The use of screen electronic devices in the evening negatively affects sleep. Yet, sleep is known to be essential for brain maturation and a key factor for good academic performance, and thus is particularly critical during childhood and adolescence. Although previous studies reported associations between screen time and sleep impairment, their causal relationship in adolescents remains unclear. Using actigraphy and daily questionnaires in a large sample of students (12 to 19 years old), we assessed screen time in the evening and sleep habits over 1 month. This included a 2 week baseline phase, followed by a 40 min sleep education workshop and a 2 week interventional phase, in which participants were asked to stop using screen devices after 9 pm during school nights. During the interventional phase, we found that the reduction of screen time after 9 pm correlated with earlier sleep onset time and increased total sleep duration. The latter led to improved daytime vigilance. These findings provide evidence that restricting screen use in the evening represents a valid and promising approach for improving sleep duration in adolescents, with potential implications for daytime functioning and health.
Introduction: Military body fat standards were implemented in the 1980s to prevent obesity and associated poor military readiness. In the past 2 decades, enforcement of existing Army body composition standards has been eroded by the steady increase in national obesity rates, the demand for new recruits especially during the 2007 surge in Iraq, and the COVID epidemic in 2020. The diminishing qualified recruit pool puts a new focus on accession standards.
Department of Nutrition, Child Growth and Development Research Center, Research Institute for Primordial Prevention of Non-Communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran.
Introduction: Modification of natural enzymes to introduce new properties and enhance existing ones is a central challenge in bioengineering. This study is focused on the development of Taq polymerase mutants that show enhanced reverse transcriptase (RTase) activity while retaining other desirable properties such as fidelity, 5'- 3' exonuclease activity, effective deoxyuracyl incorporation, and tolerance to locked nucleic acid (LNA)-containing substrates. Our objective was to use AI-driven rational design combined with multiparametric wet-lab analysis to identify and validate Taq polymerase mutants with an optimal combination of these properties.
Introduction: The association of screen time and physical activity with body weight in children has been investigated in cross-sectional and prospective studies, as well as randomized controlled trials. The present study extends previous research by examining how longitudinal within-person changes in screen time and physical activity relate to changes in Body Mass Index (BMI) in children, and how changes in screen time and physical activity relate to each other.
Methods: The data for the present study came from the PIER Youth Study.
