7,795 research outputs found

    Comparative Study on the Inhibitory Effects of α-Tocopherol and Radon on Carbon Tetrachloride-Induced Renal Damage

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    Since the 2011 nuclear accident in Fukushima, the effects of low-dose irradiation, especially internal exposure, are at the forefront of everyone’s attention. However, low-dose radiation induced various stimulating effects such as activation of antioxidative and immune functions. In this study, we attempted to evaluate the quantitative effects of the activation of antioxidative activities in kidney induced by radon inhalation on carbon tetrachloride (CCl4)-induced renal damage. Mice were subjected to intraperitoneal (i.p.) injection of CCl4 after inhaling approximately 1000 or 2000 Bq/m3 radon for 24 h, or immediately after i.p. injection of α-tocopherol (100, 300, or 500 mg/kg bodyweight). In case of renal function, radon inhalation at a concentration of 2000 Bq/m3 has the inhibitory effects similar to α-tocopherol treatment at a dose of 300–500 mg/kg bodyweight. The activities of superoxide dismutase and catalase in kidneys were significantly higher in mice exposed to radon as compared to mice treated with CCl4 alone. These findings suggest that radon inhalation has an antioxidative effect against CCl4-induced renal damage similar to the antioxidative effects of α-tocopherol due to induction of antioxidative functions

    X-ray and Radio Follow-up Observations of High-Redshift Blazar Candidates in the Fermi-LAT Unassociated Source Population

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    We report on the results of X-ray and radio follow-up observations of two GeV gamma-ray sources 2FGL J0923.5+1508 and 2FGL J1502.1+5548, selected as candidates for high-redshift blazars from unassociated sources in the {\it Fermi} Large Area Telescope Second Source Catalog. We utilize the Suzaku satellite and the VLBI Exploration of Radio Astrometry (VERA) telescopes for X-ray and radio observations, respectively. For 2FGL J0923.5+1508, a possible radio counterpart NVSS J092357+150518 is found at 1.4 GHz from an existing catalog, but we do not detect any X-ray emission from it and derive a flux upper limit F2−8keV<F_{\rm 2-8 keV} < 1.37 ×\times 10−14^{-14} erg cm−2^{-2} s−1^{-1}. Radio observations at 6.7 GHz also result in an upper limit of S6.7GHzS_{\rm 6.7 GHz} << 19 mJy, implying a steep radio spectrum that is not expected for a blazar. On the other hand, we detect X-rays from NVSS J150229+555204, the potential 1.4 GHz radio counterpart of 2FGL J1502.1+5548. The X-ray spectrum can be fitted with an absorbed power-law model with a photon index Îł\gamma=1.8−0.2+0.3^{+0.3}_{-0.2} and the unabsorbed flux is F2−8keVF_{\rm 2-8 keV}=4.3−1.0+1.1^{+1.1}_{-1.0} ×\times 10−14^{-14} erg cm−2^{-2} s−1^{-1}. Moreover, we detect unresolved radio emission at 6.7 GHz with flux S6.7GHzS_{\rm 6.7 GHz}=30.1 mJy, indicating a compact, flat-spectrum radio source. If NVSS J150229+555204 is indeed associated with 2FGL J1502.1+5548, we find that its multiwavelength spectrum is consistent with a blazar at redshift z∌3−4z \sim 3-4.Comment: 24 pages, 7 figures, 6 tables, accepted for publication in Ap

    Performance Studies of a Micromegas Chamber in the ATLAS Environment

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    Five small prototype micromegas detectors were positioned in the ATLAS detector during Large Hadron Collider running at s=7\sqrt{s} = 7 and 8 TeV8\, \mathrm{TeV}. A 9×4.5 cm29\times 4.5\, \mathrm{cm^2} double drift gap detector was placed in front of the electromagnetic calorimeter and four 9×10 cm29\times 10\, \mathrm{cm^2} detectors on the ATLAS Small Wheel, the first station of the forward muon spectrometer. The one attached to the calorimeter was exposed to interaction rates of about 70 kHz/cm270\,\mathrm{kHz}/\mathrm{cm^2} at L=5×1033 cm−2s−1\mathcal{L}=5\times 10^{33}\,\mathrm{cm^{-2}s^{-1}} two orders of magnitude higher than the rates in the Small Wheel. We present the results from performance studies carried out using data collected with these detectors and we also compare the currents drawn by the detector installed in front of the electromagnetic calorimeter with the luminosity measurement in ATLAS.Comment: 9 pages, 11 figure

    Earliest detection of the optical afterglow of GRB 030329 and its variability

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    We report the earliest detection of an extremely bright optical afterglow of the gamma-ray burst (GRB) 030329 using a 30cm-telescope at Tokyo Institute of Technology (Tokyo, JAPAN). Our observation started 67 minutes after the burst, and continued for succeeding two nights until the afterglow faded below the sensitivity limit of the telescope (approximately 18 mag). Combining our data with those reported in GCN Circulars, we find that the early afterglow light curve of the first half day is described by a broken power-law (t^{- alpha}) function with indices alpha_{1} = 0.88 +/- 0.01 (0.047 < t < t_{b1} days), alpha_{2} = 1.18 +/- 0.01 (t_{b1} < t < t_{b2} days), and alpha_{3} = 1.81 +/- 0.04 (t_{b2} < t < 1.2 days), where t_{b1} ~ 0.26 days and t_{b2} ~ 0.54 days, respectively. The change of the power-law index at the first break at t ~ 0.26 days is consistent with that expected from a ``cooling-break'' when the cooling frequency crossed the optical band. If the interpretation is correct, the decay index before the cooling-break implies a uniform ISM environment.Comment: 13 pages, 1 table and 2 figures. Accepted to the Astrophysical Journal Letter

    Mālama nā makua i nā keiki me ka hānƍ: Native Hawaiian parents caring for their children with asthma

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    Native Hawaiian children have the highest prevalence rate of asthma among all ethnicities in the State of Hawai‘i. Literature is limited regarding native Hawaiian parents’ perception and experience caring for their children with asthma. The purpose of this study is to explore contemporary native Hawaiian parents’ perspective and experience of caring for their children with asthma in the context of uncertainty. We applied a descriptive qualitative approach by means of directed content analysis using focus groups. Directed content analysis applied Mishel’s Uncertainty in Illness Theory to guide data collection, organization, and analysis. We found that parents’ personal stories about their children to be rich and enlightening. Findings verified that native Hawaiian parents experience uncertainty regarding asthma care as commonly described in the literature. Contextual influences including indigenous worldview and cultural values affected native Hawaiian parents’ perceptions and experiences with conventional asthma care. Unique findings involved the etiology of asthma, features of social support (‘ohana), and differentiation between Western medicine and traditional healing practices. As nurses focus on supporting the family’s cultural values and preferences related to asthma care and alternative remedies, native Hawaiian parents’ care of their children with asthma will be strengthened
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