A Monte Carlo simulation study for cosmic-ray chemical composition measurement with Cherenkov Telescope Array

Our Galaxy is filled with cosmic-ray particles and more than 98% of them are atomic nuclei. In order to clarify their origin and acceleration mechanism, chemical composition measurements of these cosmic rays with wide energy coverage play an important role. Imaging Atmospheric Cherenkov Telescope (IACT) arrays are designed to detect cosmic gamma-rays in the very-high-energy regime ($\sim$TeV). Recently these systems proved to be capable of measuring cosmic-ray chemical composition in the sub-PeV region by capturing direct Cherenkov photons emitted by charged primary particles. Extensive air shower profiles measured by IACTs also contain information about the primary particle type since the cross section of inelastic scattering in the air depends on the primary mass number. The Cherenkov Telescope Array (CTA) is the next generation IACT system, which will consist of multiple types of telescopes and have a km$^2$-scale footprint and extended energy coverage (20 GeV to 300 TeV). In order to estimate CTA potential for cosmic ray composition measurement, a full Monte Carlo simulation including a description of extensive air shower and detector response is needed. We generated a number of cosmic-ray nuclei events (8 types selected from H to Fe) for a specific CTA layout candidate in the southern-hemisphere site. We applied Direct Cherenkov event selection and shower profile analysis to these data and preliminary results on charge number resolution and expected event count rate for these cosmic-ray nuclei are presented.Comment: All CTA contributions at arXiv:1709.03483 , Proceedings of the 35th International Cosmic Ray Conferenc

Reanalysis of Data Taken by the CANGAROO 3.8 Meter Imaging Atmospheric Cherenkov Telescope: PSR B1706-44, SN 1006, and Vela

We have reanalyzed data from observations of PSR B1706-44, SN 1006, and the Vela pulsar region made with the CANGAROO 3.8 m imaging atmospheric Cherenkov telescope between 1993 and 1998 in response to the results reported for these sources by the H.E.S.S. collaboration. In our reanalysis, in which gamma-ray selection criteria have been determined exclusively using gamma-ray simulations and OFF-source data as background samples, no significant TeV gamma-ray signals have been detected from compact regions around PSR B1706-44 or within the northeast rim of SN 1006. We discuss reasons why the original analyses gave the source detections. The reanalysis did result in a TeV gamma-ray signal from the Vela pulsar region at the 4.5 sigma level using 1993, 1994, and 1995 data. The excess was located at the same position, 0.13 deg. to the southeast of the Vela pulsar, as that reported in the original analysis. We have investigated the effect of the acceptance distribution in the field of view of the 3.8 m telescope, which rapidly decreases toward the edge of the field of the camera, on the detected gamma-ray morphology. The expected excess distribution for the 3.8 m telescope has been obtained by reweighting the distribution of HESS J0835-455 measured by H.E.S.S. with the acceptance of the 3.8 m telescope. The result is morphologically comparable to the CANGAROO excess distribution, although the profile of the acceptance-reweighted H.E.S.S. distribution is more diffuse than that of CANGAROO. The integral gamma-ray flux from HESS J0835-455 has been estimated for the same region as defined by H.E.S.S. from the 1993-1995 data of CANGAROO to be F(> 4.0 +/- 1.6 TeV) = (3.28 +/- 0.92) x 10^{-12} photons cm^{-2} s^{-1}, which is statistically consistent with the integral flux obtained by H.E.S.S.Comment: Published in ApJ, minor improvement

Supplemental Cellular Protection by a Carotenoid Extends Lifespan via Ins/IGF-1 Signaling in Caenorhabditis elegans

Astaxanthin (AX), which is produced by some marine animals, is a type of carotenoid that has antioxidative properties. In this study, we initially examined the effects of AX on the aging of a model organism C. elegans that has the conserved intracellular pathways related to mammalian longevity. The continuous treatments with AX (0.1 to 1 mM) from both the prereproductive and young adult stages extended the mean lifespans by about 16–30% in the wild-type and long-lived mutant age-1 of C. elegans. In contrast, the AX-dependent lifespan extension was not observed even in a daf-16 null mutant. Especially, the expression of genes encoding superoxide dismutases and catalases increased in two weeks after hatching, and the DAF-16 protein was translocated to the nucleus in the AX-exposed wild type. These results suggest that AX protects the cell organelle mitochondria and nucleus of the nematode, resulting in a lifespan extension via an Ins/IGF-1 signaling pathway during normal aging, at least in part

Pemikiran Kuki Shuzo Mengenai Konsep Iki dan Relevansinya Pada Estetika Modern

This article intends to explore the concept of iki aesthetics and investigate its relevance to modern aesthetics. The method used in this article is qualitative, a literature study that specifically focuses on using the thoughts of the philosopher Kuki Shuzo in the book The Structure of Iki. The results show that iki consists of bitai, ikiji, and akirame and that iki is also still relevant for modern aesthetics. In conclusion, iki evokes a certain kind of sensibility through the tension that emerges through dualistic relationships. And this unique form of sensibility proves to still be very relevant in modern aesthetics. This is proven by the fact that Japanese aesthetics are also in demand by people outside of Japan and that there are still various inquiries into modern aesthetics whilst takin into account the role of iki.Artikel ini bertujuan untuk mengeksplorasi konsep estetika iki dan menyelidiki relevansinya pada estetika modern. Metode yang digunakan dalam artikel ini adalah metode kualitatif, studi kepustakaan yang khususnya berfokus menggunakan pemikiran filsuf Kuki Shuzo dalam buku The Structure of Iki. Hasilnya menunjukkan bahwa iki terdiri atas bitai, ikiji, dan akirame dan bahwa iki juga masih relevan bagi estetika modern. Kesimpulannya, iki menggugah jenis sensibilitas tertentu melalui ketegangan yang keluar melalui hubungan dualistik. Dan bentuk sensibilitas yang unik ini terbukti masih sangat relevan pada estetika modern. Hal ini terbuktikan fakta bahwa estetika Jepang ternyata diminati juga oleh bangsa di luar Jepang dan bahwa masih ada juga berbagai penyelidikan mengenai estetika modern yang mempertimbangkan juga peran iki

Structural characterization of Tn916-like element in Streptococcus parauberis serotype II strains isolated from diseased Japanese flounder.

AIMS: To screen for the existence and determine the structure of Tn916-like element in Streptococcus parauberis serotype II strains isolated from cultured Japanese flounder in western Japan. METHODS AND RESULTS: In this study, the structure of Tn916-like element and the flanking regions were characterized by polymerase chain reaction (PCR) and inverse PCR, followed by cloning and sequencing. The Tn916-like element is 18 031 bp in length and composed of 22 ORFs. Southern blot hybridization analysis showed that the HincII-digested internal structures of Tn916-like elements yielded two patterns among S. parauberis serotype II strains. The flanking sequences were identical with the corresponding region of S. parauberis serotype I strain except for the addition of 6-bp coupling sequence (ATCATA) being adjacent to the upstream of the element. CONCLUSION: The Tn916-like element exhibited high homology (more than 99%) with Tn916 observed in other streptococci and enterococci and was integrated in the same site of chromosome for all of the tested S. parauberis serotype II strains. SIGNIFICANCE AND IMPACT OF THE STUDY: The results indicate that the Tn916-like element encoding tet(M) gene is present in all of the tested S. parauberis serotype II strains, which are disseminated in the flounder-culturing areas in western Japan.The definitive version is available at www.blackwell-synergy.co

Probing Pulsar Winds Using Inverse Compton Scattering

We investigate the effects of inverse Compton scattering by electrons and positrons in the unshocked winds of rotationally-powered binary pulsars. This process can scatter low energy target photons to produce gamma rays with energies from MeV to TeV. The binary radio pulsars PSR B1259-63 and PSR J0045-73 are both in close eccentric orbits around bright main sequence stars which provide a huge density of low energy target photons. The inverse Compton scattering process transfers momentum from the pulsar wind to the scattered photons, and therefore provides a drag which tends to decelerate the pulsar wind. We present detailed calculations of the dynamics of a pulsar wind which is undergoing inverse Compton scattering, showing that the deceleration of the wind of PSR B1259-63 due to `inverse Compton drag' is small, but that this process may confine the wind of PSR J0045-73 before it attains pressure balance with the outflow of its companion star. We calculate the spectra and light curves of the resulting inverse Compton emission from PSR B1259-63 and show that if the size of the pulsar wind nebula is comparable to the binary separation, then the gamma-ray emission from the unshocked wind may be detectable by atmospheric Cerenkov detectors or by the new generation of satellite-borne gamma-ray detectors such as INTEGRAL and GLAST. This mechanism may therefore provide a direct probe of the freely-expanding regions of pulsar winds, previously thought to be invisible.Comment: To be published in Astroparticle Physics. 27 pages, 5 figure

ヒラメレンサ球菌症の実験感染

The capability of Streptococcus iniae to cause disease in Japanese flounder was investigated by oral and bath (30 min) challenges with low, medium and high inoculation doses. Only with the highest inoculation dose, 9.9 x 10^7 CFU/100g body weight, the oral challenge induced deaths. In the bath challenge deaths were induced even at the lowest inoculation dose, 2.9 x 10^3 CFU/mL water. Hemorrhagic lesions on the fins were observed in dead fish challenged by both methods. It is suspected that S. iniae entered through the body surface such as abrasive sites of the fins to cause disease

立命館大学21世紀COEプログラムとジョイントワークショップ

ジョイントワークショップ 立命館大学の研究「文化遺産を核とした歴史都市の防災研究拠点

タイ類由来非定型 Edwardsiella tarda の血清学的性状

The serological relationships between a non-motile variant of Edwardsiella tarda isolated from sea breams, Pagrus major and Evynnis japonica, and typical strains of E. tarda isolated from Japanese eel, Anguilla japonica and Japanese flounder, Paralichthys olivaceus, were studied. Cross-absorption test revealed that all strains shared a similar O-antigen. Agglutination tests showed the presence of heat-labile antigens on the cell surface of the non-motile strains from sea breams. Immunoelectrophoretic analysis demonstrated the relatedness of cell surface antigens among the strains from various fish species. The possibility of usage of a common vaccine for edwardsiellosis among sea breams and other fish species is suggested