231 research outputs found

    Axion Dark Matter Search with Interferometric Gravitational Wave Detectors

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    Axion dark matter differentiates the phase velocities of the circular-polarized photons. In this Letter, a scheme to measure the phase difference by using a linear optical cavity is proposed. If the scheme is applied to the Fabry-P\'erot arm of Advanced LIGO-like (Cosmic-Explorer-like) gravitational wave detector, the potential sensitivity to the axion-photon coupling constant, gaγg_{\text{a}\gamma}, reaches gaγ8×1013g_{\text{a}\gamma} \simeq 8\times10^{-13} GeV1(4×1014^{-1}\, (4 \times 10^{-14} GeV1)^{-1}) at the axion mass m3×1013m \simeq 3\times 10^{-13} eV (2×10152\times10^{-15} eV) and remains at around this sensitivity for 3 orders of magnitude in mass. Furthermore, its sensitivity has a sharp peak reaching gaγ1014g_{\text{a}\gamma} \simeq 10^{-14} GeV1^{-1} (8×1017(8\times10^{-17} GeV1)^{-1}) at m=1.563×1010m = 1.563\times10^{-10} eV (1.563×10111.563\times10^{-11} eV). This sensitivity can be achieved without loosing any sensitivity to gravitational waves.Comment: 7 pages, 2 figure

    FINGER FORCES DURING BASEBALL PITCHING

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    A 3D force transducer was installed in an official baseball to make a direct measurement of finger force imparting on the ball during pitching. Eight collegiate pitchers threw a 4- seam fastball at their maximal speed. Force was measured separately from each of the index, middle, and ring fingers, and the thumb. Peaks and peak occurrence time of computed resultant and shear forces were evaluated. Index and middle finger forces generally had a bimodal pattern with the first and second peaks appeared at about 80, and 96% of the stride foot contact period, respectively. Their force magnitude reached 90 N. and above. Magnitude of shear force was about half of the resultant force. Forces by the thumb and ring finger were less than those by the index and middle fingers. The findings indicated that the fingers were applying considerably large magnitude of force during pitching

    Methotrexate-Associated Lymphoproliferative Disorder Developed Ectopically in the Maxillary Gingiva and Bilateral Lungs

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    A 58-year-old Japanese woman complained of a painful right maxillary premolar gingiva and ulcer. The patient had RA and had been treated with several immunosuppressive drugs such as methotrexate. Head and neck CT indicated no obvious bone destruction with maxillary. However, chest CT indicated the presence of nodular mass of the bilateral lungs. FDG-PET/CT indicated the presence of increased uptake in both lesions. On immunohistochemistry, atypical large-sized lymphocytes were positive for CD20 and EBER-ISH and negative for CD3, CD5, and CD10; the Ki-67 labeling index was high, the histopathological diagnosis was EBV-positive DLBCL, and the clinical diagnosis was MTX-LPD. The patient's treatment with MTX was then discontinued; we removed the alveolar bone which necrosed after 5 weeks. The lesion and the nodular mass at the bilateral lungs had completely disappeared after 7 weeks

    The Development Status of the First Demonstration Satellite of Our Commercial Small Synthetic Aperture Radar Satellite Constellation

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    Expectations for SAR (Synthetic Aperture Radar) satellites that can observe a target area through clouds and during nighttime are emerging, especially in Asia where high cloud cover rate prevent from the satellite monitoring with optical sensors. We are now developing a small SAR satellite based on technologies of ImPACT (Impulsing PAradigm Change through disruptive Technologies) program. This program aims to develop a responsive earth observation system with the small SAR satellite, originally target for disaster monitoring. We will build a constellation of the small SAR satellites to realize short term revisits, shorter than one day to take advantage of SAR sensor that can acquire data regardless of weather and time in a day. We expect the constellation expands needs of the SAR data to business and private decision making, and develop a market for commercial use. We have almost completed the development of mission FM components of the first demo satellite. The bus system is under EM testing and FM procurements. We will launch the first demo satellite in Q1 of 2020. We are already preparing to build the second satellite and will make six satellite constellation until 2021. Our final goal is to build a constellation of 25 satellites

    SERCA2a過剰発現ラットにおけるイソプロテレノール持続投与誘導肥大心の左室力学的エネルギー学的性質の変化

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    Overexpression of cardiac sarcoplasmic reticulum Ca2 +-ATPase (SERCA2a) has been suggested as a strategic intervention for cardiac failure. However, its benefit in wild-type (WT) rats with normal SERCA2a levels seems to be small. To investigate whether it would be beneficial in a cardiac failure model with down-regulated SERCA2a levels, we made a cardiac hypertrophy model using isoproterenol infusion (1.2 mg kg− 1 day− 1 for 1 or 4 weeks; TG-ISO1w and TG-ISO4w, respectively) in SERCA2a transgenic (TG) rats and compared these rats with littermate WT rats that underwent the same treatments (WT-ISO1w and WT-ISO4w). We analyzed the left ventricular (LV) mechanoenergetics in the excised heart using our original cross-circulation system. The downward shift of curvilinear LV end-systolic pressure–volume relations (ESPVRs) observed in WT-ISO4w rats was abolished in TG-ISO4w rats. The slope and VO2 intercept of the VO2 (myocardial oxygen consumption per beat)–PVA (systolic pressure–volume area: total mechanical energy per beat) linear relation did not differ in any of the groups. The most important finding was a significantly smaller O2 cost of LV contractility in the TG-ISO4w group, which means that less O2 is needed to exert the same LV contractility, compared with the other groups. The increased ratio of SERCA2a/phospholamban returned to the level of the WT-control group only in the TG-ISO4w group. Longer-term up-regulation of mitochondrial transcription factor A for genes of mitochondrial enzymes producing ATP was observed in TG rats. In conclusion, longer-term overexpression of SERCA2a will be beneficial in the present cardiac failure model with down-regulated SERCA2a levels.博士(医学)・甲619号・平成26年3月17

    SERCA2aの持続的過剰発現は、生理的条件下では膀胱機能に影響を及ぼすが、膀胱出口部閉塞亜急性期の病的条件下では膀胱機能に影響しない

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    A functional impairment of the bladder and heart in a decompensated state caused by a pressure overload is accompanied by a decrease in the sarcoplasmic reticulum Ca2+-ATPase (SERCA2). The beneficial effects of SERCA2 overexpression in preserving cardiac functions have been previously reported. The aim of the present study was to investigate the effects of overexpressed SERCA2 on bladder functions under physiological and pathological conditions using partial bladder outlet obstruction (BOO) in SERCA2a transgenic Wistar rats (TG). Bladder cystometry and western blot analysis were performed using the wild-type Wistar rats (WT), TG, and BOO models (WTBOO and TGBOO). Persistent overexpression of SERCA2 induces reduced bladder compliance without hypertrophy in TG. BOO induces reduced bladder compliance and hypertrophy in WT and TG in the sub-acute phase, but persistent overexpression of SERCA2a in TG does not aggravate the bladder compliance and hypertrophy. In conclusion, SERCA2a overexpression affects bladder functions under physiological conditions, but not in BOO-induced sub-acute pathological conditions.博士(医学)・甲第623号・平成26年5月28

    Axion dark matter search using arm cavity transmitted beams of gravitational wave detectors

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    Axion is a promising candidate for ultralight dark matter which may cause a polarization rotation of laser light. Recently, a new idea of probing the axion dark matter by optical linear cavities used in the arms of gravitational wave detectors has been proposed [Phys. Rev. Lett. 123, 111301 (2019)]. In this article, a realistic scheme of the axion dark matter search with the arm cavity transmission ports is revisited. Since photons detected by the transmission ports travel in the cavity for odd-number of times, the effect of axion dark matter on their phases is not cancelled out and the sensitivity at low-mass range is significantly improved compared to the search using reflection ports. We also take into account the stochastic nature of the axion field and the availability of the two detection ports in the gravitational wave detectors. The sensitivity to the axion-photon coupling, gaγg_{a\gamma}, of the ground-based gravitational wave detector, such as Advanced LIGO, with 1-year observation is estimated to be gaγ3×1012g_{a\gamma} \sim 3\times10^{-12} GeV1^{-1} below the axion mass of 101510^{-15} eV, which improves upon the limit achieved by the CERN Axion Solar Telescope.Comment: 10 pages, 4 figure

    Natural van der Waals heterostructural single crystals with both magnetic and topological properties

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    Heterostructures having both magnetism and topology are promising materials for the realization of exotic topological quantum states while challenging in synthesis and engineering. Here, we report natural magnetic van der Waals heterostructures of (MnBi2Te4)m(Bi2Te3)n that exhibit controllable magnetic properties while maintaining their topological surface states. The interlayer antiferromagnetic exchange coupling is gradually weakened as the separation of magnetic layers increases, and an anomalous Hall effect that is well coupled with magnetization and shows ferromagnetic hysteresis was observed below 5 K. The obtained homogeneous heterostructure with atomically sharp interface and intrinsic magnetic properties will be an ideal platform for studying the quantum anomalous Hall effect, axion insulator states, and the topological magnetoelectric effect.Comment: 40 pages, 15 figure

    Suppression of cell cycle progression by Jun dimerization protein (JDP2) involves down-regulation of cyclin A2

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    We report here a novel role for Jun dimerization protein-2 (JDP2) as a regulator of the progression of normal cells through the cell cycle. To determine the role of JDP2 in vivo, we generated Jdp2 knock-out (Jdp2KO) mice by targeting exon 1 to disrupt the site of initiation of transcription. The healing of wounded skin of Jdp2KO mice proceeded more rapidly than that of control mice and more proliferating cells were found at wound margins. Fibroblasts derived from embryos of Jdp2KO mice proliferated more rapidly and formed more colonies than wild-type fibroblasts. JDP2 was recruited to the promoter of the gene for cyclin A2 (ccna2) at a previously unidentified AP-1 site. Cells lacking Jdp2 had elevated levels of cyclin A2 mRNA. Moreover, reintroduction of JDP2 resulted in repression of transcription of ccna2 and of cell cycle progression. Thus, transcription of the gene for cyclin A2 appears to be a direct target of JDP2 in the suppression of cell proliferation
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