Yoshihiro Mogami

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Mechanisms of gravitactic behaviors of aquatic microorganisms were investigated in terms of their mechanical basis of gravity-dependent orientation. Two mechanical mechanisms have been considered as possible sources of the orientation torque generated on the inert body. One results from the differential density within an organism (the gravity-buoyancy(More)
Microtubule sliding was induced in axonemes obtained from isolated cilia of Paramecium caudatum when they were exposed to a reactivating solution containing ATP after mild treatment with trypsin. Over a very wide range of concentrations (1 nM-4 mM), Ca2+ in the reactivating solution had no effect on the proportion of axonemes that disintegrated as the(More)
Japanese tree frogs (Hyla japonica) showed unique postures and behavior during an 8-day flight to the Russian space station Mir. When floating in the air, the animals arched their back and extended their four limbs. This posture resembles that observed during jumping or parachuting of the animals on the ground. Frog sitting on a surface bent their neck(More)
A new model explaining the gravitactic behavior of Paramecium is derived on the basis of its mechanism of gravity sensing. Paramecium is know to have depolarizing mechanoreceptor ion channels in the anterior and hyperpolarizing channels in the posterior of the cell. This arrangement may lead to bidirectional changes of the membrane potential due to the(More)
A space experiment aimed at closely observing the development and swimming activity of medaka fry under microgravity was carried out as a part of the S*T*A*R*S Program, a space shuttle mission, in STS-107 in January 2003. Four eggs laid on earth in an artificially controlled environment were put in a container with a functionally closed ecological system(More)
Bioconvection is a form of collective motion that occurs spontaneously in the suspension of swimming microorganisms. In a previous study, we quantitatively described the "pattern transition," a phase transition phenomenon that so far has exclusively been observed in bioconvection of the unicellular green alga Chlamydomonas. We suggested that the transition(More)
Editorial New year's greetings M. Mizuguchi (Japan) 1 Review Article Pacemaker in complicated and refractory breath-holding spells: When to think about it? Original Articles Manifestation of both emetic seizures and sylvian seizures in the same patients with benign partial epilepsy 18 Efficacy and tolerability of high-dose prednisone in Chinese children(More)
Motile aquatic microorganisms are known to self-organize into bioconvection patterns. The swimming activity of a population of microorganisms leads to the emergence of macroscopic patterns of density under the influence of gravity. Although long-term development of the bioconvection pattern is important in order to elucidate the possible integration of(More)
Bioconvection emerges in a dense suspension of swimming protists as a consequence of their negative-gravitactic upward migration and later settling as a blob of density greater than that of water. Thus, gravity is an important parameter governing bioconvective pattern formation. However, inconsistencies are found in previous studies dealing with the(More)