Analyzing the effects of physical activity levels on aggressive behavior in college students using a chain-mediated model.

This study aims to examine the mediating role of self-efficacy (SE) and self-control (SC) in the relationship between physical activity (PA) and aggressive behaviors (AB) among college students. It provides a basis for the prevention and control of AB among college students. This study employed a survey research methodology, including the PA Level Scale, the General Self-efficacy Scale, the Self-control Scale, and the Chinese Aggressive Behaviors Scale on 950 college students. The chain mediating effect test and Bootstrap analysis were applied. The results were as follows: (1) There was a main effect of PA on SE, SC, and AB as well as all sub-indicators (physical aggression, verbal aggression, anger, hostility, self-directed aggression), i.e., PA had a direct effect on the control of all three; (2) PA level was significantly negatively correlated with AB and significantly positively correlated with SE and SC. That is, the higher the level of PA, the better the SE and SC, and the lower the probability of AB; (3) The three pathways had mediating effects: PA → SE → AB, PA → SC → AB, PA → SE → SC → AB, with effect sizes of 8.78%, 28.63%, and 19.08%, respectively. It is concluded that regular PA is a potent method for decreasing aggressive behavior and psychological issues in university students while additionally promoting self-efficacy and self-control. Increasing the intensity of PA may enhance the effectiveness of these chain benefits.

Correlation between daily exercise load and physical fitness among primary school students / 中国学校卫生

Objective@#To understand the relationship between daily exercise load and physical fitness of primary school students, so as to provide relevant theoretical basis for the development of on campus physical education plans and the improvement of procedural physical health management for elementary school students.@*Methods@#A total of 223 students from 6 classes in a primary school in Beijing were selected by a stratified random cluster sampling method from May to June 2023. The daily exercise load of the students was monitored by Polar Verity Sense heart rate armband. The duration of moderate to vigorous physical activity (MVPA) and daily Training Impulse (TRIMP) value were calculated, and the related indexes of daily exercise load were analyzed. Chi square test and univariate Logistic regression analysis were used to analyze the correlation between daily exercise load and physical fitness assessment levels, and multi factor ordinal Logistic regression analysis was used to explore the influencing factors of physical fitness assessment levels.@*Results@#The average time spent in MVPA was (21.65±17.48) min. The TRIMP value was (361.47±124.81). The time spent in MVPA of primary school students in outdoor class, zero point sports, recess and after class PE were ( 8.86 ±8.56, 9.41±10.47, 1.97±3.12, 2.46±2.57) min, respectively. TRIMP values were (68.89±20.84, 72.83±30.27, 51.68±18.23, 19.99±5.78) in outdoor class, zero point sports, recess and after class PE, respectively. The results of univariate analysis showed that there were statistically significant differences in physical fitness levels among students with different genders, grades, and BMI ( χ 2=7.13, 19.04, 32.98, P <0.05). The duration of daily MVPA, along with TRIMP value during outdoor class, zero point sports, recess, and after PE class were all statistically significant with physical fitness levels ( OR =1.07, 1.05, 1.02, 1.03, 1.11, P <0.05). The results of multi factor ordinal Logistic regression analysis showed that the primary school grade (lower grade: OR =9.24, middle grade: OR =7.81), BMI (abnormal: OR =0.21), duration of daily MVPA in school ( OR =1.06), and TRIMP value during outdoor class ( OR =1.05) were statistically significant with physical fitness levels ( P <0.05).@*Conclusions@#There is a positive correlation between physical fitness and different grades, BMI, daily exercise load, and outdoor exercise load. Increasing daily exercise load can improve students physical health. It is suggested to tailor the school sports program to suit primary school students, increase both the intensity and duration of school daily sports, and promote procedural physical health management for elementary school students.

Novel organic-inorganic hybrid powder SrGa12O19:Mn2+-ethyl cellulose for efficient latent fingerprint recognition via time-gated fluorescence.

Latent fingerprints (LFPs) are important evidence in crime scenes and forensic investigations, but they are invisible to the naked eye. In this work, a novel fluorescent probe was developed by integrating a narrow-band-emitting green afterglow phosphor, SrGa12O19:Mn2+ (SGO:Mn), and ethyl cellulose (EC) for the efficient visualization of LFPs. The hydrophobic interactions between the powder and lipid-rich LFPs made the ridge structures more defined and easily identifiable. The background fluorescence of the substrates was completely avoided because of the time-gated fluorescence of the afterglow phosphor. All the three levels of LFP degrees were clearly imaged due to the high sensitivity. Moreover, the SGO:Mn-EC powder was highly stable in neutral, acidic, and alkaline environments. In addition, 60 day-aged LFPs were successfully visualized by the powder. All performances showed that this strategy for LFP recognition has merits such as low cost, non-destructive nature, reliability, superior universality, and legible details. Together, these results show the great application prospects of this powder in forensic identification and criminal investigation.