4,426 research outputs found

    Efeito da Azadiractina sobre Chaetosiphon fragaefolli (Cockerell, 1901) (Hemiptera: Aphididae) na cultura do morangueiro.

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    O pulgão-verde Chaetosiphon fragaefolli é o principal inseto-praga da cultura do morangueiro. Neste trabalho, foi avaliado o efeito da azadiractina para o controle do inseto em laboratório e casa de vegetação. Os tratamentos avaliados foram a azadiractina (Azamax®, 100; 200 e 300 ml.100L-1) comparado com o tiametoxam (Actara 250 WG®, 10 g.100L-1), lambda-cialotrina (Karate Zeon 50 CS®, 80 ml.100L-1) e uma testemunha (água). Os produtos foram pulverizados sobre plantas de morangueiro da cultivar Aromas infestadas artificialmente em casa de vegetação. A azadiractina foi equivalente a lambda-cialotrina e ao tiametoxam no controle de C. fragaefolii desde que realizada uma segunda pulverização sete dias após a primeira. A persistência biológica dos inseticidas lambda-cialotrina e tiametoxam foi superior a 28 dias, com um controle de 75% da população de pulgões, enquanto azadiractina apresentou menor persistência biológica, controlando 70% da população por sete dias

    Pre-exposure prophylaxis with hydroxychloroquine does not prevent covid-19 nor virus related venous thromboembolism

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    Different and several public health strategies have been planned to reduce transmission of pandemic due to SARS-CoV-2 since it started. None drugs have been confirmed as able to prevent viral transmission. Hydroxychloroquine with its immunomodulatory properties has been proposed as potential anti-viral drug in particular for prevention once viral exposure has been happen or in first phases of infection. Furthermore, in several immunological systemic disease hydroxychloroquine was able to reduce the number of thrombotic complications. So, because COVID-19 was associated to immunological imbalance and to thrombotic complications, we retrospectively analyzed the rate of infection in those patients being under treatment with this drug during COVID-19 epidemic outbreak from 8 March until 28 April in particular comparing those with pre-exposure to this treatment and those that were not taking this medication before SARS-CoV-2 viral infections

    Teias de prejuízo.

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    O ácaro-rajado (Tetranychus urticae) é uma das principais pragas que atacam a cultura do morango. Apesar do tamanho minúsculo, sua presença em altas populações é facilmente perceptível pela formação de teias nas plantas. Os danos vão da redução da taxa fotossintética até a diminuição no número e no peso dos frutos. O emprego de predadores e de produtos naturais à base de nim surge como alternativa promissora para o controle

    Bioecologia, monitoramento e controle do ácaro-rajado com o emprego da azadiractina e ácaros predadores na cultura do morangueiro.

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    Essa circular técnica tem como objetivo apresentar informações sobre a bioecologia, formas de monitoramento e controle do ácaro-rajado através do emprego de ácaros predadores e de uma formulação comercial à base de azadiractina, que podem ser empregados de forma isolada ou associados à cultura do morangueiro.bitstream/item/31206/1/cir083.pd

    Bioecologia, monitoramento e controle de Chaetosiphon fragaefolli (Cockerell, 1901) (Hemiptera: Aphididae) na cultura do morangueiro.

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    Esta circular técnica tem como objetivo apresentar informações sobre a taxonomia, a morfologia, a bioecologia, estratégias para o monitoramento e o controle do pulgão-verde, principal espécie associada ao cultivo do morangueiro no Estado do Rio Grande do Sul.bitstream/item/48473/1/Circular-Tecnica-84.pd

    Dynamic Simulations of the Kosterlitz-Thouless Phase Transition

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    Based on the short-time dynamic scaling form, a novel dynamic approach is proposed to tackle numerically the Kosterlitz-Thouless phase transition. Taking the two-dimensional XY model as an example, the exponential divergence of the spatial correlation length, the transition temperature TKTT_{KT} and all critical exponents are computed. Compared with Monte Carlo simulations in equilibrium, we obtain data at temperatures nearer to TKTT_{KT}.Comment: to appear in Phys. Rev. E in Rapid Communicatio

    Design and Test of a Forward Neutron Calorimeter for the ZEUS Experiment

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    A lead scintillator sandwich sampling calorimeter has been installed in the HERA tunnel 105.6 m from the central ZEUS detector in the proton beam direction. It is designed to measure the energy and scattering angle of neutrons produced in charge exchange ep collisions. Before installation the calorimeter was tested and calibrated in the H6 beam at CERN where 120 GeV electrons, muons, pions and protons were made incident on the calorimeter. In addition, the spectrum of fast neutrons from charge exchange proton-lucite collisions was measured. The design and construction of the calorimeter is described, and the results of the CERN test reported. Special attention is paid to the measurement of shower position, shower width, and the separation of electromagnetic showers from hadronic showers. The overall energy scale as determined from the energy spectrum of charge exchange neutrons is compared to that obtained from direct beam hadrons.Comment: 45 pages, 22 Encapsulated Postscript figures, submitted to Nuclear Instruments and Method

    NPARSEC : NTT Parallaxes of Southern Extremely Cool objects. Goals, targets, procedures and first results

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    The discovery and subsequent detailed study of T dwarfs have provided many surprises and pushed the physics and modelling of cool atmospheres in unpredicted directions. Distance is a critical parameter for studies of these objects to determine intrinsic luminosities, test binarity and measure their motion in the Galaxy. We describe a new observational programme to determine distances across the full range of T-dwarf subtypes using the New Technology Telescope (NTT)/SOFI telescope/instrument combination. We present preliminary results for ten objects, five of which represent new distances.Peer reviewe
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