Evolution of Social Power for Opinion Dynamics Networks

This article studies the evolution of opinions and interpersonal influence structures in a group of agents as they discuss a sequence of issues, each of which follows an opinion dynamics model. In this work, we propose a general opinion dynamics model and an evolution of interpersonal influence structures based on the model of reflected appraisals proposed by Friedkin. Our contributions can be summarized as follows: (i) we introduce a model of opinion dynamics and evolution of interpersonal influence structures between issues viewed as a best response cost minimization to the neighbor's actions, (ii) we show that DeGroot's and Friedkin-Johnsen's models of opinion dynamics and their evolution of interpersonal influence structures are particular cases of our proposed model, and (iii) we prove the existence of an equilibrium. This work is a step towards providing a solid formulation of the evolution of opinions and interpersonal influence structures over a sequence of issues

The impact of renewable energy sources on economic growth and CO2 emissions - a SVAR approach

Over the last years renewable energy sources (RES) have increased their share on electricity generation of most developed economies due to environmental and security of supply concerns. The aim of this paper was to analyze how an increasing share of RES on electricity generation (RES-E) affects Gross Domestic Product (GDP) and carbon dioxide (CO2) emissions. Several methodologies could be used for this purpose. The Structural Vector Autoregressive (SVAR) methodology considers the interactions among all variables in the model and is well suited to predict the effects of specific policy actions or important changes in the economy. Therefore, we chose to implement this methodology. We used a 3 variable SVAR model for a sample of four countries along the period 1960-2004. The existence of unit roots was tested to infer the stationarity of the variables. The countries chosen have rather different levels of economic development and social and economic structures but a common effort of investment in RES in the last decades. Through the impulse response functions (IRF), the SVAR estimation showed that, for all countries in the sample, except for the USA, the increasing RES-E share had economic costs in terms of GDP per capita. As expected, there was also an evident decrease of CO2 emissions per capita. The variance decomposition showed that a significant part of the forecast error variance of GDP per capita and a relatively smaller part of the forecast error variance of CO2 per capita were explained by the share of RES-E.Renewables, economic growth, CO2 emissions, SVAR

As recentes metamorfoses da saúde na Região Norte

O presente texto resulta dos trabalhos de investigação desenvolvidos no âmbito do Projecto "A Região Norte de Portugal: dinâmicas de mudança social e recentes processos de desenvolvimento" (POCI/SOC/57600/2004) seleccionado para financiamento, em concurso público, pela Fundação para a Ciência e a Tecnologia.A análise da evolução dos principais indicadores de saúde na Região Norte nas duas últimas décadas no âmbito da oferta de estabelecimentos, equipamentos e recursos humanos em saúde, assim como da acção e utilização dos serviços públicos de saúde e dos “resultados” na mortalidade infantil e materna permite identificar, em síntese, quatro tendências fundamentais 1. Uma melhoria generalizada dos níveis de saúde, ilustrada pelos seguintes fenómenos: aparente universalização e esforço de melhoramento das condições e qualidade dos cuidados de saúde; aumento dos recursos humanos de saúde, mais intenso nos enfermeiros do que nos médicos; acréscimo no número de consultas nos centros de saúde e suas extensões, de internamentos hospitalares e, sobretudo, de operações e anestesias realizadas nos hospitais do serviço público de saúde; controlo das doenças infecciosas; aumento da esperança de vida; quebra acentuada da mortalidade infantil, perinatal, neonatal e materna; alterações na estrutura das doenças e diminuição da “dor”; e aumento dos valores despendidos com a saúde. 2. A emergência de novas formas de regulação e gestão dos sistemas de saúde, que promovem a privatização, mercadorização e neoliberalização dos cuidados de saúde e a individualização da questão da saúde através dos “estilos de vida”, configurando a passagem de um modelo público integrado para um modelo público de contrato. Esta tendência é visível em vários domínios, nomeadamente: especialização dos recursos humanos; empresarialização hospitalar; aproximação do número de hospitais oficiais e particulares por habitante na Região Norte; e esforço de descentralização do financiamento dos serviços de saúde. 3. A aproximação entre a Região Norte e Portugal, apesar desta região apresentar valores mais penalizadores para todos os indicadores de saúde analisados. 4. As continuadas assimetrias intra-regionais, agravadas pela desarticulação entre os cuidados de saúde primários e mais especializados, por um lado, e entre os serviços de saúde que fazem parte da rede local e regional, por outro. A distribuição regional desigual, irregular e heterogénea dos indicadores de saúde revelam disparidades nas taxas de mortalidade infantil e uma concentração territorial dos estabelecimentos, equipamentos, profissionais e serviços de saúde mais especializados e diferenciados, destacando-se a posição dominante do Grande Porto e, em menor extensão, do Cávado. Alto Trás-os-Montes, Ave e Tâmega são as NUTS III tendencialmente mais penalizadas no que respeita o acesso e utilização dos serviços de saúde. A promoção da coesão regional exige formas de intervenção solidária localizadas, de acordo com os perfis de necessidade, oferta e utilização de serviços de saúde e não com base nos custos ou na suposta relação custo-efectividade. Mais, a eficiência, qualidade e equidade na prestação de cuidados de saúde reclama uma base social e técnica de apoio ampla e sólida, que só é possível através de um debate crítico plural e participativo que envolva todos os actores sociais nelas implicados. As recentes metamorfoses científico-tecnológicas, demográficas e sócio-económicas observadas na Região Norte poderão repercutir-se em alterações nas necessidades em saúde e o sistema de saúde regional deve preparar-se para responder de forma adequada e eficaz aos eventuais desafios que se avizinham.Fundação para a Ciência e a Tecnologia (FCT

Consentir incertezas : o consentimento informado e a (des)regulação das tecnologias de reprodução assistida

Este artigo visa a analisar os contornos locais de criação e utilização dos autoconhecimentos de médicos e “leigos” envolvidos em processos de procriação medicamente assistida a partir do confronto das práticas discursivas destes atores sociais em torno das expectativas, das incertezas e das responsabilidades associadas a estas técnicas em Portugal. Os médicos avaliam as (in)certezas das aplicações dessas técnicas com base em categorias de caráter naturalista e essencialista. Mais, esses critérios são instrumentalizados para eclipsar a ausência de explicação “científica” para os (in)sucessos, reproduzindo a crença no caráter “miraculoso” do progresso científico e tecnológico. A compreensão profana dos benefícios e das limitações dessas técnicas reflete uma atitude reverencial face à medicina e ao paradigma racionalista da perspectiva biomédica, ainda que seja possível vislumbrar alguns espaços de autonomia e resistência face às propostas médicas. As eventuais incertezas dessas técnicas são perspectivadas como efeitos excepcionais e intrínsecos à prática da medicina, aos quais têm de se submeter de forma individual. As mulheres, em particular, identificam-se como as principais responsáveis pela maximização da probabilidade de “sucesso” dessas técnicas

The expectations hypothesis of the term structure: some empirical evidence for Portugal

The purpose of this paper is to test the (rational) expectations hypothesis of the term structure of interest rates using Portuguese data for the interbank money market. The results obtained support only a very weak, long-run or "asymptotic" version of the hypothesis, and broadly agree with previous evidence for other countries. The empirical evidence supports the cointegration of Portuguese rates and the "puzzle" well known in the literature: although its forecasts of future short-term rates are in the correct direction, the spread between longer and shorter rates fails to forecast future longer rates. In the single equation framework, the implications of the hypothesis in terms of the predictive ability of the spread are also clearly rejected

THE USE of CONSORTIA for the INTERNATIONALIZATION of FIRMS – MOTA-ENGIL CASE STUDY

Internationalization has been widely studied throughout the years. Broadly, it has been predicted as irrevocable and having increasing impact on firm-related strategy. Within entry modes, consortium, has not received as much attention as others. Hence, it seems important to understand how this specific entry mode allows the entrance of firms in the international markets. This study intends to answer the question of “how” to internationalize, anticipating the consortium as the most feasible way for construction firms to enter certain markets. The reasons that determine its choice concern the specificness of the projects, markets and of the firm. In the first part of the study, we review the existent literature on consortia as an entry mode and as a tool of internationalization used by construction firms. Through this review we build a framework that reveals the motivations that lead to this choice. In the second part, we present the case study of Mota-Engil, as a potential source of valuable information which may contribute to the understanding of the phenomenon under study. This case study corroborates the motivations found to create consortia. The paper closes with its contributions, limitations and suggestions for future researches.consortia, internationalization, cooperation, construction

Domestic Impact of Internationalisation: The case of JM

The influence of internationalisation processes in the domestic activities of firms’ has not been considered as an important issue in existing models, because they tend to focus on a partial and restricted view of the firm. The purpose of this paper is to challenge that view by attempting a dynamic view of the firm is which primal importance is given to the relationship between international and domestic activities. The main research question is whether domestic activities can be significantly affected by international activities, namely knowledge transfer. Results confirm the dynamic approach adopted by firms however there are no definitive answers in terms of the domestic impact of internationalisation. Despite clear hints of evidence for the internationaldomestic relationship, there was no confirmation of this relationship at the financial level.

The Expectations Hypothesis of the Term Structure: Some Empirical Evidence for Portugal

The purpose of this paper is to test the (rational) expectations hypothesis of the term structure of interest rates using Portuguese data for the interbank money market. The results obtained support only a very weak, long-run or "asymptotic" version of the hypothesis, and broadly agree with previous evidence for other countries. The empirical evidence supports the cointegration of Portuguese rates and the "puzzle" well known in the literature: although its forecasts of future short-term rates are in the correct direction, the spread between longer and shorter rates fails to forecast future longer rates. In the single equation framework, the implications of the hypothesis in terms of the predictive ability of the spread are also clearly rejected, even for the more stable period which emerged in the middle nineties.term structure of interest rates; expectations hypothesis; hypothesis testing; cointegration; Portugal

Eye-movements in implicit artificial grammar learning

Artificial grammar learning (AGL) has been probed with forced-choice behavioral tests (active tests). Recent attempts to probe the outcomes of learning (implicitly acquired knowledge) with eye-movement responses (passive tests) have shown null results. However, these latter studies have not tested for sensitivity effects, for example, increased eye movements on a printed violation. In this study, we tested for sensitivity effects in AGL tests with (Experiment 1) and without (Experiment 2) concurrent active tests (preference- and grammaticality classification) in an eye-tracking experiment. Eye movements discriminated between sequence types in passive tests and more so in active tests. The eye-movement profile did not differ between preference and grammaticality classification, and it resembled sensitivity effects commonly observed in natural syntax processing. Our findings show that the outcomes of implicit structured sequence learning can be characterized in eye tracking. More specifically, whole trial measures (dwell time, number of fixations) showed robust AGL effects, whereas first-pass measures (first-fixation duration) did not. Furthermore, our findings strengthen the link between artificial and natural syntax processing, and they shed light on the factors that determine performance differences in preference and grammaticality classification tests.Max Planck Institute for PsycholinguisticsDonders Institute for Brain, Cognition and BehaviorVetenskapsradetSwedish Dyslexia Foundatio