37 research outputs found

    A mercury electron-bombardment ion thrustor suitable for spacecraft station keeping and altitude control

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    Mercury electron bombardment ion thrustor with radial flow propellant distributor for spacecraft attitude contro

    Plasmas and Controlled Nuclear Fusion

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    Contains research objectives, summary of research and reports on six research projects.U. S. Atomic Energy Commission (Contract AT(11-1)-3070

    Plasmas and Controlled Nuclear Fusion

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    Contains reports on four research project.U. S. Atomic Energy Commission (Contract AT(11-1)-3070

    Plasmas and Controlled Nuclear Fusion

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    Contains research objectives and reports on six research projects.U. S. Atomic Energy Commission (Contract AT(30-1)-3980

    Plasmas and Controlled Nuclear Fusion

    Get PDF
    Contains research objectives and reports on four research projects.U. S. Atomic Energy Commission (Contract AT(30-1)-3980

    Plasmas and Controlled Nuclear Fusion

    Get PDF
    Contains research objectives and summary of research on six research projects.U.S. Atomic Energy Commission (Contract AT(11-1)-3070

    Plasmas and Controlled Nuclear Fusion

    Get PDF
    Contains research objectives and reports on four research projects.U. S. Atomic Energy Commission (Contract AT(30-1)-3980)U. S. Atomic Energy Commission (GK-2581

    Impacts of climate change on plant diseases – opinions and trends

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    There has been a remarkable scientific output on the topic of how climate change is likely to affect plant diseases in the coming decades. This review addresses the need for review of this burgeoning literature by summarizing opinions of previous reviews and trends in recent studies on the impacts of climate change on plant health. Sudden Oak Death is used as an introductory case study: Californian forests could become even more susceptible to this emerging plant disease, if spring precipitations will be accompanied by warmer temperatures, although climate shifts may also affect the current synchronicity between host cambium activity and pathogen colonization rate. A summary of observed and predicted climate changes, as well as of direct effects of climate change on pathosystems, is provided. Prediction and management of climate change effects on plant health are complicated by indirect effects and the interactions with global change drivers. Uncertainty in models of plant disease development under climate change calls for a diversity of management strategies, from more participatory approaches to interdisciplinary science. Involvement of stakeholders and scientists from outside plant pathology shows the importance of trade-offs, for example in the land-sharing vs. sparing debate. Further research is needed on climate change and plant health in mountain, boreal, Mediterranean and tropical regions, with multiple climate change factors and scenarios (including our responses to it, e.g. the assisted migration of plants), in relation to endophytes, viruses and mycorrhiza, using long-term and large-scale datasets and considering various plant disease control methods

    Implementation of 3 T Lactate-Edited 3D 1H MR Spectroscopic Imaging with Flyback Echo-Planar Readout for Gliomas Patients

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    The purpose of this study was to implement a new lactate-edited 3D 1H magnetic resonance spectroscopic imaging (MRSI) sequence at 3 T and demonstrate the feasibility of using this sequence for measuring lactate in patients with gliomas. A 3D PRESS MRSI sequence incorporating shortened, high bandwidth 180° pulses, new dual BASING lactate-editing pulses, high bandwidth very selective suppression (VSS) pulses and a flyback echo-planar readout was implemented at 3 T. Over-prescription factor of PRESS voxels was optimized using phantom to minimize chemical shift artifacts. The lactate-edited flyback sequence was compared with lactate-edited MRSI using conventional elliptical k-space sampling in a phantom and volunteers, and then applied to patients with gliomas. The results demonstrated the feasibility of detecting lactate within a short scan time of 9.5 min in both phantoms and patients. Over-prescription of voxels gave less chemical shift artifacts allowing detection of lactate on the majority of the selected volume. The normalized SNR of brain metabolites using the flyback encoding were comparable to the SNR of brain metabolites using conventional phase encoding MRSI. The specialized lactate-edited 3D MRSI sequence was able to detect lactate in brain tumor patients at 3 T. The implementation of this technique means that brain lactate can be evaluated in a routine clinical setting to study its potential as a marker for prognosis and response to therapy
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