The study explored sex differences in traditional school bullying perpetration and victimization among Chinese adolescents and the effects of Machiavellianism and school climate. Data were collected from 727 adolescents (M = 16.8 years, SD = 0.9) who completed the Olweus Bully/Victim Questionnaire, Kiddie Machiavellian Scale, and School Climate Perception Questionnaire. Results showed: (1) boys were more likely to bully others and be bullied; (2) both Machiavellianism and school climate partially mediated sex differences in school bullying perpetration and victimization; (3) the chain-mediating effect of Machiavellianism and school climate on sex differences in bullying perpetration and victimization was significant. These results provide insight into the sex differences in Chinese traditional school bullying perpetration and victimization. The implications are interpreted and discussed.

Personality is distal vulnerability of negative emotions and vital to mental health. Dark Triad was significantly correlated with negative emotions, whereas the mechanisms beneath the relationships were less clear. Based on life history strategy theory (LHS) and cognitive vulnerability-transactional stress model, the study explored the relationships between Dark Triad and negative emotions and investigated the roles of negative coping style and state boredom in the relationships aforementioned during the strict period of COVID-19 lockdown in China. 464 participants ( M age = 36.78 years; SD = 10.53) finished a package of measurements online including Depression Anxiety and Stress Scale (DASS-21), Short Dark Triad (SD3), Multidimensional State Boredom Scale (MSBS), and Simplified Coping Style Questionnaire (SCSQ). The results showed there were positive relationships between Dark Triad and depression, anxiety and stress. Moreover, the relationships between Dark Triad and negative emotions were sequentially mediated by negative coping style and state boredom. The present study offered fascinating perspectives in the relationships between Dark Triad and negative emotions, and revealed how Dark Triad affected depression, anxiety and stress during the initial phase of COVID-19 pandemic and strict lockdown among Chinese population. The present results may provide important implications for the prevention and intervention of depression, anxiety and stress during COVID-19 pandemic and lockdown. Specifically, the intervention strategies that focus on reducing Dark Triad, negative coping and boredom may help offset occurrence of negative emotional states.

Based on the life history theory and broadening construction theory, the study aimed to investigate the influence of Machiavellianism on the learning-related subjective well-being and the underlying mechanism, 582 Chinese senior high school students (16.8 ± 0.9 years old) including 289 girls (48.3%) and 310 boys were recruited to participate in this study, and they anonymously filled out questionnaires regarding Machiavellianism, learning-related subjective well-being, gratitude, and subjective family economic level. The results showed that: (1) a higher level of Machiavellianism was associated with a lower level of learning-related subjective well-being; (2) gratitude partially mediated the relationship between Machiavellianism and learning-related subjective well-being; (3) subjective family economic level moderated the links between Machiavellianism and learning-related subjective well-being, and between gratitude and learning-related subjective well-being. This study explained how and when Machiavellianism affected Chinese senior high school students’ learning-related subjective well-being and provided a deeper understanding of the relationship between Machiavellianism and learning-related subjective well-being.

The kernel water content during harvest is the key factor affecting mechanized grain harvest application in China. The kernel water content during corn harvest is affected by the grain filling rate, the water content at physiological maturity, and the dehydration rate after physiological maturity. In this study, two maize varieties with differing dehydration rates: DK517 (fast dehydration) and ZD1002 (slow dehydration), were treated with exogenous ABA after heading and powdering. The effect on grain filling, water content at harvest, yield, and key differential protein expression and metabolic pathways were then determined. Yield was significantly lower in DK517 than ZD1002 after application of exogenous ABA. ABA also had a greater effect on the grain filling rate in DK517, while the timing of maximum grain filling occurred 5.72 days later than that of the control and the active grain filling period was 15.49 days longer. At 60 d after pollination, the grain water content was 23.55% in DK517 and 30.42% in ZD1002, 8.88% higher and 0.26% lower than that of the control, respectively. In DK517, a total of 861 differentially expressed proteins were screened after exogenous ABA application, and of these, 246 were up-regulated and 615 were down-regulated. In ZD1002, 118 proteins were identified, of which 56 were up-regulated and 62 were down-regulated. The findings suggest that application of exogenous ABA has differing effects on the grain filling characteristics of different maize varieties, with a greater overall effect on varieties such as DK517 with a faster dehydration rate.