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The house shrew ( Suncus murinus-S . montanus species complex) colonized regions across southern Asia and the Indian Ocean following human activity. The house shrew is distributed on islands of the Ryukyu Archipelago, the southernmost part of Japan, but the evolutionary history of the shrew on those islands and possible associations between these populations and humans remain unknown. In this study, we conducted phylogenetic and population genetic analyses based on both nuclear and mitochondrial genome sequences of house shrews. Phylogenetic analyses based on mitochondrial cytochrome b ( cytb ) sequences revealed that shrews from the Ryukyu Archipelago showed strong genetic affinity to Vietnamese and southern Chinese shrews. Demographic analyses of cytb sequences indicated a rapid population expansion event affecting the haplotype group in Vietnam, southern China, and the Ryukyu Archipelago 3300-7900 years ago. Furthermore, gene flow between Ryukyu (Yonaguni Island) and Taiwan and between Ryukyu and Vietnam inferred from f 4 statistics of the nuclear genomes suggested repeated immigration to Ryukyu in recent years. The present study demonstrates that the Nagasaki population has a different origin from the Ryukyu population. These findings elucidate the complex pattern of genetic admixture in house shrews and provide insights into their evolutionary history.

We analyzed 196 haplotype sequences from a gene-rich region (250 kb) that includes Mc1r, a gene involved in coat color regulation, to gain insight into the evolution of coat color variation in subspecies of the house mouse Mus musculus. Phylogenetic networks revealed haplotype groups from the major subspecies of M. m. castaneus (CAS), M. m. domesticus (DOM), and M. m. musculus (MUS). Using haplotype sequences assigned to each of CAS and MUS through phylogenetic analysis, we proposed migration routes associated with prehistoric humans from west to east across Eurasia. Comparing nucleotide diversity among subspecies-specific haplotypes in different geographic areas showed a marked reduction during migration, particularly in MUS-derived haplotypes from Korea and Japan, suggesting intensive population bottlenecks during migration. We found that a C>T polymorphism at site 302 (c.302C>T) in the Mc1r coding region correlated with a darkening of dorsal fur color in both CAS and MUS. However, C/C homozygous mice in MUS showed marked variation in lightness, indicating the possibility of another genetic determinant that affects the lightness of dorsal fur color. Detailed sequence comparisons of haplotypes revealed that short fragments assigned to DOM were embedded in CAS-assigned fragments, indicating ancient introgression between subspecies. The estimated age of c.302C>T also supports the hypothesis that genetic interaction between subspecies occurred in ancient times. This suggests that the genome of M. musculus evolved through gene flow between subspecies over an extended period before the movement of the species in conjunction with prehistoric humans.

Previous studies of the brown bear (Ursus arctos) on Hokkaido Island, Japan, have detected three geographically distinct subpopulations representing different mitochondrial lineages and shown that gene flow between subpopulations has occurred due to male-biased dispersal. In this study, we determined whole-genomic sequences for six Hokkaido brown bears and analyzed these data along with previously published genomic sequences of 17 brown bears from other parts of the world. We found that the Hokkaido population is genetically distinct from the other populations, keeping genetic diversity higher than the endangered populations in western Europe but lower than most populations on the continents. A reconstruction of historical demography showed no increase in population size for the Hokkaido population during the Eemian interglacial period (130,000-114,000 years ago). In a phylogenetic analysis of the autosomal data, the Hokkaido population formed a clade distinct from North American and European populations, showing that it has maintained genetic diversity independently from continental populations following geographical isolation on the island. This autosomal genetic similarity contrasts with the geographically separate mitochondrial lineages on Hokkaido and indicates the occurrence of male-driven gene flow between subpopulations., (© The Author(s) 2021. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.)

Spring leaf phenology strongly influences plant productivity in temperate deciduous forests. Many studies have detected earlier budburst and leaf maturation in smaller trees within species, and have discussed the adaptive significance of increasing carbon gain before canopy closure in small trees. However, some previous studies have found the opposite pattern, and the physiological and environmental bases for this discrepancy are incompletely understood. We investigated the spring leaf phenology of 11 deciduous species in a cool-temperate forest in Japan for 2 years with different amounts of snowfall, and also gathered data on the day of budburst from multiple studies to assess whether and how the timing of budburst is related to tree size, phylogeny, temperature and annual snowfall of study sites. We found that differences in the timing of budburst and leaf maturation between saplings (<1 m height) and short trees (1-10 m height) are larger than those between short trees and tall trees (>10 m height), resulting in non-linear relationships between timing and height in most species. Cumulative degree-days to the day of budburst were smaller in saplings than in tall trees, probably because saplings are selected to outcompete the other individuals/species to become established. Moreover, phylogenetic relatedness did not explain the difference in spring leaf phenology between saplings and tall trees in the literature survey. In addition, our literature survey showed that budburst occurred earlier in saplings of most species in sites with less snowfall, whereas budburst occurred earlier in tall trees at sites with heavy snowfall. These results suggest that the opposite patterns found in some studies may be due to (i) differences in the target size, as saplings show larger phenological discrepancies than short and tall trees, and (ii) the microclimate experienced by the tree, as sites with heavy snow show delayed sapling phenology., (© The Author(s) 2019. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Premise of the Study: Differences in leaf size are expected to be coordinated with various shoot traits and branching intensity because these relationships will influence light capture efficiency, water use, and biomechanics. Previous studies have mainly focused on interspecific patterns of these trait relationships, but not on intraspecific patterns at the geographic scale. We investigated intraspecific variation in shoot traits and branching intensity of Fagus crenata in Japan., Methods: Allometric relationships between the traits of current-year shoots and branching intensity per branch unit of 1-m length on the main axis (BI) and its coordination with latitude were investigated using trees from 10 provenances in a common garden., Key Results: Individual trees originating from lower latitudes have smaller leaves with greater leaf mass per area and nitrogen content per area, greater Huber value (stem cross-sectional area per total leaf area [ATL]) of current-year shoots, and greater BI. Notably, the slope of the log-log relationship between BI and ATL was close to -1.0 across the trees from different source sites, implying that branching in this species occurs to control leaf area., Conclusions: Shoot traits and branching intensity were apparently coordinated with leaf size to control leaf area deployment in this species. Such patterns probably reflect differences in competition for hydraulic conductance among nearby shoots within crowns, as a consequence of different meteorological conditions across the source sites., (© 2015 Botanical Society of America, Inc.)

Maximum gait speed and physical activity (PA) relate to mortality and morbidity, but little is known about gender-related differences in these factors in elderly hospitalized cardiac inpatients. This study aimed to determine differences in maximum gait speed and daily measured PA based on sex and the relationship between these measures in elderly cardiac inpatients.A consecutive 268 elderly Japanese cardiac inpatients (mean age, 73.3 years) were enrolled and divided by sex into female (n = 75, 28%) and male (n = 193, 72%) groups. Patient characteristics and maximum gait speed, average step count, and PA energy expenditure (PAEE) in kilocalorie per day for 2 days assessed by accelerometer were compared between groups.Gait speed correlated positively with in-hospital PA measured by average daily step count (r = 0.46, P < 0.001) and average daily PAEE (r = 0.47, P < 0.001) in all patients. After adjustment for left ventricular ejection fraction, step counts and PAEE were significantly lower in females than males (2651.35 ± 1889.92 vs 4037.33 ± 1866.81 steps, P < 0.001; 52.74 ± 51.98 vs 99.33 ± 51.40 kcal, P < 0.001), respectively.Maximum gait speed was slower and PA lower in elderly female versus male inpatients. Minimum gait speed and step count values in this study might be minimum target values for elderly male and female Japanese cardiac inpatients.

The purpose of this study was to determine both an association between mortality and physical activity (PA) objectively measured by accelerometer and cutoff values for PA in Japanese outpatients with heart failure (HF). This prospective observational study comprised 170 HF outpatients (mean age, 65.2 years; 77% men). Peak oxygen uptake (VO2) and the relation between ventilation and carbon dioxide production (VE/VCO2 slope) as indices of exercise capacity were measured during cardiopulmonary exercise testing with a cycle ergometer. PA was assessed by accelerometer-measured average step count (steps) per day for 1 week. Study endpoint was cardiovascular-related death. Over an average follow-up of 1,377.1 (median, 1,335) days, 31 cardiovascular-related deaths occurred. Patients were then divided into survivor (n = 139) and nonsurvivor (n = 31) groups. Brain natriuretic peptide level was significantly different between groups. Peak VO2 and steps were also significantly lower and VE/VCO2 slope higher in the nonsurvivors versus survivors. Univariate Cox proportional hazards analysis showed brain natriuretic peptide, peak VO2, VE/VCO2 slope, and steps to be significant prognostic indicators of survival. Multivariate analysis showed PA of ≤4,889.4 steps/day to be a strong and independent predictor of prognosis (hazard ratio: 2.28, 95% confidence interval: 1.31-6.30; p = 0.008). Kaplan-Meier curves after log-rank test showed significant prognostic difference between PA of ≤4,889.4 and >4,889.4 steps/day in the 2 groups (log-rank: 12.19; p = 0.0005). In conclusion, step count as objectively measured by accelerometer may be a prognostic indicator of mortality in Japanese outpatients with HF., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Background: Patients with chronic heart failure (CHF) commonly fatigue easily due to low peak oxygen uptake (peak VO(2)), an important index of exercise capacity. Maximum phonation time (MPT) is widely used to evaluate maximum vocal capabilities because it is non-invasive, quick, and inexpensive., Aim: The aim of this study was to determine the relation between MPT and exercise capacity, and MPT required to attain an exercise capacity of ≥5 metabolic equivalents (METs) in CHF outpatients., Design: Cross-sectional study., Setting: Outpatient cardiac rehabilitation unit., Population: We enrolled 111 CHF outpatients (mean age 54.2±10.1 years)., Methods: Peak VO(2) was assessed during cardiopulmonary exercise testing (CPX) as the index of exercise capacity. After CPX, we divided the patients into two groups according to exercise capacity: ≥5 METs group (N.=68) and <5 METs group (N.=43). Measurements of MPT were taken in the seated position. All patients were asked to produce a sustained vowel /a:/ for as long as possible and were verbally encouraged during respiratory effort., Results: After adjustment for patient clinical characteristics, MPT in the CHF patients was found to be significantly higher in the ≥5 METs group than in the <5 METs group (22.1±8.4 vs. 17.0±11.6 s, F=13.5, P<0.001). Receiver-operating characteristic curve analysis of exercise capacity of ≥5 METs extracted a cutoff value for MPT of 18.27 s, with a sensitivity of 0.76, 1-specificity of 0.33, and AUC value of 0.81 (95% CI: 0.70-0.87, P<0.001)., Conclusion: There were differences in MPT in relation to an exercise capacity threshold of ≥5 METs in CHF outpatients. A MPT of 18.27 sec may be the best cutoff value to identify people with or without exercise capacity of ≥5 METs., Clinical Rehabilitation Impact: Measurement of MPT may be a useful method for estimating exercise capacity in CHF outpatients.

Objective: To examine differences in physiologic and psychosocial outcomes between age groups after an exercise-based supervised-recovery phase II cardiac rehabilitation outpatient program., Design: This is a longitudinal observational study. The study assessed 442 consecutive cardiac patients. Patients were divided into the middle-aged group (<65 yrs, n = 242) and older-age group (> or =65 yrs, n = 200). Peak oxygen uptake, handgrip and knee extensor muscle strength, upper- and lower-body self-efficacy for physical activity, and physical component summary and mental component summary scores as assessed by SF-36 were measured at 1 and 3 mos after the onset of acute myocardial infarction or cardiac surgery and were compared., Results: All physiologic and psychosocial outcomes increased significantly between months 1 and 3 in both groups. However, increases were greater in the middle-aged vs. older-aged group in peak oxygen uptake (+13.1% vs. +8.7%, P < 0.01), knee extensor muscle strength (+17.6% vs. +13.3%, P = 0.01), lower-body self-efficacy for physical activity (+17.3% vs. +12.7%, P = 0.02), and physical component summary score (+5.4% vs. +2.7%, P = 0.02)., Conclusions: Age-related differences in various physiologic and psychosocial measures indicated greater improvement from an exercise-based supervised recovery-phase II cardiac rehabilitation outpatient program in middle-aged vs. older-aged patients. Older adults may derive equal mental or emotional benefit from such a cardiac rehabilitation program but do not experience as much improvement in physiologic outcomes as middle-aged adults.

Background: Whether upper-extremity and lower-extremity muscle strength can predict a prognosis of congestive heart failure (CHF) patients is unclear. This study evaluated the impact of muscle strength on long-term mortality in patients with CHF., Design: Prospective observational study of male Japanese CHF patients., Methods: Clinical characteristics (age, body mass index, left ventricular ejection fraction, heart failure etiology, and medications) were obtained from hospital records of 148 male outpatients with stable CHF. Brain natriuretic peptide was determined as an index of disease severity. Peak oxygen uptake ((Equation is included in full-text article.)), handgrip, and knee extensor muscle strength were also determined., Results: After 1331.9+/-700.3 days of follow-up, 13 cardiovascular-related deaths occurred, and the patients were divided into two groups: survival (n=135) and nonsurvival (n=13). No significant differences were found between the groups in clinical characteristics, brain natriuretic peptide levels, and knee extensor muscle strength. Peak(Equation is included in full-text article.)(P=0.011) and handgrip strength (P=0.008) were significantly lower in the nonsurvival versus survival group. Left ventricular ejection fraction, peak(Equation is included in full-text article.), and handgrip strength were found by univariate Cox proportional hazards analysis to be significant prognostic indexes of survival. Multivariate analysis, however, revealed handgrip strength to be an independent predictor of prognosis. A handgrip strength cutoff value of 32.2 kgf was determined by the analysis of receiver-operating characteristics and was assessed. Kaplan-Meier survival curves after log-rank test showed significant prognostic difference between the two groups (P=0.008)., Conclusion: Handgrip strength may be useful for forecasting prognosis in patients with CHF.

Sleep-disordered breathing (SDB) is frequently observed in patients with congestive heart failure. Recent studies have shown that SDB negatively affects the onset of congestive heart failure; however, no studies have addressed the relationship between the level of SDB and the onset time of acute dyspnea. We hypothesized that SDB affects the acute onset time of dyspnea (AOT) and investigated the relationship between SDB and AOT. We examined 80 patients (mean age, 61.6 years) with congestive heart failure in a clinically stable condition. AOT was divided into 5 time periods (0:00 - 6:00, 6:00 - 12:00, 12:00 - 18:00, 18:00 - 24:00, and unknown). The apnea-hypopnea index (AHI) was obtained based on the results of polysomnography (PSG) to evaluate the severity of SDB. Acute dyspnea occurred in 59 (73.7%) of the 80 patients. When we divided the patients into an AHI < 5 group and an AHI >or= 5 group, there was no significant difference in the AOT; however, a significant difference was observed in those divided into AHI < 20 and AHI >or= 20 groups (P < 0.001). The patients with AHI >or= 20 had more acute dys-pnea between 18:00 - 24:00 and between 0:00 - 6:00 than those with AHI < 20 (32% and 19%, and 4.1% and 4.1%, respectively). Severe SDB patients tended to have acute dyspnea between midnight and dawn. The results suggest SDB might be one of the risk factors of heart failure.

Objective: To evaluate the effect of the self-monitoring approach (SMA) on self-efficacy for physical activity (SEPA), exercise maintenance, and objective physical activity level over a 6-mo period after a supervised 6-mo cardiac rehabilitation (CR) program., Design: We conducted a randomized, controlled trial with 45 myocardial infarction patients (38 men, seven women; mean age, 64.2 yrs) recruited after completion of an acute-phase, exercise-based CR program. Patients were randomly assigned to an SMA group (n = 24) or control group (n = 21). Along with CR, the subjects in the SMA group self-monitored their weight and physical activity for 6 mos. The SMA used in this study was based on Bandura's self-efficacy theory and was designed to enhance confidence for exercise maintenance. The control group participated in CR only. All patients were evaluated with the SEPA assessment tool. Exercise maintenance, SEPA scores, and objective physical activity (average steps per week) as a caloric expenditure were assessed at baseline and during a 6-mo period after the supervised CR program., Results: Mean period from myocardial infarction onset did not differ significantly between the SMA and control groups (12.1 +/- 1.3 vs. 12.2 +/- 1.2 mos, P = 0.692). All patients maintained their exercise routine in the SMA group. Mean SEPA score (90.5 vs. 72.7 points, P < 0.001) and mean objective physical activity (10,458.7 vs. 6922.5 steps/wk, P < 0.001) at 12 mos after myocardial infarction onset were significantly higher in the SMA than control group. SEPA showed significant positive correlation with objective physical activity (r = 0.642, P < 0.001)., Conclusions: SMA during supervised CR may effectively increase exercise maintenance, SEPA, and objective physical activity at 12 mos after myocardial infarction onset.