1994 Multi-site Broadband Seismic Observation at Sakurajima Volcano, Japan

Broadband observation of volcanic earthquakes has been recently conducted at many volcanoes. At the Sakurajima Volcano in Japan, one of the most active volcanoes all over the world, we conducted two broadband seismic observations successfully in last three years. However, they left some problems in terms of the number of observation sites and recording systems. This paper reports the outline of our third observation using three broadband seismometers (Streckeisen STS-II) with continuous recording at the Sakurajima Volcano from February 18 to March 28, 1994. This observation is distinguished from the previous two by the three stations operating continuously over the entire period. Although the Sakurajima Volcano had very low seismic activities during this observation period, we observed some kinds of volcanic earthquake, A-type and B-type earthquakes and volcanic tremors, particularly one series of interesting clone events

Hertwig\u27s epithelial root sheath cells contribute to formation of periodontal ligament through epithelial-mesenchymal transition by TGF-β.

In tooth root development, periodontal ligament (PDL) and cementum are formed by the coordination with the fragmentation of Hertwig\u27s epithelial root sheath (HERS) and the differentiation of dental follicle mesenchymal cells. However, the function of the dental epithelial cells after HERS fragmentation in the PDL is not fully understood. Here, we found that TGF-β regulated HERS fragmentation via epithelial-mesenchymal transition (EMT), and the fragmented epithelial cells differentiated into PDL fibroblastic cells with expressing of PDL extracellular matrix (ECM). In the histochemical analysis, TGF-β was expressed in odontoblast layer adjacent of HERS during root development. Periostin expression was detected around fragmented epithelial cells on the root surface, but not in HERS. In the experiment using an established mouse HERS cell line (HERS01a), TGF-β1 treatment decreased E-cadherin and relatively increased N-cadherin expression. TGF-β1 treatment in HERS01a induced further expression of important ECM proteins for acellular cementum and PDL development such as fibronectin and periostin. Taken together, activation of TGF-βsignaling induces HERS fragmentation through EMT and the fragmented HERS cells contribute to formation of PDL and acellular cementum through periostin and fibronectin expression.福岡歯科大学2016年

Broadband Seismic Observations of Artificial Sources in the Kirishima Volcanic Area, Japan

We conducted broadband seismic observations of artifical explosions on December 1, 1994, in the Kirishima volcanic area, southern Kyushu, Japan. We clarified the dominant characteristics of wave-propagating paths in this area and the potential of broadband seismic observations for artifical sources. We analyzed seismograms at three sites located around one of the shot points (near Karakuni Dake) at distances shorter than 1.3 km