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Description
Dielectrophoresis has been shown in the recent past to successfully separate bioparticles of very subtle differences at high resolutions using biophysical forces. In this study, we test the biophysical differences of methicillin resistant and susceptible Staph. aureus that are known to have very similar genomes by using a modified gradient insulator-based dielectrophoresis device (g-iDEP). MRSA is commonly seen in hospitals and is the leading killer of infectious bacteria, claiming the lives of around 10,000 people annually. G-iDEP improves many capabilities within the DEP field including sample size, cost, ease of use and analysis time. This is a promising foundation to creating a more clinically optimized diagnostic tool for both separation and detection of bacteria in the healthcare field. The capture on-set potential for fluorescently tagged MRSA (801 ± 34V) is higher than fluorescently tagged MSSA (610 ± 32V), resulting in a higher electrokinetic to dielectrophoretic mobility ratio for MRSA. Since the strains have proven to be genomically similar through sequencing, it is reasonable to attribute this significant biophysical difference to the added PBP2a enzyme in MRSA. These results are consistent with other bacterial studied within in this device and have proven to be reproducible.
ContributorsSmithers, Jared (Author) / Hayes, Mark (Thesis director) / Woodbury, Neal (Committee member) / School of Criminology and Criminal Justice (Contributor) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
Chemoreception is an important method for an octopus to sense and react to its surroundings. However, the density of chemoreceptors within different areas of the skin of the octopus arm is poorly documented. In order to assess the relative sensitivity of various regions and the degree to which chemoreception is locally controlled, octopus arms were amputated and exposed to acetic acid, a noxious chemical stimulus that has previously been shown to elicit movement responses in amputated arms (Hague et al., 2013). To test this, 11 wild-caught Octopus bimaculoides (6 females, 5 males) were obtained. Acetic acid vapor was introduced in the distal oral, distal aboral, proximal oral, and proximal aboral regions of amputated arms. The frequency of the occurrence of movement was first analyzed. For those trials in which movement occurred, the latency (delay between the stimulus and the onset of movement) and the duration of movement were analyzed. The distal aboral and distal oral regions were both more likely to move than either the proximal oral or proximal aboral regions (p < 0.0001), and when they did move, were more likely to move for longer periods of time (p < 0.05). In addition, the proximal oral region was more likely to exhibit a delay in the onset of movement compared to the distal oral or distal aboral regions (p < 0.0001). These findings provide evidence that the distal arm is most sensitive to noxious chemical stimuli. However, there were no significant differences between the distal oral and distal aboral regions, or between the proximal oral and proximal aboral regions. This suggests that there may not be a significant difference in the density of chemoreceptors in the aboral versus oral regions of the arm, contrary to claims in the literature. The other independent variables analyzed, including sex, body mass, arm length, anterior versus posterior arm identity, and left versus right arm identity, did not have a significant effect on any of the three dependent variables analyzed. Further analysis of the relative density of chemoreceptors in different regions of the octopus arm is merited.
ContributorsCasleton, Rachel Marie (Author) / Fisher, Rebecca (Thesis director) / Marvi, Hamidreza (Committee member) / Gire, David (Committee member) / School of International Letters and Cultures (Contributor) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
Typical eukaryotic organelles use membranes formed by lipid bilayers in order to compartmentalize their functions within the cell. However, cells also contain membraneless organelles formed by intrinsically disordered proteins (IDPs) via liquid-liquid phase separation. The organelles form localized compartments that separate their contents from the environment.1 Here, this mechanism is used to generate artificial membraneless organelles that comprise a chemical reaction. An IDP, DEAD-box helicase (Ddx4), was bioconjugated to an enzyme, horseradish peroxidase (HRP), through the use of a bifunctional chemical linker, succinimidyl 4-(N-maleimidomethyl)cyclohexane-1-carboxylate (SMCC), in order to examine if the enzyme could be incorporated in droplets and whether its activity would be affected. The conjugation of HRP-SMCC (43.4 kDa) to Ddx4 (25.6 kDa) was successful: SDS-PAGE analysis confirmed the presence of a product that was within the range of a full conjugate.
ContributorsFavila, Saul Roberto (Author) / Ghirlanda, Giovanna (Thesis director) / Vaiana, Sara (Committee member) / Allen, James (Committee member) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
Hypoxia-responses help coordinate the growth of oxygen-transporting tissues with the growth of other tissues during development. In Drosophila, hypoxia strongly affects development with flies being reared in a low oxygen environment showing smaller body sizes and diminished tracheal growth. The primary regulator of cellular hypoxic-responses is the hypoxia-inducible factor (HIF), and under normoxic conditions, HIF-alpha is hydroxylated by prolyl hydroxylase domain (PHD) on a proline residue inside the alpha leading to the proteins proteasome degradation downstream. However, in response to reduced oxygen, cells accumulate HIF- alpha, which then joins with the constituent HIF-beta in the cytosol, forming a HIF- alpha/beta heterodimer. Which, in turn, enters the nucleus and binds to hypoxic response elements, activating the hypoxic response genes. Hyperoxia has recently been shown to stimulates metabolic rates only at the last stage Drosophila's larval development (L3), indicating oxygen limitation occurs towards the end of development. Green fluorescent protein (GFP) was added to the oxygen-dependent domain of Drosophila HIF- Alpha (Sima) and a monomeric red fluorescent protein with a nuclear localization signal (mRFP-nls) was added to a protein under the same ubiquitin-69E promoter but is not affected by changing O2 levels. Using a Leica SP5 AOBS Spectral Confocal, third instar larvae were analyzed at the cellular level with attention focused on HIF- signaling in the central nervous system (CNS). L3 Drosophila were divided into groups of 0-12h, 12-24h, 24-48h, and 48-60h corresponding to their development. In each group, flies were either treated for 10-12 hours in 5% O2 or were left normoxic before fixation. What was overwhelmingly found is that HIF-signaling was most prominent during their early development (0-12h), with a significant decline as age increased (P=<0.001). There was also an observed hypoxic effect as animals treated in lower oxygen concentrations had significantly higher HIF signaling (P=<0.001). However, this effect still declines as larvae continued developing. This data supports the idea that internal hypoxia does not become severe during late third instar growth but may occur during the actual molt of the flies.
ContributorsWerkhoven, Simon (Author) / Harrison, Jon (Thesis director) / VandenBrooks, John (Committee member) / School of Molecular Sciences (Contributor) / School of International Letters and Cultures (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
As a college student, living in an apartment or home with a kitchen, making your own food decisions can be daunting. After spending so much time either living at home and having food cooked for you or living in a dorm where food is provided, it is difficult to suddenly have to put so much thought into something that for so long you didn’t have to think about at all. Not only that, it sometimes feels like the media is screaming from all sides that you need to eat a certain way to be ‘healthy’ or ‘fit’. I hope to be able to make this process a bit easier for you through this guide I have put together from my own experience and education.
‘Healthy’ foods always seem like the best choice, but what does it really mean to be healthy? A ‘healthy diet’ can mean any number of things depending on who you ask and where you look. Media provides an endless sea of tips, tricks, and diets for ‘eating healthy’. Oxford defines health as a state of physical, mental, and social well-being with the absence of disease and infirmity; and healthy as indicative of, conducive to, or promoting good health1. It is easy to get caught up in the excitement of fad diets, but maintaining a healthy eating pattern can be quite simple when put into practice.
‘Healthy’ foods always seem like the best choice, but what does it really mean to be healthy? A ‘healthy diet’ can mean any number of things depending on who you ask and where you look. Media provides an endless sea of tips, tricks, and diets for ‘eating healthy’. Oxford defines health as a state of physical, mental, and social well-being with the absence of disease and infirmity; and healthy as indicative of, conducive to, or promoting good health1. It is easy to get caught up in the excitement of fad diets, but maintaining a healthy eating pattern can be quite simple when put into practice.
ContributorsCarlson, BreeAnna Marion (Author) / Kniskern, Megan (Thesis director) / Vega-Lopez, Sonia (Committee member) / College of Health Solutions (Contributor) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
Over the last century, the Latino population in the United States has increased dramatically. Like most ethnic groups, Latinos highly value their culture and bring aspects of it with them when they come to the United States. One such aspect of Latino culture is the use of traditional medicine. As the Latino population in the United States continues to grow, it is important that physicians and future physicians understand how the use of and belief in traditional medicine within different Latino populations can affect the healthcare experience for both provider and patient. Many physicians lack this knowledge and therefore are unsure how to proceed when confronted with these situations; in order to remedy this issue, this project seeks to propose and demonstrate a potential course that would be intended to inform pre-medical and pre-health students about traditional medicine in different Latin American countries so that they will be better prepared.
In this 3-credit course, students will gain awareness and understand the importance of Latino traditional medical practices from the perspective of future medical professionals. Students will learn about concepts such as folk illnesses and traditional religious practices within different Latino populations and will discover how these cultural beliefs can affect a patient’s attitude and cooperation in the medical office.
Through study of the traditional medicines of Puerto Rico, Mexico, and Cuba, students will be exposed to new concepts that will allow them to gain a broader understanding of their future patients, which will allow them to provide the best possible care as a physician. Students will reflect on the importance of having respect for a patient’s cultural beliefs in the medical profession, regardless of their knowledge of Spanish, so that they will be best equipped to handle these situations within the United States and abroad.
In this 3-credit course, students will gain awareness and understand the importance of Latino traditional medical practices from the perspective of future medical professionals. Students will learn about concepts such as folk illnesses and traditional religious practices within different Latino populations and will discover how these cultural beliefs can affect a patient’s attitude and cooperation in the medical office.
Through study of the traditional medicines of Puerto Rico, Mexico, and Cuba, students will be exposed to new concepts that will allow them to gain a broader understanding of their future patients, which will allow them to provide the best possible care as a physician. Students will reflect on the importance of having respect for a patient’s cultural beliefs in the medical profession, regardless of their knowledge of Spanish, so that they will be best equipped to handle these situations within the United States and abroad.
ContributorsIncha, Carmen (Author) / Estévez, Dulce (Thesis director) / Oberstein, Bruce (Committee member) / School of Molecular Sciences (Contributor) / School of International Letters and Cultures (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
Viral proteases have been implicated in harmful viral diseases, and as such are becoming increasingly relevant drug targets. Essential for drug design is a detailed knowledge of the structure of the drug target, particularly its active site and binding regions. Research in this area, however, is lacking and many protease structures remain unknown. This project aims to advance towards solving the structure of a viral cysteine protease through means of crystallization and X-ray crystallography. The wild-type protease was crystallized using sitting drop vapor diffusion. Due to the dynamic nature of proteins, crystallization is no easy feat. Initial high throughput screens using commercial kits streamlined the identification of conditions with potential to form crystals. This was followed by several rounds of optimization of crystallization parameters including pH, buffer concentration, salt concentration, additive type, and crystallization volume in an effort to find a condition suited for crystal growth. This process eventually resulted in large, well-ordered crystals suitable for further experimentation. X-ray crystallography performed on these crystals demonstrated significant diffraction patterns up to a resolution of 3.7 Angstroms, indicative of moderate success in crystallization. Initial data processing was able to identify space groups, but analysis beyond that requires a higher resolution diffraction pattern. Future research will focus on continuing to optimize crystallization conditions to obtain a higher quality crystal and thus higher resolution diffraction patterns. From that point, diffraction data can be processed to build a structural profile of the wild-type viral protease. This information will serve invaluable for future research on the structures of similar proteins and for structure-based drug design targeted towards this viral protease.
ContributorsNichols, Alexis Christine (Author) / Liu, Dr. Wei (Thesis director) / Khdour, Dr. Omar (Committee member) / Mills, Dr. Jeremy (Committee member) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
The Scientist in Me is an original children’s book, authored by Annmarie Barton and illustrated by Alison Lane, that explores the lives and specialties of five remarkable scientists from historically underrepresented backgrounds: Mary Anning, James Pollack, Temple Grandin, Percy Lavon Julian, and Ayah Bdeir. In the book, each scientist has an “Experiment” section that is meant to encourage children to immerse themselves in activities relating to the scientists’ areas of study. We believe that diversity in science is crucial for advancement, and therefore hope to inspire the next generation of scientists through immersion and representation.
ContributorsLane, Alison (Co-author) / Barton, Annmarie (Co-author) / Klemaszewski, James (Thesis director) / Fette, Donald (Committee member) / School of Molecular Sciences (Contributor) / School of Art (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
Photocurable nanocomposites have great potential within advanced manufacturing, multifunctional materials, and most specifically tissue engineering. The properties and characteristics of these nanocomposites can be tailored to mimic those of various tissues and/or cartilage, allowing the bio-inspired synthetic materials to replace them. This project investigates the effect of methacrylate-functionalized (MA-SiO2) and vinyl-functionalized (V-SiO2) silica nanoparticle loading content on the thermal, mechanical, physical, and morphological characteristics of PEG nanocomposites. It was discovered that both V-SiO2 and MA-SiO2 did not considerably impact the glass-transition temperature or hydrophilicity of the material. The gel fraction of composites containing V-SiO2 decreases with the initial addition of 3.8 wt%, but then displays an increase with further addition (>7.4 wt%) until it reaches a plateau at 10.7 wt%. Whereas, the MA-SiO2 induced no significant changes in gel fraction with increased loading. An increase in mechanical properties was also observed with increasing concentration for both sets of series. However, due to the higher crosslink density, MA-SiO2 reached its ultimate mechanical stress threshold at a lower concentration of 7.4 wt%, while V-SiO2 maxed out at 10.7 wt%. Scanning electron microscopy coupled with transmission electron microscopy revealed that V-SiO2 displayed a bimodal size distribution, while MA-SiO2 displayed only one.
ContributorsHocken, Alexis (Co-author, Co-author) / Green, Matthew D. (Thesis director) / Holloway, Julianne L. (Committee member) / Olsen, Bradley D. (Committee member) / School of Molecular Sciences (Contributor) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
With cancer rates increasing and affecting more people every year, I felt it was important to educate the younger generation about the potential factors that could put them at risk of receiving a cancer diagnosis later in life. I thought that this was important to do because most students, especially in rural communities, are not taught the factors that increase your risk of getting cancer in the future. This leads to students not having the tools to think about the repercussions that their actions can have in their distant future in regard to their risk of getting cancer. I went to six schools throughout the valley and the White Mountains of Arizona with differing education levels and demographics to provide them with prevention strategies that they could implement into their daily lives to reduce their risk of getting cancer in the future. Some of the schools had curriculums that included cancer and some of the factors that increase your risk, while others never mention what is happening biologically when a person has cancer. I introduced factors such as no smoking or tobacco use, diet, exercise, sunscreen use, avoiding alcohol, and getting screened regularly. While at each school, I discussed the importance of creating these healthy habits while they are young because cancer is a disease that comes from the accumulation of mutations that can begin occurring in their bodies even now. After my presentation, 98.6% of the 305 students who viewed my presentation felt like they had learned something from the presentation and were almost all willing to implement at least one of the changes into their daily lives.
ContributorsGoforth, Michelle Nicole (Author) / Compton, Carolyn (Thesis director) / Lake, Douglas (Committee member) / Popova, Laura (Committee member) / Dean, W.P. Carey School of Business (Contributor) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05