908 resultados para 100 years


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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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This article reports the nucleotide diversity within the control region of 42 mitochondrial chromosomes belonging to five South American native cattle breeds (Bos taurus). Analysis of these data in conjunction with B. taurus and B. indicus sequences from Africa, Europe, the Near East, India, and Japan allowed the recognition of eight new mitochondrial haplotypes and their relative positions in a phylogenetic network. The structure of genetic variation among different hypothetical groupings was tested through the molecular variance decomposition, which was best explained by haplotype group components. Haplotypes surveyed were classified as European-related and African-related. Unexpectedly, two haplotypes within the African cluster were more divergent from the African consensus than the latter from the European consensus. A neighbor-joining tree shows the position of two haplotypes compared to European/African mitochondrial lineage splitting. This different and putatively ancestral mitochondrial lineage (AA) is supported by the calibration of sequence divergence based on the Bos-Bison separation. The European/African mitochondria divergence might be subsequent (67,100 years before present) to that between AA and Africans (84,700 years before present), also preceding domestication times. These genetic data could reflect the haplotype distribution of Iberian cattle five centuries ago.

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Chicken is one of the most important sources of animal protein for human consumption, and breeding programmes have been responsible for constant improvements in production efficiency and product quality. Furthermore, chicken has largely contributed to fundamental discoveries in biology for the last 100 years. In this article we review recent developments in poultry genomics and their contribution to adding functional information to the already existing structural genomics, including the availability of the complete genome sequence, a comprehensive collection of mRNA sequences ( ESTs), microarray platforms, and their use to complement QTL mapping strategies in the identification of genes that underlie complex traits. Efforts of the Brazilian Poultry Genomics Programme in this area resulted in generation of a resource population, which was used for identification of Quantitative Trait Loci ( QTL) regions, generation of ESTs and candidate gene studies that contributed to furthering our understanding of the complex biological processes involved in growth and muscular development in chicken.

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Eriocaulaceae é uma família pantropical com dez gêneros e cerca de 1.400 espécies, com centro de diversidade no Novo Mundo, especialmente no Brasil. A última revisão da família foi publicada há mais de 100 anos, e até recentemente, as relações genéricas e infra-genéricas ainda eram pouco resolvidas. Entretanto, tem havido nos últimos 30 anos, um grande esforço por parte de pesquisadores brasileiros para preencher as lacunas existentes, utilizando caracteres morfológicos e anatômicos, complementados por dados adicionais de diferentes fontes, como palinologia, química, embriologia, genética de populações, citologia e, mais recentemente, estudos de filogenia molecular. Tal conjunto de dados tem levado a uma re-avaliação do relacionamento filogenético dentro da familia. Neste trabalho são apresentados novos dados para as regiões de ITS e trnL-F, analisadas separadamente e em combinação, usando máxima parcimônia e inferência Bayesiana. Os dados obtidos confirmam resultados já publicados, e mostram que muitos caracteres tradicionalmente usados para diferenciação e circunscrição dos gêneros dentro da família são homoplásicos. Uma nova descrição e chave genérica para a família, utilizando caracteres de várias fontes são apresentadas, refletindo a taxonomia atual das Eriocaulaceae.

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Os modelos matemáticos preditivos da erosão do solo, como a Equação Universal de Perda de Solo (EUPS), são de muita valia no planejamento de uso agrícola da terra. Tal equação, desenvolvida para estimar as perdas médias anuais de solo esperadas em dado local, para determinado sistema de manejo, apresenta como variáveis os fatores erosividade da chuva (R), erodibilidade do solo (K), comprimento do declive (L), grau do declive (S), cobertura e manejo (C) e práticas conservacionistas de suporte (P). Com o objetivo de contribuir para o planejamento conservacionista de uso do solo local, foi estimado, de forma simplificada, o fator erosividade da chuva (R) da EUPS para o município de São Manuel (SP), para uma série pluviométrica contínua de 49 anos de dados de chuva diária. Além disso, foram também calculados o período de retorno, a freqüência de ocorrência dos índices de erosividade anuais e as quantidades máximas diárias das chuvas necessárias para o dimensionamento mais adequado de canais de terraços agrícolas em nível. O valor calculado do fator R foi de 7.487 MJ mm ha-1 h-1 ano-1, esperado ocorrer no local, pelo menos, uma vez a cada 2,33 anos, com uma probabilidade de 42,92 %. Observou-se uma concentração de 81,48 % do valor total deste fator no semestre de outubro a março, indicando que, potencialmente, as maiores perdas anuais de solo por erosão são esperadas neste período. Os valores anuais do índice EI30, esperados para os períodos de retorno de 2, 5, 10, 20, 50 e 100 anos, foram de 7.216, 8.675, 9.641, 10.568, 11.768 e 12.667 MJ mm ha-1 h-1 ano-1, respectivamente. Com relação às quantidades máximas de chuva diária, para os mesmos períodos de retorno, os valores foram de 73, 98, 115, 131, 151 e 167 mm, respectivamente.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The reptile fauna in the municipality of São Paulo is well sampled due to intensive collection in the last 100 years. In the present work we provide a checklist of reptile species in São Paulo municipality based on preserved specimens in scientific collections. The reptile fauna was also characterized by three ecological parameters: habitat use, substrate use, and diet. We recorded a total of 97 reptile species (two turtles, one crocodilian, 19 lizards, seven amphisbaenians, and 68 snakes). Approximately 70% of the lizards and 40% of the snakes are typical of forest habitats of the Serra do Mar mountain range. Other squamates are typical of open formations that occur mainly on inland Cerrado habitats. All turtles and the crocodilian are associated to riparian habitats. Approximately 63% of the lizards are predominantly terrestrial, and the remaining species are arboreal. Most species of snakes are terrestrial (38%) or subterranean/criptozoic (25%) whereas a smaller proportion are arboreal (18%) or aquatic (9%). Lizards feed upon arthropods. Almost 50% of the snake species are specialized or feed mainly upon anuran amphibians. Other important items consumed by snakes are mammals (24%), lizards (18%), subterranean vertebrates (10%), and invertebrates (earthworms, mollusks and arthropods; 15%). A total of 51 reptile species have not been recorded for the last six years. Probably many of these species are extinct in the region due the intense local urbanization and habitat loss. The survey of species collected in São Paulo municipality and received in the Instituto Butantan in recent years allowed the identification of 10 lizards at least 42 snake species already occurring in the region. The high species richness of the original fauna seems related to the geographic location of the municipality, in a contact zone between forested areas of the Atlantic Forest (ombrophilous forest) and open formations (savannas, high-altitude grassland). Thus, the original habitat composition probably allowed sympatry among different species pools typical of both open and forested formations. The extant snake fauna recorded in the last three years indicates a higher loss of the species in open formations when compared to the forested areas.

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Local extinctions have cascading effects on ecosystem functions, yet little is known about the potential for the rapid evolutionary change of species in human-modified scenarios. We show that the functional extinction of large-gape seed dispersers in the Brazilian Atlantic forest is associated with the consistent reduction of the seed size of a keystone palm species. Among 22 palm populations, areas deprived of large avian frugivores for several decades present smaller seeds than nondefaunated forests, with negative consequences for palm regeneration. Coalescence and phenotypic selection models indicate that seed size reduction most likely occurred within the past 100 years, associated with human-driven fragmentation. The fast-paced defaunation of large vertebrates is most likely causing unprecedented changes in the evolutionary trajectories and community composition of tropical forests.

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Although table tennis has a tradition lasting more than 100 years, relatively little is known about players' physiological requirements - especially during competition. In this review we discuss research studies that have led to our current understanding of how the body functions during table tennis training and competition and how this is altered by training. Match and practice analysis of the table tennis game indicates that during intense practice and competition it is predominantly the anaerobic alactic system that is called into play, while the endurance system is relied on to recovery the anaerobic stores used during such effort. It is thus important for coaches to keep in mind that, while the anaerobic alactic system is the most energetic system used during periods of exertion in a table tennis game, a strong capacity for endurance is what helps a player recover quicker for the following match and the next day of competition. This paper provides a review of specific studies that relate to competitive table tennis, and highlights the need for training and research programs tailored to table tennis. © Journal of Sports Science and Medicine.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Incluye Bibliografía

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Incluye Bibliografía

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Pós-graduação em Odontologia Preventiva e Social - FOA

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)