プレート沈み込み帯における地震波低速度層―地震発生への影響と探査法

low-velocity zonesubduction zoneearthquake rupture processtrapped wavedownhole seismic observationSubduction zone drilling into a seismogenic zone has recently been planned to understand the mechanics of large thrust earthquakes. We review studies on fault zone structures in land areas and fault mechanics studies related to the fault zones. We also point out possibilities of estimating the parameters of slip-weakening and/or rate and state dependent friction laws from a parameter of thickness of fault gouges or of fault damaged zones observed in the borehole. Two types of low velocity zone, the fault and the oceanic crust low-velocity zones (FLVZ and CLVZ), can be expected along the subduction zone plate-boundary. Delineations of FLVZ and CLVZ clarify the frictional properties of the sunduction zone plate-boundary and detailed structures of the subducting oceanic crust at deeper parts. The trapped wave observation in the subduction zone borehole is a useful tool for delineating FLVZ and CLVZ in the upper parts of the subducting slab

Evaluation of oral immunotherapy efficacy and safety by maintenance dose dependency: A multicenter randomized study

Background Generally, oral immunotherapy (OIT) aims for daily administration. Recently, the efficacy of treatment with OIT at a low dose has been reported. However, the optimal dose and the evaluation of dose-dependent OIT outcome have not been described. Methods A multicenter, parallel, open-labeled, prospective, non-placebo controlled, randomized study enrolled 101 Japanese patients for treatment with OIT. We hypothesized that target dose OIT would induce short-term unresponsiveness (StU) earlier than reduced dose OIT. StU was defined as no response to 6200 mg whole egg, 3400 mg milk, and 2600 mg wheat protein, as evaluated by oral food challenge after 2-week ingestion cessation. To compare the two doses of OIT efficacy, the maximum ingestion doses during the maintenance phase of OIT were divided into 100%-dose or 25%-dose groups against their target StU dose, respectively. A total of 51 patients were assigned to the 100%-dose group [hen's egg (HE) = 26, cow's milk (CM) = 13, wheat = 12] and 50 to the 25%-dose group (HE = 25, CM = 13, wheat = 12). Primary outcome was established by comparing StU at 1 year. Secondary outcome was StU at 2 years and established by comparing allergic symptoms and immunological changes. Results The year 1 StU rates (%) for the 100%- and 25%-dose groups were 26.9 vs. 20.0 (HE), 7.7 vs. 15.4 (CM), and 50.0 vs. 16.7 (wheat), respectively. The year 2 StU rates were 30.8 vs. 36.0 (HE), 7.7 vs. 23.1 (CM), and 58.3 vs. 58.3 (wheat), respectively. There were no statistically significant differences in StU between years 1 and 2. The total allergic symptom rate in the 25%-dose group was lower than that in the 100%-dose group for egg, milk, and wheat. Antigen-specific IgE levels for egg-white, milk, and wheat decreased at 12 months. Conclusions Reduced maintenance dose of egg OIT showed similar therapeutic efficacy to the target dose. However, we were not able to clearly demonstrate the efficacy, particularly for milk and wheat. Reducing the maintenance dose for eggs, milk, and wheat may effectively lower the symptoms associated with their consumption compared to the target OIT dose. Furthermore, aggressive reduction of the maintenance dose might be important for milk and wheat, compared to the 25%-dose OIT

Differential diagnosis of memory impairment in areas affected by a natural disaster: a case report

We treated a man with a chief complaint of memory impairment after the Great East Japan Earthquake. Initially, he was diagnosed with dementia. However, after several tests, neither could a definitive diagnosis of dementia be reached, nor was there any apparent evidence for depression, epilepsy, delirium, or internal medicine diseases. During the earthquake, the patient experienced the severe trauma of watching his wife being swept away by a tsunami. Furthermore, he experienced separation from his family. Because of this traumatic experience, we suspected that dissociative disorder was involved in the development of the memory impairment and thus, we switched to treatments focusing on emotional support. Subsequently, the patient's memory impairment gradually improved. The present case demonstrates the importance of considering dissociative disorders when examining a patient with memory impairment in areas affected by disasters

Seven-plus hours of daily sedentary time and the subsequent risk of breast cancer : Japan Multi-Institutional Collaborative Cohort Study

This study aimed to investigate the association between daily sedentary time and the risk of breast cancer (BC) in a large Japanese population. The participants were 36,023 women aged 35–69 years from the Japan Multi-Institutional Collaborative Cohort Study. Cox proportional hazards analysis was used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for BC incidence in relation to time spent sedentarily (categorical variables: <7 and ≥7 hours/day [h/d]). Additionally, the associations of BC incidence to the joint effect of sedentary time with each component of physical activity, such as leisure-time metabolic equivalents (METs), frequency of leisure-time physical activity, and daily walking time, were examined. During 315,189 person-years of follow-up, 554 incident cases of BC were identified. When compared to participants who spent <7 h/d sedentary, those who spent ≥7 h/d sedentary have a significantly higher risk of BC (HR, 1.36; 95% CI, 1.07–1.71). The corresponding HRs among participants who spent ≥7 h/d sedentary with more physical activity, such as ≥1 h/d for leisure-time METs, ≥3 days/week of leisure-time physical activity, and ≥1 h/d of daily walking were 1.58 (95% CI, 1.11–2.25), 1.77 (95% CI, 1.20–2.61), and 1.42 (95% CI, 1.10–1.83), respectively, compared with those who spent <7 h/d sedentary. This study found that spending ≥7 h/d of sedentary time is associated with the risk of BC. Neither leisure-time physical activity nor walking had a BC-preventive effect in those with ≥7 h/d of sedentary time

CNVs in Three Psychiatric Disorders

BACKGROUND: We aimed to determine the similarities and differences in the roles of genic and regulatory copy number variations (CNVs) in bipolar disorder (BD), schizophrenia (SCZ), and autism spectrum disorder (ASD). METHODS: Based on high-resolution CNV data from 8708 Japanese samples, we performed to our knowledge the largest cross-disorder analysis of genic and regulatory CNVs in BD, SCZ, and ASD. RESULTS: In genic CNVs, we found an increased burden of smaller (500 kb) exonic CNVs in SCZ/ASD. Pathogenic CNVs linked to neurodevelopmental disorders were significantly associated with the risk for each disorder, but BD and SCZ/ASD differed in terms of the effect size (smaller in BD) and subtype distribution of CNVs linked to neurodevelopmental disorders. We identified 3 synaptic genes (DLG2, PCDH15, and ASTN2) as risk factors for BD. Whereas gene set analysis showed that BD-associated pathways were restricted to chromatin biology, SCZ and ASD involved more extensive and similar pathways. Nevertheless, a correlation analysis of gene set results indicated weak but significant pathway similarities between BD and SCZ or ASD (r = 0.25–0.31). In SCZ and ASD, but not BD, CNVs were significantly enriched in enhancers and promoters in brain tissue. CONCLUSIONS: BD and SCZ/ASD differ in terms of CNV burden, characteristics of CNVs linked to neurodevelopmental disorders, and regulatory CNVs. On the other hand, they have shared molecular mechanisms, including chromatin biology. The BD risk genes identified here could provide insight into the pathogenesis of BD

The effect of stem density on the probability of attack by the ambrosia beetle

1.The ambrosia beetle Platypus quercivorus uses fagaceous tree species as its hosts, and causes Japanese oak wilt by transporting and introducing the pathogenic fungus Raffaelea quercivora into the host tree. To protect fagaceous trees, it is necessary to understand the host selection process used by the beetle in heterogeneous forests. The occurrence of beetle attack on Quercus crispula and Castanea crenata was monitored from 2008 to 2011 in two 1-ha and one 0.5-ha plots established in a secondary forest. The stem and crown densities of each fagaceous tree species were calculated at 11 different spatial scales for each individual tree. Model application and selection were performed to clarify factors affecting the probability of attack by P. quercivorus. As shown in previous studies, a higher probability of attack was predicted for Q. crispula than for C. crenata, and the predicted probability of attack was lower for trees attacked in the previous year. The effect of stem density on the probability of attack was positive at a small (radius 5 m) spatial scale and negative at larger (radius 5–17.5 m) scales. We interpreted this to indicate that a dense distribution of fagaceous trees in a small area had a higher probability of attack, and that this probability decreased with an increasing density of fagaceous trees in a surrounding concentric area. A positive effect of crown density was detected, suggesting that P. quercivorus has a means of detecting host trees in areas with high crown densities of fagaceous species

Mass attack by the ambrosia beetle Platypus quercivorus occurs in single trees and in groups of trees

Bark and ambrosia beetles sometimes kill trees by attacking them en masse; however, their attack is not necessarily successful. Less than half of the fagaceous trees attacked by the ambrosia beetle Platypus quercivorus (Murayama) die, and the factors affecting this mortality are still unknown. To examine this issue, the survival of all stems of fagaceous trees attacked by the ambrosia beetle was investigated in a secondary forest from 2008 to 2010. In an area of 93 ha, 2130 stems (1278 genets) of fagaceous trees were attacked by P. quercivorus during the study period, and 813 of these stems died. A generalized additive mixed model was constructed to predict the probability of mortality of the attacked stems. A best-fit model showed that the probability of mortality was higher in Quercus crispula Blume than in Castanea crenata Sieb. & Zucc. A positive correlation was determined between the density of the attacked trees and the probability of mortality, suggesting that mass attack of P. quercivorus occurs not only on individual trees, but also on groups of trees. Assuming that trees attacked earlier in the season have a higher probability of mortality, the observed negative effects of altitude suggest that P. quercivorus initially seeks hosts at lower elevations

Low-velocity zones along subducting oceanic plates : Their implications in the subduction-zone seimogenesis and a method to detect them

low-velocity zonesubduction zoneearthquake rupture processtrapped wavedownhole seismic observationSubduction zone drilling into a seismogenic zone has recently been planned to understand the mechanics of large thrust earthquakes. We review studies on fault zone structures in land areas and fault mechanics studies related to the fault zones. We also point out possibilities of estimating the parameters of slip-weakening and/or rate and state dependent friction laws from a parameter of thickness of fault gouges or of fault damaged zones observed in the borehole. Two types of low velocity zone, the fault and the oceanic crust low-velocity zones (FLVZ and CLVZ), can be expected along the subduction zone plate-boundary. Delineations of FLVZ and CLVZ clarify the frictional properties of the sunduction zone plate-boundary and detailed structures of the subducting oceanic crust at deeper parts. The trapped wave observation in the subduction zone borehole is a useful tool for delineating FLVZ and CLVZ in the upper parts of the subducting slab