Natural History Of Syphilitic Aortitis

No large studies of cardiovascular syphilis at necropsy have been reported since 1964. We examined at necropsy 90 patients who had characteristic morphologic findings of syphilitic aortitis. None had ever undergone cardiovascular surgery. With the exception of 2 cases seen more recently, the hearts and aortas of the 90 patients were examined and categorized by one of us (W.C.R.) from 1966 to 1990. All 90 had extensive involvement of the tubular portion of the ascending aorta by the syphilitic process, which spared the sinuses of Valsalva in all but 4 patients. The aortic arch was also involved in 49 (91%) of 54 patients and the descending thoracic aorta in 47 (90%) of 52 patients. Syphilis was the cause of death in 23 (26%) of the 90 patients. It was secondary to rupture of the ascending or descending thoracic aorta in 12, severe aortic regurgitation leading to heart failure in 10, and severe narrowing of the aortic ostium of the right coronary artery in 1 patient. Of the 40 patients who had undergone serologic testing for syphilis, 28 (70%) had a positive (reactive) finding. Those patients with a negative or nonreactive test or who did not undergo a serologic test for syphilis had morphologic and histologic findings in the aorta at necropsy similar to the findings of those patients who had had a positive serologic test for syphilis. In conclusion, cardiovascular syphilis has not disappeared. In patients with dilated ascending aortas, with or without aortic regurgitation, a serologic test for syphilis is recommended. If the findings are positive or if characteristic morphologic features of cardiovascular syphilis are suspected, irrespective of the results of the serologic tests, antibiotic therapy appears desirable. (C) 2009 Elsevier Inc. All rights reserved. (Am J Cardiol 2009;104:1578-1587)Integrative Biolog

Doctor of Philosophy

dissertationPactamycin was isolated in 1961 by the former UpJohn Company and to date is the most complex aminocyclopentinol known. This natural metabolite is decorated by six contiguous stereocenters, three of which are quaternary, with each position of the cyclopen

Material Melancholy: Stranded Objects In Modern Southern Women\u27s Writing

This dissertation traces the origins and uses of a specifically southern obsession with the past. Examining how southern women writers represent the compulsion to remember, I demonstrate how, in their narratives, efforts to retain intimate relationships with an idealized past obstruct characters\u27 ability to live in the present. Their fiction aligns neatly with the dynamic described in psychoanalysis as \u27melancholia’—not least because, in each case, these relationships with the past are typically ambivalent or even destructive, and the melancholic subjects must \u27work through\u27 their damaging attachments. Typical psychoanalytic approaches, however, have neglected how such troubled remembering might be influenced by historical efforts to memorialize an imagined antebellum community by infusing objects with narratives of the past. I hope to add a cultural materialist lens to the discourse on southern melancholy by suggesting that this melancholic production is primarily accomplished by infusing objects with narratives of the past, thereby making an imagined premodern community a concrete fact of the social world. Turning to the early twentieth-century women’s memorial movement as a historical example, I argue that elite white women acted as cultural custodians of the South and were integral to the production of patriarchy. This dissertation examines the object world of the works of Katherine Anne Porter, Eudora Welty, and Zora Neale Hurston, looking for moments when objects either represent an idealized past or reveal its constructed nature. This approach demonstrates that opposed to producing ahistorical texts focused on solely domestic issues, these writers interrogate the historical process, illustrating how material culture produces a persistent yet fragile nostalgia

Combined Alterations

The world around us is in constant flux. The photographs we make of the world, no matter how true or untrue, have a direct influence on how we perceive the environment around us. Photography serves to categorize our perceptions of the world. The value of an image is not in what it represents, but in what it recalls. Photographs are fragmented and clear, imperfect and idealized all at the same time

DIRECT MEASUREMENT OF CROSSTIE-BALLAST INTERFACE PRESSURES USING GRANULAR MATERIAL PRESSURE CELLS

The magnitudes and relative pressure distributions transmitted to the crosstie-ballast interface of railroad track significantly influences the subsequent behavior and performance of the overall track structure. If the track structure is not properly designed to distribute the heavy-axle loads of freight cars and locomotives, deficiencies and inherent failures of the crossties, ballast, or underlying support layers can occur, requiring substantial and frequent maintenance activities to achieve requisite track geometrical standards. Incorporating an understanding of the pressure distribution at the crosstie-ballast interface, appropriate designs can be applied to adequately provide a high performing and long-lasting railroad track. Although this can be considered a simple concept, the magnitudes and distributions of pressures at the crosstie-ballast interface have historically proven to be difficult to quantifiably measure and assess over the years. This document describes the development and application of a method to measure average railroad track crosstie-ballast interfacial pressures using timber crossties and pressure cells specifically designed for granular materials. A procedure was specifically developed for recessing the cells in the bottoms of timber crossties. The validity of the test method was initially verified with a series of laboratory tests. These tests used controlled loads applied to sections of trackbed constructed in specifically designed resilient frames. The prototype trackbed section was intended to simulate typical in-track loading conditions and ballast response. Cells were subsequently installed at a test site on an NS Railway well-maintained mainline just east of Knoxville, TN. Six successive crossties were fitted with pressure cells at the ballast interface below the rail seat. Pressure cells were also installed at the center of two crossties where the ballast is typically not tamped or consolidated. Trackbed pressures at the crosstie-ballast interface were periodically measured for numerous revenue freight trains during a period of twenty-one months. After raising and surfacing the track, the ballast was permitted to further consolidate under normal train traffic before again measuring pressures. Having the ballast tightly and uniformly compacted under crossties is important to ensuring representative and reproducible pressure measurements. Measured maximum pressures under the rail at the crosstie-ballast interface ranged from 20 to 30 psi (140 to 210 kPa) for locomotives and loaded freight cars with smooth wheels producing negligible wheel/rail impacts. Crosstie-ballast interface pressures were typically 3 psi (20 kPa) maximum for empty freight cars with smooth wheels. Heavily loaded articulated intermodal car pressures for shared trucks tended to reach nearly 40 psi (280 kPa), actually higher than locomotive-produced pressures. The recorded pressures under the center of the ties were normally negligible, less than 1 psi (7 kPa) for locomotives and loaded freight cars. Wheel-Rail force parameters measured by nearby wheel-impact load detectors (WILD) were compared to crosstie-ballast pressure data for the same trains traversing the test site. Increases in peak WILD forces, either due to heavier wheel loads or increased impacts, were determined to relate favorably to increases in recorded trackbed pressures with a power relationship. The ratios between the peak and nominal wheel forces and trackbed pressures also have strong relationships

Using LiDAR as a monitoring device to calculate volume of rockfall over time

There are many natural hazards which threaten the stability of highway infrastructure and the safety of motoring public. Rockfall and unstable slopes are one of the major concerns. This thesis describes a method which safely and accurately evaluates rockfall on rock outcrops through the use of Light Detection and Ranging (LiDAR) data. LiDAR is an imaging technology which can be used to measure and evaluate possible rock outcrop hazards such as: rockfall, rock-avalanches, debris flows, and landslides. LiDAR produces a three dimensional point cloud of millions of points which gives spatial data on the scanned object, accurate to millimeters, in minutes. The point cloud can be exported to different formats which then can be analyzed using specialized software. The software used for LiDAR data processing was developed here at Missouri University of Science and Technology using C++ with two open source libraries: OpenCV and OpenG [Trademark]. The program aligns two point clouds and calculates the volume found in between. The volume is the rockfall over time between the two scan dates used. The rockfall volume data is then correlated with rockfall triggering events, such as freeze and thaw cycles, precipitation levels, and seismic (blasting) data. Very few rockfall volume correlations could be made with the rockfall triggering events at the outcrops tested, but further research should be done on the process with other types of rock outcrops. Some possible improvement areas are discussed in the last couple sections of this thesis. Also included are step-by-step instructions for reproducibility of the research --Abstract, page iii