286 research outputs found

    Plasma Dynamics

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    Contains reports on three research projects.Wright Air Development Division (Contract AF33(616)-3984)United States Atomic Energy Commission (Contract AT(30-1)-1842)National Science Foundation (Grant G-9330)United States Air Force, Air Force Cambridge Research Center (Contract AF19(604)-4551)United States Air Force, Air Force Cambridge Research Center, Air Research and Development Command (Contract AF19(604)-5992

    Effective interventions to increase representation of under-served groups in randomised trials in UK and Ireland: a scoping literature review [version 1; peer review: 1 approved]

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    Background Participants in clinical trials often do not reflect the populations that could benefit from the treatments being investigated. There are known barriers to trial participation for under-served groups, but limited evidence on strategies to alleviate these barriers to improve representation. This scoping review aimed to identify effective interventions and design features that improve the representation `of under-served groups in trials, focusing on the UK and Ireland. Methods We included methodological research studies that reported interventions to improve representation of ethnic minority groups, socioeconomically disadvantaged groups, older people, or those with impaired capacity to consent to randomised controlled trials, conducted in the UK and Ireland, published between 2000–2021. Systematic searches were conducted in November 2021 and data were independently extracted by two authors and narratively synthesised. Results Seven studies were included: one randomised controlled study embedded in five trials, one mixed-methods study, and five studies reporting ‘lessons learnt’ from one trial. We categorised the 47 reported interventions or strategies into nine broad themes: Recruitment sites, recruitment settings, community engagement, and communication with participants, incentives, inclusion criteria, flexibility, patient documentation, and the consent process. Only 28/47 interventions were evaluated, 23 of which were comparison of recruitment pathways. The randomised study found that a £100 incentive mentioned in the invitation letter increased positive responses overall across drug trials in cardiovascular disease and hypertension, but not for older people or those living in the most deprived areas. Invitation letters via GPs and working with communities were reported as successful recruitment pathways in recruiting different under-served populations. Conclusions Interventions aiming to improve the recruitment of under-served groups in the UK and Ireland were reported across seven papers, but their effectiveness was rarely rigorously evaluated. Included studies were context specific. Using a variety of recruitment methods is likely to help achieve a more diverse cohort

    Can X-Ray Observations Improve Optical-UV-based Accretion-rate Estimates for Quasars?

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    Article presents a study utilizing a carefully selected sample of 53 radio-quiet quasars that have Hβ and C iv λ1549 spectroscopy as well as Chandra coverage, to search for a robust accretion-rate indicator for quasars, particularly at the highest-accessible redshifts (z ∼ 6–7)

    Gemini Near Infrared Spectrograph - Distant Quasar Survey: Prescriptions for Calibrating UV-Based Estimates of Supermassive Black Hole Masses in High-Redshift Quasars

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    The most reliable single-epoch supermassive black hole mass (MBHM_{\rm BH}) estimates in quasars are obtained by using the velocity widths of low-ionization emission lines, typically the Hβ\beta λ4861\lambda4861 line. Unfortunately, this line is redshifted out of the optical band at z1z\approx1, leaving MBHM_{\rm BH} estimates to rely on proxy rest-frame ultraviolet (UV) emission lines, such as C IV λ1549\lambda1549 or Mg II λ2800\lambda2800, which contain intrinsic challenges when measuring, resulting in uncertain MBHM_{\rm BH} estimates. In this work, we aim at correcting MBHM_{\rm BH} estimates derived from the C IV and Mg II emission lines based on estimates derived from the Hβ\beta emission line. We find that employing the equivalent width of C IV in deriving MBHM_{\rm BH} estimates based on Mg II and C IV provides values that are closest to those obtained from Hβ\beta. We also provide prescriptions to estimate MBHM_{\rm BH} values when only C IV, only Mg II, and both C IV and Mg II are measurable. We find that utilizing both emission lines, where available, reduces the scatter of UV-based MBHM_{\rm BH} estimates by 15%\sim15\% when compared to previous studies. Lastly, we discuss the potential of our prescriptions to provide more accurate and precise estimates of MBHM_{\rm BH} given a much larger sample of quasars at 3.20z3.503.20 \lesssim z \lesssim 3.50, where both Mg II and Hβ\beta can be measured in the same near-infrared spectrum.Comment: 19 pages (AASTeX 6.3.1), 9 figures, accepted for publication in Ap

    Author Correction: Rapidly-migrating and internally-generated knickpoints can control submarine channel evolution (Nature Communications, (2020), 11, 1, (3129), 10.1038/s41467-020-16861-x)

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    © 2020, The Author(s). The original version of this Article contained an error in the labelling of the cross-section in Fig. 2g and the vertical axis in Fig. 2b. This has been corrected in both the PDF and HTML versions of the Article

    Effective interventions to increase representation of under-served groups in randomised trials in UK and Ireland: a scoping literature review [version 1; peer review: awaiting peer review]

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    Background: Participants in clinical trials often do not reflect the populations that could benefit from the treatments being investigated. There are known barriers to trial participation for under-served groups, but limited evidence on strategies to alleviate these barriers to improve representation. This scoping review aimed to identify effective interventions and design features that improve the representation `of under-served groups in trials, focusing on the UK and Ireland. Methods: We included methodological research studies that reported interventions to improve representation of ethnic minority groups, socioeconomically disadvantaged groups, older people, or those with impaired capacity to consent to randomised controlled trials, conducted in the UK and Ireland, published between 2000–2021. Systematic searches were conducted in November 2021 and data were independently extracted by two authors and narratively synthesised. Results: Seven studies were included: one randomised controlled study embedded in five trials, one mixed-methods study, and five studies reporting ‘lessons learnt’ from one trial. We categorised the 47 reported interventions or strategies into nine broad themes: Recruitment sites, recruitment settings, community engagement, and communication with participants, incentives, inclusion criteria, flexibility, patient documentation, and the consent process. Only 28/47 interventions were evaluated, 23 of which were comparison of recruitment pathways. The randomised study found that a £100 incentive mentioned in the invitation letter increased positive responses overall across drug trials in cardiovascular disease and hypertension, but not for older people or those living in the most deprived areas. Invitation letters via GPs and working with communities were reported as successful recruitment pathways in recruiting different under-served populations. Conclusions: Interventions aiming to improve the recruitment of under-served groups in the UK and Ireland were reported across seven papers, but their effectiveness was rarely rigorously evaluated. Included studies were context specific. Using a variety of recruitment methods is likely to help achieve a more diverse cohort

    Effective interventions to increase representation of under-served groups in randomised trials in UK and Ireland: a scoping literature review

    Get PDF
    Background Participants in clinical trials often do not reflect the populations that could benefit from the treatments being investigated. There are known barriers to trial participation for under-served groups, but limited evidence on strategies to alleviate these barriers to improve representation. This scoping review aimed to identify effective interventions and design features that improve the representation `of under-served groups in trials, focusing on the UK and Ireland. Methods We included methodological research studies that reported interventions to improve representation of ethnic minority groups, socioeconomically disadvantaged groups, older people, or those with impaired capacity to consent to randomised controlled trials, conducted in the UK and Ireland, published between 2000–2021. Systematic searches were conducted in November 2021 and data were independently extracted by two authors and narratively synthesised. Results Seven studies were included: one randomised controlled study embedded in five trials, one mixed-methods study, and five studies reporting ‘lessons learnt’ from one trial. We categorised the 47 reported interventions or strategies into nine broad themes: Recruitment sites, recruitment settings, community engagement, and communication with participants, incentives, inclusion criteria, flexibility, patient documentation, and the consent process. Only 28/47 interventions were evaluated, 23 of which were comparison of recruitment pathways. The randomised study found that a £100 incentive mentioned in the invitation letter increased positive responses overall across drug trials in cardiovascular disease and hypertension, but not for older people or those living in the most deprived areas. Invitation letters via GPs and working with communities were reported as successful recruitment pathways in recruiting different under-served populations. Conclusions Interventions aiming to improve the recruitment of under-served groups in the UK and Ireland were reported across seven papers, but their effectiveness was rarely rigorously evaluated. Included studies were context specific. Using a variety of recruitment methods is likely to help achieve a more diverse cohort
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