We use emergy-based urban metabolism analysis in this study to investigate the local coupling and telecoupling between urbanization and the eco-environment in the Beijing-Tianjin-Hebei urban agglomeration. Our analysi...We use emergy-based urban metabolism analysis in this study to investigate the local coupling and telecoupling between urbanization and the eco-environment in the Beijing-Tianjin-Hebei urban agglomeration. Our analysis encompasses the last 35 years spanning the period between 1980 and 2014. In addition, we analyze urban metabolic efficiency and environmental pressure in these couplings. There are three main conclusions of this study. First, we show that the total metabolic emergy value of the Beijing-Tianjin-Hebei urban agglomeration has increased over the last 35 years, and that external elements have replaced internal ones as the leading contributors to urban metabolism in this region. The proportion of metabolic emergy derived from external elements increased from 30.87% in 1980 to 67.43% in 2014. The emergy extroversion ratio has continued to increase over our study period, while the development of this urban agglomeration had become progressively and more heavily reliant on external elements. Second, over the study period, the metabolic emergy intensity of elements of local coupling and telecoupling in the Beijing-Tianjin-Hebei urban agglomeration has declined at an accelerating rate, from 1.15×10^(21) Sej/100 million RMB in1980 to 9.69×10^(19) Sej/100 million RMB in 2014. This reflects a continuous increase in the economic efficiency of this area.Correspondingly, emergy use per capita increased from 7.8×10^(15) Sej/person in 1980 to 5.83×10^(16) Sej/person in 2014, suggesting a gradual rise in the level of social welfare in this urban agglomeration. However, we also observed a consistently elevated environmental loading ratio(ELR) in our analysis in terms of metabolism of local coupling and telecoupling elements. This result indicates that environmental pressure has also increased constantly within the Beijing-Tianjin-Hebei urban agglomeration. Third,our analysis shows that the ELR of metabolic emergy from internal elements increased from 8.30 in 1980 to 43.46 in 2014, while the ratio from external elem展开更多
Background: Wearable monitors(WMs) are used to estimate the time spent in sedentary behaviors(SBs) and light-intensity physical activities(LPAs) and their associated energy cost; however, the accuracy of WMs in measur...Background: Wearable monitors(WMs) are used to estimate the time spent in sedentary behaviors(SBs) and light-intensity physical activities(LPAs) and their associated energy cost; however, the accuracy of WMs in measuring behaviors on the lower end of the intensity spectrum is unclear. The aim of this study was to assess the validity of 3 WMs(Acti Graph GT3X+; activ PAL, and Sense Wear 2) in estimating the intensity of SB and LPA in adults as compared with the criterion measure of oxygen uptake(VO_2) measured by indirect calorimetry.Methods: Sixteen participants(age: 25.38 ± 8.58 years) wore the ActiG raph GT3X+, activP AL, and SenseW ear 2 devices during 7 sedentary-to-light activities. VO_2(mL/kg/min) was estimated by means of a portable gas analyzer, Oxycon Mobile(Carefusion, Yorba Linda, CA, USA). All data were transformed into metabolic equivalents and analyzed using mean percentage error, equivalence plots, Bland-Altman plots, kappa statistics, and sensitivity/specificity.Results: Mean percentage error was lowest for the activ PAL for SB(14.9%) and LPA(9.3%) compared with other WMs, which were >21.2%.None of the WMs fell within the equivalency range of ±10% of the criterion mean value. Bland-Altman plots revealed narrower levels of agreement with all WMs for SB than for LPA. Kappa statistics were low for all WMs, and sensitivity and specificity varied by WM type.Conclusion: None of the WMs tested in this study were equivalent with the criterion measure(VO_2) in estimating sedentary-to-light activities;however, the activ PAL had greater overall accuracy in measuring SB and LPA than did the Acti Graph and Sense Wear 2 monitors.展开更多
目的:系统评价高强度间歇训练(HIIT)与中等强度持续训练(MICT)对代谢综合征(MetS)危险因素影响的干预效果。方法:检索PubMed、EMbase、Web of Science、中国知网、万方数据库、维普数据库从建库至2021年5月15日的有关HIIT对比MICT干预M...目的:系统评价高强度间歇训练(HIIT)与中等强度持续训练(MICT)对代谢综合征(MetS)危险因素影响的干预效果。方法:检索PubMed、EMbase、Web of Science、中国知网、万方数据库、维普数据库从建库至2021年5月15日的有关HIIT对比MICT干预MetS危险因素的随机对照试验文献,结局指标包括空腹血糖(FPG)、高密度脂蛋白(HDL-C)、三酰甘油(TG)、收缩压(SBP)、舒张压(DBP)和腰围(WC),同时检索纳入文献的参考文献,采用Cochrane协作网推荐的偏倚风险评价工具对纳入文献进行质量评价,采用Review Manager 5.4对纳入文献数据进行统计分析。PROSPERO注册号为CRD 42021249779。结果:共纳入10篇随机对照试验,涉及347例MetS病人,文献总体质量较高。MICT比HIIT降低MetS病人收缩压效果更好[MD=3.39,95%CI(1.06,5.72),P=0.004];在改善腰围[MD=-0.27,95%CI(-1.74,1.21),P=0.72]、三酰甘油[SMD=-0.14,95%CI(-0.35,0.07),P=0.19]、HDL-C[SMD=0.05,95%CI(-0.16,0.26),P=0.64]、舒张压[MD=0.75,95%CI(-0.94,2.44),P=0.39]、空腹血糖[SMD=0.08,95%CI(-0.13,0.30),P=0.45]方面差异无统计学意义。结论:现有证据表明,HIIT对比MICT干预MetS危险因素(腰围、三酰甘油、HDL-C、舒张压、空腹血糖)效果相似,但MICT在降低收缩压危险因素方面效果更好。因此,推荐MICT作为干预以高收缩压为主的MetS病人优选方案,HIIT可作为缺少时间或不能坚持持续运动人群的更佳选择。展开更多
基金supported by the Major Program of National Natural Science Foundation of China: “Coupled mechanism and interactive coercing effects between urbanization and eco-environment in mega-urban agglomerations” (Grant Nos. 41590840 & 41590842)
文摘We use emergy-based urban metabolism analysis in this study to investigate the local coupling and telecoupling between urbanization and the eco-environment in the Beijing-Tianjin-Hebei urban agglomeration. Our analysis encompasses the last 35 years spanning the period between 1980 and 2014. In addition, we analyze urban metabolic efficiency and environmental pressure in these couplings. There are three main conclusions of this study. First, we show that the total metabolic emergy value of the Beijing-Tianjin-Hebei urban agglomeration has increased over the last 35 years, and that external elements have replaced internal ones as the leading contributors to urban metabolism in this region. The proportion of metabolic emergy derived from external elements increased from 30.87% in 1980 to 67.43% in 2014. The emergy extroversion ratio has continued to increase over our study period, while the development of this urban agglomeration had become progressively and more heavily reliant on external elements. Second, over the study period, the metabolic emergy intensity of elements of local coupling and telecoupling in the Beijing-Tianjin-Hebei urban agglomeration has declined at an accelerating rate, from 1.15×10^(21) Sej/100 million RMB in1980 to 9.69×10^(19) Sej/100 million RMB in 2014. This reflects a continuous increase in the economic efficiency of this area.Correspondingly, emergy use per capita increased from 7.8×10^(15) Sej/person in 1980 to 5.83×10^(16) Sej/person in 2014, suggesting a gradual rise in the level of social welfare in this urban agglomeration. However, we also observed a consistently elevated environmental loading ratio(ELR) in our analysis in terms of metabolism of local coupling and telecoupling elements. This result indicates that environmental pressure has also increased constantly within the Beijing-Tianjin-Hebei urban agglomeration. Third,our analysis shows that the ELR of metabolic emergy from internal elements increased from 8.30 in 1980 to 43.46 in 2014, while the ratio from external elem
文摘Background: Wearable monitors(WMs) are used to estimate the time spent in sedentary behaviors(SBs) and light-intensity physical activities(LPAs) and their associated energy cost; however, the accuracy of WMs in measuring behaviors on the lower end of the intensity spectrum is unclear. The aim of this study was to assess the validity of 3 WMs(Acti Graph GT3X+; activ PAL, and Sense Wear 2) in estimating the intensity of SB and LPA in adults as compared with the criterion measure of oxygen uptake(VO_2) measured by indirect calorimetry.Methods: Sixteen participants(age: 25.38 ± 8.58 years) wore the ActiG raph GT3X+, activP AL, and SenseW ear 2 devices during 7 sedentary-to-light activities. VO_2(mL/kg/min) was estimated by means of a portable gas analyzer, Oxycon Mobile(Carefusion, Yorba Linda, CA, USA). All data were transformed into metabolic equivalents and analyzed using mean percentage error, equivalence plots, Bland-Altman plots, kappa statistics, and sensitivity/specificity.Results: Mean percentage error was lowest for the activ PAL for SB(14.9%) and LPA(9.3%) compared with other WMs, which were >21.2%.None of the WMs fell within the equivalency range of ±10% of the criterion mean value. Bland-Altman plots revealed narrower levels of agreement with all WMs for SB than for LPA. Kappa statistics were low for all WMs, and sensitivity and specificity varied by WM type.Conclusion: None of the WMs tested in this study were equivalent with the criterion measure(VO_2) in estimating sedentary-to-light activities;however, the activ PAL had greater overall accuracy in measuring SB and LPA than did the Acti Graph and Sense Wear 2 monitors.
