2005 Abstracts

July 1, 2005

Ding, Chengrui (Mike). 2005. Effects of Chirality on Amino Acid Coupling. (Charles M. Garner Biochemistry).

In biological systems, proteins synthesized from chains of amino acids are vital to the function of living organisms. These amino acids must all exhibit the same chirality. To test for an affinity between amino acids of the same chirality, we coupled n-acetyl protected L alanine, valine, isoleucine, and phenylalanine with either pure or racemic alanine methyl ester, valine methyl ester, or phenylalanine methyl ester, each of which was acidic due to extra hydrogen on its amine group. Each of the six vials was treated with diisopropyl carbodiimide (DIC), triethyl amine (TEA), and hydroxybenzotriazole (HOBt), which served as coupling agents, ultimately causing the acidic amine group and the carboxyl group of two amino acids to react and form a peptide bond. Upon analysis of each dipeptide derivative by capillary gas chromatography, little kinetic affinity for either LL or DL was detected.

Eisenberg, Michelle. 2005. The Effect of Enrichment on White-handed Gibbons (Hylobates lar). (Heidi Marcum Environmental Studies)

In the past, zoos focused only on providing for the physical needs of the animals, without any care for the psychological well-being of the animals. In the past twenty years, however, zoos have begun to appreciate animals' need for mental stimulation. Through the use environmental enrichment, many animals increase their natural behaviors while decreasing stereotypical behaviors. The goal of this study was to decrease the level of sedentary behavior of the White-handed Gibbons at Cameron Park Zoo, in Waco, Texas. To reach this goal, I first watched the Gibbons without enrichment, as a control, so that I could compare results before and after enrichment. I then filled a Buster Cube with treats for the gibbons, and placed it within their night barn. I found that the enrichment decreased sedentary behavior by over ten percent. This enrichment succeeded in stimulating the gibbons and can be cheaply and easily used in other zoos.

Smietana, Brandon. 2005. Deflated Polynomial Iterative Methods for Sparse Linear Systems with Multiple Right-Hand Sides. (Ron Morgan Mathematics)

Systems of sparse linear equations have become increasingly important in engineering and physical science. Developments in numerical linear algebra have pushed the boundaries on the size and complexity of the systems we have the capacity to model. One such development is iterative polynomial methods, specifically those arising from Krylov subspaces. These iterative methods prove superior to direct methods in their capacity to solve for immense systems with a great reduction in memory and computational requirements. In fact, iterative methods have proven themselves in applications which could not be approached using direct methods. Applications such as Quantum Chromodynamics (QCD) often require the solution of sparse matrices whose typically non-sparse factorization could not reasonably be stored, let alone computed directly. Here, the concerns of maintaining sparsity and memory requirements necessitate iterative methods. Many iterative algorithms also have guaranteed convergence bounds equaling direct methods and have become the choice algorithms for systems requiring the power of parallel computing. We examined the effects of projecting out eigenvalues from multiple right-hand sides for the symmetric Lanczos algorithm. Our results show an extensive reduction in convergence time after projection.

Lee, Matthew K. 2005. Design and Synthesis of 2-(3'-hydroxy-4'-methoxyphenyl)-3-(3"4"5"-trifluorobenzoyl)-6-methoxyindole as a Vascular Disrupting Agent. (Kevin G. Pinney - Organic Chemistry).

Cancer, the second leading cause of death in the United States, has been the target of much research. Some of the most promising cures for cancer involve Vascular Disrupting Agents (VDAs), which kill tumors by destroying their vascular structures. Newly discovered Oxi8006 has proven to be a very effective VDA. Our research aimed to improve Oxi8006 by replacing three of its methoxy groups with highly electronegative fluorine atoms. Previous studies implied that electronegative atoms in these molecular positions may improve anti-cancer ability. In a series of eight organic chemical reactions, the fluorinated Oxi8006 or 2-(3'-hydroxy-4'-methoxyphenyl)-3-(3"4"5"-trifluorobenzoyl)-6-methoxyindole was successfully synthesized. The identity of the product was confirmed by 1H, 13C, and 19F Nuclear Magnetic Resonance readings. We sent a sample to our research partners abroad for analysis of its VDA capability. The fluorinated Oxi8006 created for the first time in this research may show promise as a Vascular Disrupting Agent and as a treatment for cancer.

King, Aaron. 2005. The Effects of Lithium Deposition on Molybdenum Disulfide. (Kenneth T. Park, Laboratory for Surface Analysis and Modification).

The surface atoms of a solid have been shown to display properties unique from that of the atoms located deep within the sample. Also, it is possible to modify the surface to produce other properties that may be favorable in nanotechnology, semiconductors, optics, etc. My project dealt with molybdenum disulfide, a catalyst used primarily in the fuel industry due to its ability to resist conventional catalyst poisons such as carbon and sulfur. However, when an alkali metal is deposited on the surface of MoS2, higher alcohols (fusel oil), rather than just hydrocarbons can be synthesized from carbon monoxide and hydrogen gas. Previous evidence proposes that lithium behaves differently from the heavier alkali metals when deposited on the surface of MoS2. Lithium seems to react with MoS2, while the heavier alkali metals seem to only donate an electron. I used three experimental techniques to gain a better understanding of the interaction between lithium and molybdenum disulfide: Auger Electron Spectroscopy, Secondary Electron Emission Cutoff, and Low Energy Electron Diffraction. Our results suggest that there was a good deal of contamination at the time of measurement. Because of this, little can be said about the reaction between lithium and molybdenum disulfide.

Tharayil, Ashley. 2005. Novel Synthesis of (E)-1,2-di-(2′,3′-dihydroxy-4′-methoxyphenyl)-1,2-di-(3′′,4′′,5′′-trimethoxyphenyl)ethene as a Vascular Disrupting Agent and a Tubulin Inhibitor (Kevin G. Pinney,-Organic Science)

The objective of my research was to make a composite molecule that included the structures of both Combretastatin A-1 and Hydroxyphenstatin-two efficient vascular disrupting drugs. We hypothesized that since both molecules are tubulin inhibitors, a new molecule containing the molecular structures of both the drugs will be more or equally capable of fighting cancer. After running a series of reactions we were able to obtain our product. However, we obtained only a very small amount of the new molecule and hence the final step has to be repeated in the future to isolate our molecule. After obtaining significant amounts of the molecule, the potential of this molecule as a drug will be determined through various biological and biochemical assays at different laboratories.

Van Treuren, Jeff. 2005. Total Knee Replacement: Motion Between Tibial Implant and the Bone. (Carolyn Skurla - Engineering and Computer Science

Total Knee Replacement (TKR) is a surgery where the lower portion of the femur, the upper portion of the tibia, and the cartilage in the knee are replaced with metal and plastic components. There are two different types of implants: those with stems and those without. Likewise, there are two major fixation methods for the implant: cementing and press-fit. Dr. Skurla, of Baylor University, performed mechanical testing of the different types of implants for orthopedic surgeons from Scott & White Hospital, in Temple, Texas. The research focused on the effects of different combinations of the implants on the initial stability of the implant. My task was to assist in the designing of the test method that would be used in the research.

Walker, David. 2005. Analysis of the Microbial Communities in Manure Fermenting Tanks Converting Manure into Ethanol Producible Acids. (Peter Van Walsum Environmental Science)

As the world continues to use up the earth's supply of fossil fuels the need for alternative fuel sources will increase proportionally. Ethanol as an alternative fuel source has shown much promise. Manure is a renewable source of fiber that can be broken down into simple acids, by fermenting in holding tanks, which can then be converted into ethanol. It is important to know how the manure's microbial communities differ as it undergoes fermentation from one holding tank to another to maximize necessary acid production. The reaction between manure cultures in a fermenting reactor and carbon sources indicate much about the microbial communities of the manure cultures. The carbon-utilization patterns (CUPs) of these microbial communities indicate changes in the microbial population that occurs over time between reactors. Our tests showed that the microbial communities differ from reactor to reactor and that the manure cultures in the latter stages of fermentation have more inhibition to the production of needed acids. These results indicate maximizing acid production, and thus ethanol production, from manure cultures in the shortest amount of time requires that the manure cultures be treated differently depending upon its position in the fermentation process.

Weng, Rachel. 2005. Tissue Modification Using Covalent Chemistry. (Bob Kane Chemistry/Biochemistry).

Fresh tissue surfaces can be covalently modified with small molecules as well as functional proteins in a spatially-defined fashion by physically limiting the sites of exposure of the tissue to the reagents. As an example, periodate-based oxidation can result in the conversion of vicinal diols to carbonyl compounds, which can then be treated with biotin hydrazide to evoke a condensation reaction. The presence of the desired modifications has been detected primarily using chemiluminescent techniques. For biotin-modified surfaces, avidin-horseradish peroxidase can be selectively immobilized and will provide a signal in the presence of luminal. However, previous experiments on meniscus have shown positive results on the background, consequently, propositions were made suggesting that sufficient carbonyl groups already existed on the native tissues. The results of this project suggest that there are less free carbonyl groups on the pericardium than on the meniscus, which means that different tissues require different chemical methods to modify them.