28 research outputs found

    To the Edge of M87 and Beyond: Spectroscopy of Intracluster Globular Clusters and Ultra Compact Dwarfs in the Virgo Cluster

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    We present the results from a wide-field spectroscopic survey of globular clusters (GCs) in the Virgo Cluster. We obtain spectra for 201 GCs and 55 ultracompact dwarfs (UCDs) using the Hectospec on the Multiple Mirror Telescope, and derive their radial velocities. We identify 46 genuine intracluster GCs (IGCs), not associated with any Virgo galaxies, using the 3D GMM test on the spatial and radial velocity distribution.They are located at the projected distance 200 kpc â‰Č\lesssim R â‰Č\lesssim 500 kpc from the center of M87. The radial velocity distribution of these IGCs shows two peaks, one at vrv_{\rm r} = 1023 km s−1^{-1} associated with the Virgo main body, and another at vrv_{\rm r} = 36 km s−1^{-1} associated with the infalling structure. The velocity dispersion of the IGCs in the Virgo main body is σGC∌\sigma_{\rm{GC}} \sim 314 km s−1^{-1}, which is smoothly connected to the velocity dispersion profile of M87 GCs, but much lower than that of dwarf galaxies in the same survey field, σdwarf∌\sigma_{\rm{dwarf}} \sim 608 km s−1^{-1}. The UCDs are more centrally concentrated on massive galaxies, M87, M86, and M84. The radial velocity dispersion of the UCD system is much smaller than that of dwarf galaxies. Our results confirm the large-scale distribution of Virgo IGCs indicated by previous photometric surveys. The color distribution of the confirmed IGCs shows a bimodality similar to that of M87 GCs. This indicates that most IGCs are stripped off from dwarf galaxies and some from massive galaxies in the Virgo.Comment: 19 pages, 20 figures, 8 tables, accepted for publication in Ap

    Optical Spectroscopy of Supernova Remnants in M81 and M82

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    We present spectroscopy of 28 SNR candidates as well as one H II region in M81, and two SNR candidates in M82. Twenty six out of the M81 candidates turn out to be genuine SNRs, and two in M82 may be shocked condensations in the galactic outflow or SNRs. The distribution of [N II]/H{\alpha} ratios of M81 SNRs is bimodal. M81 SNRs are divided into two groups in the spectral line ratio diagrams: an [O III]-strong group and an [O III]-weak group. The latter have larger sizes, and may have faster shock velocity. [N II]/H{\alpha} ratios of the SNRs show a strong correlation with [S II]/H{\alpha} ratios. They show a clear radial gradient in [N II]/H{\alpha} and [S II]/H{\alpha} ratios: dLog ([N II]/H{\alpha})/dLog R = -0.018 {\pm} 0.008 dex/kpc and dLog ([S II]/H{\alpha})/dLog R = -0.016 {\pm} 0.008 dex/kpc where R is a deprojected galactocentric distance. We estimate the nitrogen and oxygen abundance of the SNRs from the comparison with shock-ionization models. We obtain a value for the nitrogen radial gradient, dLog(N/H)/dLogR = -0.023 {\pm} 0.009 dex/kpc, and little evidence for the gradient in oxygen. This nitrogen abundance shows a few times flatter gradient than those of the planetary nebulae and H II regions. We find that five SNRs are matched with X-ray sources. Their X-ray hardness colors are consistent with thermal SNRs.Comment: 19 pages, 24 figures, 5 tables, ApJ accepte

    Ethanol extract of Scutellaria baicalensis Georgi prevents oxidative damage and neuroinflammation and memorial impairments in artificial senescense mice

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    Aging is a progressive process related to the accumulation of oxidative damage and neuroinflammation. We tried to find the anti-amnesic effect of the Scutellaria baicalens Georgia (SBG) ethanol extract and its major ingredients. The antioxidative effect of SBG on the mice model with memory impairment induced by chronic injection of D-galactose and sodium nitrate was studied. The Y-maze test was used to evaluate the learning and memory function of mice. The activities of superoxide dismutase, catalase and the content of malondialdehyde in brain tissue were used for the antioxidation activities. Neuropathological alteration and expression of bcl-2 protein were investigated in the hippocampus by immunohistochemical staining. ROS, neuroinflammation and apoptosis related molecules expression such as Cox-2, iNOS, procaspase-3, cleaved caspase-3, 8 and 9, bcl-2 and bax protein and the products of iNOS and Cox-2, NO, PGE2, were studied using LPS-activated Raw 264.7 cells and microglia BV2 cells. The cognition of mice was significantly improved by the treatment of baicalein and 50 and 100 mg/kg of SBG in Y-maze test. Both SBG groups showed strong antioxidation, antiinflammation effects with significantly decreased iNOS and Cox-2 expression, NO and PGE2 production, increased bcl-2 and decreased bax and cleaved caspase-3 protein expression in LPS induced Raw 264.7 and BV2 cells. We also found that apoptotic pathway was caused by the intrinsic mitochondrial pathway with the decreased cleaved caspase-9 and unchanged cleaved caspase-8 expression. These findings suggest that SBG, especially high dose, 100 mg/kg, improved the memory impairments significantly and showed antioxidation, antiinflammation and intrinsic caspase-mediated apoptosis effects

    Sebastian Kneipp and the Natural Cure Movement of Germany: Between Naturalism and Modern Medicine

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    This study discusses the historical significance of the Natural Cure Movement of Germany, centering on the Kneipp Cure, a form of hydrotherapy practiced by Father Sebastian Kneipp (1821-1897). The Kneipp Cure rested on five main tenets: hydrotherapy, exercise, nutrition, herbalism, and the balance of mind and body. This study illuminates the reception of the Kneipp Cure in the context of the trilateral relationship among the Kneipp Cure, the Natural Cure Movement in general, and modern medicine. The Natural Cure Movement was ideologically based on naturalism, criticizing industrialization and urbanization. There existed various theories and methods in it, yet they shared holism and vitalism as common factors. The Natural Cure Movement of Germany began in the early 19th century. During the late 19th century and the early 20th century, it became merged in the Lebensreformbewegung (life reform movement) which campaigned for temperance, anti-tobacco, and anti-vaccination. The core of the Natural Cure Movement was to advocate the world view that nature should be respected and to recognize the natural healing powers of sunlight, air, water, etc. Among varied natural therapies, hydrotherapy spread out through the activities of some medical doctors and amateur healers such as Johann Siegmund Hahn and Vincenz Prie ÎČ nitz. Later, the supporters of hydrotherapy gathered together under the German Society of Naturopathy. Sebastian Kneipp, one of the forefathers of hydrotherapy, is distinguished from other proponents of natural therapies in two aspects. First, he did not refuse to employ vaccination and medication. Second, he sought to be recognized by the medical world through cooperating with medical doctors who supported his treatment. As a result, the Kneipp cure was able to be gradually accepted into the medical world despite the “quackery” controversy between modern medicine and the Natural Cure Movement. Nowadays, the name of Sebastian Kneipp remains deeply engraved on the memories of German people through various Kneipp spa products, as well as his books such as My water Cure and Thus Shalt Thou Live! Wörishofen, where Kneipp had served as catholic priest as well as hydrotherapist for 42 years from 1855, changed its name to “Bad Wörishofen” (“Wörishofen Spa” in German). The Kneipp Cure and the Natural Cure Movement became a source of ecologica l thought which is currently gaining more and more sympathy from German people. It is regarded as a lieu de mĂ©moire (site of memory) reflecting the collective identity of German people

    Airline Cabin Crew Team System’s Positive Evaluation Factors and Their Impact on Personal Health and Team Potency

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    Recently, many airline companies have trialed introducing team systems to manage crew members and enhance competitiveness systematically through the efficiency of manpower operation. Cabin crew members share in a sense of unity when spending time with team members outside of work hours. Cabin crews must be able to resolve unexpected issues—fires, aircraft defects, medical emergencies, and sudden airflow changes—quickly and accurately. As unexpected issues may result in major accidents, it is crucial that cabin crew members can take responsibility for passenger safety and offer satisfactory services to customers. Furthermore, most cabin duties require cooperation and are highly interdependent; thus, respect and teamwork are essential. This empirical study aims to identify and examine the positive factors of the team system used to evaluate causalities in job satisfaction, team potency, and mental health. The research model is developed based on a theoretical review, focusing on five positive factors—sense of belonging, mutual support, communication, motivation, and work flexibility—and dependent variables: job satisfaction, team potency, and mental health. Sense of belonging, communication, and work flexibility significantly affected team potency along with job satisfaction. This study has practical implications, providing guidance for the sustainable development of team systems for airline crew management

    The Color Gradients of the Globular Cluster Systems in M87 and M49

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    International audienceAbstract Combining data from the ACS Virgo Cluster Survey and the Next Generation Virgo cluster Survey, we extend previous studies of color gradients of the globular cluster (GC) systems of the two most massive galaxies in the Virgo cluster, M87 and M49, to radii of ∌15 R e (∌200 kpc for M87 and ∌250 kpc for M49, where R e is the effective radius). We find significant negative color gradients, i.e., becoming bluer with increasing distance, out to these large radii. The gradients are driven mainly by the outward decrease in the ratio of red to blue GC numbers. The color gradients are also detected out to ∌15 R e in the red and blue subpopulations of GCs taken separately. In addition, we find a negative color gradient when we consider the satellite low-mass elliptical galaxies as a system, i.e., the satellite galaxies closer to the center of the host galaxy usually have redder color indices, for both their stars and their GCs. According to the “two phase” formation scenario of massive early-type galaxies, the host galaxy accretes stars and GCs from low-mass satellite galaxies in the second phase. So an accreted GC system naturally inherits the negative color gradient present in the satellite population. This can explain why the color gradient of the GC system can still be observed at large radii after multiple minor mergers
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