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X-ray diffraction (XRD) is extensively used in archaeometric investigation. Herein, we provide a novel XRD spectrum-based untargeted strategy for the classification of ancient painted pottery for various dynasties. It was accomplished using the original spectrum without a phase identification. To eliminate the influence of baseline drift, a new baseline drift correction algorithm was specifically designed for XRD spectra. The algorithm was implemented using local minimum values in the analyzed signal in an iterative optimization manner. The results indicated that with the aid of the algorithm, the baseline drift problem can be successfully resolved, and the classification of ancient painted pottery can be greatly improved. Finally, the developed strategy was successfully used to discriminate ancient painted pottery from the Han and Tang dynasties in the cities of Guyuan and Zhongwei, China. The developed untargeted strategy had the remarkable advantage of almost automatic data analysis. The toolbox of our strategy can be obtained from the authors. [ABSTRACT FROM AUTHOR]

The expansion of high-speed railway (HSR) has opened up new freight capacity on traditional railway (TR) lines in China. In order to increase China’s railway volume of containers transported to port terminals, this paper estimates the HSR and TR modal splits for passenger transport. Then, the TR capacity used for passengers is calculated via traffic assignment model, and the number of passenger trains on TR lines is estimated and then deducted from total TR capacity. The remaining balance gives the freight capacity of a TR line. Moreover, a bi-level programming model is built to optimise the location of railway freight terminals and the corresponding train dispatching frequencies in a case in which trains on TR lines and trucks on highways are both used to transport containers to port terminals. The ports of Shanghai and Ningbo with their hinterlands are used as a case study for numerical analysis. [ABSTRACT FROM AUTHOR]

Many lakes in China suffer from algal bloom problems. However, the spatial and temporal distribution of lacustrine algal blooms at the national scale has not been well characterized. Here, we developed an automated algal bloom surface scums (hereafter referred to as algal bloom) detection algorithm for Moderate‐Resolution Imaging Spectroradiometer (MODIS) images based on a normalized floating algal index and the Commission on Illumination colorimetry system. This algorithm was then applied to 35,556 daily MODIS images acquired between 2003 and 2020 to hindcast the spatial and temporal dynamics of lacustrine algal blooms in 171 lakes in China. The results show that 103 (60.2%) of the examined lakes have been affected by algal blooms over the past two decades, and the bloom occurrence in 95 lakes showed an increasing trend. The prevailing increasing trends of algal blooms in Chinese lakes were also manifested by an earlier onset time and prolonged potential occurrence period. We found that approximately 80% of the historical algal blooms occurred under calm water surfaces (wind speed <3 m/s) and high temperatures (>16°C), and we revealed positive correlations between bloom occurrence and fertilizer use. We further demonstrated that the increasing trends in algal blooms were highly linked to recent increases in air temperature. The results here not only highlight the severe lacustrine algal bloom problems in China but also provide important baseline information for lake management and restoration efforts for the government. Key Points: Spatiotemporal dynamics of algal blooms in 171 lakes in China were analyzed by an automated algal bloom detection algorithm for Moderate‐Resolution Imaging Spectroradiometer images60.2% of the lakes have been affected by algal blooms, and 95 lakes showed increasing trendsThe increasing trends were highly linked to recent increases in air temperature [ABSTRACT FROM AUTHOR]

Over the past half-century, drastically increased chemical fertilizers have entered agricultural ecosystems to promote crop production on the Yangtze Plain, potentially enhancing agricultural nutrient sources for eutrophication in freshwater ecosystems. However, long-term trends of nitrogen dynamics in terrestrial ecosystems and their impacts on eutrophication changes in this region remain poorly studied. Using a process-based ecosystem model, we investigated the temporal and spatial patterns of nitrogen use efficiency (NUE) and nitrogen leaching on the Yangtze Plain from 1979–2018. The agricultural NUE for the Yangtze Plain significantly decreased from 50 % in 1979 to 25 % in 2018, with the largest decline of NUE in soybean, rice, and rapeseed. Simultaneously, the leached nitrogen from cropland and natural land increased, with annual rates of 4.5 and 0.22 kg N ha -1 yr -2 , respectively, leading to an overall increase of nitrogen inputs to the 50 large lakes. We further examined the correlations between terrestrial nutrient sources (i.e., the leached nitrogen, total phosphorus sources, and industrial wastewater discharge) and the satellite-observed probability of eutrophication occurrence (PEO) at an annual scale and showed that PEO was positively correlated with the changes in terrestrial nutrient sources for most lakes. Agricultural nitrogen and phosphorus sources were found to explain the PEO trends in lakes in the western and central part of the Yangtze Plain, and industrial wastewater discharge was associated with the PEO trends in eastern lakes. Our results revealed the importance of terrestrial nutrient sources for long-term changes in eutrophic status over the 50 lakes of the Yangtze Plain. This calls for region-specific sustainable nutrient management (i.e., nitrogen and phosphorus applications in agriculture and industry) to improve the water quality of lake ecosystems. [ABSTRACT FROM AUTHOR]

Tin and tungsten are important metals for the industrializing society. Deciphering the origin and evolution of hydrothermal fluids responsible for their formation is critical to underpin genetic models of ore formation. Traditional approaches obtain isotopic information mainly from bulk analysis of both ore and gangue minerals, or less frequently from in situ analysis of gangue minerals, which either bear inherited complexities and uncertainties or are indirect constraints. Hence, directly obtaining isotopic information from ore minerals such as cassiterite by in situ techniques is warranted. However, this has been hampered by challenges from both analytical and applicational aspects. In this study, we first demonstrate a lack of crystallographic orientation effects during cassiterite ion microprobe oxygen isotope analysis. Along with our newly developed matrix-matched reference material, the Yongde-Cst, which has a recommended δ18O value of 1.36 ± 0.16‰ (VSMOW) as defined by gas source isotope ratio mass spectrometry, in situ oxygen isotope analysis of cassiterite now is possible. We further refine the oxygen isotope fractionation (1000 ln α) for quartz-cassiterite by first-principles calculations, which is given by the equation of 1.259 × 106/T2 + 8.15 × 103/T − 4.72 (T is temperature in Kelvin). The 1000 ln α for quartz-cassiterite has a sensitive response to temperature, and makes cassiterite-quartz an excellent mineral pair in oxygen isotope thermometry, as described by the equation of T (℃) = 2427 × (δ18Oqtz − δ18Ocst)−0.4326 − 492.4. Using the well-established 1000 ln α of quartz-water, 1000 ln α of cassiterite-water is derived as 2.941 × 106/T2 − 11.45 × 103/T + 4.72 (T in Kelvin), which shows a weak response to temperature. This makes cassiterite an ideal mineral from which to derive δ18O of fluids as robust temperature estimates are no longer a prerequisite. We have applied oxygen isotope analysis to cassiterite samples from six Sn(-W) deposits in China. The results show considerable variability in δ18O values both within a single deposit and among studied deposits. Combining the δ18O of cassiterite samples and the equilibrium oxygen isotope fractionation, we find that the δ18O values of ore-forming fluids show a strong magmatic affinity with variable but mostly no to low degree involvements (~0-10%) of meteoric water, hence our results invite a reassessment on the extent and role of meteoric water in Sn-W mineralization. This study demonstrates that in situ oxygen isotope analysis of cassiterite is a promising tool to refine sources of ore-forming fluids, and to decode hydrothermal dynamics controlling tin and tungsten mineralization. [ABSTRACT FROM AUTHOR]

GLDAS2.0 provides long‐term fine resolution gridded hydrometeorological data sets, which are necessary for water‐related studies, particularly in some transboundary rivers that are partially without observation. Yet, GLDAS2.0 has only been validated at limited locations, and few studies have been conducted to develop approaches to correct the GLDAS2.0 data for transboundary rivers. This work assessed the GLDAS2.0 data and developed approaches to correct their uncertainties for studies in large transboundary rivers in the Tibetan Plateau and Northeast China (NC). To achieve these goals, observational data from 1982 to 2010 and a water and energy budget‐based distributed hydrological model including biosphere after calibration and validation were employed. We find that the GLDAS2.0 data (except for wind speed) can reasonably replicate observed seasonal variations. However, its specific humidity and wind speed have large uncertainty, and precipitation has large uncertainty in summer. In NC, the trends of its precipitation, air temperature, downward longwave radiation, and wind speed are consistent with the observations. In the Yarlung Tsangpo, Lancang, and Nu Rivers, the trends of all GLDAS2.0 data reproduce the observation very well, that is, wetting, warming, and dimming trends. Validations show that the corrections are effective and the corrected forcing data can be successfully used in hydrological simulation with improved performance than the raw GLDAS2.0 data, which demonstrates the usefulness of the methodology and corrected forcing data to hydrometeorological studies in transboundary rivers in China as well as in other nearby regions/countries. Plain Language Summary: GLDAS2.0 provides long‐term hydrometeorological data sets, which are necessary for water‐related studies, particularly in some transboundary rivers that are partially without observation. This work assessed GLDAS2.0 data and developed approaches to correct their uncertainties for studies in large transboundary rivers in the Tibetan Plateau (TP) and Northeast China (NC). In NC, the trends of GLDAS2.0 precipitation, air temperature, downward longwave radiation, and wind speed are consistent with observations. In TP, the trends of all the GLDAS2.0 data reproduce observation very well. Validations show that the corrections are effective and the corrected data have improved performance than raw GLDAS2.0 data in hydrological simulation. Key Points: Specific humidity and wind speed have large uncertainty, and precipitation has large uncertainty in summerTrends of precipitation, air temperature, downward longwave radiation, and wind speed are consistent with observationEquations are developed to reduce forcing data uncertainty, and validations show that the equations are effective [ABSTRACT FROM AUTHOR]

Background: Delay in diagnosis and treatment worsens the disease and clinical outcomes, which further enhances the transmission of tuberculosis (TB) in the community. Therefore, this study aims to assess treatment delay and its associated factors among childhood pleural TB patients in China.Methods: Between January 2006 and December 2019, consecutive patients aged ≤15 years with definite or possible pleural TB were included for analysis. Treatment delay duration was defined as the time interval from the onset of symptoms to treatment initiation and was stratified into two categories: < 30 days, ≥30 days (median delay day is 30 days). The electronic medical records of children were reviewed to obtain demographic characteristics, clinical characteristics, laboratory examinations, and radiographic findings. Univariate and multivariate logistic regressions were used to explore the factors associated with treatment delay in patients.Results: A total of 154 children with pleural TB were included, with a mean age of 12.4 ± 3.3 years. The median treatment delay was 30 days (interquartile range, 10-60 days) and 51.3% (n = 79) of patients underwent a treatment delay. Multivariate analysis revealed that heart rate (≤92 beats/min, age-adjusted OR = 2.503, 95% CI: 1.215, 5.155) and coefficient of variation of red cell distribution width (RDW-CV, ≥12.9%, age-adjusted OR = 4.705, 95% CI: 2.048, 10.811) were significant risk factors for treatment delays in childhood pleural TB.Conclusion: Our findings suggested that a significant treatment delay occurs among children with pleural TB in China. Patients with a low heart rate or a high RDW-CV experienced delays in the initiation of anti-TB therapy. Therefore, well awareness of the associations between clinical characteristics and treatment delay may improve the management of children with pleural TB and enable us to develop preventive strategies to reduce the treatment delay. [ABSTRACT FROM AUTHOR]

Temporal monitoring of inland water bodies using remote sensing images is often impeded by missing data caused by clouds and other adverse conditions. To date, various data recovery algorithms have been developed based on the water occurrence threshold (WOT), where the contaminated pixels are recovered by using long-term historical water distribution information. Here, we propose an improved algorithm, enhanced WOT (EWOT), which addresses the issue of mismatch between the water occurrence product and the actual historical water presence that has been neglected by previous WOT algorithms. The EWOT algorithm achieved an overall high accuracy (with a mean absolute percentage error (MAPE) = 5.1%) and prevailed against a representative WOT algorithm. The accuracy could be further reduced (MAPE = 1.6%) after the application of a novel quality control process. In addition, the temporal coverage of the high-quality surface water area time series was improved by an average of 26.2%, and the percent count and percent area of lakes with high-quality reconstructed data reached as high as 84.5% and 94.7%, respectively, facilitating the utilization of these data in further time series analysis. In general, the improvement was closely associated with the extent of the contamination before recovery. We evaluated the algorithm's ability to be implemented on a large scale in China, and the results generally were in line with previous studies. Nonetheless, our high-quality annual-based dataset presented a more comprehensive and continuous representation of the changes in lake area spanning from 2000 to 2019. The significance of improving the existing WOT algorithms is highlighted in this study, and the proposed method can be readily extended to lakes worldwide, thus providing a valuable data source to examine the causes and possible impacts of lake dynamics. • A novel improvement towards current WOT-based reconstruction algorithms. • A robust quality control process by utilizing two effective quality indicators. • A significant improvement for the overall quality of the lake area time series. • An annual lake area dataset for 4936 natural lakes and 2237 reservoirs in China. • A substantial yet diverse lake area changes between 2000 and 2019 in China. [ABSTRACT FROM AUTHOR]

The impoundment of the Three Gorges Dam (TGD) has led to significant inundation shrinkage and water level decrease in China's largest freshwater lake, Poyang Lake. However, little is known about the influence on the lake's wetland landscapes. Here, using Moderate Resolution Imaging Spectroradiometer (MODIS) observations and a phenology-based decision tree approach, we present the spatial and temporal changes of the major wetland cover types from 2000 to 2014. Over the 15-year period, both total coverage of vegetation ( Carex spp., Triarrhena lutarioriparia L. - Phragmites, sparse grass, and Zizania latifolia communities) and the area of each community (excluding floating aquatic macrophytes community or FAM) showed significantly increasing trends, with vegetation expanded towards the lake center. In contrast, the areas of water and mudflat have decreased significantly since the TGD impoundment, and they were mainly replaced by prominently expanded vegetated areas. The transition maps during 2000–2014 show that the vegetation community transitions occurred mainly from hydrophilic cover types to those adapted to dryer conditions. Despite the significant changes in wetland cover types, the most preferable water depth for each cover type remained stable before and after the TGD. In conclusion, the vegetation compositions are primarily controlled by water depth, indicating that the recent wetland changes can be directly linked to the TGD-induced hydrological regime-shift. These results provide a critical reference for local authorities to assess the potential influence of the newly proposed dam in this lake and to optimize its future operations with respect to modulating water levels. [ABSTRACT FROM AUTHOR]

This paper reviews China's future fossil fuel supply from the perspectives of physical output and net energy output. Comprehensive analyses of physical output of fossil fuels suggest that China's total oil production will likely reach its peak, at about 230 Mt/year (or 9.6 EJ/year), in 2018; its total gas production will peak at around 350 Bcm/year (or 13.6 EJ/year) in 2040, while coal production will peak at about 4400 Mt/year (or 91.9 EJ/year) around 2020 or so. In terms of the forecast production of these fuels, there are significant differences among current studies. These differences can be mainly explained by different ultimately recoverable resources assumptions, the nature of the models used, and differences in the historical production data. Due to the future constraints on fossil fuels production, a large gap is projected to grow between domestic supply and demand, which will need to be met by increasing imports. Net energy analyses show that both coal and oil and gas production show a steady declining trend of EROI (energy return on investment) due to the depletion of shallow-buried coal resources and conventional oil and gas resources, which is generally consistent with the approaching peaks of physical production of fossil fuels. The peaks of fossil fuels production, coupled with the decline in EROI ratios, are likely to challenge the sustainable development of Chinese society unless new abundant energy resources with high EROI values can be found. [ABSTRACT FROM AUTHOR]

Using four decades of Landsat observations between 1978 and 2014, we documented and studied the long-term dynamics of the inundation conditions in the Jianghan Plain, Central China. Three morphological factors, including inundation areas, perimeters and shoreline developments (SDs), of the 51 selected lakes were calculated. Significant long-term morphological changes were found in lakes in the Jianghan Plain. The total area dramatically increased from 838.0 km2 in 1978 to 1200.8 km2 in 1989, and an overall decreasing trend was observed in the later period. The changing patterns of the perimeters and SDs were different from the inundation areas, especially for the largest lake in this area (Honghu). The inconsistent changes between the inundation area and the other two morphological parameters were likely caused by increasing human activities. This study demonstrated the importance of remote sensing in obtaining multi-decadal lake changes in terms of both the inundation area and the morphological complexity. [ABSTRACT FROM AUTHOR]

The Middle and Lower Yangtze River (MLY) basin holds the most freshwater in East Asia; however, the conditions of basin-scale water turbidity remain unknown. In this work, a remote sensing algorithm was developed to estimate the concentrations of the total suspended sediments (TSS) in large lakes and reservoirs over the MLY basin and was based on a band ratio between 555 nm and 645 nm of the atmospherically corrected surface reflectance of the Moderate Resolution Imaging Spectroradiometer (MODIS). In situ samples used to calibrate the algorithm were collected from 58 lakes and reservoirs with a TSS range of 1 to 300 mg L − 1 , and the uncertainty of this algorithm was 30–40%. The algorithm was subsequently applied to a total of 102 lakes and reservoirs located in the MLY basin to derive TSS maps from 2000 to 2014 at a 250 m spatial resolution, and the first comprehensive document of the TSS distributions and dynamics of large inland waters of the MLY basin was created. The seasonal patterns among the selected water bodies were similar, with the largest TSS concentrations occurring in the first and fourth quarters in a year and the lowest values occurring in the third quarter. In contrast, spatial heterogeneities were revealed by the 15-year long-term mean TSS climatology information. Although most lakes downstream of Poyang Lake were turbid with 15-year TSS climatology values of 45–100 mg L − 1 , waters between Poyang and Doting Lake were relatively clearer with TSS climatology values of 15–45 mg L − 1 , and the clearest waters (< 15 mg L − 1 ) were found in reservoirs. The turbidity of 64.5% (e.g., 49/76) for lakes in Class II exhibited a decreasing trend over the 15-year period, and the Three Gorges Reservoir (TGR) and Dongting Lake in Class I also showed significant TSS declines. Analysis with meteorological data shows that the intra-annual variations appear to be significantly correlated with local precipitation, with a time lag of two months for TSS. The prominent TSS decreasing trend of the lakes in Class II was probably linked to the significant NDVI increase in the MLY basin, whereas the TSS decrease in the TGR and Dongting Lake is likely to be attributed to the impoundment of the Three Gorges Dam. The TSS environmental data record (EDR) of large inland waters presented in this study serves as an important reference for future water quality monitoring and evaluation in the MLY and in China. [ABSTRACT FROM AUTHOR]

Wetlands provide important ecosystem functions for water alteration and conservation of bio-diversity, yet they are vulnerable to both human activities and climate changes. Using four decades of Landsat and HJ-1A/1B satellites observations and recently developed classification algorithms, long-term wetland changes in Poyang Lake, the largest freshwater lake of China, have been investigated in this study. In dry seasons, while the transitions from mudflat to vegetation and vice versa were comparable before 2001, vegetation area increased by 620.8 km 2 (16.6% of the lake area) between 2001 and 2013. In wet seasons, although no obvious land cover changes were observed between 1977 and 2003, ~ 30% of the Nanjishan Wetland National Nature Reserve (NWNNR) in the south lake changed from water to emerged plant during 2003 and 2014. The changing rate of the Normalized Difference Vegetation Index (NDVI) in dry seasons showed that the vegetation in the lake center regions flourished, while the growth of vegetation in the off-water areas was stressed. Rapid NDVI increase was also found in the NWNNR in the wet seasons. The relationships between the water levels and vegetation coverage also showed two regimes in both dry and wet seasons for the pre-Three Gorges Dam (TGD) period (before 2003) and post-TGD period (after 2003). Analyses of long-term hydrological and meteorological data clearly indicated that while local precipitation remained stable, the water level of Poyang Lake decreased significantly after the impoundment of the TGD, which is likely the main reason for the wetland expansion in recent years. [ABSTRACT FROM AUTHOR]

Stem cell implantation has been utilized for the repair of spinal cord injury; however, it shows unsatisfactory performance in repairing large scale lesion of an organ. We hypothesized that dental follicle cells (DFCs), which possess multipotential capability, could reconstruct spinal cord defect (SCD) in combination with biomaterials. In the present study, mesenchymal and neurogenic lineage characteristics of human DFCs (hDFCs) were identified. Aligned electrospun PCL/PLGA material (AEM) was fabricated and it would not lead to cytotoxic reaction; furthermore, hDFCs could stretch along the oriented fibers and proliferate efficiently on AEM. Subsequently, hDFCs seeded AEM was transplanted to restore the defect in rat spinal cord. Functional observation was performed but results showed no statistical significance. The following histologic analyses proved that AEM allowed nerve fibers to pass through, and implanted hDFCs could express oligodendrogenic lineage maker Olig2 in vivo which was able to contribute to remyelination. Therefore, we concluded that hDFCs can be a candidate resource in neural regeneration. Aligned electrospun fibers can support spinal cord structure and induce cell/tissue polarity. This strategy can be considered as alternative proposals for the SCD regeneration studies. [ABSTRACT FROM AUTHOR]

Harmful algal blooms depend on several factors linked to climate and catchment conditions. Blooms can show significant daily, monthly, seasonal, inter-annual variability as well as horizontal variation in a lake. In the present study, we use satellite data to explore the sensitivity of different sections of a large eutrophic lake (Lake Taihu) to climate and catchment-related drivers. Bloom coverage in the larger open areas of the lake, historically less eutrophic, has increased over the last 12 years even though extensive efforts were made to improve catchment conditions. Decadal trends in these lake sections were more sensitive to climate conditions and nutrient concentrations compared with the more enclosed eutrophic bays. Bloom coverage was bimodal during the year, with regional differences occurring during the second maximum. Links between climate variability, nutrients, and bloom coverage suggest that major bloom events are likely to continue to occur. [ABSTRACT FROM AUTHOR]

• Winter warming rate is faster than spring in RCP6.0 and RCP8.5, and similar in RCP2.6. • Winter air temperature increasing rate almost double that in spring in 2030–2059. • Snow contribution to spring average runoff decreases by at least 39% in 2030–2059. • Snow contribution to spring maximum discharge decreases by at least 23% in 2030–2059. • Spring snow melt runoff peak moves from April to March in 2070–2099 under RCP8.5. As an important agriculture production area in the world and a flood prone area, future hydro-climate changes in winter and spring in Northeast China could have remarkable influence on spring water resources and flood. Yet, studies on future hydro-climate variations with special considerations of snow influences remain limited so far in the region. Here, we studied future winter and spring hydro-climate changes to the end of the century with special considerations of snow variations under the RCP2.6, RCP6.0 and RCP8.5 scenarios in Northeast China. A water and energy budget-based distributed biosphere hydrological model with improved snow physics was implemented. We find that winter and spring are warming 0.08 °C and 0.06 °C annually under 30 years moving average in RCP8.5. Air temperature increasing rate in winter is approximately two times higher than that in spring in 2030–2059. In this period, snow melt contribution to spring average runoff and maximum runoff decrease by at least 39% and 23%, respectively, and spring soil moisture decreases by 7%. The spring snow melt runoff peak will move from April to March under the warmest climate condition (i.e., 2070–2099 in RCP8.5). The earlier snow melt renders the snow melt contribution to total runoff decrease to almost zero in May, which could increase drought severity. This study sheds some lights on changes in hydrological regimes under climate change with a focus on snow melt and the influences in the entire Northeast China for the first time, and is helpful for adaption to future climate change. [ABSTRACT FROM AUTHOR]

The article focuses on a study conducted for determining the physiological profile of elite Chinese women wrestlers. The physiological profile included testing of maximal running oxygen consumption, anaerobic power, shoulder, knee and back isokinetic torque. Most of the back and knee isokinetic torques were found to slowly increase with weight categories.

Abstract: China''s largest freshwater lake, Poyang Lake, is well known for its ecological and economic importance as well as its rapid changes in lake inundation areas. However, due to technical difficulties, to date long-term records of its dynamic inundation areas are lacking, not to mention how they are affected by climate change and/or human activities. Using Moderate Resolution Imaging Spectroradiometer (MODIS) medium-resolution (250-m) data collected between 2000 and 2010 and an objective water/land delineation method, we documented and studied the short- and long-term characteristics of lake inundation. Significant seasonality and inter-annual variability were found in the monthly and annual mean inundation areas. The inundation area ranged between 714.1km2 in October 2009 and 3162.9km2 in August 2010, and the inundation area during any particular year could change by a factor of 2.3–3.2. During the 11-year period, the maximum possible inundation area was 14 times the minimum possible inundation area, indicating extreme variability. Both the annual mean and minimum inundation areas showed statistically significant declining trends from 2000 to 2010 (−30.2km2 yr−1 and−23.9km2 yr−1, p<0.05). The changes of the inundation area were primarily driven by local precipitation during non-summer months, while during summer months of July to September when the outflow into the Yangtze River was impeded the effect of precipitation became less significant. These results provide long-term baseline data to monitor future changes in Poyang Lake''s inundation area in a timely fashion, for example quantifying the extreme drought conditions during spring 2011. [Copyright &y& Elsevier]

We explored the potential of the environment and disaster monitoring and forecasting small satellite constellations (HJ-1A/1B satellites) charge-coupled device (CCD) imagery (spatial resolution of 30 m, revisit time of 2 days) in the monitoring of total suspended sediment (TSS) concentrations in dynamic water bodies using Poyang Lake, the largest freshwater lake in China, as an example. Field surveys conducted during October 17-26, 2009 showed a wide range of TSS concentration (3-524 mg/L). Atmospheric correction was implemented using the Fast Line-of-sight Atmospheric Analysis of Spectral Hypercubes (FLAASH) module in ENVI with the aid of aerosol information retrieved from concurrent Terra/Moderate Resolution Imaging Spectroradiometer (MODIS) surveys, which worked well at the CCD bands with relatively high reflectance. A practical exponential retrieval algorithm was created between satellite remote sensing reflectance and in-situ measured TSS concentration. The retrieved results for the whole water area matched the in-situ data well at most stations. The retrieval errors may be related to the problem of scale matching and mixed pixel. In three selected subregions of Poyang Lake, the distribution trend of retrieved TSS was consistent with that of the field investigation. It was shown that HJ-1A/1B CCD imagery can be used to estimate TSS concentrations in Poyang Lake over synoptic scales after applying an appropriate atmospheric correction method and retrieval algorithm. [ABSTRACT FROM AUTHOR]

Abstract: Using MODIS 250-m resolution data, we developed a novel approach to derive the bottom topography of Poyang Lake, the largest freshwater lake of China (>3000km2 at maximum inundation) for every year between 2000 and 2009. The approach differs from other traditional methods (sonar, Lidar, optical inversion, and Radar) but takes advantage of the fast-changing nature of the lake''s inundation area. On every image, the water/land boundary is effectively a topographic isobath after correction for the water level gradient. Thus, the ~10/year carefully selected MODIS images provided incremental topographic isobaths, from which bottom topography was derived every year. Such-derived topographic maps were validated using limited historical data and other consistency checks. Most of the lake bottom showed an elevation of 12m to 17m (referenced against the elevation reference of the Woosung Horizontal Zero). Significant inter-annual variability of the bottom topography from 2000 to 2009 was found for some of the lake''s bottom, with more areas associated with bottom elevation increases than decreases. The changes and inter-annual variability in the bottom topography were attributed to the combined effect of human activities (e.g., sand dredging and levee construction) and weather events. One example was the increased bottom elevation from 2002 to 2003, which was apparently due to the excessive precipitation in 2002 and the impoundment of the Three-Gorges Dam in 2003. The 10-year record of the bottom topography of this highly dynamic lake provides baseline information to monitor the impact of future engineering and management activities, to estimate the lake''s water and sediment budgets, and to aid ship navigation. [Copyright &y& Elsevier]

Abstract: Uncertainty modeling now engages the attention of researchers in spatial temporal change analysis in remote sensing. Some studies proposed to use random sets for modeling the spatial uncertainty of image objects with uncertain boundaries, but none have considered the parameter determination problem for large datasets. In this paper we refined the random set models for monitoring monthly changes in wetland vegetation areas from series of images. Twelve cloud-free HJ-1A/1B images from April 2009 to March 2010 were used for monitoring spatial-temporal changes of Poyang Lake wetlands. We applied random sets to represent spatial uncertainty of wetland vegetation that were extracted from normalized difference vegetation index (NDVI) maps. Time series of random sets reflect the seasonal differences of location and extents of the wetlands, whereas degree of uncertainties indicated by SD and CV indices reflect the gradual change of the wetland vegetation in space. Results show that the uncertain extents of wetland vegetation change through the year, achieving the largest range and uncertainty degree in autumn. This coincides with the highly heterogeneous vegetation status in autumn, since the wetland recovers gradually after flooding and young vegetation emerges at gradually changing densities, thus providing forage in different ecological zones for different types of migratory birds. We conclude that the random set model enriches spatial-temporal modeling of phenomena which are uncertain in space and dynamic in time. [Copyright &y& Elsevier]

Abstract: In South China, the Datangpo black shales (663Ma–654.5Ma) were deposited during the Cryognian interglacial time between the Sturtian and Marinoan glaciations. Multi-geochemical proxies, including different iron speciation and relevant ratios (FeHR/FeT, FeP/FeHR and FeT/Al ratios) and molybdenum concentrations, were used to reconstruct the paleo-depositional environment of this black shale horizon. The ratios of different iron species (FeHR/FeT >0.38 and FeP/FeHR <0.80) suggest an overall anoxic conditions (ferruginous) over the deposition of the black shales, although intermittent euxinic (FeHR/FeT >0.38 and FeP/FeHR ≈0.80) and oxic (FeHR/FeT <0.38) intervals could have occurred. Furthermore, FeT/Al ratios (FeT/Al≤0.51) confirm that water column may not be persistent euxinia during the deposition of the Datangpo black shales. Meanwhile, molybdenum concentrations show a decreasing trend towards the top of the black shales, reconciling the gradual oxygenating trend during this period as stated above. Compared to δ 34SPy values in the Mesoproterozoic deep ocean, more positive δ 34SPy values of this study may result from a small size of sulfate reservoir. The small-size sulfate reservoir and concurrent enrichment of molybdenum indicate that the ocean chemistry in the Cryogenian Period is similar to that in the Archean Eon. [Copyright &y& Elsevier]

China's largest desert freshwater lake, Hongjian Nur (HN), which is the largest habitat of relict gull (Larus relictus), has rapidly changed in recent years. However, it is difficult to quantitatively monitor the dynamics of the lake and determine the causes of its changes due to the lack of in situ observation. In this study, a remote sensing-based approach was utilized to overcome these limitations. The monthly water areas during 1990–2017 were first extracted from Landsat multispectral images via an improved method based on the floating algae index (FAI). Then, lake surface elevations measured by real-time kinematics (RTK) were used to calculate the variations in the water storage of HN. Finally, the driving factors of the rapidly changed HN in different periods were investigated by correlation analysis. The result indicated that the drivers affecting the water storage of HN in different periods were not the same. Climate change was the main driving factor of lake level fluctuation during the HN relatively stable stage (1990–1998). Drought and the intensification of human activities were the main factors for the rapid shrinkage of the HN during 1999–2010. Human activities, especially coal-related industries and reservoir impoundment, likely was the primary factors driving the decrease in the water storage of HN from 2010 to 2015. After 2015, the policies that decreased the water consumed by human activities formulated by the government and humid climate were the main factor for the expansion of HN. [ABSTRACT FROM AUTHOR]

The article presents a study which examines the trends of physical education classroom teaching based on the analysis of the 5th Session of Demonstration and Observation of Physical Education Teaching in Elementary and Middle Schools in China. It notes that the study found that physical education classroom teaching had changed and objectives were set more accurately and expressed in a clear way. Furthermore, the study determined that classroom teaching strategies were more diversified.

Over the past half century, the Yangtze Plain of China has experienced rapid economic development. Lake reclamation (i.e., conversion of natural lake/wetland areas to agricultural/urban land or aquaculture, thereby reducing the area of natural waters) in particular has greatly contributed to meeting the increasing demands for food and urban development. However, until now, a comprehensive quantification and understanding of historical anthropogenic lacustrine exploitation in this region has been lacking, prohibiting assessment of the impacts of these activities. We used Landsat observations from 1973 to 2018 to track reclamation-induced changes in 112 large lakes (97.8% of the total lake area) in the Yangtze Plain. We show that 41.6% (6056.9 km2) of the total lake area has been reclaimed since the 1970s. The expansion of agricultural and built-up lands dominated the reclamation activities in the 1970s, while the increase of aquaculture zones has prevailed since the mid-1980s. Reclamation activities were closely connected to government policies and major socio-economic events and had strong impacts on lake hydrology, flood risk mitigation capacity, and water quality as revealed by satellite and in situ observations. This new quantitative understanding of anthropogenic reclamation and its associated impacts on Yangtze Plain freshwater lakes can underpin the development of strategies to reduce the impacts of lake reclamation on environmental quality. The study has also demonstrated the unique strength of using long-term series satellite images in tracking historical environmental changes in a substantial region of the world, and the methods used here are potentially extendable to other inland and coastal areas to understand similar human-environment interaction problems. • Five decades of Landsat to assess the reclamation of 112 Yangtze Plain lakes. • 41.6% of the total lake area has been reclaimed in this region since the 1970s. • Reclamation activities strongly connected to policies and socioeconomic events. • Lake reclamation has dramatic impacts on the local hydrology and water quality. [ABSTRACT FROM AUTHOR]

The eutrophication problems in lakes on the Yangtze Plain of China have attracted global concern. However, a comprehensive assessment of the eutrophication status and its evolution is still lacking for these regional lakes, mostly because of technical difficulties and/or insufficient data to cover the large region. Our study attempts to fill this knowledge gap by using the entire archive of remote sensing images from two satellite ocean color missions (MEdium Resolution Imaging Spectrometer, or MERIS (2003−2011), and Ocean and Land Color Instrument, or OLCI (2017–2018)), together with in situ data on remote sensing reflectance and chlorophyll-a (Chla) concentrations across various lakes on the Yangtze Plain. A machine learning-based piecewise Chla algorithm was developed in this study, with special considerations to improve algorithm performance under lower Chla conditions. Remotely sensed Chla and algal bloom areas were then used to classify the eutrophication status of 50 large lakes on the Yangtze Plain, and the frequent satellite observations enabled us to estimate the probability of eutrophication occurrence (PEO) for each examined lake. The long-term mean Chla ranged from 17.58 mg m−3 to 43.86 mg m−3 on the Yangtze Plain, and severe floating algal blooms were found in 7 lakes. All 50 lakes had high climatological PEO values (50%) during the study period, indicating a generally high probability of eutrophication in lakes on the Yangtze Plain. However, 21 out of 51 lakes exhibited statistically significant (p <.05) decreasing trends in PEO during the observation period, suggesting an overall improvement in the water quality of lakes on the Yangtze Plain in recent years. The methods developed here are expected to contribute to real-time monitoring of drinking water safety for local regions, and the long-term results provide valuable baseline information for future lake conservation and restoration efforts. • We developed a machine learning-based Chla algorithm for Yangtze Plain lakes. • Chla and algal bloom areas were used to classify eutrophication in 50 lakes. • Our results show a high probability of eutrophication in Yangtze Plain lakes. • We found an overall improvement in water quality of these lakes. [ABSTRACT FROM AUTHOR]

Gauge observed runoff can reflect influences of both natural hydrological cycle and human intervention. The Global Land Data Assimilation System (GLDAS) 2.0 and 2.1 provide abundant runoff which are useful for water resources assessment in ungauged/poorly gauged regions. However, GLDAS2.0 and GLDAS2.1 runoff have only been validated and inter‐compared in very limited regions. In this study, they are evaluated and inter‐compared utilizing gauge observation in 11 large river basins in China. Results show their runoff have large uncertainties: absolute values of relative bias (|RB|) being above 39% and Nash‐Sutcliffe efficiency lower than 0.15 on average, but GLDAS2.1 is better. Both of them have large uncertainty in the Tibetan Plateau:|RB|are higher than 40%. The gap between GLDAS runoff and observations could attribute to both GLDAS system uncertainty and the fact that GLDAS does not consider human intervention. Therefore, cautions should be taken when using them in coupled human‐natural systems. Plain Language Summary: Runoff data of the Global Land Data Assimilation System (GLDAS) 2.0 and 2.1 have only been validated and inter‐compared in very limited regions. We evaluated and inter‐compared GLDAS2.0 and GLDAS2.1 runoff data utilizing gauge observation in 11 large river basins in China. We found that they have large uncertainties, especially in the Tibetan Plateau. The uncertainty may result from the system itself, such as forcing data and models used. In addition, human intervention may also contribute to the uncertainty, because the system did not consider human influence. We suggest that cautions must be taken when using them. Key Points: Both GLDAS2.0 and GLDAS2.1 have large uncertainties, but GLDAS2.1 is better: absolute values of relative bias are above 39%In the Tibetan Plateau, absolute value of relative bias is 64% for GLDAS2.0 and is larger than in the Middle and Northeast China [ABSTRACT FROM AUTHOR]

The water environment has experienced prominent changes worldwide in recent decades, especially in inland waters. As an important lake region in China, the water turbidity of lakes/reservoirs in the Northeast Plain-Mountainous Region (NPLR) remains less understood, especially the influencing mechanisms of regional climatic conditions and human activities. To enhance the knowledge of turbidity dynamics and explanatory variables of NPLR water bodies, long-term turbidity estimates of lakes/reservoirs were derived from Moderate Resolution Imaging Spectroradiometer (MODIS)-Aqua observations between 2003 and 2019. The results show that most lakes/reservoirs became less turbid in NPLR during the study period, as indicated by a decreasing turbidity trend of 0.05–2.4 nephelometric turbidity units (NTU)/year. Overall, the decreased turbidity was mainly attributed to the decreased wind speed (from 2003 to 2012, r = 0.85, p < 0.01), but also to the increased normalized difference vegetation index (NDVI) of the forest region (r = −0.80, p < 0.01), with the latter being a result of the forest protection efforts of the Chinese government. The increased snowmelt depth also contributed to a substantial turbidity decline in April. In addition, distinct seasonal patterns of turbidity were observed in the NPLR, with less turbid water in the wet season (i.e., from June to August) and turbid water in the dry season (i.e., October, November, and April in the next year). This result is attributed to the rapid seasonal dynamics of precipitation and runoff. This study provided a comprehensive analysis on the influencing mechanisms of turbidity dynamics in NPLR lakes; in particular, for the first time, revealed the impacts of the national policy-mandated forest development and the snowmelt depth on lake turbidity. These findings will provide vital information for government decision-making in water environment protection in NPLR and other similar areas with densely distributed lakes. • All the examined lakes in northeastern China became less turbid from 2003 to 2019. • The decreased turbidity was mainly due to the decreased wind speed before 2012. • Forest development contributed greatly to turbidity declines after 2012. • Global warming-induced snowmelt increase led to a turbidity decrease in April. [ABSTRACT FROM AUTHOR]

Abstract: The Laobao Formation, a black chert sequence, was deposited in deep-water in the terminal Ediacaran Nanhua Basin. The chert samples have finely laminated fabric, and have no distinct recrystallization or metasomatic relict texture. There is an extremely limited detrital component and no obvious hydrothermal influence. Therefore, the chert appears to be an authigenic deep-water precipitate. The trace elements in the chert were mainly derived from seawater and thus could be a relatively unique proxy for late Precambrian seawater conditions. Redox-sensitive trace elements and relevant ratios were used to reconstruct the depositional environment of the chert sequence. Combined with iron species results of the Laobao Formation, enrichments in redox-sensitive trace elements (U, V, Mo), depleted Mn, very low Th/U ratios (<2), high V/Sc (>7.9) and V/(V+Ni) (>0.6) ratios suggest an overall anoxic and ferruginous conditions over the deposition of the chert. The pyrite sulfur isotope compositions are between −15.4‰ and 11.0‰, and show a decreasing trend toward the top of the section, possibly implying sulfate concentration gradually increased in the terminal Ediacaran Nanhua Basin, which is consistent with implication of their pyrite framboid diameter characteristics. Our data confirm that deep-water in the Nanhua Basin was still anoxic and ferruginous, and it was progressively oxidized during the terminal Ediacaran period, which could create necessary conditions for the emergence and rapid evolution of multicellular metazoans. [Copyright &y& Elsevier]

The impoundment of the Three Gorges Reservoir (TGR), the largest hydropower project in the world, has altered the sediment deposition and erosion regime of downstream-linked rivers and lakes. The extent to which the TGR impoundment has changed the surface areas of the two largest freshwater lakes in China, Lake Dongting and Lake Poyang, remains largely unknown. Here, we compared the surface areas of the two lakes pre and post the TGR impoundment as well as with a modelled non-TGR scenario. We found that the mean surface areas of Lake Dongting and Lake Poyang during the post-TGR period (2003–2016) were significantly smaller than in the pre-TGR period (1956–2002) and in the modelled non-TGR scenario (2003–2016). The impoundment of TGR has led to a shift from a sediment deposition regime to an erosion-dominated regime of the downstream-linked rivers and the two lakes. The impoundment of TGR further changed the seasonal variabilities in discharge and water level in the downstream-linked rivers and the two lakes, especially in the flood season. Our results suggest that TGR resulted in a 5.1%, 16.2%, and 12.2% decrease of the surface area of Lake Dongting in June 2003–September 2006, October 2006–September 2008, and October 2008–December 2016, respectively, and a corresponding decrease of 12.4%, 19.6%, and 15.8% for Lake Poyang. These changes cannot be attributed to variations in rainfall as no significant differences were found in the annual or monthly mean rainfall in the watersheds upstream of Luoshan and Jiujiang + Hukou between the pre-TGR and the post-TGR period. Our results call for the development of a strong holistic management plan for cascading reservoirs, including TGR, to minimize the damage of downstream lake ecosystems. Unlabelled Image • How TGR has changed the surface area of two largest freshwater lakes remains unknown. • TGR impoundment significantly reduces the expanse of the two lakes. • TGR impoundment led to shift in sedimentation regimes of the two lakes. • The development of strong holistic management plan for cascading reservoirs is needed. [ABSTRACT FROM AUTHOR]

Remote sensing of water quality in turbid coastal and inland waters requires accurate atmospheric correction, which is technically challenging. While previous efforts have shown the advantage of using the short-wave infrared (SWIR) bands instead of near-infrared (NIR) bands for atmospheric correction, such an approach could only be applied to the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Aqua satellite (MODISA). This is because MODIS data from the Terra satellite (MODIST) contain more noise and other sensor artifacts, thus this sensor has been generally regarded by the ocean color research community as not being able to provide science quality data. Here, we address this technical challenge through noise reduction and regional vicarious calibration adjustment, and demonstrate preliminary success using turbid Taihu Lake as an example. The noise in the three SWIR bands was evaluated first, and then reduced through a noise reduction method. The SWIR bands were adjusted over open-ocean waters using the well-calibrated NIR ocean bands (1-km resolution) and radiative transfer, which were then used to adjust the land bands (250-m and 500-m resolution) in the visible and NIR over turbid waters where concurrent field-measured reflectance spectra are available. Of all three combinations of SWIR bands, the combination of 1240 and 1640-nm bands was found to perform the best, showing significantly improved retrieval accuracy for Taihu Lake, leading to recovery of low-quality MODIST data to higher-quality data comparable to MODISA, and thus doubling valid data coverage. Testing of this approach on another highly turbid lake (Chaohu Lake, China) showed similar results. While the general application of this approach to turbid lakes still needs to be tested as local tuning of the calibration coefficients may be required, these results suggest that MODIST may be used as effectively as MODISA for monitoring Taihu Lake water quality. [ABSTRACT FROM AUTHOR]

• Nine state-of-the-art Chla algorithms for inland waters were evaluated. • Sensitivity of Chla algorithms to AC was quantified for the first time. • An RFR algorithm insensitive to AC uncertainty was developed for turbid lakes. • OLCI Chla products showed most lakes in eastern China are eutrophic. A robust and reliable chlorophyll-a (Chla) concentration algorithm is still lacking for optically complex waters due to the lack of understanding of the bio-optical process. Machine learning approaches, which excel at detecting potential complex nonlinear relationships, provide opportunities to estimate Chla accurately for optically complex waters. However, the uncertainties in atmospheric correction (AC) may be amplified in different Chla algorithms. Here, we aim to select one state-of-the-art algorithm or establish a new algorithm based on machine learning approaches that less sensitive to AC uncertainties. Firstly, nine state-of-the-art empirical, semianalytical, and optical water types (OWT) classification-based Chla algorithms were implemented. These existing algorithms showed good performance by using in situ database, however, failed in actual OLCI applications due to their sensitivity to AC uncertainties. Thus, four popular machine learning approaches (random forest regression (RFR), extreme gradient boosting (XGBoost), deep neural network (DNN), and support vector regression (SVR)) were then employed. Among them, the "RFR-Chla" model performed the best and showed less sensitivity to AC uncertainties. Finally, the Chla spatiotemporal variations in 163 major lakes across eastern China were mapped from OLCI between May 2016 and April 2020 using the proposed RFR-Chla model. Generally, the lakes in eastern China are severely eutrophic, with an average Chla concentration of 33.39 ± 6.95 μg/L. Spatially, Chla in the south of eastern China was significantly higher than those in northern lakes. Seasonally, Chla was high in the summer and autumn and low in the spring and winter. This study provides a reference for water quality monitoring in turbid inland waters suffering certain AC uncertainties and supports aquatic management and SDG 6 reporting. [ABSTRACT FROM AUTHOR]

• Lacustrine DOM quantity rose significantly with reclamation. • Reclamation lowered average molecular weight but increased the biolability of DOM. • Reclamation yielded higher content of chromophoric and humic-like fluorescent DOM. • More lipids and condensed aromatics were contained in DOM with reclamation. In recent decades, the reclamation of lakes has captured 42% of the total lake area of the Yangtze Plain in China and introduced additional pressure on lacustrine water quality. While lacustrine dissolved organic matter (DOM) is critical in regulating biogeochemical processing and aquatic biodiversity, the impact of reclamation on the molecular-level characteristics of lacustrine DOM remains unexplored. Here, the DOM characteristics altered by reclamation practices in the Yangtze Plain lakes were investigated using fluorescence spectroscopy, nuclear magnetic resonance spectroscopy, and Fourier transform ion cyclotron resonance mass spectrometry. Results demonstrated that reclamation not only elevated the quantity (on average +32%) but also altered the characteristics and composition of lacustrine DOM. Compared to the natural water sites close by, reclamation sites did not significantly alter the DOM aromaticity but significantly lowered the average molecular weight and increased the biolability of DOM. The chromophoric DOM and humic-like fluorescent components were remarkably elevated, but not the protein-like fluorescent components. More lipid-like and condensed aromatic-like components were detected in the lacustrine DOM as compared to the lignin-like, carbohydrate-like, and protein-like components, which may be driven by the increased microbial processing. Overall, the significant alteration in characteristics and composition of lacustrine DOM highlights the potential impact of reclamation on the DOM biogeochemical cycle and the environmental quality in aquatic ecosystems. [Display omitted] [ABSTRACT FROM AUTHOR]

Widespread water losses in endorheic river basins have triggered ecological disasters. Agricultural irrigation has been one of the major drivers of water losses. It is imperative to address the water conflict between agriculture and ecosystems in arid regions, but significant gaps remain in knowledge of the water-agriculture-ecosystem nexus. The Heihe River Basin, China's second largest endorheic river basin, lost its terminal lake in the 1990 s due to a rapid decline in river discharge to the downstream area, but the lake has returned quickly since the early 2000 s. A system analysis on the recovery of the lake is performed in this study, fusing field observations, remote sensing data, and ecohydrological model simulations. The major findings show that the waning and waxing of the lake are driven remotely by agricultural irrigation in the midstream area, rather than the climate. A one-decade effort involving diversion restrictions in the middle reach, starting from 2000, has recovered the lake to the condition of the early 1970 s. Under historical climate conditions, saving extra irrigation water may change the recovery trajectory but would not significantly enhance the stability level. The aquifer connected to the lake acts as a buffer, receiving leakage from the lake under normal conditions while discharging water to the lake under dry conditions. The overall water efficiency of water conservation for lake restoration during 2002–2012 is estimated to be only 3.5% due to significant riverbed leakage in the downstream area. Nevertheless, leakage loss is beneficial to the recovery of groundwater and vegetation downstream. Whether the diversion restriction needs modification depends on the tradeoff between ecological services provided by the lake and its related ecosystems and economic benefit produced by the midstream agriculture. This study provides insight into agricultural water management and ecological conservation in endorheic river basins in a fast-changing global environment. • Remote connection between agriculture and ecosystems in an arid region was revealed. • One-decade flow regulation restored a dried endorheic lake to its historical area. • The aquifer acts as a water buffer which stabilizes the lake's restoration process. • The overall water efficiency of the flow regulation for lake restoration is 3.5%. • Flow regulation for lake restoration has a spillover effect of vegetation recovery. [ABSTRACT FROM AUTHOR]

• Landsat data can map turbidity in Wuhan, China during its urbanization. • Turbidity shows fluctuating and declining trends associated with city policies. • Increases of ISA and NDVI are correlated to decline of turbidity since 2005. • Rainfall and human-activities affect seasonal and annual variations of turbidity. Understanding of turbidity, an indicator of water quality, is of great importance in cities and can have significant implications for human society. Many users are interested in mapping turbidity using remote sensing tools for long-term and large-scale monitoring. This study aims to derive turbidity maps in an urbanizing city and to identify the driving factors for better decision-making and water quality management. Taking Wuhan, the most rapidly urbanizing metropolis in central China, as an instance, the water turbidity is monitored using Landsat observations from 1987 to 2019, and the relationships of turbidity and climatic/human factors are examined. Climatic factors are represented by meteorological conditions (rainfall, wind speed, temperature, and water vapor pressure) and human factors are characterized by the normalized difference vegetation index (NDVI) and impervious surface area (ISA). The results demonstrated that: (1) the seasonal mean turbidity increased from spring to summer (34.28 NTU to 36.27 NTU), decreased in autumn (25.04 NTU), and increased again in winter (37.20 NTU), and the variations were related to changes in rainfall; and (2) the annual mean turbidity was fluctuatingly stable during 1987–2004 and decreased by 1 NTU/yr. since 2005. The decline of water turbidity was highly correlated to the increase of NDVI and ISA with p values < 0.01. The study indicates that meteorological conditions affect seasonal variations in turbidity, while human factors have long-term impacts. A cautious approach to human activities during urbanization is needed to achieve a balance between water quality protection and the city's developments. [ABSTRACT FROM AUTHOR]

Water clarity is a well-established first-order indicator of water quality and has been used globally by water regulators in their monitoring and management programs. Assessments of water clarity in lakes over large temporal and spatial scales, however, are rare, limiting our understanding of its variability and the driven forces. In this study, we developed and validated a robust Secchi disk depth (Z SD) algorithm for lakes across China based on two water color parameters, namely Forel-Ule Index (FUI) and hue angle α, retrieved from MODIS data. The MODIS Z SD model shows good results when compared with in-situ measurements from 17 lakes, with a 27.4% mean relative difference (MRD) in the validation dataset. Compared with other empirical Z SD models, our FUI and α-based model demonstrates improved performance and adaptability over a wide range of water clarity and trophic states. This algorithm was subsequently applied to MODIS measurements to provide a comprehensive assessment of water clarity in large lakes (N = 153) across China for the first time. The mean summer Z SD of the studied lakes between 2000 and 2017 demonstrated marked spatial and temporal variations. Spatially, the Z SD of large lakes presented a distinct spatial pattern of "high west and low east" over China. This spatial pattern was found to be associated with the significant differences in lake depth and altitude between west and east China while China's population, GDP, temperature, and precipitation distribution have also contributed to a certain extent. Temporally, the Z SD of most lakes increased during this period, with an overall mean rate of 3.3 cm/yr for all lakes. Here, 38.6% (N = 59) of the lakes experienced a significant increase in their Z SD value during the past 18 years while only 8.5% (N = 13) showed a significant decreasing trend. Significant increases in lake Z SD were observed in west China, which were found to correlate with the increase of air temperature and lake surface area. This is possibly a response of the lakes in west China to climate change. In the lake systems of east China, which are predominately used as a drinking water source, the increase in lake Z SD was found to be strongly correlated with changes in local GDP (gross domestic production), NDVI (normalized difference vegetation index) and lake surface area, suggesting a combined effect of the implemented management practices and climatic variability. The results of this study provide important information for water quality conservation and management in China, and also highlight the value of satellite remote sensing in monitoring water quality over lakes at a large scale and long-term. • Developed a Z SD estimation algorithm for lakes in a wide range of water clarity based on FUI and α retrieved from MODIS data. • Revealed significant spatial and temporal patterns of water clarity in 153 large lakes across China between 2000 and 2017. • Water clarity in most of the lakes increased during the past 18-year period, especially in west China. • Significant increases of lake clarity in west China are attributed to the climate change. • Local GDP growth can contribute to the increase of lake clarity in east China. [ABSTRACT FROM AUTHOR]

Both regional species pool and local community assembly mechanism drive the microbial diversity patterns across geographical gradients. However, little has been done to separate their effects on the β diversity patterns of microbial communities involved in nitrogen (N) cycling in river ecosystems. Here, we use high-throughput sequencing of the archaeal amoA, bacterial amoA, nirK, and nirS genes, null model, and neutral community model to distinguish the relative importance of species pool and local assembly processes for ammonia-oxidizing and denitrifying communities in river wetlands along a latitudinal gradient in eastern China. Results indicated that the β diversity of the nirS-type denitrifying community co-varied with γ diversity and environmental heterogeneity, implying that regional species pool and heterogeneous selection explained variation in β diversity. However, the β diversity of ammonia-oxidizing and nirK-type denitrifying communities did not correlate with γ diversity and environmental heterogeneity. The continuous hump distribution of β deviation along the latitudinal gradient and the lower species dispersal rate indicated that the dispersal limitation shaped the variation in β diversity of ammonia-oxidizing and nirK-type denitrifying communities. Additionally, biotic interactions drove ammonia-oxidizing and nirS-type denitrifying communities by influencing species co-occurrence patterns. Our study highlights the importance of regional species pool and local community assembly processes in shaping geographical patterns of N-cycling microorganisms and extends knowledge of their adaptability to a continuously changing environment on a large scale., (© 2024 John Wiley & Sons Ltd.)

Objective: To investigate the influence of subjective exercise experience on adolescent trait anxiety and to reveal the mediating effect of exercise behavior., Methods: Using the Subjective Exercise Experience Scale (SEES), Physical Exercise Rating Scale (PARS-3), and Trait Anxiety Inventory (T-AI), a questionnaire survey was conducted among 500 adolescents in Southwest China, and the SPSS21.0 and AMOS21.0 statistical analysis software was used to statistics and analysis on the questionnaires., Results: 1) Among adolescents, the exercise behavior of boys was significantly higher than that of girls (p < 0.05), and the subjective exercise experience of students aged 9 to 12 was significantly higher than that of students aged 12 to 15 (p < 0.05). 2) The subjective exercise experience could directly and positively predict exercise behavior (β = 0.45, p < 0.001) and negatively predict trait anxiety (β = -0.26, p < 0.05), and exercise behavior could directly and negatively predict trait anxiety (β = -0.32, p < 0.01). 3) The exercise behavior played a partial mediating effect between subjective exercise experience and trait anxiety (the mediation effect was -0.14). Among them, compared with low- and high-exercise amounts, the exercise behavior of moderate exercise amounts had the strongest mediating effect between subjective exercise experience and trait anxiety., Conclusion: The good subjective exercise experience not only has direct benefits for improving trait anxiety in adolescents but also helps to improve their exercise behavior, enrich daily physical exercise activities, and indirectly promote the reduction of trait anxiety., (© 2023. BioMed Central Ltd., part of Springer Nature.)

Based on the monthly monitoring of Bao'an Lake in Hubei Province from 2018 to 2020, the eutrophication level of Bao'an Lake in the middle reaches of the Yangtze River is investigated using the comprehensive trophic level index (TLI), chromophoric dissolved organic matter (CDOM) absorption coefficient, and the phytoplankton water quality biological method. The influencing factors are then identified. The results demonstrate that the overall water quality of Bao'an Lake remained at levels III-V during 2018-2020. Due to different eutrophication assessment methods, the results are different, but all show that Bao'an Lake is in a eutrophication state as a whole. The eutrophication level of Bao'an Lake is observed to vary with time, exhibiting an increasing then decreasing trend between 2018-2020, while levels are high in summer and autumn, and low in winter and spring. Moreover, the eutrophication level of Bao'an Lake presents an obviously varying spatial distribution. Potamogeton crispus is the dominant species of the Bao'an Lake, the water quality is good in spring when Potamogeton crispus vigorously grows, but poor in summer and autumn. The permanganate index (COD Mn ) and total phosphorous (TP), total nitrogen (TN), and chlorophyll a (Chl-a) contents are identified as the main influencing factors of the eutrophication level of Bao'an Lake, with a significant relationship observed between Chl-a and TP ( p < 0.01). The above results provide a solid theoretical basis for the ecological restoration of Bao'an Lake.

Background: Patients with recurrent implantation failure (RIF) may have more uterine contractions. Several observational studies suggested that atosiban administration around embryo transfer resulted in higher pregnancy rates in RIF patients. This study aimed to evaluate the effect of atosiban given before fresh embryo transfer on pregnancy outcomes of women with RIF., Methods: A prospective, randomized, double-blind controlled clinical trial was performed in IVF center of Shanghai First Maternity and Infant Hospital. According to a computer-generated randomization list, 194 infertile women with RIF received fresh embryo transfer between July 2017 and December 2019 were randomly allocated into the atosiban (n = 97) and the placebo (n = 97) groups. Women in the treatment group received atosiban intravenously about 30 min before embryo transfer with a bolus dose of 6.75 mg over one minute. Those in the placebo group received only normal saline infusion for the same duration., Results: There was no significant difference in the live birth rate between the atosiban and placebo groups (42.3% vs 35.1%, P = 0.302, RR = 1.206 (0.844-1.723)). No significant differences were found between the two groups in the positive pregnancy test, clinical pregnancy, ongoing pregnancy, miscarriage, multiple pregnancy, ectopic pregnancy and implantation rates. Similar results were found when stratified by the number of embryos previously transferred, number of previous failed embryo transfers, frequency of endometrial peristalsis on embryo transfer day (≥ 3 waves/min) or serum estradiol (E 2 ) on the day of hCG above the median level. And, there was no correlation between the serum E 2 level on the day of hCG and the frequency of endometrial peristalsis on embryo transfer day. The frequency of endometrial peristalsis on embryo transfer day, total FSH/HMG dosage and duration were the significant factors which independently predicted the likelihood of a live birth., Conclusions: These results suggested that atosiban treatment before fresh embryo transfer might not improve the live birth rate in RIF patients., Trial Registration: The study had been approved by the Institutional Review Board of the hospital (2017 ethics No.43) and was registered under Clinicaltrials.gov with an identifier NCT02893722., (© 2022. The Author(s).)

This study aimed to reveal the distribution characteristics and sources of dissolved organic matter (DOM) in sediments of typical lakes in the southeastern of the Hubei province and provide a reference for pollution control of eutrophic lakes. The sediments of four typical lakes (Liangzi, Baoan, Daye, and Qingshan) in the southeastern of the Hubei Province were investigated in May 2019. Ultraviolet-visible (UV-Vis) absorption spectroscopy and excitation-emission matrixes characteristics of DOM were obtained by UV-Vis spectrophotometry and three-dimensional fluorescence spectroscopy. Moreover, the DOM fluorescence components were resolved by parallel factor analysis (PARAFAC). The results showed that: (1) The absorption coefficient a350 in surface sediments followed the order: Baoan Lake (16.99 ± 3.82 m−1) > Qingshan Lake (15.37 ± 3.8 m−1) > Liangzi Lake (12.54 ± 5.58 m−1) > Daye Lake (12.43 ± 1.43 m−1). Specifically, with increasing depth in the sediment cores, a350 increased and then gradually decreased in Daye Lake and Baoan Lake, but fluctuated in Liangzi Lake and Qingshan Lake with a roughly decreasing trend. (2) Two humic-like components (C1, C2) and one protein-like component (C3) were identified via PARAFAC. This analysis also showed that the surface sediment fluorescent dissolved organic matter (FDOM) was dominated by protein-like, while the sediment core FDOM was dominated by humic-like in Liangzi Lake. The proportion of humic-like in FDOM was higher than protein-like in surface sediments and sediment cores of Baoan, Daye, and Qingshan Lakes. (3) The DOM of surface sediments in the Liangzi Lake comprised mostly autochthonous components, mainly produced by the vital activities of aquatic organisms. The DOM of surface sediments in Baoan Lake and Qingshan Lake showed weak humic and moderate autochthonous characteristics. The humification of DOM in sediment cores of Liangzi, Baoan, and Qingshan Lakes gradually decreased from depth to the surface. The DOM in surface sediments of Daye Lake had strong humic and moderate autochthonous characteristics. (4) In general, the DOM of lake sediments in southeastern Hubei Province has dual-contribution characteristics representing terrigenous and endogenous sources. In the restoration and treatment of lake ecology, both internal and terrestrial pollution should be considered. At the same time, it is noteworthy that cyanobacteria depletion and aquatic residues caused potential internal pollution.

Land use and landscape pattern highly affect water quality. Their relationship can assist in land-use management and improve land-use efficiency. In this study, a water quality survey of rivers and lakes was performed in 2020 to analyze the effects of land use and the landscape pattern on the water quality of the rivers and lakes in the Baoan Lake basin and is expected to provide a reference for land use planning. The results demonstrated that the effects of land use on water quality were generally higher during the dry season than during the wet season; however, the opposite was demonstrated for the landscape pattern index. Cropland and urban land were closely correlated with deteriorating water quality, with contributions to total nitrogen, total phosphorous, and ammonia nitrogen in the basin. The impact of the landscape pattern of the basin on water quality was controlled by the original land-use type. In addition, the landscape configuration formed different land-use types to produce different effects on water quality. The basin scale better explained the changes in water quality, especially for construction land, followed by the 250 m and 500 m scales in the buffer zone.

Enclosure fisheries have accommodated the widespread expansion of aquaculture in many lakes throughout the Yangtze Plain (YP), China, for over four decades. Such practices have increased food provision but have also triggered various detrimental environmental consequences. To restore ecosystem functions, the Chinese government recently implemented specific regulations to remove enclosure fences from lakes throughout the YP. However, little information is available on the spatial and temporal distributions of the enclosure fences, particularly in relation to the enforcement of recent policy changes. Using synthetic aperture radar (SAR) satellite images taken between 2002 and 2018, we conducted the first comprehensive assessment of the interannual changes in enclosure fences in 17 large lakes throughout the YP. Consistent decreases in fence density were found in most lakes after 2015; 15 lakes had >50% of their fences removed, while 9 lakes had >90% removed. The timing and implementation of the development and destruction of enclosure fisheries were related to government policy; before 2015, regional dynamics in enclosure fisheries were attributed to provincial policies, whereas the nearly ubiquitous fence demolition after 2015 was likely a response to national policy. This study represents remotely sensed evidence that demonstrates the importance of both local and national environmental policies and their effectiveness in mitigating ongoing human impacts on vulnerable and valuable natural resources. These findings provide valuable baseline information for future lake environmental monitoring and restoration in the YP region, and the methods used here could be applied to other lacustrine and coastal regions experiencing similar aquaculture activities., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: mcr-1-mediated colistin resistance in Enterobacteriaceae is concerning, as colistin is used in treating multidrug-resistant Enterobacteriaceae infections. We identified trends in human fecal mcr-1-positivity rates and colonization with mcr-1-positive, third-generation cephalosporin-resistant (3GC-R) Enterobacteriaceae in Guangzhou, China, and investigated the genetic contexts of mcr-1 in mcr-1-positive 3GC-R strains., Methods: Fecal samples were collected from in-/out-patients submitting specimens to 3 hospitals (2011-2016). mcr-1 carriage trends were assessed using iterative sequential regression. A subset of mcr-1-positive isolates was sequenced (whole-genome sequencing [WGS], Illumina), and genetic contexts (flanking regions, plasmids) of mcr-1 were characterized., Results: Of 8022 fecal samples collected, 497 (6.2%) were mcr-1 positive, and 182 (2.3%) harbored mcr-1-positive 3GC-R Enterobacteriaceae. We observed marked increases in mcr-1 (0% [April 2011] to 31% [March 2016]) and more recent (since January 2014; 0% [April 2011] to 15% [March 2016]) increases in human colonization with mcr-1-positive 3GC-R Enterobacteriaceae (P < .001). mcr-1-positive 3GC-R isolates were commonly multidrug resistant. WGS of mcr-1-positive 3GC-R isolates (70 Escherichia coli, 3 Klebsiella pneumoniae) demonstrated bacterial strain diversity; mcr-1 in association with common plasmid backbones (IncI, IncHI2/HI2A, IncX4) and sometimes in multiple plasmids; frequent mcr-1 chromosomal integration; and high mobility of the mcr-1-associated insertion sequence ISApl1. Sequence data were consistent with plasmid spread among animal/human reservoirs., Conclusions: The high prevalence of mcr-1 in multidrug-resistant E. coli colonizing humans is a clinical threat; diverse genetic mechanisms (strains/plasmids/insertion sequences) have contributed to the dissemination of mcr-1, and will facilitate its persistence., (© The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Controlling agricultural greenhouse gas emissions, such as N 2 O, is important in mitigating global climate warming. Through monitoring the dynamics of N 2 O emission fluxes, we investigated the effect of organic nitrogen (N) substitution of synthetic N on N 2 O emissions and the yield of winter wheat and summer maize in the Guanzhong Plain of Shaanxi Province, China. The study involved six treatments, consisting of no fertilizer (CK), synthetic N, phosphorus (P), and potassium (K) fertilizers alone (NPK), 75% NPK+25% organic N through manure (25%M), 50% NPK+50% organic N (50%M), 25% NPK+75% organic N (75%M), 100% organic N (100%M). The results showed that the peak value of the N 2 O emission flux appeared after fertilization, rainfall, and irrigation. In the wheat season, the emission flux of N 2 O varied from -1.33 to 144.2 μg·(m 2 ·h) -1 , with the highest peak value in the NPK treatment. In the maize season, the emission flux of N 2 O varied from 88.2 to 1800.1 μg·(m 2 ·h) -1 , and the 50%M treatment showed the highest peak value. The range in the total amount of N 2 O emissions from the different treatments in the wheat-maize rotation system was 429.8-2632.1 g·hm -2 , and the amount for the treatments decreased in order as follows:50%M > 25%M > NPK > 75%M > 100%M > CK. The yields of wheat, maize, or wheat plus maize were significantly higher in the fertilized treatments compared to the CK. Organic substitution treatments significantly increased wheat yield by 26.1% to 50.0% relative to the NPK treatment. While the maize yield in 50%M and 75%M treatments was similar to that in the NPK treatment, the 25%M and 100%M treatments showed significantly lower yields than with the NPK treatment. The total yield of wheat plus maize varied from 9166 to 17496 kg·hm -2 , of which total yield was significantly higher with 50%M and 75%M compared to NPK. Overall, the 75%M treatment is the best measure to guarantee crop yield and to reduce N 2 O emissions in the wheat-maize rotation system based on a one year study in the Guanzhong plain of Shaanxi Province.

Objective: To investigate the impact of impoundment and active public health interventions on rodent populations and rodent-borne diseases in the Three Gorges reservoir region from 1997 to 2012., Methods: Surveillance data from 1997 to 2012 were extracted from the Public Health Surveillance System of The Three Gorges established in 1997. Temporal changes in the incidences of hemorrhagic fever with renal syndrome (HFRS) and leptospirosis, rodent density, pathogen-carrying rates, and their correlations were analyzed., Results: The average indoor and outdoor rodent densities decreased overall from 1997 to 2012. The average densities decreased by 47.72% (from 4.38% to 2.29%) and 39.68% (from 4.41% to 2.66%), respectively, after impoundment (2003-2012) compared with before impoundment (1997-2002). The average annual incidence rates of HFRS and leptospirosis were 0.29/100,000 and 0.52/100,000, respectively, and decreased by 85.74% (from 0.68/100,000 to 0.10/100,000) and 95.73% (from 1.47/100,000 to 0.065/100,000), respectively, after impoundment compared with before impoundment. Incidences of HFRS and leptospirosis appear to be positively correlated with rodent density in the reservoir area., Conclusion: This study demonstrated that rodent density and incidences of rodent-borne diseases decreased and were maintained at low levels during construction of the Three Gorges dam. Measures that reduce rodent population densities could be effective in controlling rodent-borne diseases during large-scale hydraulic engineering construction., (Copyright © 2016 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.)

We identified New Delhi metallo-β-lactamase (NDM-1)-producing Citrobacter freundii GB032, Escherichia coli GB102, and Acinetobacter baumannii GB661 in urine and stool samples from a single patient in China. Plasmid profiling and Southern blotting indicated that blaNDM-1 from GB032 and that from GB102 were likely located on the same plasmid, while blaNDM-1 from GB661 was located on a very large (>400-kb) plasmid. This case underscores the broad host range of blaNDM-1 and its potential to spread between members of the family Enterobacteriaceae and A. baumannii., (Copyright © 2015, American Society for Microbiology. All Rights Reserved.)

Background: Metarhizium anisopliae, a soil-borne entomopathogen found worldwide, is an interesting fungus for biological control. However, its efficacy in the fields is significantly affected by environmental conditions, particularly moisture. To overcome the weakness of Metarhizium and determine its isolates with antistress capacity, the efficacies of four M. anisopliae isolates, which were collected from arid regions of Yunnan Province in China during the dry season, were determined at different moisture levels, and the efficacy of the isolate MAX-2 from Shangri-la under desiccation stress was evaluated at low moisture level., Results: M. anisopliae isolates MAX-2, MAC-6, MAL-1, and MAQ-28 showed gradient descent efficacies against sterile Tenebrio molitor larvae, and gradient descent capacities against desiccation with the decrease in moisture levels. The efficacy of MAX-2 showed no significant differences at 35% moisture level than those of the other isolates. However, significant differences were found at 8% to 30% moisture levels. The efficacies of all isolates decreased with the decrease in moisture levels. MAX-2 was relatively less affected by desiccation stress. Its efficacy was almost unaffected by the decrease at moisture levels > 25%, but slowly decreased at moisture levels < 25%. By contrast, the efficacies of other isolates rapidly decreased with the decrease in moisture levels. MAX-2 caused different infection characteristics on T. molitor larvae under desiccation stress and in wet microhabitat. Local black patches were found on the cuticles of the insects, and the cadavers dried without fungal growth under desiccation stress. However, dark black internodes and fungal growth were found after death of the insects in the wet microhabitat., Conclusions: MAX-2 showed significantly higher efficacy and superior antistress capacity than the other isolates under desiccation stress. The infection of sterile T. molitor larvae at low moisture level constituted a valid laboratory bioassay system in evaluating M. anisopliae efficacy under desiccation stress.

Ever since its planning in the 1990s, the Three Gorges Dam (TGD) caused endless debate in China on its potential impacts on the environment and humans. However, to date, synoptic assessment of environmental changes and their potential linkage with the TGD is still lacking. Here, we combine remote sensing, meteorological, and hydrological observations to investigate the potential influence of the TGD on the downstream freshwater lakes. A 10 year Moderate Resolution Imaging Spectroradiometer (MODIS) time series from 2000 to 2009 revealed significantly decreasing trends (3.3 and 3.6%/year) in the inundation areas of the two largest freshwater lakes of China (Poyang Lake and Dongting Lake) downstream of the TGD since its impoundment in 2003, after which both relative humidity and surface runoff coefficient of the lakes' drainages also dropped dramatically. These environmental changes appear to be linked to the TGD.