Existence, uniqueness and asymptotic behavior of the solutions to the fully parabolic Keller-Segel system in the plane

In the present article we consider several issues concerning the doubly parabolic Keller-Segel system in the plane, when the initial data belong to critical scaling-invariant Lebesgue spaces. More specifically, we analyze the global existence of integral solutions, their optimal time decay, uniqueness and positivity, together with the uniqueness of self-similar solutions. In particular, we prove that there exist integral solutions of any mass, provided that \e>0 is sufficiently large. With those results at hand, we are then able to study the large time behavior of global solutions and prove that in the absence of the degradation term the solutions behave like self-similar solutions, while in presence of the degradation term global solutions behave like the heat kernel

Investment in new HUB for Oil & Gas Engineering Centres by Oil & Gas Services Companies

Mestrado em FinançasO renovado interesse na indústria petrolífera coloca-a no topo da lista de prioridades de investimento estrangeiro para alguns países. A competitividade empresarial é um factor bastante importante numa Sociedade global e, como tal, um factor que não pode ser descurado a este nível. O objectivo deste trabalho assenta no estudo de uma decisão de investimento referente à possível expansão da actividade de empresas prestadoras de serviços na indústria petrolífera. Além da definição do enunciado da situação, uma resolução é apresentada. Esta resolução assenta em três metodologias distintas: - Modelo Free Cash-Flow; - Análise Strengths, Weaknesses, Opportunities e Threats (SWOT); - Modelo Matriz Híbrida. O modelo de Free Cash-Flow permitiu considerar os custos de capital de cada empresa e chegar a uma conclusão sobre o país/local que apresenta as métricas financeiras mais apelativas. A análise SWOT oferece-nos uma visão mais generalista acerca dos países considerados sobre a perspectiva de investimento.. Com o intuito de analisar factores estratégicos induzidos por parâmetros externos (de forma a não considerar apenas métricas financeiras), foi criada uma Matriz Híbrida e foi realizada a respectiva análise. Neste seguimento, os resultados apresentados pelo Modelo de Matriz Híbrida deverão ser considerados aquando da decisão de expansão. Foi possível concluir que a melhor opção base é a criação de um escritório em Portugal. Apesar desta conclusão, a solução óptima é observada quando contabilizamos os custos de abrir um escritório em Portugal e quando, simultaneamente, consideramos os impostos que são pagos na Holanda (devido à sua política de impostos mais atractiva).The renewed interest in the Oil & Gas sector places this Industry at the top of the list of priorities for some countries in order to attract foreign investment. Corporate competitiveness is, therefore, an extremely important vehicle for a globalized Society. The aim of the present work was to study the possible investment contemplated by an expansion decision taken by some Oil & Gas Services companies. Besides the definition of the problem, an adequate resolution is also presented. This resolution is sustained by three distinct methodologies: - Free Cash-Flow Model; - Strengths, Weaknesses, Opportunities and Threats (SWOT) analysis; - Hybrid Matrix Model. The Free Cash-Flow Model enabled us to consider costs of capital and come to a decision regarding the country that presented the best financial results. The SWOT analysis provided a more generalist view over the several analysed countries. With the purpose of analysing strategic factors induced by external parameters (besides the financial field), the Hybrid Matrix Model was created and a study was carried out. Subsequently, the results presented by the Hybrid Matrix Model shall be taken into account when choosing a location for an international expansion. It was possible to conclude that the best base scenario is observed when opening an Office in Portugal. However, the optimal solution would be opening an Office in Portugal and account the profits/losses in the Netherlands, mixing the country that presents the lowest costs with the country that has the best taxation policies

Os neuroléticos na perturbação do espetro do autismo

Trabalho de projecto de mestrado em Medicina (Pediatria), apresentado á Faculdade de Medicina da Universidade de CoimbraIntrodução: A perturbação do espetro do autismo é uma patologia crónica do neurodesenvolvimento, com apresentação em idades precoces cujos principais sintomas são défices na comunicação, na interação social e padrões de comportamentos restritivos e estereotipados. Frequentemente os indivíduos apresentam associados sintomas disruptivos como auto e hetero agressividade, agitação psicomotora, birras, hiperatividade e alterações de humor, que interferem gravemente com a sua qualidade de vida e das suas famílias. O tratamento farmacológico destes sintomas baseia-se em várias classes de medicamentos, sendo os neuroléticos a mais utilizada, uma vez que demonstra maior eficácia e segurança. A farmacogenética tem sido decisiva na procura das causas para esta perturbação, demonstrando já alguns avanços na descoberta de genes que interferem na farmacodinâmica e no tipo de reações adversas dos neuroléticos e que prometem optimizar a utilização destes nos quadros de autismo. Objetivo: Rever as indicações dos neuroléticos nos quadros de autismo, no que à eficácia e reações adversas diz respeito. Materiais e Métodos: Revisão realizada com base na literatura disponível na base de dados Pubmed, referente à utilização dos neuroléticos na perturbação do espectro do autismo. Conclusões: Os resultados dos estudos analisados sugerem que os neuroléticos são úteis na abordagem dos sintomas associados ao autismo. Apenas a risperidona e o aripiprazol têm indicação legal para o tratamento da irritabilidade relacionada com as perturbações do espetro do autismo, contudo os restantes fármacos utilizados off label também demonstram eficácia nestes quadros. As reações adversas são frequentes, sendo os efeitos extrapiramidais, o aumento de peso e a sonolência os mais observadosIntroduction: Autism spectrum disorder is a chronic neurodevelopmental disease, which appears at early ages, whose core symptoms are deficits in communication, social interaction and restrictive and stereotyped behavior. Often these individuals have associated disruptive symptoms, like aggression and self-injury, agitation, tantrums, hyperactivity and mood swings, which interfere with their quality of life and their families. The pharmacological treatments are based on various classes of drugs, where neuroleptics are the most commonly used, since they show better efficacy and safety. Pharmacogenetics has been decisive in the search for the causes for autism, already showing advances in the discovery of genes that influence in pharmacodynamics and in the type of adverse reactions of neuroleptics drugs that promise to optimize that use in autism. Objective: Review the indications, related with efficacy and safety, of neuroleptics drugs in autism Spectrum disorders. Methods: was reviewed based on the literature available in the Pubmed database, regarding the use of neuroleptics in autism spectrum disorder. Conclusions: The results of the studies reviewed suggest that neuroleptics drugs are useful in the treatment of the symptoms associated with autism. Only risperidone and aripiprazole have legal statement for the treatment of irritability related to autism spectrum disorders, however the remaining drugs used off label also demonstrate efficacy in these disorders. Adverse reactions are common, where extrapyramidal side effects, weight gain and drowsiness are the most observe

Impact of Geo-distribution and Mining Pools on Blockchains: A Study of Ethereum

Given the large adoption and economical impact of permissionless blockchains, the complexity of the underlying systems and the adversarial environment in which they operate, it is fundamental to properly study and understand the emergent behavior and properties of these systems. We describe our experience on a detailed, one-month study of the Ethereum network from several geographically dispersed observation points. We leverage multiple geographic vantage points to assess the key pillars of Ethereum, namely geographical dispersion, network efficiency, blockchain efficiency and security, and the impact of mining pools. Among other new findings, we identify previously undocumented forms of selfish behavior and show that the prevalence of powerful mining pools exacerbates the geographical impact on block propagation delays. Furthermore, we provide a set of open measurement and processing tools, as well as the data set of the collected measurements, in order to promote further research on understanding permissionless blockchains.Comment: To appear in 50th IEEE/IFIP International Conference on Dependable Systems and Networks (DSN), 202

CAPI: cloud computing API

Cloud Computing is an emerging business model to provide access to IT resources in a pay per use fashion. Those resources range from low-level virtual machines, passing by application platforms and ending in ready to use software delivered through the Internet, creating a layered stack of differentiated services. Different cloud vendors tend to specialize in different levels, offering different services each with its own proprietary API. This clearly led to provider lock-in and hinders the portability of a given application between different providers. The goal of this paper is therefore to provide an abstraction of the different levels of services in order to reduce vendor lock-in and improve portability, two issues that we believe impair the adoption of the Cloud Computing model

Ciência Avícola: Uma perspetiva laboratorial

Némery Jean-Claude. I. L'union européenne. In: Droit et gestion des collectivités territoriales. Tome 36, 2016. Les élections locales françaises 2014-2015. pp. 603-605

A peer-to-peer service architecture for the Smart Grid

Short paperThe Smart Grid vision needs to address hard challenges such as interoperability, reliability and scalability before it can become fulfilled. The need to provide full interoperability between current and future energy and non-energy systems and its disparate technologies along with the problem of seamless discovery, configuration, and communication of a large variety of networked devices ranging from the resource constrained sensing devices to the large machines inside a data center requires an agnostic Service Oriented Architecture. Moreover, the sheer scale of the Smart Grid and the criticality of the communication among its subsystems for proper management, demands a scalable and reliable communication framework able to work in an heterogeneous and dynamic environment. In this position paper, we propose a generic framework, based on Web Services for interoperability, and epidemic or gossip based communication protocols for reliability and scalability, that can serve a general management substrate where several Smart Grid problems can be solved. We illustrate the flexibility of the proposed framework by showing how it can be used in two specific scenarios.Important challenges in interoperability, reliability, and scalability need to be addressed before the Smart Grid vision can be fulfilled. The sheer scale of the electric grid and the criticality of the communication among its subsystems for proper management, demands a scalable and reliable communication framework able to work in an heterogeneous and dynamic environment. Moreover, the need to provide full interoperability between diverse current and future energy and non-energy systems, along with seamless discovery and configuration of a large variety of networked devices, ranging from the resource constrained sensing devices to servers in data centers, requires an implementation-agnostic Service Oriented Architecture. In this position paper we propose that this challenge can be addressed with a generic framework that reconciles the reliability and scalability of Peer-to-Peer systems, with the industrial standard interoperability of Web Services. We illustrate the flexibility of the proposed framework by showing how it can be used in two specific scenarios