4,723 research outputs found

    Efeito do cultivo de espécies vegetais sobre a população de Pratylenchus brachyurus na soja.

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    O presente trabalho, conduzido em casa de vegetação da Embrapa Soja, em Londrina, PR, no período de novembro/2011 a março/2012, teve como objetivos principais conhecer a reação de 23 espécies vegetais a Pratylenchus brachyurus e avaliar a influência da incorporação de suas fitomassas (parte aérea e raízes) no solo sobre as população do nematoide e performance da soja semeada, na sequência, nos vasos. Os fatores de reprodução (FR) de P. brachyurus obtidos nas diferentes espécies vegetais avaliadas variaram de zero (Crotalaria spectabilis, crambe, guandu ‘Fava Larga’ e tremoço branco) a 4,8 (Lab- Lab ‘Rongai’). As espécies vegetais com FR mais altos, independente da quantidade/composição da fitomassa incorporada, resultaram sempre em populações do nematoide mais elevadas nas raízes da soja (‘CD 202’). De todas as espécies vegetais testadas, apenas as C. specetabilis (FR=zero) e C. ochroleuca (FR=0,3) reduziram de fato a população original (1.000 nematoides) de P. brachyurus no vaso

    Insights into the association of potassium intake with blood pressure: results of a dose-response meta-analysis of randomized controlled trials

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    Introduction: Observational studies provide evidence for an association between potassium intake and BP levels. However, uncertainties still exist about the size and the shape of this relation. Conversely, experimental studies have not been used to estimate dose-response curves, since standard methods can only be applied in trials including at least three exposure groups. Materials and Methods: We carried out a systematic review of the evidence concerning the effect of potassium supplementation on blood pressure in epidemiologic experimental studies. Following a PubMed search up to June 20, 2019, we included randomized controlled trials (RCTs) encompassing potassium supplementation as the only intervention for at least four weeks. We used a restricted cubic spline model and the ‘one-stage’ approach to perform a dose-response meta-analysis, a newly-developed statistical procedure which allows inclusion of studies with as few as two categories of exposure (Stat Methods Med Res. 2019;28:1579-1596). Finally, we repeated the analyses stratifying for hypertensive status and use of anti-hypertensive medication. Results: Overall, we included 33 studies carried out in adult population, with potassium supplementation ranging from 30 to 140 mmol/day. RCTs’ duration ranged from 4 up to 26 weeks. Most of the studies have a cross-over design (N=24), include hypertensive individuals (N=27) and subjects not under anti-hypertensive medication (N=27). Overall, an increase of 40, 80 and 120 mmol/day of potassium resulted in reductions of SBP by -5.64 (95% CI - 8.78, -2.50), -4.62 (-6.41, -2.84) and -2.54 mmHg (95% CI -5.14, +0.06), respectively. Higher potassium intakes also resulted in reduced DBP levels by -3.57 (95% CI -5.55, -1.59), -3.07 (95% CI -5.07, -1.08), and -1.92 mmHg (95% CI -5.65, 1.81). The effect of increasing potassium intake on BP was larger among hypertensives than normotensives, and among pharmacologically untreated hypertensives compared to their treated counterparts. Subgroup analyses according to study design (parallel vs. crossover) yielded similar results. Discussion: With the application of advanced dose-response modeling on RCT results, we found a U-shaped relation between potassium intake and blood pressure. A low to moderate increase in potassium intake resulted in a progressive reduction in blood pressure, which was reversed at higher levels of potassium supplementation. The effect was stronger among untreated hypertensives. Supported by grant GP-EFSA-AFSCO-2017-01 GA09 of the European Food Safety Authority - EFSA. The text reflects only the authors' view; and EFSA is not responsible for any use that may be made of the information it contains. Conflict of Interest: There is no conflict of interes

    Using XDAQ in Application Scenarios of the CMS Experiment

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    XDAQ is a generic data acquisition software environment that emerged from a rich set of of use-cases encountered in the CMS experiment. They cover not the deployment for multiple sub-detectors and the operation of different processing and networking equipment as well as a distributed collaboration of users with different needs. The use of the software in various application scenarios demonstrated the viability of the approach. We discuss two applications, the tracker local DAQ system for front-end commissioning and the muon chamber validation system. The description is completed by a brief overview of XDAQ.Comment: Conference CHEP 2003 (Computing in High Energy and Nuclear Physics, La Jolla, CA

    The CMS Event Builder

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    The data acquisition system of the CMS experiment at the Large Hadron Collider will employ an event builder which will combine data from about 500 data sources into full events at an aggregate throughput of 100 GByte/s. Several architectures and switch technologies have been evaluated for the DAQ Technical Design Report by measurements with test benches and by simulation. This paper describes studies of an EVB test-bench based on 64 PCs acting as data sources and data consumers and employing both Gigabit Ethernet and Myrinet technologies as the interconnect. In the case of Ethernet, protocols based on Layer-2 frames and on TCP/IP are evaluated. Results from ongoing studies, including measurements on throughput and scaling are presented. The architecture of the baseline CMS event builder will be outlined. The event builder is organised into two stages with intelligent buffers in between. The first stage contains 64 switches performing a first level of data concentration by building super-fragments from fragments of 8 data sources. The second stage combines the 64 super-fragments into full events. This architecture allows installation of the second stage of the event builder in steps, with the overall throughput scaling linearly with the number of switches in the second stage. Possible implementations of the components of the event builder are discussed and the expected performance of the full event builder is outlined.Comment: Conference CHEP0

    Low energy high angular resolution neutral atom detection by means of micro-shuttering techniques: the BepiColombo SERENA/ELENA sensor

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    The neutral sensor ELENA (Emitted Low-Energy Neutral Atoms) for the ESA cornerstone BepiColombo mission to Mercury (in the SERENA instrument package) is a new kind of low energetic neutral atoms instrument, mostly devoted to sputtering emission from planetary surfaces, from E ~20 eV up to E~5 keV, within 1-D (2x76 deg). ELENA is a Time-of-Flight (TOF) system, based on oscillating shutter (operated at frequencies up to a 100 kHz) and mechanical gratings: the incoming neutral particles directly impinge upon the entrance with a definite timing (START) and arrive to a STOP detector after a flight path. After a brief dissertation on the achievable scientific objectives, this paper describes the instrument, with the new design techniques approached for the neutral particles identification and the nano-techniques used for designing and manufacturing the nano-structure shuttering core of the ELENA sensor. The expected count-rates, based on the Hermean environment features, are shortly presented and discussed. Such design technologies could be fruitfully exported to different applications for planetary exploration.Comment: 11 page
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