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Supernovae are vital to supplying necessary elements to forming bodies in our solar systems. This project studies the creation of a subset of these necessary elements, called short-lived radionuclides (SLRs). SLRs are isotopes with relatively short half-lives and can serve as heat sources for forming planetary bodies, and their traces

Supernovae are vital to supplying necessary elements to forming bodies in our solar systems. This project studies the creation of a subset of these necessary elements, called short-lived radionuclides (SLRs). SLRs are isotopes with relatively short half-lives and can serve as heat sources for forming planetary bodies, and their traces can be used to date stellar events. Computational models of asymmetric supernovae provide opportunities to study the effect of explosion geometry on the SLR yields. We are most interested in the production of \iso{Al}{26}, \iso{Fe}{60}, and \iso{Ca}{41}, whose decayed products are found in our own solar system. To study the effect of explosion asymmetries in supernovae, we use TYCHO stellar evolution code, SNSHP smooth particle hydrodynamics code for 3D explosion simulations, Burn code for nucleosythesis post-processing, and Python code written to analyze the output of the post-processing code.
ContributorsJohnson, Charlotte (Author) / Young, Patrick (Thesis director) / Lunardini, Cecilia (Committee member) / Department of Physics (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
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Description
News outlets frequently portray people with disabilities as either helpless victims or objects of motivation. Portrayal of people with disabilities has improved over the years, but there is still room to grow. News outlets tend to make disability the center of the story. A story about a disabled person is

News outlets frequently portray people with disabilities as either helpless victims or objects of motivation. Portrayal of people with disabilities has improved over the years, but there is still room to grow. News outlets tend to make disability the center of the story. A story about a disabled person is primarily about their disability, with their other accomplishments framed by it.

As one example of the victimhood narrative, ABC News used to run a special called My Extreme Affliction as part of 20/20 until 2012. As the name implies, the specials covered people with disabilities, specifically extreme versions. One 2008 episode on Tourette’s syndrome described Tourette’s like it was some sort of demonic possession. The narrator talked about children who were “prisoners in their own bodies” and a family that was at risk of being “torn apart by Tourette’s.” I have Tourette’s syndrome myself, which made ABC’s special especially uncomfortable to watch. When not wringing their metaphorical hands over the “victims” of disability, many news outlets fall into the “supercrip” narrative. They refer to people as “heroes” who “overcome” their disabilities to achieve something that ranges from impressive to utterly mundane. The main emphasis is on the disability rather than the person who has it. These articles then exploit that disability to make readers feel good. As a person with a disability, I am aware that it impacts my life, but it is not the center of my life. The tics from my Tourette’s syndrome made it difficult to speak to people when I was younger, but even then they did not rule me.

Disability coverage, however, is still incredibly important for promoting acceptance and giving people with disabilities a voice. A little over a fifth of adults in the United States have a disability (CDC: 53 million adults in the US live with a disability), so poor coverage means marginalizing or even excluding a large amount of people. Journalists should try to reach their entire audience. The news helps shape public opinion with the stories it features. Therefore, it should provide visibility for people with disabilities in order to increase acceptance. This is a matter of civil rights. People with disabilities deserve fair and accurate representation.

My personal experience with ABC’s Tourette’s special leads me to believe that the media, especially the news, needs to be more responsible in their reporting. Even the name “My Extreme Affliction” paints a poor picture of what to expect. A show that focuses on sensationalist portrayals in pursuit of views further ostracizes people with disabilities. The emphasis should be on a person and not their condition. The National Center for Disability Journalism tells reporters to “Focus on the person you are interviewing, not the disability” (Tips for interviewing people with disabilities). This people-first approach is the way to improve disability coverage: Treat people with disabilities with the same respect as any other minority group.
ContributorsMackrell, Marguerite (Author) / Gilger, Kristin (Thesis director) / Doig, Steve (Committee member) / Walter Cronkite School of Journalism & Mass Comm (Contributor) / School of Politics and Global Studies (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
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Description
Proteins continually and naturally incur evolutionary selection through mutagenesis that optimizes their fitness, which is primarily determined by their function. It is known that allosteric regulation alters a protein's conformational dynamics leading to functional changes. We have computationally introduced a mutation at a predicted regulatory site of a short, 46

Proteins continually and naturally incur evolutionary selection through mutagenesis that optimizes their fitness, which is primarily determined by their function. It is known that allosteric regulation alters a protein's conformational dynamics leading to functional changes. We have computationally introduced a mutation at a predicted regulatory site of a short, 46 residue-long, protein interaction module composed of a WW domain and corresponding polyproline ligand (PDB id: 1k9r). The dynamic flexibility index (DFI) was computed for the binding site of the wild type and mutant WW domains to quantify the mutations effect on the rigidity of the binding pocket. DFI is used as a metric to quantify the resilience of a given position to perturbation along the chain. Using steered molecular dynamics (SMD), we also measure the effect of the point mutation on allosteric regulation by approximating the binding free energy of the system calculated using Jarzynski's Equality. Calculation of the DFI shows that the overall flexibility of the protein complex increases as a result of the distal point mutation. Total change in DFI percentile of the binding site showed a 0.067 increase suggesting an allosteric, loss of function mutation. Furthermore, we see that the change in the binding free energy is greater for that of the mutated complex supporting the idea that an increase in flexibility is correlated to a decrease in proteinlig and binding affinity. We show that sequence mutation of an allosteric site affects the mechanical stability and functionality of the binding pocket.
ContributorsMarianchuk, Tegan (Author) / Ozkan, Sefika (Thesis director) / Ros, Robert (Committee member) / Barrett, The Honors College (Contributor) / Department of Physics (Contributor)
Created2018-05
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Description

Optometry is an important field in medicine as it allows people a chance to have their vision corrected and it serves as a health screening opportunity for those who receive a dilated eye examination. One of the largest barriers to receiving a dilated eye exam is insurance coverage. Most health

Optometry is an important field in medicine as it allows people a chance to have their vision corrected and it serves as a health screening opportunity for those who receive a dilated eye examination. One of the largest barriers to receiving a dilated eye exam is insurance coverage. Most health insurance policies have limited optometric coverage. By expanding health insurance plans to be more inclusive of optometric care, people who use these health insurance plans will have a better access of care.

ContributorsFurey, Colleen (Author) / Ruth, Alissa (Thesis director) / Mullen, Tyler (Committee member) / School of Life Sciences (Contributor) / Department of Physics (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Description

Lyme disease is a common tick-borne illness caused by the Gram-negative bacterium Borrelia burgdorferi. An outer membrane protein of Borrelia burgdorferi, P66, has been suggested as a possible target for Lyme disease treatments. However, a lack of structural information available for P66 has hindered attempts to design medications to target

Lyme disease is a common tick-borne illness caused by the Gram-negative bacterium Borrelia burgdorferi. An outer membrane protein of Borrelia burgdorferi, P66, has been suggested as a possible target for Lyme disease treatments. However, a lack of structural information available for P66 has hindered attempts to design medications to target the protein. Therefore, this study attempted to find methods for expressing and purifying P66 in quantities that can be used for structural studies. It was found that by using the PelB signal sequence, His-tagged P66 could be directed to the outer membrane of Escherichia coli, as confirmed by an anti-His Western blot. Further attempts to optimize P66 expression in the outer membrane were made, pending verification via Western blotting. The ability to direct P66 to the outer membrane using the PelB signal sequence is a promising first step in determining the overall structure of P66, but further work is needed before P66 is ready for large-scale purification for structural studies.

ContributorsRamirez, Christopher Nicholas (Author) / Fromme, Petra (Thesis director) / Hansen, Debra (Committee member) / Department of Physics (Contributor) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Description

TSPO was discovered in 1977 and it’s function is still currently unknown. Significant research has suggested that TSPO functions in steroidogenesis to import cholesterol from the mitochondrial outer membrane (MOM) to the mitochondrial inner membrane (MIM) where it is converted into steroids. There were two indications that this is TSPOs

TSPO was discovered in 1977 and it’s function is still currently unknown. Significant research has suggested that TSPO functions in steroidogenesis to import cholesterol from the mitochondrial outer membrane (MOM) to the mitochondrial inner membrane (MIM) where it is converted into steroids. There were two indications that this is TSPOs main function: its elevated levels in steroidogenic tissue and its primary location in the MOM. There is evidence of TSPO binding cholesterol with high affinity, however there is not currently evidence of TSPO transporting cholesterol. STAR, ACBD1, and ACBD3 are proteins thought to be associated with TSPO and steroidogenesis. However, the distribution of these proteins in various eukaryotes show little similarity suggesting that TSPO functions independently. The function of TSPO in steroid synthesis has been called into question because a well-cited research paper claimed that TSPO knockdown resulted in embryonic lethal mice, however there was no evidence presented from their study and this experiment did not produce the same results when repeated in later studies. There are also studies that show TSPO may not be involved in regulation of sterols, but instead may regulate cell stress. The elevated levels of TSPO during inflammation suggest a role for TSPO in cellular stress. Binding interactions with porphyrins and heme also support that TSPO may modulate stress levels. We used the phylogeny of TSPO in order to gain greater insight into the evolutionary function of TSPO. NCBI BLAST searches revealed that TSPO was present in bacteria and had a widespread but patchy distribution in a small set of eukaryotes. From these initial results, we were prompted to search a larger set of eukaryotes for TSPO. All of the prokaryotic and eukaryotic TSPO sequences were used to create a phylogenetic tree that would provide greater insight into the evolution and function of TSPO. If TSPO was from a common ancestor, it is probable that its function is related to sterol regulation whereas if gained in eukaryotes by horizontal gene transfer from bacteria its function is related to stress regulation. The phylogenetic tree was most consistent with an ancestral origin of TSPO with an evolutionary function related to steroid synthesis regulation. However, there is not sufficient research to confirm the function of TSPO.

ContributorsLarson, Stephanie (Author) / Wideman, Jeremy (Thesis director) / Poon, Pak (Committee member) / Barrett, The Honors College (Contributor) / School of Music, Dance and Theatre (Contributor) / School of Life Sciences (Contributor)
Created2021-12
Description

This qualitative study sought to investigate the potential reaction between the 3,3',5,5'-tetramethylbenzidine (TMB) radical and LAF-1 RGG, the N-terminus domain of an RNA helicase which functions as a coacervating intrinsically disordered protein. The study was performed by adding horseradish peroxidase to a solution containing TMB and either LAF-1 or tyrosine

This qualitative study sought to investigate the potential reaction between the 3,3',5,5'-tetramethylbenzidine (TMB) radical and LAF-1 RGG, the N-terminus domain of an RNA helicase which functions as a coacervating intrinsically disordered protein. The study was performed by adding horseradish peroxidase to a solution containing TMB and either LAF-1 or tyrosine in various concentrations, and monitoring the output through UV-Vis spectroscopy. The reacted species was also analyzed via MALDI-TOF mass spectrometry. UV-Vis spectroscopic monitoring showed that in the presence of LAF-1 or tyrosine, the reaction between HRP and TMB occurred more quickly than the control, as well as in the highest concentration of LAF-1, the evolution of a peak at 482 nm. The analysis through MALDI-TOF spectrometry showed the development of a second peak likely due to the reaction between LAF-1 and TMB, as the Δ between the peaks is 229 Da and the size of the TMB species is 240 Da.

ContributorsDavis, Morgan (Author) / Ghirlanda, Giovanna (Thesis director) / Heyden, Matthias (Committee member) / Mazor, Yuval (Committee member) / Barrett, The Honors College (Contributor) / Department of Physics (Contributor) / School of Molecular Sciences (Contributor)
Created2022-12
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Description

We present the isotope yields of two post-explosion, three-dimensional 15 M_sol core-collapse supernova models, 15S and 15A, and compare them to the carbon, nitrogen, silicon, aluminum, sulfur, calcium, titanium, iron, and nickel isotopic compositions of presolar SiC stardust. We find that material from the interior of a core-collapse supernova can

We present the isotope yields of two post-explosion, three-dimensional 15 M_sol core-collapse supernova models, 15S and 15A, and compare them to the carbon, nitrogen, silicon, aluminum, sulfur, calcium, titanium, iron, and nickel isotopic compositions of presolar SiC stardust. We find that material from the interior of a core-collapse supernova can form a rare subset of SiC stardust, called SiC D grains, characterized by enrichments of the isotopes 13C and 15N. The innermost material of these core-collapse supernovae is operating in the neutrino-driven regime and undergoes rapid proton capture early in the explosion, providing these isotopes which are not present in such large abundances in other stardust grains of supernova origin.

ContributorsSchulte, Jack (Author) / Bose, Maitrayee (Thesis director) / Foy, Joseph (Committee member) / School of Earth and Space Exploration (Contributor) / Department of Physics (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Description

Cells have mechanisms in place to maintain the specific lipid composition of distinct organelles including vesicular transport by the endomembrane system and non-vesicular lipid transport by lipid transport proteins. Oxysterol Binding Proteins (OSBPs) are a family of lipid transport proteins that transfer lipids at various membrane contact sites (MCSs). OSBPs

Cells have mechanisms in place to maintain the specific lipid composition of distinct organelles including vesicular transport by the endomembrane system and non-vesicular lipid transport by lipid transport proteins. Oxysterol Binding Proteins (OSBPs) are a family of lipid transport proteins that transfer lipids at various membrane contact sites (MCSs). OSBPs have been extensively investigated in human and yeast cells where twelve have been identified in Homo sapiens and seven in Saccharomyces cerevisiae. The evolutionary relationship between these well-characterized OSBPs is still unclear. Reconstructed OSBP phylogenies revealed that the ancestral Saccharomycotinan had four OSBPs, the ancestral Holomycotan had five OSBPs, the ancestral Holozoan had six OSBPs, the ancestral Opisthokont had three OSBPs, and the ancestral Eukaroyte had three OSBPs. Our analysis identified three clades of ancient OSBPs not present in animals or fungi.

ContributorsSingh, Rohan (Author) / Wideman, Jeremy (Thesis director) / Gile, Gillian (Committee member) / Barrett, The Honors College (Contributor) / School of Human Evolution & Social Change (Contributor) / School of Life Sciences (Contributor)
Created2022-05