31 resultados para Non-Local Model
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Unlike injury to the peripheral nervous system (PNS), where injured neurons can trigger a regenerative program that leads to axonal elongation and in some cases proper reinnervation, after injury to the central nervous system (CNS) neurons fail to produce the same response. The regenerative program includes the activation of several injury signals that will lead to the expression of genes associated with axonal regeneration. As a consequence, the spawned somatic response will ensure the supply of molecular components required for axonal elongation. The capacity of some neurons to trigger a regenerative response has led to investigate the mechanisms underlying neuronal regeneration. Thus, non-regenerative models (like injury to the CNS) and regenerative models (such as injury to the PNS) were used to understand the differences underlying those two responses to injury. To do so, the regenerative properties of dorsal root ganglion (DRG) neurons were addressed. This particular type of neurons possesses two branches, a central axon, that has a limited capacity to regenerate; and a peripheral axon, where regeneration can occur over long distances. In the first paradigm used to understand the neuronal regeneration mechanisms, we evaluated the activation of injury signals in a non-regenerative model. Injury signals include the positive injury signals, which are described as being enhancers of axonal regeneration by activating several transcription factors. The currently known positive injury signals are ERK, JNK and STAT3. To evaluate whether the lack of regeneration following injury to the central branch of DRG neurons was due to inactivation of these signals, activation of the transcription factors pELK-1, p-c-jun (downstream targets of ERK and JNK, respectively) and pSTAT3 were examined. Results have shown no impairment in the activation of these signals. As a consequence, we further proceed with evaluation of other candidates that could participate in axonal regeneration failure. By comparing the protein profiles that were triggered following either injury to the central branch of DRG neurons or injury to their peripheral branch, we were able to identify high levels of GSK3-β, ROCKII and HSP-40 after injury to the central branch of DRG neurons. While in vitro knockdown of HSP-40 in DRG neurons showed to be toxic for the cells, evaluation of pCRMP2 (a GSK3-β downstream target) and pMLC (a ROCKII downstream target), which are known to impair axonal regeneration, revealed high levels of both proteins following injury to the central branch when comparing with injury to their peripheral one. Altogether, these results suggest that activation of positive injury signals is not sufficient to elicit axonal regeneration; HSP-40 is likely to participate in the cell survival program; whereas GSK3-β and ROCKII activity may condition the regenerative capacity following injury to the nervous system.(...)
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Strong consolidation is one of the most evident developments of banking markets around the world in recent decades. This change is raising questions on how and to what an extent competition is affected by the expansion of the largest banks. The aim of the present study is to measure the degree of competition in the Portuguese commercial banking market in the long-run, during the period ranging from1960 to 2013, by using the non-structural model developed by Panzar and Rosse. The main findings are that the Portuguese banking system, despite the legal restrictions in place, operated mostly in a market with some degree of competition and, at some points in time, presented some interesting competitive features. More recently, it has evolved into functioning as a cartel.
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RESUMO - O movimento de integração dos cuidados de saúde tem como objectivo a procura de modelos de prestação de cuidados mais compreensivos, integrados e continuados. A determinação do grau de integração de cuidados pode ser realizada a partir da percepção dos profissionais de saúde, sendo os inquéritos por questionários uma fonte comummente utilizada neste tipo de estudos. O presente estudo, designado por EGIOS II, tem como objetivos: a) determinar o grau de percepção de integração, dos profissionais das Unidades Locais de Saúde; b) comparar a percepção do grau de integração dos profissionais entre 2010 e 2015; c) comparar a percepção do grau de integração dos profissionais que trabalham nas Unidades Locais de Saúde e em instituições não organizadas em Unidades Locais de Saúde; e d) identificar as áreas de maior e menor percepção de integração. O instrumento de recolha de dados utilizado, foi um inquérito por questionário, que pretende avaliar a percepção do grau de integração dos profissionais de acordo com as dimensões clínica, informação, normativa, administrativa, financeira e sistémica, em 53 itens. O inquérito foi estruturalmente adaptado do Health System Integration Study, tendo apresentado validade e fiabilidade. O inquérito foi aplicado em 22 instituições, a nível nacional, Unidades Locais de Saúde e a Centros Hospitalares / Hospitais e Agrupamentos de Centros de Saúde. A caraterização EGIOS II dividiu-se em quatro fases: preparação e envio dos ofícios; identificação dos interlocutores; envio dos inquéritos; e avaliação dos resultados. O inquérito apresentou uma taxa de resposta de 27%, representando 2085 respostas ao inquérito. Pode afirmar-se que globalmente o estudo apresenta representatividade estatística, com um intervalo de confiança de 95%. Os resultados indicam que os profissionais das Unidades Locais de Saúde em 2015 reportam maiores níveis de percepção de integração, quando comparados os dados com o estudo de 2010. Acrescenta-se que os profissionais das Unidades Locais de Saúde têm um maior grau de percepção de integração, do que os profissionais dos Centros Hospitalares / Hospitais e Agrupamentos de Centros de Saúde, não organizados em ULS. As dimensões administrativa, financeira e clínica são as que apresentam um menor grau de percepção de integração e as dimensões normativa e informação uma maior percepção de integração. Os órgãos de administração e órgãos de gestão intermédia apresentam uma percepção de integração superior comparativamente aos médicos e enfermeiros dos serviços hospitalares e cuidados de saúde primários. Foram identificadas nove recomendações que poderão servir como base para um plano de ação subsequente do presente estudo ou para aplicação em futuros estudos. Este estudo pode auxiliar no diagnóstico de problemas e barreiras da integração de cuidados, em que serviços atuar e ainda, identificar quais as estratégias e processos a priorizar de forma a melhorar a integração de cuidados de saúde.
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Mutable state can be useful in certain algorithms, to structure programs, or for efficiency purposes. However, when shared mutable state is used in non-local or nonobvious ways, the interactions that can occur via aliases to that shared memory can be a source of program errors. Undisciplined uses of shared state may unsafely interfere with local reasoning as other aliases may interleave their changes to the shared state in unexpected ways. We propose a novel technique, rely-guarantee protocols, that structures the interactions between aliases and ensures that only safe interference is possible. We present a linear type system outfitted with our novel sharing mechanism that enables controlled interference over shared mutable resources. Each alias is assigned separate, local roles encoded in a protocol abstraction that constrains how an alias can legally use that shared state. By following the spirit of rely-guarantee reasoning, our rely-guarantee protocols ensure that only safe interference can occur but still allow many interesting uses of shared state, such as going beyond invariant and monotonic usages. This thesis describes the three core mechanisms that enable our type-based technique to work: 1) we show how a protocol models an alias’s perspective on how the shared state evolves and constrains that alias’s interactions with the shared state; 2) we show how protocols can be used while enforcing the agreed interference contract; and finally, 3) we show how to check that all local protocols to some shared state can be safely composed to ensure globally safe interference over that shared memory. The interference caused by shared state is rooted at how the uses of di↵erent aliases to that state may be interleaved (perhaps even in non-deterministic ways) at run-time. Therefore, our technique is mostly agnostic as to whether this interference was the result of alias interleaving caused by sequential or concurrent semantics. We show implementations of our technique in both settings, and highlight their di↵erences. Because sharing is “first-class” (and not tied to a module), we show a polymorphic procedure that enables abstract compositions of protocols. Thus, protocols can be specialized or extended without requiring specific knowledge of the interference produce by other protocols to that state. We show that protocol composition can ensure safety even when considering abstracted protocols. We show that this core composition mechanism is sound, decidable (without the need for manual intervention), and provide an algorithm implementation.
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Critical Issues in Environmental Taxation: International and Comparative Perspectives: Volume VI, 699-715
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Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.
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The basic motivation of this work was the integration of biophysical models within the interval constraints framework for decision support. Comparing the major features of biophysical models with the expressive power of the existing interval constraints framework, it was clear that the most important inadequacy was related with the representation of differential equations. System dynamics is often modelled through differential equations but there was no way of expressing a differential equation as a constraint and integrate it within the constraints framework. Consequently, the goal of this work is focussed on the integration of ordinary differential equations within the interval constraints framework, which for this purpose is extended with the new formalism of Constraint Satisfaction Differential Problems. Such framework allows the specification of ordinary differential equations, together with related information, by means of constraints, and provides efficient propagation techniques for pruning the domains of their variables. This enabled the integration of all such information in a single constraint whose variables may subsequently be used in other constraints of the model. The specific method used for pruning its variable domains can then be combined with the pruning methods associated with the other constraints in an overall propagation algorithm for reducing the bounds of all model variables. The application of the constraint propagation algorithm for pruning the variable domains, that is, the enforcement of local-consistency, turned out to be insufficient to support decision in practical problems that include differential equations. The domain pruning achieved is not, in general, sufficient to allow safe decisions and the main reason derives from the non-linearity of the differential equations. Consequently, a complementary goal of this work proposes a new strong consistency criterion, Global Hull-consistency, particularly suited to decision support with differential models, by presenting an adequate trade-of between domain pruning and computational effort. Several alternative algorithms are proposed for enforcing Global Hull-consistency and, due to their complexity, an effort was made to provide implementations able to supply any-time pruning results. Since the consistency criterion is dependent on the existence of canonical solutions, it is proposed a local search approach that can be integrated with constraint propagation in continuous domains and, in particular, with the enforcing algorithms for anticipating the finding of canonical solutions. The last goal of this work is the validation of the approach as an important contribution for the integration of biophysical models within decision support. Consequently, a prototype application that integrated all the proposed extensions to the interval constraints framework is developed and used for solving problems in different biophysical domains.
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Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para a obtenção do grau de Mestre em Engenharia do Ambiente
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Trabalho apresentado no âmbito do Mestrado em Engenharia Informática, como requisito parcial para obtenção do grau de Mestre em Engenharia Informática
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33rd IAHR Congress: Water Engineering for a Sustainable Environment
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Dissertação apresentada para obtenção do Grau de Doutor em Engenharia do Ambiente pela Universidade Nova de Lisboa,Faculdade de Ciências e Tecnologia
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Thesis submitted to Faculdade de Ciências e Tecnologia of the Universidade Nova de Lisboa, in partial fulfillment of the requirements for the degree of Master in Computer Science
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Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Computational Logic
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Dissertação para obtenção do Grau de Mestre em Engenharia Biomédica
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Dissertação apresentada para cumprimento dos requisitos necessários à obtenção do grau de Mestre em Terminologia e Gestão da Informação de Especialidade