Middle Tennessee State University
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Modeling Asymmetric Cell Division of Pathogenic Yeast within Host Macrophages for Comparison to Fluorescence Confocal Microscopy Data
No full textCryptococcus neoformans is a fungal pathogen found most commonly in soil and bird droppings. This pathogen causes pulmonary infections and can establish long-lasting intracellular infections in macrophages. While most healthy individuals are not impacted by exposure to these fungi, those who are immunocompromised may experience pulmonary infections. If Cryptococcus neoformans disseminates from the lung, it can infect the central nervous system and cause fungal meningitis.
Our ultimate objective is to study the replication of this fungal pathogen in two macrophage cell lines, J774 macrophages and fetal liver-derived alveolar-like macrophages (FLAMs) by using florescence confocal microscopy. Intracellular growth of Cryptococcus neoformans is usually studied in J774 macrophages. We are interested in comparing the growth of Cryptococcus neoformans in FLAMs to that in J774 cells because the lung is the most common site of initial Cryptococcus neoformans infection, and FLAMs are more similar to alveolar macrophages from the lung than J774 cells.
In this work, we develop a stage-structured model for the asymmetric cell division of Cryptococcus neoformans in macrophages which is compatible with empirical data. Quantifying changes in growth and division under perturbations and assigning statistical significance requires a model of the expected growth and division pattern. A small population size combined with asymmetric division makes the go-to model of continuous exponential growth inappropriate for quantifying changes in growth rate and assigning statistical significance. Our stage-structured model is useful because it more accurately captures the dynamics of a small and asymmetrically dividing cellular population. We couple this model with an error model for the process of detecting and counting fungal cells in order to counteract some of the difficulties of collecting the empirical data, especially the challenge of reliably detecting fungal cells that are very small.M.S
“kamala IS brat:” How Exposure to Online Campaign Content Impacts Young Adults’ Political Organization-Public Relationships and Political Participation
No full textThe 2024 United States presidential election saw political campaigns leverage social media trends, including memes, AI-generated visuals, policy-focused messaging, and attack ads, to engage young voters. Despite these efforts, youth voter turnout declined, raising questions about the effectiveness of these digital strategies. This study examines how exposure to these four major campaign content types influences young adults’ political organization-public relationships (POPR) with their parties and political participation, with social media engagement and perceived political authenticity as mediating variables.
A survey of 496 United States citizens (ages 18-29) tested the impact of these content types on POPR and participation. Findings show that policy-focused content was the most effective, increasing engagement, authenticity, participation, and POPR. AI-generated visuals boosted engagement and POPR but did not enhance authenticity, while opponent attacks weakened authenticity and party relationships. Notably, political memes had no significant effect on engagement, authenticity, participation, or POPR, challenging their assumed effectiveness as a mobilization tool.
These results suggest that digital campaign strategies should prioritize substantive policy messaging over viral content. While AI can drive engagement, it does not necessarily foster trust, and negative campaigning may alienate young voters rather than mobilize them. The study emphasizes the need for credible, policy-driven, and strategically balanced digital campaign communication to translate online engagement into real-world political action.M.S
Assessing Algorithmic Bias in Machine Learning Classifiers: A Fairness Evaluation
No full textIn the realm of healthcare, AI stands as an invaluable tool for performing several
important tasks, such as the classification of diseases and the preprocessing of healthcare
data. It excels in organizing medical documentation, enabling remote patient monitoring,
and extracting critical information from EHR systems. With the benefits that AI provides,
it is important that its predictions are unbiased, particularly when it relates to a patient.
A biased model could lead to unfair outcomes for subgroups within a population. AI
should be able to give accurate predictions regardless of a patient’s demographics. This
study examines algorithmic bias in machine learning classifiers (MLCs). Six classifiers —
Logistic Regression, Random Forest, Gaussian Naive Bayes, K-Nearest Neighbors (KNN),
and Gradient Boost—were evaluated for predictive performance and fairness. In addition, an
Artificial Neural Network (ANN) is also trained and tested for its accuracy and fairness. Two
experiments are performed to analyze these models. In the second experiment, the Gradient
Boost model is transformed into an XGBoost model to analyze its performance. The findings
show that, overall, the Random Forest model gave the best results. This work contributes to
the development of equitable AI systems in healthcare by providing comparative insights
into classifier biases.M.S
Philosophies of Death in the Works of F. Scott Fitzgerald and Ernest Hemingway
No full textAt perhaps its most basic level, literature explores how to live, and philosophy, in part, examines what living means. Though seemingly paradoxical, the philosophers who deal extensively with and primarily study questions of existence are the philosophers who most often confront the matter of death. Three philosophers share commonalities among their framings of death: Horace (65 BC-8 BC), Søren Kierkegaard (1813-1855), and Jean-Paul Sartre (1905-1980). Common to each philosopher is the inclusion of death as part of the framework of life and human experience.
While these philosophers pose intellectual answers to questions about existence in light of death, certain American authors provide possible answers through the stories they create in literature as they examine the human condition—the very nature of existing. Dubbed members of the Lost Generation, F. Scott Fitzgerald (1896-1940) and Ernest Hemingway (1899-1961) wrestled with philosophical concerns in their fiction. World War I left Fitzgerald and Hemingway disillusioned and restless, with a desire to search, to wander, and to explore—desires which are reflected in the characters they created, characters who engage deeply in living.
As these two authors work out the question of how to live, they somewhat obsessively include the fact of life’s finitude. The pervading topic of death peppers their narratives, and life seems to be dictated by death. Similarly, Horace, Kierkegaard, and Sartre see death as an informant to life and their philosophies reflect as much. For both the authors and philosophers, to understand how to view life, one must understand how to view death—an understanding which takes into consideration questions of how to exist, explorations of the human condition, and to what end meaning can be found. Their philosophies about death, which illuminates their philosophies of life, are distinguishable and evident in the works of both Fitzgerald and Hemingway.Ph.D
Effect of palmar digital analgesia (as a result of "nerving") on forelimb loading over varied surfaces at the walk and trot - a pilot study
No full textPalmar digital neurectomy or “nerving” removes the sensation to the heel region of the
hoof, while analgesia or “blocking” results in temporary loss of sensation. This pilot study
examined the effect of loss of sensation in the forelimb heel (blocking). Three horses were fitted
to hoof sensors on the front hooves. Horses completed the same randomized tests of walking and
trotting on hard and soft ground pre and post-nerve blocking. Interaction of ground and blocking
status was significant for area (P < 0.0001), with post-blocking having greater loaded area than
pre while tracking on hard ground (P = 0.008). The same interaction was found significant for
force (P <0.0001), with tracking over hard ground being greater post-blocking than pre (P =
0.008). Stride duration was longer pre-blocking than post (P = 0.0017). Findings from this pilot
study show that temporary blocking impacts forelimb loading and that ground may be important
in tracking for horses with removed sensation to the forelimb heel.M.S
Uncovering the Impact of Growth Mindset Factors on the Text Selection of Middle School Students
No full textNational Common Core State Standards hold that students become increasingly more capable of comprehending complex text throughout their school years. There is high importance for students to increase their reading of complex text in order to support reading development. Text complexity research shows the factor of complex text offers students the opportunity to gain more vocabulary and knowledge as well as experience with more syntactically complex sentences and text structures. With regard to enhanced academic success, interventions using Carol Dweck’s growth mindset concepts promote the consideration of non-cognitive factors amidst student growth in learning. However, research reveals growth mindset interventions have shown limited effects amongst elementary and adolescent-aged students. Some growth mindset interventions have, however, shown some effects for at-risk students. This study examined the relationship among student growth mindset, attitudes of reading complex text, text selection choices, and reading comprehension. Middle schoolers in the sixth grade were administered a growth mindset and text complexity survey. They also completed a standardized comprehension measure. They participated in a daily text selection task in which they had three different levels of text to choose from. On the last day, students were randomly assigned to two conditions, one in which they received directions intended to promote a growth mindset about text selection and a control condition. Contrary to hypotheses, the results indicated that students with a higher growth mindset tended to choose less complex text. Additionally, there was a statistically negative relationship between student growth mindset and reading comprehension, suggesting students with a higher growth mindset tended to have lower scores in comprehension. In contrast, results also revealed that on average, students with exposure to growth mindset directions made more rigorous text selections than those without growth mindset instructions. However, those differences were not statistically significant.Ph.D
Redefining an African American Cultural Landscape: The Relocation and Preservation of the Lee-Buckner Rosenwald School
No full textThe Lee-Buckner Rosenwald School’s history and place in the Duplex community of Williamson County, Tennessee, is not unlike other rural African American schools in the South. In 1868, the Freedman’s Bureau established the Rural Hill School in a log building that doubled as the Rural Hill United Methodist Church and served the Rural Hill community. In the 1890s the Rural Hill community was renamed the Duplex community, and the school became the Lee School and subsequently the Lee-Buckner School. In 1927 the African American residents of Duplex raised money and received funds form the Rosenwald Fund to build a new schoolhouse on the adjacent property to the former Rural Hill Methodist Episcopal Church and School. The new schoolhouse became the Lee-Buckner Rosenwald School and served the Duplex community until 1965 when schools in Williamson County were integrated. The schoolhouse was abandoned until February 2024 when it was relocated to the campus of Franklin Grove Estate and Gardens in the city of Franklin in Williamson County. Lee-Buckner School was a part of the African American cultural landscape that formed the Duplex community which, like other rural African American communities, were built around churches, schools, and cemeteries. The absence of the Lee-Buckner School from the Duplex community leaves a physical and historical void. In its new location it is imperative to preserve and interpret the school building, its history, and how it fits into a new landscape that once enslaved African Americans and later denied them ownership of the property.Ph.D
Neurotic and Need a Nap: How Personality Affects Weekend Recovery, Engagement, and Exhaustion
No full textWorkplace recovery is defined as the process of replenishing expended resources that
were lost at work (Sonnentag & Fritz, 2007; Bennett et al., 2015). This process is important for
employee productivity, health, and well-being, as it helps employees reduce negative outcomes
from demands and decreases short-term strain reactions (Sonnentag et al, 2010). To fully
examine the recovery process, two studies were conducted examining how engaging in each of
four recovery experiences over a weekend may lead to a change in employee engagement and
exhaustion levels. A second goal of this study was to examine the moderating role of neuroticism
on the relationship between weekend recovery experiences and changes in exhaustion and
engagement over the weekend. The first study was conducted with a sample of 163 nurses, and
the second study was conducted with a sample of 14 nurses. There were no significant findings
from either study. Exploratory analysis, however, revealed that mastery was a valid predictor of
nurses level of engagement on Monday morning. Furthermore, the results indicated that
neuroticism was a moderator of the relationship between mastery and control activities and
engagement levels on Monday morning. These findings highlight the importance of engaging in
mastery and control experiences for increased engagement at work.M.A
The Effects of Altered Font for Students With and Without Decoding Difficulties
No full textDyslexia fonts have existed for nearly 20 years. These fonts were designed for readers with dyslexia to make it easier for them to read. Some advocates claim that these specialized fonts mediate the effects of dyslexia, while critics point out the lack of research showing their effectiveness and the high costs of accessing the fonts. Current research on altered fonts shows mixed effects. This research aims to extend the existing research base on altered fonts for students with dyslexia. In a recent meta-analysis, Shewalter et al. (2023) found relatively few studies that have measured reading accuracy or rate in deep orthographic languages like English. Even fewer studies have measured reading comprehension using altered fonts. Therefore, this study measured the effects of altered fonts compared to standard fonts on reading accuracy, reading rate, and reading comprehension for students with and without decoding difficulties. The study implemented a within-subject quasi-experimental design with participants from grades 3, 4, and 5 from a public elementary school in Tennessee. Participants read word lists and passages printed in five different font types: Times New Roman (TNR), TNR with added spacing, Arial, Arial with added spacing, and OpenDyslexic font. By utilizing altered and unaltered fonts that vary in characteristics (e.g., serif/sans serif type style, added spacing), the study attempted to parse out the effects of the individual font characteristics.Ph.D
Unpacking the Work-Related Thoughts that Follow you Home: Anticipation, Rumination, and Exhaustion
No full textStress is a prevalent challenge in everyday life, particularly affecting employee well-being in the workplace. This study examined the effects of off-job thinking, namely anticipation and rumination concerning work, on the relationship between stress and exhaustion experienced by individuals. Participants were recruited from two populations of nurses and were asked to respond to a series of questionnaires. In Study 1, we examine these effects in a sample of 21 oncology nurses from Vanderbilt University Medical Center (VUMC). Using multilevel mediation models, we found that stress was positively associated with work-related rumination and negative anticipation, but rumination and anticipation did not significantly predict or mediate the relationship between stress and exhaustion. The results indicated a poor model fit, which was acknowledged given the small sample size. In Study 2, we expanded on these findings by investigating the role of off-job thoughts as a mediator between stress and exhaustion in a larger sample of 167 nurses recruited from Prolific. The results showed that higher levels of appraised stress were positively associated with both rumination and negative anticipation, which in turn were related to increased exhaustion. However, like Study 1, neither work-related rumination nor negative anticipation significantly mediated the relationship between stress and exhaustion. These findings suggest that while stress affects rumination and anticipation, these factors do not serve as key mediators in the stress-exhaustion process.M.A