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1] The alpine meadow ecosystem on the Qinghai-Tibetan Plateau may play a significant role in the regional carbon cycle. To assess the CO 2 flux and its relationship to environmental controls in the ecosystem, eddy covariance of CO 2 , H 2 O, and energy fluxes was measured with an open-path system in an alpine meadow on the plateau at an elevation of 3,250 m. Net ecosystem CO 2 influx (Fc) averaged 8.8 g m À2 day À1 during the period from August 9 to 31, 2001, with a maximum of 15.9 g m À2 day À1 and a minimum of 2.3 g m À2 day À1 . Daytime Fc averaged 16.7 g m À2 day À1 and ranged from 10.4 g m À2 day À1 to 21.7 g m À2 day À1 during the study period. For the same photosynthetic photon flux density (PPFD), gross CO 2 uptake (Gc) was significantly higher on cloudy days than on clear days. However, mean daily Gc was higher on clear days than on cloudy days. With high PPFD, Fc decreased as air temperature increased from 10°C to 23°C. The greater the difference between daytime and nighttime air temperatures, the more the sink was strengthened. Daytime average water use efficiency of the ecosystem (WUEe) was 8.7 mg (CO 2 )(g H 2 O) À1 ; WUEe values ranged from 5.8 to 15.3 mg (CO 2 )(g H 2 O) À1 . WUEe increased with the decrease in vapor pressure deficit. Daily albedo averaged 0.20, ranging from 0.19 to 0.22 during the study period, and was negatively correlated with daily Fc. Our measurements provided some of the first evidence on CO 2 exchange for a temperate alpine meadow ecosystem on the Qinghai-Tibetan Plateau, which is necessary for assessing the carbon budget and carbon cycle processes for temperate grassland ecosystems. Short-term variation of CO 2 flux in relation to environmental controls in an alpine meadow on the Qinghai-Tibetan Plateau,

Background High burnout has been reported in physician populations. Although the standardized residency training (SRT) in China includes components that might put residents at a higher risk for burnout, the burnout of Chinese medical residents is unknown. This study aimed to evaluate the prevalence of burnout and the associated risk and protective factors for medical residents in the SRT program in Shanghai, China. Methods This study was a prospective cross-sectional design. A random sampling strategy was used to recruit 330 resident physicians from four SRT sites in Shanghai, and 318 completed questionnaires were returned. Respondents completed a self-made questionnaire including demographic and work characteristics, four burnout and wellness-specific surveys. Bivariate analyses and hierarchical multiple regression models were used to analyze factors associated with three sub-scales of burn out separately. Results The overall burnout rate was 71.4%. Low level rate of personal accomplishment (PA) was extremely high at 69.5%. Night shift experience, high occupational stress, and low social support were significant predictors, which explained 49.1% variance of emotional exhaustion (EE) (F = 26.528, P < 0.01). Factors that significantly predicted depersonalization (DP) included male gender, senior residents, night shift experience, high occupational stress, and low psychological empathy, which explained 51.5% variance totally (F = 29.004, P < 0.01). Senior residents, high income, low occupational stress, and high empathy were also significant predictors of decreased personal achievement (PA), which explained 18.4% variance totally (F = 12.897, P < 0.01). Conclusions There was a high burnout rate among SRT residents in Shanghai. Occupational stress and several work-related factors were significant and strong risk factors for burnout, while empathy and social support were mild protective factors. Decreased work-related demands and increased access to resources could assist residents in reducing their work stress and improving their well-being.