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Purpose: We examine how adolescent free time allocation—namely, screen time and outdoor time—is associated with mental health and academic performance in rural China. Methods: This paper used a large random sample of rural junior high school students in Ningxia (n = 20,375; age=13.22), with data collected from self-reported demographic questionnaires (to assess free time allocation), the Strengths and Difficulties Questionnaire (to assess mental health), and a standardized math test (to measure academic performance). We utilized a multivariate OLS regression model to examine associations between free time allocation and adolescent outcomes, controlling for individual and family characteristics. Results: Our sample's screen time and outdoor time both averaged around 1 hour. About 10% of the sample adolescents reported behavioral difficulties, while a similar percentage (11%) reported abnormal prosocial behaviors. Adolescents with higher levels of screen time (> 2 hours) were 3 percentage points more likely to have higher levels of behavioral difficulties (p< 0.001), indicating that excessive screen time was associated with worse mental health. Meanwhile, outdoor time was associated with better mental health, and positive correlations were observed at all levels of outdoor time (compared to no outdoor time, decreasing the likelihood of higher levels of behavioral difficulties by between 3 and 4 percentage points and of lower prosocial scores by between 6 and 8 percentage points; all p's< 0.001). For academic performance, average daily screen times of up to 1 hour and 1– 2 hours were both positively associated with standardized math scores (0.08 SD, p< 0.001; 0.07 SD, p< 0.01, respectively), whereas there were no significant associations between outdoor time and academic performance. Conclusion: Using a large sample size, this study was the first to examine the association between adolescent free time allocation with mental health and academic performance, providing initial insights into how rural Chinese adolescents can optimize their free time. [ABSTRACT FROM AUTHOR]

Researchers and winemakers have recently paid more attention to biodynamic (BDN) and organic (ORG) vineyard management to produce more healthy and regional wines. However, little attention has been paid to the correlation between agricultural systems, microbiota, and wine quality in biodynamic and organic wines in Ningxia, China. In this study, volatiles of wine and microorganism diversities during the wine fermentation using Cabernet Sauvignon grapes from vineyards of biodynamic, non-dynamics (BNDc, i.e., conventional one which was close to BND, considered to be a control of BND), organic, and non-organic (ORGc, i.e., conventional one which was close to BND, considered to be a control of ORG) in Ningxia, China were investigated. Hanseniaspora uvarum , Cladosporium sp., and Alternaria alternata were the main three fungal species, and Lactobacillus kunkeei , Citrus maxima , and Tatumella ptyseos were the main three bacterial species. Surprisingly, BDNc and ORG showed a significantly higher diversity of fungal communities than BDN and ORGc. The network in BDNc was the most complex, with the highest average degree and density and a higher clustering coefficient. Managing biodynamic and organic vineyards could result in floral, herb, spice, and medium floral aromas with low temperate fruit, tropical fruit, and berry flavors to wines. The correlation between agricultural systems, microbiota, and wine sensory systems showed that lactic acid bacteria (Lactobacillus) played critical roles in ORG and BDN by offering pleasant sensory and nutritional benefits. Moreover, Nowamyces globulus , Hanseniaspora uvarum , Lactobacillus johnsonii , Fusarium sp., Microterricola viridarii , Citrus maxima , Sphingomonas faeni , Cladosporium sp., Cladosporium ramotenellum , Cladosporium cladosporioides , Kodamaea ohmeri and Lactobacillus plantarum were positively correlated with aroma compounds. This study improves our understanding of the influence of vineyard management on microorganism succession and wine characteristics, providing a reference and scientific basis for the development of BDN and ORG wines. [Display omitted] • Organic (ORG) and biodynamic wines (BDN) were made from vineyards in Ningxia. • The microbial diversity, aroma, and their relations to BDN and ORG were studied. • The fermentative and oenological properties of BDN and ORG varied. • The co-occurrence network complexity varied across BDN, ORG, and conventional wines. • Lactobacillus provides a pleasant smell and nutrition in BDN and ORG. [ABSTRACT FROM AUTHOR]