Publications by authors named "C Clark"

4,669 Publications

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Corrigendum to: Ashamed and Alone-Risk Factors for Alcohol Craving Among Depressed Emerging Adults.

Alcohol Alcohol 2021 Jul 31. Epub 2021 Jul 31.

Department of Psychology, York University, 4700 Keele St, North York, ON, M3J 1P3, Canada.

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http://dx.doi.org/10.1093/alcalc/agab058DOI Listing
July 2021

Impact evaluation of the Care Tipping Point Initiative in Nepal: study protocol for a mixed-methods cluster randomised controlled trial.

BMJ Open 2021 07 26;11(7):e042032. Epub 2021 Jul 26.

Gender Justice Team, CARE USA, Atlanta, Georgia, USA.

Introduction: Girl child, early and forced marriage (CEFM) persists in South Asia, with long-term consequences for girls. CARE's Tipping Point Initiative (TPI) addresses the causes of CEFM by challenging repressive gender norms and inequalities. The TPI engages different participant groups on programmatic topics and supports community dialogue to build girls' agency, shift inequitable power relations, and change community norms sustaining CEFM.

Methods/analysis: The Nepal TPI impact evaluation has an integrated, mixed-methods design. The quantitative evaluation is a three-arm, cluster randomised controlled trial (control; Tipping Point Programme (TPP); TPP+ with emphasised social norms change). Fifty-four clusters of ~200 households were selected from two districts (27:27) with probability proportional to size and randomised. A household census ascertained eligible study participants, including unmarried girls and boys 12-16 years (1242:1242) and women and men 25+ years (270:270). Baseline participation was 1134 girls, 1154 boys, 270 women and 270 men. Questionnaires covered agency; social networks/norms; and discrimination/violence. Thirty in-depth interviews, 8 key-informant interviews and 32 focus group discussions were held across eight TPP/TPP+ clusters. Guides covered gender roles/aspirations; marriage decisions; girls' safety/mobility; collective action; perceived shifts in child marriage; and norms about girls. Monitoring involves qualitative interviews, focus groups and session/event observations over two visits. Qualitative analyses follow a modified grounded theory approach. Quantitative analyses apply intention to treat, regression-based difference-in-difference strategies to assess impacts on primary (married, marriage hazard) and secondary outcomes, targeted endline tracing and regression-based methods to address potential selection bias.

Ethics/dissemination: The Nepal Social Welfare Council approved CARE Nepal to operate in the study districts. Emory (IRB00109419) and the Nepal Health Research Council (161-2019) approved the study. We follow UNICEF and CARE guidelines for ethical research involving children and gender-based violence. Study materials are here or available on request. We will share findings through clinicaltrials.gov, CARE reports/briefs and publications.

Trial Registration Number: NCT04015856.
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http://dx.doi.org/10.1136/bmjopen-2020-042032DOI Listing
July 2021

Quantification of the uncertainties within the radiotherapy dosimetry chain and their impact on tumour control.

Phys Imaging Radiat Oncol 2021 Jul 28;19:33-38. Epub 2021 Jun 28.

Department of Chemical and Process Engineering, University of Surrey, Guildford, UK.

Background And Purpose: Dose delivered during radiotherapy has uncertainty arising from a number of sources including machine calibration, treatment planning and delivery and can impact outcomes. Any systematic uncertainties will impact all patients and can continue for extended periods. The impact on tumour control probability (TCP) of the uncertainties within the radiotherapy calibration process has been assessed.

Materials And Methods: The linear-quadratic model was used to simulate the TCP from two prostate cancer and a head and neck (H&N) clinical trial. The uncertainty was separated into four components; 1) initial calibration, 2) systematic shift due to output drift, 3) drift during treatment and 4) daily fluctuations. Simulations were performed for each clinical case to model the variation in TCP present at the end of treatment arising from the different components.

Results: Overall uncertainty in delivered dose was +/-2.1% (95% confidence interval (CI)), consisting of uncertainty standard deviations of 0.7% in initial calibration, 0.8% due to subsequent calibration shift due to output drift, 0.1% due to drift during treatment, and 0.2% from daily variations. The overall uncertainty of TCP (95% CI) for a population of patients treated on different machines was +/-3%, +/-5%, and +/-3% for simulations based on the two prostate trials and H&N trial respectively.

Conclusion: The greatest variation in delivered target volume dose arose from calibration shift due to output drift. Careful monitoring of beam output following initial calibration remains vital and may have a significant impact on clinical outcomes.
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http://dx.doi.org/10.1016/j.phro.2021.06.004DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8295844PMC
July 2021

Ramadan Observance Is Associated with Impaired Kung-Fu-Specific Decision-Making Skills.

Int J Environ Res Public Health 2021 Jul 9;18(14). Epub 2021 Jul 9.

Institute of Primary Care, University of Zurich, 8006 Zurich, Switzerland.

The aim of the present study is to evaluate the effect of Ramadan observance (RAM) on decision-making in Kung-Fu athletes. Fourteen male Kung-Fu athletes (mean age = 19 ± 3 years) completed two test sessions: before Ramadan (BR) and at the end of Ramadan (ER). In the afternoon of each session (between 16:00 h and 18:00 h), participants completed: Epworth Sleepiness Scale (ESS), Profile of Mood States (POMS), and Pittsburg Sleep Quality Index (PSQI). Subjects also reported subjective fatigue, alertness, and concentration. Additionally, all participants performed video-based decision-making tasks (i.e., reaction time and decision-making). Results indicated that reaction time decreased by 30% at ER vs. BR ( < 0.01). However, decision-making decreased by 9.5% at ER vs. BR ( < 0.05). PSQI results indicated sleep quality score, sleep duration, and sleep efficiency were negatively affected at ER compared to BR ( < 0.05). ESS was higher at ER compared to BR ( < 0.05). In addition, fatigue scores, estimated by the POMS and current subjective feelings (i.e., fatigue, concentration, and alertness), were also negatively affected at ER compared to BR ( < 0.05). In conclusion, Ramadan observance was associated with an adverse effect on sleep and decision making, as well as feelings of fatigue, alertness, and concentration.
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http://dx.doi.org/10.3390/ijerph18147340DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8305331PMC
July 2021

Properties of a New Group of Cosmic Nuclei: Results from the Alpha Magnetic Spectrometer on Sodium, Aluminum, and Nitrogen.

Phys Rev Lett 2021 Jul;127(2):021101

Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwan.

We report the properties of sodium (Na) and aluminum (Al) cosmic rays in the rigidity range 2.15 GV to 3.0 TV based on 0.46 million sodium and 0.51 million aluminum nuclei collected by the Alpha Magnetic Spectrometer experiment on the International Space Station. We found that Na and Al, together with nitrogen (N), belong to a distinct cosmic ray group. In this group, we observe that, similar to the N flux, both the Na flux and Al flux are well described by the sums of a primary cosmic ray component (proportional to the silicon flux) and a secondary cosmic ray component (proportional to the fluorine flux). The fraction of the primary component increases with rigidity for the N, Na, and Al fluxes and becomes dominant at the highest rigidities. The Na/Si and Al/Si abundance ratios at the source, 0.036±0.003 for Na/Si and 0.103±0.004 for Al/Si, are determined independent of cosmic ray propagation.
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http://dx.doi.org/10.1103/PhysRevLett.127.021101DOI Listing
July 2021
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