Digital Commons Network^™

Comparison Of The Biodiversity Of Culturable Yeast From Four Different Habitats, Frank V. Addeo

All Master's Theses

Yeasts are ubiquitous unicellular fungi that play critical roles in decomposition, nutrient cycling, and fermentation processes across diverse ecosystems. Despite their ecological and biotechnological importance, the diversity and distribution of wild yeast populations in many temperate regions remain poorly characterized. This study evaluated how classifier thresholds influence species assignment and functional inference from internal transcribed spacer 2 (ITS2) Sanger sequences of cultured yeasts collected from diverse habitats in central Washington. The project aimed to assess the stability of taxonomic calls across classifier settings and to illustrate how methodological decisions shape downstream ecological conclusions. Samples from each habitat were enriched under …

Low Energy Availability And Dietary Factors In High School Runners, Natalie E. Allik

All Master's Theses

ABSTRACT

LOW ENERGY AVAILABILITY AND DIETARY FACTORS IN HIGH SCHOOL RUNNERS

By

Natalie Elizabeth Allik

June 2026

Context: Low energy availability (LEA) is associated with adverse health and performance outcomes in athletes and may be particularly concerning during adolescence when growth and bone development are ongoing. Although inadequate carbohydrate (CHO) intake has been proposed as a contributor to LEA, limited research has examined this relationship in adolescent endurance athletes. Objective: To examine dietary intake, bone mineral density (BMD), and eating disorder (ED) risk in adolescent distance runners with and without LEA. Methods: Eighteen adolescent distance runners (15.7 ± 1.2 years; …

Exploring Students' Perceptions Of Active Learning Practices And Their Role In Critical Thinking Development In Undergraduate Biology Education, Kwame Kyeremah

All Master's Theses

As the global landscape becomes increasingly complex and undergoes more rapid changes than ever before, critical thinking has become an indispensable skill for addressing challenges in society, science, and the workplace. Despite its widespread adoption in undergraduate STEM education, active learning remains poorly understood from the student's perspective. This study investigated how undergraduate biology students perceived active learning in a ten-week biostatistics course (BIOL 213) at Central Washington University, and whether those perceptions aligned with critical thinking gains measured by the California Critical Thinking Skills Test with Numeracy (CCTST-N). A convergent mixed-methods design integrated student perception and mindset survey data …

Low Energy Availability And Dietary Factors In High School Runners, Natalie E. Allik

All Master's Theses

Context: Low energy availability (LEA) is associated with adverse health and performance outcomes in athletes and may be particularly concerning during adolescence when growth and bone development are ongoing. Although inadequate carbohydrate (CHO) intake has been proposed as a contributor to LEA, limited research has examined this relationship in adolescent endurance athletes. Objective: To examine dietary intake, bone mineral density (BMD), and eating disorder (ED) risk in adolescent distance runners with and without LEA. Methods: Eighteen adolescent distance runners (15.7 ± 1.2 years; 7 males, 11 females) completed baseline assessments including anthropometrics, dual-energy X-ray absorptiometry (DXA), a 24-hour dietary recall, …

Missing Planktivore Functions Drive Global Variation In Reef Fish Productivity, James Gahan, Helen F. Yan, David R. Bellwood, Graham J. Edgar, Leo T. Nankervis, Alexandre C. Siqueira, Rick D. Stuart-Smith, Sterling B. Tebbett

Research outputs 2022 to 2026

The functioning of high-diversity ecosystems, such as coral reefs, is intrinsically tied to the integrity and efficiency of the trophic pathways within these systems. Coral reef productivity depends, in part, on the input of external nutrients, primarily zooplankton, that is assimilated by extraordinarily diverse fish communities. The plankton–planktivore trophic pathway is thus crucial for sustaining the productivity that exemplifies coral reef ecosystems; however, it remains poorly understood at large spatial scales. Here we explore global patterns in reef fish community structure, revealing a major discrepancy between the Indo-Pacific and Caribbean in the productivity and fisheries potential of planktivorous reef fishes. …

Peptidomic Profiling Of In Vitro Digesta From Diverse Microalgae Species, Sara Hamzelou, Damien Belobrajdic, Henri Brook, Wei Chen, Fletcher Hiten, Kim Lee Chang, Diane Purcell, Utpal Bose, Simone Osborne, Cassandra Pegg, Michelle L. Colgrave

Research outputs 2022 to 2026

Microalgae are a sustainable protein source, yet few species are used for human nutrition. This study evaluated eight species for protein quality, digestibility, and peptide profiles after simulated gastrointestinal digestion using INFOGEST. Amino acid content, and intestinal-phase peptide mixtures were analysed by mass spectrometry. The methanol precipitation method was used to separate digested (supernatant) and undigested (pellet) peptides following in vitro INFOGEST digestion. The pellet was further separated by molecular weight into 3–10 kDa and >10 kDa fractions to isolate the lower molecular weight peptides from the higher ones. This separation method enabled the identification of potential digested peptides within …

Varying Dna Methylation Patterns In The Florida Sand Skink (Plestiodon Reynoldsi) In Relation To Fire Histories, Victoire Hj Litre

College of Graduate Studies: Theses & Dissertations

Epigenetics is the study of changes in phenotype not caused by changes in DNA sequence. DNA methylation is the most well-studied epigenetic mechanism in an ecological context. Reptiles use DNA methylation to respond to environmental stressors and differences among habitats. The Florida Sand Skink (Plastidome reynoldsi) is federally listed as a threatened species. They are endemic to the threatened, fire-dependent Florida scrub habitat. As they persist in burned habitats, the Florida Sand Skink must be able to rapidly respond to wildfires. To better understand how the Florida Sand Skink adjusts to fire-driven habitat changes, it is important to …

Independent And Interactive Effects Of Stack Height And Heel Width On Spatiotemporal Parameters, Knee Joint Kinetics, And Ground Reaction Forces During Running, Hao Cai

College of Graduate Studies: Theses & Dissertations

This study investigated the independent and interactive effects of stack height (SH) and heel width (HW) on lower-extremity biomechanics during running. Specifically, the study examined how variations in midsole geometry influenced spatiotemporal parameters, knee joint kinetics, and ground reaction forces (GRF). Twelve recreational runners (8 males, 4 females) completed treadmill running trials at 16 km/h under nine shoe conditions that systematically varied in SH (25, 45, and 65 mm) and HW (81, 93, and 105 mm). Lower-extremity kinematics were collected using a Theia3D markerless motion capture system, and GRF data were recorded using an instrumented treadmill. A two-way repeated-measures ANOVA …

Impact Of Tactical Breathing On Marksmanship And Cognitive Function After Anaerobic Fatigue In Law Enforcement Personnel, Jackson D. Gilleland

College of Graduate Studies: Theses & Dissertations

Background: Tactical breathing is commonly used in law enforcement training to regulate stress, yet limited evidence exists regarding its acute effectiveness following physical fatigue. Purpose: To examine whether a brief tactical breathing intervention improves shooting performance and heart rate variability (HRV) following anaerobic fatigue in law enforcement officers. Methods: Thirty-eight officers completed baseline HR/HRV and a shoot/no-shoot scenario, followed by a maximal 500-m row and post-fatigue shooting. Participants were assigned to either a control group or a tactical breathing group, which received brief instruction and coaching before post-testing. Results: No significant between-group differences were observed for A-zone accuracy, shot time, …

Assessing Climate-Driven Shifts In Floral Resource Availability For Bees On Barrier Islands In The Southeastern U.S., Hannah Brown

College of Graduate Studies: Theses & Dissertations

Climate change can alter the timing of bee and angiosperm phenology, potentially reshaping the seasonal availability of floral resources for bee species. Although plant-pollinator phenology has been widely studied in temperate systems, less is known about these dynamics in subtropical coastal ecosystems, such as barrier islands in the southeastern United States. In this study, we examined climate-driven changes in bee activity and floral resource availability across 16 barrier-island sites spanning from Florida to Virginia. Using museum bee occurrence records, herbarium-derived flowering phenology models, site-specific floristic inventories, and published bee-plant interaction data, we estimated species-specific bee activity periods and daily floral …

Exploring The Impact Of Adverse Childhood Experiences On Preventive Healthcare Utilization In Rural Georgia, Ryan R. Traylor

College of Graduate Studies: Theses & Dissertations

This study examines the relationship between Adverse Childhood Experiences (ACEs) and preventive healthcare use among adults in Georgia, specifically within rural populations facing structural barriers. Using 2023 Georgia Behavioral Risk Factor Surveillance System (BRFSS) data, the research analyzes associations between ACE exposure, rural residence, and preventive care outcomes, including physical exams and flu vaccinations. Guided by an intersectionally adapted version of Andersen’s Behavioral Model of Health Services Use, the study evaluates how predisposing factors, enabling resources, and perceived barriers relate to healthcare engagement. Logistic regression analyses assess the correlation of ACE exposure, cost barriers, provider access, and sociodemographics with preventive …

The Influence Of Localized Water Quality On Eastern Oysters (Crassostrea Virginica) And Their Internal Microbiome Under Changing Environmental Conditions, Jessie Rivera Lafreniere

College of Graduate Studies: Theses & Dissertations

Oysters are found ubiquitously in estuaries along the Georgia coast, where marsh morphology and large daily tidal fluctuations create dynamic and stressful conditions to which oysters may be locally adapted. Based on water quality data from the Sapelo Island National Estuarine Research Reserve, it is evident that changing climatic conditions are rapidly causing shifts in water quality that may be adversely affecting oyster health, especially as ocean acidification alters the carbonate buffering capacity, increasing the amplitude of daily pH variations. Importantly, the rate of change of conditions are not uniform within estuaries, varying on spatial and temporal scales. The symbiotic …

Cogram: A Computational Pipeline For Genome Assembly And Reconstruction Using Graph Neural Networks, William Coggins

College of Graduate Studies: Theses & Dissertations

Genome assembly — the reconstruction of a complete DNA sequence from short, overlapping reads — remains a fundamental challenge in computational biology. A central difficulty is distinguishing true genomic overlaps from spurious connections arising from repetitive sequences, a task that traditional assemblers address through hand-tuned heuristic rules applied to de Bruijn or overlap graphs. This thesis introduces COGRAM (Coggins–Ramasamy Assembly Method), a genome assembly pipeline that reframes sequence reconstruction as an edge classification task on a k-mer overlap graph, replacing heuristic graph cleaning with a learned model.

COGRAM constructs a directed overlap graph from raw sequencing reads using a k-mer …

The Effects Of Stress-Related Hormones On Excitatory Synapse Formation, Autumn C. Garvey

Honors Undergraduate Theses

Stress profoundly influences brain function through neuromodulatory hormones that regulate synaptic plasticity, yet how temporal patterns of hormone exposure shape excitatory synapse formation remains poorly understood. This study investigates how exposure to stress hormones, norepinephrine and cortisol, affects excitatory synapse development. While existing research primarily compares concentration models, real-world stress occurs in variable patterns that may produce distinct neural outcomes. To address this gap, differentiated Neuro2A neuronal cells are exposed to norepinephrine or cortisol under a continuous treatment paradigm designed to model chronic stress conditions. Following treatment, immunofluorescence imaging is utilized to quantify excitatory synapse formation through analysis of presynaptic …

Horizontal Gene Transfer And Reciprocal Chimerism In Compactonostoc (Nostocales, Cyanobacteriophyta) With Evidence For Two New Species In The Genus., Daniel Al Fatayri

Masters Essays

The genus Nostoc has long been known to be polyphyletic, and recent taxonomic work has segregated several Nostoc-like lineages into new genera, including Compactonostoc. Until now, Compactonostoc shennongjiaensis was the only described species in the genus. In a survey of biological soil crusts from Santa Catalina Island (California, USA), we isolated two Nostoc- like strains that phylogenetically affiliate with Compactonostoc. A polyphasic approach based on morphology, 16S rRNA gene phylogeny, 16S–23S ITS secondary structure, and cloned ribosomal operons revealed that each strain harbors two highly divergent ribosomal operon types. One operon (Type 2) is closely related to C. shennongjiaensis and …

The Depuration Of Microplastic Pollution In Aquacultured Indian River Lagoon Oysters, Lee Nguyen

Honors Undergraduate Theses

Plastics are widely used in consumer goods and industrial manufacturing, and their degradation into microplastics (MP, size < 5 mm) has created an emergent environmental pollutant. Plastics readily enter aquatic environments, where they accumulate additional contaminants and bioaccumulate in organisms. While MP contamination in marine ecosystems is well documented, less is known about MP presence in aquacultured shellfish. Depuration, the process of purging contaminants from shellfish, is conducted in sterile seawater without food, which may cause oyster starvation and death. To date, MP depuration has not been examined in the aquacultured eastern oyster (Crassostrea virginica) in published studies. This study had 3 goals: 1) evaluate the effects of algal feed on oyster survival during depuration, 2) determine the effect of algal feed on depuration effectiveness, and 3) investigate the effect of a ten-day depuration on MP concentration in aquacultured C. virginica soft tissue. MP were quantified in oyster tissues, biodeposits, and in industrial algal feed. Tissues were digested using alkaline solutions, manually examined via microscopy, and analyzed using Fourier-Transform Infrared Spectroscopy (FTIR) to investigate MP polymer …