Using wet-bulb globe temperature meters to examine the effect of heat on various tennis court surfaces.

In this study, we evaluated the thermal environments of different tennis courts using wet-bulb globe temperature (WBGT) meters. WBGT meters were installed in an outdoor hard court, sand-filled artificial grass court, and clay court (a softball field), and measurements were taken hourly from 9:00 to 17:00 on weekdays from June 1 to September 21, 2022. The results were compared with data from different courts and the nearest Japan Meteorological Agency station (JMA WBGT) based on the Japan Sports Association's guidelines for exercise to prevent heat stroke. The median WBGT on each court was significantly higher for hard courts at the "Warning" (25 ≤ JMA WBGT < 28) level or above, sand-filled artificial grass courts at the "Severe Warning" (28 ≤ JMA WBGT < 31) level or above, and clay courts at the "Danger" (31 ≤ JMA WBGT) level than the JMA WBGT. Compared with the JMA WBGT, hard and sand-filled artificial grass courts are played on under particularly hot conditions. The results of this study could indicate to tournament organizers and coaches the importance of measuring the WBGT on each court surface from an early stage to prevent heat-related incidents.

Effects of continuous supplementation of Acanthopanax senticosus Harms on the cardiac autonomic function of community-dwelling elderly individuals during resting and standing tests: a randomized controlled trial.

Background: Cardiac autonomic function (CAF) decreases with aging, and Acanthopanax senticosus Harms (ASH) consumption reportedly induces anti-stress effects. This study aimed to assess the effect of continuous supplementation of ASH on CAF during resting and standing tests in the elderly population. Methods: This double-blind, randomized controlled trial was conducted in the morning in a laboratory setting and was carried out between June 2017 and July 2017 at Kambaikan, Doshisha University (Karasuma-higashi-iru, Imadegawa-dori, Kamigyo-ku, Kyoto 602-8580, Japan). In total, 28 community-dwelling elderly individuals (mean ± standard deviation = 72.5 ± 4.5 years) were included. Each subject was instructed to consume ASH or placebo supplements twice daily for 4 weeks. An autonomic reflex orthostatic tolerance recorder was used to measure CAF in pre- and post-intervention phases. Parameters were measured in a seated position and included coefficient of variation of R-R intervals (CVRR), low frequency (LF), high frequency (HF), LF/HF ratio, blood pressure, and heart rate (HR). Changes in each parameter were evaluated before and after standing. All parameters were defined as the difference between the mean value obtained in a standing position for 2 min and that obtained in a 2-min seated position. Results: A two-way analysis of variance revealed a significant group-time interaction effect on CVRR, HF, and ΔLF/HF ratio. Following the intervention, CVRR, HF, LF/HF ratio, systolic blood pressure (SBP), HR, ΔLF/HF ratio, ΔSBP, and ΔHR improved significantly in the ASH group only. Conclusions: Four-week supplementation of ASH improved CAF in community-dwelling elderly individuals during resting and standing tests. Clinical Trial Registration: https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000031218, UMIN Clinical Trials Registry (UMIN000027251).

Age-wise examination of the association of obesity based on body mass index and waist circumference with metabolic diseases in comprehensive health checkup participants.

Aim: Body mass index and waist circumference are used for obesity diagnosis and screening of visceral fat; however, their evidence in older adults is insufficient. This study investigated the age-specific association of body mass index and waist circumference with metabolic diseases, assessing their applicability as diagnostic criteria for individuals aged ≥65 years. Methods: Analysis included 46,324 individuals aged ≥18 years, categorized into five age groups: 18-44, 45-54, 55-64, 65-74, and ≥75 years. Logistic regression analyses identified associations between obesity and metabolic diseases, stratified by age and sex. Results: Men with obesity based on body mass index had a significantly high risk of hypertension, diabetes mellitus, and dyslipidemia across all age groups (all, p < 0.05). Obesity based on waist circumference was significantly positively associated with all metabolic diseases (all, p < 0.05). Women with obesity based on body mass index and waist circumference had a significantly high risk of all metabolic diseases across all age groups (all, p < 0.05), except for diabetes mellitus in individuals aged ≥75 years. Conclusions: Participants with obesity based on body mass index and waist circumference exhibited a high risk of hypertension, diabetes mellitus, and dyslipidemia among those aged 18-74 years and men aged ≥75 years. This study contributes to the early prevention and control of metabolic diseases.

A body shape index is useful for BMI-independently identifying Japanese patients with obesity at high risk of cardiovascular disease.

BACKGROUND AND AIM: Obesity with multiple metabolic syndrome (MetS) components and/or with skeletal muscle loss is at high risk of cardiovascular disease (CVD). This study aimed to clarify the utility of anthropometric indices for identifying patients with overweight/obese at high risk of CVD based on having multiple MetS components and skeletal muscle loss. METHODS & RESULTS: This cross-sectional study included 188 overweight/obese (BMI ≥25 kg/m2, Japanese patients; 73 men and 115 women, mean age 55.7 years). First, we performed correlation analysis among seven anthropometric indices, body mass index (BMI), percentage body fat, waist circumference (WC), waist-to-hip ratio (WHpR), waist-to-height ratio (WHtR), a body shape index (ABSI), and body roundness index (BRI). Unlike the others, only ABSI was not correlated with BMI. Then, we conducted receiver operating characteristic analysis to assess the predictive abilities of anthropometric indices for having multiple MetS components. WC, WHpR, WHtR, BRI, and ABSI had significant predictive abilities for having multiple MetS components. Furthermore, multiple regression analysis showed that only ABSI had significantly negative associations with all sarcopenia-evaluated indices (skeletal muscle mass index [SMI], handgrip strength [HGS], and muscle quality [MQ]), irrespective of sex and age. Finally, an analysis of covariance showed that the high ABSI group had significantly lower SMI and HGS than the low ABSI group, irrespective of sex and age. CONCLUSION: ABSI was deemed useful for BMI-independently identifying Japanese patients with overweight/obese at high risk of CVD based on having multiple MetS components and skeletal muscle loss. Clinical trials (the unique trial number and the name of the registry) ID: UMIN000042726.

Flexible Attachment and Detachment of Centromeres and Telomeres to and from Chromosomes.

Accurate transmission of genomic information across multiple cell divisions and generations, without any losses or errors, is fundamental to all living organisms. To achieve this goal, eukaryotes devised chromosomes. Eukaryotic genomes are represented by multiple linear chromosomes in the nucleus, each carrying a centromere in the middle, a telomere at both ends, and multiple origins of replication along the chromosome arms. Although all three of these DNA elements are indispensable for chromosome function, centromeres and telomeres possess the potential to detach from the original chromosome and attach to new chromosomal positions, as evident from the events of telomere fusion, centromere inactivation, telomere healing, and neocentromere formation. These events seem to occur spontaneously in nature but have not yet been elucidated clearly, because they are relatively infrequent and sometimes detrimental. To address this issue, experimental setups have been developed using model organisms such as yeast. In this article, we review some of the key experiments that provide clues as to the extent to which these paradoxical and elusive features of chromosomally indispensable elements may become valuable in the natural context.

Neighborhood Socioeconomic Characteristics Associated with the COVID-19 Incidence in Elementary School Children: An Ecological Study in Osaka City, Japan.

We aimed to determine whether neighborhood socioeconomic characteristics are associated with the coronavirus disease 2019 (COVID-19) incidence in elementary school children and, if so, the associated characteristics. We obtained data on the number of infected children from 282 public elementary schools and the socioeconomic characteristics of each school district in Osaka City, Japan. We examined associations between these variables through negative binomial regression analyses. The proportion of employment in the wholesale and retail trade industry and the college graduation rate were significantly positively and negatively associated, respectively, with the total number of COVID-19-infected children. It was discovered that percentages of employment in the accommodation and food service industries in Wave 2, wholesale and retail trade industries after Wave 3, and healthcare and social assistance industries in Wave 5 were significantly positively associated with the number of infected children; likewise, the college graduation rate in Wave 5 was significantly negatively associated with the number of infected children. Our findings provide insight into the relevant and important areas of focus for public health policymakers and practitioners to ensure reduced disparities in COVID-19 infection rates.

Neighborhood-level socioeconomic factors moderate the association between physical activity and relative age effect: a cross-sectional survey study with Japanese adolescents.

BACKGROUND: Relative age effect is defined as a phenomenon where children born early generally perform better than children born later in the same cohort. Physical activity is an important factor that might be influenced by the relative age effect. Socioeconomic factors (e.g., parent's income, education level) are also associated with the adolescent's physical activity. However, no existing study has examined whether socioeconomic factors moderate the relative age effect on the adolescent's physical activity. This study aims to clarify whether and how birth month and socioeconomic factors relate to organized sports and physical activity among adolescents in Japan. METHODS: We conducted a questionnaire survey targeting 21,491 adolescents who live in a widespread neighborhood. We included 8102 adolescents (4087 males and 4015 females: mean age 13.1 ± 1.4) in the analysis. Based on the participants' birth months, we divided them into four groups (April to June, July to September, October to December, January to March). We asked participants to report their organized sports participation. Using the International Physical Activity Questionnaire for Japanese Early Adolescents, we identified their moderate to vigorous physical activity (MVPA). Neighborhood-level socioeconomic factors (areal deprivation, average annual income, education level) were analyzed based on national surveys, such as the population census. We performed multilevel logistic and linear regression analysis for organized sports participation and MVPA, respectively. Moreover, a simple slope analysis was implemented if the interaction between birth month and socioeconomic factor was significant in the multilevel linear regression analysis. RESULTS: Among males, relatively younger adolescents (adolescents who were born later in the same grade) were less likely to participate in organized sports activites (OR=0.90, 95% CI 0.82-0.97, p<0.05), while both males and females engaged in less MVPA (b=-0.54, b=-0.25, p< 0.01, respectively). We observed an interaction between birth month and socioeconomic factors. Among males in low-income neighborhoods, and females in more deprived neighborhoods, relatively younger adolescents engaged in less MVPA. CONCLUSIONS: Socioeconomic factors moderate the relative age effect on adolescents' physical activity. The relative age effect on adolescents' physical activity might be more likely to appear among adolescents from socioeconomically disadvantaged neighborhoods.

A combined index of waist circumference and muscle quality is associated with cardiovascular disease risk factor accumulation in Japanese obese patients: a cross-sectional study.

PURPOSE: To identify obese patients at high risk of cardiovascular disease (CVD) using a combined index of obesity and sarcopenia. METHODS: In this cross-sectional study, we firstly conducted analysis of covariance to select each index most associated with the CVD risk score, the number of concomitant CVD risk factors, among obesity- (body mass index, percentage body fat, or waist circumference [WC]) and sarcopenia-evaluated indices (skeletal muscle mass index, handgrip strength, or muscle quality [MQ]), respectively in 188 Japanese obese patients (BMI ≥ 25 kg/m2, 73 men and 115 women). Next, we conducted multivariate logistic regression analysis to compare the four groups (Group A-D) classified by medians of the selected indices. RESULTS: WC and MQ were selected as the indices most associated with the CVD risk scores, respectively. The CVD risk score was significantly higher in Group B (low WC and low MQ) and Group D (high WC and low MQ) with higher prevalence of diabetes as compared with Group A (low WC and high MQ). Adjusted for sex and age, odds ratios for CVD risk scores = 2 were significantly higher in Group B, Group C (high WC and high MQ), and Group D compared with Group A. Furthermore, odds ratios for CVD risk scores = 3 were significantly higher only in Group D compared with Group A (4.29 [95% confidence interval: 1.49-12.33], p = 0.007). CONCLUSION: Combined index of WC and MQ was useful in Japanese obese patients at high risk of CVD, regardless sex and age.

Phase angle from bioelectrical impedance analysis is a useful indicator of muscle quality.

BACKGROUND: Methods that facilitate muscle quality measurement may improve the diagnosis of sarcopenia. Current research has focused on the phase angle (PhA) obtained through bioelectrical impedance analysis (BIA) as an indicator of cellular health, particularly cell membrane integrity and cell function. The current study therefore aimed to evaluate the relationship between the PhA and muscle quality and muscle-related parameters and to determine factors associated with the PhA. Moreover, we attempted to determine the cut-off value of PhA for predicting sarcopenia. METHODS: First-year university students (830 male students, 18.5 ± 0.6 years old; 422 female students, 18.3 ± 0.5 years old) and community-dwelling elderly individuals (70 male individuals, 74.4 ± 5.5 years old; 97 female individuals, 73.1 ± 6.4 years old) were included. PhA and other body composition data were measured using BIA, while muscle quality was calculated by dividing handgrip strength by upper limbs muscle mass. The relationship between PhA and the aforementioned parameters were then analysed, after which the cut-off value of PhA for predicting sarcopenia was examined. RESULTS: Multiple linear regression analysis revealed that age, skeletal muscle mass index (SMI), and muscle quality were independently associated with PhA in both sexes [male (age: standardized regression coefficient (ß) = -0.43, P < 0.001, SMI: ß = 0.61, P < 0.001, muscle quality: ß = 0.13, P < 0.001) and female (age: ß = -0.56, P < 0.001, SMI: ß = 0.52, P < 0.001, muscle quality: ß = 0.09, P = 0.007)]. Participants with sarcopenia had a significantly lower PhA compared with those without it (sarcopenia vs. non-sarcopenia: young male participants, 5.51 ± 0.41° vs. 6.25 ± 0.50°, P < 0.001; young female participants, 4.88 ± 0.16° vs. 5.37 ± 0.44°, P = 0.005; elderly female participants: 4.14 ± 0.29° vs. 4.63 ± 0.42°, P = 0.009). Although no significant findings were observed in elderly male participants, the same tendency was noted. Receiver operating characteristic (ROC) curve analysis indicated that PhA had good predictive ability for sarcopenia in young male, elderly male, young female, and elderly female participants (area under the ROC curve of 0.882, 0.838, 0.865, and 0.850, with cut-off PhA values of 5.95°, 5.04°, 5.02°, and 4.20° for predicting sarcopenia, respectively). CONCLUSIONS: The PhA reflected muscle quality and exhibited good accuracy in detecting sarcopenia, suggesting its utility as an index for easily measuring muscle quality, which could improve the diagnosis of sarcopenia.

Association of Neighborhood Food Environment and Physical Activity Environment With Obesity: A Large-Scale Cross-Sectional Study of Fifth- to Ninth-Grade Children in Japan.

Objective: This study examined the relationship between neighborhood food and physical activity environment, and obesity among elementary and junior high school students in Japan. Methods: The participants were fifth- to ninth-grade children (n=7277), who were attending municipal schools in Japan. Percent overweight (POW) was calculated using their age, gender, height, and weight, which were collected through a questionnaire. A POW of < 20% was considered non-obese, while ≥ 20% was considered obese. Furthermore, using a geographic information system, we investigated the density of convenience stores, fast-food stores, casual restaurants, supermarkets and department stores, parks, sports facilities, stations, and intersections in the school district. Additionally, from the census, we obtained information regarding the population density of the municipality where the participants' schools were located. Multiple logistic regression analysis was used to examine the relationship between obesity and food environment (the food environment model), between obesity and physical activity environment (the physical activity environment model), and among obesity, food, and physical activity environment (the food and physical activity environment model). Results: In the food environment model and the food and physical activity environment model, the density of convenience stores showed a significant positive association. In the physical activity environment model, the density of stations showed a significant negative association. Conclusion: This study's findings can contribute to the development of appropriate community interventions for improving children's health in Japan and similar areas.

The relationship between sleep habits, lifestyle factors, and achieving guideline-recommended physical activity levels in ten-to-fourteen-year-old Japanese children: A cross-sectional study.

The current focus of meeting the physical activity guidelines for children and young people include preventing conditions such as high blood cholesterol, high blood pressure, metabolic syndrome, obesity, low bone density, depression, and injuries. However, the relationship between sleep habits and meeting physical activity guidelines is still unclear. This study aimed to assess this relationship among fifth- to eighth-grade (ages 10-14) Japanese children. This cross-sectional study included 3,123 children (boys: 1,558, girls: 1,565, mean age: 12.5 ± 1.2 years). Questionnaires were used to assess parameters such as moderate-to-vigorous physical activity per day, school and weekend night sleep durations, social jetlag, daytime sleepiness, napping, screen time, and breakfast intake. Participants were divided into an achievement and a non-achievement group depending on their physical activity guideline achievement status (i.e., whether they met the children's physical activity guideline of 60 min or more of moderate-to-vigorous physical activity per day). Then, to determine the sleep habits in relation to the children's achievement of guideline-recommended physical activity levels, multivariate logistic regression analyses were conducted. In fifth- and sixth-grade (ages 10-12) boys, an inverse association was observed between physical activity guideline achievement and daytime sleepiness. In seventh- and eighth-grade (ages 12-14) boys, physical activity guideline achievement was inversely associated with social jetlag and skipping breakfast. Additionally, in seventh- and eighth-grade girls, physical activity guideline achievement was inversely associated with inappropriate sleep duration on weekends and screen time. These results suggest that meeting the physical activity guideline is related to favorable sleep habits in Japanese children. However, their relevance may differ by school type and gender.

Comparison of quadriceps setting strength and knee extension strength tests to evaluate lower limb muscle strength based on health-related physical fitness values in elderly people.

OBJECTIVE: Conventionally, knee extension strength is often used as the indicator for lower limb muscle strength; however, several recent studies have also used quadriceps setting strength. This study aimed to investigate and compare the association of quadriceps setting and knee extension strength with health-related physical fitness. METHODS: We evaluated quadriceps setting strength and isometric knee extension strength in 75 elderly subjects (mean age, 76.8±5.3 years) to determine their lower limb muscle strength. Health-related physical fitness was evaluated using the physical fitness test advocated by the Ministry of Education and Culture, Sports, Science and Technology in Japan. The test consists of the following components: grip strength, sit-up, sit and reach, one leg standing with eyes open, 10 m obstacle walk and 6 min walk. RESULTS: When adjusted for age, sex and body mass index, quadriceps setting strength was significantly correlated with grip strength, number of sit-ups, sit and reach distance, 10 m obstacle walking time and 6 min walking distance. In contrast, knee extension strength was associated only with grip strength and number of sit-ups. CONCLUSION: More health-related physical fitness parameters with quadriceps setting strength than knee extension strength. Quadriceps setting strength may be superior to knee extension strength as a predictor of health-related physical fitness.

Appendicular muscle mass and exercise/sports participation history in young Japanese women.

Background: It remains unclear how past exercise habits can affect the skeletal muscle mass in adulthood in Japanese populations. Aim: The purpose of the present investigation was to examine the association of appendicular muscle mass (AMM) and skeletal muscle mass index (SMI) with the history of exercise and/or physical activity participation in Japanese women. Subjects and methods: One hundred and twenty females, aged between 18 and 28 years old, participated in the present investigation. Using a dual-energy X-ray absorptiometry scanner, the appendicular lean soft tissue, which is considered as a measure of AMM, was evaluated. Skeletal muscle mass index (SMI) was also assessed. Furthermore, all subjects answered a physical activity questionnaire. Results: Exercise habits at 7 years of age or older positively affected the AMM and SMI. The results of the multiple regression analysis showed that exercise history at 16-18 years of age as well as the current status of exercise and/or physical activity participation was a significant predictor of SMI and AMM. Conclusions: These results indicate that not only the past history of participation in physical and/or sports activities but also the current status of daily physical activity and sports activity play an important role in maintaining appropriate SMI and AMM in young women.

Role of serum myostatin in the association between hyperinsulinemia and muscle atrophy in Japanese obese patients.

AIMS: The protein myostatin is a member of the transforming growth factor ß superfamily. This is mainly expressed in skeletal muscle and negatively regulates skeletal muscle growth. The present study aimed to elucidate the associations among circulating myostatin level, skeletal muscle mass, and metabolic profiles in Japanese obese patients. METHODS: Japanese obese outpatients (n = 74) were enrolled. We measured clinical parameters, quantified serum myostatin levels, and examined their associations in a cross-sectional manner. RESULTS: Both total skeletal muscle mass and serum myostatin level were higher in males than in females. Among 74 patients, serum myostatin level was positively correlated with skeletal muscle mass and serum immunoreactive insulin (IRI) level [correlation coefficient (r) = 0.294, P = 0.011; r = 0.262, P = 0.024, respectively]. Furthermore, multivariate linear regression analysis revealed that serum myostatin level was positively correlated with IRI after adjusting for gender and skeletal muscle mass (ß-coefficient = 0.230, P = 0.029, R2 = 0.236). CONCLUSIONS: In obese patients, serum myostatin level was elevated in conjunction with an increase in IRI level independent of skeletal muscle mass. This may imply possible novel pathological implications of serum myostatin in muscle mass and metabolism in obese patients with hyperinsulinemia.

Total energy expenditure of 10- to 12-year-old Japanese children measured using the doubly labeled water method.

BACKGROUND: To establish Japanese children's estimated energy requirements, total energy expenditure (TEE) data measured using the doubly labeled water (DLW) method is needed. This study aimed to 1) obtain basic TEE data from Japanese children measured using DLW (TEEDLW), 2) compare TEEDLW with TEE estimated by various estimation formulas to calculate their accuracy, and 3) develop a new equation to estimate TEE using body composition and pedometers. METHODS: TEE was measured using DLW in 56 10- to 12-year-old Japanese children (33 boys, 23 girls). Physical activity level (PAL) was calculated by dividing TEEDLW by estimated resting energy expenditure. To assess their physical activity, participants wore pedometers during the 7-d DLW period. Total body water was calculated from 2H and 18O; fat-free mass (FFM) and fat mass (FM) were then determined. RESULTS: In boys and girls of normal weight, TEEDLW was 2067 ± 230 kcal/d and 1830 ± 262 kcal/d, respectively. Average PAL was 1.58 ± 0.17. FFM was strongly related to TEE (r = 0.702, p < 0.01). After adjusting for FFM and FM, step count was significantly associated with TEE (r = 0.707, p < 0.01). The TEE estimation formula used in the Dietary Reference Intakes (DRI) for the United States and Canada estimated TEEDLW with high accuracy (bias: 2.0%) in both sexes. We developed new equations for TEE consisting of FFM and step count, which accounted for 68% and 65% of TEE variance in boys and girls, respectively: boys, 47.1 × FFM (kg) + 0.0568 × step count (steps/d) - 122, and girls, 55.5 × FFM (kg) + 0.0315 × step count (steps/d) - 117. CONCLUSIONS: The TEE in 10- to 12-year-old Japanese children measured using DLW was approximately 7% lower for boys and 12% lower for girls compared to the current Japanese DRI. If PAL can be accurately determined, the equation in the DRI for the United States and Canada may be applicable to Japanese children. In addition, TEE could be predicted using FFM and step count.

The intron in centromeric noncoding RNA facilitates RNAi-mediated formation of heterochromatin.

In fission yeast, the formation of centromeric heterochromatin is induced through the RNA interference (RNAi)-mediated pathway. Some pre-mRNA splicing mutants (prp) exhibit defective formation of centromeric heterochromatin, suggesting that splicing factors play roles in the formation of heterochromatin, or alternatively that the defect is caused by impaired splicing of pre-mRNAs encoding RNAi factors. Herein, we demonstrate that the splicing factor spPrp16p is enriched at the centromere, and associates with Cid12p (a factor in the RNAi pathway) and the intron-containing dg ncRNA. Interestingly, removal of the dg intron, mutations of its splice sites, or replacement of the dg intron with an euchromatic intron significantly decreased H3K9 dimethylation. We also revealed that splicing of dg ncRNA is repressed in cells and its repression depends on the distance from the transcription start site to the intron. Inefficient splicing was also observed in other intron-containing centromeric ncRNAs, dh and antisense dg, and splicing of antisense dg ncRNA was repressed in the presence of the RNAi factors. Our results suggest that the introns retained in centromeric ncRNAs work as facilitators, co-operating with splicing factors assembled on the intron and serving as a platform for the recruitment of RNAi factors, in the formation of centromeric heterochromatin.

Optimal Conditions for Obtaining Valid Step Count Measurements in Hospitalized Patients with Abnormal Gait.

OBJECTIVE: This study investigated the optimum conditions for obtaining valid step-count measurements for patients with abnormal gait. METHODS: Subjects comprised 61 hospitalized patients with abnormal gait. Four different devices were tested: Active Style Pro (AS), Walking Style (WS), Lifecorder PLUS, and Steps. The same device type was attached to the waist on both the affected and the unaffected side. Patients then walked 25 m at a comfortable speed. This test was repeated four times, once for each device. The measurement error (ME) and walking parameters (gait velocity, step length, and cadence) were calculated from the test data. ME scores smaller than 3% and 10% were classified as valid: scores above these standards were classified as invalid. Walking parameter values that identified the invalid group with a specificity of 0.95 were set as the cut-off velocity (COV), the cut-off step length (COS), and the cut-off cadence. Sensitivity values >0.40 and positive predictive values >80% were then set as necessary conditions. RESULTS: COV values were 0.90 m/s (AS on the unaffected side at 3% ME and AS on the affected side or the unaffected side at 10% ME), 0.92 m/s (WS on the unaffected side at 10% ME), and 0.98 m/s (WS on the affected side at 3% ME). COS values were 0.50 m (AS on the affected side at 10% ME) and 0.52 m (AS on the unaffected side at 3% ME). CONCLUSION: The most accurate measurements were obtained using AS attached to the unaffected side with a gait velocity of >0.90 m/s.

Population-reaction model and microbial experimental ecosystems for understanding hierarchical dynamics of ecosystems.

Understanding ecosystem dynamics is crucial as contemporary human societies face ecosystem degradation. One of the challenges that needs to be recognized is the complex hierarchical dynamics. Conventional dynamic models in ecology often represent only the population level and have yet to include the dynamics of the sub-organism level, which makes an ecosystem a complex adaptive system that shows characteristic behaviors such as resilience and regime shifts. The neglect of the sub-organism level in the conventional dynamic models would be because integrating multiple hierarchical levels makes the models unnecessarily complex unless supporting experimental data are present. Now that large amounts of molecular and ecological data are increasingly accessible in microbial experimental ecosystems, it is worthwhile to tackle the questions of their complex hierarchical dynamics. Here, we propose an approach that combines microbial experimental ecosystems and a hierarchical dynamic model named population-reaction model. We present a simple microbial experimental ecosystem as an example and show how the system can be analyzed by a population-reaction model. We also show that population-reaction models can be applied to various ecological concepts, such as predator-prey interactions, climate change, evolution, and stability of diversity. Our approach will reveal a path to the general understanding of various ecosystems and organisms.

Shugoshin forms a specialized chromatin domain at subtelomeres that regulates transcription and replication timing.

A chromosome is composed of structurally and functionally distinct domains. However, the molecular mechanisms underlying the formation of chromatin structure and the function of subtelomeres, the telomere-adjacent regions, remain obscure. Here we report the roles of the conserved centromeric protein Shugoshin 2 (Sgo2) in defining chromatin structure and functions of the subtelomeres in the fission yeast Schizosaccharomyces pombe. We show that Sgo2 localizes at the subtelomeres preferentially during G2 phase and is essential for the formation of a highly condensed subtelomeric chromatin body 'knob'. Furthermore, the absence of Sgo2 leads to the derepression of the subtelomeric genes and premature DNA replication at the subtelomeric late origins. Thus, the subtelomeric specialized chromatin domain organized by Sgo2 represses both transcription and replication to ensure proper gene expression and replication timing.

Acentric chromosome ends are prone to fusion with functional chromosome ends through a homology-directed rearrangement.

The centromeres of many eukaryotic chromosomes are established epigenetically on potentially variable tandem repeats; hence, these chromosomes are at risk of being acentric. We reported previously that artificially created acentric chromosomes in the fission yeast Schizosaccharomyces pombe can be rescued by end-to-end fusion with functional chromosomes. Here, we show that most acentric/functional chromosome fusion events in S. pombe cells harbouring an acentric chromosome I differed from the non-homologous end-joining-mediated rearrangements that result in deleterious dicentric fusions in normal cells, and were elicited by a previously unidentified homologous recombination (HR) event between chromosome end-associated sequences. The subtelomere repeats associated with the non-fusogenic ends were also destabilized in the surviving cells, suggesting a causal link between general subtelomere destabilization and acentric/functional chromosome fusion. A mutational analysis indicated that a non-canonical HR pathway was involved in the rearrangement. These findings are indicative of a latent mechanism that conditionally induces general subtelomere instability, presumably in the face of accidental centromere loss events, resulting in rescue of the fatal acentric chromosomes by interchromosomal HR.