Taku Takeuchi

Learn More
We construct a protostellar disk model that takes into account the combined effect of viscous evolution, photoevaporation and the differential radial motion of dust grains and gas. For T Tauri disks, the lifetimes of dust disks that are mainly composed of millimeter sized grains are always shorter than the gas disks' lifetimes, and become similar only when(More)
We examined the time course of light adaptation in the visual motion system. Subjects judged the direction of a two-frame apparent-motion display, with the two frames separated by a 50-ms interstimulus interval of the same mean luminance. The phase of the first frame was randomly determined on each trial. The grating presented in the second frame was phase(More)
OBJECT Detachable platinum coils are widely used in the endovascular treatment of intracranial aneurysms. The use of coil placement produces a higher incidence of aneurysm recurrence compared with surgical clipping. To reduce the incidence of recurrence by promoting clot organization, the authors designed a platinum coil coated with tenascin-C (TNC), an(More)
We analyze the dynamics of gas-dust coupling in the presence of stellar radiation pressure in circumstellar disks, which are in a transitional stage between the gas-dominated, optically thick, primordial nebulae, and the dust-dominated, optically thin Vega-type disks. Meteoroids and dust undergo radial migration, either leaving the disk due to a strong(More)
Dural arteriovenous fistula (DAVF) is rarely associated with parkinsonism. A 52-year-old woman presented with a rare case of DAVF manifesting as parkinsonism and subsequently akinetic mutism. She showed dramatic recovery after endovascular treatment. We also review 10 published reports of DAVF presenting with parkinsonism. The clinical features of these(More)
From millimeter observations of classical T Tauri stars, it is suggested that dust grains in circumstellar disks have grown to millimeter size or larger. However, gas drag on such large grains induces rapid accretion of the dust. We examined the evolution of dust disks composed of millimeter sized grains, and showed that rapid accretion of the dust disk(More)
We present millimeter imaging observations in the 1200 µm continuum of the disk around β Pic. With the 25 ′′ beam, the β Pic disk is unresolved perpendicularly to the disk plane (≤ 10 ′′), but slightly resolved in the northeast-southwest direction (26 ′′). Peak emission is observed at the stellar position. A secondary maximum is found 1000 AU along the disk(More)
The morphology of spermatozoa and the distribution of intramembranous particles (IMPs) in sperm-head membranes in teleostean fish were examined ultrastructurally to clarify the presence of characteristic arrays (parallelogram or hexagon in packing) of IMPs. The following four species of fish were used: goldfish (Carassius auratus), loach (Misgurnus(More)
  • 1