965 resultados para Cape Cod Bay
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This paper presents findings based on a palynological investigation of artificially accreting (plaggen) soils from the settlement of Village Bay, Hirta, in the St Kilda archipelago, which was perhaps the most distant and inhospitable outpost of sustained human habitation in the British Isles. The soils were developed principally through the addition of turf ash and seabird waste, although some ash may have been derived from upland peats. It is assumed that the woodland pollen signal (much lower in the soils than in an upland peat site nearby) represents off-island sources. Corylus avellana-type pollen (frequent in upland sites), along with Potentilla-type, may provide markers in the Village Bay profiles for the addition of ashed hillside turf, and possibly peat, to the plaggen soils. Cereal-type pollen is well represented through the profiles and is often strongly associated with the record for Chrysanthemum segetum (corn marigold), a frequent indicator of arable land. The Brassicaceae signal may partly reflect the cultivation of cabbages; Chelidonium majus (greater celandine) may have been grown for medicinal use. Soil mixing has rendered radiocarbon dating meaningless at this site, but the establishment of a change in cultivation regime before AD 1830 may have been identified from the patterns of pollen concentration and preservation in the profiles. © 2008 Elsevier B.V. All rights reserved.
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This paper focuses attention on the fortunes of Darwin's theory among the English-speaking community in Cape Colony during the latter part of the nineteenth century. The paper begins with a review of early encounters with Darwin dwelling particularly on the response of figures like Roderick Noble - professor and editor of the Cape Monthly Magazine, the geologist John Shaw, and Sir Henry Barkly, governor of the colony. Besides these more theoretical responses, Darwin's ideas were also mobilised in a range of scientific inquiries on such subjects as birds and butterflies. But most conspicuous was the use of evolutionary thought-forms in the work of the eminent philologist Wilhelm Bleek, cousin of Darwin's leading German apologist, Ernst Haeckel. The prevailing sense is of a liberal intelligentsia calmly interacting with a novel theory with all due deference. During the 1870s, an address by Langham Dale at the South African Public Library injected new energy into the Darwin discussion. Dale expressed disquiet over some of the anthropological implications of evolution as well as its apparent reductionism, and this stimulated a range of reactions. Several anonymous commentators responded but the most sustained evaluation of Dale's position emanated from the Queenstown physician and later politician, Sir William Bisset Berry. Then, in 1874, copious extracts from John Tyndall's infamous 'Belfast Address' were printed in the Cape Monthly and this added yet further impetus to the debate. Tyndall's seeming materialism bothered a number of readers, not least Hon William Porter, former attorney-general of Cape Colony. To figures like these the materialist extrapolations of radical Darwinians such as Haeckel were deeply disturbing, not just for religious reasons, but because they seemed to destabilise the moral and pedagogic progressivism that lay at the heart of their civilising credo. While reservations about Darwin's proposals were certainly audible, taken in the round Darwinian conversations among the English-speaking literati at the Cape were conducted with liberal sentiments, not least when evolutionary science approached questions of race. For Darwin's writings were seen to confirm a monogenetic account of the origin and unity of the human race, and could readily be called upon to justify the paternalistic ideology that governed colonial affairs.
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The spectral sensitivity of visual pigments in vertebrate eyes is optimized for specific light conditions. One of such pigments, rhodopsin (RH1), mediates dim-light vision. Amino acid replacements at tuning sites may alter spectral sensitivity, providing a mechanism to adapt to ambient light conditions and depth of habitat in fish. Here we present a first investigation of RH1 gene polymorphism among two ecotypes of Atlantic cod in Icelandic waters, which experience divergent light environments throughout the year due to alternative foraging behaviour. We identified one synonymous single nucleotide polymorphism (SNP) in the RH1 protein coding region and one in the 3' untranslated region (3'-UTR) that are strongly divergent between these two ecotypes. Moreover, these polymorphisms coincided with the well-known panthophysin (Pan I) polymorphism that differentiates coastal and frontal (migratory) populations of Atlantic cod. While the RH1 SNPs do not provide direct inference for a specific molecular mechanism, their association with this dim-sensitive pigment indicates the involvement of the visual system in local adaptation of Atlantic cod.
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The genomic architecture underlying ecological divergence and ecological speciation with gene flow is still largely unknown for most organisms. One central question is whether divergence is genome-wide or localized in 'genomic mosaics' during early stages when gene flow is still pronounced. Empirical work has so far been limited, and the relative impacts of gene flow and natural selection on genomic patterns have not been fully explored. Here, we use ecotypes of Atlantic cod to investigate genomic patterns of diversity and population differentiation in a natural system characterized by high gene flow and large effective population sizes, properties which theoretically could restrict divergence in local genomic regions. We identify a genomic region of strong population differentiation, extending over approximately 20 cM, between pairs of migratory and stationary ecotypes examined at two different localities. Furthermore, the region is characterized by markedly reduced levels of genetic diversity in migratory ecotype samples. The results highlight the genomic region, or 'genomic island', as potentially associated with ecological divergence and suggest the involvement of a selective sweep. Finally, we also confirm earlier findings of localized genomic differentiation in three other linkage groups associated with divergence among eastern Atlantic populations. Thus, although the underlying mechanisms are still unknown, the results suggest that 'genomic mosaics' of differentiation may even be found under high levels of gene flow and that marine fishes may provide insightful model systems for studying and identifying initial targets of selection during ecological divergence.
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A Ilha de Santiago, situada no Arquipélago de Cabo Verde, é dominada por um clima seco e árido, interrompido por curtos períodos de chuvas torrenciais, com grande capacidade de transporte de sedimentos ao longo de vales profundos e encaixados, tributários da Ribeira Seca, onde se situa a Barragem do Poilão, construída em 2006. Os resultados de um levantamento batimétrico da albufeira da barragem realizado em Março de 2013, apontam para uma taxa de sedimentação anual próxima de 90 000 m3 /ano, fazendo com que, em apenas 7, anos a capacidade de armazenamento da albufeira tenha diminuído quase para metade. Os valores determinados neste estudo recomendam a tomada de medidas urgentes por parte do governo de Cabo Verde, no sentido da dragagem e desassoreamento da albufeira do Poilão.
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Poilão dam reservoir (Cape Verde Archipelago) is in critical conditions, owing the excessive silting up, the high concentration of nitrates and the pronounced anoxia all over the lake. Considering that the most suitable remediation strategy is the removal of the bottom sediments where nutrients are preferentially concentrated, we have done a geochemical study, in order of evaluating their suitability to agricultural use. Analyses indicate that sediments are rich in a few key nutrients, when compared with parent soils. Thus, adding suitable sediments to nearby degraded soils can improve food crops for smallholder farmers living in close proximity to this system.
Implementing a Videoconferencing Studio in Cape Verde to Support a Blended Learning Education System
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In 2004, the Calouste Gulbenkian Foundation invited the University of Aveiro to develop an education and training program in advanced topics of ICT for Cape Verde. The focus should be on technologies to support the development of distance education. Two years later, when the program was started, the University of Aveiro had a high-performance videoconferencing Studio installed by the Foundation for National Scientific Computing. However, the investment to duplicate this high quality structure and operating costs were not compatible neither with the project’s budget nor with the technological options available in Cape Verde. This paper demonstrates the decision-making process by an economically viable option to meet the needs and local peculiarities.
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Dissertação de Mestrado, Gestão da Água e da Costa, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2007
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Tese de dout., Ciências e Tecnologia das Pescas, Faculdade de Ciências do Mar e do Ambiente, Universidade do Algarve, 2005
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The region of the Northeast Atlantic represents a gradient between two oceanographic regimes: (i) the subtropical waters of southern Portugal and southwestern Spain, and (ii) the temperate waters characterizing the northwestern and northern Iberian coasts (Cantabrian Sea) and the rest of the Bay of Biscay along the French coast.
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This study attempts to implement a hydrodynamic operational model which can ultimately be used for projecting oil spill dispersal patterns and also sewage, pollution and can also be used in wave forecasting. A two layer nested model was created using MOHID Water, which is powerful ocean modelling software. The first layer (father) is used to impose the boundary conditions for the second layer (son). This was repeated for two different wind dominant regimes, Easterly and Westerly winds respectively. A qualitative comparison was done between measured tidal data and the tidal output. Sea surface temperature was also qualitatively compared with the model’s results. The results from both simulations were analysed and compared to historical literature. The comparison was done at the surface layer, 100 metre depth and at 800m depth. In the surface layer the first simulation generated an upwelling event near Cape St. Vincent and within the Algarve. The second simulation generated a non-upwelling event within which the surface was flow reversed and the warm water mass was along the Algarve coastline and evening turning clockwise around Cape St. Vincent. At the 100 metre depth for both simulations, velocity vortexes were observed near Cape St. Vincent travelling northerly and southerly at various instances. At 800metre depth a strong oceanic flow was observed moving north westerly along the continental shelf.
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The loggerhead turtle (Caretta caretta) is an endangered marine reptile for whom assessing population health requires knowledge of demographic parameters such as individual growth rate. In Cape Verde, as within several populations, adult female loggerhead sea turtles show a size-related behavioral and trophic dichotomy. While smaller females are associated with oceanic habitats, larger females tend to feed in neritic habitats, which is reflected in their physiological condition and in their offspring. The ratio of RNA/DNA provides a measure of cellular protein synthesis capacity, which varies depending on changes in environmental conditions such as temperature and food availability. The purpose of this study was to evaluate the combined use of morphometric data and biochemical indices as predictors of the physiological condition of the females of distinct sizes and hatchlings during their nesting season and how temperature may influence the physiological condition on the offspring. Here we employed biochemical indices based on nucleic acid derived indices (standardized RNA/DNA ratio-sRD, RNA concentration and DNA concentration) in skin tissue as a potential predictor of recent growth rate in nesting females and hatchling loggerhead turtles. Our major findings were that the physiological condition of all nesting females (sRD) decreased during the nesting season, but that females associated with neritic habitats had a higher physiological condition than females associated with oceanic habitats. In addition, the amount of time required for a hatchling to right itself was negatively correlated with its physiological condition (sRD) and shaded nests produced hatchlings with lower sRD. Overall, our results showed that nucleic acid concentrations and ratios of RNA to DNA are an important tool as potential biomarkers of recent growth in marine turtles. Hence, as biochemical indices of instantaneous growth are likely temperature-, size- and age-dependent, the utility and validation of these indices on marine turtles stocks deserves further study.
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Dissertação de mestrado, Aquacultura, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2011
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The South Carolina Department of Natural Resources provides maps to recreational and state shellfish grounds, available to the public for recreational harvesting or to commercial harvest. This map shows the location of Gray Bay PSG - R234 Recreational Shellfish Ground in Charleston County.
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The South Carolina Department of Natural Resources provides maps to recreational and state shellfish grounds, available to the public for recreational harvesting or to commercial harvest. This map shows the location of Hickory Bay PSG - R274 Recreational Shellfish Ground in Charleston County.