599 research outputs found

    Computer prediction of three-dimensional potential flow fields in which aircraft propellers operate: Computer program description and users manual

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    A method was developed for predicting the potential flow velocity field at the plane of a propeller operating under the influence of a wing-fuselage-cowl or nacelle combination. A computer program was written which predicts the three dimensional potential flow field. The contents of the program, its input data, and its output results are described

    Computer prediction of three-dimensional potential flow fields in which aircraft propellers operate

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    A computer program was developed to calculate the three dimensional, steady, incompressible, inviscid, irrotational flow field at the propeller plane (propeller removed) located upstream of an arbitrary airframe geometry. The program uses a horseshoe vortex of known strength to model the wing. All other airframe surfaces are modeled by a network source panels of unknown strength which is exposed to a uniform free stream and the wing-induced velocity field. By satisfying boundary conditions on each panel (the Neumann problem), relaxed boundary conditions being used on certain panels to simulate inlet inflow, the source strengths are determined. From the known source and wing vortex strengths, the resulting velocity fields on the airframe surface and at the propeller plane are obtained. All program equations are derived in detail, and a brief description of the program structure is presented. A user's manual which fully documents the program is cited. Computer predictions of the flow on the surface of a sphere and at a propeller plane upstream of the sphere are compared with the exact mathematical solutions. Agreement is good, and correct program operation is verified

    Ertapenem-Induced Encephalopathy in a Patient With Normal Renal Function

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    Drug-induced neurotoxicity is a rare adverse reaction associated with ertapenem. Encephalopathy is a type of neurotoxicity that is defined as a diffuse disease of the brain that alters brain function or structure. We report a patient with normal renal function who developed ertapenem-induced encephalopathy manifesting as altered mental status, hallucinations, and dystonic symptoms. The patient’s symptoms improved dramatically following ertapenem discontinuation, consistent with case reports describing ertapenem neurotoxicity in renal dysfunction. Since clinical evidence strongly suggested ertapenem causality, we utilized the Naranjo Scale to estimate the probability of an adverse drug reaction to ertapenem. Our patient received a Naranjo Scale score of 7, suggesting a probable adverse drug reaction, with a reasonable temporal sequence to support our conclusion

    The proton's longitudinal spin structure studied through the weak interaction in pp collisions

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    For many years there has been limited knowledge of the spin structure of the proton. The degree to which the antiquarks and gluons of radiative origin inside the proton contribute to the total spin is particularly not well confined. The PHENIX experiment at RHIC has made measurements that have, and will, better confine these spin contributions. One of these measurements, made possible by a series of experimental upgrades, is a study of the single spin asymmetry in W boson production (ALWA_L^W) in polarized proton-proton collisions. In this measurement, the parity violating weak interaction serves, compared to than previously used techniques, as a cleaner and more direct probe of flavor separated quark and antiquark spin-dependent momentum distributions. This is most significant in the case of the antiquark distributions, which are currently not well constrained. PHENIX has taken data toward this measurement in 2013, analysis of the data was performed, and preliminary ALWA_L^W results have been released. Work is currently underway to finalize these results for forthcoming publication. Once finalized, these results will be included in a global fit along with data from other experiments to reduce the uncertainty of the antiquarks' contribution to proton spin. This dissertation will detail the theoretical basis for this measurement and describe the experimental and analytic procedures used to obtain the result, with special emphasis on contributions from the author

    Clostridium tertium Peritonitis and Concurrent Bacteremia in a Patient With a History of Alcoholic Cirrhosis

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    Spontaneous bacterial peritonitis (SBP) is a recognized cause of morbidity and mortality in cirrhotic patients. Enterobacteriaceae have been isolated from the majority of peritonitis cases and the gram negative aerobe Escherichia coli is the most commonly isolated organism. Anaerobic organisms are rarely isolated because of the high oxygen tension in ascetic fluid. We report a patient with a history of alcoholic cirrhosis who developed SBP and concurrent bacteremia with the anaerobe Clostridium tertium. The patient was successfully treated with intravenous antibiotics and was discharged home on oral ciprofloxacin. This case report is unique in that it is the fourth documented Clostridium tertium SBP case, utilized MALDI-TOF mass spectrometry for organism identification, and susceptibility testing for select antibiotics was performed

    Aircraft noise prediction program theoretical manual: Rotorcraft System Noise Prediction System (ROTONET), part 4

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    This document describes the theoretical methods used in the rotorcraft noise prediction system (ROTONET), which is a part of the NASA Aircraft Noise Prediction Program (ANOPP). The ANOPP code consists of an executive, database manager, and prediction modules for jet engine, propeller, and rotor noise. The ROTONET subsystem contains modules for the prediction of rotor airloads and performance with momentum theory and prescribed wake aerodynamics, rotor tone noise with compact chordwise and full-surface solutions to the Ffowcs-Williams-Hawkings equations, semiempirical airfoil broadband noise, and turbulence ingestion broadband noise. Flight dynamics, atmosphere propagation, and noise metric calculations are covered in NASA TM-83199, Parts 1, 2, and 3

    Use of chromatin immunoprecipitation (ChIP) to detect transcription factor binding to highly homologous promoters in chromatin isolated from unstimulated and activated primary human B cells

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    The Chromatin Immunoprecipiation (ChIP) provides a powerful technique for identifying the in vivo association of transcription factors with regulatory elements. However, obtaining meaningful information for promoter interactions is extremely challenging when the promoter is a member of a class of highly homologous elements. Use of PCR primers with small numbers of mutations can limit cross-hybridization with non-targeted sequences and distinguish a pattern of binding for factors with the regulatory element of interest. In this report, we demonstrate the selective in vivo association of NF-κB, p300 and CREB with the human Iγ1 promoter located in the intronic region upstream of the Cγ1 exons in the immunoglobulin heavy chain locus. These methods have the ability to extend ChIP analysis to promoters with a high degree of homology

    Protein structure prediction using multiple deep neural networks in the 13th Critical Assessment of Protein Structure Prediction (CASP13)

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    We describe AlphaFold, the protein structure prediction system that was entered by the group A7D in CASP13 Submissions were made by three free-modelling methods which combine the predictions of three neural networks. All three systems were guided by predictions of distances between pairs of residues produced by a neural network. Two systems assembled fragments produced by a generative neural network, one using scores from a network trained to regress GDT_TS. The third system shows that simple gradient descent on a properly constructed potential is able to perform on-par with more expensive traditional search techniques and without requiring domain segmentation. In the CASP13 free-modelling assessors' ranking by summed z-scores, this system scored highest with 68.3 vs 48.2 for the next closest group. (An average GDT_TS of 61.4.) The system produced high-accuracy structures (with GDT_TS scores of 70 or higher) for 11 out of 43 free-modelling domains. Despite not explicitly using template information, the results in the template category were comparable to the best performing template-based methods
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