Mass Spectrometry in the Elucidation of the Glycoproteome of Bacterial Pathogens

Presently some three hundred post-translational modifications are known to occur in bacteria in vivo. Many of these modifications play critical roles in the regulation of proteins and control key biological processes. One of the most predominant modifications, N- and O-glycosylations are now known to be present in bacteria (and archaea) although they were long believed to be limited to eukaryotes. In a number of human pathogens these glycans have been found attached to the surfaces of pilin, flagellin and other surface and secreted proteins where it has been demonstrated that they play a role in the virulence of these bacteria. Mass spectrometry characterization of these glycosylation events has been the enabling key technology for these findings. This review will look at the use of mass spectrometry as a key technology for the detection and mapping of these modifications within microorganisms, with particular reference to the human pathogens, Campylobacter jejuni and Mycobacterium tuberculosis. The overall aim of this review will be to give a basic understanding of the current ‘state-of-the-art’ of the key techniques, principles and technologies, including bioinformatics tools, involved in the analysis of the glycosylation modifications

A vapor generator for transonic flow visualization

A vapor generator was developed for use in the NASA Langley Transonic Dynamics Tunnel (TDT). Propylene glycol was used as the vapor material. The vapor generator system was evaluated in a laboratory setting and then used in the TDT as part of a laser light sheet flow visualization system. The vapor generator provided satisfactory seeding of the air flow with visible condensate particles, smoke, for tests ranging from low subsonic through transonic speeds for tunnel total pressures from atmospheric pressure down to less than 0.1 atmospheric pressure

Conserved Aspartate Residues and Phosphorylation in Signal Transduction by the Chemotaxis Protein CheY

The CheY protein is phosphorylated by CheA and dephosphorylated by CheZ as part of the chemotactic signal transduction pathway in Escherichia coli. Phosphorylation of CheY has been proposed to occur on an aspartate residue. Each of the eight aspartate residues of CheY was replaced by using site-directed mutagenesis. Substitutions at Asp-12, Asp-13, or Asp-57 resulted in loss of chemotaxis. Most of the mutant CheY proteins were still phosphorylated by CheA but exhibited modified biochemical properties, including reduced ability to accept phosphate from CheA, altered phosphate group stability, and/or resistance to CheZ-mediated dephosphorylation. The properties of CheY proteins bearing a substitution at position 57 were most aberrant, consistent with the hypothesis that Asp-57 is the normal site of acyl phosphate formation. Evidence for an alternate site of phosphorylation in the Asp-57 mutants is presented. Phosphorylated CheY is believed to cause tumbling behavior. However, a dominant mutant CheY protein that was not phosphorylated in vitro caused tumbling in vivo in the absence of CheA. This phenotype suggests that the role of phosphorylation in the wild-type CheY protein is to stabilize a transient conformational change that can generate tumbling behavior

The role of Christian schools in secondary education

Thesis (M.A.)--Boston University N.B.: No title page, Pagination error: pg. i

Prayer Fellowship in the First Half of Synod’s History

The title of an article which appeared in the very first issue of the Ohio Synod\u27s Columbus Theological Magazine may well describe the question of Missouri Synod fellowship. It has been The Burning Question since its very inception and even before its organization as a synod. The present study on fellowship is not the first attempt to deal with the question. It certainly won\u27t be the last. This thesis is an attempt to look at fellowship in the Missouri Synod historically and theologically, assemble material which may be helpful to others who research the subject, and draw some conclusions from the assembled material

Reshaping expectations for web-based collaborative learning

We offered an experimental graduate course built around a World Wide Web-based collaborative learning experience; five graduate students participated. The World Wide Web served as the primary platform on which knowledge was compiled, shared, and synthesized. We built a WWW-based annotated bibliography and synthesized information from several disciplines. Net Forum-based discussions included student responses to questions posed by the instructors and by other students. The Web was valued most as a tool for information dispersal. As a result, students learned more from their peers than they had in other courses. However, students found brainstorming and conversation using Net Forum, a list server, and electronic mail cumbersome and intimidating. Participants noted a need for personal contact to develop the sense of community critical to fruitful collaboration. Complex issues were brought to closure in several face-to-face meetings. In future offerings, we envision an extended course that begins with community-building meetings (live or video) before migrating to intense WEb-based collaboration. We will use the Web\u27s text and image capabilities for sharing complex information over long distances and time periods, and we will downplay the expectation of immediate response and focus instead on considered response. We will use Web-based conferencing technology for brainstorming and real-time interaction among participants. Institutions may have to increase flexibility in the timing and structure of courses to facilitate inter-institutional offerings

Steady and unsteady transonic pressure measurements on a clipped delta wing for pitching and control-surface oscillations

Steady and unsteady pressures were measured on a clipped delta wing with a 6-percent circular-arc airfoil section and a leading-edge sweep angle of 50.40 deg. The model was oscillated in pitch and had an oscillating trailing-edge control surface. Measurements were concentrated over a Mach number range from 0.88 to 0.94; less extensive measurements were made at Mach numbers of 0.40, 0.96, and 1.12. The Reynolds number based on mean chord was approximately 10 x 10 to the 6th power. The interaction of wing or control-surface deflection with the formation of shock waves and with a leading-edge vortex generated complex pressure distributions that were sensitive to frequency and to small changes in Mach number at transonic speeds