2,105 research outputs found

    Far-UV Emissions of the Sun in Time: Probing Solar Magnetic Activity and Effects on Evolution of Paleo-Planetary Atmospheres

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    We present and analyze FUSE observations of six solar analogs. These are single, main-sequence G0-5 strs selected as proxies for the Sun at several stages of its main-sequence lifetime. The emission features in the FUSE 920-1180 A wavelength range allow for a critical probe of the hot plasma over three decades in temperature. Using the flux ratio CIII 1176/977 as diagnostics, we investigate the dependence of the electron pressure of the transition region as a function of the rotation period, age and magnetic activity. The results from these solar proxies indicate that the electron pressure of the stellar ~10^5-K plasma decreases by a factor of about 70 between the young, fast-rotating magnetically active star and the old, slow-rotating inactive star. Also, the observations indicate that the average surface fluxes of emission features strongly decrease with increasing stellar age and longer rotation period. The emission flux evolution with age or rotation period is well fitted by power laws, which become steeper from cooler chromospheric (10^4 K) to hotter coronal (10^7 K) plasma. The relationship for the integrated (920-1180 A) FUSE flux indicates that the solar far-ultraviolet emissions were about twice the present value 2.5 Gyr ago and about 4 times the present value 3.5 Gyr ago. Note also that the FUSE/FUV flux of the Zero-Age Main Sequence Sun could have been higher by as much as 50 times. Our analysis suggests that the strong FUV emissions of the young Sun may have played a crucial role in the developing planetary system, in particular through the photoionization, photochemical evolution and possible erosion of the planetary atmospheres. (abridged)Comment: 15 pages, 8 figures, accepted for publication in Ap

    ‘Scotland's different’: Narratives of Scotland's distinctiveness in the post-Brexit-vote era

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    While Scotland has been portrayed as an outlier in the context of Brexit, we know relatively little about how ordinary people in Scotland, including a growing migrant population, make sense of this (political and media) narrative. In order to address this gap, in this article I look at everyday narratives of Scotland's distinctiveness in the post-Brexit-vote era among the long-settled population and Polish – and to a lesser degree other European Union – migrants in the East End of Glasgow. By drawing upon scholarship on everyday nationalism and imagined communities, I explore discursive claims which romanticise Scotland as different and ‘welcoming’ of immigration and position it in binary opposition to England. How is Scotland produced as different in the context of Brexit? How are these stories used to re-imagine increasingly diverse Scottish society? In what ways are they being employed by migrant communities

    Training of Instrumentalists and Development of New Technologies on SOFIA

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    This white paper is submitted to the Astronomy and Astrophysics 2010 Decadal Survey (Astro2010)1 Committee on the State of the Profession to emphasize the potential of the Stratospheric Observatory for Infrared Astronomy (SOFIA) to contribute to the training of instrumentalists and observers, and to related technology developments. This potential goes beyond the primary mission of SOFIA, which is to carry out unique, high priority astronomical research. SOFIA is a Boeing 747SP aircraft with a 2.5 meter telescope. It will enable astronomical observations anywhere, any time, and at most wavelengths between 0.3 microns and 1.6 mm not accessible from ground-based observatories. These attributes, accruing from the mobility and flight altitude of SOFIA, guarantee a wealth of scientific return. Its instrument teams (nine in the first generation) and guest investigators will do suborbital astronomy in a shirt-sleeve environment. The project will invest $10M per year in science instrument development over a lifetime of 20 years. This, frequent flight opportunities, and operation that enables rapid changes of science instruments and hands-on in-flight access to the instruments, assure a unique and extensive potential - both for training young instrumentalists and for encouraging and deploying nascent technologies. Novel instruments covering optical, infrared, and submillimeter bands can be developed for and tested on SOFIA by their developers (including apprentices) for their own observations and for those of guest observers, to validate technologies and maximize observational effectiveness.Comment: 10 pages, no figures, White Paper for Astro 2010 Survey Committee on State of the Professio

    The powers in PowerPoint: Embedded authorities, documentary tastes, and institutional (second) orders in corporate Korea

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    Microsoft PowerPoint is both the bane and banality of contemporary South Korean office work. Corporate workers spend countless hours refining and crafting plans, proposals, and reports in PowerPoint that often lead to conflicts with coworkers and overtime work. This article theorizes the excessive attention to documents in modern office contexts. Where scholars have been under the impression that institutional documents align with institutional purposes, I describe a context in which making documents for individual purposes and making them for work exist under a basic tension. Based on fieldwork in corporate Korea between 2013 and 2015, I describe how Korean office workers calibrate documents to the tastes of superiors who populate the managerial chain. These practices leave little trace of real "work" on paper, but they are productive for navigating complex internal labor markets and demonstrating a higher order value of attention toward others. These findings suggest that institutional and individual authorities are not competing projects inside organizations but become entangled in increasingly complex participatory encounters, even as they are channeled through a seemingly simple software like PowerPoint. [documents, expertise, authority, technology, South Korea

    A survey of pediatricians' attitudes regarding influenza immunization in children

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    <p>Abstract</p> <p>Background</p> <p>The Advisory Committee on Immunization Practices advocates that influenza immunization is the most effective method for prevention of illness due to influenza. Recommendations for vaccination of children against influenza have been revised several times since 2002, and as of 2008 include all children 6 months to 18 years of age. Nevertheless, influenza immunization rates have remained low.</p> <p>Methods</p> <p>We surveyed practicing pediatricians in Maryland in the spring of 2007 to determine their attitudes and practices toward childhood influenza immunization.</p> <p>Results</p> <p>The overall response to the survey was 21%. A total of 61% of respondents reported that immunization either is cost neutral or produces a loss, and 36.6% noted it was minimally profitable. Eighty-six percent of respondents were receptive to supporting school-based immunization programs, and 61% indicated that they would participate in such programs. Respondents reported higher rates of immunization of select patient groups than those noted by the Centers for Disease Control and Prevention</p> <p>Conclusion</p> <p>Vaccination was reported to occur at multiple types of patient encounters, as recommended. Survey respondents stated that practice-based immunization was not a profitable service. Pediatricians were supportive of school-based immunization programs, and more than half stated they would be actively involved in such programs. School-based programs may be critical to achieving high vaccination coverage in the school-aged population.</p
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