著者
Junko Kamiguri Noriko Tsuchiya Ruri Hidema Zenji Yatabe Masahiko Shoji Chihiro Hashimoto Robert Bernard Pansu Hideharu Ushiki
出版者
The Biophysical Society of Japan
雑誌
BIOPHYSICS (ISSN:13492942)
巻号頁・発行日
vol.8, pp.11-19, 2012 (Released:2012-01-17)
参考文献数
29
被引用文献数
2 2

The contraction process of living Vorticella sp. in polymer solutions with various viscosities has been investigated by image processing using a high-speed video camera. The viscosity of the external fluid ranges from 1 to 5 mPa·s for different polymer additives such as hydroxypropyl cellulose, polyethylene oxide, and Ficoll. The temporal change in the contraction length of Vorticella sp. in various macromolecular solutions is fitted well by a stretched exponential function based on the nucleation and growth model. The maximum speed of the contractile process monotonically decreases with an increase in the external viscosity, in accordance with power law behavior. The index values approximate to 0.5 and this suggests that the viscous energy dissipated by the contraction of Vorticella sp. is constant in a macromolecular environment.
著者
Junko Kamiguri Noriko Tsuchiya Ruri Hidema Masatoshi Tachibana Zenji Yatabe Masahiko Shoji Chihiro Hashimoto Robert Bernard Pansu Hideharu Ushiki
出版者
The Biophysical Society of Japan
雑誌
BIOPHYSICS (ISSN:13492942)
巻号頁・発行日
vol.8, pp.1-9, 2012 (Released:2012-01-17)
参考文献数
17
被引用文献数
3 3

The contraction process of living Vorticella sp. has been investigated by image processing using a high-speed video camera. In order to express the temporal change in the stalk length resulting from the contraction, a damped spring model and a nucleation and growth model are applied. A double exponential is deduced from a conventional damped spring model, while a stretched exponential is newly proposed from a nucleation and growth model. The stretched exponential function is more suitable for the curve fitting and suggests a more particular contraction mechanism in which the contraction of the stalk begins near the cell body and spreads downwards along the stalk. The index value of the stretched exponential is evaluated in the range from 1 to 2 in accordance with the model in which the contraction undergoes through nucleation and growth in a one-dimensional space.