Clocks & Sleep最新文献

The visual and non-visual effectiveness of light is often determined by measuring the spectrally weighed irradiance on the corneal plane. This is typically achieved using spectral irradiance or illuminance measurements, captured in a hemispheric (2π) geometry with a diffuser. However, the human binocular field of view (FOV) is not a perfect hemisphere, as it is occluded both upward and downward. Previous research on FOV-restricted measurements is limited, leaving the error from using hemispheric measurements for non-visual quantities undefined. In our study, we tackled this issue by designing and 3D printing FOV occlusions as attachments to spectral measurement devices. We took measurements with and without the occlusion in various laboratory (light from different directions) and real-world lighting situations (light typically from above). Our findings reveal a reduction of visual and melanopic values due to the FOV occlusion. These ranged from negligible to more than 60% in realistic scenarios. Interestingly, the reduction was consistent for both visual and melanopic parameters, as the distribution of light in the FOV was generally spectrally homogeneous. An exception occurred in a specific artificial laboratory situation, where the melanopic daylight (D65) efficacy ratio changed by more than a factor of 2 solely because of the FOV occlusion. Additionally, we observed that head orientation had a marked effect on all quantities measured. In conclusion, our results highlight the potential for substantial errors when solely relying on vertical, hemispheric measurements in experiments and non-visual lighting design projects. We encourage the (additional) use of FOV occlusion in eye-level measurements for typical viewing directions, and we are providing open-source 3D-print files to facilitate this practice.

The Society for Light Treatment and Biological Rhythms (SLTBR) held this year's annual meeting at the Ecole Polytechnique Fédérale (EPFL) in Lausanne, Switzerland from 30 May to 1 June in conjunction with the Day Light Academy (DLA) [...].

Objectives: We test the hypothesis that the incidence of sleep problems is influenced by socio-demographic variables, particularly social deprivation and ethnicity. Methods: Self-reports of sleep duration and sleep difficulties (waking in the night, sleeping in the day, difficulty waking and snoring), personal wealth (household income, property-owning, etc.), ethnic group, employment, education, as well as post-code-based Townsend Social Deprivation, were extracted from UK Biobank's cohort of c500,000 British-domiciled adults (40-70 years). Analyses contrasted the incidence of different sleep problems and a composite measure of these (the Problematic Sleep Index) across groups. Results: Almost one-third of participants reported sleeping shorter (24.7%), or longer (7.7%) than age-corrected recommended sleep durations. The incidence of shorter or longer sleep increased with social deprivation and varied with ethnicity. Snoring, waking during the night, finding it difficult to get up in the morning and sleeping in the daytime were subject to similar effects. The Problematic Sleep Index showed being younger, male, employed, home-owning, having a higher household income, having a higher level of educational achievement, and time in education were all associated with better sleep, as was living in a more affluent area and being White. Conclusions: Sleep problems in Britain show a social gradient, independently of a range of other demographic and social influences, suggesting that sleep quality differs with and between ethnic groups. These sleep inequalities suggest that the protective and recuperative effects of sleep are disproportionately distributed across society and should encourage us to consider the potential benefits of community-specific sleep interventions.

(1) Background: In 2013, the results of a pioneer study on abnormalities in the levels and circadian rhythmicity of expression of circadian clock genes in cancerous thyroid nodules was published. In the following years, new findings suggesting the involvement of circadian clockwork dysfunction into malignant transformation of thyroid tissue were gradually accumulating. This systematic review provides an update on existing evidence regarding the association of these genes with thyroid tumorigenesis. (2) Methods: Two bibliographic databases (Scopus and PubMed) were searched for articles from inception to 20 March 2023. The reference lists of previously published (nonsystematic) reviews were also hand-searched for additional relevant studies. (3) Results: Nine studies published between 2013 and 2022 were selected. In total, 9 of 12 tested genes were found to be either up- or downregulated. The list of such genes includes all families of core circadian clock genes that are the key components of three transcriptional-translational feedback loops of the circadian clock mechanism (BMAL1, CLOCK, NPAS2, RORα, REV-ERBα, PERs, CRYs, and DECs). (4) Conclusions: Examination of abnormalities in the levels and circadian rhythmicity of expression of circadian clock genes in thyroid tissue can help to reduce the rate of inadequate differential preoperative diagnosis for thyroid carcinoma.

Coronavirus disease (COVID-19) is a global pandemic, which is not only a severe public health issue but also significantly impacts the physical activity, sleep habits, and mental health of university students. Thus, we examined the association between behavioral restrictions due to COVID-19 and sleep patterns and mental health in first-year Japanese university students. Four hundred and twenty-two students (253 males and 169 females; age, 18.7 ± 1.0 years) participated in our questionnaire study. Under the behavioral restrictions due to COVID-19, 193 students (127 males and 66 females) responded to the questionnaire online from home. The participants did not visit the university during the survey period. The data acquired the year before the COVID-19 pandemic (2018 and 2019) were used as control data (126 males and 103 females). The questionnaire consisted of four sections: (1) demographic and lifestyle variables, (2) the Pittsburgh Sleep Quality Index, (3) the Japanese version of the Epworth Sleepiness Scale, and (4) the Patient Health Questionnaire-9. Our data revealed that self-restraint due to COVID-19 was associated with better sleep and mental health. In addition, mental health was independent of sleep, while sleep was related to mental health. These differences were more pronounced in male than in female students. This finding could be due to physical activity at night, part-time work, and long commuting times during the pre-pandemic period.

Social restriction measures (SRM) implemented during the COVID-19 pandemic led to a reduction in time spent outdoors (TSO). The aim of this study was to describe TSO and evaluate its association with sleep outcomes, optimism, happiness and health-status before and during SRM. Two online surveys were conducted in 2017 (N = 1004) and 2020, during SRM (N = 1010), in samples representative of the age, sex and region of the Austrian population. Information on the duration of TSO, sleep, optimism, happiness and health-status was collected. Multivariable-adjusted logistic regression models were used to study the association of TSO with chronic insomnia, short sleep, late chronotype, optimism, happiness and self-rated health-status. The mean TSO was 3.6 h (SD: 2.18) in 2017 and 2.6 h (SD: 1.87) during times of SRM. Men and participants who were older, married or in a partnership and lived in a rural area reported longer TSO. Participants who spent less time outdoors were more likely to report short sleep or a late chronotype in both surveys and, in 2020, also chronic insomnia. Less TSO was associated with lower happiness and optimism levels and poor health-status. Our findings suggest that TSO may be a protective factor for sleep, mood and health, particularly during stressful and uncertain times.

The main aim of this study was to explore how melatonin onset timing and phase angle to bedtime in healthy older adults are impacted by prior light exposure. A total of 13 healthy older (ages 56-74) individuals were studied on two successive evenings. Prior to the first evening, the participants were in self-selected lighting conditions for the first 4-6 h of the day and then were in dim light (3 lux) until their scheduled bedtime. On the second day, individuals from Project A remained in the dim lighting conditions throughout the entire day but those in Project B were in more typical indoor lighting (~90 lux) throughout the day. On both evenings, hourly blood samples were collected and assayed for melatonin, and melatonin onset timing and phase angle to sleep onset was determined. Overall, melatonin onset was earlier and the phase angle was larger on Night 1 than on Night 2. In Project A there was no significant difference between melatonin onset on night 1 vs. night 2. However, in Project B melatonin onset was significantly later on Night 2 (in typical indoor lighting) than on Night 1 (in dim lighting). Our results suggest that in older people, uncontrolled bright light early in the day did not impact the timing of dim light melatonin onset (DLMO) when assessed later that same evening. However, in older adults, exposure to ordinary room light during melatonin phase assessment appeared to suppress melatonin, leading to a later observed time of melatonin onset, as has been reported previously for young adults.

Micro-arousals and the repeated desaturation of oxyhemoglobin, which are typical in obstructive sleep apnea syndrome (OSAS), have adverse effects on the health of patients, leading to a wide range of complications such as cardiovascular (arterial hypertension, pulmonary hypertension, chronic heart failure, arrhythmias, myocardial infarction), cerebrovascular (strokes), metabolic (insulin resistance, obesity, diabetes mellitus, metabolic syndrome), gastrointestinal (non-alcoholic liver disease), urinary (chronic renal failure), and neuropsychiatric complications as well as a wide range of malignancies. These, in turn, have multilateral effects on familial, occupational, and social life, as well as increasing the risks of road traffic accidents and accidents at the workplace. Awareness, timely screening, and the prevention of complications play important roles in diagnosing and treating comorbid conditions. This review focuses on comorbidities in OSAS and the effect of Continuous Positive Airway Pressure (CPAP) therapy on their prognoses.

During the COVID-19 lockdown, a distortion of time passage has been widely reported in association with a change in daily rhythm. However, several variables related to these changes have not been considered. The purpose of the present study was to assess the changes in dispositional mindfulness, time experience, sleep timing and subjective memory functioning. A longitudinal study was conducted on 39 Italian adults (53.85% males; 35.03 ± 14.02 years) assessing mindfulness, ad hoc questions of sleep habits during workdays and free days, chronotypes, subjective time experience, and memory functioning before (December 2019-March 2020) and during (April 2020-May 2020) the first Italian COVID-19 lockdown. Participants reported delayed sleep timing, a slowdown in the perception of the present time, a decrease of time pressure, and an increase in the feeling of time expansion/boredom. In addition to correlations between mindfulness, memory functioning, and subjective sleep duration during workdays, a mediation model showed that changes in the dispositional mindfulness determined a delay of bedtime during workdays through the mediation effect of increased feeling of time expansion/boredom. This finding highlighted the role of mindfulness in reducing the feeling of time expansion/boredom for regulating the sleep timing. The theoretical and practical implications of the findings are discussed.

In this narrative review article, we discuss the role of sleep deprivation (SD) in memory processing in rodent models. Numerous studies have examined the effects of SD on memory, with the majority showing that sleep disorders negatively affect memory. Currently, a consensus has not been established on which damage mechanism is the most appropriate. This critical issue in the neuroscience of sleep remains largely unknown. This review article aims to elucidate the mechanisms that underlie the damaging effects of SD on memory. It also proposes a scientific solution that might explain some findings. We have chosen to summarize literature that is both representative and comprehensive, as well as innovative in its approach. We examined the effects of SD on memory, including synaptic plasticity, neuritis, oxidative stress, and neurotransmitters. Results provide valuable insights into the mechanisms by which SD impairs memory function.