765 research outputs found

    Appréciation de l'efficacité des fongicides contre la pourriture brune des cabosses du cacaoyer due au PHYTOPHTHORA PALMIVORA (Butl.) Butl. dans les conditions naturelles : Essai de mise au point d'une méthode rapide

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    Pour tester l'efficacité préventive des fongicides contre Phytophthora palmivora sur cabosses, on compare l'évolution des taux d'attaque de groupes de cabosses non traités servant de témoin et des groupes de cabosses de même taille recevant le fongicide à tester, ces groupes de cabosses constituant les parcelles élémentaires. Au cours de la campagne 1966 (Août, sept., oct.) observation de 174 couples d'arbres qui ont été affectés à 1) contrôle de la valeur de la méthode, a) par un essai "à blanc", b) par un essai cuivre, 2) première application de divers fongicides tels que manèbe, le zinèbe, le mancozèbe. La méthode est efficace (différence significative entre les témoins et les arbres recevant une bouillie cuprique). La méthode est rapide: résultats entre 4 à 6 semaines. En dehors des applications cupriques, seul le mancozèbe a montré une certaine efficacit

    New Air Quality Targets & Interim Goals for Fine Particulate Matter – PM2.5: Implications for the West Midlands

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    This document provides a comprehensive overview of the implications of more stringent PM2.5 targets on air quality and public health in the West Midlands. By examining the sources and levels of PM2.5 pollution, exploring potential air quality scenarios and strategies, and estimating the health burden, this document seeks to inform stakeholders and decision makers in their efforts to improve air quality and reduce associated health risks and inequalities

    Vector Correlators in Lattice QCD: methods and applications

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    We discuss the calculation of the leading hadronic vacuum polarization in lattice QCD. Exploiting the excellent quality of the compiled experimental data for the e^+e^- --> hadrons cross-section, we predict the outcome of large-volume lattice calculations at the physical pion mass, and design computational strategies for the lattice to have an impact on important phenomenological quantities such as the leading hadronic contribution to (g-2)mu and the running of the electromagnetic coupling constant. First, the R(s) ratio can be calculated directly on the lattice in the threshold region, and we provide the formulae to do so with twisted boundary conditions. Second, the current correlator projected onto zero spatial momentum, in a Euclidean time interval where it can be calculated accurately, provides a potentially critical test of the experimental R(s) ratio in the region that is most relevant for (g-2)mu. This observation can also be turned around: the vector correlator at intermediate distances can be used to determine the lattice spacing in fm, and we make a concrete proposal in this direction. Finally, we quantify the finite-size effects on the current correlator coming from low-energy two-pion states and provide a general parametrization of the vacuum polarization on the torus.Comment: 16 pages, 9 figure files; corrected a factor 2 in Eq. (7) over the published versio

    Prevalence of hypertension and its associated risk factors in a rural black population of Mthatha town,South Africa

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    The occurrence of hypertension has been increasing alarmingly in both low and middle-income countries. Despite acknowledging hypertension as the most common life-threatening risk factor for cardiovascular disease (CVD), a dearth of data is available on the prevalence, awareness, and determinants of hypertension in rural parts of South Africa. The principal aim of the current study is to determine the prevalence and associated risk factors of hypertension among a black rural African population from the Mtatha town of Eastern Cape Province. Methods: This was a cross-sectional study, and individuals over 18 years of age were randomly screened using a World Health Organization stepwise questionnaire. Sociodemographic information, anthropometric measurements, fasting blood glucose levels, and three independent blood pressure (BP) readings were measured. Blood pressure measurements were classified according to the American Heart Association guidelines. Univariate and multivariate analyses were performed to determine the significant predictors of hypertension. Results: Of the total participants (n = 556), 71% of individuals had BP scores in the hypertensive range. In univariate analysis, age, westernized diet, education, income, and diabetic status, as well as overweight/obese status were positively associated with the prevalence of hypertension

    Determination of the η\eta and η\eta' Mixing Angle from the Pseudoscalar Transition Form Factors

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    The possible range of ηη\eta-\eta' mixing angle is determined from the transition form factors Fηγ(Q2)F_{\eta \gamma}(Q^2) and Fηγ(Q2)F_{\eta' \gamma}(Q^2) with the help of the present experimental data. For such purpose, the quark-flavor mixing scheme is adopted and the pseudoscalar transition form factors are calculated under the light-cone pQCD framework, where the transverse momentum corrections and the contributions beyond the leading Fock state have been carefully taken into consideration. We construct a phenomenological expression to estimate the contributions to the form factors beyond the leading Fock state based on their asymptotic behavior at Q20Q^2\to 0 and Q2Q^2\to\infty. By taking the quark-flavor mixing scheme, our results lead to ϕ=38.0±1.0±2.0\phi= 38.0^{\circ}\pm 1.0^{\circ}\pm 2.0^{\circ}, where the first error coming from experimental uncertainty and the second error coming from the uncertainties of the wavefunction parameters. The possible intrinsic charm component in η\eta and η\eta' is discussed and our present analysis also disfavors a large portion of intrinsic charm component in η\eta and η\eta', e.g. fηc50MeV|f^c_{\eta'}|\le 50 {\rm MeV}.Comment: 18 Pages, 3 figures. Several references added. To be published in EPJ

    A quantitative release assessment for the noncommercial movement of companion animals : risk of rabies reintroduction to the United Kingdom

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    In 2004, the European Union (EU) implemented a pet movement policy (referred to here as the EUPMP) under EU regulation 998/2003. The United Kingdom (UK) was granted a temporary derogation from the policy until December 2011 and instead has in place its own Pet Movement Policy (Pet Travel Scheme (PETS)). A quantitative risk assessment (QRA) was developed to estimate the risk of rabies introduction to the UK under both schemes to quantify any change in the risk of rabies introduction should the UK harmonize with the EU policy. Assuming 100 % compliance with the regulations, moving to the EUPMP was predicted to increase the annual risk of rabies introduction to the UK by approximately 60-fold, from 7.79 × 10(-5) (5.90 × 10(-5) , 1.06 × 10(-4) ) under the current scheme to 4.79 × 10(-3) (4.05 × 10(-3) , 5.65 × 10(-3) ) under the EUPMP. This corresponds to a decrease from 13,272 (9,408, 16,940) to 211 (177, 247) years between rabies introductions. The risks associated with both the schemes were predicted to increase when less than 100 % compliance was assumed, with the current scheme of PETS and quarantine being shown to be particularly sensitive to noncompliance. The results of this risk assessment, along with other evidence, formed a scientific evidence base to inform policy decision with respect to companion animal movement

    Timing performance of a Micro-Channel-Plate Photomultiplier Tube

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    The spatial dependence of the timing performance of the R3809U-50 Micro-Channel-Plate PMT (MCP-PMT) by Hamamatsu was studied in high energy muon beams. Particle position information is provided by a GEM tracker telescope, while timing is measured relative to a second MCP-PMT, identical in construction. In the inner part of the circular active area (radius r5.5 mm) the time resolution of the two MCP-PMTs combined is better than 10 ps. The signal amplitude decreases in the outer region due to less light reaching the photocathode, resulting in a worse time resolution. The observed radial dependence is in quantitative agreement with a dedicated simulation. With this characterization, the suitability of MCP-PMTs as t0 reference detectors has been validated.Peer reviewe
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