A COMPARATIVE ANALYSIS: BIOMECHANICAL DIFFERENCES BETWEEN HIPPOTHERAPEUTIC MECHANICAL HORSES
Thomas Jefferson Senior High School
Faculty Mentor: Dr. Carolyn Skurla
Department of Mechanical Engineering
Hippotherapy is a form of physical therapy employing horses to rehabilitate people who need to improve their balance, flexibility, posture, and motor skills. Animals have been used as a part of therapeutic treatment since the 1700s, but more recently hippotherapy has become a focus of many researchers for its direct benefits. Most commonly, children and young adults with cerebral palsy (CP) are the focus of these studies. Children with CP lack normal pelvic movement. By riding a therapeutic horse it has been found that significant improvements in their pelvic range of motion and other functional abilities occur. The fundamental goal of this research is to quantify the movements and benefits of a mechanical horse compared to a live horse. In our research, we used three different hippotherapeutic mechanical horses to collect motion capture data. We compared movement data from the mechanical horses to that of a live horse. Using these results, engineers will be able to determine whether mechanical horses are as beneficial as live horse therapeutic riding.
WHAT CAUSES EARTHQUAKES AND TSUNAMIS IN THE NORTHEAST CARIBBEAN?
Faculty Mentor: Dr. Jay Pulliam
Department of Geology
The Puerto Rico Trench is the deepest part of the Atlantic Ocean, with the lowest gravity anomaly on Earth, and is prone to earthquakes and tsunamis. It is located north of Puerto Rico and was formed by the North American tectonic plate subducting beneath the Caribbean tectonic plate. It is hypothesized that a tear in the North American plate caused--or perhaps just allowed--a portion of the trench to collapse, causing an increase of earthquakes since 2004. This project was designed to determine whether there is such a tear and, if so, whether it is partially responsible for the collapse of the Puerto Rico Trench. In 2007, researchers placed five ocean-bottom seismographs (OBSs) to the east of the Puerto Rico Trench. We examined six months worth of data from the OBSs and marked arrivals of the primary (P) and secondary (S) waves from regional earthquakes that occurred during the OBS deployment. These “picks” can be used to locate the origin, or hypocenter, of each event. Since most of the OBSs are on the far side of the Trench, they yield accurate locations when combined with the picks from the Puerto Rico Seismic Network (PRSN). Our results will help improve the accuracy of hypocenter estimates for regional events and lower the detection level for earthquake monitoring with PRSN stations alone. With more accurate locations and a more comprehensive catalog of events we will be able to determine whether these earthquakes are occurring along a line within the subducted North American plate, and therefore indicate tearing of the plate.
APPORTIONMENT OF THE HOUSE OF REPRESENTATIVES, NEUTRALITY RELATED TO LARGER AND SMALLER STATES
Daniel D Sheng
The Hill-Huntington method, which uses a rounding procedure, is currently used to apportion the seats of the U.S. House of Representatives. However, research suggests that this method is biased in favor of either larger or smaller states. Other methods have been proposed as alternatives to the Hill-Huntington method. These means of apportioning belong to a group of methods known as divisor methods, where each method is associated with a strictly increasing divisor criterion. The notion of relative bias was explored, and data based on ten methods, including the identric-mean method, were examined in this project. An efficient and straightforward algorithm, programmed in Java, was developed for implementing these divisor methods. The algorithm showed a connection between traditional implementations of divisor methods and Huntington's ranking functions (priority values). In view of this research, there seems to be few reasons supporting the use of the Hill-Huntington method, instead of Webster’s method, to apportion the House of Representatives.
ANALYSIS OF STARCH SYNTHESIS IN QUALITY PROTEIN MAIZE
Liberal Arts and Science Academy
Faculty Mentor: Dr. Bryan Gibbon
Department of Biology
The opaque2 (o2) mutant of maize has higher lysine content than the nutritional content found in normal maize due to increased lysine content as a result of reduction in the synthesis of zein proteins. However, this mutant strain is flawed, due to traits such as brittleness, that make it a poor choice for agricultural purposes. Quality protein maize (QPM) has both good nutritional quality and a hard endosperm that is uncommon in other strains of corn due to the presence of the o2 mutation. By comparing the activity of different starch synthesis enzymes in both the QPM and the o2 mutant strain, we will gain a better understanding of the factors that affect kernel structure. To investigate these activities, we performed zymogram analysis of developing maize endosperm. The starch enzyme activity was visualized by separating the proteins on a native gel and then transferring them to a substrate gel. After staining, the bands representing amylase, and the debranching and branching enzymes were visible. We have compared the zein protein profiles of many different maize lines and performed zymogram analysis of selected mutants, wild type and QPM lines. In the future, this knowledge may help to increase the nutritional quality of maize at a more rapid pace.
SYNTHESIS OF NOVEL BIOREDUCTIVELY-LINKED VASCULAR DISRUPTING AGENTS FOR THE TREATMENT OF CANCER
Westlake High School
Faculty Mentor: Dr. Kevin Pinney
Department of Chemistry & Biochemistry
The tumor microenvironment is characterized by disorganized vasculature and hypoxic conditions. These characteristics can be exploited by vascular disrupting agents (VDAs) and bioreductive drugs. VDAs disrupt the tumor vasculature by interfering with the dynamic process of microtubule formation in endothelial cells; bioreductive drugs intercalate with DNA which results in the destruction of cells. The objective of this project was to synthesize a novel molecule with a double mechanism of action comprised of a VDA linked with a bioreductive drug. This molecule will be introduced into the bloodstream in its inactive linked form. Upon entering hypoxic areas, the bioreductive trigger will be reduced and release the VDA. Once cleaved, the released VDA will deprive the tumor of oxygen and nutrients by inducing vascular shutdown. Concurrently, the reduced bioreductive drug will damage the DNA and destroy the cells.
DESIGN AND SYNTHESIS OF A COMBRETASTATIN A-4 (CA4) ANALOG INCORPORATING A BIOREDUCTIVE TRIGGER
Frisco Centennial High School
Faculty Mentor: Dr. Kevin Pinney
Department of Chemistry/Biochemistry
Derived from the African bush willow tree, the combretastatin family of compounds represents an exciting avenue of research in chemotherapy due to their ability to serve as Vascular Disrupting Agents (VDAs). VDAs are able to induce necrosis in tumor cells by cutting off the blood supply, and thus the supply of oxygen and nutrients, essentially starving the cells to death. In order to accomplish this, VDAs selectively target the rapidly dividing immature endothelial cells lining the networks of blood vessels produced through tumor angiogenesis. CA4 and its analogs have been effective at inhibiting the assembly of the microtubules that form a portion of the cytoskeleton of cells. The cellular morphology induced by this drug includes a rounding up of the endothelial cells along the blood vessels, resulting in occlusion of the vessels and the prevention of blood flow. (Z)-2-(4’-Methoxy-3’-aminophenyl)-1-(3,4,5-trifluorophenyl)ethene is an excellent inhibitor of tubulin polymerization and is moderately cytotoxic in both the NCI-H460 lung cancer and the DU-145 prostrate cancer cell lines. To create a more selective therapeutic treatment for cancer, we have synthesized a CA4 bioreductive prodrug analog to preferentially target the hypoxic cells in tumors. Once inside the tumor microenvironment, this novel molecule is expected to afford its active (toxic) species through reductive activation catalyzed by reductase enzymes.
STUDIES IN DUSTY PLASMA: A POWER/PRESSURE DEPENDANT PHASE DIAGRAM FOR CONDUCTIVE GOLD/SILVER COATED MELAMINE FORMALDEHYDE IN A GEC RADIO FREQUENCY REFERENCE CELL.
Brooks C. McMaster
Memorial High School
Faculty Mentor: Lorin S. Matthews
Department of Astrophysics
Dusty plasma, a collection of ions, electrons and dust particles, has applications in everything from deep space analysis to semiconductor manufacturing and fusion experiments. In this experiment, the characteristics of conducting dust in a plasma were analyzed using a General Electronics Conference (GEC) radio frequency reference cell. When dust enters a plasma environment, it acquires a negative charge; the degree of this charge depends upon the kind of dust and ambient plasma conditions such as electron and ion density. By negatively charging an electrode at the bottom of the chamber, we can create a potential well, trapping the negatively charged dust and electrons above the electrode. The way in which the particles react to each other within this well, from forming a stable crystal to degenerating into liquid or gaseous collections, characterizes the phase of the system. Stable crystals are characterized as solid and dynamic systems are characterized as gaseous. In this experiment, 8.93 mm gold/silver coated melamine formaldehyde (mf) particles were use to construct a phase diagram for different plasma powers and pressures. A Langmuir probe was used to measure the floating and plasma potentials, electron temperature, and electron density. This analysis has not previously been done for conductive dust. The data will be compared to results obtained using non-conductive dust (uncoated mf) and a second GEC rf reference cell.
SIMULATING THE INTERACTIONS BETWEEN PARTICLES OF DIFFERENT SIZE IN A DUSTY PLASMA
Dusty plasmas, ionized gas containing macroscopic particles, are present in several fields of science and play a role in the production of silicon chips, the development of fusion power and the study of galactic nuclei. Through experiment and simulation we can find ways to manipulate them and optimize the efficiency in industrial applications, and further our understanding of dusty plasmas in astrophysics. An essential property of dusty plasmas is the interaction between dust particles. To study this interaction, we used two different computer models to simulate a GEC cell, a device used to create plasma at the CASPER laboratory, located in Waco, Texas. We obtained plasma parameters, such as gas temperature and electric potential using a fluid model, and solved the forces between the dust grains using an N-body code, giving us the precise geometry of the dust crystals formed in the cell. We simulated dust particles of two sizes in the cell. The main forces acting on the grains included gravity and the electrostatic force. The dust levitated at the position where these two forces balance. Since the different size dust had different masses, the two dust clouds formed at different heights above the lower electrode. To make the dust clouds interact, we used thermophoresis, a force due to a temperature gradient in the background gas. To add thermophoresis, we heated the lower electrode, causing a temperature difference between the plasma closer to and farther away from the bottom electrode. In this paper, we present the results from our models.
PHOTOCHEMICAL PROTEIN CROSSLINKING WITH NAPHTHALIMIDES
Damage to the meniscus is difficult to repair due to avascular qualities of the cartilage. This problem has been examined through photo-oxidative tissue crosslinking. Previous results show that 4-substituted-1,8-naphthalimides photochemical crosslinking in collagen, a primary compound in menisci. In this project, we use 5 differently substituted napthalimides. We verify the conclusion, determined through previous experiments, that naphthalimide 5 catalyzed photochemical crosslinking of RNase in the greatest yield. Proteins such as RNase and lysozyme were coupled with various 4-substituted-1,8-naphthalimides to further investigate photochemical crosslinking of proteins. In addition, we investigated the inhibition of protein crosslinking using the neurotransmitter, dopamine. Because of dopamine’s ease of oxidation, it was expected that dopamine would react more vigorously with the activated naphthalimide than would the protein and thereby inhibit the naphthalimide catalyzed protein crosslinking. This hypothesis was also extended to the compound tyramine, which is less oxidizable than dopamine and therefore should not be as inhibitory to protein crosslinking. A biotin marker was then attached to dopamine and tyramine in order to examine the reaction of the biotin compound with the protein using western blotting.
SEPARATION OF FATTY ACIDS AND POLLUTANTS USING SIZE EXCLUSION CHROMATOGRAPHY: CONTAMINANT CORRELATIONS WITH FATTY ACID PROFILES IN BOWHEAD WHALE BLUBBER
Salina K. Lee
Brazoswood High School
Lake Jackson, TX
Faculty Mentor: Dr. Stephen Trumble
Department of Biology
Typical methods for the identification and quantification of ubiquitous pollutants in the environment include Gas Chromatography (GC) and Size Exclusion Chromatography (SEC), which isolate fatty acids or contaminants respectively in collected samples. This project uses an innovative technique of combining GC analysis with the Gel Permeation Chromatography (GPC) form of the SEC process to generate a separation of fatty acids and target contaminants that can be identified simultaneously within a single sample of Bowhead whale (Balaena mysticetus) blubber. Bowhead whale blubber collected from Barrow, Alaska, provides excellent samples for contaminant analysis due to the long lifespan of bowhead whales, during which target analytes accumulate within distinct layers of their blubber. The semi-volatile organic pollutant compounds examined in this project are: brominated flame-retardants, polychlorinated biphenyls (PCB) and polybrominated diphenylethers (PBDE). Once a definite fatty acid profile is generated from the blubber sample, a correlation curve will be plot from the GC and used for comparison with the contaminants also found within the sample. The eventual findings will help researchers further evaluate chemical contamination in the environment and link chemical exposure in arctic whales to develop a better understanding of the hazards to human health from similar chemicals. Trends and future perspectives of capillary GC and SEC will be developed for the continuation of environmental analysis.