47 research outputs found

    Diversidade e Estrutura Genéticas de Bryconamericus aff. Iheringii (Characiformes: Characidae) na Área de Influência do Reservatório da Itaipu

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    Trabalho de Conclusão de Curso apresentado ao Instituto Latino-Americano de Ciências da Vida e Natureza da Universidade Federal da Integração Latino-Americana, como requisito parcial à obtenção do título de Bacharel em Ciências Biológicas – Ecologia e Biodiversidade.A diversidade genética é necessária para que as populações evoluam e se adaptem às mudanças ambientais, e comumente, está distribuída em um padrão dentro e entre populações que é referido como estrutura genética. O isolamento e a existência de poucos caminhos migratórios entre águas doces implicam na estruturação genética, principalmente, para peixes que possuem baixa mobilidade. Peixes de pequeno porte (≤ 15 cm de comprimento), que habitam riachos, representam, no mínimo 50% de toda a ictiofauna sul-americana e apresentam um alto grau de endemismo, devido, em parte, à sua baixa capacidade de deslocamento. Neste contexto, o presente trabalho objetivou avaliar a diversidade e a estrutura genéticas do caracídeo Bryconamericus aff. iheringii na área de influência do reservatório da Itaipu Binacional. Para isto, foram analisados 47 espécimes, 23 coletados em riachos da margem direita (Paraguai) e 24 coletados em riachos da margem esquerda (Brasil) do reservatório da Itaipu. Para acessar sua diversidade genética, foi empregado o marcador molecular D-loop, sendo estimado o número de haplótipos, os índices de diversidade haplotípica e nucleotídica e o nível de estruturação entre as diferentes amostras. B. aff. iheringii apresentou níveis de diversidade genética dentro do padrão relatado para a espécie, com moderados (amostras do Paraguai) a altos (amostras do Brasil) níveis de diversidade, o que se deve, sobretudo, ao fato de que quase todos os riachos paraguaios analisados são de uma única microbacia, enquanto os riachos brasileiros são de quatro microbacias diferentes. As populações não parecem ter respondido a eventos drásticos recentes, pois mesmo as presentes em regiões sob a pressão de atividades agrícolas, mostram variações no DNA mitocondrial. Foram encontrados altos níveis de estruturação genética entre o conjunto de amostras paraguaio e brasileiro e entre as microbacias dentro de cada país, o que se deve, principalmente, aos processos de colonização destas drenagens, os quais possivelmente envolvem fundadores com diferentes linhagens haplotípicas. Além disso, parece plausível que o rio Paraná (reservatório da Itaipu) funciona como uma barreira ao fluxo gênico entre as diferentes margens e entre suas microbacias. Deste modo, a identificação de linhagens é de grande importância, pois a manutenção da diversidade genética de uma espécie depende de sua preservação. Considerando a importância de estudos genético-populacionais para a conservação de espécies, espera-se que este trabalho possa servir como base para futuros estudos mais amplos com peixes de riachos

    Assay precision and risk of misclassification at rule-out cut-offs for high-sensitivity cardiac troponin

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    Clinical trials and guidelines support the use of very low high-sensitivity cardiac troponin (hs-cTn) results to rule-out a myocardial infarction (MI) ( 1) ). The International Federation of Clinical Chemistry and Laboratory Medicine Committee on Clinical Applications of Cardiac Biomarkers committee, through a modeling approach, suggests assays need to have a lower limit near 3 ng/L and an analytical variation of 10% below 7 ng/L if these low values are to perform consistently in practice ( 2) ). Our objectives for the present study were to assess: i) if any type of instrument or individual instrument could achieve a coefficient of variation (CV) of ≤10% at very low hs-cTn cut-offs (i.e., targets) recommended in clinical pathways; ii) the frequency of results at the hs-cTn target, above the target and below the target, with the latter group representing potential misclassification to the low risk group where the target level would in the intermediate risk range.<br/

    Analysis of real GDP growth rates of greater China: An asymmetric conditional volatility approach

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    10.1016/j.chieco.2004.06.011China Economic Review154424-44

    Modelling of multilayer on-chip transformers

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    An analytical model has been proposed for multilayer stacked on-chip transformers, including the effects of the eddy current losses in the metal layers and Si substrate. The model gives good agreement with S-parameter measurements on structures fabricated using a four-metal-layer 0.35μm CMOS process. It is shown that proper account of the eddy current losses is necessary to predict accurately the S-parameter characteristics of on-chip transformers at higher frequencies. © The Institution of Engineering and Technology 2006

    A physical analytical model of multilayer on-chip inductors

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    An analytical model of multilayer on-chip inductors for CMOS integrated circuits based on physical principles has been developed. It provides accurate prediction of the self-resonant frequency, and eddy-current losses in the metal and Si substrate, as compared with experimental and numerical simulation results. The model includes improvements in the evaluation of eddy currents in metals caused by the proximity effect, and the equivalent capacitances in multilayer inductors. The Q factors deduced from the model agree well with experimental and numerical simulation results for multilayer inductors over a wide range of frequencies and widths of metal segments. © 2005 IEEE

    Perceptual Integrality of Foreign Segmental and Tonal Information: Dimensional Transfer Hypothesis

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    Studies in Second Language Acquisition - SLA-RR-2022-003

    Modelling volatility asymmetry of business cycles in the U.S.

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    MODSIM07 - Land, Water and Environmental Management: Integrated Systems for Sustainability, Proceedings933-93

    Cognates are advantaged over non-cognates in early bilingual expressive vocabulary development

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    Bilinguals need to learn two words for most concepts. These words are called translation equivalents, and those that also sound similar (e.g., banana—banane) are called cognates. Research has consistently shown that children and adults process and name cognates more easily than non-cognates. The present study explored if there is such an advantage for cognate production in bilinguals’ early vocabulary development. Using longitudinal expressive vocabulary data collected from 47 English–French bilinguals starting at 16–20 months up to 27 months (a total of 219 monthly administrations in both English and French), results showed that overall children produced a greater proportion of cognates than non-cognates on the MacArthur-Bates Communicative Development Inventories. The findings suggest that cognate learning is facilitated in early bilingual vocabulary development. Just as in monolinguals, these results suggest that phonological overlap supports bilingual language acquisition

    Cognates are advantaged in early bilingual expressive vocabulary development

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    Bilinguals need to learn two words for most concepts. These words are called translation equivalents, and those that also sound similar (e.g., banana—banane) are called cognates. Research has consistently shown that children and adults process and name cognates more easily than non-cognates. The present study explored if there is such an advantage for cognate production in bilinguals’ early vocabulary development. Longitudinal expressive vocabulary data were collected from 47 English–French bilinguals starting at 16–20 months up to 27 months (a total of 219 monthly administrations in both English and French). Children produced a greater proportion of cognates than non-cognates, and the interval between producing a word and its translation equivalent was about 10–15 days shorter for cognates than for non-cognates. The findings suggest that cognate learning is facilitated in early bilingual vocabulary development, such that phonological overlap supports bilinguals in learning phonologically similar words across their two languages
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