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Description
Spaceflight and spaceflight analogue culture enhance the virulence and pathogenesis-related stress resistance of the foodborne pathogen Salmonella enterica serovar Typhimurium (S. Typhimurium). This is an alarming finding as it suggests that astronauts may have an increased risk of infection during spaceflight. This risk is further exacerbated as multiple studies indicate that spaceflight negatively impacts aspects of the immune system. In order to ensure astronaut safety during long term missions, it is important to study the phenotypic effects of the microgravity environment on a range of medically important microbial pathogens that might be encountered by the crew. This ground-based study uses the NASA-engineered Rotating Wall Vessel (RWV) bioreactor as a spaceflight analogue culture system to grow bacteria under low fluid shear forces relative to those encountered in microgravity, and interestingly, in the intestinal tract during infection. The culture environment in the RWV is commonly referred to as low shear modeled microgravity (LSMMG). In this study, we characterized the stationary phase stress response of the enteric pathogen, Salmonella enterica serovar Enteritidis (S. Enteritidis), to LSMMG culture. We showed that LSMMG enhanced the resistance of stationary phase cultures of S. Enteritidis to acid and thermal stressors, which differed from the LSSMG stationary phase response of the closely related pathovar, S. Typhimurium. Interestingly, LSMMG increased the ability of both S. Enteritidis and S. Typhimurium to adhere to, invade into, and survive within an in vitro 3-D intestinal co-culture model containing immune cells. Our results indicate that LSMMG regulates pathogenesis-related characteristics of S. Enteritidis in ways that may present an increased health risk to astronauts during spaceflight missions.
ContributorsKoroli, Sara (Author) / Nickerson, Cheryl (Thesis director) / Barrila, Jennifer (Committee member) / Ott, C. Mark (Committee member) / School of Life Sciences (Contributor) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
The International Space Station (ISS) utilizes recycled water for consumption, cleaning and air humidity control. The Environmental Control and Life Support Systems (ECLSS) have been rigorously tested at the NASA Johnson Space Center. Despite the advanced engineering of the water recovery system, bacterial biofilms have been recovered from this potable water source. Microbial contamination of potable water poses a potential threat to crew members onboard the ISS. Because astronauts have been found to have compromised immune systems, bacterial strains that would not typically be considered a danger must be carefully studied to better understand the mechanisms enabling their survival, including polymicrobial interactions. The need for a more thorough understanding of the effect of spaceflight environment on polymicrobial interactions and potential impact on crew health and vehicle integrity is heightened since 1) several potential pathogens have been isolated from the ISS potable water system, 2) spaceflight has been shown to induce unexpected alterations in microbial responses, and 3) emergent phenotypes are often observed when multiple bacterial species are co- cultured together, as compared to pure cultures of single species. In order to address these concerns, suitable growth media are required that will not only support the isolation of these microbes but also the ability to distinguish between them when grown as mixed cultures. In this study, selective and/or differential media were developed for bacterial isolates collected from the ISS potable water supply. In addition to facilitating discrimination between bacteria, the ideal media for each strain was intended to have a 100% recovery rate compared to traditional R2A media. Antibiotic and reagent susceptibility and resistance tests were conducted for the purpose of developing each individual medium. To study a wide range of targets, 12 antibiotics were selected from seven major classes, including penicillin, cephalosporins, fluoroquinolones, aminoglycosides, glycopeptides/lipoglycopeptides, macrolides/lincosamides/streptogramins, tetracyclines, in addition to seven unclassified antibiotics and three reagents. Once developed, medium efficacy was determined by means of growth curve experiments. The development of these media is a critical step for further research into the mechanisms utilized by these strains to survive the harsh conditions of the ISS water system. Furthermore, with an understanding of the complex nature of these polymicrobial communities, specific contamination targeting and control can be conducted to reduce the risk to crew members. Understanding these microbial species and their susceptibilities has potential application for future NASA human explorations, including those to Mars.
ContributorsKing, Olivia Grace (Author) / Nickerson, Cheryl (Thesis director) / Barrila, Jennifer (Committee member) / Ott, Mark (Committee member) / School of Sustainability (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-12
Description
Graphene has the ability to advance many common fields, including: membranes, composites and coatings, energy, and electronics. For membranes, graphene will be used as a filter for desalination plants which will reduce the cost of desalination and greatly increase water security in developing countries. For composites and coatings, graphene's strength, flexibility, and lightweight will be instrumental in producing the next generation of athletic wear and sports equipment. Graphene's use in energy comes from its theorized ability to charge a phone battery in seconds or an electric car in minutes. Finally, for electronics, graphene will be used to create faster transistors, flexible electronics, and fully integrated wearable technology.
ContributorsSiegel, Adam (Author) / Adams, James (Thesis director) / Krause, Stephen (Committee member) / Materials Science and Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
This is a two-part thesis, completed in conjunction with my Materials Science and Engineering Capstone Project. The first part involves the design and testing of cold-extruded high-density polyethylene for student oboe reeds. The goal of this section was to create a longer-lasting reed that produces a similar sound to a cane reed, has less variation in quality, and costs less per year than cane reeds. For low-income students in particular, the cost of purchasing cane oboe reeds ($500-$2,000 per year) is simply not feasible. This project was designed to allow oboe to be a more affordable option for all students. Money should not be a factor that limits whether or a not a child is able to explore their interests. The process used to create the synthetic reed prototype involves cold-extrusion of high-density polyethylene in order to induce orientation in the polymer to replicate the uniaxial orientation of fibrous cane. After successful cold-extrusion of a high-density polyethylene (HDPE) cylinder, the sample was made into a reed by following standard reedmaking procedures. Then, the HDPE reed and a cane reed were quantitatively tested for various qualities, including flexural modulus, hardness, and free vibration frequency. The results from the design project are promising and show a successful proof of concept. The first prototype of an oriented HDPE reed demonstrates characteristics of a cane reed. The areas that need the most improvement are the flexural modulus and the stability of the higher overtones, but these areas can be improved with further development of the cold-extrusion process. The second part of this thesis is a survey and analysis focusing on the qualitative comparison of synthetic and cane oboe reeds. The study can be used in the future to refine the design of synthetic reeds, more specifically the cold-extruded high-density polyethylene student oboe reed I designed, to best replicate a cane reed. Rather than approaching this study from a purely engineering mindset, I brought in my own experience as an oboist. Therefore, the opinions of oboists who have a wide range of experience are considered in the survey. A panel of five oboists participated in the survey. They provided their opinion on various aspects of the five reeds, including vibrancy, response, stability, resistance, tone, and overall quality. Each of these metrics are rated on a scale from one to five, from unacceptable to performance quality. According to the survey, a participant's personal, hand-made cane reed is overall the most preferred option. My prototype HDPE student reed must be improved in many areas in order to rank near the other four reeds. However, its vibrancy and resistance already rival that of a Jones student reed. As this is just the first prototype, that is a significant accomplishment. With further refinement of the cold-extrusion and reedmaking method, the other areas of the HDPE reed may be improved, and the reed may eventually compete with the existing synthetic and cane reeds on the market.
ContributorsMitchell, Alexis Jacqueline (Author) / Adams, James (Thesis director) / Schuring, Martin (Committee member) / School of Music (Contributor) / Materials Science and Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
The gastrointestinal (GI) tract is home to a complex and diverse microbial ecosystem that contributes to health or disease in many aspects. While bacterial species are the majority in the GI tract, their cohabitants, fungal species, should not be forgotten. Children with autism spectrum disorder (ASD) often suffer from GI disorders and associated symptoms, implying a role the bacterial and fungal gut microbiota play in maintaining human health. The irregularities in GI symptoms can negatively affect the overall quality of life or even worsen behavioral symptoms the children present. Even with the increase in the availability of next-generation sequencing technologies, the composition and diversities of fungal microbiotas are understudied, especially in the context of ASD. We therefore aimed to investigate the gut mycobiota of 36 neurotypical children and 38 children with ASD. We obtained stool samples from all participants, as well as autism severity and GI symptom scores to help us understand the effect the mycobiome has on these symptoms. By targeting the fungal internal transcribed spacer (ITS) and bacterial 16S rRNA V4 regions, we obtained fungal and bacterial amplicon sequences, from which we investigated the diversities, composition, and potential link between two different ecological clades. From fungal amplicon sequencing results, we observed a significant decrease in the observed fungal OTUs in children with ASD, implying a lack of potentially beneficial fungi in ASD subjects. We performed Bray-Curtis principal coordinates analysis and observed significant differences in fungal microbiota composition between the two groups. Taxonomic analysis showed higher relative abundances of Candida , Pichia, Penicillium , and Exophiala in ASD subjects, yet due to a large dispersion of data, the differences were not statistically significant. Interestingly, we observed a bimodal distribution of Candida abundances within children with ASD. Candida's relative abundance was not significantly correlated with GI scores, but children with high Candida relative abundances presented significantly higher Autism Treatment Evaluation Checklist (ATEC) scores, suggesting a role of Candida on ASD behavioral symptoms. Regarding the bacterial gut microbiota, we found marginally lower observed OTUs and significantly lower relative abundance of Prevotella in the ASD group, which was consistent with previous studies. Taken together, we demonstrated that autism is closely linked with a distinct gut mycobiota, characterized by a loss of fungal and bacterial diversity and an altered fungal and bacterial composition.
ContributorsPatel, Jigar (Author) / Krajmalnik-Brown, Rosa (Thesis director) / Kang, Dae Wook (Committee member) / Adams, James (Committee member) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
As the prevalence and awareness of Autism Spectrum Disorder (ASD) increases, so does the variety of treatment options for primary symptoms (social interaction, communication, behavior) and secondary symptoms (anxiety, hyperactivity, GI problems, and insomnia). Various treatments, from Adderall to Citalopram to Flax Seed Oil promise relief for these symptoms. However, very little research has actually been done on some of these treatments. Additionally, the research that has been done fails to compare these treatments against one another in terms of symptom relief. The Autism Treatment Effectiveness Survey, written by Dr. James Adams, director of the Autism/Asperger's Research Program at ASU, and graduate student/program coordinator Devon Coleman, aims to fill this gap. The survey numerically rates medications based on benefit and adverse effects, in addition to naming specific symptoms that are impacted by the treatments. However, the survey itself was retrospective in nature and requires further evidence to support its claims. Therefore, the purpose of this research paper is to evaluate evidence related to the results of the survey. After the performing an extensive literature review of over 70 different treatments, it appears that the findings of the Autism Treatment Effectiveness Survey are generally well supported. There were a few minor discrepancies regarding the primary benefitted symptom, but there was not enough of a conflict to discount the information from the survey. As research is still ongoing, conclusions cannot yet be drawn for Nutritional Supplements, although the current data looks promising.
ContributorsAnderson, Amy Lynn (Author) / Adams, James (Thesis director) / Coleman, Devon (Committee member) / School of Nutrition and Health Promotion (Contributor) / W.P. Carey School of Business (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Vitamins and minerals are, by definition, essential substances that are necessary for good health, and needed by every cell and organ to function appropriately. A deficiency of any one vitamin or mineral can be very serious. Although a very healthy diet rich in vegetables, fruits, and protein can provide sufficient amounts of most vitamins and minerals, many people do not consume an adequate diet. During pregnancy, there is an increased need for vitamins and minerals to promote a healthy pregnancy and a healthy baby. Prenatal supplements are intended to supplement a normal diet to ensure that adequate amounts of vitamins and minerals are consumed. The US Food and Drug Administration (FDA) has established Recommended Dietary Allowances for total vitamin/mineral intake from food and supplements, but they have not established recommendations for prenatal supplements. Therefore, there is a very wide variation in the content and quality of prenatal supplements. Many prenatal supplements contain only minimal levels of some vitamins and few or no minerals, in order to minimize cost and the number of pills. This results in insufficient vitamin/mineral supplementation for many women, and hence does not fully protect them or their children from pregnancy complications and health problems. Therefore, we have created our own set of recommendations for prenatal supplements. Our recommendations are based primarily on four sources: 1) FDA's Recommended Daily Allowances for pregnant women, which are estimated to meet the needs of 97.5% of healthy pregnant women. 2) FDA's Tolerable Upper Limit, which is the maximum amount of vitamins/minerals that can be safely consumed without any risk of health problems. 3) National Health and Nutrition Examination Survey (NHANES), which evaluates the average intake of vitamins and minerals by women ages 20-40 years in the US 4) Research studies on vitamin/mineral deficiencies or vitamin/mineral supplementation during pregnancy, and the effect on pregnancy, birth, and child health problems. In summary, the RDA establishes minimum recommended levels of vitamin/mineral intake from all sources, and the NHANES establishes the average intake from foods. The difference is what needs to be consumed in a supplement, on average. However, since people vary greatly in the quality of their diet, and since most vitamins and minerals have a high Tolerable Upper Limit, we generally recommend more than the difference between the RDA and the average NHANES. Vitamins generally have a larger Tolerable Upper Limit than do minerals. So, we recommend that prenatal vitamin/mineral supplements contain 100% of the RDA for most vitamins, and about 50% of the RDA for most minerals. However, based on additional research studies described below, in some cases we vary our recommendations from those averages.
ContributorsSorenson, Jacob (Author) / Adams, James (Thesis director) / Pollard, Elena (Committee member) / College of Integrative Sciences and Arts (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
In injection molded plastic parts, knit lines occur where opposing streams of material fuse together while the mold cavity fills. When parts with knit lines experience external loading, the knit lines cause areas of mechanical weakness. This weakness is especially drastic in fiber-reinforced polymers due to an unfavorable orientation of fibers at the knit line. A possible way to reduce the impact of knit lines is to incorporate overflow tabs into the mold design. An overflow tab is a chamber attached to the mold cavity that provides an extra space for the end of material flow to occur. Research shows that overflow tabs improve the fiber orientation at the knit line, resulting in increased mechanical strength. The goal of this study is to utilize overflow tabs to optimize the knit line strength of nylon 6-6 that is 30% carbon fiber reinforced. In this project, an initial overflow tab is first designed. Then four modifications are made to the tab design, each altering a separate variable while holding the others constant. The design changes explored for the tab in this project include adding radii to the inlet, shifting the inlet location, increasing the inlet cross-sectional area by 50%, and increasing the tab chamber volume by 50%. Specimens were molded using the initial tab design and the modified tab designs. Testing for this experiment consists of three specimens of each type for three-point bending tests, and five specimens of each type for tensile tests. The material properties analyzed are the flexural modulus, flexural strength, tensile modulus, and tensile strength. From the testing, the tab with the 50% increased volume consistently yielded the highest results and showed large improvement from the initial tab design. However, the other three tab modifications either showed negative change or slight improvement from the initial tab design. Based on the results of this study, the overflow tab volume is the most beneficial design parameter to adjust.
ContributorsJones, Justin Michael (Author) / Adams, James (Thesis director) / Wamsley, Steven (Committee member) / Computer Science and Engineering Program (Contributor) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
The purpose of this honors project is to analyze the difference between different powder separation techniques, and their suitability for my capstone project – ‘Effect of Powder Reuse on DMLS (Direct Metal Laser Sintering) Product Integrity’. Due to the nature of my capstone project, my group needs to characterize foreign contaminants in IN 718 (Ni-based superalloy) powder with a mean diameter around 40um. In order to clearly analyze the contaminants and recycle useful IN 718 powders, powder separation is favorable since the filtered samples will be much easier to characterize rather than inspect all the powders at once under microscope. By conducting literature review, I found that powder separation is commonly used in Geology, and Chemistry department. To screen which combination of techniques could be the best for my project, I have consulted several research specialists, obtained adequate knowledge about powder separation. Accordingly, I will summarize the pros and cons of each method with regard the specific project that I am working on, and further explore the impacts of each method under economical, societal, and environmental considerations. Several powder separation techniques will be discussed in details in the following sections, including water elutriation, settling column, magnetic separation and centrifugation. In addition to these methods, sieving, water tabling and panning will be briefly introduced. After detailed comparison, I found that water elutriation is the most efficient way to purity IN718 powder for reuse purpose, and recovery rate is as high as 70%, which could result in a significant reduction in the manufacturing cost for Honeywell since currently Honeywell only use virgin powders to build parts, and 90% of the leftover powders are discarded.
ContributorsLuo, Zheyu (Author) / Adams, James (Thesis director) / Tasooji, Amaneh (Committee member) / Materials Science and Engineering Program (Contributor) / School of Sustainability (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Honeywell is currently extending the reach of additive manufacturing (AM) in its product line and expects to produce as much as 40% of its inventory through AM in five years. Additive manufacturing itself is expected to grow into a $3.1 billion dollar industry in the next 5 to 10 years. Reusing IN 718 powder, a nickel-based super alloy metal powder, is an ideal option to reduce costs as well as reduce waste because it can be used with additive manufacturing, but the main obstacles are lack of procedure standardization and product quality assurances from this process. The goal of the capstone project, "Effect of Powder Reuse on DMLS (Direct Metal Laser Sintering) Product Integrity," is to create a powder characterization protocol in order to determine if the IN 718 powder can be reused and what effect the IN 718 reused powder has on the mechanical properties of the products Honeywell fabricates. To provide context and impact of this capstone project, this paper serves to identify the benefits of AM for Honeywell and the cost effectiveness of reusing the powder versus using virgin powder every time. It was found that Honeywell's investment in AM is due to the cost effectiveness of AM, versatility in product design, and to ensure Honeywell remains competitive in the future. In terms of reducing expenses, reusing powder enables costs to be approximately 45% less than using virgin powder. With these key pieces of information, the motivations for this capstone project are understood to a fuller and more profound degree.
ContributorsQuigley, Elizabeth (Co-author) / Luo, Zheyu (Co-author) / Murella, Anoosha (Co-author) / Lee, Wey Lyn (Co-author) / Adams, James (Thesis director) / Tasooji, Amaneh (Committee member) / Materials Science and Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05