http://hdl.handle.net/2374.OX/103131 2013-05-23T21:32:10Z http://hdl.handle.net/2374.OX/107965 FUNCTIONAL TESTS OF β TUBULINS IN DROSOPHILA SPERM TAIL MORPHOLOGY Washington, Ashley L. Drosophilid Beta 2 tubulin has not evolved in 60 million years; variant forms of the protein cannot support spermtail function. Here we test if a unique synergism among amino acids 29, 55, and 57 underlies Beta 2’s function and stasis, by transforming flies with a chimeric gene consisting of Beta 1 tubulin with Beta 2 codons exchanged at these sites. Sperm of transformed flies undergo tests for fertility, motility and cross-sectional ultrastructure to determine if the chimeric gene supports Beta 2 function. Though transformed flies were not recovered, a second project in related Dipterans suggests synergism may underlie Beta 2’s evolutionary stasis. Mosquito Beta 2, and the major Beta 1 and Alpha 1 tubulins, are evolving rapidly in Anopheles mosquitoes. Anopheles mosquitoes have a 9 + 1, rather than 9 + 2 axoneme, possibly relaxing requirements for tubulin function. Alternatively, absence of the Beta 2 synergism may release tubulin evolution. 2009-04-10T08:22:20Z http://hdl.handle.net/2374.OX/107964 Experiments in Vortex Formation of Plunging & Flapping Flat Plates Stanley, Daniel C. Reynolds number, Strouhal number, and formation number are insufficient to quantify the flow properties of a flapping wing system. These parameters do not take enough information from the input variables into account. As part of the current study, the velocity profile and angle of attack were varied during a single pure plunge flapping stroke using an infinite aspect ratio flat plate. Although the velocity profile was either a constant velocity or quarter-sine velocity, the average Reynolds number was held constant at 3000. Strong differences in the flow structure, both qualitatively and quantitatively, were obtained. A new metric is proposed that is able to take these differences in the input variables into account. This metric utilizes the theory of maximum work potential and statistical regressions of the experimental data in order to obtain a model of the experimental parameter space. With this model, estimates of the desired outputs can be made given values for the inputs. The main portion of this study focuses on the differences in flow structure, using qualitative and quantitative techniques, due to finite aspect ratio and flapping about a hinge point. Data at various spanwise and chordwise locations were taken in order to analyze the leading edge, trailing edge, and tip vortices. A small study was also conducted on the effects of changing Reynolds number. It was found that for the infinite aspect ratio plate, using a quarter-sine velocity profile, instead of a constant velocity profile, enhances the production of circulation. Operating at a slight angle of attack (85° instead of 90°) also enhances circulation production; however, operating at a large angle of attack (60° instead of 90°) has the opposite effect due to pinch-off of both the leading and trailing edge vortices. Hinging the wing at the root and using a finite aspect ratio causes the constant velocity profile to produce higher values of circulation than the quarter-sine velocity profile. This trend is the opposite of that seen for the infinite aspect ratio cases. It was also found that flapping in this highly three-dimensional manner greatly hinders the production of circulation as compared to the infinite aspect ratio, pure plunge experiments. 2009-04-10T08:22:07Z http://hdl.handle.net/2374.OX/107963 “A Cry for Justice:” Daniel A. Rudd’s Ecclesiologically-Centered Vision of Justice in the American Catholic Tribune Agee, Gary Bruce In his seminal work, The History of Black Catholics in the United States, Dom Cyprian Davis O.S.B. attempted to set a broader framework within which “future historical research” at the local level might occur. This dissertation is one such academic endeavor. Building on the historical work of both Davis and Joseph H. Lackner S.M., this dissertation examines the nature of the “cry for justice” as it was communicated in the American Catholic Tribune, a weekly, nineteenth century, black newspaper printed by Daniel A. Rudd, an influential African American Catholic publisher, educator and civil rights leader. During the years of this newspaper’s publication, 1886-1897, Rudd promoted an ecclesiologically-centered vision of justice which presumed for the Catholic Church an essential role in the establishment of race justice in America. An examination of Rudd’s life and work reveals that though Rudd agitated for full equality for African Americans throughout his life, three distinct approaches can be discerned which roughly correspond to three periods in his life. During the Springfield Period, 1881-1886, Rudd promoted a “Fredrick Douglass-like” political/judicial activist approach. During the Cincinnati/Detroit Period, 1887-1897, he championed an ecclesiologically-centered approach. Finally, throughout the Southern Period, from 1900 onward, the Catholic laymen advocated a “Booker T. Washington-like” economic, self-help approach for achieving full equality for blacks. 2009-04-10T08:21:54Z