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The Taoer River, a representative ecologically sensitive area in Northeast China, has undergone great climate changes and rapid social developments since 1961. Subsequently, a substantial alteration of the streamflow regime was observed and severe eco-environmental problems were becoming prominent. To provide decision makers the scientific basis for effective resource management and sound future planning, it is crucial to understand and assess the impacts of the climate variability and human activities on streamflow in this region. In this study, we combined an observation-based statistical analysis and physical modeling experiments to address this broad question. The Mann-Kendall and Sen's slope were used to examine the trends and the moving t test was used to identify change points for the streamflow, precipitation, and potential evapotranspiration datasets. A statistically significant upward trend ( α = 5 %) was found for annual streamflow. An abrupt change point was identified in 1985 for the basin outlet station at Taonan. Accordingly, the streamflow was divided into baseline and changed period for attribution analysis. To investigate the impacts of climate change and human activities on annual streamflow, we applied a distributed hydrological model and six Budyko-type functions during the two periods. The results indicated that climate change and human activities accounted for about 45 and 55 % of the changes in streamflow, respectively. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the prevalence and visual acuity (VA) outcomes of cataract surgery in adults of the Bai Nationality populations in rural China. Methods: We conducted a population-based cross-sectional survey (from randomly selected block groups) of Chinese Bai Nationality aged ≥50 years in southwestern China. Presenting visual acuity (PVA), best corrected visual acuity (BCVA) were recorded and a detailed eye examination was carried out. For all aphakic and pseudophakic subjects identified, information on the date, setting, type, and complications of cataract surgery were recorded. In eyes with VA <20/63, the principal cause of visual impairment was identified. Results: Of 2133 (77.8% of 2742) subjects, 99 people (129 eyes) had undergone cataract surgery. The prevalence of cataract surgery was 4.6%. Surgical coverage among those with PVA <20/200 in both eyes because of cataract was 52.8%. Unoperated cataract was associated with older age. The main barrier to cataract surgery was lack of awareness and knowledge, cost, and fear. Among the 129 cataract-operated eyes, 22.5% had PVA of ≥20/32, 25.6% had PVA of 20/40 to 20/63, 23.3% had PVA <20/63 to 20/200, and 28.7% had PVA<20/200. With BCVA, the percentages were 42.6%, 23.3%, 10.9%, and 23.3%, respectively. Aphakia (odds ratio [OR], 8.49; P<0.001) and no education (OR, 10.18; P = 0.001) or less education (OR, 6.49; P = 0.014) were significantly associated with postoperative visual impairment defined by PVA, while aphakia (OR, 8.49; P<0.001) and female gender (OR, 4.19; P = 0.004) were significantly associated with postoperative visual impairment by BCVA. The main causes of postoperative visual impairment were refractive error, retinal disorders and glaucoma. Conclusions: Half of those with bilateral visual impairment or blindness because of cataract remain in need of cataract surgery in Bai population. Surgical uptake and visual outcomes should be further improved in the future. [ABSTRACT FROM AUTHOR]

Drought is one of the most costly natural disasters in the world. Understanding the drought characteristics in space and time will help deepen our apprehension of the drought formation and evolution mechanisms. It can also contribute to design monitoring system for drought warning and mitigation. In this study, we analyzed meteorological droughts, using the Standardized Precipitation Index, for Lancang River Basin, Southwest China. The 46-year (1960-2005) daily precipitation observations from 35 meteorological stations in the basin were used to derive the drought index. Spatial patterns and temporal patterns of the drought characteristics at multiple scales were investigated. The results utilizing the Principal Component Analysis and K-means clustering methods suggest that the study area can be divided into four sub-regions geographically with each sub-region having its own distinctive temporal evolution patterns of droughts. The temporal variability of droughts was investigated using the Empirical Mode Decomposition (EMD) analysis and the wavelet method. The EMD analysis showed that more than 60 % of the variance of the drought is associated with intra-decadal fluctuations in precipitation, except for one sub region, represented by the Changdu station. The wavelet transform showed an evolution of the main cycle near 3-7 years for most parts of the study area. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of the study was to describe the prevalence, severity, and associated risk factors for pterygium in a population-based sample of rural residents of the Bai minority population in rural Dali, China., Methods: A population-based survey of Chinese Bai Nationality aged ≥50 years from randomly selected block groups in southwestern China was conducted. A clinical examination by experienced ophthalmologists was carried out, and the presence of pterygium was diagnosed at the examination. Pterygium was graded clinically by slit lamp examination. Questionnaires were conducted on risk factors., Results: From a total of 2742 eligible subjects, 2133 (77.8%) were examined. The prevalence of pterygium was high (overall 39.0% [95% confidence interval (CI) 37.0-41.0]). Women had a higher rate than men (27.3% vs. 11.7%, respectively). In multivariate analysis, pterygium was independently associated with increasing age (odds ratio [OR] 1.55 [95% CI 1.24-1.93], 1.47 [95% CI 1.13-1.91], and 1.79 [95% CI 1.17-2.73], respectively, for persons 60-69 years, 70-79 years, and 80 years and older compared with 50-59 years), female sex (OR 1.42 [95% CI 1.08-1.88]), lack of formal education (OR 1.26 [95% CI 1.03-1.56]), and presence of outdoor work (OR 1.51 [95% CI 1.10-1.92]). Height, weight, hypertension, diabetes, smoking, and alcohol use history were not associated with pterygium., Conclusions: The prevalence of pterygium in Dali is 39.0% among Chinese Bai aged 50 years and older. Independent associations with increasing age (>59 years), female sex, lack of education, and occupations linked to outdoor work suggest a multifactorial cause of this condition.

Purpose: To assess the prevalence and causes of visual impairment in the elderly Bai ethnic group in rural China., Methods: Random cluster sampling was used to identify the Bai ethnic group 50 years and older living in the Dali county of Yunnan, China. Presenting visual acuity (PVA) and best-corrected visual acuity (BCVA) were measured using the Early Treatment Diabetic Retinopathy Study visual chart. Blindness and low vision were defined according to World Health Organization criteria. The major cause of visual impairment was identified for all participants who were visually impaired., Results: Of the 2742 eligible individuals, 2133 (77.8%) participated in the study, and 2115 (77.1%) had visual acuity data available. With the PVA, the prevalence of blindness and low vision was 3.59% and 15.22%, respectively. When the BCVA was used, these rates were reduced to 2.88% and 7.75%. Blindness and low vision were associated with older age and lack of education, but no sex difference was seen. Based on the BCVA, the predominant causes of blindness were cataract (70.5%), corneal opacity (8.2%), and glaucoma (6.6%). The majority of PVA-defined low vision cases were attributable to cataract (53.0%) and uncorrected refractive error (22.0%)., Conclusions: A higher rate of visual impairment was seen in this Bai nationality sample than has been reported from the Han nationality population in rural China. Since potentially treatable eye disease, cataract, and uncorrected refractive error were the most important causes of visual impairment in this population, affordable provision of surgery and low-vision rehabilitation programs would help to address this problem.