2007 MU theses - Access restricted to MU
https://hdl.handle.net/10355/4079
2024-03-28T11:39:15ZActivation of astrocytes: involvement of NADPH oxidase and cytosolic phospholipase A2
https://hdl.handle.net/10355/6270
Activation of astrocytes: involvement of NADPH oxidase and cytosolic phospholipase A2
Hu, Chunhua
[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Reactive oxygen species (ROS) are produced in cells by enzymic and non-enzymic mechanisms and play important roles in the pathogenesis of neurodegenerative diseases. However, mechanisms for the increase in ROS and their effects leading to altered cell metabolism have not been studied in detail in the central nervous system. In the first series of studies, we examined ROS production in primary rat astrocytes and their downstream effects on changes in signaling cascades and morphology using menadione. ROS production induced by menadione was completely inhibited by NADPH oxidase inhibitors including apocynin and gp91ds-tat. Menadione also stimulated phosphorylation of p38 and ERK, and caused actin polymerization and which can be inhibited by inhibitors for NAPDH oxidase and MAPK. In the second part, we tested the role of cytosolic phospholipase A2 in astrocytes in response to oxidative stress. Menadione increased the immunoreactivity of phospho-cPLA2 and caused plasma membranes to become more gel-like, which were abrogated by down regulating cPLA2 with siRNA. In summary, our study demonstrated the important role of NAPDH oxidase in production of ROS and their link to activation of MAPK pathways and cPLA2 in astrocytes. We further demonstrated that excess production of ROS, such as that mediated by menadione, can alter cell membrane properties, morphology, and cytoskeletal arrangement and in turn cell death mechanism.--From public.pdf
"August 2007."; The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file.; Includes bibliographical references.; Thesis (M.S.) University of Missouri-Columbia 2007.
2007-01-01T00:00:00ZArs coquinaria: a study of early Roman cooking wares and their uses
https://hdl.handle.net/10355/5993
Ars coquinaria: a study of early Roman cooking wares and their uses
Schmidl, Christina Margaret
[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Cooking ware is important for studying how people around the Early Roman Empire cooked and ate. As utilitarian ware, it did not change drastically for several centuries. It was not considered important for studying until the 1920s and has since slowly developed influenced by anthropology, science, and technology. The cooking ware from England, Greece, and the Levant region, has been studied and placed into different forms with regards to the bottom of the vessel, the shape, and the material. The bottoms of the vessels indicate whether an oven or hearth was used in cooking and help explain the diets, regional food, and recipes of each region. The sites of Usk and Exeter had flat based cooking vessels, while the eastern Mediterranean sites had a combination of both flat and round-bottomed vessels, thus indicating the differences and similarities in diet and cooking methods throughout the entire Roman Empire.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file.; Title from title screen of research.pdf file (viewed on November 9, 2007); Includes bibliographical references.; Thesis (M.A.) University of Missouri-Columbia 2007.; Dissertations, Academic -- University of Missouri--Columbia -- Art history and archaeology.
2007-01-01T00:00:00ZBlast resistant design for roof systems
https://hdl.handle.net/10355/7974
Blast resistant design for roof systems
McClendon, Mark Andrew
[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] The design of structures to resist explosive loads has become more of a concern to the engineering community. This research focuses on the design techniques for the loading on roof structures and the resistance of open web steel joists. A procedure has been developed to devise a uniform dynamic load on a roof that matches the response from blast loads. This research uses finite element analysis to evaluate the responses from numerically calculated blast loads and compares them to the equivalent loading response and the response of experimentally measured roof blast pressures. While the responses from finite element modeling matched the experimental responses, the equivalent loading procedure did not adequately predict the initial peak deflection or the maximum deflection. The response of several structural members used in roof construction, such as hot-rolled steel beams and reinforced concrete slabs, are well documented and understood. Open web steel joists (OWSJ) are other types of common roof components. Their responses under loading are not clearly defined, and current methods extrapolate techniques used in the design and analysis of hot-rolled steel beams and reinforced concrete. It is believed that the failure mechanisms of OWSJ significantly are not accurately being taken into account. The resistance function is computed from three tests and compared to current methodologies. It is recommended that an analytical resistance function for OWSJ be clearly defined, which includes all failure limit states.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file.; Title from title screen of research.pdf file (viewed on April 1, 2008); Includes bibliographical references.; Thesis (M.S.) University of Missouri-Columbia 2007.; Dissertations, Academic -- University of Missouri--Columbia -- Civil engineering.
2007-01-01T00:00:00ZCharacterization of mechanical properties of fused deposition modeling manufactured polycarbonate composites
https://hdl.handle.net/10355/5986
Characterization of mechanical properties of fused deposition modeling manufactured polycarbonate composites
Guggari, Prasad
[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] The use of composites in all products - from sporting goods to bridges to satellites - is increasing due to the ability of composite structures to provide the required strength while still being lightweight. This research focuses on the characterization of material properties of such polycarbonate composites manufactured by the Fused Deposition Modeling (FDM) method. The approach comprises of tensile testing of FDM manufactured samples following the ASTM D 638-03 and ASTM D 3039-00 standards. This gives the mechanical properties of either individual polycarbonate fibers or the lamina, which serves as input to a mathematical formulation developed in Matlab. Image mesostructure analysis is carried out to measure fiber geometric properties which are incorporated in the first part of the code. This generates random fiber geometry to simulate the geometric characteristics of actual FDM samples. It also aids in the calculation of the void content based on fiber orientation which is used to scale the properties generated from tensile testing of individual fibers. These parameters are then used as input to the later part of the code which is based on the Classical Laminate Theory and is used to calculate the overall laminate properties depending on fiber orientation and raster pattern. The properties generated by this code are compared with the tested samples and are found to be in good agreement with each other.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file.; Title from title screen of research.pdf file (viewed on April 14, 2008); Includes bibliographical references.; Thesis (M.S.) University of Missouri-Columbia 2007.; Dissertations, Academic -- University of Missouri--Columbia -- Mechanical and aerospace engineering.
2007-01-01T00:00:00Z