2009 McNair Scholars

Eunice Alcantara
Computer Engineering

Title: Automatic Guitar Tuner
Abstract: An electric tuner is a device used by musicians to measure the pitch of a signal. Musicians, whose passion is to play their musical instrument, often have to hassle with tuning. Guitarists nearly always have to adjust the tuning of each string before playing. It can become burdensome to be carrying a small electric tuner everywhere they go, and especially if the pegs need to be tweaked a bit during a show because of intonation. The purpose of this project is to create an automatic tuner that will tune the strings of a guitar in seconds. Matlab is used to detect the signal from the string that was plucked. It will determine if it needs adjustment. If so, a servo is used to move the pegs until it reaches perfect tuning.

Laci Alexander
Psychology

Title: The Relationship Between Human Ratings of Beluga Personality and Beluga Behavioral Patterns
Abstract: Although it is clear that individual differences abound in cetaceans, the systematic study of such differences is in its infancy. In this study, we compared human ratings of the personality characteristics of five belugas with the belugas actual behaviors. The rating measure was adapted from one that has been successfully used to assess personality in dolphins. Five trainers, who were very familiar with the belugas, rated each animal on 30 personality characteristics. An independent analysis of the belugasbehaviors was conducted using video records collected one month before, during, and one month after the ratings were made. Individual behaviors, such as approaching novel objects or touching an object, were scored in terms of one of five personality dimensions (e.g., openness to new experience). The results for the human ratings of beluga personality and the results for the behavioral assessment of personality were then compared. These comparisons demonstrated that human ratings of an animal personality are in fact related to the animalactual behavior, but that some human-rated characteristics are more likely than others to be reflected in an animalbehavioral predispositions. For example, ratings of curiosity and exploratory behavior were strongly correlated with an animalbehaviors, but ratings concerning compassion and friendliness were less strongly related. Given these results, future studies of cetacean personality should use both human ratings of animals with which they are familiar and coding of an individualbehavior in order to obtain the most accurate description of a particular animalpersonality. In addition, these findings have implications for better understanding differences in maternal care by cetaceans as well as explaining various social interactions between animals.

Daniel Araujo
Biology

Title: Isolation of Modifiers of an Alcohol-Resistant Gene
Abstract: An increased resistance to the sedating effects of ethanol is a behavioral risk for alcoholism in humans. In Drosophila melanogaster, white rabbit (whir) mutants show a decrease in RhoGAP18B activity and an increased resistance to the sedating effects of ethanol. A decrease in RhoGAP18B activity has also been shown to induce a rough-eye phenotype. In order to implicate genes in the RhoGAP18B pathway, we performed a genetic screen by crossing mutants containing RNAi against RhoGAP18B with several stock deficiencies and examining the eye phenotypes of the resultant progeny. Most of the deficiencies used in this study did not greatly modify the rough-eye phenotype. However, deficiencies 3012 and 3127 are promising because of their ability to drastically enhance and suppress the rough-eye phenotype, respectively. Through this study, we aim to find homologous genes that are present in humans and which represent risk factors for alcoholism.

Gina Buffaloe
Physics/Mathematics

Title: Temperatures and Abundances of Ethane and Acetylene in the Jovian Atmosphere
Abstract: This project investigates temperatures and abundances of the various hydrocarbons that compose the troposphere and stratosphere of Jupiter's atmosphere. We focus on CH4, H2, C2H2, C2H6 observations retrieved during May and June 2009 using the NASA Infrared Telescope Facility (IRTF) in conjunction with the Texas Echelon cross Echelle Spectrograph (TEXES). Using TEXES to gather high spectral resolution data in select infrared wavelength regions enables us to probe the vertical temperature profile of Jupiter's upper atmosphere in great detail. The spatially homogeneous distribution of methane in the Jovian atmosphere indicates that differences in observed intensities are due to differences in temperature at different altitudes rather than abundances. Using this data to derive temperatures we will then use the inferred temperatures to model the emission due to C2H2 and C2H6 in order to derive the abundances of these molecules.

Joseph Campbell III
Electrical Engineering

Title: Thermal Lensing in Aqueous Media
Abstract: The dynamics of near-infrared (NIR) laser thermal lensing (i.e. thermal blooming) in a water-filled artificial eye geometry are investigated experimentally with a confocal imaging system, and through computer simulations. The dynamics of focal position and beam size at fixed imaging planes as a function of laser wavelength, power, and beam size are examined using a wavelength-tunable laser. Wavelengths are selected in order to vary the magnitude absorption coefficient of water in the near-infrared optical spectrum. We find significant time-dependent changes in beam focal geometry and variations in the magnitude of the effects throughout the range of experimental parameters. The results are examined in the context of furthering the understanding of laser safety standards applied to near-infrared lasers.

Servando Cordova
Electrical Engineering

Title: Designing a Magnetic Micropallet Collection Probe
Abstract: The study of individual cells is critical to biomedical research. Microarray technology allows for a high throughput of data. Adherent cells are grown on a micropallet array surface composed of photopatternable 1002F polymer, with each micropallet holding a single cell. Individual cells can then be identified, tracked, and separated. The micropallets are doped with magnetic nanoparticles which allow the micropallets to be manipulated using magnetic fields. A magnetic probe is being developed to collect and transport selected micropallets. An effective probe will facilitate and expedite the process of transporting collected micropallets. Design considerations for the probe include: core material, wire gauge, and shape of the electromagnet.

Lisa Duran
Engineering Science

Title: A Study of Meteorological Differences Between Caves in Different Geologies
Abstract: In the San Antonio area, cave passages form in three different geological formations; the Austin Chalk, the Edwards Limestone, and the Glenrose Limestone. Data taken from within two different caves in the Austin Chalk and the Glenrose Limestone will assist in discovering how meteorological effects differ, and what quantity of CO2 may be venting to the outer atmosphere. Three Pasco GLX data loggers were used to gather carbon dioxide, barometric pressure, temperature, and airflow data in the caves at 10-minute intervals. Within each cave, the data loggers were set up to determine if significant differences in any of the parameters were present within each cave environment. Results showed differences in temperature between the caves and within the caves, and the temperature changes were seen to correlate with changes in barometric pressure. A difference in carbon dioxide levels was also noted between the two caves, which was analyzed using a student t-test, and could be attributed to many factors. Calculations revealed the quantity of carbon dioxide estimated to be released during the exhalation cycles from the caves, showing the contribution that is made to atmospheric carbon dioxide levels during the summer months.

Jessica Esquivel
Electrical Engineering/Applied Physics

Title: MicroBooNE: LArSoft Simulation Runs and PMT Stress Tests
Abstract: MicroBooNE is a Liquid Argon Time Projection Chamber detector(LArTPC) that detects and analyzes neutrino interactions using the FermiLab booster neutrino beam as well as the Neutrinos from the Main Injector beam(NuMi). This experiment was proposed to look into the excess of low energy neutrino events observed by the Mini-BooNE experiment. Unlike MiniBooNE, MicroBooNE has the capability to distinguish between electrons and photons. Since a significant fraction of the background in Mini-BooNe is due to know sources of photons, this greatly increases the signal to background ratio as well as giving this experiment the capability to answer the question of whether or not the excess of low energy neutrino events are electrons or photons. MicroBooNE is also the beginning for future large liquid argon detectors used for analysing CP violation in neutrino interactions, proton decay, and the main topic of this paper, Super Novae detection.

Luis Esquivel
Biology

Title: Hydroxocobalamin and Epinephrine Improve Survival in a Swine Model of Cyanide-Induced Cardiac Arrest: A Randomized Trial
Abstract: Hydroxocobalamin (HOCB) is recognized as an antidote for cyanide (CN) poisoning. However, the effect of HOCB at the point of cardiac arrest has not been investigated. Hypothesis: First, we postulate an increase in the survival rate of swine models treated with HOCB compared to controls. As a result we also expect to see a recovery in blood pressure, lactate, and coronary perfusion pressure compared to swine models treated with epinephrine (EPI). Methods: Throughout the study all 45 swine (38-42 kg) were intubated, anesthetized, and instrumented. To reach cardiac arrest (MAP < 30 mm Hg) cyanide was infused (0.2 mg/kg/min). At cardiac arrest an intravenous bolus of HOCB (150 mg/kg), EPI (0.02 mg/kg), or saline (control) was randomly given to the animals. To perform CPR a machine was used to provide chest compressions and the animals were monitored for 60 min post-cardiac arrest. Vasopressor infusion (EPI 0.1 mcg/kg/min) was used in all arms after ROSC for SBP < 90 mm Hg. Results: Baseline weight, time to arrest, and the cyanide dose at arrest were similar (5.07 mg/kgSEM, 4.32 mg/kg4.29mg/kg). Over the course of the study a total of 23 swine died. Death occurred in 4 swine from the HOCB group, 4 swine from the EPI group, and all 15 swine from the control group (p < 0.001). ROSC at 5 min and 10 min were the same in treatment groups (p > 0.9). Vasopressor infusion after ROSC was necessary for hypotension in 2/11 HOCB groups and in 11/11 EPI groups (p < 0.001). At 2 and 4 min post-arrest, coronary perfusion pressures were greater than 15 mm Hg in treatment groups. At arrest, mean serum cyanide (4.26, 3.88, 4.1 mcg/ml, p = 0.71) and lactate levels (7.5, 6.86, 7.07 mmol/L, p = 0.69) were the same in all groups. At 60 min, mean serum lactate (4.9 vs. 12.1 and 14.9 mmol/L, p < 0.0001) and pH (7.34 vs. 7.153 and 7.154, p < 0.0001) improved in the HOCB group. Serial serum CN levels in the HOCB group were lower than control and EPI groups after arrest until study ended (p < 0.004). Conclusions: HOCB and EPI when compared to the saline bolus proved to yield a positive progression in the survival rate of cyanide induced cardiac arrest swine models.

Samantha Franklin
Physics

Title: Near Infrared Laser Tissue Damage Mechanism Transition
Abstract: Optical absorption in pigmentation decreases and approaches that of water in the near infrared region of the spectrum. We have hypothesized that there should be very little difference in laser damage threshold to pigmented versus non-pigmented tissues in this region of the spectrum. We have theoretically and experimentally probed this wavelength region such that the role of the pigmentation is measured and understood. A specially-prepared cell culture is employed, which can be exogenously pigmented to any desired concentration. In the region of 800-1200nm, we show that the damage threshold can be increased at the shorter wavelengths by approximately 1.5-fold when pigmentation is absent, while thresholds are relatively unaffected near the upper limit of the experimental wavelength region.

D'Neshia Frederick
Psychology/Criminal Justice

Title: Are There Gender Differences in Condom Attitudes Among Youth?
Abstract: The purpose of the current research is to assess if there are gender differences in condom attitudes in youth. Participants consisted of 30 males and 30 females taken from the Dallas County Juvenile Department. The Condom Attitude Scale- Adolescent version and it six subscales (relationship safety, perceived risk, interpersonal impact, safety, effect on sexual experience, and promiscuity) were used to asses condom attitudes. The current research also used the CHOICES intervention/prevention program to educate youth about risky behaviors and how to handle these situations when encountered. A repeated measures analysis of variance (ANOVA) was use to examine the relationship between genders (male vs. female) at different time points (baseline vs. 6 month follow up) and the CAS-A total scores and the CAS-A sub-scales. Results revealed that there are differences between gender and time points but not in the interaction between time points and gender.

Dean Garcia
Psychology

Title: Life-Course Events Leading to Desistance from Gangs and Crime: Case Studies in the Lives of Aging Ex-Gang Members
Abstract: The purpose of this research is to understand the life course events from youth to old age of ex-gang members that lead to a desistance from crime. This will be accomplished by interviewing a sample of ex-gang members aged 65 to 70, who will be asked to recall turning points or drastic changes in the life course which can be interpreted as pivotal points that bisect the past from the present, or future during their life course which caused them to initiate a desistance process from criminal activity. Consequently, these turning points would have influenced them to pursue a more conventional, socially acceptable life style. Social control theory states that as an individual develops meaningful social ties with others (i.e., marriage and military service) desistance will be facilitated and crime extinguished. We expect to find, during the respondent recollection of pertinent turning points, that solid social ties to conventional groups will aid desistance from criminal activity. All things considered, future research should focus on a more complete understanding of turning points that lead to desistance from crime.

Elisabeth Jones
History

Title: Cultural Revision and Incorporation in Laredo
Abstract: This paper evaluates how the socio economic status determined the race relations in the region between the late 1850and early 1900 including the difference between the race relations on a ranch versus race relations in Laredo. Also, how the celebrations of certain holidays, especially the celebration of George Washington's birthday, contributed to the merging of two cultures to form a more Americanized border town.

Cruz Lara
Electrical Engineering

Title: Liquid Nitrogen Car
Abstract: This project purpose is to convert a gasoline powered vehicle into one which runs solely on liquid nitrogen. Such a Zero Emissions Vehicle offers many benefits. Since the source of liquid nitrogen is air (78% of air is composed of nitrogen), it is readily available at a low cost. No expensive and environmentally hazardous battery technology would be required, and fill up times would be a matter of minutes. One of the most alluring benefits of the widespread use of such a vehicle is the fact that as liquid nitrogen is manufactured, some amount of airborne pollutants are removed from the air. This could include the capturing and sequestering of greenhouse gases such as CO2 and other gases directly linked to climate change and global warming. To do this the vehicle engine must be stripped of all components that deal with ignition, injection, and exhaust. An automatic valve system will then be developed and installed to control the flow of nitrogen. The gas produced by boiling liquid nitrogen will be fed to the head of the engine making the piston move which then moves the car.

Rebecca Lopez
Psychology/Criminal Justice

Title: From the UK to the US: Modifying the Learning Practice Inventory
Abstract: The Learning Practice Inventory (LPI), an instrument developed in the United Kingdom, provides an organization with feedback on organizational learning qualities, advising them on the areas that need strengthening and those that need to be set as a priority. The purpose of this study is to modify and improve this instrument so that it can be applicable to clinical nursing units in the United States. Nurses from various units at a large hospital in southwest Texas served as participants for this study. Through a personal interview, nurses reviewed and evaluated the LPI, providing feedback to the researcher for modifications to the instrument. The results indicated that the LPI could be improved through phrasing, word choice and length modifications. The absence of organizational learning and learning organization research amongst clinical nursing units emphasizes the need for a tool, such as the LPI, to adhere to the continuous changes in American health care.

Christopher Medina
Psychology

Title: Writing from the Authentic Self: An Expressive Writing Intervention for Homosexual Males
Abstract: The purpose of this study is to determine if an expressive writing intervention can reduce stress for homosexual males. Participants will be asked to write for twenty minutes each day for three consecutive days. Participants will write about the deepest thoughts and feelings regarding experiences as a sexual minority. In addition, participants will be given the Perceived Stress Scale to measure the level of stress in three instances: before the writing intervention, after the writing intervention, and a month later. We expect that participants will experience a significant reduction in stress after writing about their experiences as a sexual minority.

Sandra Montoya
Finance

Title: The Current Financial Crisis and its Impact on World Markets
Abstract: The current global economic crisis had its origins in the United States with the boost of the subprime mortgage market. However, the causes of the crisis started earlier in time with a variety of weakness in regulations, management strategies, rating estimations, and innovative financial instruments. What started as a one country's recession, the U.S, spread to be a crisis among advanced countries, and finally became a worldwide turmoil affecting markets of all developed, developing, and emerging nations. Businesses all around the world are struggling to maintain profitability and to adapt in tough times; therefore, adopting the right strategies to fight change is crucial to remain in business.

Dina Robles
Physics/Chemistry

Title: Characterization of Tissues: Optical and Morphological Properties of Skin
Abstract: We present a summary of methodologies for the determination of optical properties of tissues in the near infrared (NIR) optical spectrum. The goal of the study is to provide a means of quickly and accurately measuring optical properties in the near-infrared spectrum, where little data is currently available. A double integrating sphere experimental setup is employed along with new, custom tissue sample holders. Three lasers of differing wavelengths (532nm, 1064nm, and 1313nm) are employed. The inverse adding-doubling numerical method is described along with its application to the extraction of optical coefficients. Data summarizing the calibration and testing of the experimental apparatus is presented, along with preliminary measurements of the optical properties of tissues in the near infrared spectrum.

Sandra Ryan
Biochemistry

Title: Evaluating the Role of Melanosomes in Intracellular Photo-Oxidation of RPE Cells
Abstract: Melanosomes have been shown to exhibit both antioxidant and pro-oxidant activities. Our hypothesis is that the melanosome should confer oxidative protection for the RPE cell. To determine oxidative protection, controls, melanosome particles, and black latex beads were exposed to sublethal 488nm laser light. The initial rates of oxidation were used for the analysis. The preliminary results show enhanced oxidation with the latex beads, but no effect with the melanosomes.

Aaron Trevino
Computer Science/Mathematics

Title: Unpredicted Educational Uses of Video Games
Abstract: Many computer games have recently been examined for educational benefits. The work presented here looks at popular video games that are not characterized as educational and suggests possible knowledge and skills that may be supported or enhanced by playing these games. A scoring process is presented to calculate the educational potential of a video game. The summarized results of applying this scoring process are presented with the potential educational areas for over 300 games. It appears that role-playing games may have the best potential for educational uses and that the top benefits include improving reflexes, planning and strategy skills. Furthermore, games with the Electronic Software Review Board (ESRB) rating of T for Teen had an overall higher average than other ESRB scores. The data suggests that each game should be considered on a case-by-case basis for any potential educational purposes and benefits.

Amanda Tristan
Biology

Title: Acute and Chronic Effects of Nicotinic Agonists: Hypothermia and Scheduled Controlled Responding
Abstract: Several nicotine cessation medications are currently on the market including the nicotinic agonist varenicline (VAR) commercially known as Chantix. However, little is known about its mechanism in the cessation of nicotine abuse. Much of the research involving VAR was partnered with acute nicotine treated laboratory animals. The findings are important and relevant, but not easily translatable since quitting smoking is a problem for chronic smokers not the occasional smoker. Hypothermia occurs for a short period of time when using nicotine. Tolerance is developed with chronic nicotine use. This is illustrated in a decrease of hypothermic effect in chronically treated mice. Chronic nicotine was administered to mice. Rate of response through operant conditioning, and body temperature was measured. Rate of response decreased. Body temperature decreased and returned to normal within the 60 min session. We have yet to see tolerance develop; once we have VAR treatment will begin. Studying VAR behavioral and physiological effects allow a better understanding of its mechanism.

Claudia Valladolid
International Relations/Speech Communication

Title: Gateways to Democracy Aid: An Analysis Based on USAID Distributions
Abstract: From the authoritarian Chile and Philippines, to communist Poland and all the way to the racial apartheid in South Africa, democratic successes have developed to give a voice to their populations. As a facilitator for transitions, USAID has spent nearly $10 billion in over 100 countries to support democratization and good governance. This agency has managed the bulk of bilateral economic assistance since its establishment in 1961. As a sub-set of foreign aid, which has been well studied, the democracy aid allocation selection process that takes place within the USAID Center for Democracy and Governance has not been identified. This is crucial to look at as dramatic threats to democracy in this twenty-first century come from transnational terrorist organizations and fragile states, not so much from strong authoritarian regimes.This study assesses factors that contribute to the decision on whether a country becomes a recipient of USAID democracy aid or not.

Rose Vasquez
International Business/Marketing

Title: Explaining Changing Attitudes Toward Immigration: A Quantitative Analysis
Abstract: The continued debate over immigrants and immigration policy demonstrates that there is a wide range of opinions and attitudes towards immigrants and immigration policy. The focus of this research is to identify the factors that influence attitudes toward immigrants within the United States and to determine whether there has been any change in attitudes and the factors that influence those attitudes as a result of heightened security concerns after 9/11. By using data from the 1996 and 2004 General Social Survey (GSS), bivariate and multivariate statistical analyses were performed to address the following research questions: has there been a change in public opinion towards immigrants from 1996 to 2004?; what role do demographic, socio-economic, and security factors have on attitudes towards immigrants in 1996 and 2004?; and does greater proximity and interaction lead to increased acceptance or increased hostility toward immigrants? It was hypothesized that: 1.) attitudes toward immigrants were more favorable in 2004 than in 1996; 2.) the impact of socio-economic and demographic factors on attitudes towards immigration remains the same in 1996 and 2004; 3.) the impact of security concerns on attitudes towards immigration is greater in 2004 than 1996 (as result of heightened security concerns after 9/11).; and 4.) more interaction with immigrants leads to greater acceptance. The results found that attitudes towards immigrants are more positive in 2004 than 1996. Socio-economic factors do have an impact on attitudes, especially level of education, but that the importance of these factors decreases in 2004 compared to 1996. And while race also influences attitudes in both 1996 and 2004, gender does not in either year. If future research can determine why and how these factors influence attitudes, it may be possible to develop strategies to minimize negative attitudes and encourage a stable, pluralistic, democratic society within the U.S.

Ashly Waltman
Chemistry

Title: Effect of High Glucose on VEGF-Induced Endothelial Cell Migration
Abstract: Endothelial cell (EC) migration is the first critical step in the vascular wound healing process and is induced by vascular endothelial growth factor (VEGF). VEGF induces endothelial nitric oxide synthase (eNOS) expression and nitric oxide (NO) production that facilitates EC migration. High plasma glucose level common in diabetic patients is toxic to endothelial cells and hinders normal processes of EC migration. Delayed EC migration could contribute to microvascular complications, leading to amputations in people with diabetes. To determine whether high glucose could inhibit VEGF mediated EC migration, in vitro cultures of bovine aortic endothelial cells (BAEC) were used in this study. By applying a deliberate injury, EC migration was observed under conditions of VEGF and high glucose. Since eNOS is a key component involved in migration, Western blotting technique was performed to determine the difference in eNOS expression in BAEC exposed to VEGF in the presence or absence of high glucose. Observing the stained cells under high glucose environment concluded that high glucose indeed inhibited VEGF-mediated endothelial cell migration. Results of Western blotting indicated that in high glucose environment, eNOS expression was downregulated even in the presence of VEGF. These results indicate that high glucose delays VEGF-induced endothelial cell migration. Reduced eNOS expression influenced by high glucose could cause this delay in endothelial migration.

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