DPOC e VIH

Perrat Charles. Rapports financiers. In: Bulletin de la Société Nationale des Antiquaires de France, 1943-1944, 1948. pp. 86-88

Reconstructing triangulated surfaces from unorganized points through local skeletal stars

Surface reconstruction from unorganized points arises in a variety of practical situations such as range scanning an object from multiple view points, recovery of biological shapes from twodimensional slices, and interactive surface sketching. [...]Reconstrução da superfície de pontos desorganizados surge em uma variedade de situações práticas, tais como rastreamento de um objeto a partir de vários pontos de vista, a recuperação de formas biológicas de fatias bi-dimensionais, e esboçar superfícies interativas. [...

Ressonância mecânica em cromossomas humanos

Trabalho final de mestrado integrado em Medicina, apresentado à Faculdade de Medicina da Universidade de Coimbra.Desencadear um fenómeno de ressonância mecânica em cromossomas poderá resultar na sua destruição e comprometer a sobrevivência celular. Criou-se um modelo virtual de braços de cromossomas: um cone excêntrico com características próprias de cada braço. Utilizando simulações computacionais (COMSOL Multiphysics 4.4®), chegou-se à frequência natural em dois modos de vibração de vários cromossomas. A diferença média entre as várias frequências obtidas foi de cerca de 2 kHz em ambos modos de vibração, sendo necessário adicionar 100 000 pares de bases ou aumentar 1 nm para que haja variação de 1 Hz na frequência natural. Conclui-se que modificando a massa e o comprimento dos braços dos cromossomas de forma significativa, produz-se uma alteração na frequência de ressonância. Isto poderá conduzir ao desenvolvimento de uma terapia que destrua seletivamente cromossomas.Producing a mechanical resonance phenomenon in chromosomes could lead to its destruction. A virtual model of chromosome arms was created: eccentric cone with characteristics specific for each arm. Using virtual simulations (COMSOL Multiphysics 4.4®), natural frequency was found for various chromosomes, in two modes of vibrations. The mean difference between those frequencies was about 2 kHz in both vibration modes. It was necessary to add 100,000 base pairs or increase 1 nm in chromosomes arm to get a change of 1 Hz in natural frequency. Therefore, changing mass and length of chromosome’s arm, in a significant manner, will produce a change in its resonant frequency. This could lead to a new therapy which destroys chromosomes selectively

Macro determinants of nonperforming loans in Portugal

This study uses a VAR methodology to evaluate the impact of the macroeconomic conditions and money supply in the fluctuation of nonperforming loans for the Portuguese economy. Additionally, the feedback effect of nonperforming loans growth to the economy and specially to the credit supply is analised. The study is motived by the hypothesis that loan quality is procyclical and that the fast growth of credit supply has a positive relation with the growth of nonperforming loans. The hypothesis that nonperforming loans reinforce economic fragilities and credit market frictions is also tested. Empirical results corroborate both hypothesis presented. Hence, it was possible to establish that the macroeconomic conditions measured by GDP and unemployment and the fast growth of credit supply contribute to the development of nonperforming loans. Furthermore, the growth of nonperforming loans reinforces the economic cycle, as it contributes to the deterioration of macroeconomic conditions and creates frictions in the credit market that may results in a credit crunch.NSBE - UN

Macroeconomic impacts of politics and policy: applications to financial and real markets

A PhD Dissertation, presented as part of the requirements for the Degree of Doctor of Philosophy from the NOVA - School of Business and EconomicsInternational capital flows hold a notable economic relevance within OECD countries, showing clear reactions to economic policy and to governments’ political profile. This study explores these impact channels and tests them empirically. A game theoretical model is built, rationalizing the hypothesis that (a) left-leaning cabinets implement higher taxes and higher public expenditures and that (b) minoritarian or coalition cabinets react less actively to productivity shocks. The model predicts, thus, a negative reaction by capital flows to left-leaning cabinets and an uncertain reaction to both minorities and coalitions, depending on how efficient their inaction is – trade-off between productivity-boosting and policy uncertainty/“noise”. Model predictions are tested to on a set of 23 OECD democratic countries, in the period 1960-2008. The hypothesis that left-leaning cabinets set higher taxes finds empirical support. This policy divergence is more intense in the context of single-party cabinets, suggesting that coalitions may be associated to fiscal policy inaction/blending. Consistently, equity inflows react positively to single-party right cabinets. FDI net flows react negatively to majoritarian cabinets and positively to budget deficits, signaling sensitivity to environment stability and fiscal stimulus. Oppositely, equity inflows react positively to majoritarian cabinets (potentially more active in countering negative GDP shocks) and negatively to budget deficits and public expenditure (potentially anticipating higher taxes). The magnitude of the direct impacts of political profiles on capital flows range from 0.3 to 4.7 GDP percentage points (0.5–2.5 standard deviations of the respective sample flows). Reactions to fiscal policy are attenuated when left or right cabinets are in office

Preparation of acute midbrain slices containing the superior colliculus and periaqueductal Gray for patch-clamp recordings

This protocol is a practical guide for preparing acute coronal slices from the midbrain of young adult mice for electrophysiology experiments. It describes two different sets of solutions with their respective incubation strategies and two alternative procedures for brain extraction: decapitation under terminal isoflurane anaesthesia and intracardial perfusion with artificial cerebrospinal fluid under terminal isoflurane anaesthesia. Slices can be prepared from wild-type mice as well as from mice that have been genetically modified or transfected with viral constructs to label subsets of cells. The preparation can be used to investigate the electrophysiological properties of midbrain neurons in combination with pharmacology, opto- and chemogenetic manipulations, and calcium imaging; which can be followed by morphological reconstruction, immunohistochemistry, or single-cell transcriptomics. The protocol also provides a detailed list of materials and reagents including the design for a low-cost and easy to assemble 3D printed slice recovery chamber, general advice for troubleshooting common issues leading to suboptimal slice quality, and some suggestions to ensure good maintenance of a patch-clamp rig

Innate heuristics and fast learning support escape route selection in mice

When faced with imminent danger, animals must rapidly take defensive actions to reach safety. Mice can react to threatening stimuli in ∼250 milliseconds and, in simple environments, use spatial memory to quickly escape to shelter. Natural habitats, however, often offer multiple routes to safety that animals must identify and choose from. This is challenging because although rodents can learn to navigate complex mazes, learning the value of different routes through trial and error during escape could be deadly. Here, we investigated how mice learn to choose between different escape routes. Using environments with paths to shelter of varying length and geometry, we find that mice prefer options that minimize path distance and angle relative to the shelter. This strategy is already present during the first threat encounter and after only ∼10 minutes of exploration in a novel environment, indicating that route selection does not require experience of escaping. Instead, an innate heuristic assigns survival value to each path after rapidly learning the spatial environment. This route selection process is flexible and allows quick adaptation to arenas with dynamic geometries. Computational modeling shows that model-based reinforcement learning agents replicate the observed behavior in environments where the shelter location is rewarding during exploration. These results show that mice combine fast spatial learning with innate heuristics to choose escape routes with the highest survival value. The results further suggest that integrating prior knowledge acquired through evolution with knowledge learned from experience supports adaptation to changing environments and minimizes the need for trial and error when the errors are costly

A qualidade em E-services : conceptualização e investigação empírica

Mestrado em Gestão de OperaçõesO fornecimento de serviços de qualidade num ambiente virtual cria novos desafios às empresas. Com o crescimento dos serviços em geral, e com o advento da internet, têm-se assistido a uma migração da prestação de serviços via canais tradicionais para outro canal de fornecimento, a internet. Neste contexto, torna-se crucial assegurar a qualidade dos serviços oferecidos como mecanismo de fixação e fidelização dos clientes. Assim, este trabalho investigou duas questões: i) Quais são os determinantes da qualidade em e-services? Neste processo, propomos uma nova forma de classificar os processos de e-service e apresentamos um conjunto de determinantes da qualidade que se pretende que sejam representativos dos diferentes contextos operacionais e suficientemente generalizáveis para todos os e-services. ii) Será que a qualidade de e-services tem um impacto positivo na lealdade, tal como acontece nos serviços tradicionais? A este respeito, realizamos um estudo de inquérito cujos resultados sugerem que a qualidade de um web site tem um impacto positivo na lealdade dos clientes. ABSTRACT: Delivering service quality in a virtual environment creates new challenges for service providers. With the increase of the weight of the service sector and with the arrival of the internet, we have witnessed a migration of services from traditional channels to the internet channel. In this context, it becomes crucial to assure the good levels of service quality as a mechanism for customer retention and loyalty. As such, this study investigates the following questions: i) What are the determinants of e-service quality? In this process, we propose a new classification of e-service processes and present a set of quality dimensions which are intended to be representative of different operational contexts and generalizable for all types of e-services. ii) Does e-service quality have an impact on customer loyalty, as it happens in traditional services? In this respect, we conducted a survey study whose results suggest that the quality of a web site has a positive impact on customer loyalty