“Changes in Escherichia coli and Pseudomonas aeruginosa Grown in Mixed Culture for 500 Generations”
In nature microorganisms grow in a mixed culture environment, microbes use virulence factors to survive and compete. Biofilm are a type of virulence that microorganisms use to protect themselves from other microorganisms in competition. Bioflim also aid in protection from the human immune system. Microbes have a short generation time and can multiply within hours, unlike humans or animals whose generation times are usually years apart. Our research is an experimental evolution study on microorganisms and the effects that this has on mixed culture interactions vs. pure culture growth. We are examining if long term generational growth of microorganism displays any changes in their ability to compete for resources and if there are any genetic or physiology changes observed. We are working with Escherichia coli MG1655 strain and Pseudomonas aeruginosa strains PAO1 and PA14. Each strain is grown in LB broth with two glass beads both in pure and mixed culture. The beads promote biofilm growth. Each day one bead is transferred to a new tube, and this is done for a total of 500 generations or a total of two full months. After each strain is grown up to 500 generations, competition tests are conducted using antibiotic plates. Currently we have observed that there are only small differences in the growth rates in mixed culture, compared to pure culture. More competition tests are still being conducting currently. In the future we hope to look more closely at the genetic variations in these microorganisms if significant differences are found in the growth patterns.
“Identification of Mitochondrial Proteins in Durum Wheat”
Mitochondria are organelles present in both animal and plant cells that produce energy and are involved in various processes such as signaling, cell differentiation, and programmed cell death. There are approximately 2000 proteins within the mitochondria, of which less than 100 are mitochondrial encoded. Several human genetic disorders and phenotypic variations in plants are known to be the result of alterations of mitochondrial genes. Although the rice mitochondrial proteome has been analyzed, wheat still remains uninvestigated. The purpose of this project was to investigate the mitochondrial proteome in Triticum turgidum L., Durum wheat, by observing patterns in both membrane and soluble proteins using 1D and 2D gel electrophoresis. Mitochondria were prepared from 10-day old Durum wheat plants using differential centrifugation and percoll density gradients. Mitochondria were lysed by three freeze thaw cycles and the membranes separated by centrifugation. The soluble fraction was concentrated by vacuum distillation and the proteins precipitated. The membrane fraction was extracted with chloroform to remove lipids. The samples were solubilized with destreak rehydration buffer (GE Healthcare) and separated by IEF (pH 3-10 NL) and then separated in the second dimension by SDS-PAGE. The samples were also analyzed using 1D SDS- PAGE. The comparison of the 1D and 2D gels revealed significantly more proteins in the soluble fraction. Future research will include identification of the proteins in each fraction to better understand the function of mitochondria in plants.
“The Efficacy of Garlic as an Antibacterial Agent”
The widespread use of antibiotics as growth promotants in livestock feed has led to a marked increase in multi-drug resistant super infections in both humans and animals. This study was designed to determine if garlic, an ancient herbal remedy, has biostatic and/or bactericidal properties in vitro. The efficacy of various garlic preparations was tested in vitro on: C. freundii, E. coli, S. epidermidis and S. marcescens. In broth cultures grown for 24 hours, bactericidal properties of fresh garlic extract (FGE) were similar to chloramphenicol (positive control) in three out of the four bacterial species studied. Moreover, a study utilizing broth cultures grown for 96 hours prior to plating, clearly showed that FGE was far superior to the positive control in the treatment of S. epidermidis; however, its effectiveness was diminished for the other three bacterial species. In summary, FGE (i) was effective in controlling bacterial growth in vitro, (ii) may be a viable option for inhibiting bacterial growth in vivo, and (iii) should be tested as a sustainable alternative to antibiotics used as prophylactic agents in livestock.
“Development of a Structured Horseback Riding Therapeutic Program for Young Adults with Cerebral Palsy”
My thesis will concentrate on the development of a therapeutic horseback riding program for young adults with Cerebral Palsy enrolled in the non-profit program, Always Wanted a Riding Experience (A.W.A.R.E) in San Marcos, Texas. My observations for this research project involve a 21-year-old female with severe spastic quadriplegia Cerebral Palsy. The structured program I will develop will target the physiological benefits for her body as well as incorporate social and cognitive goals using behavioral and learning models. These models will help analyze the patient’s self-perception in her group and individual therapy. The main component explored in my research targets hippotherapy effects in building trunk and postural stability. I will also explore how therapeutic horse riding sessions can relate to her specific goals in her future career. In return, my thesis will add for potential modifications to future cerebral palsy clients’ programs offered at A.W.A.R.E. My research will also make contributions to the use of hippotherapy treatment and therapeutic horseback riding for the Cerebral Palsy population.
Timothy Glenn Conner
“A Simulation Based Study for Evaluating Different Tooling Approaches for the FDFF Process”
The purpose of this research was to determine the optimum tooling method to achieve good layering alignment and bonding between sliced layers for building functional metallic parts for the FDFF process. The three alignment methods studied were internal feature alignment, fully nested alignment, and selected slices alignment. Three methods were compared by finite element method by Ansys/Inventor as well as cost, ease of manufacture, and ease of use. The results for the internal features alignment showed good pressure at the point of application and diminished pressure outward. Both the fully nested and selected slices alignment methods showed even application of pressure throughout the part. The uneven application of pressure made the internal features method the least desired. The fully nested and selected slices methods had many similar positives such as ease of alignment and even application of pressure. The fully nested method had several limitations including a fully enclosed design requiring a CNC mill. The selected slices method was found to be the best method of the three because it was less expensive to produce, shared the advantages with the fully nested method, and was an open design.
“Characterization of Telomerase Expression and Telomere Length in Xiphophorus”
Research focusing on telomere length and telomerase expression has become increasingly important due to the association of these two biological endpoints with cellular aging and cancer. However, in vivo studies examining telomeres and telomerase are limited to only a few vertebrate models. Currently, research relies upon the traditional use of laboratory mice strains that have telomeres with extremely long lengths and high variability. More recently, fish species have been shown to provide a potentially informative model for examining the role of telomeres and telomerase within intact animals. As a current model for melanoma research and a new world live-bearing genus, Xiphophorus had not previously been assessed for telomere length. To add to the knowledge base of telomere and telomerase biology we have begun to assess telomere length and telomerase expression among several species of Xiphophorus.
Amanda M. Duran
“Characterization of Singlet Oxygen Generated DNA-Protein Cross-Links”
Cancer cells have been shown to be under an increased level of oxidative stress. DNA is prone to oxidation at the guanine base. 8-oxo-7,8-dihydro-2’-deoxyguanosine (8OdG) is the primary oxidation product and is a biomarker of cellular oxidative damage. 8OdG is a potent mutagen that leads to a G to T transversion when left unrepaired. However, 8OdG detection proved unreliable as it has an even more favorable oxidation potential than dG which leads to hyper-oxidation and the formation of several well-known adducts. These adducts have been shown to occur in cells treated with heavy metals. An oxidative DNA-protein crosslink (DPC) is one such product. To study DPCs, we used pancreatic ribonuclease A protein, short DNA molecules with a guanine repeat, and photo-oxidants (riboflavin or rose bengal) to facilitate DPC formation. DPCs were analyzed by gel electrophoresis and differential staining. DPCs were additionally characterized as replication stops in a primer extension assay.
“Restoring a Downtown & Strengthening a Community”
Cities are usually identified by the character of their downtown area. The idea of a “downtown” creates a sense of nostalgia for older generations that is slowly dissipating among younger contemporaries. Downtown Mainstreet areas are important for its ability to support local business, provide revenue for communities, and serve as entertainment and community building for locals and visitors. It has become imperative to restore a city’s downtown region to maintain its individuality. The city of Seguin, TX has been working to renovate its historical downtown district since 1981 through the Texas Main Street Program. For Seguin to thrive, it must provide for their fairly large population of college students and older retirement-age citizens, as well as newcomers. A fall semester devoted to historical research, community, economic, demographic and site analysis, has found that residential spaces, retail businesses, and restaurant venues are all needed in the city of Seguin. For the historic Vivroux hardware building, our goal as interior design students is to determine what unique business will attempt to revitalize the community. An environment that provides for socialization, not only for one group of individuals, but for all, and is architecturally current while maintaining the historically nostalgia of the surrounding historic district will bring the community into the downtown area. In doing so, keeping Seguin’s historical integrity in mind will restore and renew the city and its people.
“Uranium Remediation in Hanford Vadose Zone Sediments by Ammonia Gas Treatment”
An estimated 202,703 kg of uranium (U) has been released to the ground surface at the Department of Energy’s Hanford Site in Hanford, WA, and is present in the vadose zone and groundwater as a contaminant. Various efforts to remediate this contamination are focused on reducing the transport of U to the accessible environment. Previous laboratory studies have shown that ammonia gas treatment of sediment decreases the overall mobility of the uranium, as there is less aqueous and adsorbed U and a greater fraction of U-containing precipitates. The goal of this study is to quantify the geochemical changes that occur from ammonia gas treatment at differing concentrations of ammonia gas for different time periods. Data was compared between batch experiments (vials with no gas flow) and 20-ft long 1-D column (i.e., gas flow) experiments. The results showed that greater ammonia treatment increased the sediment pH and mineral dissolution for both the column and the batch experiments. Over time, the pH remained fairly constant, yet some pore water cation/anion concentrations decreased and others remained constant. Even after a short time period of experimentation (800 hours), uranium surface phases indicated changes to less mobile phases. This study showed that ammonia gas treatment of sediment is successful in decreasing the mobility of uranium. Additional experimentation and modeling is needed to quantify precipitates that form during ammonia gas treatment, which will allow for this treatment to be applied to the field.
“Evidence of Hybrid Speciation in Iris Nelsonii”
Hybridization often results in the production of hybrids with lower fitness than the hybridizing taxa. However, in some systems, hybrid lineages may be fit in a novel habitat such that the hybrid lineage can diverge from the progenitor species. Homoploid hybrid speciation involves the evolution of reproductive isolation between such a hybrid lineage and the originally hybridizing taxa. Iris nelsonii is a purported homoploid hybrid species derived from hybridization between three widespread species of Louisiana Iris: Iris brevicaulis, I. fulva, and I. hexagona. I conducted a survey of the genetic variation in populations of the three widespread species and I. nelsonii in order to investigate the origin of I. nelsonii. Iris retrotransposon display fragment variation indicates that I. nelsonii is a stabilized species that shares much of its fragment variation with I. fulva. These data are consistent with previous analyses of allozyme and random amplified fragment polymorphisms within this system.
Jennie Tudor Gray
“Writing a Youth Non-Fiction Book on Contemporary Women Artists”
It has come to my attention over my career in various bookstores and libraries that there is a void in the book market as far as books on contemporary women artists for a youth market. My honors thesis would consist of helping fill this gap by writing said book. The book will attempt to highlight the life and artworks of women artists from around the globe. The book will be geared to students as well as a resource for educators as it will include lesson plan activities that correspond to each artist.
“Confrontational vs. Avoidance Approaches to Fighting Addiction”
Does how a person chooses to respond to an addiction trigger affect success in efforts to abstain? The current study explores this question by measuring participants’ tendency to choose “confrontation” or “avoidance” strategies in response to addiction triggers and success in efforts to quit smoking.
The goal of this research is to begin to build psychological measurements into an alcohol addiction treatment program. Before proposing such a program, however, preliminary data is being gathered with students attempting to quit smoking. It is proposed that individuals that choose to “confront” triggers will report more successful abstinence (report fewer “slips”) than those who choose “avoidance” strategies in response to triggers.
Data is still being gathered but preliminary analyses suggest that those participants who responded to “trigger scenarios” with “confrontation” strategies report more successful abstinence efforts on weekly follow-up contacts than those participants who chose “avoidance” strategies in response to the same trigger scenarios. Full analyses and implications of these findings for alcohol addiction treatment will be explored.
Corey S. Jackson
“Solving the Musician's Dilemma: One Community's HAAM, Another Community's Example”
Austin, Texas is the Live Music Capital of the World. It is home to over 8,000 working musicians and many world-famous music venues and events. Austin’s music industry provides over 10,000 jobs and contributes nearly $1 billion annually to the local economy, yet most Austin musicians live at or below the federal poverty level, without health insurance. Health Alliance for Austin Musicians (HAAM) is a nonprofit organization that brings together doctors, local businesses, and community donors in a network providing basic preventive health services to this essential segment of the community. HAAM is a unique service stemming from Austin’s unique culture, but a nation of musicians share this healthcare dilemma. Chicago, Illinois is home to over 80,000 musicians, and a music scene that provides over 65,000 jobs, contributing over $15 billion annually to Chicago’s economy. Currently, there is not a local nonprofit organization that supports uninsured musicians in Chicago with affordable primary healthcare. Could Chicago benefit from a nonprofit organization that connects musicians to local health services? I believe HAAM’s example could be used to derive a model which other communities across the country, like Chicago, can adapt to their distinctive personalities. I intend to prove this in three parts: the story of HAAM’s genesis and services; a comparison between Austin and Chicago, using “The Windy City” as a case for this general framework; and an online presence, that will host a short film and raise awareness about how communities can help their musicians, all while saving the community money.
“Ammonia Toxicity to Asian Clams (Corbicula fluvimea) Under Field Conditions in Wilbarger Creek (Travis County, Texas)”
Freshwater mussels are one of the most rapidly declining groups of animals in aquatic ecosystems. Most freshwater mussels have a lower tolerance to ammonia (a commonly occurring pollutant) than other groups of aquatic organisms. We investigated the toxicity of ammonia to Asian clams (Corbicula fluvimea) using water from Wilbarger Creek (Travis County, Texas), where a large wastewater treatment plant (a major source of ammonia) has been permitted for construction. We exposed Corbicula collected from Wilbarger Creek to seven concentrations of ammonia for 24 hours to determine the LC50 of ammonia under actual stream conditions. We used reagent-grade ammonium chloride as our source of ammonia, and measured concentration of total nitrogen as ammonia (TAN) by chemical assay. Our results showed no toxicity at the lowest four concentrations (.5, .8, 1.3, and 2.4 mg/L), and low to moderate toxicity at the highest two (5 and 10 mg/L). These results demonstrate that significant freshwater mussel mortality can occur even at the maximum daily concentration of 10 mg/L allowed by the Texas Commission of Environmental Quality (TCEQ), and can be used to help guide policy makers’ decisions concerning allowable ammonia concentrations.
Velcro Connections (VX) is first and foremost a social networking tool. My goal is to build a website where different talented individuals can post profiles in order to entice anyone willing to pay their price to hire them for a service. The idea was founded around local San Marcos musicians whom I have discovered that I believe are being severely underutilized. These artists, and others of non-musical orientation, stand to benefit from the increased opportunities of employment, and increased exposure, whereas public and private venues (including private house parties) will have easy access to a vast and diverse yet easily available group of artists at affordable prices. The site will be free to use, however I would personally rake a small percentage of both the money made by the performer(s) and the venue.
“Elemental and Nutritional Variability in Aquatic and Terrestrial Arthropods”
Aquatic and terrestrial arthropods are important food resources for both terrestrial and aquatic consumers. For example, emergent adult aquatic arthropods are consumed by many species of birds. On the other hand, terrestrial arthropods that fall into aquatic systems can be a very important food resource for fishes. While the temporal patterns of abundance among these arthropod groups is well documented, there is an assumption that aquatic and terrestrial arthropods are similar in their nutritional value which is indicated by the ratios of carbon and nitrogen in the body tissues. We analyzed the C:N ratios of several arthropod taxa from both aquatic and terrestrial ecosystems to determine if the nutritional value among these groups varies significantly among taxa, habitat, and trophic level (herbivores vs. predators).
“Research, Reuse, Revitalize: Designing a Texas Community’s Future”
Historic preservation celebrates and revitalizes the historic architecture of the past, but can also become a catalyst that restructures the local economy––in turn––creating job opportunities, business opportunities, and increasing the city’s overall economic system. Since 1981, through their Texas Main Street Program, The Texas Historical Commission has recognized the creation of almost 6,400 businesses in main street districts. Seguin is a Charter Member of the Texas Main Street program. This program is dedicated to the economic revitalization of downtown through historic preservation. Seguin's downtown is also recognized as an Accredited National Main Street City by the National Trust for Historic Preservation. Seguin’s Main Street Program and Texas State’s Research and Environmental Design students and faculty, have teamed up to collaborate and encourage more growth to Seguin’s historic district. The vision is to restore a half-block of buildings adjacent to the courthouse square which includes a hardware store from 1868. The design development included plans for residential, restaurant, and commercial retail spaces. Our research––of both the community and the building site––is to reflect in our design proposal, taking into account community history and demographics, maps, housing information, site history and style, price analysis, and zoning information. In addition, our research captures how the surrounding community affects the design, and in turn how the redesign of the former hardware store impacts the local economy. The goal––as design students––is to be the visionary for the betterment of the community.
Kellen Elizabeth Stanley
“Memory as Childhood Videotape: The Marnie Video Performance”
In this life, we as human beings cling to our memories for documentation of existence. In the past two years, I've been working with a certain childhood memory captured on videotape. I refer to this specific tape as 'the Marnie video;' it acts as a remnant of my four-year old self in front of a technology capturing a storytelling performance. I long to have this memory play in front of me, without a television, mirroring the Samuel Beckett play, Krapp's Last Tape. Krapp yearns to hear the playback of voice recordings telling of his past, but tragically he can never physically go back into the memory. Beckett's comment on remembrance informs my approach of performance and theater as the main outlet of this thesis. Rehearsing with collaborating actors and musicians will bring me to the process that physically reconnects to this memory. I propose to create a sensory experience that triggers nostalgia in everyone involved, specifically channeling my childhood memory of the Marnie video as the main space of this performance.
Victoria L. Thornton
“What Is Infidelity? Perceptions Based Upon Biological Sex and Personality”
The current study examined perceptions of infidelity, paying particular attention to how these perceptions would differ based upon biological sex and personality traits, specifically agency, communion, and their unmitigated counterparts. The study utilized a sample of 125 male and 233 female college students. In addition to the personality measures, participants completed a 19-item checklist that assessed their perceptions of specific items that could potentially be construed as infidelity. It was hypothesized that females would construe more items as infidelity than males. It was also predicted that unmitigated communion and communion would be positively correlated with these perceptions and that unmitigated agency would be negatively correlated with these perceptions. No correlation was predicted between agency and infidelity. All hypotheses were supported. Implications and suggestions for future research will be discussed.
“Metamodeling-Based Approximations for Optimization”
Artificial Neural Networks (ANN) and Linear Regression Model are two techniques that may be used to approximate functionalities hidden in raw data. When these data are generated with a model – like a simulation model- then the ANN and linear regression models are called ‘metamodels’. Artificial Neural Networks are viable metamodeling techniques since they are able to learn from examples, and are interesting because they deal effectively with uncertainty and noisy data, and are capable of universal approximation under specific conditions. Linear Regression is certainly a viable technique as it has been the workhorse of function approximation in statistics for many years. The purpose of this research was to compare accuracy, usability, and efficiency of both types of the metamodels described above in the particular context of a simulation optimization algorithm that uses function approximation as a key element in its structure. In order to carry out such comparison, a series of well-known test functions were used to be subjected to minimization: 1) Sphere, 2) Rosenbrock, 3) Rastringin, 4) Griewank, 5) Goldstein-Price, 6) Easom, and 7) Schfewel. The optimal solutions are well established for all these functions and can be easily accessed in the global optimization literature. In the Simulation Optimization Algorithm used in this work, one will choose the metamodeling technique, either ANN or Linear Regression, to approximate the values of each of the seven functions based on a finite sample obtained following a Central Composite Design (CCD). The CCD is a design (from the Design of Experiments field) that is known for its adequacy to study nonlinear behavior in experimental values. After obtaining values through the CCD for a particular function, the best solution is chosen as an incumbent. A metamodel is then created and subjected to optimization using Excel Solver under a multiple starting points scheme. The Excel Solver uses the Generalized Reduced Gradient algorithm for nonlinear optimization purposes. After a potential minimum is obtained, a true objective function value is obtained by evaluating the candidate solution in the targeted test function. Then, three stopping criteria are checked: Stop if 1) the potential minimum belongs to the original CCD; 2) the R squared is 100%; or 3) a predefined maximum number of iterations have been achieved. If none of the stopping criteria is met, the incumbent solution is added to the available known points and a new metamodel is created, thereby starting a new iteration. On every iteration, the new candidate solution is compared to the incumbent for updating purposes. When meeting a stopping criterion, the incumbent is reported and the algorithm ends. The materials used in this research were the Excel Solver for optimization, Matlab to model the ANN, and Minitab to find the regression and the R squared of the approximations. Graphics were used for supporting analysis and eventual conclusions. Analyzing the preliminary results, it is important to notice that ANNs were able to converge to the best known solutions in the least number of iterations, which would indicate that using a complex metamodel actually helped efficiency. This, of course should be balanced against the work of solving a more complex optimization problem. Furthermore, when trying the regression metamodels, it was interesting to see that a higher order model showed better results in this case. The results thus far, as it can be appreciated, go in the direction predicted when it comes to metamodel complexity. The next steps in this work should be to confirm the preliminary result to then extend the study to include further test functions of different kinds. The expected utility of this project is to shed some light in terms of what kind of metamodel should be used when applying the simulation optimization algorithm, especially in light of seeking a low number of iterations to find attractive solutions. This project was part of an NSF REU summer experience for Saul Villarreal and Monique Grier at University of Puerto Rico at Mayaguez. (NSF REU 0851879, PI: Dr. Viviana Cesani).
“Trafficking Patterns of Candida albicans Cell Mutants Within Murine Macrophages Upon Phagocytosis”
Candida albicans is an opportunistic pathogen that costs over one billion dollars a year to treat. The duration and severity of candidial infection are dependent upon interactions between Candida and the innate immune system, specifically host phagocytes such as macrophages. Affected individuals are typically immune compromised or suffer from genetic defects in innate immune system signaling pathways. Macrophages play a key role in overcoming candidiasis, but C. albicans possesses a number of mechanisms to evade destruction after phagocytosis, most notably filamentous hyphae formation. The impact of cell wall proteins in preventing yeast destruction is not well characterized. Surprisingly, the intracellular fate of C. albicans within macrophages has not been well characterized either, but previous work has suggested it does not undergo the classical phagosomal maturation process. In this study, strains of Candida defective in certain cell w! all proteins that are candidates to mediate the aberrant trafficking were transformed with a GFP tag using electroporation to follow their fate in the macrophage after phagocytosis. Whether these defective cell wall proteins aided in Candida survival or resulted in their rapid destruction was studied. Initial attempts to transform five of the C. albicans strains were unsuccessful and we identified a defect within the GFP expression plasmid. The plasmid was reconstructed and confirmed to be correct. This has allowed us to retransform the original strains in order to test the original hypothesis, and these experiments are underway.
“Physical and Mechanical Properties of the Parts Bonded by the FDFF Process”
Fully Dense Freeform Fabrication is an emerging engineering practice involving additive manufacturing, as oppose to material removal, to laminate slices with variable thicknesses bonded together with a bonding material. The focus of the current research is producing fully dense metallic parts by using heat, pressure, and bonding materials such as soldering and brazing materials. In this research, the mechanical and physical properties of the final parts are evaluated and compared with parts that are machined out of a solid block. Physical properties are mainly electrical and thermal conductivity. Mechanical properties include stress and bending tests are conducted according to ASTM standards. Design of experiments method is used to test the effects of bonding material (i.e., different percentages of tin-bismuth) and thickness on the physical and mechanical properties.