336 research outputs found

    Efeito do alumínio e de Glomus leptotichum Shenck e Smith no desenvolvimento de cultivares de Leucaena leucocephala (Lam.) de Wit tolerante e intolerante ao alumínio

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    A greenhouse experiment was carryed out to evaluate the mycorrhiza x toxic Al interaction in the substrate using a factorial design 2x2x2. Two cultivars of Leucaena leucocephala; a Al-tolerant (plant 49 - Estrada do Bongue) and another Al-intolerant (NO 749), were grown in washed sand and sterilized with addition of nutrient solution. The mycorrhiza was established with the inoculation of Glomus leptotichum Shenck e Smith and a control plot without VA fungi. It were evaluated two Al levels, 0 and 9 ppm, added to nutrient solution. The plants were harvested at 65 days after seedlings transplantation and shoot height, shoot dry matter weight, root colonization and shoot concentration of N, P, K,Ca, Mg and Al were determined. The following results can be formulated from the experiment herein analyzed: a), there was a plant growth increased and uptake of nutrient promoted by Glomus leptotichum, b) the Al-intolerant cultivar showed greater mycorrhizal dependence and were more benefit, presenting greater shoot dry matter weight and shoot nutrients acumulation. In these experimental conditions there was not significant difference between the Al levels used and also there was not interference in the cultivars growth.Com o objetivo de avaliar a interação micorrízica X Al tóxico no substrato efetuou-se um experimento fatorial 2x2x2, em casa de vegetação, no Departamento de Genética da ESALQ/USP, em Piracicaba. Foram empregadas duas cultivares de Leucaena leucocephala, uma Al - tolerante (Planta 49 - Estrada do Bongue) e outra Al-intolerante (NO749), cultivadas em areia lavada e esterilizada, com adição de solução nutritiva. A micorriza foi estabelecida com a inoculação de Glomus teptotichum Shenck e Smith no substrato, mantendo-se como testemunha a ausência do fungo. Dois níveis de Al foram avaliados, 0 e 9 ppm, adicionados à solução nutritiva. Aos 65 dias após o transplante das plântulas procedeu-se à colheita e foram determinados o peso da metária seca da parte aérea, altura de planta, porcentagem de colonização radicular, teor e quantidade acumulada de N, P, K, Ca, Mg e Al na parte aérea. Observou-se um acentuado efeito promotor da micorriza em Leucaena, o que geroulhe incrementos tanto no desenvolvimento da planta como na absorção de nutrientes. A cultivar intolerante ao Al tóxico mostrou-se mais dependente da micorriza e inclusive mais beneficiada,apresentando os maiores acréscimos na produção de matéria seca e acúmulo de nutrientes na parte aérea. Nas condições do experimento não houve acentuada diferença entre as doses de Al empregadas e, apesar do maior acúmulo do elemento em plantas micorrizadas, não foi observado interferência no desenvolvimento das cultivares

    Bacterial community composition and diversity of two different forms of an organic residue of bioenergy crop

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    The use of residue of sugarcane ethanol industry named vinasse in fertirrigation is an established and widespread practice in Brazil. Both non-concentrated vinasse (NCV) and concentrated vinasse (CV) are used in fertirrigation, particularly to replace the potassium fertilizer. Although studies on the chemical and organic composition of vinasse and their impact on nitrous oxide emissions when applied in soil have been carried out, no studies have evaluated the microbial community composition and diversity in different forms of vinasse. We assessed the bacterial community composition of NCV and CV by non-culturable and culturable approaches. The non-culturable bacterial community was assessed by next generation sequencing of the 16S rRNA gene and culturable community by isolation of bacterial strains and molecular and biochemical characterization. Additionally, we assessed in the bacterial strains the presence of genes of nitrogen cycle nitrification and denitrification pathways. The microbial community based on 16S rRNA sequences of NCV was overrepresented by Bacilli and Negativicutes while CV was mainly represented by Bacilli class. The isolated strains from the two types of vinasse belong to class Bacilli, similar to Lysinibacillus, encode for nirK gene related to denitrification pathway. This study highlights the bacterial microbial composition particularly in CV what residue is currently recycled and recommended as a sustainable practice in sugarcane cultivation in the tropics

    Antihydrogen formation dynamics in a multipolar neutral anti-atom trap

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    Antihydrogen production in a neutral atom trap formed by an octupole-based magnetic field minimum is demonstrated using field-ionization of weakly bound anti-atoms. Using our unique annihilation imaging detector, we correlate antihydrogen detection by imaging and by field-ionization for the first time. We further establish how field-ionization causes radial redistribution of the antiprotons during antihydrogen formation and use this effect for the first simultaneous measurements of strongly and weakly bound antihydrogen atoms. Distinguishing between these provides critical information needed in the process of optimizing for trappable antihydrogen. These observations are of crucial importance to the ultimate goal of performing CPT tests involving antihydrogen, which likely depends upon trapping the anti-atom

    Effect of Burkholderia tropica and Herbaspirillum frisingense strains on sorghum growth is plant genotype dependent

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    Sorghum is a multipurpose crop that is cultivated worldwide. Plant growth-promoting bacteria (PGPB) have important roles in enhancing sorghum biomass and nutrient uptake and suppressing plant pathogens. The aim of this research was to test the effects of the endophytic bacterial species Kosakonia radicincitans strain IAC/BECa 99, Enterobacter asburiae strain IAC/BECa 128, Pseudomonas fluorescens strain IAC/BECa 141, Burkholderia tropica strain IAC/BECa 135 and Herbaspirillum frisingense strain IAC/BECa 152 on the growth and root architecture of four sorghum cultivars (SRN-39, Shanqui-Red, BRS330, BRS509), with different uses and strigolactone profiles. We hypothesized that the different bacterial species would trigger different growth plant responses in different sorghum cultivars. Burkholderia tropica and H. frisingense significantly increased the plant biomass of cultivars SRN-39 and BRS330. Moreover, cultivar BRS330 inoculated with either strain displayed isolates significant decrease in average root diameter. This study shows that Burkholderia tropica strain IAC/BECa 135 and H. frisingense strain IAC/BECa 152 are promising PGPB strains for use as inocula for sustainable sorghum cultivation

    Search For Trapped Antihydrogen

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    We present the results of an experiment to search for trapped antihydrogen atoms with the ALPHA antihydrogen trap at the CERN Antiproton Decelerator. Sensitive diagnostics of the temperatures, sizes, and densities of the trapped antiproton and positron plasmas have been developed, which in turn permitted development of techniques to precisely and reproducibly control the initial experimental parameters. The use of a position-sensitive annihilation vertex detector, together with the capability of controllably quenching the superconducting magnetic minimum trap, enabled us to carry out a high-sensitivity and low-background search for trapped synthesised antihydrogen atoms. We aim to identify the annihilations of antihydrogen atoms held for at least 130 ms in the trap before being released over ~30 ms. After a three-week experimental run in 2009 involving mixing of 10^7 antiprotons with 1.3 10^9 positrons to produce 6 10^5 antihydrogen atoms, we have identified six antiproton annihilation events that are consistent with the release of trapped antihydrogen. The cosmic ray background, estimated to contribute 0.14 counts, is incompatible with this observation at a significance of 5.6 sigma. Extensive simulations predict that an alternative source of annihilations, the escape of mirror-trapped antiprotons, is highly unlikely, though this possibility has not yet been ruled out experimentally.Comment: 12 pages, 7 figure

    An Integrated TCGA Pan-Cancer Clinical Data Resource to Drive High-Quality Survival Outcome Analytics

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    For a decade, The Cancer Genome Atlas (TCGA) program collected clinicopathologic annotation data along with multi-platform molecular profiles of more than 11,000 human tumors across 33 different cancer types. TCGA clinical data contain key features representing the democratized nature of the data collection process. To ensure proper use of this large clinical dataset associated with genomic features, we developed a standardized dataset named the TCGA Pan-Cancer Clinical Data Resource (TCGA-CDR), which includes four major clinical outcome endpoints. In addition to detailing major challenges and statistical limitations encountered during the effort of integrating the acquired clinical data, we present a summary that includes endpoint usage recommendations for each cancer type. These TCGA-CDR findings appear to be consistent with cancer genomics studies independent of the TCGA effort and provide opportunities for investigating cancer biology using clinical correlates at an unprecedented scale. Analysis of clinicopathologic annotations for over 11,000 cancer patients in the TCGA program leads to the generation of TCGA Clinical Data Resource, which provides recommendations of clinical outcome endpoint usage for 33 cancer types
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