1,734 research outputs found

    Uniform Silicon Isotope Ratios Across the Milky Way Galaxy

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    We report the relative abundances of the three stable isotopes of silicon, 28^{28}Si, 29^{29}Si and 30^{30}Si, across the Galaxy using the v=0,J=1→0v = 0, J = 1 \to 0 transition of silicon monoxide. The chosen sources represent a range in Galactocentric radii (RGCR_{\rm GC}) from 0 to 9.8 kpc. The high spectral resolution and sensitivity afforded by the GBT permit isotope ratios to be corrected for optical depths. The optical-depth-corrected data indicate that the secondary-to-primary silicon isotope ratios 29Si/28Si^{29}{\rm Si}/^{28}{\rm Si} and 30Si/28Si^{30}{\rm Si}/^{28}{\rm Si} vary much less than predicted on the basis of other stable isotope ratio gradients across the Galaxy. Indeed, there is no detectable variation in Si isotope ratios with RGCR_{\rm GC}. This lack of an isotope ratio gradient stands in stark contrast to the monotonically decreasing trend with RGCR_{\rm GC} exhibited by published secondary-to-primary oxygen isotope ratios. These results, when considered in the context of the expectations for chemical evolution, suggest that the reported oxygen isotope ratio trends, and perhaps that for carbon as well, require further investigation. The methods developed in this study for SiO isotopologue ratio measurements are equally applicable to Galactic oxygen, carbon and nitrogen isotope ratio measurements, and should prove useful for future observations of these isotope systems.Comment: 18 pages, 12 figures, 2 tables. Published in The Astrophysical Journal, Volume 839, Issue

    SIR-C/X-SAR free flyer concept

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    Viewgraphs on Spaceborne Imaging Radar (SAR) - C/X- Synthetic Aperture Radar (SAR) Free Flyer concept are presented. An overview, science objectives, science rationale, geophysical parameters from SAR, programmatic goals, concept description, and a candidate mission description are included

    An Exploratory Study of Clergy\u27s Perceived Stress Related to their Counseling Duties

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    This exploratory study examined the possible relationship between clergy\u27s level of counseling training and their perceived stress related to counseling duties. Interest in the topic stemmed from this researcher\u27s social work field placement within a church counseling center. Ordained clergy belonging to United Methodist, Roman Catholic, and American Baptist churches were surveyed regarding amount of time spent counseling, counselling training, and perceived stress related to counseling. Findings differed from those previous studies on clergy stress that reported high stress levels. Less than half of clergy reported moderate to high stress levels. However, limited qualitative data provided in this study did indicate definite frustration with counseling training and suggests the need for further exploration on this topic. A relationship between counseling training and stress level was suggested. Clergy indicated a high interest level in future collaboration with social workers regrading counseling training and ideas. This study will ultimately be important for social work professionals in the development of educational programming and collaboration with theological professionals in order to provide comprehensive counseling services for individuals and families. With current governmental cutbacks in social service funding, the church may become an extremely important resource in providing counseling and other social services to those in need

    Patient satisfaction with lower gastrointestinal endoscopy: doctors, nurse and nonmedical endoscopists

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    Aim Assessment of patient satisfaction with lower gastrointestinal endoscopy (LGE) comprising colonoscopy and flexible sigmoidoscopy is gaining increasing importance. We have now trained non healthcare professionals such as nonmedical endoscopists (NMEs) to perform LGE to overcome shortage of trained endoscopists. The aim of this study was to prospectively determine patient satisfaction, factors affecting satisfaction with LGE and to compare with nurses, NME and medical endoscopists, in terms of patient satisfaction. Method Consecutive patients undergoing LGE answered specially developed patient satisfaction questionnaire at discharge and 24 h thereafter. This questionnaire was a modification of m-Group Health Association of America questionnaire. Construct and face validity of questionnaire were tested by an expert group. Demographic and clinical data was prospectively collected. Multivariate regression analysis was performed to determine factors influencing patient satisfaction. Results Some 503 patients were surveyed after LGE. Examinations were performed by nurse (n = 105), doctor (n = 191), or NMEs (n = 155). There were no differences between three groups in terms of completion rates/complications. No differences were detected between endoscopists in patient rating for overall satisfaction (P = 0.6), technical skills (P = 0.58), communication skills (P = 0.61) or interpersonal skills (0.59). Multivariate regression analysis showed that higher preprocedure anxiety, history of pelvic operations/hysterectomy and higher pain scores were associated with adverse patient satisfaction and preprocedure anxiety, history of hysterectomy and female gender were associated with higher pain scores. Conclusion This study has shown that there are no differences in patient satisfaction with LGE performed by nurse, doctor or NME. The most important factor affecting patient satisfaction is degree of discomfort/pain experienced by patient

    A Tri-Lab Programmatic Model for Nuclear Weapons Records Retention

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    The Carnegie Hubble Program: The Distance and Structure of the SMC as Revealed by Mid-infrared Observations of Cepheids

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    Using Spitzer observations of classical Cepheids we have measured the true average distance modulus of the SMC to be 18.96±0.01stat±0.03sys18.96 \pm 0.01_{stat} \pm 0.03_{sys} mag (corresponding to 62±0.362 \pm 0.3 kpc), which is 0.48±0.010.48 \pm 0.01 mag more distant than the LMC. This is in agreement with previous results from Cepheid observations, as well as with measurements from other indicators such as RR Lyrae stars and the tip of the red giant branch. Utilizing the properties of the mid--infrared Leavitt Law we measured precise distances to individual Cepheids in the SMC, and have confirmed that the galaxy is tilted and elongated such that its eastern side is up to 20 kpc closer than its western side. This is in agreement with the results from red clump stars and dynamical simulations of the Magellanic Clouds and Stream.Comment: Accepted for publication in ApJ. 38 Pages, 11 figures. Figure 9 is interactive. Spitzer photometry for all Cepheids available as online tabl
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