The U.S. experience with motorcycle helmets affords an important insight into the responses of adolescents to age-specific laws. Political contention has led to a number of U.S. state law changes back and forth between universal and age-specific laws. Because both kinds of law require adolescent motorcyclists to wear helmets, relatively few studies have focused on how the law type affects their behavior.
Differential behavior is tested by a systematic review of literature, leading to a meta-analysis, in relation to the experience of various states' motorcycle helmet laws. An electronic search was conducted for before-and-after studies in U.S. states that include data on adolescent helmet usage - both with a universally applicable motorcycle helmet law, and with an age-restricted law (usually, under-21 or under-18) - from observational, injury or fatality records for a certain period (e.g., 12 months) pre and post the state law change.
The search yielded ten studies, including two that compared a set of age-specific law states with a set of universal law states over the same time period. Heterogeneity analysis of seven single-state studies with raw data revealed an acceptable fit for a random-effects model. Additional noncompliance with age-restricted laws was indicated by an attributable percentage among exposed of over 65% and odds ratio exceeding 4.
About two-thirds of adolescent noncompliance with age-restricted motorcycle helmet usage laws disappears with universal applicability. Evidence from numerous international studies of youth reaction to helmet laws suggests that a large part of the greater compliance with universal laws is due to their conveying a more convincing message that helmets afford protection against injury. Practical Applications: The meta-analysis provides fresh, young-rider perspective on the continuing debate over motorcycle-helmet laws. Broader insight into adolescent psychology suggests considering alternatives to age-restricted laws more widely in safety and health policy.

Adolescent noncompliance with age-specific versus universal US motorcycle helmet laws: Systematic review and meta-analysis.

Non-compliance with smoke-free law is one of the determinants of untimely mortality and morbidity globally. Various studies have been conducted on non-compliance with smoke-free law in public places in different parts of the world; however, the findings are inconclusive and significantly dispersed. Moreover, there is a lack of internationally representative data, which hinders the evaluation of ongoing international activities towards smoke-free law. Therefore, this meta-analysis aimed to assess the pooled prevalence of non-compliance with smoke-free law in public places.
International electronic databases, such as PubMed/MEDLINE, Science Direct, Cochrane Library, CINAHL, African Journals Online, HINARI, Semantic Scholar, google and Google Scholar were used to retrieve the relevant articles. The study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols (PRISMA) guidelines. The Higgs I
A total of 23 articles with 25,573,329 study participants were included in this meta-analysis. The overall pooled prevalence of non-compliance with smoke-free law was 48.02% (95% CI: 33.87-62.17). Extreme heterogeneity was observed among the included studies (I
As the prevalence of non-compliance with smoke-free law is high in public places, it calls for urgent intervention. High non-compliance was found in food and drinking establishments and healthcare facilities. In light of these findings, follow-up of tobacco-free legislation and creating awareness that focused on active smokers particularly in food and drinking establishments is recommended.

Non-compliance with smoke-free law in public places: a systematic review and meta-analysis of global studies.

AbstractAll organisms struggle to make sense of environmental stimuli in order to maximize their fitness. For animals, the responses of single cells and superorganisms to stimuli are generally proportional to stimulus ratios, a phenomenon described by Weber's law. However, Weber's law has not yet been used to predict how plants respond to stimuli generated from their symbiotic partners. Here we develop a model for quantitatively predicting the ratios of carbon (C) allocation to symbionts that provide nutrients to their plant host. Consistent with Weber's law, our model demonstrates that the optimal ratio of resources allocated to a less beneficial relative to a more beneficial symbiont scale to the ratio of the growth benefits of the two strains. As C allocation to symbionts increases, the ratio of C allocation to two strains approaches the square root of the ratio of symbiotic growth benefits (e.g., a worse symbiont providing one-fourth the benefits gets 

Optimal Allocation Ratios: A Square Root Relationship between the Ratios of Symbiotic Costs and Benefits.

As face masks became mandatory in most countries during the COVID-19 pandemic, adverse effects require substantiated investigation.
A systematic review of 2,168 studies on adverse medical mask effects yielded 54 publications for synthesis and 37 studies for meta-analysis (on 
We found significant effects in both medical surgical and N95 masks, with a greater impact of the second. These effects included decreased SpO
Masks interfered with O
Face mask side-effects must be assessed (risk-benefit) against the available evidence of their effectiveness against viral transmissions. In the absence of strong empirical evidence of effectiveness, mask wearing should not be mandated let alone enforced by law.
https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021256694, identifier: PROSPERO 2021 CRD42021256694.

Physio-metabolic and clinical consequences of wearing face masks-Systematic review with meta-analysis and comprehensive evaluation.

Ramadan is one of the five pillars of Islam, during which fasting is obligatory for all healthy individuals. Although pregnant women are exempt from this Islamic law, the majority nevertheless choose to fast. This review aims to identify the effects of Ramadan fasting on the offspring of Muslim mothers, particularly on fetal growth, birth indices, cognitive effects and long-term effects. A systematic literature search was conducted until March 2020 in Web of Science, Pubmed, Cochrane Library, Embase and Google Scholar. Studies were evaluated based on a pre-defined quality score ranging from 0 (low quality) to 10 (high quality), and 43 articles were included. The study quality ranged from 2 to 9 with a mean quality score of 5.4. Only 3 studies had a high quality score (>7), of which one found a lower birth weight among fasting women. Few medium quality studies found a significant negative effect on fetal growth or birth indices. The quality of articles that investigated cognitive and long-term effects was poor. The association between Ramadan fasting and health outcomes of offspring is not supported by strong evidence. To further elucidate the effects of Ramadan fasting, larger prospective and retrospective studies with novel designs are needed.

Ramadan Fasting during Pregnancy and Health Outcomes in Offspring: A Systematic Review.

Co-parenting interventions have been offered, particularly to enhance paternal involvement in infant care. However, little is known about whether such co-parenting interventions can be effective in improving the psychological health of families and co-parenting outcomes during the postpartum period.
The aim of this review was to examine the effects of interventions on the co-parenting relationship of families, the psychological health of members involved, and on co-parenting outcomes during the postpartum period.
This was a systematic review with a meta-analysis. Randomized controlled trials of co-parenting intervention studies were selected following the standardized methods recommended by the Cochrane Handbook for Systematic Reviews of Interventions Version 6. The Cochrane Risk of Bias Assessment tool was used to assess the risk of bias in the included studies.
Twelve co-parenting randomized controlled trials were included in this review. Most studies reported positive effects in promoting at least one domain of co-parenting in mothers and/or fathers, especially in co-parenting support, couple communication, parent-child interactions and reducing co-parenting undermining. Meta-analysis showed that mothers in the intervention group showed significantly lower depressive symptoms compared to those in the control group. The only online co-parenting intervention identified produced similar effects to that of face-to-face interventions on improving co-parenting support, and reducing co-parenting undermining. Only one study focused on parent-grandparent co-parenting, which reported positive effects on 'family management' and 'cooperation in childcare between mothers with depressive symptoms and their 'mother-in-law'. Another study found that significantly more mothers continue to breastfeed in the intervention group compared to the control group at 12 weeks postpartum as a positive outcome in co-parenting.
Co-parenting interventions have demonstrated some positive effects on co-parenting support, co-parenting undermining, couple communication, parent-child interactions of parents and the depressive symptoms of mothers. Limited evidence was found on the overall effects on co-parenting, division of labor, childrearing agreement, the psychological health of fathers, parenting self-efficacy and baby feeding practices. Further studies are recommended to examine the effects of interventions for intergenerational (parent-grandparent) families on co-parenting, the psychological health in parenting, parenting self-efficacy and baby feeding practices during the postpartum period by adopting online approaches.

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