Fingerprinting Sources of the Sediments Deposited in the Riparian Zone of the Ruxi Tributary Channel of the Three Gorges Reservoir (China)

The riparian zone of the Three Gorges Reservoir serves as a critical transitional zone located between the aquatic and surrounding terrestrial environments. The periodic anti-seasonal alternation of wet and dry periods results in an intensive exchange of substance within the riparian zone. The discrimination of the sources of the sediments deposited within the riparian zone is of fundamental importance for the evaluation of the soil pollution and associated environmental impacts and for the protection of the water quality in the reservoir. In this study, a composite fingerprinting technique has been applied to apportion the sediment sources for the riparian zone with different elevations, ranging between 145—155, 155–165, and 165–175 m in a typical tributary channel. From a sediment perspective, the sediments suspended from the Yangtze mainstream represent the primary sources of the riparian deposits. From a contamination perspective, the sediment input from the Ruxi tributary channel represents an important source of pollution for the riparian environment. More effective sediment and sediment-associated contaminant control plans are needed to reduce the potential environmental problems of the riparian zone

The Mediating and Moderating Effects of Teacher Preference on the Relations between Students’ Social Behaviors and Peer Acceptance

Tested on a sample of 1,365 Hong Kong primary school students from five grades, teacher preference or the extent to which the classroom teacher likes a child in the class was found to both mediate and, to a lesser extent, moderate the relations between children’s social behaviors and peer acceptance across age groups. The mediating effect suggests that peer acceptance responds not only to the behavior of a student but also to how much the classroom teacher likes or dislikes the student. The moderating effect suggests that the associations between student social behaviors and peer acceptance differ as functions of teacher preference. The mediating teacher preference was stronger with younger children, whereas a stronger moderating teacher preference was found for the older children. These findings confirm the supposition that three social processes involving the teacher, children, and peers contribute to children’s social status and relations in the classroom

Dynamical alterations of brain function and gut microbiome in weight loss

ObjectiveIntermittent energy restriction (IER) is an effective weight loss strategy. However, little is known about the dynamic effects of IER on the brain-gut-microbiome axis.MethodsIn this study, a total of 25 obese individuals successfully lost weight after a 2-month IER intervention. FMRI was used to determine the activity of brain regions. Metagenomic sequencing was performed to identify differentially abundant gut microbes and pathways in from fecal samples.ResultsOur results showed that IER longitudinally reduced the activity of obese-related brain regions at different timepoints, including the inferior frontal orbital gyrus in the cognitive control circuit, the putamen in the emotion and learning circuit, and the anterior cingulate cortex in the sensory circuit. IER longitudinally reduced E. coli abundance across multiple timepoints while elevating the abundance of obesity-related Faecalibacterium prausnitzii, Parabacteroides distasonis, and Bacterokles uniformis. Correlation analysis revealed longitudinally correlations between gut bacteria abundance alterations and brain activity changes.ConclusionsThere was dynamical alteration of BGM axis (the communication of E. coli with specific brain regions) during the weight loss under the IER

Concentrations and Stoichiometric Characteristics of C, N, and P in Purple Soil of Agricultural Land in the Three Gorges Reservoir Region, China

Soil stoichiometry is an essential tool for understanding soil nutrient balance and cycling. Previous studies have recognized that some relationships were observed between particle size and carbon and nitrogen parameters. This study attempted to evaluate nutrient element concentrations and their stoichiometric ratios of surface soil (0–10 cm) under different land use types (forest, sloping arable land, paddy fields, and orchards). and different particle sizes (<32 µm, <63 µm, and <125 µm) from a small typical hilly catchment (0.35 km2) in the Three Gorges Reservoir Region of China. The contents of soil organic carbon (SOC), total nitrogen (TN). and total phosphorus (TP) were measured, and the ratios of C:N, C:P, N:P were calculated. The results indicated that land use type and soil particle size have diverse impacts on the studied indexes (SOC, TN, TP, C:N, C:P, and N:P). Six indexes were significantly affected by land use type (p < 0.01), while only C:N ratio was statistically influenced by soil particle size (p < 0.05). Furthermore, several significant differences of studied parameters of four land use types grouped within three particle sizes were found. The concentrations of SOC (12.34~13.46 g kg−1), TN (1.27~1.59 g kg−1), and TP (0.71~0.92 g kg−1) in the study site were lower than the national average values of China. Moreover, the productivity in the study area was mainly limited by TN concentration. Additionally, the concentration of TP decreased obviously with the increase in particle size. Furthermore, various coupling relationships were validated by linear and nonlinear fitting among different indexes. At the small catchment scale, take forest as a reference, human activities have significant impact on C-N-P stoichiometry (p < 0.05). Especially, tillage may reduce SOC and TN contents, leading to a decline in soil quality. Overall, our findings can provide a basis for rational utilization and sustainable development of land resources

Influence of Precipitation Characteristics and Vegetation on Runoff and Sediment: A Case on the Basin in the Three Gorges Reservoir Region

Sediment is the main carrier of pollutants in river channels. This study analyzed the distribution characteristics of precipitation, runoff, and sediment and their response characteristics in the Daning River basin. Based on daily precipitation (1979–2017), runoff (1989–2017), and sediment (1997–2017) time series, the Gini concentration index, precipitation concentration index (PCI), precipitation concentration degree (PCD), and precipitation concentration period were applied to assess the concentration characteristics of precipitation, runoff, and sediment on the daily, monthly, and seasonal scales. At each intensity level, precipitation was negatively correlated to the PCI and PCD. The normalized difference vegetation index (NDVI) values had strong negative correlations with rainy days with light precipitation (0.1–9.9 mm). The degrees of concentration were in the same order for the multiscale analysis: runoff < precipitation < sediment. Although the amount of daily precipitation of more than 25 mm displayed a significant increasing trend, suggesting an increased risk of flood and soil erosion, the significantly improved vegetation cover reduced the sediment-carrying capacity of the surface runoff, with significant decreases in the total amount and multiscale concentration degrees of sediment being observed. The results of the study provide a reference for the improvement of the potable water safety and ecological environment in the Three Gorges Reservoir region

Comparing Exploratory Structural Equation Modeling and Existing Approaches for Multiple Regression with Latent Variables

<p>Exploratory structural equation modeling (ESEM) is an approach for analysis of latent variables using exploratory factor analysis to evaluate the measurement model. This study compared ESEM with two dominant approaches for multiple regression with latent variables, structural equation modeling (SEM) and manifest regression analysis (MRA). Main findings included: (1) ESEM in general provided the least biased estimation of the regression coefficients; SEM was more biased than MRA given large cross-factor loadings. (2) MRA produced the most precise estimation, followed by ESEM and then SEM. (3) SEM was the least powerful in the significance tests; statistical power was lower for ESEM than MRA with relatively small target-factor loadings, but higher for ESEM than MRA with relatively large target-factor loadings. (4) ESEM showed difficulties in convergence and occasionally created an inflated type I error rate under some conditions. ESEM is recommended when non-ignorable cross-factor loadings exist.</p

The Role of Paddy Fields in the Sediment of a Small Agricultural Catchment in the Three Gorges Reservoir Region by the Sediment Fingerprinting Method

Identifying sediment sources is a prerequisite for developing sediment management strategies. Erosion sediment derived from a small agriculture catchment is an important component of sediment inflow in the Three Gorges Reservoir Area. Paddy fields are one of the major land-use types in this region and can have both positive and negative effects on sediment. In this study, two different source group classification schemes were used to analyze the effect of paddy fields on the sediment in a typical small agriculture catchment in the Three Gorges Reservoir Region. A total of 32 soil source samples were collected from four kinds of land-use types (13 from dry land, 5 from orchards, 8 from paddy fields, and 6 from forest) in the Shipanqiu catchment. Moreover, the properties consisted of 41 elements and 12 element ratios were analyzed. Composite fingerprinting methodology was applied to discriminate and quantify the sediment source contributions. Additionally, element ratio was used as the fingerprint property in the fingerprinting application. The results showed that the element ratio was verified as an effective fingerprint property. Additionally, the relative sediment contributions of the potential land-use sources were 55.25% of dry land, 32.69% of orchards, and 12.06% of forest. Paddy fields played a role of sink rather than of source in this study. Accordingly, both forest and paddy fields are effective sediment management strategies. Particularly, paddy fields are a preferred choice for soil erosion control in mountainous and hilly areas. Furthermore, the proper management of paddy fields can help promote sediment retention and reduce soil erosion, which have positive effects on both the environment and agricultural productivity

A Developed Framework for the Multi-District Ecological Compensation Standards Integrating Ecosystem Service Zoning in an Urban Area in China

Ecological compensation is an effective means to adjust relationships among stakeholders in order to conserve and/or sustainably use ecosystem services. The current ecological compensation standards (ECS) do not well reflect the differences in ecological, social, and economic development. Thus, we took a typical urbanization area (the Suzhou&ndash;Wuxi&ndash;Changzhou region) in China as an example, because of its prominent contradiction between rapid socio-economic development and fragile ecosystem. Combined with the ecological, economic, and social conditions, the methods of ecosystem service value (ESV) evaluation, cluster analysis, and scenario analysis were used to propose an optimized spatial zoning method and optimal development scenario. Then, the ECS by different zones were determined by using ESV assessment, cost-benefit analysis, and contingent valuation method. The results showed that (1) the regions were divided into two categories, with a total of four zones: ESV output areas (synergetic development zones (SDZ) and ecological conservation zones (ECZ)) and ESV input areas (ecological degradation zones (EDegZ) and economic development zones (EDevZ)); (2) among five scenarios, the best development mode in the future was the protection and development scenario, which was consistent with the existing planning; and (3) the ECS for the SDZ should be paid about 1.94 billion Yuan/year, the ECZ should be paid about 0.80 billion Yuan/year, the ECS for the EDegZ should pay about 2.20&ndash;2.25 million Yuan/year, and the EDevZ should pay about 0.06&ndash;7.33 million Yuan/year. By feasibility analysis, the ESV input areas were fully capable of inter-regional compensation, which could promote the effective purchase of ecological services. The developed evaluation framework of ECS in this study can accurately provide a scientific basis for the determination of ecological compensation regulations and policies in the future