Research

Tissue inhibitors of metalloproteinases (TIMPs) comprise a family of four proteins in humans that modulate the turnover of the extracellular matrix by regulating the activities of endopeptidases that catalyze its degradation, especially the matrix metalloproteinases (MMP). In general, the four TIMPs are broad-spectrum tight binding inhibitors of MMPs with individual differences in specificity. In this study, we attempted to understand the basis of such variation by using membrane type-1 MMP (MT1-MMP) as a model, since it is inefficiently inhibited by TIMP-1 in contrast with the other TIMPs. We designed and engineered mutations in the N-domain of TIMP-1, based on current knowledge of TIMP interactions. By measuring inhibition levels of each mutant against several MMPs, including MT1-MMP, we were able to obtain a triple mutant with an vii improved affinity for MT1-MMP.

The graying of America as a sociological and health care phenomenon continues to dictate the demand for creative and innovative interventions that can directly influence the quality of life of nursing home residents. Creative Reminiscence is a program that fosters the active reliving of the past through narration, such as in story-telling, and the use of creative art expression to uncover meaningful life events or valuable life experiences. The purpose of this study was to investigate and describe the meaningful life events elicited by the experience of Creative Reminiscence using a phenomenographic approach. Existing (archived) data-transcribed interviews, poetry and painting on planters that were obtained from 20 participants of the Creative Reminiscence program entitled Le Jardin de Sante were analyzed. Five variations of meaningful memories evoked by Creative Reminiscence were identified. These are described as follows: (a) memories that rejuvenate the elder's sense of connectio n; (b) memories that revive the elder's sense of love and intimacy; (c) memories that restore the elder's sense of being; (d) memories that reassert the elder's sense of control; and (e) memories that reinstitute the elder's sense of purpose. In a caring interaction with Creative Reminiscence, the nursed are able to transcend, moving back in time (past) to appreciate segment(s) of their lives, with triumphs and disappointments that give meaning to their inner conflict/human struggle (present), and integrate a sense of confidence and acceptance of their lives to sustain well-being and a sense of wholeness. This research highlights the similarities and differences in the description of memories by the nursing home residents evoked during Creative Reminiscence.

This study presents an experimental investigation into the effects of running biodiesel fuel blends on conventional diesel engines. Bio fuels provide a way to produce fuels without redesigning any of the engine technology present today, yet allowing for green house emissions to decrease. Bio-diesel is one of these types of emerging bio-fuels, which has an immediate alternative fuel aspect to it, while providing a decrease in green house emissions, as well as a solution to recycling used Waste Vegetable Oils which are other wise disposed. This study shows how by blending bio-diesel with petroleum diesel at intervals of B5, B10, B15, and B20 decrease green house emissions can significantly while maintaining similar performance output and efficiency with respect to 100% petroleum diesel.

Public administration addresses issues that competing and aligning groups determine to be meaningful enough to address. However, there seems to be no shared universally objective ways of remedying anything. Everything is up for argument. Additionally, attempting to solve one set of problems often creates other connected problems and/or unintended consequences. So, public work ever [sic] never ends. This dissertation's purpose was to contribute a new theoretical understanding of the experience and practice of public administration. Its research addressed if and how a grounded existential theoretical framework could emerge that would help practitioners and scholars understand and describe public administrative efforts and experiences. Currently, there is no existential theory of public administration. This dissertation sought to initiate work in that direction. This dissertation employed a grounded theory methodology to collect information from Senior Executive Service (SES) members, to analyze the information for emerging concepts and theoretical relevance through constant comparison, and to discover/construct a theoretical framework for understanding public administrative efforts and experiences. "The grounded theory approach is a general methodology of analysis linked with data collection that uses a systematically applied set of methods to generate an inductive theory about a substantive area" (Glaser, 1992, p. 16).

Ants are ubiquitous and ecologically important, yet little is known of ants within Pakistan. I studied ants collected from houses and apartments in Karachi, Pakistan to determine which ants are common indoor ants. Ants were attracted by spilling syrups and sodas on the floor which were left overnight. The following morning the ants were collected using an aspirator. A total of eleven species were found. Of these eight were well-known pest ants with worldwide distributions: Paratrechina longicornis, Tetramorium simillimum, Monomorium pharaonis, Monomorium subopacum, Monomorium destructor, Tapinoma melanocephalum, Pheidole megacephala, and Tetramorium bicarinatum. Three others, Camponotus sp., Pheidole sp., and Solenopsis sp., not identified to species were probably native species. Paratrechina longicornis and M. subopacum were the two most dominant species that were found in the highest abundance.

The kinesin superfamily of microtubule motor proteins is subdivided into families based upon structure and function. KIF9 is the founding member of the Kinesin-9 family, which is a largely uncharacterized group of kinesins. It was originally identified by sequence homology to other kinesins. Subsequent studies have shown that KIF9 interacts with proteins involved in cell shape remodeling, cell migration and proper centrosomal positioning. We have examined KIF9 function in mammalian cells using shRNA-mediated knockdown and GFP-plasmid overexpression. By knocking dow KIF9 expression in these cells, we have seen several effects on normal cell cycle progression. Using various cell cycle markers, we have observed a decrease in the number of cells in late S phase. In addition, there is a marked increase in the number of cells in early mitosis in unexpected time intervals. We propose that KIF9 is required for proper cell progression, via a potentially novel checkpoint mechanism.

Aging is a process characterized by accumulated oxidative damage to DNA, proteins, and lipids,which leads to the gradual degeneration of cellular activity. Mitochondria play a central role in aging because they produce both cellular energy and oxidative stress. As resultof accumulated oxidative damage, mitochondria function decays, which leads to a cellular energy deficit and compromises cellular function. Iron is an essential nutrient reequired by mitodhondria to function optimally. It has been proved that iron supplementation increases the lifespan of several yeast strains, including superoxide dismutase mutants. We are interested in finding where the iron is going and what it might be doing that is beneficial to the cell. We have used Saccharomyces cerevisiae as our molecular model of aging. Our results indicate that the extra iron is being transported into the mitochoindria.

Aconitase is an important enzyme in the citric Acid Cycle, is needed for maintenance of mitochondrial DNA, is a key regulator of iron in the cell, and is very sensitive to oxidative stress. We have isolatd the yeast ACO1 gene, which codes for aconitase, and randomly mutated it to create a mutant library of cells each expressing a different version of ACO1. We will select for oxidative stress resistant aconitase in S. cerevisiae by subjecting strains to successive rounds of heat shock and competitive growth against other mutants. The "winner" of this competition will then be analyzed for which version of aconitase it is expressing, which may lead to increased longevity.

In my thesis work, I attempted to construct a plasmid that would allow stable integration of genes into the Saccharomyces cerevisiae yeast genome under the control of the repressible TetO promoter. The yeast ACO1 gene was cloned under the control of the TetO operator and the tTA transactivator. This construct was inserted into yeast cells in order to observe the effects of aconitase overexpression on aging. Unfortunately, the transformed cells appeared incapable of aconitase expression as determined by glutamic acid auxptrophy, a phenotype of aconitase mutants. We have sequenced the pIT1ACO1 plasmid and have found many abnormalities in the promoter region. If the plasmid can be made to function as intended, the resulting yeast strain can be used in the future to determine if aconitase plays an important role in cellular aging.

Aneuploid tumor cells have characteristically unstable genomes which can be caused by mitotic defects such as multipolar spindles. Multipolarity relies upon the presence of extra centrosomes to form. However, some cells, both cancerous and noncancerous are able to avoid the formation of multipolar spindles through centrosomal clustering. Previous research has shown that there are a large number of genes whose activity contributes to the clustering activity, making analysis of individual components of the process difficult. In order to better understand centrosomal clustering in cancer cells, we induced supernumerary centrosomes in a genomically normal cell line, RPE, to observe how the normal cells cope with extra centrosomes. Using colcemid to induce extra centrosomes in the RPE cell line, we observed an intact clustering mechanism in fixed cells. Further manipulation of the cells has allowed us to induce multipolarity in this cell line using various disrupters of cell-cycle checkpoint and dynein function.