Purpose: This 2-year follow-up study aimed to examine the associations between total volume, frequency, duration, and speed of walking with subsequent sleep difficulty in older adults.Methods: A total of 800 older adu...Purpose: This 2-year follow-up study aimed to examine the associations between total volume, frequency, duration, and speed of walking with subsequent sleep difficulty in older adults.Methods: A total of 800 older adults aged 65 years and over participated in the first survey in 2012 and 511 of them were followed 2 years later.The 5-item Athens Insomnia Scale(AIS-5) was used to measure sleep difficulty. Frequency, duration, and speed of outdoor walking were self-reported. Walking speed was assigned a metabolic equivalent value(MET) from 2.5 to 4.5. Total walking volume in MET-h/week was calculated as frequency × duration × speed. Negative binomial regressions were performed to examine the associations between volume and components of walking with subsequent sleep difficulty with covariates of age, sex, education, marital status, living arrangement, smoking, alcohol consumption, mental health, Charlson Index, exercise(excluding walking), and sleep difficulty at baseline.Results: Participants with low walking volume had a higher level of sleep difficulty 2 years later compared with those with high walking volume(incident rate ratios = 1.61, p = 0.004). When speed, frequency, and duration of walking were simultaneously entered into 1 model, only walking speed was significantly associated with subsequent sleep difficulty(after the model was adjusted for covariates and baseline sleep difficulty).Sensitivity analyses showed that walking duration emerged as a significant predictor among 3 walking parameters, with 2-year changes of sleep scores as dependent variable.Conclusion: Total amount of walking(especially faster walking and lasting for more than 20 min) is associated with less subsequent sleep difficulty after 2 years among older adults.展开更多
A firm may expand in two ways： by tangible expansion through an increase in the scale of the physical company, or by intangible expansion, an optimization process drawing on both the firm＇s physical entity as well a...A firm may expand in two ways： by tangible expansion through an increase in the scale of the physical company, or by intangible expansion, an optimization process drawing on both the firm＇s physical entity as well as virtual resources, producing borderless growth. We take a case study approach to explore borderless development at business, managerial, and operational levels and to study four facilitators of borderless development： information technology, the virtual world, virtual operations, and concentration on core business. We conclude that firms may achieve global dominance in their area of core competency through borderless development.展开更多
The article presents the results of recent investigations into Holter monitoring of ECG, using non-linear analysis methods. This paper discusses one of the modern methods of time series analysis--a method of determini...The article presents the results of recent investigations into Holter monitoring of ECG, using non-linear analysis methods. This paper discusses one of the modern methods of time series analysis--a method of deterministic chaos theory. It involves the transition from study of the characteristics of the signal to the investigation of metric （and probabilistic） properties of the reconstructed attractor of the signal. It is shown that one of the most precise characteristics of the functional state of biological systems is the dynamical trend of correlation dimension and entropy of the reconstructed attractor. On the basis of this it is suggested that a complex programming apparatus be created for calculating these characteristics on line. A similar programming product is being created now with the support of RFBR. The first results of the working program, its adjustment, and further development, are also considered in the article.展开更多
文摘Purpose: This 2-year follow-up study aimed to examine the associations between total volume, frequency, duration, and speed of walking with subsequent sleep difficulty in older adults.Methods: A total of 800 older adults aged 65 years and over participated in the first survey in 2012 and 511 of them were followed 2 years later.The 5-item Athens Insomnia Scale(AIS-5) was used to measure sleep difficulty. Frequency, duration, and speed of outdoor walking were self-reported. Walking speed was assigned a metabolic equivalent value(MET) from 2.5 to 4.5. Total walking volume in MET-h/week was calculated as frequency × duration × speed. Negative binomial regressions were performed to examine the associations between volume and components of walking with subsequent sleep difficulty with covariates of age, sex, education, marital status, living arrangement, smoking, alcohol consumption, mental health, Charlson Index, exercise(excluding walking), and sleep difficulty at baseline.Results: Participants with low walking volume had a higher level of sleep difficulty 2 years later compared with those with high walking volume(incident rate ratios = 1.61, p = 0.004). When speed, frequency, and duration of walking were simultaneously entered into 1 model, only walking speed was significantly associated with subsequent sleep difficulty(after the model was adjusted for covariates and baseline sleep difficulty).Sensitivity analyses showed that walking duration emerged as a significant predictor among 3 walking parameters, with 2-year changes of sleep scores as dependent variable.Conclusion: Total amount of walking(especially faster walking and lasting for more than 20 min) is associated with less subsequent sleep difficulty after 2 years among older adults.
文摘A firm may expand in two ways： by tangible expansion through an increase in the scale of the physical company, or by intangible expansion, an optimization process drawing on both the firm＇s physical entity as well as virtual resources, producing borderless growth. We take a case study approach to explore borderless development at business, managerial, and operational levels and to study four facilitators of borderless development： information technology, the virtual world, virtual operations, and concentration on core business. We conclude that firms may achieve global dominance in their area of core competency through borderless development.
文摘The article presents the results of recent investigations into Holter monitoring of ECG, using non-linear analysis methods. This paper discusses one of the modern methods of time series analysis--a method of deterministic chaos theory. It involves the transition from study of the characteristics of the signal to the investigation of metric （and probabilistic） properties of the reconstructed attractor of the signal. It is shown that one of the most precise characteristics of the functional state of biological systems is the dynamical trend of correlation dimension and entropy of the reconstructed attractor. On the basis of this it is suggested that a complex programming apparatus be created for calculating these characteristics on line. A similar programming product is being created now with the support of RFBR. The first results of the working program, its adjustment, and further development, are also considered in the article.
