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Purpose: Organic pollutants' transport, transformation, and biological effectiveness in soils depend mainly on their chemical forms. Therefore, in addition to studying the total content of pollutants, it is essential to understand the forms of organic pollutants in soils. In this study, we measured the speciations of polycyclic aromatic hydrocarbons (PAHs), including desorbing fraction, non-desorbing fraction, and bound residues, in soil samples from the Zhongliangshan karst terrain in Chongqing, southwest China. We also investigated the occurrence of PAHs in soils of the region. Moreover, we used principal component analysis (PCA) to analyze the relationship between soil properties and different speciations of PAHs in soils. The contents of ΣPAH16 ranged from 319.69–1215.64 ng/g, with a mean value of 615.02 ng/g. Desorbing fraction PAHs were significant, accounting for 34–81% of the total PAHs. The ratio of different speciations ordered as soluble > organic solvent extracted > bound residues. 2-3-ring were the major components of the total PAHs content in soils and desorbing fraction. PCA analysis determined that soil organic matter (SOM), total nitrogen (TN), and soil bulk density significantly affected the non-desorbing fraction, and pH and total organic carbon (TOC) had a significant positive correlation with the bound residues. The karst area is a complex and fragile ecosystem. The speciation of PAHs in soils is of great importance for assessing their risk and for remediation. However, most studies have focused on the concentration and distribution of PAHs in karst soils. Therefore, in this paper, we investigated the distribution of PAHs in soils in karst areas by investigating the distribution of different speciations of PAHs in soils. We also investigated the key factors influencing the distribution of different speciations. Materials and methods: Ten sites were selected in Zhongliangshan karst terrain, where 0–20 cm of soil was collected and the concentrations of 16 PAHs were measured. Three speciations of 16 PAHs in soils were extracted by sequential extraction. And the standard methods recommended by the Chinese Society of Soil Science were used to determine the basic soil properties. Result and discussion: In this study, we measured the speciation of PAHs in soil samples from the Zhongliangshan karst terrain in Chongqing, southwest China, including desorbing fraction, non-desorbing fraction, and bound residues. The total content of the 16 PAHs ranged from 319.69 to 1215.64 ng/g, with an average value of 615.02 ng/g. The desorbing fraction was significant, accounting for 34–81% of the total PAHs. The ratio of different speciations is ordered as desorbing fraction > non-desorbing fraction > bound residues. 2–3-ring were the major components of the total PAHs content in soils and each speciation. The PCA results show a significant effect of soil organic matter, TN, and soil bulk density on the non-desorbing fraction. pH and TOC had a relatively significant positive correlation with bound residues. Conclusions: This paper investigated the contamination status of PAHs in surface soils in the karst terrain of southwest China, and the speciation of PAHs. Under the special geological structure background in karst areas, studying the occurrence forms and influencing factors of PAHs pollutants in soils is of great significance for a deeper understanding of the occurrence forms of pollutants and effective control of their diffusion. [ABSTRACT FROM AUTHOR]

The vast majority of rural settlements in Western China are located in the ecologically sensitive and diverse mountainous environment, which also experienced rapid changes in policy and institutional interventions over the past 40 years. At present, in the transitional period of "post-poverty alleviation," they have more opportunities to re-integrate themselves into the large regional development. However, there is a lack of systematic evaluation and cognition of the related functions of the spatial structure between the settlements at the regional village scale and town scale. Therefore, in this paper, the theory of complex adaptive system and its analytical NK model were introduced, and a quantitative measurement framework was constructed for the adaptability level of this kind of rural settlement spatial structure organization so as to explore the effective path for its global optimization. Taking Xinglong Town of Chongqing in the western mountainous area as an example, it was found from the analysis that (1) the number of villages at a high comprehensive adaptation level has increased over time, which has an obvious positive correlation with the construction of transportation network, and a structural adsorption effect. (2) The spatial structure of the rural settlement system in the region has changed from weak industrial nodes – traffic single branch connection – public service decentralized coverage in 2010 to the organizational adaptation characteristics of stable industrial agglomeration – traffic expansion and extension – public service continuous coverage in 2019. (3) The spatial elements related to industry and public service in each village have an increasingly significant impact on the reconstruction and differentiation of its spatial structure. Finally, based on the changing trend of adaptability level and the correlation characteristics of regional space, in this paper, the spatial structure optimization strategy of Xinglong Town is put forward, which provides a reference basis for the coordinated development of the town and village space under the township-level planning in the western region. [ABSTRACT FROM AUTHOR]

It will contribute to ameliorating the national carbon trading system and further benefit the realization of China's carbon peaking and carbon neutrality goals through in-depth study and summarize the effectiveness of carbon trading policy implementation in pilot areas. Based on the multi-phase difference-in-differences approach and synthetic control method, this paper utilizes China's provincial panel data from 2006 to 2020 to comprehensively assess the Porter effect (including the economic and green innovation effects) and carbon mitigation effect of carbon trading policy from the overall and local perspectives. Then the robustness test and mechanism analysis are carried out. The findings show that: (1) from the overall effect, the carbon trading policy brings a noticeable carbon mitigation effect and Porter effect, and the intensity of the impact keeps changing over time; (2) there is significant heterogeneity in the local effects of this policy on the eight pilot provinces and cities, with only Chongqing obtaining both the Porter effect and the carbon mitigation effect, while the rest of the regions do not yield the triple dividend of economic, environmental, and green innovation simultaneously; (3) there are much more prominent environment and green innovation effects in the developed regions, while the underdeveloped ones have better economic development and no green innovation effect; (4) the policy can bring environmental and economic dividends through energy structure optimization. However, due to the carbon rebound effect, stimulating green innovation pathways can only boost the economy while carbon emissions increase instead. The research conclusions can provide the decision support and policy direction for policies related to China's carbon market. [ABSTRACT FROM AUTHOR]

Despite growing scholarly attention on the role of urban networks for understanding regional dynamics, there has been limited research examining the impact of cities' transportation network connections on regional market integration. This paper analyzes China's four major urban agglomerations: the Yangtze River Delta, the Pearl River Delta, Beijing-Tianjin-Hebei, and Chengdu-Chongqing. Applying a spatial Durbin model to cross-sectional datasets for 2019, we provide insight into the role of cities' transportation network connections in promoting regional market integration, considering both the potentially heterogeneous impact of network connections and the interplay between network and agglomeration externalities. Our results indicate that: (1) cities' transportation network connections have an inverted 'U'-shaped effect on regional market integration; (2) transportation network connections have spatial spillover effects; (3) the positive impact of transportation network connections on regional market integration becomes more pronounced as city size decreases; and (4) there are neither complementary nor substitution effects between network and agglomeration externalities. We reflect on the broader implications of our empirical findings for regional development strategies and discuss possible avenues for further research. [ABSTRACT FROM AUTHOR]

The development of urbanization has changed the original land cover and exacerbated the urban heat island effect, seriously affecting the sustainable development of the ecological environment. Research on urban heat island characteristics and land cover changes in five major urban agglomerations in China to provide a reference for preventing thermal environmental risks and urban agglomeration construction planning. This paper estimates the surface urban heat island intensity (SUHII) of the five major urban agglomerations in China from 2003 to 2019 based on Google Earth Engine (GEE) through the urban–rural dichotomy, analyzes their trends through the Sen + M–K trend analysis method, and combines the detrending rate matrix to analyze the impact of land cover type shift on urban heat island change. Research shows that (1) the land cover types of the five major urban agglomerations in China have changed considerably from 2003 to 2019, and all five major urban agglomerations in China experienced varying degrees of urban expansion. (2) The annual average value of SUHII decreases in Beijing-Tianjin-Hebei, Yangtze River Delta, and middle reaches of the urban agglomerations, while the annual average value of SUHII increases in Chengdu-Chongqing and Pearl River Delta urban agglomerations. (3) The spatial composition of land cover types in the five major urban agglomerations in China is highly spatially correlated with urban heat islands, with urban land and bare land urban heat islands being the most pronounced. (4) The land cover type shift has the most significant heat island impact on Beijing-Tianjin-Hebei, Yangtze River Delta, and Chengdu-Chongqing urban agglomerations. (5) The land cover change (LCC) with an increasing trend in SUHII is mainly bare land converted to arable land, and water bodies, grassland, forest land, and arable land converted to urban land. [ABSTRACT FROM AUTHOR]

In the past decade, Public Rental Housing (PRH) has become the program of providing affordable rental housing to low- and middle-income households in China. Even though descriptions of the governance results are numerous, the previous studies are not underpinned by a theoretical foundation from a governance perspective, nor have they empirically examined whether PRH governance works on the ground. This explorative and empirical paper aims to fill this gap of an outcome-oriented evaluation of the impacts of governance as perceived by the final user. Central government formulated the objective for PRH governance as maintaining stability in the society. Whether the tenants perceive the goal of social stability as achieved was measured along three governance outcome dimensions: satisfaction with housing quality, satisfaction with housing quantity, and willingness to communicate with the government about PRH governance. Data were collected from questionnaires to PRH-tenants in Chongqing, the most important pilot city of PRH provision in China. The findings show that the perceived governance outcomes were quite mixed as tenants were moderately satisfied with PRH housing quantity, but less satisfied with housing quality, and thought they could relatively easily communicate with local government. In view of these mixed outcomes, to strengthen the effectiveness of PRH governance in the eyes of the tenants, this study suggests local governments: (1) to rethink and redevelop the performance evaluation; (2) to rethink the relations with non-governmental actors and organise a monitoring system that will assist in optimizing housing quality; and (3) to facilitate tenants' communication with local government. [ABSTRACT FROM AUTHOR]

The number of people in China aged 60 and older has risen from 10.0% in 1999 to 17.9% in 2018, signaling that Chinese society is facing an unprecedented challenge to care for their ageing population. With the decline of traditional family support for elderly relatives and subsequent development of social provisions for them, nursing homes are expected to increasingly take on a caregiving role in the coming years. Therefore, this paper first ascertains the spatial distribution of nursing homes in China. Based on a global ordinary least squares (OLS) model and geographically weighted regression model, it then investigates which socio-economic factors affect the spatial distribution of nursing homes and the degree of their influence. Study results show that, (1) nursing homes are mainly located in the Bohai Bay Economic Zone and the Yangtze River Delta region, with fewer in western cities, except Chongqing; (2) urbanisation and fiscal expenditures are the main drivers for promoting nursing homes in the Yangtze River Delta region and southwest China; (3) the increase of nursing homes in the Pearl River Delta and Northeast China may largely rely on the level of social welfare, social welfare services, and higher number of elderly people; (4) outward migration poses a major challenge to the development of nursing home services in southwest China, and North and Central China Plain, given that population size is positively associated with the number of nursing homes, and (5) population migration from west to east is continuing, so regional collaboration between east and west is urgently needed to cope with the ageing issues. This research advocates for more detailed and region- and city-targeted elderly care policies on the basis of actual situations in cities and regions. [ABSTRACT FROM AUTHOR]

Owing to the lockdowns associated with the Coronavirus Disease 2019(COVID-19) pandemic, carbon emissions were significantly reduced. However, the accurate impacts on the personal transport sector since then remain unclear. To further investigate the influence of sudden public health emergencies on actual carbon emissions from personal electric vehicles, this paper examined the travel patterns and corresponding carbon emissions of plug-in hybrid electric vehicles (PHEVs) operating in Chongqing, China, before and after COVID-19. The results revealed that the pandemic has reshaped the travel patterns of vehicle drivers, with a 9 % reduction in the postpandemic fleet average daily travel mileage. Currently, the total daily carbon emissions of a PHEV with a range of 80 km (PHEV80) are 6.24 kg, which is 13 % lower than emissions from conventional vehicles and 32 % higher than those from electric battery-powered vehicles before the pandemic. Since COVID-19, there has been a 24 % decrease in carbon emissions from PHEV80 vehicles for the fleet and a 30 % maximum increase for individuals. Furthermore, considering the integration of 50 % renewable energy into China's power grid by 2025, PHEVs can better mitigate the fluctuations in carbon emissions associated with sudden public health emergencies compared with conventional vehicles. [ABSTRACT FROM AUTHOR]

The high environmental pollution load caused by the massive pollutant emissions and the accumulation of endogenous and cross-regional pollution has become an important obstacle to the current ecological civilization construction in the Yangtze River Economic Belt (YREB) in China. Taking the YREB as an example, by using four environmental pollutant emission indicators, including chemical oxygen demand (COD), ammonia nitrogen (NH3-N), sulfur dioxide (SO2), and nitrogen oxides (NOx), this paper established an environmental pollution load index (EPLI) based on the entropy-based measurement. Moreover, the Spatial Durbin Model was used to quantitatively analyze the drivers and spatial effects of environmental pollution load. Finally, specific scientific references were provided for formulating environmental regulations of pollution source control in the YREB. The results showed that: 1) During 2011–2015, the EPLI in the YREB was reduced significantly and the environmental pollution load increased from upstream to downstream. Among them, the pollution load levels in the Upper Mainstream subbasin, Taihu Lake subbasin, and Lower Mainstream subbasin were the most prominent. 2) The environmental pollution load situation in the YREB was generally stable and partially improved. High load level areas were mainly concentrated in the Yangtze River Delta Region and the provincial borders in upstream, midstream, and downstream areas. The high load level areas already formed in Chengdu and Chongqing were also the key regulatory points in the future. 3) The degree of local environmental pollution load was apparently affected by the adjacent cities. The population size, industrialization level, and the fiscal decentralization not only drove the increase of the local environmental pollution load level, but also affected the adjacent areas through the spatial spillover effects. The land development intensity mainly drove the increase in the local EPLI in the YREB. While factors such as economic development level and agricultural economic share could only act on the environmental pollution load process in adjacent cities. 4) According to the differentiation characteristics of drivers of each city, the YREB was divided into seven zones based on k-medoids cluster method, and targeted zoning control policy recommendations for alleviating environmental pollution load in the YREB were proposed. [ABSTRACT FROM AUTHOR]

With the continuous socio-economic development, the Chinese government has readjusted its poverty alleviation and development strategies, and established the targeted poverty alleviation policies in an attempt to holistically build a well-off society. Based on the panel data of nine national poverty-stricken counties (districts) in Chongqing in the Three Gorges Reservoir Region from 1998 to 2015, this paper quantitatively analyzed the effect of the national poverty alleviation policies in the context of targeted poverty alleviation by adopting the methodologies of a break-point regression and a panel regression. The results show that: (1) The national policy for targeted poverty alleviation has a significant effect on poverty reduction, and this effect has manifested since the beginning of its implementation, i.e. the net income of farmers in 2012 increased by 12.41%, as against that during 2010–2011. The per capita net income of farmers has increased by 33.64% from 2011 to 2015 during the implementation period of the targeted poverty alleviation policy, as against that during 1998–2010. The policy effect during 2011–2015 is also evident, for the net income of farmers increased by 21.23% compared with that from the beginning of the policy implementation in 2012; (2) Economic activity of the market and gross value of agricultural product in the poverty-stricken areas have significantly increased farmers' net income, specifically, for every 1% increase in the degree of market economic activity, farmers' net income will increase by 48.74%; Furthermore, for every 1% increase in gross value of agricultural product, the farmers' net income will increase by 3.7%. Finally, this paper proposed corresponding policy recommendations based on these findings. [ABSTRACT FROM AUTHOR]

Assessment of the disaster resilience index (DRI) is an effective decision support tool for managing natural disasters. This study holds that disaster resilience is a dynamic process accompanied by coping capacity, adaptive capacity, and transformative capacity in different phases; therefore, we develop a three-dimensional capacity-based framework using seven indicators (including 38 subindicators) to map the multigoals for measuring resilience at the household level. Our data were acquired through questionnaire responses by 516 representative rural households in mountainous hazard-prone areas in Chongqing, China. The results reveal that more households are deemed "low resilience" and that geographical spatial differences exist in the DRI across the case regions. Several factors affecting the ability to survive, bounce back, and bounce forward from mountain hazards for rural households were found in China. The framework constructed in this paper offers a new perspective for a holistic understanding of disaster resilience. [ABSTRACT FROM AUTHOR]

In China, there is a growing number of urban renewal projects due to the rapid growth of the economy and urbanization. To meet the needs of urban development, urban renewal requires a sound decision-making approach involving various stakeholder groups. However, current urban renewal decision-making is criticized for poor efficiency, equity, and resulting in many unintended adverse outcomes. It is claimed that high-level transaction costs (e.g., a great deal of time spent on negotiation and coordination) are the factors hidden behind the problems. However, few studies have analyzed urban renewal decision-making in a transaction costs perspective. Using the case of Chongqing, this paper aims at adopting transaction costs theory to understand the administrative process of urban renewal decision-making in China. This research focuses on four key stakeholder groups: municipal government, district government, local administrative organizations, and the consulting parties. A transaction costs analytical framework is established. First, the decision-making stages of urban renewal and involved key stakeholder groups are clarified. Second, the transactions done by different stakeholder groups in each stage is identified, thus to analyze what types of transaction costs are generated. Third, the relative levels of transaction costs among different stakeholder groups were measured based on the interview. The empirical analysis reveals how transaction costs occur and affect urban renewal decision-making. Finally, policy implications were proposed to reduce transaction costs in order to enhance urban renewal. [ABSTRACT FROM AUTHOR]

Groundwater from karst subterranean streams is among the world's most important sources of drinking water supplies, and the hydrochemical characteristics of karst water are affected by both natural environment and people. Therefore, the study of karst groundwater hydrochemistry and its solutes' sources is very important to ensure the normal function of life support systems. This paper focused on the major ion chemistry and sulfate isotope of karst groundwater in Chongqing for tracing the sulfate sources and related hydrochemical processes. Hydrochemical types of karst groundwater in Chongqing were mainly of the Ca-HCO type or Ca(Mg)-HCO type. However, some hydrochemical types were the K + Na + Ca-SO type (G25 site) or Ca-HCO + SO type (G26 and G14 sites), indicating that the hydrochemistry of these sites may be strongly influenced by anthropogenic activities or unique geological characteristics. The δS-SO of collected karst groundwater sample fell into a range of −6.8 to 21.5 ‰, with a mean value of 5.6 ‰. In dolomite aquifer, the δS-SO value ranges from −4.3 to 11.0 ‰, and in limestone aquifer, it ranged from −6.8 to 21.5 ‰. The groundwater samples from different land use types showed distinctive δS-SO value. The δS-SO value of groundwater samples had range of −6.8 to 16.7 ‰ (mean 4.0 ‰, n = 11) in cultivated land areas, 1.5-21.5 ‰ (mean 7.2 ‰, n = 20) in forested land areas, and −4.3 to 0.8 ‰ (mean −1.7 ‰, n = 2) in coalmine areas. The δS-SO values of groundwater samples collected from factory area and town area were 2.2 and 9.9 ‰, respectively. According to the δS information of potential sulfate sources, this paper discussed the possible sulfate sources of collected karst groundwater samples in Chongqing. The variations of both δS and 1/SO values of the groundwater samples indicated that the atmospheric acid deposition (AAD), dissolution of gypsum (GD), oxidation of sulfide mineral (OS) or anthropogenic inputs (SF: sewage or fertilizer) contributed to sulfate in karst groundwater. The influence of oxidation of sulfide mineral, atmospheric acid deposit and anthropogenic inputs to groundwater in Chongqing karst areas was much widespread. For protecting, sustaining, and utilizing the groundwater resources, the sewage possibly originating from urban, mine or industrial area must be controlled and treated, and the use of fertilizer should be limited. [ABSTRACT FROM AUTHOR]

Changes in cultivated land in China are related to food security for nearly 1.4 billion people. Administrative ruling has decomposed the goal of cultivated land protection in China and implemented it from top to bottom, so that cultivated land data have nested attributes. Although related research on cultivated land changes has achieved fruitful results, these studies have neglected the scale effect created by the nested structure of cultivated land data, and it is easy for the policy to lose its effect in scaling. A two-layer linear model of the hierarchical linear model is constructed in this paper based on spatial autocorrelation and scale variance analyses to analyse the different spatial scales for cultivated land changes and reveal the interaction mechanism of the driving factors at different spatial scales. The results show the following: (1) The smaller the spatial scale of the study area, the easier the spatial correlation of the cultivated land quantity distribution. (2) An analysis of the driving factors of cultivated land change in Chongqing finds that 33.80% of the differences are from the functional block scale and 66.20% are from the district or county scale. (3) We found that the spatial scale has a certain impact on the effectiveness of the driving factors of cultivated land changes. Large-scale driving factors will change the correlation between small-scale driving factors and cultivated land change. In the future, the problem of scale effects should be considered in the field of cultivated land management, the effects of different driving forces at various scales should be considered and the scientific decomposition of cultivated land protection tasks according to the spatial scale should be carried out to improve the efficiency of the protection of cultivated land. [ABSTRACT FROM AUTHOR]

The resettlement of residents to new urban areas in the Three Gorges Reservoir region, China, has generally adopted the local resettlement method, but engineering disturbances in conjunction with heavy rainfall have contributed to landslide instability. This paper discusses the influential factors and formation mechanism of the Jinjiling landslide in Jiangdong District, Wushan County, Chongqing, China. This study concludes that the cutting and filling of slopes have led to loading of the rear edge and open cut excavation at the downhill side of landslide. More importantly, the filling of channels with surface soil has blocked the surface water discharge channel along the landslide body, thereby transforming surface water into groundwater. Therefore, under heavy rainfall, the groundwater level in the Jinjiling landslide rose substantially, resulting in large deformation in approximately August 1, 2018. After emergency treatment, including groundwater pumping, the landslide deformation slowed considerably. The rising groundwater caused by filling of the slope was the key factor influencing the landslide. Based on the deformation characteristics and formation mechanism of the landslide, comprehensive control measures referred to as the "drainage+unloading+support" scheme are proposed, and drainage should be the focus of this type of landslide protection project. The results of this study may provide a reference for similar slope engineering projects. [ABSTRACT FROM AUTHOR]

This study explored subjective responses towards various environmental quality parameters. It would be helpful to approach an overall comfort improvement relating to physics. In order to investigate the combined effects of sound, light and heat on the overall comfort of pedestrians, which could be evaluated by overall comfort vote, two residential areas in Yubei District, Chongqing (a Cfa city in China) were selected for field measurements and questionnaires. Three were three key findings were concluded based on subjective responses to environmental parameters via multiple linear regression. First, the average outdoor neutral temperature, mean neutral sound level and neutral illumination intensity were determined to be 26.6 °C (determined by physiologically equivalent temperature), 56.5 dBA (determined by A-weighted equivalent continuous sound level) and 21.4 klx (determined by LUX), respectively. Second, considering the effects of both physiology and psychology, thermal perceptions varied for acoustic and light environments. Residents partially had lower neutral temperatures at the noisy condition. Third, environmental quality factors had a significant effect on overall comfort. Positive correlation between physiologically equivalent temperature and overall comfort vote was found (sig < 0.000); while the effects of sound pressure and light intensity were not always significant. Hence, thermal stress played a significant role in people's overall comfort. This study has explored the effects of three environment quality parameters on human perceptions. It provided better understanding against dwellers' feelings under complex circumstances. Future urban design and planning works should consider the cooling factors regarding contextual acoustical and visual environments. [ABSTRACT FROM AUTHOR]

The construction of The Three Gorges Reservoir has changed land use structure and reconstituted landscape pattern as imparts significant influence upon the land use structure and ecological environment of Three Gorges Reservoir Regions. The ecological safety of reservoir area is extremely dependent on unique location and special geological conditions of Zhongxian County, the center of Three Gorges Reservoir Regions in Chongqing, and therefore, ecological environment of reservoir area will be changed with the transition of land use in Zhongxian County. Based on land use data in 2000, 2005, 2010, this paper chooses influencing factors from aspects of natural topographic and geomorphological conditions, accessibility to economic development and land use expansion, and then establishes Logistic-CA-Markov (Logistic-Cellular Automata-Markov) and WLC-CA-Markov (Weighted Linear Combination- Cellular Automata- Markov) models so as to simulate spatial pattern of land use of Zhongxian County. The results demonstrate that WLC-CA-Markov model established here has better controllability and higher simulation precision (the kappa coefficient is 0.9295). In the future development of Zhongxian County, the area of grassland and plow land will be reduced continuously, the area of construction land will be expanded obviously mostly because of the added area both near the water and in the north of Zhongxian county, the area of woodland will be increased to a little extent, the area of water area and unused land has gentle change. In the sustainable scenario, the area of grassland will be reduced slightly, the area of water area keeps steady, the area of plow land is reduced but higher than red line of plow land, the area of construction land is increased with significantly smaller increase amplitude than that in the natural development scenario, and the woodland is increased. This scenario coordinates ecological environment with economic development of regional society and turns out to be the best development scenario of land use. [ABSTRACT FROM AUTHOR]

Exploring English intelligibility in linguistically diverse environments, such as China, is crucial for improving cross-cultural dialog and tailoring language instruction to address the phonetic hurdles of non-native speakers. This research employed a phonetic experimental methodology to assess the intelligibility of English spoken by college students from the Bashu dialect region of Southwest China to an international audience. Data from 40 intermediate English-proficient students in Sichuan and Chongqing were analyzed using open-ended questionnaires and evaluative scales. The findings revealed that the influence of the Bashu dialect significantly impeded the accurate articulation of specific English phonemes, thereby exerting an impact on the international intelligibility of their spoken English. Notably, notwithstanding their conspicuous accents, the research concluded that the English enunciated by these students generally retained intelligibility for global audiences. The study identified a spectrum of pronunciation challenges, encompassing issues with phonetic sounds, recurrent mispronunciations, and variances in accent and prosody, collectively contributing to an overarching influence on intelligibility. Grounded in international listener feedback, this study proffers strategies to augment the intelligibility of spoken English among Chinese learners originating from dialect-specific regions, thereby fostering the amelioration of their communicative skills and bolstering their confidence when engaging with global audiences. [ABSTRACT FROM AUTHOR]

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As an important industrial city, Chongqing has experienced rapid economic growth in recent years, but at the same time the growth has been accompanied by serious pollution problems. Water quality monitoring shows that the waters of Chongqing are widely polluted. In this paper, the human capital approach is applied to assessing the economic losses and damages caused by water pollution in Chongqing. Based on previous studies and empirical investigations, water pollution-induced damage can be categorized into two general types; damage to ecosystems, including agriculture; and damage to non-ecosystems, including industry. The economic loss estimation of each type of the damage is conducted by taking into account a group of relevant parameters and methods. [ABSTRACT FROM AUTHOR]

Water resources are the basis of both regional sustainable development and a sustainable socioeconomy. Moreover, the evaluation of water resource security is a prerequisite for effective water resources management. Existing water resource problems have become one of the most significant factors limiting sustainable development. How to effectively identify stress factors and assess existing water resource management measures is important basis to achieve security issues. With Chongqing City of China, stress factors and the efficiency of water management measures were evaluated in this paper. The pressure, status, and response framework allows for the assessment of water resources based on three subsystems: the pressure subsystem, the status subsystem, and the response subsystem. Using an entropy-weighted set pair model, Chongqing's water resource security from 2000 to 2011 was evaluated in an effort to determine the source of the pressure on the water resources system and to evaluate the efficiency of present response measures. The results show that water resource security has generally improved in Chongqing, which was in the Moderate Warning Level from 2000 to 2006 and in the Critical Safety Level from 2007 to 2011. The pressure on the water resources system in Chongqing mainly comes from rapid economic growth, urbanization, and the development of agriculture in Three Gorges Reservoir. However, some response measures have exhausted their capacity for improvement, while the enforcement of others has not been adequate. The main reason for improvement in the water resources system in Chongqing is the increase in forest coverage and the continuous investment in ecological management of the Three Gorges Reservoir. [ABSTRACT FROM AUTHOR]

Recent events have shifted the way the Chinese state responds to organized crime and corruption. The re-definition of organized crime, improved judicial oversight and the re-assessment of 'strike-hard' style police campaigns are key reforms. This paper discusses the recent changes in law, practice and oversight in the context of a brief overview of criminal groups in China and the Chongqing policing model. Revisions to the criminal law are described and the likely outcomes are assessed in the context of the key struggle to contain corruption and organized crime. [ABSTRACT FROM AUTHOR]

This paper reports the similarities and differences in how 'expert mathematics teacher' is conceptualized by mathematics educators in Hong Kong and Chongqing, two cities in China which share similar but different cultural and social backgrounds. Thirty-seven mathematics education researchers, school principals with mathematics education background, and mathematics teachers were interviewed on their perceptions of expert mathematics teacher. It is found that in both cities an expert mathematics teacher should have a profound knowledge base in mathematics, teaching, and students; strong ability in teaching; and a noble personality and a spirit of life-long learning. As for differences, an expert mathematics teacher should have the ability to conduct research, mentor other teachers, and have profound knowledge of examination and educational theories in Chongqing. These attributes were not found in Hong Kong. These similarities and differences are discussed, and relevant social and cultural factors in the two contexts are examined. [ABSTRACT FROM AUTHOR]

Groundwater quality in karst regions is largely controlled by natural processes and anthropogenic activities. Over the past 10 years, dissolved Sr and its radiogenic isotope, Sr/Sr, were widely used to trace the sources of solutes in groundwater. However, there is little research about hydrogeochemistry and Sr isotopic compositions of the karst groundwater in Chongqing karst area. In this paper, thirty-five representative karst groundwater samples were collected from different aquifers (limestone and dolomite) and various land use types. Hydrochemical types of karst groundwater in Chongqing were mainly of the Ca-HCO type or Ca(Mg)-HCO type. The dissolved Sr concentrations of the studied groundwater ranged from 0.57 to 15.06 μmmol/L, and the Sr/Sr varied from 0.70751 to 0.71627. The groundwater samples from different aquifers and land use types showed distinctive dissolved Sr concentrations and Sr/Sr. The very positive relationship between Ca/Sr and Mg/Sr in dolomite and limestone aquifers suggests that Ca, Mg and Sr element come mainly from the release of carbonate rock under the groundwater-rock-CO gas interaction. According to the Sr/Sr ratio, the Sr element in karst groundwater in Chongqing was controlled by the weathering of limestone, dolomite and silicate rock (allogenic water in a non-karst area). The relationship Sr/Sr versus Sr/[K + Na] shows that the anthropogenic inputs also obviously contribute to the Sr contents. The research results show that the karst groundwater in Chongqing is facing serious crisis of water quality, and needs to be protected further. [ABSTRACT FROM AUTHOR]

The current methods used to select the schemes for cleaner production in China have some disadvantages. This paper presents research on gray correlation analysis with application to one cement factory in Chongqing, China. The results show that the gray correlation analysis can effectively avoid the subjective bias on the scheme selection for cleaner production. Schemes for cleaner production selected by the gray correlation analysis have better performance than those selected by the traditional method based on economic, environmental and technical indices. [ABSTRACT FROM AUTHOR]

Parkinson's disease (PD) is the second most common human neurodegenerative disorder, and the pathogenesis of it remains poorly understood. Limited studies have shown that both long- and short-term exposure to air pollutants may be associated with increased risk of PD while lacking evidence on the effects of intermediate-term exposure. In this study, over-dispersed Poisson generalized additive models (GAMs) were applied to explore the association between intermediate-term sulfur dioxide (SO2) exposure and outpatient visits for PD in Chongqing, China, and further stratified analyses were performed by age and gender. A total of 39,984 PD cases from January 1, 2014, to December 31, 2019 (2191 days) were included. The association of intermediate-term SO2 exposure with outpatient visits for PD was statistically significant: per 1 μg/m3 increase of SO2 corresponded to 2.34% (95% CI: 0.88%, 3.80%) elevation in monthly PD outpatient visits at lag 0 (the concurrent month). Stratified analyses showed that the associations between SO2 and PD outpatient visits were stronger in younger (≤ 60 years) and female patients. In conclusion, intermediate-term SO2 exposure can be associated with an increased risk of PD outpatient visits. Our results highlight the importance of recognizing the role of intermediate-term SO2 exposure in the development of PD. In addition to focusing on the effects of long-term or short-term air pollutants, it is necessary to pay more attention to the health effects of intermediate-term exposure time windows of air pollutants, which will facilitate policy formulation and public health interventions for health risks. [ABSTRACT FROM AUTHOR]

Urban agglomerations have emerged as the primary drivers of high-quality economic growth in China. While recent studies have examined the urban expansion patterns of individual cities, a comparative study of the urban expansion patterns of urban agglomerations at two different scales is required for a more comprehensive understanding. Thus, in this study, we conduct a two-scale comparative analysis of urban expansion patterns and their driving factors of the two largest urban agglomerations in western and central China, i.e., Chengdu-Chongqing urban agglomeration (CCUA) and the Middle Reaches of Yangtze River urban agglomerations (MRYRUA) at both the urban agglomeration and city levels. We investigate the urban expansion patterns of CCUA and MRYRUA between 2000 and 2020 using various models, including the urban expansion rate, fractal dimension, modified compactness, and gravity-center method. Then we use multiple linear regression analysis and geographically weighted regression (GWR) to explore the magnitude and geographical differentiation of influences for economic, demographic, industrial structure, environmental conditions, and neighborhood factors on urban expansion patterns. Our findings indicate that CCUA experienced significantly faster urban growth compared to MRYRUA. There is an excessive concentration of resources to megacities within the CCUA, whereas there is a lack of sufficient collaboration among the three provinces within the MRYRUA. Additionally, we identify significant differences in the impacts of driving forces of CCUA and MRYRUA, as well as spatial heterogeneity and regional aggregation in the variation of their strength. Our two-scale comparative study of urban expansion patterns will not only provide essential reference points for CCUA and MRYRUA but also serve as valuable insights for other urban agglomerations in China, enabling them to promote sustainable urban management and foster integrated regional development. [ABSTRACT FROM AUTHOR]

The scientific and fair positioning of monitoring locations for surface displacement on slopes is a prerequisite for early warning and forecasting. However, there is no specific provision on how to effectively determine the number and location of monitoring points according to the actual deformation characteristics of the slope. There are still some defects in the layout of monitoring points. To this end, based on displacement data series and spatial location information of surface displacement monitoring points, by combining displacement series correlation and spatial distance influence factors, a spatial deformation correlation calculation model of slope based on clustering analysis was proposed to calculate the correlation between different monitoring points, based on which the deformation area of the slope was divided. The redundant monitoring points in each partition were eliminated based on the partition's outcome, and the overall optimal arrangement of slope monitoring points was then achieved. This method scientifically addresses the issues of slope deformation zoning and data gathering overlap. It not only eliminates human subjectivity from slope deformation zoning but also increases the efficiency and accuracy of slope monitoring. In order to verify the effectiveness of the method, a sand-mudstone interbedded Counter-Tilt excavation slope in the Chongqing city of China was used as the research object. Twenty-four monitoring points deployed on this slope were monitored for surface displacement for 13 months. The spatial location of the monitoring points was discussed. The results show that the proposed method of slope deformation zoning and the optimized placement of monitoring points are feasible. [ABSTRACT FROM AUTHOR]

The analysis of urban carbon metabolism will help to mitigate global warming and achieve China's "Dual Carbon" targets. Taking the main urban area of Chongqing (MUAC) as an example, this study accounted for the carbon release and carbon absorption in MUAC, constructed an urban carbon flow model based on the land–carbon nexus, and evaluated the urban carbon metabolic system from 2000 to 2020 by using the ecological network analysis method. The results show that MUAC is dominated by a "carbon source" effect, and the net carbon flow is always negative. The negative carbon flow mainly comes from the conversion of cultivated land to construction land, and the positive carbon flow mainly comes from the conversion of construction land to cultivated land and woodland. The ecological relationship of carbon metabolism in MUAC is dominated by exploitation and control relationships, which mainly exist in the ecological relationship between construction land and cultivated land, and the spatial distribution is concentrated in the central and western areas of MUAC. Our research results can provide a reference for Chongqing's green and low-carbon sustainable development as a means toward the realization of the "Dual Carbon" targets and provide a reference for other similar mountainous cities in western China. [ABSTRACT FROM AUTHOR]

The current research aims to examine variation in psychopathic personality traits and life history strategies during COVID-19 lockdown period in different areas of China. In Study 1 (N = 564), participants completed explicit measures of psychopathic traits and of life history strategy. To attenuate common method biases, Study 2 (N = 267) employed an alternative measure of psychopathy and an indirect measure of life history strategy, namely, future-discounting. Across two studies, we found consistent and significant evidence that participants from Wuhan, the initial epicenter of the pandemic, evidenced a faster life history strategy and a markedly higher level of psychopathic traits than did participants from Chongqing, which was less affected by the virus. Furthermore, a consistent pattern of correlation between life history strategy and psychopathy was observed across different groups of participants. We also replicated some previously reported studies but found that not all sex effects were consistent with life history in Chinese populations. Taken together, these findings suggest that individuals may show a high degree of variation in life history speed and psychopathic traits in response to unpredictable and adverse environments, which provide support for extended life history plasticity. [ABSTRACT FROM AUTHOR]

A compressed-fracture slumping mode of the tower-column unstable rock mass is unusual, and the damage-catastrophe mechanism is a critical scientific issue in the mountainous disaster. Taking Zengziyan W12# unstable rock mass collapse in Jinfo mountain, Nanchuan District of Chongqing Municipality in China as an example, a multi-factor coupled damage-catastrophe geomechanical model consisted of freezing–thawing, dissolution, load, and the water-weakening effect was built. A damage constitutive model and a total damage evolution analytical formula were attained based on the equivalent strain principal, and the improved water-weakening function was easier to access in the indoor test. We generalize the geomechanical model into an equivalent spring model, and the energy balance theory acquires the damage fold-catastrophe model and gains the failure criterion of the compressed-fracture slumping mode and an eigenvalue expression of the critical mutation displacement. The theoretical catastrophic displacement value fits the real displacement inflection point value basically and the damage-catastrophe model is reasonable. The research can predict the damage evolution process and the critical catastrophic displacement eigenvalue of the compressed-fracture slumping mode of a tower-column unstable rock mass and provide theoretical support for the geo-disaster prevention in the mountainous zone. [ABSTRACT FROM AUTHOR]

Natural hazards and urbanization put enormous pressure on cities and affect their sustainable development. Against the backdrop of the increasingly prominent urban disease, a comprehensive urban vulnerability assessment has a positive effect on improving the quality of urbanization. In this study, prefecture-level cities in Southwest China were taken as the study area, and their vulnerability was studied dynamically from 2010 to 2019. The four major systems were integrated, and a comprehensive vulnerability evaluation index system was constructed. Game theory and TOPSIS were combined to minimize the impact of subjective factors on the results. The results indicate that the overall vulnerability of Southwest China shows an irregular downward trend and strong spatial heterogeneity. There are 5 cities with very high vulnerability and 1 with very low vulnerability in 2010, accounting for 15.15% and 3.03% of the total number of cities, respectively. In contrast, the results for 2019 are the opposite, with 1 city with very high vulnerability and 5 cities with very low vulnerability. The better the economic situation, the lower the urban vulnerability. And there is a non-strictly negative correlation between urban vulnerability and urban size. When the difference in size between two cities is large enough, the vulnerability of the larger city is significantly lower. Leading development cities such as Chengdu and Chongqing have low vulnerability, while high vulnerability is mainly distributed in cities with poor infrastructure. On the basis of results, the research can be regarded as reference for urban management and coordinated development. [ABSTRACT FROM AUTHOR]

Multiple carbonate cliffs are distributed in the karst mountain areas of southwestern China. The dynamic process and failure mechanism of rockfalls in the cliffs are complicated and undefined, and can be dangerous for settlements. Moreover, it is difficult to identify the potential for such failures before they occur. The rockfall of the Zengziyan cliff at Chongqing, China, is used as an example for studying this type of failure and to determine the developmental characteristics of rockfall, expounding on the evolving process from a cliff to an unstable rock mass through to rockfall. A fracturing–crashing failure mode is proposed, based on the evolutionary characteristics of damage development, compression-induced fracturing, rock mass crashing and overall rockfall. Finite difference numerical simulations were used to analyse and validate the failure mode of the Zengziyan cliff under three simulation conditions. The results of the simulations indicated that strength deterioration at the bottom of the cliff was the root cause of its fracturing–crashing rockfall. The outcomes of this paper could provide a new analytical model and theoretical basis for identifying and analysing similar types of geological disasters in the mountainous areas of southwestern China, and may provide valuable reference information for further mechanical analysis, stability evaluation and engineering prevention of unstable rock masses prone to a fracturing–crashing rockfall. [ABSTRACT FROM AUTHOR]

Background: Rocky desertification is an economic, social, and environmental problem, which refers to the processes and human activities that transform a karst area covered by vegetation and soil into a rocky landscape. The effects of different types of soil cover on ecohydrological processes during the revegetation of areas undergoing karst rocky desertification remain unclear. Taking different measures for different ecohydrological situations will benefit re-vegetation in karst rocky desertification areas. Methods and aims: Monthly/heavy rainfall hydrochemical data and the δ13C of dissolved inorganic carbon (DIC) in karst water samples from January 2017 to December 2019 were obtained. This revealed the controlling mechanisms on hydrochemical processes by δ13CDIC under different soil cover conditions in the dip/anti-dip slopes of a karst trough valley in Ganxi Town, Chongqing City, southwestern China. Results: Hydrochemical variations are controlled by climate, soil, and vegetation and show clear seasonality. The δ13CDIC values (−16.88‰ to −3.49‰) in the study area were higher than the theoretical value (−14.00‰). In addition, it was observed that rain accelerated soil erosion (R2=0.7) in the karst trough valley and human activities (exogenous acid) resulted in DIC loss. The slopes, soil, and bare rock cover on the dip slope were different from that on the anti-dip slope, leading to the difference in their re-vegetation statuses. Conclusions: In this study, we found that different vegetation restoration schemes and treatment measures should be implemented between the dip and anti-dip slope. The protection of soil and water resources, especially soil, is the key to ecological restoration in rocky desertification areas. [ABSTRACT FROM AUTHOR]

Located in the eastern edge of the Sichuan Basin (SCB) in the southwest China, Chongqing is a mountainous region with typical complex topographic features. Using the hourly rainfall observation data of high-density 1686 meteorological stations in Chongqing during warm season from 2009 to 2016, we investigated the diurnal characteristics of precipitation affected by complex topography. The complex mountainous terrain has a significant impact on diurnal variations and distinct regional features of rainfall amount, frequency, and intensity. The stations located in the higher complex mountainous areas have greater rainfall amount, frequency, and intensity than those in the lower surrounding areas. In addition, the detailed characteristics of the rainfall amount and frequency in the four study regions further show that the rainfall amount and frequency significantly increase with the rise of elevation, especially in the area that terrain height sharply increases along the mountain extending direction. The diurnal variation of the rainfall amount is characterized by a bimodal structure with a dominant early-morning peak occurring at approximately 0700 LST (23 UTC) and a weaker secondary late-afternoon peak at approximately 1600 LST (08 UTC), while the rainfall frequency has a single early-morning peak. The terrain height has a significant impact on the proportions of the early-morning rainfall. With the elevation increasing in the four study regions, the proportions of rainfall amount (frequency) that occurs during early-morning period decrease. [ABSTRACT FROM AUTHOR]

The coal-bearing Longtan Formation is widely distributed in South China. However, its gas concentration often exceeds the standard limit in tunnels, which compromises the safety of tunnel construction and operation. In this study, statistical analysis of gas-bearing tunnels in the Longtan Formation (GTLF) and coal bed methane (CBM) experiment of Longtan Formation as related to engineering information, gas content, and pressure are discussed with the regional distribution features and influencing factors of GTLF revealed. The hazards of Longtan Formation in each province to tunnels are evaluated by fuzzy synthetic evaluation approach. The findings strongly suggest that the distribution of GTLF is characterized by east–west zonation and controlled by coal-rich zones and sedimentary facies. The western region is more harmful than the eastern region because of weak tectonic movement and more developed karstification. The influencing factors mainly include coal seam conditions, sedimentary environments, tectonic evolution history, hydrogeology, geological structure, and CBM weathering zone. Longtan Formation in Guizhou and Chongqing is the most harmful to tunnels. [ABSTRACT FROM AUTHOR]

ABSTRACT: The Nanwenquan (South Hot Spring) and Xiao quan (Small Hot Spring) in the Nanwenquan anticline are well-known attraction for their geothermal water, but currently, the two natural hot springs have hot flow naturally. In order to protect the geothermal water resource, the evolution of hydrodynamic field must be researched for the causation of the hydrodynamic field destroyed. The finite element numerical simulation was adopted and quantitative study on the geothermal water hydrodynamic field. The finite element model was set up to simulate the research sites, the simulated water level was compared with the actual water level, the feasibility of this model was proved when the simulated water level is approximate to actual one, and an applicable finite element model was obtained. The finite element model was used to simulate the evolution of the hydrodynamic field. This paper supplies a basis to exploit adequately and protect effectively the geothermal water resource, at the same time it is proved feasible in practice to apply finite element numerical simulation to quantitative study of the geothermal water. [Copyright &y& Elsevier]

Chongqing City in China has suffered from serious air pollution and acid rain caused by low graded raw coal (sulfur=ca. 3≈5%, ash=ca. 30%) combustion. In this paper, the situation of atmospheric pollution and acid rain in Chongqing are discussed, the reduction efficiency for sulfur dioxide (SO2) with the bio-briquetting of the raw coal that is one of countermeasures for emission control of air pollutants due to domestic consumes was determined. The research indicated that the frequency of acid rain was high, more than 50% at urban area, and its pH was low, about 4.5. Under our experimental conditions, the reducing efficiency of sulfur SO2 emission from high sulfur coal-biomass briquette amounted to 87%. The field investigation indicated that SO2 indoor concentrations in case of using bio-briquette dropped to 1/2≈1/3 of the raw coal. [ABSTRACT FROM AUTHOR]

Coal seam mining is one of the most widely participated engineering activities in China. This study examined the failure process induced by underground thin coal seam mining of Wangxia perilous rock in Chongqing, China. Numerical simulation was conducted on the stress, displacement and plastic deformation with Fast Lagrangian Analysis of Continua 3D (FLAC3D). Results show that tensile stress is dominant and it keeps increasing during coal mining. The stability failure process experiences four stages from the perspective of crack propagation. A new simplified subsidence prediction method was proposed for quick engineering applications. The relationship between mining geometric parameters and rock mass stability was established and the ultimate mining dimensions were suggested. The simplified method was demonstrated to be reliable. [ABSTRACT FROM AUTHOR]

This article describes the Zhongbao landslide that occurred in Liujing Village, Tudi Township, Wulong District, Chongqing, China, on July 25, 2020. Due to the catastrophic soil and rock landslide, the houses and village roads of three villagers in the landslide area are damaged and formed weirs. The landslide eventually formed a barrier lake. In order to reveal the failure mechanism of the landslide, aerial data was collected on the landslide site using UAV and high-resolution remote sensing images. The characteristics of the landslide are analyzed based on the geological conditions and the properties of the rock formations in the landslide area. The continuous intense rainfall increased the water content of the landslide in this area, increasing its weight. Increasing the water content softens the sliding surface and lowers strength. Therefore, the rock and soil mass on the upper slope slides along the sliding surface under the action of gravity, causing a shale rock mass of about 1.3 million cubic meters to slide quickly from the upper part of the slope into the V-shaped valley and form a barrier dam and barrier lake. By evaluating the rising height of the initial dammed lake, the affected area can be predicted. Through the analysis of the study area, it can provide references for the failure mechanism of landslides, the characteristics of landslide bounce, and the risk assessment of cofferdams in Southwest China. [ABSTRACT FROM AUTHOR]

Context: Understanding patterns and drivers of urbanization is essential for urban sustainability, but such understanding is lacking for mountainous regions. Objectives: This study had three objectives: (1) to quantify the spatiotemporal patterns of urban expansion in Chongqing, the largest mountainous metropolitan area in China, during 1990–2015; (2) to explore major drivers for the observed urbanization patterns; and (3) to identify the spatial signatures of Chongqing's urbanization which differ from those of topographically flat urban regions for sustainable urban planning in mountainous regions. Methods: We used multiple metrics to characterize urbanization patterns and expansion modes. Pearson correlation analysis and Classification and Regression Trees (CART) were used to identify potential drivers. Results: The built-up area of Chongqing increased five times during 1990–2015 with regional variations. Three growth modes—leapfrog, edge-expansion, and infilling, took place concurrently, but their relative dominance varied in time and space with leapfrog as the dominant mode in recent years. The major drivers of built-up area expansion changed from demography to economy, with topographic constraints attenuating over time. Compared to flat urban regions in China, the spatial signatures of Chongqing's urbanization were characterized by greater dominance of leapfrog expansion mode with smaller and more regularly-shaped patches. Conclusions: The unique patterns and drivers of urban expansion in Chongqing provide new insights of urbanization in mountainous regions for sustainable urban planning. We have proposed a conceptual urban planning framework for mountainous cities based on landscape sustainability science, GeoDesign, and regional landscape characteristics. [ABSTRACT FROM AUTHOR]

Fluoride is an essential trace element for humans, and its deficiency or excess in the environment could lead to disease. To investigate the spatial distribution and health risk assessment of fluoride (F−) in drinking water, 302 tap water samples from Chongqing urban areas, China, were collected to analyze F− using an ion chromatograph. The results showed that (1) F− concentration in drinking water ranged from 0.100 to 0.503 mg/L, with an average of 0.238 ± 0.045 mg/L. (2) The spatial autocorrelation analysis showed that high–low clusters were mostly located in Dadukou District and Beibei District, while low–low clusters were mainly in southern Banan District. (3) The fluoride average daily doses of children, teens and adults were 0.030, 0.029 and 0.031 mg/(kg day). (4) Hazard quotients of excessive fluoride (HQe) of children, teens and adults were 0.51 ± 09, 0.49 ± 0.09 and 0.52 ± 0.10, respectively (inferior to 1.00), whereas hazard quotients of inadequate fluoride (HQi) of those groups were 1.21 ± 0.26, 1.23 ± 0.26 and 1.15 ± 0.25, respectively (superior to 1.00). Therefore, average daily fluoride intake of residents with drinking water was inadequate. This could pose dental caries and osteoporosis threats for residents from Chongqing urban areas. [ABSTRACT FROM AUTHOR]

The site formation for the construction of a new airport in a mountainous region is typically performed by cutting and filling a hill section. The fill materials are subjected to seasonal changes and large variations in water content. The water content change renders the fill material to be characterized as unsaturated or saturated. This study aims to investigate the influence of matric suction on the time-dependent compression behavior of one local soil as a fill material for the construction of a new runway of an airport in Chongqing city, a mountainous region in China. A series of unsaturated drained triaxial tests were conducted on this coarse-grained soil to obtain the relationship between the effective stress parameter, χ, and the matric suction. Subsequently, multistaged compression tests were performed on this soil using a newly designed suction-controlled oedometer apparatus. The influence of suction on the time-dependent compression behavior of the fill material is emphasized. The results indicate that the matric suction can increase the compression stiffness, and that the unloading–reloading index varies nonlinearly with suction. A linear relationship between the time-dependent compression coefficient and normalized effective vertical loading is established. The linear relationship is subsequently used to predict the time-dependent compression coefficient to describe the time-dependent behavior of the fill under unsaturated conditions. Further, a nonlinear function based on the work of Yin (Géotechnique 49(5):699–707, 1999) is adopted to describe the development of time-dependent compression. The results indicate that the prediction obtained from the two newly proposed methods are promising, and can predict the nonlinear time-dependent compression behavior of this coarse-grained soil. [ABSTRACT FROM AUTHOR]

Background: Karst areas in southwestern China exhibit ecological degradation in the form of rocky desertification. Local governments launched large-scale afforestation and other ecological restoration programs to curb this trend. Soil thickness is a key limiting factor for vegetation restoration in Karst areas, but the relationship between ecological restoration and soil thickness remains unclear. Further, afforestation consumes large amounts of water, which impacts water supply in karst areas. In this study, we used GIS and statistical analyses to determine rocky desertification sensitivity and its driving factors in karst areas of Chongqing municipality over the past decade. Results: Soil thickness is one of the key factors that restrict ecological restoration of rocky desertification. From 2000 to 2010, rocky desertification sensitivity in karst areas was on the rise along with an increase in afforestation. Areas of high sensitivity were mainly distributed in Pengshui County, Wulong District, and Youyang County; Shizhu County had the lowest overall incidence of desertification. Spatial distribution of rocky desertification was significantly affected by rainfall and soil thickness. Regression analysis showed that the main factors controlling changes in rocky desertification in natural forest over time were precipitation which explained 23.73% of total variance, and soil thickness which explained 23.42% of total variance. Soil thickness and soil water content had a higher correlation coefficient (at 0.516) in natural forests than in planted forests. Conclusion: This study showed that increases in soil thickness in a karst area had a significant positive impact on the fragile ecological environment. This indicates that ecosystem restoration in karst areas will benefit from addressing soil thickness. [ABSTRACT FROM AUTHOR]

A Gram-stain-negative, rod-shaped, non-motile, facultatively anaerobic bacterium, designated FJ4-8T, was isolated from a rotten hemp rope in Chongqing City, PR China. Phylogenetic analysis of 16S rRNA gene sequences indicated that the isolate was closely related to members of the family Sphingobacteriaceae, with the highest similarity to Pedobacter tournemirensis TF5-37.2-LB10T (95.3%) and low similarities to all other species of the genus Pedobacter (90.4–93.9%). Phylogenetic analyses demonstrated that strain FJ4-8T formed a stable subclade with Pedobacter tournemirensis TF5-37.2-LB10T. The clade with these two strains branched adjacent to a clade containing three species of the genus Arcticibacter. MK-7 was detected as the only respiratory quinone. The major fatty acids composed iso-C15:0, iso-C17:0 3-OH and summed feature three. Phosphatidylethanolamine, three aminophospholipids and one unidentified lipid were found as the major polar lipids. The major polyamine was identified as sym-homospermidine. The DNA–DNA hybridization value between strain FJ4-8T and Pedobacter tournemirensis TF5-37.2-LB10T was 42.0 ± 2.5%. Based on its phylogenetic, chemotaxonomic and phenotypic characteristics, the novel strain and TF5-37.2-LB10T were found to be different from members of genera Pedobacter and Arcticibacter. FJ4-8T and TF5-37.2-LB10T represented different species. Therefore, FJ4-8T should be classified as a novel species of a novel genus in the family Sphingobacteriaceae, for which the name Pararcticibacter amylolyticus gen. nov., sp. nov. is proposed. The type strain is FJ4-8T (= KCTC 62640T = CCTCC AB 2018052T). The draft genome sequence is 6290, 449 bp in length, the genomic DNA G+C content was 44.4 mol%. Pedobacter tournemirensis TF5-37.2-LB10T should be transferred to the novel genus as Pararcticibacter tournemirensis comb. nov. (The type strain is TF5-37.2-LB10T (= DSM 23085T = CIP 110085T = MOLA 820T). [ABSTRACT FROM AUTHOR]

With significant climate warming, droughts over Southwest (SW) China are drawing increasing interest. By using the Mann-Kendall trend test, the continuous wavelet transform (CWT), the rotated empirical orthogonal function (REOF), and the random forest method (RF), this study focused on the trends and spatial variability in wetness/dryness as well as further investigated the potential factors by analyzing the behaviors of precipitation, temperature, and teleconnection indices in SW China. Results show that there are a slight drying trend and a remarkable spatial variation in the patterns of wetness/dryness. Due to the decreasing precipitation and increasing temperature, the drying trend (especially for severe and extreme droughts) significantly increases in the Yunnan-Guizhou Plateau and the Chongqing-Hubei region in the past decades. Additionally, the droughts in this region may also be directly or indirectly affected by the complex karst topographic and hydrological process. The variable importance analysis between climate index and standardized precipitation evapotranspiration index (SPEI) suggests that Atlantic Oscillation (AO) and Sunspots (SS) are the two most important influencing factors for the variations in dryness/wetness over SW China. Particularly, SS (AO) can be the largest influencing factor for the Yunnan-Guizhou Plateau and the Chongqing-Hubei region (Northern and Central Tibet). Besides, El Niño-Southern Oscillation (ENSO), North Atlantic Oscillation (NAO), Indian Ocean Dipole (IOD), and Pacific Decadal Oscillation (PDO) indices also show an impact on the variations in dryness/wetness, but their contributions are different in different regions. The results of this study provide certain references for mitigating the potential widespread impact of drought hazards in SW China. [ABSTRACT FROM AUTHOR]

This research examines residential satisfaction in a large Public Rental Housing (PRH) program in the developing municipality of Chongqing, a city located in western China. Twenty-three critical factors were identified through intensive literature review and incorporated into a large-sample survey of eight residential estates of PRH in Chongqing. The survey data were analysed using factor analysis, one sample T-test, stepwise multiple regression analysis, and ANOVA. The results showed generally, the residents neither expressed satisfaction nor dissatisfaction with their current housing situation in the estates sampled. Five domains of residential satisfaction were identified ranging from dwelling features, dwelling facilities, public facilities, neighbourhood environment to housing policy. Factors in the domain of dwelling features, dwelling facilities and housing policies were found to make positive contribution to the residential satisfaction, while negative contributions were made by the factors in the domains of public facilities and neighbourhood environment. Three key determinants of overall residential satisfaction were identified using multiple regression, namely public facilities, neighbourhood environment and housing policies. In addition, the results revealed that age, education, family income, residence length and housing type have significant impact on residential satisfaction with PRH programs. Consequently, related policy interventions could be introduced to improve the residential satisfaction in public rental housing. [ABSTRACT FROM AUTHOR]

We aimed to systematically evaluate the accuracy of nCD64 in diagnosing infection in patients with autoimmune diseases. Studies were searched in PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, Wanfang, and Chongqing VIP databases up to October 2018. There was no restriction for language and age. Prospective studies examining the accuracy of nCD64 in diagnosing infection in patients with autoimmune diseases were included. The Quality Assessment of Diagnostic Accuracy Studies-2 tool was used to assess the quality of eligible studies. Stata 15.1 and Meta-DiSc 1.4 software were used for data analysis. Eleven studies fulfilled the inclusion criteria (677 patients, 229 patients with bacterial infection, and 448 without infection). The pooled sensitivity and specificity of nCD64 were 89% (95% confidence interval (CI) 82–93) and 94% (95% CI 91–96), respectively. The pooled positive likelihood ratio and negative likelihood ratio were 14.9 (95% CI 9.3–23.8) and 0.12 (95% CI 0.07–0.20), respectively. The diagnostic odds ratio and area under the summary receiver operating characteristic curve were 123 (95% CI 53–283) and 0.97 (95% CI 0.95–0.98), respectively. The univariate meta-regression analysis showed that region, type of disease, antibiotic therapy, and presentation of nCD64 measurement results were responsible for the heterogeneity. The Deeks' funnel plot asymmetry test showed that there was no publication bias (p = 0.15). nCD64 has a good overall diagnostic performance for differentiating infection from disease flare in patients with autoimmune diseases. Further studies are needed to confirm the optimized cutoff value. [ABSTRACT FROM AUTHOR]

Tuberculosis (TB) is a global infectious disease and one of the ten leading causes of death worldwide. As TB incidence is seasonal, a reliable forecasting model that incorporates both seasonal and trend effects would be useful to improve the prevention and control of TB. In this study, the X12 autoregressive integrated moving average (X12-ARIMA) model was constructed by dividing the sequence into season term and trend term to forecast the two terms, respectively. Data regarding the TB report rate from January 2004 to December 2015 were included in the model, and the TB report data from January 2016 to December 2016 were used to validate the results. The X12-ARIMA model was compared with the seasonal autoregressive integrated moving average (SARIMA) model. A total of 383,797 cases were reported from January 2004 to December 2016 in Chongqing, China. The report rate of TB was highest in 2005 (151.06 per 100,000 population) and lowest in 2016 (72.58 per 100,000 population). The final X12-ARIMA model included the ARIMA (3,1,3) model for the trend term and the ARIMA (2,1,3) model for the season term. The SARIMA (1,0,2) * (1,1,1)12 model was selected for the SARIMA model. The mean absolute error (MAE) and mean absolute percentage error (MAPE) of fitting and predicting performance based on the X12-ARIMA model were less than the SARIMA model. In conclusion, the occurrence of TB in Chongqing is controlled, which may be attributed to socioeconomic developments and improved TB prevention and control services. Applying the X12-ARIMA model is an effective method to forecast and analyze the trend and seasonality of TB. [ABSTRACT FROM AUTHOR]