The 1923 Kanto Earthquake and an Experiment for Disseminating Resources from Its Consequences: Construction of Photographs and Map Database for the Great Kanto Earthquake

Japan is one of the most seismically active countries in the world. Many consequences induced by past disastrous earthquakes were recorded on various forms such as investigation reports, damage statistics,personal experience stories, paintings, photographs, fi lms, and maps. These materials provide not only information concerning actual circumstances around the past events, but also valuable suggestions onthe disaster prevention for future earthquakes. We are trying to construct a database in the photographs and map for the Great Kanto earthquake of September 1, 1923 that gave socio-economic impact remarkably to the modernized Japan. In this paper, the outline of this earthquake is described based on the outcomes from recent researches, and then our experiment to construct the database is presented

Study on Dynamic Characteristics of a Pile Group Foundation

The earthquake response of a structure on group of piles is investigated. The test model, which is employed in this study, is a foundation on four piles. Three conditions are prepared for examination of the contact effects of the foundation bottom and the backfilling effects on dynamic characteristics of the foundation on the piles. Forced vibration tests are carried out for ascertaining the impedance functions as the inertial interaction, and earthquake observations for the earthquake input motion as the kinematic interaction. On the basis of the test and the observation results, the correlation analyses are executed for examining the applicability of the analytical method based on the substructure method in which the three-dimensional wave propagation theory is applied for calculation of the Green\u27s functions. The analytical method is concluded to have sufficient applicability for the practical design procedure of a structure on pile group

National trends in the outcomes of subarachnoid haemorrhage and the prognostic influence of stroke centre capability in Japan: retrospective cohort study

Objectives To examine the national, 6-year trends in in-hospital clinical outcomes of patients with subarachnoid haemorrhage (SAH) who underwent clipping or coiling and the prognostic influence of temporal trends in the Comprehensive Stroke Center (CSC) capabilities on patient outcomes in Japan.Design Retrospective study.Setting Six hundred and thirty-one primary care institutions in Japan.Participants Forty-five thousand and eleven patients with SAH who were urgently hospitalised, identified using the J-ASPECT Diagnosis Procedure Combination database.Primary and secondary outcome measures Annual number of patients with SAH who remained untreated, or who received clipping or coiling, in-hospital mortality and poor functional outcomes (modified Rankin Scale: 3–6) at discharge. Each CSC was assessed using a validated scoring system (CSC score: 1–25 points).Results In the overall cohort, in-hospital mortality decreased (year for trend, OR (95% CI): 0.97 (0.96 to 0.99)), while the proportion of poor functional outcomes remained unchanged (1.00 (0.98 to 1.02)). The proportion of patients who underwent clipping gradually decreased from 46.6% to 38.5%, while that of those who received coiling and those left untreated gradually increased from 16.9% to 22.6% and 35.4% to 38%, respectively. In-hospital mortality of coiled (0.94 (0.89 to 0.98)) and untreated (0.93 (0.90 to 0.96)) patients decreased, whereas that of clipped patients remained stable. CSC score improvement was associated with increased use of coiling (per 1-point increase, 1.14 (1.08 to 1.20)) but not with short-term patient outcomes regardless of treatment modality.Conclusions The 6-year trends indicated lower in-hospital mortality for patients with SAH (attributable to better outcomes), increased use of coiling and multidisciplinary care for untreated patients. Further increasing CSC capabilities may improve overall outcomes, mainly by increasing the use of coiling. Additional studies are necessary to determine the effect of confounders such as aneurysm complexity on outcomes of clipped patients in the modern endovascular era