Asthma mortality among children and adolescents in China,2008–2018

Background Asthma mortality among children and adolescents at the national level in China was unreported.The aim of this study was to analyze the mortality of asthma among children and adolescents in China using a nationally representative database.Methods This was a descriptive study using data from the Disease Surveillance Points(DSPs)system.All asthma‐related deaths among children and adolescents aged 0–19 years occurring in DSPs across China from 2008 to 2018 were included.Multilevel Poisson regression models were used to compute the total,age-,gender-,region-and residence-specific asthma mortality rates and to investigate the significance of trends and factors associated with asthma mortality.Data from the National Bureau of Statistics were used to estimate the national asthma deaths.Results Total asthma mortality rate among Chinese children and adolescents fluctuated between 0.020(0.009,0.045)and 0.059(0.025,0.137)per 100,000 and showed an overall downward trend(RR,0.909;95%CI 0.854–0.968)during the study period(2008–2018).Asthma mortality rate was higher in the western China(RR 2.356,95%CI 1.513,3.669)and varied over a ninefold range among DSPs in China.The estimated number of deaths decreased by 51.38%from 2008(n=148;95%CI 58,379)to 2018(n=71;95%CI 34,109).Conclusions Asthma mortality rate among children and adolescents in China was at a low level compared to rates worldwide and decreased significantly from 2008 to 2018.Compared with most countries in the world,the number of asthma deaths was higher in China.

Optimizing crown density and volume estimation across two coniferous forest types in southern China via Boruta and Cubist methods

Quantifying forest stand parameters is crucial in forestry research and environmental monitoring because it provides important factors for analyzing forest structure and comprehending forest resources.And the estimation of crown density and volume has always been a prominent topic in forestry remote sensing.Based on GF-2 remote sensing data,sample plot survey data and forest resource survey data,this study used the Chinese fir(Cunninghamia lanceolata(Lamb.)Hook.)and Pinus massoniana Lamb.as research objects to tackle the key challenges in the use of remote sensing technology.The Boruta feature selection technique,together with multiple stepwise and Cubist regression models,was used to estimate crown density and volume in portions of the research area’s stands,introducing novel technological methods for estimating stand parameters.The results show that:(i)the Boruta algorithm is effective at selecting the feature set with the strongest correlation with the dependent variable,which solves the problem of data and the loss of original feature data after dimensionality reduction;(ii)using the Cubist method to build the model yields better results than using multiple stepwise regression.The Cubist regression model’s coefficient of determination(R^(2))is all more than 0.67 in the Chinese fir plots and 0.63 in the P.massoniana plots.As a result,combining the two methods can increase the estimation accuracy of stand parameters,providing a theoretical foundation and technical support for future studies.