The Impact of Altered Timing of Eating, Sleep and Work Patterns on Human Health

Some 20% of the population is required to work outside the regular 9:00 a.m.–5:00 p.m. working day, and this number is likely to increase as economic demands push work hours into the night for many companies. These irregular schedules mean workers often have to sleep during the day and be awake at night. This causes a misalignment between normal day-light entrained internal physiological processes, such as metabolism and digestion, and the external environment. As a direct consequence, night workers have poorer health than day workers, even after controlling for lifestyle and socioeconomic status. The purpose of this Special Issue is to highlight the interrelationships between timing of food intake and diet quality with sleep and work patterns in humans with an emphasis on randomized controlled trials or meta-analyses of data from published studies

PER3 Polymorphism Predicts Cumulative Sleep Homeostatic but Not Neurobehavioral Changes to Chronic Partial Sleep Deprivation

The variable number tandem repeat (VNTR) polymorphism 5-repeat allele of the circadian gene PERIOD3 (PER3(5/5)) has been associated with cognitive decline at a specific circadian phase in response to a night of total sleep deprivation (TSD), relative to the 4-repeat allele (PER3(4/4)). PER3(5/5) has also been related to higher sleep homeostasis, which is thought to underlie this cognitive vulnerability. To date, no study has used a candidate gene approach to investigate the response to chronic partial sleep deprivation (PSD), a condition distinct from TSD and one commonly experienced by millions of people on a daily and persistent basis. We evaluated whether the PER3 VNTR polymorphism contributed to cumulative neurobehavioral deficits and sleep homeostatic responses during PSD.PER3(5/5) (n = 14), PER3(4/5) (n = 63) and PER3(4/4) (n = 52) healthy adults (aged 22-45 y) demonstrated large, but equivalent cumulative decreases in cognitive performance and physiological alertness, and cumulative increases in sleepiness across 5 nights of sleep restricted to 4 h per night. Such effects were accompanied by increasing daily inter-subject variability in all groups. The PER3 genotypes did not differ significantly at baseline in habitual sleep, physiological sleep structure, circadian phase, physiological sleepiness, cognitive performance, or subjective sleepiness, although during PSD, PER3(5/5) subjects had slightly but reliably elevated sleep homeostatic pressure as measured physiologically by EEG slow-wave energy in non-rapid eye movement sleep compared with PER3(4/4) subjects. PER3 genotypic and allelic frequencies did not differ significantly between Caucasians and African Americans.The PER3 VNTR polymorphism was not associated with individual differences in neurobehavioral responses to PSD, although it was related to one marker of sleep homoeostatic response during PSD. The comparability of PER3 genotypes at baseline and their equivalent inter-individual vulnerability to sleep restriction indicate that PER3 does not contribute to the neurobehavioral effects of chronic sleep loss

Catechol-O-Methyltransferase Val158Met Polymorphism Associates with Individual Differences in Sleep Physiologic Responses to Chronic Sleep Loss

Val158Met polymorphism was a novel marker in healthy adults of differential vulnerability to chronic partial sleep deprivation (PSD), a condition distinct from total sleep loss and one experienced by millions on a daily and persistent basis. allelic frequencies were higher in whites than African Americans.-related treatment responses and risk factors for symptom exacerbation

Using visual methodology: Social work student's perceptions of practice and the impact on practice educators.

This is an Accepted Manuscript of an article published by Taylor & Francis in Practice: Social Work in Action on 21-6-18, available online: https://doi.org/10.1080/09503153.2018.1476477Practice learning within social work education plays a significant part in students’ educational journey. Little is understood about the emotional climate of placements. This paper presents a small scale qualitative study of 13 social work students’ perceptions of their relationship with a practice educator (PE) and 6 PE’s perceptions of these emotional experiences. Visual methodology was employed over a two-phased research project, first social work students were asked to draw an image of what they thought practice education looked like, phase two used photo eliciation, PEs were then asked to explore the meaning of these images. Results demonstrated that social work students focused on their own professional discourse, the identity of PEs, power relationship and dynamics between themselves and PEs, the disjointed journey and practice education in its entirity. Whilst the PEs shared their personal views of practice education and reflected on this, both groups had a shared understanding of practice education including its values and frustrations. Keywords: social work placements, visual methodology, practice educator

Exploring Multitasking Performance and Fatigue with the MATB-II: A Narrative Review.

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Investigation of the effectiveness of a split sleep schedule in sustaining sleep and maintaining performance

Shift work is common in today's society, and is associated with negative health outcomes, and accidents and incidents. These detrimental effects can be primarily attributed to sleeping and working at an adverse circadian time. The aim of this study was to examine whether a split sleep schedule is as effective as a consolidated day shift or night shift schedule for maintaining performance and sustaining sleep. Fifty-three healthy male volunteers (mean ± SD age = 26.51 ± 4.07 years) underwent a randomized three condition study design. A split sleep condition involving two 5-h sleeping opportunities in 24 h [time in bed (TIB) 0300 h-0800 h and 1500 h-2000 h] was compared to a 10-h consolidated nighttime sleep (TIB 2200 h-0800 h) and 10-h consolidated daytime sleep (TIB 1000 h-2000 h). All participants underwent a baseline period of 10 h of nocturnal time in bed (TIB) followed by a 5-d simulated workweek spent in one of the three conditions. Polysomnography, psychomotor vigilance task, digit-symbol substitution task and subjective state were assessed. During the 5-d simulated workweek, participants in the nighttime sleep condition slept the most (total sleep time per day (TST) 8.4 h ± 13.4 min), followed by the split sleep condition (TST 7.16 h ± 14.2 min) and the daytime sleep condition (TST 6.4 h ± 15.3 min). Subjective sleepiness was highest in the daytime sleep condition and lowest in the nighttime sleep condition. No significant differences in performance were observed between the conditions. Compared to a nighttime consolidated sleep opportunity or split sleep, placement of a consolidated sleep opportunity during the day yielded truncated sleep and increased sleepiness. Further research in real-world situations is warranted to fully assess the efficacy of alternative split sleep schedules for improving safety and productivity

Caffeine Consumption and Sleep Quality in Australian Adults

Caffeine is commonly consumed to help offset fatigue, however, it can have several negative effects on sleep quality and quantity. The aim of this study was to determine the relationship between caffeine consumption and sleep quality in adults using a newly validated caffeine food frequency questionnaire (C-FFQ). In this cross sectional study, 80 adults (M ± SD: 38.9 ± 19.3 years) attended the University of South Australia to complete a C-FFQ and the Pittsburgh Sleep Quality Index (PSQI). Caffeine consumption remained stable across age groups while the source of caffeine varied. Higher total caffeine consumption was associated with decreased time in bed, as an estimate of sleep time (r = −0.229, p = 0.041), but other PSQI variables were not. Participants who reported poor sleep (PSQI global score ≥ 5) consumed 192.1 ± 122.5 mg (M ± SD) of caffeine which was significantly more than those who reported good sleep quality (PSQI global score < 5; 125.2 ± 62.6 mg; p = 0.008). The C-FFQ was found to be a quick but detailed way to collect population based caffeine consumption data. The data suggests that shorter sleep is associated with greater caffeine consumption, and that consumption is greater in adults with reduced sleep quality

Partial and sleep-stage-selective deprivation

Occupational, family, and social pressures have led to a society that sleeps less. In 1960, a survey by the American Cancer Society found that people slept, on average, 8 h per night. This figure has dropped today to 6.7 h, a decrease of 15% in less than one generation. This fall may be due to medical conditions, sleep disorders, or medications that inhibit sleep, as well as lifestyle disrupters such as jet lag, exam stress, or parenting infants. With the change toward a 24-h society, working outside of the 9-to-5 day has also become increasingly prevalent. Shift workers commonly obtain less sleep than permanent daytime workers as daytime sleep is sacrificed to accommodate social, family, and leisure activities. Sleep deprivation causes between $43 billion and$56 billion worth of accidents annually, as well as contributing to a substantial number of injuries and deaths worldwide. Humans are biologically programmed to sleep at night, and going without sleep has a range of deleterious consequences for cognitive performance, health, and well-being. This article will first outline the methodologies used to investigate partial sleep deprivation in humans and animals and discuss the neurobehavioral, physiological, and psychosocial consequences of reduced sleep. The article will then describe the function of sleep stages, again summarizing methodologies and reviewing the findings from rapid eye movement (REM) and slow-wave sleep (SWS) selective sleep stage deprivation studies in humans and animals