Physical Relation of Source I to IRc2 in the Orion KL Region

We present mid-infrared narrow-band images of the Orion BN/KL region, and N-band low-resolution spectra of IRc2 and the nearby radio source "I." The distributions of the silicate absorption strength and the color temperature have been revealed with a sub-arcsecond resolution. The detailed structure of the 7.8 micron/12.4 micron color temperature distribution was resolved in the vicinity of IRc2. A mid-infrared counterpart to source I has been detected as a large color temperature peak. The color temperature distribution shows an increasing gradient from IRc2 toward source I, and no dominant temperature peak is seen at IRc2. The spectral energy distribution of IRc2 could be fitted by a two-temperature component model, and the "warmer component" of the infrared emission from IRc2 could be reproduced by scattering of radiation from source I. IRc2 itself is not self-luminous, but is illuminated and heated by an embedded luminous young stellar object located at source I.Comment: 20 pages, 11 figures. Minor corrections had been done in the ver.2. Accepted for publication in PAS

Liesegang Texture Found in Pyrophyllite Ore Deposits, Shobara district, Southwest Japan: Photograph collection

Liesegang textures are commonly occurred in pyrophyllite ore deposits in Shobara district, Southewest Japan. Color photographs of mode of occurrence, handspecimens and characteristic microtextures are presented. At the Sankin-motoyama outcrop, Liesegang texture is developed more than 500m long along the strike direction of the host rhyolitic rocks. The Liesegang texture is developed in the pyrophyllite rich zone and the texture is characterized by alternate of light and deep color bands. The light color is white to grey and the deep color is rather various such as brown, purple and grey. Two types of bands are recognizable, one is parallel and the other is perpendicular to the bedding plane of host rhyollitic rocks, respectively. The former is found in the marginal part whereas the latter mainly in the central part. Cylindrical Liesegang ring whose size is in the range from 10 to 50 cm is also common. The shape of the central core is various such as sphere, ellipsoid and cube. The band width of the Liesegang texture is various from few millimeters to several tens centimeters. Under the microscope, double or triple hematite rings are commonly observed in the deep color part and towards the light color part, shape of the rings becomes more and more irregular. The boundary of light and deep color bands is clearly recognized under the microscope by sudden development of opaque minerals in the deep color part and the boundary is irregular compared with straight appearance observed in the out crop. Detailed description of the texture will be appeared elsewhere

Micro-textures of Hematite in the Liesegang Rocks, Found in Pyrophyllite Deposits, Shobara District, Southwest Japan.

Characteristic micro-textures of hematite found commonly in the Liesegang rocks collected from pyrophyllite ore deposits, Shobara district, southwest Japan were investigated. Detailed observations of the Liesegang rocks under the high magnification reflection microscope with oil immersion lens reveal that almost all of opaque grains are composed of needle-shaped very fine crystals with less than few microns in width and 5-10 microns in length. Moreover, doughnut-like texture, which is characteristic in the Liesegang rock (Yamashita et al., 1996), is mainly composed of the needle-shaped fine crystals. In many cases, the rings are composed of radiated aggregates of the needle-shaped hematite crystals. The size of the most predominant rings is less than 10µm in diameter, and double, triple and multi rings are also common. The optical properties of these opaque crystals under the reflection microscope are almost similar to those of ordinary hematite, i.e., weak but noticeable bireflectance and distinct anisotropism (e.g., Uytenbogaardt, 1971). X-ray powder diffraction data indicate that most of the opaque minerals are hematite with small amount of goethite. However, under the reflection microscope, distinguishment of the two minerals is not possible

Spherulitic Textures Found in Pyrophyllite Ore Deposits, Shobara District, Southwest Japan: Photograph Collection

Spherulitic textures are commonly found in pyrophyllite ore deposits in Shobara district, Hiroshima Prefecture, Japan. Color photographs of the mode of occurrence, hand specimens and characteristic micro-textures are presented. The spherulitic textures occur mainly in the upper most horizon of the ore deposits, i.e., in pyrophyllite zone and weakly altered host rhyolitic rocks. The size of the spherulites is from few millimeters to several centimeters in diameter and the spherulites with several millimeters diameter is the most predominant. Color of the spherulites is also variable such as grey, dark blue, dark purple and greenish color. Under the microscope, the textures can be divided into two types, one is "radiation" and the other is "aggregation" types, respectively. The aggregation type is further subdivided into a) with fine grain rim and b) with coarse grain rim. The constituent minerals of the spherulite are feldspar, quartz, pyrophyllite, sericite, diaspore, hematite and goethite

Crystalline Silicate Feature of the Vega-like star HD145263

We have observed the 8-13 $\mu$m spectrum (R$\sim$250) of the Vega-like star candidate HD145263 using Subaru/COMICS. The spectrum of HD145263 shows the broad trapezoidal silicate feature with the shoulders at 9.3 $\mu$m and 11.44 $\mu$m, indicating the presence of crystalline silicate grains. This detection implies that crystalline silicate may also be commonly present around Vega-like stars. The 11.44 $\mu$m feature is slightly shifted to a longer wavelength compared to the usual 11.2-3 $\mu$m crystalline forsterite feature detected toward Herbig Ae/Be stars and T Tauri stars. Although the peak shift due to the effects of the grain size can not be ruled out, we suggest that Fe-bearing crystalline olivine explains the observed peak wavelength fairly well. Fe-bearing silicates are commonly found in meteorites and most interplanetary dust particles, which originate from planetesimal-like asteroids. According to studies of meteorites, Fe-bearing silicate must have been formed in asteroidal planetesimals, supporting the scenario that dust grains around Vega-like stars are of planetesimal origin, if the observed 11.44 $\mu$m peak is due to Fe-bearing silicates.Comment: accepted for Publication in ApJ

Effect of econazole on membrane calcium transport in rat thymocytes

Econazole, one of azole antifungals, is proven to exhibit an inhibitory action on Mycobaterium tuberculosis and its multidrug-resistant strains under in vitro and ex vivo conditions. However, econazole has been used as a pharmacological tool for inhibiting capacitative Ca2+ influx and exerts multiple effects on cellular Ca2+ circumstance. Therefore, to suggest the toxic effect of econazole at therapeutic concentrations, we have tested on the effect on membrane Ca2+ transport in rat thymocytes by using a flow cytometer with Fluo-3, an indicator of intracellular Ca2+. Econazole at concentrations of 1-3 μM increased membrane Ca2+ permeability and inhibited capacitative Ca2+ influx without affecting passive Ca2+ influx, Ca2+ release from intracellular Ca2+ store sites, and membrane Ca2+ pump. Econazole at 0.3 μM, a therapeutic concentration against tuberculosis caused by multidrug-resistant and latent M. tuberculosis, did not affect membrane Ca2+ transport. It may be suggested that econazole at therapeutic concentrations exerts no side effect related to Ca2+

Stress relaxation arrested the mainshock rupture of the 2016 Central Tottori earthquake

地震の破壊はなぜ止まるのか? --2016年鳥取県中部地震の断層サイズを決めたもの--. 京都大学プレスリリース. 2021-08-12.After a large earthquake, many small earthquakes, called aftershocks, ensue. Additional large earthquakes typically do not occur, despite the fact that the large static stress near the edges of the fault is expected to trigger further large earthquakes at these locations. Here we analyse ~10, 000 highly accurate focal mechanism solutions of aftershocks of the 2016 Mw 6.2 Central Tottori earthquake in Japan. We determine the location of the horizontal edges of the mainshock fault relative to the aftershock hypocentres, with an accuracy of approximately 200 m. We find that aftershocks rarely occur near the horizontal edges and extensions of the fault. We propose that the mainshock rupture was arrested within areas characterised by substantial stress relaxation prior to the main earthquake. This stress relaxation along fault edges could explain why mainshocks are rarely followed by further large earthquakes