607 research outputs found

    Morphological dissimilarity among mangabeira tree populations from Amapá and Paraíba, Brazil.

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    Mangabeira fruits are collected from native populations under anthropic pressure. It is therefore essential to obtain morphogenetic information to genetically improve populations, thereby preventing genetic erosion. This research was carried out in the state Amapá and aimed to verify the morphological dissimilarity between two populations, one composed of 36 native progenies and one of eight progenies from Paraiba, outlined in lattices with two replications and six plants per part. The evaluated characteristics were: agronomic value (VA), treetop circumference (CCP), plant height (ALP), estimated number of fruits per plant (NEF), fruit color (COF), average weight of 10 fruits (PMF), fruit diameter (DF), average pulp weight of ten fruits (PMP), average length of 10 fruits (CMF), average number of seeds of 10 fruits (NMS). Our results indicate that the phenotype was mainly determined by responses to environmental changes; in the correlations, inherent fruit characteristics (weight, size, and color) did not affect the VA, while biometric characters influenced VA values. Higher plants presented larger fruits and a larger diameter, bigger quantities, there is also apparent contrast, with a larger amount of smaller size; the populations are dissimilar, indicating the possibility of obtaining of diverging superior segregating

    Repetibilidade de produção de grãos em soja nas condições do Amapá.

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    A soja é uma cultura agrícola extremamente importante para o Brasil, expandido sua ocupação em novas fronteiras de cerrado no Norte do País, incluindo o Amapá, que tem despertado interesse dos agricultores por sua localização estratégica. Por este motivo é fundamental que se verifique a presença de estabilidade produtiva nas condições deste Estado, através da análise de repetibilidade. Desta forma a Embrapa Amapá desenvolveu pesquisas com cultivares comerciais em sua área de cerrado entre os anos de 2008 a 2013, sendo avaliada a produtividade de grãos (PG, em kg/ha). Os experimentos foram instalados em blocos casualizados, representados por quatro linhas de 5 metros, quatro repetições, as principais conclusões obtidas foram há presença de maior contribuição residual e da interação GxE; a relação baixa de CVg/CVe, associado com valor médio de herdabilidade, indicam que serão necessários metodologias mais rigorosas e complexas para se realizar a seleção; há necessidade de melhorar o controle experimental (maior número de repetições, aumento de área útil e melhor controle de manejo); as metodologias CPCOV e CPCOR indicaram repetibilidade média e as demais baixa, que indica dificuldade de previsão do comportamento dos genótipos avaliados

    Structural characterization of Co‐Re superlattices

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    Co‐Re superlattices were prepared with nominal periodicities of 65–67 Å and varying bilayer composition. The structural characterization was made by x‐ray diffraction and Rutherford backscattering spectrometry (RBS). First, second, and third order satellites are observed in the x‐ray diffractogram at 2θ values and with intensities close to those predicted by simulation. This confirms the coherence of the superlattice. RBS measurements combined with RUMP simulations give information on interface sharpness and the absolute thicknesses of the Co and Re layers. Discrepancies between the experimental and simulated diffractograms are found for Co thicknesses below 18 Å

    Temporal dynamics of hot desert microbial communities reveal structural and functional responses to water input

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    8 páginas, 4 figuras. -- The first publication is available at https://www.nature.comThe temporal dynamics of desert soil microbial communities are poorly understood. Given the implications for ecosystem functioning under a global change scenario, a better understanding of desert microbial community stability is crucial. Here, we sampled soils in the central Namib Desert on sixteen different occasions over a one-year period. Using Illumina-based amplicon sequencing of the 16S rRNA gene, we found that α-diversity (richness) was more variable at a given sampling date (spatial variability) than over the course of one year (temporal variability). Community composition remained essentially unchanged across the first 10 months, indicating that spatial sampling might be more important than temporal sampling when assessing β-diversity patterns in desert soils. However, a major shift in microbial community composition was found following a single precipitation event. This shift in composition was associated with a rapid increase in CO2 respiration and productivity, supporting the view that desert soil microbial communities respond rapidly to re-wetting and that this response may be the result of both taxon-specific selection and changes in the availability or accessibility of organic substrates. Recovery to quasi pre-disturbance community composition was achieved within one month after rainfall.We gratefully acknowledge financial support from the National Research Foundation of South Africa (grant no.81779 and TTK2008052000003), the Research Council of Norway (grant No. 180352) and the University of the Western Cape. Partial support was also provided under the Laboratory Directed Research and Development Program at PNNL, a multiprogram national laboratory operated by Battelle for the U.S. Department of Energy under contract DE-AC05-76RL01830.Peer reviewe

    Integrated dual-color InGaN light-emitting diode array through transfer printing

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    We demonstrate an integrated dual-color InGaN light-emitting diode (LED) array by transfer printing blue LED structures from their silicon growth substrate in between the pixels of a pre-processed green LED array on a sapphire substrate

    One More Piece in the VACV Ecological Puzzle: Could Peridomestic Rodents Be the Link between Wildlife and Bovine Vaccinia Outbreaks in Brazil?

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    BACKGROUND: Despite the fact that smallpox eradication was declared by the World Health Organization (WHO) in 1980, other poxviruses have emerged and re-emerged, with significant public health and economic impacts. Vaccinia virus (VACV), a poxvirus used during the WHO smallpox vaccination campaign, has been involved in zoonotic infections in Brazilian rural areas (Bovine Vaccinia outbreaks - BV), affecting dairy cattle and milkers. Little is known about VACV's natural hosts and its epidemiological and ecological characteristics. Although VACV was isolated and/or serologically detected in Brazilian wild animals, the link between wildlife and farms has not yet been elucidated. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we describe for the first time, to our knowledge, the isolation of a VACV (Mariana virus - MARV) from a mouse during a BV outbreak. Genetic data, in association with biological assays, showed that this isolate was the same etiological agent causing exanthematic lesions observed in the cattle and human inhabitants of a particular BV-affected area. Phylogenetic analysis grouped MARV with other VACV isolated during BV outbreaks. CONCLUSION/SIGNIFICANCE: These data provide new biological and epidemiological information on VACV and lead to an interesting question: could peridomestic rodents be the link between wildlife and BV outbreaks
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