418 research outputs found

    Single shot, temporally and spatially resolved measurements of fast electron dynamics using a chirped optical probe

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    A new approach to rear surface optical probing is presented that permits multiple, time-resolved 2D measurements to be made during a single, ultra-intense ( > 1018 W cm−2) laser-plasma interaction. The diagnostic is capable of resolving rapid changes in target reflectivity which can be used to infer valuable information on fast electron transport and plasma formation at the target rear surface. Initial results from the Astra-Gemini laser are presented, with rapid radial sheath expansion together with detailed filamentary features being observed to evolve during single shots

    Modelling the Main ionospheric trough using the Electron Density Assimilative Model (EDAM) with assimilated GPS TEC

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    The main ionospheric trough is a large-scale spatial depletion in the electron density distribution at the interface between the high- and mid-latitude ionosphere. In western Europe it appears in early evening, progresses equatorward during the night, and retreats rapidly poleward at dawn. It exhibits substantial day-to-day variability and under conditions of increased geomagnetic activity it moves progressively to lower latitudes. Steep gradients on the trough-walls on either side of the trough minimum, and their variability, can cause problems for radio applications. Numerous studies have sought to characterize and quantify the trough behaviour. The Electron Density Assimilative Model (EDAM) models the ionosphere on a global scale. It assimilates observations into a background ionosphere, the International Reference Ionosphere 2007 (IRI2007), to provide a full 3-D representation of the ionospheric plasma distribution at specified times and days. This current investigation studied the capability of EDAM to model the ionosphere in the region of the main trough. Total electron content (TEC) measurements from 46 GPS stations in western Europe from September to December 2002 were assimilated into EDAM to provide a model of the ionosphere in the trough region. Vertical electron content profiles through the model revealed the trough and the detail of its structure. Statistical results are presented of the latitude of the trough minimum, TEC at the minimum and of other defined parameters that characterize the trough structure. The results are compared with previous observations made with the Navy Ionospheric Monitoring System (NIMS), and reveal the potential of EDAM to model the large-scale structure of the ionospherepublishersversionPeer reviewe

    Development Of A Smoke-free Homes Intervention For Parents: An Intervention Mapping Approach

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    Exposure to second-hand smoke (SHS) is associated with various ill-health outcomes for children and adults. Barriers to creating a smoke-free home (SFH) are well-documented. Feasible and effective interventions to create smoke-free homes for disadvantaged households are lacking. Interventions that include providing parents with objective information about the impact of smoking on air quality in their home may be particularly effective. This study describes the development of a novel, theory- and evidence-based smoke-free homes intervention using objectively-assessed air quality feedback. The intervention was developed using the six-step Intervention Mapping (IM) protocol. Findings from literature reviews, focus groups with parents, interviews with health/care professionals, and expert panel discussions shaped intervention content and materials. Findings highlighted the importance of parents receiving personalised information on second-hand smoke levels in their home. Professionals considered the use of non-judgemental language essential in developed materials. Previous literature highlighted the need to address home smoking behaviour at a household rather than individual level. The AFRESH intervention is modular and designed to be delivered face-to-face by healthcare professionals. It includes up to five meetings with parents, two sets of five days’ air quality monitoring and personalised feedback, and the option to involve other household members in creating a smoke-free home using educational, motivational, and goal setting techniques. Further research is needed to evaluate the acceptability and effectiveness of the AFRESH intervention and which specific groups of parents this intervention will most likely benefit. IM was a useful framework for developing this complex intervention. This paper does not present evaluation findings

    Rowntree and the search for a British approach to management

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    Finding qualitative research: an evaluation of search strategies

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    BACKGROUND: Qualitative research makes an important contribution to our understanding of health and healthcare. However, qualitative evidence can be difficult to search for and identify, and the effectiveness of different types of search strategies is unknown. METHODS: Three search strategies for qualitative research in the example area of support for breast-feeding were evaluated using six electronic bibliographic databases. The strategies were based on using thesaurus terms, free-text terms and broad-based terms. These strategies were combined with recognised search terms for support for breast-feeding previously used in a Cochrane review. For each strategy, we evaluated the recall (potentially relevant records found) and precision (actually relevant records found). RESULTS: A total yield of 7420 potentially relevant records was retrieved by the three strategies combined. Of these, 262 were judged relevant. Using one strategy alone would miss relevant records. The broad-based strategy had the highest recall and the thesaurus strategy the highest precision. Precision was generally poor: 96% of records initially identified as potentially relevant were deemed irrelevant. Searching for qualitative research involves trade-offs between recall and precision. CONCLUSIONS: These findings confirm that strategies that attempt to maximise the number of potentially relevant records found are likely to result in a large number of false positives. The findings also suggest that a range of search terms is required to optimise searching for qualitative evidence. This underlines the problems of current methods for indexing qualitative research in bibliographic databases and indicates where improvements need to be made

    Single-Use Plastic Bans: Exploring Stakeholder Perspectives on Best Practices for Reducing Plastic Pollution

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    In this study, we conducted and documented workshops and interviews in Norway and Slovenia to identify stakeholder and future generation opinions and mitigation strategies for solving one of the most prominent environmental issues: plastic pollution. As part of the EU H2020 project GoJelly, stakeholders were brought together to explore their perceptions on considering jellyfish mucus as a new resource to contribute to reducing plastic pollution from entering the marine environment. The study was conducted in the spring of 2019, in a context directly after the European Union (EU) announced its Directive to ban the most commonly used single-use plastic (SUP) items. The study applied the snowball method as a methodological choice to identify relevant stakeholders. Systems thinking was utilized as a participatory modelling approach, which allowed for the creation of conceptual mind maps from the various workshops and interviews, to understand consumers' consciousness, and to map out ideas on plastic pollution reduction. Plastic pollution takes place on a global scale and stakeholders discussed their individual perceptions of national and international solutions that could be put in place to solve it, including the opportunities around utilizing jellyfish mucus to filter and capture micro- and nanoplastic. We found that industry stakeholders in both case areas were generally more accepting of policy and increased innovation moving forward, but placed weight on the scientific community to conduct more research on the pollution issue and propose solutions. Future generation stakeholders (youth aged 14–18), however, put emphasis on consumer behavior and buying patterns of single-use products fueling the plastic crisis.publishedVersio
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