12,658 research outputs found

    Dispersive spherical optical model of neutron scattering from Al27 up to 250 MeV

    Get PDF
    A spherical optical model potential (OMP) containing a dispersive term is used to fit the available experimental database of angular distribution and total cross section data for n + Al27 covering the energy range 0.1- 250 MeV using relativistic kinematics and a relativistic extension of the Schroedinger equation. A dispersive OMP with parameters that show a smooth energy dependence and energy independent geometry are determined from fits to the entire data set. A very good overall agreement between experimental data and predictions is achieved up to 150 MeV. Inclusion of nonlocality effects in the absorptive volume potential allows to achieve an excellent agreement up to 250 MeV.Comment: 13 figures (11 eps and 2 jpg), 3 table

    Анизотропно-пучковая неустойчивость лазерной плазмы

    Get PDF
    При распространении мощного лазерного импульса вдоль внешнего магнитного поля в плазме возбуждается широкий спектр вистлерных мод с частотами ниже электронной циклотронной частоты, что приводит к появлению надтепловых электронов и установлению плато на первоначально максвелловской функции распределения. В результате развивается анизотропно-пучковая неустойчивость и происходит трансформация энергии быстрых электронов в энергию электростатических колебаний плазмы.При розповсюдженні потужного лазерного імпульсу вздовж зовнішнього магнітного поля в плазмі збуджується широкий спектр вістлерних мод з частотами нижче електронної циклотроної частоти, що призводить до появи надтеплових електронів і встановленню плато на первісно максвеллівській функції розподілу. У результаті розвивається анізотропно-пучкова нестійкість і відбувається трансформація енергії швидких електронів в енергію електростатичних коливань плазми.In the propagation of intense laser pulse along the external magnetic field in a plasma excited a wide range of whistler modes with frequencies below the electron cyclotron frequency, which leads to the suprathermal electrons and the establishment of a plateau on the original Maxwellian distribution functions. As a result, develops anisotropically-stream instability and a transformation of fast electron energy in the energy of electrostatic plasma oscillations

    Discerning the relationship between geminiviral infection and vesicle trafficking using virus induced gene silencing

    Get PDF
    Tomato yellow leaf curl disease is one of the most important threats to tomato crops worldwide. One of its causal agents, Tomato yellow leaf curl Sardinian virus (TYLCSV) is a monopartite member of the genus Begomovirus from the family Geminiviridae. Due to the few proteins encoded by their viral genome, geminiviruses rely heavily on host cellular machineries and interact with a wide range of plant proteins to complete all processes required for infection, such as viral replication, movement and suppression or evasion of plant defence mechanisms. The identification of the host proteins involved in viral infection will be an important step towards the understanding of the mechanisms underlying this process. In our laboratory, transgenic Nicotiana benthamiana plants containing a green fluorescent protein (GFP) expression cassette flanked by two direct repeats of the intergenic region of TYLCSV have been constructed (2IR plants). When these plants are infected with TYLCSV, an overexpression of the reporter gene is observed in those cells where the virus is actively replicating. These plants have been used together with virus induced gene silencing (VIGS) in an effort to identify host genes involved in the infection process using a reverse genetics approach. Using this combined technique our group has identified two genes δ-COP and ARF 1, involved in retrograde vesicle trafficking, which are essential for the infectious process. We are currently assaying genes codifying proteins involved in different pathways of the vesicle trafficking system: Sar1b, γ subunit of AP1, Sec24, SYT1 and two that encode the heavy chain of triskelion proteins. Their effect over viral infection will be presented and discussedUniversidad de Málaga. Campues de Excelencia Internacional Andalucía Tech

    Identifying the function of vesicle trafficking in geminiviral infection using virus induced gene silencing

    Get PDF
    Tomato yellow leaf curl Sardinian virus (TYLCSV) is one of the causal agent of the tomato yel-low leaf curl disease, one of the most important threats to tomato crops worldwide. TYLCSV is a monopartite member of the genus Begomovirus from the family Geminiviridae. To carry out a full infection, geminiviruses need to move inside the infected cell and from one cell to an-other for which they depend on diverse cellular factors. While cell-to-cell movement has been described to occur through plasmodesmata, the way in which geminiviruses move inside the host cells is yet unknown. The identification of the host proteins involved in viral infection will be an important step to-wards the understanding of the mechanisms underlying this process. In our laboratory, trans-genic Nicotianabenthamiana plants containing a green fluorescent protein (GFP) expression cassette flanked by two direct repeats of the intergenic region of TYLCSV have been construct-ed (2IR plants). When these plants are infected with TYLCSV, an overexpression of the reporter gene is observed in those cells where the virus replicates. These plants have been used to-gether with virus induced gene silencing (VIGS) in an effort to identify host genes involved in the infection process using a reverse genetics approach. Using this combined technique our group has identified two genes δ-COP and ARF 1, involved in retrograde vesicle trafficking, which are essential for the infectious process. We are current-ly assaying genes codifying proteins involved in different pathways of the vesicle trafficking system: Sar1b, γ subunit of AP1, Sec24, SYT1 and two that encode the heavy chain of triskelion proteins. Their effect over virus infection will be presented and discussed.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Applying remote sensing and GIS techniques in solving rural county information needs

    Get PDF
    The project designed was to acquaint county government officials and their clientele with remote sensing and GIS products that contain information about land conditions and land use. Other users determined through the course of this project were federal agencies working at the county level, agricultural businesses and others in need of spatial information. The specific project objectives were: (1) to investigate the feasibility of using remotely sensed data to identify and quantify specific land cover categories and conditions for purposes of tax assessment, cropland area measurements and land use evaluation; (2) to investigate the use of satellite remote sensing data as an aid in assessing soil management practices; and (3) to evaluate the use of remotely sensed data to assess soil resources and conditions which affect productivity
    corecore