Bratteli, John. 2001. Surface Science. Baylor University. Kenneth Park, Ph.D. (Department of Physics).
As electronic components shrink, their ratios of surface area to volume increase. Surface science labs such as the Laboratory for Surface Analysis and Modification (LSAM) at Baylor University study the structures and properties of various materials at their surface and near-surface levels. Surface scientists are involved in creating new semiconductors and methods of using them. My work here involved analyzing data and improving the Ultra High Vacuum system for new experimental work. I ran tests to determine current versus temperature values on a new crucible, which is crucial to understanding the properties of evaporating surface layers onto a substrate. I maintained the system and also came up with some design ideas for improvements on the current model. My work will help LSAM improve the state of experimental data on the surface properties of many materials.
Casey, Gray. 2001. An analysis of the Belousov-Zhabotinskii reaction. Baylor University. John Davis, Ph. D. (Department of Mathematics).
The Belousov-Zhabotinskii reaction is one of many oscillating reactions. It produces spiraling waves of magenta and blue originating at a point or points that move outward in a target pattern formation. The reaction is autocatalytic and demonstrates a sudden change known as a Hopf Bifurcation. Because of this, it is referred to as the prototype oscillator, and is the most widely studied oscillating reaction. The information that is gained can aid in the understanding of other oscillators, such as the beating of the heart. Because the reaction is so complex, it is very hard to analyze using only physics or chemistry. We, therefore, must use mathematics to explain the unexpected pattern formation and investigate its underlying structure to shed some light on the behavior of the system under certain assumptions. To do so, we must first change the chemical formulas into a system of differential equations, write those in a vector matrix, find the stability matrix, take its eigenvalues, and use the eigenvalues to show that the system oscillates.' ' Montague, Shelby. 2001. Engineering the Tobacco Mosaic Virus to Increase Stability and Protein Production in Plants. Baylor University. Tamarah Adair, Ph. D. (Department of Biology).
One goal of biotechnology is to produce proteins in mass quantities for research and medicine. These proteins have many applications, including use as vaccines and anti-HIV drugs. Genetically manipulating plant viruses is one method of protein production. A recombinant tobacco mosaic virus (TMV), called 30B, has been developed to produce proteins in plants, but it this process has many problems. The overall goal is to engineer 30B to increase its stability and effectiveness in protein production. Two main steps involved in this project are inserting an intron into a location of the genome determined to be unstable, and adding a DNA promoter. This is a multi-step mutagenesis procedure; the current project included performing restriction digestions, ligations, and transformations to transfer the desired sequence of 30B into pTZ18U, a plasmid containing a phage promoter. The resulting plasmid was then isolated from the bacteria and treated with helper phage to infect the CJ236 strain of E. Coli to produce a single stranded DNA containing uracils. This is the extent of the project performed thus far. Future steps will involve a mutagenesis of the single stranded DNA to insert the intron, and transformation of a second strain of bacteria.
Fabricius, Anne. 2001. Synthesis of a Combretastatim A-1 Derivative Designed to Function as a Tubulin Inhibitor and Vascular Targeting Agent. Baylor University. Kevin G. Pinney, Ph. D. Vani P. Mocharla, Ph.D. Viroopaksha Velishala (Department of Chemistry and Biochemistry).
In the late 1970's, Professor George R. Pettit (Arizona State University) discovered combretastatin A-4 (CA-4) in Combretum caffrum, a bush willow indigenous to South Africa. Subsequently, Dr. Dai Chaplin (Oxigene, Inc) found that CA-4 with an added phosphate (which increases solubility and is called CA-4P) showed selective vascular targeting. This vascular targeting was effectively stopped malignant tumor growth. Additional studies have resulted in the discovery of a variety of natural products from Combretum caffrum which are strong inhibitors of tubulin assembly. This current study has focused on the preparation of a new derivative of the diphosphate salt CA-1P, which incorporates a ketone rather than a double bond on the ring bridge. The synthesis of the desired keto-nor-ene-combretastatin A-1 diphosphate (keto-nor-ene-CA-1P) required a series of reactions and careful purifications in order to isolate the desired intermediates as well as the final product. Chromatography, drying, washing, and filtering were common methods employed. It is anticipated that this new molecule will prove effective in selective vascular targeting and hence will have the potential to be an improved chemotherapeutic agent for solid tumor cancers.
Paolino, David. 2001. Developing New Protein Crosslinking Molecules. Baylor University. Dr. Robert Kane (Department of Chemistry and Biochemistry).
Protein crosslinking, a process by which protein molecules seek and bind with other proteins, is a new technology that is constantly being refined. There are many compounds that adequately bind proteins and crosslink them, but a molecule has not yet been made that can perform this task to the desired level (that is to crosslink many proteins securely and safely) and with low enough cytotoxicity rates to be of practical use yet. Our research group worked with a simple anhydride compound (Bromonapthalicanhydride) to perform the crosslinking reactions. Many different possible compounds can be added on to this simple anhydride to obtain varying levels of effectiveness, and during my time here I tested two of these possibilities. The first was the addition of the amine Diethylethylenedamine and a thiol group to the anhydride, and the second was the addition of the amine Ethylenedioxybisethylamine and a thiol. In order to create the compound I used several tests and machines including thin layer chromatography (TLC), nuclear magnetic resonance (NMR), a column, extraction and gel electrophoresis. At the time of this writing the effectiveness of my compounds is unknown, but a continued effort to find even more effective protein crosslinking molecules with lower levels of toxicity will open the door for many exciting practical and safe uses of protein crosslinking in the future.
Chan, Brenda. 2001. Effects of Adolescent Ethanol Exposure on the Reinforcing Properties of Ethanol During a Subsequent Adult Exposure. Baylor University. Dr. Jim Diaz-Granados (Department of Neuroscience).
Alcohol use is becoming more prevalent among America's youth. Statistics indicate that alcohol experimentation begins as early as fifth grade and escalates in junior high and high school. Strong evidence suggested by epidemiological studies indicates that early alcohol consumption can increase the risk of alcohol dependency later in life. It is known that the central nervous system (CNS) is still undergoing important developmental changes during a person's adolescent years. Therefore, not only does early alcohol consumption increase the probability of adult dependence, it may disrupt normal CNS development which may lead to neurological, psychological, emotional, and behavioral problems. The purpose of this project is to examine the effect of adolescent ethanol exposure on the reinforcing properties of ethanol, through use of conditioned place preference (CPP), during a subsequent adult exposure. It is hypothesized that adult mice having previous adolescent exposure will show a greater preference for the ethanol-paired environment as compared to ethanol-naïve adult mice. Adolescent C3H mice were exposed to 64 hours of either ethanol vapor or regular air and tested six weeks later for CPP. In addition, to further examine the effect of the age of pre-exposure, adult mice were pre-exposed to ethanol and six weeks later tested for CPP. Results of this experiment show that ethanol pre-exposure during adolescence, but not during adulthood, significantly increases the positive rewarding properties of ethanol. Adolescent pre-exposure to ethanol may lead to disruptions in physiological development, which increase usceptibility to the reinforcing properties of ethanol in adulthood.
Hoppe, Todd. 2001. Determining the Effects of Chronic Ethanol Exposure on Subsequent Withdrawal Severity During Adulthood. Baylor University. Jaime L. Diaz-Granados Ph.D. (Department of Psychology and Neuroscience).
According to a study by the National Institutes of Health, early adolescent alcohol abuse leads to a significant increase in the probability of alcohol dependency in adulthood. In light of recent findings showing that the adolescent central nervous system (CNS) is still undergoing important developmental changes, it is possible that alcohol exposure during this period may lead to long-lasting changes seen in adulthood. The purpose of this study was to examine the effect of repeated alcohol withdrawals during adolescence and the long-term effects of adolescent ethanol exposure on subsequent responsiveness to repeated withdrawals in adulthood. Adolescent C3H/He were randomly assigned to treatment groups that received either chronic ethanol exposure (64 hours), intermittent ethanol exposure (four 16-hour bouts), a single 16-hour exposure, or no ethanol exposure. Upon removal from the chambers, animals were either tested for withdrawal severity (via handling-induced convulsions) or placed in normal colony conditions until adult testing 6 weeks later. The results revealed that, unlike adult animals, adolescents that received chronic ethanol exposure suffered more severe withdrawal symptoms as compared to those receiving the intermittent ethanol exposure. In addition, adult mice who received chronic ethanol exposure during adolescence showed greater seizure activity following repeated episodes of withdrawal compared to the other pre-exposed or naïve animals. Therefore, the results of this experiment, in conjunction with the results of previous experiments, suggest that alcohol abuse is particularly damaging to the developing adolescent central nervous system, which may lead to greater susceptibility to the severe symptoms of alcohol withdrawal in adulthood. ' '
Yu, Wing-kei. 2001. Preparation of Diagnostic and Data Collection Systems at the HIDPL. Baylor University. Truell Hyde, Ph. D. (Department of Physics).
At the recently refurbished Hypervelocity Impacts and Dusty Plasmas Lab (HIDPL), the preparation of diagnostics is the final task that must be' completed before scientific work can begin. Some of the planned experiments' include a study of the boundary conditions for formation of dust crystals' in plasma and the effects of hypervelocity particle impacts on carbon' nanotubes. The lab has available for these studies a GEC Reference Cell,' an electrostatic accelerator, and two Class 4 LASERs. Several instruments' are used to collect data; they include thermocouples, vacuum ionization gauges,' oscilloscopes, LASER fans, and CCD cameras. Most of these diagnostic devices' work on the same principle: they convert an outside occurrence into a' change in voltage, which is measured. Their output is then routed into' a computer running LabVIEW, the standard program used in computerized lab automation and measurement. The resulting measurements are used to draw conclusions and ensure repeatability. Additionally, I worked on another summer program, CASPER, which preparied these diagnostic systems. By the end of the summer, the HIDPL should have its first research experiment underway.
Maxcey, Catherine. 2001. Environmental Enrichment for Captive Animals. Baylor University. Professor Heidi Marcum (Department of Environmental Studies).
Enrichment, a term coined by animal behaviorists, is a principal of animal husbandry used to enhance a captive animal's level of cognitive thought. It' addresses the organism's mental and psychological needs, as well as its physical ones, increases optimal reproduction in order to conserve endangered species and educates zoo visitors of the importance of enriched environments. We worked with white rhinoceroses (Ceratotherium simum), African lions (Panthera leo), and Sumatran tigers (Panthera tigris sumatrae). We hypothesized that when given enrichment opportunities, captive animals will become more active, and exhibit less stereotypical behavior. Each species was first observed without enrichment. Behavioral ethograms and time budget diagrams were constructed, revealing if stereotypical behavior occurred. Data were recorded using interval scan forms that showed how each individual responded to a particular enrichment device. Rhino enrichment included: (1) alfalfa cubes, (2) fruit and vegetables day yard, and (3) moving hay to novel area within day yard. Lion and tiger enrichment incorporated: (1) blood bait, (2) novel scent trails, (3) fruit, and (4) kudu urine path leading to peppermint flavored ice. While enrichment increased locomotive and exploratory activity in each species, the organisms reverted to their stereotypical behavior afterwards. Additional research is required to determine optimal enrichment activities for each species. It was determined, however, that advances in habitat design and novel managerial practices are mandatory to create an optimal captive environment.'
'Shi, Helen. 2001. Carbonic Acid Pretreatment of Corn Stover for Ethanol Production. Baylor University. G. Peter van Walsum, Ph. D. (Department of Environmental Studies).
As oil reserves diminish and the price of oil rises, alternative fuels such as ethanol, or more specifically bioethanol (ethanol produced from biomass) are becoming more feasible. Corn stover, the residue left on the ground after corn harvesting, is one of the most largely available feedstocks for the production of bioethanol. However, a chief challenge in the conversion process is the development of environmentally friendly and effective pretreatment techniques to break down the complex sugars that are present in cellulosic biomass. In this study, the effectiveness of the pretreatment of corn stover using carbonic acid versus liquid hot water was tested. Temperatures for these tests ranged from 180°C to 220°C, while reaction times ranged from 2 to 32 minutes. Afterwards, samples were tested for the amount of sugars released, UV-visual light absorbance (indicating toxicity), and pH levels. The results showed that carbonic acid had a noticeably greater effect than water on the amount of monomer and oligomer sugars released, representing greater efficacy. Although absorbance measurements were inconclusive, the presence of carbonic acid did raise the final pH of the samples, which may indicate reduced toxicity due to acetic acid. These results indicate that the use of carbonic acid is potentially a viable technique in the pretreatment of corn stover and that perhaps carbonic acid hydrolysis can be applied to other processes.'