Takashi Onaka

Learn More
  • T. Onaka, K. Yagi
  • 1990
The effects of an opioid receptor antagonist, naloxone (NAL), were studied on the changes in pituitary hormone secretion induced by emotional stress. Male Wistar rats were trained with tone stimuli paired with electric footshocks and tested with the tone and environmental cue signals for emotional stress of fear acquired by learning as described previously(More)
  • T. Onaka, K. Yagi, M. Hamamura
  • 1988
In an attempt to find whether vasopressin (VP) secretion is suppressed by learned emotional stress, we have given rats under a hypertonic condition simultaneously applied light and tone that had been paired previously with footshocks and have quantified immunoreactive VP (ir-VP) in the plasma. In a training session light (60 watt) and tone (2 kz) of 3-s(More)
The lightweight cryogenic telescope on board the Japanese infrared astronomical satellite, ASTRO-F, which is scheduled to be launched early in 2006, forms an F/6 Ritchey-Chretien system with a primary mirror of 710 mm in diameter. The mirrors of the ASTRO-F telescope are made of sandwich-type silicon carbide (SiC) material, comprising a porous core and a(More)
A mechanism for creating an enantioenrichment in the amino acids, the building blocks of the proteins, that involves global selection of one handedness by interactions between the amino acids and neutrinos from core-collapse supernovae is defined. The chiral selection involves the dependence of the interaction cross sections on the orientations of the spins(More)
beta Pictoris (beta Pic) is a main-sequence star with an edge-on dust disk that might represent a state of the early Solar System. The dust does not seem to be a remnant from the original protoplanetary disk, but rather is thought to have been generated from large bodies like planetesimals and/or comets. The history and composition of the parent bodies can(More)
The birth of very massive stars is not well understood, in contrast to the formation process of low-mass stars like our Sun. It is not even clear that massive stars can form as single entities; rather, they might form through the mergers of smaller ones born in tight groups. The recent claim of the discovery of a massive protostar in M17 (a nearby giant(More)
Mid-infrared (MIR) images of the Herbig Ae star HD 142527 were obtained at 18.8 and 24.5 µm with the Subaru/COMICS. Bright extended arc-like emission (outer disk) is recognized at r = 0. ′′ 85 together with a strong central source (inner disk) and a gap around r = 0. ′′ 6 in the both images. Thermal emission of the eastern side is much brighter than that of(More)
The Infrared Camera (IRC) is one of two focal-plane instruments on the AKARI 1 satellite. It is designed for wide-field deep imaging and low-resolution spectroscopy in the near-to mid-infrared (1.8–26.5 µm) in the pointed observation mode of AKARI. IRC is also operated in the survey mode to make an all-sky survey at 9 and 18 µm. It comprises three channels.(More)
We present the first results of AKARI Infrared Camera near-infrared spec-troscopic survey of the Large Magellanic Cloud (LMC). We detected absorption features of the H 2 O ice 3.05µm and the CO 2 ice 4.27µm stretching mode toward seven massive young stellar objects (YSOs). These samples are for the first time spectroscopically confirmed to be YSOs. We used(More)