Screen Time Correlates of Bullying Perpetration and Victimization in Brazilian Adolescents.

This study is an investigation of the associations of time spent in different screen time activities with bullying among Brazilian adolescents. In this cross-sectional study, adolescents answered questions related to bullying in the past 30 days and reported the weekly volume of screen time spent studying, working, watching videos, playing video games, and using social media applications. Multilevel logistic regression models were used.

Cross-Sectional Associations of Screen Time Activities With Alcohol and Tobacco Consumption Among Brazilian Adolescents.

Little is known about the association between specific types of screen time and adolescents' substance use. Thus, this study aimed to investigate the associations between screen time for studying, working, watching movies, playing games, and using social media and frequency of alcohol and tobacco use. In this cross-sectional study, Brazilian adolescents answered survey questions related to frequency of tobacco and alcohol consumption, and reported their daily volume of five types of screen time.

Association of sleep timing and sleep variability with health-related outcomes in a sample of Brazilian adolescents.

Objectives: This cross-sectional study aimed to examine the relationships of sleep timing and sleep variability with depressive symptoms, health-related quality of life (HRQoL), daytime sleepiness, and body mass index (BMI) in adolescents.

Methods: Adolescents from three schools ( = 571, 56% female, 16.3 ± 1.

New Aluminum Syntactic Foam: Synthesis and Mechanical Characterization.

Metal matrix syntactic foams (MMSF) are advanced cellular materials constituted by a system of a minimum of two phases, in which a dispersion of hollow particles is embedded by a continuous metal matrix. The incorporation of porous fillers favors the development of low-density materials with exceptional behavior for damping vibrations, impacts, and blast effects, shielding acoustic, thermal, and electromagnetic energies. There are three main techniques to produce them: infiltration casting technique (ICT), stir casting technique (SCT), and powder metallurgy technique (P/M).

Bidirectional Daily Associations Between Accelerometer-Measured Sleep and Physical Activity in Brazilian High School Students.

Purpose: This study analyzed day-to-day estimates of bidirectional associations between sleep parameters and intensity-specific physical activity and assessed whether the timing of physical activity influences these relationships.

Methods: The sample was comprised of 651 high school students (51.2% female, 16.