An integrated environmental improvement of marshlands:impact on control and elimination of schistosomiasis in marshland regions along the Yangtze River,China

Background:Schistosomiasis is a global snail-transmitted infectious disease of poverty.Transmission control had been achieved in China in 2015 after the control efforts for over 60 years.Currently,the remaining core regions endemic for Schistosoma japonicum are mainly located in the marshland and lake regions along the Yangtze River basin.Methods:During the period from 2001 through 2015,an integrated environmental improvement of the marshlands was carried out through the implementation of industrial,agricultural and resources development projects in Yizheng County along the Yangtze River.S.japonicum infection in humans,livestock and snails was estimated by serology,stool examination,hatching technique and microscopy during the 15-year study period to evaluate the effect of the integrated environmental improvement on control and elimination of schistosomiasis.Results:A 0.05%overall rate of S.japonicum infection was observed in snails during the 15-year study period,and no infected snails were detected since 2012.The overall prevalence of S.japonicum infection was 0.09%in humans during the study period,and no human infection was found since 2012.In addition,only 13 bovines were identified with S.japonicum infection in 2003 during the 15-year study period,and since 2004,no infection was found in livestock.Conclusion:The results of the present study demonstrate that the implementation of industrial,agricultural and water resources development projects,not only alters snail habitats in marshland regions,and promotes local economic development,which appears a win-to-win strategy to block the transmission of S.japonicum and accelerate socio-economic development along the Yangtze River.

Multiple positive periodic solutions for a generalized delayed population model with an exploited term

In this paper, the existence of two positive periodic solutions for a generalized delayed population model with an exploited term is established by using the continuation theorem of the coincidence degree theory.

Numerical simulation of the effects of global warming on vegetation in Asia

The response of vegetation to global warming is closely related to human living environment,and uncertainty in understanding the response remains.This study aims to investigate the effects of CO_(2),temperature and precipitation changes under global warming on natural vegetation in Asia.The biophysical/dynamic vegetation model SSiB4/TRIFFID was employed to perform numerical experiments under different climate scenarios for Asia using the Princeton global forcing dataset(1948–2006).The results showed that precipitation and CO_(2) were the key factors for vegetation growth.The effect of temperature on natural vegetation varied among the study regions.Generally,an increase in temperature was conducive to vegetation growth in eastern Asia,but not in the arid and semi-arid areas of western Asia.In arid and semi-arid areas or in the vicinity of desert,the forcing effects of temperature,precipitation and CO_(2) were more remarkable,which led to a noticeable change in the area of bare land.In terms of the distribution of vegetation species,the above forcing had a greater impact on shrubs,C3 grasses and C4 plants,but less of an impact on broadleaf and coniferous forest.It was also found that,although there was a notable positive correlation between precipitation and vegetation leaf area index in northern high latitudes,the vegetation cover did not increase with precipitation,which was countered by the negative effect of surface cooling in summer.