1,495 research outputs found

    Rendimento do óleo essencial de Ocimum selloi benth. submetido a diferentes adubos orgânicos em associação ou não à adubação verde.

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    Este trabalho teve por objetivo verificar o efeito de diferentes adubos orgânicos em associação ou não com adubo verde no rendimento de óleo essencial de folhas de Ocimum selloi Benth., planta nativa do Brasil. O experimento foi conduzido na área experimental da Embrapa Meio Ambiente (CNPMA), localizado no município de Jaguariúna, em duas áreas distintas, sendo uma delas submetidas anteriormente ao plantio e incorporação de adubo verde (Crotalaria juncea). Os tratamentos utilizados foram: T1 - testemunha (solo sem adubação), T2 - cama de aviário (5 kg/m2), T3 - hidrolisado de peixe (produto comercial Fishfértil - 5 mL/m2) e T4 - composto orgânico (4 kg/m2). A colheita foi realizada 180 dias após o plantio, em Janeiro de 2011, sendo colhidas as plantas úteis (quatro plantas por parcela). Os óleos essenciais das folhas foram extraídos por hidrodestilação em aparelho tipo Clevenger modificado. Avaliou-se o rendimento de óleo essencial sobre o rendimento de fitomassa seca. O elineamento experimental adotado foi o esquema fatorial 2x4, com quatro repetições (DBC). As médias obtidas foram submetidas à análise de variância seguida de teste de médias (Tukey). Não foram observadas diferenças significativas no rendimento do óleo essencial de folhas de O. selloi submetidas ou não à adubação verde, em associação aos diferentes tipos de adubo orgânico quando os mesmos foram comparados à testemunha. Com base nos resultados obtidos, pode-se concluir que, nas condições ensaiadas, as adubações verde e orgânica não influenciaram no rendimento do óleo essencial de Ocimum selloi

    Transcriptome Analysis in Spleen Reveals Differential Regulation of Response to Newcastle Disease Virus in Two Chicken Lines.

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    Enhancing genetic resistance of chickens to Newcastle Disease Virus (NDV) provides a promising way to improve poultry health, and to alleviate poverty and food insecurity in developing countries. In this study, two inbred chicken lines with different responses to NDV, Fayoumi and Leghorn, were challenged with LaSota NDV strain at 21 days of age. Through transcriptome analysis, gene expression in spleen at 2 and 6 days post-inoculation was compared between NDV-infected and control groups, as well as between chicken lines. At a false discovery rate <0.05, Fayoumi chickens, which are relatively more resistant to NDV, showed fewer differentially expressed genes (DEGs) than Leghorn chickens. Several interferon-stimulated genes were identified as important DEGs regulating immune response to NDV in chicken. Pathways predicted by IPA analysis, such as "EIF-signaling", "actin cytoskeleton organization nitric oxide production" and "coagulation system" may contribute to resistance to NDV in Fayoumi chickens. The identified DEGs and predicted pathways may contribute to differential responses to NDV between the two chicken lines and provide potential targets for breeding chickens that are more resistant to NDV

    Absolute and convective instabilities of parallel propagating circularly polarized Alfvén waves: numerical results

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    Context.The stability of parallel propagating circularly polarized Alfvén waves (pump waves) has been studied for more than four decades with the use of normal mode analysis. It is well known that the normal mode analysis does not answer the question if a pump wave looks stable or unstable in a particular reference frame. To answer this question it is necessary to find out if the instability is absolute or convective in this reference frame. Aims.We extend our previous study of absolute and convective instabilities of pump waves with small amplitude to pump waves with arbitrary amplitude. Methods.To study the absolute and convective instabilities of pump waves with arbitrary amplitude we numerically implement Brigg's method. Results.We show that the wave is absolutely unstable in a reference frame moving with the velocity U with respect to the rest plasma if U satisfies the inequality Ul Ur) we study the signalling problem. We show that spatially amplifying waves exist only when the signalling frequency is in two symmetric frequency bands, and calculate the dependences of the boundaries of these bands on U for different values of a . We also obtain the dependences of the maximum spatial amplification rate on U for different values of a . The implication of these results on the interpretation of observational data from space missions is discussed. In particular, it is shown that circularly polarized Alfvén waves propagating in the solar wind are convectively unstable in a reference frame of any realistic spacecraft

    Soil classification from visible/near-infrared diffuse reflectance spectra at multiple depths.

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    Abstract : Visible/near-infrared diffuse reflectance spectroscopy (VNIRS) offers an alternative to conventional analytical methods to estimate various soil attributes. However, the use of VNIRS in soil survey and taxonomic classification is still underexplored. We investigated the potential use of VNIRS to classify soils in a region with variable soils, geology, and topography in southeastern Brazil. We combined principal component (PC) analysis, and multinomial logistic regression to classify 291 soils at the levels of suborder (second highest), and suborder with textural classification (STC), described in the field according to the Brazilian Soil Classification System. Soil visible/near-infrared (400-2500 nm) spectra were collected from three depth intervals (0-20, 40-60, and 80-100 cm), and combined in sequence to compose a pseudo multi-depth spectral curve, which was used to derive the classification models. The percent of correctly classified soils at the suborder level was 79% using 20 PCs, and 96% using 30 PCs. At the STC level, soils were correctly classified in 100%, and 78% of the cases using 20, and 30 PCs, respectively. Given the inherent complexity and variability within soil taxonomic groups, and in contrast the similarity among different groups, combining spectral data from different depths in multivariate classification offered a simple and inexpensive solution to adequately distinguish soils. This novel approach could improve soil classification and survey in a cost-efficient manner, supporting sustainable use, and management of tropical soils

    Physiological characterization of common bean (Phaseolus vulgaris L.) genotypes, water-stress induced with contrasting response towards drought.

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    Among the three annual common bean seasons in Brazil, two of them are subject to drought. The objective of this study was to identify physiological traits in common bean under water restriction. The common beans genotypes, BAT 477 (tolerant to water-stress) and Perola (sensitive to water-stress), were grown under greenhouse conditions under two different watering regimes: irrigated (control treatment) and non-irrigated (stress treatment). The water deficit treatment consisted of suspension of irrigation to the plants at 10 days after emergence (DAE) (at the V2 physiological stage) for 30 days, followed by the irrigation?s re-establishment at 40 DAE (at the R6-R7 physiological stage) up to the phase of physiological maturity of the grains for assessment of grain yield and production components. Under water-stress, BAT 477 showed less reduction in grain yield (33%), more capacity for osmotic adjustment (0.30 MPa) and superiority in the root system´s development (~50%) compared to Perola that showed a 53% reduction in the grain yield and 0.06 MPa of osmotic adjustment. In this study, the robustness of the root system and osmotic adjustment are the main physiological indicators of tolerance to water deficit in common bean plants

    Enhancing digital soil mapping in southeastern Brazil: incorporating stream density and soil reflectance from multiple depths.

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    This study proposes a novel and simple method to incorporate laboratory soil spectral data in the production of digital soil maps

    The filamentous fungi culture collection of the Department of Food Science (CCDCA), Federal University of Lavras, Brazil

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    Brazil has one of the highest levels of biological diversity due to its large geographical area, high coverage by rainforests, and endemic biomes, such as the Brazilian Atlantic Forest, Cerrado and Caatinga. Of the estimated 1.5 million species of fungi only 5% are known. Much of this unknown biodiversity is in the tropics, which is seriously threatened by some agricultural activities, reinforcing the urgent need for biodiversity studies in these areas. The maintenance and preservation of fungal cultures are important elements for such a requirment. The establishment of a culture collection of filamentous fungi in the Mycotoxins and Mycology Laboratory, Department of Food Science (CCDCA), Federal University of Lavras (UFLA) commenced from the bases of species maintenance, taxonomy, biotechnology and toxigenicity. The laboratory was established in 2007 to preserve potentially mycotoxigenic fungi, especially ochratoxin A and aflatoxins producers, which were isolated from food. Currently the CCDCA has more than 1000 isolates of Aspergillus, Penicillium, Cladosporium, Fusarium, Alternaria, Chaetomium, Mucor, Eurotium, and Neosartorya. A total of 66 species are represented which were isolated from food, cave environments, and soils of the Brazilian Atlantic Forest, Cerrado and Caatinga. A total of 328 cultures are preserved and maintained by periodic subculture, 137 by mineral oil preservation, and 550 by filter paper preservation. The staff trains graduate students in the taxonomy of major taxa of importance to agricultural research and food science. Finally, the CCDCA and UFLA, Brazil, in collaboration with the IBB-Biological Engineering Centre, Micoteca da Universidade do Minho, Portugal, intend to develop a project on polyphasic studies of Aspergillus and Penicillium isolated from various substrates, sources, and environments in Brazil. To pursue this aim CCDCA intends to: a) preserve Aspergillus and Penicillium strains for comparative studies between Brazilian regions and worldwide; b) foster the study of Aspergillus and Penicillium for biotechnological and toxigenic potential, and training in identification, preservation and distribution; c) establish quality control of fungal assays; and d) establish the CCDCA as a member of the global network of culture collections and participate in the international forums and organisations related to culture collections
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