Only one-dimensional (1D)deformation along the radar line of sight (LOS)can be obtained using differential interferometry synthetic aperture radar (D-InSAR),and D-InSAR observation is insensitive to deformation in the...Only one-dimensional (1D)deformation along the radar line of sight (LOS)can be obtained using differential interferometry synthetic aperture radar (D-InSAR),and D-InSAR observation is insensitive to deformation in the north direction.This study inferred three-dimensional (3D)deformation of a mining subsidence basin by combining the north-south deformation predicted by a probability integral method with the LOS deformation obtained by D-InSAR.The 15235 working face in Fengfeng mining area (Hebei Province,China)was used as the object of study.The north-south horizontal movement was predicted by the probability integral method according to the site's geological and mining conditions.Then,the vertical and east-west deformation fields were solved by merging ascend-orbit RadarSAT-2, descend-orbit TerraSAR,and predicted north-south deformation based on a least squares method.Comparing with the leveling data,the results show that the vertical deformation accuracy of the experimental method is better than the inversed vertical deformation neglecting the horizontal deformation.Finally,the impact of the relationship between the azimuth of the working face and the SAR imaging geometry on the monitoring of the mining subsidence basin was analyzed.The results can be utilized in monitoring mining subsidence basins by single SAR image sources.展开更多
Successful fertilization in animals depends on competition among millions of sperm cells, whereas double fertilization in flowering plants usually involves just one pollen tube releasing two immobile sperm cells. It i...Successful fertilization in animals depends on competition among millions of sperm cells, whereas double fertilization in flowering plants usually involves just one pollen tube releasing two immobile sperm cells. It is largely a mystery how the plant sperm cells fuse efficiently with their female targets within an embryo sac. We show that the initial positioning of sperm cells upon discharge from the pollen tube is usually inopportune for gamete fusions and that adjustment of sperm cell targeting occurs through release and re-adhesion of one sperm cell, while the other connected sperm cell remains in stagnation. This enables proper adhesion of each sperm cell to a female gamete and coordinates the gamete fusions. Our 〈br〉 findings reveal inner embryo sac dynamics that ensure the reproductive success of flowering plants and suggest a requirement for sperm cell differentiation as the basis of double fertilization.展开更多
What is already known about this topic?Soil-transmitted helminthiasis(STH)is distributed widely in China and a large number of the population is afflicted.However,trends of STH infections are decreasing.What is added ...What is already known about this topic?Soil-transmitted helminthiasis(STH)is distributed widely in China and a large number of the population is afflicted.However,trends of STH infections are decreasing.What is added by this report?The most recent data indicates that the overall prevalence of STH was 1.29% in 2018 in China,which was based on the national sentinel surveillance and demonstrates a continuous decline pattern.What are the implications for public health practice?Considering the current prevalence in China and various endemic statuses in different regions,precision control measures should be implemented for the control and elimination of STH in China.展开更多
Summary What is already known about this topic?Amebiasis is caused by infection with Entamoeba histolytica.As a severe sequence in amebiasis,amoebic dysentery is tracked by China’s National Notifiable Disease Reporti...Summary What is already known about this topic?Amebiasis is caused by infection with Entamoeba histolytica.As a severe sequence in amebiasis,amoebic dysentery is tracked by China’s National Notifiable Disease Reporting System.What is added by this report?From 2005 to 2019,a total of 28,229 cases of amoebic dysentery and 7 resulting deaths were reported in China.The annual incidence rate had significantly decreased from 0.26/100,000 in 2006 to 0.06/100,000 in 2019,and most cases were reported from southern China and in children.展开更多
基金the National Natural Science Foundation of China (Grant Nos.41272389 and 41604005)A Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (No.SZBF2011-6-B35)+2 种基金Special Fund for Public Projects of National Administration of Surveying, Mapping,and Geoinformation of China (No.201412016)Project supported by the Basic Research Project of Jiangsu Province (Natural Science Foundation)(No.BK20160218)the State Key Laboratory of Geohazard Prevention and Geoenviromnent Protection (Chengdu University of Technology)(No.SKLGP2016K008).
文摘Only one-dimensional (1D)deformation along the radar line of sight (LOS)can be obtained using differential interferometry synthetic aperture radar (D-InSAR),and D-InSAR observation is insensitive to deformation in the north direction.This study inferred three-dimensional (3D)deformation of a mining subsidence basin by combining the north-south deformation predicted by a probability integral method with the LOS deformation obtained by D-InSAR.The 15235 working face in Fengfeng mining area (Hebei Province,China)was used as the object of study.The north-south horizontal movement was predicted by the probability integral method according to the site's geological and mining conditions.Then,the vertical and east-west deformation fields were solved by merging ascend-orbit RadarSAT-2, descend-orbit TerraSAR,and predicted north-south deformation based on a least squares method.Comparing with the leveling data,the results show that the vertical deformation accuracy of the experimental method is better than the inversed vertical deformation neglecting the horizontal deformation.Finally,the impact of the relationship between the azimuth of the working face and the SAR imaging geometry on the monitoring of the mining subsidence basin was analyzed.The results can be utilized in monitoring mining subsidence basins by single SAR image sources.
基金supported by the National Basic Research Program of China (2013CB126900)the National Natural Science Foundation of China (30570102)
文摘Successful fertilization in animals depends on competition among millions of sperm cells, whereas double fertilization in flowering plants usually involves just one pollen tube releasing two immobile sperm cells. It is largely a mystery how the plant sperm cells fuse efficiently with their female targets within an embryo sac. We show that the initial positioning of sperm cells upon discharge from the pollen tube is usually inopportune for gamete fusions and that adjustment of sperm cell targeting occurs through release and re-adhesion of one sperm cell, while the other connected sperm cell remains in stagnation. This enables proper adhesion of each sperm cell to a female gamete and coordinates the gamete fusions. Our 〈br〉 findings reveal inner embryo sac dynamics that ensure the reproductive success of flowering plants and suggest a requirement for sperm cell differentiation as the basis of double fertilization.
基金supported by the National Health Commission of China and China CDC.
文摘What is already known about this topic?Soil-transmitted helminthiasis(STH)is distributed widely in China and a large number of the population is afflicted.However,trends of STH infections are decreasing.What is added by this report?The most recent data indicates that the overall prevalence of STH was 1.29% in 2018 in China,which was based on the national sentinel surveillance and demonstrates a continuous decline pattern.What are the implications for public health practice?Considering the current prevalence in China and various endemic statuses in different regions,precision control measures should be implemented for the control and elimination of STH in China.
文摘Summary What is already known about this topic?Amebiasis is caused by infection with Entamoeba histolytica.As a severe sequence in amebiasis,amoebic dysentery is tracked by China’s National Notifiable Disease Reporting System.What is added by this report?From 2005 to 2019,a total of 28,229 cases of amoebic dysentery and 7 resulting deaths were reported in China.The annual incidence rate had significantly decreased from 0.26/100,000 in 2006 to 0.06/100,000 in 2019,and most cases were reported from southern China and in children.