Diapause is a programmed developmental arrest that has evolved in a wide variety of organisms and allows them survive unfavorable seasons. This developmental state is particularly common in insects. Based on circumstantial evidence, pupal diapause has been hypothesized to result from a cessation of prothoracicotropic hormone (PTTH) secretion from the brain. Here, we provide direct evidence for this classical hypothesis by determining both the PTTH titer in the hemolymph and the PTTH content in the brain of diapause pupae in the cabbage army moth Mamestra brassicae. For this purpose, we cloned the PTTH gene, produced PTTH-specific antibodies, and developed a highly sensitive immunoassay for PTTH. While the hemolymph PTTH titer in non-diapause pupae was maintained at high levels after pupation, the titer in diapause pupae dropped to an undetectable level. In contrast, the PTTH content of the post-pupation brain was higher in diapause animals than in non-diapause animals. These results clearly demonstrate that diapause pupae have sufficient PTTH in their brain, but they do not release it into the hemolymph. Injecting PTTH into diapause pupae immediately after pupation induced adult development, showing that a lack of PTTH is a necessary and sufficient condition for inducing pupal diapause. Most interestingly, in diapause-destined larvae, lower hemolymph titers of PTTH and reduced PTTH gene expression were observed for 4 and 2 days, respectively, prior to pupation. This discovery demonstrates that the diapause program is already manifested in the PTTH neurons as early as the mid final instar stage.
We have developed an over 60-inch size Moth-eye anti-reflection surface, which has original shaped nanostructures. The minimum reflectance was 0.02% and the average was less than 0.04% with little wavelength dependence. Moreover an anti-glare function was added. The 60-inch LCD applied AG Moth-eye surface had an excellent visibility in bright environments.
Diapause, a programmed developmental arrest at a specific stage, is common in insects and is regulated by hormones. It is well established that in pupal diapause, cessation of ecdysteroid secretion from the prothoracic glands (PGs) after pupal ecdysis leads to diapause initiation, while resumption of its secretion induces post-diapause development. However, what regulates the activity of the glands is poorly understood, especially for the glands of diapause-terminated pupae. In the present study, we investigate the mechanisms by which post-diapause development is regulated in the cabbage armyworm Mamestra brassicae. We demonstrate that the brain is necessary for the initiation of post-diapause development and that the factor in the brain responsible for the activation of the PGs is the prothoracicotropic hormone (PTTH). Further, through measuring the hemolymph PTTH titers by time-resolved fluoroimmunoassay, we show that PTTH is actually released into the hemolymph prior to the activation of the PGs. Although its peak titer is much lower than expected, this low concentration of PTTH is most likely still effective to activate the PGs of post-diapause pupae, because the responsiveness to PTTH of the glands at this stage is very high compared to that of nondiapause pupal PGs. These results strongly suggest that in M. brassicae, PTTH serves as a trigger to initiate pupa-adult development after diapause termination by stimulating the PGs to secrete ecdysteroid.
Abstract— The new LCD display mode (ASM mode) which has the axially symmetric orientation of liquid crystal molecules and the micro‐cell structure corresponding to each pixel is described in this paper. The electro‐optic characteristics of this mode afford high contrast (CR ≥ 200, at normal direction) and the wide viewing angle characteristics without contrast inversion (±60° in both up‐down and left‐right directions).
Space-borne astronomical instruments require extensive characterization on the ground before launch. In the hard X-ray region however, it is difficult for a laboratory-based beamline using a conventional X-ray source to provide a capability sufficient for pre-flight high-precision calibration. In this paper, we describe an experiment to characterize a hard X-ray telescope at a synchrotron facility, mainly on the basis of experimental setup and examples of measured results. We have developed hard X-ray telescopes consisting of Wolter-I grazing incidence optics and platinum-carbon multilayer supermirror coatings. The telescopes have been characterized at the synchrotron facility SPring-8 beamline BL20B2. The measurements at BL20B2 have great advantages such as extremely high flux, large-sized and less-divergent beam, and monochromatic beam covering the entire hard X-ray region from 8 to over 100 keV. The telescope was illuminated by monochromatic hard X-rays, and the focused image was measured by high resolution hard X-ray imagers. The entire telescope aperture was mapped by a small beam, and the effective area and the point spread function were obtained as well as local optical properties for further diagnostics of the characteristics of the telescope.
We have developed advanced Axially Symmetric Aligned Microcell Mode using negative dielectric liquid crystal (N-type ASM mode) first in the world. Using compe nsation film for this N-type ASM mode cell realizes the wide viewing angle of ± ±80°° in all azimuths, and high contrast ratio of 300:1. The structure of this N-type ASM mode panel is suitable for large-sized display panels. This mode is applicable for such active display panels as TFT and PALC 1) display , regardless of the difference of their drive systems. We consider that this N-type ASM mode becomes(N-type ASM mode) a key technology for the next-generation monitors.1.
In this study, we identified ecdysteroidogenic enzymes in the cabbage armyworm, Mamestra brassicae, and demonstrated reduced expression of these genes during diapause. Some insects employ a temporary developmental arrest, diapause, to survive in severe environments. The titres of the moulting hormone ecdysteroid were reduced in diapause pupae of M. brassicae; therefore, ecdysteroidogenesis might be suppressed by a diapause-specific mechanism. To clarify expression changes of ecdysteroidogenic enzyme genes during diapause in M. brassicae, we first identified the genes for seven ecdysteroidogenic enzymes: Neverland, Non-molting glossy (Nm-g), CYP307A1 (Spook), CYP306A1 (Phantom), CYP302A1 (Disembodied), CYP315A1 (Shadow) and CYP314A1 (Shade). Enzymatic assays using heterologous expression in Drosophila Schneider 2 (S2) cells and analysis of mRNA distribution indicated that the identified genes were ecdysteroidogenic enzymes of M. brassicae. Expression levels of these ecdysteroidogenic enzyme genes were compared between prothoracic glands in different pupal stages throughout diapause. Immediately after pupation, diapause-destined pupae showed similar expression levels of ecdysteroidogenic enzyme genes to those of nondiapause pupae. All of these genes showed reduced gene expression after diapause initiation. Expression was immediately increased in diapause-destined pupae at the postdiapause quiescence phase. These results indicate that reduced expression of ecdysteroidogenic enzyme genes suppresses ecdysteroidogenesis and maintains developmental arrest during diapause.
Hard X-ray focusing observation is important to reveal non-thermal emission mechanism and origin in active galaxies and clusters of galaxies. We have carried out the hard X-ray observation throughout the InFOCµS program, which is an international balloon-borne experiment in collaboration with NASA/GSFC and Nagoya University. The telescope is conical approximation of Wolter-I optics with 8 m focal length and 40 cm diameter. It consists of 255 nested thin (0.17 mm thickness) reflectors with incidence angles of 0.10 • to 0.36 • . Reflectors are coated with depth-graded platinum-carbon (Pt/C) multilayers, so-called supermirrors, with periodic length of 2.6 to 13 nm and bi-layer number of 28 to 79, depending on incidence angles. We are now continuously fabricating advanced next hard X-ray telescope for the second InFOCµS flight in 2004. Compared with the first telescope, the following improvements have been made on the second one. Supermirror reflectors have wider sensitivity in energy band of 20 − 60 keV adopting optimum supermirror design for balloon observation, and smaller interfacial roughness owing to complete replication technique. For upgrading of the image quality, we then adopted stiffer reflector substrate, selected replication mandrel with better shape, and the modified telescope housing with higher alignment accuracy for reflectors. The performance of the new hard X-ray telescope was measured in X-ray beamline facility in ISAS/JAXA and synchrotron radiation facility SPring-8. The effective area and image quality are obtained to be 45 cm 2 at 30 keV and 23 cm 2 at 40 keV, and 2.5 arcmin in half power diameter, respectively. In this paper we report our development of the upgraded hard X-ray telescope for the second balloon flight experiment.
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