Towards Collisions of Inhomogeneous Shockwaves in AdS

We perform a numerical simulation of the evolution of inhomogeneities with transverse profile in a collision of gravitational shockwaves in asymptotically anti-de Sitter spacetime. This constitutes a step closer towards an accurate holographic description of the thermalization of a strongly coupled plasma, which can model the dynamics of heavy ion collisions. The results indicate that the considered inhomogeneities typically become hydrodynamical earlier or at the same moment when hydrodynamics applies to the background, even though they decay slowly.Comment: 11 pages, 4 figures; added figure and new results. Mathematica notebooks can be found at http://users.physics.uoc.gr/~fernandez/Page5.htm

Local supersymmetry in supergravity

We have studied the local supersymmetry in two D = 4 supergravity models, with N = 1 and N = 2, given the Lagrangians. We have used a simple method based on the differential of the action H, which provides an alternative systematic derivation of the gauge field variations in the first order formalism. This method may be used to find non-relativistic limits of supergravity models.Departamento de Física Teórica, Atómica y ÓpticaMáster en Físic

Cuidados de enfermería en los efectos secundarios de la quimioterapia: Revisión Bibliográfica

El cáncer es un grupo de enfermedades que aparecen con gran frecuencia en la población. Entre las distintas modalidades de tratamiento disponibles, la quimioterapia es una de las que más sintomatología produce en el paciente. El hecho de que la quimioterapia ataque a todas las células en crecimiento, y no sólo a las que se encuentran afectadas por la enfermedad, hace que los efectos secundarios que aparecen afecten a todos los aparatos y sistemas del organismo. Esta gran cantidad de reacciones adversas supone un deterioro general del paciente, incrementando la pérdida de autonomía y de salud que ya de por sí supone la enfermedad. En el apartado de introducción de esta revisión se explicarán algunos de estos efectos secundarios ocasionados por el tratamiento, como la diarrea, el estreñimiento o las náuseas. Después, se expondrán los objetivos principales del trabajo, siendo en este caso la revisión de las publicaciones existentes, la actualización de información y el facilitar la búsqueda de información. Posteriormente, en la sección de material y métodos, se explicará qué metodología se ha utilizado para la localización de los artículos y libros utilizados para realizar la revisión bibliográfica. En este caso, la bibliografía principal se basa en libros de oncología, y se complementa con artículos. A continuación, en el apartado de resultados y discusión, se realizará una comparación mediante tablas de las recomendaciones más defendidas por los autores, donde se expone, por ejemplo, que realizar una correcta higiene bucal en la mucositis produce mayores beneficios que masticar hielo. Inmediatamente después de cada tabla, aparecerá su correspondiente discusión, aclarando y ampliando la información descrita en la tabla. Finalmente, aparecerán las conclusiones realizadas del trabajo, donde se sugiere como conclusión principal que sería conveniente elaborar una guía detallada para los pacientes con lo expuesto en el trabajo.Grado en Enfermerí

De retibus socialibus et legibus momenti

Online Social Networks (OSNs) are a cutting edge topic. Almost everybody --users, marketers, brands, companies, and researchers-- is approaching OSNs to better understand them and take advantage of their benefits. Maybe one of the key concepts underlying OSNs is that of influence which is highly related, although not entirely identical, to those of popularity and centrality. Influence is, according to Merriam-Webster, "the capacity of causing an effect in indirect or intangible ways". Hence, in the context of OSNs, it has been proposed to analyze the clicks received by promoted URLs in order to check for any positive correlation between the number of visits and different "influence" scores. Such an evaluation methodology is used in this paper to compare a number of those techniques with a new method firstly described here. That new method is a simple and rather elegant solution which tackles with influence in OSNs by applying a physical metaphor.Comment: Changes made for third revision: Brief description of the dataset employed added to Introduction. Minor changes to the description of preparation of the bit.ly datasets. Minor changes to the captions of Tables 1 and 3. Brief addition in the Conclusions section (future line of work added). Added references 16 and 18. Some typos and grammar polishe

Exploring Determinants of Urban Motorcycle Accident Severity: The Case of Barcelona

Public authorities and road users alike are increasingly concerned by recent trends in road safety outcomes in Barcelona, which is the European city with the highest number of registered Powered Two-Wheel (PTW) vehicles per inhabitant,. In this study we explore the determinants of motorcycle and moped accident severity in a large urban area, drawing on Barcelona’s local police database (2002-2008). We apply non-parametric regression techniques to characterize PTW accidents and parametric methods to investigate the factors influencing their severity. Our results show that PTW accident victims are more vulnerable, showing greater degrees of accident severity, than other traffic victims. Speed violations and alcohol consumption provide the worst health outcomes. Demographic and environment-related risk factors, in addition to helmet use, play an important role in determining accident severity. Thus, this study furthers our understanding of the most vulnerable vehicle types, while our results have direct implications for local policy makers in their fight to reduce the severity of PTW accidents in large urban areas.Road Safety, Motorcycles, Mopeds, Accidents, Severity, Transportation

A Full Non-Monotonic Transition System for Unrestricted Non-Projective Parsing

Restricted non-monotonicity has been shown beneficial for the projective arc-eager dependency parser in previous research, as posterior decisions can repair mistakes made in previous states due to the lack of information. In this paper, we propose a novel, fully non-monotonic transition system based on the non-projective Covington algorithm. As a non-monotonic system requires exploration of erroneous actions during the training process, we develop several non-monotonic variants of the recently defined dynamic oracle for the Covington parser, based on tight approximations of the loss. Experiments on datasets from the CoNLL-X and CoNLL-XI shared tasks show that a non-monotonic dynamic oracle outperforms the monotonic version in the majority of languages.Comment: 11 pages. Accepted for publication at ACL 201