1,977 research outputs found

    Harmonic generation of gravitational wave induced Alfven waves

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    Here we consider the nonlinear evolution of Alfven waves that have been excited by gravitational waves from merging binary pulsars. We derive a wave equation for strongly nonlinear and dispersive Alfven waves. Due to the weak dispersion of the Alfven waves, significant wave steepening can occur, which in turn implies strong harmonic generation. We find that the harmonic generation is saturated due to dispersive effects, and use this to estimate the resulting spectrum. Finally we discuss the possibility of observing the above process.Comment: 7 page

    Nonlinear Interactions Between Gravitational Radiation and Modified Alfven Modes in Astrophysical Dusty Plasmas

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    We present an investigation of nonlinear interactions between Gravitational Radiation and modified Alfv\'{e}n modes in astrophysical dusty plasmas. Assuming that stationary charged dust grains form neutralizing background in an electron-ion-dust plasma, we obtain the three wave coupling coefficients, and calculate the growth rates for parametrically coupled gravitational radiation and modified Alfv\'{e}n-Rao modes. The threshold value of the gravitational wave amplitude associated with convective stabilization is particularly small if the gravitational frequency is close to twice the modified Alfv\'en wave-frequency. The implication of our results to astrophysical dusty plasmas is discussed.Comment: A few typos corrected. Published in Phys. Rev.

    Should I grow wildflowers? Agrilink, your growing guide to better farming

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    Each Agrilink kit has been designed to be both comprehensive and practical. As the kits are arranged to answer questions of increasing complexity, they are useful references for both new and experienced producers of specific crops. Agrilink integrates the technology of horticultural production with the management of horticultural enterprises. REPRINT INFORMATION - PLEASE READ! For updated information please call 13 25 23 or visit the website www.deedi.qld.gov.au (Select: Queensland Industries – Agriculture link) This publication has been reprinted as a digital book without any changes to the content published in 2000. We advise readers to take particular note of the areas most likely to be out-of-date and so requiring further research: see detailed information on first page of the kit. Even with these limitations we believe this information kit provides important and valuable information for intending and existing growers. This publication was last revised in 2000. The information is not current and the accuracy of the information cannot be guaranteed by the State of Queensland. This information has been made available to assist users to identify issues involved in the production of wildflowers. This information is not to be used or relied upon by users for any purpose which may expose the user or any other person to loss or damage. Users should conduct their own inquiries and rely on their own independent professional advice. While every care has been taken in preparing this publication, the State of Queensland accepts no responsibility for decisions or actions taken as a result of any data, information, statement or advice, expressed or implied, contained in this publication

    Mixed-data-model heterogeneous compilation and OpenMP offloading

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    Heterogeneous computers combine a general-purpose host processor with domain-specific programmable many-core accelerators, uniting high versatility with high performance and energy efficiency. While the host manages ever-more application memory, accelerators are designed to work mainly on their local memory. This difference in addressed memory leads to a discrepancy between the optimal address width of the host and the accelerator. Today 64-bit host processors are commonplace, but few accelerators exceed 32-bit addressable local memory, a difference expected to increase with 128-bit hosts in the exascale era. Managing this discrepancy requires support for multiple data models in heterogeneous compilers. So far, compiler support for multiple data models has not been explored, which hampers the programmability of such systems and inhibits their adoption. In this work, we perform the first exploration of the feasibility and performance of implementing a mixed-data-mode heterogeneous system. To support this, we present and evaluate the first mixed-data-model compiler, supporting arbitrary address widths on host and accelerator. To hide the inherent complexity and to enable high programmer productivity, we implement transparent offloading on top of OpenMP. The proposed compiler techniques are implemented in LLVM and evaluated on a 64+32-bit heterogeneous SoC. Results on benchmarks from the PolyBench-ACC suite show that memory can be transparently shared between host and accelerator at overheads below 0.7 % compared to 32-bit-only execution, enabling mixed-data-model computers to execute at near-native performance

    Factor VIII:C concentrate purified from plasma using monoclonal antibodies: human studies

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    Conventional clotting factor concentrates have, until recently, been of intermediate purity, containing less than 1% of the coagulation factor, and greater than 99% extraneous plasma proteins such as fibrinogen, fibronectin, gamma globulins, and traces of many others. We report here the results of a new factor VIII concentrate that is purified from human plasma using a mouse monoclonal antibody to factor VIII:vWF in an affinity chromatography system. The resultant concentrate has an activity of between 3,000 and 5,000 U/mg protein before albumin is added as a stabilizer. Seven patients with severe hemophilia A and no inhibitor who were positive for antibody to human immunodeficiency virus (HIV) have been treated solely with this concentrate for over 24 months. Factor usage in these patients has ranged from 611 U/kg/yr to 2,022 U/kg/yr. These patients have infused approximately once per week on the average, most often for joint hemorrhages. The efficacy of the concentrate is excellent. No allergic reactions have occurred and no factor VIII antibodies have developed. In these seven patients mean CD4 counts stabilized (856 +/- 619 at screen v 778 +/- 686 at 24 months) and there was reversal of skin test anergy. In a comparison group on conventional intermediate purity concentrate chosen retrospectively decreases in mean CD4 cell counts similarly did not occur. However, the number of the comparison patients who were anergic increased over the course of the study. These observations indicate the possibility that more highly purified concentrates may stabilize immune function in HIV seropositive patients

    A prospective study of asthma incidence and its predictors: the RHINE study.

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    To access publisher full text version of this article. Please click on the hyperlink in Additional LinkThe objective of this longitudinal study was to estimate the incidence rate of asthma, and to compare the incidence between subjects with or without baseline reporting of certain respiratory symptoms. A follow-up of the random population samples in the European Respiratory Health Survey (ECRHS) in Sweden, Norway, Denmark, Iceland and Estonia was conducted in 1999-2001, in a population aged 30-54 yrs at follow-up (n=14,731). Asthma was defined as reporting either asthma or physician-diagnosed asthma, and a reported year when asthma symptoms were first noticed. Incidence rates, incidence rate ratios and hazard ratios were calculated with 95% confidence intervals. The incidence rate of asthma was 2.2 cases per 1,000 person-yrs. The incidence was higher among females (2.9 cases.1,000 person-yrs(-1)) than among males (1.5 cases.1,000 person-yrs(-1)). When subjects with baseline reporting of wheezing were excluded, the incidence rate decreased to 1.7 cases.1,000 person-yrs(-1), with a further decrease to 1.5 cases.1,000 person-yrs(-1) after exclusion of subjects with wheezing, nocturnal dyspnoea, chest tightness and cough. There was a strong association between onset of asthma and wheezing at baseline. In this prospective, population-based study, the incidence rate of asthma in the whole population sample ranged 1.5-2.2.1,000 person-yrs(-1), with a higher incidence range among females. The incidence was dependent on the extent to which subjects with respiratory symptoms were excluded from follow-up. Hence, for comparability between studies, the exclusion criteria in the follow-up population must be stated
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