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<p> Forty iso-females lines of Drosophila melanogaster were surveyed by SDS-PAGE for length polymorphisms in their heat shock proteins. None was observed. The 70K and 27K HSP's were further analyzed by peptide mapping using Staphylococcus aureas va protease, acid hydrolysis and chymotrypsin. Again, no variation was observed. </p> <p> Thirty-seven species of Drosophila were surveyed for length variation in their heat shock proteins by SDS-PAGE. No variation was observed in HSP84 or HSP70 among any of the species. HSP36 was shown to vary in mobility only, especially among species from different species groups. The small HSP's showed the greatest interspecies variation, especially in the Repleta and Virilis groups. This variation included mobility and band number differences. </p> <p> The results from the 36K HSP's were used to construct a Drosophila species group phylogeny. These groups, shown in descending order of age, are Saltans, Victoria, Melanogaster, Willistoni, Repleta, and Virilis. </p> / Thesis / Master of Science (MSc)

A survey of restriction enzyme polymorphisms was performed with fifteen iso-female lines of D. melanogaster amd eighteen single representaives of other Drosophila species. Three enzymes: Bam H1, Eco R1, and Pst 1 were used to probe the genetic structure of the region containing the genes Hsp 22, Hsp 23, Hsp 26, and Hsp 27. The results for within D. melanogaster show that all variation in the DNA sequence is limited to the non-coding region. The restriction patterns confirm the hypothesis that the hsp 22-27 genes are a result of tandem duplications. The values for Nei's estimate of sequence diversity (delta) are 0.034 between populations of D. melanogaster, 0.113 between sibling species, and 0.123 between nonsibling species. These estimates were compared to values obtained for protein and enzyme variation. DNA sequence divergence between nonsibling species versus nonsibling species show less differentiation than protein and enzyme divergence. The restriction enzyme phenotype was used to generate phylogenies which is in approximate agreement with previously reported phylogenies. Molecular drive and selectionist hypotheses of differential rates of evolution during cladogenesis and anagenesis are discussed. / Thesis / Master of Science (MS)

This thesis was concerned with the effects of shock intensity on discriminative escape conditioning. At the lowest shock intensity there was a bimodal distribution of nonresponding animals at one mode and responders at the other mode. Optimum performance occurred at the lowest shock intensity at which 100% of the animals responded. At higher shock intensities performance deteriorated. An attempt to test the Yerkes-Dodson Law failed to yield conclusive results. Finally, it was found that shock intensity affected performance rather than learning. / Thesis / Doctor of Philosophy (PhD)

Aedes aegypti is an important vector of the viruses that cause dengue fever, dengue hemorrhagic fever, and yellow fever. In depth genetic studies of vector species have been made possible due to the availability of genome sequences and techniques for producing stably transformed mosquitoes. These resources have also contributed to the establishment of new genetics-based approaches to the control of vector borne disease. Genetic studies of Ae. aegypti have benefited from the ability to drive targeted transgene expression, however a ubiquitous inducible promoter has not been identified in this mosquito. The Drosophila melanogaster heat shock 70 promoter has been shown to drive inducible expression in heterologous systems; however, DmHsp70 possesses significant basal activity in Aedes aegypti. This study characterized the sequence and expression of the heat shock 70 genes of Aedes aegypti. AaHsp70 genes were found to be organized in two clusters, each comprised of three divergent pairs. AaHsp70 genes exhibited robust expression upon heat shock in larvae, pupae, and adults as well as in heads, salivary glands, midguts and ovaries. Genomic regions upstream of AaHsp70 genes were found to drive heat-inducible expression of a reporter in both cell and embryo assays. Deletion analysis of AaHsp70-derived promoters yielded two ~1.5 kb genomic fragments that maintained robust heat inducibility in these systems. Aedes aegypti were transformed with AaHsp70-luciferase gene cassettes using the transposable element Mos1. AaHsp70-luciferase transcripts accumulated specifically after heat shock, and displayed a pattern of rapid induction and decay similar to endogenous AaHsp70 genes. Heat-induced expression of luciferase was observed in transgenic larvae, pupae and adults as well as heads, midguts and ovaries but not salivary glands, with levels varying between transgenic strains. The effect of heat shock on the endogenous RNAi pathway as well as the effect of blood feeding on the expression of AaHsp70 genes was investigated, though reproducible results could not be obtained using the assays employed. In conclusion, the heat shock 70 gene family of Aedes aegypti was identified and characterized. The AaHsp70 promoters described could be valuable for gene function studies as well as for the precise timing of the expression of anti-pathogen molecules. / Ph. D.

Combining shock and vibration isolation into a single isolation system package is explored through the use of an air spring in parallel with a controlled magnetorheological fluid damper. The benefits of combining shock and vibration isolation into a single package is discussed. Modeling and control issues are investigated and test and simulation results are discussed. It is shown that this hybrid isolation system provides significantly increased performance over current state-of-the-art passive systems. Also explored is the feasibility of scavenging and storing ambient shipboard vibration energy for use in powering the isolation system. To date the literature has not adequately explored the direct design of a combined shock and vibration isolation system. As shock and vibration isolation are typically conflicting goals, the traditional approach has been to design separate shock and vibration isolation systems and operate them in parallel. This approach invariably leads to compromises in terms of the performance of both systems. Additionally, while considerable research has been performed on magnetorheological fluids and devices based on these fluids, there has been little research performed on the use of these fluids in devices that are subjected to high velocities such as the velocity seen by a ship exposed to underwater near-miss explosive events. Also missing from the literature is any research involving the scavenging and storage of ambient shipboard vibration energy. While the focus of this work is on the use of this scavenged energy to power the subject isolation system, many other uses for this energy can be envisioned. Experimental and analytical results from this research clearly show the advantages of this hybrid isolation system. Drop tests show that inputs as great as 167 g's were reduced to 3.42 g's above mount at 1.11 inches of deflection using a Velocity Feedback controller suggested by the author. When contrasted with typical test results with similar inputs, the subject isolation system achieved reductions in above mount accelerations of 300% and reductions in mount deflections of 200% over current state-of-the-art passive shipboard isolation systems. Furthermore, simulations using a validated model of the isolation system suggest that this performance improvement can be achieved in multi-degree-of-freedom isolation systems as well. It was shown that above mount accelerations in the vertical and athwartship directions could be effectively limited to a predefined value, while achieving the absolute minimum mount defections, using an Acceleration Limiting Bang-Bang controller suggested by the author. Further experimentation suggests that the subject isolation system could be entirely self-powered from scavenged ambient shipboard vibration energy. An experiment using an energy scavenging and storage system consisting of a Piezoelectric Stack Generator and a bank of ultracapacitors showed that enough energy could be harvested to power the isolation system though several shock events. / Ph. D.

The affects of hydrodynamic shock wave treatment on the bacterial flora of raw beef and poultry were evaluated. Hydrodynamic shock waves were generated in an aqueous treatment medium by either the detonation of two types of explosive charges (explosively-generated hydrodynamic shock waves [EHSW]) (a binary or a molecular explosive) or by electrical discharge (high voltage arc discharge Hydrodyne (TM [HVADH; Hydrodyne, Inc.]). A variety of sample types (whole steaks, ground beef, a water and ground beef slurry) were used to determine the lethality affects of EHSW on cells of the marker microorganism Listeria innocua suspended in a simple broth medium. These sample types were used in order to evaluate the affects of the process not only on the surface, but throughout the bulk of the samples in order to determine whether EHSW could also be used as a non-thermal alternative to reduce the bacterial flora of non-intact or ground meats. The levels of psychrotrophic, lactic, and coliform populations on the surface of whole eye of round steaks submitted to EHSW processing did not differ (P> 0.05) from those of untreated whole eye of round steaks. Parameters expected to influence the nature, magnitude, and propagation of the hydrodynamic shock wave were also varied and evaluated in order to determine which individual parameter or combination of parameters affected the bactericidal potential of EHSW or HVADH processing. Treatment with EHSW failed (P > 0.05) to produce lethality effects on the psychrotrophic, lactic, and coliform populations of ground beef, regardless of the composition and mass of explosive used, the number of successive EHSW treatments used, the relative distance between the explosive charge and the top surface of the sample, or the temperature of the water used in the treatment chamber. EHSW processing did not change (P >0.05) the bacterial population of treated ground beef samples when compared to untreated controls during a five day refrigerated storage study. No lethality effects were observed (P >0.05) in ground beef samples treated by HVADH when samples were subjected to one, two, or three successive HVADH treatments. Minimal penetration of surface inoculated bacteria was observed for both beef steaks and boneless skinless chicken breasts subjected to EHSW and HVADH, respectively. In EHSW-treated beef eye of round steaks, marker bacteria were detected within the first 300 um of tissue below the inoculated surface, 50-100 um beyond the depth of untreated surface inoculated steaks. In HVADH-treated boneless skinless chicken breasts, marker bacteria were detected within the first 200 um below the inoculated surface, 50-100 um beyond the depth of untreated surface inoculated boneless skinless chicken breasts. This suggests that although no difference in the bacteriological populations was observed between EHSW treated, HVADH treated, and untreated control samples of whole steaks (and ground beef treated with both HVADH and EHSW), HVADH and EHSW treatments affect the movement of surface bacteria. United States Department of Agriculture (USDA) guidelines suggest intact beef steaks be cooked to achieve a cooked color appearance on the surface and raw poultry be cooked to an internal temperature of 77° C to inactivate the pathogens Escherichia coli O157:H7 and salmonellae which are of concern in beef and poultry, respectively. By following these guidelines during proper cooking, consumers achieve thermal inactivation of these pathogens. Since the movement of the marker bacterium observed in treated steaks and boneless skinless chicken breasts was minimal, proper cooking of the products would be expected to inactivate vegetative bacterial cells at this depth. Therefore, EHSW and HVADH treated whole beef steaks and boneless skinless chicken breasts would not be expected to pose a bacterial hazard if the products were properly cooked. / Ph. D.

In this analytical investigation of the initial response of a thin, circular, homogeneous, and isotropic ring to a transverse shock pulse, the radial and tangential components of displacement and velocity are found in series form by use of Duhamel's integral. A plane shock front is assumed to propagate normal to a diameter of the ring with constant linear velocity and to be followed by a parabolic decay. It is also assumed that the motion of the ring does not influence the pressure of the wave and that the wave exerts only radial forces on the ring. Classical, small-deflection linear theory, neglecting rotatory inertia and shear effects, is used in conjunction with the classical treatment of distinct extensional and flexural modes. For the stated loading scheme, Duhamel 's integral cannot be obtained in closed form; however, by use of numerical integration an example problem is solved and the resulting displacement and velocity histories are plotted. The flexural velocity showed unexpectedly large values at relatively late times. An alternate analytical solution using a double Fourier series is also developed, but no numerical results were determined. The flexural response from the solution of an approximate problem consisting of a moving concentrated force on a ring was also investigated to help explain this unexpected response. An area deserving further consideration is raised by the problem of the relative importance of using a sweeping type load as opposed to using the mathematically simpler all-at-once type loading. / M.S.

As a racecar negotiates a track, it is subjected to many inputs at both high and low frequencies. These inputs come from the track surface, the motion of the body, and from aerodynamic disturbances. The damper's ability to control these inputs leads to improved grip at the tires, which increases overall handling of the vehicle. Since dampers have always been assumed to be primarily velocity dependent, little work has gone into exploring damper's frequency dependent nature. Therefore, this study evaluates the effect input frequency has on the damper's output force. Utilizing experimental testing, with a state of the art damper dynamometer, and computer simulation with a parametric damper model developed for this study, several inputs and key parameters are tested, and the damper's frequency dependent nature starts to emerge. Constant peak velocity sinusoidal and sinusoidal sweep inputs are used for the experimental testing. The results show that as the input frequency is increased, the damper's output force lissajou transitions from the characteristic shape of a damper's lissajou to a shape characteristic of a spring's lissajou. This change in the lissajou is linked to hysteretic effects, which includes the gas spring effect. Damper parameters that are suspected to contribute to the hysteretic effects are explored with computer simulation and additional experimental testing. The results from this show that fluid preparation, fluid type, initial gas pressure, and friction have a predictable effect on the damper's output force. / Master of Science