Development of a Cellular Fiber Spinning Technology for Regenerative Medicine

In order to prove that our textile hollow fiber spinning apparatus was adequate for cellular encapsulation, we confirmed the viability and metabolic activity of green fluorescent protein (GFP) labeled bovine mammary epithelial cells (MAC-Ts) that were encapsulated in either the wall or lumen of alginate fibers. After a 21 day in vitro macroscopic evaluation, no decrease in fluorescence was observed; and it was determined that MAC-Ts encapsulated under both methods produced lactic acid and consumed glucose. Histomorphological analyses revealed that the diameter of the MAC-Ts increased under both encapsulation scenarios, with little to no evidence of cell cluster propagation. Based on our findings within this feasibility study, we posit that our spinning apparatus can be used to encapsulate cells, and will suffice as an enabling technology for use in regenerative medicine

Exploring a combined quantitative and qualitative research approach in developing a culturally competent dietary behavior assessment instrument

Cultural competence is widely recognized as an essential strategy for reducing health disparities. As the United States' population becomes increasingly ethno-culturally diverse, these disparities are becoming even more pronounced. One particular challenge in this regard concerns overweight/obesity prevalence among American adults, as a disproportionately high number of racial and ethnic minority adults are classified as overweight or obese. Dietary behavior assessments are often utilized by health and human services professionals to obtain the data necessary to promote goals such as the reduction and elimination of overweight/obesity across all ethno-cultural groups. The primary objective of this research study was to develop, test, and evaluate a culturally-competent dietary behavior assessment instrument by effectively synthesizing qualitative methods from Cognitive Anthropology with appropriate survey research and quantitative statistical methods. Specifically, a quantitative methods triangle of hierarchical cluster analysis, binary logistic regression, and Poisson regression in conjunction with the free listing qualitative research technique from Cognitive Anthropology was explored as a possible combined methodological approach for researchers and public health professionals wishing to develop a comprehensive understanding of dietary behaviors at the local community level. Binary logistic regression and Poisson regression enabled the relationship between selected food categories and certain demographic/cultural indicators to be modeled, while hierarchical cluster analyses enabled modeling of the distinct patterns of food category groupings that comprise individuals' regular diet. Additionally, initial qualitative analyses of the raw data promoted an understanding of the influence that the local fast food and dine-in restaurant environment has on the dietary behaviors of the target population. The results of this study suggest that a quantitative methods triangle of hierarchical cluster analysis, binary logistic regression analysis, and Poisson regression analysis founded upon qualitative research principles has potential for use as a combined methodological approach for researchers and public health professionals wishing to develop a comprehensive understanding of dietary behaviors at the local community level. By employing these techniques, researchers can analyze individual dietary behaviors and eating patterns from a multifaceted perspective. In turn, public health professionals can develop community-based, cross-culturally relevant programs and interventions that are equally effective across all ethno-cultural groups in their target population.Ph.D.Committee Chair: Vidakovic, Branislav; Committee Member: Edwards, Paula; Committee Member: Griffin, Paul; Committee Member: Grinter, Rebecca; Committee Member: Mullis, Rebecc

Marketing of Tomatoes in Gregg County, Texas

The lack of an efficient marketing system is stifling farm income from tomatoes in Gregg County. It has been predicted that if something is not done to improve the marketing conditions, Gregg County will be out of the marketing business in about 5 years. U.S.D.A. studies show that: East Texas has too many single buyers and commodity markets (60 to 65 tomato sheds) to operate efficiently for buyers and sellers. There is no question among people who are a part of East Texas vegetable businesses where the trouble lies. They all agree that farmers can produce more than they can sell profitably. Marketing is always pointed out as the number 7 problem.1 With a view towards improving the marketing of tomatoes by Negro growers, a study of present marketing practices were made among them. Current marketing information was obtained and analyzed in respect to sales, transportation facilities, cost incurred, and prices received for tomatoes. The ultimate objectives of this thesis is to present a study of marketing practices as they exist presently, and offer possible suggestions in an effort to improve practices as they occurred among Negroes farming in Gregg County, Texas. Fifty Negro Farmers in Gregg County, Texas were included in the study. These fifty represented a total of all Negro tomato growers in Area I of Gregg County. 1Ralph L. Watts, The Vegetable Growing Business (New York: Orange Judd Publishing Company, 1946), p. 218

EXAMINING THE EDUCATIONAL EXPERIENCES OF COMMUNITY DAY SCHOOL GRADUATES: A NARRATIVE INQUIRY

Community day school graduates enter society with decisions about college, career, and work. Community day schools operate as a non-traditional education system that provides a separate and often unique education to many disenfranchised students, with lessened accountability protocols to assess whether these systems prepare graduates for life after high school. The number of community day schools and enrollment is declining, due in part to excessive changes within the law and stricter guidelines required to be met

Experimental validation of a two-dimensional shear-flow model for determining acoustic impedance

Tests were conducted to validate a two-dimensional shear-flow analytical model for determining the acoustic impedance of a liner test specimen in a grazing-incidence, grazing-flow environment. The tests were limited to a test specimen chosen to exhibit minimal effects of grazing flow so that the results obtained by using the shear-flow analytical model would be expected to match those obtained from normal-incidence impedance measurements. Impedances for both downstream and upstream sound propagation were generally consistent with those from normal-incidence measurements. However, sensitivity of the grazing-incidence impedance to small measurement or systematic errors in propagation constant varied dramatically over the range of test frequencies

On the Use of Experimental Methods to Improve Confidence in Educed Impedance

Results from impedance eduction methods developed by NASA Langley Research Center are used throughout the acoustic liner community. In spite of recent enhancements, occasional anomalies persist with these methods, generally at frequencies where the liner produces minimal attenuation. This investigation demonstrates an experimental approach to educe impedance with increased confidence over a desired frequency range, by combining results from successive tests with different cavity depths. A series of tests is conducted with three wire-mesh facesheets, for which the results should be weakly dependent on source sound pressure level and mean grazing flow speed. First, a raylometer is used to measure the DC flow resistance of each facesheet. These facesheets are then mounted onto a frame and a normal incidence tube is used to determine their respective acoustic impedance spectra. A comparison of the acoustic resistance component with the DC flow resistance for each facesheet is used to validate the measurement process. Next, each facesheet is successively mounted onto three frames with different cavity depths, and a grazing flow impedance tube is used to educe their respective acoustic impedance spectra with and without mean flow. The no-flow results are compared with those measured in the normal incidence tube to validate the impedance eduction method. Since the anti-resonance frequency varies with cavity depth, each sample provides robust results over a different frequency range. Hence, a combination of results can be used to determine the facesheet acoustic resistance. When combined with the acoustic reactance, observed to be weakly dependent on the source sound pressure level and grazing flow Mach number, the acoustic impedance can be educed with increased confidence. Representative results of these tests are discussed, and the complete database is available in electronic format upon request

Survey of minority officers in the Navy: attitudes and opinions on recruiting and retention

This thesis addresses the reasons why minority officers joined the Navy and their attitudes toward continued service. Focused interviews were conducted with over 100 minority officers in the Navy at various locations around the country. All interviews were taped and then transcribed. Thirteen general themes emerged from the responses of the officers. These themes covered many topics, including the people who most influenced an officer's decision to join the Navy, perceptions of inequitable treatment, and continuing concerns about racism. A number of conclusions were drawn from the research, which revealed a strong opinion among minority officers that the Navy's Equal Opportunity environment and minority recruitment policies can be improved. Recommendations addressed several areas of possible improvement and proposed further research regarding minority attitudes toward the Navy and Marine Corps. This study was sponsored by the Office of the Chief of Naval Personnel (PERS-61) and the Defense Health Resources Study Center at the Naval Postgraduate School.http://archive.org/details/surveyofminority1094535149NANAU.S. Navy (U.S.N.) authors

Explanation of Anomalous Behavior Observed in Impedance Eduction Techniques Using Measured Data

Several enhancements that improve the accuracy and robustness of an impedance eduction technique that use an automatic optimizer are presented. These enhancements are then used to launch an intensive investigation into the cause of anomalous behavior that occurs for a small number of test conditions. This anomalous behavior is investigated for both a hardwall insert and a conventional liner. The primary conclusions of the study are that: (1) for the hard wall insert, the anomalies are due to narrow peaks in the objective function, (2) For the conventional liner, the anomalies are due to the presence of an extremely flat objective function, and (3) the anomalies appear to be triggered by inconsistencies between the duct propagation model and the measured data. At high frequencies, the duct propagation model may need to include the effects of higher-order duct modes, whereas at low frequencies, the effects of the mean boundary layer may have to be included

Impedance Eduction in Ducts with Higher-Order Modes and Flow

An impedance eduction technique, previously validated for ducts with plane waves at the source and duct termination planes, has been extended to support higher-order modes at these locations. Inputs for this method are the acoustic pressures along the source and duct termination planes, and along a microphone array located in a wall either adjacent or opposite to the test liner. A second impedance eduction technique is then presented that eliminates the need for the microphone array. The integrity of both methods is tested using three sound sources, six Mach numbers, and six selected frequencies. Results are presented for both a hardwall and a test liner (with known impedance) consisting of a perforated plate bonded to a honeycomb core. The primary conclusion of the study is that the second method performs well in the presence of higher-order modes and flow. However, the first method performs poorly when most of the microphones are located near acoustic pressure nulls. The negative effects of the acoustic pressure nulls can be mitigated by a judicious choice of the mode structure in the sound source. The paper closes by using the first impedance eduction method to design a rectangular array of 32 microphones for accurate impedance eduction in the NASA LaRC Curved Duct Test Rig in the presence of expected measurement uncertainties, higher order modes, and mean flow

Impedance Eduction in Large Ducts Containing Higher-Order Modes and Grazing Flow

Impedance eduction test data are acquired in ducts with small and large cross-sectional areas at the NASA Langley Research Center. An improved data acquisition system in the large duct has resulted in increased control of the acoustic energy in source modes and more accurate resolution of higher-order duct modes compared to previous tests. Two impedance eduction methods that take advantage of the improved data acquisition to educe the liner impedance in grazing flow are presented. One method measures the axial propagation constant of a dominant mode in the liner test section (by implementing the Kumarsean and Tufts algorithm) and educes the impedance from an exact analytical expression. The second method solves numerically the convected Helmholtz equation and minimizes an objective function to obtain the liner impedance. The two methods are tested first on data synthesized from an exact mode solution and then on measured data. Results show that when the methods are applied to data acquired in the larger duct with a dominant higher-order mode, the same impedance spectra are educed as that obtained in the small duct where only the plane wave mode propagates. This result holds for each higher-order mode in the large duct provided that the higher-order mode is sufficiently attenuated by the liner