161 research outputs found
Quadricuspid aortic valve with aortic insufficiency: a rare echocardiographic finding
Introduction: Quadriscupidaortic valve (QAV) is a rare congenital heart defect typically found incidentally without any associated cardiac defects. The functional status of QAV is pure aortic insufficiency (AI), however, clinical manifestations are dependent on the functional status of the valve, presenting in the fifth or sixth decade of life due to progressive degeneration of the leaflets. In our case, we present a 37-year-old female who developed post-partum dyspnea with elevated brain natriuretic peptide (BNP) levels concerning for heart failure. Transesophageal echocardiography (TEE) revealed a preserved ejection fraction with aortic regurgitation consistent with valvular heart failure, however, incidentally showed a QAV.
Case Presentation: A 37-year-old female 5 days post cesarean section presented with dyspnea on exertion. Her physical examination was significant for a decrescendo diastolic murmur at the aortic area and bibasilar rales. Pertinent labs revealed a BNP level elevation of 345 pg/mL with normal troponin levels. Given her symptoms and elevated biomarkers, a transthoracic echocardiogram was obtained and was suggestive of AI. She was referred for transesophageal echocardiogram for better visualization of the aortic valve. TEE revealed a QAV with all four leaflets equal in size with normal thickness and mobility. Moderate malcoaptation of all valves was present and severe AI was visualized. Planimetry of aortic regurgitant orifice was measured at 0.29 cm2, the AI jet was greater than 65% of left ventricular outflow tract, pressure half time calculated at 252 ms, and venacontracta measured 0.6 cm. Her systolic (ejection fraction 60%) and diastolic function were both preserved. After diuresis, she was discharged home and followed up with structural heart and cardiac surgery. She was to have a CT coronary angiography performed part of her pre-operative evaluation, but was lost to follow up.
Discussion: QAV is a rare congenital cardiac anomaly that is typically found incidentally. The most prevalent complication of QAV is AI, however, these patients are also at increased risk for infective endocarditis. This is due to the progressive degeneration of the leaflets from the asymmetric mechanical stress around the four cusps. Echocardiography allowed for visualization of the aortic valve and for quantification of the degree of AI. Given her clinical presentation and cardiac risk factors, it was unclear what was causing her symptoms on admission. Through echocardiography, a diagnosis was made and the patient was able to receive appropriate care. The advancement in imaging techniques has increased the capability to diagnose QAV and its complications. The definitive treatment of QAV with AI is valve replacement, which was recommended to our patient.
Conclusion: QAV is a rare congenital disease that most commonly manifests with AI. QAV is typically found incidentally in the fifth and sixth decade of life and best visualized by TEE. Definitive management of QAV is valve replacement.https://scholarlycommons.henryford.com/merf2020caserpt/1034/thumbnail.jp
A Research-Based Model for Digital Mapping and Art History: Notes from the Field
Most digital mapping in art history today divides the research process from the visualization aspects of the project. This problem became the focus of a summer institute that Paul Jaskot and Anne Kelly Knowles ran at Middlebury College with the support of the Samuel H. Kress Foundation. Our article both reports on the institute and suggests how research questions can complement digital mapping methods. We conclude with three case studies of spatial questions in art history and discuss the Fellowsâ use of GIS to explore examples from Qing Dynasty China, medieval Gotland, and contemporary New York City
Hadron Spectroscopy with COMPASS at CERN
The aim of the COMPASS hadron programme is to study the light-quark hadron
spectrum, and in particular, to search for evidence of hybrids and glueballs.
COMPASS is a fixed-target experiment at the CERN SPS and features a two-stage
spectrometer with high momentum resolution, large acceptance, particle
identification and calorimetry. A short pilot run in 2004 resulted in the
observation of a spin-exotic state with consistent with the
debated . In addition, Coulomb production at low momentum transfer
data provide a test of Chiral Perturbation Theory. During 2008 and 2009, a
world leading data set was collected with hadron beam which is currently being
analysed. The large statistics allows for a thorough decomposition of the data
into partial waves. The COMPASS hadron data span over a broad range of channels
and shed light on several different aspects of QCD.Comment: 4 pages, 5 figure
Isoscalar-isovector mass splittings in excited mesons
Mass splittings between the isovector and isoscalar members of meson nonets
arise in part from hadronic loop diagrams which violate the Okubo-Zweig-Iizuka
rule.
Using a model for these loop processes which works qualitatively well in the
established nonets, I tabulate predictions for the splittings and associated
isoscalar mixing angles in the remaining nonets below about 2.5 GeV, and
explain some of their systematic features.
The results for excited vector mesons compare favorably with experiment.Comment: 8 RevTeX pages, including 1 LaTeX figure.
CMU-HEP93-23/DOE-ER-40682-4
Globalisation, âChinese Wallsâ and Industrial Labour
Summaries This article analyses how globalisation â in particular China's integration into global trade and investment flows â has affected industrial labour. It is argued that globalisation has led to discernible pressures as a result of the concentration of world market production in the coastal areas and the heavy reliance on reprocessing exports. These pressures have been mediated by the Chinese institutional structure which includes social rules, the institutional legacy of state socialism and the interests and autonomy of governments. The implications for industrial labour of the combination of the pressures from globalisation and the Chinese institutional structure are examined
Close-to-threshold Meson Production in Hadronic Interactions
Studies of meson production at threshold in the hadron--hadron interaction
began in the fifties when sufficient energies of accelerated protons were
available. A strong interdependence between developments in accelerator
physics, detector performance and theoretical understanding led to a unique
vivid field of physics. Early experiments performed with bubble chambers
revealed already typical ingredients of threshold studies, which were
superseded by more complete meson production investigations at the nucleon beam
facilities TRIUMF, LAMPF, PSI, LEAR and SATURNE. Currently, with the advent of
the new cooler rings as IUCF, CELSIUS and COSY the field is entering a new
domain of precision and the next step of further progress.
The analysis of this new data in the short range limit permits a more
fundamental consideration and a quantitative comparison of the production
processes for different mesons in the few--body final states. The
interpretation of the data take advantage of the fact that production reactions
close-to-threshold are characterized by only a few degrees of freedom between a
well defined combination of initial and exit channels. Deviations from
predictions of phase-space controlled one-meson-exchange models are indications
of new and exciting physics. Precision data on differential cross sections,
isospin and spin observables -- partly but by no means adequately available --
are presently turning up on the horizon. There is work for the next years and
excitement of the physics expected. Here we try to give a brief and at the same
time comprehensive overview of this field of hadronic threshold production
studies.Comment: 100 pages, Review article to be published in Prog. Part. Nucl. Phys.
Vol. 49, issue 1 (2002
Bayesian networks for raster data (BayNeRD): plausible reasoning from observations
This paper describes the basis functioning and implementation of a computer-aided Bayesian Network (BN) method that is able to incorporate expertsâ knowledge for the benefit of remote sensing applications and other raster data analyses: Bayesian Network for Raster Data (BayNeRD). Using a case study of soybean mapping in Mato Grosso State, Brazil, BayNeRD was tested to evaluate its capability to support the understanding of a complex phenomenon through plausible reasoning based on data observation. Observations made upon Crop Enhanced Index (CEI) values for the current and previous crop years, soil type, terrain slope, and distance to the nearest road and water body were used to calculate the probability of soybean presence for the entire Mato Grosso State, showing strong adherence to the official data. CEI values were the most influencial variables in the calculated probability of soybean presence, stating the potential of remote sensing as a source of data. Moreover, the overall accuracy of over 91% confirmed the high accuracy of the thematic map derived from the calculated probability values. BayNeRD allows the expert to model the relationship among several observed variables, outputs variable importance information, handles incomplete and disparate forms of data, and offers a basis for plausible reasoning from observations. The BayNeRD algorithm has been implemented in R software and can be found on the internet.
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