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Title: EVALUATION OF DYNAMIC SPEED FEEDBACK SIGNS ON FREEWAY INTERCHANGE RAMPS
Creator: Mahmud, Md Shakir
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Dynamic speed feedback signs (DSFS) are promising countermeasure to reduce curve speeds and subsequent lane departures at freeway interchange ramps, although their use in such contexts has been limited. Consequently, the impact of DSFS on driver performance at interchange ramps has remained unproven. To that end, research was performed to determine the effect of DSFS installed at freeway interchange ramps on measures of driver behavior, particularly vehicular speeds approaching and entering...
Show moreDynamic speed feedback signs (DSFS) are promising countermeasure to reduce curve speeds and subsequent lane departures at freeway interchange ramps, although their use in such contexts has been limited. Consequently, the impact of DSFS on driver performance at interchange ramps has remained unproven. To that end, research was performed to determine the effect of DSFS installed at freeway interchange ramps on measures of driver behavior, particularly vehicular speeds approaching and entering the ramp curve. To accomplish this objective, a series of field evaluations were conducted at six freeway interchange ramps possessing significant horizontal curvature. Several factors were tested during these evaluations, including: DSFS messaging strategy, positioning of the DSFS with respect to the start of the curve and side of the ramp, physical characteristics of the DSFS, radar detection range, interchange type, and temporal effects. Speed data were collected using one of these three techniques selected based on the site characteristics and types of data desired: 1) a series of high-definition video cameras, 2) handheld LIDAR, and 3) a speed-trailer. Several measures of effectiveness including speed at different locations, speed of drivers at different speed percentiles, and initial braking location were analyzed using appropriate regression techniques. Considering all phases of the field evaluation, it was concluded that DSFS are an effective countermeasure for reducing the speeds of vehicles approaching and entering horizontal curves on freeway exit ramps. The most critical aspect influencing the effectiveness of the DSFS as a speed reduction countermeasure was the longitudinal positioning of the sign relative to the ramp curve. Overall, the presence of a DSFS positioned near the start of the curve resulted in curve entry speeds that were, on average, 1.5 mph to 5.3 mph lower than without a DSFS present at the site. When the DSFS was present near the start of the curve, the lowest curve entry speeds were observed for cases where the feedback message activated when vehicles were within 250 to 400 ft of the start of the curve. Regarding DSFS lateral position, both the right-side-mounted and forward-mounted (i.e., ramp gore area) installations resulted in similar curve entry speeds. Furthermore, there were no discernable differences in curve entry speeds between 15-inch and 18-inch display panels, nor were speeds impacted by the inclusion of an advisory speed panel. In terms of feedback message, the most effective strategy was to display the measured speed alternating with a SLOW DOWN message. The effects on driver behavior associated with the DSFS were consistent between system interchanges and service interchanges, and across all vehicle types. The DSFS was equally effective irrespective of the mainline speed limit or ramp advisory speed. However, more pronounced speed reduction effects were observed for faster drivers (i.e., those within the highest quantiles) compared to the slower or average drivers. Furthermore, there was no evidence of temporal changes in driver behavior during the initial 14 months of operation of the permanent DSFS installation evaluated here. Finally, message activation did not show any significant effect on the speeds of mainline (i.e., non-exiting) vehicles. These findings were subsequently utilized towards the development of guidelines and recommendations for future use of DSFS at freeway interchange ramps.
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Title: Network Embeddings for Data Clustering, Transition State Identification, and Energy Landscape Analysis
Creator: Mercurio, Paula
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Many chemical and biochemical systems can be intuitively modeled using networks. Dueto the size and complexity of many biochemical networks, we require tools for efficient network analysis. Of particular interest are techniques that embed network vertices into vector spaces while preserving important properties of the original graph. In this article, we investigate several aspects of node embedding, propose a novel method of generating node embeddings, and explore applications to biochemical...
Show moreMany chemical and biochemical systems can be intuitively modeled using networks. Dueto the size and complexity of many biochemical networks, we require tools for efficient network analysis. Of particular interest are techniques that embed network vertices into vector spaces while preserving important properties of the original graph. In this article, we investigate several aspects of node embedding, propose a novel method of generating node embeddings, and explore applications to biochemical systems. We introduce a new method for generating low-dimensional node embeddings for directed graphs using random walk sampling and demonstrate the usefulness of this method for identifying transition states of stochastic chemical reaction systems, detecting relationships between nodes, and studying the structure of the original network. In addition, we propose an efficient scheme for numerical implementation of network embedding based on deterministic computations of commute times rather than random walk trials. We develop a novel implementation of stochastic gradient descent (SGD) based on a low-dimensional sparse approximation of the original random walk on the graph, and show that this approach can improve the performance of node embeddings. This method can be further extended for entropy-sensitive adaptive network embedding by incorporating principles from metadynamics and hierarchical network embedding, allowing for applications to the analysis of molecular structures. By adjusting the edge weights of the network by a Gaussian term, similarly to the metadynamics approach, we ensure that areas that have already been explored extensively by the random walk (i.e., the edges with the largest weights) will be de-emphasized over time, allowing additional iterations of the embedding process to reveal details about other areas of the graph. We show that this approach lends itself well to systems that are influenced by entropy or temperature effects and biochemical systems where the potential energy landscape depends on the system’s configuration at a given time, either by itself or in conjunction with transition path theory. We demonstrate the effectiveness and performance of each of our methods on several datasets and biochemical examples.
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Title: INVESTIGATING TEST DELIVERY MODES WITHIN VIDEO-CONFERENCED ENGLISH SPEAKING PROFICIENCY ASSESSMENT
Creator: Choi, Jin Soo
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Nonverbal behavior is essential in human interaction (Gullberg, de Bot, & Volterra, 2008; McNeill, 1992, 2005). For second language speakers, nonverbal features can be helpful for successful and efficient communication (e.g., Dahl & Ludvigsen, 2014). However, due to the complexity of nonverbal features, language testing institutions have conventionally employed an asynchronous format (e.g., audio-only mode), focusing on the test-taker’s verbal features. Recently, the advance in technology,...
Show moreNonverbal behavior is essential in human interaction (Gullberg, de Bot, & Volterra, 2008; McNeill, 1992, 2005). For second language speakers, nonverbal features can be helpful for successful and efficient communication (e.g., Dahl & Ludvigsen, 2014). However, due to the complexity of nonverbal features, language testing institutions have conventionally employed an asynchronous format (e.g., audio-only mode), focusing on the test-taker’s verbal features. Recently, the advance in technology, and most importantly, the coronavirus pandemic (COVID-19) outbreak in late 2019 and early 2020, have accelerated the use of video-conferencing applications in educational contexts, including speaking tests (Nakatsuhara, Inoue, Berry, & Galaczi, 2021). Accordingly, the synchronous test delivery mode (video-conferencing), which presents test-takers’ visual information, is a timely and necessary approach to addressing the impact of nonverbal features on L2 oral communication. In response to these issues, I investigated the comparability of different delivery modes of speaking proficiency assessment. This study aimed to understand the dimensionality of the measured speaking construct and the impact of test-takers’ visual information on rater behavior. Two datasets were used to address the research goals: first dataset (i.e., dataset 1) included scores of 110 test-takers, assessed by eight trained raters; second dataset (i.e., dataset 2) included scores of 284 prospective international teaching assistants (ITAs), assessed by 12 professional and certified raters. I collected dataset 1, and English language learning and testing program at a Midwest University provided dataset 2. I used two quantitative techniques to analyze both datasets: confirmatory factor analysis (CFA) and Multifaceted Rasch model (MFRM) analysis. For dataset 1, I qualitatively analyzed the raters’ verbal reports. Dataset 1 had an asynchronous format; all test-takers’ performances were recorded for rating. Eight trained raters gave scores to the audio-recorded and video 1 mode (test-taker and test giver were displayed). Three weeks later, the raters assessed video 2 mode (only test-taker’s visual information was displayed). Within one month, raters participated in a one-on-one semi-structured interview. Dataset 2 stems from an operational testing context. This dataset has only scores, as I borrowed the data from the operational English testing program at the university. The scores were first given by examiners in a synchronous format (Live mode) and later by raters in an asynchronous format (Recorded mode). CFA findings indicated the multi-dimensional aspect of the underlying construct of speaking for both datasets, but the high inter-correlations showed that these are associated. Findings of MFRM revealed that raters showed leniency when rating (a) video mode over audio-only mode (dataset 1) and (b) synchronous mode over asynchronous mode (dataset 2). Findings suggest that using the video-conferenced delivery mode may be beneficial. However, the degree of usefulness across video modes differed, and how the raters utilized test-takers’ nonverbal behaviors (e.g., gaze) varied. Thus, I decided that further investigation is needed to sufficiently support the use of video-conferencing applications to complement the physical face-to-face delivery mode. Overall, future research is highly recommended regarding the standardization of scoring of nonverbal features about the types of video mode, which would assist with the practical and valid application of virtual speaking tests.
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Title: ENGINEERING B. SUBTILIS TRANSCRIPTIONAL CONTROL AND PHYSIOLOGY FOR THE ADVANCEMENT OF BACTERIOTHERAPIES
Creator: Greeson, Emily Marilynn
Date: 2022
Collection: Electronic Theses & Dissertations
Description: This dissertation explores to avenues of improvement for current bacteriotherapy approaches. Cody Madsen and I worked closely to advance engineered B. subtilis as a modular platform technology and Dr. Ashley Makela was instrumental in the in vivo studies (Chapter 2). In Chapter 2, transcriptional control of B. subtilis will demonstrate the ability to use magnetothermal energy generated by superparamagnetic iron oxide nanoparticles (SPIONs) and alternating magnetic fields (AMF) to induce...
Show moreThis dissertation explores to avenues of improvement for current bacteriotherapy approaches. Cody Madsen and I worked closely to advance engineered B. subtilis as a modular platform technology and Dr. Ashley Makela was instrumental in the in vivo studies (Chapter 2). In Chapter 2, transcriptional control of B. subtilis will demonstrate the ability to use magnetothermal energy generated by superparamagnetic iron oxide nanoparticles (SPIONs) and alternating magnetic fields (AMF) to induce temperature-sensitive repressors. Chapter 3 demonstrates how synthetic biology techniques can allow engineered B. subtilis to invade epithelial cells with the “zipper” mechanism. This was a collaborative effort as it was a multidisciplinary study and the contributions of Cody Madsen, Evran Ural, Dr. Ashley Makela, Dr. Bige Unluturk, and Victoria Toomajian were important and have been specifically noted in author contributions at the end of Chapter 3.Most patients on organ transplant waitlists will need alternative therapeutics due to a deficit of organ donations. Regenerative medicine approaches, including cellular reprogramming are being used to help address the deficit, but there are limitations. Bacteriotherapies aim to better deliver the therapeutics to a variety of targets, however, most approaches do so externally to the target cells. B. subtilis, a generally recognized as safe organism, engineered to express listeriolysin O (LLO) has been shown to replicate in the cytoplasm of macrophages and deliver transcription factors and modulate cell surface markers, cytokines, and chemokines. This mechanism of uptake only works with phagocytic cells creating an opportunity for the engineering of B. subtilis that targets internalization into non-phagocytic cells. When introducing known virulence factors into non-native organisms it is important to consider controlling the gene expression while trying to remain as minimally invasive as possible. Alternating magnetic fields (AMF) cause local temperature increases in regions with Superparamagnetic iron oxide nanoparticles (SPIONs), and we investigated the ability of this magnetic hyperthermia approach to regulate temperature-sensitive repressors (TSRs) in bacteria. Magnetic hyperthermia-based control of bacterial gene expression would advance development of bacteriotherapies and expand options of regulated bacterial transcription. TSRs block transcription in a temperature-dependent manner. B. subtilis was coated with three SPION variations, plain-dextran, amine- or carboxyl-coated and the interactions and AMF responses were characterized and induction of the TSRs was demonstrated using AMF. Murine intramuscular injections revealed continual association of SPIONs with B. subtilis. While there was no induction via AMF in vivo, pairing TSRs with magnetothermal energy using SPIONs for localized heating with AMF can lead to regional bacterial transcriptional control, a minimally invasive method that could be used with virulence factors and therapeutics. To delivery therapeutics to epithelial cells, B. subtilis llo was engineered to express internalin A (InlA), a protein native to Listeria monocytogenes. Internalin A is an adhesin that binds to the E-cadherin host cell receptor found in epithelial cells and mediates a “zipper” mechanism of invasion. B. subtilis llo inlA demonstrated cytosolic persistence and B. subtilis llo remained extracellular. Ultimately, the engineering of B. subtilis transcriptional control and physiology creates a new modular approach to regenerative medicine, cellular reprogramming, and cancer therapy that can be used in human health applications.
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Title: Accountability Through Programmatic Goods Distribution : The Ghanaian National Health Insurance Scheme
Creator: Anderson, Stephen Edward
Date: 2022
Collection: Electronic Theses & Dissertations
Description: One way in which political leaders gain support in democratic systems is by distributing goods to citizens. Theories of accountability suggest that when political authorities provide these goods to citizens, they will be rewarded. Yet, incumbents have at their disposal multiple mechanisms through which they can distribute goods to citizens. Generally, goods are either distributed through programmatic or non-programmatic means. This dissertation evaluates how the mechanism through which goods...
Show moreOne way in which political leaders gain support in democratic systems is by distributing goods to citizens. Theories of accountability suggest that when political authorities provide these goods to citizens, they will be rewarded. Yet, incumbents have at their disposal multiple mechanisms through which they can distribute goods to citizens. Generally, goods are either distributed through programmatic or non-programmatic means. This dissertation evaluates how the mechanism through which goods are distributed influences the ways in which citizens evaluate goods performance and political leaders. I address this question by focusing on the distribution of healthcare in the West African country of Ghana. I propose a theory to explain the process by which individuals reward or punish incumbent leaders for healthcare provision distributed via a national health insurance scheme (programmatic distribution) and targeted monetary transfers (non-programmatic distribution). The central insight proposed by the theory is that the characteristics of healthcare distribution via a national insurance scheme lead individuals to evaluate incumbent leaders based on the quality of goods they receive, while the nature of healthcare distribution through targeted transfers leads individuals to evaluate incumbents based not on the quality of goods they acquire, but on their receipt of a transfer. Interview and survey research accord with these propositions. I find that individuals are more likely to sanction incumbents for poor performance when low-quality healthcare goods are distributed through a national insurance scheme. When these same low-quality goods are acquired via monetary handouts, individuals are less likely to sanction incumbents for the quality of said goods. In the latter case, poor performance is not associated with the quality of healthcare goods acquired by citizens, but whether or not the necessary resources for the acquisition of these goods were dispensed by incumbents. I contribute to the literature on goods distribution and accountability and provide novel theory and evidence on the impact of programmatic distribution and incumbent support.
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Title: Investigating Cognition in Howard Engel's Memory Book : Literary Interventions and Intercessions in Scientific Models of Memory
Creator: Cave, Kylene N.
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Crime fiction orbits around the concept of memory. At its core, crime narratives are concerned with reconstructing the past, bringing to light the events surrounding the criminal mystery. Memory also manifests in the genre’s detective figures, its modes of detection, and in the eyewitness testimonies used to solve the criminal mystery. In most crime narratives memory operates as a simplistic plot device used to temporarily complicate the mystery and, as such, it is rarely read beyond the...
Show moreCrime fiction orbits around the concept of memory. At its core, crime narratives are concerned with reconstructing the past, bringing to light the events surrounding the criminal mystery. Memory also manifests in the genre’s detective figures, its modes of detection, and in the eyewitness testimonies used to solve the criminal mystery. In most crime narratives memory operates as a simplistic plot device used to temporarily complicate the mystery and, as such, it is rarely read beyond the cursory scope of trauma. This dissertation, however, argues that crime narratives depicting extreme and rare cases of memory—like amnesia—help trace the boundaries around average functioning memory and reveal useful ways for conceptualizing how memory functions, and what disciplines have the impetus to do so. In this dissertation I argue that Howard Engel’s novel, Memory Book (2005), examines the complexities of memory by accomplishing three narratological tasks, distinguishing it from other crime fiction narratives and their more traditional handling of issues of memory and recall. The first task involves placing memory at the center of the narrative and elevating the mystery of the mind to the forefront of the plot. In placing memory at its center, the novel pushes back against traditional and widely popular scientific models of memory as merely the process of remembering and forgetting, advocating for a theory that is more complex and heterogenous. The second narratological task involves the novel’s ability to act as a literary intercessor on behalf of the sciences to translate and disseminate theories of memory to the layperson. Within this task, however, I assert that the novel not only passively intercedes, but actively intervenes in the study of memory by highlighting the inherent limitations of purely scientific or medical models of memory. In exposing these constraints, the novel also suggests a blended, transdisciplinary approach to conceptualizing human memory function and the mind. Lastly, the final task asserts that Memory Book is distinct because its narrative is infused with elements of lived experience, elements the scientific method is incapable of capturing in its probing of memory and cognition. Pointing specifically to Engel’s authorship and the circumstances surrounding the narrative’s composition following a stroke, I argue that the text intentionally blurs the boundaries between reality and fiction as a way of investigating the real-world implications of wrestling with memory loss and brain-injury based amnesia. Each of these narratological tasks is systematically analyzed by engaging with the Howard Engel’s memoir—The Man Who Forgot How to Read—deeply engaging with the novel’s paratextual elements, and through a detailed close reading of the novel.
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Title: USING NOVEL EXPERIMENTAL PROCEDURES TO ELICIT CONSUMER FOOD PREFERENCES AND DEMAND UNDER DIFFERENT CHOICE ENVIRONMENTS
Creator: Kilders, Valerie
Date: 2022
Collection: Electronic Theses & Dissertations
Description: The food system is in a constant state of change driven by the social and bio-physical environment. Acknowledging the role that innovations and preference adaptations on the consumer side play in this process, in this dissertation I use cutting-edge experimental procedures to assess consumer demand in three areas: food-away-from-home (FAFH), sustainable food products, and new food technologies. In the first chapter I determine the impact dining settings have on consumer demand for FAFH, while...
Show moreThe food system is in a constant state of change driven by the social and bio-physical environment. Acknowledging the role that innovations and preference adaptations on the consumer side play in this process, in this dissertation I use cutting-edge experimental procedures to assess consumer demand in three areas: food-away-from-home (FAFH), sustainable food products, and new food technologies. In the first chapter I determine the impact dining settings have on consumer demand for FAFH, while also evaluating how a tax levied on red meat dishes would impact low- and high-income consumers. Capturing both substitution and complementarity patterns, I employ a food menu basket-based choice experiment approach, which permits respondents to freely pick and combine a range of food items at different price levels. I find that respondent’s orders in the delivery setting are typically higher in calories and most items act as complements for one another, while menu items are substitutes in the dine-in setting. The red meat tax that I simulate is regressive towards low-income individuals in the delivery setting but not in the dine-in setting. Thematically corresponding with the red meat tax, in the second chapter I study the market potential of “low carbon” ribeye steaks. In conjunction with this empirical component, I also propose the use of a reference price informed design that mirrors respondent’s price expectations for actual food shopping situations. I find the market potential of meat with a lower carbon footprint is relatively small, with conventional meat taking up most of the market share. Our results also show that a reference price informed design best describes choices and leads to more conservative market share estimates than traditional designs. One way to achieve a lower carbon footprint could be the use of gene-editing. In my third chapter, I therefore assess consumer preferences and willingness to pay (WTP) for milk from cows gene-edited to produce less methane. In doing so, I also analyze whether and how preferences for new food technologies are affected by information on the climate impact of dairy production. I supplement this analysis with an exploration of what medium of information (video vs. text) has the strongest impact on consumer acceptance and how responses change depending on whether respondents get to opt-in to seeing information or are forced to see the respective information. I find that gene-edited milk is discounted relative to other available alternatives. Results also show that choice outcomes differ between respondents seeking additional information and those remaining willfully ignorant. Giving respondents autonomy over their knowledge gathering is a significant factor in determining choice behavior. In sum, findings from these three chapters can be used to inform producers, policymakers, and the food industry, as well as improve the way food experiments are designed within the realm of food choices and beyond.
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Title: ELUCIDATION AND REPURPOSING OF PLANT DITERPENOID BIOSYNTHETIC PATHWAYS
Creator: Miller, Garret P.
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Terpenoids are the largest class of specialized metabolites in plants, with widespread uses ranging from fragrances and cosmetics to biofuels, antifeedants, and pharmaceuticals. Terpenoids are derived from a small set of prenyl diphosphate substrates which are cyclized into different terpene scaffolds by terpene synthases. These scaffolds are then modified by various tailoring enzymes—typically starting with cytochrome P450s—into functionalized terpenoids. Given the structural complexity of...
Show moreTerpenoids are the largest class of specialized metabolites in plants, with widespread uses ranging from fragrances and cosmetics to biofuels, antifeedants, and pharmaceuticals. Terpenoids are derived from a small set of prenyl diphosphate substrates which are cyclized into different terpene scaffolds by terpene synthases. These scaffolds are then modified by various tailoring enzymes—typically starting with cytochrome P450s—into functionalized terpenoids. Given the structural complexity of many of these metabolites, total chemical synthesis is often challenging to achieve at a relevant scale and cost, and as such, biosynthetic methods are increasingly being employed as an alternative for their production. The work presented in this dissertation describes the elucidation of two terpenoid biosynthetic pathways and the repurposing of known pathways to convert synthetic substrates not found in nature. First, three steps constituting the full biosynthetic pathway to leubethanol, an antimicrobial diterpenoid active against multidrug-resistant TB, was elucidated in the Texas Sage (Leucophyllum frutescens). Second, seven steps in the biosynthetic pathway towards structurally complex diterpenoid alkaloids were elucidated in the Siberian Larkspur (Delphinium grandiflorum). Third, twenty-four terpene synthases were screened for activity against twenty synthetic substrate analogs not found in nature, resulting in fifty-six new products and demonstrating the ability to derivatize terpene scaffolds through the derivatization of a starting substrate. In all, this work expands access to different classes of terpenoids through the elucidation of biosynthetic pathways and semi-biosynthesis of terpene scaffolds not found in nature, allowing for more feasible and sustainable production of these structurally complex compounds.
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Title: Lovecraft's Wake : Pessimism and Contemporary Weird Fiction
Creator: Conley, Richard Lance
Date: 2022
Collection: Electronic Theses & Dissertations
Description: This dissertation examines select writings from H.P. Lovecraft and a group of contemporary authors of weird fiction in the context of a wake, a term defined in two precise ways. The first meaning of “wake” refers to an influential disturbance in the history of weird fiction left by Lovecraft’s writings, a seismic shift at the level of what the genre represents and the kinds of questions it asks. The second definition of “wake” refers to the fact that someone (or something) has passed, and we,...
Show moreThis dissertation examines select writings from H.P. Lovecraft and a group of contemporary authors of weird fiction in the context of a wake, a term defined in two precise ways. The first meaning of “wake” refers to an influential disturbance in the history of weird fiction left by Lovecraft’s writings, a seismic shift at the level of what the genre represents and the kinds of questions it asks. The second definition of “wake” refers to the fact that someone (or something) has passed, and we, the living, attend a wake to acknowledge this passing. With these two definitions in hand, the project argues that a group of contemporary weird fiction authors are writing in and at Lovecraft’s wake. Put differently, certain aspects of his fictional corpus have been revised by a group of contemporary weird fiction authors such that we can, on the one hand, acknowledge Lovecraft’s undeniable influence and the notion that to compose weird fiction in the present is to find one’s self always already writing in Lovecraft’s wake, and, on the other, to move beyond both some of the more dated questions his writing raises as well as the blatantly racist elements of some of his writing(s). Additionally, the contemporary weird authors examined in this project frame different manifestations of pessimism as a worldview that remains contingent, not on an indifferent cosmos, but on human communities in doomed worlds and the horrors that they inflict on each other in that context. In sum, the authors writing in and at Lovecraft’s wake want us not to combat the persistence of pessimism but rather to learn to accept it such that we can live with others in the fundamentally finite time allotted to each of us in a more peaceful way.
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Title: PERSUADING THROUGH FICTIONAL TELEVISION : A MIXED METHODS INVESTIGATION OF GENRE EXPECTATIONS
Creator: McClaran, Sharon-Nicole
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Genres provide an effective way for viewers to categorize, select, and evaluate entertainment television (TV) programs (Bilandzic & Rössler, 2004; Hawkins et al., 2001). People tend to know, for example, whether they will enjoy a medical drama or animated comedy based on their prior experience watching shows of that genre. Despite growing interest in entertainment media as a vehicle for persuasion, minimal research has considered how genre may influence receptivity to and acceptance of...
Show moreGenres provide an effective way for viewers to categorize, select, and evaluate entertainment television (TV) programs (Bilandzic & Rössler, 2004; Hawkins et al., 2001). People tend to know, for example, whether they will enjoy a medical drama or animated comedy based on their prior experience watching shows of that genre. Despite growing interest in entertainment media as a vehicle for persuasion, minimal research has considered how genre may influence receptivity to and acceptance of persuasive appeals in fictional TV programming (J. Cohen & Weimann, 2000; Grabe & Drew, 2007). Even less work has offered theoretical explanations for why genre may impact the persuasion process. Across three studies, this dissertation, guided by expectancy-violations theory (Burgoon, 1993, 2015), offers a thorough investigation into how audiences consider fictional TV genres and whether those expectations influence the success of subsequent persuasive attempts.In Study 1, qualitative interviews were conducted to gauge how viewers feel about using fictional TV shows for persuasion and whether genre is an influential factor in their assessments. The results provided preliminary evidence that viewers hold strong expectations for the likelihood and appropriateness of persuasive appeals in certain genres. In Study 2, persuasion-relevant expectations, including content credibility, learning potential, and likelihood of distributing an educational message, were tested for ten fictional TV genres (animated comedy, animated drama, comedy, crime comedy, crime drama, general drama, historical drama, medical comedy, medical drama, science-fiction/fantasy). Results of the online survey provided strong statistical support that viewers consider the content of TV genres differently and that these expectations influence hypothetical acceptance of an educational appeal. Lastly, Study 3 offered an experimental manipulation of genre (historical fiction vs. science- fiction/fantasy) to test whether genre expectation violations and message resistance explain the success of entertainment media in facilitating persuasion. Although the hypotheses were not supported in Study 3, post-hoc analyses found genre to influence participants’ perceived persuasive intent, which in turn, influenced attitudes, descriptive norms, and behavioral intention toward daily stretching. The cumulative results of this dissertation stress the importance of genre study in the entertainment media persuasion scholarship and offer several avenues for future research.
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Title: Development and Assessment of Predictive Models for Improved Swine Farming
Creator: Han, Junjie
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Prediction of outcomes is critical in both swine breeding and management. This necessitates the development of predictive models that address challenges in swine farming. For predictive modeling, there have been significant advances in deep learning. Nevertheless, there are needs to adapt deep learning-based models for specific swine farming problems including genomic prediction and behavior analysis. Furthermore, there is not yet a clear guideline on how to validate a model in this field....
Show morePrediction of outcomes is critical in both swine breeding and management. This necessitates the development of predictive models that address challenges in swine farming. For predictive modeling, there have been significant advances in deep learning. Nevertheless, there are needs to adapt deep learning-based models for specific swine farming problems including genomic prediction and behavior analysis. Furthermore, there is not yet a clear guideline on how to validate a model in this field. The overarching goal of this dissertation was to validate a collection of predictive models for improved swine farming with applications to precision management, phenotyping, and breeding. The first study addressed the pig genomic prediction problem. Differential evolution was utilized to optimize deep learning (DL) hyperparameters that affected the predictive performance of DL models. Performance of optimized DL was compared with “best practice” DL architectures selected from literature and baseline DL models with randomly specified hyperparameters. Optimized models showed clear improvement. Further, differential evolution saved considerable time compared to traditional optimization approaches e.g., grid search. Despite the success of genomic prediction, phenotyping has become a bottleneck in breeding programs as it is still time-consuming and labor-intensive. Computer vision (CV) can be used to automate the phenotyping process. Nonetheless, there are limited amount of public data for CV development in livestock farming. Most published CV applications to livestock farming were developed using rather small datasets, and their broader validity remained unknown. Therefore, the second study aimed at reviewing publicly available image datasets that were used for CV algorithms in livestock farming and the validation methods in the related work. Through the review, we could not find public datasets that addressed pigs’ agonistic behaviors (negative social behaviors), which is an important topic in swine farming. Given this, the third study aimed at collecting a video dataset to study pig’s agonistic behavior and adapting a state-of-the-art DL pipeline to classify pigs’ agonistic behaviors through video analysis. The pipeline was validated through various training-validation data partitions, where the training data were used for model development and the validation data were used for model evaluation. Results showed that splitting the training and validation sets at random led to over-optimistic estimates of model performance. The last study focused on developing and validating a statistical model for the analysis of pigs’ social interactions. Generalized linear mixed models were fitted, and a Bayesian framework was used for parameter estimation and posterior predictive model checking. The predictive performance of the models varied depending on the validation strategy, where three strategies were defined: random cross-validation, block-by-social-group cross-validation, and block-by-focal-animals validation. In conclusion, this dissertation provides information about how state-of-the-art models can be adapted for and validated in swine farming applications. Future directions of this research could aim at creating reference imagery datasets in swine farming that provides a platform for CV applications and developing integrated computer vision systems, which eventually assists in prediction tasks for improved pig management and breeding.
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Title: Assuming Ambiguity
Creator: Conklin, Rebecca C.
Date: 2022
Collection: Electronic Theses & Dissertations
Description: This dissertation considers ambiguity throughout the history of Rhetoric and Composition, a discipline generally concerned with clarity, concision, and correctness as key attributes of “good” writing. In the first part of this dissertation, I draw from the theoretical contributions made by Simone de Beauvoir in The Ethics of Ambiguity (1947) and show how the central tensions she wrestled with in that text mirror the tensions experienced at the dawn of this discipline, tensions that have (re...
Show moreThis dissertation considers ambiguity throughout the history of Rhetoric and Composition, a discipline generally concerned with clarity, concision, and correctness as key attributes of “good” writing. In the first part of this dissertation, I draw from the theoretical contributions made by Simone de Beauvoir in The Ethics of Ambiguity (1947) and show how the central tensions she wrestled with in that text mirror the tensions experienced at the dawn of this discipline, tensions that have (re)emerged throughout subsequent decades. I trace the disciplinary conversations in the decades following World War II, as Rhetoric and Composition sought to define itself and its space in increasingly neoliberal, corporate college and university structures. Summarizing field conversations around the problems of relevance, content/standards, teachers and students, and assessment, I show how the gap between disciplinary knowledge/best practices bumps up against the demands of a profit-driven university. This project offers another way of thinking and doing through a praxis of ambiguity, explored and articulated through five guiding verbs: imagine, emerge, expand, intuit, and situate. Through these guiding verbs, I explore how these verbs and the scholarship that supports them may offer ways to intentionally disrupt the presence of white supremacy culture in teaching, research, and administration in the discipline by making visible the characteristics of this culture and sketching the outlines of an interventional framework based on a praxis of ambiguity, offering avenues for future research.
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Title: Adaptation to agriculture in a serious crop weed, weedy radish (raphanus raphanistrum)
Creator: Garrison, Ava
Date: 2022
Collection: Electronic Theses & Dissertations
Description: The colonization of novel environments requires organisms to shift their trait means in response to differing abiotic and biotic conditions in order to survive and persist. This response can be done via phenotypic plasticity (a trait shift in response to the environment), adaptation (a trait shift due to genetic change), or both strategies can be used together, with plasticity “buying time” for adaptation to occur. The colonization of novel environments is especially important to the...
Show moreThe colonization of novel environments requires organisms to shift their trait means in response to differing abiotic and biotic conditions in order to survive and persist. This response can be done via phenotypic plasticity (a trait shift in response to the environment), adaptation (a trait shift due to genetic change), or both strategies can be used together, with plasticity “buying time” for adaptation to occur. The colonization of novel environments is especially important to the establishment of agricultural weeds worldwide, which thrive in these extreme environments of intense competition and frequent disturbance. In this dissertation, I address the establishment and evolution of a harmful agricultural weed, weedy radish (Raphanus raphanistrum), as well as its divergence from a wild relative of the same species, the native radish ecotype. I first investigated the hypothesis of phenotypic plasticity “buying time” for adaptation to agricultural fields in weedy radish. Using growth chambers to simulate the ancestral (native) and derived (weedy) environments of weedy radish, I performed a reciprocal transplant with the weedy and native radish ecotypes. I found phenotypic plasticity between environments and genetic divergence between ecotypes to be equally common among traits, suggesting similar importance of plasticity and adaptation in weedy radish establishment. Further, in the majority of traits that were both plastic and differentiated between ecotypes, the direction of change matched, with the weedy environment producing phenotypic shifts in the direction of the weedy ecotype mean. This suggests plasticity in these traits may have enabled the subsequent adaptation and ecotype differentiation, supporting the buying-time hypothesis. Next, I explored the role of the plant hormone Gibberellic Acid (GA) in the evolution of weedy radish. Using exogenous application of GA both in the greenhouse and in weedy and native growth chamber environments, I found evidence that there has been an evolutionary change in the role of GA in trait expression between the two ecotypes. Namely, weedy radish is less responsive to GA application than native radish, suggesting either upregulation in GA production in weeds, or a lower level of GA required to enable gene expression in the weedy ecotype. This change in gene regulation by GA may have been important in the evolution of weedy radish in the agricultural field. Finally, I assessed the likelihood of weedy radish diverging from a native ancestor via adaptive evolution. I found that adaptive evolution was likely in the establishment of weedy radish due to increased fitness of the weedy ecotype compared to the native ecotype in the agricultural field. I also found traits under directional selection in the native ecotype, with the key takeaway that faster flowering is adaptive in the agricultural fields. I finally looked at the ability of weedy radish to evolve advanced flowering in the agricultural field via standing genetic variance by artificially selecting for early flowering in native radish. I found that in only two generations of selection, native populations significantly advanced their flowering time, supporting the notion of weedy radish rapidly adapting to agricultural conditions via standing genetic variation alone. Taken together, these findings work to piece together the evolutionary history of weedy radish, providing insight into its mechanisms of establishment. This work also contributes to our overall understanding of rapid evolution and phenotypic plasticity in the colonization of novel environments, in agricultural weeds and beyond.
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Title: INVESTIGATING THE IMPACT OF ANTIOXIDANT SUPPLEMENTATION ON MUSCLE ANTIOXIDANT STATUS AND THE SKELETAL MUSCLE PROTEOME IN THOROUGHBRED RACEHORSES
Creator: Henry, Marisa LeeAnn
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Glutathione (GSH) and Coenzyme Q10 (CoQ10) are potent cellular antioxidants that work to mitigate oxidative stress arising from reactive oxygen species (ROS) production. GSH is not well absorbed because it is broken down into individual amino acids in the small intestines. Cysteine is the rate limiting amino acid in GSH synthesis but is not well absorbed and is instead largely produced from methionine intracellularly. N-acetyl cysteine (NAC) supplementation has been studied as an alternative...
Show moreGlutathione (GSH) and Coenzyme Q10 (CoQ10) are potent cellular antioxidants that work to mitigate oxidative stress arising from reactive oxygen species (ROS) production. GSH is not well absorbed because it is broken down into individual amino acids in the small intestines. Cysteine is the rate limiting amino acid in GSH synthesis but is not well absorbed and is instead largely produced from methionine intracellularly. N-acetyl cysteine (NAC) supplementation has been studied as an alternative to cysteine or GSH supplements and has been shown to increase the amount of circulating cysteine and increase transport activity for this reduced form in humans. GSH concentrations in skeletal muscle have been measured in only a few studies in other species. Neither GSH nor NAC have been previously studied in the skeletal muscle of horses. CoQ10 is an electron transporter in the mitochondrial electron transport chain (ETC) where it transfers electrons either from complex I or complex II to complex III. Within the ETC, complex I has been shown to be the primary source of ROS during exercise in comparison to the other complexes. Due to its location and function, CoQ10 can also function as a potent membrane bound antioxidant and mitigate ROS produced through the ETC. CoQ10’s function as an antioxidant and electron transporter has not been studied in great depth in horses. Branched chain amino acid (BCAA) supplements are three essential amino acids that have been shown to have positive effects on protein synthesis through the mammalian target of rapamycin pathway (mTOR). BCAA can serve as an energy source in skeletal muscle where they are directly metabolized in the tricarboxylic acid cycle. There are a limited number of studies of the impact of BCAA supplementation on equine skeletal muscle and none have looked at BCAA combined with antioxidant supplements. The overarching objective of this dissertation was to evaluate the impact of antioxidant supplementation on fit, healthy Thoroughbred horses. The first study supplemented NAC and CoQ10 to maximally exercising Thoroughbreds to determine its effect on the redox equilibrium and skeletal muscle proteome. We determine that NACQ increases muscle GSH concentrations post exercise while increasing TCA cycle enzymes and enhancing capacity for cellular NADPH production. The second study measured the effect of a single dose of differing amounts and formulations of CoQ10 on plasma CoQ10 concentrations. We determined that individual horses have different absorption responses, with 50% showing no response. The third study analyzed chronic CoQ10 supplementation’s effect on plasma CoQ10 concentrations, concentrations or activities of skeletal muscle antioxidants, mitochondrial respiration, and the skeletal muscle proteome. Results supported CoQ10’s function as an antioxidant and ability to alter the contribution of complex I and complex II to electron transfer without increasing mitochondrial volume density. The final study of this dissertation analyzed the impact of NAC and BCAA supplementation on sub-maximally exercising Thoroughbreds by measuring antioxidant status and alterations to the skeletal muscle proteome before and after exercise. This study identified no changes in skeletal muscle GSH concentrations and ROS before or after exercise but did find differentially expressed proteins within the ETC, redox reactions, and glycolysis after submaximal exercise. All supplements warrant further investigation in horses with myopathies.
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Title: PRE-SERVICE SCIENCE TEACHERS’ ARTICULATION AND REVISION OF FRAMEWORKS OF SCIENCE TEACHING IN A JUSTICE-ORIENTED METHODS CLASS
Creator: Brien, Sinéad Carroll
Date: 2022
Collection: Electronic Theses & Dissertations
Description: The reasons particular people enjoy science, pursue science, and see themselves as science people, or not, are diverse and complex (Brickhouse, et al., 2000). The ways that teachers present science and value particular ways of knowing and doing in the classroom can influence which students see themselves as science people (Carlone et al, 2011). When teachers treat one particular cultural way of knowing in science as the superior way of knowing, specifically Eurocentric ethnoscience with its...
Show moreThe reasons particular people enjoy science, pursue science, and see themselves as science people, or not, are diverse and complex (Brickhouse, et al., 2000). The ways that teachers present science and value particular ways of knowing and doing in the classroom can influence which students see themselves as science people (Carlone et al, 2011). When teachers treat one particular cultural way of knowing in science as the superior way of knowing, specifically Eurocentric ethnoscience with its grounding in whiteness, heteropatriarchy, Protestantism, and settler colonialism, they create/maintain a hierarchy of knowledge that limits how all students can participate and see themselves in science, in particular girls, Black students, Indigenous students, and students of Color (Archer et al., 2010; Bang et al., 2012; Mutegi, 2013). Especially as Eurocentric ethnoscience is often presented as neutral, objective and universal (Harding, 2006), science teachers may not realize that there are multiple ways to know and do in science. In this study I draw from Gee’s (2016) conception of Framework Discourse Analysis to posit that pre-service science teachers (PSTs) can be supported to articulate, question, and revise their socially-derived ideas/expectations of science and teaching (i.e., their “frameworks” of science and teaching) through participation in my two-semester long Science Teaching Methods Class focused on justice-oriented science teaching. Through a case study of three PSTs’ select artifacts from the class and interviews the summer after the class, I identified each PST’s frameworks of science and teaching, how PSTs questioned and revised these across Methods Class, and which types of Methods Class activities supported this articulation, questioning, and revising of frameworks. I found that all PSTs clearly articulated their frameworks of science and teaching and that a pluralist/contextual framework of science was important in developing justice-oriented science teaching frameworks. In addition, the types of Methods Class activities that supported clearer articulation of science and teaching frameworks were those focused on connecting science and culture, expanding notions of what it meant to be a “successful” science student, and methods to recognize and address the sociopolitical in science and teaching in the classroom. These findings have implications for the use of Gee’s (2016) Framework Discourse Analysis as a guide for raising critical consciousness and recognizing value in multiple ways of knowing and doing. In addition, they raise questions about criteria for recruiting pre-service science teachers and assessing their readiness to enter the field of teaching as justice-oriented science teachers.
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Title: INVESTIGATIONS INTO THE VIRUS-LIKE PARTICLE BACTERIOPHAGE Qβ AS A CARRIER PLATFORM IN CONJUGATE VACCINES AGAINST CANCER AND ALZHEIMER’S DISEASE
Creator: McFall-Boegeman, Hunter Sean
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Traditional vaccines are made of either killed or live-attenuated viruses. Killed virus vaccines may suffer from weak immune responses and live attenuation is an inexact science that can take years. There has been an interest in developing alternative vaccine technologies. One class of vaccine technology that has shown promise is the subunit conjugate vaccine. In such vaccines only antigenically relevant portions of infectious agents are conjugated to a carrier capable of stimulating a...
Show moreTraditional vaccines are made of either killed or live-attenuated viruses. Killed virus vaccines may suffer from weak immune responses and live attenuation is an inexact science that can take years. There has been an interest in developing alternative vaccine technologies. One class of vaccine technology that has shown promise is the subunit conjugate vaccine. In such vaccines only antigenically relevant portions of infectious agents are conjugated to a carrier capable of stimulating a stronger immune response. The use of virus-like particles as carriers in conjugate vaccines has shown promise, allowing for the targeting on non-traditional vaccine targets. In this dissertation we report on the use of the virus-like particle Qβ as a carrier in conjugate vaccines targeting cancer and Alzheimer’s disease. Cancer’s ability to escape the immune response requires a total immune response ensure that cancer does not mutate and return resistant to previously used immunotherapies. Previous use of Qβ-based conjugate vaccines against cancer have focused eliciting humoral responses. Herein we report lessons learned from the attempts to functionalize Qβ to elicit cellular immune response in a manner that would minimize the effect on a potential humoral response. Alzheimer’s disease is one of the most common causes of dementia and is hallmarked by the aggregation of tau. A Qβ-based conjugate vaccine targeting the tau-tau binding sites was synthesized and evaluated. Immunization generated a strong humoral immune response superior to a KLH-based conjugate vaccine targeting the same epitope. Generated antibodies were able to preferentially recognize disease associate forms of tau and stain tau in human tissue.
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Title: SEMI-ANALYTICAL METHOD FOR THE ANALYSIS AND DESIGN OF CYLINDERS WITH CONTROLLABLE ELASTIC POST-BUCKLING RESPONSE
Creator: Imani Azad, Ali
Date: 2022
Collection: Electronic Theses & Dissertations
Description: Research over the past ten years has generated an increased interest in studying elastic structural instabilities as a useful response for smart applications rather than a failure. Buckling under axial compression is a type of structural instability that can be used for rapid geometric transformations (switching) and energy harvesting applications, if the deformations arising from buckling are properly controlled. Controlling transverse deformations due to buckling in slender elements usually...
Show moreResearch over the past ten years has generated an increased interest in studying elastic structural instabilities as a useful response for smart applications rather than a failure. Buckling under axial compression is a type of structural instability that can be used for rapid geometric transformations (switching) and energy harvesting applications, if the deformations arising from buckling are properly controlled. Controlling transverse deformations due to buckling in slender elements usually needs external constraints/boundaries. Short thin-walled cylinders can experience several elastic buckling events under axial compression without additional constraints. However, predicting the post-buckling response in cylinders is very challenging, particularly far in the post-buckling regime since they are highly sensitivity to initial imperfections.The concept of cylinders with non-uniform stiffness distribution (NSD) was recently proposed to localize a cylinder’s buckling events in targeted zones. This notion has been proven effective for controlling the number of elastic buckling events, the sequence at which they occur, and the regions experiencing buckling. However, this information is not enough to design NSD cylinders for smart applications, which requires being able to predict the actual applied force for each buckling event, the end shortening of the cylinder for the buckling event, the drop in force, the drop in strain energy, and the post-buckling stiffness of the cylinder. Here, a semi-analytical model has been developed to predict the elastic post-buckling response of NSD cylinders under compression. The developed semi-analytical model is based on three general steps: • Separate the NSD cylinder into parallel segments, • Simplify and predict the response of each segment, and • Integrate the response of individual segments. The first step in predicting the elastic post-buckling response of a cylindrical segment was to simplify its geometry into a cylindrical panel with uniform thickness. Linear springs are connected to the top and bottom of the uniform cylinder to match the stiffness of the simplified segment to the actual one. Based on classical shell theory, the elastic post-buckling response of a cylindrical panel is solved as a boundary value differential equation using the pseudo-arclength method. Comparing the post-buckling response of four cylinders from the proposed semi-analytical model with the response of the same cylinders from the experiment and finite element analysis showed the effectiveness of the proposed model. Results from the proposed model predict well the axial deformation and force level corresponding to buckling events more accurately than the post-buckling stiffness. The response of cylindrical panels for a large variety of dimensions is needed to design NSD cylinders for targeted post-buckling behavior. Thus, the classic differential equation of the cylindrical panels under axial compression was solved independently of the material's cylinder radius and elastic modulus. These results allowed the development of design maps for several post-buckling responses such as axial strain and stresses corresponding to the first buckling event, force, and energy drops from the buckling event, the secondary (or post-buckling) stiffness of the panel, the radial deformation at the panel center, and the maximum von Mises stress in the panel. By using genetic programming, predictive equations were developed for each design parameter to relate it to the geometry of the panels. Three cylinders were designed using the developed design maps to validate the proposed approach. One NSD cylinder was designed to undergo several buckling events under compression at pre-defined end shortenings. A second NSD cylinder was designed to feature a post-buckling force-deformation response that plateaus at a constant force level. The third cylinder was designed to experience the same force drop at each buckling event and in identical axial end shortenings after the first event. Finite element analyses of the designed cylinders verified that using the proposed design procedure using the developed design maps provides NSD cylinders with a post-buckling response that is very close to the desired one, and the ultimate design goal can be achieved by slight modifications to the geometry of the cylinder. This study advances the knowledge on the elastic buckling and post-buckling response of slender cylindrical shells under axial compression and provides an approach to analyze and design them for a desired far post-buckling response. The proposed framework, which combines the notion of decomposing NSD cylindrical segments into linear and nonlinear springs in series, a semi-analytical model for NSD equivalent panels, and design maps for several nonlinear responses provides insight for designing these elements for smart devices and structures relying on structural instabilities. This work expands the harnessing of elastic instabilities to the area of thin-shell buckling under compression, which has received less attention in comparison to other forms of structural instability.
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Title: The Storyteller’s Granddaughtxr : (Re)Envisioning Methodologies for Healing and Liberation
Creator: Furman, Olivia Ann
Date: 2022
Collection: Electronic Theses & Dissertations
Description: My dissertation is an arts-based embodiment, in the form of an exhibition in the LookOut Gallery of Snyder-Phillips Hall at Michigan State University (MSU). This exhibition is the culmination of my interdisciplinary auto-ethnographic dissertation study, within which I utilize Black feminist-womanist storytelling methodology (Baker-Bell, 2017) and Black womxn's literacies of critical self-reflection, art-making, and Afrofuturist dreaming to articulate my own Black womxn's standpoint (Collins,...
Show moreMy dissertation is an arts-based embodiment, in the form of an exhibition in the LookOut Gallery of Snyder-Phillips Hall at Michigan State University (MSU). This exhibition is the culmination of my interdisciplinary auto-ethnographic dissertation study, within which I utilize Black feminist-womanist storytelling methodology (Baker-Bell, 2017) and Black womxn's literacies of critical self-reflection, art-making, and Afrofuturist dreaming to articulate my own Black womxn's standpoint (Collins, 2002). This collection is an inquiry, a piecing together of quilting, collage, speculative fiction, my story, and the intergenerational stories of other Black womxn and femmes to consider the ways our ancestors, identities, and embodied knowledges inform our method(ologie)s of sustainability, healing, and liberation.*Keywords: womanist, Black feminist, storytelling, interdisciplinary, auto-ethnography*Throughout my work, I use an “x” in words such as womxn, mothxrs & othermothxrs to disrupt binary conceptualizations of gendered identities, and to be inclusive of the diverse range of queer and gendered identities and experiences.
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Title: LIFETIME MEASUREMENTS OF THE NEUTRON-RICH 36,38SI ISOTOPES
Creator: Grinder, Mara Mikelah
Date: 2022
Collection: Electronic Theses & Dissertations
Description: The shell structure of nuclei far from stability evolves from the standard shell modelpicture that accurately describes stable nuclei. Experimental evidence has been given by changes in structural properties of nuclei such as the shell closures. The evolution of shell structure is gradual and must be studied by looking systematically at isotopic or isotonic nuclear chains. Studies of these chains can deepen the understanding of shell structures, magic numbers and the collective natures of...
Show moreThe shell structure of nuclei far from stability evolves from the standard shell modelpicture that accurately describes stable nuclei. Experimental evidence has been given by changes in structural properties of nuclei such as the shell closures. The evolution of shell structure is gradual and must be studied by looking systematically at isotopic or isotonic nuclear chains. Studies of these chains can deepen the understanding of shell structures, magic numbers and the collective natures of nuclei far from stability. The neutron rich silicon isotopes display evidence of shell evolution seen in the ratio of the low-lying excitation energies. 34Si has a closed shell nature with a proton bubble structure which evolves along the isotopic chain to the absence of the N=28 shell closure expected in 42Si. Another complementary way to probe these changes is by studying the reduced transition rates of the first 2+ and 4+ states. The ratio of the reduced transition rates has characteristic values for different collective modes. However, these values are not known for isotopes that are more neutron rich than 30Si. The reduced transition rates can be compared to various theoretical models to understand the changes taking place in this neutron-rich region. This work discusses an experiment that studied 36Si and 38Si to determine the lifetimes of their excited states and to determine the reduced transition rates of the first 2+ and 4+ states in both nuclei. From these B(E2) values, the ratio is calculated and compared to the collective models and shell model calculations. The recoil distance measurement was con- ducted at the National Superconducting Cyclotron Laboratory using the S800 Spectrograph, the GRETINA array, and the TRIPLEX plunger. The experiment successfully measured the lifetimes of the 2+1 and 4+1 states in 38Si and the 4+1 and 6+1 states in 36Si. Results from the measurement included the confirmation of the 2383-keV state in 38Si that had only been seen once before. The B(E2) values determined from the experiment indicate the reduced collectivity for the first 4+ states of 36,38Si indicating the persistence of the N=20 magic number through 36Si and 38Si.
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Title: DESIGNING OUR FREEDOM : A NARRATIVE INQUIRY AND VISUAL RHETORICAL ANALYSIS OF BLACK WOMEN ENTREPRENEURS DIGITAL CONTENT STRATEGY ON SOCIAL NETWORKING SITES
Creator: Wourman, Ja'La Janice
Date: 2022
Collection: Electronic Theses & Dissertations
Description: This study explores the role of race and identity in Black women entrepreneurship and how each of these play a part when developing content for online audiences. The purpose of this study was to better understand how our intersecting identities are important to draw upon or consider, when conducting research in work-place studies or entrepreneurship for technical and professional communication scholars. And with the rise of digital platforms, I wanted to better understand if the...
Show moreThis study explores the role of race and identity in Black women entrepreneurship and how each of these play a part when developing content for online audiences. The purpose of this study was to better understand how our intersecting identities are important to draw upon or consider, when conducting research in work-place studies or entrepreneurship for technical and professional communication scholars. And with the rise of digital platforms, I wanted to better understand if the entrepreneurial journey factors into the design process of developing content for online audiences. To answer these questions, I used a narrative inquiry approach to conduct 5 separate interviews for each of my participants. The purpose of the interviews was to amplify the voices of each of my participants drawing from Patricia Hill Collins and the Combahee River Collective’s Black feminist theory. I then conducted a content analysis of 3 images from each of my participants business Instagram profiles, to demonstrate how design and cultural background can play a role in developing content. The results from this study revealed 3 major outcomes from each of the interviews and 4 emerging themes in the images used for all 5 participants content analysis of Instagram. Together, the themes and outcomes show a direct correction of race, culture, and design in content strategy. Using this data, I was able to develop tenets to help scholars and practitioners imagine a culturally centered design framework for developing content for diverse audiences and situations.
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