4,789 research outputs found

    Diversity of plant growth-promoting bacteria associated with sugarcane

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    The sugarcane (Saccharum spp) presents economic importance, mainly for tropical regions, being an important Brazilian commodity. However, this crop is strongly dependent on fertilizers, mainly nitrogen (N). This study assessed the plant growth-promoting bacteria (PGPB) associated with sugarcane that could be used as a potential inoculant to the crop. We evaluated the genetic diversity of PGPB in the plant tissue of sugarcane varieties (RB 867515, RB 1011, and RB 92579). The primer BOX-A1R was used to differentiate the similar isolated and further sequencing 16S rRNA ribosomal gene. The 16S rRNA gene showed the presence of seven different genera distributed into four groups, the genus Bacillus, followed by Paenibacillus (20%), Burkholderia (14%), Herbaspirillum (6%), Pseudomonas (6%), Methylobacterium (6%), and Brevibacillus (3%). The molecular characterization of endophytic isolates from sugarcane revealed a diversity of bacteria colonizing this plant, with a possible biotechnological potential to be used as inoculant and biofertilizers

    Produtividade e composição bromatológica de milho em sistema de plantio direto submetido a fontes de nitrogênio.

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    O nitrogênio é o nutriente mais absorvido e com maior influencia na produtividade de grãos para cultura do milho. O experimento foi realizado na FZEA/USP em Pirassununga-SP, com o cultivo de milho em sistema de plantio direto. O delineamento experimental foi em blocos completos casualizados com quatro repetições e dez tratamentos: testemunha + gesso, testemunha absoluta, uréia, uréia + gesso, uréia + sulfato de amônio (SAM), nitrato de amônio (NA), NA + gesso, NA + SAM, SAM e Fusion Amonium Sulfate Nitrate (FASN) com objetivo de avaliar a utilização do FASN determinando os parâmetros produtivos e bromatológicos. Os maiores rendimentos foram obtidos pelos tratamentos com NA, SAM, FASN e as combinações, uréia + gesso, uréia + SAM, que adicionados à combinação NA + SAM, obtiveram as maiores eficiências de uso do N, enquanto que, os dois tratamentos sem aplicação de N foram inferiores aos demais tratamentos. Para os parâmetros bromatológicos não houve diferença entre os tratamentos, assim, concluiu-se que o FASN pode ser utilizado para o cultivo de milho em sistema de plantio direto com eficiência e produtividade semelhante a fertilizantes nitrogenados tradicionais sem alteração dos parâmetros bromatológicos

    Thermostability of cardosin A from Cynara cardunculus L.

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    The structural stability of cardosin A, a plant aspartic proteinase (AP) from Cynara cardunculus L., has been investigated by high-sensitivity differential scanning calorimetry, intrinsic fluorescence and circular dichroism spectroscopy, and enzymatic activity assays. Even though the thermal denaturation of cardosin A is partially irreversible, valid thermodynamic data can be obtained within a wide pH region. Also, although cardosin A is a heterodimeric enzyme its thermal denaturation occurs without simultaneous dissociation to unfolded monomers. Moreover, in the 3-7 pH region the excess heat capacity can be deconvoluted into two components corresponding to two elementary two-state transitions, suggesting that the two polypeptide chains of cardosin A unfold independently. Detailed thermodynamic and structural investigations of cardosin A at pH=5.0, at which value the enzyme demonstrates maximum stability and enzymatic activity, revealed that after thermal denaturation the polypeptide chains of this protein retain most of their secondary structure motifs and are not completely hydrated.http://www.sciencedirect.com/science/article/B6THV-47P1SF6-4/1/edc14f851e47459fcd87b748d068439

    Topological speckles

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    The time evolution of a topological Su-Schrieffer-Heeger chain is analyzed through the statistics of speckle patterns. The emergence of topological edge states dramatically affects the dynamical fluctuations of the wavefunction. The intensity statistics is found to be described by a family of noncentral chi-squared distributions, with the noncentrality parameter reflecting on the degree of edge-state localization. The response of the speckle contrast with respect to the dimerization of the chain is explored in detail as well as the role of chiral symmetry-breaking disorder, number of edge states, their energy gap, and the locations between which the transport occurs. In addition to providing a venue for speckle customization, our results appeal to the use of speckle patterns for characterization of nontrivial topological properties.Comment: 6 pages, 4 figure

    Model for determining flow diameter and economic velocity in water elevating systems

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    The purpose of this paper was to develop a model for calculating the economical flow diameter and velocity, by obtaining the economical diameter, using Swamee's friction factor equation, by minimizing the total annual cost. The application of the model to a regular supply condition showed that the diameter of the actual condition, 250 mm, compared with the diameter calculated by the mode, at the same tariff as that applied to the property (ground), 284.1 mm, involved the necessity to generate, transmit, and distribute extra electrical energy, due to the higher load loss caused by the original diameter, approximately 30800 kWh/year. This means that in one year, the consumer would spend R$2,804.00 more on pumping cost alone

    Chaos in Anisotropic Pre-Inflationary Universes

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    We study the dynamics of anisotropic Bianchi type-IX models with matter and cosmological constant. The models can be thought as describing the role of anisotropy in the early stages of inflation. The concurrence of the cosmological constant and anisotropy are sufficient to produce a chaotic dynamics in the gravitational degrees of freedom, connected to the presence of a critical point of saddle-center type in the phase space of the system. The invariant character of chaos is guaranteed by the topology of the cylinders emanating from unstable periodic orbits in the neighborhood of the saddle-center. We discuss a possible mechanism for amplification of specific wavelengths of inhomogeneous fluctuations in the models. A geometrical interpretation is given for Wald's inequality in terms of invariant tori and their destruction by increasing values of the cosmological constant.Comment: 14 pages, figures available under request. submitted to Physical Review

    Multicentric Genome-Wide Association Study for Primary Spontaneous Pneumothorax

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    Despite elevated incidence and recurrence rates for Primary Spontaneous Pneumothorax (PSP), little is known about its etiology, and the genetics of idiopathic PSP remains unexplored. To identify genetic variants contributing to sporadic PSP risk, we conducted the first PSP genome-wide association study. Two replicate pools of 92 Portuguese PSP cases and of 129 age- and sex-matched controls were allelotyped in triplicate on the Affymetrix Human SNP Array 6.0 arrays. Markers passing quality control were ranked by relative allele score difference between cases and controls (|RASdiff|), by a novel cluster method and by a combined Z-test. 101 single nucleotide polymorphisms (SNPs) were selected using these three approaches for technical validation by individual genotyping in the discovery dataset. 87 out of 94 successfully tested SNPs were nominally associated in the discovery dataset. Replication of the 87 technically validated SNPs was then carried out in an independent replication dataset of 100 Portuguese cases and 425 controls. The intergenic rs4733649 SNP in chromosome 8 (between LINC00824 and LINC00977) was associated with PSP in the discovery (P = 4.07E-03, ORC[95% CI] = 1.88[1.22-2.89]), replication (P = 1.50E-02, ORC[95% CI] = 1.50[1.08-2.09]) and combined datasets (P = 8.61E-05, ORC[95% CI] = 1.65[1.29-2.13]). This study identified for the first time one genetic risk factor for sporadic PSP, but future studies are warranted to further confirm this finding in other populations and uncover its functional role in PSP pathogenesis
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