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Freeruns
Published in Sue Binkley, Biological Clocks, 2020
Some dictionary definitions of the word clock differentiate a clock from a watch. A watch is a clock carried about on a person. Since individual organisms are themselves able to generate rhythms, the biological clock can be thought of as a biological watch.
What Actually Is Sleep?
Published in Zippi Dolev, Mordechai Zalesch, Judy Kupferman, Sleep and Women's Health, 2019
Zippi Dolev, Mordechai Zalesch, Judy Kupferman
It is interesting to note that the Nobel Prize in medicine or physiology was awarded in 2017 to American researchers Jeffery C. Hall, Michael Rossbach, and Michael Yang for the discovery of the molecular mechanisms that control the circadian rhythm. The biological clock is designed to adapt the activity of living organisms to the regular rhythm of the day–night cycle.
Summary and Development of a New Approach to Senescence
Published in Nate F. Cardarelli, The Thymus in Health and Senescence, 2019
In human terms, we want to reset the biological clocks so as to enhance the quality of life during the senescent period. Slowing the clock should retard immune decline and thus improve health at all ages. Whether the maximum life span is amenable to manipulation by genetic or radiation means remains to be explored.
The association between bedtime and cardiac autonomic control in community-dwelling older adults – The Yilan study, Taiwan
Published in Chronobiology International, 2023
Chen-Shin Hung, Nai-Wei Hsu, Hsi-Chung Chen, Chung-Yeh Deng, Pesus Chou
In terms of clinical implications, the TP of HRV typifies the overall cardiac autonomic function and indicates the general health status. LF had the highest correlation with age among all parameters of the frequency domain analysis for HRV (Kuo et al. 1999); specifically, higher LF power indicates younger biological age. Thus, our findings suggest that older adults who go to bed late may have better overall health status, including younger biological age, than their counterparts. Our findings may be explained by two mechanisms. Biologically, the younger biological clock tends to have a later sleep-wake phase (Brown et al. 2011). In addition, older adults who are accustomed to sleeping late, which is regarded as deleterious for health, but could maintain health across the life span, may reflect a resultant group of selective survival. Our findings also echoed the literature that older adults with late bedtime had better self-perceived health and less physical function limitation than those with early bedtime (Habte-Gabr et al. 1991). Accordingly, higher levels of social communication and participation in social activity among older adults with late bedtime could be partially attributed to their improved physical condition (Monk and Buysse 2014).
Time of Day Influence on Postural Balance of Young and Older Men
Published in Experimental Aging Research, 2023
Vasileios Mylonas, Thomas Nikodelis, Iraklis Kollias
Many of the human physiologic mechanisms, however, are not consistent around the clock, but they display variance throughout the day (Widmaier, Raff, & Strang, 2014). The biological clock that regulates such variations is called the Circadian clock or Circadian Rhythm. Some of the primary functions of that clock are regulating the sleep-wake cycle, glucose homeostasis, body temperature, and more. Light is the main stimulus of the circadian clock, although more factors may be regulators such as temperature, hormones, and diet (Serin & Acar Tek, 2019). The circadian clock through the melatonin level, an indicator of the environmental light-dark circle, recognizes the time of day and then synchronizes various systems to optimize the body’s physiologic function (Nava Zisapel & Zisapel, 2018). The function of the circadian rhythm is noticed in the sleep-wake cycle. Sleepiness results from two factors summing up. First, the sleepiness adds up during the waking state, and second the circadian regulation sustains a 24-hour rhythm that determines the sleep schedule, mainly influenced by environmental temperature. Sleep is prohibited during the day and enhanced during the night for an organism with a smooth-running circadian clock. (Lack & Wright, 2007). These fluctuations are not fixed for everyone. The individual response to circadian rhythmicity is a characteristic called Chronotype and it is what defines a person as a morning-type (M-type), evening-type (E-type) or neither-type (N-type) (Adan et al., 2012).
The influences and regulatory mechanisms of magnetic fields on circadian rhythms
Published in Chronobiology International, 2022
Long-Sheng Tang, Zi-Xuan Fan, Xiao-Fei Tian, Shi-Min He, Cheng Ji, An-Qi Chen, Da-Long Ren
Natural phenomena, such as the day-night cycle and the seasonal cycle, affect almost all species on the earth. The biological clock is an endogenous mechanism of the organisms to adapt to the environment, facilitating the efficient use of energy and resources. A circadian clock refers to a process that generates the periodical change of life activities in a living system with a cycle of about 24 h, which was formed in the evolution process of the organism to better adapt to the environment. Accurate rhythm is not only determined by the periodic changes of the internal circadian proteins but also is affected by the external environments such as light and temperature (Dunlap 1999). Circadian rhythms can generally be governed by the central and peripheral clocks, which together play a fascinating “circadian rhythm symphony” (Rosenwasser and Turek 2015). The state of the circadian rhythm can be generally reflected in the body’s behavior, heart rate, immunity, endocrine and other physiological functions, as well as the rhythmic expression of clock genes. The current molecular model of the circadian clock indicates that the regulation of circadian rhythm is mainly completed by the transcription-translation feedback pathways, involving core clock genes such as Clock, Bmal, Per, Cry and so on (Figure 1). Circadian rhythms coordinate many physiological functions including the body’s circulation, nerves, immunity, endocrine and other functions involved at the level of the hormone (Che et al. 2017).