Association between Active School Travel and Depressive Symptoms among 51,702 Adolescents in 26 Low- and Middle-Income Countries

Little is known about the role of active school travel(AST)on mental health among adolescents.Thus,this study aimed to explore the AST-depression association among adolescents aged 12–15 years from 26 low-and middle-income countries(LMICs).Data from the Global School-based Student Health Survey were analyzed in 51,702 adolescents[mean(SD)age 13.8(1.0)years;49.3%boys).Both depressive symptoms and AST were assessed by a single question self-reported measure,respectively.Participants who reported having 5 days or above were considered as AST.Multivariable logistic regression analysis(accounting for sampling weights)was performed while controlling for gender,age,physical activity,sedentary behavior,and food insecurity,and a countrywide meta-analysis was undertaken.The prevalence of depressive symptoms and AST were 30.1%and 37.0%,respectively.Compared with those not having AST,adolescents with AST were less likely to have self-reported depressive symptoms(OR=0.88,95%CI:0.85-0.93)regardless of gender.Countrywide meta-analysis demonstrated that having AST versus not having AST was associated with 12%lower odds for depressive symptoms(OR=0.88;95%CI:0.82-0.94)but with a moderate between-country heterogeneity(I^(2)=59.0%).Based on large samples of adolescents from LMICs,it would be expected that AST may play a critical role in preventing adolescent depression worldwide.However,it is necessary to consider more country-specific factors when implementing AST-related mental health interventions.Future studies should adopt the solid study design to confirm or negate our researchfindings.

Modeling urban housing price： The perspective of household activity demand

Existing studies about the modeling of urban housing price have figured out sets of factors and the main focus is on the relative spatial location. Generally, this line of research is descriptive rather than modeling in nature. The underlying reasons for the distribution of housing price are largely unexplored and more research is needed. The paper therefore attempted to systematically explore the spatial heterogeneities of urban housing price based on the urban activity interaction rule. Using Beijing as a case study, this study first developed a new measurement of accessibility which directly depicts the cost and possibilities to access opportunities of different activities such as employments, educational, shopping and medical services. From the perspective of demands of different households, the paper then modelled the relationships between urban housing price and these accessibilities and found that the distribution pattern of housing price can be relatively well represented by this model that the R^2 could achieve 0.7. We investigated the relationship between housing price and the demands of different kinds of households categorized by households of one-generation, two-generation, three-generation and four-and-plus-generation and found that the demands of household of four-and-plus-generations is the most highly correlated with housing prices. The reason might be that this kind of household has more household members and the demands are more diverse and complex, which is more similar to the distributions of all kinds of activity opportunities in the real world. In the end of the paper, some implications for policy-making are proposed based on the results of the analyses.