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Autophagy has recently been shown to be required for tapetal programmed cell death (PCD) and pollen maturation in rice. A transcriptional regulatory network is also known to play a key role in the progression of tapetal PCD. However, the relationship between the gene regulatory network and autophagy in rice anther development is mostly unknown. Here, we comprehensively analyzed the effect of autophagy disruption on gene expression profile during the tapetal PCD in rice anther development using high-throughput RNA sequencing. Expression of thousands of genes, including specific transcription factors and several proteases required for tapetal degradation, fluctuated synchronously at specific stages during tapetal PCD progression in the wild-type anthers, while this fluctuation showed significant delay in the autophagy-deficient mutant Osatg7-1. Moreover, gene ontology enrichment analysis in combination with self-organizing map clustering as well as pathway analysis revealed that the expression patterns of a variety of organelle-related genes as well as genes involved in carbohydrate/lipid metabolism were affected in the Osatg7-1 mutant during pollen maturation. These results suggest that autophagy is required for proper regulation of gene expression and quality control of organelles and timely progression of tapetal PCD during rice pollen development.

Purpose: Daily variations of physical activity in the elderly remain unclear. We thus used a uniaxial accelerometer/pedometer to examine the variability of step counts for 1 yr, determining the minimum number of days observation needed to obtain reliable estimates of annual physical activity. Methods: Subjects were 37 males and 44 females, healthy Japanese, aged 65-83 yr. The pedometer was worn on the waistband throughout 1 yr, accumulating information on the individual's daily step count. Results: The step count spectrum showed peaks with periods of 2.3, 3.5, and 7.0 d and an aperiodic component that had a greater power at low frequencies (i.e., non-white noise). These characteristics were absent in randomly resequenced data. To ensure that 80% of total variance was attributable to between-subjects variance, 25 and 8 consecutive days of observation were needed in male and female subjects, respectively. To achieve 90% on this same measure of reliability, 105 and 37 consecutive days of observation were required. In contrast, 4 d of randomly timed observations yielded 80% reliability for both men and women, and 11 and 9 d gave 90% reliability in men and women, respectively. If sampling also took account of season and day of the week, the respective observation periods for men and women were reduced to 8 and 4 d (i.e., 2 and 1 consecutive days of sampling every 89 d) for 80% and to 16 and 12 d (i.e., 4 and 3 consecutive days every 89 d) for 90% reliability. Conclusion: When estimating annual step counts, seasonal and/or random sampling of data allows collection of reliable data during substantially fewer days than needed for consecutive observations. [ABSTRACT FROM AUTHOR]

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An abstract of the "Sleep is not disrupted by exercise in patients with chronic fatigue syndromes," by F. Togo and colleagues is presented.

Laboratory-based studies have shown that psychological stress caused by response to various stressors triggers acute changes in the cardiovascular system. A better understanding is needed of the emerging evidence on temporal associations between psychological stress and cardiovascular responses in natural settings. This study examined the association of psychological stress and heart rate variability (HRV) in daily life, at high resolution over 2 weeks, taking the effect of physical activity into account. Participants (n = 34) completed ecological momentary assessments (EMA) 6 times per day, reporting levels of perceived stress, low-arousal negative affect (LNA), and high-arousal negative affect. Chest-mounted heart-rate monitors were worn to assess HRV. Multilevel models were used to examine the association between psychological stress levels and preceding/subsequent HRV. Reduced time domain HRV measures (mean and standard deviation of R-wave to R-wave intervals) during the prior hour predicted higher levels of perceived stress. Frequency domain HRV measures higher low to high frequency (LF/HF) and lower HF to total power (HF nu) ratios during the preceding 10 min predicted higher perceived stress levels, suggesting the dominance of sympathetic nervous system activity. EMA reports of higher perceived stress levels were associated with reduced time domain HRV measures during the following 10 min. On the other hand, higher LNA were related to increased HRV measures, such as lower LF/HF and higher HF nu during the following hour. The dynamic associations observed may have therapeutic implications for 'just-in-time' interventions in the management of daily stress and cardiovascular health., (© 2024 The Author(s). Stress and Health published by John Wiley & Sons Ltd.)

Background: Having no or few confidants is found to be associated with more severe mental health problems and a higher prevalence of depression in adults, but research examining this association in adolescents is scarce. Social relationships may be particularly critical during adolescence, as it is an important developmental period during which vulnerability to mental health problems increases. The present study examined the relationship between having no or few confidants and anxiety/depressive symptoms in adolescents., Methods: Cross-sectional self-report survey targeting 7-12th grade students (age range: 12-18) was conducted in public junior and senior high schools in Mie and Kochi, Japan. Data from 17,829 students (49.7% boys) were analyzed. Associations between anxiety/depressive symptoms (12-item General Health Questionnaire; score range: 0-12) and the number of confidants (None, 1-3, or ≥ 4) were examined using multilevel regression analyses. The analyses were stratified by gender and school level (junior/senior high), and adjusted for experiences of being physically abused and bullied and the interactions of these experiences with the number of confidants., Results: Having no or 1-3 confidants was associated with more anxiety/depressive symptoms, compared to having ≥ 4 confidants (p < 0.001) in all stratified groups. Having no confidants was associated with more anxiety/depressive symptoms than having 1-3 confidants (p < 0.001); in senior high boys, no difference was observed between having no confidants and having 1-3 confidants. In addition, in senior high boys, victims of bullying who have confidants reported significantly less anxiety/depressive symptoms than the victims who have no confidants (p < 0.01)., Conclusions: Adolescents who had no or few confidants had more anxiety/depressive symptoms. Attention needs to be paid to better identify these adolescents, and avenues to support them need to be established., (© 2024. The Author(s).)

Research in adolescents suggests associations between psychotic-like experiences (PLEs) and self-injurious thoughts and behaviors (SITBs), but insights into their temporal relationship, which may inform prediction, have been limited. Psychological distress (PD; symptoms of depression and anxiety) has been related to both PLEs and SITBs, and may modulate this relationship. Given that PLEs have been linked to the development of several mental disorders, and the relationships between SITBs and suicide, it is important to better understand their relationship. The present study sought to investigate these factors using a longitudinal school-based design. Adolescents (n = 1685, ages 12-18) completed annual self-report assessments (6 time points) on PLEs, SITBs (suicidal ideation (SI) and self-harm (SH)), as well as PD. The longitudinal associations between PLEs and SITBs were analyzed, employing two cross-lagged panel models (CLPMs), with and without adjustment for PD. Unadjusted CLPMs revealed significant bidirectional temporal associations between PLEs and SITBs (both SI and SH), suggesting that PLEs both predicted and were predicted by SITBs. When adjusting for PD, the effect of SI on PLEs remained significant, but not PLEs on SI; bidirectional associations between PLEs and SH also remained significant. A bidirectional longitudinal relationship where both PLEs and SITBs can precede (and perhaps predict) each other was suggested in adolescents. PD may play a particular role in situations where PLEs are followed by SI. Heightened awareness about relationships between these phenotypes may be an important step toward facilitating timely interventions for both mental disorders and suicide., (© 2023. The Author(s).)

Introduction: Parents and guardians (hereafter caregivers) of teenagers need high levels of mental health literacy (MHL) to manage mental health problems arising in teenagers in their care. Previous studies assessing MHL levels in caregivers of teenagers have reported mixed results, making it difficult to clearly estimate caregiver MHL levels. This study aimed to investigate MHL levels in Japanese caregivers of regular teenagers., Methods: Responses from caregivers (n = 1,397) of students entering junior and senior high schools to a self-administered online questionnaire were analyzed. The questionnaire assessed (a) knowledge about mental health/illnesses and (b) attitudes towards mental health problems in teens in their care (e.g., recognition of depression as a medical illness and intention to engage in helping behaviors)., Results: The average proportion of correct answers to the knowledge questions (n = 7) was 55.4%; about one tenth (9.2%) of caregivers correctly answered only one or none of the questions. Few caregivers correctly answered about the life-time prevalence of any mental illnesses (46.1%) and appropriate sleep duration for teenagers' health (16.5%). The proportions of caregivers who had the intention to listen to the teen in their care, consult another person, and seek professional medical help if the teen suffered from depression were 99.5%, 91.5% and 72.7%, respectively., Conclusions: Many teenagers' caregivers appeared to be willing to help the teens in their care if they were suffering from mental health problems. However, there was much room for improvement in knowledge on mental health/illnesses and intention to seek help from medical professionals. Efforts toward better education should be made., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Kusaka, Foo, Yamaguchi, Yukawa, Arai, Sawamura, Togo and Sasaki.)

Objective: Higher BMI, lower quality of diet and a higher percentage of breakfast-skippers have been reported among rotating shift (RS) workers compared with day shift (DS) workers. As such, this study examined the association between breakfast skipping, habitual food consumption and BMI in RS workers., Design: Japanese nurses were studied using a self-administered questionnaire that assessed the height, weight, breakfast consumption habits, dietary consumption, physical activity, sleep habits, chronotype and demographic characteristics of the participants., Setting: A cross-sectional study was conducted in a population of nurses in Japan. Dietary and health-related questionnaires were mailed to 5536 nurses aged 20-59 years, working at 346 institutions., Participants: A total of 3646 nurses at 274 institutions responded to the questionnaire. After removing those who met the exclusion criteria, 2450 participants were included in the statistical analysis., Results: The RS breakfast-skippers had lower total energy intake, diet quality and higher BMI than DS workers, whereas the RS breakfast-consumers had a higher total energy intake and BMI than the DS workers. In the RS workers, breakfast skipping on the days of DS and the end days of evening/night shift was associated with a poorer diet quality. Additionally, breakfast skipping on the days of DS was positively associated with BMI, independent of the total energy intake and diet quality., Conclusions: Breakfast skipping on workdays may contribute to a difference in dietary intake and BMI between RS workers and DS workers and may increase BMI in RS workers, independent of dietary intake.

The longitudinal relationship between psychotic-like experiences (PLEs) and short habitual sleep in adolescents remains to be investigated. We examined the effect of habitual sleep length (time-in-bed: TIB) on the risk of subsequent year PLEs and vice versa, in grade 7-12 students (ages: 12-18, n = 1,685) followed over 6 years. Yearly longitudinal data were analyzed using cross-lagged panel models. Shorter weekday TIB was associated with a higher risk of subsequent year PLEs; PLEs did not affect subsequent year TIB. Compared to a TIB of 8-9 h, 5-6 h increased PLEs likelihood 1.8 times; <5 h increased this 6-fold., Competing Interests: Declaration of Competing Interest None., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Study Objectives: Despite considering it as a common geriatric condition, sarcopenia is linked to various behavioral factors that may be changeable. As sleep is one of the important routines in physiological homeostasis, further investigating the underlying relationships of sleep behavior with sarcopenia is urgently needed. We examined the association between sleep parameters (ie, sleep duration, bedtime, wake time, or midsleep time) and sarcopenia risks in older adults, in the total sample and age group subsamples., Methods: A total of 1,068 older adults in Taiwan were included. Data on bedtime, wake time, and sleep duration were collected through telephone interview. Midsleep time was calculated by the midpoint of bedtime and wake time. Sarcopenia was screened by the SARC-F questionnaire composed of 5 questions (the strength, assistance in walking, rising from a chair, climbing stairs, and falls) as well as higher scores was related to greater risks. Generalized additive models were conducted to examine the nonlinear relationships between sleep parameters and sarcopenia risks., Results: The covariate-adjusted analysis showed that a reverse J-shaped relationship for sleep duration and sarcopenia risk ( P < .001) and a significant association for wake time and the SARC-F score ( P  = .009) in total sample, with considering age-related interaction. No associations were found in the other sleep parameters (bedtime and midsleep time) and sarcopenia in older adults. Similar associations were observed between wake time and the SARC-F score across age groups, while diverse associations of sleep duration with the SARC-F score were found in different age groups., Conclusions: The sleep pattern is significantly associated with sarcopenia risks in aging adults. Improving inappropriate sleep behaviors in older adults is suggested to prevent a decline in muscle function and promote healthy aging., Citation: Huang W-C, Lin C-Y, Togo F, et al. Nonlinear associations between sleep patterns and sarcopenia risks in older adults. J Clin Sleep Med . 2022;18(3):731-738., (© 2022 American Academy of Sleep Medicine.)

Psychological stress (PS) in daily life can trigger acute changes in cardiovascular function and may lead to increased risk of cardiovascular problems. Prior laboratory-based studies provide little evidence on temporal changes in the associations between PS and cardiovascular responses in natural settings. We hypothesized that daily PS would be associated with higher heart rate (HR) and lower heart rate variability (HRV). Using smartphones, ten participants (four females, 21.1±1.1 years) completed ecological momentary assessment (EMA) 6 times a day for two weeks regarding their current affective state. Participants rated levels of PS, as well as 3 high-arousal negative affect (HNA: Anxious, Annoyed, and Upset), and 3 low-arousal negative affect (LNA: Sluggish, Bored, and Sad) states. They also wore a chest-mounted heart-rate monitor and a wrist accelerometer to monitor cardiovascular response and physical activity, respectively. HR and HRV variables in the time intervals (5, 30, 60 min) before and after EMA were used as indicators of cardiovascular response. Multilevel modeling was used to examine the association between affect and HR/HRV, controlling for physical activity. Higher HR and lower HRV were related to subsequent greater feelings of stress at the 5 and 30-min time intervals. No significant associations were observed between cardiovascular parameters and subsequent affective states, suggesting that the acute exaggerated cardiovascular responses occurred due to PS. Higher LNA was related to antecedent/subsequent lower HR or higher HRV within 2 hours, while HNA was unrelated to HR or HRV for all time intervals, suggesting that both high/low arousal NA were not related to exaggerated cardiovascular response. Understanding psychological feelings of stress and LNA may be helpful in the management of daily cardiovascular health.

Background: School teachers are well-positioned to recognize mental health problems in their students and to help them seek appropriate help. Therefore, teachers need to have high levels of mental health literacy (MHL). In East Asia, however, few studies have examined MHL levels in teachers. In this study, MHL levels were investigated in Japanese teachers., Methods: Teachers (n = 665) from 27 Japanese high schools answered a self-administered questionnaire which assessed (a) knowledge about mental health/illnesses, (b) correct recognition of specific illnesses (depression, schizophrenia and panic disorder), (c) confidence in helping students with depressive symptoms, and (d) confidence in teaching mental health knowledge to students., Results: The average proportion of correct answers to the knowledge questions (n = 20) was 58.1%. The proportion of those who correctly answered about the presence of a sharp increase of mental illnesses in adolescence was 51.7%. Few teachers correctly answered about the life-time prevalences of major mental illness in general (21.9%), depression (37.8%) and schizophrenia (19.8%). Depression, schizophrenia and panic disorder in vignette were correctly recognized by 54.1, 35.3 and 78.0% of teachers, respectively. Correct recognition was significantly lower in male than in female teachers. Only a small proportion of teachers had confidence in helping depressed students (19.9%) and in teaching mental health knowledge to students (11.1%)., Conclusions: MHL in Japanese high school teachers appears to be low. Education programs should be developed and implemented to improve teacher MHL with the aim of helping them to support students suffering from mental health problems., (© 2021. The Author(s).)

This study aimed to investigate the associations between objectively measured sleep timing and habitual dietary intake among university students. We hypothesized that a later chronotype and larger social jetlag (SJL) are associated with an undesirable dietary intake. The 82 healthy university students included in this study were asked to undertake a seven-day wrist activity recording. All the participants also completed a self-administered questionnaire during the recording period, including questions on demographic characteristics and habitual dietary intakes. Dietary intake and the score for adherence to the Japanese Food Guide Spinning Top (food guide score) over the previous month were evaluated using a self-reported diet history questionnaire. Nocturnal sleep timing and total sleep time for each night were estimated using the recorded wrist activity. Chronotype was calculated as weekend (WE) mid-sleep time corrected for catch-up sleep on weekdays (WDs). SJL was calculated by subtracting WD mid-sleep time from WE mid-sleep time. Multivariable linear regression showed that a later chronotype was significantly (P < .05) associated with a lower consumption of eggs, greater consumption of grains, and lower food guide score. Multivariable linear regression also showed significant (P < .05) associations of a larger value in SJL with a lower total energy intake, lower consumption of grains, and greater consumption of sugar and confectioneries. The results suggest that chronotype and SJL may be differently associated with undesirable dietary intake in young adults. These findings have important implications for developing novel strategies, focusing on sleep timing, for improving dietary intakes and preventing lifestyle-related diseases., Competing Interests: Author Declarations None of the authors have any conflict of interest relating to this study, (Copyright © 2021. Published by Elsevier Inc.)

Study Objectives: The aim of this research was to investigate the relationships between objectively measured sleep duration and physical function in older adults., Methods: We recruited community-dwelling older adults aged ≥ 60 years old in Taipei City, Taiwan. Sleep duration was measured with accelerometers and recorded as the total hours of sleep per night for each participant. The following physical functions were assessed: 1) grip strength (measured by handgrip dynamometer), 2) balance (1-leg standing test), 3) lower body strength (5-timed chair stand), 4) basic mobility (timed up and go test), 5) gait speed (5-m walk test). The relationships between sleep duration and physical function outcomes were analyzed using generalized additive models, controlling for objectively measured sedentary behavior and moderate-to-vigorous physical activity, and other sociodemographic variables., Results: A total of 121 older adults (men = 28.9%; mean age = 70.0 ± 5.0 years) was included in this study. A positive association of sleep duration with grip strength was found after adjusting for covariates (P = .005). No significant associations were observed between sleep duration and the other physical function outcomes., Conclusions: For older adults, lengthening their sleep duration may be helpful to enhance the grip strength. This result has implications for improving their health by targeting better performance in specific physical functions. Further studies of sleep duration and physical function among older adults should investigate the underlying mechanisms., (© 2021 American Academy of Sleep Medicine.)

Introduction: School-based education is a potentially effective approach for improving mental health literacy (MHL) in adolescents. This study evaluated the effects of the "Short MHL Program (SMHLP)", a brief (50 min), school teacher-led program, on MHL in adolescents in a quasi-cluster randomized controlled trial., Methods: A total of 975 high school first graders (age 15-16) in Japan were allocated to classes such that gender and academic achievement ratios were almost equivalent at the time of admission to the high school. They were assigned at the class level to the SMHLP (n = 364 from 10 classes) or a control group (n = 611 from 17 classes). The program consisted of a 50-minute session and was delivered by a school teacher. The students completed a self-report questionnaire at 3 time points: pre-, (immediately) post- and 2-month follow-up. Outcomes included "Knowledge about mental health/illnesses", "Recognition of the necessity to seek help", "Intention to seek help", and "Intention of helping peers". Mixed effects modeling was employed for analyses., Results: Scores of all outcomes were significantly improved in the intervention group compared to the control group post-intervention (p < .001). These improvements were maintained at 2-months follow-up for all outcomes (p < .001-.05). Questionnaire scores did not differ between groups at baseline., Conclusions: The effect of the SMHLP was confirmed in grade 10 students. Brief, yet effective programs can be a viable option to promote understanding of mental health problems and have the potential to be incorporated into regular school curriculum. "., Competing Interests: Declarations of competing interest None., (Copyright © 2020. Published by Elsevier Ltd.)

This study aims to investigate independent associations of habitual sleep durations and sleep timings on weekdays and weekends with depressive symptoms in adolescents who have classes in the morning. We studied grade 7-9 students (942 males and 940 females, aged 12-15 years), who had classes in the morning, at public junior high schools in Japan in a cross-sectional design. The students answered a self-report questionnaire, which covers habitual sleep durations, bedtimes and wake-up times on weekdays and weekends, and depressive symptoms. The Short Mood and Feelings Questionnaire (SMFQ) was used to determine the level of depressive symptoms. The relationship between the variables on sleep habits and the SMFQ score were studied using multivariate linear regression and generalized additive models (GAM), controlling for sex, age and school. Multivariate linear regression analysis revealed that sleep duration on weekdays and relative mid-sleep time on weekdays (i.e. mid-sleep time on weekdays - mid-sleep time on weekends) were independently significantly ( p < .001) associated with the SMFQ score. GAM analysis also revealed that sleep duration on weekdays (a reverse J-shaped relationship) and the relative mid-sleep time on weekdays (a negative monotonic/linear relationship) were independently significantly ( p < .001) associated with the SMFQ score. These associations were confirmed in both males and females when they were analyzed separately. These results suggest that sleep duration on weekdays and the relative mid-sleep time on weekdays may be independently associated with the level of depressive symptoms in junior high school students who have classes in the morning. These findings may have important implications for the development of novel strategies for preventing mental health problems in adolescents.

Aim: The prevalence of mental disorders increases sharply during adolescence. Therefore, school teachers are in a good position to provide initial assistance to students with mental health problems. Although effects of a number of mental health literacy programs aimed at teachers have been reported, they have not yet been reviewed in a systematic manner. This study conducted a systematic review of the effectiveness of mental health literacy programs for teachers., Methods: PubMed, PsycINFO, CINAHL, ERIC, Web of Science and reference lists of included studies were searched in September 2018. Studies that quantitatively measured at least one of the main components of mental health literacy, including (a) knowledge of mental illnesses, (b) stigma towards mental illnesses, (c) confidence in helping students, and (d) behaviour of helping students, were included regardless of study design. Risk of bias was rated for each included study according to the Cochrane tool for randomized studies and the Cochrane tool, for raondomized studies, and the Risk of Bias Assessment Tool for Nonrandomized Studies (RoBANS), for nonrandomized studies., Results: Sixteen studies met the inclusion criteria, including 1 randomized controlled trial (RCT), 2 cluster RCTs, 1 controlled before-and-after study and 12 case series. Most of the studies claimed significant improvement of knowledge, attitudes, behaviour and/or confidence. However, the overall quality for all outcomes was relatively low; 15 studies had high/unclear risk of bias due to lack of allocation concealment, not controlling for confounders, and/or inadequate analysis for attrition., Conclusions: More high quality evidence is required before the effectiveness of mental health literacy programs for teachers can be established., (© 2019 John Wiley & Sons Australia, Ltd.)

Weight status and self-weight perception are related to social relationship issues. Studies have suggested links between non-normal weight status or weight perception and youths having fewer confidants, but these relationships are unclear and remain to be studied. This preliminary cross-sectional study examined the effects of weight status and weight perception on the number of confidants in adolescents. Self-report data from 15,279 grade 7-12 students (54.2% boys) were analyzed. The number of confidants (0-3 or ≥ 4) was examined, according to five weight status categories (underweight, low-normal weight, mid-normal weight (reference), high-normal weight, overweight, with Body Mass Index corresponding to ≤ 18.5, ≤ 20.0, ≤ 22.5, ≤ 25.0 and > 25.0 in adults, respectively), and five weight perception categories (too thin, a bit thin, good (reference), a bit fat, too fat). Boys and girls who were overweight and those who perceived themselves to be too fat were significantly more likely to have few confidants. High-normal weight in girls and self-perception of being a bit fat in boys were also associated with having few confidants. In boys, underweight and self-perception of being too thin were additionally associated with having few confidants. Adolescents with non-normal weight status or weight perception may have fewer confidants and require more social support., Competing Interests: The authors have declared that no competing interests exist.

Aim: A concise teacher-led program for mental health literacy (MHL), suitable for schools with tight schedules was developed, and its effects were examined in pre-teens., Methods: Participants comprised 662 grade 5 to 6 students from nine Japanese elementary schools. The program consisted of a 45-minute session, delivered by school teachers using a 10-minute animated film. Program focuses included: mental health problems are common, can be associated with lifestyle and that seeking help from reliable adults is a key to finding solutions. Participants filled out self-report questionnaires before, immediately after and 3 months post-intervention. Changes in MHL were analyzed using multilevel models., Results: Knowledge about mental health/illnesses, recognition of mental health state and intention to help peers/seek help when suffering from mental health problems, were significantly improved immediately and 3 months post-intervention., Conclusions: Concise teacher-led programs administered in schools can have positive and lasting effects on MHL in pre-teens., (© 2018 John Wiley & Sons Australia, Ltd.)

Although effects of sleep duration and physical activity (PA) have been demonstrated on mental health in adolescents, their interactive effect has not been studied. This cross-sectional study first examines this interactive effect on anxiety/depression in adolescents. A total of 983 Japanese students aged 12-17 were studied, using a self-report questionnaire. The interaction of sleep duration and amount of PA and their main effects on anxiety/depression, assessed using the 12-item General Health Questionnaire (GHQ-12), were investigated employing multiple regression, adjusting for grade and sex. Sleep duration and amount of PA were classified as being adequate or not, according to the duration and amount recommended by the National Sleep Foundation and World Health Organization, respectively. As a result, the interaction between sleep duration and amount of PA and their main effects were statistically significant. GHQ-12 score was significantly better in adolescents with either adequate sleep or adequate PA, not both, than those with neither adequate sleep nor adequate PA. The score, however, seemed no further improved in those with both adequate sleep and PA. The present study suggests that effects of sleep and PA on mental health need to be studied with consideration to their interaction., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Objective: One of the highly characteristic features of sleep is the cyclic occurrence of non-rapid eye movement (NREM) and REM sleep, which is referred to as the ultradian rhythm of sleep. Even though REM sleep was discovered over half a century ago, surprisingly, the mechanism of the ultradian REM sleep rhythm has not yet been fully elucidated. In the present study, we aim to provide a mechanistic insight into the generation of the ultradian REM sleep rhythm. Approach and Main results: By simulating hypnograms with the dynamic features of sleep stage transitions, i.e. stage transition probabilities and stage-specific survival time functions, we show that the second-order Markov transition probabilities and the stage-specific survival time functions can reproduce the central position (∼90 min) of the REM-onset intervals (ROIs), but with a larger variance in distribution. In addition, we demonstrate the direct effect of the increased probability of the transitions from light to deep sleep within NREM sleep on the prolongation of the ROIs in a dose-response manner., Significance: These results suggest that dynamic sleep stage transitions constitute the basis of the formation of the ultradian rhythm of sleep; however, further elaboration of the model would be required to reduce the variability in rhythmicity.

There is growing interest in within-person associations of objectively measured physical and physiological variables with psychological states in daily life. Here we provide a practical guide with SAS code of multilevel modeling for analyzing physical activity data obtained by accelerometer and self-report data from intensive and repeated measures using ecological momentary assessments (EMA). We review previous applications of EMA in research and clinical settings and the analytical tools that are useful for EMA research. We exemplify the analyses of EMA data with cases on physical activity data and affect and discuss the future challenges in the field.