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.
Displaying 1 - 10 of 41
Description
There has long been a link tied between obesity and such pathological conditions as nonalcoholic fatty liver disease and type two diabetes. Studies have shown that feeding rats a diet high in fat results in hepatic steatosis and steatohepatitis. Using a novel short term diet of six weeks with male adolescent Sprague-Dawley rats, our laboratory sought to investigate the early effects of high fat intake on the liver. Prior findings in our laboratory found that a high fat diet (HFD) leads to nonalcoholic fatty liver disease as well as other symptoms of metabolic syndrome. This study hypothesized that rats fed a 60% HFD for 6 weeks, unlike a high sucrose or standard chow diet, would have an elevated expression of pro-inflammatory cytokines associated with steatohepatitis. TNF-α, TLR4 and XBP1 were chosen for their link to hepatic inflammation. The results of this study found that contrary to the hypothesis, the high fat diet did not induce significant changes in the expression of any inflammatory marker in comparison to a high sucrose or control chow diet.
ContributorsCalhoun, Matthew (Author) / Sweazea, Karen (Thesis director) / Deviche, Pierre (Reviewer) / Barrett, The Honors College (Contributor)
Created2015-05
Description
Western diets, high in dietary fat and red meat, are associated with hyperglycemia and weight gain, symptoms that promote insulin resistance and diabetes. Previous studies have shown that elevated glucose promotes glycation of circulating proteins such as albumin, which is thought to lead to hyperglycemia complications. It was hypothesized that diets with no meat consumption (pesco-vegetarian and lacto-vegetarian) would reduce protein glycation, in comparison to a diet with meat. Forty six healthy adult omnivorous subjects were randomized into one of three groups and instructed to either consume red meat (i.e. meat) or poultry twice per day (control), eliminate meat and increase fish consumption (pesco-vegetarian), or adopt a vegetarian diet devoid of fish, meat or poultry (lacto-vegetarian) for four weeks. Fasting plasma samples were collected from participants at baseline and after 4 weeks of the dietary intervention. Plasma glucose concentrations were measured using a commercially available kit. Percent glycated albumin was measured on a separate aliquot of plasma by mass spectrometry. Plasma glucose concentrations were significantly increased following 4-weeks of pesco-vegetarian diet (P=0.002, paired t-test). Neither the lacto-vegetarian (P=0.898) or the control diet (P=0.233) affected plasma glucose concentrations. Despite the significant increase in plasma glucose following a pesco-vegetarian diet, no change in percent glycated albumin was observed (P>0.50, ANOVA). These findings may indicate a protective effect of the pesco-vegetarian diet on protein glycation in the presence of elevated plasma glucose and suggest the need for additional studies to examine the link between increased fish consumption and glucose regulation.
ContributorsRaad, Noor (Author) / Sweazea, Karen (Thesis director, Committee member) / Borges, Chad (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2015-05
Description
Birds have unusually high plasma glucose concentrations compared to mammals of similar size despite their high metabolic rate. While birds use lipids as their main source of energy, it is still unclear how and why they maintain high plasma glucose concentrations. To investigate a potential underlying mechanism, this study looks at the role of lipolysis in glucose homeostasis. The purpose of this study is to examine the effects of decreased glycerol availability (through inhibition of lipolysis) on plasma glucose concentrations in mourning doves. The hypothesis is that decreased availability of glycerol will result in decreased production of glucose through gluconeogenesis leading to reduced plasma glucose concentrations. In the morning of each experiment, mourning doves were collected at the Arizona State University Tempe campus, and randomized into either a control group (0.9% saline) or experimental group (acipimox, 50mg/kg BM). Blood samples were collected prior to treatment, and at 1, 2, and 3 hours post-treatment. At 3 hours, doves were euthanized, and tissue samples were collected for analysis. Acipimox treatment resulted in significant increases in blood glucose concentrations at 1 and 2 hours post- treatment as well as renal triglyceride concentrations at 3 hours post-treatment. Change in plasma free glycerol between 0h and 3h followed an increasing trend for the acipimox treated animals, and a decreasing trend in the saline treated animals. These results do not support the hypothesis that inhibition of lipolysis should decrease blood glycerol and blood glucose levels. Rather, the effects of acipimox in glucose homeostasis appear to differ significantly between birds and mammals suggesting differing mechanisms for glucose homeostasis.
ContributorsKouteib, Soukaina (Author) / Sweazea, Karen (Thesis director) / Deviche, Pierre (Committee member) / Chandler, Douglas (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2015-05
Description
With the rising prevalence of obesity and diabetes, novel treatments to help mitigate or prevent symptoms of these conditions are warranted. Prior studies have shown that fossilized plant materials found in soil lowers blood sugar in a mouse model of diabetes. The goal of this study is to determine whether a similar organometallic complex (OMC) could prevent insulin resistance in the skeletal muscle brought on by chronic high fat intake by examining the protein expression of key enzymes in the insulin signaling pathway and examining glucoregulatory measures. Six-week-old periadolescent male Sprague-Dawley rats (n=42) were randomly chosen to be fed either a high fat diet (HFD) (20% protein, 20% carbohydrates [6.8% sucrose], 60% fat) or a standard chow diet (18.9% protein, 57.33% carbohydrates, 5% fat) for 10 weeks. Rats from each diet group were then randomly assigned to one of three doses of OMC (0, 0.6, 3.0 mg/mL), which was added to their drinking water and fasting blood glucose was measured at baseline and again at 10 weeks. After 10 weeks, rats were euthanized, and soleus muscle samples were isolated, snap-frozen, and stored at -80°C until analyses. Fasting plasma glucose was measured using a commercially available glucose oxidase kit. Following 6 and 10 weeks, HFD rats developed significant hyperglycemia (p<0.001 and p=0.025) compared to chow controls which was prevented by high dose OMC (p=0.021). After 10 weeks, there were significant differences in fasting serum insulin between diets (p=0.009) where levels were higher in HFD rats. No significant difference was seen in p-PI3K expression between groups. These results suggest that OMC could prevent insulin resistance by reducing hyperglycemia. Further studies are needed to characterize the effects of diet and OMC on the insulin signaling pathway in skeletal muscle, the main site of postprandial glucose disposal. This study was supported by a grant from Isagenix International LLC as well as funds from Barrett, the Honors College at Arizona State University, Tempe Campus.
ContributorsStarr, Ashlee (Author) / Sweazea, Karen (Thesis director) / Johnston, Carol (Committee member) / Hyatt, JP (Committee member) / Sanford School of Social and Family Dynamics (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-12
Description
CD4+CD25+ FOXP3+ cells are recognized as the most reliable regulatory T cell subset. However, the intracellular nature of the FOXP3 transcription factor limits its use for the isolation or selection of viable regulatory T cells for adoptive immunotherapy. Nuclear localization of FOXP3 has been more strongly associated with induced regulatory T cell (Treg) function than increased expression of FOXP3 alone. Several different cell culture methods and T cell activation techniques can induce increased expression of FOXP3 in a variety of T cell models, but Rapamycin (an mTOR inhibitor) was recently shown to differentially induce nuclear localization of FOXP3 when compared with IL-10 and TGFβ. Feline Tregs have been well characterized and share many of the phenotypic and functional characteristics of murine and human Tregs. We cultured feline Mya-1 T cells in conditions that would differentially promote effector or regulatory phenotypes and correlated nuclear localization of FOXP3 with other quantitative morphologic features using imaging flow cytometry. We compared the morphologic features of cells with high intra-nuclear concentrations of FOXP3 cultured without IL-2, with IL-2, and with IL-2 and Rapamycin before and after non-specific antigenic stimulation with Concanavalin-A. This analysis may help identify a population of pure regulatory T cells that would be more likely to maintain regulatory function following in-vitro expansion and activation. Furthermore, the feline T cell model could help elucidate important differences between murine and human Treg cells that would further translational efforts in adoptive immunotherapy. Now, we ask if nuclear localization of FOXP3 could be used to identify other morphologic differences between activated effector and regulatory T cells using a feline T cell line.
ContributorsRojas, Arturo Nikolas (Author) / Sweazea, Karen (Thesis director) / Mexas, Angela (Committee member) / Murphy, Andrea (Committee member) / School of Nutrition and Health Promotion (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
The natural habitat as well as the food abundance and food sources of avian species is changing due to urbanization, and such anthropocentric actions could lead to devastating impacts on bird populations. As changes in distribution and nutrition are thought to be related to the gut microbiome, the goal of this study was to determine the relationship between nutritional markers, including body mass, gizzard mass, triglycerides, free glycerol and glycogen, and the gut microbiome in urban and rural house sparrows (Passer domesticus), to understand physiological differences between urban and rural house sparrows. We hypothesized that increased access to human refuse, through urbanization, may significantly alter the gut microbiome and thus, the nutritional physiology-the effects of foods on metabolism-of urban birds. Fecal samples were collected from rural (n=13) and urban (n=7) birds to characterize the gut microbiome and plasma samples were collected to measure nutritional markers using commercially available kits. Following euthanasia, liver samples were collected to measure triglycerides, free glycerol and glycogen. While there were no significant differences in circulating triglycerides or free glycerol between populations, urban birds had significantly greater blood glucose (p=0.046) compared to rural birds, when normalized to body mass. Additionally, rural birds had significantly more plasma uric acid (p=0.016) and liver free glycerol (p=0.044). Higher blood glucose suggests greater accessibility to carbohydrates in an urban setting or higher rates of gluconeogenesis. Uric acid is a byproduct of purine catabolism and a potent antioxidant. Thus, higher uric acid suggests that rural birds may utilize more protein for energy. Finally, higher liver free glycerol in rural birds suggests they metabolize more fat but could also indicate that urban birds have greater glycerol gluconeogenesis, which may consume free glycerol resulting in higher glucose concentrations. However, the current study does not provide evidence for this as there were no significant differences in the gluconeogenic enzyme PEPCK-C levels between urban and rural house sparrows (p= 0.165). While triglyceride, glucose, and uric acid levels differed between urban and rural birds, there were additionally no significant differences in the gut microbiome, indicating that although nutritional physiology can be affected by distribution and varying food availability and sources, differences in the gut microbiome are evident at the phyla level.
ContributorsGadau, Alice (Author) / Sweazea, Karen (Thesis director) / Whisner, Corrie (Committee member) / Crawford, Melisa (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
In this article we present a low-cost force-sensing quadrupedal laminate robot platform. The robot has two degrees of freedom on each of four independent legs, allowing for a variety of motion trajectories to be created at each leg, thus creating a rich control space to explore on a relatively low-cost robot. This platform allows a user to research complex motion and gait analysis control questions, and use different concepts in computer science and control theory methods to permit it to walk. The motion trajectory of each leg has been modeled in Python. Critical design considerations are: the complexity of the laminate design, the rigidity of the materials of which the laminate is constructed, the accuracy of the transmission to control each leg, and the design of the force sensing legs.
ContributorsShuch, Benjamin David (Author) / Aukes, Daniel (Thesis director) / Sodemann, Angela (Committee member) / Engineering Programs (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Morbid obesity is associated with cardiovascular and metabolic disorders. A major contributor to the pathogenesis of these diseases is impaired vasodilation resulting from elevated reactive oxygen species (ROS). This is because certain ROS such as superoxide are raised with obesity and scavenge the endogenous vasorelaxant nitric oxide, resulting in hypertension. The objective of this study was to measure the ability of genistein to quench superoxide in the vasculature of ob/ob mice, an animal model of obesity and type 2 diabetes. Genistein is an isoflavonic phytoestrogen naturally found in soy products. While genistein has documented antioxidant and anti-inflammatory properties, it is not known whether this protects the vasculature from oxidative stress. Genistein was hypothesized to reduce superoxide in arteries from female ob/ob mice. The superoxide indicator dihydroethidium (DHE) [2µL/mL HEPES buffer] was added to isolated aortae and mesenteric arteries from mice fed either a control (standard rodent chow containing 200-300 mg genistein/kg) or genistein-enriched (600mg genistein/kg rodent chow) diets for 4 weeks. Frozen tissues sections were collected onto glass microscope slides and examined using confocal microscopy. Contrary to the hypothesis, a diet containing twice the amount of genistein found in standard chow did not significantly reduce superoxide concentrations in aortae (p=0.287) or mesenteric arteries (p=0.352). Superoxide dismutase, an antioxidant enzyme that breaks down superoxide, was significantly upregulated in the genistein-enriched diet group (p=0.004), although this elevation did not promote the breakdown of superoxide. In addition, the inflammatory marker iNOS was not downregulated in the genistein-enriched diet group (p>0.05). The results indicate that high amounts of isoflavones, like genistein, may not exhibit the purported antioxidant effects in the vasculature of obese or diabetic subjects. Further studies examining arteries from ob/ob mice fed a genistein-free diet are needed to elucidate the true effects of genistein on oxidative stress.
ContributorsSimperova, Anna Marie (Co-author) / Al-Nakkash, Layla (Co-author) / Ricklefs, Kristin (Co-author) / Faust, James J. (Co-author) / Sweazea, Karen L. (Co-author) / Sweazea, Karen (Thesis director) / Gonzales, Rayna (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor) / T. Denny Sanford School of Social and Family Dynamics (Contributor)
Created2014-05
Description
High fat diets (HFD) are known to cause hepatic non-alcoholic steatosis in rats in as few as four weeks. Accumulation of triglycerides in liver and skeletal muscle is associated with insulin resistance and obesity. However, studies of fat accumulation in cardiac muscle are not as prevalent. Therefore, the first hypothesis of this study was that HFD would lead to hepatic steatosis as well as lipid accumulation in pectoralis and cardiac muscles, tissues responsible for the majority of postprandial glucose disposal. Prior studies also indicated that HFD leads to increased inflammation and oxidative stress within the vasculature resulting in impaired endothelium-dependent vasodilation, however biomarkers of immune system reactivity were not assessed. Therefore, the second aim of this study was to explore additional pathways of immune system reactivity and stress (natural antibodies; heat shock protein 60 (HSP60)) in rats fed either a control (chow) or high fat (HFD) diet. HSP60 has also recently been recognized as an early marker of vascular dysfunction in humans. The hypothesis was that immune system reactivity and early vascular dysfunction would be heightened in rats fed a HFD compared to chow-fed controls. Young male Sprague-Dawley rats (140-160g) were maintained on a chow diet (5% fat, 57.33% carbohydrate, 3.4kcal/g) or HFD (60% fat, 20% carbohydrate, 5.24 kcal/g) for 6 weeks. HFD rats developed hepatic steatosis with significantly elevated liver triglyceride concentrations compared to chow-fed controls (20.73±2.09 vs.9.75±0.52 mg triglycerides/g tissue, respectively; p=0.001). While lipid accumulation appeared to be evident in the pectoralis muscle from HFD rats, triglyceride concentrations were not significantly different from controls. Likewise, there was no evidence of lipid infiltration in cardiac muscles of HFD rats. Lipid accumulation in the liver of overweight HFD rats may contribute to the observed insulin resistance in these animals. Contrary to the second hypothesis, there were no significant differences in plasma HSP60 expression between HFD and chow rats (p>0.05). Likewise, hemagglutination and hemolysis responses were similar between HFD and chow-fed rats (p>0.05). These findings suggest that immune system responses may not be affected by 6 weeks of high fat intake and that HSP60 is not an early marker of vascular dysfunction in this rodent model.
ContributorsLiss, Tyler Jessee (Author) / Sweazea, Karen (Thesis director) / Shaibi, Gabriel (Committee member) / Johnston, Carol (Committee member) / Barrett, The Honors College (Contributor) / School of Nutrition and Health Promotion (Contributor) / School of Historical, Philosophical and Religious Studies (Contributor)
Created2013-05
Description
It is presently believed that brown adipose tissue (BAT) is an important tissue in the control of obesity because it has the propensity to increase energy expenditure. The purpose of this study was to attempt to quantify the thermogenesis of BAT when four rats were exposed to a progression of low-fat to high-fat diet. Exogenous norepinephrine (NE) injections (dose of 0.25 mg/kg i.p.) were administered in order to elicit a temperature response, where increases in temperature indicate increased activity. Temperatures were measured via temperature sensing transponders that had been inserted at the following three sites: interscapular BAT (iBAT), the abdomen (core), and lower back (reference). Data showed increased BAT activity during acute (2-3 weeks) high fat diet (HFD) in comparison to low fat diet (LFD), but a moderate to marked decrease in BAT activity during chronic HFD (6-8 weeks) when compared to acute HFD. This suggests that while a HFD may initially stimulate BAT in the short-term, a long-term HFD diet may have negative effects on BAT activation.
ContributorsSivak, Hanna (Author) / Sweazea, Karen (Thesis director) / Herman, Richard (Committee member) / Caplan, Michael (Committee member) / School of Life Sciences (Contributor) / College of Integrative Sciences and Arts (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12