860 resultados para STEPPING-STONES


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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Theoretical and empirical studies demonstrate that the total amount of forest and the size and connectivity of fragments have nonlinear effects on species survival. We tested how habitat amount and configuration affect understory bird species richness and abundance. We used mist nets (almost 34,000 net hours) to sample birds in 53 Atlantic Forest fragments in southeastern Brazil. Fragments were distributed among 3 10,800-ha landscapes. The remaining forest in these landscapes was below (10% forest cover), similar to (30%), and above (50%) the theoretical fragmentation threshold (approximately 30%) below which the effects of fragmentation should be intensified. Species-richness estimates were significantly higher (F = 3715, p = 0.00) where 50% of the forest remained, which suggests a species occurrence threshold of 30-50% forest, which is higher than usually occurs (<30%). Relations between forest cover and species richness differed depending on species sensitivity to forest conversion and fragmentation. For less sensitive species, species richness decreased as forest cover increased, whereas for highly sensitive species the opposite occurred. For sensitive species, species richness and the amount of forest cover were positively related, particularly when forest cover was 30-50%. Fragment size and connectivity were related to species richness and abundance in all landscapes, not just below the 30% threshold. Where 10% of the forest remained, fragment size was more related to species richness and abundance than connectivity. However, the relation between connectivity and species richness and abundance was stronger where 30% of the landscape was forested. Where 50% of the landscape was forested, fragment size and connectivity were both related to species richness and abundance. Our results demonstrated a rapid loss of species at relatively high levels of forest cover (30-50%). Highly sensitive species were 3-4 times more common above the 30-50% threshold than below it; however, our results do not support a unique fragmentation threshold.

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The zip folder comprises a text file and a gzipped tar archive. 1) The text file contains individual genotype data for 90 SNPs, 9 microsatellites and the mitochondrial ND4 gene that were determined in deep-sea hydrothermal vent mussels from the Mid-Atlantic Ridge (genus Bathymodiolus). Mussel specimens are grouped according to the population (pop)/location from which they have been sampled (first column). The remaining columns contain the respective allele/haplotype codes for the different genetic loci (names in the header line). The data file is in CONVERT format and can be directly transformed into different input files for population genetic statistics. 2) The tar archive contains NetCDF files with larval dispersal probabilities for simulated annual larval releases between 1998 and 2007. For each simulated vent location (Menez Gwen, Lucky Strike, Rainbow, Vent 1-10) two NetCDF files are given, one for an assumed pelagic larval duration of 1 year and the other one for an assumed pelagic larval duration of 6 months (6m).

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Um modelo dedicado ao planejamento da conservação e restauração de habitats deve incluir informações estratégicas para assegurar a eficácia e de fácil obtenção, para assegurar a agilidade necessária. Planos e estratégias para conservação usualmente são complexos e demandam informações detalhadas, difíceis de se obter, como inventários biológicos e certos tipos de mapeamento, o que traz limitações em termos de disponibilidade, qualidade e custo das informações. Assim, procurou-se testar a eficiência de métodos simples para a seleção, em escala local, de áreas prioritárias para conservação de habitats fortemente fragmentados e reduzidos, uma situação comum no sul do Brasil, usando dados de imagens LANDSAT e planos de informações disponíveis em mapeamentos comuns, e trabalho de campo. Inicialmente analisou-se a estrutura da paisagem e o padrão de fragmentação em parte da região norte do estado do Paraná, e testar se tamanho e forma são adequados para selecionar os fragmentos florestais mais importantes para a conservação, ou seja, as que contribuem para manter maior quantidade e melhor qualidade de habitats, bem como tenham maior impacto (positivo) na conectividade e em outras variáveis da paisagem. Os resultados mostram que a floresta madura cobre cerca de 3% da paisagem, e a cobertura florestal total atinge perto de 8%, consistindo principalmente de pequenos fragmentos (82% tem entre 1 e 10 ha). Fragmentos grandes (>100 ha) são apenas 1,4% dos remanescentes, mas somam 34% da área de floresta. Apesar de estarem sujeitos a efeitos de borda em toda ou quase toda a sua área, fragmentos pequenos mostraram ter um papel importante na conectividade da paisagem. Numa área maior, foi feita uma pré-seleção de áreas com potencial para estabelecimento de redes de conservação. A pré-seleção procurou responder às seguintes perguntas: 1-Quais são os sítios com maior potencial para a conservação da biodiversidade? 2-Quais são os sítios sob maior risco para objetivos de conservação? e 3-Quais sítios têm melhores oportunidades para o estabelecimento de zonas de conservação de uso múltiplo? Foi identificado um conjunto de 11 fragmentos pertencendo a 5 sub-regiões, sofrendo variados graus de pressão antrópica. Adicionalmente, usando medidas simples de estrutura da paisagem, relacionadas com tamanho, forma e conectividade dos fragmentos, procurou-se identificar tipos estruturais de fragmentos, como uma forma alternativa para auxiliar o estabelecimento de prioridades para conservação a partir do seu papel, efetivo ou potencial, na paisagem. Foram identificados 5 tipos de fragmentos, pequenos (ilhotas isoladas, trampolins), médios (núcleos auxiliares e corredores) e grandes (núcleos principais), que podem ser usados para subsidiar estratégias de conservação. Utilizando informações sobre a estrutura da paisagem, hidrografia e legislação ambiental, propõe-se aqui uma estratégia de conservação para o complexo das bacias dos ribeirões Apertados-Três Bocas (CATB), ordenando atividades de restauração e conservação de fragmentos florestais, criação e expansão de unidades de conservação, além da proposição de formas de uso do solo compatíveis com o entorno de unidades de conservação.

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Background: Models describing nuclear fragmentation and fragmentation fission deliver important input for planning nuclear physics experiments and future radioactive ion beam facilities. These models are usually benchmarked against data from stable beam experiments. In the future, two-step fragmentation reactions with exotic nuclei as stepping stones are a promising tool for reaching the most neutron-rich nuclei, creating a need for models to describe also these reactions. Purpose: We want to extend the presently available data on fragmentation reactions towards the light exotic region on the nuclear chart. Furthermore, we want to improve the understanding of projectile fragmentation especially for unstable isotopes. Method: We have measured projectile fragments from (10,12-18C) and B10-15 isotopes colliding with a carbon target. These measurements were all performed within one experiment, which gives rise to a very consistent data set. We compare our data to model calculations. Results: One-proton removal cross sections with different final neutron numbers (1 pxn) for relativistic C-10,C-12-18 and B10-15 isotopes impinging on a carbon target. Comparing model calculations to the data, we find that the EPAX code is not able to describe the data satisfactorily. Using ABRABLA07 on the other hand, we find that the average excitation energy per abraded nucleon needs to be decreased from 27 MeV to 8.1 MeV. With that decrease ABRABLA07 describes the data surprisingly well. Conclusions: Extending the available data towards light unstable nuclei with a consistent set of new data has allowed a systematic investigation of the role of the excitation energy induced in projectile fragmentation. Most striking is the apparent mass dependence of the average excitation energy per abraded nucleon. Nevertheless, this parameter, which has been related to final-state interactions, requires further study.

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The Blue Highway is a collection of eleven literary short stories and ten miniatures that depict men in trouble, searching for a code to live by. The miniatures are repressed memories, appearing suddenly like the tips of ice bergs and act as stepping stones (tension bridges) between the larger works. The stories begin at the end with "Time Out", the story of Frank, a down and out homeless vet at the end of his rope. Then we begin the journey along "The Blue Highway" with Danny and his gang of teenage bandits, taking themselves to Disney World to see if they can recapture their lost dream. On our journey we will meet Mark, the ex-killer, an old Cuban fisherman who will not give up his honor, a young man on a way to a war who discovers a fantastic treasure, a soldier on his way home again, two MP's who nearly kill the wrong man, we will spend a night on an African savannah with wild hyenas and finally, meet a grandfather who discovers the one gift which might save his family. The same gift which might save Frank as well. ^

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In the year 2000, approximately 1.1 billion people lived in extreme poverty while developed countries spent US$600 billion a year on defense. The Heavily Indebted Poor Countries (HIPC) Initiative is a recent component of a larger poverty reduction strategy supported by the International Financial Institutions, as well as many developed and developing countries. By implementing lessons of the past fifty years, this program attempts to diminish misery around the globe. As such, it provides debt relief while seeking to enable the poorest countries to simultaneously attain sustainable debt and promote human development. Interest in poverty reduction around the globe reemerged in the 1990s. This study contributes directly to this recent effort by presenting a nuanced approach that builds on the stepping-stones generated by other poverty scholars. To fulfill its goal, this investigation applies a political economy framework. Within this framework, the author conducts an actor-specific analysis. This dissertation addresses the following question: How do domestic and international actors respond to the implementation of poverty alleviation strategies? The author assumes actors desire to maximize their utility calculation and suggests these calculations are based on the player's motivations and external influences. Based on their motivations, the external influences, and the initiative's guidelines, each actor develops a set of expectations. To fulfill those expectations, stake holders utilize one or several strategies. Finally, the actors' ability to achieve their expectations determines each player's assessment of the initiative. The framework described is applied in an in-depth, actor-specific analysis of the HIPC in Bolivia. Bolivia's National Revolution represents the country's first attempt at reducing poverty. Since then, all governments have taken specific steps to combat poverty at the local and national levels. The Initiative for Heavily Indebted Poor Countries (HIPC) is one of the most recent macro strategies of this kind. The case study demonstrated that three factors (national ownership, effective sponsorship and the local context) determine the success levels of poverty reduction strategies from abroad. In addition, the investigation clearly shows that poverty reduction is not the sole motivation in the implementation of poverty alleviation strategies. All actors, however, share the dream of poverty reduction.

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The Blue Highway is a collection of eleven literary short stories and ten miniature that depict men in trouble, searching for a code to live by. The miniatures are repressed memories, appearing suddenly like the tips of ice bergs and act as stepping stones (tension bridges) between the larger works. The stories begin at the end with "Time Out", the story of Frank, a down and out homeless vet at the end of his rope. Then we begin the journey along "The Blue Highway" with Danny and his gang of teenage bandits, taking themselves to Disney World to see if they can recapture their lost dream. On our journey we will meet Mark, the ex-killer, an old Cuban fisherman who will not give up his honor, a young man on a way to a war who discovers a fantastic treasure, a soldier on his way home again, two MP's who nearly kill the wrong man, we will spend a night on an African savannah with wild hyenas and finally, meet a grandfather who discovers the one gift which might save his family. The same gift which might save Frank as well.

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Adoption of new cattle management practices by Indonesian smallholders occurs less as a ‘technology transfer’ in the classical sense but rather as a series of conscious decisions by farming households weighing risks and resources as well as matching innovations to livelihood strategies. This paper uncovers the context of decisions and communication of innovations by way of social networks. The research looks at two geographically distinct cases where new cattle management practices have been introduced. We apply the lens of a common sense framework initially introduced by Clifford Geertz. Smallholder decisions are analysed within a socio-cultural context and a particular set of resources, risks and livelihood objectives. We show that the respective value placed on land, cattle and food security is central to adoption of new cattle management techniques. Far from accepting everything novel, smallholders are selective and willing to make changes to their farming system if they do not conflict with livelihood strategies. Innovations are communicated through a range of existing social networks and are either matched to existing livelihood strategies or perceived as stepping-stones out of agriculture.

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Underwater censuses by divers were used to study the fish assemblages from two unexplored Atlantic seamounts in the Cape Verde archipelago. Fifty three species of 27 families were recorded: 27 in Northwest Bank and 46 in João Valente Bank. Northwest Bank had dense schools, while João Valente Bank had higher species richness and smaller schools. Both seamounts were dominated mainly by coastal species directly depending on seabed habitat (Demersal or benthopelagic). Of the 53 fish species recorded, 22.6% were of continental African origin, while 9.4% and 5.7% were endemic of the Cape Verde Islands and of the Macaronesia province, respectively. Most species (64.2%) had a very wide biogeographic distribution: cosmopolitan (22.6%), amphi-Atlantic (28.3%) and Atlantic-Mediterranean (13.2%). Northwest Bank and João Valente Bank may have a permanent fish community supported by various oceanographic-topographic interactions. João Valente Bank seems more diverse, which is probably associated with algae cover and with a larger area providing additional suitable and more varied habitats. The geographic proximity to the coast and the presence of oceanic and/or oceanodromous species suggests that the upper part of these seamounts may act both as attraction points and as “stepping-stones” for the dispersal of coastal species.

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Gettysburg and Ormond are seamounts belonging to the Gorringe Bank, which is located on the Europen-African plate boundary. Given the importance of these oceanic features for understanding marine biodiversity patterns, two surveys were carried out in 1998 (Gettysburg) and 1999 (Ormond) using diving, photography and video for species identification and abundance evaluation. Of the 9 fish species found at Gettysburg and 11 at Ormond, 6 were common to both sites and these included the dominant species: the oceanic and commercially important, Seriola rivoliana, and the coastal, typically Atlantic-Mediterranean Coris julis and Anthias anthias. The strong representation of coastal, demersal and Atlantic-Mediterranean species in the Gorringe Bank region and the presence of Abudefduf luridus, an endemic Macaronesian species, at Gettysburg suggests that the upper part of these seamounts may have acted and still act as “stepping stones” for the dispersal of coastal species.

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En vista de las inequidades entre mujeres y hombres como las implicaciones que éstas posan sobre la seguridad alimentaria y el desarrollo agro-rural, la Organización de las Naciones Unidas para la Agricultura y la Alimentación (FAO) ha incursionado en procesos de comunicación para el desarrollo con un proyecto que innovador, integra un enfoque de género.

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Este documento evidencia las posiciones hegemónicas que han llegado a ocupar las empresas más poderosas del país, basándose en el estudio de datos cuantitativos del conteo de las cien empresas con mejores ventas para los años 2013 y 2014, según la revista Gerente. Se usan cinco variables: ventas totales, activos, pasivos, patrimonio y utilidades netas. En la primera sección, se hace una revisión bibliográfica que conecta el origen de la hegemonía en un panorama económico con la influencia del neoliberalismo y la globalización en el actual tejido industrial colombiano. Posteriormente, se realiza una explicación sobre la metodología aplicada para el estudio de la base de datos; la cual es seguida por una exposición de los resultados obtenidos a partir de herramientas estadísticas como el análisis de correlación lineal, quintiles y variaciones porcentuales. Finalmente, se aborda el Programa de Transformación Productiva, esto con el objetivo de mostrar los puntos focales que necesitan especial atención para lograr catalizar el desarrollo económico de Colombia.