16,967 research outputs found

    Simultaneous VLBI Astrometry of H2O and SiO Masers toward the Semiregular Variable R Crateris

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    We obtained, for the first time, astrometrically registered maps of the 22.2 GHz H2O and 42.8, 43.1, and 86.2 GHz SiO maser emission toward the semiregular b-type variable (SRb) R Crateris, at three epochs (2015 May 21, and 2016 January 7 and 26) using the Korean Very-long-baseline Interferometry Network. The SiO masers show a ring-like spatial structure, while the H2O maser shows a very asymmetric one-side outflow structure, which is located at the southern part of the ring-like SiO maser feature. We also found that the 86.2 GHz SiO maser spots are distributed in an inner region, compared to those of the 43.1 GHz SiO maser, which is different from all previously known distributions of the 86.2 GHz SiO masers in variable stars. The different distribution of the 86.2 GHz SiO maser seems to be related to the complex dynamics caused by the overtone pulsation mode of the SRb R Crateris. Furthermore, we estimated the position of the central star based on the ring fitting of the SiO masers, which is essential for interpreting the morphology and kinematics of a circumstellar envelope. The estimated stellar coordinate corresponds well to the position measured by Gaia

    Masses and decay constants of pions and kaons in mixed-action staggered chiral perturbation theory

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    Lattice QCD calculations with different staggered valence and sea quarks can be used to improve determinations of quark masses, Gasser-Leutwyler couplings, and other parameters relevant to phenomenology. We calculate the masses and decay constants of flavored pions and kaons through next-to-leading order in staggered-valence, staggered-sea mixed-action chiral perturbation theory. We present the results in the valence-valence and valence-sea sectors, for all tastes. As in unmixed theories, the taste-pseudoscalar, valence-valence mesons are exact Goldstone bosons in the chiral limit, at non-zero lattice spacing. The results reduce correctly when the valence and sea quark actions are identical, connect smoothly to the continuum limit, and provide a way to control light quark and gluon discretization errors in lattice calculations performed with different staggered actions for the valence and sea quarks.Comment: 8 pages, 9 figures, extended with more explanation. arXiv admin note: text overlap with arXiv:1311.626

    Coaching transitions across borders:The pursuit of individuals advancing coaching careers in the competitive global landscape of Olympic sports

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    Intensified international competition for sporting success has facilitated coachesā€™ cross-national migration, which constitutes a space for coachesā€™ career transitions and development. This paper examines elite coachesā€™ international migration as part of coaching career transitions within the context of the global sporting arms race. Using a qualitative case study design, data were generated from documents and semi-structured interviews with six South Korean coaches who had moved to Western nations to coach national teams in two Olympic sports. The analysis reveals an underlying mechanism of the coachesā€™ international mobility: ā€˜dual imbalancesā€™ existing between the sending and receiving countries ā€“ one in the levels of sporting performance; the other in the perceived levels of modernisation in coaching cultures and sports systems. The migration opportunities were created by the ā€˜performance imbalanceā€™ between the home nation and destinations amid the structural context of the global sporting arms race. However, equally important is the individualsā€™ strategic initiative to seize the opportunities for their career development and mitigate the perceived ā€˜modernisation imbalanceā€™ in coaching practices. By highlighting coachesā€™ agentic capacity to navigate their career pathways within the global context, this study contributes empirically to the literature on both international coach migration and coaching transitions

    Concurrence of Stevens-Johnson Syndrome and Bilateral Parotitis after Minocycline Therapy

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    Minocycline is an antibiotic of tetracycline derivatives that is commonly used in the treatment of moderate to severe acne vulgaris. It has been reported to cause rare adverse events from mild cutaneous eruption to severe forms including drug-induced lupus, serum sickness-like reaction, and hypersensitivity reactions, etc. The risks of adverse events attributed to minocycline have not been ascertained reliably and there are concerns about the safety of minocycline which could possibly result in life-threatening events such as the Stevens-Johnson syndrome. Here we demonstrate an unusual case of Stevens-Johnson syndrome in conjunction with bilateral parotitis after the intake of minocycline in a Korean boy suggesting discreet use of the drug
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