A hybrid model for predicting spatial distribution of soil organic matter in a bamboo forest based on general regression neural network and interative algorithm

A general regression neural network model,combined with an interative algorithm(GRNNI)using sparsely distributed samples and auxiliary environmental variables was proposed to predict both spatial distribution and variability of soil organic matter(SOM)in a bamboo forest.The auxiliary environmental variables were:elevation,slope,mean annual temperature,mean annual precipitation,and normalized difference vegetation index.The prediction accuracy of this model was assessed via three accuracy indices,mean error(ME),mean absolute error(MAE),and root mean squared error(RMSE)for validation in sampling sites.Both the prediction accuracy and reliability of this model were compared to those of regression kriging(RK)and ordinary kriging(OK).The results show that the prediction accuracy of the GRNNI model was higher than that of both RK and OK.The three accuracy indices(ME,MAE,and RMSE)of the GRNNI model were lower than those of RK and OK.Relative improvements of RMSE of the GRNNI model compared with RK and OK were 13.6%and 17.5%,respectively.In addition,a more realistic spatial pattern of SOM was produced by the model because the GRNNI model was more suitable than multiple linear regression to capture the nonlinear relationship between SOM and the auxiliary environmental variables.Therefore,the GRNNI model can improve both prediction accuracy and reliability for determining spatial distribution and variability of SOM.

Tuberculosis/HIV Coinfection and Treatment Trends-China, 2015−2019

Introduction:New data has become available on the implementation of tuberculosis/human immunodeficiency virus(TB/HIV)two-way screening and anti-TB treatment for TB/HIV coinfected patients in China from 2015 to 2019,which can be used to propose key strategies for further TB/HIV prevention and treatment.Methods:The report on TB/HIV coinfection in the mainland of China from 2015 to 2019 was collected to compare the annual trend and the rate of geographical distribution.Results:From 2015 to 2019,the proportion of TB screening using chest x-ray or sputum examination among HIV-positive people increased from 79.8%to 88.0%(p<0.01).The proportion ranged from 40.7%to 97.1%among various provincial-level administrative divisions(PLADs),with a median of 87.3%.TB prevalence among HIV-positive people decreased from 1.1%to 0.8%(p<0.01)over the 5 years.The proportion of HIV testing among TB patients increased from 46.0%to 64.0%(p<0.01).The prevalence of HIV among TB patients increased from 0.8%to 1.1%(p<0.01).The success rate of anti-TB treatment for TB/HIV patients was 87.6%,and the primary reason for unsuccessful treatment were death(5.3%)and other reason such as availability of only basic treatment options(5.0%).Conclusions and Implications for Public Health Practice:TB/HIV two-way screening in China improved significantly during the 5-year period,however there were large regional differences and gaps in target HIV-screening rates among TB patients,suggesting that two-way screening in some PLADs and the HIV screening among TB patients should be strengthened.Early diagnosis,early treatment,and treatment management of TB/HIV patients should also be strengthened.

Effect of surface roughness on the angular acceleration for a droplet on a super-hydrophobic surface

The motion of droplets on a super‐hydrophobic surface,whether by sliding or rolling,is a hot research topic.It affects the performance of super‐hydrophobic materials in many industrial applications.In this study,a super‐hydrophobic surface with a varied roughness is prepared by chemical‐etching.The adhesive force of the advancing and receding contact angles for a droplet on a super‐hydrophobic surface is characterized.The adhesive force increases with a decreased contact angle,and the minimum value is 0.0169 mN when the contact angle is 151.47°.At the same time,the motion of a droplet on the superhydrophobic surface is investigated by using a high‐speed camera and fluid software.The results show that the droplet rolls instead of sliding and the angular acceleration increases with an increased contact angle.The maximum value of the angular acceleration is 1,203.19 rad/s^(2) and this occurs when the contact angle is 151.47°.The relationship between the etching time,roughness,angular acceleration,and the adhesion force of the forward and backward contact angle are discussed.