Methane exchange in a poorly-drained black spruce forest over permafrost observed using the eddy covariance technique

Ecosystem-scale methane (CH4) exchange was observed in a poorly-drained black spruce forest over permafrost in interior Alaska during the snow-free seasons of 2011–2013, using the eddy covariance technique. The magnitude of average CH4 exchange differed depending on wind direction, reflecting spatial variation in soil moisture condition around the observation tower, due to elevation change within the small catchment. In the drier upper position, the seasonal variation in CH4 emission was explained by the variation in soil water content only. In the wetter bottom, however, in addition to soil temperature and soil water content, seasonal thaw depth of frozen soil was also an important variable explaining the seasonal variation in CH4 exchange for this ecosystem. Total snow-free season (day of year 134–280) CH4 exchanges were 12.0 ± 1.0, 19.6 ± 3.0, and 36.6 ± 4.4 mmol m−2 season−1 for the drier upper position, moderately wet area, and wetter bottom of the catchment, respectively. Observed total season CH4 emission was nearly one order smaller than those reported in other northern wetlands, due probably to the relatively low ground water level and low soil temperature. The interannual variation of total snow-free season CH4 emission in the wetter bottom of the catchment was influenced by the amount of rainfall and thaw depth. On the other hand, in the drier upper position the amount of rainfall did not strongly affect the total season CH4 emission. Different responses of CH4 exchange to environmental conditions, depending on the position of a small catchment, should be considered when estimating the spatial variation in CH4 exchange accurately in ecosystems over permafrost.ArticleAGRICULTURAL AND FOREST METEOROLOGY. 214(0):157-168 (2015)journal articl

First Results of Axion Dark Matter Search with DANCE

Axions are one of the well-motivated candidates for dark matter, originally proposed to solve the strong CP problem in particle physics. Dark matter Axion search with riNg Cavity Experiment (DANCE) is a new experimental project to broadly search for axion dark matter in the mass range of $10^{-17}~\mathrm{eV} < m_a < 10^{-11}~\mathrm{eV}$. We aim to detect the rotational oscillation of linearly polarized light caused by the axion-photon coupling with a bow-tie cavity. The first results of the prototype experiment, DANCE Act-1, are reported from a 24-hour observation. We found no evidence for axions and set 95% confidence level upper limit on the axion-photon coupling $g_{a \gamma} \lesssim 8 \times 10^{-4}~\mathrm{GeV^{-1}}$ in $10^{-14}~\mathrm{eV} < m_a < 10^{-13}~\mathrm{eV}$. Although the bound did not exceed the current best limits, this optical cavity experiment is the first demonstration of polarization-based axion dark matter search without any external magnetic field.Comment: 9 pages, 8 figure

Effects of Different Types of Dietary Fibers on Fermentation by Intestinal Flora

Purpose: A treatment for chronic constipation is dietary fiber intake. This study aimed to determine the effects of different types of dietary fibers on the microbiota in the large intestine. Methods: Nine healthy volunteers participated in this study. Breath hydrogen test was used to determine the dietary fiber fermentations. The presence of hydrogen in the breath indicates intestinal bacterial activities. Participants fasted overnight and ate white bread (200 g) with 10 g of each type of dietary fiber: (1) cellulose, (2) soy fiber, (3) guar gum, and (4) control (without any dietary fiber). Samples were collected before and every 1 hour after eating, for 8 h. Another test compared the effects between cellulose and guar gum with a loaded food, which activates intestinal fermentation, and samples were collected using the same methods. Results: During 8 h of measurements, breath hydrogen concentration in the soy fiber group were higher than that of the control, but were not significantly different. Changes in the guar gum group were similar to those in the control. However, breath hydrogen concentrations in the cellulose group did not increase even after eating white bread that caused large intestinal fermentation 2.9 ± 0.7 ppm, which was significantly lower than that of the guar gum group (7.4 ± 1.7 ppm, p < 0.01). In the study with a well-fermented food intake, cellulose reduced breath hydrogen concentrations, but its difference with that of the guar gum group was statistically non-significant. Conclusion: Cellulose might have a suppressive effect on large intestinal fermentation. Therefore, this compound may be beneficial in treating chronic constipation

Genetic population structure of the precious coral Corallium japonicum in the Northwest Pacific

Population sizes of the Japanese red coral Corallium japonicum have been severely affected by poaching and overfishing. Although genetic structure and connectivity patterns are considered important parameters for conservation strategies, there are few studies focusing on the population genetics of C. japonicum in the Northwest Pacific. We examined the genetic population structure of C. japonicum, in the Northwest Pacific. We used restriction-site-associated DNA sequencing (RAD-seq), which can be used to identify genome-wide single-nucleotide polymorphism (SNPs), to reveal detailed within-species genetic variations. Using the variable SNP loci identified from this analysis, we successfully evaluated the population-level genetic diversity and patterns of gene flow among multiple populations of C. japonicum around Japan. The results of genetic analysis basically showed that gene flow is widely maintained in the geographic range examined in this study, but the analysis in combination with larval dispersal simulations revealed several populations that were genetically distinct from the other populations, suggesting geographically limited gene flows. The information obtained from this study will be useful for the design of effective management schemes for C. japonicum, which is under threat from overfishing

Clinical Outcomes and Genetic Analyses of Restrictive Cardiomyopathy in Children

BACKGROUND: Restrictive cardiomyopathy in children is rare and outcomes are very poor. However, little information is available concerning genotype-outcome correlations. METHODS: We analyzed the clinical characteristics and genetic testing, including whole exome sequencing, of 28 pediatric restrictive cardiomyopathy patients who were diagnosed from 1998 to 2021 at Osaka University Hospital in Japan. RESULTS: The median age at diagnosis (interquartile range) was 6 (2.25-8.5) years. Eighteen patients received heart transplantations and 5 patients were on the waiting list. One patient died while waiting for transplantation. Pathologic or likely-pathogenic variants were identified in 14 of the 28 (50%) patients, including heterozygous TNNI3 missense variants in 8 patients. TNNT2, MYL2, and FLNC missense variants were also identified. No significant differences in clinical manifestations and hemodynamic parameters between positive and negative pathogenic variants were detected. However, 2- and 5-year survival rates were significantly lower in patients with pathogenic variants (50% and 22%) compared with survival in patients without pathogenic variants (62% and 54%; P=0.0496, log-rank test). No significant differences were detected in the ratio of patients diagnosed at nationwide school heart disease screening program between positive and negative pathogenic variants. Patients diagnosed by school screening showed better transplant-free survival compared with patients diagnosed by heart failure symptoms (P=0.0027 in log-rank test). CONCLUSIONS: In this study, 50% of pediatric restrictive cardiomyopathy patients had pathogenic or likely-pathogenic gene variants, and TNNI3 missense variants were the most frequent. Patients with pathogenic variants showed significantly lower transplant-free survival compared with patients without pathogenic variants.Ishida H., Narita J., Ishii R., et al. Clinical Outcomes and Genetic Analyses of Restrictive Cardiomyopathy in Children. Circulation: Genomic and Precision Medicine 16, 382 (2023); https://doi.org/10.1161/CIRCGEN.122.004054