Exploration of sleep as a specific risk factor for poor cardiometabolic and mental health & the comparison of subjective and objective assessments of sleep

Ph. D. ThesisNumerous studies have attempted to evaluate the impact of sleep on cardiometabolic and mental health, although most of the population-based studies utilised self-reported sleep assessment and health status. Therefore, the main aim of this project is to explore the relationship between accelerometer measured sleep and cardiometabolic and mental health amongst the UK Biobank participants. The UK Biobank collected extensive information of the general UK population. They have also collected accelerometry data allowing the extraction of sleep duration and quality. Disease status was obtained from their primary care record. Out of the 84,411 participants with available processable accelerometry data, 17.3% slept 8 hours/night. Short sleep duration was significantly associated with the male gender, older age, high body mass index, social deprivation and ethnic minority group (p<0.001). A significant ‘U-shaped’ association was found between sleep duration and metabolic disease status. Both short and long sleep durations were also associated with negative mood and worse cognitive performances including slower reaction time and worse visual memory (p<0.001). These findings showed the importance of sleep in maintaining health. However, sleep misperception was found to be common leading to a discrepancy between subjective and objective measurements of sleep. A cross-sectional analysis was conducted on 28 human participants (11 controls and 17 patients). Sleep was assessed using a paper sleep diary, wrist-worn tri-axial accelerometer and laboratory-based polysomnography. The level of cortisol, melatonin, mitochondrial DNA damage and gene expression was measured using saliva, urine, skin swab and hair samples, respectively. An overestimation of sleep duration was observed in this study which is consistent with the UK Biobank analysis. Patients were found to have a longer sleep duration, but a lower sleep efficiency. Moreover, patients were found to have a lower level of melatonin and cortisol. A ‘U-shaped’ association was found between sleep duration and mitochondrial DNA damage level. Finally, circadian rhythm and mitochondria-related pathways have been identified in the gene expression analysis. However, these associations were not found to be statistically significant. Therefore, it is proposed that larger sample size should be considered in future studies informed in part by further power calculations based upon the findings presented in the current thesis.BBSRC and Unileve

Quantum Induced Coherence Light Detection and Ranging

Quantum illumination has been used to improve the signal-to-noise ratio in light detection and ranging (LiDAR). Relying on coincidence detection, such a quantum LiDAR has a resolution limited by the response time of the detector and suffers from jamming noise. Inspired by the Zou-Wang-Mandel experiment, we build a quantum induced coherence (QuIC) LiDAR without directly detecting the photons reflected from the object, intrinsically immune to environmental and jamming noise. The key element is that the reflected photons are used to erase the which-way information of its entangled partners, whose light path is scanned to obtain the distance of the object via single photon interference rather than coincidence detection. In QuIC LiDAR, the noise accompanying the reflected probe light from the object cannot enter our detector. This method paves a new way of battling noise in precise quantum electromagnetic sensing and ranging.Comment: 6 pages, 4 figure

Impacts of the COVID-19 Pandemic on the Bereaved: A Study of Bereaved Weibo Users

The&nbsp;global&nbsp;COVID-19&nbsp;pandemic&nbsp;may significantly affect&nbsp;the&nbsp;experiences&nbsp;of&nbsp;death and bereavement. This&nbsp;study&nbsp;aimed to learn from recent outbreaks&nbsp;ofinfectious diseases and further understand their&nbsp;impacts&nbsp;on&nbsp;bereavement. We obtained psychological status scores for 32 individuals&nbsp;bereaved&nbsp;due to&nbsp;COVID-19&nbsp;and 127 individuals&nbsp;bereaved&nbsp;due to non-COVID-19&nbsp;causes using&nbsp;the&nbsp;online ecological recognition (OER) approach. Next,&nbsp;a&nbsp;sentiment analysis and independent sample t-test were performed to examine&nbsp;the&nbsp;differences between these two groups.&nbsp;The&nbsp;results indicated that&nbsp;the&nbsp;individuals&nbsp;bereaved&nbsp;due to&nbsp;COVID-19&nbsp;were more insecure and more preoccupied with&nbsp;the&nbsp;grief&nbsp;of&nbsp;the&nbsp;moment than those&nbsp;bereaved&nbsp;due to non-COVID-19&nbsp;reasons, while&nbsp;the&nbsp;latter group had higher depression scores than&nbsp;the&nbsp;former group. This&nbsp;study&nbsp;can guide policy-makers and clinical practitioners to provide more targeted and sustainable post-bereavement support for both&nbsp;bereaved&nbsp;groups during&nbsp;the&nbsp;COVID-19&nbsp;period.</p

Objective sleep assessment in >80,000 UK mid-life adults: Associations with sociodemographic characteristics, physical activity and caffeine.

Study objectivesNormal timing and duration of sleep is vital for all physical and mental health. However, many sleep-related studies depend on self-reported sleep measurements, which have limitations. This study aims to investigate the association of physical activity and sociodemographic characteristics including age, gender, coffee intake and social status with objective sleep measurements.MethodsA cross-sectional analysis was carried out on 82995 participants within the UK Biobank cohort. Sociodemographic and lifestyle information were collected through touch-screen questionnaires in 2007-2010. Sleep and physical activity parameters were later measured objectively using wrist-worn accelerometers in 2013-2015 (participants were aged 43-79 years and wore watches for 7 days). Participants were divided into 5 groups based on their objective sleep duration per night (8 hours). Binary logistic models were adjusted for age, gender and Townsend Deprivation Index.ResultsParticipants who slept 6-7 hours/night were the most frequent (33.5%). Females had longer objective sleep duration than males. Short objective sleep duration (ConclusionsObjectively determined short sleep duration was associated with male gender, older age, low social status and high coffee intake. An inverse 'U-shaped' relationship between sleep duration and physical activity was also established. Optimal sleep duration for health in those over 60 may therefore be shorter than younger groups