Non-linear Preheating with Scalar Metric Perturbations

We have studied preheating of field perturbations in a 3-dimensional lattice including the effect of scalar metric perturbations, in two generic models of inflation: chaotic inflation with a quartic potential, and standard hybrid inflation. We have prepared the initial state for the classical evolution of the system with vanishing vector and tensor metric perturbations, consistent with the constraint equations, the energy and momentum constraints. The non-linear evolution inevitably generates vector and tensor modes, and this reflects on how well the constraint equations are fulfilled during the evolution. The induced preheating of the scalar metric perturbations is not large enough to backreact onto the fields, but it could affect the evolution of vector and tensor modes. This is the case in hybrid inflation for some values of the coupling $g$ and the height of potential $V_0^{1/4}$. For example with $V_0^{1/4} \simeq 10^{15}$ GeV, preheating of scalar perturbations is such that their source term in the evolution equation of tensor and vector becomes comparable to that of the field anisotropic stress.Comment: 15 pages, 12 eps figure

Solar axions in large extra dimensions

We wish to thank Barbara and Janusz Sylwester who kindly shared with us the SphinX measurements of solar X-rays and who answered with details our questions about the working principles of the SphinX detector. MBG would like to thank the LPSC (UGA, CNRS, Grenoble INP) for kind hospitality. The work of MBG has been partially supported by MICINN (PID2019-105943GB-I00/AEI/10.13039/501100011033) and "Junta de Andalucia" grants P18-FR-4314 and A-FQM-211-UGR18.The axion could be used as a probe for extra dimensions. In large extra dimensions, besides the QCD axion one obtains an infinite tower of massive Kaluza-Klein (KK) states. We describe the processes of KK axions production in the Sun via the axion-photon coupling, g(a gamma gamma), and we derive the number density of KK axions that get trapped into the solar gravitational field and then accumulate over cosmic times. The large multiplicity of states, as well as their masses in the keV-range, deeply alter the phenomenology of the axion. This scenario leads us to propose the presence of KK axions as an interpretation of the non-thermal distribution of the solar X-rays. In this work, we dedicate special attention on the astrophysical and cosmological bounds that apply to the model. In particular, we show how the KK axions may escape the EBL limit that constrains standard ALPs in the same mass range. Present searches for KK axions make use of the decay channel, a -> gamma gamma, for which we revise the event rate; our value lies orders of magnitude below the rate usually quoted in the literature. This major conclusion stems from recent measurements of the luminosity of the quiet Sun which acts as an irreducible limit. The revised model remains a viable and an attractive explanation for multiple astrophysical observations, and we propose several approaches to search for solar KK axions in the near future.Spanish GovernmentEuropean Commission PID2019-105943GB-I00/AEI/10.13039/501100011033Junta de Andalucia P18-FR-4314 A-FQM-211-UGR1

How is CSR incorporated into a firm's strategy: the pedagogical case study of Henkel

Corporate Social Responsibility is a trending subject among company's communication towards their consumers, but the truth is that only a few companies can really own the concept of CSR, by having it as a key factor of its business strategy. The process of successfully implement a strategy that takes into account the impact of their operations in society and the environment constitutes a challenge for the management and it has to include a long-term perspective. This pedagogical case study aims to assess how does Henkel, the world's number one adhesives producer and one of the biggest Home Care and Beauty FMCG companies globally, integrates Corporate Social Responsibility into its business strategy. Moreover, this case will identify Henkel’s driver for being in business, the way it delivers additional value to its various stakeholders and what influence CSR has in the decision-making process and the day-to-day operations. This essay can be a practical tool to comprehend the scale of strategic management on a renowned company, provide guidelines for what is essential when implementing a CSR strategy, and the benefits and challenges that can be meet.A Responsabilidade Social das empresas (RSE) é uma nova tendência presente nos canais de comunicação dirigidos aos seus clientes, contudo são poucas as empresas que aplicam efetivamente este conceito de Responsabilidade Social como fator chave na sua estratégia de negócio. O sucesso da implementação desta estratégia, que tem em conta o impacto das suas operações na sociedade e no meio ambiente, constitui um desafio para a gestão e deve incluir uma perspetiva a longo-prazo. O presente caso de estudo pedagógico propõe analisar se a Henkel, a maior produtora de "Adhesive Technologies" do mundo e globalmente uma das maiores empresas de "Home Care" e "Beauty Care", integra o conceito de Responsabilidade Social das empresas na sua estratégia de negócio. Adicionalmente, este caso de estudo irá identificar as motivações da empresa para permanecer no negócio, como é que gera valor para os seus "stakeholders" e qual a influência que a RS tem ao longo do processo de tomada de decisão e nas operações do dia-a-dia. Este caso de estudo pedagógico pode ser uma ferramenta prática para compreender a dimensão da gestão estratégica de uma empresa de renome, para apresentar diretrizes sobre os elementos essenciais na implementação de uma estratégia de RSE. assim como os potenciais benefícios e desafios que possam ser apresentados

Expressiveness and Instrumentality of Crime Scene Behavior in Spanish Homicides

One of the current trends in the study of criminal profiling consists of developing theoretical and methodological typologies to offer information of operational use in police investigations. The objective of this work was to verify the validity of the instrumental/expressive model, so as to establish homicide typologies based on modus operandi relationships, characteristics of the victims, and characteristics of perpetrators. The sample consisted of 448 homicide cases registered in the database of the Homicide Revision Project of the Office of Coordination and Studies of the Spanish Secretary of State and Security. Through multidimensional scaling and cluster analysis, three expressive homicide subtypes were identified (expressive-impulsive, expressive-distancing, and expressive-family), as well as two instrumental homicide subtypes (instrumental-opportunist and instrumental-gratification). The expressive homicide typologies accounted for almost 95% of all of the studied cases, and most of the homicides occurring in Spain were found to take place between individuals who know one another (friends, family members, intimate couples/ex-couples). The findings from this study suggest that the instrumental/expressive model may be a useful framework for understanding the psychological processes underlying homicides, based on the study of relationships between the crime and aggressor characteristics, which may be very helpful in the prioritization of suspect

Analysis of Measures of Quantitative Association Rules

This paper presents the analysis of relationships among different interestingness measures of quality of association rules as first step to select the best objectives in order to develop a multi-objective algorithm. For this purpose, the discovering of association rules is based on evolutionary techniques. Specifically, a genetic algorithm has been used in order to mine quantitative association rules and determine the intervals on the attributes without discretizing the data before. The algorithm has been applied in real-word climatological datasets based on Ozone and Earthquake data.Ministerio de Ciencia y Tecnología TIN2007-68084-C-00Junta de Andalucía P07-TIC-0261

Analysis of the evolution of the Spanish labour market through unsupervised learning

Unemployment in Spain is one of the biggest concerns of its inhabitants. Its unemployment rate is the second highest in the European Union, and in the second quarter of 2018 there is a 15.2% unemployment rate, some 3.4 million unemployed. Construction is one of the activity sectors that have suffered the most from the economic crisis. In addition, the economic crisis affected in different ways to the labour market in terms of occupation level or location. The aim of this paper is to discover how the labour market is organised taking into account the jobs that workers get during two periods: 2011-2013, which corresponds to the economic crisis period, and 2014-2016, which was a period of economic recovery. The data used are official records of the Spanish administration corresponding to 1.9 and 2.4 million job placements, respectively. The labour market was analysed by applying unsupervised machine learning techniques to obtain a clear and structured information on the employment generation process and the underlying labour mobility. We have applied two clustering methods with two different technologies, and the results indicate that there were some movements in the Spanish labour market which have changed the physiognomy of some of the jobs. The analysis reveals the changes in the labour market: the crisis forces greater geographical mobility and favours the subsequent emergence of new job sources. Nevertheless, there still exist some clusters that remain stable despite the crisis. We may conclude that we have achieved a characterisation of some important groups of workers in Spain. The methodology used, being supported by Big Data techniques, would serve to analyse any alternative job market.Ministerio de Economía y Competitividad TIN2014-55894-C2-R y TIN2017-88209-C2-2-R, CO2017-8678

¿Han de estar los futuros profesores en Europa cortados por el mismo patrón?

En este trabajo examinamos algunas dimensiones de la nueva realidad de la formación de los profesores en el contexto de la convergencia europea. En este sentido, la función del profesor, en tanto que educador, no se entiende ni se puede reconocer bajo parámetros exclusivamente técnicos. Reconocemos un componente cultural y social en su labor que modula constantemente el modo de pensar, de trazar estrategias, de diseñar, de implicarse en las tareas o de persistir en la realización de metas y objetivos. Concluimos enfatizando la importancia del conocimiento en la acción como vía segura para la optimización formativa de los profesores._______________________________In this work we examine some aspects of the new reality concerning teacher education in the context of the European Convergence.In this sense, the work of the professor as educator is not understood and can not be recognized in terms of exclusively technical parameters. We recognize cultural and social components to teachers' work that constantly regulate ways of thinking, drawing up strategies, designing, dedicating oneself to tasks, and persisting in the accomplishment of goals and objectives. We conclude by emphasizing the importance of understanding in action as a sure way toward optimizing teacher education

New solar X-ray constraints on keV Axion-Like Particles

The decay of Axion-Like Particles (ALPs) trapped in the solar gravitational field would contribute to the observed solar X-ray flux, hence constraining ALP models. We improve by one order of magnitude the existing limits in the parameter space $(g_{a\gamma\gamma}, m)$ by considering ALPs production via photon coalescence. For $g_{ae} \neq 0$, we demonstrate that trapped ALPs can be Compton-absorbed while crossing the Sun, resulting in two regimes in the exclusion limits, with a transition triggered by $g_{ae}$. Out of the transitional region, the solar X-ray constraints on ALPs are exclusively governed by $g_{a\gamma\gamma}$.Comment: 6 pages, 4 figure

Investiga??o do Uso de Ressoadores com Geometria Matrioska em Antenas Planares

Com todo o crescimento na ?rea de telecomunica??es atrav?s de aplica??es que utilizam a comunica??o sem fio, a demanda por novos dispositivos cada vez menores e mais eficientes para esse sistema tem crescido. A antena ? um elemento essencial no sistema de comunica??o sem fio, e tem sido desej?vel que ela seja miniaturizada conservando o desempenho. Diante dessas condi??es, a antena de microfita tem obtido destaque por sua facilidade de adequa??o em diferentes tipos de superf?cies e facilidade de fabrica??o. Algumas t?cnicas t?m sido desenvolvidas para obter a miniaturiza??o das antenas de microfita, sendo uma dessas t?cnicas a Defected Ground Structure (DGS), que mediante a inser??o de fendas no plano de terra da antena ocasiona modifica??es nos seus par?metros de modo que se obt?m uma diminui??o da frequ?ncia de resson?ncia sem alterar o tamanho e o desempenho da antena. Essas fendas podem apresentar diferentes geometrias, havendo trabalhos que obtiveram bons resultados utilizando an?is circulares repartidos (SRR, Split Ring Ressonators) como base para essa abertura no plano de terra. Neste trabalho ? apresentada a antena de microfita retangular com estrutura DGS baseada nas geometrias matrioskas fechada e aberta, tendo como suporte para compara??o dos resultados a antena de microfita retangular com estrutura DGS baseada nos SRR, verificando a redu??o da frequ?ncia de resson?ncia para as antenas de microfita e observado os efeitos das resson?ncias das estruturas DGS nessa redu??o. Dessa forma, estruturas DGS baseadas nas geometrias matrioska e SRR foram utilizadas em antenas de microfita com frequ?ncias de resson?ncias em 2,5 GHz, 3 GHz e 3,5 GHz. O melhor resultado, considerando a redu??o da frequ?ncia de resson?ncia, coeficiente de reflex?o e ganho, foi obtido com a antena de microfita com a estrutura DGS contendo quatro elementos baseadas na geometria matrioska aberta ressoando em aproximadamente 2,5 GHz. Com essa miniaturiza??o, a ?rea do patch da antena de microfita foi reduzida em at? 45,6%, sendo observado que quanto menor a resson?ncia da estrutura DGS maior a redu??o da frequ?ncia da antena de microfitaIFPB e CAPES/FAPES