6,838 research outputs found

    Systematic Studies of Jet Quenching in Hot Nuclear Matter

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    The early universe was filled with a primordial form of matter called Quark Gluon Plasma that only exists at extremely high temperatures and densities, many times hotter than the core temperature of suns. By colliding heavy nuclei at top energies at machines like the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC) we can create and investigate tiny bubbles of Quark Gluon Plasma for very short periods of time before they cool and decay. We can use so-called QCD jets i.e. highly energetic quarks and gluons to penetrate and probe these artificially created Quark Gluon Plasma bubbles by comparing them with jets created in vacuum in control experiments. This is a wonderful tool to study properties of this exotic form of matter. We conduct a systematic study of the functional relationship between the so-called jet quenching strength ̂ and the plasma entropy density s. Our main goal is to explore the possibility of enhanced energy loss when the plasma temperature is close to the phase transition, temperature between the Quark Gluon Plasma and ordinary nuclear matter. We will simulate jets in Quark Gluon Plasma for a variety of colliding nuclei and collision energies. Existing experimental data will lead to constraints on the relationship between the plasma entropy density and the quenching strength. We were able to qualitatively confirm the results by Liao and Shuryak [8] who postulated an enhancement of ̂ around the phase transition. For Pb Pb collisions at the LHC we can show that such scenario leads to predictions of relatively small energy loss and small elliptic flow which can be compared to future experimental data

    MINERVA : Model drIveN and sErvice oRiented framework for the continuous improVement of business process & relAted tools

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    Organizations are facing several challenges nowadays, one of the most important ones being their ability to react quickly to changes either to their business process (BP) models or to the software implementing them. These changes can come from different sources: external requirements from partners or the market, or new internal requirements for the way that things are carried out by the defined BPs; they may also arise from improvement opportunities detected for the BPs defined, based on BPs execution monitoring and execution evaluation that is done by the organization, and/or its partners and customers. The increasing complexity of both BPs models and the software implementing them, requires the changes needed or the improvements to be carefully weighed against the impact their introduction will have; they ought also to be carried out in a systematic way to assure a successful development. Two key elements are to provide these requirements: the separation of BPs definition from their implementation to minimize the impact of changes in one to the other, and a process to introduce the changes or improvements in the existing BPs and/or software implementing them. Business Process Management (BPM) provides the means for guiding and supporting the modeling, implementation, deployment, execution and evaluation of BPs in an organization, based on the BP lifecycle. The realization of BPs by means of services provides the basis for separating their definition from the technologies implementing them and helps provide a better response to changes in either of the layers defined -definition and implementation of business processes- with minimum impact on the other. Modeling of both BP and services is a key aspect to support this vision, helping provide traceability between elements from one area to the other, so easing the analysis of the impact of changes, among other things. Models have proven to play an important role in the software development process, one of its key uses in the context of BP realization by means of services is that of designing services at a more abstract level than with specific technologies, also promoting reuse by separating services logic from its implementation. MINERVA: Model drIveN & sErvice oRiented framework for the continuous business process improVement & relAted tools is the framework that has been defined in this thesis work; it takes into account all the aspects mentioned, in which the SOC and MDD paradigms are applied to BPs focusing on their continuous improvement, extending an existing BP lifecycle with explicit execution measurement and improvement activities and elements. It is made up of three dimensions: i) conceptual, which defines the concepts that are managed throughout the framework. ii) methodological, which defines a methodology for service oriented development from BPs with automatic generation of SoaML service models from BPMN2 models, along with a continuous improvement process based on execution measurement of the occurrences of BPs in the organization to carry out the improvement effort. iii) tools support for the whole proposal based on several existing tools we have integrated, along with new ones we have developed. The proposals in MINERVA have been validated by means of an experiment and two case studies carried out in the context of real projects in two organizations, from which, as the main result of the applications performed, it can be concluded that MINERVA can be a useful and key guide for the continuous improvement of BPs realized by services and for the development of service oriented systems from BPs, with automatic generation of service models from BP models.Las organizaciones se enfrentan en la actualidad a varios retos, siendo uno de los más importantes su capacidad para reaccionar rápidamente a los cambios ya sea en sus modelos de procesos de negocio (PN) o en el software que los implementa. Estos cambios pueden provenir de distintas fuentes: requisitos externos de socios o del mercado, o nuevos requisitos internos para la forma en que las cosas se llevan a cabo por los PNs definidos; también pueden surgir de las oportunidades de mejora detectadas para los PNs definidos, en base al monitoreo y evaluación de la ejecución de los PNs llevada a cabo por la organización, y/o sus socios y clientes. La creciente complejidad de los modelos de PNs y del software que los implementa, requiere que los cambios o las mejoras sean sopesados cuidadosamente contra el impacto que su introducción tendrá; también deben llevarse a cabo de manera sistemática para asegurar un desarrollo exitoso. Dos elementos son clave para proveer estos requisitos: la separación de la definición de los PNs de su implementación, para minimizar el impacto de los cambios de uno en otro, y un proceso para introducir los cambios o mejoras en los PNs y/o en el software que los implementa. La Gestión de Procesos de Negocio (Business Process Management, BPM) proporciona los medios para guiar y apoyar el modelado, implementación, despliegue, ejecución y evaluación de PNs en una organización, basado en el ciclo de vida de PNs. La realización de PNs con servicios proporciona la base para la separación de su definición de las tecnologías para implementarlos, y ayuda a proporcionar una mejor respuesta a los cambios en cualquiera de las capas definidas -definición e implementación de procesos de negocio- con un impacto mínimo sobre la otra. El modelado de PNs y servicios es un aspecto clave para apoyar esta visión, ayudando a proveer trazabilidad entre los elementos de un área a la otra, por lo tanto facilitando el análisis del impacto de los cambios, entre otras cosas. Los modelos han demostrado jugar un papel importante en el proceso de desarrollo de software, uno de sus usos principales en el contexto de la realización de PNs con servicios es el de diseñar servicios a un nivel más abstracto que con tecnologías específicas, promoviendo la reutilización separando la lógica de los servicios de su implementacion. MINERVA: Model drIveN & sErvice oRiented framework for the continuous business process improVement & relAted tools es el marco que se ha definido en este trabajo de tesis, que toma en cuenta todos los aspectos mencionados, en el cual los paradigmas de Computación Orientada a Servicios (Service Oriented Computing, SOC) y Desarrollo Dirigido por Modelos (Model Driven Development, MDD) se aplican a los PNs con foco en su mejora continua, extendiendo un ciclo de vida PN existente con actividades y elementos explícitos para la medición de la ejecución y mejora de PNs. El marco se compone de tres dimensiones: i) conceptual, que define los conceptos que se manejan en todo el marco. ii) metodológica, que define una metodología para el desarrollo orientado a servicios desde PNs, con generación automática de modelos de servicio en SoaML desde modelos en BPMN2, junto con un proceso de mejora continua basado en la medición de la ejecución de las ocurrencias de los PNs en la organización para llevar a cabo el esfuerzo de mejora. iii) soporte de herramientas para la propuesta completa basado en la integracion de varias herramientas existentes, junto con otras nuevas que hemos desarrollado. Las propuestas de MINERVA han sido validadas por medio de un experimento y dos casos de estudio realizados en el marco de proyectos reales en dos organizaciones, de los cuales, como resultado principal de las aplicaciones realizadas, se puede concluir que MINERVA puede ser una guía útil y clave para la mejora continua de PNs realizados por servicios y para el desarrollo de sistemas orientados a servicios desde PNs, con generación automática de modelos de servicio a partir de modelos de PN

    Review Article of 'Buying into the Regime' and 'The Chicken and the Quetzal'

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    Review of: Buying Into the Regime: Grapes and Consumption in Cold War Chile and the United States, Heidi Tinsman. (Durham: Duke University Press, 2014. 363 pp.) ISBN 978-0-8223-5535-9. Price 28.95TheChickenandtheQuetzal:IncommensurateOntologiesandPortableValuesinGuatemalasCloudForest,PaulKockelman.(Durham:DukeUniversityPress,2016.190pp.)ISBN9780822360728.Price28.95 The Chicken and the Quetzal: Incommensurate Ontologies and Portable Values in Guatemala’s Cloud Forest, Paul Kockelman. (Durham: Duke University Press, 2016. 190 pp.) ISBN 978-0-8223-6072-8. Price 23.9

    The Effects of Acute Stress Exposure on Neural Correlates of Pavlovian Conditioning with Monetary Gains and Losses

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    Pavlovian conditioning involves the association of an inherently neutral stimulus with an appetitive or aversive outcome, such that the neutral stimulus itself acquires reinforcing properties. Across species, this type of learning has been shown to involve subcortical brain regions such as the striatum and the amygdala. It is less clear, however, how the neural circuitry involved in the acquisition of Pavlovian contingencies in humans, particularly in the striatum, is affected by acute stress. In the current study, we investigate the effect of acute stress exposure on Pavlovian conditioning using monetary reinforcers. Participants underwent a partial reinforcement conditioning procedure in which neutral stimuli were paired with high and low magnitude monetary gains and losses. A between-subjects design was used, such that half of the participants were exposed to cold stress while the remaining participants were exposed to a no stress control procedure. Cortisol measurements and subjective ratings were used as measures of stress. We observed an interaction between stress, valence, and magnitude in the ventral striatum, with the peak in the putamen. More specifically, the stress group exhibited an increased sensitivity to magnitude in the gain domain. This effect was driven by those participants who experienced a larger increase in circulating cortisol levels in response to the stress manipulation. Taken together, these results suggest that acute stress can lead to individual differences in circulating cortisol levels which influence the striatum during Pavlovian conditioning with monetary reinforcers

    Bonds, lone pairs, and shells probed by means of on-top dynamical correlations

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    The Electron Localization Function (ELF) by Becke and Edgecombe [J. Chem. Phys. {\bf 92}, 5397 (1990)] is routinely adopted as a descriptor of atomic shells and covalent bonds. Since the ELF and its related quantities find useful exploitation also in the construction of modern density functionals, the interest in complementing the ELF is linked to both the quests of improving electronic structure descriptors and density functional approximations. The ELF uses information which is available by considering parallel-spin electron pairs in single-reference many-body states. In this work, we complement this construction with information obtained by considering antiparallel-spin pairs whose short-range correlations are modeled by a density functional approximation. As a result, the approach requires only a contained computational effort. Applications to a variety of systems show that, in this way, we gain a spatial description of the bond in H2_2 (which is not available with the ELF) together with some trends not optimally captured by the ELF in other prototypical situations

    Predicting signatures of anisotropic resonance energy transfer in dye-functionalized nanoparticles

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    Resonance energy transfer (RET) is an inherently anisotropic process. Even the simplest, well-known F\"orster theory, based on the transition dipole-dipole coupling, implicitly incorporates the anisotropic character of RET. In this theoretical work, we study possible signatures of the fundamental anisotropic character of RET in hybrid nanomaterials composed of a semiconductor nanoparticle (NP) decorated with molecular dyes. In particular, by means of a realistic kinetic model, we show that the analysis of the dye photoluminescence difference for orthogonal input polarizations reveals the anisotropic character of the dye-NP RET which arises from the intrinsic anisotropy of the NP lattice. In a prototypical core/shell wurtzite CdSe/ZnS NP functionalized with cyanine dyes (Cy3B), this difference is predicted to be as large as 75\% and it is strongly dependent in amplitude and sign on the dye-NP distance. We account for all the possible RET processes within the system, together with competing decay pathways in the separate segments. In addition, we show that the anisotropic signature of RET is persistent up to a large number of dyes per NP.Comment: 9 pages, 5 figures. Supplementary information available at http://pubs.rsc.org/en/content/articlelanding/2016/ra/c6ra22433d/unauth#!divAbstrac

    An Analysis on TED Talks: The Use of the Preposition and Conjunction ‘As’

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    Most of the studies dealing with the emerging oral genre of TED Talks have focused on the use of them as a way of teaching and learning, however, fewer studies have emphasized its structure or function. This essay deals with the study of different POS of the functional word as in different TED Talks being classified by their function and topic. More specifically, it is the study of the frequency and use of as as a preposition and conjunction on two sub-corpora with the help of the software Sketch Engine. It aims to show the process and selection criteria to compile a corpus, to study the usage of the preposition and conjunction as, and to manually analyze the errors that the software could be made. The results show that the preposition as is used to a higher extent in both sub-corpora, and consequently, in the whole specialized corpus. Keywords: As, TED Talk, corpus,La mayoría de los estudios que tratan el género oral en auge de las charlas TED se han centrado en el uso de éstas como forma de enseñanza y aprendizaje, sin embargo, son menos los estudios que se han centrado en su estructura o función. Este trabajo aborda el estudio de las diferentes categorías gramaticales de la palabra funcional “as” en diferentes charlas TED clasificadas por su función y temática. Más concretamente, se trata del estudio de la frecuencia y el uso de “as” como preposición y conjunción en dos sub-corpus con la ayuda del software Sketch Engine. El objetivo principal es mostrar el proceso y los criterios de selección para compilar un corpus, estudiar el uso de la preposición y la conjunción “as”, y analizar manualmente los errores cometidos por el software al analizar automáticamente los datos. Los resultados muestran que la preposición “as” se usa en un porcentaje mayor en ambos sub-corpus, y como resultado, en la totalidad del corpus especializado.Departamento de Filología InglesaGrado en Estudios Inglese

    “Don’t stop speaking”: Using game-based learning to promote fluency in the EFL classroom

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    Nowadays, one of the most important objectives is that our students learn in high school without seeing it as a punishment. This MA Thesis deals with an educational proposal “Don’t stop speaking” based on game-based learning to promote oral production, more specifically, fluency in the EFL classroom. It is a whole academic year educational proposal with one session per unit, in which I propose two types of sessions, an analogue and a digital one, for teachers to choose from. I want students to leave the routine by working cooperatively and using ICTs in the classroom. It would be possible to reduce the affective filter and achieve a more relaxed environment for students to learn and speak a foreign language, which is something that students are often afraid of.Una de las cosas más importantes hoy en día es que nuestros alumnos aprendan en los institutos sin verlo como un castigo. Este Trabajo de Fin de Máster presenta una propuesta educativa "Don't stop speaking" enfocada en el aprendizaje basado en el juego para promover la producción oral, más concretamente, la fluidez en el aula de inglés como lengua extranjera. Se trata de una propuesta educativa para todo el curso académico con una sesión por unidad, en la que propongo dos tipos de sesiones, una analógica y otra digital, para que los profesores puedan elegir. Quiero que los alumnos salgan de la rutina trabajando de forma cooperativa y utilizando las TICs en el aula. Se conseguiría reducir el filtro afectivo y lograr un ambiente más relajado para que los alumnos aprendan y hablen una lengua extranjera que es algo a lo que los alumnos temen a menudo.Máster en Profesor de Educación Secundaria Obligatoria y Bachillerato, Formación Profesional y Enseñanzas de Idioma
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