24 research outputs found

    Severe Coarctation of the Aorta: A Delayed Diagnosis

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    INTRODUCTION: Coarctation of the aorta (CoA) is a congenital heart disease characterized by narrowing of the aorta near the aortic isthmus. The incidence of CoA is 4 out of every 10,000 births, accounting for 6–8% of all congenital heart disease. It is common for CoA to be accompanied by other cardiovascular abnormalities, such as bicuspid aortic valve, ventricular septal defects, and mitral valve stenosis. Early diagnosis and treatment of CoA is crucial to improving morbidity and mortality associated with this disease as the mean age of death in untreated coarctation is 34 years. CASE DESCRIPTION: A 10 year old male presented to the outpatient pediatric clinic for an acute illness. On examination, he was found to be hypertensive with a blood pressure of 126/69 accompanied by a systolic heart murmur. Medical history included the diagnosis of a heart murmur at a 2 year well child examination before the patient was lost to follow-up until age 9. Upon re-establishment he was noted to have a II/VI systolic heart murmur. He was seen multiple times during year 10 of life where this murmur was consistently documented. Referral to cardiology for further evaluation was made. At presentation to the cardiologist, patient was found to be well appearing with clear lung sounds and a III/VI systolic murmur heard best at the left upper sternal boarder with radiation throughout the chest. During examination absent femoral and lower extremity pulses with pale lower extremity nail beds were also noted. Echocardiogram demonstrated severe CoA, bicuspid aortic valve, and aortic root dilatation. He was started on metoprolol for aortic root dilatation. Referral for heart catheterization was made for planned stenting to relieve the coarctation. DISCUSSION: Heart murmurs are a common finding on pediatric exams. The primary care provider typically determines which heart murmurs are pathologic and require follow-up. In the setting of a heart murmur there are clinical signs that indicate when further follow-up with cardiology is needed, including absent distal pulses, hypertension, radiation of the murmur throughout the chest, and discrepancy between upper and lower extremity blood pressure. Early referral to cardiology is imperative for any murmur that is not innocent to prevent delayed diagnosis of pathologic lesions. This case demonstrates the importance of checking blood pressure and lower extremity pulses in the setting of an asymptomatic patient with a heart murmur.N

    Geochemistry and mineralogy of the phonolite lava lake, Erebus volcano, Antarctica: 1972–2004 and comparison with older lavas

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    Author Posting. © Elsevier B.V., 2008. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Journal of Volcanology and Geothermal Research 177 (2008): 589-605, doi:10.1016/j.jvolgeores.2007.11.025.Mount Erebus, Antarctica, is a large (3794 m) alkaline open-conduit stratovolcano that hosts a vigorously convecting and persistently degassing lake of anorthoclase phonolite magma. The composition of the lake was investigated by analyzing glass and mineral compositions in lava bombs erupted between 1972 and 2004. Matrix glass, titanomagnetite, olivine, clinopyroxene, and fluor-apatite compositions are invariant and show that the magmatic temperature (~1000°C) and oxygen fugacity (ΔlogFMQ = -0.9) have been stable. Large temperature variations at the lake surface (ca. 400 - 500°C) are not reflected in mineral compositions. Anorthoclase phenocrysts up to 10 cm in length feature a restricted compositional range (An10.3-22.9Ab62.8-68.1Or11.4-27.2) with complex textural and compositional zoning. Anorthoclase textures and compositions indicate crystallization occurs at low degrees of effective undercooling. We propose shallow water exsolution causes crystallization to occur and shallow convection repeats this process multiple times, yielding extremely large anorthoclase crystals. Minor variations in eruptive activity from 1972 to 2004 are decoupled from magma compositions. The variations probably relate to changes in conduit geometry within the volcano and/or variable input of CO2-rich volatiles into the upper-level magma chamber from deeper in the system. Eleven bulk samples of phonolite lava from the summit plateau that range in age from 0 ± 4 ka to 17 ± 8 ka were analyzed for major and trace elements. Small compositional variations are controlled by anorthoclase content. The lavas are indistinguishable from modern bulk lava bomb compositions and demonstrate that Erebus volcano has been erupting lava and tephra from the summit region with the same bulk composition for ~17 ka.The work at Erebus volcano and the continued operation of the Mount Erebus Volcano Observatory is supported by grants (OPP-0229305, ANT-0538414) from the Office of Polar Programs, National Science Foundation

    Interacting Galaxies in the A901/902 Supercluster with STAGES

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    We present a study of galaxy mergers and the influence of environment in the Abell 901/902 supercluster at z~0.165. We use HST ACS F606W data from the STAGES survey, COMBO-17, Spitzer 24um, and XMM-Newton X-ray data. Our analysis utilizes both a visual classification system, and quantitative CAS parameters to identify systems which show evidence of a recent or ongoing merger of mass ratio >1/10. Our results are: (1) After visual classification and minimizing the contamination from false projection pairs, we find that the merger fraction f_merge is 0.023+/-0.007. The estimated fractions of likely major mergers, likely minor mergers, and ambiguous cases are 0.01+/-0.004, 0.006+/-0.003, and 0.007+/-0.003, respectively. (2) The mergers lie outside the cluster core of radius R < 0.25 Mpc: the lack of mergers in the core is likely due to the large galaxy velocity dispersion in the core. Mergers populate the region (0.25 Mpc < R <= 2 Mpc) between the core and outskirt. In this region, the estimated frequency of mergers is similar to those seen at typical group overdensities. This suggests ongoing growth of the clusters via accretion of group and field galaxies. (3) We compare our observed merger fraction with those reported in other clusters and groups out to z~0.4. Existing data points on the merger fraction for L<= L* galaxies in clusters allow for a range of evolutionary scenarios. (4) The fraction of mergers, which lie on the blue cloud is 80%+/-18% versus 34%+/-7% for non-interacting galaxies, implying that interacting galaxies are preferentially blue. (5) The average SFR, based on UV or UV+IR data, is enhanced by a factor of ~1.5 to 2 in mergers compared to non-interacting galaxies. However, mergers in the clusters contribute only a small fraction (between 10% and 15%) of the total SFR density.(Abridged)Comment: Accepted for publication in ApJ. 34 pages, 16 figures. Version with full resolution figures available at: http://www.as.utexas.edu/~alh/apj/int/ ; updated abridged abstrac

    The SAMI Galaxy Survey: Quenching of Star Formation in Clusters I. Transition Galaxies

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    We use integral-field spectroscopy from the SAMI Galaxy Survey to identify galaxies that show evidence of recent quenching of star formation. The galaxies exhibit strong Balmer absorption in the absence of ongoing star formation in more than 10% of their spectra within the SAMI field of view. These Hd-strong (HDS) galaxies (HDSGs) are rare, making up only similar to 2% (25/1220) of galaxies with stellar mass log(M-*/M-circle dot) &gt; 10. The HDSGs make up a significant fraction of nonpassive cluster galaxies (15%; 17/115) and a smaller fraction (2.0%; 8/387) of the nonpassive population in low-density environments. The majority (9/17) of cluster HDSGs show evidence of star formation at their centers, with the HDS regions found in the outer parts of the galaxy. Conversely, the HDS signal is more evenly spread across the galaxy for the majority (6/8) of HDSGs in low-density environments and is often associated with emission lines that are not due to star formation. We investigate the location of the HDSGs in the clusters, finding that they are exclusively within 0.6R(200) of the cluster center and have a significantly higher velocity dispersion relative to the cluster population. Comparing their distribution in projected phase space to those derived from cosmological simulations indicates that the cluster HDSGs are consistent with an infalling population that has entered the central 0.5r(200,3D) cluster region within the last similar to 1 Gyr. In the eight of nine cluster HDSGs with central star formation, the extent of star formation is consistent with that expected of outside-in quenching by ram pressure stripping. Our results indicate that the cluster HDSGs are currently being quenched by ram pressure stripping on their first passage through the cluster

    The SAMI Galaxy Survey: Quenching of Star Formation in Clusters I. Transition Galaxies

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    We use integral-field spectroscopy from the SAMI Galaxy Survey to identify galaxies that show evidence of recent quenching of star formation. The galaxies exhibit strong Balmer absorption in the absence of ongoing star formation in more than 10% of their spectra within the SAMI field of view. These Hd-strong (HDS) galaxies (HDSGs) are rare, making up only similar to 2% (25/1220) of galaxies with stellar mass log(M-*/M-circle dot) > 10. The HDSGs make up a significant fraction of nonpassive cluster galaxies (15%; 17/115) and a smaller fraction (2.0%; 8/387) of the nonpassive population in low-density environments. The majority (9/17) of cluster HDSGs show evidence of star formation at their centers, with the HDS regions found in the outer parts of the galaxy. Conversely, the HDS signal is more evenly spread across the galaxy for the majority (6/8) of HDSGs in low-density environments and is often associated with emission lines that are not due to star formation. We investigate the location of the HDSGs in the clusters, finding that they are exclusively within 0.6R(200) of the cluster center and have a significantly higher velocity dispersion relative to the cluster population. Comparing their distribution in projected phase space to those derived from cosmological simulations indicates that the cluster HDSGs are consistent with an infalling population that has entered the central 0.5r(200,3D) cluster region within the last similar to 1 Gyr. In the eight of nine cluster HDSGs with central star formation, the extent of star formation is consistent with that expected of outside-in quenching by ram pressure stripping. Our results indicate that the cluster HDSGs are currently being quenched by ram pressure stripping on their first passage through the cluster.M.S.O. acknowledges the funding support from the Australian Research Council through a Future Fellowship (No. FT140100255). M.H. acknowledges support from an NSERC Discovery Grant, from the Australian Astronomical Observatory Distinguished Visitor Scheme and from the Australian Research Council Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D) also as a Distinguished Visitor. K.O. received support from VICI grant No. 016.130.338 of the Netherlands Foundation for Scientific Research (NWO). J.B.H. is supported by an ARC Laureate Fellowship that funds Jesse van de Sande and an ARC Federation Fellowship that funded the SAMI prototype. S.B. acknowledges the funding support from the Australian Research Council through a Future Fellowship (No. FT140101166). J.J.B. acknowledges support of an Australian Research Council Future Fellowship (No. FT180100231). L.C. is the recipient of an Australian Research Council Future Fellowship (No. FT180100066) funded by the Australian Government. J.vd.S. is funded under BlandHawthorn’s ARC Laureate Fellowship (No. FL140100278). C.F. acknowledges funding provided by the Australian Research Council (Discovery Projects No. DP150104329 and No. DP170100603, and Future Fellowship No. FT180100495), and the Australia-Germany Joint Research Cooperation Scheme (UADAAD). B.G. is the recipient of an Australian Research Council Future Fellowship (No. FT140101202). Support for A.M.M. is provided by NASA through Hubble Fellowship grant No. HSTHF2-51377 awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract No. NAS5-26555. N.S. acknowledges support of a University of Sydney Postdoctoral Research Fellowship. S.K.Y. acknowledges support from the Korean National Research Foundation (grant No. 2017R1A2A1A05001116) and by the Yonsei University Future Leading Research Initiative (grant No. 2015-22-0064)

    The Influence of Manga on the Graphic Novel

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    This material has been published in The Cambridge History of the Graphic Novel edited by Jan Baetens, Hugo Frey, Stephen E. Tabachnick. This version is free to view and download for personal use only. Not for re-distribution, re-sale or use in derivative works. © Cambridge University PressProviding a range of cogent examples, this chapter describes the influences of the Manga genre of comics strip on the Graphic Novel genre, over the last 35 years, considering the functions of domestication, foreignisation and transmedia on readers, markets and forms

    Cost-effective hazardous fuels reduction and biomass utilization : a case study from Wallowa County, Oregon

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    2 pagesUtilizing woody biomass from hazardous fuels reduction projects may make forest restoration more cost effective while creating local economic benefits. However, there is a lack of evidence about how projects can be designed for these outcomes. Wallowa Resources and the Wallowa- Whitman National Forest (WWNF) partnered to test if mechanical treatment with biomass utilization was cost effective in comparison to hand thinning, piling, and burning using a hazardous fuels reduction project called Reservoir Biomass. We studied the benefits and challenges of this approach.This briefing paper was made possible with funding from the US Endowment for Forestry and Communities and USDA Rural Development

    Forest restoration and biomass utilization for multiple benefits : a case study from Wallowa County, Oregon

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    12 pagesUpdated edition. In 2011, the Ecosystem Workforce Program produced a first version of this working paper, which analyzed the Reservoir Biomass project’s costs and outcomes when it was in progress. Since that time, the project has been completed. To document its final outcomes, we have released this updated edition of Working Paper #29. This second version includes updated information about acres treated, materials removed, and costs per acre.Forest restoration and biomass utilization on public lands can create improved stand conditions and opportunities for local economic benefit. In Wallowa County, local nonprofit organization Wallowa Resources and the Wallowa-Whitman National Forest have partnered to restore forest health and watershed conditions. With funding from the USDA Forest Service through the American Recovery and Reinvestment Act (ARRA) and the US Endowment, they tested whether mechanical treatment with biomass removal and utilization is costeffective in achieving desired stand improvement and local benefit, in comparison to hand thinning, piling, and burning. They piloted this approach in 2009–11 on a hazardous fuels reduction project called the Reservoir Biomass project.This project is made possible through financial support from the U.S. Endowment for Forestry and Communities and USDA Rural Development
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