Effects of PM2.5 Exposure in Different Air Quality Grades on Daily Outpatient Visits for Childhood Asthma in Shijiazhuang, China

Asthma is a common chronic inflammatory disorder that is more prevalent in children than in adults.China has seen an increasing prevalence of childhood asthma in recentdecades[1].Earlier studies have shown that air particulate matter (PM),particularly fine particulate matter(PM2.5)[2],is an important factor triggering childhood asthma. Since nationalPM2.5data were nota vailabl euntil 2013,

Optimization of Shanghai marine environment monitoring sites by integrating spatial correlation and stratified heterogeneity

The water quality grades of phosphate（PO4-P） and dissolved inorganic nitrogen（DIN） are integrated by spatial partitioning to fit the global and local semi-variograms of these nutrients. Leave-one-out cross validation is used to determine the statistical inference method. To minimize absolute average errors and error mean squares,stratified Kriging（SK） interpolation is applied to DIN and ordinary Kriging（OK） interpolation is applied to PO4-P.Ten percent of the sites is adjusted by considering their impact on the change in deviations in DIN and PO4-P interpolation and the resultant effect on areas with different water quality grades. Thus, seven redundant historical sites are removed. Seven historical sites are distributed in areas with water quality poorer than Grade IV at the north and south branches of the Changjiang（Yangtze River） Estuary and at the coastal region north of the Hangzhou Bay. Numerous sites are installed in these regions. The contents of various elements in the waters are not remarkably changed, and the waters are mixed well. Seven sites that have been optimized and removed are set to water with quality Grades III and IV. Optimization and adjustment of unrestricted areas show that the optimized and adjusted sites are mainly distributed in regions where the water quality grade undergoes transition.Therefore, key sites for adjustment and optimization are located at the boundaries of areas with different water quality grades and seawater.

Feature extraction of jujube fruit wrinkle based on the watershed segmentation

The degree of surface wrinkles on a dried jujube fruit(Ziziphus jujuba Mill.)is an important quality grading criterion.The aim of this research was to propose an image processing method based on the watershed segmentation to extract the wrinkle features of jujube fruits.Original images of jujube fruit taken under cyan light were transformed into grayscale images.The noise in these images was then removed by morphological reconstruction.The H-minima extended transformation was used to label the foreground of jujube fruit images after reconstruction,and the labeled foreground regions were segmented by a distance transform-based watershed algorithm.Then,the grayscale images were filtered with a local range filter.The segmentation function was obtained using the minima imposition method.Finally,a watershed segmentation was used to extract the wrinkle features of jujube fruits.Experiments on 304 images of jujube fruit showed that the accuracy of wrinkle-based grading obtained by the algorithm was 92.11%,which proved that this method could be used to classify jujube wrinkles.