40,653 research outputs found

    Characterising resistance to Turnip mosaic virus (TuMV) in Turnip (Brassica rapa rapa)

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    A Brassica rapa rapa L. line has been identified with high resistance to seven isolates of Turnip mosaic virus (TuMV) (including UK 1, CHN 5, CZE 1, CDN 1, GBR 6, POL 1 and UK 4) representing the major pathotypes of the virus. Resistant plants showed no symptoms following mechanical inoculation with TuMV and no virus was detected in the plants by ELISA. A cross was made between the rapid-cycling Brassica rapa line R-o-18 (which has been found to be susceptible to all the TuMV isolates) and a plant from the resistant B. rapa rapa line. The small amount of the F1 generation seed available from this cross has been grown and inoculated with the seven TuMV isolates. F1 plants were uniformly resistant to the UK 1 isolate of TuMV, uniformly susceptible to the CHN 5 isolate (only 2 plants inoculated) and segregated for resistance and susceptibility to the other five TuMV isolates. This suggested that the parent B. rapa rapa plant used in the cross was probably homozygous for one, or more dominant resistance genes to the UK 1 isolate of TuMV and heterozygous for one, or more dominant resistance genes to the other TuMV isolates. When self seed (S1) from the parent plant from the resistant line was inoculated with the TuMV isolates GBR 6 and UK 4, the segregation for the former isolate was not significantly different from 3 resistant to 1 susceptible, whereas for the latter isolate, the segregation was 4 resistant to 9 susceptible, suggesting resistance to GBR 6 is controlled by a single dominant gene, whereas resistance to UK 4 is controlled by two or more dominant resistance genes. The putative resistance genes appear to confer hitherto unknown dominant TuMV resistance specificities, and in combination have the exciting potential of providing durable resistance to TuMV

    Prethermalization Production of Dark Matter

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    At the end of inflation, the inflaton field decays into an initially nonthermal population of relativistic particles which eventually thermalize. We consider the production of dark matter from this relativistic plasma, focusing on the prethermal phase. We find that for a production cross section σ(E)En\sigma(E)\sim E^n with n>2n> 2, the present dark matter abundance is produced during the prethermal phase of its progenitors. For n2n\le 2, entropy production during reheating makes the nonthermal contribution to the present dark matter abundance subdominant compared to that produced thermally. As specific examples, we verify that the nonthermal contribution is irrelevant for gravitino production in low scale supersymmetric models (n=0n=0) and is dominant for gravitino production in high scale supersymmetry models (n=6n=6).Comment: 12 pages, 4 figure

    Relativistic dark matter at the Galactic center

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    In a large region of the supersymmetry parameter space, the annihilation cross section for neutralino dark matter is strongly dependent on the relative velocity of the incoming particles. We explore the consequences of this velocity dependence in the context of indirect detection of dark matter from the galactic center. We find that the increase in the annihilation cross section at high velocities leads to a flattening of the halo density profile near the galactic center and an enhancement of the annihilation signal.Comment: 13 pages, 9 figure

    Langmuir dark solitons in dense ultrarelativistic electron-positron gravito-plasma in pulsar magnetosphere

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    Nonlinear propagation of electrostatic modes in ultrarelativistic dense elelectron-positron gravito-plasma at the polar cap region of pulsar magnetosphere is considered. A nonlinear Schr\"{o}dinger equation is obtained from the reductive perturbation method which predicts the existence of Langmuir dark solitons. Relevance of the propagating dark solitons to the pulsar radio emission is discussed.Comment: 6 pages, 7 figures. Accepted for publication in Astrophysics and Space Science. arXiv admin note: text overlap with arXiv:astro-ph/9808047 by other authors without attributio

    Gravitational perturbations from oscillons and transients after inflation

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    We study the scalar and tensor perturbations generated by the fragmentation of the inflaton condensate into oscillons or transients after inflation, using nonlinear classical lattice simulations. Without including the backreaction of metric perturbations, we find that the magnitude of scalar metric perturbations never exceeds a few ×103\times 10^{-3}, whereas the maximal strength of the gravitational wave signal today is O(109)\mathcal{O}(10^{-9}) for standard post-inflationary expansion histories. We provide parameter scalings for the α\alpha-attractor models of inflation, which can be easily applied to other models. We also discuss the likelihood of primordial black hole formation, as well as conditions under which the gravitational wave signal can be at observationally interesting frequencies and amplitudes. Finally, we provide an upper bound on the frequency of the peak of the gravitational wave signal, which applies to all preheating scenarios.Comment: 18 pages, 8 figure

    The charged inflaton and its gauge fields: preheating and initial conditions for reheating

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    We calculate particle production during inflation and in the early stages of reheating after inflation in models with a charged scalar field coupled to Abelian and non-Abelian gauge fields. A detailed analysis of the power spectra of primordial electric fields, magnetic fields and charge fluctuations at the end of inflation and preheating is provided. We carefully account for the Gauss constraints during inflation and preheating, and clarify the role of the longitudinal components of the electric field. We calculate the timescale for the back-reaction of the produced gauge fields on the inflaton condensate, marking the onset of non-linear evolution of the fields. We provide a prescription for initial conditions for lattice simulations necessary to capture the subsequent nonlinear dynamics. On the observational side, we find that the primordial magnetic fields generated are too small to explain the origin of magnetic fields on galactic scales and the charge fluctuations are well within observational bounds for the models considered in this paper.Comment: 48 pages, 6 figures, 2 appendices, v3: references added, minor changes to text, to appear in JCA

    Kinerja Dinas Kehutanan Dan Perkebunan Kabupaten Donggala Dalam Proses Pelaksanaan Rencana Kerja Tahun 2014

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    After the implementation of the act of number 25 th of 2004 on the national planning systim, The implementation of the work plan expected arrgement of stakeholder engagement both in organization and community. This process it is a guarantee inception harmonisation organization in achieving a good performance.Hence this study attempts to actualize renja 2014 to set out in budget work plan 2014 and described the impact of implentasi of the performance of the forestry office and plantation Donggala. The methodology used is descriptive qualitative.Excavation data over technique interviews, observation, and study documentation, conducted in two stages.The first stage with variable-variable used is the quality of the work plan, the KUA and PPAS, and budget plan work variable bound us and officials involved in the process of implementation variable free us. The second stage is measuring performance by the effectiveness of, the quality of services and responsibilitas as variable bound and the and staff at the office of forestry and plantation and other stakeholders as variable free.To research there are also variable moderator the local regulations the way the process budgeting until performance. The conclusion of this study is it turns out that the implementation of the work plan year 2014 on the performance of the forestry office and plantation donggala happened inconsistency of work plans and the budget work plan so it influences the effectiveness of , the quality of services and responsibilitas in public service and the technical the forestry office and plantation donggala. The cause was the low quality of documents work plan, that has not been coordination between related agencies involved in budgeting, the domination leadership of skpd and council in priority setting activities and poor participation officials skpd and the community in the process of drafting the and activities. Advice who writers proposing is required the increase in coordination and capacity building officials involved either directly or indirectly in the process of developing a budget and work plan on the skpd level need to the reduction of the domination power in the process of drafting the work plan budget
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