A proteolytic activity has been shown to be associated with the heat shock protein 70 (hsp70). In order to study this, I have constructed RNA transcribing vectors with the coding sequences of the D. melanogaster (pBUG7) and the human (pMAN70) genes coding hsp70, and with an internal deletion (pBUG301) in D. melanogaster. Proteins from 37 kDa to 70 kDa were translated in a rabbit reticulocyte lysate in the presence of 35S-methionine from RNA synthesized in vitro off the full length templates (pBUG7, and pMAN70), or altered templates. Restriction digestion of pBUG7 with BamH I and Nar I yields templates that produce carboxy-terminal truncated proteins of 37 kDa and 61 kDa respectively. The full length and the truncated proteins contain a proteolytic activity when assayed by SDS/PAGE in two dimensions. The internally deleted protein does not maintain the proteolytic activity. The proteolytic activity was shown not to be the result of non-enzymatic cleavage. A general serine proteinase inhibitor eliminates the proteolytic activity of the full length human and D. melanogaster hsp70. This evidence shows that the proteolytic activity is directly connected to hsp70.

The overarching goal of this work is to advance the current knowledge of hydrodynamic instabilities (namely, Richtmyer-Meshkov and Kelvin-Helmholtz instabilities) and associated turbulent mixing phenomena which is important for several emerging technologies and verification/validation of numerical models being developed to study these phenomena. Three experimental campaigns were designed to focus on understanding the evolution of the instability under different impulsive acceleration histories and highlight the impact of initial conditions on the developing turbulent flow environment. The first campaign highlights the importance of initial baroclinic torque distribution along the developing shocked interface in a twice-shocked variable-density flow environment. The second campaign is a parametric study which aims at providing a large dataset for validating models in literature as well as simulations. In the last study, a new type of initial condition was designed to study the effect of initial conditions on late time turbulent flows. A description of the optical diagnostic techniques developed in our laboratory in order to complete these studies will be given. Now each campaign will be introduced. In the first campaign, an inclined interface perturbation is used as the initial condition. The Mach number (1.55), angle of inclination (60 degrees), and gas pair (N2/CO2) were held constant. The parameter which changed was the distance that the initial condition was placed relative to the end of the shock tube (i.e., the end of the test section). Three distances were used. The vorticity distribution was found to be very different for the most developed case after reshock. Furthermore, the most developed case started to develop an inertial range before reshock. The second campaign is parametric and seeks to test a proposed inclined interface scaling technique. The data is also useful for comparing to Ares simulation results. The parameter space covered Mach number (1.55 and 2.01), inclination angle (60 degrees and 80 degrees), and Atwood number (0.23 and 0.67). PLIF was developed and used to collect data for four cases before and after reshock. Linear and nonlinear cases developed very differently before reshock, but their mixing widths converged after reshock. The last campaign involves a new perturbation technique which generates what will be referred to as a complex interface. Counter-flowing jets were placed near the interface exit ports to create shear. The perturbation was made more complex by also injecting light (heavy) gas into the heavy (light) one. Density and velocity statistics were collected simultaneously. The complex case retained a signature of the inclined interface perturbation at late time before reshock and developed a larger inertial range than its inclined interface counterpart. Important parameters for a variable-density turbulence model are also presented.

International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / Acquiring shock and vibration data from flight vehicles through rf telemetry links has numerous associated challenges. Yet, these measurements are important to establish environmental specifications to provide a basis for system or component design and testing. The principal limitation in acquiring these measurements is the frequency bandwidth available for data transmission. This limited bandwidth is often responsible for invalid data being accepted as valid. This work provides a brief review of time and frequency division multiplexing to identify the potential error contributors to shock and vibration measurements. Its focus is on the design of acceleration measurement systems to eliminate these errors and optimize individual measurement channel performance.

International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The Instrumentation and Telemetry Departments at Sandia National Laboratories have been instrumenting earth penetrators for over thirty years. Recorded acceleration data is used to quantify penetrator performance. Penetrator testing has become more difficult as desired impact velocities have increased. This results in the need for small-scale test vehicles and miniature instrumentation. A miniature recorder will allow penetrator diameters to significantly decrease, opening the window of testable parameters. Full-scale test vehicles will also benefit from miniature recorders by using a less intrusive system to instrument internal arming, fusing, and firing components. This single channel concept is the latest design in an ongoing effort to miniaturize the size and reduce the power requirement of acceleration instrumentation. A micro-controller/memory based system provides the data acquisition, signal conditioning, power regulation, and data storage. This architecture allows the recorder, including both sensor and electronics, to occupy a volume of less than 1.5 cubic inches, draw less than 200mW of power, and record 15kHz data up to 40,000 gs. This paper will describe the development and operation of this miniature acceleration recorder. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under contract DE-AC04- 94Al85000."

published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy

No description available.

No description available.

This study addressed the question of whether or not a stimulus paired with the termination of shock would acquire a positive conditioned reinforcing function. Previous investigators have suggested that a stimulus paired with shock termination must increase the frequency of a response upon which it is made contingent. This test for conditioned reinforcement is incomplete because multiple stimulus functions will be established during conditioning trials that can influence the rate of responding. The solution to this multiple stimulus control problem involved the effects of reinforcement upon events antecedent to the criterion response. Reinforcement results in the establishment of discriminative stimulus control. The test for conditioned reinforcement from shock termination, therefore, would involve using the presumed conditioned reinforcer to establish discriminative control for a response. Subjects were four male albino rats of the Wistar strain. The experimental procedure was divided into three phases. The initial phase involved consecutive trials in which a tone was paired with shock offset. The next phase continued tone/shock offset pairings and, in addition, the tone alone was presented sometimes for establishment of a lever press. In the third phase an attempt was made to bring the lever press under the discriminative stimulus control of a light. A successful response shaping effect was obtained for two of the four rats. There was no establishment of discriminative stimulus control for level pressing for the two rats who proceeded to the discrimination test for conditioned reinforcement. Conditioned reinforcement from shock termination was not revealed in this study. The establishment of stable discriminative control over the criterion response would require a strong reinforcer relative to the other established stimulus functions. Future research should concentrate on developing procedures to maximize the conditioned reinforcing properties while minimizing the control from competing stimulus functions.

Hemorrhagic shock is a clinical syndrome involving widespread cellular dysfunction and resulting in injury to many organs. Resuscitation from hemorrhagic shock is similar to reperfusion after ischemia, but differs in that some blood flow persists during shock. Ischemia-reperfusion produces oxygen radicals in many organs, including the liver of the rat and the human. The hypothesis of this project was that oxygen radicals are produced and cause hepatic injury during resuscitation from hemorrhagic shock. The production of oxygen radicals within the liver should cause lipid peroxidation and tissue injury. Manipulation of defenses against oxygen radicals should decrease the hepatic injury caused by hemorrhagic shock and resuscitation. The blood pressure of Sprague-Dawley rats was reduced to 35-40 mm Hg by blood withdrawal for two hours, followed by reinfusion of withdrawn blood. Plasma alanine aminotransferase (ALT) levels rose and injury to hepatocytes and non-parenchymal cells was found on transmission electron microscopy. The presence of lipid peroxidation was determined by quantitation of ethane exhalation and hepatic content of thiobarbituric acid reactive substances (TBARS). Ethane exhalation was elevated during the hypotensive phase and after resuscitation. Hepatic TBARS levels were elevated after resuscitation only. The same hemorrhagic shock protocol was used to determine the effect of antioxidant manipulation on hepatic injury. The antioxidants superoxide dismutase, catalase, or deferoxamine produced no reduction in hepatic injury. The administration of phorone reduced hepatic non-protein sulfhydryl content and increased plasma ALT levels nine fold at 24 hours after resuscitation. The development of lipid peroxidation and the exacerbation of liver injury by the administration of phorone suggest that oxygen radicals are produced in the liver during hemorrhagic shock and resuscitation. However, the administration of antioxidants provided no protection. Therefore, it seems unlikely the oxygen radicals are involved in the pathogenesis of liver injury in this model. It is possible that the lipid peroxidation occurs after the cell is irreversible injured.

The present research compared the psychosocial responses of Type A and Type B individuals following myocardial infarction. Differences in self-referential style and responsiveness to an uncontrollable event were of interest. Thirty-three post-MI patients were followed over a three month period. Self-report measures were administered at two weeks, one month, and three months post-MI to assess levels of psychosocial adjustment and factors associated with adjustment. Type A individuals were more self-involved and reported a greater frequency of negative self-statements following the heart attack. They appeared more depressed, reported more symptoms, had lower expectancies for success, and were hypersensitive to a perceived lack of control relative to Type B's. They resumed activities sooner, but delayed their return to work. No differences between the two groups were found on measures of information seeking, medical compliance, health locus of control, or life satisfaction. The results were discussed with reference to previous research on the Type A behavior pattern and implications for cardiac rehabilitation were presented.