11 research outputs found

    Co-evolution model of Colletotrichum lindemuthianum (melanconiaceae, melanconiales) races that occur in some Brazilian regions

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    Colletotrichum lindemuthianum, the causal agent of anthracnose in the common bean (Phaseolus vulgaris L.), displays a high level of virulence diversity, which explains the large number of existing pathotypes. Several lines of evidence indicate that such diversity is, at least in part, due to plant and pathogen co-evolution. A co-evolution model based on the binary classification of 25 races identified in Brazil by inoculation of differential cultivars and random amplified polymorphic DNA (RAPD) data is proposed. In this model, races 8 and 64 that infected bean cultivar Cornell 49-242 (Are gene) and Mexico 222 (Mexico I gene) are considered to be sources of two important evolutionary routes. Inferences about undescribed races from Brazil could be made.<br>Colletotrichum lindemuthianum (Sacc. &amp; Magn.) Scrib., agente causal da antracnose do feijoeiro comum (Phaseolus vulgaris L.), possui alto nĂ­vel de diversidade de virulĂȘncia, o que explica o elevado nĂșmero de patĂłtipos existentes. A partir de trabalhos anteriores sobre a classificação binĂĄria de 25 raças identificadas no Brasil e sua relação com agrupamentos RAPD, foi possĂ­vel construir um modelo de evolução de tais raças. As raças 8 e 64, que foram compatĂ­veis com os cultivares Cornell 49-242 (gene Are) e MĂ©xico 222 (gene MĂ©xico I), se apresentam como possĂ­veis origens de duas importantes rotas de evolução. InferĂȘncias de raças ainda nĂŁo detectadas no Brasil puderam ser feitas

    Migration of crystals during the filling of semi-solid castings

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    In cold-chamber high-pressure die castings (HPDC), the microstructure consists of coarse externally solidified crystals (ESCs) that are commonly observed in the central region of cross sections. In the present work, controlled laboratory scale casting experiments have been conducted with particular emphasis on the flow and solidification conditions. An A356 aluminum alloy was used to produce castings by pouring semi-solid metal through a steel die. Microstructures similar to those encountered in HPDC have been produced and the resulting microstructure is found to depend on the melt and die temperature: (1) the fraction of ESCs determines the extent of migration to the central region; (2) a maximum packing determines the area fraction of ESCs in the center; and (3) the die temperature affects the position of the ESCs-a higher die temperature can induce a displaced ESC distribution. It is found that the n-figration of crystals to the central region requires a flow, which is constrained at all melt/die interfaces. Furthermore, potential lift mechanisms are discussed. An assessment of the Saffman lift force on individual particles shows it has no significant effect on the migration of ESCs

    Characteristics of Icy Surfaces

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    Measurement of pion, kaon and proton production in proton–proton collisions at √s = 7 TeV

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    The measurement of primary π±\pi ^{\pm }π±, K±K^{\pm }K±, ppp and p‟{\overline{{p}}}pÂŻ production at mid-rapidity (|y| &lt;|y|&amp;lt; 0.5) in proton–proton collisions at s\sqrt{s}s=== 7 TeV performed with a large ion collider experiment at the large hadron collider (LHC) is reported. Particle identification is performed using the specific ionisation energy-loss and time-of-flight information, the ring-imaging Cherenkov technique and the kink-topology identification of weak decays of charged kaons. Transverse momentum spectra are measured from 0.1 up to 3 GeV/ccc for pions, from 0.2 up to 6 GeV/ccc for kaons and from 0.3 up to 6 GeV/ccc for protons. The measured spectra and particle ratios are compared with quantum chromodynamics-inspired models, tuned to reproduce also the earlier measurements performed at the LHC. Furthermore, the integrated particle yields and ratios as well as the average transverse momenta are compared with results at lower collision energies. © 2015, CERN for the benefit of the ALICE collaboration

    Transverse momentum spectra of charged particles in proton-proton collisions at 1as=900 GeV with ALICE at the LHC

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    The inclusive charged particle transverse momentum distribution is measured in proton-proton collisions at s=900 GeV at the LHC using the ALICE detector. The measurement is performed in the central pseudorapidity region (|\u3b7|<0.8) over the transverse momentum range 0.15<10 GeV/c. The correlation between transverse momentum and particle multiplicity is also studied. Results are presented for inelastic (INEL) and non-single-diffractive (NSD) events. The average transverse momentum for |\u3b7|<0.8 is \u3008pT\u3009INEL=0.483\ub10.001 (stat.)\ub10.007 (syst.) GeV/c and \u3008pT\u3009NSD=0.489\ub10.001 (stat.)\ub10.007 (syst.) GeV/c, respectively. The data exhibit a slightly larger \u3008pT\u3009 than measurements in wider pseudorapidity intervals. The results are compared to simulations with the Monte Carlo event generators PYTHIA and PHOJET. \ua9 2010

    Two- and three-pion quantum statistics correlations in Pb-Pb collisions at root S-NN=2.76 TeV at the CERN Large Hadron Collider

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    Correlations induced by quantum statistics are sensitive to the spatiotemporal extent as well as dynamics of particle-emitting sources in heavy-ion collisions. In addition, such correlations can be used to search for the presence of a coherent component of pion production. Two- and three-pion correlations of same and mixed charge are measured at low relative momentum to estimate the coherent fraction of charged pions in Pb-Pb collisions at root S-NN = 2.76 TeV at the CERN Large Hadron Collider with ALICE. The genuine three-pion quantum statistics correlation is found to be suppressed relative to the two-pion correlation based on the assumption of fully chaotic pion emission. The suppression is observed to decrease with triplet momentum. The observed suppression at low triplet momentum may correspond to a coherent fraction in charged-pion emission of 23% +/- 8%

    Two-and three-pion quantum statistics correlations in Pb-Pb collisions at root S-NN=2.76 TeV at the CERN Large Hadron Collider

    No full text
    Correlations induced by quantum statistics are sensitive to the spatiotemporal extent as well as dynamics of particle-emitting sources in heavy-ion collisions. In addition, such correlations can be used to search for the presence of a coherent component of pion production. Two- and three-pion correlations of same and mixed charge are measured at low relative momentum to estimate the coherent fraction of charged pions in Pb-Pb collisions at root S-NN = 2.76 TeV at the CERN Large Hadron Collider with ALICE. The genuine three-pion quantum statistics correlation is found to be suppressed relative to the two-pion correlation based on the assumption of fully chaotic pion emission. The suppression is observed to decrease with triplet momentum. The observed suppression at low triplet momentum may correspond to a coherent fraction in charged-pion emission of 23% +/- 8%

    Underlying Event Measurements In Pp Collisions At √s = 0:9 And 7 Tev With The Alice Experiment At The Lhc

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    2012
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