IKONOS Image-Based Extraction of the Distribution Area of Stellera chamaejasme L. in Qilian County of Qinghai Province, China

Stellera chamaejasme L. (S. chamaejasme) is one of the primary toxic grass species (poisonous plants) distributed in the alpine meadows of Qinghai Province, China. In this study, according to the distinctive phenological characteristics of S. chamaejasme, the spectral differences between S. chamaejasme in the full-bloom stage and other pasture grasses were analyzed and the red, blue, and near-infrared bands of IKONOS image were determined as the diagnostic bands of S. chamaejasme recognition. Feature indexes related to S. chamaejasme were established using the diagnostic bands, and $NDVI_{blue} = (\rho_{nir} − \rho_{blue})/(\rho_{nir} + \rho_{blue})$ obtained as S. chamaejasme sensitive index based on the linear regression analysis between the indexes derived from field spectra and the actual cover fraction of S. chamaejasme communities. The distribution area of S. chamaejasme was extracted by using the index $NDVI_{blue}$ derived from IKONOS multispectral image in Qilian County of Qinghai Province, China and the verified result reached an overall accuracy of 90.71%. The study indicated that high resolution multispectral satellite images (such as IKONOS images) had significant potential in remote sensing recognition of toxic grass species

Assessment of echinococcosis control in Tibet Autonomous Region, China

International audienceAbstract Background In China the highest prevalence of echinococcosis is in Tibet Autonomous Region (TAR). The government has issued documents and implemented comprehensive prevention and control measures focusing on controlling the source of infection of echinococcosis. It was very important to understand the implementation and effect of infectious source control measures. The purpose of this study was to examine the implementation of measures to control infectious source (domestic and stray dogs) in TAR and to assess their effectiveness. Methods We collected data on domestic dog registration and deworming and stray dog sheltering in 74 counties/districts in the TAR from 2017 to 2019. Fecal samples from domestic dogs were collected from randomly selected towns to determine Echinococcus infection in dogs using coproantigen ELISA. We analyzed the data to compare the canine rate of infection between 2016 and 2019. The data analysis was performed by SPSS statistical to compare dog infection rate in 2016 and 2019 by chi-square test, and ArcGIS was used for mapping. Results From 2017 to 2019, 84 stray dog shelters were built in TAR, and accumulatively 446,660 stray or infected dogs were arrested, sheltered, or disposed of. The number of domestic dogs went downward, with an increased registration management rate of 78.4% (2017), 88.8% (2018), and 99.0% (2019). Dogs were dewormed 5 times in 2017, 12 times in 2018, and 12 times in 2019. The dog infection rate was 1.7% (252/14,584) in 2019, significantly lower than 7.3% (552/7564) from the survey of echinococcosis prevalence in Tibet in 2016 ( P < 0.05). Conclusion Between 2017 and 2019, the number of stray dogs and infection rate of Echinococcus spp. in domestic dogs decreased significantly, indicating that dogs were effectively controlled as a source of infection in TAR and reflecting a significant decrease in the risk of echinococcosis transmission. Graphical Abstrac

Prevalence and spectrum of p53 mutations associated with smoking in breast cancer

To explore the role of smoking in breast cancer, we undertook a population-based study to evaluate the prevalence and spectrum of p53 mutations in the breast tumors of smokers and nonsmokers. We evaluated 456 archival invasive breast tumors for mutations in exons 4-8 of the p53 gene, using single-strand conformational polymorphism analysis and manual sequencing. Statistical analyses were performed to determine the association of p53 mutations with clinical and smoking characteristics. Of 108 mutations identified, 77 (71%) were point mutations and 31 (29%) were deletions or insertions. A higher prevalence of p53 mutations was found in the breast tumors of current smokers (36.5%; P = 0.02) compared with never smokers (23.6%), whereas fewer mutations were found in former smokers (16.2%; P = 0.09). After adjustment for age, race, menopausal status, clinical stage, tumor size, and family history of breast cancer, current smokers were significantly more likely to harbor any p53 mutation [odds ratio (OR), 2.11; 95% confidence interval (CI), 1.17-3.78], p53 transversions (OR, 3.37; 95% CI, 1.03-11.06), and G:C-->T:A transversions (OR, 10.53; 95% CI, 1.77-62.55) compared with never smokers. Stage at diagnosis did not account for the increase in p53 mutation-positive breast cancer among current smokers. Former smokers were also more likely than never smokers to harbor G:C-->T:A transversions (OR, 2.43; 95% CI, 0.37-15.73), although this association was not statistically significant. Among former smokers, the prevalence of p53 mutations varied with time since quitting: former smokers who quit smoking for longer than 1 year had a lower prevalence of p53 mutations (10.5% for 1-5 years and 12.9% for >5 years) than those who had stopped smoking within the year of their cancer diagnosis (26.3%). Our results indicate that cigarette smoking appears to modify the prevalence and spectrum of p53 mutations in breast tumors. Moreover, the difference in mutational spectra observed between smokers and nonsmokers is suggestive of the genotoxic effects of smoking in breast tissue