The ScholarShip

The ScholarShip is a digital archive for the scholarly output of the ECU community. Its mission is to capture, preserve, and make available the intellectual output of East Carolina University's faculty, staff, and students.

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Access status: Open Access ,
Investigating Predictors of the Transition from Fat to Carbohydrate Oxidation in Overweight Individuals during Submaximal Exercise
(East Carolina University, May 2025) Smith, Garrett
ABSTRACT Purpose: This study is important for knowing the mechanisms behind fuel transitions from fat to carbohydrate oxidation, so that we can further understand what the main predictors are in this crossover point in a group of people who are currently overweight and are at risk of obesity. Understanding what factors are associated with the transition from fat to carbohydrate oxidation will help us better recognize who could be at risk for metabolic diseases later in life. Methods: Up to 60 subjects (29 ± 7 yr) men and women classified as overweight (26.4 ± 1.8 kg/m2) were recruited and participated in this observational study. Blood pressure and blood metabolites were measured after an overnight fast. Lactate was also measured before and after a three-day eucaloric high-fat (70 %) diet. The homeostatic model assessment for insulin resistance (HOMA-IR) was calculated as a measure of insulin resistance. Visceral adipose tissue mass was determined via dual X-ray absorptiometry. A 65% VO2 max test was then administered to assess the transition point from fat to carbohydrate oxidation. Prior to the test, age, height, weight, and resting heart rate was first collected from the participant. A 10-lead ekg was also attached to the participant for continuous monitoring which is essential throughout the test. The participant was then ordered to maintain a steady cadence of 50-70 revolutions per minute (RPM) throughout the exercise phase. The test duration is typically between six and twelve minutes, allowing the participant to reach a steady-state heart rate. Throughout the test, heart rate and their perceived exertion (RPE) were recorded at the end of each stage using the Borg scale to gauge the individuals level of intensity of each stage. Once the individual’s 65% of their VO2 max was achieved, the test then transitioned to a cool-down phase. During this stage the resistance was decreased on the ergometer and the participant was told to cycle at a low intensity for several minutes. This allowed for adequate time for blood pressure and heart rate to return to resting levels. Once the values returned to normal levels, the test was then terminated. Results: To investigate the associations between various physiological, metabolic characteristics and the primary variable of transition time, a series of Pearson correlations were performed. Each variable was analyzed in relation to the independent value of transition time. The level of significance of each variable was assessed using the corresponding P-value (significance level) and R-value. Among all the variables tested, carbohydrate oxidation (CHOX), fat oxidation (FAOX), age, and body mass index (BMI) emerged as the statistically significant predictors (p < 0.05) of transition time, each demonstrating a meaningful level of significance. CHOX displayed the strongest connection with a p-value of 0.01 and an r-value of -0.36. FAOX was also a statistically significant predictor with a p-value of 0.04. Another variable that was significant was age, which yielded a p-value of 0.02 with an r-value of 0.35. The last variable we tested that showed significance as predictor of transition time was BMI (p= 0.02, r-value= -0.33). Several variables (fat mass, lactic acid, % body fat, REE, among others) failed to demonstrate statistically significant relationships with the transition time from fat to carbohydrates, and their significance was minimal. Discussion: This study identified carbohydrate oxidation, fat oxidation, age, and BMI as significant predictors of the transition from fat to carbohydrate oxidation during submaximal exercise. These findings suggest that both substrate utilization patterns and basic physiological characteristics can have significant influence on an individual's metabolic flexibility. With substrate oxidation patterns, BMI, and age being significant indicators of transition time, traditional fitness markers such as VO₂ max, resting energy expenditure, and time to exhaustion did not show a significant enough correlation. These findings suggest that metabolic flexibility is influenced more by physiological factors such as body composition and substrate oxidative capacity rather than peak aerobic and exercise performance. Future research of this transition should aim to validate these findings in larger and more diverse populations. This includes individuals with obesity, different ethnic backgrounds, and varying levels of physical activity. This would be of great benefit for continuing research in the future.
Access status: Open Access ,
Art as a Language: Exploring the Challenges and Opportunities for English Language Learner Support in Elementary Art Classrooms
(East Carolina University, July 2025) Butler, Alicia
Art education provides a powerful and unique platform for supporting English Language Learner (ELL) students in developing language skills through creative and engaging instruction. The visual, experiential, and collaborative nature of art offers significant opportunities to facilitate vocabulary acquisition and comprehension. However, elementary art teachers often face substantial challenges in maximizing this potential due to gaps in professional development (PD) and systemic barriers that hinder their ability to meet ELL students’ needs effectively. This study investigates these challenges by examining the PD opportunities available to elementary art teachers, the systemic obstacles they encounter, and the resources they require to better support ELL students in their classrooms. Using a mixed-methods approach, data were collected through surveys and interviews with elementary art teachers across North Carolina, providing a comprehensive analysis of their experiences, perceptions, and strategies. Results reveal a critical lack of targeted PD that equips art educators with the tools to implement language acquisition strategies. Additional systemic barriers, such as limited access to resources, insufficient collaboration time with ESL specialists, and inadequate institutional support, further compound these challenges. Despite these obstacles, findings underscore the immense potential of art instruction to enhance language learning through its inherently visual and interactive processes.
Access status: Embargo ,
SOCIAL REGULATION OF THE THALAMIC PARATHYROID HORMONE TYPE II (PTH2) NEUROPEPTIDE IN ZEBRAFISH (DANIO RERIO)
(East Carolina University, July 2025) Simon, Abigahill N
Social dominance is prevalent among social species. It allows group members to divide limited resources according to social rank. However, social dominance is often accompanied by aggression, stress and anxiety as group members establish their social relationships. These social stressors often lead to behavioral and neurophysiological consequences. This study examined the physiological effects of social dominance on the thalamic parathyroid system. Parathyroid Hormone Type II (PTH2) is a neuropeptide within the vertebrae thalamus serving as a sensory integration and relay center for stress responses. Studies using zebrafish (Danio rerio) as an organismal model of study reveal how behavioral decisions impact social relationships while highlighting the brain regions that are modulated by social behavior. Though PTH2 is expressed within the thalamic nucleus of zebrafish, the neurological mechanisms examining the role of PTH2 in information processing and stress responses to social behaviors remain poorly understood. Based on the idea that the presence of PTH2 affects behavior on a phenotypic level, I hypothesized that the thalamic PTH2 nucleus morphological and functional organization could be socially regulated. Using phosphorylated ribosomal S6 expression as a measure of cellular activity, I hypothesized that morphological differences in the PTH2 system leads to physiological changes. Moreover, I hypothesized that changes in the social environment because of social rise and social fall or social isolation will lead to a corresponding plasticity in the structural and functional organization of the PTH2 system. My results reveal that social dominance influences the number of PTH2 expressing cells: After one week of social interactions the number of PTH2 cells is higher in dominants compared to subordinates and communals (control), but this difference is abolished after two-weeks of interactions. Secondly, I show that PTH2 neurons expression of PS6, a marker of cellular activity is significantly upregulated in dominants compared to subordinates after one week of social interactions. Thirdly, social rise and fall in rank shifts the expression of PS6 and PS6 fluorescence intensity to reflect the animals’ current social status, but social reversal has limited effect on the number of PTH2 cells. Finally, social isolation or re-isolation of dominant animals show decreased PTH2 cell count and PS6 cellular activity, suggesting that re-isolation further modulates the molecular plasticity of the PTH2 neuropeptide circuit. These results provide new insights of how social isolation and aggressive interactions influence the plasticity of the PTH2 system in the context of social anxiety and stress.
Access status: Embargo ,
Analysis of venom gland gene functions between adaptive radiations of Hawaiian Spiders
(East Carolina University, July 2025) Simmons, Shania Carol Suzinn
The Hawaiian Tetragnatha spiders are a compelling model for studying adaptive radiation because of their rapid diversification into distinct ecological forms, including orb-weaving and ground-hunting species. This thesis investigates how evolutionary pressures have influenced functional gene expression in the venom glands of eight Tetragnatha species native to the Hawaiian Islands. The study examines whether ecological variation among species is reflected at the molecular level through comparative transcriptomic analysis and functional annotation using Gene Ontology (GO) terms. RNA was extracted and sequenced from venom glands, and the resulting data were used to identify GO terms associated with gene function, biological processes, and cellular localization. Functional annotations were performed using Blast2GO and InterProScan. Data were further analyzed and visualized through Principal Component Analysis (PCA), semantic scatterplots, tree maps, and word clouds. The findings reveal distinct differences in venom gland gene functions between orb-weaving and spiny-legged spiders. Ground-hunting species displayed greater diversity in molecular activities related to neurotoxicity, signal transduction, and enzymatic processes, which may support their active foraging strategies. These results demonstrate that ecological adaptation can drive not only changes in behavior and morphology but also divergence in gene expression patterns related to venom. This research links molecular data with ecological context and contributes to a broader understanding of how adaptive radiation shapes the evolution of functionally important traits in non-model organisms.
Access status: Embargo ,
Occupational Hazards Among Mosquito Control Operators And Other Pesticide Handlers
(East Carolina University, July 2025) Sharma Bastakoti, Naina
The rise of mosquito-borne diseases is a serious public health concern. Mosquito control employees work within municipal/county health departments, public works, private companies, and other agencies. These outdoor workers encounter various occupational health and safety hazards, including exposure to arthropods (e.g., stinging or biting insects, pathogen vectors), pesticides, physical demands of carrying/lifting heavy equipment, heat stress, and solar ultraviolet (UV) radiation. Mosquito control employees may take part in employer-provided training sessions and workshops focused on pesticide safety, appropriate application, and exposure reduction. Nevertheless, additional training may be required to reduce workplace health and safety risks. We conducted a survey of members of the North Carolina Mosquito and Vector Control Association (NCMVCA) and the Virginia Mosquito Control Association (VMCA) (N=60 respondents, 28.2% response rate). The survey showed that mosquito control involves professionals from various agencies, including but not limited to environmental health and vector control. Backpack sprayers (average weight=18.6 kg) were utilized by 41.7% of respondents. Individuals who reported using a backpack sprayer were significantly (p=0.015) related to those experiencing a slip, trip, or fall at work. Most respondents (76.7%) participated in health and safety training organized by their employer. Training and personal protective equipment (PPE) can mitigate the risks from occupational safety hazards. Mosquito control employees protect public health from mosquito-borne diseases by reducing mosquito populations. Here, results indicate that these outdoor workers encounter various potential hazards, such as heavy/loud equipment, pesticide exposure, heat stress, and irregular terrain. Personnel utilize several forms of PPE, yet safety issues may still occur. Routine and effective training can help prevent occupational exposures and reduce worker risks. This work also explores pesticide-related occupational injuries and fatalities among outdoor workers in the United States from 2009 to 2023, derived from 36 incidents documented by the Occupational Safety and Health Administration. Among these incidents, 14 were fatal, 17 necessitated hospitalizations, and 5 resulted in non-hospitalized injuries, with pest control workers comprising one-third of the cases, and others included other pesticide handlers (e.g. farm/agriculture workers), and those exposed to drifted pesticides. The majority of victims were male (80.6%), with prevalent causes of incidents comprised of chemical exposure, heat stress, and equipment-related incidents. These findings underscore the ongoing hazards in pesticide-related professions and the pressing necessity for enhanced worker safety protocols and laws.