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The aim of this study was to compare third molar development in a London population of self-assigned Black British or other Black ethnicity (the Black British group) with that of self-assigned White British subjects. The significance of population differences in dental age estimation (DAE) in these groups has been debated but not previously studied in the UK. This thesis reviews the literature associated with the maturation of children and young adults, the techniques and challenges associated with age estimation and establishing the 18-year-old threshold, and the evidence for and significance of ethnic variability in dental development. Data was collected from dental panoramic tomographs (DPTs) of 5,590 subjects aged 6.00 -23.99 years: 3,555 White British and 2,035 Black British, aiming for 50 male and 50 female subjects in each 6-monthly age band. At every Demirjian stage (TDS) A-H of all third molars, subjects of Black ancestry were younger compared to those of White ancestry with mean ages for males and females generally at least one year and 1.5 years apart respectively. For the lower left third molar the mean ages at TDS A-H, in both males and females, were highly significantly different (p<0.001). Wide age ranges were seen for all third molar TDS in both ethnic groups. In 17-year-old males, 75% of the Black British group and 43% of the White British group had lower left third molars at TDS G or H. In 18-year-old males, these figures were 88% and 61% respectively. Hypodontia, with or without third molar agenesis (TMA), was approximately twice as likely in the White British group compared to the Black British group, and TMA only was approximately three times as likely. Developmentally missing teeth were shown to be associated with delayed third molar development. These findings confirm the variability of third molar development, the limitations of DAE for determining the 18-year-old threshold, and the important significance of ethnicity in DAE.

With the pressure in education to develop a 21st century learner with higher-level thinking skills, many educators connected previous state curriculum to the Common Core State Standards (CCSS). Missouri's Department of Education experts paired the previous state's curriculum known as the Missouri Grade Level Expectations (MO GLEs) with a corresponding CCSS based on Webb's depth-of-knowledge model in a document commonly referred to as the Missouri Crosswalk. This quantitative content analysis study compared the MO GLEs and CCSS by quantifying the language using an adapted and revised Bloom's taxonomy framework. This study tested for a cognitive difference in means and for a possible relationship between the two documents using the Missouri Crosswalk in each grade level from 1-5 in the areas of English Language Arts (ELA) and Mathematics (MA). This study revealed no overall difference in means between the MO GLEs and the CCSS within the content areas of ELA and MA, grades 1-5. Although the results seemed as though CCSS did not offer more higher-level thinking opportunities than the MO GLEs, the researcher noticed a trend in the amount of objectives assigned in each cognitive category. In a further analysis that divided the objectives into higher-level and lower-level thinking, the results showed CCSS generally had more higher-level thinking opportunities than the MO GLEs. The contradicting results showed the importance of closely analyzing the two documents in order to adjust instruction. This study also revealed no cognitive relationship between the paired CCSS and MO GLEs aligned in the Missouri Crosswalk for all grades in both ELA and MA with the exception of fifth grade ELA. The structural difference in the ELA and MA crosswalk prompted an investigation of the objectives labeled "direct alignment" found only in the ELA crosswalk. The result showed no relationship between the higher-level thinking skills in the ELA GLE and the "direct" paired CCSS in all grade levels except fourth grade. Generally speaking, when adjusting instruction based on the objectives labeled "direct", only grade 4 ELA teachers may find the Missouri Crosswalk helpful since it was the only grade level to show a cognitive relationship. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]

Polymers under stress, such as during flow or stretching, exhibit deformations that can greatly affect the properties of the material. Bonds within these large molecules stretching and breaking can lead to important consequences for the behavior of the system, and affect the nature of the synthesis and processing of large scale quantities of these materials. Current computer models attempting to simulate these systems have shortcomings that lead them unable to predict many of the properties of these systems that have been observed experimentally, indicating fundamental problems in the treatment of how these molecules deform and cleave. We will attempt to address these shortcomings at a both a quantum level and a molecular dynamics level.

von Willebrand factor (VWF) is an abundant plasma glycoprotein that is essential for the maintenance of hemostasis. Deficiencies in VWF cause the common bleeding disorder von Willebrand disease (VWD). In addition, abnormalities of VWF processing are thought to contribute to the pathogenesis of thrombotic thrombocytopenic purpura (TTP). The studies comprising this thesis focus on post-translational mechanisms contributing to the regulation of VWF function. The first set of studies expands previous work on the RIIIS/J mouse, a model of type 1 VWD. Prior studies identified a switch in the expression of the Galgt2 glycosyltransferase gene as the underlying genetic mechanism causing decreased VWF levels in this mouse strain. Ectopic expression of Galgt2 in endothelial cells, the site of synthesis of VWF, leads to altered post-translational modification of VWF and increased clearance from plasma. We now describe progress toward the identification of the DNA sequences responsible for this unique regulatory switch in gene expression. The Galgt2 expression pattern is characterized further, and transgenic studies narrow the genetic interval containing the elements necessary for controlling its wild-type expression. In addition, we investigate the role of the hepatic asialoglycoprotein receptor in mediating the clearance of GALGT2-modified VWF. The second series of studies investigates the molecular basis of TTP, a thrombotic disorder associated with altered VWF processing. Using a positional cloning approach, we describe mutations in the ADAMTS13 gene, encoding a zinc metalloproteinase, as the cause of familial TTP. We also demonstrate that recombinant ADAMTS13 cleaves VWF, and that TTP patient mutations impair this proteolytic activity. Together, these studies shed further light on the post-translational regulation of VWF function and contribute to the understanding of the mechanisms underlying the variable expressivity of VWD and the molecular basis of TTP.