Post University On-the-Job Training for Engineers

Our national need for qualified scientists and engineers is greater now than at any other time in our history. Fortunately, we can point with pride to this need as a measure of the impact of science and technology on our way of life. In effect, we have made such rapid strides In advancing established sciences and in opening new technological fields that we have proved the value of the scientist and engineer to society, and, as a-result, have created an expanding demand for their services which we must now attempt to satisfy. This demand we face is also due to the changing skills and high degree of specialization required to perform in these new technological fields. The colleges and universities are doing their part to provide current graduates with a modern technical foundation, but we cannot afford to ignore the thousands of experienced engineers and scientists already employed by private industry and government. As employers, we have an obligation to these men and women to see that they are provided with an understanding of the latest advances that modern technology has to offer; that we develop them in particular specialty areas characteristic of a given field of work; and, equally important, that we assist them in the transition from one field to another as the technological emphasis shifts. Practically all technological industries have experienced and continue to experience rapid changes in their activities. The aerospace business, in particular, has been characterized by extremely rapid, in fact revolutionary, changes during the relatively short period of its existence0 At the National Aeronautics and Space Administration, successor to the National Advisory Committee for Aeronautics, for example, we have encountered the fun impact of a changing science and technology. Indeed, as a research organization, we have undoubtedly contributed, in some measure, to this change. Within the NASAs Lewis Research Center, we have approximately 800 research scientists and engineers who have matured professionally in an environment which is essentially one of continuous learning - an experience which comes close to being a form of post graduate training in itself. This environment, in addition to providing continuous evolutionary changes, has also provided two major revolutions which have made this development picture more complex. We will describe these environmental changes which have occurred at the Lewis Research Center and discuss the various techniques and programs we have employed to provide for the professional development of our staff. The Lewis Research Center has had an Interesting and exciting l8-year history of aerospace propulsion research and development. It began during the early years of World War II as an expansion of the Power Plant Division of the NCA Langley Center with the mission of conducting research required for the development of improved reciprocating engines and to study the associated problems of subsonic propulsion aerodynamics, It was only a few years later, however, that turbojet and ramjet propulsion and supersonic flight research became our main concern. This transition to jet type engines and higher speeds was our first major technological change. The aerodynamics of propellers became the aerodynamics of high speed turbine and compressor blades; the fuel ignition and carbon deposition problems were transferred from a cyclical or Intermittent high compression combustion chamber to a continuous combustion zone within a thin-walled metal shell; aerodynamics problems were thrust into the supersonic range; and high temperature materials began to play an increasingly critical role. Although this transition still required the same basic knowledge and principles as before, the new engine types did involve a different emphasis and variety of consideration not generally familiar to our scientists and engineers

Binge Ethanol Leads to Decreased Macrophage Accumulation in Infected Cutaneous Wounds

Trauma patients who consumed alcohol prior to sustaining injuries have higher rates of morbidity and mortality than those with comparable injuries who did not drink. Additionally, those who drank had impaired wound healing and increased susceptibility to infection. Despite these clinical observations, few studies have explored the effect of ethanol on the innate immune cell function in a healing wound or how this may alter resolution of cutaneous infection. A murine model of ethanol and cutaneous wound infection was used to examine bacterial growth and recruitment of innate immune cells. Mice were given either ethanol (2.2 g/kg) or saline 30 minutes prior to being subjected to six 3 mm dorsal punch wounds and Staphylococcus aureus (104 CFU/wound). At 24 hours after injury and infection, wound tissue was collected. There was a 3.6 fold increase in bacterial growth in the infected wounds of ethanol-exposed mice relative to those given vehicle prior to wound infection. This elevated bacterial growth was accompanied by an increase in the percentage of open wound area realative to wounds from mice that were immediately sacrificed after being injured (p\u3c0.0001). To determine the contribution of ethanol-related alterations in the innate immune response to this heightened bacterial colonization, we examined wound neutrophil and macrophage accumulation in the wounds by immunofluorescent imaging. At 24 hours, no differences were observed in the number of neutrophils at the infected wound site regardless of ethanol exposure. In contrast, macrophage accumulation was 45% lower in wounds from ethanol-exposed mice relative to vehicle-treated animals (p\u3c0.05). This decrease in macrophage recruitement was accompanied by a 24% reduction in the level of macrophage chemoattractant protein-1 (MCP-1) in wound homogenates from ethanol exposed mice, however, this differences was not significant. Consistent with the lack of change in the number of wound neutrophils, we also failed to detect a difference in the wound content of neutrophil chemokines, KC and macrophage inflammatory protein-2 (MIP-2). To further explore differences in innate immune response due to alcohol, we examined phagocytosis of S. aureus by neutrophils and macrophages in the wound. However, no evidence of phagocytosis by either cell was observed due to a lack of bacterial dissemination into the tissue adjacent to the wound. Together, these data show that ethanol impairs macrophage accumulation at the infected wound site 24 hours after injury and suggest that the reduction in these cells in ethanol-exposed mice could contribute to reduced bacterial clearance and increased wound size

Articulating the Work Experiences of Chief Medical Officers: A Qualitative Study

The contention between physicians and administrators in U.S. hospital systems has never been as divergent as it is today. The reasons for this conflict are found in historical and contemporary literature stemming from differences in group beliefs, variability of professional goals, and changes in recent healthcare policies and directives in this country. For the U.S. healthcare system to flourish amid these noted challenges, hospital system leaders must focus on the physician and administrator group differences and conflicts toward more group interdependence and balance. In my dissertation, the chief medical officer (CMO) is introduced and empirically studied as the linchpin of group cohesion and as someone who is vitally important to 21st-century healthcare and hospital systems. Current literature regarding CMO practice provides limited insight on the position. Therefore, I engaged a qualitative methodology and design to better understand CMOs in a particular healthcare system. The case study design helped capture the findings that suggest that current literature falls short of discussing and fostering the processes by which CMOs perform their job. Thus, I engaged a new process-centric view in order to better understand CMO practice. Through interviewing a select group of CMOs, my findings revealed that this unique group of physician leaders faced practical challenges regarding definition of their role, building and maintaining credibility with their physician colleagues, and development of the position. By bringing these issues to the forefront empirically, I discovered the challenging reality of my participants through their experiences as translators, advocates, aligners, and protectors of their patients, colleagues, hospitals, and, ultimately, the healthcare system. Overall, the experiences of my participants fostered the creation of implications for research, practice, and future studies regarding performance of the CMO position in support of U.S. healthcare system goals

Coking of JP-4 fuels in electrically heated metal tubes

A limited exploratory investigation of the rate of coking of four JP-4 fuels in electrically heated metal tubes was conducted in order to provide design information for fuel prevaporizers for turbojet-engine combustors. The fuels tested included two production and two minimum-quality JP-4 type fuels. The heating tube was operated at fuel pressures of approximately 500, 400, and 50 pounds per square inch. The operating fuel temperature was varied between approximately 600 degrees and 1200 degrees F

Hippocampal Volume Differences in Gulf War Veterans with Current Versus Lifetime Posttraumatic Stress Disorder Symptoms

Background: Decreased hippocampal volume is described in posttraumatic stress disorder (PTSD) and depression. However, it is not known whether it is a risk factor for the development of PTSD or a consequence of PTSD. We sought to determine the effects of PTSD and depressive symptoms on hippocampal volume. Methods: Clinical and magnetic resonance imaging data were collected in a cross sectional study of 244 GulfWarveterans. Measures included lifetime and current Clinician Administered PTSD Scale, Hamilton Depression Scale, Life Stressor Checklist, and Lifetime Drinking History. Magnetic resonance imaging data were acquired with a 1.5-T scanner and analyzed with automated and semiautomated image processing techniques. Results: Eighty-two veterans had lifetime PTSD, 44 had current PTSD, and 38 had current depression. In the linear regression analysis, current PTSD symptoms (standardized coefficient B= .25, p =.03) but neither lifetime PTSD symptoms nor current depression were associated with smaller hippocampal volume. Gender, age, history of early life trauma, education, lifetime and current alcohol use, current marijuana use, and treatment with antidepressants did not have independent effects. Participants with chronic PTSD had, on average, a smaller hippocampus compared with those with remitted PTSD. Conclusions: The finding that current but not lifetime PTSD symptom severity explains hippocampal size raises two possibilities: either a small hippocampus is a risk factor for lack of recovery from PTSD (trait) or PTSD effects on hippocampal volume are reversible once PTSD symptoms remit and the patient recovers (state)

Heterophilic Binding of L1 on Unmyelinated Sensory Axons Mediates Schwann Cell Adhesion and Is Required for Axonal Survival

This study investigated the function of the adhesion molecule L1 in unmyelinated fibers of the peripheral nervous system (PNS) by analysis of L1- deficient mice. We demonstrate that L1 is present on axons and Schwann cells of sensory unmyelinated fibers, but only on Schwann cells of sympathetic unmyelinated fibers. In L1-deficient sensory nerves, Schwann cells formed but failed to retain normal axonal ensheathment. L1-deficient mice had reduced sensory function and loss of unmyelinated axons, while sympathetic unmyelinated axons appeared normal. In nerve transplant studies, loss of axonal-L1, but not Schwann cell-L1, reproduced the L1-deficient phenotype. These data establish that heterophilic axonal-L1 interactions mediate adhesion between unmyelinated sensory axons and Schwann cells, stabilize the polarization of Schwann cell surface membranes, and mediate a trophic effect that assures axonal survival