Spatiotemporal dynamics of population density in China using nighttime light and geographic weighted regression method

The distribution and dynamic changes of regional or national population data with long time series are very important for regional planning,resource allocation,government decision-making,disaster assessment,ecological protection,and other sustainability research.However,the existing population datasets such as LandScan and WorldPop all provide data from 2000 with limited time series,while GHS-POP only utilizes land use data with limited accuracy.In view of the limited remote sensing images of long time series,it is necessary to combine existing multi-source remote sensing data for population spatialization research.In this research,we developed a nighttime light desaturation index(NTLDI).Through the cross-sensor calibration model based on an autoencoder convolutional neural network,the NTLDl was calibrated with the same period Visible Infrared Imaging Radiometer Suite Day/Night Band(VIRS-DNB)data.Then,the geographically weighted regression method is used to determine the population density of China from 1990 to 2020 based on the long time series NTL.Furthermore,the change characteristics and the driving factors of China's population spatial distribution are analyzed.The large-scale,long-term population spatialization results obtained in this study are of great significance in government planning and decision-making,disaster assessment,resource allocation,and other aspects.

miR-23a/b suppress cGAS-mediated innate and autoimmunity

Cyclic GMP-AMP synthase(cGAS),a key sensor of intracellular DNA,is essential for eliciting innate immunity against infection,whereas aberrant activation of cGAS by endogenous DNA promotes severe autoimmune diseases.However,it is largely unknown how cGAS expression is regulated during pathogen infection and autoimmunity.Here,we report that during herpes simplex virus type 1(HSV-1)infection,two microRNAs(miR-23a and miR-23b)whose levels significantly decrease due to their interaction with the lncRNA Oasl2-209 directly regulate the expression of cGAS.Overexpression of miR-23a/b markedly dampens cytosolic DNA-induced innate immune responses,whereas inhibition of miR-23a/b enhances these responses.Mice treated with miR-23a/b agomirs exhibit increased susceptibility to HSV-1 infection.Moreover,cGAS is significantly upregulated in the Trex1^(−/−)mouse autoimmune disease model.Administration of miR-23a/b blunts self DNA-induced autoinflammatory responses in Trex1^(−/−)mice.Collectively,our study not only reveals a novel regulatory mechanism of cGAS expression by miRNAs but also identifies a potential therapy for cGAS-related autoimmune diseases.