885 resultados para Rainbow trout.


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There is a need for better links between hydrology and ecology, specifically between landscapes and riverscapes to understand how processes and factors controlling the transport and storage of environmental pollution have affected or will affect the freshwater biota. Here we show how the INCA modelling framework, specifically INCA-Sed (the Integrated Catchments model for Sediments) can be used to link sediment delivery from the landscape to sediment changes in-stream. INCA-Sed is a dynamic, process-based, daily time step model. The first complete description of the equations used in the INCA-Sed software (version 1.9.11) is presented. This is followed by an application of INCA-Sed made to the River Lugg (1077 km2) in Wales. Excess suspended sediment can negatively affect salmonid health. The Lugg has a large and potentially threatened population of both Atlantic salmon (Salmo salar) and Brown Trout (Salmo trutta). With the exception of the extreme sediment transport processes, the model satisfactorily simulated both the hydrology and the sediment dynamics in the catchment. Model results indicate that diffuse soil loss is the most important sediment generation process in the catchment. In the River Lugg, the mean annual Guideline Standard for suspended sediment concentration, proposed by UKTAG, of 25 mg l− 1 is only slightly exceeded during the simulation period (1995–2000), indicating only minimal effect on the Atlantic salmon population. However, the daily time step simulation of INCA-Sed also allows the investigation of the critical spawning period. It shows that the sediment may have a significant negative effect on the fish population in years with high sediment runoff. It is proposed that the fine settled particles probably do not affect the salmonid egg incubation process, though suspended particles may damage the gills of fish and make the area unfavourable for spawning if the conditions do not improve.

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Recombination is thought to occur only rarely in animal mitochondrial DNA ( mtDNA). However, detection of mtDNA recombination requires that cells become heteroplasmic through mutation, intramolecular recombination or ' leakage' of paternal mtDNA. Interspecific hybridization increases the probability of detecting mtDNA recombinants due to higher levels of sequence divergence and potentially higher levels of paternal leakage. During a study of historical variation in Atlantic salmon ( Salmo salar) mtDNA, an individual with a recombinant haplotype containing sequence from both Atlantic salmon and brown trout ( Salmo trutta) was detected. The individual was not an F1 hybrid but it did have an unusual nuclear genotype which suggested that it was a later-generation backcross. No other similar recombinant haplotype was found from the same population or three neighbouring Atlantic salmon populations in 717 individuals collected during 1948 - 2002. Interspecific recombination may increase mtDNA variability within species and can have implications for phylogenetic studies.

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We derive general analytic approximations for pricing European basket and rainbow options on N assets. The key idea is to express the option’s price as a sum of prices of various compound exchange options, each with different pairs of subordinate multi- or single-asset options. The underlying asset prices are assumed to follow lognormal processes, although our results can be extended to certain other price processes for the underlying. For some multi-asset options a strong condition holds, whereby each compound exchange option is equivalent to a standard single-asset option under a modified measure, and in such cases an almost exact analytic price exists. More generally, approximate analytic prices for multi-asset options are derived using a weak lognormality condition, where the approximation stems from making constant volatility assumptions on the price processes that drive the prices of the subordinate basket options. The analytic formulae for multi-asset option prices, and their Greeks, are defined in a recursive framework. For instance, the option delta is defined in terms of the delta relative to subordinate multi-asset options, and the deltas of these subordinate options with respect to the underlying assets. Simulations test the accuracy of our approximations, given some assumed values for the asset volatilities and correlations. Finally, a calibration algorithm is proposed and illustrated.

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In 1917 D.H. Lawrence's whole outlook on the social and cultural environment of his country was embodied in his attitude towards the literary marketplace. The suppression of The Rainbow in 1915 and his opposition to the war contributed to his feeling of detachment from what he called ‘the bourgeois world, the world which controls press, publication and all’. Presenting new archival evidence, this article examines the publishing history of the poetry volume Look! We Have Come Through, issued by Chatto & Windus in 1917. Closer examination of the motives of the individual editors involved in the production of the volume reveals why Lawrence was required to make changes to his text but also why the firm were eager to publish a volume that was to have little commercial impact. Issued at a critical moment in Lawrence's relationship with the marketplace, and in the history of literary modernism, the episode shows how, in spite of general hostility to his work, there were forces in the mainstream publishing market that were keen to embrace modern literary forms and take risks with the work of authors whose subject-matter was challenging and potentially dangerous.

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Collagen activates mammalian platelets through a complex of the immunoglobulin (Ig) receptor GPVI and the Fc receptor γ-chain, which has an immunoreceptor tyrosine-based activation motif (ITAM). Cross-linking of GPVI mediates activation through the sequential activation of Src and Syk family kinases and activation of PLCγ2. Nucleated thrombocytes in fish are activated by collagen but lack an ortholog of GPVI. In this study we show that collagen activates trout thrombocytes in whole blood and under flow conditions through a Src kinase driven pathway. We identify the Ig receptor G6f-like as a collagen receptor and demonstrate in a cell line assay that it signals through its cytoplasmic ITAM. Using a morpholino for in vivo knock-down of G6f-like levels in zebrafish, we observed a marked delay or absence of occlusion of the venous and arterial systems in response to laser injury. Thus, G6f-like is a physiologically relevant collagen receptor in fish thrombocytes which signals through the same ITAM-based signalling pathway as mammalian GPVI, providing a novel example of convergent evolution.

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In this work we present new coupled channel calculations with the Sao Paulo potential (SPP) as the bare interaction, and an imaginary potential with system and energy independent normalization that has been developed to take into account dissipative processes in heavy-ion reactions. This imaginary potential is based on high-energy nucleon interaction in nuclear medium. Our theoretical predictions for energies up to approximate to 100 MeV/nucleon agree very well with the experimental data for the p, n + nucleus, (16)O + (27)Al, (16)O + (60)Ni, (58)Ni + (124)Sn, and weakly bound projectile (7)Li + (120)Sn systems. (C) 2008 Elsevier B.V. All rights reserved.

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The Delaware River provides half of New York City's drinking water, is a habitat for wild trout, American shad and the federally endangered dwarf wedge mussel. It has suffered four 100‐year floods in the last seven years. A drought during the 1960s stands as a warning of the potential vulnerability of the New York City area to severe water shortages if a similar drought were to recur. The water releases from three New York City dams on the Delaware River's headwaters impact not only the reliability of the city’s water supply, but also the potential impact of floods, and the quality of the aquatic habitat in the upper river. The goal of this work is to influence the Delaware River water release policies (FFMP/OST) to further benefit river habitat and fisheries without increasing New York City's drought risk, or the flood risk to down basin residents. The Delaware water release policies are constrained by the dictates of two US Supreme Court Decrees (1931 and 1954) and the need for unanimity among four states: New York, New Jersey, Pennsylvania, and Delaware ‐‐ and New York City. Coordination of their activities and the operation under the existing decrees is provided by the Delaware River Basin Commission (DRBC). Questions such as the probability of the system approaching drought state based on the current FFMP plan and the severity of the 1960s drought are addressed using long record paleo‐reconstructions of flows. For this study, we developed reconstructed total annual flows (water year) for 3 reservoir inflows using regional tree rings going back upto 1754 (a total of 246 years). The reconstructed flows are used with a simple reservoir model to quantify droughts. We observe that the 1960s drought is by far the worst drought based on 246 years of simulations (since 1754).

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O presente artigo aborda as aproximações do teatro do oprimido na modalidade do arco-íris do desejo, método de terapia e teatro criado por Augusto Boal com a Psicologia, em especial com o psicodrama. O teatro do oprimido é frequentemente comparado e até mesmo confundido com o psicodrama, daí a necessidade de apontarmos algumas semelhanças e diferenças entre os dois métodos, as teorias que inspiraram seus criadores, bem como os objetivos que procuravam alcançar. Procuraremos problematizar o uso das técnicas do arco-íris do desejo considerando a função e a preparação do curinga para aplicá-las, seu manejo, bem como o lugar de autoridade que lhe é conferido. As técnicas boalianas devem ser utilizadas com o devido cuidado, pois é necessário não perder de vista as possíveis consequências que o seu uso indevido pode provocar nos participantes, posto que são técnicas mobilizadoras de fortes conteúdos emocionais.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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No presente trabalho, estudamos a quebra da simetria quiral na pseudo eletrodinâmica quântica em (2+1) dimensões usando o formalismo das equações de Schwinger-Dyson e investigamos as semelhanças deste modelo com a criticalidade encontrada na EDQ3 e EDQ4. Usando a aproximação “quenched-rainbow”, mostramos que existe um acoplamento crítico αcc = π/16, acima do qual existe a geração de massa para os férmions e portanto, ocorrendo a quebra da simetria quiral. Também estudamos o caso com N campos fermiônicos usando a expansão 1/N na aproximação “unquenched-rainbow”, onde obtemos um número crítico Nc abaixo do qual a simetria quiral é quebrada e, para valores acima, a simetria é restaurada. No limite de acoplamento forte (g -- ∞), mostramos que este número crítico é o mesmo encontrado na EDQ3 na expansão 1/N.

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There are cardiopathies that acometem the dogs, being able this being congenital or acquired and lately have grown the number of cases due to the increase of the life expectancy of these animals becoming each time more necessary prevention methods. In recent years innumerable research is being carried through to understand the influence of the fish oil in the cardiopathies. The fish oil ingestion, Omega 3, has shown beneficial effect in the prevention of cardiovascular illnesses in such a way in the men as in the animals. Such effect this related to the presence of acid greasy polyunsaturateds n-3, mainly acid the eicosapentaenóico (EPA) and acid the docosahexaenóico (DHA). These substances can be found in foods as marine cold water fish (salmon, tuna, sardine and Trout), hemp seeds and soy. The present study, therefore, it has as objective to carry through an update on the use of the fish oil in the treatment of cardiopathies in dogs

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)