13,278 research outputs found

    The Immigration and Trade Link in the European Union Integration Process

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    The aim of this paper is to analyse the link between immigration and trade among EU countries, particularly, in the context of the 2004 enlargement. The study tests whether the increase in immigrant stock from New Member States has any impact on the exports from the EU-15 to those markets or not. To that end the study applies an extended gravity model of international trade to panel data for three countries – Germany, Denmark and Portugal. The results show that increasing immigration from both New Member States and EU15 countries has a positive impact on the exports of both Portugal and Denmark. The results also suggest that less restrictive immigration policies have a positive impact on exports, and contribute to the normalization of exports of these countries to New Member States. Finally, these results do not hold in the case of Germany.International trade, immigration, European Union, economic integration, gravity model

    Estimation and dynamics of above ground biomass with very high resolution satellite images in Pinus pinaster stands

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    Biomass estimation is a tool for evaluating stands and forest dynamics. Traditional indirect methods use forest inventories and allometric functions at tree level to evaluate biomass at plot level, and an extrapolation method to assess an area. The goal of this study was the development of allometric functions for Pinus pinaster with crown horizontal projection derived from very high spatial resolution satellite images as an independent variable, as well as their application to the analysis of above ground biomass dynamics. The fitted functions show a good performance. The function used to estimate the above ground biomass per grid in 2004, 2007 and 2011 for the study area enable the evaluation of their temporal dynamics. From 2004 to 2007 it decreased in 90.5% of the study area, due to forest fires and cuts to control the pinewood nematode; from 2007 to 2011 increased in 45.6% and decreased in 51.6%, the latter corresponding to cuts to control the aforementioned disease. In 76.4% of the burnt areas, natural regeneration resulted in an increase of above ground biomass. The method's main advantages are the simultaneous evaluation of small or large areas and, when implemented in a GIS, it allows straightforward monitoring over a short period of time

    Biochemical and toxicological effects of organic (herbicide Primextra® Gold TZ) and inorganic (copper) compounds on zooplankton and phytoplankton species

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    In Europe, mainly in the Mediterranean region, an intensive usage of pesticides was recorded during the past 30 years. According to information from agricultural cooperatives of the Mondego valley (Figueira da Foz, Portugal), Primextra® Gold TZ is the most used herbicide in corn crop fields and one of the 20 best-selling herbicides in Portugal. Copper is mainly used in pesticide formulations. This study aims to determine the ecotoxicological and biochemical (namely fatty acid profiles) effects of the herbicide Primextra® Gold TZ and the metal copper on marine plankton. The organisms used in this study are three planktonic species: the marine diatom Thalassiosira weissflogii, the estuarine copepod Acartia tonsa and nauplii of the marine brine shrimp Artemia franciscana. Fatty acids (FAs) are one of the most important molecules transferred across the plant-animal interface in aquatic food webs and can be used as good indicators of stress. The conducted lab incubations show that T. weissflogii is the most sensitive species to the herbicide followed by A. tonsa (EC50 =0;0.0078 mg/L and EC50 =0;0.925 mg/L, respectively), whereas the copepod was the most sensitive species to the metal followed by T. weissflogii (EC50 =0.234 mg/L and EC50 =0.383 mg/L, respectively). A. franciscana was the most tolerant organism both to the herbicide and to the metal (EC50 =20.35 mg/L and EC50 = 18.93 mg/L, respectively). Changes in the FA profiles of primary producer and primary consumers were observed, with the increase of saturated FA and decrease of unsaturated FA contents, especially of highly unsaturated FAs that can be obtained mainly from food and therefore are referred to as ‘essential FA’. The study suggests that discharges of Primextra® Gold TZ or other pesticides mainly composed by copper may be a threat to plankton populations causing changes in the FA contents and thus in their nutritive value, with severe repercussions for higher trophic levels and thus the entire food web

    Influence of umbrella pine (Pinus pinea L.) stand type and tree characteristics on cone production

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    Most umbrella pine (Pinus pinea L.) stands are managed as agroforestry systems, whose main production is fruit, due to the edible and highly nutritious kernels, and are frequently associated to natural or seeded pastures and grazing. The stands have low density, in order to enhance crown growth and fruit production. Nevertheless, cone production, both with regard to number and weight, varies greatly between stands, trees and years. In this study were selected three agroforestry systems, representative of umbrella pine stands whose main production is fruit, and one stand representative of the timber production system, where fruit is the secondary production. It was evaluated the variability in cone production as a function of the tree’s diameter at breast height and crown diameter and the individual tree’s competition status. The results indicate that stands managed in agroforestry systems with lower competition and individuals with larger diameter at breast height and crown diameter tend to produce more and heavier cones per tree. The first two principal components of the principal component analysis explain 84 % of the variance in cone production, trees’ dimensions and competition index. Tree competition status has a negative impact on production per tree

    Looking for the Core of a Knowledge-based Sea Cluster: A Social Network Analysis in a Maritime Region

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    For more than two decades cluster policies have emerged as a central focus for decision-makers trying to instigate territorial development. The benefits, especially in terms of collective learning, knowledge sharing and other types of agglomeration economies and spill-over effects, are well stressed in the regional science literature. Today the relevance of maritime activities and marine resources to economic development is acknowledged. For several European countries, the Atlantic Ocean is part of their common history, identity and potential for developing advanced economic niches of excellence. There is no surprise that several regions are trying to implement their development strategies based on a broad Sea Cluster notion that encompasses a diversity of economic activities such as fisheries and aquaculture, coastal tourism, marine transports and activities based on marine sciences and maritime technologies. Based on the results of a trans-regional evaluation performed for the Atlantic Area under project KIMERAA, this paper evaluates the consolidation of the Sea Cluster in the Algarve, a Portuguese region internationally known by its coastal tourism. The region has also been experiencing a growing capacity in economic activities linked to marine sciences. This regional cluster did not emerge spontaneously and there are several initiatives to promote it. Interviews to regional actors showed light on two important issues. i) Which organization should be the main mediator to bridge science to market? ii) Who is the actor that is in a better position to assume a pivotal role in the formal consolidation of the cluster? Using social network analysis the main knowledge transfer mediator and the central actors are identified. Their roles and specific policy implications are underlined.

    Institutions and growth: a developing country case study

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    The Brazilian municipalities show an enormous inequality on its development level. Even within the states considered relatively prosperous, there are huge internal disparities on income levels. The richest Brazilian municipality's GDP per capita is about 190 times greater than the poorest municipality's, according to IBGE (2000) database. A possible explanation for this phenomenon relies on institutional theory. Many theoretical and empirical studies, mainly based on cross-country data, emphasize the role played by institutions on the determination of long run development. Nevertheless, there still is little research concerning the income differences within the national territory and its connection to institutional quality. The literature points out that institutions matter for the level of economic development because of their effects on political power distribution, generation of economic opportunities, innovation, human capital accumulation, and so on. Based on this assumption, the present study main goal is to analyze the effects of Brazilian municipalities' institutional quality on their GDP per capita levels. The results indicate that institutions are relevant and its importance is greater for large municipalities. On the other hand, human capital human capital is more important to small municipalities. To address the endogeneity problem inherent to the relationship between institutions and development, we employ the 2SLS method.institutions, income level, brazilian municipalities

    Effects of Forest Stand Structure in Biomass and Carbon

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    Biomass has been gaining an increased interest due to its importance in sustainable forest management and in carbon sequestration. Biomass in each forest stand varies according to its structure and influences not only the biomass per area unit but also its distribution in space and time. The structure analysis with absolute stand density measures and structure and diversity measures and indices for the number of trees and basal area does not always reflect the above-ground biomass distribution and variability. The use of above-ground biomass as an absolute density measure and the development of diversity measures and indices derived from it enable further details in the stand structure characterisation. The results of this study highlighted the differences between pure even-aged, pure multiaged, mixed even-aged and mixed multiaged structures. The measures and indices of above-ground biomass are considered primordial as they integrate the horizontal and the vertical distribution, thus enabling a more detailed evaluation of biomass and carbon stocks

    Narrative Matters in Intercultural Learning – contributions from Jerome Bruner

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    Neste artigo argumenta-se que o texto literário, ou a ‘narrativa como forma de arte’ nos termos de Jerome Bruner (1986, p.15), pode actuar como um catalizador para a aprendizagem intercultural. Jerome Bruner, entre outros, desenvolveu conceitos que contribuem para clarificar e justificar a relação inerente entre a experiência de leitura do texto literário e a interculturalidade. O conceito de cultura de Bruner como um forum, um espaço de negociação, de interpretação, de (re)criação de significados, é muito apropriado numa perspectiva educacional informada por objectivos interculturais. A aprendizagem intercultural é um processo complexo de (re)negociação de significados e a interacção com o texto literário um contributo inestimável ao proporcionar o contacto com formas culturais inscritas num contexto. À medida que os leitores se apercebem que produtos, valores e crenças correspondem a construções sociais e culturais e que as diferenças culturais provêm dos diferentes modos como diferentes culturas representam a realidade, tornam-se intérpretes e leitores mais competentes do mundo fascinante e problemático em que vivemos. A nossa sociedade é marcadamente heterogénea. Quanto mais consciente o leitor estiver do facto de que as suas acções são influenciadas culturalmente, mais eficazmente poderá assumi-las ou contestá-las. O valor do texto literário nesta perspectiva, baseia-se, essencialmente, na contribuição para a apreciação da diversidade e consciencialização de que as realidades são construídas e a interpretação e a negociação ferramentas que usamos para mediar a relação com os outros. Palavras chave: intercultural; Jerome Bruner; texto literári
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