Summary
The purpose of this study was to investigate if and how sleep physiology is affected by naturally occurring high work stress and identify individual differences in the response of sleep to ...stress. Probable upcoming stress levels were estimated through weekly web questionnaire ratings. Based on the modified FIRST‐scale (Ford insomnia response to stress) participants were grouped into high (n = 9) or low (n = 19) sensitivity to stress related sleep disturbances (Drake et al., 2004). Sleep was recorded in 28 teachers with polysomnography, sleep diaries and actigraphs during one high stress and one low stress condition in the participants home. EEG showed a decrease in sleep efficiency during the high stress condition. Significant interactions between group and condition were seen for REM sleep, arousals and stage transitions. The sensitive group had an increase in arousals and stage transitions during the high stress condition and a decrease in REM, whereas the opposite was seen in the resilient group. Diary ratings during the high stress condition showed higher bedtime stress and lower ratings on the awakening index (insufficient sleep and difficulties awakening). Ratings also showed lower cognitive function and preoccupation with work thoughts in the evening. KSS ratings of sleepiness increased during stress for the sensitive group. Saliva samples of cortisol showed no effect of stress. It was concluded that moderate daily stress is associated with a moderate negative effect on sleep sleep efficiency and fragmentation. A slightly stronger effect was seen in the sensitive group.
Despite the common notion that stress impairs sleep there is little published data showing that sleep (polysomnography (PSG)) is impaired across several sleep episodes in individuals who complain of ...daily stress during the same period. The present paper aimed at investigating such a connection. 33 subjects had 3 sleeps recorded with PSG at home across 6 weeks and kept a sleep/wake diary each day, including 3-hourly ratings of stress (scale 1–9). The stress ratings and the conventional PSG parameters were averaged across time. A stepwise multiple regression analysis showed that the best predictors of stress were Stage 1 sleep (beta = 0.49), latency to Stage 1 sleep (0.47) (adjusted for anxiety and age). Other sleep continuity variables had significant correlations with stress (reversed) but did not enter the multiple regression analysis. The correlation between stress before the start of the study and PSG data was not significant. It was concluded that moderately increased stress over a longer period of time is related to moderate signs of disturbed sleep during that period. This may be of importance when considering stress as a work environment problem.
As a means of psychological distancing, pretend play may facilitate emotion regulation. Up to now, however, the empirical evidence for a relation between these two is not consistent. The present ...study examines the impact of pretend play on reflective emotion regulation of expression with a disappointing gift task using the strategy of role-taking. Fifty-two children aged 3 to 6 years were motivated to deceive the experimenter volitionally by false smiling, regardless of whether they received an attractive gift, an unattractive gift, or no gift. Twenty-five of the children accomplished the task in the context of a pretend play where they were playfully guided to take on a role assumed to facilitate reflective emotion regulation of expression. The other 27 children received only a direct verbal instruction. As an indication of successful reflective emotion regulation of expression, twelve adult naïve observers judged children's videotaped behavior according to the quality of emotion that the children seemed to experience. This impression analysis showed no impact of experimental variation and thus no facilitating effect of pretend play with a given task-convenient role. While happiness ratings in the pretend play group did not correlate to children's quality of play, they positively correlated to children's joy of playing.
This study explores the prevalence of attributed causes of disturbed sleep and the association between stress‐disturbed sleep and age, sex, and sleep duration on weekdays as well as weekends in a ...representative sample. A nationally representative sample (n = 1,128, response rate 72.8%), stratified for sex and age, completed a computer‐assisted phone survey that included questions about sleep disturbances and attributed causes. Stress was the main attributed cause of sleep disturbance (35.1%), most frequently attributed by younger women (χ2 = 26.5, p < 0.001). Prevalence of stress‐disturbed sleep was higher with lower age (B = −0.05, odds ratio (OR) = 0.94, CI = 0.91, 0.98). There was a trend, however, toward a significant interaction between age and sex, with women in the older age‐groups more frequently reporting stress‐disturbed sleep than older men (B = −0.02, OR = 1.022, CI = 1.003, 1.042). Weekday sleep duration decreased with increased stress‐disturbed sleep, with an inverse relationship on weekends except for those reporting stress‐disturbed sleep more than 5 days per week (F = 10.5, p < 0.001), who also had the shortest weekend sleep duration. Sleep disturbances were commonly attributed to stress, and more strongly so in women younger than 46 years. Stress‐disturbed sleep during weekdays seems to be potentially compensated for with extended sleep on weekends, except for those with continuous stress‐disturbed sleep.
Abstract Background/objectives The connection between stress and sleep is well established in cross-sectional questionnaire studies and in a few prospective studies. Here, the intention was to study ...the link between stress and sleep on a day-to-day basis across 42 days. Methods Fifty participants kept a sleep/wake diary across 42 days and responded to daily questions on sleep and stress. The results were analyzed with a mixed model approach using stress during the prior day to predict morning ratings of sleep quality. Results The results showed that bedtime stress and worries were the main predictors of sleep quality, but that, also, late awakening, short prior sleep, high quality of prior sleep, and good health the prior day predicted higher sleep quality. Conclusions Stress during the day predicts subsequent sleep quality on a day-to-day basis across 42 days. The observed range of variation in stress/worries was modest, which is why it is suggested that the present data underestimates the impact of stress on subsequent sleep quality.
The connection between stress and sleep is well established in cross-sectional questionnaire studies and in a few prospective studies. Here, the intention was to study the link between stress and ...sleep on a day-to-day basis across 42days.
Fifty participants kept a sleep/wake diary across 42days and responded to daily questions on sleep and stress. The results were analyzed with a mixed model approach using stress during the prior day to predict morning ratings of sleep quality.
The results showed that bedtime stress and worries were the main predictors of sleep quality, but that, also, late awakening, short prior sleep, high quality of prior sleep, and good health the prior day predicted higher sleep quality.
Stress during the day predicts subsequent sleep quality on a day-to-day basis across 42 days. The observed range of variation in stress/worries was modest, which is why it is suggested that the present data underestimates the impact of stress on subsequent sleep quality.
Stress and sleep problems are increasingly common in society with consequences not only for individual health, but also high societal costs. The focus of this thesis is how sleep is affected by ...day-to-day variation in naturally occurring stress, the impact of individual vulnerability to stress-related sleep disturbances and the causes people attribute their disturbed sleep to. This was investigated through polysomnographically (PSG) recorded sleep in home-settings during periods of different levels of work stress, sleep diaries over extended periods and a population-based survey on prevalence and association of stress and disturbed sleep.The results suggest that moderate intensity, short-term stress has a limited negative impact on sleep, in terms of a decreased sleep efficiency and self-rated non-restorative sleep. However, the response was stronger in individuals with a pre-existing trait of vulnerability to stress induced sleep disturbances, resulting in a more fragmented sleep and decreased duration of rapid eye movement (REM) sleep. Although the day-to-day variation in sleep quality appeared to be quite sensitive to small variations in stress level, a key factor seemed to be the presence of stressful thoughts and worries at bedtime.The weekend appeared to serve as a possibility to compensate the sleep impairment of the workweek, as sleep duration was extended and the amount of slow wave sleep (SWS) increased. In chronically stressed individuals in the general population however, sleep duration was not compensated, instead a reduction was seen for both weekdays and weekend, suggesting an impaired recovery ability related to a high frequency of stress.The general population, particularly the women and persons in the younger age-groups, most commonly attributed their sleep problems to stress. The highest prevalence of stress was seen in the 35-44 age group, while the peak for prevalence of stress disturbed sleep occurred a little later, in the age 45-54 years.It was concluded that the most common attribution of poor sleep is stress, and that everyday stress had a negative effect on polysomnography, but at a rather modest level, although the effect was larger on those reporting a pre-existing sleep sensitivity to stress.
Thank god it's Friday – sleep improved Petersen, Helena; Kecklund, Göran; D'Onofrio, Paolo ...
Journal of sleep research,
October 2017, Volume:
26, Issue:
5
Journal Article
Peer reviewed
Open access
Summary
The weekend is usually seen as a window of recovery. Thus, sleep before a day off may be less impaired than that before a workday. However, very few polysomnographical studies have ...investigated this hypothesis. Therefore, the aim of the present study was to compare sleep before a workday with that before a weekend. Seventeen teachers participated. Sleep was recorded with polysomnography on one weekday night during the workweek, and on a workday (Friday) followed by a day off. Sleep diaries and actigraphs were also used. Weekend sleep showed delayed bedtime and time of rising, a longer total sleep time (45 min), increased N3 and N1, and decreased N2 and REM. Sleep spindles were reduced. The results remained after truncation to the shortest common sleep duration (5 h). The increase in N3 from weekday sleep to Friday night sleep was positively correlated with N1 change (r = 0.853, P ≤ 0.001), and negatively correlated with N2 change (r = −0.614, P ≤ 0.001). Subjective ratings showed that weekend sleep was associated with less awakening problems and lower subjective arousal during the day. The authors concluded that weekend sleep was longer, and showed increased N3 and N1. The authors suggest that the N3 increase before the day off is a result of lower stress, while the N1 increase may be an effect of sleep spindle suppression via the increase of N3 (which would suppress sleep spindles), thus reducing N2 and enhancing N1.
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Previous issue date: 2017-03-27
The supercritical extraction emerged at the last decades as a green;
technology and as an alternative process to produce natural products and food. The;
process of supercritical extraction, using CO2 as a solvent, has been extensively;
studied, but there are fewer works about scale-up. Therefore, this work proposes to;
study the industrial supercritical fluid extraction of caffeine from yerba mate to;
produce decaffeinated yerba mate, an innovative product in the market, and caffeine,;
a product that has equal or even more value in the market than the main product.;
Design basis of this work are the experimental results of supercritical extraction in;
pilot scale and the appliance of a scale-up method based on the maintenance of the;
solvent mass flow and the raw-material mass flow proportion. Thus, process data;
sheet of main equipment were generated: extraction vessel, heat exchanger and high;
pressure pump. The maximum daily caffeine extraction capacity was estimated at;
two tons and the solvent mass flow rate of 22 t/h was obtained from the equation;
residence time of the solvent, maintaining constant the porosity of the 0.79 bed;
obtained in scale pilot. In addition, a process flow diagram was proposed for an;
industrial scale plant supercritical extraction of caffeine from yerba mate.
A extra??o supercr?tica emergiu nas ?ltimas d?cadas como uma tecnologia;
verde promissora e uma alternativa para o processamento de alimentos e produtos;
naturais. O processo de extra??o supercr?tica, utilizando CO2 como solvente, vem;
sendo extensivamente estudado, mas poucos ainda s?o os trabalhos que visam o;
escalonamento do processo. Logo, este trabalho prop?e estudar o processo;
industrial de extra??o supercr?tica de cafe?na a partir da erva-mate, que tem como;
meta produzir erva-mate descafe?nada, produto inovador no mercado, e cafe?na, um;
subproduto t?o ou mais valorizado que o produto principal. A base de c?lculo s?o os;
experimentos realizados em escala piloto e a utiliza??o de m?todo de aumento de;
escala que prop?e a manuten??o de propor??o de massa de solvente e massa de;
mat?ria-prima. Sendo assim, foram geradas folhas de dados de processo para os;
principais equipamentos: vaso extrator, trocadores de calor e bomba de alta press?o.;
A capacidade di?ria m?xima de extra??o de cafe?na foi prevista em duas toneladas e;
a vaz?o m?ssica de solvente de 22 toneladas/hora foi obtida a partir do;
equacionamento de tempo de resid?ncia do solvente, mantendo constante a;
porosidade do leito de 0,79 obtida em escala piloto. Al?m disto, foi proposto um;
fluxograma para uma planta em escala industrial de extra??o supercr?tica da cafe?na;
a partir da erva mate.
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