原点未知の３母数対数正規分布について

創立５０周年記念号(2

Variation analysis of multiple tsunami inundation models

Researchers have developed tsunami inundation models based on nonlinear shallow water equations to estimate tsunami propagation and inundation. However, their empirical results are not in perfect agreement with those of other research institutes, even though the same governing equations are used. Therefore, we quantitatively evaluated the variability of tsunami simulations in this study. Several research institutes have conducted tsunami simulations under the same input conditions using tsunami inundation models adopted for tsunami hazard assessment, resulting in a certain degree of variability among them. By examining the spatial and temporal differences in various physical quantities, we identified the characteristic topography where the variability between tsunami simulations increases. A novel method for calculating statistics from the area integrals of physical quantities was proposed to demonstrate the variability in the overall simulation results. In addition, the effects of different setting parameters and computational environments on the simulation results of a single model were evaluated. The findings of this study are expected to not only serve as a basis to verify the reliability of source codes employed by users of the tsunami inundation model, but also contribute useful technical information to advance probabilistic tsunami hazard assessment in the future

Genome-wide identification and gene expression profiling of ubiquitin ligases for endoplasmic reticulum protein degradation

Endoplasmic reticulum (ER)-associated degradation (ERAD) is a mechanism by which unfolded proteins that accumulate in the ER are transported to the cytosol for ubiquitin–proteasome-mediated degradation. Ubiquitin ligases (E3s) are a group of enzymes responsible for substrate selectivity and ubiquitin chain formation. The purpose of this study was to identify novel E3s involved in ERAD. Thirty-seven candidate genes were selected by searches for proteins with RING-finger motifs and transmembrane regions, which are the major features of ERAD E3s. We performed gene expression profiling for the identified E3s in human and mouse tissues. Several genes were specifically or selectively expressed in both tissues; the expression of four genes (RNFT1, RNF185, CGRRF1 and RNF19B) was significantly upregulated by ER stress. To determine the involvement of the ER stress-responsive genes in ERAD, we investigated their ER localisation, in vitro autoubiquitination activity and ER stress resistance. All were partially localised to the ER, whereas CGRRF1 did not possess E3 activity. RNFT1 and RNF185, but not CGRRF1 and RNF19B, exhibited significant resistance to ER stressor in an E3 activity-dependent manner. Thus, these genes are possible candidates for ERAD E3s.This study was supported by Grants-in-Aid for Scientific Research (KAKENHI) 15K21706, 26460099, 24300135, 22020032, 25251014, 15K15067, 15K20001, 15K18377 and 15K19516 from the Ministry of Education, Culture, Sports, Science and Technology, Japan and also supported by the Takeda Science Foundation. We thank H. Hishigaki and Otsuka GEN Research Institute for bioinformatic analysis. We also thank M. Minami and T. Uehara for the helpful discussions. We are grateful to T. Yoshikawa, T. Ike, Y. Maeoka, Y. Wada and Z. Cao for their technical assistance. The authors would like to thank Enago (www.enago.jp) for the English language review

Association of lower limb muscle mass and energy expenditure with visceral fat mass in healthy men

BACKGROUND: A high-calorie diet and physical inactivity, an imbalance between caloric intake and energy consumption, are major causes of metabolic syndrome (MetS), which manifests as accumulation of visceral fat and insulin resistance. However, the lifestyle-related factors associated with visceral fat mass in healthy men are not fully understood. METHODS: We evaluated visceral fat area (VFA), skeletal muscle mass, caloric intake, and energy expenditure in 67 healthy male participants (mean age, 36.9 ± 8.8 years; body mass index 23.4 ± 2.5 kg/m(2)). RESULTS: Multiple regression analysis showed that the total skeletal muscle mass (P < 0.001) were negatively and age (P < 0.001) were positively associated with VFA. Lower limb muscle mass (P < 0.001) was strongly associated with VFA. However, total caloric intake, total energy expenditure, and energy expenditure during exercise were not associated with VFA. CONCLUSIONS: Skeletal muscle mass especially lower limb muscle mass negatively contributes to visceral fat mass in healthy men. Therefore, maintaining lower limb muscular fitness through daily activity may be a useful strategy for controlling visceral obesity and metabolic syndrome

Increase in serum triglyceride was associated with coronary plaque vulnerability in a patient with rheumatoid arthritis

AbstractRates of morbidity and mortality from cardiovascular disease are high in patients with rheumatoid arthritis (RA); however, the mechanisms and biomarkers that reflect coronary plaque vulnerability have not yet been established. We present a case of acute coronary syndrome (ACS) presumably caused by exacerbation of chronic inflammation of RA, in which an abrupt increase in serum triglyceride was seen on the day of onset of ACS but not during effort angina. This case suggests that RA patients with an abrupt increase in triglyceride need intensive care including anti-platelet and statin therapy for the prevention of coronary plaque rupture.<Learning objective: Triglyceride might be a sensitive biomarker of activated macrophages and plaque vulnerability in patients with RA. RA patients with an abrupt increase in triglyceride might need intensive care including anti-platelet and statin therapy for the prevention of coronary plaque rupture.