FDM simulation of long-period ground motions around Oita Prefecture, Japan, using a land-ocean unified 3D structure model

Oita prefecture is located in northeastern part of Kyushu Island which is characterized by active subduction of the Philippine Sea plate (PHS) beneath the Eurasian plate and several active volcanoes along with the volcanic front. Oita area has frequently been damaged by large earthquakes and tsunamis since ancient times. From the point of view of disaster prevention, it is important to investigate the feasibility of strong ground motion prediction using realistic structural models. In this paper we use a land-ocean unified 3D (three-dimensional) structure model around Oita prefecture, which includes land and sea-floor topography and a seawater layer as well as subsurface structures of the arc side and the PHS slab to conduct the FDM (finite-difference method) simulations of strong ground motion in land and ocean areas for the 2015 Southern Oita, Japan, earthquake (MJMA5.7) whose hypocenter is located in the PHS slab. The simulated long-period (2–20 s) ground motions reproducing observed records demonstrate substantial contributions of thick low-velocity sediment layers in and around Beppu Bay and Oita basin to development of the motions. We also examine the topographic effects on the seismic motion by analyzing the simulation results to show the strong enhancement of the later phases

ノコギリヒラタムシ食害小麦に含まれる定着活性ケトステロイド

From hexane extract of wheat flour infested by the sawtoothed gain beetle [Oryzaephilus surinamensis (L.); Coleoptera; Silvanidae, three ketosteroids,cholestan-3-one(3),ergostan-3-one(4)and stigmastan-3-one(5),were obtained in a mixture and identified as arrestants to this weevil.世界的に著名な貯穀害虫であるノコギリヒラタムシによって食害された小麦のヘキサン抽出物中には、未食害の小麦には含まれない、数種のノコギリヒラタムシ定着活性物質が存在し、このうちの2種の活性物質が既に構造解明された。本研究では種々の機器分析、および市販化合物からの誘導などにより、未知の活性物質がcholestan-3-one,ergostan-3-one,stifmastan-3-one の混合物であると同定した

Intralesional steroid infusion using a spray tube to prevent stenosis after endoscopic submucosal dissection of esophageal cancer

Background/Aims Intralesional steroid injections have been administered as prophylaxis for stenosis after esophageal endoscopic submucosal dissection. However, this method carries a risk of potential complications such as perforation because a fine needle is used to directly puncture the postoperative ulcer. We devised a new method of steroid intralesional infusion using a spray tube and evaluated its efficacy and safety. Methods Intralesional steroid infusion using a spray tube was performed on 27 patients who underwent endoscopic submucosal dissection for superficial esophageal cancer with three-quarters or more of the lumen circumference resected. The presence or absence of stenosis, complications, and the number of endoscopic balloon dilations (EBDs) performed were evaluated after treatment. Results Although stenosis was not observed in 22 of the 27 patients, five patients had stenosis and dysphagia requiring EBD. The stenosis in these five patients was relieved after four EBDs. No complications related to intralesional steroid infusion using the spray tube were observed. Conclusions Intralesional steroid infusion using a spray tube is a simple and safe technique that is adequately effective in preventing stenosis (clinical trial number, UMIN000037567)

Study on the relationship between rainfall, topography and landslide volume in the recent debris flow disasters in Hiroshima, Japan

Three types of sediment volume estimation equations were developed by analyzing the relationship between rainfall, topography (e.g. slope gradient, relative height) and the volume of collapsed sediment in 1 km grid for heavy rainfall events (2014 and 2018 events) in Hiroshima Prefecture where intensive slope failures and debris flows occurred. All three equations showed a tendency for the volume of collapsed sediment per unit area to increase with increasing rainfall. However, some equations showed the rate of increase tends to gradually plateau