Improved Anthropogenic SO2 Retrieval from High-Spatial-Resolution Satellite and its Application during the COVID-19 Pandemic.

Sulfur dioxide (SO2) measured by satellites is widely used to estimate anthropogenic emissions. The Sentinel-5 Precursor (S-5P) operational SO2 product is overestimated compared to the ground-based multiaxis differential optical absorption spectroscopy (MAX-DOAS) measurements in China and shows an opposite variation to the surface measurements, which limits the application of TROPOspheric monitoring instrument (TROPOMI) products in emissions research. Radiometric calibration, a priori profiles, and fitting windows might cause the overestimation of S-5P operational SO2 product. Here, we improve the optimal-estimation-based algorithm through several calibration methods. The improved retrieval agrees reasonably well with the ground-based measurements (R > 0.70, bias <13.7%) and has smaller biases (-28.9%) with surface measurements over China and India. It revealed that the SO2 column in March 2020 decreased by 51.6% compared to March 2019 due to the lockdown for curbing the spread of the COVID-19 pandemic, and there was a decrease of 50% during the lockdown than those after the lockdown, similar to the surface measurement trend, while S-5P operational SO2 product showed an unrealistic increase of 19%. In India, the improved retrieval identified obvious "hot spots" and observed a 30% decrease of SO2 columns during the lockdown.

Developmental Pattern of Diurnal Cortisol Rhythm and Sex-Specific Associations With Psychopathological Symptoms During Pubertal Transition.

OBJECTIVE: This study aimed to examine the developmental pattern of diurnal cortisol rhythm during pubertal transition and its prospective association with psychopathological symptoms. METHODS: A cohort of 1158 children consisting of 608 boys and 550 girls aged 7 to 9 years (mean [standard deviation] age = 8.04 [0.61] years) were recruited in the Anhui Province of China in 2015 (wave 1). A single awakening sample was collected at baseline, and three additional samples were collected at one weekday in wave 2 to wave 4. Four indices of cortisol activity were evaluated and calculated across the day: awakening cortisol level, cortisol awakening response, the area under the curve with respect to ground (AUC), and the diurnal cortisol slope. In each wave, pubertal development was assessed by testicular size in boys and Tanner scales in girls. Psychopathological symptoms were ascertained in waves 2 to 4. RESULTS: Multilevel mixed models revealed no significant pubertal changes in diurnal cortisol activity in girls. In boys, awakening cortisol (ß = -0.005, p = .004) and total cortisol output (lnAUC, ß = -0.005, p = .040) significantly decreased across pubertal transition. Higher awakening cortisol and total cortisol output (lnAUC) were associated with higher scores on internalizing symptoms in girls (ß = 0.82, p < .001; ß = 0.62, p = .012) and externalizing symptoms in boys (ß = 0.73, p = .001; ß = 0.55, p = .019) during the 3-year follow-up. In contrast, no associations were found between cortisol awakening response and diurnal cortisol slope with psychopathological symptom scores in boys or girls. CONCLUSIONS: Development of diurnal cortisol activity during pubertal transition occurs in a sex-specific manner. Awakening cortisol level and daily total cortisol output may serve as markers for psychopathology during pubertal transition.

Heightened HPA-axis stress reactivity and accelerated pubertal progression predicts depressive symptoms over 4-year follow up.

Pubertal timing has been suggested as biological factors implicated in the onset of depression in girls. This study aims to examine the prospective association between accelerated pubertal progression with depressive symptoms, and to further explore the possible role of individual reactivity to social stress in this association. A total of 56 girls with early puberty timing (assessed through breast Tanner stage) and 56 age-matched normal breast development girls were recruited at Wave 1 (grade 3) and followed for 4 years biennially. Hypothalamic-pituitary-adrenal axis stress reactivity was indexed by four cortisol samples collected before, during and after the Groningen Social Stress Test (GSST) at Wave 1. Depressive symptoms were interviewed through Mood & Feeling Questionnaire (MFQ) at each wave. About 42.9% (24/56) from early pubertal timing group and 19.6% (11/56) from normal control group were found accelerated breast development during 4-year follow-up. Mixed effects linear models illustrated that among accelerated breast development girls, those with heightened stress reactivity is likely to have a 6.62 (95% CI, 1.14-12.11)-point higher MFQ scores, and 41.9% (95%CI: 25.2 to 58.6%) higher probability for depressive symptoms, compared with girls with persistent normal breast development and moderate stress reactivity. However, no similar effects were found in girls with accelerated breast development but attenuated stress reactivity. The finding suggests that heightened cortisol reactivity to social stress may represent a useful biomarker in identifying girls at greatest risk of development of depressive symptoms following accelerated pubertal progression.

Prospective association between adverse childhood experiences and pubertal development / 中国学校卫生

Objective@#To explore the impact of adverse childhood experiences on pubertal development,and to provide a reference for conducting the targeted intervention in the early stage.@*Methods@#A cluster sampling method was used to randomly select students of grades 3 to 4 from three primary schools in Ma’anshan municipality of Anhui province in October 2017. Self-reported childhood adverse experiences (ACEs), including physical, emotional and sexual abuse, as well as physical and emotional neglect were collected. Testicular volume and breast Tanner stage were assessed. A follow-up survey was conducted one year later to assess ACEs and pubertal development. ACEs of each dimension were divided into non-exposure group, transient exposure group and sustained exposure group according to ACEs exposure at baseline and follow-up. Multivariate linear regression model was used to analyze the relationship between ACEs exposure and pubertal development after 1-year follow-up.@*Results@#Sustained emotional abuse was positively associated with increased breast Tanner stage and testicular volume (breast: β=0.36, 95%CI=0.09-0.63, P<0.01; testicular volume: β=1.07, 95%CI=0.47-1.66, P<0.01); sustained physical abuse was positively associated with decreased testicular volume (β=-0.83, 95%CI=-1.58--0.08, P<0.05); sustained and transient sexual abuse were significant positively associated with decreased breast Tanner stages (sustained: β=-1.43, 95%CI=-2.86--0.02, P<0.05; transient: β=-0.45, 95%CI=-0.73--0.19, P<0.05); sustained emotional neglect was positively associated with increased breast Tanner staging (β=0.33, 95%CI=0.06-0.61, P<0.05) and decreased testicular volume (β=-0.19, 95%CI=-1.38--0.19, P<0.01).@*Conclusion@#Sustained emotional abuse was associated with early pubertal development in boys and girls,and the specitic mechanisam differences of different ACES puberty development effects and the gender differences of the same ACES puberty development effects need to be furthur explored.

Cohort study of association between caesarean section and pubertal development in boys and girls / 中国学校卫生

Objective@#To examine the prospective effect of cesarean section on pubertal development after controlling the polygenic susceptibility for early puberty in boys and girls,and to provide a reference for choosing a delivervary way beneficial to pubertal development.@*Methods@#Cluster sampling method was used to select 997 students of grade 1 to 3 from 2 priwary schools in Bengbu of Anhui in 2016 to establish the puberty development cohort. Delivery mode,birth weight,gestational age,early teeding way,family income and parental educational background were derived from parental questionnaire. Breast Tanner stage and testicular volume of 997 children were annually assessed. The polygenic risk score (PRS) was computed based on 17 SNPs derived from published genome-wide association studies for early pubertal timing. Kaplan-Meier analyses was used to examine associations between cesarean section with pubertal development in boys and girls.@*Results@#The average age of 997 children was 8.01±0.84 years old, and average BMI was (17.96±2.96) kg/m2. The prevalence of cesarean section for boys and girls was 43.30% and 32.47%, respectively. At baseline, the detection of thelarche in girls delivered by cesarean section (39.89%) was higher than that of girls delivered naturally (4.39%) (χ2=118.65, P<0.01). Similar result was observed during the last follow-up, the detection of thelarche in girls born by cesarean section (95.21%) was higher than girls born vaginally (68.48%), respectively (χ2=51.42, P<0.01). After adjusting for confounding factors (age, BMI, birthweight, infancy feeding, gestational age, household monthly income and parental education), girls delivered by cesarean section had maturation at significantly younger than girls who delivered naturally (Hazard Ratio, HR=1.98，95%CI=1.67-2.34，P<0.01).@*Conclusion@#Caesarean section might increase the risk of earlier age at pubertal onset in a sex-specific manner. Whether natural delivery could be one of the protective measures to prevent early pubertal timing in children warrants further investigation.

Parental warmth buffers against the effect of childhood bullying victimization on internalizing symptoms / 中国学校卫生

Objective@#To investigate the longitudinal association between peer bullying victimization and internalizing symptoms, and to examine whether parental warmth buffers against this effect,so as to provide a reference for improving the mental health of the special group of children.@*Methods@#Students in grade 4 and grade 5 from three primary schools in Ma’anshan, Anhui Province were selected in Oct. 2017 with informed consent. Height, weight and pubertal development were objectively assessed. Internalizing symptoms and peer bullying victimization were evaluated at baseline and 1-year follow-up by using the MacArthur Health and Behavior Questionnaire-Child. Children were classified into three groups as non-bullying, non-consistent and consistent bullying victimization group. Multiple linear regression model was used to analyze whether the association between peer bullying victimization and internalizing symptoms varied across different parental warmth groups.@*Results@#Compared with non-bullying victimization group, consistent-and non-consistent bullying victimization had higher internalizing symptoms at baseline and 1-year follow-up(P<0.01). Students reported consistent, non-consistent bullying victimization under moderate parental warmth had lower internalizing symptoms at baseline and 1-year follow-up than those reported under low parental warmth group(P<0.01). Multiple liner regression showed that consistent bullying victimization [β=0.66(95%CI=0.33-0.99), 0.37(95%CI=0.15-0.59), 0.58(95%CI=0.31-0.84), P<0.05] and non-consistent bullying victimization[β=0.33(95%CI=0.18-0.47), 0.28(95%CI=0.13-0.41), 0.29(95%CI=0.08-0.51),P<0.05] were associated with higher 1-year follow-up internalizing symptoms in non-consistent, moderate-and low parental warmth group, while such association was not observed in consistent parental warmth group.@*Abstract@#The experience of peer bullying victimization increases the risk of internalizing symptoms and this finding suggests that parental warmth help to buffer children from the internalizing symptoms associated with bullying victimization.

Hierarchical hybrid peroxidase catalysts for remediation of phenol wastewater.

We report a new family of hierarchical hybrid catalysts comprised of horseradish peroxidase (HRP)-magnetic nanoparticles for advanced oxidation processes and demonstrate their utility in the removal of phenol from water. The immobilized HRP catalyzes the oxidation of phenols in the presence of H2 O2 , producing free radicals. The phenoxy radicals react with each other in a non-enzymatic process to form polymers, which can be removed by precipitation with salts or condensation. The hybrid peroxidase catalysts exhibit three times higher activity than free HRP and are able to remove three times more phenol from water compared to free HRP under similar conditions. In addition, the hybrid catalysts reduce substrate inhibition and limit inactivation from reaction products, which are common problems with free or conventionally immobilized enzymes. Reusability is improved when the HRP-magnetic nanoparticle hybrids are supported on micron-scale magnetic particles, and can be retained with a specially designed magnetically driven reactor. The performance of the hybrid catalysts makes them attractive for several industrial and environmental applications and their development might pave the way for practical applications by eliminating most of the limitations that have prevented the use of free or conventionally immobilized enzymes.

Spatial and seasonal variability of CO2 flux at the air-water interface of the Three Gorges Reservoir.

Diffusive carbon dioxide (CO2) emissions from the water surface of the Three Gorges Reservoir, currently the largest hydroelectric reservoir in the world, were measured using floating static chambers over the course of a yearlong survey. The results showed that the average annual CO2 flux was (163.3 +/- 117.4) mg CO2/(m2.hr) at the reservoir surface, which was larger than the CO2 flux in most boreal and temperate reservoirs but lower than that in tropical reservoirs. Significant spatial variations in CO2 flux were observed at four measured sites, with the largest flux measured at Wushan (221.9 mg CO2/(m2.hr)) and the smallest flux measured at Zigui (88.6 mg CO2/(m(2).hr)); these differences were probably related to the average water velocities at different sites. Seasonal variations in CO2 flux were also observed at four sites, starting to increase in January, continuously rising until peaking in the summer (June-August) and gradually decreasing thereafter. Seasonal variations in CO2 flux could reflect seasonal dynamics in pH, water velocity, and temperature. Since the spatial and temporal variations in CO2 flux were significant and dependent on multiple physical, chemical, and hydrological factors, it is suggested that long-term measurements should be made on a large spatial scale to assess the climatic influence of hydropower in China, as well as the rest of the world.

Preliminary report on methane emissions from the Three Gorges Reservoir in the summer drainage period.

Recently reported summertime methane (CH4) emissions (6.7 +/- 13.3 mg CH4/(m2 x hr)) from newly created marshes in the drawdown area of the Three Gorges Reservoir (TGR), China have triggered broad concern in academic circles and among the public. The CH4 emissions from TGR water surfaces and drawdown areas were monitored from 3rd June to 16th October 2010 with floating and static chambers and gas chromatography. The average CH4 emission flux from permanently flooded areas in Zigui, Wushan and Yunyang Counties was (0.33 +/- 0.09) mg CH4/(m2 x hr). In half of these hottest months of the year, the wilderness, cropland and deforested drawdown sites were aerobic and located above water level, and the CH4 emissions were very small, ranging from a sink at 0.12 mg CH4/(m2 x hr) to a source at 0.08 mg CH4/(m2 x hr) except for one mud-covered site after flood. Mean CH4 emission in flooded drawdown sites was 0.34 mg CH4/(m2 x hr). The emissions from the rice paddy sites in the drawdown area were averaged at (4.86 +/- 2.31) mg CH4/(m2 x hr). Excepting the rice-paddy sites, these results show much lower emission levels than previously reported. Our results indicated considerable spatial and temporal variation in CH4 emissions from the TGR. Human activities and occasional events, such as flood, may also affect emission levels. Long-term CH4 measurements and modeling in a large region are necessary to accurately estimate greenhouse gas emissions from the TGR.

Formation of SnO2 hollow nanospheres inside mesoporous silica nanoreactors.

We report an interesting approach for efficient synthesis of SnO(2) hollow spheres inside mesoporous silica "nanoreactors". The as-prepared products are shown to have a uniform size distribution and good structural stability. When evaluated for their lithium storage properties, these SnO(2) hollow spheres manifest improved capacity retention.

Net mitigation potential of straw return to Chinese cropland: estimation with a full greenhouse gas budget model.

Based on the carbon-nitrogen cycles and greenhouse gas (GHG) mitigation and emission processes related to straw return and burning, a compound greenhouse gas budget model, the "Straw Return and Burning Model" (SRBM), was constructed to estimate the net mitigation potential of straw return to the soil in China. As a full GHG budget model, the SRBM addressed the following five processes: (1) soil carbon sequestration, (2) mitigation of synthetic N fertilizer substitution, (3) methane emission from rice paddies, (4) additional fossil fuel use for straw return, and (5) CH4 and N2O emissions from straw burning in the fields. Two comparable scenarios were created to reflect different degrees of implementation for straw return and straw burning. With GHG emissions and mitigation effects of the five processes converted into global warming potential (GWP), the net GHG mitigation was estimated. We concluded that (1) when the full greenhouse gas budget is considered, the net mitigation potential of straw return differs from that when soil carbon sequestration is considered alone; (2) implementation of straw return across a larger area of cropland in 10 provinces (i.e., Shanghai, Jiangsu, Zhejiang, Fujian, Jiangxi, Hubei, Hunan, Guangdong, Guangxi, and Hainan) will increase net GHG emission; (3) if straw return is promoted as a feasible mitigation measure in the remaining provinces, the total net mitigation potential before soil organic carbon (SOC) saturation will be 71.89 Tg CO2 equivalent (eqv)/yr, which is equivalent to 1.733% of the annual carbon emission from fossil fuel use in China in 2003; (4) after SOC saturation, only 13 of 21 provinces retain a relatively small but permanent net mitigation potential, while in the others the net GHG mitigation potential will gradually diminish; and (5) the major obstacle to the feasibility or permanence of straw return as a mitigation measure is the increased CH4 emission from rice paddies. The paper also suggests that comparable scenarios in which all the related carbon-nitrogen cycles are taken into account be created to estimate the mitigation potentials of organic wastes in different utilizations and treatments.

[Greenhouse gas emission from reservoir and its influence factors].

Reservoirs are significant sources of emissions of the greenhouse gases. Discussing greenhouse gas emission from the reservoirs and its influence factors are propitious to evaluate emission of the greenhouse gas accurately, reduce gas emission under hydraulic engineering and hydropower development. This paper expatiates the mechanism of the greenhouse gas production, sums three approaches of the greenhouse gas emission, which are emissions from nature emission of the reservoirs, turbines and spillways and downstream of the dam, respectively. Effects of greenhouse gas emission were discussed from character of the reservoirs, climate, pH of the water, vegetation growing in the reservoirs and so on. Finally, it has analyzed the heterogeneity of the greenhouse gas emission as well as the root of the uncertainty and carried on the forecast with emphasis to the next research.

Effects of elevated ozone on growth and yield of field-grown rice in Yangtze River Delta, China.

With rapid industrialization and urbanization in the Yangtze Delta, China, the tropospheric ozone concentration has increased to levels that induce crop yield loss. Rice, a widely grown crop in China, was investigated in field-established, open-top chambers. Four treatments were used: charcoal-filtered air (CF), non-charcoal-filtered air (NF), and charcoal-filtered air with two levels of additional ozone (O3-1 and O3-2). The AOT40s (accumulated hourly mean ozone concentration above 40 ppbv) were 0, 0.91, 23.24, and 39.28 ppmv x h for treatment of CF, NF, O3-1, and O3-2, respectively. The rice height and biomass were reduced in the elevated ozone concentration. Less organic matter partitioning to roots under the elevated ozone significantly decreased rice root activity. The yield loss was 14.3% and 20.2% under O3-1 and O3-2 exposure, respectively. This was largely caused by a reduction in grain weight per panicle.

[Assessment on the availability of nitrogen fertilization in improving carbon sequestration potential of China's cropland soil].

With reference to the situation of nitrogen fertilization in 2003 and the recommendations from agricultural experts on fertilization to different crops, two scenarios, namely, 'current situation' and 'fertilization as recommended', were set for estimating the current and potential carbon sequestration of China's cropland soil under nitrogen fertilization. After collecting and analyzing the typical data from the long-term agricultural experiment stations all over China, and based on the recent studies of soil organic matter and nutrient dynamics, we plotted China into four agricultural regions, and estimated the carbon sequestration rate and potential of cropland soil under the two scenarios in each province of China. Meanwhile, with the data concerning fossil fuel consumption for fertilizer production and nitrogen fertilization, the greenhouse gas leakage caused by nitrogen fertilizer production and application was estimated with the help of the parameters given by domestic studies and IPCC. We further proposed that the available carbon sequestration potential of cropland soil could be taken as the criterion of the validity and availability of carbon sequestration measures. The results showed that the application of synthetic nitrogen fertilizer could bring about a carbon sequestration potential of 21.9 Tg C x a(-1) in current situation, and 30.2 Tg C x a(-1) with fertilization as recommended. However, under the two scenarios, the greenhouse gas leakage caused by fertilizer production and application would reach 72.9 Tg C x a(-1) and 91.4 Tg C x a(-1), and thus, the actual available carbon sequestration potential would be -51.0 Tg C x a(-1) and -61.1 Tg C x a(-1), respectively. The situation was even worse under the 'fertilization as recommended' scenario, because the increase in the amount of nitrogen fertilization would lead to 10. 1 Tg C x a(-1) or more net greenhouse gas emission. All these results indicated that the application of synthetic nitrogen fertilizer could not be taken as a feasible measure for the carbon sequestration of cropland soil in China. Since synthetic fertilizer application is the basic guarantee of China's crop production, it was suggested to increase the efficiency of synthetic nitrogen fertilizer, and at the same time, to cut down the synthetic nitrogen fertilizer production and its application on the premise that the crop yield should be ensured.

[Inventory of final energy-carbon consumption and its structure in Beijing].

Final energy-carbon consumption by different sectors and fuel types in Beijing from 1995 to 2005 and energy structure were presented according to IPCC reference approach and statistical data. Specific discussion of energy-carbon consumption category of each industry in 2005 was given. From 1995 to 2005, total and per capita final energy-carbon consumption increased respectively by 71.5% and 38.4%, while final energy-carbon consumption intensity descended by 66.2%. The energy-carbon consumption of Industry was the highest and accounted for about 53.0%-68.0% of total energy-carbon consumption (an average of 14.59 Mt), followed by tertiary industry, which accounted for about 15.0%-30.5% (an average of 5.23 Mt). Moreover, compared with 1995, the energy-carbon consumption of urban residential life had increased 2.02 times in 2005. At present, energy-carbon consumption of Industry is still the predominant part, and the adjustment of industrial structure hasn't yet changed its position. The structure of final energy-carbon consumption in Beijing has become steady since 2002. Although energy structure adjustments were conducted, carbon consumption still increased with the increase of energy use.

[Methane emission from aquatic vegetation zones of Wuliangsu Lake, Inner Mongolia].

To quantify the variations of methane fluxes from different aquatic vegetation zones, two-year measurements were measured at different aquatic vegetation zones and water depths using static chamber technique during two growing season from April to October in 2003 and 2004. Results showed that the average emission flux of CH4 from Potamogeton pectinatus (submerged macrophyte) growing zones was (3.44 +/- 1.60) mg x (m2 x h)(-1), 78.06% lower than that from Phragmites australis (emergent macrophyte). Significant seasonal and diurnal variations of CH4 emission were observed for Phragmites community; however, the variations were minor for P. pectinatus. Sediment temperature at 5 cm and photosynthesis active radiation were important factors influencing seasonal and diurnal variations of CH4 fluxes from Phragmites zone. Annual methane flux from the lake was 1 024.6 t and 1 156.7 t in 2003 and 2004, respectively.