Associations of Residential Greenness with Depression and Anxiety in Rural Chinese Adults

BACKGROUND Depression and anxiety are top contributors to non-fatal health loss globally.Several studies have indicated the association between residential greenness and mental health.METHOD The participants(n=27,366)were recruited from four counties in Henan Province,China during 2015–2017.Symptoms of depression and anxiety were evaluated using the Patient Health Questionnaire-2(PHQ-2)and the Generalized Anxiety Disorder-2(GAD-2)in the baseline survey.The level of residential greenness during the 3-year period before the baseline survey was assessed using the Moderate Resolution Imaging Spectroradiometer(MODIS)Normalized Difference Vegetation Index(NDVI)and Enhanced Vegetation Index(EVI).The mixed-effect linear regression model was applied to examine the associations of residential greenness with depression and anxiety.RESULTS The results of adjusted models showed that the score of PHQ-2(Dscore and 95%confidence interval[CI])decreased by-0.024(-0.041,-0.006)and-0.022(-0.038,-0.004)with an interquartile range(IQR)increase in NDVI and EVI within a 1,000-m buffer radius,respectively.The score of GAD-2(Dscore and 95%CI)decreased by-0.024(-0.040,-0.006)and-0.028(-0.044,-0.011),in relation to an IQR increase in NDVI and EVI within a 1,000-m buffer radius,respectively.CONCLUSIONS A higher level of residential greenness was significantly associated with lower risk of depression and anxiety in rural areas of Henan Province.Improving residential greenness accessibility may help to promote the mental health of rural populations.

Experimental and numerical investigations of the compressive behavior of carbon fiber-reinforced polymer-strengthened tubular steel T-joints

A method for strengthening damaged tubular steel T-joints under axial compression by wrapping them with carbon fiber-reinforced polymer(CFRP)sheets was proposed and evaluated.The influence of the CFRP strengthening on the failure mode and load capacity of T-joints with different degrees of damage was investigated using experiments and finite element analyses.Five T-joints were physically tested:one bare joint to obtain the peak load and corresponding displacement(D1m),two reinforced joints to provide a reference,and two pre-damaged then retrofitted joints to serve as the primary research objects.The ratio of the pre-loaded specimen chord displacement to the value of D1m was considered to be the degree of damage of the two retrofitted joints,and was set to 0.80 and 1.20.The results demonstrate that the maximum capacity of the retrofitted specimen was increased by 0.83%–15.06%over the corresponding unreinforced specimens.However,the capacity of the retrofitted specimen was 2.51%–22.77%lesser compared with that of the directly reinforced specimens.Next,111 numerical analysis models(0.63≤b≤0.76,9.70≤g≤16.92)were established to parametrically evaluate the effects of different geometric and strengthening parameters on the load capacity of strengthened tubular T-joints under different degrees of damage.The numerical analysis results revealed that the development of equivalent plastic strain at the selected measuring points was moderated by strengthening with CFRP wrapping,and indicated the optimal CFRP strengthening thickness and wrapping orientation according to tubular T-joint parameters.Finally,reasonable equations for calculating the load capacity of CFRP-strengthened joints were proposed and demonstrated to provide accurate results.The findings of this study can be used to inform improved CFRP strengthening of damaged tubular steel structures.