The Effects of Different Durations of Night-Time Supplementary Lighting on the Growth, Yield, Quality and Economic Returns of Tomato.

To achieve higher economic returns, we employ inexpensive valley electricity for night-time supplementary lighting (NSL) of tomato plants, investigating the effects of various durations of NSL on the growth, yield, and quality of tomato. Tomato plants were treated with supplementary light for a period of 0 h, 3 h, 4 h, and 5 h during the autumn-winter season. The findings revealed superior growth and yield of tomato plants exposed to 3 h, 4 h, and 5 h of NSL compared to their untreated counterparts. Notably, providing lighting for 3 h demonstrated greater yields per plant and per trough than 5 h exposure. To investigate if a reduced duration of NSL would display similar effects on the growth and yield of tomato plants, tomato plants received supplementary light for 0 h, 1 h, 2 h, and 3 h at night during the early spring season. Compared to the control group, the stem diameter, chlorophyll content, photosynthesis rate, and yield of tomatoes significantly increased upon supplementation with lighting. Furthermore, the input-output ratios of 1 h, 2 h, and 3 h NSL were calculated as 1:10.11, 1:4.38, and 1:3.92, respectively. Nonetheless, there was no detectable difference in yield between the 1 h, 2 h, and 3 h NSL groups. These findings imply that supplemental LED lighting at night affects tomato growth in the form of light signals. Night-time supplemental lighting duration of 1 h is beneficial to plant growth and yield, and its input-output ratio is the lowest, which is an appropriate NSL mode for tomato cultivation.

Hydrochemical characteristics and quality assessment of groundwater in Guangxi coastal areas, China.

Groundwater is a main source of water supply in Guangxi Province, China. The urbanization expansion and ocean dynamic may change the groundwater quality, which is an important issue due to its effects on human health. In this paper, the influence of seawater intrusion and anthropogenic activity on the Guangxi coastal aquatic environment was assessed by geochemical and multivariate statistical methods. The result indicated that the chemical composition of groundwater in the study area is obviously associated with seawater and the main groundwater types were Ca·Na-Cl, Ca·Na-HCO3, and Ca-HCO3·Cl. The groundwater evolution path from land to sea in Guangxi is Ca-HCO3 â†’ Na·Mg-Cl. The origin of salts in the study area is mainly controlled by mineral weathering, the hydrogen and oxygen isotopes contents point to the aqueous source of atmospheric precipitation. According to the results of PCA, seawater intrusion and pollution caused by human activities play an increasingly important role in the evolution of groundwater characteristics. Seawater intrusion is the main factor for the increase of groundwater salinity in Guangxi, while domestic sewage, industrial waste, fertilizers, and pesticides may contribute to the nitrate pollution of groundwater, especially in Beihai. The degree of groundwater nitrate pollution is as follows: Fangchenggang < Qinzhou < Beihai, which is associated with the degree of urbanization in the coastal area. Finally, the results of the water quality index (WQI) assessment show that 82.8 % of the samples were classified as excellent, while there is still a need to be vigilant about groundwater pollution caused by seawater intrusion and groundwater pollution. The results will be valuable for sustainable groundwater resource management in Guangxi coastal zone.

Identifying the characteristics and potential risk of seawater intrusion for southern China by the SBM-DEA model.

Seawater intrusion (SWI) seriously affects the economic development of coastal areas in southern China, and understanding its mechanisms is the basis for effective control of SWI. Hydrogeochemical methods and slack-based measurement data envelopment analysis (SBM-DEA) are used to study the characteristics and potential risk of SWI in coastal cities of southern China. Types and distribution of SWI, coastal groundwater evolution, geological-geographic and economic threatens of SWI, potential SWI risk, and environmental management recommendations are explored. The results show that the intrusion areas of Zhejiang and Guangdong account for 94.1 % of the total intrusion area of southern China, and the intrusion degree in Zhejiang is the highest, followed by Guangdong and Fujian. SWI is prone to occur on the sandy and silty coasts of the plain area of southern China; it accelerates the groundwater evolution speed and shortens the evolution path. SBM-DEA can be well applied to evaluate the potential risk of SWI events, and the results indicate a noticeable difference in the environmental performance level of coastal cities in southern China. The low environmental performance level (<0.3) and severe SWI of Taizhou and Zhanjiang indicate that SWI gradually worsens with economic development. In contrast, the high environmental performance level (>0.7) and low SWI of Wenzhou, Fuzhou, Quanzhou, Shantou, and Beihai indicate that the potential risk of SWI is gradually decreasing. Moreover, this study confirms that the environmental Kuznets curve (EKC) phenomenon exists in SWI events for southern China, and SWI-EKC indicates that the urban development of south China is approaching maturity. The specific case of SWI and EPL in coastal cities of south China jointly indicates that optimizing industrial structure, implementing a resources management policy, and improving citizens' environmental awareness are fundamental measures to resolve the contradiction between economic development and environmental problems.

Associations Between Sedentary Behavior, Physical Activity, and Out-of-Pocket Health Care Expenditure: Evidence From Chinese Older Adults.

OBJECTIVE: This study examined the associations between sedentary behavior, physical activity, and health care expenditures among Chinese older adults. METHOD: We conducted a survey on 4,165 older men and women living in major cities in China. Sedentary behavior and physical activity were measured by the Physical Activity Scale for the Elderly questionnaire. Health care costs were assessed by self-reported out-of-pocket health care expenditures across outpatient care, inpatient care, medication, and formal caregiver expenses. RESULTS: Sedentary behavior was associated with an increase in annual out-of-pocket health care expenditures by approximately USD$37 for each additional sedentary hour (p < .001). Physical activity was associated with a decrease in annual health care expenditures by approximately USD$1.2 for each one Physical Activity Scale for the Elderly score (p < .001). Physical activity was a less salient indicator of health care expenditure for men than women. CONCLUSIONS: Reducing sedentary behavior among older men and women and promoting physical activity, especially among men, may be important strategies to reduce out-of-pocket health care expenditures in China.

The association between ambient fine particulate air pollution and physical activity: a cohort study of university students living in Beijing.

BACKGROUND: Air pollution has become a substantial environmental issue affecting human health and health-related behavior in China. Physical activity is widely accepted as a method to promote health and well-being and is potentially influenced by air pollution. Previous population-based studies have focused on the impact of air pollution on physical activity in the U.S. using a cross-sectional survey method; however, few have examined the impact on middle income countries such as China using follow-up data. The purpose of this study is to examine the impact of ambient fine particulate matter (PM2.5) air pollution on physical activity among freshmen students living in Beijing by use of follow-up data. METHODS: We conducted 4 follow-up health surveys on 3445 freshmen students from Tsinghua University from 2012 to 2013 and 2480 freshmen completed all 4 surveys. Linear individual fixed-effect regressions were performed based on repeated-measure physical activity-related health behaviors and ambient PM2.5 concentrations among the follow-up participants. RESULTS: An increase in ambient PM2.5 concentration by one standard deviation (44.72 µg/m3) was associated with a reduction in 22.32 weekly minutes of vigorous physical activity (95% confidence interval [CI] = 24.88-19.77), a reduction in 10.63 weekly minutes of moderate physical activity (95% CI = 14.61-6.64), a reduction in 32.45 weekly minutes of moderate to vigorous physical activity (MVPA) (95% CI = 37.63-27.28), and a reduction in 226.14 weekly physical activity MET-minute scores (95% CI = 256.06-196.21). The impact of ambient PM2.5 concentration on weekly total minutes of moderate physical activity tended to be greater among males than among females. CONCLUSIONS: Ambient PM2.5 air pollution significantly discouraged physical activity among Chinese freshmen students living in Beijing. Future studies are warranted to replicate study findings in other Chinese cities and universities, and policy interventions are urgently needed to reduce air pollution levels in China.

Body weight status and health-care expenditure among university retirees in Beijing, China.

OBJECTIVE: This study examined the impact of overweight and obesity on health-care expenditure among university retirees in Beijing, China. METHODS: Annual health surveys of retirees were conducted at Tsinghua University during 2011-2016. Individual random-effect regressions were performed to estimate incremental health-care expenditures attributable to overweight/obesity, adjusting for various individual characteristics. RESULTS: Compared to their normal-weight counterparts, obesity was associated with an increase in annual out-of-pocket expenditure on outpatient care by 27%, inpatient care 19% and medication 15%, and an increase in annual total out-of-pocket health-care expenditure by 33%. Overweight was associated with an increase in annual out-of-pocket expenditure on inpatient care by 13%, and an increase in annual total out-of-pocket health-care expenditure by 13%. The impact of obesity on health-care expenditure was statistically significant among men but not women. CONCLUSION: Overweight, and obesity in particular, was associated with substantial increases in out-of-pocket health-care expenditures among Chinese older adults.