著者
阿部 邦昭
出版者
日本歯科大学
雑誌
日本歯科大学紀要. 一般教育系 = Bulletin of the Nippon Dental University. General education (ISSN:03851605)
巻号頁・発行日
vol.41, pp.7-12, 2012-03-20

We analyzed initial waves of the 2010 Bonin Island tsunami which was recorded at tide stations in Japan. After reducing tidal level from the record we identified the initial wave and determined the arrival time, polarity, double amplitude and period. The amplitude, normalized at 1000 km in the epicentral distance in the assumption of geometrical spreading, was plotted to the period relative to dominant period of seiche. The resonance curve represents itself having the maximum at 1.4. Thus it is concluded that the initial wave follows a law of resonance. It suggests that the initial wave is amplified by the background oscillation.
著者
岡 俊哉
出版者
日本歯科大学
雑誌
日本歯科大学紀要. 一般教育系 = Bulletin of the Nippon Dental University. General education (ISSN:03851605)
巻号頁・発行日
vol.48, pp.5-12, 2019-03-30

A swelling similar to that of the human hypophysis occurs in the caudal spinal cord of teleost fish. This is referred to as the “urophysis” and forms the caudal neurosecretory system together with neurosecretory cells (Dahlgren cells) located upstream of the urophysis and the fiber path from the cells. The details of the function of this system is still unknown, and study of the urophysis in fishes has declined. Amazingly, it was found that urotensin II, a peptide hormone isolated and purified from the fish urophysis, was expressing also in humans, as a potent vasoconstrictor. Recently, research on peptide hormones isolated from the urophysis has been actively performed for development of new drugs for human medicine. In this paper, this elusive fish urophysis and the caudal neurosecretory system will be discussed, and a new idea regarding the function of this system will be proposed.
著者
阿部 邦昭 Abe Kuniaki
出版者
日本歯科大学
雑誌
日本歯科大学紀要. 一般教育系 (ISSN:03851605)
巻号頁・発行日
vol.41, pp.7-12, 2012-03

We analyzed initial waves of the 2010 Bonin Island tsunami which was recorded at tide stations in Japan. After reducing tidal level from the record we identified the initial wave and determined the arrival time, polarity, double amplitude and period. The amplitude, normalized at 1000 km in the epicentral distance in the assumption of geometrical spreading, was plotted to the period relative to dominant period of seiche. The resonance curve represents itself having the maximum at 1.4. Thus it is concluded that the initial wave follows a law of resonance. It suggests that the initial wave is amplified by the background oscillation.