Inadequate water quality can mean that water is unsuitable for a variety of human uses, thus exacerbating freshwater scarcity. Previous large-scale water scarcity assessments mostly focused on the ...availability of sufficient freshwater quantity for providing supplies, but neglected the quality constraints on water usability. Here we report a comprehensive nationwide water scarcity assessment in China, which explicitly includes quality requirements for human water uses. We highlight the necessity of incorporating water scarcity assessment at multiple temporal and geographic scales. Our results show that inadequate water quality exacerbates China's water scarcity, which is unevenly distributed across the country. North China often suffers water scarcity throughout the year, whereas South China, despite sufficient quantities, experiences seasonal water scarcity due to inadequate quality. Over half of the population are affected by water scarcity, pointing to an urgent need for improving freshwater quantity and quality management to cope with water scarcity.
Based on a total of 519 images, the composite images with the lowest possible cloud cover were generated at pixel level with image synthesis method on Google Earth Engine (GEE) platform. The Remote ...Sensing Ecological Index (RSEI) was adopted, and calculated in an efficient way with the assistance of parallel cloud computing of the GEE platform. The RSEI was used in this paper to evaluate and monitor the eco-environmental quality of the Lhasa Metropolitan Area. Results show that: (1) The ecological quality is better in the west than in the east of Lhasa Metropolitan Area, with Lhasa as an approximate dividing point. The ecological quality improved and then deteriorated dramatically before 2000, with the mean RSEI value dropping from 0.51 to 0.46; the trend was followed by a gradual increase up until 2017, with the mean RSEI value increased from 0.46 to 0.55. (2) The RSEI is weakly and positively correlated with socioeconomic indicators. This indicates that the population growth and economic development did not negatively influence the ecological quality, but actually boosted it. (3) The GEE can serve as an efficient computing platform for the assessment and monitoring of eco-environmental quality in vast regions.
•Park visiting characteristics should be considered in estimating park access.•Access to parks for elderly residents is unequal.•In newly built areas, the higher the housing price, the higher park ...accessibility.
Many countries are facing an aging population crisis, triggering major concerns over how to best provide services for older people. Parks are an important public service resource for older people living in urban areas. Due to the uneven geographic distribution of parks within a city, elderly people may have unequal access to this resource, based on their socioeconomic status. This park access issue has been under-examined among older populations, who may be more vulnerable and have limited physical mobility. The two-step floating catchment area (2SFCA) method has been increasingly used to measure access to parks; however, a “catchment area,” defined as the traveling distance to a resource, may be biased against older subjects, due to the lack of behavior-based information within traditional census data. To bridge this methodological gap within the literature, this study sought to estimate park access for the elderly, using the 2SFCA method and new data sources (mobile phone data), in order to determine if older people experience inequitable park access owing to their socioeconomic status. Based on a spatial and multivariate analysis of data collected in Beijing, we find that housing price, the distance to commercial areas and greenspaces are significant influencing factors of the park accessibility; elderly people living in newly built areas, the lower the housing price, the lower accessibility to parks. These findings may assist municipal policy makers in the planning and management of park access for aging citizens.
Ubiquitination is an important post-translational modification that can be reversed by a family of enzymes called deubiquitinating enzymes (DUBs). Ubiquitin-specific protease 28 (USP28), a member of ...the DUBs family, functions as a potential tumour promoter in various cancers. However, the biological function and clinical significance of USP28 in pancreatic cancer (PC) are still unclear. Here, we showed that PC tumours had higher USP28 expression compared with that of normal pancreatic tissues, and high USP28 level was significantly correlated with malignant phenotype and shorter survival in patients with PC. Overexpression of USP28 accelerated PC cell growth, whereas USP28 knockdown impaired PC cell growth both in vitro and in vivo. Further, we found that USP28 promoted PC cell growth by facilitating cell cycle progression and inhibiting apoptosis. Mechanistically, USP28 deubiquitinated and stabilised FOXM1, a critical mediator of Wnt/β-catenin signalling. USP28-mediated stabilisation of FOXM1 significantly promoted nucleus β-catenin trans-activation, which in turn led to the activation of the Wnt/β-catenin pathway. Finally, restoration of FOXM1 expression abolished the anti-tumour effects of USP28-silencing. Thus, USP28 contributes to PC pathogenesis through enhancing the FOXM1-mediated Wnt/β-catenin signalling, and could be a potential diagnostic and therapeutic target for PC cases.
Pancreatic cancer is one of the most fatal cancers in humans. While it thrives in a state of malnutrition, the mechanism by which pancreatic cancer cells adapt to metabolic stress through metabolic ...reprogramming remains unclear. Here, we showed that UBR5, an E3 ubiquitin ligase, was significantly upregulated in pancreatic cancer patient samples compared to the levels in adjacent normal tissues. Levels of UBR5 were closely related to a malignant phenotype and shorter survival among pancreatic cancer patients. Multivariate analyses also revealed that UBR5 overexpression was an independent predictor of poor outcomes among patients with pancreatic cancer. Functional assays revealed that UBR5 contributes to the growth of pancreatic cancer cells by inducing aerobic glycolysis. Furthermore, we demonstrated that UBR5 knockdown increased levels of fructose-1,6-bisphosphatase (FBP1), an important negative regulator in the process of aerobic glycolysis in many cancers. We found a significant negative correlation between levels of UBR5 and FBP1, further demonstrating that UBR5-induced aerobic glycolysis is dependent on FBP1 in pancreatic cancer cells. Mechanistically, UBR5 regulates FBP1 expression by modulating C/EBPα, directly binding to C/EBPα, and promoting its ubiquitination and degradation. Together, these results identify a mechanism used by pancreatic cancer cells to survive the nutrient-poor tumour microenvironment and also provide insight regarding the role of UBR5 in pancreatic cancer cell adaptation to metabolic stresses.
•The park service areas are estimated by the distribution of park visitors.•Multi-source geographical data are used to delineate the park service area.•Park service area relates to park ...types.•External factors significantly affect park service area.
The rapid process of urbanization aggravates the imbalance between the supply and demand of urban public services. Urban parks are among the most important urban public services, and their use efficiency has been an important index for urban planning. Therefore, it is essential to estimate well their service area and influencing factors. Traditional survey data used to analyze the characteristics of urban park services are limited by small samples and high cost. Owing to thriving information communication technologies, vast amounts of human activity data have become available that enable understanding of human travel behavior. In this study, we analyzed a park service area, which is defined as the zone of influence of individual parks, in Beijing, and the factors that influence the service area. First, the service area was estimated using 1-SDE based on mobile phone signaling data. A multiple linear regression model was then used to analyze the influence of factors on the park service area. The results show that (1) external factors including population density, the number of commercial facilities, and traffic convenience have significant influences on the park service area; (2) employment places positively influence the park service area on the weekday; and (3) other factors such as park design and park reputation had inconsistent effects on the park service area, in either sign or significance, regarding the weekday and the weekend. The findings of this study will be of practical value when designing parks or undertaking city planning in the future.
•GIS with big data provides geospatial information to fight COVID-19.•Big data showed power on epidemic transmission analysis and prevention decision making support.•Challenges still continue in data ...aggregation, knowledge discovery, and dynamic expression.
The outbreak of the 2019 novel coronavirus disease (COVID-19) has caused more than 100,000 people infected and thousands of deaths. Currently, the number of infections and deaths is still increasing rapidly. COVID-19 seriously threatens human health, production, life, social functioning and international relations. In the fight against COVID-19, Geographic Information Systems (GIS) and big data technologies have played an important role in many aspects, including the rapid aggregation of multi-source big data, rapid visualization of epidemic information, spatial tracking of confirmed cases, prediction of regional transmission, spatial segmentation of the epidemic risk and prevention level, balancing and management of the supply and demand of material resources, and social-emotional guidance and panic elimination, which provided solid spatial information support for decision-making, measures formulation, and effectiveness assessment of COVID-19 prevention and control. GIS has developed and matured relatively quickly and has a complete technological route for data preparation, platform construction, model construction, and map production. However, for the struggle against the widespread epidemic, the main challenge is finding strategies to adjust traditional technical methods and improve speed and accuracy of information provision for social management. At the data level, in the era of big data, data no longer come mainly from the government but are gathered from more diverse enterprises. As a result, the use of GIS faces difficulties in data acquisition and the integration of heterogeneous data, which requires governments, businesses, and academic institutions to jointly promote the formulation of relevant policies. At the technical level, spatial analysis methods for big data are in the ascendancy. Currently and for a long time in the future, the development of GIS should be strengthened to form a data-driven system for rapid knowledge acquisition, which signifies that GIS should be used to reinforce the social operation parameterization of models and methods, especially when providing support for social management.
Display omitted
Because cities have different attractions for laborers, people migrate from city to city, which may widen the gap between cities. Analyzing the fluxes and directions of migrant flows can help us ...clarify the regional difference of urban development. Using migration data inferred from passenger travels during 2016 Spring Festival from Tencent Location Big Data, this paper analyzed the unbalanced migration between cities and the spatial difference of urban development. Network analysis methods are employed to evaluate interactions among cities. A community detection method identifies 19 city communities, and the directions of migrant flows in the communities are explored. The PageRank algorithm is employed to evaluate the importance of cities on the migration network and divide the cities into 5 grades, and then the hierarchical structure of the migrant network is illustrated and analyzed. Indices based on migrant populations indicate that the most attractive cities for laborers are along the east coast and that cities in the central region export a significant number of laborers. PageRank and attractiveness values are compare with socio-economic data, and the results indicate that both PageRank and attractiveness are positively correlated with the economic and development level of cities, while PageRank works better. It suggests that Spring Festival travel data in China can be used as migration data, however, it should be facilitated with network methods to disclose the relationship between Spring Festival travel and urban development.
•Studying urbanization from the perspective of interactions among cities.•Disclosing the spatial differentiation of urbanization using migrant data.•Discovering the groups of cities with a community detection algorithm.•Identifying the importance of cities with the PageRank algorithm.
Understanding the spatiotemporal dynamics of urban population is crucial for addressing a wide range of urban planning and management issues. Aggregated geospatial big data have been widely used to ...quantitatively estimate population distribution at fine spatial scales over a given time period. However, it is still a challenge to estimate population density at a fine temporal resolution over a large geographical space, mainly due to the temporal asynchrony of population movement and the challenges to acquiring a complete individual movement record. In this article, we propose a method to estimate hourly population density by examining the time‐series individual trajectories, which were reconstructed from call detail records using BP neural networks. We first used BP neural networks to predict the positions of mobile phone users at an hourly interval and then estimated the hourly population density using log‐linear regression at the cell tower level. The estimated population density is linearly correlated with population census data at the sub‐district level. Trajectory clustering results show five distinct diurnal dynamic patterns of population movement in the study area, revealing spatially explicit characteristics of the diurnal commuting flows, though the driving forces of the flows need further investigation.
Increased human activity threatens inland water quality in China. Major efforts have been made to alleviate water pollution since 2001. Understanding how water quality responds to these forces can ...help to guide future efforts to maintain water security and sustainability. We here analyzed the nationwide variability of inland water quality across China from 2003 to 2017 and its responses to anthropogenic discharges. We show that water quality has been improved markedly or was maintained at favorable levels over the country because of reduced discharges in the industrial, rural, and urban residential sectors. However, growing discharges from the agricultural sector threaten these gains. Moreover, the present status of water pollution is relatively severe in north and northeast China. Our findings suggest that China's water quality would further benefit from more flexible strategies for mitigation measures, which respond to regional differences in the factors that influence water pollution levels in specific regions.
PDF
