Purpose: To test the effectiveness of sitting surfaces with varied amounts of stability on muscle activity and energy expenditure.Methods: Using a within-participants repeated measures design, 11 healthy young-adult f...Purpose: To test the effectiveness of sitting surfaces with varied amounts of stability on muscle activity and energy expenditure.Methods: Using a within-participants repeated measures design, 11 healthy young-adult females(age = 20.0 ± 1.8 years) were measured using indirect calorimetry to assess energy expenditure, and electromyography to assess muscular activation in trunk and leg musculature under 3different sitting surfaces: flat-firm surface, air-filled cushion, and a stability ball. Data were analyzed using repeated measures analysis of variance with follow-up pairwise contrasts used to determine the specific effects of sitting surface on muscle activation and energy expenditure.Results: Significantly greater energy expenditure was recorded for the stability ball(p = 0.01) and the cushion(p = 0.03) over the flat surface(10.4% and 9.6% greater, respectively), with no differences between the ball and the cushion. Both the ball and the cushion produced higher tibialis anterior activation over the flat surface(1.09 and 0.63 root-mean-square millivolts(RMSmv), respectively), while the stability ball produced higher soleus activity over both cushion and flat surfaces(3.97 and 4.24 RMSmv, respectively). Additionally, the cushion elicited higher adductor longus activity over the ball and flat surfaces(1.76 and 1.81 RMSmv, respectively), but no trunk musculature differences were revealed.Conclusion: Compliant surfaces resulted in higher levels of muscular activation in the lower extremities facilitating increased caloric expenditure.Given the increasing trends in sedentary careers and the increases in obesity, this is an important finding to validate the merits of active sitting facilitating increased caloric expenditure and muscle activation.展开更多
By applying co-integration analysis,the Granger causality test and an error correction model,the dependency between the energy consumption and the gross domestic product of China was examined.In a further step an anal...By applying co-integration analysis,the Granger causality test and an error correction model,the dependency between the energy consumption and the gross domestic product of China was examined.In a further step an analysis was done to establish a correlation between the economic growth of different industries and China's energy consumption.An evidence-based study showed that a co-integration relationship exists between the gross energy consumption and the GDP of China and that the two variables possess bi-directional causality.The energy consumption for the secondary industry has a markedly stimulative effect to the economic growth.This paper also uses an error correction model(ECM)to explain the short-term behavior of energy demands.展开更多
Quantitative analysis of saccharin in preserved fruits was performed by High Performance Liquid Chromatography （HPLC）. The separation was observed on a reversed phase ODS C）8 column （4.6 × 250 mm）. Mobile ph...Quantitative analysis of saccharin in preserved fruits was performed by High Performance Liquid Chromatography （HPLC）. The separation was observed on a reversed phase ODS C）8 column （4.6 × 250 mm）. Mobile phase system consisted of ammonium acetate buffer： Methanol （60：40 v/v） at a flow rate of 1.0 mL.min^-1, and UV detector was set at 235 nm. The calibration curve of saccharin was linear in the concentration range between 1 to 100 mg·L^-1）, while the detection limit of saccharin was found to be 0.08 mg.L^-1. The mean value of recovery was 98.24% with standard deviation of0.32% （n=12）. The proposed method was successfully applied to determine the amount of saccharin in 12 preserved fruits, commercially available in Chiang Mai local markets. The results showed that the saccharin contents were found in the range of 6.22-78.60 mg.kg^-1.展开更多
文摘Purpose: To test the effectiveness of sitting surfaces with varied amounts of stability on muscle activity and energy expenditure.Methods: Using a within-participants repeated measures design, 11 healthy young-adult females(age = 20.0 ± 1.8 years) were measured using indirect calorimetry to assess energy expenditure, and electromyography to assess muscular activation in trunk and leg musculature under 3different sitting surfaces: flat-firm surface, air-filled cushion, and a stability ball. Data were analyzed using repeated measures analysis of variance with follow-up pairwise contrasts used to determine the specific effects of sitting surface on muscle activation and energy expenditure.Results: Significantly greater energy expenditure was recorded for the stability ball(p = 0.01) and the cushion(p = 0.03) over the flat surface(10.4% and 9.6% greater, respectively), with no differences between the ball and the cushion. Both the ball and the cushion produced higher tibialis anterior activation over the flat surface(1.09 and 0.63 root-mean-square millivolts(RMSmv), respectively), while the stability ball produced higher soleus activity over both cushion and flat surfaces(3.97 and 4.24 RMSmv, respectively). Additionally, the cushion elicited higher adductor longus activity over the ball and flat surfaces(1.76 and 1.81 RMSmv, respectively), but no trunk musculature differences were revealed.Conclusion: Compliant surfaces resulted in higher levels of muscular activation in the lower extremities facilitating increased caloric expenditure.Given the increasing trends in sedentary careers and the increases in obesity, this is an important finding to validate the merits of active sitting facilitating increased caloric expenditure and muscle activation.
基金Projects TSFZLXKF2006-3 supported by the China Lixin Risk Management Research Institute Foundation of Shanghai Municipal Education Commission90210035 by the National Natural Science Foundation of China
文摘By applying co-integration analysis,the Granger causality test and an error correction model,the dependency between the energy consumption and the gross domestic product of China was examined.In a further step an analysis was done to establish a correlation between the economic growth of different industries and China's energy consumption.An evidence-based study showed that a co-integration relationship exists between the gross energy consumption and the GDP of China and that the two variables possess bi-directional causality.The energy consumption for the secondary industry has a markedly stimulative effect to the economic growth.This paper also uses an error correction model(ECM)to explain the short-term behavior of energy demands.
文摘Quantitative analysis of saccharin in preserved fruits was performed by High Performance Liquid Chromatography （HPLC）. The separation was observed on a reversed phase ODS C）8 column （4.6 × 250 mm）. Mobile phase system consisted of ammonium acetate buffer： Methanol （60：40 v/v） at a flow rate of 1.0 mL.min^-1, and UV detector was set at 235 nm. The calibration curve of saccharin was linear in the concentration range between 1 to 100 mg·L^-1）, while the detection limit of saccharin was found to be 0.08 mg.L^-1. The mean value of recovery was 98.24% with standard deviation of0.32% （n=12）. The proposed method was successfully applied to determine the amount of saccharin in 12 preserved fruits, commercially available in Chiang Mai local markets. The results showed that the saccharin contents were found in the range of 6.22-78.60 mg.kg^-1.
