2007 AAPP Monograph Series

The African American Professors Program (AAPP) at the University of South Carolina is proud to publish the seventh edition of its annual monograph series. Furthermore, it is an honor to celebrate the remarkable tenth anniversary of AAPP through these manuscripts. The program recognizes the significance of offering its scholars a venue to engage actively in research and publish papers related thereto. Parallel with the publication of their refereed manuscripts is the opportunity to gain visibility among scholars throughout institutions worldwide. Scholars who have contributed papers for this monograph are to be commended for adding this responsibility to their academic workload. Writing across disciplines adds to the intellectual diversity of these papers. From neophytes, relatively speaking, to an array of very experienced individuals, the chapters have been researched and comprehensively written. Founded in 1997 through the Department of Educational Leadership and Policies in the College of Education, AAPP was designed to address the underrepresentation of African American professors on college and university campuses. Its mission is to expand the pool of these professors in critical academic and research areas. Sponsored by the University of South Carolina, the W.K. Kellogg Foundation, and the South Carolina General Assembly, the program recruits doctoral students for disciplines in which African Americans currently are underrepresented among faculty in higher education. The continuation of this monograph series is seen as responding to a window of opportunity to be sensitive to an academic expectation of graduates as they pursue career placement and, at the same time, one that allows for the dissemination of products to a broader community. The importance of this monograph series has been voiced by one of our 2002 AAPP graduates, Dr. Shundele LaTjuan Dogan, formerly an Administrative Fellow at Harvard University and a Program Officer for the Southern Education Foundation. She is currently a Program Officer for the Arthur M. Blank Foundation in Atlanta. Dr. Dogan wrote: One thing in particular that I want to thank you for is having the African American Professors Program scholars publish articles for the monograph. have to admit that writing the articles seemed like extra work at the time. However, in my recent interview process, organizations have asked me for samples of my writing. Including an article from a published monograph helped to make my portfolio much more impressive. You were \u27right on target\u27 in having us do the monograph series. (AAPP 2003 Monograph, p. xi) The African American Professors Program dedicates this 2007 tenth anniversary publication as a special contribution to its readership and hopes that each will be inspired by this interdisciplinary group of manuscripts. John McFadden, Ph.D. The Benjamin Elijah Mays Distinguished Professor Emeritus Director, African American Professors Program University of South Carolinahttps://scholarcommons.sc.edu/mcfadden_monographs/1009/thumbnail.jp

Early deletion of neuromeres in Wnt-1 -/- mutant mice: Evaluation by morphological and molecular markers

The Wnt-1 gene is required for the development of midbrain and cerebellum; previous work showed that knockout of Wnt-1 causes the loss of most molecular markers of these structures in early embryos and deletion of these structures by birth. However, neither the extent of early neuronal defects nor any possible alterations in structures adjacent to presumptive midbrain and cerebellum were examined. By using a neuron-specific antibody and fluorescent axon tracers, we show that central and peripheral neuronal development are altered in mutants during initial axonogenesis on embryonic day 9.5. The absence of neuronal landmarks, including oculomotor and trochlear nerves and cerebellar plate, suggests that both mesencephalon and rhombomere 1 (r1) are deleted, with the remaining neural tube fused to form a new border between the caudalmost portion of the prosencephalon (prosomere 1, or p1) and r2. Central axons accurately traverse this novel border by forming normal longitudinal tracts into the rhombencephalon, implying that the cues that direct these axons are aligned across neuromeres and are not affected by the deletion. The presence of intact p1 and r2 is further supported by the retention of markers for these two neuromeres, including a marker of p1, the Sim-2 gene, and an r2-specific lacZ transgene in mutant embryos. In addition, alterations in the Sim-2 expression domain in ventral prosencephalon, rostral to p1, provide novel evidence for Wnt-1 function in this region. © 1996 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50070/1/7_ftp.pd

The Actin-Driven Movement and Formation of Acetylcholine Receptor Clusters

A new method was devised to visualize actin polymerization induced by postsynaptic differentiation signals in cultured muscle cells. This entails masking myofibrillar filamentous (F)-actin with jasplakinolide, a cell-permeant F-actin–binding toxin, before synaptogenic stimulation, and then probing new actin assembly with fluorescent phalloidin. With this procedure, actin polymerization associated with newly induced acetylcholine receptor (AChR) clustering by heparin-binding growth-associated molecule–coated beads and by agrin was observed. The beads induced local F-actin assembly that colocalized with AChR clusters at bead–muscle contacts, whereas both the actin cytoskeleton and AChR clusters induced by bath agrin application were diffuse. By expressing a green fluorescent protein–coupled version of cortactin, a protein that binds to active F-actin, the dynamic nature of the actin cytoskeleton associated with new AChR clusters was revealed. In fact, the motive force generated by actin polymerization propelled the entire bead-induced AChR cluster with its attached bead to move in the plane of the membrane. In addition, actin polymerization is also necessary for the formation of both bead and agrin-induced AChR clusters as well as phosphotyrosine accumulation, as shown by their blockage by latrunculin A, a toxin that sequesters globular (G)-actin and prevents F-actin assembly. These results show that actin polymerization induced by synaptogenic signals is necessary for the movement and formation of AChR clusters and implicate a role of F-actin as a postsynaptic scaffold for the assembly of structural and signaling molecules in neuromuscular junction formation

Calibrating Teledyne-e2v’s ultraviolet image sensor quantum efficiency processes

Teledyne-e2v's sensors and wafer-scale processing are widely used for high performance imaging across soft X-ray and optical bands. In the ultraviolet spectral range, the combination of short absorption lengths (below 10 nm) and high reflectance (up to 75 %) can strongly limit the quantum efficiency. Direct detection capability relies on back-illumination and back-thinning processes to be applied to a sensor to remove dead layers from the optical path. As the thinning process leaves an unacceptably thick backside potential well as well as a highly reflective surface, in-house ultraviolet-specific (e.g. for WUVS) or third-party processes (e.g. delta-doping for FIREBall) are required. We have calibrated Teledyne-e2v's latest in-house wafer-scale proprietary processes with monochromatic synchrotron radiation over a wide spectral range in the ultraviolet domain (λ=40 nm – 400 nm) at the Metrology Light Source of the Physikalisch-Technische Bundesanstalt. The first process is a shallow p+ implantation that permits the thinning of the backside potential well. It is available in two different levels: basic and enhanced. The second type of enhancement is a specific anti-reflective coating to increase the back-surface transmittance for distinct spectral ranges. In this paper, we will present comparative quantum efficiency calibration of both passivation stages and of two different ultraviolet specific anti-reflective coatings (applied on enhanced passivation devices). Also, their stability after intense ultraviolet illumination will be shown. These measurements will permit Teledyne-e2v to extend the quantum efficiency data of their most recent processes across the soft X-ray to near-infrared spectrum