9,882 research outputs found

    Nash Equilibria in the Response Strategy of Correlated Games

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    In nature and society problems arise when different interests are difficult to reconcile, which are modeled in game theory. While most applications assume uncorrelated games, a more detailed modeling is necessary to consider the correlations that influence the decisions of the players. The current theory for correlated games, however, enforces the players to obey the instructions from a third party or "correlation device" to reach equilibrium, but this cannot be achieved for all initial correlations. We extend here the existing framework of correlated games and find that there are other interesting and previously unknown Nash equilibria that make use of correlations to obtain the best payoff. This is achieved by allowing the players the freedom to follow or not to follow the suggestions of the correlation device. By assigning independent probabilities to follow every possible suggestion, the players engage in a response game that turns out to have a rich structure of Nash equilibria that goes beyond the correlated equilibrium and mixed-strategy solutions. We determine the Nash equilibria for all possible correlated Snowdrift games, which we find to be describable by Ising Models in thermal equilibrium. We believe that our approach paves the way to a study of correlations in games that uncovers the existence of interesting underlying interaction mechanisms, without compromising the independence of the players

    Impact of the economic crisis on human resources for health policies in Southern EU countries

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    Background The economic and financial crisis which started in the European Union in 2008 affected some countries more than others. Cyprus, Greece, and Portugal had to receive emergency financial aid from the so-called Troika (International Monetary Fund, Central European Bank, European Commission) and consequently were imposed severe austerity measures. All sectors were affected, including health. This paper focuses on the effects of the crisis on the health workforce, which represents the largest share of expenditures in the sector, and on policy responses from these three governments to measures ‘imposed' by the Troika. Methods A systematic search of peer-reviewed and grey literature, and key sources such as government websites was performed. Interviews with key informants were also conducted. Country data and information served to assess policy responses and their effects on the availability, accessibility, acceptability and quality of human resources for health. Results Countries responded to the crisis and to the conditions set by lenders by reducing or freezing salaries and benefits, by cutting on recruitment and even dismissing personnel, by increasing workloads, and by introducing other cost containment measures. The three countries do not seem to have used the crisis as an opportunity to make efficiency gains and thereby improve the performance of their health workforce. Conclusions This paper is included in the Workshop because it discusses policy responses to a major economic shock by governments facing external constraints, which at the same time limited their capacity for action and provided opportunities for reforminfo:eu-repo/semantics/acceptedVersio

    Encurralados na pandemia de COVID-19: o efeito da preocupação com o risco e das emoções no burnout nos profissionais de saúde

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    The COVID-19 pandemic poses critical challenges for the health care workers (HCWs) around the world due to the increasing demands imposed on health care systems. This study aims to investigate how risk concern impacts burnout via positive and negative affect. Further, the moderating role of risk exposure (low, medium, and high) in this parallel mediation model is examined. A sample of 257 Portuguese HCWs answered a questionnaire. Structural equation modeling (SEM) analysis was applied. Results showed that risk concern positively influences negative affect – but not positive affect – and, consequently, burnout. Contrary to our expectations, this indirect effect was not greater for individuals in the high-risk group (vs. low-risk group), which can be explained by individual and organizational factors' buffering role. These findings draw healthcare organizations' attention to the hazardous effects of risk concern on HCWs' well-being.info:eu-repo/semantics/publishedVersio

    Corrections to the Boltzmann mean free path in disordered systems with finite size scatterers

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    The mean free path is an essential characteristic length in disordered systems. In microscopic calculations, it is usually approximated by the classical value of the elastic mean free path. It corresponds to the Boltzmann mean free path when only isotropic scattering is considered, but it is different for anisotropic scattering. In this paper, we work out the corrections to the so called Boltzmann mean free path due to multiple scattering effects on finite size scatterers, in the s-wave approximation, ie. when the elastic mean free path is equivalent to the Boltzmann mean free path. The main result is the expression for the mean free path expanded in powers of the perturbative parameter given by the scatterer density.Comment: 12 page

    A local landscape in transition between production and consumption: can new management arrangements preserve the local landscape character?

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    Around towns in the Alentejo region, the landscape is dominated by a characteristic agricultural small scale mosaic. These areas are central in the region landscape character, – even if the large scale latifundia landscape of the extensive silvo-pastoral systems is most commonly associated with the region. In the last two decades, these parcels became extremely attractive for new comers, who settle in the rural context as residents, week-end visitors, being often also lifestyle farmers. The paper presents a case-study landscape, in Montemor-o-Novo, a small town 100 km from Lisbon, highly subject to the pressure for consumption uses, by urban users. The study shows that the new owners, even if they have settled in the area due to the tranquility and social bindings of the rural, end up doing farming, with new or reshaped production objectives, markets and models, but at the same time maintaining the traditional farm systems. Thus, the landscape character is maintained, so far. Nevertheless, the role of these neo-rurals and lifestyle farmers is still an unseen role, both by the agriculture and the planning sectors. And thus the question is, whether the combination of actors and land management drivers will continue maintaining the landscape in the futur

    Reflecting on collaborative research into the sustainability of Mediterranean agriculture: A case study using a systematization of experiences approach

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    This article describes how a research institute went about reviewing the relationship between its members and external research partners in engaging in collaborative research. A systematization of experiences (SE) process was implemented to enable such review and draw implications for the institute’s strategy regarding research into the sustainability of Mediterranean agriculture. The SE exercise included four workshops attended by selected researchers, one questionnaire survey targeting the institute’s research community, and three focus group discussions with external research partners. The rate of participation by researchers decreased during the process; however, those that followed through to the end of the SE exercise found it to be useful in clarifying both individual and institutional perspectives. Further, SE was seen as a vehicle for increasing the level of understanding between researchers and their willingness to engage in collaborative actions. However, the rapid pace of today’s academic world and the dominant mode of evaluating scientific performance were identified as hindering the conditions needed to allow the necessary space and time for reflection and collaborative efforts. Therefore, the results highlight the current tension between the production of scientific knowledge according to existing patterns and the development of socially meaningful research

    Influência do substrato na formação de mudas de mangueira (Mangifera indica L.) em tubetes.

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    O objetivo deste estudo e avaliar a influencia do substrato na formacao de mudas de mangueira em tubetes.bitstream/CNPAT-2010/5386/1/Pa-070.pd

    Emergy analysis of a silvo-pastoral system, a case study in southern Portugal

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    The Mediterranean silvo-pastoral system known as Montado, in Portugal, is a complex land use system composed of an open tree stratum in various densities and an herbaceous layer, used for livestock grazing. Livestock also profit from the acorns, and the grazing contributes to avoid shrub encroachment. In the last 20 years, subsidies from the European Union have greatly promoted cattle rearing in this system and the introduction of heavy breeds, at the expense of sheep, goats or the native cattle breeds. The balance of the traditional system is thus threatened, and a precise assessment of the balance between the different components of the system, therefore is highly needed. The goal of this study was to gain a better understanding of a Montado farm system with cattle rearing as the major economic activity by applying the emergy evaluation method to calculate indices of yield, investment, environmental loading and sustainability. By integrating different ecosystem components, the emergy evaluation method allows a comprehensive evaluation of this complex and multifunctional system at the scale of an individual farm. This method provides a set of indices that can help us understand the system and design management strategies that maximize emergy flow in the farm. In this paper, we apply the emergy evaluation method to a Montado farm with cattle rearing, as a way to gain a better understanding of this system at the farm scale. The value for the transformity of veal (2.66E+06 sej J−1) is slightly higher, when compared to other systems producing protein. That means that the investment of nature and man in this product was higher and it requires a premium price on the market. The renewability for Holm Oaks Farm (49 %), lower than for other similar systems, supports the assumption that this is a farm in which, comparing with others, the number of purchased inputs in relation to renewable inputs provided by nature, is higher. The Emergy Investment Ratio is 0.91 for cattle rearing compared to a value of 0.49 for cork and 0.43 for firewood harvesting, making it clear that cattle rearing is a more labor demanding activity comparing with extractive activities as cork and firewood harvesting

    Management of Montados and Dehesas for High Nature Value: an interdisciplinary pathway

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    Mediterranean oak woodlands, Montados in Portugal and Dehesas in Spain have long been acknowledged as potential land use systems of high nature and social value providing relevant ecosystem services and biodiversity conservation. Nevertheless, these systems are now under severe threat, both due to abandonment in certain areas and overuse in others, extremes that may be limited by appropriate management practices and strategies. The High Nature Value concept can be a pathway for the understanding and assessment of management practices best adapted to the balance of the Montado and Dehesa, and also to the assessment of the thresholds of change, so that the long term sustainability of the Montado systems is preserved. This special issue aims to contribute for the understanding of how the Montado and Dehesa classification as High Nature Value may be a path for sustainable management. This classification can be achieved by different ways and implies different components of the Montado, and thus the first four papers of this special issue address different approaches and methodologies for the identification of HNV Dehesas and Montados, the following seven papers deal mostly with the effect of management practices on biodiversity and other Dehesas and Montados values and finally the last two papers address the causes for Montado decline and suggest mitigation measures for that decline
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