132,118 research outputs found

    Asymmetries of solar coronal extreme ultraviolet emission lines

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    The profiles of emission lines formed in the corona contain information on the dynamics and the heating of the hot plasma. Only recently has data with sufficiently high spectral resolution become available for investigating the details of the profiles of emission lines formed well above 10^6 K. These show enhanced emission in the line wings, which has not been understood yet. Line profiles of Fe XV formed at 2.5 MK acquired by the Extreme ultraviolet Imaging Spectrometer (EIS) onboard the Hinode solar space observatory are studied using multi Gaussian fits, with emphasis on the resulting line widths and Doppler shifts. In the major part of the active region, the spectra are best fit by a narrow line core and a broad minor component. The latter contributes some 10% to 20% to the total emission, is about a factor of 2 broader than the core, and shows strong blueshifts of up to 50 km/s. On average, the line width increases from the footpoints to the loop top for both components. A component with high upflow speeds can be found also in small restricted areas. The coronal structures consist of at least two classes that are not resolved spatially but only spectroscopically and that are associated with the line core and the minor component. Because of their huge line width and strong upflows, it is proposed that the major part of the heating and the mass supply to the corona is actually located in source regions of the minor component. The siphon flows and draining loops seen in the line core component are consistent with structures found in a 3D MHD coronal model. Despite the quite different appearance of the large active region corona and small network elements seen in transition region lines, both show similar line profile characteristics. This indicates that the same processes govern the heating and dynamics of the transition region and the corona.Comment: Astronomy & Astrophysics (accepted), 17 pages, 13 figure

    Tevatron Collider Operations and Plans

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    Run II of the Tevatron Collider is reviewed, emphasizing operations through March 15, 2004. The Run II Luminosity Upgrade plans and luminosity projections through 2009 are discussed.Comment: 8 pages - including 4 figures and 1 photograph to be published in proceedings of XXXIXth Rencontre de Moriond conference on ElectroWeak Interactions and Unified Theories, La Thuile, Aosta Valley, Italy, March 21-28, 200

    Questioning the Quantitative Imperative: Decision Aids, Prevention, and the Ethics of Disclosure

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    Patients should not always receive hard data about the risks and benefits of a medical intervention. That information should always be available to patients who expressly ask for it, but it should be part of standard disclosure only sometimes, and only for some patients. And even then, we need to think about how to offer it

    On the Serialisation of Parallel Programs

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    Panpsychism: Ubiquitous Sentience

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    This public article presents three arguments for the plausibility of panpsychism: the view that sentience is a fundamental and ubiquitous element of actuality. Thereafter is presented a brief exploration of why panpsychism has been spurned. The article was commissioned by High Existence. – Introduction – 1. The Genetic Argument – 2. The Abstraction Argument – 3. The Inferential Argument – Why Panpsychism is Spurned – End Remark

    Discounting a Surgical Risk: Data, Understanding, and Gist

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    Excerpt: A few days after the surgery, Ms. Reid came in for an emergency appointment with Dr. Feng. It was obvious that she was irate,but her voice could barely be heard above the noise of the clinic. "I thought you said this was rare," she said, shaking a printout of a journal article on the subject. My recurrent laryngeal nerve was injured. I'm a teacher, and I have children! I need my voice. I would have never done the surgery if I knew there was a 4 percent risk that I would lose my voice!" Was Dr. Feng negligent in explaining the risks of surgery to Ms. Reid? Was she required to use precise percentages of risk
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