La gobernanza global de la energía

La energía está ligada al desarrollo económico y la seguridad nacional. A menudo los gobiernos han entendido la energía como un área de la «alta política» donde los intereses nacionales predominan sobre los intereses colectivos. Sin embargo, la evolución del concepto de seguridad energética, la creciente conciencia de que es necesario mejorar el acceso a los servicios de energía modernos así como evitar un cambio climático peligroso, modificó esa aproximación hacia los problemas energéticos. La gobernanza energética global se ha convertido en el concepto de análisis de la colaboración internacional. Entender el concepto de gobernanza energética global precisa conocer la naturaleza y la magnitud del ámbito energético. Igualmente importante es conocer quién es el responsable de tomar las decisiones. Sólo entonces seremos capaces de tomar las medidas adecuadas. Este artículo se centra en analizar dos elementos: por qué la energía es un problema mundial y quién la gobierna.Energy is linked to economic development and national security. Governments have often understood energy as an area of «high politics» where national interests are above collective interests. However, the evolution of the concept of energy security, the growing awareness of the need to improve access to modern energy and to avoid dangerous climate change transformed the way of confronting energy issues. Global energy governance has become the concept for analyzing international collaboration. Conceiving of global energy governance demands understanding the nature and magnitude of energy. Equally important is to know who is responsible for taking the decisions. Only then we will be able to make appropriate steps. This article focuses on both elements: why energy is a global issue and who governs it

Range-only benthic Rover localization off the central California coast

Nowadays, the use of autonomous vehicles for ocean research has increased, since these vehicles have a better cost/performance ratio than crewed vessels or oceanographic ships. For example, autonomous surface vehicles can be used to localize underwater targets. This paper describes a mission to find a crawling robot - Benthic Rover - on the abyssal plain in the north eastern Pacific, using single-beacon localization from onboard a Wave Glider autonomous surface vehicle. While the Wave Glider is moving around the surface in the target zone, it takes ranges between the target and itself using acoustic modems. With these ranges it can compute the target location, as a Long Baseline (LBL) system. The benefit of this approach is the reduction of cost and complexity relative to deployment of a traditional shipboard LBL system. Additionally, this is a mobile system, and can cover long distances, and can geolocate multiple targets over a large area.Postprint (author's final draft

Range-only underwater target localization : error characterization

Locating a target from range measurements using only one mobile transducer has been increased over the last years. This method allows us to reduce the high costs of deployment and maintenance of traditional fixed systems on the seafloor such as Long Baseline. The range-only single-beacon is one of the new architectures developed using the new capabilities of modern acoustic underwater modems, which can be time synchronization, time stamp, and range measurements. This document presents a method to estimate the sources of error in this type of architecture so as to obtain a mathematical model which allows us to develop simulations and study the best localization algorithms. Different simulations and real field tests have been carried out in order to verify a good performance of the model proposed.Postprint (published version

Optimal path shape for range-only underwater target localization using a Wave Glider

Underwater localization using acoustic signals is one of the main components in a navigation system for an autonomous underwater vehicle (AUV) as a more accurate alternative to dead-reckoning techniques. Although different methods based on the idea of multiple beacons have been studied, other approaches use only one beacon, which reduces the system’s costs and deployment complexity. The inverse approach for single-beacon navigation is to use this method for target localization by an underwater or surface vehicle. In this paper, a method of range-only target localization using a Wave Glider is presented, for which simulations and sea tests have been conducted to determine optimal parameters to minimize acoustic energy use and search time, and to maximize location accuracy and precision. Finally, a field mission is presented, where a Benthic Rover (an autonomous seafloor vehicle) is localized and tracked using minimal human intervention. This mission shows, as an example, the power of using autonomous vehicles in collaboration for oceanographic research.Peer ReviewedPostprint (author's final draft

Tipologías de consumidores de alcohol dentro de la práctica del botellón en tres ciudades españolas.

En este trabajo se entrevistó a 6.009 jóvenes que practican botellón (14-25 años) en tres ciudades de la Comunidad Valenciana, realizando un muestreo estratifi cado de centros de Secundaria, Bachiller,CF y Universidad. Se efectuó un análisis de conglomerados en dos fases con cada muestra con dos objetivos: identifi car tipologías de consumidores de alcohol en el botellón y realizar una validación cruzada de la solución obtenida. Las variables consideradas en los análisis fueron: sexo, grupo de edad (universitarios: U; estudiantes Secundaria: ES), realización o no de episodios intensivos de consumo, años practicando botellón y gramos de alcohol ingeridos. Los resultados muestran evidencia de validez de la estructura obtenida para los jóvenes que realizan episodios intensivos de consumo de alcohol, ya que aparece una estructura de cuatro grupos en las tres muestras (varones U, varones ES, mujeres U,mujeres ES), siendo siempre los varones quienes más consumen. Además, los ES consumen iguales cantidades de hol que los U, aunque llevan menos años consumiendo. Por su parte, entre los jóvenes que no realizan episodios intensivos de consumo de alcohol se observa cierta variabilidad en la estructura, siendo manifi esta la tendencia de las mujeres a igualar su consumo con el de los varones. Different typologies of alcohol consumers in the practice of «botellon» in three Spanish cities. In this work, 6,009 youngsters (14-25 years old) who practice the «botellon» were interviewed in three cities of the Valencian Community. After a stratifi ed sampling among college and noncollege students, a two-step cluster analysis was carried out for each sample with two aims: to identify different types of alcohol consumers in the practice of the «botellon» and to carry out a crossed validation of the results obtained. The variables included in the analysis were the following: gender, age group (university students: U; adolescent students: ES), performance of intensive episodes of consumption (yes/no), number of years practicing the «botellon» and grams of alcohol ingested. The results show the validity of the structure obtained for youngsters, revealing intensive episodes of alcohol consumption, as a fourgroup structure appeared in all three samples (male U, male ES, female U, female ES), in which men were always at the top of alcohol ingestion. Furthermore, ES consumed the same amount of alcohol as U, even though they had been consuming for less time. However, the youngsters who did not report intensive episodes of alcohol consumption showed some structure variability, with a tendency among women to match men"s levels of alcohol consumptio

Slow and fast micro-field components in warm and dense hydrogen plasmas

The aim of this work is the investigation of the statistical properties of local electric fields in an ion-electron two component plasmas for coupled conditions. The stochastic fields at a charged or at a neutral point in plasmas involve both slow and fast fluctuation characteristics. The statistical study of these local fields based on a direct time average is done for the first time. For warm and dense plasma conditions, typically $N_{e}\approx 10^{18}cm^{-3}$, $$, well controlled molecular dynamics (MD) simulations of neutral hydrogen, protons and electrons have been carried out. Relying on these \textit{ab initio} MD calculations this work focuses on an analysis of the concepts of statistically independent slow and fast local field components, based on the consideration of a time averaged electric field. Large differences are found between the results of these MD simulations and corresponding standard results based on static screened fields. The effects discussed are of importance for physical phenomena connected with stochastic electric field fluctuations, e.g., for spectral line broadening in dense plasmas.Comment: 4 pages, 4 figures, submitted to Phys. Rev. Let

Motivation to quit as a predictor of smoking cessation and abstinence maintenance among treated Spanish smokers

Introduction: Although quitting motivation predicts smoking cessation, there have been inconsistent findings regarding motivation predicting long-term maintenance of abstinence. Moreover, most such research has been conducted in North America and the United Kingdom. The aim of this study was to examine motivation to quit as a predictor of smoking cessation and of abstinence maintenance in a Spanish sample. Method: The sample comprised 286 Spanish smokers undergoing psychological treatment for smoking cessation. Motivation to quit was assessed pre-treatment and post-treatment with the Readiness to Quit Ladder. Abstinence post-treatment and at 6 month follow-up was biochemically verified. Results: Participants with higher levels of pre-treatment and post-treatment motivation were more likely to be abstinent at the end of the treatment (OR. = 1.36) and at 6 month follow-up (OR. = 4.88). Among abstainers at the end of the treatment (61.9%), higher levels of motivation to quit post-treatment predicted maintaining abstinence at 6 months (OR. = 2.83). Furthermore, participants who failed to quit smoking reported higher levels of motivation to quit post-treatment than they had pretreatment (p<. .001). Conclusions: Motivation to quit smoking predicted short and long-term cessation, and also predicted long-term maintenance of abstinence. These results have implications for understanding motivational processes of smoking cessation in general, while extending research to Spanish smokers. They may also help in the design of cessation and relapse-prevention interventions. Specifically, the results suggest that motivational enhancement is important throughout the cessation and maintenance periods

Tracing drought effects from the tree to the stand growth in temperate and Mediterranean forests: insights and consequences for forest ecology and management

How drought affects tree and stand growth is an old question, but is getting unprecedented relevance in view of climate change. Stress effects related to drought have been mostly studied at the individual tree level, mostly investigating dominant trees and using their responses as indicator for the impact at the stand level. However, findings at tree and stand level may differ, as the stand responses include interactions and feedbacks that may buffer or aggravate what is observed at the individual tree level. Here, we trace drought effects on growth and development from tree to the stand scale. Therefore, we analyse annually measured data from long-term experiments in temperate and Mediterranean forests. With this analysis, we aim to disclose how well results of dominant tree growth reflect stand-level behaviour, hypothesizing that drought resistance of dominant trees’ can strongly deviate from the overall sensitivity of the stand. First, we theoretically derive how drought responses at the stand level emerge from the tree-level behaviour, thereby considering that potential drought resistance of individual trees is modulated by acclimation and tree–tree interactions at the stand level and that the overall stress response at the stand level results from species-specific and size-dependent individual tree growth and mortality. Second, reviewing respective peer-reviewed literature (24 papers) and complementing findings by own measurements (22 experiments) from temperate and Mediterranean monospecific and mixed-species forests, we are able to reveal main causes for deviations of tree-level and stand-level findings regarding drought stress responses. Using a long-term experiment in Norway spruce (Picea abies (L.) KARST.) and European beech (Fagus sylvatica L.), we provide evidence that the species-dependent and size-dependent reactions matter and how the size–frequency distribution affects the scaling. We show by examples that tree-level derived results may overestimate growth losses by 25%. Third, we investigate the development of the growth dominance coefficient based on measurements gathered at the Bavarian forest climate stations. We show that drought changes stand biomass partitioning in favour of small trees, reduce social differentiation, and homogenize the vertical structure of forests. Finally, we discuss the drought-related consequences of the social class-specific growth reaction patterns for inventory and monitoring and highlight the importance of these findings for understanding site-specific stand dynamics, for forest modelling, and for silvicultural management

Acoustic tag tracking: first experiments

Nowadays, the use of autonomous vehicles for ocean research has increased, since these vehicles have a better cost/performance ratio than crewed vessels or oceanographic ships. For example, autonomous surface vehicles can be used to localize underwater targets. Whereas different research works are focused in target tracking using acoustic modems (or USBL), in this paper a new method called Area-Only target tracking is presented, which uses the signal generated by acoustic TAGs. This document, the first tests are presented and their results discussed, which were conducted in the Monterey Bay.Peer Reviewe