Hydrodynamic motion of guiding elements within a magnetic switchyard in fast ignition conditions

Magnetic collimation via resistivity gradients is an innovative approach to electron beam control for the cone-guided fast ignition variant of inertial confinement fusion. This technique uses a resistivity gradient induced magnetic field to collimate the electron beam produced by the high-intensity laser–plasma interaction within a cone-guided fast ignition cone-tip. A variant of the resistive guiding approach, known as the “magnetic switchyard,” has been proposed which uses shaped guiding elements to direct the electrons toward the compressed fuel. Here, the 1D radiation-hydrodynamics code HYADES is used to investigate and quantify the gross hydrodynamic motion of these magnetic switchyard guiding elements in conditions relevant to their use in fast ignition. Movement of the layers was assessed for a range of two-layer material combinations. Based upon the results of the simulations, a scaling law is found that enables the relative extent of hydrodynamic motion to be predicted based upon the material properties of the switchyard, thereby enabling optimization of material-combination choice on the basis of reducing hydrodynamic motion. A multi-layered configuration, more representative of an actual switchyard, was also simulated in which an outer Au layer is employed to tamp the motion of the outermost guiding element of the switchyard

Evaluating the Outcomes of the Menthol Cigarette Ban in England by Comparing Menthol Cigarette Smoking Among Youth in England, Canada, and the US, 2018-2020

Importance: Menthol cigarettes were prohibited in England in May 2020 and nationally in Canada in October 2017 but remain permitted in the US. Evidence on the outcomes of menthol cigarette bans among youth outside of Canada, and the characteristics of youth smokers, is lacking. Objectives: To evaluate the outcomes of menthol cigarette bans on youth menthol cigarette smoking and to characterize youth menthol cigarette smokers in terms of demographics and cigarette consumption and dependence. Design, Setting, and Participants: This survey study uses data from online repeat cross-sectional International Tobacco Control Youth Tobacco and Vaping Surveys conducted in 2018, 2019, February 2020, and August 2020. Participants included past 30-day smokers aged 16 to 19 years. Data analysis was performed from March 2021 to January 2022. Main Outcomes and Measures: Usually smoke a brand of cigarettes that was menthol, including capsule. Exposures: Menthol cigarette ban, comparing 3 countries over time: Canada, where a ban already existed, England, where a ban was implemented during the study, and the US, where no national ban was present. Age, sex, race, and consumption and dependence were also examined by menthol smoking in each country, and in England before vs after the ban. Results: The analytical sample comprised 7067 participants aged 16 to 19 years, of whom 4129 were female and 5019 were White. In England, the weighted percentage of youth smokers who reported smoking a menthol or capsule cigarette brand was stable in the 3 survey waves before the menthol ban (2018 to February 2020, 9.4% vs 12.1%; adjusted odds ratio [AOR], 1.03; 95% CI, 0.99-1.06; P = .15) but decreased to 3.0% after the ban (February 2020 vs August 2020, AOR, 1.07; 95% CI, 1.04-1.10; P 5 vs 1, AOR, 1.10; 95% CI, 1.03-1.18; P = .007), or had urges to smoke every or most days (AOR, 1.08; 95% CI, 1.02-1.14; P = .006); and among smokers in Canada who perceived themselves as addicted to cigarettes (AOR, 1.02; 95% CI, 1.00-1.03; P = .01). Conclusions and Relevance: In this survey study, the proportion of youth smokers who smoke menthol (including capsule) cigarettes decreased substantially after the menthol ban in England. This association was consistent across all demographic groups. Perceived addiction among menthol smokers was also lower where menthol cigarettes were banned

Noticing education campaigns or public health messages about vaping among youth in the US, Canada, and England from 2018 to 2022

Purpose: Public health campaigns have the potential to correct vaping misperceptions. However, campaigns highlighting vaping harms to youth may increase misperceptions that vaping is equally/more harmful than smoking. Vaping campaigns have been implemented in the US and Canada since 2018, and in England since 2017, but with differing focus: youth vaping prevention (US/Canada) and smoking cessation (England). We therefore examined country differences and trends in noticing vaping campaigns among youth and, using 2022 data only, perceived valence of campaigns and associations with harm perceptions. Methods: Seven repeated cross-sectional surveys of 16–19-year-olds in US, Canada, England (2018-2022, N=92,339). Results: Over half of youth reported noticing vaping campaigns, and noticing increased from Aug’18-Feb’20 (US:55.2-74.6%,AOR=1.21,95%CI=1.18-1.24; Canada:52.6-64.5%,AOR=1.13,1.11-1.16; England:48.0-53.0%,AOR=1.05,1.02-1.08) before decreasing (Canada) or plateauing (England/US) to Aug’22. Increases were most pronounced in the US, then Canada. Noticing was most common on websites/social media, school, and television/radio. In 2022 only, most campaigns were perceived to negatively portray vaping and this was associated with accurately perceiving vaping as less harmful than smoking among youth who exclusively vaped (AOR=1.46,1.09-1.97). Conclusion: Consistent with implementation of youth vaping prevention campaigns in the US and Canada, most youth reported noticing vaping campaigns/messages, and most were perceived to negatively portray vaping

Perspectives of patients and healthcare professionals on mHealth for asthma self-management

Copyright ©ERS 2017. Mobile healthcare (mHealth) has the potential to revolutionise the self-management of long-term medical conditions such as asthma. A user-centred design is integral if mHealth is to be embraced by patients and healthcare professionals. The aim of this study was to determine the perspectives of individuals with asthma and healthcare professionals on the use of mHealth for asthma self-management. We used a sequential exploratory mixed methods design; focus groups informed the development of questionnaires, which were disseminated to individuals with asthma and healthcare professionals. Focus group participants (18 asthma patients and five healthcare professionals) identified 12 potential uses of mHealth. Questionnaire results showed that individuals with asthma (n=186) most frequently requested an mHealth system to monitor asthma over time (72%) and to collect data to present to healthcare teams (70%). In contrast, healthcare professionals (n=63) most frequently selected a system alerting patients to deteriorating asthma control (86%) and advising them when to seek medical attention (87%). Individuals with asthma were less likely than healthcare professionals (p < 0.001) to believe that assessing medication adherence and inhaler technique could improve asthma control. Our data provide strong support for mHealth for asthma self-management, but highlight fundamental differences between the perspectives of patients and healthcare professionals

Trends in E-Cigarette and Tobacco Cigarette Purchasing Behaviors by Youth in the United States, Canada, and England, 2017–2022

Objectives: This paper describes trends in youth e-cigarette (EC) and tobacco cigarette (TC) purchasing behaviors in Canada, England, and the United States (US) in relationship to changing minimum legal age (MLA) laws.Methods: Data are from eight cross-sectional online surveys among national samples of 16- to 19-year-olds in Canada, England, and the US conducted from 2017 to 2022 (N = 104,467). Average wave percentage change in EC and TC purchasing prevalence and purchase locations were estimated using Joinpoint regressions.Results: EC purchasing increased between 2017 and 2022, although the pattern of change differed by country. EC purchasing plateaued in 2019 for the US and in 2020 for Canada, while increasing through 2022 for England. TC purchasing declined sharply in the US, with purchasing from traditional retail locations declining, while purchasing from social sources increased. Vape shops were the most common location for EC purchasing, although declining in England and the US.Conclusion: Trends in EC and TC purchasing trends in the US are consistent with the expected impact of the federal MLA law increasing the legal age to 21 years in December 2019