Sleep deficiency in spaceflight is associated with degraded neurobehavioral functions and elevated stress in astronauts on six-month missions aboard the International Space Station

Astronauts are required to maintain optimal neurobehavioral functioning despite chronic exposure to the stressors and challenges of spaceflight. Sleep of adequate quality and duration is fundamental to neurobehavioral functioning, however astronauts commonly experience short sleep durations in spaceflight (<6 h). As humans embark on long-duration space exploration missions, there is an outstanding need to identify the consequences of sleep deficiency in spaceflight on neurobehavioral functions. Therefore, we conducted a longitudinal study that examined the sleep-wake behaviors, neurobehavioral functions, and ratings of stress and workload of N=24 astronauts before, during, and after 6-month missions aboard the International Space Station (ISS). The computerized, Reaction SelfTest (RST), gathered astronaut report of sleep-wake behaviors, stress, workload, and somatic behavioral states; the RST also objectively assessed vigilant attention (i.e., Psychomotor Vigilance Test-Brief). Data collection began 180 days before launch, continued every 4 days in-flight aboard the ISS, and up to 90 days post-landing, which produced N=2,856 RSTs. Consistent with previous ISS studies, astronauts reported sleeping ~6.5 h in-flight. The adverse consequences of short sleep were observed across neurobehavioral functions, where sleep durations <6 h were associated with significant reductions in psychomotor response speed, elevated stress, and higher workload. Sleep durations <5 h were associated with elevated negative somatic behavioral states. Furthermore, longer sleep durations had beneficial effects on astronaut neurobehavioral functions. Taken together, our findings highlight the importance of sleep for the maintenance of neurobehavioral functioning and as with humans on Earth, astronauts would likely benefit from interventions that promote sleep duration and quality.

Recumbency as an Equine Welfare Indicator in Geriatric Horses and Horses with Chronic Orthopaedic Disease

Recumbency is a prerequisite for horses achieving rapid eye movement (REM) sleep and completing a full sleep cycle. An inability to lie down due to environmental insecurities or pain results in REM sleep deficiency, which can cause substantial impairment of welfare and health. Therefore, the present study used wearable automated sensor technology on 83 horses housed in an animal sanctuary to measure and compare the recumbency, locomotion, and standing time budgets of geriatric horses with and without chronic lameness to younger adult sound and lame horses. Recumbency times ranged from 0 to 319 min per day with an overall mean of 67.4 (±61.9) minutes; the time budget for locomotion was 19.1% (±11.2% s.d.) and for standing 75.6% (±13.1 s.d.). Interestingly, neither age nor lameness due to chronic orthopedic disease had a significant influence on recumbency times in this study. Eight horses showed symptoms of REM deficit. These horses had significantly shorter lying times (7.99 ± 11.4 min) and smaller locomotion time budgets than the other horses enrolled in this study (73.8 ± 61.8 min), indicating a general compromise of well-being. Thus, wearable sensor technology can be used to identify horses with low recumbency times at risk for REM sleep deficiency and to assess and monitor equine welfare objectively.

The Risk Related to the Influence of Sleep Deprivation on the Reliability of Human on the Example of Pilot

The purpose of this publication is to discuss the issues related to the operator sleep deficiency, its effects and the resulting risk. The issue is discussed on the example of a pilot, as a position in which the probability of occurrence of the phenomenon is high, with consequences of its occurrence that can be very severe. Despite the fact, the authors try to present the issues in a universal way enabling reference to a wide spectrum of different types of operators. In the article, concepts such as risk and fatigue are characterized. Furthermore, short and long-term fatigue are discussed, as well as the impact of shift work on human health and reliability. The second part presents methods of fatigue monitoring useful in aviation. The summary emphasizes the need for a holistic approach to the issue of crew fatigue in the management and the need for actions before commencing with work.

A review of treatment plans for the biological clock of astronauts: A systematic review

Since the start of civilization and even further back, humankind has been dreaming of flying. Recently, this dream has come true and reached beyond that and sends astronauts to outer space. However, by achieving this milestone, we encountered new problems that were new to humanity. One of the biggest problems is having a sleeping disorder and disruption of the biological clock. It is essential because having a sleep disorder makes astronauts unable to function at 100% capacity, and in outer space, it is dangerous. Some treatments for sleep disorders include drug therapy, such as Dexedrine, temazepam, modafinil, bupropion, melatonin, zolpidem, dextroamphetamine, light treatment, or a trickling sleep/wake schedule, according to NASA's guidelines. This study aimed to review the treatments for sleep disorders and disruption of the biological clock aimed at astronauts during space flights. We presented the different treatments and discussed and oriented the next prospect of research on sleep in space. Therefore, there will be guidelines for astronauts during their flights. Since the beginning of space travel, there have been many papers regarding space and weightlessness on the adverse effects on health. Studies have described the effect of space travel and the environment of microgravity on health. A few studies include both the short- and long-term effects of microgravity on the biological clock. With this new dawn and sending new astronauts to International Space Station (ISS) with NASA and SpaceX commercial Falcon 9 rocket, which opened a new horizon for spaceflights, it is even more important to consider the adverse effects microgravity on health. Purpose: This review aims to specifically analyze the biological clock, sleep deficiency, and circadian disorders. As we acknowledge, there is a sleep deficiency associated with complex microgravity environs and space missions before and after launch. Material and methods: Two researchers searched a thorough and detailed search of the PubMed database with the keywords mentioned below. The search was performed in November 2020 without any time limitations. We only included human studies and articles in the English language. Results: A total of 148 articles were found, and after going through titles, 77 articles were chosen for checking abstracts. Finally, only 12 manuscripts were accepted for data extraction. Conclusion: It is essential for health care involved in space travel providers to help pre-emptively identify problems that may prevent severe consequences during a microgravity environment. Sleep and circadian factors are the fundamental issues of human fatigue, and aviation schedules significantly impact both. We should admire a computerized fatigue model for having a better approach to studying the impact of scheduling.

Supervision of a self-driving vehicle unmasks latent sleepiness relative to manually controlled driving

Human error has been implicated as a causal factor in a large proportion of road accidents. Automated driving systems purport to mitigate this risk, but self-driving systems that allow a driver to entirely disengage from the driving task also require the driver to monitor the environment and take control when necessary. Given that sleep loss impairs monitoring performance and there is a high prevalence of sleep deficiency in modern society, we hypothesized that supervising a self-driving vehicle would unmask latent sleepiness compared to manually controlled driving among individuals following their typical sleep schedules. We found that participants felt sleepier, had more involuntary transitions to sleep, had slower reaction times and more attentional failures, and showed substantial modifications in brain synchronization during and following an autonomous drive compared to a manually controlled drive. Our findings suggest that the introduction of partial self-driving capabilities in vehicles has the potential to paradoxically increase accident risk.

A Smart Health (sHealth) Centric Method Toward Estimation of Sleep Deficiency Severity from Wearable Sensor Data Fusion

Sleep deficiency impacts the quality of life and may have serious health consequences in the long run. Questionnaire-based subjective assessment of sleep deficiency has many limitations. On the other hand, objective assessment of sleep deficiency is challenging. In this study, we propose a polysomnography-based mathematical model for computing baseline sleep deficiency severity score and then investigated the estimation of sleep deficiency severity using features available only from wearable sensor data including heart rate variability and single-channel electroen-cephalography for a dataset of 500 subjects. We used Monte-Carlo Feature Selection (MCFS) and inter-dependency discovery for selecting the best features and removing multi-collinearity. For developing the Regression model we investigated both the frequentist and the Bayesian ap-proaches. An Artificial Neural Network achieved the best performance of RMSE = 5.47 and an R-squared value of 0.67 for sleep deficiency severity estimation. The developed method is com-parable to conventional methods of Functional Outcome of Sleep Questionnaire and Epworth Sleepiness Scale for assessing the impact of sleep apnea on sleep deficiency. Moreover, the results pave the way for reliable and interpretable sleep deficiency severity estimation using a wearable device in Smart Health.

Modeling the Influence of Chronic Sleep Restriction on Cortisol Circadian Rhythms, with Implications for Metabolic Disorders

Chronic sleep deficiency is prevalent in modern society and is associated with increased risk of metabolic and other diseases. While the mechanisms by which chronic sleep deficiency induces pathophysiological changes are yet to be elucidated, the hypothalamic–pituitary–adrenal (HPA) axis may be an important mediator of these effects. Cortisol, the primary hormone of the HPA axis, exhibits robust circadian rhythmicity and is moderately influenced by sleep and wake states and other physiology. Several studies have explored the effects of acute or chronic sleep deficiency (i.e., usually from self-selected chronic sleep restriction, CSR) on the HPA axis. Quantifying long-term changes in the circadian rhythm of cortisol under CSR in controlled conditions is inadequately studied due to practical limitations. We use a semi-mechanistic mathematical model of the HPA axis and the sleep/wake cycle to explore the influence of CSR on cortisol circadian rhythmicity. In qualitative agreement with experimental findings, model simulations predict that CSR results in physiologically relevant disruptions in the phase and amplitude of the cortisol rhythm. The mathematical model presented in this work provides a mechanistic framework to further explore how CSR might lead to HPA axis disruption and subsequent development of chronic metabolic complications.

Nutrition Habits of Polish Nurses: An Approach

Background: Chronic stress, unlimited working time and the shift working system as well as sleep deficiency may lead to the occurrence of nutrition disorders among nurses. Aim: The aim of the paper was an assessment of the nutrition habits of nurses. It was an observational study conducted from June 2017 to May 2018 among nurses (n = 1080) in Silesia in Poland. Data was obtained using a range of questionnaires. Results: Body mass index (BMI) of the analysed nurses demonstrated overweight/obesity in 490 (45.5%) of them. Nearly all the diets of the analysed nurses (n = 1021; 94.5%) required improvement. Younger nurses (<31 years old) demonstrated a greater tendency to indulge in habitual overeating, and those having additional employment demonstrated poorer nutrition habits compared to those without additional employment. Conclusion: The analysed nurses made numerous dietary mistakes which, as a consequence, can lead to obesity. Emotional overeating was the dominant nutrition habit in the studied group of nurses. Nurses who were overweight/obese, nurses who had additional employment and younger nurses demonstrated tendencies toward improper nutrition choices, i.e., the tendency to overeat or restrain oneself from eating.

587 Temporal Daily Relationships Between Sleep Deficiency and Pain in Youth with Systemic Lupus Erythematosus

Introduction Systemic Lupus Erythematosus (SLE) is a chronic, inflammatory autoimmune disorder characterized by recurrent episodes of pain and is more prevalent in youth of color. Although sleep deficiency (poor quality and an inadequate amount of sleep) and pain are interrelated, most of what is known about SLE pain and sleep rely on reports from adults. Less is known about these associations in youth with SLE, leaving a critical gap in care for this population. This study aims to describe the temporal daily relationships between sleep deficiency and pain in 11-to 18-year-old youth with SLE. Methods Twenty-three youth (n=21 girls, n=9 Hispanic) with SLE (mean age=14.7 □ 2.2) participated in the study. Youth wore actigraphy and completed electronic sleep diaries for consecutive 10 days. Actigraphic sleep variables (Total Sleep Time [TST], Sleep Efficiency [SE]) and self-reported Sleep Quality (diary SQ) were examined as predictors of next-day pain in the morning. Average daytime pain was examined as a predictor of nighttime sleep (both actigraphic and self-reported sleep variables). Pubertal stage and ethnicity (Hispanic vs. Non-Hispanic) were entered as covariates in all models. Results Of the sample, the mean TST was 7 □ 1.2 hours and the mean SE was 73.5 □ 9.2% as measured by actigraphy. On average, diary SQ negatively predicted next-day pain in the morning (p &lt;.001). On average, pain negatively predicted TST (p &lt;.05) and diary SQ (p &lt;.001). The within-subject relationships between sleep and next-day pain were not significant. Daytime pain predicted neither actigraphic nor self-reported sleep quality. Conclusion Poor sleep is a modifiable behavior, and improving sleep quality may reduce pain intensity in youth with SLE. Although further study is needed, the findings suggest that sleep is a potential target for interventions to alleviate symptoms of pain in this population. Support (if any) This work was funded by NIH/NINR P30NR016585 (MPI: MMH, TMW), R21NR017471 (TMW); University of Washington, School of Nursing, Research and Intramural Funding (RIFP); Hester McLaws Nursing Scholarship.