Since their discovery and chemical characterization in the 1930s, flavins have been recognized as being capable of both one- and two-electron transfer processes, and as playing a pivotal role in ...coupling the two-electron oxidation of most organic substrates to the one-electron transfers of the respiratory chain. In addition, they are now known as versatile compounds that can function as electrophiles and nucleophiles, with covalent intermediates of flavin and substrate frequently being involved in catalysis. Flavins are thought to contribute to oxidative stress through their ability to produce superoxide, but at the same time flavins are frequently involved in the reduction of hydroperoxides, products of oxygen-derived radical reactions. Flavoproteins play an important role in soil detoxification processes via the hydroxylation of many aromatic compounds, and a simple flavoprotein in liver microsomes catalyses many reactions similar to those carried out by cytochrome P450 enzymes. Flavins are involved in the production of light in bioluminescent bacteria, and are intimately connected with light-initiated reactions such as plant phototropism and nucleic acid repair processes. Recent reports also link them to programmed cell death. The chemical versatility of flavoproteins is clearly controlled by specific interactions with the proteins with which they are bound. One of the main thrusts of current research is to try to define the nature of these interactions, and to understand in chemical terms the various steps involved in catalysis by flavoprotein enzymes.
The growing number of sport-based youth development interventions provide a potential avenue for integrating sport meaningfully into the U.S. public health agenda. However, efficacy and quality must ...be reliably established prior to widespread implementation.
A comprehensive search of databases, peer-reviewed journals, published reviews, and both published and unpublished documents yielded 10,077 distinct records. Title and abstract screening, followed by full-text screening using 6 criteria, resulted in 56 distinct studies (coalescing into 10 sport-based youth development intervention types) included in the synthesis. These studies were then independently assessed and critically appraised.
Limited efficacy data were identified, with the quality of methods and evidence largely classified as weak. Processes likely to contribute to the outcomes of sport-based youth development interventions were identified (e.g., predictors of ongoing engagement, alignment between target population and intervention, intervention design), although more rigorous research is needed on these and other processes. Physical health outcomes were only studied in 3 of the 10 intervention types.
The evidence base does not yet warrant wide-scale implementation of sport-based youth development interventions for public health goals within the U. S., although there is promising research that identifies areas for further exploration.
Long-term potentiation (LTP) and long-term depression (LTD) remain widely accepted vertebrate models for the cellular and molecular mechanisms that underlie synaptic changes during learning and ...memory. Although LTD is a phenomenon that occurs in many regions of the CNS, it is clear that the mechanisms recruited in its induction and expression can vary, depending on many factors, including brain region and developmental time point. LTD in the hippocampus and cerebellum is probably the best characterized, although there are also other brain areas where mechanisms of LTD are well understood, and where it is thought to have a functional role.
Abstract
Background
Previous research has shown that school recess can provide children with physical, social and cognitive benefits; yet, recess opportunities and experiences may be different for ...different groups of children, specifically for children living in lower income environments, children of different racial groups other than white, and for children with disabilities. Parent perceptions of recess are important to consider as they serve as advocates for their children’s access and opportunities at school as well as an additional informant for children’s experiences at recess that may be useful for policymakers and school boards to consider.
Objective
To examine parent perceptions of recess by children’s disability status, children’s race and ethnicity, and family household income.
Method
Participants included 473 parents from the U.S.A. stratified across six household income levels. Data were collected through an online survey using Prolific in May of 2020. Confirmatory factor analyses were run for measures assessing parents’ perception of belonging and victimization at recess, recess policies, and recess procedures. Regression analyses were run to examine if parents’ perception of recess were predicted by race, income, or child disability status.
Results
Results revealed that parents’ perceptions of recess were predicted by child disability status but not race or income. Specifically, parents’ perceptions were significantly predicted by child disability status regarding victimization (
b
= .13,
SE
= .06,
p
= .05), recess policies about withholding recess (
b
= .171,
SE
= .07,
p
= .01), and finally, student engagement at recess (
b
= .165,
SE
= .07,
p
= .02).
Conclusion
Results show that parents of children with a disability perceive a different recess experience for their child that involves more instances of victimization compared to parents of typically developing children. Based on these findings, school, district, and state policy makers could consider ensuring that recess includes multiple activities, is supervised by adults, and is a space where conflict resolution occurs, for creating a more inclusive environment for children with disabilities.
To date, there is scant literature that examines the recess context concurrent with, but separate from, levels of physical activity. The primary purpose of the current study was to examine how recess ...quality impacted physical activity levels, and how this was moderated by gender. A secondary purpose was to examine if differences in children's engagement in activities occurred between recess sessions scored as low- or high- quality.
This was an observational study of children at 13 urban elementary schools in the U.S. Across the 13 schools, data were collected at 55 recess sessions, with 3419 child-level observations (n = 1696 boys; n = 1723 girls). Physical activity data were collected using Fitbit accelerometers, recess quality data were collected using the Great Recess Framework - Observational Tool (GRF-OT), recess engagement data were collected using the Observation of Playground Play (OPP), and basic psychological need satisfaction (BPNS) data were collected using a modified version of the BPNS for recess physical activity survey. Primary analyses were conducted using Hierarchical Linear Modeling (HLM) with children nested within recess sessions.
Gender moderated the relationship between adult engagement and moderate-to-vigorous physical activity (MVPA) (b = .012; 95% CI .001, .024), student behavior and MVPA (b = -.014; 95% CI -.021, -.007), and student behaviors and light physical activity (b = .009, 95% CI .003, .015). Both boys and girls engaged in more play during recess sessions scored as high quality on the GRF-OT. Children reported higher levels of basic psychological need satisfaction at recesses sessions scored as high quality on the GRF-OT.
Results of the current study showed that the quality of the recess environment, and the interactions of both adults and students in that environment, need to be taken into consideration in future school-based recess studies.
It is widely believed that long-term depression (LTD) and its counterpart, long-term potentiation (LTP), involve mechanisms that are crucial for learning and memory. However, LTD is difficult to ...induce in adult cortex for reasons that are not known. Here we show that LTD can be readily induced in adult cortex by the activation of NMDA receptors (NMDARs), after inhibition of glutamate uptake. Interestingly there is no need to activate synaptic NMDARs to induce this LTD, suggesting that LTD is triggered primarily by extrasynaptic NMDA receptors. We also find that de novo LTD requires the activation of NR2B-containing NMDAR, whereas LTP requires activation of NR2A-containing NMDARs. Surprisingly another form of LTD, depotentiation, requires activation of NR2A-containing NMDARs. Therefore, NMDARs with different synaptic locations and subunit compositions are involved in various forms of synaptic plasticity in adult cortex.
To examine the relationship between school recess policies, the quality of the recess environment and body mass index (BMI) among elementary school children.
Observational.
Data were collected at 23 ...schools across four geographically distinct regions of the United States. Measures included recess observations using the Great Recess Framework-Observational Tool (GRF-OT), recess policies were collected with the School Physical Activity and Policy Assessment, and BMI was obtained through height and weight measurements among 429 students in third and fifth grade.
Results showed that school policies related to recess access significantly predicted children’s BMI, and school policies related to investment in recess significantly predicted recess quality as measured by the GRF-OT.
Results from this study can be used to help inform future research regarding how school recess policies can impact child-level outcomes and the recess environment.
•School’s investment in recess significantly predicts the quality of the recess environment.•Presence of school policies relating to access to recess significantly predicted one measure of children’s physical health.•Two thirds of participating elementary schools provide less than 30 minutes of recess per school day.
Physical activity (PA) remains the primary behavioral outcome associated with school recess, while many other potentially relevant indicators of recess remain unexamined. Few studies have assessed ...observations of teacher/student interactions, peer conflict, social interactions, or safety within the recess environment. Furthermore, a psychometrically-sound instrument does not exist to examine safety, resources, student engagement, adult engagement, pro-social/anti-social behavior, and student empowerment on the playground. The purpose of the current study was to develop a valid, and reliable, assessment tool intended for use in measurement of the contextual factors associated with recess.
An iterative and multi-step process was used to develop a tool that measures safety and structure, adult engagement and supervision, student behaviors, and transitions at recess. Exploratory structural equation modeling (Mplus v. 7.4) was used to examine the underlying measurement model with observational data of the recess environment collected at 649 school-based recess periods that spanned across 22 urban/metropolitan areas in the USA. Data were also collected by two researchers at 162 recess sessions across 9 schools to examine reliability.
A 17-item observation instrument, the Great Recess Framework - Observational Tool (GRF-OT), was created. Findings of exploratory structural equation modeling (ESEM) analyses supported factorial validity for a 4-factor solution and linear regressions established convergent validity where 'structure and safety', 'adult engagement and supervision', and 'student behaviors' were all significantly related to observed activity levels. Each sub-scale of the GRF-OT showed adequate levels of inter-rater reliability and test-retest reliability analysis indicated a higher level of stability for the GRF-OT when using a three-day average across two time points as compared to a two-day average.
Initial evidence for a valid, and reliable, assessment tool to observationally measure the recess environment with a specific focus on safety, resources, student engagement, adult engagement, pro-social/anti-social behavior, and student empowerment was established in this study. Use of the GRF-OT can inspire evaluation, and subsequent intervention, to strategically create consistent, appropriate, and engaging school recess that impact children's physical, cognitive, social and emotional development.
Previous research has shown the most common memory of physical education (PE) was embarrassment, and that childhood memories of PE relate to physical activity (PA) attitude, intention, and sedentary ...behavior in adulthood 13. Recess memories may have a similar effect on adult attitudes towards PA, given that recess is a physically active part of the school day, yet is more autonomous and less supervised than PE. Recent literature has supported this, as Massey and colleagues (2021b) reported memories of recess enjoyment were associated with PA enjoyment in adulthood, whereas negative recess memories were associated with social isolation. In an effort to better understand recess memories, and how they may be related to adult behaviors, the purpose of this study was to examine qualitative descriptions of adults’ worst recess memories as it related to physical and social health.
Mixed methods design; inductive content analysis and analysis of covariance.
As part of a larger project, 433 participants between the ages of 19 and 77 (M = 44.91; SD = 15.35) were asked to recall their worst recess memories and the grades in which those memories occurred. Participants identified as predominantly female (52%), White (72%), and college educated (46%). Data analysis was conducted via an inductive content analysis by three research team members.
The most common negative memories included isolating experiences, physical injuries, victimization, and contextual factors (e.g., weather). Through a series of analysis of covariance, self-reported isolation and self-efficacy of exercise were significantly related to participants with social isolation and physical injury memories respectively.
This study adds to a growing line of research documenting the importance of recess as a developmentally impactful environment with implications for physical and emotional health.
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