scholarly journals Circadian rhythms determined by cosine curve fitting: Analysis of continuous work and sleep-loss data

1985 ◽  
Vol 17 (6) ◽  
pp. 630-641 ◽  
Author(s):  
Paul Naitoh ◽  
Carl E. Englund ◽  
David H. Ryman
Author(s):  
Nicholas J Saner ◽  
Matthew J-C Lee ◽  
Jujiao Kuang ◽  
Nathan W Pitchford ◽  
Gregory D Roach ◽  
...  

AbstractSleep loss has emerged as a risk factor for the development of impaired glucose tolerance. The mechanisms underpinning this observation are unknown; however, both mitochondrial dysfunction and circadian misalignment have been proposed. Given that exercise improves glucose tolerance, mitochondrial function, and alters circadian rhythms, we investigated whether exercise may counteract the effects induced by inadequate sleep. We report that sleeping 4 hours per night, for five nights, reduced glucose tolerance, with novel observations of associated reductions in mitochondrial function, sarcoplasmic protein synthesis, and measures of circadian rhythmicity; however, incorporating three sessions of high-intensity interval exercise (HIIE) during this period mitigates these effects. These data demonstrate, for the first time, a sleep loss-induced concomitant reduction in a range of physiological processes linked to metabolic function. These same effects are not observed when exercise is performed during a period of inadequate sleep, supporting the use of HIIE as an intervention to mitigate the detrimental physiological effects of sleep loss.


2002 ◽  
Vol 57 (5) ◽  
pp. 277-280 ◽  
Author(s):  
Yoshihiro Okamoto ◽  
Haruhiko Motohashi

The local structure of motlen ZrCl4 in LiCl-KCl eutectic was investigated by using an X-ray absorption fine structure (XAFS) of the Zr K-absorption edge. The nearest Zr4+-Cl- distance and coordination number from the curve fitting analysis were (2.51±0.02) Å and 5.9±0.6, respectively. These suggest that a 6-fold coordination (ZrCl6)2- is predominant in the molten mixture.


Author(s):  
Ben B. Morgan ◽  
Bill R. Brown ◽  
Earl A. Alluisi

The work efficiency of 10 subjects during a 48-hr period of continuous work and sleep loss was assessed using the synthetic-work technique. Performance during the period of stress was found to be significantly influenced by the circadian rhythm. Decrements first occurred after approximately 18 hr of continuous work, and performance decreased to an average of 82% of baseline during the early morning hours of the first night. Performance improved to about 90% of baseline during the daytime of the second day but decreased to approximately 67% during that night. All measures of performance recovered to baseline levels following a 24-hr period of rest and recovery.


1976 ◽  
Vol 190 (1) ◽  
pp. 193-201 ◽  
Author(s):  
M. S. Shunmugam ◽  
V. Radhakrishnan

SYNOPSIS In this paper, a method to compute the reference line for the surface profiles by the random process analysis is explained. This reference line is compared with the other practical reference lines, namely the electrical mean line and the envelope. This method is also an interesting and useful tool for the curve fitting analysis.


Sign in / Sign up

Export Citation Format

Share Document