Comparison of body length and age between sea-run and resident wakasagi, Hypomesus nipponensis, in Lake Ogawara, Honsyu, Japan

Hypomesus nipponensisanadromyresidenceotolith daily incremen

Study on Mechanism of Caisson Type Sea Wall Movement During Earthquakes

Model vibration tests under gravity and centrifuge model vibration tests in 50G were performed to investigate the behavior of caisson type sea mill with reclaimed ground below and behind the caisson. In the tests, sliding of caisson occurred only during excitation, which indicates that it is impossible to predict the displacement of caisson and the deformation of back-fill ground without taking account of both inertia force of caisson and dynamic earth pressure. As for the dynamic earth pressure acts on the caisson, it was found that when input acceleration is small, the dynamic earth pressure seems to restrain the movement of caisson and the excess pore water pressure hardly occurs. On the other hand, when input acceleration is large enough to cause liquefaction, the dynamic earth pressure seems to promotes the movement of caisson

Application of spherical substrate to observe bacterial motility machineries by Quick-Freeze-Replica Electron Microscopy

3-D Structural information is essential to elucidate the molecular mechanisms of various biological machineries. Quick-Freeze Deep-Etch-Replica Electron Microscopy is a unique technique to give very high-contrast surface profiles of extra- and intra-cellular apparatuses that bear numerous cellular functions. Though the global architecture of those machineries is primarily required to understand their functional features, it is difficult or even impossible to depict side- or highly-oblique views of the same targets by usual goniometry, inasmuch as the objects (e.g. motile microorganisms) are placed on conventional flat substrates. We introduced silica-beads as an alternative substrate to solve such crucial issue. Elongated Flavobacterium and globular Mycoplasmas cells glided regularly along the bead\u27s surface, similarly to those on a flat substrate. Quick-freeze replicas of those cells attached to the beads showed various views; side-, oblique- and frontal-views, enabling us to study not only global but potentially more detailed morphology of complicated architecture. Adhesion of the targets to the convex surface could give surplus merits to visualizing intriguing molecular assemblies within the cells, which is relevant to a variety of motility machinery of microorganisms