12,314 research outputs found

    Levantamento de vírus em lavouras de alho o Brasil.

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    O presente trabalho teve o objetivo de realizar a diagnose viral em amostras de alho provenientes de lavouras localizadas nos municípios de Planaltina - DF, Cristópolis - BA, Mirangaba - BA e Bueno Brandão - MG

    Levantamento da diversidade de vírus em batata-doce no Brasil.

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    O presente trabalho teve o objetivo de realizar um levantamento de vírus no Banco ativo de Germoplasma de batata-doce da Embrapa Hortaliaças

    Longevity of risks in software development projects: a comparative analysis with an academic environment

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    The study presented in this paper was developed in an academic environment. All subjects involved in this research are enrolled in the Information Systems Master’s Degree of the University of Minho. The main objective of this study is to demonstrate the need for the continuity of studies about the risks presented in software development projects. For this purpose, we analyzed more than four hundred risks and about one hundred problems faced and documented by the working groups. With the collected data we defined a list of twenty risks and conducted a comparative study of these risks with others already formalized in previous industrial studies. The comparison data was analyzed and interpreted, and important conclusions were made.info:eu-repo/semantics/publishedVersio

    Germinação de sementes de malícia e salsa em diferentes condições de temperatura e luz.

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    Resumo também publicado em: REUNIÃO ANUAL DA SOCIEDADE BRASILEIRA DE ZOOTECNIA, 37., 2000, Viçosa, MG. Resumos dos trabalhos apresentados. Viçosa, MG: Sociedade Brasileira de Zootecnia, 2000. p. 98

    Análise dos preços da manga do Vale do São Francisco nos mercados interno e externo: um estudo de séries temporais para o Brasil, Estados Unidos e União Européia (2003- 2013).

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    A teoria econômica baseada na lei da oferta e da demanda mostra que no período em que a oferta de um bem qualquer excede muito à sua procura, seu preço tende a cair. Já em períodos nos quais a demanda supera a oferta desse bem, a tendência é o aumento do seu preço. O objetivo desta pesquisa é analisar os preços de exportação da manga do Vale do São Francisco, com o Brasil, os Estados Unidos e a União Europeia no período entre 2003 a 2013, como também a causalidade dos mercados supracitados. A partir de séries temporais, a relação entre os preços baseou-se em estimações de um modelo vetorial autorregressivo e também o teste de causalidade de Granger, respectivamente. O teste de Granger verifica se o preço de um determinado mercado é capaz de causar Granger a previsão de outro mercado ? levando em consideração os mercados analisados no presente estudo. Os resultados mostram que as séries de preços são estacionárias e que os preços do mercado interno brasileiro sofrem influência dos Estados Unidos e da União Europeia, ou seja, é um mercado tomador de preços. Já o preço de exportação para os Estados Unidos, é influenciado pela União Europeia. Entretanto, a mesma, não sofre influência de nenhum dos mercados analisados, pois, segundo resultado do estudo, é formadora de preços

    New Insights From Pre-Columbian Land Use and Fire Management in Amazonian Dark Earth Forests

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    This is the final version of the article. Available from Frontiers Media via the DOI in this record.Anthropogenic climate change driven by increased carbon emissions is leading to more severe fire seasons and increasing the frequency of mega-fires in the Amazon. This has the potential to convert Amazon forests from net carbon sinks to net carbon sources. Although modern human influence over the Earth is substantial, debate remains over when humans began to dominate Earth's natural systems. To date, little is known about the history of human land use in key regions like the Amazon. Here, we examine the history of human occupation from a ~8,500 year-old sediment core record from Lake Caranã (LC) in the eastern Amazon. The onset of pre-Columbian activity at LC (~4,500 cal yr B.P.) is associated with the beginning of fire management and crop cultivation, later followed by the formation of Amazonian Dark Earth soils (ADEs) ~2,000 cal yr B.P. Selective forest enrichment of edible plants and low-severity fire activity altered the composition and structure of forests growing on ADEs (ADE forests) making them more drought susceptible and fire-prone. Following European colonization (1661 A.D.), the Amazon rubber boom (mid-1800s to 1920 A.D.) is associated with record-low fire activity despite drier regional climate, indicating fire exclusion. The formation of FLONA Reserve in 1974 A.D. is accompanied by the relocation of traditional populations and a fire suppression policy. Despite suppression efforts, biomass burning and fire severity in the past decade is higher than any other period in the record. This is attributed to combined climate and human factors which create optimal conditions for mega-fires in ADE forests and threatens to transform the Amazon from a net carbon sink to a net carbon source. To help mitigate the occurrence of mega-fires, a fire management policy reducing fire-use and careful fire management for farming may help to reduce fuel loads and the occurrence of mega-fires in fire-prone ADE forests. As both natural and anthropogenic pressures are projected to increase in the Amazon, this study provides valuable insights into the legacy of past human land use on modern ADE forest composition, structure, and flammability that can inform ecological benchmarks and future management efforts in the eastern Amazon.Funding for this research was supported by the PAST (Pre-Columbian Amazon-Scale Transformations) European Research Council Consolidator Grant to JI (ERC_Cog 616179). Research was conducted under permit 01506.004836/2014-69 from the Instituto do Patrimônio Histórico e Artístico Nacional (IPHAN) and ICMBio permit 106/14-FNT. We thank all residents of Maguarí and Jamaraquá community for their hospitality and help
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