computer Engineering department at the University of New Brunswick (UNB), Canada .Peer ReviewedPostprint (author's final draft

GuaB Activity Is Required in Rhizobium tropici During the Early Stages of Nodulation of Determinate Nodules but Is Dispensable for the Sinorhizobium meliloti–Alfalfa Symbiotic Interaction

The guaB mutant strain Rhizobium tropici CIAT8999-10T is defective in symbiosis with common bean, forming nodules that lack rhizobial content. In order to investigate the timing of the guaB requirement during the nodule formation on the host common bean by the strain CIAT899-10.T, we constructed gene fusions in which the guaB gene is expressed under the control of the symbiotic promoters nodA, bacA, and nifH. Our data indicated that the guaB is required from the early stages of nodulation because full recovery of the wild-type phenotype was accomplished by the nodA-guaB fusion. In addition, we have constructed a guaB mutant derived from Sinorhizobium meliloti 1021, and shown that, unlike R. tropici, the guaB S. meliloti mutant is auxotrophic for guanine and induces wild-type nodules on alfalfa and Medicago truncatula. The guaB R. tropici mutant also is defective in its symbiosis with Macroptilium atropurpureum and Vigna unguiculata but normal with Leucaena leucocephala. These results show that the requirement of the rhizobial guaB for symbiosis is found to be associated with host plants that form determinate type of nodules.Fil: Collavino, Mónica Mariana. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Riccillo, Pablo M.. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; ArgentinaFil: Grasso, Daniel Horacio. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Crespi, Martín. Centre National de la Recherche Scientifique; FranciaFil: Aguilar, Orlando Mario. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; Argentin