Seismicity controlled by resistivity structure : the 2016 Kumamoto earthquakes, Kyushu Island, Japan

The M JMA 7.3 Kumamoto earthquake that occurred at 1:25 JST on April 16, 2016, not only triggered aftershocks in the vicinity of the epicenter, but also triggered earthquakes that were 50–100 km away from the epicenter of the main shock. The active seismicity can be divided into three regions: (1) the vicinity of the main faults, (2) the northern region of Aso volcano (50 km northeast of the mainshock epicenter), and (3) the regions around three volcanoes, Yufu, Tsurumi, and Garan (100 km northeast of the mainshock epicenter). Notably, the zones between these regions are distinctively seismically inactive. The electric resistivity structure estimated from one-dimensional analysis of the 247 broadband (0.005–3000 s) magnetotelluric and telluric observation sites clearly shows that the earthquakes occurred in resistive regions adjacent to conductive zones or resistive-conductive transition zones. In contrast, seismicity is quite low in electrically conductive zones, which are interpreted as regions of connected fluids. We suggest that the series of the earthquakes was induced by a local accumulated stress and/or fluid supply from conductive zones. Because the relationship between the earthquakes and the resistivity structure is consistent with previous studies, seismic hazard assessment generally can be improved by taking into account the resistivity structure. Following on from the 2016 Kumamoto earthquake series, we suggest that there are two zones that have a relatively high potential of earthquake generation along the western extension of the MTL

Safety and efficacy of capsule endoscopy for patients with newly diagnosed Crohn's disease: A multicenter retrospective study

Crohn's disease (CD) is a chronic inflammatory disease that develops at a young age and frequently leads to intestinal resection. Capsule endoscopy (CE) can directly and non-invasively inspect the entire small bowel mucosa. We suspected that CE could be a good diagnostic tool for detecting CD in young patients. The aim of this study was to investigate the safety and efficacy of CE in patients with newly diagnosed CD and to evaluate the CE findings, especially in the upper small bowel of young patients. We retrospectively investigated 32 patients with newly diagnosed CD from 5 institutions. Patient characteristics, clinical course, and characteristics of CE findings were analyzed. The total small intestine observation rate was 93%, and the retention rate was 3% (1/32). No abnormality was identified by ileocolonoscopy in 46% (15/32), and transition of small bowel lesions (TSL) was found in 35% (12/34) of the patients. The frequency of longitudinal ulcers and cobblestones in the upper small intestine was significantly higher in younger patients (<= 20 years). Moreover, positive findings in the upper small intestine were predominantly observed in younger patients (<= 20 years). CE for patients with newly diagnosed CD was safe and useful, especially for the detection of upper small bowel lesions in young patients