437 research outputs found

    The Role of Transcatheter Aortic Valve Replacement in Heyde Syndrome

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    This is a case of a pleasant 81 year-old male who presented to the ED complaining of chest pain with activity for the past 3-4 weeks. He reports of chest pain with minimal exertion of walking across the parking lot to the car. This has been a substantial change from his baseline, he currently works as a mason. He was referred to the ED by his primary care physician after having abnormal lab result showing low hemoglobin of 7.6. During the admission he underwent work up of his chest pain and symptomatic anemia. The patient’s anemia was attributed to intestinal arteriovenous malformations seen in the cecum and ascending colon during colonoscopy. He had a 2-D ECHO showing severe aortic valve stenosis. The patient was diagnosed with Heyde syndrome which is the association acquired von Willebrand deficiency with aortic stenosis and gastrointestinal angiodysplasia. Here we discuss the pathophysiology of Heyde syndrome and the role of TAVR in treatment of our patient.https://scholarlycommons.henryford.com/merf2020caserpt/1094/thumbnail.jp

    Three-dimensional multi-fluid model of a coronal streamer belt with a tilted magnetic dipole

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    Abstract. Observations of streamers in extreme ultraviolet (EUV) emission with SOHO/UVCS show dramatic differences in line profiles and latitudinal variations in heavy ion emission compared to hydrogen Ly-α emission. In order to use ion emission observations of streamers as the diagnostics of the slow solar wind properties, an adequate model of a streamer including heavy ions is required. We extended a previous 2.5-D multi-species magnetohydrodynamics (MHD) model of a coronal streamer to 3-D spherical geometry, and in the first approach we consider a tilted dipole configuration of the solar magnetic field. The aim of the present study is to test the 3-D results by comparing to previous 2.5-D model result for a 3-D case with moderate departure from azimuthal symmetry. The model includes O5+ ions with preferential empirical heating and allows for calculation of their density, velocity and temperature in coronal streamers. We present the first results of our 3-D multi-fluid model showing the parameters of protons, electrons and heavy ions (O5+) at the steady-state solar corona with a tilted steamer belt. We find that the 3-D results are in qualitative agreement with our previous 2.5-D model, and show longitudinal variation in the variables in accordance with the tilted streamer belt structure. Properties of heavy coronal ions obtained from the 3-D model together with EUV spectroscopic observations of streamers will help understanding the 3-D structures of streamers reducing line-of-sight integration ambiguities and identifying the sources of the slow solar wind in the lower corona. This leads to improved understanding of the physics of the slow solar wind

    Observed and simulated coronal UV lines at solar minimum activity: The impact of the 3D tilted coronal streamer belt

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    The aim of this study is to improve the knowledge of the slow solar wind origin. In particular, we compute the emissivities and the intensities of UV spectral lines starting from the physical parameters of a time-dependent 3D three-fluid MHD model of the tilted coronal streamer belt. The results obtained from the model are compared in the extended corona (at 1.5 and 1.9 R�) to the UV spectroscopic data from the Ultraviolet Coronagraph Spectrometer (UVCS) onboard SOHO in the streamer belt during the minimum of solar activity (1996). The discussion is focused on the importance of the projection effects due to the integration along the line of sight in the coronal ultraviolet observations of streamer core dimming

    Spectroscopic signature of Alfv\'en waves damping in a polar coronal hole up to 0.4 solar radii

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    Between February 24-25, 2009, the EIS spectrometer onboard the Hinode spacecraft performed special "sit & stare" observations above the South polar coronal hole continuously over more than 22 hours. Spectra were acquired with the 1" slit placed off-limb covering altitudes up to 0.48 R_\odot (3.34×1023.34\times 10^2 Mm) above the Sun surface, in order to study with EIS the non-thermal spectral line broadenings. Spectral lines such as Fe {\sc xii} λ\lambda186.88, Fe {\sc xii} λ\lambda193.51, Fe {\sc xii} λ\lambda195.12 and Fe {\sc xiii} λ\lambda202.04 are observed with good statistics up to high altitudes and they have been analyzed in this study. Results show that the FWHM of Fe {\sc xii} λ\lambda195.12 line increases up to 0.14\simeq 0.14 R_\odot, then decreases higher up. EIS stray light has been estimated and removed. Derived electron density and non-thermal velocity profiles have been used to estimate the total energy flux transported by Alfv\'en waves off-limb in polar coronal hole up to 0.4\simeq 0.4 R_\odot. The computed Alfv\'en wave energy flux density fwf_w progressively decays with altitude from fw1.2106f_w \simeq 1.2 \cdot 10^6 erg cm2^{-2} s1^{-1} at 0.03 R_\odot down to fw8.5103f_w \simeq 8.5 \cdot 10^3 erg cm2^{-2} s1^{-1} at 0.4 R_\odot, with an average energy decay rate Δfw/Δh4.5105\Delta f_w / \Delta h \simeq -4.5 \cdot 10^{-5} erg cm3^{-3} s1^{-1}. Hence, this result suggests energy deposition by Alfv\'en waves in a polar coronal hole, thus providing a significant source for coronal heating.Comment: Physical units of the Alfv\'en wave Energy Decay Rate Δfw/Δh\Delta f_w / \Delta h revised with respect to the published version. Scientific results and conclusions unchange

    Morphology, dynamics and plasma parameters of plumes and inter-plume regions in solar coronal holes

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    Coronal plumes, which extend from solar coronal holes (CH) into the high corona and - possibly - into the solar wind (SW), can now continuously be studied with modern telescopes and spectrometers on spacecraft, in addition to investigations from the ground, in particular, during total eclipses. Despite the large amount of data available on these prominent features and related phenomena, many questions remained unanswered as to their generation and relative contributions to the high-speed streams emanating from CHs. An understanding of the processes of plume formation and evolution requires a better knowledge of the physical conditions at the base of CHs, in plumes and in the surrounding inter-plume regions (IPR). More specifically, information is needed on the magnetic field configuration, the electron densities and temperatures, effective ion temperatures, non-thermal motions, plume cross-sections relative to the size of a CH, the plasma bulk speeds, as well as any plume signatures in the SW. In spring 2007, the authors proposed a study on "Structure and dynamics of coronal plumes and inter-plume regions in solar coronal holes" to the International Space Science Institute (ISSI) in Bern to clarify some of these aspects by considering relevant observations and the extensive literature. This review summarizes the results and conclusions of the study. Stereoscopic observations allowed us to include three-dimensional reconstructions of plumes. Multi-instrument investigations carried out during several campaigns led to progress in some areas, such as plasma densities, temperatures, plume structure and the relation to other solar phenomena, but not all questions could be answered concerning the details of plume generation process(es) and interaction with the SW.Comment: To appear on: The Astronomy and Astrophysics Review. 72 pages, 30 figure

    On the dynamics of solar polar plumes observed by SoHO/UVCS

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    We investigate the plasma outflow in solar polar plumes by using SoHO/UVCS observations of May 2005. Despite the fact that data have been acquired more than ten years ago, UVCS spectral observations in the intermediate corona still represent a unique opportunity of studying the plasma dynamics at those heliocentric distances. The Doppler dimming technique is applied to the O VI doublet and H I Lyman-α spectral lines, to infer the outflow speed and the electron density in plumes and interplumes. Our aim is to, investigate if plumes, in the intermediate corona, are to be considered static structures or if they dynamically expand, contributing to the fast solar wind

    Profiles and outcome of traditional healing practices for severe mental illnesses in two districts of Eastern Uganda

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    Background : The WHO estimates that more than 80% of African populations attend traditional healers for health reasons and that 40%–60% of these have some kind of mental illness. However, little is known about the profiles and outcome of this traditional approach to treatment. Objective : The purpose of this study was to describe the profiles and outcome of traditional healing practices for severe mental illnesses in Jinja and Iganga districts in the Busoga region of Eastern Uganda. Methods : Four studies were conducted. Study I used focus group discussions (FGDs) with case vignettes with local community members and traditional healers to explore the lay concepts of psychosis. Studies II and III concerned a cross-sectional survey of patients above 18 years at the traditional healer's shrines and study IV was made on a prospective cohort of patients diagnosed with psychosis in study III. Manual content analysis was used in study I; quantitative data in studies II, III, and IV were analyzed at univariate, bivariate, and multivariate levels to determine the association between psychological distress and socio-demographic factors; for study IV, factors associated with outcome were analyzed. One-way ANOVA for independent samples was the analysis used in Study IV. Results : The community gave indigenous names to psychoses (mania, schizophrenia, and psychotic depression) and had multiple explanatory models for them. Thus multiple solutions for these problems were sought. Of the 387 respondents, the prevalence of psychological distress was 65.1%, where 60.2% had diagnosable current mental illness, and 16.3% had had one disorder in their lifetime. Over 80% of patients with psychosis used both biomedical and traditional healing systems. Those who combined these two systems seemed to have a better outcome. All the symptom scales showed a percentage reduction of more than 20% at the 3- and 6-month follow-ups. Conclusion : Traditional healers shoulder a large burden of care of patients with mental health problems. This calls for all those who share the goal of improving the mental health of individuals to engage with traditional healers

    Development of Dietary-Based Toxicity Reference Values to Assess the Risk of Chlorophacinone to Non-Target Raptorial Birds

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    Regulatory changes in the use of some second-generation anticoagulant rodenticides in parts of North America may result in expanded use of first-generation anticoagulant rodenticides (FGARs). Recent toxicological studies with captive raptors have demonstrated that these species are considerably more sensitive to the FGAR diphacinone than traditional avian wildlife test species (mallard, bobwhite). We have now examined the toxicity of the FGAR chlorophacinone (CPN) to American kestrels fed rat tissue mechanically amended with CPN, or rat tissue containing biologically-incorporated CPN, for 7 days. Nominal CPN concentrations in these diets were 0.15, 0.75, and 1.5 μg/g food wet weight, and actual CPN concentration in diets were analytically verified as being close to target values. Food intake was consistent among groups, body weight fluctuated by less than 6%, exposure and adverse effects were generally dose-dependent, and there were no dramatic differences in toxicity between mechanically-amended and biologically-incorporated CPN diets. Using benchmark dose statistical methods, toxicity reference values at which clotting times were prolonged in 50% of the kestrels was estimated to be about 80 μg CPN consumed/kg body weight-day for prothrombin time and 40 μg CPN/kg body weight-day for Russell’s viper venom time. Based upon carcass CPN residues reported in rodents from field baiting studies, empirical measures of food consumption in kestrels, and dietary-based toxicity reference values derived from the 7-day exposure scenario, some free-ranging raptors consuming CPN-exposed prey might exhibit coagulopathy and hemorrhage. These sublethal responses associated with exposure to environmentally realistic concentrations of CPN could compromise survival of exposed birds
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