16 research outputs found

    Origins of the Ambient Solar Wind: Implications for Space Weather

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    The Sun's outer atmosphere is heated to temperatures of millions of degrees, and solar plasma flows out into interplanetary space at supersonic speeds. This paper reviews our current understanding of these interrelated problems: coronal heating and the acceleration of the ambient solar wind. We also discuss where the community stands in its ability to forecast how variations in the solar wind (i.e., fast and slow wind streams) impact the Earth. Although the last few decades have seen significant progress in observations and modeling, we still do not have a complete understanding of the relevant physical processes, nor do we have a quantitatively precise census of which coronal structures contribute to specific types of solar wind. Fast streams are known to be connected to the central regions of large coronal holes. Slow streams, however, appear to come from a wide range of sources, including streamers, pseudostreamers, coronal loops, active regions, and coronal hole boundaries. Complicating our understanding even more is the fact that processes such as turbulence, stream-stream interactions, and Coulomb collisions can make it difficult to unambiguously map a parcel measured at 1 AU back down to its coronal source. We also review recent progress -- in theoretical modeling, observational data analysis, and forecasting techniques that sit at the interface between data and theory -- that gives us hope that the above problems are indeed solvable.Comment: Accepted for publication in Space Science Reviews. Special issue connected with a 2016 ISSI workshop on "The Scientific Foundations of Space Weather." 44 pages, 9 figure

    Exploring the experience of weight loss in people with advanced cancer

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    Aim: This paper reports a study of the experience of and concerns about weight loss described by patients with advanced cancer, their caregivers and nurse specialists.Background: Weight loss is reported to be one of the commonest symptoms experienced by patients with advanced cancer. There is evidence that it can be of concern to patients and their caregivers. However, little is known about why this is the case or how people might be helped to live with the symptom.Method: An exploratory study with a purposive sample of 30 patients, 23 caregivers, and 14 specialist nurses from the South of England was conducted in 2003. The in-depth interviews focused on the experience of weight loss and its management. Interviews were transcribed verbatim, then analysed using an approach informed by Wolcott's framework for qualitative data analysis and Miles and Huberman's 'mixed strategy for cross-case analysis'.Findings: Concern was experienced when advanced cancer became visible through weight loss. Visible weight loss symbolized proximity to death, loss of control and both physical and emotional weakness. Despite this, weight loss was not routinely assessed by palliative care nurse specialists, who, like others in the patient's social network, respected a weight loss taboo in the belief that little could be done to help people live with the symptom.Conclusion: Weight loss-related concern might be mitigated if clinicians adopted a systematic and proactive approach to the management of the symptom that breaks through the weight loss taboo
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