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“At some point, the rubber meets the road”: A Case of Racialized Recruitment and Yield Practices at One Historically White Land-Grant in the Deep South
No full textThis critical qualitative case study interrogated the racialized recruitment and enrollment practices at one historically and predominantly white land-grant institution in the Deep South. The purpose of this study was to interrogate how Magnolia University, nested within the increasingly hostile post-affirmative action/anti-DEI legal landscape, prioritized engaging with Black prospective students. Five participants – three professional staff members and two currently enrolled Black student leaders – responsible for supporting recruitment and enrollment efforts were interviewed. To make meaning of the data, Ray’s (2019) theory of racialized organizations was employed as an analytic framework using writing as inquiry techniques. Findings reveal how the positive credentialing of whiteness at Magnolia University guided the unequal resource distribution and differential agency of institutional actors responsible for engaging with prospective Black students. As such, Magnolia University is currently at a crossroads between prioritizing (over)compliance with inequitable legislation and their espoused DEI values. Implications for practice, policy, and future research that prioritizes Black student recruitment, enrollment (and retention) for historically and predominantly white land-grant institutions like Magnolia University are discussed
Masking corporatas with communitas rhetoric: How the National Football League influences fans through their public messages
Full text linkThis study examines the National Football League's (NFL) complex communication strategies, focusing on how teams navigate the tension between two opposing rhetorical frameworks: corporatas and communitas. Corporatas, characterized by competition, hierarchy, and profitability, contrasts with communitas, which emphasizes community, equality, and shared passion (Boyd & Stahley, 2008). By analyzing press releases and social media posts—specifically, those addressing player trades, releases, and promotions—this research explores how NFL teams balance these competing discourses to maintain fan engagement while upholding their corporate interests. This study employs a rhetorical analysis of NFL team communications to examine how organizations craft messages that address business imperatives and fan engagement. Social media platforms and team press releases provide teams with a direct means of engaging audiences to balance professionalism, transparency, and fan loyalty. The analysis highlights the rhetorical strategies teams employ to reinforce brand identity, manage public perception, and navigate sports communication in the digital era.
The findings enhance understanding of how professional sports organizations merge corporate identity with community messaging. By showing the relationship between corporatas and communitas, this research provides insights into fan engagement and organizational expectations in professional sports. Ultimately, it emphasizes the balance NFL teams need to maintain for competitive success and strong emotional ties with fans
OPTIMIZING WARM WATER AQUACULTURE: DIETARY SUPPLEMENTS, AND TEMPERATURE EFFECTS ON GROWTH, HEALTH AND MICROBIOME
No full textWith the rise of the global population, the increasing food demand has led to the intensification of farmed aquatic animal production. These intensified practices require substantial resources, including specialized feed and water. The high demand for fish protein strains production systems, leading to higher stocking densities and increased stress on fish. Additionally, these aquaculture practices have increasingly become unsustainable due to their high resource demand and environmental impact. This affects warm water aquaculture worldwide and in the southern USA. To find solutions to the unsustainable aquaculture practices, four independent studies were conducted to explore new technologies with the effects of dietary supplements on the growth, health, and microbiome of two major warm water aquacultural species in the USA.
Biofloc technology is an innovative technology that can be used to propagate warm water aquatic species. It is based on the mass production of heterogenous microorganisms that are beneficial to aquatic species and maintain the carbon and nitrogen ratio of the system. Some of the advantages of biofloc systems include good water quality conditions, reduced water usage, increased biosecurity, and reduced feed conversion ratio. This closed aquaculture system provides environmental and production advantages that will be well suited for the growing food demands. To further explore the application of biofloc systems, the first trial was conducted to investigate how probiotics as dietary supplements influence the growth and health of Nile tilapia.
Nile tilapia are well adapted to biofloc systems. This study evaluated the effects of the two commercial probiotics, AP193 and BiOWiSH FeedBuidler Syn 3 on growth parameters, disease resistance and innate immunity of Nile tilapia. When the fish were challenged with a common Nile tilapia pathogen (Streptococcus iniae), the probiotic-fed fish had enhanced disease resistance. However, growth was not affected by the probiotics fed to the fish. This study gave us insights into the fact that applying dietary supplements in biofloc systems might be a sustainable approach to provide extra protection to aquatic species reared in intensified systems.
The second study was conducted to optimize the functions of the biofloc system by combining biofloc systems with hydroponic systems. Nile tilapia and romaine lettuce were grown in a biofloc integrated decoupled aquaponic system. Two health-promoting dietary feed additives, a protease complex and a humic substance, were used as treatment groups. Although no growth differences were observed, the feed additive-treated romaine lettuce exhibited higher chlorophyll content. The microbiome of Nile tilapia fecal samples, biofloc water, and root samples were also examined. The application of health-promoting additives have positively influenced microbial diversity, indicating the benefits of using health-promoting dietary additives in aquaponic systems.
The subsequent study further explored aquaponic systems with other microbe-derived dietary supplements. Two commercial postbiotics with fermented yeast products (DVAQUA and NutriTek) were used. This study also revealed no differences in Nile tilapia and romaine lettuce growth. Still, it showed increased survival rates in Nile tilapia when challenged with another bacterial pathogen (Flavobacterium oreochromis). Significant variations in various alpha diversity indices (Shannon diversity index, Chao1, and observed species) of fecal and root microbial communities were also observed, emphasizing the influence of yeast-derived supplements on aquaponic systems.
A final study focused on channel and hybrid catfish to optimize production in warmer temperatures. The study investigated the impact of high temperatures on these two species of catfish fed with plant-based diets supplemented with alternative animal protein sources. Results demonstrated reduced survival and growth metrics at high temperatures, with diet and temperature affecting digestibility coefficients, immune responses, and gene expression. Histological analysis also showed alterations in connective tissue structures in the gut of channel catfish at high temperatures.
In response to the increasing need of sustainable and resilient aquaculture systems, these studies collectively provide insights into optimizing warm water aquaculture through strategic dietary supplementation and temperature management to enhance the growth, disease resistance and microbiome composition. These findings will further support the development of innovative aquaculture practices that will be capable of meeting the growing demands under changing environmental conditions
Stay Interviews and Teacher Retention in Private Schools
Full text linkTeacher retention remains a critical challenge in private K-12 schools, where high attrition rates can disrupt student learning and institutional stability. This study examines the effectiveness of stay interviews as a proactive strategy for improving teacher retention by identifying and addressing workplace well-being factors. Grounded in Seligman’s PERMA model of well-being, the research employs a mixed-methods approach, integrating quantitative survey data with qualitative interviews to gain a comprehensive understanding of teachers’ experiences and perspectives.
The study was conducted at Presbyterian Christian School (PCS), where educators participated in a stay interview survey measuring workplace well-being and retention factors. The survey utilized a seven-point Likert scale and included open-ended questions to capture nuanced insights. In the qualitative phase, semi-structured interviews were conducted with teachers to explore key themes related to job satisfaction, work-life balance, organizational trust, and mental health support. Findings revealed that when stay interviews were followed through with meaningful action, they provided valuable improvements in workplace conditions, increased teacher engagement, and strengthened institutional trust. Teachers reported that effective stay interviews led to tangible changes in administrative support, resource allocation, and professional development opportunities.
By integrating qualitative and quantitative data, this study provides evidence that well-executed stay interviews can serve as a powerful retention tool in private K-12 schools. The research underscores the importance of aligning stay interviews with broader school initiatives, ensuring actionable follow-up, and fostering a culture of trust and psychological safety
Understanding Execution Faults in Ansible-based Configuration Management
Full text linkAnsible is a popular tool for implementing the practice of infrastructure as code. While usage of the tool yields benefits for practitioners, faulty execution of Ansible configuration scripts can cause serious consequences, such as crashes. An analysis of execution faults, i.e., faults that occur in Ansible's executor component, can aid practitioners in validation and verification activities to facilitate reliable execution of configuration scripts. An empirical study of 33 execution faults collected from the open-source Ansible repository was conducted. I derive 6 fault categories and 4 fault consequences. By analyzing 33 issue reports related to execution faults, I also derive properties to perform verification of the executor component in Ansible. Using formal verification, I reproduce one fault, and identify one new fault in the executor component of Ansible, which has been confirmed to be valid by Ansible contributors. Dataset and source code used for this thesis are publicly available online
Characterization of phagocytic hemocytes within the hemolymph of the American cockroach
No full textPhagocytosis is a function of the immune system found across eukaryotes that is necessary for both innate and adaptive immune systems. Much of our current knowledge of immune functions traces back to the ability of specialized cells in an organism to recognize, engulf, and destroy particles. Insects are the largest numbered organisms on the planet with some estimatinges that 75% of all species of living organisms insects. This incredibly large and diverse order of organisms is often overlooked outside of a few species that have been used as model organisms. One such overlooked insect is the American cockroach (Periplaneta americana. These insects are cosmopolitan as they can be found in almost every environment. This includes close proximity to humans such that they are often encountering many of the same potentially deadly microorganisms, or have the possibility of being vectors of disease spread. The American cockroach could prove to be a useful model organism to study the effects of the microbiome on the immune system
With this in mind there are two aims of this thesis research: 1) to identify which cells in the hemolymph of the American cockroach are the phagocytes using modern techniques such as flow cytometry; 2) to describe some characteristics of phagocytosis in conventional cockroaches to provide a foundation for future studies. The treatments tested in this study include incubation time, temperature, and different bacterial and fungal stimuli, as well as the use of peptides to inhibit phagocytosis
Quantifying the Impact of Porosity on Mode I Fracture Behavior in Advanced Composite Materials
No full textAdvanced composite material applications are rapidly proliferating within the aerospace industry, but challenges remain to their more widespread adoption due to the influence of process-induced defects. The complex manufacturing efforts to combine multiple discrete materials inevitably result in porosity being a pervasive issue for composite materials. These process-induced defects impair material reliability and limit the application potential of advanced composite materials.
While the impacts of porosity on composite materials' elastic properties are widely researched numerically and analytically, gaps remain in quantifying porosity's effect on advanced composites' crack resistance. Another challenge within this study is that porosity is stochastic, which means that the material characterization tests for two specimens with the same porosity level will produce two different results.
This work will focus on the mode I delamination behavior of porous composites. A 'pristine' specimen and a purposefully engineered defected specimen validate the ability to accurately model a well-defined porous system within an established modeling procedure, the cohesive zone model. This process expands to evaluate stochastic porosity through random pore generation and random sampling. Despite the collapse of the self-similar crack assumption, this method proposes a way to calculate an effective mode I strain energy release rate within these frameworks. Further, this study investigates the impact of local pores on the local effective mode I strain energy release rate. Additionally, this study opens the door to leveraging a dataset from random sampling to train a machine learning (ML) algorithm to predict material behavior based on a given porous microstructure and quantify the impact of various pore parameters on the system
Material Characterization of Undoped & Doped Lead-Free Solders under High Strain Rates and Solder Joint Reliability for Combined Effects of Vibrations and High-Temperature Surroundings
No full textIn the rapidly advancing fields of automotive, oil exploration, and military electronics, components are increasingly required to operate under extreme conditions, characterized by high and low temperatures and transient loads with high strain rates. Such demanding environments subject electronic products to strain rates ranging from 1 to 100 per second, and temperatures from -65 °C to 200 °C. These harsh conditions often result in significant mechanical stresses on solder joints, which are among the most vulnerable points in electronic assemblies during operations involving shock and vibration. This research work aims to investigate the mechanical behavior of solder alloys under these extreme conditions, focusing particularly on the impact of high strain rates, thermal aging, and elevated temperatures on the reliability of solder joints.
The research focuses on three types of solder alloys: a conventional un-doped solder SAC305, and two doped solders, SAC-Q and M758. These doped solders have been recently developed to enhance resistance to aging and creep, without compromising strength or melting point. Experimental investigations were conducted to characterize the mechanical behavior of these solders across a wide temperature range (-65 °C to +200 °C) and strain rates (10–75 s⁻¹). The specimens were tested in both pristine and thermally aged conditions, with aging durations extending up to one year at 100 °C. Key mechanical properties, including Ultimate Tensile Strength (UTS) and Elastic Modulus (E), are measured and compared across the different solder alloys. The results revealed significant variations in mechanical properties due to temperature, strain rate, and aging, with doped solders such as SAC-Q and M758 exhibiting better resistance to degradation compared to SAC305. The addition of dopants like Bismuth (Bi) and Nickel (Ni) improved the performance of SAC-Q and M758 by reducing property deterioration over time, particularly under prolonged thermal storage.
The study also focuses on the extraction of Anand Model constants for both pristine and aged SAC solders across various aging durations. The Anand Viscoplasticity Model equations are fitted to the experimental stress-strain data, allowing for accurate predictions of solder behavior under different conditions. To validate the predictive capability of the Anand Model, the stress-strain curves predicted by the model are compared with the experimental data, for understanding the accuracy of the model in simulating the real-world behavior of solder alloys. The research further explores the evolution of Anand Parameters with respect to thermal aging duration for SAC305, SAC-Q, and M758 solder alloys. In addition to experimental and modeling efforts, this thesis explores the predictive potential of Bismuth content in solder alloys. A novel prediction framework was developed to estimate mechanical properties, such as UTS and E, for Bi-enhanced solders based on trends observed in experimental data. Higher Bi content was shown to reduce property degradation at high strain rates, making such solders more suitable for applications with prolonged high-temperature exposure.
The study also includes a finite element analysis (FEA) for drop/shock events using the extracted Anand Model constants for a PCB-PBGA324 package assembly. The board-level drop tests are performed according to JEDEC standards, employing the Input-G method. The analysis aims to compare hysteresis loops and accumulated plastic work densities for the various SAC solders, evaluating the extent of damage to solder joints per impact under various test conditions. Additionally, for vibration study a test vehicle comprising a PCB-CABGA208 Package assembly with SAC-Q solder joints is prepared and tested to failure. Test conditions include temperatures of up to 150 °C, and harmonic vibrations up to 10g acceleration levels. The experimental data obtained from the tests are correlated with FEA-based modal analysis results. The research investigates the effect of operating temperatures on the first natural frequency of test boards and captures vibration events using high-speed cameras and Digital Image Correlation (DIC) method. Finally, the dissertation addresses the characteristic life and failure modes of solder joints in Package-PCB assemblies subjected to high-temperature vibration. Both experimental and FEA methods are used to establish damage relationships for life prediction. By combining these experimental and computational approaches, this research contributes to a thorough understanding of the mechanical behavior of solder joints under harsh environmental conditions.
The comprehensive datasets, validated constitutive models, and predictive frameworks developed in this research advance the state of the art in solder joint reliability. The findings provide critical insights into the material selection and design of electronic assemblies for harsh environments, contributing to enhanced performance and reliability. This work has significant implications for industries such as automotive, aerospace, and defense, where the failure of electronic components can have catastrophic consequences. In summary, this thesis delivers a holistic approach to understanding and predicting solder joint behavior under extreme conditions. Through experimental investigations, advanced material modeling, and FEA simulations, it addresses key challenges in solder joint reliability. The contributions of this research are expected to guide future developments in solder materials and reliability analysis, ensuring the safe and efficient operation of electronic assemblies in demanding environments
Hormonal regulation for the prevention of cognitive decline of Alzheimer’s disease
No full textAlzheimer’s disease (AD) is the most common form of dementia, with its two pathological hallmarks being the abnormal accumulation of amyloid beta (Aβ) and the hyperphosphorylation of tau, leading to neuronal degradation. Aging is known to be the number one contributing risk factor for AD, with reproductive senescence proving a clear driver for pathological development. Luteinizing hormone (LH) has become a recent subject of research for its role in the etiology of AD, with LH levels jumping upon reproductive senescence. Recent evidence suggests that LH serves as a novel target for dementia treatment, including AD. We hypothesized that AD pathology and memory deficits will be prevented by the reduction of LH levels via a novel adeno-associated virus (AAV) vector treatment in female APP/PS1 mice. In the current study, AAV-mediated anti-LH antibody treatment was tested to investigate its ability to prevent cognitive decline and AD pathologies in the APP/PS1 mouse model of AD. We investigated changes in locomotor activity, short-term working memory, anxiety-like behaviors, and hippocampal-dependent spatial reference memory and learning. Additionally, the ability for AAV-mediated anti-LH antibody treatment to prevent the AD pathologies Aβ plaques and hyperphosphorylated tau was investigated. This work contributes to a growing body of evidence which suggests a therapeutic potential for targeting elevated LH levels in the prevention or treatment of AD
Teaching and Assessing Decision-Making Across the Physics Curriculum
Full text linkProblem solving is prevalent in all levels of physics and receives considerable attention in physics education research. This dissertation focuses on investigations of problem-solving in understudied areas of the physics curriculum: courses for non-STEM majors and graduate-level courses. The first study describes the design, implementation, and evaluation of laboratory activities for non-science majors which scaffolded experimental design and decision-making over a semester. Students exhibited shifts toward more expert-like views of experimental physics and improved capabilities make experimental decisions. The activities designed in this study drew on existing frameworks in the PER community, but no such curricular frameworks exist at the graduate level. Thus, the next study used semi-structured interviews and textual analysis to identify physics instructors’ expectations for problem-solving in graduate coursework, as well as how problem-solving is implemented and assessed in practice. Instructors expected far more problem-solving skills than were practiced in coursework. The final study discusses the development of an assessment to measure a broader range of problem-solving skills in quantum mechanics and describes evidence for the face validity of the assessment. Together, these chapters expand our understanding of problem-solving in classrooms and build the groundwork for future interventions