Predicting the geoeffective properties of coronal mass ejections: current status, open issues and path forward.
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ABSTRACT:
SUBMITTER: Vourlidas A
PROVIDER: S-EPMC6527953 | biostudies-literature | 2019 Jul
REPOSITORIES: biostudies-literature
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Project description:Coronal mass ejections (CMEs) are large-scale expulsions of coronal plasma and magnetic field propagating through the heliosphere. Because CMEs are observed by white-light coronagraphs which, by design, occult the solar disc, supporting disc observations (e.g. in EUV, soft X-rays, Halpha and radio) must be employed for the study of their source regions and early development phases. We review the key properties of CME sources and highlight a certain causal sequence of effects that may occur whenever a strong (flux-massive and sheared) magnetic polarity inversion line develops in the coronal base of eruptive active regions (ARs). Storing non-potential magnetic energy and helicity in a much more efficient way than ARs lacking strong polarity inversion lines, eruptive regions engage in an irreversible course, making eruptions inevitable and triggered when certain thresholds of free energy and helicity are crossed. This evolution favours the formation of pre-eruption magnetic flux ropes. We describe the steps of this plausible path to sketch a picture of the pre-eruptive phase of CMEs that may apply to most events, particularly the ones populating the high end of the energy/helicity distribution, that also tend to have the strongest space-weather implications. This article is part of the theme issue 'Solar eruptions and their space weather impact'.
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Project description:BackgroundDespite their importance, the number of outcomes research studies conducted in India are lesser than other countries. Information about the distribution of existing outcomes research resources and relevant expertise can benefit researchers and research groups interested in conducting outcomes research studies and policy makers interested in funding outcomes research studies in India. We have reviewed the literature to identify and map resources described in outcomes research studies conducted in India.MethodsWe reviewed the following online biomedical databases: Pubmed, SCIRUS, CINAHL, and Google scholar and selected articles that met the following criteria: published in English, conducted on Indian population, providing information about outcomes research resources (databases/registries/electronic medical records/electronic healthcare records/hospital information systems) in India and articles describing outcomes research studies or epidemiological studies based on outcomes research resources. After shortlisting articles, we abstracted data into three datasets viz. 1. Resource dataset, 2. Bibliometric dataset and 3. Researcher dataset and carried out descriptive analysis.ResultsOf the 126 articles retrieved, 119 articles were selected for inclusion in the study. The tally increased to 133 articles after a secondary search. Based on the information available in the articles, we identified a total of 91 unique research resources. We observed that most of the resources were Registries (62/91) and Databases ( 23/91) and were primarily located in Maharashtra (19/91) followed by Tamil Nadu (11/91), Chandigarh (8/91) and Kerala (7/91) States. These resources primarily collected data on Cancer (44/91), Stroke (5/91) and Diabetes (4/91). Most of these resources were Institutional (38/91) and Regional resources (35/91) located in Government owned and managed Academic Institutes/Hospitals (57/91) or Privately owned and managed non - Academic Institutes/Hospitals (14/91). Data from the Population based Cancer Registry, Mumbai was used in 41 peer reviewed publications followed by Population based Cancer Registry, Chennai (17) and Rural Cancer Registry Barshi (14). Most of the articles were published in International journals (139/193) that had an impact factor of 0-1.99 (43/91) and received an average of 0-20 citations (55/91). We identified 193 researchers who are mainly located in Maharashtra (37/193) and Tamil Nadu (24/193) states and Southern (76/193) and Western zones (47/193). They were mainly affiliated to Government owned & managed Academic Institutes /Hospitals (96/193) or privately owned and managed Academic Institutes/ Hospitals (35/193).ConclusionsGiven the importance of Outcomes research, relevant resources should be supported and encouraged which would help in the generation of important healthcare data that can guide health and research policy. Clarity about the distribution of outcomes research resources can facilitate future resource and funding allocation decisions for policy makers as well as help them measure research performance over time.
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