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This article proposes a general framework of a Markov Switching GARCH model with a mixture of truncated Gaussian to model asset returns with price limits in China. Theoretically, while retaining many convenient statistical properties of the Gaussian distribution, the proposed model also assumes a flexible time-varying volatility structure to accommodate the feature of the return data under price restrictions in China, such as the clusters near the bounds (due to the 'bound effect'). Empirically, we apply the model to eight representative stocks from Shanghai and Shenzhen stock markets in China. Lastly, we find that our proposed model dominates the conventional volatility models in terms of Value-at-Risk measures. [ABSTRACT FROM AUTHOR]

Characterizing the availability of opportunities to residents has been a long-term aim in health care geographic investigation. It is important to measure the degree of inequity in health care accessibility and to identify underserved areas, due to the uneven distribution of health care services. In this study, JavaScript was used to calculate travel time based on Amap, as this can provide a more reliable data support to measure the health care accessibility in Xi'an communities, China. Based on the overall equity, herein, an attempt was made to quantify the equity of health care accessibility, and to identify health care underserved areas inside the different communities. Results show that the accessibility to low-level health care services is high in the northern areas and low in the southern areas, while the accessibility to high-level and comprehensive health care services shows a clear core-periphery spatial structure. Moreover, the overall equity of the health care accessibility is relatively low, and the inequity of high-level health care accessibility is further aggravated. Furthermore, the quantified equity of accessibility to high-level and comprehensive health care services in the central urban areas is better; however low-level health care services are relatively inadequate. There are significant differences among health care underserved areas, in particular, for the worst equity and the lowest accessibility areas (A1) and the worse equity and the lowest accessibility areas (B1) in high-level underserved areas. Notably, the sharing of health care services and the reasonable flow of health technical personnel among different levels of health institutions can make the high-level health care services in the central urban areas have a greater trickle effect on the surrounding areas. [ABSTRACT FROM AUTHOR]

Based on the discovery of the "natural orange soil layer" in the wall foundation of the Ming Great Wall in Huangzhong County, Xining City, northwest China, this paper reveals the mechanism behind the barrier effect of this layer on the salinity deterioration through the combination of qualitative judgment and quantitative testing. Based on this mechanism, the conventional lime soil was improved by adding modified polyvinyl alcohol as the cementing agent and fly ash, thereby generating a modified cushion material. Indoor tests of freeze-thaw and temperature-humidity cycles for the modified cushion material were then conducted alongside field tests of rammed restorations in the basal sapping zone with and without the modified cushion. The test results show that the modified cushion materials have excellent durability and act as a substantial barrier to salinity deterioration. The research results provide a new approach to repairing the basal sapping of earthen sites. [ABSTRACT FROM AUTHOR]

• We developed an integrated model to quantify biodiversity by habitat quality. • Cultivated land mainly transfers into woodland, with some of construction land. • Biodiversity habitat quality under ecological protection scenarios is best. • The biodiversity of the upper and lower reaches in 2030 shows trend of improvement. The temporal and spatial dynamics of biodiversity and its future trends are of great significance for maintaining biodiversity pattern and ensuring regional ecological security in the Nanliu River Basin of Beibu Gulf. At present, most studies are concerned with the assessment of biodiversity in historical period, but few studies focused on the prediction of biodiversity under several scenarios in future years, and the history and future spatial simulation of habitat quality has not been carried out. Therefore, the establishment of biodiversity simulation studies under different scenarios in the future plays a crucial role in the sustainable development of regional social economy. This study takes Nanliu River Basin, which only flows into the sea in the Beibu Gulf, as the research object. Based on land use data and social and economic data interpreted from remote sensing data in 2000, 2010 and 2020, Conversion of Land Use and its Effects at Small Region Extent (CLUE-S) model was used to simulate and predict land use patterns for ecological protection scenarios, natural growth scenarios and food security scenarios in 2030. The Integrated Valuation of Ecosystem Service and Tradeoff (InVEST) model was used to evaluate the biodiversity of different scenarios in the past and future and discuss the habitat quality and degradation degree of biodiversity in the watershed. Results were presented as follows. In 2000–2020, an increasing trend of construction land, shrub land and water area was found in the Nanliu River basin of Beibu Gulf. The largest increase was observed in construction land, and the largest decrease was noted in cultivated land and woodland. The best habitat quality will be under the ecological protection scenario in 2030. The biodiversity in the upstream and downstream of the three scenarios showed varying degrees of improvement, and the midstream exhibited a degradation trend. The research results of this paper can make up for the vacancy of biodiversity habitat evaluation system in Nanliu River Basin at home and abroad, and have important theoretical and practical significance for promoting ecological protection and ecological planning of watershed. [ABSTRACT FROM AUTHOR]

Karst rocky desertification (KRD) has become one of the most serious ecological and environmental problems in karst areas. At present, mapping KRD with a high accuracy and on a large scale is still a difficult problem in the control of KRD. In this study, a random forest (RF) based on maximum information coefficient and correlation coefficient feature selection is proposed to predict KRD. Nine predictors stood out as feature factors to estimate KRD. Rock exposure was the most important predictor, followed by fractional vegetation cover for the prediction of KRD processes. The kappa and classification accuracy indexes were to evaluate the performance of the model. We recorded overall accuracy rate and kappa index values of 94.7% and 0.92 for the testing datasets respectively. The RF model was then used to predict the KRD in 2001, 2011, 2016, and 2020, and it was found that the KRD in the study area has exhibited a positive trend of improvement. Therefore, the use of multisource remote sensing data combined with the RF model can obtain better prediction results of KRD, thereby providing a new idea for large-scale estimation of the KRD in peak-cluster depression., (© 2022. The Author(s).)

Background: Isotopic discrimination, dietary composition and feeding regime determine the carbon and nitrogen stable isotope ratios of animals. Accordingly, measurement of the stable isotope ratios of carbon and nitrogen can be a potential method to identify patterns of pork production., Results: In the current study, we investigated the carbon and nitrogen isotopic ratio in pork from organic and conventional systems. The average carbon and nitrogen isotope ratios for various organic tissues, including hair, blood and defatted meat, were higher than those of conventionally raised ones. The discriminant analysis results based on the combination of carbon and nitrogen isotopic ratios in defatted meat reached a 100% correct classification. Furthermore, the variation in carbon and nitrogen stable isotope ratios of retail organic and conventional pork has been studied over 1 year. The results suggested that organic pork had a higher δ(13) C value than that of the conventional pork in all but three fortnights. Grouping of the δ(15) N data showed that the δ(15) N value in organic pork was higher than that of the conventional one throughout the whole year., Conclusion: The method established in the present study provides a potential detection that can be highly valuable to prevent fraudulent labelling of organic pork. © 2015 Society of Chemical Industry., (© 2015 Society of Chemical Industry.)

Food consumption is one of the key exposure routes of humans to contaminants. This article evaluated the residue levels of 51 pesticides and 16 polychlorinated biphenyls (PCBs) in selected fish and food items which were commonly consumed in the Nantong area of Jiangsu Province, Southeast China. The 51 pesticides and 16 PCBs were analyzed by highly sensitive gas chromatography-tandem mass spectrometry (GC-MS/MS). The results showed that organochlorine pesticides such as dichlorodiphenyltrichloroethanes (DDTs), hexachlorocyclohexanes (HCHs), hexachlorobenzene (HCB) and mirex and other pesticides including chlorpyrifos, pyrethroid pesticides, metolachlor, pyridaben and trifluralin were frequently detected in the samples, which was consistent with the accumulation level and characteristics of these toxic chemicals in human adipose tissue of people living in Nantong. Meanwhile, correlation of the residue level of toxic chemicals with their physical chemical properties and historic use pattern in Nantong area was observed. Combined with dietary survey results at the same sampling locations, human health risk assessment of ingestion through the dietary route was performed. The results suggested that the non-cancer risks of the chemicals investigated can be considered negligible in the Nantong area, however, the cancer risks from lifetime dietary exposure to DDTs and HCB have exceeded the acceptable levels.