125 research outputs found

    K\"ahler manifolds with negative holomorphic sectional curvature, K\"ahler-Ricci flow approach

    Full text link
    Recently, Wu-Yau and Tosatti-Yang established the connection between the negativity of holomorphic sectional curvatures and the positivity of canonical bundles for compact K\"ahler manifolds. In this short note, we give anothe proof of their theorems by using the K\"ahler-Ricci flow.Comment: 4pages, minor change

    Spatiotemporal analysis of the UPR transition induced by methylmercury in the mouse brain

    Get PDF
    Methylmercury (MeHg), an environmental toxicant, induces neuronal cell death and injures a specific area of the brain. MeHg-mediated neurotoxicity is believed to be caused by oxidative stress and endoplasmic reticulum (ER) stress but the mechanism by which those stresses lead to neuronal loss is unclear. Here, by utilizing the ER stress-activated indicator (ERAI) system, we investigated the signaling alterations in the unfolded protein response (UPR) prior to neuronal apoptosis in the mouse brain. In ERAI transgenic mice exposed to MeHg (25 mg/kg, S.C.), the ERAI signal, which indicates activation of the cytoprotective pathway of the UPR, was detected in the brain. Interestingly, detailed ex vivo analysis showed that the ERAI signal was localized predominantly in neurons. Time course analysis of MeHg exposure (30 ppm in drinking water) showed that whereas the ERAI signal was gradually attenuated at the late phase after increasing at the early phase, activation of the apoptotic pathway of the UPR was enhanced in proportion to the exposure time. These results suggest that MeHg induces not only ER stress but also neuronal cell death via a UPR shift. UPR modulation could be a therapeutic target for treating neuropathy caused by electrophiles similar to MeHg

    LHC Reach of Low Scale Gauge Mediation with Perturbatively Stable Vacuum

    Full text link
    Very light gravitino scenario m_{3/2} < 16 eV is very interesting, since there is no cosmological problem. However in such a scenario, stability of the vacuum is an important issue. Recently, Yonekura and one of the authors RS have investigated the parameter space of a low scale gauge mediation with a perturbatively stable vacuum and found that there are severe upper bound on the gaugino masses. In this paper, we show that such a model can be completely excluded/discovered at very early stage of the LHC run.Comment: 10 pages, 1 figure; v2: minor collection

    Fault detection system for ICRF transmission line in LHD

    Get PDF
    The transmission line is one of the most important components of ion cyclotron range of frequencies (ICRF) heating devices. In the case of unexpected trouble on the line, such as a breakdown, immediate power-off is necessary in order to avoid severe damage on the line. Breakdowns are difficult to detect with a reflection monitor, since the reflection may originate from a change in the antenna-plasma coupling. In the Large Helical Device (LHD), a Fault Detection System (FDS) for the transmission line was developed, which detects the breakdown utilizing the unbalance of three signals from the both ends of the line. For the precise balancing in the normal condition, the calibration is iteratively conducted. FDS is insensitive to the change of the antenna impedance, therefore, FDS can detect breakdown clearly. Frequency shift is also detectable with the FDS applied to a long transmission line. Therefore, the self-oscillation accompanying frequency shift could be detected in addition to breakdown
    corecore