1,492 research outputs found

    Phyllosticta citricarpa and sister species of global importance to Citrus.

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    Several Phyllosticta species are known as pathogens of Citrus spp., and are responsible for various disease symptoms including leaf and fruit spots. One of the most important species is P. citricarpa, which causes a foliar and fruit disease called citrus black spot. The Phyllosticta species occurring on citrus can most effectively be distinguished from P. citricarpa by means of multilocus DNA sequence data. Recent studies also demonstrated P. citricarpa to be heterothallic, and reported successful mating in the laboratory. Since the domestication of citrus, different clones of P. citricarpa have escaped Asia to other continents via trade routes, with obvious disease management consequences. This pathogen profile represents a comprehensive literature review of this pathogen and allied taxa associated with citrus, focusing on identification, distribution, genomics, epidemiology and disease management. This review also considers the knowledge emerging from seven genomes of Phyllosticta spp., demonstrating unknown aspects of these species, including their mating behaviour.TaxonomyPhyllosticta citricarpa (McAlpine) Aa, 1973. Kingdom Fungi, Phylum Ascomycota, Class Dothideomycetes, Order Botryosphaeriales, Family Phyllostictaceae, Genus Phyllosticta, Species citricarpa.Host rangeConfirmed on more than 12 Citrus species, Phyllosticta citricarpa has only been found on plant species in the Rutaceae.Disease symptomsP. citricarpa causes diverse symptoms such as hard spot, virulent spot, false melanose and freckle spot on fruit, and necrotic lesions on leaves and twigs.Useful websitesDOE Joint Genome Institute MycoCosm portals for the Phyllosticta capitalensis (https://genome.jgi.doe.gov/Phycap1), P. citriasiana (https://genome.jgi.doe.gov/Phycit1), P. citribraziliensis (https://genome.jgi.doe.gov/Phcit1), P. citrichinaensis (https://genome.jgi.doe.gov/Phcitr1), P. citricarpa (https://genome.jgi.doe.gov/Phycitr1, https://genome.jgi.doe.gov/Phycpc1), P. paracitricarpa (https://genome.jgi.doe.gov/Phy27169) genomes. All available Phyllosticta genomes on MycoCosm can be viewed at https://genome.jgi.doe.gov/Phyllosticta

    QCD sum rules analysis of the rare B_c \rar X\nu\bar{\nu} decays

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    Taking into account the gluon correction contributions to the correlation function, the form factors relevant to the rare B_c \rar X \nu\bar{\nu} decays are calculated in the framework of the three point QCD sum rules, where XX stands for axial vector particle, AV(Ds1)AV(D_{s1}), and vector particles, V(D,Ds)V(D^*,D^*_s). The total decay width as well as the branching ratio of these decays are evaluated using the q2q^2 dependent expressions of the form factors. A comparison of our results with the predictions of the relativistic constituent quark model is presented.Comment: 21 Pages, 2 Figures and 5 Table

    Nonlinear spinor field in Bianchi type-I Universe filled with viscous fluid: numerical solutions

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    We consider a system of nonlinear spinor and a Bianchi type I gravitational fields in presence of viscous fluid. The nonlinear term in the spinor field Lagrangian is chosen to be λF\lambda F, with λ\lambda being a self-coupling constant and FF being a function of the invariants II an JJ constructed from bilinear spinor forms SS and PP. Self-consistent solutions to the spinor and BI gravitational field equations are obtained in terms of τ\tau, where τ\tau is the volume scale of BI universe. System of equations for τ\tau and \ve, where \ve is the energy of the viscous fluid, is deduced. This system is solved numerically for some special cases.Comment: 15 pages, 4 figure

    Chapter 12 - Human settlements, infrastructure and spatial planning

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    Urbanization is a process that involves simultaneous transitions and transformations across multiple dimensions, including demographic, economic, and physical changes in the landscape. Each of these dimensions presents different indicators and definitions of urbanization. The chapter begins with a brief discussion of the multiple dimensions and definitions of urbanization, including implications for GHG emissions accounting, and then continues with an assessment of historical, current, and future trends across different dimensions of urbanization in the context of GHG emissions (12.2). It then discusses GHG accounting approaches and challenges specific to urban areas and human settlements. In Section 12.3, the chapter assesses the drivers of urban GHG emissions in a systemic fashion, and examines the impacts of drivers on individuals sectors as well as the interaction and interdependence of drivers. In this section, the relative magnitude of each driver's impact on urban GHG emissions is discussed both qualitatively and quantitatively, and provides the context for a more detailed assessment of how urban form and infrastructure affect urban GHG emissions (12.4). Here, the section discusses the individual urban form drivers such as density, connectivity, and land use mix, as well as their interactions with each other. Section 12.4 also examines the links between infrastructure and urban form, as well as their combined and interacting effects on GHG emissions. Section 12.5 identifies spatial planning strategies and policy instruments that can affect multiple drivers, and Section 12.6 examines the institutional, governance, and financial requirements to implement such policies. Of particular importance with regard to mitigation potential at the urban or local scale is a discussion of the geographic and administrative scales for which policies are implemented, overlapping, and / or in conflict. The chapter then identifies the scale and range of mitigation actions currently planned and / or implemented by local governments, and assesses the evidence of successful implementation of the plans, as well as barriers to further implementation (12.7). Next, the chapter discusses major co-benefits and adverse side-effects of mitigation at the local scale, including opportunities for sustainable development (12.8). The chapter concludes with a discussion of the major gaps in knowledge with respect to mitigation of climate change in urban areas (12.9)

    Analysis of Ωb(bss)\Omega_b^-(bss) and Ωc0(css)\Omega_c^0(css) with QCD sum rules

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    In this article, we calculate the masses and the pole residues of the 1/2+{1/2}^+ heavy baryons Ωc0(css)\Omega_c^0(css) and Ωb(bss)\Omega_b^-(bss) with the QCD sum rules. The numerical values MΩc0=(2.72±0.18)GeVM_{\Omega_c^0}=(2.72\pm0.18) \rm{GeV} (or MΩc0=(2.71±0.18)GeVM_{\Omega_c^0}=(2.71\pm0.18) \rm{GeV}) and MΩb=(6.13±0.12)GeVM_{\Omega_b^-}=(6.13\pm0.12) \rm{GeV} (or MΩb=(6.18±0.13)GeVM_{\Omega_b^-}=(6.18\pm0.13) \rm{GeV}) are in good agreement with the experimental data.Comment: 18 pages, 18 figures, slight revisio

    Strong Couplings of Heavy Mesons to A Light Vector Meson in QCD

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    We make a detailed analysis of the BBρ(DDρ)BB\rho(DD\rho) and BBρ(DDρ)B^*B\rho(D^{*}D\rho) strong couplings gBBρ(gDDρ)g_{BB\rho}(g_{DD\rho}) and gBBρ(gDDρ)g_{B^*B\rho}(g_{D^{*}D\rho}) using QCD light cone sum rules(LCSR). The existing some negligence is pointed out in the previous LCSR calculation on gBBρ(gDDρg_{B^*B\rho} (g_{D^{\ast}D\rho}) and an updated estimate is presented. Our findings can be used to understand the behavior of the B,DρB,D \to \rho semileptonic form factors at large momentum transitions.Comment: 15 pages, latex, 2 figures, version appearing in PRD, typos correcte

    Thermodynamic Description of the Relaxation of Two-Dimensional Euler Turbulence Using Tsallis Statistics

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    Euler turbulence has been experimentally observed to relax to a metaequilibrium state that does not maximize the Boltzmann entropy, but rather seems to minimize enstrophy. We show that a recent generalization of thermodynamics and statistics due to Tsallis is capable of explaining this phenomenon in a natural way. The maximization of the generalized entropy S1/2S_{1/2} for this system leads to precisely the same profiles predicted by the Restricted Minimum Enstrophy theory of Huang and Driscoll. This makes possible the construction of a comprehensive thermodynamic description of Euler turbulence.Comment: 15 pages, RevTe

    Scale-free static and dynamical correlations in melts of monodisperse and Flory-distributed homopolymers: A review of recent bond-fluctuation model studies

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    It has been assumed until very recently that all long-range correlations are screened in three-dimensional melts of linear homopolymers on distances beyond the correlation length ξ\xi characterizing the decay of the density fluctuations. Summarizing simulation results obtained by means of a variant of the bond-fluctuation model with finite monomer excluded volume interactions and topology violating local and global Monte Carlo moves, we show that due to an interplay of the chain connectivity and the incompressibility constraint, both static and dynamical correlations arise on distances rξr \gg \xi. These correlations are scale-free and, surprisingly, do not depend explicitly on the compressibility of the solution. Both monodisperse and (essentially) Flory-distributed equilibrium polymers are considered.Comment: 60 pages, 49 figure

    Measurement of D*+/- meson production in jets from pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

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    This paper reports a measurement of D*+/- meson production in jets from proton-proton collisions at a center-of-mass energy of sqrt(s) = 7 TeV at the CERN Large Hadron Collider. The measurement is based on a data sample recorded with the ATLAS detector with an integrated luminosity of 0.30 pb^-1 for jets with transverse momentum between 25 and 70 GeV in the pseudorapidity range |eta| < 2.5. D*+/- mesons found in jets are fully reconstructed in the decay chain: D*+ -> D0pi+, D0 -> K-pi+, and its charge conjugate. The production rate is found to be N(D*+/-)/N(jet) = 0.025 +/- 0.001(stat.) +/- 0.004(syst.) for D*+/- mesons that carry a fraction z of the jet momentum in the range 0.3 < z < 1. Monte Carlo predictions fail to describe the data at small values of z, and this is most marked at low jet transverse momentum.Comment: 10 pages plus author list (22 pages total), 5 figures, 1 table, matches published version in Physical Review
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