Coherent photonuclear reactions for isotope transmutation

Coherent photonuclear isotope transmutation (CPIT) produces exclusively radioactive isotopes (RIs) by coherent photonuclear reactions via E1 giant resonances. Photons to be used are medium energy photons produced by laser photons backscattered off GeV electrons. The cross sections are as large as 0.2 - 0.6 b, being independent of individual nuclides. A large fraction of photons is effectively used for the photonuclear reactions, while the scattered GeV electrons remain in the storage ring to be re-used. CPIT with medium energy photons provides specific/desired RIs with the high rate and the high density for nuclear science, molecular biology and for nuclear medicines.Comment: 8 pages, 2 figure

The past, the present, and the future of future-oriented mental time travel: Editors' introduction

This introductory chapter reviews research on future-oriented mental time travel to date (the past), provides an overview of the contents of the book (the present), and enumerates some possible research directions suggested by the latter (the future)

Implementation Adherence and Perspectives of the PhysicaL ActivitY (PLAY) Policy Study: A Process Evaluation

This study entailed a process evaluation of the Childcare PhysicaL ActivitY (PLAY) Policy. Early childhood educators (ECEs) in childcare centres (n = 5) delivered the policy (which included 8 recommendations) and documented adherence (i.e., dose) in daily implementation logs. Program evaluation surveys (n = 21) and interviews (n = 10) were completed post-intervention to assess barriers/facilitators, feasibility, enjoyment, and likelihood of future implementation. Descriptive statistics and thematic analysis were conducted. Adherence was highest for delivery of child-directed play (85.9%) and lowest for delivery of frequent outdoor periods (16.5%). Participants reported they were likely to continue policy implementation, excluding frequent outdoor periods (0 = not at all likely to 5 = extremely likely; M = 2.19; SD = 1.21). Noteworthy themes identified by ECEs included weather as a barrier, and verbal prompts as a solution for increasing physical activity. These findings suggest ECEs found the policy appropriate for implementing in childcare

“Return to Play”: The Impact of, and Changes to, Ontario Children’s Physical Activity During COVID-19

This dissertation explored parents’ and their children’s perspectives of returning to play/sport during the COVID-19 pandemic in Ontario, Canada, and assessed how children’s physical activity levels changed during COVID-19. To understand the initial impact of the pandemic, Study 1 (August 2020) explored the influence of family sociodemographic factors (e.g., housing type) and risk tolerance (using the validated Tolerance of Risk in Play Scale) on parents’ return to play/sport attitudes. Via interviews with parents (n = 9) and children (n = 12), Study 2 (December 2020 – January 2021) gathered participants’ experiences of getting active during COVID-19. In Study 3, parent-reported data collected from both baseline and follow-up surveys (August 2021) were examined to understand the impact of the pandemic on children’s physical activity. In Study 1, it was found that parents’ attitudes concerning their children’s return to play/sport varied by socialization, support, and safety-related attitudes; however, attitudes were most positive towards safety-related items. Specifically, parents reported that having their children at home with them during COVID-19 made them feel safe (M = 3.86, SD = 1.11). Qualitative data revealed that parents had mixed levels of comfort about their children’s return to play/sport. Parental risk tolerance did not influence attitudes. In Study 2, children reported missing important people (e.g., coaches) as the main reason for wanting to return to play/sport, and children who had returned reported having no concerns with following COVID-19 protocols. Parents and children noted declines in children’s activity levels during COVID-19; however, they referenced getting active outdoors and virtual opportunities (e.g., YouTube) as common facilitators. Results from Study 3 revealed decreases in the proportion of children achieving 60 minutes of physical activity/day during periods of lockdown (i.e., pre-lockdown: before March 2020; during lockdown: March 2020 – June 2020; January 2021 – May 2021; and post-lockdown: August – December 2021). Generalized linear mixed-effects models revealed that the proportion of children achieving 60 minutes of physical activity/day pre-lockdown (63%) declined during lockdown (21%) and then increased post-lockdown (54%). Several demographic variables (e.g., household income) moderated results suggesting family-level factors may have influenced children’s activity during COVID-19. In conclusion, findings from this study reveal the impact of COVID-19 on children’s play/sport and provide realistic strategies families can implement to increase activity during a pandemic

Fluoride Exposure in Michigan Schoolchildren

Recent trends in the prevalence of dental caries in children, as well as a possible increase in the prevalence of dental fluorosis, have prompted some researchers to suggest the reassessment of water fluoride concentration standards. Instead of reducing water fluoride concentrations, an alternative approach would be to limit the use of, or reduce the fluoride concentration of, dentifrices, mouthrinses, and supplements. Information about the use of these other sources of fluoride, however, is scarce. Using data from a 1987 survey of Michigan schoolchildren, exposure to selected fluoride sources as well as tooth brushing habits are described. Responses from questionnaires revealed that, overall, 98.5 percent of the children have used fluoride dentifrices, 27 percent have used topical fluoride rinses, 72.5 percent have had at least one exposure to professionally applied topical fluoride, and 27percent have used dietary fluoride supplements. Although the use of fluoride dietary supplements was appropriate for most children residing in fluoride-deficient Cadillac, the percentages of children in the other communities who have ingested these supplements suggest that these products are being prescribed improperly. Given the almost universal use of fluoride dentifrices at an early age, it may be time to investigate the use of reduced fluoride dentifrices for children. In addition, continuing efforts to decrease inappropriate dietary fluoride supplementation are required.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65672/1/j.1752-7325.1990.tb03552.x.pd