Through the back door : Melungeon literacies and 21st century technologies

The Melungeons, a minority recognized in Southern Appalachia where they settled in the early 1800s, have mixed heritage—European, Mediterranean, Native American, and Sub-Saharan African. Their dark skin and distinctive features have marked them and been the cause of racial persecution both by custom and by law in Appalachia for two centuries. Their marginalization has led to an insider mentality, which I call a “literacy” of Melungeon-ness that affects every facet of their lives. Just a century ago, while specialized practices such as farming, preserving food, hunting, gathering, and distilling insured survival in the unforgiving mountain environment, few Melungeons could read or write. Required to pay property taxes and render military service, they were denied education, suffrage, and other legal rights. In the late 1890s visionary Melungeon leader Batey Collins invited Presbyterian homemissionaries to settle in one Tennessee Melungeon community where they established a church and built a school of unparalleled excellence. Educator-ministers Mary Rankin and Chester Leonard creatively reified the theories of Dewey, Montessori, and Rauschenbusch, but, despite their efforts, school literacy did not neutralize difference. Now, taking reading and writing for granted, Melungeons are exploring their identity by creating websites and participating in listserv discussions. These online expressions, which provide texts for rhetorical, semiotic, and socio-linguistic analysis, illustrate not solidarity but fragmentation on issues of origins and legitimacy. Armed with literacies of difference stemming from both nature and nurture, Melungeons are using literacy practices to embrace the difference they cannot escape.

ALTERNATING CURRENT DIELECTROPHORETIC MANIPULATION OF ERYTHROCYTES IN MEDICAL MICRODEVICE TECHNOLOGY

Medical microdevices have gained popularity in the past few decades because they allow the medical laboratory to be taken out into the field and for disease diagnostics to happen with a smaller sample volume, at a lower cost and much faster. Blood is the human body's most readily available and informative diagnostic fluid because of the wealth of information it provides about the body's general health including enzymatic, proteomic and immunological states. The purpose of this project is to optimize operating conditions and study ABO-Rh erythrocytes dielectrophoretic responses to alternating current electric signals. The end goal of this project is the creation of a relatively inexpensive microfluidic device, which can be used for the ABO-Rh typing of a blood sample. This dissertation presents results showing how blood samples of a known ABO- Rh blood type exhibit differing behavior to the same electrical stimulus based on their blood type. The first panel of donors and experiments, presented in Chapter 4 occurred when a sample of known blood type was injected into a microdevice with a T-shaped electrode configuration and the erythorcytes were found to rupture at a rate specific to their ABO-Rh blood type. The second set of experiments, presented in Chapter 5, were originally published in Electrophoresis in 20111. Novel in this work was the discovery that treatment of human erythrocytes with β-galactosidase successfully removed ABO surface antigens such that native A and B blood no longer agglutinated with the proper antibodies. This work was performed in a medium of conductivity 0.9S/m which is close to the measured conductivity of pooled plasma (~1.1S/m). The ability to perform dielectrophoresis experiments at physiological conductivities conditions is advantageous for future portable devices because the device/instrument would not need to store dilution buffers. The final results of this project, presented in Chapter 6, explore the entire dielectrophoretic spectra of the ABO-Rh erythrocytes including the cross-over frequency and the magnitudes of the positive or negative dielectrophoretic response. These were completed at lower medium conductivities of 0.1S/m and 0.01-0.04S/m. These results show that by using the sweep function built into the Agilent alternating current generator it is possible to explore how a single group of blood cells will react to rapid changes in frequency and will provide the user with curve that can be matched the theoretical dielectrophoretic response curves. As a whole this project shows that it is possible to distinguish human erythrocytes by their ABO-Rh blood type via three different dielectrophoretic methods. This work builds on the foundation of that it is possible to distinguish healthy from infected cells2-7, similar cell types1,7-14 and other work regarding the dielectrophoresis of human erythrocytes1,10,11. This work has implications in both medical diagnostics and future dielectrophoretic work because it has shown that ABO-Rh blood type is now a factor, which must be identified when working with a human blood sample. It also shows that the creation of a microfluidic device that subjects human erythrocytes to a dielectrophoretic impulse and then exports an ABO-Rh blood type is a near future possibility.