Relationships between sleep efficiency and lifestyle evaluated by objective sleep assessment: SLeep Epidemiology Project at University of Tsukuba.

Objectively measured sleep efficiency has recently been shown to be associated with health problems. Although several factors have previously been reported to be associated with sleep efficiency, most of these studies were conducted on older or younger adults, and the factors associated with sleep efficiency in healthy workers remain unknown. The aim of this study was to investigate the relationship between sleep efficiency and lifestyle factors using sleep measurement data recorded by an activity meter worn by workers. In total, 693 workers (male, 43.6%; mean age, 42.7 ± 11.3 years) were recruited from five offices in 2017. Sleep was measured over the period of 1 week by actigraphy. Workers' attributes, lifestyle habits, and occupational stress were identified using a questionnaire, and the association of sleep efficiency with lifestyle, occupational stress, and attributes was explored by logistic regression analysis. A logistic regression analysis using attributes and occupational stress as adjustment variables revealed that "longer sleeping hours on weekends than on weekdays" [odds ratios (OR), 0.66; 95% confidence interval (CI), 0.47-0.94], "water ingestion at bedtime" [OR, 2.09; 95% CI, 1.28-3.41], and "smartphone use at bedtime" [OR, 1.90; 95% CI, 1.28-2.83] were associated with decreased sleep efficiency. This study found that lifestyle habits were associated with sleep efficiency among workers. It is necessary to verify whether intervention in these lifestyle habits would contribute to the improvement of sleep efficiency in future studies.

Prevalence, characteristics, and psychological outcomes of workplace cyberbullying during the COVID-19 pandemic in Japan: a cross-sectional online survey.

BACKGROUND: The rapid introduction of teleworking due to the coronavirus disease 2019 pandemic has led to concerns about increases in cyberbullying (CB) worldwide. However, little is known about workplace CB in non-Western countries. The first objective was to clarify the prevalence and characteristics regarding workplace CB victimization in Japan. The second objective was to demonstrate the psychological outcomes of CB victimization in combination with traditional bullying (TB). METHODS: We conducted an anonymous, cross-sectional, Internet-based survey targeting regular employees in Japan (N = 1200) in January 2021. We investigated CB victimization using the Inventory of Cyberbullying Acts at Work and TB victimization by using the Short Negative Act Questionnaire. Possible explanatory factors for TB/CB victimization were sociodemographic variables, personality trait, chronic occupational stress, organizational climate, and gratitude at work. We also measured psychological distress, insomnia, and loneliness to assess adverse effects of workplace bullying. Two-step cluster analysis was used in determining the patterns combined with TB and CB victimization. Hierarchical binomial logistic regression analysis was used. RESULTS: In total, 8.0% of employees reported experiencing CB on a weekly basis. CB victimization was associated with younger age, managerial position, higher qualitative workload, and active information dissemination via the Internet, and frequency of teleworking. Three clusters based on TB and CB victimization patterns were identified: those who belong to the first cluster suffered neither from TB and CB (81.0%), the second cluster suffered only from TB (14.3%), and the third cluster suffered from both TB and CB (4.8%). The third cluster exhibited higher odds ratios (ORs) and 95% confidence intervals (CIs) for psychological distress (OR = 12.63, 95% CI = 4.20-38.03), insomnia (OR = 6.26, 95% CI = 2.80-14.01), and loneliness (OR = 3.24, 95% CI = 1.74-6.04) compared to the first cluster. CONCLUSIONS: These findings firstly clarify the prevalence and correlated factors of CB victimization among employees in Japan. Further, we showed that psychological wellbeing can be impaired by the coexistence of TB and CB. Our research could be the first step to develop the effective countermeasures against workplace CB.

Ibaraki's Amabie-chan usage and its association with infection prevention behavior and fear of COVID-19: a cross-sectional preliminary survey of the Tsukuba Salutogenic Occupational Cohort Study.

BACKGROUND: Ibaraki's Amabie-chan is a COVID-19 infection control system unique to Ibaraki prefecture, Japan. It requires residents to register each time they visit events, commercial facilities, and restaurants. The number of registrations has been limited, and its function alerting about people positive for COVID-19 infection seems not to be working. Nevertheless, registration with the system might have some impact on the user's behavior. In the current preliminary survey, the possible impact of Ibaraki's Amabie-chan on infection prevention behavior and fear of COVID-19 was investigated. METHODS: A cross-sectional, web-based, anonymous, and self-administered survey was conducted at two workplaces in Tsukuba Science City, Ibaraki, Japan. The first survey was conducted at one of the workplaces in November 2020, and the second survey, at the other workplace in February 2021. Variables of interest were sex, age group, marital status, employment status, Ibaraki's Amabie-chan use, COVID-19 Contact-Confirming Application use, ten items of infection prevention behaviors, and fear of COVID-19. Hierarchical linear regression analysis was performed. RESULTS: In both surveys, use of Ibaraki's Amabie-chan was significantly associated with COCOA use and with "physical condition management such as body temperature measurement." No association was found with other infection prevention behaviors or with fear of COVID-19. CONCLUSIONS: Our findings did not provide sufficient evidence for the effectiveness of Ibaraki's Amabie-chan in regard to users' infection control behavior. Further detailed study is needed to investigate the effectiveness in terms of infection prevention and the cost-effectiveness of Ibaraki's Amabie-chan.

Morning preference is associated with subjective happiness among Japanese female workers: A moderation analysis by sleep characteristics from the SLEPT study.

Research on mental health in working populations has predominantly focussed on negative outcomes, while studies on the positive aspects of life remain very limited, especially in Japan. Although morningness has recently been considered a factor for being happy, the role of sleep characteristics as it relates to the association between morningness and happiness has not been substantiated. The aim of this study is to investigate the associations between diurnal preference and level of subjective happiness in healthy, full-time, daytime workers in Japan. We also tested the moderation effect of sleep parameters on the relationship between diurnal preference and subjective happiness. This is an exploratory analysis from the cross-sectional data of the SLeep Epidemiology Project at the University of Tsukuba (SLEPT Study). Subjective happiness was evaluated using a single-item question. Diurnal preference was assessed using the Morningness-Eveningness Questionnaire (MEQ), in which higher scores indicate greater tendency to have morning preference. The participants underwent assessment of sleep parameters for 7 consecutive days using a waist-worn actigraphy device and kept a sleep diary. Sleep parameters investigated were subjective sleep quality, sleep disturbance, daytime sleepiness, weekend oversleep, total sleep time, sleep onset time, wake time, and sleep efficiency. A total of 205 males (average 42.6 ± 10.4 years) and 272 females (41.1 ± 9.8 years) were eligible for analysis. Hierarchical liner regression analysis was used to show the relationships of subjective happiness with MEQ score, and the sleep parameters. Further, moderation analysis was conducted by adding the interaction between MEQ score and the sleep parameters. After adjusting for age, psychological distress, self-rated health, and occupational stress, we found that subjective happiness was significantly associated with higher MEQ score and sleep efficiency but only in female. The moderating role of sleep parameters was not found. We discussed the implications of the obtained results and a possible strategy to maintain and improve subjective happiness of female workers who have evening preference.

Comparison of predicted psychological distress among workers between artificial intelligence and psychiatrists: a cross-sectional study in Tsukuba Science City, Japan.

OBJECTIVES: Psychological distress is a worldwide problem and a serious problem that needs to be addressed in the field of occupational health. This study aimed to use artificial intelligence (AI) to predict psychological distress among workers using sociodemographic, lifestyle and sleep factors, not subjective information such as mood and emotion, and to examine the performance of the AI models through a comparison with psychiatrists. DESIGN: Cross-sectional study. SETTING: We conducted a survey on psychological distress and living conditions among workers. An AI model for predicting psychological distress was created and then the results were compared in terms of accuracy with predictions made by psychiatrists. PARTICIPANTS: An AI model of the neural network and six psychiatrists. PRIMARY OUTCOME: The accuracies of the AI model and psychiatrists for predicting psychological distress. METHODS: In total, data from 7251 workers were analysed to predict moderate and severe psychological distress. An AI model of the neural network was created and accuracy, sensitivity and specificity were calculated. Six psychiatrists used the same data as the AI model to predict psychological distress and conduct a comparison with the AI model. RESULTS: The accuracies of the AI model and psychiatrists for predicting moderate psychological distress were 65.2% and 64.4%, respectively, showing no significant difference. The accuracies of the AI model and psychiatrists for predicting severe psychological distress were 89.9% and 85.5%, respectively, indicating that the AI model had significantly higher accuracy. CONCLUSIONS: A machine learning model was successfully developed to screen workers with depressed mood. The explanatory variables used for the predictions did not directly ask about mood. Therefore, this newly developed model appears to be able to predict psychological distress among workers easily, regardless of their subjective views.

Differences in psychological distress between managers and non-managers in female workers: a cross-sectional study in Tsukuba Science City, Japan.

The Japanese government has made efforts towards the advancement of women into society; thereby, the proportion of female managers has been increasing. Recent reports have shown that managers tend to be in poor health condition. However, little research has been conducted to examine the psychological health of female managers. Therefore, the aim of our study was to reveal the difference of psychological distress by occupational position in female workers with focus on occupational stress. A cross-sectional survey was conducted in 2017 via an anonymous, self-administered questionnaire distributed to workers in Tsukuba City, Japan. Student unpaired t test was used to compare occupational stress and psychological distress by occupational position. Binomial logistic regressions were used to analyze factors that affect psychological distress separately in managers and non-managers. A total of 1543 women (168 managers, 1375 non-managers) were analyzed. Managers showed higher occupational stress but lower psychological distress than non-managers. Problems in interpersonal relationships was positively associated with psychological distress, whereas occupation as a researcher/academic was negatively associated with psychological distress in managers. Mental workload and problems in interpersonal relationships were positively associated with psychological distress, whereas reward from work and support were negatively associated with psychological distress in non-managers. Managers and non-managers both showed an association between psychological distress and problems of interpersonal relationships. Non-managers might have higher psychological distress due to lower reward from work. It is important to increase reward from work and to develop female workers' interpersonal skills in order to reduce the psychological distress of female workers.

Relationships between insomnia, long working hours, and long commuting time among public school teachers in Japan: a nationwide cross-sectional diary study.

OBJECTIVES: The present study aimed to clarify the prevalence and risk factors of insomnia among public school teachers in Japan by examining the relationships between working hours, commuting time, and insomnia. Time spent on work activities among teachers with insomnia was also investigated. METHODS: This study was a secondary analysis of data obtained in a 2016 survey of working conditions among public elementary/junior high school teachers in Japan. A total of 11,390 teachers (women: 47.4%, average age: 42.2 ± 11.3 years) were selected for analysis. The relationships between working hours, commuting time, and insomnia were evaluated using a binomial logistic regression model. The primary outcome was insomnia, defined by a score of ≥6 on the Athens Insomnia Scale. Explanatory factors were working hours/week, commuting time/day, six subscales of occupational stress, age group, presence of children, type of job, type of the school, and the urbanicity of the school. RESULTS: In total, 41.7% of men and 44.0% of women were classified into the insomnia group. The insomnia group spent more time preparing for lectures, and a significant association was observed between insomnia and long working hours and commuting time. Results of multivariate logistic regression analysis showed that long working hours, long commuting time, and urbanicity of the school were statistically significantly associated with insomnia. CONCLUSIONS: Insomnia is common among public school teachers in Japan. Our findings suggest the importance of reducing the time spent on working to prevent insomnia.

Medical Transport for 769 COVID-19 Patients on a Cruise Ship by Japan Disaster Medical Assistance Team.

The Diamond Princess cruise ship, carrying 3711 passengers and crew members, docked at Yokohama Port in Japan on February 3, 2020. A quarantine was immediately instituted because 1 passenger who had disembarked in Hong Kong was confirmed to have tested positive for coronavirus disease 2019 (COVID-19). After the quarantine began, all passengers and crew were tested using the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) polymerase chain reaction assay on the ship, 696 of whom tested positive. In total, 769 patients, including 696 with COVID-19, required transport to a hospital. The Japan Disaster Medical Assistance Team (DMAT) successfully picked up and safely transported the COVID-19 patients using a novel classification system to prioritize patients. The Japan DMAT transported 203 patients to hospitals in Kanagawa and another 566 patients to hospitals in 15 different prefectures.

Clinical course of 2019 novel coronavirus disease (COVID-19) in individuals present during the outbreak on the Diamond Princess cruise ship.

We investigated the clinical course of individuals with 2019 novel coronavirus disease (COVID-19) who were transferred from the Diamond Princess cruise ship to 12 local hospitals. The conditions and clinical courses of patients with pneumonia were compared with those of patients without pneumonia. Among 70 patients (median age: 67 years) analyzed, the major symptoms were fever (64.3%), cough (54.3%), and general fatigue (24.3%). Forty-three patients (61.4%) had pneumonia. Higher body temperature, heart rate, and respiratory rate as well as higher of lactate dehydrogenase (LDH), aspartate aminotransferase (AST), and C-reactive protein (CRP) levels and lower serum albumin level and lymphocyte count were associated with the presence of pneumonia. Ground-glass opacity was found in 97.7% of the patients with pneumonia. Patients were administered neuraminidase inhibitors (20%), lopinavir/ritonavir (32.9%), and ciclesonide inhalation (11.4%). Mechanical ventilation and veno-venous extracorporeal membrane oxygenation was performed on 14 (20%) and 2 (2.9%) patients, respectively; two patients died. The median duration of intubation was 12 days. The patients with COVID-19 transferred to local hospitals during the outbreak had severe conditions and needed close monitoring. The severity of COVID-19 depends on the presence of pneumonia. High serum LDH, AST and CRP levels and low serum albumin level and lymphocyte count were found to be predictors of pneumonia. It was challenging for local hospitals to admit and treat these patients during the outbreak of COVID-19. Assessment of severity was crucial to manage a large number of patients.

School Ijime (Bullying) Experience Is a Possible Risk Factor for Current Psychological Distress among Science City Workers: A Cross-Sectional Study in Tsukuba, Japan.

Early-life adversities are considered to have long-term impact on health. There have been many studies regarding the experience of being bullied and its harmful psychological influence, but such influence on workers remains to be investigated in Japan. We therefore aimed to examine the prevalence of workers with experiences of being bullied or bullying others during childhood and adolescence and to clarify the relation between those experiences and current psychological distress. A cross-sectional study using an anonymous self-report web questionnaire was conducted in November 2017. The study population was 19,481 workers belonging to the Tsukuba Science City Network, and we analyzed the data of 6,015 participants (3,715 men and 2,300 women, aged between 20 years and 59 years). The percentages of participants with experiences of being bullied were 51.5% for men and 56.2% for women; those with experiences of bullying others were 36.5% of men and 29.4% of women. Relations between experiences of bullying and psychological distress were assessed using Chi-squared tests. Logistic regression analyses with psychological distress as an objective variable and experiences of bulling as explanatory variables were performed using those who had no bulling experiences as control. In both men and women, experiences of being bullied were significantly associated with psychological distress after adjustment socioeconomic factors (the odds ratios were 1.26 for men (95% CI = 1.05-1.52) and 1.72 for women (95% CI = 1.39-2.13)). Consideration of past social experiences, such as being bullied, is useful for mental health management among workers reporting psychological distress.

Association between flourishing mental health and occupational stress among workers of Tsukuba Science City, Japan: a cross-sectional study.

BACKGROUND: Flourishing, defined as the coexistence of hedonic and eudaimonic well-being, is the most favorable end of the mental health spectrum. A growing body of evidence has demonstrated the association between flourishing mental health and favorable work-related outcomes. However, epidemiology of flourishing mental health is scarce in Japan. Moreover, the relationship between flourishing mental health and occupational stress has not been elaborated. Therefore, the aim of this study was to elucidate (1) the prevalence of flourishing mental health and (2) the association between flourishing mental health and occupational stress among Japanese workers. METHODS: The present survey was conducted in from February to March 2017 via an anonymous, self-administered, and web-based questionnaire among workers in Tsukuba Science City, Japan. Mental Health Continuum Short Form was used to assess flourishing mental health. We performed binomial logistic regression analyses to calculate the adjusted odds ratios (AOR) and 95% confidence intervals (CI) of occupational stress for flourishing mental health, controlling for sociodemographic factors. RESULTS: A total of 7012 respondents (4402 men, 2610 women) were analyzed. The overall prevalence of flourishing mental health among the respondents was 12.4%. Full-time (permanent) workers were less likely to be flourishing. Reward from work (AOR = 2.34, 95% CI = 2.04-2.68), support from colleagues and superiors (AOR = 1.67, 95% CI = 1.44-1.94), and workload (AOR = 1.19, 95% CI = 1.05-1.36) were positively associated with flourishing mental health, whereas mental workload (AOR = 0.65, 95% CI = 0.57-0.75) was inversely associated with flourishing mental health. CONCLUSIONS: The findings of the present study shed light on the association between flourishing mental health and occupational stress.

Non-Regular Employment Status Is Associated with Psychological Distress among Young Researchers: A Cross-Sectional Study in Tsukuba, Japan.

Non-regular employment is increasing and its mental health impact is a globally important problem. In Japan, non-regularly employed researchers are increasing, especially within young age groups, because employment quotas were not sufficiently expanded against rapid increasing number of doctorate holders. It is therefore important to understand the relationship between non-regular employment and mental health. The significance of our research is to contribute to the improvement of researchers' mental health by clarifying the influence of employment status on psychological distress. We conducted a cross-sectional, web-based survey in 2017 via an anonymous, self-administered questionnaire distributed to workers in Tsukuba Science City, Japan. The survey questionnaire items included employment status, psychological distress, occupational stress, sex, age, and income. We analyzed 2,762 valid responses in two categories (1,850 regular employment, 912 non-regular employment) and two subcategories based on age according to the definition of "young researcher" by the Ministry of Health, Labor and Welfare (20-39 years vs. 40-59 years). Psychological distress was defined as a total K6 score of 5 or greater. Binomial logistic regression was used to calculate odds ratios and 95% confidence intervals for psychological distress. Non-regular employment was significantly associated with psychological distress in the age 20-39 group but not in the age 40-59 group. At the age 20-39 group, a negative association was shown between psychological distress and reward from work (i.e., pride in their job, ability utilization, and sense of accomplishment). Support to increase psychological work rewards may be important in reducing psychological distress for young non-regularly employed researchers.

Relationship between workplace social capital and suicidal ideation in the past year among employees in Japan: a cross-sectional study.

BACKGROUND: A growing body of evidence has demonstrated the associations between social capital and health. In residential or geographical areas, social capital has attracted attention for its protective effects against suicide. However, to this date, the relationship between social capital and suicidal ideation is not fully elaborated in the occupational setting. Therefore, the aim of the present study was to examine the association between workplace social capital and suicidal ideation in the past year among employees in Japan. METHODS: A cross-sectional, web-based survey was conducted in February/March 2017 via an anonymous self-administered questionnaire distributed to workers in Tsukuba Science City, Japan. Binomial logistic regressions were used to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) for suicidal ideation in the past year, controlling for age group, marital status, educational attainment, and annual household income. The results were shown stratified by sex and occupation. RESULTS: In total, 7255 of 19,481 workers responded, out of which we could analyze 6325 responses (4030 men, 2295 women). The prevalence of suicidal ideation in the past year was 5.9% for men and 7.8% for women. Low workplace social capital was statistically significantly associated with suicidal ideation both for men (OR = 2.57, 95% CI = 1.72-3.83) and for women (OR = 1.75, 95% CI = 1.15-2.66), compared with high workplace social capital after controlling for socioeconomic factors. CONCLUSION: Higher workplace social capital was associated with a reduced risk of suicidal ideation in the past year. Promoting workplace social capital could contribute to preventing suicide among employees in Japan.

Specificity of Fur binding to the oxidative stress response gene promoter in the facultative anaerobic archaeon Thermoplasma volcanium.

The genome of the facultative anaerobic thermoacidophilic archaeon Thermoplasma volcanium contains the open-reading frames (ORFs) tvsod and tvogg, which are predicted to encode a putative superoxide dismutase and an 8-oxoguanine DNA glycosylase, respectively. Tvsod is immediately upstream of tvogg, and these two ORFs are aligned in a head-to-tail manner in a single operon. A previous study showed that T. volcanium contains an ORF (TVN0292) encoding the ferric uptake regulator (Fur) and that the T. volcanium Fur protein (TvFur) binds to its own promoter in a metal-dependent manner in vitro. Here, we demonstrated that TvFur also binds to the tvsod-tvogg promoter and determined the TvFur-binding sequences in the tvsod-tvogg promoter by DNaseI footprinting analysis. These results suggest that Fur is required for resistance against reactive oxygen species in this facultative anaerobic archaeon.

Transcriptional factor fur from Thermoplasma volcanium binds its own promoter DNA in a divalent cation-dependent manner.

Because archaea possess many respiratory enzymes or radical scavengers with catalytic domains that contain iron, the expression of the genes encoding these enzymes might be regulated by iron acquisition. The genome of an archaeon, Thermoplasma volcanium contains a gene that encodes Fur (TVN0292). The fur gene of T. volcanium was amplified by PCR, and cloned into plasmid pET28a. TvFur (T. volcanium Fur protein) was expressed in E. coli cells and then purified. EMSA revealed that TvFur binds to its own promoter DNA. The binding to its own promoter was in an Mn(2+)-, Zn(2+)-, and Ni(2+)-dependent manner. DNase I footprinting analysis revealed that the binding sequence of tvfur promoter was 5'-G TTATTAT G TTTATAT A TTAATTA G-3'. An analysis utilizing oligonucleotides in TvFur-binding sequences revealed that TvFur binds to the TATA-box or regions in the vicinity of the TATA-box in the promoter. These results indicated that TvFur regulates transcription depending on the availability of environmental divalent cations.

Melanin synthesis inhibitors from Lespedeza floribunda.

In the course of our search for new melanin synthesis inhibitors from plants, 40 new flavonoids and 11 known flavonoids were isolated from the roots of Lespedeza floribunda Bunge. The structures of the new compounds were determined by MS and NMR analyses, and the absolute configurations by CD spectra. Many of the compounds inhibited melanin synthesis in normal human epidermal melanocytes (NHEM), and compounds 3, 7, 8, 11, 16, 24, 27, 29, 33, 43, 45, and 51 were particularly inhibitory. Their activities were stronger than that of hydroquinone, which is known as a major skin-lightening drug.