Barrett, The Honors College Thesis/Creative Project Collection
Barrett, The Honors College at Arizona State University proudly showcases the work of undergraduate honors students by sharing this collection exclusively with the ASU community.
Barrett accepts high performing, academically engaged undergraduate students and works with them in collaboration with all of the other academic units at Arizona State University. All Barrett students complete a thesis or creative project which is an opportunity to explore an intellectual interest and produce an original piece of scholarly research. The thesis or creative project is supervised and defended in front of a faculty committee. Students are able to engage with professors who are nationally recognized in their fields and committed to working with honors students. Completing a Barrett thesis or creative project is an opportunity for undergraduate honors students to contribute to the ASU academic community in a meaningful way.
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- Creators: School of Life Sciences
Description
Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related mortality in the USA and throughout the world. Two phenotypes that promote this deadly outcome are the invasive potential of NSCLC and the emergence of therapeutic resistance in this disease. There is an unmet clinical need to understand the mechanisms that govern NSCLC cell invasion and therapeutic resistance, and to target these phenotypes towards abating the dismal five-year survival of NSCLC. The expression of the tumor necrosis factor receptor superfamily, member 12A (TNFRSF12A; Fn14) correlates with poor patient survival and invasiveness in many tumor types including NSCLC. We hypothesize that suppression of Fn14 will inhibit NSCLC cell motility and reduce cell viability. Here we demonstrate that atorvastatin calcium treatment reduces Fn14 expression in NSCLC cell lines. Prior to Fn14 protein suppression, atorvastatin calcium modulated the expression of the Fn14 modulators P-ERK1/2 and P-NF-κβ. Atorvastatin calcium treatment inhibited the migratory capacity in H1975, H2030 and H1993 cells by at least 55%. When chemotactic migration in H2030 cells was induced by the Fn14 ligand TNF-like weak inducer of apoptosis (TWEAK) treatment, atorvastatin calcium successfully negated any stimulatory effects. Inversely, treatment of NSCLC cells with cholesterol resulted in a statistically significant increase in migration. Depletion of Fn14 expression via siRNA suppressed the migratory effect of cholesterol. Finally, atorvastatin calcium treatment sensitized cells to radiation treatment, reducing cell survival. These data suggest that atorvastatin calcium may inhibit NSCLC invasiveness through a mechanism involving Fn14, and may be a novel therapeutic target in NSCLC tumors expressing Fn14.
ContributorsCornes, Victoria Elisabeth (Author) / Stout, Valerie (Thesis director) / Whitsett, Timothy (Committee member) / Carson, Vashti (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2015-05
Description
Collaborative learning has been found to enhance student learning experiences through interaction with peers and instructors in a way that typically does not occur in a traditional lecture course. However, more than half of all collaborative learning structures have failed to last very long after their initial introductions which makes understanding the factors of collaboration that make it successful very important. The purpose of this study was to evaluate collaborative learning in a blended learning course to gauge student perceptions and the factors of collaboration and student demographics that impact that perception. This was done by surveying a sample of students in BIO 282 about their experiences in the BIO 281 course they took previously which was a new introductory Biology course with a blended learning structure. It was found that students agree that collaboration is beneficial as it provides an opportunity to gain additional insight from peers and improve students' understanding of course content. Also, differences in student gender and first generation status have less of an effect on student perceptions of collaboration than differences in academic achievement (grade) bracket.
ContributorsVu, Bethany Thao-Vy (Author) / Stout, Valerie (Thesis director) / Brownell, Sara (Committee member) / Wright, Christian (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2014-05
Description
As a major cause of nosocomial infections, biofilms such as those caused by Staphylococcus aureus and Staphylococcus epidermidis pose large concerns in the field of healthcare due to their extreme durability and resistance to treatment. While all biofilms grow similarly in a series of three stages: 1. Adhesion 2. Maturation 3. Dispersal, Staphylococcal species such as S. aureus and S. epidermidis make use of unique growth factors in order to form prolific and durable biofilms. Due to the prevalence and risks associated with bacteria, many antibacterial methods have been created to treat bacterial infections. Although many antibacterial methods exist, there is still a great need for additional and more effective methods to treat and prevent serious bacterial infections associated with biofilm growth, because incidences of bacterial infection and resistance, especially in medical settings, are on the rise. In recent research, the exotoxin tolaasin, produced by the bacterium Pseudomonas tolaasii has briefly been shown to exhibit antibacterial effects. Based on previous research and tolaasin's observed pore forming and detergent properties, it is hypothesized that tolaasin will disrupt and prevent staphylococcal biofilm growth either independently or synergistically with existing antibiotics. If this is confirmed, tolaasin may have major implications within the future of healthcare, particularly in the field of antibiotics. In order to optimally use tolaasin as an anti-biofilm agent, potential anti-biofilm applications would aim to prevent and treat biofilm infections at the most common sites of biofilm growth such as catheters, medical instruments, implanted medical devices, and surgical sites. In addition, under the assumption that tolaasin will be found effective in inhibiting biofilm growth and infection, this thesis proposes future anti-biofilm technologies that could use tolaasin as an anti-biofilm agent in order to prevent biofilms and associated infections. While there are many potential and promising ways that tolaasin could be used as an anti-biofilm agent in the future, there are still possible limitations that would need to be investigated through further research before these applications can come to fruition. Ultimately, if future research successfully determines that tolaasin can be used to make anti-biofilm technologies that are biocompatible, durable, and effective, then technologies using tolaasin as an anti-biofilm agent may more effectively ensure sterility of medical devices and prevent bacterial biofilms and infections, and may eventually save lives.
ContributorsCoumans, Hanna Jo (Author) / Stout, Valerie (Thesis director) / Cabirac, Gary (Committee member) / Muralinath, Maneesha (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2015-05
Description
Staphylococcus aureus and Staphylococcus epidermidis are among the most common causes of hospital-acquired infections5, 7, 8. Despite the advancements in modern antimicrobials, infections from these organisms can be very difficult to treat, and equally as difficult to prevent 6,7. These organisms’ abilities to form biofilms are directly related to their abilities to cause infections. In biofilms, the staphylococcal species can survive antibiotics and immune responses much better than planktonic cells7. Tolaasin—a toxin and natural biosurfactant produced by P. tolaasii—has been briefly tested against biofilm formation, and the results suggested that it could have inhibitory effects. In order to further confirm and expand upon this potentially useful data, additional testing was performed to determine the effects of tolaasin on the two organisms. In addition, laser treatment was tested on E. faecalis in order to supplement our current understanding of biofilm behavior, and provide additional data to suggest alternative agents against biofilm growth.
This thesis addresses the following questions: What are the best methods to test the effects of tolaasin, cephalexin and laser on the biofilms of S. aureus and S. epidermidis? Does tolaasin prevent or disrupt biofilm formation in S. aureus and S. epidermidis? Does tolaasin work synergistically with cephalexin to prevent biofilm growth and maturation in S. aureus and S. epidermidis? And, what effects does laser treatment have on E. faecalis biofilms? In order to answer these questions, tolaasin was isolated from P. tolaasii, and biofilms were pre-treated with tolaasin. Trials were performed with tolaasin, cephalexin, or a combination of both. The effectiveness of each treatment was determined by observing the biofilm growth. The protocols were then optimized and trials were repeated. Additionally, E. faecalis biofilms were exposed to laser treatment. Using confocal microscopy, the biofilms were observed and quantitative results were used to determine the effectiveness of the treatment. Overall, the results indicated that tolaasin has little effect on biofilm growth. However, further investigation is necessary to confirm these results due to some inconsistent data obtained over the course of the trials. Variations and improvements to the protocol are necessary to accurately determine tolaasin’s potential role in healthcare. Finally, the results of the laser trials suggest that EDTA in conjunction with laser treatment could be useful in cleaning root canals and eliminating post-procedural biofilms—thereby preventing infections.
This thesis addresses the following questions: What are the best methods to test the effects of tolaasin, cephalexin and laser on the biofilms of S. aureus and S. epidermidis? Does tolaasin prevent or disrupt biofilm formation in S. aureus and S. epidermidis? Does tolaasin work synergistically with cephalexin to prevent biofilm growth and maturation in S. aureus and S. epidermidis? And, what effects does laser treatment have on E. faecalis biofilms? In order to answer these questions, tolaasin was isolated from P. tolaasii, and biofilms were pre-treated with tolaasin. Trials were performed with tolaasin, cephalexin, or a combination of both. The effectiveness of each treatment was determined by observing the biofilm growth. The protocols were then optimized and trials were repeated. Additionally, E. faecalis biofilms were exposed to laser treatment. Using confocal microscopy, the biofilms were observed and quantitative results were used to determine the effectiveness of the treatment. Overall, the results indicated that tolaasin has little effect on biofilm growth. However, further investigation is necessary to confirm these results due to some inconsistent data obtained over the course of the trials. Variations and improvements to the protocol are necessary to accurately determine tolaasin’s potential role in healthcare. Finally, the results of the laser trials suggest that EDTA in conjunction with laser treatment could be useful in cleaning root canals and eliminating post-procedural biofilms—thereby preventing infections.
ContributorsChristopher, Zachary Kyle (Author) / Stout, Valerie (Thesis director) / Haydel, Shelley (Committee member) / Muralinath, Maneesha (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2014-05
Description
Studies have demonstrated that viruses such as human immunodeficiency virus [HIV], M13 bacteriophage, and murine cytomegalovirus [MCMV] have been effectively inactivated by exposure to ultra short-pulsed lasers (6,7,10,11,14,15,17). Ultra short pulse laser shows promise as a new method for non-invasive antiviral treatments (17). This method can be used to prevent problems such as drug resistance that is currently rising in numbers. According to the Center for Disease Control [CDC], there are more than two million people in the United States of America that are infected with antimicrobial-resistant infections and at least 23,000 deaths per year occur as a result (19). In this study, ultra-short pulses, specifically Ti-Sapphire Laser [USP Ti-Sapphire Laser] will be evaluated for viral inactivation. The virus chosen for this study was MS2 bacteriophage, which is a non- enveloped, icosahedral, single-stranded RNA [ssRNA] bacteriophages that infects F+ pilus Escherichia coli (16). It was hypothesized that ultrashort pulses from a Ti-Sapphire laser will inactivate MS2 bacteriophage. Inactivation was measured using plaque-forming units [PFU/mL] as an indicator. It was expected that there would be an increase in inactivation of MS2 bacteriophage with an increase in irradiation duration. The results indicated that MS2 bacteriophage was highly sensitive to irradiation treatments of the USP Ti-Sapphire Laser. The concentration of MS2 bacteriophage decreased by 107 PFU/mL after being treated for various time periods ranging from 5 minutes to 150 minutes. Longer duration of USP Ti- Sapphire Laser treatment inactivated more MS2 Bacteriophage.
ContributorsApablasa, Nayeli Aleysa (Author) / Stout, Valerie (Thesis director) / Jacobs, Bertram (Committee member) / Tsen, Kong-Thong (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2014-05
Description
Esophageal adenocarcinoma is one of the largest growing cancer types in the United States and the whole world. One of the only known precursors to EAC is Barrett’s Esophagus, the changing of the normal squamous cells which line the esophagus into intestinal cells, following repeated exposure to gastric acids via gastroesophageal reflux disease. There is limited knowledge of the mutations and drivers that contribute to EAC’s low 5-year survival rates, demonstrating a need to identify new therapeutic targets. Given the development of EAC from chronic inflammation and acidic microenvironment, elevated expression of tumor necrosis factor receptor super family member 12A (TNFRSF12A, FN14) and its corresponding ligand, TWEAK, is correlated with disease progression. The functional role of the TWEAK/FN14 signaling axis is well documented in other cancer types, contributing to tumor invasion, migration, and survival. However, reports have shown the TWEAK/FN14 signaling axis can contribute “pro-cancer” and “anti-cancer” phenotypes in different tumor microenvironments. In this study, we seek to demonstrate the functional role of TWEAK and FN14 in EAC survival and migration. We hypothesized TWEAK/FN14 signaling would promoted EAC cell survival and migration. In this study, we illustrate increased expression of FN14 with disease progression. Following treatment with TWEAK, human EAC cell lines had increased sensitivity to standard chemotherapy treatment in vitro. Treatment with TWEAK also correlated with increased cellular migration, most likely in correlation with NF-κB activation. Finally, we showed that inhibition of FN14 via siRNA significantly reduced EAC survival and increased efficacy of standard of care treatments. This data suggests a diverse functional role of the TWEAK/FN14 signaling axis in EAC, and may be a potential target for novel therapeutics.
ContributorsFornefeld, Lucas Christien (Author) / Stout, Valerie (Thesis director) / Whitsett, Timothy (Committee member) / Carson, Vashti (Committee member) / School of Life Sciences (Contributor) / W. P. Carey School of Business (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12