38 research outputs found

    Local Effects on Strain Seismogram at Matsushiro Seismological Observatory - 1. Love Waves

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    We proposed a simple method to evaluate local effects on a strain seismogram, and applied the method to investigation of the effects at Matsushiro Seismological Observatory, Japan Meteorological Agency, central Japan, for a Love wave in a period range of 170 - 400 sec. First, we took a ratio of EW to NS component strain for a Love wave on a timefrequency plane. Although NS and EW component strain for a Love wave travelling in any direction have the same amplitude theoretically, the ratio of observed EW to NS component strain was 0.7. Next, we compared the strain seismogram with a velocity seismogram recorded with STS-1 broadband seismometer. A ratio of a partial derivative of a displacement field with respect to time to that with respect to wave propagation direction equals a phase velocity of the wave theoretically. Utilizing the fact, we estimated the phase velocity of a Love wave using the observed velocity and strain seismogram, after NS component strain had been multiplied by 0.7. The result was 24% smaller than the theoretical phase velocity. Finally, we compared the velocity seismogram with other velocity seismograms recorded by STS-1 seismometers at F-net observation stations near Matsushiro and by STS-2 seismometer at Matsushiro, and found that the every deviation from Matsushiro was less than 10%. From these results, we conclude that the EW and NS component strain seismograms have been amplified by factors of 1.32 and 1.88 for a Love wave, respectively. This fact, which may be because of local geology and/or topography effects, must be taken into account when the strain seismogram is used for seismological applications such as the CMT inversion and research on earth¡¦s free oscillations

    Insights on the Sun birth environment in the context of star-cluster formation in hub-filament systems

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    Cylindrical molecular filaments are observed to be the main sites of Sun-like star formation, while massive stars form in dense hubs, at the junction of multiple filaments. The role of hub-filament configurations has not been discussed yet in relation to the birth environment of the solar system and to infer the origin of isotopic ratios of Short-Lived Radionuclides (SLR, such as 26^{26}Al) of Calcium-Aluminum-rich Inclusions (CAIs) observed in meteorites. In this work, we present simple analytical estimates of the impact of stellar feedback on the young solar system forming along a filament of a hub-filament system. We find that the host filament can shield the young solar system from the stellar feedback, both during the formation and evolution of stars (stellar outflow, wind, and radiation) and at the end of their life (supernovae). We show that the young solar system formed along a dense filament can be enriched with supernova ejecta (e.g., 26^{26}Al) during the formation timescale of CAIs. We also propose that the streamers recently observed around protostars may be channeling the SLR-rich material onto the young solar system. We conclude that considering hub-filament configurations as the birth environment of the Sun is important when deriving theoretical models explaining the observed properties of the solar system.Comment: Accepted for publication in The Astrophysical Journal Letter

    Gefitinib (IRESSA) sensitive lung cancer cell lines show phosphorylation of Akt without ligand stimulation

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    BACKGROUND: Phase III trials evaluating the efficacy of gefitinib (IRESSA) in non-small cell lung cancer (NSCLC) lend support to the need for improved patient selection in terms of gefitinib use. Mutation of the epidermal growth factor receptor (EGFR) gene is reported to be associated with clinical responsiveness to gefitinib. However, gefitinib-sensitive and prolonged stable-disease-defined tumors without EGFR gene mutation have also been reported. METHODS: To identify other key factors involved in gefitinib sensitivity, we analyzed the protein expression of molecules within the EGFR family, PI3K-Akt and Ras/MEK/Erk pathways and examined the sensitivity to gefitinib using the MTT cell proliferation assay in 23 lung cancer cell lines. RESULTS: We identified one highly sensitive cell line (PC9), eight cell lines displaying intermediate-sensitivity, and 14 resistant cell lines. Only PC9 and PC14 (intermediate-sensitivity) displayed an EGFR gene mutation including amplification. Eight out of the nine cell lines showing sensitivity had Akt phosphorylation without ligand stimulation, while only three out of the 14 resistant lines displayed this characteristic (P = 0.0059). Furthermore, the ratio of phosphor-Akt/total Akt in sensitive cells was higher than that observed in resistant cells (P = 0.0016). Akt phosphorylation was partially inhibited by gefitinib in all sensitive cell lines. CONCLUSION: These results suggest that Akt phosphorylation without ligand stimulation may play a key signaling role in gefitinib sensitivity, especially intermediate-sensitivity. In addition, expression analyses of the EGFR family, EGFR gene mutation, and FISH (fluorescence in situ hybridization) analyses showed that the phosphorylated state of EGFR and Akt might be a useful clinical marker of Akt activation without ligand stimulation, in addition to EGFR gene mutation and amplification, particularly in adenocarcinomas

    A randomized, double-masked, placebo-controlled crossover trial on the effects of L-ornithine on salivary cortisol and feelings of fatigue of flushers the morning after alcohol consumption

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    Abstract Background Residual alcohol effects on physiological and psychological symptoms are commonly experienced the morning after alcohol consumption. The purpose of this study was to assess the effects of L-ornithine on subjective feelings and salivary stress markers the morning after alcohol consumption and to investigate whether L-ornithine acutely accelerates ethanol metabolism. Methods This study had a randomized, placebo-controlled, double-masked crossover design. Subjects were all healthy Japanese adults with the ‘flusher’ phenotype for alcohol tolerance. In experiment 1, 11 subjects drank 0.4 g/kg body weight alcohol 1.5 h before their usual bedtime. Half an hour after drinking, they ingested either a placebo or 400 mg ornithine. The next morning on awakening, subjects completed a questionnaire containing a visual analog scale (VAS), the Oguri-Shirakawa-Azumi sleep inventory MA version (OSA-MA), and a profile of mood states (POMS) and collected a saliva sample for measurement of salivary stress markers (cortisol, secretory immunoglobulin A, and α-amylase). In experiment 2, placebo or 400 mg ornithine were administrated to 16 subjects both before and after drinking, and the feeling of drunkenness, breath ethanol concentration and one-leg standing time were repeatedly investigated until 180 min after alcohol consumption. Results There were significant decreases in “awareness”, “feeling of fatigue” and “lassitude” VAS scores and in “anger-hostility” and “confusion” POMS scores and a significant increase in “sleep length” in the OSA-MA test. Salivary cortisol concentrations on awakening were reduced after ornithine supplementation. There were no differences between ornithine and placebo in any of the subjective or physiological parameters of acute alcohol metabolism. Conclusions Taking 400 mg ornithine after alcohol consumption improved various negative feelings and decreased the salivary stress marker cortisol the next morning. These effects were not caused by an increase in acute alcohol metabolism.</p
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