scholarly journals Optimization of light exposure and sleep schedule for circadian rhythm entrainment

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0251478
Author(s):  
Jiawei Yin ◽  
A. Agung Julius ◽  
John T. Wen
Keyword(s):  
Circadian Rhythm ◽  
Light Intensity ◽  
Process Model ◽  
Light Exposure ◽  
Shift Workers ◽  
Wide Range ◽  
Gradient Descent Algorithm ◽  
Time Optimal ◽  
Sleep Schedule ◽  
Light Input

The circadian rhythm, called Process C, regulates a wide range of biological processes in humans including sleep, metabolism, body temperature, and hormone secretion. Light is the dominant synchronizer of the circadian rhythm—it has been used to regulate the circadian phase to cope with jet-lag, shift work, and sleep disorder. The homeostatic oscillation of the sleep drive is called Process S. Process C and Process S together determine the sleep-wake cycle in what is known as the two-process model. This paper addresses the regulation of both Process C and Process S by scheduling light exposure and sleep based on numerical simulations of circadian rhythm and sleep mathematical models. This is a significant step beyond the existing literature that only considers the entrainment of Process C. Regulation of the two-process model poses several unique features and challenges: 1. Process S is non-smooth, i.e., the homeostatic dynamics are different in the sleep and wake regimes; 2. Light only indirectly affects Process S through Process C; 3. Light does not affect Process C during sleep. We consider two scenarios: optimizing light intensity as the control input with spontaneous (i.e., unscheduled) sleep/wake times and jointly optimizing the light intensity and the sleep/wake times, which allows limited delayed sleep and early waking as part of the decision variables. We solve the time-optimal entrainment problem for the two-process model for both scenarios using an extension of the gradient descent algorithm to non-smooth systems. To illustrate the efficacy of our time-optimal entrainment strategies, we consider two common use cases: transmeridian travelers and shift workers. For transmeridian travelers, joint optimization of the two-process model avoids the unrealistic long wake duration when only Process C is considered. The entrainment time also decreases when both the light input and the sleep schedule are optimized compared to when only the light input is optimized. For shift workers, we show that the entrainment time is significantly shortened by optimizing the night shift working light.

scholarly journals Medications for Sleep Schedule Adjustments in Athletes

2017 ◽  
Vol 10 (1) ◽  
pp. 35-39 ◽  
Author(s):  
Matthew B. Baird ◽  
Irfan M. Asif
Keyword(s):  
Circadian Rhythm ◽  
Clinical Review ◽  
Sports Medicine ◽  
Sports Performance ◽  
Level Of Evidence ◽  
Shift Workers ◽  
Sleep Schedule ◽  
And Performance ◽  
Pharmacologic Agents ◽  
Level 2

Context: Sleep schedule adjustments are common requirements of modern-day athletes. Many nonpharmacologic and pharmacologic strategies exist to facilitate circadian rhythm shifts to maximize alertness and performance during competition. This review summarizes the evidence for commonly used pharmacologic agents and presents recommendations for the sports medicine provider. Evidence Acquisition: MEDLINE searches were performed using the following keywords: sleep aids, circadian rhythm adjustment, athletes and sleep, caffeine and sports, melatonin and athletes, and sleep aids and sports. Pertinent articles were extracted and discussed. Study Design: Clinical review. Level of Evidence: Level 2. Results: There are very few available studies investigating pharmacologic sleep aids in athletes. Data from studies involving shift workers and airline personnel are more abundant and were used to formulate recommendations and conclusions. Conclusion: Melatonin, caffeine, and nonbenzodiazepine sleep aids have a role in facilitating sleep schedule changes in athletes and maximizing sports performance through sleep enhancement.

scholarly journals Energy Balance and Control of Body Weight: Possible Effects of Meal Timing and Circadian Rhythm Dysregulation

Nutrients ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 3276
Author(s):  
Alessio Basolo ◽  
Susanna Bechi Genzano ◽  
Paolo Piaggi ◽  
Jonathan Krakoff ◽  
Ferruccio Santini
Keyword(s):  
Circadian Rhythm ◽  
Energy Balance ◽  
Energy Demand ◽  
Light Exposure ◽  
Caloric Intake ◽  
Actual Behavior ◽  
Adequate Food ◽  
Meal Timing ◽  
Wide Range ◽  
Main Components

Conservation of the energy equilibrium can be considered a dynamic process and variations of one component (energy intake or energy expenditure) cause biological and/or behavioral compensatory changes in the other part of the system. The interplay between energy demand and caloric intake appears designed to guarantee an adequate food supply in variable life contexts. The circadian rhythm plays a major role in systemic homeostasis by acting as “timekeeper” of the human body, under the control of central and peripheral clocks that regulate many physiological functions such as sleep, hunger and body temperature. Clock-associated biological processes anticipate the daily demands imposed by the environment, being synchronized under ideal physiologic conditions. Factors that interfere with the expected demand, including daily distribution of macronutrients, physical activity and light exposure, may disrupt the physiologic harmony between predicted and actual behavior. Such a desynchronization may favor the development of a wide range of disease-related processes, including obesity and its comorbidities. Evidence has been provided that the main components of 24-h EE may be affected by disruption of the circadian rhythm. The sleep pattern, meal timing and meal composition could mediate these effects. An increased understanding of the crosstalk between disruption of the circadian rhythm and energy balance may shed light on the pathophysiologic mechanisms underlying weight gain, which may eventually lead to design effective strategies to fight the obesity pandemic.

scholarly journals PSB27: A thylakoid protein enabling Arabidopsis to adapt to changing light intensity

2015 ◽  
Vol 112 (5) ◽  
pp. 1613-1618 ◽  
Author(s):  
Xin Hou ◽  
Aigen Fu ◽  
Veder J. Garcia ◽  
Bob B. Buchanan ◽  
Sheng Luan
Keyword(s):  
Photosystem Ii ◽  
Light Intensity ◽  
Light Adaptation ◽  
Light Exposure ◽  
Starch Accumulation ◽  
State Transitions ◽  
Potential Candidate ◽  
Subsequent Work ◽  
Variable Intensity ◽  
Changing Light

In earlier studies we have identified FKBP20-2 and CYP38 as soluble proteins of the chloroplast thylakoid lumen that are required for the formation of photosystem II supercomplexes (PSII SCs). Subsequent work has identified another potential candidate functional in SC formation (PSB27). We have followed up on this possibility and isolated mutants defective in the PSB27 gene. In addition to lack of PSII SCs, mutant plants were severely stunted when cultivated with light of variable intensity. The stunted growth was associated with lower PSII efficiency and defective starch accumulation. In response to high light exposure, the mutant plants also displayed enhanced ROS production, leading to decreased biosynthesis of anthocyanin. Unexpectedly, we detected a second defect in the mutant, namely in CP26, an antenna protein known to be required for the formation of PSII SCs that has been linked to state transitions. Lack of PSII SCs was found to be independent of PSB27, but was due to a mutation in the previously described cp26 gene that we found had no effect on light adaptation. The present results suggest that PSII SCs, despite being required for state transitions, are not associated with acclimation to changing light intensity. Our results are consistent with the conclusion that PSB27 plays an essential role in enabling plants to adapt to fluctuating light intensity through a mechanism distinct from photosystem II supercomplexes and state transitions.

Application of melatonin for prevention and treatment of circadian rhythm disorders

2021 ◽  
Vol 19 (2) ◽  
pp. 34-38
Author(s):  
A. S. SAMOYLOV ◽  
◽  
N. V. RYLOVA ◽  
A. V. ZHOLINSKIY ◽  
I. V. BOLSHAKOV ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Side Effects ◽  
Light Exposure ◽  
The Body ◽  
Optimal Dosage ◽  
Vital Activity ◽  
Time Zone ◽  
Prevention And Treatment ◽  
Time Of Administration ◽  
Circadian Rhythm Disorders

The article presents data from the Russian and foreign literature of the properties of melatonin, its role in the vital activity of the body and the regulation of circadian rhythms. The features of using the drug in desynchronosis, the optimal dosage and time of administration, as well as the possibility of its use in combination with non-pharmacological treatment methods are discussed. These methods include dosed light exposure and exercise. Additionally, new studies are considered, indicating the beneficial effect of melatonin and its agonists on the immune, cardiovascular, endocrine and nervous systems. Based on the collected data, it is asserted that melatonin can significantly accelerate the process of adaptation to a new time zone without the development of side effects. Therefore, this drug is the most effective and safe treatment for desynchronosis. It is also important to note that the study of the multifaceted effects of melatonin on body functions opens up great prospects in the treatment of many diseases.

scholarly journals Excessive mechanical strain accelerates intervertebral disc degeneration by disrupting intrinsic circadian rhythm

2021 ◽  
Author(s):  
Sheng-Long Ding ◽  
Tai-Wei Zhang ◽  
Qi-Chen Zhang ◽  
Wang Ding ◽  
Ze-Fang Li ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Intervertebral Disc ◽  
Mechanical Loading ◽  
Disc Degeneration ◽  
Intervertebral Disc Degeneration ◽  
Night Shift ◽  
Mechanical Strain ◽  
Inhibitory Effect ◽  
Shift Workers ◽  
Normal Environment

AbstractNight shift workers with disordered rhythmic mechanical loading are more prone to intervertebral disc degeneration (IDD). Our results showed that circadian rhythm (CR) was dampened in degenerated and aged NP cells. Long-term environmental CR disruption promoted IDD in rats. Excessive mechanical strain disrupted the CR and inhibited the expression of core clock proteins. The inhibitory effect of mechanical loading on the expression of extracellular matrix genes could be reversed by BMAL1 overexpression in NP cells. The Rho/ROCK pathway was demonstrated to mediate the effect of mechanical stimulation on CR. Prolonged mechanical loading for 12 months affected intrinsic CR genes and induced IDD in a model of upright posture in a normal environment. Unexpectedly, mechanical loading further accelerated the IDD in an Light-Dark (LD) cycle-disrupted environment. These results indicated that intrinsic CR disruption might be a mechanism involved in overloading-induced IDD and a potential drug target for night shift workers.

scholarly journals Business Process Models in the Context of Predictive Process Monitoring

2021 ◽  
Vol 28 (1) ◽  
pp. 39-46
Author(s):  
Florian Spree
Keyword(s):  
Process Monitoring ◽  
Business Process ◽  
Process Model ◽  
Academic Research ◽  
Research Area ◽  
Process Models ◽  
Business Process Model ◽  
Business Process Models ◽  
Wide Range ◽  
Predictive Process

Predictive process monitoring is a subject of growing interest in academic research. As a result, an increased number of papers on this topic have been published. Due to the high complexity in this research area a wide range of different experimental setups and methods have been applied which makes it very difficult to reliably compare research results. This paper's objective is to investigate how business process models and their characteristics are used during experimental setups and how they can contribute to academic research. First, a literature review is conducted to analyze and discuss the awareness of business process models in experimental setups. Secondly, the paper discusses identified research problems and proposes the concept of a web-based business process model metric suite and the idea of ranked metrics. Through a metric suite researchers and practitioners can automatically evaluate business process model characteristics in their future work. Further, a contextualization of metrics by introducing a ranking of characteristics can potentially indicate how the outcome of experimental setups will be. Hence, the paper's work demonstrates the importance of business process models and their characteristics in the context of predictive process monitoring and proposes the concept of a tool approach and ranking to reliably evaluate business process models characteristics.

In vitro studies on the induction of sporogenous tissue on leaves of cinnamon fern. I. Environmental factors

1972 ◽  
Vol 50 (12) ◽  
pp. 2673-2682 ◽  
Author(s):  
William H. Harvey ◽  
James D. Caponetti
Keyword(s):  
Environmental Factors ◽  
Light Intensity ◽  
Environmental Conditions ◽  
Light Exposure ◽  
Progressive Increase ◽  
Light Phase ◽  
Sporogenous Tissue ◽  
Light Darkness

Intact, set III, cinnamon fern cataphyll and frond primordia, which were shown to have no predisposition to fertility in situ, produced sporangia when excised and cultured under sterile conditions in Knudson's medium supplemented with various levels of sucrose and maintained on 11 different regimens of light, darkness, and temperature for 10 weeks. Increasing levels of sucrose resulted in increased fertility under all environmental conditions, but the highest percentage of fertility was obtained under conditions of continuous dark at 26 °C. As the length of the light phase of the photoperiods decreased, a progressive increase in induction of fertile leaves was observed, suggesting that periods of long light exposure are inhibitory to the initiation of sporangia. Conversely, as the light intensity was increased, an inhibition of sporophyll differentiation occurred. Sporangia excised from dark-induced sporophylls and cultured in the light produced viable spores which germinated yielding haploid gametophytes that ultimately produced sporophytes.

Abstract P160: Non-invasive Method to Assess Human Circadian Rhythms

Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Daian Chen ◽  
S Justin Thomas ◽  
David A Calhoun ◽  
David M Pollock ◽  
Jennifer S Pollock
Keyword(s):  
Circadian Rhythm ◽  
Circadian Rhythms ◽  
Salivary Cortisol ◽  
Metabolic Diseases ◽  
Clock Genes ◽  
Light Exposure ◽  
Rna Isolation ◽  
Buccal Cells ◽  
Non Invasive ◽  
Salivary Melatonin

Circadian rhythms are controlled by an endogenous time-keeping system oscillating approximately on a 24-h cycle under constant conditions. These rhythms depend on a network of interacting genes and proteins, including transcriptional activators such as CLOCK, NPAS2, and ARNTL (BMAL1), which induce transcription of the clock genes Period ( Per1 , Per2 , and Per3 ) and Cryptochrome ( Cry1 and Cry2 ). Human salivary cortisol and melatonin follow a clear circadian rhythm as well. Disruption of the circadian rhythm and sleep-wake cycles are considered risk factors for a variety of health problems, especially hypertension and other cardiovascular and metabolic diseases. Here we put together practical methods for assessing circadian rhythms in adult subjects conducted by each individual. This method is non-invasive, inexpensive and provides a predictive profile of an individual’s circadian rhythm related to clock-controlled gene expression in buccal cells, salivary cortisol, salivary melatonin, and subject’s activity or sleep. Subjects are instructed on how to obtain buccal cells using swabs (Whatman OmniSwab) from the inside of their cheeks and collect saliva using salivettes (Sarstedt) every 4 hours starting at 6am, for 2 consecutive days. Subjects also wear actigraphy watches (Phillips Respironics) during the 2 days, to record their activity, light exposure and estimates of sleep times. To monitor adherence to correct time point collections, each subject is given an electronic vial called eCAP (Information Mediary Corp) that records the exact time the container is opened to place samples once collected. We demonstrate feasibility to extract up to 150ng/μl of RNA (Ambion RNAqueous-Micro Total RNA Isolation Kit) from buccal cells swabs. Salivary melatonin and cortisol are measured by radioimmunoassay (Buhlmann Lab) with melatonin peak levels ranging from 14 to 23 pg/ml and cortisol peak levels ranging from 10 to 24 ng/ml. We suggest that buccal cell expression of clock-controlled genes, salivary melatonin, salivary cortisol, and actigraphy data are valuable in providing reliable assessment of human circadian rhythm profiles under a variety of conditions.

P–372 Maternal circadian disruption is associated with impaired rhythmic expression of molecular clock genes and IUGR during placenta development in mice

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
N I Bektas ◽  
G Akcay ◽  
N Derin ◽  
D Adiguzel ◽  
C Celik-Ozenci
Keyword(s):  
Circadian Rhythm ◽  
Locomotor Activity ◽  
Molecular Clock ◽  
Clock Genes ◽  
Weight Ratio ◽  
Circadian Disruption ◽  
Control Group ◽  
Shift Workers ◽  
Rhythmic Expression ◽  
Registration Number

Abstract Study question Are molecular clock genes (MCGs) expressed rhythmically in mouse placenta, and whether maternal circadian rhythm disruption (MCRD) is associated with intrauterine growth retardation (IUGR) through disturbing rhythmic expression of MCGs? Summary answer Maternal circadian disruption causes impaired rhythmic expression of MCGs (Bmal1, Clock, Npas2, Per1, Per2, Per3, Cry1, and Cry2) and IUGR during placenta development in mice. What is known already The world economy is based on a 24/7 society and shift work or jet travel across time zones disrupts circadian rhythm in pregnant women. Evidence indicates that gestational chrono-disruption results in IUGR. Mature mouse and human placenta express MCGs. There is no information in the literature on whether the MCG expression in the placenta is rhythmic or not and whether the rhythmic expression of MCGs is impaired due to MCRD during pregnancy. Also, it is not known whether the association with MCRD and IUGR is related to MCGs. Study design, size, duration Young adult female BALB/c mice were paired with males until vaginal plug formation was verified. Females were randomly assigned to two groups: control and phase-advance. Controls remained on a constant 12-hr light:12-hr dark cycle, whereas phase-advanced mice were subjected to 6-hr advances in the LD cycle every 5 days. Placentae (n = 1329) and fetuses were obtained from 144 mice at Zeitgeber time (ZT)0, ZT6, ZT12, and ZT18 days 12, 14, and 16 of pregnancy. Participants/materials, setting, methods The following analysis was performed: (i) open field test was used for locomotor activity evaluations to confirm MCRD, (ii) placenta/fetus weight ratio for evaluation of IUGR development, (iii) morphometric evaluation of placental compartments utilizing H&E staining (iv) gene expression analysis of MCGs utilizing qRT-PCR. One-way and Two-way ANOVA test followed by Holm-Sidak posthoc test was used for multiple comparisons. Values are expressed as mean ± standard error, and values below p < 0.05 were considered statistically significant. Main results and the role of chance Expression of MCGs (Bmal1, Clock, Npas2, Per1, Per2, Per3, Cry1, and Cry2) was rhythmic in the early and mature placenta development stages (days 12, 14, 16). Locomotor activity tests reveal that the total distance covered on the 16th day of pregnancy significantly decreased compared to the control group (p = 0.000158). The ratio of the time spent in the outer/inner quadrant, an anxiety indicator, significantly increased in the MCRD group on the 14th (p = 0.0351) and 16th days of pregnancy (p = 0.000329). While the number of fetuses was similar in both groups for all gestational days (p = 0.896), in the MCRD group, the fetus/placenta weight ratio decreased significantly on the 12th and 16th days of pregnancy (p < 0.001). Thus, IUGR developed due to MCRD. Histomorphometry analysis of the placental compartments revealed a significant reduction in the spongiotrophoblast layer’s size on all days of pregnancy and the labyrinth layer on day 16 (p < 0.05). Finally, the rhythmic expression MCGs were impaired in placentas obtained from MCRD groups on days 12th, 14th, 6th of pregnancy (p < 0.001). In conclusion, we found a robust relationship with the disturbed MCGs expression and occurrence of IUGR during a chrono-disrupted gestation. Limitations, reasons for caution Since this study was conducted in mice, care should be taken when translating the results to humans. Wider implications of the findings: Our results in mice are important for initiating basic science knowledge regarding the outcomes of maternal chrono-disruption. Moreover, research in the placenta of gestational chrono-disrupted mothers, such as shift-workers, are urgently needed to translate our findings into the clinic. Trial registration number TUBITAK–119S121 and Akdeniz University Research Projects Unit TYL–2018–3960

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