Co-benefits of the National Key Ecological Function Areas in China for carbon sequestration and environmental quality

IntroductionThe National Key Ecological Functional Areas (NKEFAs) are location-oriented ecological engineering of China, which rely on the main functional area planning. The co-benefits of ecological product supply and ecological environment improvement of NKEFAs has not been fully assessed in the literature.MethodsNKEFAs is considered a quasi-natural experiment, and the time-varying difference-in-differences (DID) model is used to assess the impact of NKEFAs on carbon sequestration (CS) and environmental quality (EQ) based on the panel data of 330 cities in China from 2001 to 2019. Then, we explore whether the co-benefits of ecological product supply and eco-environment protection can be achieved.Results and discussionNKEFAs can enhance CS and EQ and thus achieve co-benefits for both. NKEFAs can achieve the co-benefits of CS and EQ through territory spatial allocation and labor force aggregation, but industrial structure upgrading only positively mediates the impact of NKEFAs on CS. The co-benefits of CS and EQ are heterogeneous across functional area types, geospatial locations, and quantiles, while only CS at windbreak-sand fixation area, northwestern region, and low quantile regions is enhanced. This study makes a theoretical and methodological contribution to the existing literature on the policy effect assessment of ecological engineering. It also provides a comprehensive framework for evaluating the ecological effects of relevant policies in other countries by integrating the co-benefits of ecological products and eco-environment, analyzing regional heterogeneity, and exploring the underlying mechanisms

STAR: A Structure and Texture Aware Retinex Model

© 2020 IEEE. Retinex theory is developed mainly to decompose an image into the illumination and reflectance components by analyzing local image derivatives. In this theory, larger derivatives are attributed to the changes in reflectance, while smaller derivatives are emerged in the smooth illumination. In this paper, we utilize exponentiated local derivatives (with an exponent γ ) of an observed image to generate its structure map and texture map. The structure map is produced by been amplified with γ \u3e 1, while the texture map is generated by been shrank with γ \u3c 1. To this end, we design exponential filters for the local derivatives, and present their capability on extracting accurate structure and texture maps, influenced by the choices of exponents γ. The extracted structure and texture maps are employed to regularize the illumination and reflectance components in Retinex decomposition. A novel Structure and Texture Aware Retinex (STAR) model is further proposed for illumination and reflectance decomposition of a single image. We solve the STAR model by an alternating optimization algorithm. Each sub-problem is transformed into a vectorized least squares regression, with closed-form solutions. Comprehensive experiments on commonly tested datasets demonstrate that, the proposed STAR model produce better quantitative and qualitative performance than previous competing methods, on illumination and reflectance decomposition, low-light image enhancement, and color correction. The code is publicly available at https://github.com/csjunxu/STAR

Ultrasound-Assisted Extraction of Total Flavonoids from Pteris cretica L.: Process Optimization, HPLC Analysis, and Evaluation of Antioxidant Activity

In the present work, the ultrasonic-assisted extraction (UAE) of total flavonoids (TF) from Pteris cretica L. was optimized by response surface methodology (RSM) on the basis of a single-factor experiment. The optimized UAE parameters were as follows: Ethanol concentration 56.74%, extraction time 45.94 min, extraction temperature 74.27 °C, and liquid/solid ratio 33.69 mL/g. Under the optimized conditions, the total flavonoids yield (TFY) was 4.71 ± 0.04%, which was higher than that obtained by heat reflux extraction (HRE). The extracts were further analyzed by HPLC, and five major flavonoids, including rutin, quercitrin, luteolin, apigenin, and luteolin-7-O-glucoside, were identified and quantified. Furthermore, the results of the antioxidant test showed that the TF extract obtained under optimized UAE conditions exhibited good 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•) and 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical (ABTS+•), nitric oxide radical (NO•) scavenging activities, and ferrous ion (Fe2+) chelating capacity, with IC50 values of 74.49, 82.92, 89.12, and 713.41 µg/mL, respectively. Results indicated that the UAE technique developed in this work was an efficient, rapid, and simple approach for the extraction of flavonoids with antioxidant activity from P. cretica

Spatial Agglomeration Pattern and Driving Factors of Grain Production in China since the Reform and Opening Up

Since the reform and opening up, regional imbalances in the development of market economy and urbanization have significantly changed the spatial agglomeration pattern of grain production (GP) in China. To characterize GP by the yield, we used the gravity center (GC) and standard deviation ellipse (SDE) to investigate the evolution characteristics of the spatial agglomeration pattern of GP and its three major crops with wheat, maize and rice in China, then establish a spatial econometric model to explore the natural and socioeconomic drivers of GP at the national level, at different crops and at different regions. The research results indicate that the GC of GP gradually shifts and expands to the northeast and presents a spatial distribution pattern in a “northeast–southwest” direction. The GC of wheat production mainly expands upwards in the east–west direction. The GC of maize production shifts in a direction that is more consistent with grain production, and there is an expansion trend in the east–west direction, while the GC of rice production has the largest north–south span, and continues to expand upward to the north by the east. The status of grain production in Northeast China and Northwest China is rising and the importance of grain production in the Southeast coastal areas are decreasing. The importance of wheat and corn production in North China continues to strengthen, and Northeast China is becoming more important for rice production, but the middle and lower reaches of the Yangtze River are still important rice producing regions. Changes in GP with significant spatial dependence are jointly affected by many factors, such as natural and socio-economic factors, and there are obvious differences among different food crops and different division regions, with the most prominent positive effects being the multiple crop index (MCI), arable land per capita (AL) and agricultural mechanization (MECH), while economic growth and urbanization are significantly negative

Spatiotemporal Differences, Dynamic Evolution and Trend of the Coupled Coordination Relationship between Urbanization and Food Security in China

Scientific assessment of the coupled coordination degree between urbanization and food security (CDUFS) revealed regional differences and sources. Dynamic evolution and trends are important references for achieving a coordinated interaction between high-quality urbanization and ensuring food security. Specifically, the CDUFS was measured using prefectural panel data in China from 2000 to 2019 and the coupling coordination degree model, which revealed its spatial correlation and differentiation. On this basis, in order to examine the spatiotemporal differences and evolution of the CDUFS, the Dagum–Gini coefficient and Kernel density estimation were innovatively used to analyze its regional differences and evolution distribution. The spatial Markov chain was further employed to examine the evolution trend of the CDUFS. The study found that the CDUFS showed a downward trend in fluctuation within the low coordination interval. There was a positive spatial correlation, with a more stable distribution pattern of high–high and low–low clusters. The regional differences in the CDUFS were obvious and the overall difference has expanded. The main source of regional differences among different food functional areas was inter-regional differences, followed by intra-regional differences. The regional difference between food main producing areas and food main marketing areas was the highest. The CDUFS shows a single-peak distribution; the imbalance between regions was still prominent with a left trailing phenomenon and no convergence. The CDUFS has the stability of maintaining the original state, and the probability of leapfrogging evolution is low in the short term. Finally, the geospatial effect plays an important role in the dynamic evolution of the CDUFS

Urbanization and Grain Production Pattern of China: Dynamic Effect and Mediating Mechanism

The flow and reallocation of agricultural production factors induced by urbanization play an important role in the changes of the grain production pattern (GPP). Using provincial panel data from 1996 to 2018 in China as the research sample, the center of gravity transfer–standard deviation ellipse model was applied to understand the change characteristics of GPP. Next, a dynamic spatial panel econometric model was established to test the impact of urbanization on GPP, and a spatial mediated effect model was used to identify the mediated transmission paths played by cropland utilization, planting structure adjustment, and agricultural technology progress in this impact process. The main conclusions showed that (1) the grain production COG of China transferred to the northeast, gradually resulting in a spatial pattern from the northeast to the southwest; (2) the urbanization process has a significant negative impact on the GPP, with each unit increase in urbanization resulting in a 0.30% decrease in the grain production concentration index; (3) cropland utilization, planting structural adjustment, and agricultural technology progress play significant mediating roles in the impact of urbanization on the GPP, and their mediating effects can weaken the direct negative impact of urbanization, among which the mediating effect of planting structure adjustment is the highest (13.9%). The study findings provide a new perspective for further understanding the relationship between urbanization and grain production pattern and also provide theoretical references and practical insights for improving the allocation efficiency of agricultural production factors and formulating scientific regional planning policies for grain production in the high-quality transformation of urbanization

Re-Estimation of Agricultural Production Efficiency in China under the Dual Constraints of Climate Change and Resource Environment: Spatial Imbalance and Convergence

Climate change and farmland environmental pollution have put greater pressure on the sustainability of agricultural production. Based on the provincial panel data of mainland China from 1978 to 2018, climate variables such as precipitation, temperature, and sunshine hours are included into the input indicators, and agricultural non-point source pollution and carbon emissions are taken as undesirable outputs, the agricultural production efficiency (APE) under the dual constraints of climate change and the resource environment was estimated by the super slacks-based measure (SBM)-undesirable model. On the basis of the trajectory of the imbalanced spatiotemporal evolution of APE shown by Kernel density estimation and the standard deviational ellipse (SDE)–center of gravity (COG) transfer model, the spatial convergence model was used to test the convergence and differentiation characteristics of APE. Under the dual constraints, APE presents a “bimodal” distribution with a stable increase in fluctuation, but it is still at a generally low level and does not show polarization, among which the APE in the northeast region is the highest. The COG of APE tends to transfer towards the northeast, and the coverage of the SDE is shrinking, so the overall spatial pattern is characterized by a tendency of clustering towards the north in the north-south direction and a tendency of imbalance in the east-west direction. APE has significant spatial convergence, and there is a trend of “latecomer catching-up” in low-efficiency regions. The introduction of spatial correlation accelerates the convergence rate and shortens the convergence period. The convergence rate is the highest in the central and western regions, followed by that in the northeastern region, and the convergence rate is the lowest in the eastern region. In addition, the convergence rate in different time periods has a phase change. The process of improving the quality and efficiency of agricultural production requires enhancing the adaptability of climate change, balancing the carrying capacity of the resource environment, and strengthening inter-regional cooperation and linkage in the field of agriculture

Re-Estimation of Agricultural Production Efficiency in China under the Dual Constraints of Climate Change and Resource Environment: Spatial Imbalance and Convergence

Climate change and farmland environmental pollution have put greater pressure on the sustainability of agricultural production. Based on the provincial panel data of mainland China from 1978 to 2018, climate variables such as precipitation, temperature, and sunshine hours are included into the input indicators, and agricultural non-point source pollution and carbon emissions are taken as undesirable outputs, the agricultural production efficiency (APE) under the dual constraints of climate change and the resource environment was estimated by the super slacks-based measure (SBM)-undesirable model. On the basis of the trajectory of the imbalanced spatiotemporal evolution of APE shown by Kernel density estimation and the standard deviational ellipse (SDE)–center of gravity (COG) transfer model, the spatial convergence model was used to test the convergence and differentiation characteristics of APE. Under the dual constraints, APE presents a “bimodal” distribution with a stable increase in fluctuation, but it is still at a generally low level and does not show polarization, among which the APE in the northeast region is the highest. The COG of APE tends to transfer towards the northeast, and the coverage of the SDE is shrinking, so the overall spatial pattern is characterized by a tendency of clustering towards the north in the north-south direction and a tendency of imbalance in the east-west direction. APE has significant spatial convergence, and there is a trend of “latecomer catching-up” in low-efficiency regions. The introduction of spatial correlation accelerates the convergence rate and shortens the convergence period. The convergence rate is the highest in the central and western regions, followed by that in the northeastern region, and the convergence rate is the lowest in the eastern region. In addition, the convergence rate in different time periods has a phase change. The process of improving the quality and efficiency of agricultural production requires enhancing the adaptability of climate change, balancing the carrying capacity of the resource environment, and strengthening inter-regional cooperation and linkage in the field of agriculture

Network pharmacology, bioinformatics, and experimental validation to identify the role of Hedyotis diffusa willd against gastric cancer through the activation of the endoplasmic reticulum stress

Background: Globally, gastric cancer (GC) is recognized as the third leading cause of cancer-related deaths and the fifth most prevalent malignant disease. Multiple studies have indicated that Hedyotis diffusa Willd, in pinyin, called Bai Hua She Cao (BHSSC), a traditional Chinese medicine (TCM) is an herbal remedy for cancer treatment. However, the specific mechanisms underlying its anti-tumor properties and mode of action are still unclear. Methods: To determine the role of BHSSC in GC, candidate target genes were selected from The Encyclopedia of Traditional Chinese Medicine (ETCM) and analyzed using network pharmacology, bioinformatics, and experimental validation. Differentially expressed genes (DEGs) associated with gastric cancer were obtained from RNA sequencing (RNA-seq) data sourced from The Cancer Genome Atlas-Stomach adenocarcinoma (TCGA-STAD). The Reactome Pathway was examined using Analysis Tools, while KEGG pathways were analyzed using KOBAS. Gene Ontology (GO) evaluations were performed using WebGestalt and DAVID. The relationships between proteins were investigated using the STRING database. Furthermore, cell viability, colony formation, and cell migration ability were conducted in gastric cancer cells, BGC-823 and MGC-803. Results: Network pharmacology and bioinformatics analyses revealed a significant association between BHSSC and metabolic pathways. In vitro experiments demonstrated that BHSSC effectively suppressed gastric cancer cell proliferation and colony formation, inhibited cell migration, and activated the endoplasmic reticulum (ER) stress. Furthermore, it was found that enhancement of the expression of IRE1α and BIP is the mechanism by which BHSSC activates ER stress. Conclusions: The findings suggest that BHSSC exerts its effects through modulation of metabolic pathways, leading to the suppression of cell proliferation, inhibition of cell migration, and activation of the endoplasmic reticulum. These results provide valuable insights into the mechanisms underlying the therapeutic effects of BHSSC in GC and support its potential as a novel treatment option

Urbanization and Grain Production Pattern of China: Dynamic Effect and Mediating Mechanism

The flow and reallocation of agricultural production factors induced by urbanization play an important role in the changes of the grain production pattern (GPP). Using provincial panel data from 1996 to 2018 in China as the research sample, the center of gravity transfer–standard deviation ellipse model was applied to understand the change characteristics of GPP. Next, a dynamic spatial panel econometric model was established to test the impact of urbanization on GPP, and a spatial mediated effect model was used to identify the mediated transmission paths played by cropland utilization, planting structure adjustment, and agricultural technology progress in this impact process. The main conclusions showed that (1) the grain production COG of China transferred to the northeast, gradually resulting in a spatial pattern from the northeast to the southwest; (2) the urbanization process has a significant negative impact on the GPP, with each unit increase in urbanization resulting in a 0.30% decrease in the grain production concentration index; (3) cropland utilization, planting structural adjustment, and agricultural technology progress play significant mediating roles in the impact of urbanization on the GPP, and their mediating effects can weaken the direct negative impact of urbanization, among which the mediating effect of planting structure adjustment is the highest (13.9%). The study findings provide a new perspective for further understanding the relationship between urbanization and grain production pattern and also provide theoretical references and practical insights for improving the allocation efficiency of agricultural production factors and formulating scientific regional planning policies for grain production in the high-quality transformation of urbanization