119 research outputs found

    Age-related asymmetry in left–right ears of sound lateralization with respect to four different rise times

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    An experimental investigation was conducted to elucidate the auditory characteristics of the older adult population. The study involved 24 older adult and 24 young participants, with the aim of exploring their horizontal lateralization ability. This was achieved by presenting 1-kHz pure tones to the participants’ right and left ears while introducing interaural time differences (ITDs). We examined the impact of four rise times (2, 5, 20, and 50 ms) on the onset of the test sound. The findings revealed that older adult participants exhibited lower levels of lateralization than young participants. Moreover, both older adult and young participants demonstrated diminished recognition of the onset portion as the rise time increased. Of particular significance was the conspicuous presence of a right ear advantage (REA) among young participants as the rise time was extended (statistically significant between the left and right ears at the 1% level, considering an ITD of 0.8 ms and a rise time of 50 ms). In contrast, older adult participants did not exhibit REA, even with a prolonged rise time (not significant at the 5% level at the same condition). These results indicate that the REA is not only present in language, as previously observed, but also extends to a pure tone in young participants. The older adult participants exhibited reduced performance in both left-and right-ear sound recognition. The influence of hearing threshold and preferred ear on sound lateralization performance was minimal. Therefore, it can be inferred that factors other than hearing threshold or preferred ear contribute to the presence of REA in young participants or its decline with age. The central and/or corpus callosum functions may also contribute to this phenomenon

    Measurement of electrostatic potential fluctuation using heavy ion beam probe in large helical device

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    Heavy ion beam probe (HIBP) for large helical device (LHD) has been improved to measure the potential fluctuation in high-temperature plasmas. The spatial resolution is improved to about 10 mm by controlling the focus of a probe beam. The HIBP is applied to measure the potential fluctuation in plasmas where the rotational transform is controlled by electron cyclotron current drive. The fluctuations whose frequencies change with the time constant of a few hundreds of milliseconds and that with a constant frequency are observed. The characteristics of the latter fluctuation are similar to those of the geodesic acoustic mode oscillation. The spatial profiles of the fluctuations are also obtained

    Phase Ib/II study of nivolumab combined with palliative radiation therapy for bone metastasis in patients with HER2-negative metastatic breast cancer

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    Radiation therapy (RT) can enhance the abscopal effect of immune checkpoint blockade. This phase I/II study investigated the efficacy and safety of nivolumab plus RT in HER2-negative metastatic breast cancer requiring palliative RT for bone metastases. Cohort A included luminal-like disease, and cohort B included both luminal-like and triple-negative disease refractory to standard systemic therapy. Patients received 8 Gy single fraction RT for bone metastasis on day 0. Nivolumab was administered on day 1 for each 14-day cycle. In cohort A, endocrine therapy was administered. The primary endpoint was the objective response rate (ORR) of the unirradiated lesions. Cohorts A and B consisted of 18 and 10 patients, respectively. The ORR was 11% (90% CI 4–29%) in cohort A and 0% in cohort B. Disease control rates were 39% (90% CI 23–58%) and 0%. Median progression-free survival was 4.1 months (95% CI 2.1–6.1 months) and 2.0 months (95% CI 1.2–3.7 months). One patient in cohort B experienced a grade 3 adverse event. Palliative RT combined with nivolumab was safe and showed modest anti-tumor activity in cohort A. Further investigations to enhance the anti-tumor effect of endocrine therapy combined with RT plus immune checkpoint blockade are warranted

    Excitation of helically-trapped-energetic-ion driven resistive interchange modes with intense deuterium beam injection and enhanced effect on beam ions/bulk plasmas of LHD

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    Energetic ion driven resistive InterChange modes (EICs) accompanying repeated bursts of the magnetic fluctuations were found in hydrogen campaign of large helical device. The pressure gradient of helically trapped energetic particles, which are mainly produced by perpendicularly injected beams, drives this mode. Recently, perpendicular neutral beam injection (PERP-NBI) systems are upgraded for deuterium plasma campaign. The beam energies of the two PERP-NBIs are increased from 40/40 keV to 60/80 keV, respectively. And the injection powers increase from 6/6 MW to 9/9 MW, as well. As results of these upgrades of NBIs, the β value of helically trapped energetic ions, , has increased up to  ∼0.35% and induced EICs with larger bursts and smaller repetition frequencies. It is found that the threshold of to excite EICs increases with deuterium PERP-NBIs. The amplitude of each burst and effect on energetic beam ions become larger when is larger. In addition, a large electrostatic potential about  −25 kV is observed when EICs are excited, which is about two times larger than the potential observed in hydrogen campaign. The transient increases of the electron density and temperature in edge regions are clearly observed when the electrostatic potential is formed

    The title of this Accepted manuscrpt was "Observation of strong destabilization of stable modes with a half frequency associated with chirping EGAMs in the LHD".

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    Abrupt and strong excitation of a mode has been observed when the frequency of a chirping energetic-particle driven geodesic acoustic mode (EGAM) reaches twice the geodesic acoustic mode (GAM) frequency. The frequency of the secondary mode is the GAM frequency, which is a half-frequency of the primary EGAM. Based on the analysis of spatial structures, the secondary mode is identified as a GAM. The phase relation between the secondary mode and the primary EGAM is locked, and the evolution of the growth rate of the secondary mode indicates nonlinear excitation. The results suggest that the primary mode (EGAM) contributes to nonlinear destabilization of a subcritical mode

    Recent Results from LHD Experiment with Emphasis on Relation to Theory from Experimentalist’s View

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    he Large Helical Device (LHD) has been extending an operational regime of net-current free plasmas towardsthe fusion relevant condition with taking advantage of a net current-free heliotron concept and employing a superconducting coil system. Heating capability has exceeded 10 MW and the central ion and electron temperatureshave reached 7 and 10 keV, respectively. The maximum value of β and pulse length have been extended to 3.2% and 150 s, respectively. Many encouraging physical findings have been obtained. Topics from recent experiments, which should be emphasized from the aspect of theoretical approaches, are reviewed. Those are (1) Prominent features in the inward shifted configuration, i.e., mitigation of an ideal interchange mode in the configuration with magnetic hill, and confinement improvement due to suppression of both anomalous and neoclassical transport, (2) Demonstration ofbifurcation of radial electric field and associated formation of an internal transport barrier, and (3) Dynamics of magnetic islands and clarification of the role of separatrix
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