Repository logo
 

Master's Theses

Permanent URI for this collectionhttp://hdl.handle.net/10342/124

Browse

Recent Submissions

Now showing 1 - 20 of 3950
  • ItemOpen Access
    EXPERIMENTAL AND NUMERICAL STUDY ON THE COMPARISON OF POINT-ABSORBER WAVE ENERGY CONVERTERS
    (East Carolina University, December 2024) Cortez, Benjamin
    The objective of this thesis is to investigate how buoy geometry affects the performance of point absorber wave energy converters. Five different buoy geometries were designed, each with the same initial diameter and total height. These models were then tested using the same experimental conditions. The experimental phase was conducted in a lab scale wave tank and involved the use of a LVDT sensor to measure buoy displacement, wave height gauges to measure water height, and a high-speed camera to record the experiments. The models were tested completely perpendicular to the water as well as at different angles with the water. ANSYS AQWA was used for numerical analysis of the buoys. The buoy models were modeled perpendicular to the water using the wave conditions that were recorded in the wave tank as well as the wave conditions that were recorded at Jennette’s Pier (Nags Head, NC) over five days. AQWA wave tank simulations output graphs depicting amplitude, radiation forces and gravitational forces for each buoy while the environmental simulations focused on amplitude only. Buoyancy forces were calculated for each model (perpendicular to the water only). The experimental results showed the overall trend that as angle of inclination increased, the buoy amplitude would decrease. The most likely reason why the ranges decreased as the angle of inclination increased was because as the LVDT sensor was inclined, the shield of the sensor began acting as an inclined plane creating friction between the sensor shield and armature. One model consistently outperformed the other models in both the wave tank and environmental simulations. The wave tank simulations also suggested a correlation between volume and buoy amplitude. There were differences between the experimental results and numerical wave tank results. This could have been because of friction between the sensor armature and shield, irregular wave shapes in the wave tank, certain parts not modeled in AQWA, and negative damping values in AQWA. Further studies into buoy geometry in point absorbers should examine performance changes when changing materials to examine the relationship between mass and buoy performance more thoroughly.
  • ItemOpen Access
    VISUAL ATTENTION AND SELF-EFFICACY IN COED CHEERLEADING
    (East Carolina University, December 2024) Chambers, Mikayla Yvette
    Approximately 35,000 cheerleading injuries were reported annually for participants between the ages of 5-25 years old (Amy et al., 2021). Self-efficacy, role, and attention provide predictive information and contribution to the quality of motor execution, including group settings. However, there remains a gap in knowledge about the activity of cheerleading and the growing rate of injuries PURPOSE: Therefore, the purpose of this study was to examine the extent to which self-efficacy relates to visual fixation duration and frequency in co-ed cheerleading, and if visual fixation and duration differ between base and flyer across self-identifying role, skill level, and roles observed (flyer and base). METHODS: Members of the same university’s coed cheerleading team consisting of male and female participants between the ages of 18-25 participated in the study. Inclusion criteria were as follows: 1) current member of a collegiate coed cheerleading team 2) normal or corrected to normal vision 3) no current self-reported neurological illness/injury. Eligible subjects were recruited through email. The sample consisted of (n = 3) males and (n = 2). participants completed a self-efficacy questionnaire and watched a series of progressively difficult stunts, categorized into 3 levels of difficulty. Visual attention was measured using eye tracking to determine fixation count and duration. RESULTS: Multiple t-tests were used to test the relationships between each variable. Across each skill level self-efficacy decreased for easy M = 9.63, SD = 0.42. Flyers fixated in the flyer AOI (Mfreq = 134.75) less compared to how much the bases fixated in the flyer AOI (Mfreq = 148.69). The shortest fixation occurred during the hard skill level in the flyer AOI for bases (1316.611 ms) and flyers (1377.263 ms). The correlation between self-efficacy and fixation count of the base was negative and medium to large but not significant for easy, medium, and hard tasks (r = -.78, -.81, -.41; p = .12, .09, .49). The correlation between self-efficacy and fixation duration of the base was negative and small to medium but not significant easy, medium, and hard tasks (r = -.31, -.58, -.19; p = .61, .31, .76)There were no significant differences observed across bases and flyers for fixation count and duration (t = .34 - 1.92; p = .15 - .75). Significant differences were observed across skill level for fixation count (Mfreq = 13.80; p = < .001, η²ₚ = .70) and duration on the flyer AOI (Mfreq = 19.54; p = < .001, η²ₚ = .77). No significant differences were observed across base and flyer AOIs except in the instance of fixation count during the medium skill difficulty (t = 2.73, p < .05, d = 1.22). Regardless of role, participants looked at the flyer more often (M = 60.87) than the bases (M = 43.67) during the medium tasks. CONCLUSION: According to the present study, confidence is associated with changes in visual attention. Additionally, visual attention differs by role, and skill difficulty. From this data we have seen influences on teamwork, specifically in coed cheerleading while highlighting the high risks in stunting.
  • ItemOpen Access
    The Effects of Bat Grip Type on Baseball Hitting Performance
    (East Carolina University, December 2024) Langston, Macon
    INTRO: The success of a hitter for the longest time was defined by batting average but in today’s game success is more focused on performance metrics such as bat speed, attack angle, and exit speed. One aspect of hitting that has been shown to have a potential effect on performance is the way you grip the bat. The few common ways to grip the bat include the “conventional grip” (aka normal grip), choked up grip, and the “palmar hamate grip” (aka pinky or pinky off grip). The palmar hamate grip is becoming more popular across baseball as there is belief that it can increase performance. If there is some type of performance benefit, it would be valuable to investigate the mechanism or explanation for the improvement in performance. With the wrist being near the bat and slight movements potentially affecting the orientation of the bat, an analysis should be performed to see if changes in wrist kinematics could explain potential performance benefits from the palmar hamate grip. Prior research in regards to the palmar hamate grip and its effect on performance and wrist kinematics is limited. Additionally, a major limitation in prior research is not accounting for grip preference. PURPOSE: The main purpose of this study was to analyze the effect of the palmar hamate grip on baseball hitting performance in comparison to the conventional grip, accounting for grip preference. The secondary purpose of this study was to analyze the effect of the palmar hamate grip on wrist kinematics in comparison to the conventional grip, also accounting for grip preference. METHODS: Twenty-one high school and collegiate right-handed hitters (ages 16-22) participated and were separated into two groups based on grip preference (conventional, n = 14; palmar hamate, n = 7). The study consisted of two conditions: in the first, participants completed 5 maximal effort swings off a tee with their preferred grip; in the second, participants completed 5 maximal effort swings off a tee with their non preferred grip. Bat speed and attack angle were measured via Blast Motion sensor, exit speed was measured via Stalker Sport 2 radar gun, and smash factor was calculated by dividing exit speed by bat speed. Wrist kinematics were measured via 12 camera Qualisys 3D motion capture system. Wrist angle at contact, wrist range of motion (ROM), wrist angular velocity at contact, and maximum angular velocity in all three axes (x-flexion/extension, y-ulnar/radial deviation, z-pronation/supination) for both left and right wrists were calculated in V3D. RESULTS: Statistical significances were found for attack angle and smash factor but not for bat speed or exit speed. For attack angle, a significant difference was found between the palmar preferred and conventional preferred group in the preferred grip condition (8.57 ± 4.29° vs. 4.37 ± 4.13°, p < 0.05). Additionally, within the palmar preferred group a significant difference was found between the preferred and non-preferred grip conditions (8.57 ± 4.29° vs. 7.14 ± 5.00°, p < 0.05). For smash factor, the only significant difference found was between the preferred and non-preferred grip conditions within the conventional preferred group (1.16 ± 0.03 vs. 1.18 ± 0.03, p < 0.05), however this difference is not meaningful (d = 0.46). Wrist kinematic variables that showed significance included: left wrist flexion/extension angle at contact, left wrist pronation/supination angle at contact, left wrist flexion/extension ROM, left wrist ulnar/radial ROM, left wrist flexion/extension angular velocity at contact, and left wrist flexion/extension maximum velocity. However, the significance found for these variables were not clear in their effect on performance. No other significances were found for other wrist kinematic variables. CONCLUSION: The findings of this study indicate that the palmar hamate grip has some influence on attack angle, but not bat speed, exit speed, or smash factor. Also, the palmar hamate grip had no clear effect on wrist kinematics, suggesting the change in attack angle seen could potentially be due to other body kinematics. The more positive attack angle seen with the palmar preferred group compared to the conventional preferred group in the preferred grip condition is meaningful. Having a more positive attack angle helps in matching the bat path with the downward angle of the incoming pitch which maximizes the chance of solid contact and generates more optimal launch angle potentially leading to increased power and ball flight distance. Given that the changes in attack angle acutely were modest, the findings suggest long term training with the palmar hamate grip would be needed to improve attack angle.
  • ItemOpen Access
    Understanding the Use of Emerging Technology in the Middle School Art Classroom
    (East Carolina University, December 2024) Murphy, Aleix Kobie
    This study explores the use of emerging technology in middle school art classrooms. It is intended to assist the Wake County Public School System’s Middle School Professional Learning Community identify where their members most need support accessing resources and guidance for emerging technology integration. The research methods included a survey and an interview. A sample size represented the middle school art teachers within the county. 22 teachers completed the survey, and two were interviewed. The participating art teachers gave insights into factors that influence their perspectives of technology integration and opinions on the support received from the professional learning community and school system. Art teachers indicated a need for technology-oriented professional development opportunities, the facilitation of technology training to promote digital citizenship for their students, potential collaborations between art and career and technical education departments, and funding for both installations and maintenance of technologies. Overall, the findings highlighted the need for increased guidance and support from the professional learning community and school system to help teachers integrate technology effectively into their art classrooms.
  • ItemOpen Access
    METAMORPHIC TESTING PRIORITIZATION FOR FAIRNESS EVALUATION IN LARGE LANGUAGE MODELS
    (East Carolina University, December 2024) Giramata, Suavis
    ABSTRACT Large language models (LLMs) face challenges in detecting fairness related faults due to the oracle problem, where it is difficult to define correct outputs for all scenarios. This research applies metamorphic testing (MT) as a solution, focusing on the prioritization of metamorphic relations (MRs) based on their diversity scores to maximize fault detection efficiency. The study hypothesizes that MRs with high diversity scores, indicating significant dif- ferences between source and follow-up test cases, are more likely to reveal faults related to fairness and bias in LLMs. To test this, several diversity metrics, including cosine similarity, sentiment analysis, and named entity recognition, are used to quantify differences between test cases. The proposed approach is evaluated on two popular LLMs, GPT and LLaMA, comparing it against random, fault-based, and distance-based MR ordering strategies. The results indicate that prioritizing high-diversity MRs significantly improves fault de- tection speed and effectiveness, particularly for identifying biases across sensitive attributes. Specifically, our proposed Total Diversity Score-based approach shows a 91.6% improvement in fault detection over the Random-Based approach at the first MR, gradually reducing to 21.05% by the fifth MR. Additionally, compared to the Distance-Based method, our ap- proach achieves an initial 130% improvement in fault detection rate, decreasing to 1.61% by the ninth MR before performance levels stabilize. Notably, our approach also performs closely to the Fault-Based prioritization, offering a balanced and effective method for uncov- ering faults efficiently.
  • ItemOpen Access
    UNDERSTANDING THE GRAY ZONE IN THE MARITIME DOMAIN: A CASE STUDY OF RUSSIA AND NATO IN THE BALTIC SEA
    (East Carolina University, December 2024) Klewicki, Brandon James
    This thesis investigates the evolving challenges in the maritime gray zone by conducting a case study on Russia's activities in the Baltic Sea and their impact on NATO and adjacent nations. It argues that Russia has adopted gray zone tactics in the maritime domain against NATO in the Baltic Sea region, and NATO is currently not postured to adequately deter these measures. It analyzes Russia’s clandestine tactics, including the covert transportation of ballistic missiles, deployment of undersea research vessels for malicious purposes, and disruption of maritime traffic using unconventional means in a concerted effort to coerce NATO without breaching the threshold of armed conflict. The study emphasizes the constraints faced by actors in effectively countering these actions, such as legal limitations on maritime operations and barriers to information sharing and cooperation among allied states. The research highlights the pressing need for enhanced coordination, intelligence, surveillance, and reconnaissance strategies to address the escalating gray zone threats in the maritime domain.
  • ItemOpen Access
    77%
    (East Carolina University, December 2024) Boone, Tamla
    Reflecting on my visits to sculptural exhibitions worldwide, I often observe a portrayal of a specific population characterized by features like pointed noses, straight hair, and predominantly pink or beige skin tones. While undeniably lovely, I question whether there exists a broader spectrum of beauty that could be showcased in these displays—a form of Non-traditional Beauty. My concept of beauty transcends conventional norms and embraces what is typically viewed as different, unattractive, or even awkward by societal standards—the "Uns." I challenge the perception that pink skin is the epitome of beauty and ponder why unique characteristics like crooked teeth, distinctive scars, colored skin, and unconventional body shapes are not celebrated in art. True artistry lies in the willingness to take risks and explore the unconventional. In my thesis, I cultivate a space where diverse forms of beauty are celebrated through a dynamic allure of authenticity and especially children, should see themselves reflected in museum settings. I hope to awaken a deeper appreciation for the multifaceted beauty that exists in every individual—the awakening of true beauty in the eye of the beholder.
  • ItemEmbargo
    The Resonance and Articulation of the Roman Moral Imagination in the Historical Thought of Sallust and Plutarch
    (East Carolina University, December 2024) Philips, James Patrick
    Within the Roman historical imagination from Polybius forward a “lapsarian motif” emerges that embodies the fundamental concerns of the Roman moral tradition. Even as it is transposed to different keys and arranged differently in successive authors, the melody remains discernible. For these historians, including Polybius, Sallust, and Livy, the original Roman virtus had become corrupted through a succession of foreign wars, leading to a society morally enervated by a multitude of vices. In contrast to the interpretation of modern historians who attribute the crises of the late Roman Republic to economic and social factors, the ancient historians consistently attribute the problems to a crisis of morality. Drawing on the idea of the longue durée from the Annales school of history, this thesis examines the moral thought of the Roman historical tradition often dismissed by modern historiography. In the process, it argues for a continuity of moral concern in Roman historical thought from Cato the Censor onward, seeking to understand the evolution of the moral tradition expounded by historians of the late Republic, such as Sallust, and assess its continuity with the ethical and historical reflection of the Principate and High Empire periods through the writings of Plutarch.
  • ItemOpen Access
    The Optimization of Golgi-Cox Staining in Parallel with Immunofluorescence to Colocalize the Adhesion Protein, N-Cadherin, to Developing Synapses
    (East Carolina University, December 2024) Frank, Victoria Elizabeth-Ray
    Numerous neurodevelopmental disorders, including Autism Spectrum Disorders (ASD), exhibit altered synapse formation. Post-mortem brain samples from idiopathic cases of ASD exhibit increased numbers of dendritic spines, which are the primary site of excitatory synapse formation. Excitatory synapses facilitate action potential formation, underlying cognitive functions such as learning and memory formation. Excitatory synapses develop in stages: synapse formation begins when post-synaptic spine precursors adhere to a pre-synaptic axon partner. As synapses mature, dendritic spines undergo a morphological transition from filopodia-like spine precursors to mushroom-shaped dendritic spines. These morphological changes increase the surface area adjacent to the axon partner, as well as the number of neurotransmitter receptors, thereby increasing the likelihood of action potential propagation. We are interested in the mechanisms of synapse formation, maturation, and maintenance. While there is considerable research on experience-dependent synapse maturation after birth, we lack understanding of the molecular mechanisms that initiate synapse formation and how these mechanisms are altered by ASD-associated genetic mutations and/or environmental factors. To address how synapse adherence occurs, we developed techniques to visualize association of the known synaptic adhesion molecule, N-Cadherin, with developing synapses. In this study we will be presenting the process of optimizing Golgi-Cox staining in embryonic mouse brain tissue to visualize post-synaptic dendritic spine morphology and using immunofluorescence in mouse brains to study N-Cadherin’s association with developing synapses. Our hypothesis stated that as synapse development progresses there will be an increase in N-Cadherin localized to synapses. Using these techniques, we saw trends which suggest that as the brain develops there will be an increase in the density of N-Cadherin positive synapses over time. Limitations of this study though prevented the acceptation or rejection of our hypothesis, instead it was inconclusive. The association we observed for the increase of N-Cadherin positive synapses over time, suggests a role for N-Cadherin in synapse stabilization/maturation. Further, significant differences were observed in that N-Cadherin positive synapses were larger than the negative N-Cadherin synapses on average. This supports the postulation that N-Cadherin promotes excitatory synapse maturation. Future research will use knockdown approaches to examine the role of N-Cadherin at distinct stages of synapse formation in neuronal cell cultures.
  • ItemEmbargo
    Impact of Health Literacy and Social Support on the Survival of Hispanic Chronic Kidney Disease Patients
    (East Carolina University, December 2024) Stallings, Taylor Lee
    ABSTRACT Background: Chronic kidney disease (CKD) is a significant public health concern in the United States (U.S.), particularly among Hispanic populations, as its prevalence is rising. Limited health literacy (HL) in CKD patients hinders self-management of the disease and health-related outcomes. Social support (SS) significantly influences CKD patient outcomes, yet its interplay with HL remains unexplored. We investigated HL, perceived SS, and sociodemographic factors among Hispanic CKD patients, assessing their impact on mortality related-risk. Methods: We analyzed data stemming from the Hispanic sub cohort of the Chronic Renal Insufficiency Cohort (CRIC) study, a longitudinal examination of CKD and cardiovascular disease risk factors over 15 years. Measures included HL (Short Test of Functional Health Literacy in Adults), SS (Medical Outcomes Study Social Support Survey), and sociodemographic factors, with marital status as a metric for SS. We conducted linear regressions to examine the relationship between HL, SS, a sociodemographic factor. Additionally, we conducted a series of Cox proportional hazards models to assess the impact of HL, SS, and sociodemographic factors on survival outcomes. Results: While a total of 327 individuals were enrolled in the H-CRIC study, only 140 participants were included in the current study due to having complete data at year 5 (39.8% male, Mage=59.01, SD=11.17). U.S. birthplace, age, and educational attainment significantly predicted HL scores, while SS did not. Cox proportional hazard models were run to assess the impact of HL on mortality of Hispanic CKD patients. HL was predictive of death (HR = .978, p<.05) and lower HL was associated with earlier mortality. In additional models including social support variables, unmarried status was approaching significance, indicating that it is also associated with increased risk of death (HR = .548, p<.05). When controlling for other mortality risk factors, older age (p=<0.05), participant sex (p= <.01), having diabetes (p= <.001), having CVD (p=<.05), and lower eGFR (p=<.05) were predictive of increased mortality risk, and marriage status- approached significance whereas HL in later models became non-significant (p= .707). Conclusion: Our study highlights the significant impact of sociodemographic factors, including birthplace, age, and education on health literacy scores. Notably, participants born in the U.S. exhibited higher HL scores, emphasizing the need for culturally tailored interventions to bridge HL gaps among diverse populations. These findings emphasize the need for regular assessment and continued monitoring of HL and social support in Hispanic patients with chronic kidney disease as it has been shown to increase mortality risk. Future research should aim to create culturally competent tailored interventions to address the gaps in literacy within diverse populations.
  • ItemEmbargo
    The Knight of Red and White
    (East Carolina University, December 2024) Black, Nathan James
    The Knight of Red and White is a work of creative fiction. This portion comprises the first seven chapters of a longer novel-length story. The story features aspects of a classic high adventure tale with elements of political intrigue in a fantasy setting. The narrative centers around themes of religion’s positive and negative influences on society, examining how religion comes to shape nations and history. This story is told from multiple perspectives in the third person and gathers a collection of characters from many different walks of society. From royals to knights, to servants, diplomats, revered clergymen, and street musicians: the story attempts to show the world from every angle and every opinion on faith or the lack thereof. The chapters present a world where faith can be used for great evil and miraculously noble deeds. In this universe religion acts as its magic system, setting a loose analogy to outlooks in our real world. Some characters adhere to faith, some see it as a tool to gain political power, some turn away from it, and others only wish to find a way to survive around it, having no strong feelings one way or another. This story hopes to give rise to discussions about where people find not just answers to universal questions, but where we find confidence and identity through theological and philosophical viewpoints. It seeks to unravel where words turn from personal affirmations to hard-held beliefs, and, by extension, find how beliefs change the destinies of people and the world itself.
  • ItemEmbargo
    INVESTIGATION INTO THE ORTHO-FUNCTIONALIZATION OF 2-ARYLOXYPYRIDINES USING α-KETO AMIDES VIA PLATINUM-ASSISTED C-H ACTIVATION
    (East Carolina University, December 2024) Lares, Cristian Guadalupe
    Transition metals are commonly used to catalyze thermodynamically unfavorable reactions, decreasing the activation energy required to break stable bonds and reform new bonds. Activation of a C-H bond can lead to the formation of more reactive C-X bonds, where X=N, O, Cl, Br, I, and Si, allowing for further reactivity or synthesis. Platinum was used as a catalyst as it serves as a soft Lewis acid, in an organic soluble cis-bis(benzonitrile)dichloroplatinate(II), cis-Pt(PhCN)2Cl2, in order to facilitate in C-H activation. Aryloxypyridines have been used as the scaffolding in several bioactive compounds, from insecticides to human enzyme inhibitors. α-keto amides have shown to have anti-inflammatory and anti-cancer properties, rendering them great candidates for study. The α-keto amides were introduced to the reaction as 2-(dialkylamino)-2-oxoacetyl chloride, as chlorine serves a good leaving group. By utilizing the pyridyl nitrogen as a directing group, the platinum catalyst can undergo rapid ligand exchange and bind itself to the aryloxypyridine. The platinum facilitated C-H activation by the interaction with the 2-(dialkylamino)-2-oxoacetyl chloride, functionalizing an ortho-position on the aryl ring. An array of different 2-aryloxypyridines was tested, with different functional groups at the ortho-, meta-, and para-positions, in order to determine the effects of resonance, induction, and steric hindrance had on the overall reaction. Three different α-keto amide containing acylating agents were tested to see how the size of the dialkyl groups performed in reactivity, where alkyl=methyl, ethyl, and isopropyl. A range of 14% to 88% was found for products using 2-(diethylamino)-2-oxoacetyl chloride, a range of 13% to 57% was found for products using 2-(dimethylamino)-2-oxoacetyl chloride, and a range of 19% to 84% was found for products using 2-(diisopropylamino)-2-oxoacetyl chloride. Due to the wide range of product yields from these reactions, a series of thermal degradations studies were conducted to determine how fragile the different 2-(dialkylamino)-2-oxoacetyl chloride were at the reaction temperature of 155°C. While the 2-(dialkylamino)-2-oxoacetyl chlorides were stable by themselves at 155°C, they underwent rapid degradation under the presence of cis-Pt(PhCN)2Cl2, as the acylating agents underwent decarbonylation.
  • ItemEmbargo
    Characterizing the Binding of Toxic Heavy Metal Cadmium to Human Cardiac Troponin C: Insight into Wild-type Conformational Dynamics via Hydrogen/Deuterium Exchange Mass Spectrometry and Thiol Quantification of Truncated N-domain Constructs Using Ellman’s Reagent
    (East Carolina University, December 2024) Warfel, Riley
    Divalent cadmium, Cd(II), is a toxic heavy metal ion that can disrupt biochemical pathways through its ability to mimic essential metals or bind adventitiously to various proteins. An emerging body of evidence suggests that the soft acid Cd(II), contrary to the predicted behavior postulated by the Hard-Soft Acid-Base (HSAB) theory, often shows a binding preference for oxygen-rich sites in proteins, many of which natively bind the hard acid calcium, Ca(II). Given the demonstrated link between Cd(II) exposure and cardiovascular disease, human cardiac troponin C (hcTnC)—a Ca(II) binding EF-hand protein essential for heart muscle contraction—has been chosen as a model to characterize such Cd(II) binding. This study expands the current understanding of Cd(II) interaction with this system by examining the potential role of sulfhydryl-containing cysteine residues at positions 35 and 84—located in EF-hand loop I and the linker region, respectively—in disulfide formation or Cd(II) coordination. To explore these interactions, native-PAGE analyses and thiol quantification with Ellman’s reagent (also referred to as DTNB) were conducted on truncated wild-type and cysteine-replacement mutant N-domain hcTnC constructs. Furthermore, this study observed the conformational dynamics of full-length wild-type hcTnC in the presence and absence of Ca(II) or Cd(II) via hydrogen/deuterium exchange mass spectrometry (HDX-MS) to gain insight into structural changes that occur upon metal binding. DTNB and native-PAGE results indicate that in the truncated N-domain, disulfide bond formation is negligible, and Cd(II) does not bind to cysteine residues C35 or C84 at stoichiometric ratios, though it subtly interacts with both thiols (~20%) at excess metal concentrations. These findings support a recent model of Cd(II) binding to hcTnC, suggesting that these cysteines do not play a primary role in Cd(II) coordination. Additionally, peptide-level HDX-MS revealed that both Ca(II) and Cd(II) elicit the canonical reduction in exchange at predicted binding sites, consistent with the current model which suggests Cd(II) binds to Loops III and IV in the C-domain and Loop II in the N-domain. Moreover, both metals also induced non-canonical, although not unprecedented, promotion of deuterium uptake in regions away from the binding site of the N-domain, suggesting an allosteric response, albeit with distinct differences noted between the essential and toxic metals. Taken together, these findings advance the ongoing investigation into Cd(II) binding to hcTnC, offering new insights into how this heavy metal may exert its toxicity and impact subsequent protein-protein interactions within the troponin complex.
  • ItemEmbargo
    PERI-IMPLANT ACTIVITY RESTRICTION IN CARDIOVASCULAR IMPLANTABLE ELECTRONIC DEVICE PATIENTS: DOES ACTIVITY RESTRICTION RESULT IN LONG-TERM RATES OF LOW-LEVEL ACTIVITY IN PATIENTS?
    (East Carolina University, December 2024) Jordan, Elizabeth Wilson
    Cardiovascular implantable electronic devices (CIEDs), specifically implantable cardioverter defibrillators (ICDs) and cardiac resynchronization therapy defibrillators (CRT-Ds) are life-saving devices utilized to care for patients at risk for sudden cardiac arrest. ICDs and CRT-Ds have become increasingly used worldwide and within the United States (US), with over 110,000 devices implanted every year in the US (Green et al., 2016). The implantation procedure for the ICD and CRT-D limits patients from engaging in activities that require using their arm or lifting heavy objects from 4-6 weeks post-implant. Physical activity is limited to allow the implanted leads time to become fibrosed. Regardless, cardiac patients need to return to physical activity for both its physical and mental benefits. The resumption of activity following this time is likely variable, but no published information is available to determine the impact or duration of physical activity restriction. Importantly, all modern ICDs and CRT-Ds have an accelerometer in the device that can continuously monitor patient movement and physical activity and store the data. Research has consistently highlighted that physical activity is a predictor of cardiovascular outcomes and patients’ quality of life, specifically in individuals with CIEDs (Rosman et al., 2018). Given that many of these patients already struggle with engagement in physical activity, coupled with the adjustment to a new device and recovery restrictions, it is plausible that this may impact their levels of activity. Additionally, many patients endure an increase in psychological stressors post-implantation, such as a fear of shocks which may also contribute to a reduction in activity consequently impacting their quality of life (Sears et al., 2023). Changes in health status may also impact patients’ activity levels such as new-onset atrial fibrillation, atrial tachycardia, or ICD shock experiences. Lastly, given the high incidence of cardiovascular disease and decreased resources within rural areas, this may result in lower levels of physical activity (Turecamo et al., 2023). The combination of recovery restrictions, psychological factors, rurality, and the onset of symptoms may create a burden on patients that influences their engagement in physical activity in turn, impacting their long-term cardiovascular outcomes. The present study aimed to determine how peri-implant activity restrictions within ICD and CRT-D patients seen in a rural-serving cardiology clinic impact long-term rates of activity engagement for up to 6 months post procedure. 294 patients from ECU Health who have a Biotronik ICD or CRT-D device that were in the archival data set from 2014 to 2023 were included in the study. Descriptive analyses revealed that the mean age of the sample was 61.76 (SD = 12.29) with 67.79% identifying as male and 52.04% identifying their racial/ethnic background as non-Hispanic Black. Pre-existing cardiac and psychological co-morbidities prior to device implantation were common within the sample and the majority of the sample received their device due to heart failure (79.93%). Major findings of the present study included a) plateaued activity levels after two months following device implantation (95.90 minutes per day in month 1 and 116.93 minutes per day in month 2) b) no significant difference in activity levels between patients with device detected atrial arrhythmias vs. patients without arrhythmias and c) no significant difference in activity levels between patients who experienced defibrillator shocks vs. patients who had not. The findings in the present study demonstrated decreased physical activity patterns up to 6 months following implantation in a rural-serving clinic. In the future, device and accelerometer data should be utilized for research and to determine mechanisms of utilization to provide interventions, improve patient care, patient quality of life, and overall health outcomes.
  • ItemEmbargo
    Adverse Childhood Experiences, Risk-taking, and Protective Factors
    (East Carolina University, May 2025) Stickel, Daniel
    Researchers have discovered many detrimental effects of adverse childhood experiences (ACEs). While these outcomes can have far-reaching effects into adulthood, experiencing adversity can also exert proximal impacts on children. An outcome of recent interest in trauma literature is increased risk-taking behavior. I designed the current study to investigate the possible relationship between ACEs and risk-taking in children in the Adolescent Brain Cognitive Development (ABCD) Study funded by the NIH. Additionally, I explored the role of close friends and school protective factors as potential moderators in the hypothesized relationship between adverse experiences and risk-taking. My results indicate that ACEs do not significantly predict risk-taking as it was measured in the ABCD Study using a computerized laboratory task. Furthermore, neither having a close friend nor school protective factors moderated the relationship between ACEs and risk-taking. Parent income, ADHD symptoms, and sex of the participant did significantly predict scores on the risk-taking task. Findings are discussed and recommendations for future research are provided.
  • ItemEmbargo
    EXAMINING THE LIVED EXPERIENCES OF AFRICAN AMERICAN AND SOUTH ASIAN PARENTS OF CHILDREN WITH DISABILITIES
    (East Carolina University, December 2024) Pearce, Chrishay Yanise
    This study aimed to understand the lived experiences of African American and Asian Indian parents of children with disabilities in North Carolina. Using qualitative research, interviews were conducted online via Zoom to understand their experiences taking care of their children with disabilities. Parents had to be either African American or Asian Indian living in North Carolina with a child between the ages of 5-8 with a diagnosed disability to participate in the study. All participants were African American parents from eight North Carolina counties. Eight participants were female, and four were male. Their ages ranged between 25-33 years. The data were analyzed using content analysis, which revealed four major themes with subthemes. The four themes were (1) Lived Experiences as an African American Parent, (2) The Frustrations of Barriers, and (3) Much Needed Familial and Systematic Support. Implications and directions for future research are provided at the end.
  • ItemEmbargo
    GRAVITY CONSTRAINTS ON THE TECTONIC EVOLUTION OF THE SIBUNDOY VALLEY, EASTERN CORDILLERA OF COLOMBIA
    (East Carolina University, December 2024) Rosero, Stalin Alexander
    The Sibundoy Valley is a hinterland basin, located in the Eastern Cordillera of Colombia, near the Ecuadorian border. The valley trends to the northeast and has a rhomboidal shape with an approximate area of 100 km2. The hinterland basin is near the wedge top of a retro-arc basin between the Andean magmatic arc and the Guiana craton. Here, multiple fault types are active due to oblique convergence between the Nazca Plate and South America Plate. The North Andean Block is moving with a slip rate of 21-22 mm/year eastward and a 5-6 mm/year northward. Therefore, two potential models are proposed to explain the tectonic evolution of the Sibundoy Valley. In model 1, a step over between strike-slip faults produced a pull apart basin. In model 2, a system of reverse faults produced a contractional piggyback basin. To distinguish between these models, a combination of surface geology, gravity modeling and density measurements has been used. Complete Bouguer Anomaly values indicate that the Sibundoy Valley has a negative anomaly of 30 mGal. The density of the basin infill is approximately 1.8 g/cm3. This density estimate is constrained by measured values of surface rocks and comparison of variable density subsurface gravity models. Overall, the 3-D shape of the basin was determined by gridding together multiple 2-D gravity transect models. These show the basin has a half-graben shape where the deepest depression (-1300 m) is located at the southwestern side of the basin, and it thins to the northeast. It is likely that a normal fault created most of the accommodation space at the southwestern side of the basin, creating the half-graben shape. The northwest to southeast trending models suggests that a shallowly dipping fault outcrops at the northwestern side of the basin and extends as a master fault underneath the basin to the south. Gravity models also disallow a traditional strike-slip step over geometry as steep strike-slip basin bounding faults do not fit measured gravity data. Unfortunately, the gravity models do not provide the kinematics of the master fault, despite well constraining its geometry so the three different types of basins (piggyback, pull-apart, and hinterland basins) are still possible. Nevertheless, a rifting (or supradetachment) hinterland basin may be the most likely model to describe the tectonic evolution of the basin, considering the shape of the basin, geologic setting, and transtentional kinematics of the faults.
  • ItemEmbargo
    A Pilot Study of Immersive Virtual Reality Tai Chi Program on Physical and Mental Health Among Older Adults
    (East Carolina University, December 2024) Ardon Lobos, Marcos Enrique
    Tai Chi is well-recognized as a recreational therapy intervention that offers significant physical and mental health benefits for older adults. Advances in technology have made Tai Chi accessible through virtual reality, yet there is limited research on the experiences and effects of immersive virtual reality Tai Chi (IVTC) on health outcomes among older adults. Therefore, the purpose of this thesis was to investigate whether IVTC is effective in promoting physical and mental health in this population. Nineteen older adults participated in two weekly 30–40-minute IVTC sessions over four weeks. A paired t-test was conducted to analyze the differences between pre- and post-test results for each participant. The findings revealed significant improvements in balance and reductions in stress levels among the participants. These results suggest that the IVTC program the IVTC program could serve as a promising, technology-driven intervention for older adults at higher risk of falls and mental distress. Furthermore, these findings highlight the need for further research to assess the efficacy of IVTC as a promising approach for diverse populations.
  • ItemOpen Access
    The Impact of Alcohol Misuse and Intellectual Disability on Occupational Safety
    (East Carolina University, December 2024) Eickemeyer, Mary
    In the United States, people with disabilities have the right to live and work in the least restrictive environments possible based on their needs. However, workers with intellectual disabilities struggle with shortcomings in both intellectual ability and adaptive capacity which can put them at higher risk for occupational injury particularly if they also cannot recognize how their own behaviors such as binge drinking might impact that risk at work. The objective of this research was to discover if disability status and/or disability type had an effect on binge drinking in the state of Minnesota when controlling for age, sex(m/f), and race. Data from the 2018 Minnesota Behavioral Risk Factor Surveillance System was utilized for this study. Negative binomial regression analysis revealed that there was no statistical significance related to disability status or disability type. However, both sex and age were statistically significant at a 95% confidence level. Similar to other research, this result found that younger men in general including those with disabilities were more likely to binge drink than women and people in any other age group. Occupational safety implications include offering alcohol misuse counseling services in the work setting, screening for off-hours alcohol use routinely as a part of occupational accident investigations, and encouraging workers to seek support when feeling pressured to binge drink during social situations.
  • ItemOpen Access
    HORSE VERSUS HORSE SIMULATOR: AN INVESTIGATION OF SENSORY PROCESSING PATTERNS AND ENGAGEMENT IN CHILDREN WITH AUTISM SPECTRUM DISORDER
    (East Carolina University, December 2024) Bezanson, Zoey A
    Purpose: This study aimed to determine if there was a statistically significant difference in engagement levels in children with autism spectrum disorder (ASD) when participating in therapeutic activities on a horse or horse-riding simulator, the MiraColt™. Further, it aimed to determine if there was a relationship between sensory processing patterns and engagement levels of children when participating in therapeutic activities on a MiraColt™. Lastly, it aimed to determine if there was a relationship between sensory processing patterns and engagement levels of children when participating in therapeutic activities on a horse. Method: This pilot study used a one group quasi-experimental repeated measures design. Participants (n=6) were children aged 5-12 years old who completed two separate visits for the conditions. The first visit consisted of a 10-minute tabletop activity to establish a baseline of engagement, administration of Evaluation of Ayres Sensory Integration (EASI) tests (postural control, bilateral integration, ocular motor and praxis, and balance), and condition one which was participating in therapeutic activities while riding the MiraColt™ for 20 minutes. During the second visit, participants participated in condition two, which was therapeutic activities while riding the horse for 20 minutes. The tabletop activity and riding conditions were video recorded, and engagement levels were assessed using a pilot measure developed for this study. The Wilcoxon signed rank test explored differences in total engagement level scores of the two riding conditions. Spearman’s rho correlations were conducted to assess the relationships between sensory processing patterns and engagement levels of children during therapeutic activities on a MiraColt™ and on a horse. Results: No statistically significant differences were found in total engagement level scores between children with ASD participating in therapeutic activities while riding the MiraColt™ and the horse (p=0.92). There was a statistically significant positive correlation between the ocular praxis EASI test and engaged behaviors when participating in therapeutic activities while riding the horse (p = 0.05). Additionally, there were statistically significant positive correlations for the postural control EASI test and engaged behaviors for both riding conditions, the MiraColt (p = 0.03) and the horse (p = 0.01). Conclusion: This study did not find a significant difference in engagement levels between the two riding conditions, which suggests that horse riding simulators may be a suitable alternative to engaging children with ASD in therapeutic activities when horse riding is not feasible. Positive relationships between the riding conditions and the EASI tests suggest that postural control and ocular praxis may play a role in a child with ASD's ability to engage during multisensory activities. Future research with a larger sample size is needed to increase the statistical rigor and generalizability of these results. Further investigation must also be completed to evaluate the validity, reliability, and sensitivity of the engagement measure used in this study.