[Evaluation of the quality of human settlement in downtown Fuzhou based on multi-source data]. / åŸºäºŽå¤šæºæ•°æ®çš„ç¦å·žå¸‚ä¸­å¿ƒåŸŽåŒºäººå± çŽ¯å¢ƒè´¨é‡è¯„ä»·.

The objective evaluation of human settlement in cities helps find the problems exposed in urban development and make targeted adjustments to improve urban environment. Taking the downtown of Fuzhou as the research area, the residential area as the research unit, using multi-source data such as meteorological monitoring data, remote sensing imagery, map points of interest data (POI), and land planning data, we constructed monitoring system of urban human settlement from four aspects: environmental health and comfort, traffic convenience, city safety, and life conve-nience. The TOPSIS method was used to conduct a comprehensive evaluation of human settlement. The results showed that the human settlement level of downtown Fuzhou was quite different, which was high in the central area and low in the peripheral areas. The human settlement index was high in the middle of the urban area, low in the eastern and southern areas, with mixed high and low values in the western and northern areas. In each index layer, the characteristics of high-high agglomeration and low-low agglomeration of traffic convenience and life convenience were consistent with the distribution of high and low value clusters of the human settlement. Convenient transportation and complete service facilities had a greater impact on human settlement. The environmental health and comfort were characterized by interior low and edge high of the city, while city safety was characterized by interior high and edge low.

Risk assessment and genomic characterization of Zika virus in China and its surrounding areas.

BACKGROUND: Zika virus (ZIKV) has emerged as a global pathogen causing significant public health concerns. China has reported several imported cases where ZIKV were carried by travelers who frequently travel between China and ZIKV-endemic regions. To fully characterize the ZIKV strains isolated from the cases reported in China and assess the risk of ZIKV transmission in China, comprehensive phylogenetic and genetic analyses were performed both on all ZIKV sequences of China and on a group of scientifically selected ZIKV sequences reported in some of the top interested destinations for Chinese travelers. METHODS: ZIKV genomic sequences were retrieved from the National Center for Biotechnology Information database through stratified sampling. Recombination event detection, maximum likelihood (ML) phylogenetic analysis, molecular clock analysis, selection pressure analysis, and amino acid substitution analysis were used to reconstruct the epidemiology and molecular transmission of ZIKV. RESULTS: The present study investigated 18 ZIKV sequences from China and 70 sequences from 16 selected countries. Recombination events rarely happens in all ZIKV Asian lineage. ZIKV genomes were generally undergone episodic positive selection (17 sites), and only one site was under pervasive positive selection. All ZIKV imported into China were Asian lineage and were assigned into two clusters: Venezuela-origin (cluster A) and Samoa-origin cluster (cluster B) with common ancestor from French Polynesia. The time of most recent common ancestors of Cluster A dated to approximately 2013/11 (95% highest posterior density [HPD] 2013/06, 2014/03) and cluster B dated to 2014/08 (95% HPD 2014/02, 2015/01). Cluster B is more variable than Cluster A in comparison with other clusters, but no varied site of biological significance was revealed. ZIKV strains in Southeast Asia countries are independent from strains in America epidemics. CONCLUSIONS: The genetic evolution of ZIKV is conservative. There are two independent introductions of ZIKV into China and China is in danger of autochthonous transmission of ZIKV because of high-risk surrounding areas. Southeast Asia areas have high risk of originating the next large-scale epidemic ZIKV strains.