Tsunami Risk in Japanese Coast and Recent Mitigation Technique using Removable Breakwater

In this paper, the tsunami risk in the west coast of Japan is introduced. Especially, the inundation risk in Osaka city is discussed. Three visor gates are installed at the mouths of main rivers in the city. The gates are mainly installed to prevent the storm surge due to typhoons but they are effective to reduce the tsunami height at the mouth point of river. Though the gates are necessary to prevent the tsunami inundation, the stability against tsunami forces is not enough because the gates were constructed in 1960s. Therefore, the removable breakwater is now under consideration to reduce the tsunami force. The hydraulic experiment was carried out in order to investigate the applicability of the removable breakwater. The reduction rate by the breakwater was derived from the experiment

Study Of Wave-Induced Scour Depth Around Group Of Piles Using Support Vector Machines

Various arrangements of pile groups are widely being used as supports of marine structures. As piles are located on erodible beds of the sea, scouring is a threat to such structures and the scour depth amounts should be considered well in their designs. Though most of these supports are constructed in form of groups of piles, majority of studies were concentrated on predictions of scouring around single piles whereas the arrangement of the piles and the spaces between them in arrangements as well as their geometry, sediment and wave characteristics should also be studied. Despite the importance of the scour hole depths, the existing prediction formulas are not capable of accurate estimations around pile groups with different arrangements. Hence, developing a robust model for the estimation of scour depth seems necessary. One of the most common approaches as an alternative to empirical ones is the soft computing methods. Artificial Neural Network as the most famous data-mining method has been successfully applied in scour studies. But there are still needs of more assessments in their applications on pile group case studies. In addition, Support Vector Machines as one of the recently applied soft computing models in scouring has scarcely been studied so far. In this study, series of large scale scouring experiments were done for various arrangements of pile groups with different pile and arrangement characteristics exposed to waves of shallow water and equilibrium scour depth around them were measured in wave basin of Ujigwa Open Laboratory of Kyoto University. Finally, by applying the provided experimental data, the applicability of data mining models were assessed in predictions of pile group scour properties. Results indicate that, data mining approaches can provide more reliable predictions of scouring properties due to waves compared to current available empirical formulae

Anodal Transcranial Direct Current Stimulation Induces High Gamma-Band Activity in the Left Dorsolateral Prefrontal Cortex During a Working Memory Task: A Double-Blind, Randomized, Crossover Study

Transcranial direct current stimulation (tDCS) has been shown to have mixed effects on working memory (WM) capacity in healthy individuals. Different stimulation paradigms may account for these discrepancies, with certain features being favored. To determine the effect in the context of anodal tDCS, we investigated whether anodal tDCS induced cortical oscillatory changes during a WM task. Specifically, we tested whether anodal offline tDCS over the left prefrontal cortex (PFC) enhances WM capacity by modulating the oscillatory activity in the left dorsolateral PFC (DLPFC) using magnetoencephalography (MEG). This study employed a double-blind, randomized, crossover design, in which 24 healthy right-handed participants conducted MEG recordings during a 3-back task after administration of 2 mA tDCS or sham stimulation as a placebo. Our results showed that the effect of tDCS did not appear in the behavioral indices—WM accuracy (d′) or reaction time (RT). From the results of the time-frequency analysis, significant event-related synchronization (ERS) in the high-gamma band (82–84 Hz) of the left DLPFC was found under the tDCS condition; however, ERS was not correlated with WM capacity. Furthermore, we calculated the modulation index (MI), which indicates the strength of phase-amplitude coupling (PAC). tDCS significantly decreased MI of the left DLPFC, representing the theta-gamma PAC during the n-back task using color names as verbal stimuli. Our results suggest that although tDCS increased the gamma-band oscillation indicating greater neural activity in the left DLPFC, it did not lead to an improvement of WM capacity; this may be due to the inability of gamma-band oscillation to couple with the task-induced theta wave. WM capacity might not increase unless theta-gamma PAC is not enhanced by tDCS

Psychosocial twin cohort studies in Japan: the Keio Twin Research Center (KoTReC)

The Keio Twin Research Center (KoTReC) was established in 2009 at Keio University to combine two longitudinal cohort projects — the Keio Twin Study (KTS) for adolescence and adulthood and the Tokyo Twin Cohort Project (ToTCoP) for infancy and childhood. KoTReC also conducted a two-time panel study of self-control and psychopathology in twin adolescence in 2012 and 2013 and three independent anonymous cross-sectional twin surveys (ToTcross) before 2012 — the ToTCross, the Junior and Senior High School Survey and the High School Survey. This article introduces the recent research designs of KoTReC and its publications

シュッケツセイ ショウカセイ カイヨウ ニ タイスル アルゴン プラズマ ギョウコホウ ニヨル ナイシキョウテキ シケツジュツ ノ リンショウテキ ケントウ

出血性消化性潰瘍に対する止血法として非接触法であるアルゴンプラズマ凝固法を施行しその有用性と安全性を検討した。出血性潰瘍と診断されアルゴンプラズマ凝固法による止血術がなされた胃潰瘍17例,十二指腸潰瘍6例計23症例を対象とした。静脈性出血である湧出性出血,動脈性出血である拍動性・噴出性出血および活動性出血のない露出性血管症例に対し第一選択として,またはクリッピング術にて止血の得られなかった症例に対しアルゴンプラズマ凝固法を施行した。全体での一次止血率は83%と高率であり,再出血率は21%であった。クリッピング術にて止血困難な症例に対しても75%と有効であった。部位別では内視鏡的に正面視し難い後壁病変でも86%と高い止血率であった。潰瘍出血に対するアルゴンプラズマ凝固法は,手技的に容易で偶発症も認めず安全で有用な止血法と思われた。Background : Endoscopic treatment such as injection therapy and hemoclipping is known to be effective as hemostatic treatment for upper gastrointestinal bleeding. Argon plasma coagulation (APC) is a new modality of electrosurgery to apply high frequency electric current into tissue to cause defined thermal and coagulating effects and may be beneficial for hemostasis of gastrointestinal bleeding. The aim of the present study was to assess prospectively the usefulness of endoscopic APC for peptic ulcer bleeding. Methods Patients with upper GI bleeding manifested by hematemesis or melena were included in this study. APC was carried out with the use of argon source APC 300 and high frequency generator ICC 200 (ERBE, Germany) when active bleeding from an ulcer or a visible vessel in an ulcer bed was found. Results A total of 23 patients with bleeding from peptic ulcer underwent APC. Arterial spurting was found in 5 patients, oozing in 10 and a visible vessel in 8. Initial hemostasis was achieved in 19 of 23 patients (83%). With respect to the type of bleeding, hemostasis success was 4/5 (80%) in patients with spurting, 8/10 (80%) with oozing, and 7/8 (88%) with a visible vessel. In the particular patients in whom endoscopic clipping failed to get hemostasis, hemostasis was achieved in 6/8 (75%). In terms of location, the rate of hemostasis by APC was 8/9 (89%) for lesions located in the body, 4/4 (100%) in the angle, 3/4 (75%) in the antrum, and 4/6 (67%) in the duodenum, with no significant difference. For the posterior lesions where frontal access was hard to obtain, APC resulted in a higher rate of hemostasis (86%). Rebleeding within 10 days was observed in 4/19 (21%) after initial hemostasis. No serious complication was encountered. Conclusions Endoscopic APC for bleeding peptic ulcerations resulted in a higher rate of initial hemostasis with a considerably lower rate of rebleeding. In patients with unsuccessful hemostasis by endoscopic clipping, a high rate of hemostasis was achieved by APC. Thus, APC may provide an effective and safe modality for treatment of bleeding ulcerations

シンキン マデ センツウ シタ イカイヨウ ノ イチ ボウケン レイ

症例は57歳,男性。脳硬塞にて入院中であったが,吐血をきたし内視鏡検査を施行した。胃体上部前壁に活動性潰瘍を認めた。潰瘍底は発赤した隆起を形成し心拍動に一致した動揺が認められた。内視鏡治療は断念し緊急手術の予定であったが,多量の出血をきたし手術に至らず出血性ショックで死亡した。剖検にて胃壁の漿膜から横隔膜を貫き心筋まで穿通した胃潰瘍と診断した。生前には心筋障害を示唆する臨床所見はなく,胃潰瘍の心への穿通は診断困難であった。消化性胃潰瘍の心への穿通は稀であり文献的考察を加え報告する。57-year-old man was admitted to our hospital because of cerebral infarction. After admission, he had hematemesis and underwent endoscopic examination. Gastric ulcer with oozing was noted at the anterior wall of the body. The ulcer bed was reddish and protruding with heart beat. Because of the difficulty of endoscopic hemostasis, we planned to perform urgent surgery for the bleeding ulcer. However, he died from hemorrhagic shock before surgery. At autopsy, penetration of gastric ulcer into the myocardium was found. It was difficult to make accurate diagnosis before death because of the lack of ECG findings to indicate myocardial damage. Herein, a rare case of penetration of gastric ulcer into the heart (pericardium and myocardium) has been reported

Probability Analysis of Submarine Slope Stability with Consideration of the Spatial Variability of Sediment Strength

With the development of ocean engineering, the stability evaluation of submarine slopes has become more essential for the problems relating the stability of submarine foundations and the safety of offshore structures. The properties of marine sediments vary spatially in nature, and because of the depositional processes and the effective overburden pressure, there is an increasing trend with depth for the undrained shear strength of marine clay. To consider the spatial variability of soil strength in the stability evaluation of submarine slopes, the random field method and the limit equilibrium method are integrated in our study. A novel response surface method is proposed based on the Gaussian process regression to reduce the number of calls for direct slope stability analysis in the Monte Carlo simulations. Then illustrative examples of an infinite clay slope model and a two-dimensional submarine slope model are analyzed, taking the spatial variability of soil strength into consideration. The computational burden of the analysis using the surrogate model is significantly reduced making the prediction of submarine landslides more efficient