121 research outputs found

    Velocity Structure of Jets in Coronal Hole

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    Velocity structures of jets in a coronal hole have been derived for the first time. Hinode observations revealed the existence of many bright points in coronal holes. They are loop-shaped and sometimes associated with coronal jets. Spectra obtained with the Extreme ultraviolet Imaging Spectrometer (EIS) on board Hinode are analyzed to infer Doppler velocity of bright loops and jets in a coronal hole of the north polar region. Elongated jets above bright loops are found to be blue-shifted by 30 km/s at maximum, while foot points of bright loops are red-shifted. Blue-shifts detected in coronal jets are interpreted as upflows produced by magnetic reconnection between emerging flux and the ambient field in the coronal hole.Comment: 11 pages, 7 figures, accepted for publication in PASJ Hinode special issu

    Examination of the Application Support Layer of CCSDS SOIS Using SpaceWire Communication Stack and Low-Code User Application

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    As a SmallSat grows, there is an increasing need for high-speed and high-functioning sub-networks, such as SpaceWire, to connect equipment to the OBC and store large amounts of optical image data. SpaceWire has the ability for time-sensitive delivery, fast communication, and flexible network topology construction. JAXA/ISAS has developed SIB2, a low-code user application that designs telemetry commands based on a database stored on the satellite. SIB2 has a code generation function called SIB2Generator, which outputs code that performs the behavior of telemetry commands during sender/receiver and is used as a template for user applications. On the other hand, the Application Support Layer of CCSDS SOIS is positioned between sub-networks and user applications. And then, service types are defined in the Application Support Layer, but no concrete implementation interface is specified. Therefore, we have implemented an examination of the Command and Data Acquisition Services layer using SIB2 and the SpaceWire communication stack. In the executed study, we adopted the SpaceWire RMAP Library, a class library that makes SpaceWire communication. Using this library, we have designed and developed the Application Support Layer, integrating the SpaceWire application stack based on the SIB2 database design and the user application code generated by SIB2Generator

    Discovery of Non Thermal X-Rays from the Northwest Shell of the New SNR RX J1713.7-3946: The Second SN1006 ?

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    We report ASCA results of a featureless X-ray spectrum from RX J1713.7-3946, a new shell-like SNR discovered with the ROSAT all sky survey. The northwest part of RX J1713.7-3946 was in the field of the ASCA Galactic Plane Survey Project and was found to exhibit a shell-like structure. The spectrum, however shows neither line emission nor any signature of a thermal origin. Instead, a power-law model with a photon index of 2.4-2.5 gives reasonable fit to the spectrum, suggesting a non-thermal origin. Together with the similarity to SN1006, we propose that RX J1713.7-3946 is the second example, after SN1006, of a synchrotron X-ray radiation from a shell of SNRs. Since the synchrotron X-rays suggest existence of extremely high energy charged particles in the SNR shell, our discovery should have strong impact on the origin of the cosmic X-rays.Comment: 4 pages, 3 postscript figure

    Search for Hot Gas in the Local Group with ASCA

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    An X-ray study was made to examine whether some part of the soft X-ray background is coming from hot gas in the Local Group. For this purpose, four consecutive pointings were made with ASCA toward a sky region between M 31 and M 33, which is close to the direction of the center of the Local Group. By comparing the X-ray surface brightness in this sky direction with that in another blank sky region near the north equatorial pole, an upper limit on any soft excess X-ray background was determined to be 2.8×109\times10^{-9} erg cm2^{-2} s1^{-1} sr1^{-1} with a 90% confidence level statistical error. Assuming an optically thin thermal bremsstrahlung energy spectrum (Raymond-Smith model) for a temperature of 1 keV and a β\beta-model electron density distribution for a core radius of 100 kpc for the X-ray halo, the upper limit of the central plasma density was obtained to be 1.3×104\times10^{-4} cm3^{-3}. The plasma column density is too low to contribute significantly to the observed quadrupole anisotropy in the cosmic microwave background.Comment: 21pages, 6 figures, paper will be published to PASJ Vol.54, No.

    Cost Analysis of Screening for IgA Nephropathy Using Novel Biomarkers

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    [Objectives] IgA nephropathy (IgAN) is the most common primary chronic glomerulonephritis and a major cause of end-stage kidney disease worldwide. Novel biomarkers, including the aberrantly glycosylated IgA1 and glycan-specific antibodies, could be useful in the diagnosis of IgAN. The aim of this study was to assess the cost analysis of IgAN screening using novel biomarkers in addition to the conventional screening compared with conventional screening alone. [Methods] To estimate the medical expense of each strategy related to renal disease for 40 years, we developed an analytical decision model. The decision tree started at “40 years of age with first-time hematuria.” It simulated 2 clinical strategies: IgAN screening using the novel biomarkers (group N) and conventional screening (group C). The analysis results were presented as medical expenses from a societal perspective. Discounting was not conducted. [Results] The expected medical expense per person for 40 years was ¥31.2 million (~291000)ingroupNand¥33.4million( 291 000) in group N and ¥33.4 million (~312 000) in group C; hence, expense in group N was lower by ¥2.2 million (~$21 000). In group N, the expected value of IgAN increased by 5.67% points (N 48.44%, C 42.77%) and that of dialysis introduction decreased by 0.85% points (N 19.06%, C 19.91%). In the sensitivity analysis, expenses could be reduced in almost all cases except when renal biopsy using conventional screening was performed at the rate of 73% or higher. [Conclusion] Screening for IgAN using novel biomarkers would reduce renal disease–related expenses

    Discovery of a new pulsating X-ray source with a 1549.1-s period, AX J183220-0840

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    A new pulsating X-ray source, AX J183220-0840, with a 1549.1-s period was discovered at R.A.= 18h32m20s and Dec.=-8d40'30'' (J2000, uncertainty=0.6degree) during an ASCA observation on the Galactic plane. The source was observed two times, in 1997 and in 1999. A phase-averaged X-ray flux of 1.1E-11 ergs cm-2 s-1 and pulsation period of 1549.1+/-0.4 s were consistently obtained from these two observations. The X-ray spectrum was represented by a flat absorbed power-law with a photon-index of =~0.8 and an absorption column density of =~1.3E22 cm-2. Also, a signature of iron K-shell line emission with a centroid of 6.7 keV and an equivalent width of approximately 450 eV was detected. From the pulsation period and the iron-line feature, AX J183220-0840 is likely to be a magnetic white dwarf binary with a complexly absorbed thermal spectrum with a temperature of about 10 keV.Comment: 13 pages, 4 figures, accepted for publication in ApJ Letter

    GADD45β Determines Chemoresistance and Invasive Growth of Side Population Cells of Human Embryonic Carcinoma

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    Side population (SP) cells are an enriched population of stem, and the existence of SP cells has been reported in human cancer cell lines. In this study, we performed an SP analysis using 11 human cancer cell lines and confirmed the presence of SP cells in an embryonic carcinoma cell line, NEC8. NEC8 SP cells showed characteristics of cancer stem cells, such as high growth rate, chemoresistance and high invasiveness. To further characterize the NEC8 SP cells, we used DNA microarrays. Among 38,500 genes, we identified 12 genes that were over-expressed in SP cells and 1 gene that was over-expressed in non-SP cells. Among these 13 genes, we focused on GADD45b. GADD45b was over-expressed in non-SP cells, but the inhibition of GADD45b had no effect on non-SP cells. Paradoxically, the inhibition of GADD45b significantly reduced the viability of NEC8 SP cells. The inhibition of ABCG2, which determines the SP phenotype, had no effect on the invasiveness of NEC8 SP cells, but the inhibition of GADD45b significantly reduced invasiveness. These results suggest that GADD45b, but not ABCG2, might determine the cancer stem cell-like phenotype, such as chemoresistance and the high invasiveness of NEC8 SP cells, and might be a good therapeutic target

    Hinode Calibration for Precise Image Co-alignment between SOT and XRT (November 2006 -- April 2007)

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    To understand the physical mechanisms for activity and heating in the solar atmosphere, the magnetic coupling from the photosphere to the corona is an important piece of information from the Hinode observations, and therefore precise positional alignment is required among the data acquired by different telescopes. The Hinode spacecraft and its onboard telescopes were developed to allow us to investigate magnetic coupling with co-alignment accuracy better than 1 arcsec. Using the Mercury transit observed on 8 November 2006 and co-alignment measurements regularly performed on a weekly basis, we have determined the information necessary for precise image co-alignment and have confirmed that co-alignment better than 1 arcsec can be realized between Solar Optical Telescope (SOT) and X-Ray Telescope (XRT) with our baseline co-alignment method. This paper presents results from the calibration for precise co-alignment of CCD images from SOT and XRT.Comment: 8 pages, 9 figures, accepted for publication in PASJ (Hinode Special issue

    Marylosides A-G, Norcycloartane Glycosides from Leaves of Cymbidium Great Flower ‘Marylaurencin’

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    Seven novel norcycloartane glycosides, maryloside A–G (1–7), were isolated from the leaves of Cymbidium Great Flower ‘Marylaurencin’, along with a known norcycloartane glycoside, cymbidoside (8). These structures were determined on the basis of mainly NMR experiments as well as chemical degradation and X-ray crystallographic analysis. The isolated compounds (1–6 and 8) were evaluated for the inhibitory activity on lipopolysaccharide (LPS) and interferon-γ (IFN-γ)-stimulated nitric oxide (NO) production in RAW 264.7 cells. Consequently, 1 and 3 exhibited moderate activity
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