5,862 research outputs found

    Bulbos úmidos a partir da irrigação por gotejamento subsuperficial com ågua de abastecimento e efluente de esgoto tratado

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    The use of treated sewage effluent (TSE) combined with the subsurface drip irrigation (SDI) method in agriculture can decrease the costs of agricultural production, in attempts to fertigate crops more efficiently. In this study it was compared the dimensions of the wet bulb formed by the application of TSE and municipal water supply (MWS) in an Oxisoil. We have evaluated the effect of water quality and discharge between drippers used in sugarcane crop. Three trenches were opened and 21 three-rod TDR probes were setup in a mesh and a dripper was buried at 0.30 m, for each constant discharge of 1.0 L h-1and 1.6 L h-1. Comparing results from different wetted soil profiles it was observed that the vertical and horizontal dimensions of the wet bulb are similar for both MWS and TSE, being peculiars according to the discharges used and volume applied. Regardless the water quality, an increase of 60% in discharge decreased the deepest infiltration.352242253O uso de efluente de esgoto tratado (EET), combinado com o mÊtodo de irrigação por gotejamento subsuperfical (IGS) na agricultura, pode reduzir os custos de produção agrícola, fertirrigando de maneira eficiente as culturas. Neste artigo, compararam-se as dimensþes do bulbo úmido formado pela aplicação de EET e ågua de abastecimento municipal (AAM), em um Latossolo Vermelho distrofÊrrico. Avaliou-se o efeito da qualidade da ågua e da vazão entre gotejadores utilizados na cultura da cana-de-açúcar. Três trincheiras foram abertas e 21 sondas de TDR com três hastes foram instaladas em malha, e um gotejador foi enterrado a 0,30 m, para cada vazão constante de 1,0 Lh-1 e 1,6 Lh-1. Comparando os resultados de diferentes perfis de umidade do solo, sugere-se que as dimensþes vertical e horizontal do bulbo úmido sejam similares para a AAM e para o EET, sendo peculiares de acordo com as vazþes utilizadas e o volume aplicado. Independentemente da qualidade da ågua, o aumento de 60% na vazão reduziu a infiltração em profundidade

    Generation and validation of genetic markers for the selection of carioca dry bean genotypes with the slow-darkening seed coat trait

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    Slow darkening (SD) is a trait that helps to maintain a brighter seed coat appearance in certain market classes of dry beans. The aim of this study was to generate new fluorescence-based markers and validate previously identified microsatellite markers for linkage to the SD trait in lines of the carioca market class. Four segregating populations were generated by Embrapa, the Brazilian Agricultural Research Corporation, from crosses between the SD cultivar BRSMG Madrepe´rola and the regular-darkening cultivars BRS Estilo, BRS Cometa, BRS Nota´vel and BRS Sublime. These populations were screened with the simple-sequence markers Pvsd- 1158 and PVM02TC116 and with a TaqManTM marker designed for the single-nucleotide polymorphism (SNP) PvbHLHp12804. A KASP marker was also designed for the PvbHLHp12804 marker for testing on advanced carioca lines developed by the University of Saskatchewan. In the carioca lines developed by Embrapa, PVM02TC116 proved unsuitable for marker-assisted selection (MAS). Both the Pvsd-1158 and PvbHLHp12804 markers were found to be tightly linked to the gene responsible for the SD trait, with genetic distances calculated at 2.8 cM for Pvsd-1158 and 2.0 and 3.1 cM for PvbbHLHp12804, respectively. These markers presented more than 97% of selection efficiency. The genotypic scoring using the PvbHLHp12804 KASP marker was perfectly correlated with the phenotype in all lines of the University of Saskatchewan. The results of this study validates the use of Pvsd-1158 as a gel-based marker for SD in carioca beans. The new fluorescence-based SNP PvbHLHp12804 markers exhibited very tight linkage to SD in carioca and pinto bean lines. These markers will be ideal for MAS for the SD trait in these market classes

    Potential application for antimicrobial and antileukemic therapy of a flavonoid-rich fraction of Camellia sinensis

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    The antimicrobial and antileukemic effect of a purified fraction of flavonoids from the leaves of Camellia sinensis was evaluated. An extraction yield of 9.77 mg.g-1 total flavonoids was recovered through a pressurized liquid extraction associated with solid-phase extraction. This fraction was tested against pathogenic microorganisms (Staphylococcus, Salmonella, and Enterococcus), considering the minimum inhibitory concentration. In addition, the human monocyte cell line THP-1, derived from a patient with acute monocytic leukemia, was used for the antitumor assay. The results show that the flavonoid-rich fraction obtained by coupling a Pressurized Liquids Extraction in-line with a Solid Phase Extraction (PLE-SPE) has a high antimicrobial effect and resulted in cell cycle blockage G0 / G1, increased DNA fragmentation, and altered leukemic cell morphology. These results suggest that a flavonoid-rich fraction obtained from Camellia sinensis can be applied as potential adjuvants in chemotherapy treatment to mitigate the side effects caused by chemotherapy or even as a supplement to cancer therapy9 pĂĄgina

    Mitigation of nitrous oxide emissions in grazing systems through nitrification inhibitors: a meta-analysis

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    Grasslands are the largest contributor of nitrous oxide (N2O) emissions in the agriculture sector due to livestock excreta and nitrogen fertilizers applied to the soil. Nitrification inhibitors (NIs) added to N input have reduced N2O emissions, but can show a range of efficiencies depending on climate, soil, and management conditions. A meta-analysis study was conducted to investigate the factors that influence the efficiency of NIs added to fertilizer and excreta in reducing N2O emissions, focused on grazing systems. Data from peer-reviewed studies comprising 2164 N2O emission factors (EFs) of N inputs with and without NIs addition were compared. The N2O EFs varied according to N source (0.0001-8.25%). Overall, NIs reduced the N2O EF from N addition by 56.6% (51.1-61.5%), with no difference between NI types (Dicyandiamide-DCD; 3,4-Dimethylpyrazole phosphate-DMPP; and Nitrapyrin) or N source (urine, dung, slurry, and fertilizer). The NIs were more efficient in situations of high N2O emissions compared with low; the reduction was 66.0% when EF > 1.5% of N applied compared with 51.9% when EF 10 kg ha(-1). NIs were less efficient in urine with lower N content (<= 7 g kg(-1)). NI efficiency was negatively correlated with soil bulk density, and positively correlated with soil moisture and temperature. Better understanding and management of NIs can optimize N2O mitigation in grazing systems, e.g., by mapping N2O risk and applying NI at variable rate, contributing to improved livestock sustainability

    Structural and functional papez circuit integrity in amyotrophic lateral sclerosis

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    Cognitive impairment in amyotrophic lateral sclerosis (ALS) is heterogeneous but now recognized as a feature in non-demented patients and no longer exclusively attributed to executive dysfunction. However, despite common reports of temporal lobe changes and memory deficits in ALS, episodic memory has been less explored. In the current study, we examined how the Papez circuit—a circuit known to participate in memory processes—is structurally and functionally affected in ALS patients (n = 20) compared with healthy controls (n = 15), and whether these changes correlated with a commonly used clinical measure of episodic memory. Our multimodal MRI approach (cortical volume, voxel-based morphometry, diffusion tensor imaging and resting state functional magnetic resonance) showed reduced gray matter in left hippocampus, left entorhinal cortex and right posterior cingulate as well as increased white matter fractional anisotropy and decreased mean diffusivity in the left cingulum bundle (hippocampal part) of ALS patients compared with controls. Interestingly, thalamus, mammillary bodies and fornix were preserved. Finally, we report a decreased functional connectivity in ALS patients in bilateral hippocampus, bilateral anterior and posterior parahippocampal gyrus and posterior cingulate. The results revealed that ALS patients showed statistically significant structural changes, but more important, widespread prominent functional connectivity abnormalities across the regions comprising the Papez circuit. The decreased functional connectivity found in the Papez network may suggest these changes could be used to assess risk or assist early detection or development of memory symptoms in ALS patients even before structural changes are established

    Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

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    A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE

    Search for New Physics with Jets and Missing Transverse Momentum in pp collisions at sqrt(s) = 7 TeV

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    A search for new physics is presented based on an event signature of at least three jets accompanied by large missing transverse momentum, using a data sample corresponding to an integrated luminosity of 36 inverse picobarns collected in proton--proton collisions at sqrt(s)=7 TeV with the CMS detector at the LHC. No excess of events is observed above the expected standard model backgrounds, which are all estimated from the data. Exclusion limits are presented for the constrained minimal supersymmetric extension of the standard model. Cross section limits are also presented using simplified models with new particles decaying to an undetected particle and one or two jets

    Combined search for the quarks of a sequential fourth generation

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    Results are presented from a search for a fourth generation of quarks produced singly or in pairs in a data set corresponding to an integrated luminosity of 5 inverse femtobarns recorded by the CMS experiment at the LHC in 2011. A novel strategy has been developed for a combined search for quarks of the up and down type in decay channels with at least one isolated muon or electron. Limits on the mass of the fourth-generation quarks and the relevant Cabibbo-Kobayashi-Maskawa matrix elements are derived in the context of a simple extension of the standard model with a sequential fourth generation of fermions. The existence of mass-degenerate fourth-generation quarks with masses below 685 GeV is excluded at 95% confidence level for minimal off-diagonal mixing between the third- and the fourth-generation quarks. With a mass difference of 25 GeV between the quark masses, the obtained limit on the masses of the fourth-generation quarks shifts by about +/- 20 GeV. These results significantly reduce the allowed parameter space for a fourth generation of fermions.Comment: Replaced with published version. Added journal reference and DO
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