Paleo-parasitological study on the soils collected from archaeological sites in old district of Seoul City

A paleo-parasitological study was performed on soil samples from archaeological sites in the old district of Seoul Metropolitan City (Old Seoul City) where the capital of the Joseon Kingdom was constructed about 600 years ago. The sampling sites were the original locations of the Royal Palace Wall, Yukjo Street and the Royal Arsenal. Microscopic examinations showed that parasite eggs of Clonorchis sinensis, Diphyllobothrium latum, Ascaris sp. and Trichuris sp. remained in the soil strata, which were estimated to represent the 14th-19th centuries. We suspect that the medieval citizens of Old Seoul City, numbering around 200,000, might have been made vulnerable to parasite infection by a combination of bad hygiene, inadequate sewer system and seasonal flooding.     

基于腾讯迁徙大数据的长三角城市群春运人口流动时空特征

开展城市群人口流动研究对促进区域人口有序流动和城市群协同发展具有重要的理论和实践指导意义。本文基于腾讯迁徙大数据，运用GIS空间统计和K-shell分解等方法，从人口流动总量、位序、时序和网络层级等方面，对我国长三角城市群2018年春运期间的人口流动特征进行系统研究。结果表明：①长三角城市群春运期间大规模的“返乡流”和“返城流”呈现明显的对称性，并分别于除夕和第一个工作日达到最高峰。②经济发展水平相对较高的上海、苏州、杭州等为劳动力输入型城市，而经济发展水平相对较低的盐城、安庆和滁州等为劳动力输出型城市。③长三角城市群内部人口流动网络具有明显的层级特征，其中上海和杭州是人口辐射核心城市，上海-合肥、上海-南京、上海-杭州等是人口流动的主体路径；空间上东部-西部横向人口流动最为频繁，大体呈现“Z”字形。