2013 MU dissertations - Access restricted to UM
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Item Random set models for growth with applications to nowcasting(University of Missouri--Columbia, 2013) Dey, Rima; Dey, Rima[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] We develop models to capture the growth or evolution of objects over time as well as provide forecasts to describe the object in future states utilizing information from the current state. For this purpose, we propose methodologies to model random sets (RS) using Germ-Grain theory. The RS that describes the objects in a hierarchical Bayesian framework can have either overlapping or non-overlapping grains. We investigate three types of growth models, namely, hereditary, birth-death and mixed type. In the hereditary growth model, the germ of a grain arises from the previous state, whereas in birth-death it does not belong to any of the previous grains. The mixed type is a combination of the other two. Furthermore, we consider two approaches to capture the growth process with the first developing a bound on the individual grain of the RS and the second evolving the parameters defining the grains directly. Estimation of model parameters is carried out using Markov chain Monte Carlo (MCMC). In addition, we develop an alternative approach to Reversible Jump MCMC or Birth-Death MCMC that is capable of sampling a varying dimensional parameter space. This method is based on the Boolean model, the most commonly used RS. We illustrate our methodologies on simulated data in order to demonstrate its ability of fitting the underlying growth process and forecasting an unobserved state. The methodologies are further exemplified with several applications to nowcasting of severe weather precipitation fields as obtained from weather radar images, where severe storm cells are treated as random sets.Item The Cold War, the New World Order, and the War on Terror : U.S. presidents' use of Orwell's big brother myth(University of Missouri--Columbia, 2013) Smith, James Scott; McKinney, Mitchell S.; Warner, Benjamin R.[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] This dissertation argues a dystopian myth exists in the United States' political consciousness that warns citizens about the fear totalitarianism. Born out of George Orwell's novel 1984, the Big Brother myth is articulated by presenting a totalitarian foe, creating an us vs. them scenario, and depicting a dystopian world into the near distant future. This study examined U.S. Presidents' Inaugural and State of the Union addresses from 1953-2012 and found that presidents used the Big Brother myth to garner support for their policies and initiatives. Cold War presidents used the myth the most but even after the collapse of the Soviet Union, the fear of totalitarianism was still used a primary argument during the War on Terror. Specifically, President George W. Bush utilized the myth as a means to garner support for military action against terrorists and the Axis of Evil.Item Elucidating the roles of the ATP7A copper transporter in cultured cells, tumor growth and metastasis(University of Missouri--Columbia, 2013) Zhu, Sha 1984-; Petris, Michael J.[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Copper is an essential trace metal in all organisms. In humans, copper plays structural and catalytic roles for numerous enzymes and is required for cellular respiration, connective tissue development, pigment formation, iron absorption and mobilization, integrity of the central nervous and immune systems. However, copper can also be toxic when present in excessive amounts, owing to its ability to facilitate reactive oxygen species (ROS) production. Because of the vital yet potentially toxic roles of copper, organisms have evolved delicate homeostatic control of copper uptake, intracellular distribution and export. Cellular copper homeostasis is maintained by several key regulators including: Copper transporter 1 (CTR1) and copper efflux transporters (ATP7A and ATP7B). Mutations in ATP7A or ATP7B disrupt the homeostatic copper balance, leading to Menkes disease (systemic copper deficiency) or Wilson disease (copper overload). ATP7A controls the cellular export of copper and the function of ATP7A is largely regulated by its subcellular localization. To regulate copper homeostasis, ATP7A cycles between the trans-Golgi network (TGN) and the plasma membrane constitutively or in a copper-dependent manner. A single endocytic di-leucine motif in the cytoplasmic tail of ATP7A was previously shown to regulate ATP7A internalization. Other than the maintenance of copper homeostasis, there are emerging studies demonstrating critical roles of ATP7A in cancer drug resistance and cancer progression. The platinum-based chemotherapy drug cisplatin is widely used to treat cancer. However, clinical use of cisplatin is limited by either severe side effects or acquired resistance. Copper transport pathways are proposed to be responsible in part for tumor resistance to cisplatin. In vitro observations suggested that high levels of ATP7A mediate vesicular sequestration of cisplatin and contribute to drug resistance. Furthermore, increased ATP7A expression is associated with clinical resistance to cisplatin chemotherapy and poor prognoItem Stem cells and DNA methylation reprogramming in pigs(University of Missouri--Columbia, 2013) Zhao, Mingtao, 1983-; Prather, Randall S.[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] In mammals, the majority of cells in the body contain the same genome as other cells. The concept of nuclear totipotency has been well demonstrated by cloning animals generated by somatic cell nuclear transfer. Thus the fundamental difference between a stem cell and a differentiated cell is their distinct epigenetic identity. Upon fertilization, the paternal and maternal genomes undergo extensive epigenetic reprogramming to establish the totipotent state of a zygote. The pluripotent state is then restricted in the inner cell mass (ICM) of a blastocyst where embryonic stem cells are derived. Epigenetically, there is a wave of genome-wide DNA demethylation post fertilization and de novo methylation around implantation. The implanted epiblast further differentiates and generates various cells of the three germ layers (ectoderm, mesoderm and endoderm). Multipotent stem cells can be derived from embryonic and adult tissues, such as skin, bone marrow and nervous system. The hypothesis of the thesis was that the epigenetic modifications are dynamically associated with the developmental stages and determine the cell identity. In Chapter 3, we isolated and characterized the multipotency of porcine skin-derived progenitors (SKPs) and fetal brain-derived neural stem cells (NSCs). In Chapter 4, we found porcine SKPs could incorporate into the early embryos and contribute to various somatic tissues of the three germ layers in postnatal chimeras. However, this developmental potential was compromised when they differentiated into fibroblasts. In addition, NSCs failed to incorporate into the host embryos and contribute to chimeric piglets. The distinct developmental potential of SKPs, NSCs and fibroblasts is probably attributed to their different epigenetic states since they shared the same genome. In Chapter 5, we observed locus-specific dynamic DNA methylation reprogramming in early porcine embryos. The local DNA methylation reprogramming in early embryos is diverse and is probably associated with the multiple functions of DNItem The firm, uncertainty, and entrepreneurship(University of Missouri--Columbia, 2013) Won, Jong Chul; Klein, Peter G.[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Uncertainty provides entrepreneurs with profit opportunity and, also, dissipates the opportunity. Therefore, entrepreneurs have intention to utilize and cope with uncertainty with their entrepreneurial perception on the market. One of the ways to use firms to manipulate uncertainty is merger and acquisition. In this dissertation, the influences of merger and acquisition, especially vertical integration, on uncertainty, and of entrepreneurial judgment in merger and acquisition decision are discussed. First, the effect of asset specificity on firm-level uncertainty is discussed by comparing the values of market transactions and vertical integration. Second, the influence of asset specificity on systematic and unsystematic risks of the vertically integrated firm is tested by estimating and comparing on the difference of systematic and unsystematic risks of before and after vertical integration under the consideration of the influence of asset specificity on business profiles. Lastly, I explain the influence of entrepreneurship in sourcing decisions with the analysis of transaction cost economics, the resource based view, and real options from perspective of entrepreneurship.