Digital Commons Network^™

Sea Otter Behavior And Prey Composition Across Alternative Reef States In Monterey, Ca: Applying Ecological Theory To Kelp Restoration, Carter Hawkins

Master's Theses

Due to a myriad of factors, giant kelp (Macrocystis pyrifera) abundance along the California coast has decreased in select areas, leading to the formation of lower-diversity ecosystems dominated by purple sea urchins (Strongylocentrotus purpuratus), known as “urchin barrens.” While sea otters (Enhydra lutris) are keystone predators that help maintain kelp forests through predation on sea urchins, in Monterey, they avoid barren sea urchins due to their low energetic value and abundance of other habitat types, limiting their influence in these areas. From 2021-2023, sea urchin culling at Tankers Reef, a former barren site in Monterey Bay, was conducted to promote …

Acoustic Presence Of Humpback Whales (Megaptera Novaeangliae) In U.S. West Coast National Marine Sanctuaries, John C. Barkowski

Master's Theses

Humpback whales are one of many species of marine mammal that utilize sound in multiple aspects of their lives in the oceans. By collecting acoustic data from multiple areas across the habitat of these animals, we can investigate spatiotemporal patterns in their sound production to better understand their life history strategy. This study uses three years of passive acoustic data collected concurrently from three U.S. West Coast National Marine Sanctuaries to look for spatiotemporal patterns in humpback whale song and non-song vocalizations. Additionally, this study investigated correlations between upwelling conditions and the onset of song to explore links between the …

A Pilot Study Exploring Vitamin D, Mental Health, And Gastrointestinal Health In Humans, Brianna C. Williams

Master's Theses

Mental disorders are experienced by nearly one billion people worldwide. Depression is one of the most common. Treatments exist, yet a devastating 75% of individuals suffering from depression do not receive adequate treatment. An emerging treatment strategy includes exploring the connection between mental health and nutrition, which includes the areas of gut health and nutrient deficiencies. Vitamin D is obtained through food, supplements, and sunlight. Many individuals are considered deficient (25[OH]D concentrations < 12 ng/mL) or insufficient (25[OH]D concentrations < 20 ng/mL). Purpose: This study aimed to explore mental and gastrointestinal (GI) health using surveys and lipopolysaccharide binding protein (LBP) concentrations, a biomarker of GI health, in individuals considered 25(OH)D deficient (DEF) vs not deficient (N-DEF). Methods: This cross-sectional study recruited physically active participants aged 18-45 years who underwent three evaluations in one visit. Health was assessed using surveys to evaluate mental health, GI symptoms, and vitamin D intake. Serum from fasting blood samples was used with an enzyme-linked immunosorbent assay to determine 25(OH)D and LBP concentrations. Unpaired t-tests were used to compare DEF vs N-DEF and significance was set at p < 0.05. Results: Thirty-two participants (mean age 25.3 ± 6.3 years) with mean and body fat percentage of 24.0% ± 10.7%, were placed into DEF (n=16) and N-DEF (n=16) categories. Interestingly, five of the 16 participants in DEF (31%) showed some level of depression (scores ranging from mild to severe) and only two of the 16 participants in N-DEF iv (13%) scored positively in the depression category (scores ranging from mild to moderate). Additionally, the participant with the lowest 25(OH)D concentration (5.42 ng/mL) was the only participant to meet the “severe” depression category criteria, with a score of 24 compared to other participants who scored within 0-16. Also, the only participant who scored “severe” in the stress category, was in the bottom 20% of 25(OH)D concentrations. As for GI health, the difference between average GI scores and average serum LBP concentrations between the groups were not statistically significant. Conclusion: There were no significant differences between DEF and N-DEF in perceived depression (p = 0.16), anxiety (p = 1.0), stress (p = 0.96), GI symptoms (P values ranged from 0.27 to 1.00), nor in LBP concentrations (p = 0.77). Funding: Support was received from the Graduate Student Association and College of Natural Health Sciences at the University of Northern Colorado.

Investigating The Influence Of Experimental Parameters On The Formation Of Gold Nanoparticles: A Green Synthesis And Design Of Experiments Approach, Isaac Opeyemi Subuloye

Master's Theses

This thesis examines the green synthesis of gold nanoparticles using catechin, a naturally occurring plant-derived compound, as both a reducing and capping agent. The synthesis process was guided by a structured Design of Experiments (DOE) methodology to ensure systematic investigation and optimization. A two-phase experimental approach was adopted. First, a full factorial screening design was used to evaluate the effects of catechin concentration, NaOH concentration, and pre-reaction time. This was followed by an optimization phase using a face-centered composite design to identify conditions that produce nanoparticles with ideal characteristics. The nanoparticles were analyzed using UV-visible spectroscopy and dynamic light scattering …

Negative Affect And Cannabis Use Outcomes In College Students: The Mediating Effect Of Protective Behavioral Strategies, Morgan Haga

Master's Theses

Particularly considering the ongoing changes in legalization, there has been a growing prevalence of cannabis use among college students. Similarly, students have endorsed increased mental health concerns following the COVID-19 pandemic. Resulting in a cycle of harmful use, research has supported a positive relationship between negative affect and cannabis-related negative outcomes. Protective behavioral strategies for marijuana (PBSM) have been successful in reducing cannabis-related negative outcomes; however, the frequency and utility of PBSM use for students experiencing increased negative affect is unknown. Participants included 330 college students (M_age = 19.17) from 12 U.S. universities who were predominately White non-Hispanic …

High-Resolution Event Stratigraphy Of Ostracods In The Ozan Formation Of Texas And Arkansas, Denali L. John

Master's Theses

This study focuses on the high-resolution event stratigraphic framework of the lower Campanian Ozan Formation in Northeast (NE) Texas and Southwest AR which is richly fossiliferous in ostracods. Little research has been published on the Ozan Formation and even less dealing with Ozan ostracods. Additionally, correlation of Upper Cretaceous units between Texas and AR is controversial due to the general lack of good exposures in both regions and extensive faulting in Northeast Texas despite similar depositional environment across the region. This study calibrates the ranges of ostracods and creates an event stratigraphic composite that is orders of magnitude higher in …

Connecting For Success: Evaluating The Frequency Of Check & Connect Meetings On Student Behavior, Kaylee S. Mckinney

Master's Theses

Dropout prevention efforts commonly address risk factors including chronic absenteeism, which continues to be a nationwide concern. Check & Connect is a student engagement intervention that aims to improve graduation rates and mitigate several risk factors of dropout. Previous research has failed to address if the frequency of Check & Connect meetings results in varied effectiveness of the intervention. The current study aims to evaluate the effects of modified frequency of Check & Connect meetings on academic engagement, term grade average, absences, and office discipline referrals through the use of a multiple baseline across participants design. Results revealed that students …

Forgotten Landscapes: Using Original Land Surveys To Understand The Historic Distribution Of Cane Brakes In Wayne County, Ms, Chad Mackness

Master's Theses

This study investigates the historical presence and ecological significance of Arundinaria gigantea (giant cane) in 1810, Wayne County, Mississippi, using original survey documents. These records provide rare quantitative insights into the distribution of cane brakes, revealing that A. gigantea possibly represented up to 44% of the surveyed landscape, likely second only to Pinus palustris (longleaf pine).

This research involved digitizing historical surveyors' notes, transcribing them into a structured format, and extracting spatial data for GIS analysis. The methodology developed for this research can be used to ensure the preservation and usability of these historical documents for future research. …

Assessment Of Estuarine Respiration And Benthic Nutrient Fluxes In Mississippi Sound, Nur Pasha Sufian

Master's Theses

This study quantified seasonal and spatial variability of both water column and benthic respiration rates as well as benthic nutrient fluxes along the Mississippi Sound. Respiration was measured in recirculating incubation chambers using Firesting optical DO sensors (PyroScience GmbH), and changes in nutrient concentrations were assessed. Mean water column respiration rates ranged from 0.35 and 2.76 µM O₂ hr⁻¹, with the lowest rates in the winter and the highest in the summer while detectable nutrient concentrations (ammonium, (NH₄⁺), and soluble reactive phosphate (PO₄³⁻)) showed only slight decreases (< 1 µM) over all seasons. Sediment incubation chambers consistently had much greater oxygen declines than the water incubations and showed seasonal trends with the highest mean respiration rates measured in the summer and the lowest mean in the winter, with a range from 107.4 to 1514.9 µmol O₂ m⁻² hr⁻¹ (2.6 to 36.3 mmol O₂ m⁻² d⁻¹). Sediment incubations consistently showed increases in NH₄⁺ concentrations in the overlying water, resulting in calculated NH₄⁺ benthic flux rates of 0.73 to 379.01 µM N m⁻² hr⁻¹ with the lowest rates in the winter and highest rates in the summer. Although PO₄³⁻ concentrations were often below detection in cooler seasons, PO₄³⁻ flux also peaked during the summer (< 28.8 µmol P m⁻² hr⁻¹). In this study, temperature was a key regulator for estuarine respiration and benthic nutrient flux rates, and these rates were positively correlated with porewater nutrient concentrations and sedimentary organic matter. These findings illustrate that benthic respiration can contribute to water column hypoxia and that sediments serve as a source of nutrients to the water column. Overall, these findings provide us with valuable insight about the seasonal coupling of oxygen demand and nutrient flux in the Mississippi Sound and provide valuable baseline data for future biogeochemical modelling of hypoxia, eutrophication, and productivity.

Do Finances Determine Our Fate?: Understanding The Relationships Between Socioeconomic Status, Inflammation, And Cancer Recurrence Risk, Faith Wilbourne

Master's Theses

Individuals of a low socioeconomic status (SES) are more likely to experience a cancer recurrence relative to individuals with a higher SES. This may be partially explained by the stressors of living with a low SES. These stressors can increase inflammatory markers known to elevate the risk of cancer development. Health-promoting behaviors such as exercise, adequate sleep, and a healthy diet can reduce systemic inflammation. Health behaviors may therefore moderate any potential relationship between SES and cancer recurrence risk. This study explored associations between SES (income, educational attainment) and inflammatory markers related to cancer recurrence while seeking to determine if …

Female Preference And Prezygotic Isolation In The Fundulus Notatus Species Complex, Emilee K. Holderness

Master's Theses

Understanding how reproductive isolation arises between closely related species is central to evolutionary research. Hybridization is widespread across taxa and shaped by interactions among environmental factors, evolutionary history, genetic compatibility, and behavior. These forces often operate nonlinearly across space and time, yet mate choice is frequently assessed under artificial conditions that may not reflect natural behavior. To address this limitation, female mate preference was investigated within the Fundulus notatus species complex, where F. notatus and F. olivaceus hybridize at varying rates across replicate contact zones. Using a free-choice design, behavioral trials were conducted with individuals from populations characterized by high …

Inside The Walls Of The Asylum: Exploring The Lives Of Individuals In The Mississippi State Asylum (1855-1935), Savannah V. Logan

Master's Theses

The Mississippi State Asylum (MSA), established in 1855, was the first such institution in but has been largely forgotten about since its closure in 1935. The cemetery associated with the facility, which is located on the University of Mississippi Medical Center campus, was recently rediscovered with new construction. As part of the Asylum Hill project, the remains of seven of the 7000 burials along with their mortuary artifacts were analyzed and allowed these forgotten individuals to once again regain their voice and tell a portion of their life story through osteobiographies.

The sample, dating to 1855-1899, included five males and …

Exploring Fisheries Species Distribution Shifts In Response To Freshwater Inflow Through The Bonnet Carré Spillway Using Species Distribution Models, David T. May

Master's Theses

The Bonnet Carre Spillway (BCS) is a flood control structure on the Mississippi River (MR) ~52 km upstream of New Orleans. The BCS protects downstream communities from MR flooding by diverting floodwaters into Lake Pontchartrain when the MR exceeds 5.18m flood stage. Diverted waters flow east into the Mississippi Sound (MSS), introducing turbid, nutrient rich freshwater to the estuary before draining into the Gulf of Mexico. BCS openings have become much more frequent in the last decade, though little work has been done to explore the impact of the BCS on nektonic fisheries species. Here, a series of seasonal Maximum …

Coyote (Canis Latrans) And Non-Target Wildlife Responses To Livestock Guardian Dogs At Sheep Grazing Sites On The California Central Coast, Tricia T. Nguyen

Master's Theses

Livestock depredation is one of the oldest and most widespread forms of human-wildlife conflict. The coyote (Canis latrans), a midsized canid, represents a significant proportion of domestic sheep depredations in the United States, costing livestock producers an estimated 24.6 million dollars annually. Management strategies for coyote-sheep depredation vary widely in their effectiveness and in their level of public support. Identifying appropriate strategies for farms, ranches, and other sheep grazing sites remains a pressing need due to the potentially negative consequences for surrounding ecosystems and socioeconomic outcomes for sheep producers. The livestock guardian dog (LGD) is a nonlethal control …

Mechanoregulation Of Osteogenesis And Adipogenesis Of Human Mesenchymal Stem Cells, Justin Caron

Master's Theses

Bone-related diseases (e.g., osteoporosis) are primarily treated with pharmacologic therapies that often exhibit limited efficacy and substantial side effects. Currently, bone marrow derived mesenchymal stem cells (MSCs) have become one of most important cell options in bone regeneration due to readily available sources, strong proliferation abilities, weak immune rejection responses, and strong osteogenic differentiation potential. While identifying the most effective approach to enhance osteogenic differentiation of MSCs for bone regeneration is challenging, understanding the regulatory mechanisms is crucial for improving therapeutic efficacy. Recent research has focused on developing strategies to enhance osteogenesis, which involve biophysical and biochemical stimulation. Mechanical and …

Assessment Of A Muscadine Grape (Vitis Rotundifolia) Mapping Population For Tolerance To Pierce’S Disease Pathogen Xylella Fastidiosa And Resistance To Black Rot Disease Pathogen Guignardia Bidwellii, Anushka Tennakoon

Master's Theses

Pierce’s disease (PD) and black rot disease cause severe economic losses for grape production under humid and warm conditions. Identifying resistance genes is crucial for controlling these disease by developing resistant cultivars. Muscadine grape (Vitis rotundifolia) cultivar ‘Pam’ has been identified to possess a high level of resistance to diseases. To elucidate the genetic basis of the resistance to the causal pathogens Xylella fastidiosa and Guignardia bidwellii in this cultivar, parents and 141 F1 individuals developed from open pollinated ‘Pam’ were evaluated for two seasons under natural disease pressure. The mapping population was genotyped using genotyping-by-sequencing (GBS) and …

Drug Delivery, Disulfide Crosslinked Hydrogel Coating For Polydimethylsiloxane (Pdms) Implant Materials, Paul A. Contos, Paul Anthony Contos

Master's Theses

Though polydimethylsiloxane (PDMS) is often used in medical devices due to its desirable mechanical properties and biocompatibility, its surface is often prone to bacterial adhesion. This is especially a problem for catheters, where bacteria can adhere and form biofilms that can in turn result in Urinary Tract Infections (UTI). In order to deter the presence of UTI causing bacteria on PDMS catheters, methods were developed to formulate a disulfide crosslinked hydrogel coating and create a methodology to allow adhesion to a PDMS substrate. The hydrogel coating discussed in this paper will be synthesized by chemically crosslinking stimuli-responsive vesicles, that carry …

Using Livestreaming Technology To Answer Novel Questions About The Behavior And Physiological Ecology Of The Prairie Rattlesnake (Crotalus Viridis), Max C. Roberts

Master's Theses

Recent advances in remote monitoring technology are opening up new opportunities for developing innovative natural history and biological research methodologies. In particular, the emergence of livestreaming camera technology has made recording remote video of wild and secretive animals much easier and made it possible to collect data at extremely fine temporal resolutions. In 2024, Project RattleCam launched a livestreaming camera at a Prairie Rattlesnake (Crotalus viridis) den in Colorado. The goal of this work was to study Prairie Rattlesnake behavior 24-7 throughout the species’ active season with minimal human disturbance. Additionally, I used this system to study the …

Investigating Rattlesnake Social Networks And Improving Their Public Image Through Unobtrusive Technologies And Community Science, Owen M. Bachhuber

Master's Theses

While technology is often blamed for humans’ increasing disconnect with nature, it can also serve as a tool to facilitate empathy and conservation action for wildlife. Snakes are among the most feared animals on the planet, though their understudied social interactions provide opportunities to make scientific discoveries and change public perceptions. Project RattleCam was founded as a camera trap project in 2021 and launched the first off-grid livestream on a den of wild Prairie Rattlesnakes (Crotalus viridis) in 2024. Both camera types captured hundreds of Prairie Rattlesnakes gathering in the summer as they prepared to give birth to pups before …

The Influence Of Rhodolith Algae On Life History Of The Painted Urchin, Lytechinus Pictus, Celine X. De Jong

Master's Theses

Rhodolith beds are globally distributed hotspots of diversity and productivity and serve as nursery habitats for some marine invertebrates. Poorly understood is whether rhodolith beds are nurseries because invertebrate larvae actively select them for settlement or migrate to them at later life stages. We studied the nursery role of rhodolith beds for the painted urchin, Lytechinus pictus at Santa Catalina Island, CA, USA. Subtidal surveys showed that in areas with greater live rhodolith cover, urchin density increased as well as mean urchin size. In caged substrate choice experiments, urchins selected rhodolith substrate relative to carbonate sand, supporting the notion that …

Experienced Latinx Urban Gardeners In San Jose, Ca, Offer Strategies For Climate Justice And Resilience, Claudia S. Damiani Fontana

Master's Theses

Low-income and underinvested communities will be disproportionately affected by climate change due to limited resources, inadequate infrastructure, and insufficient support systems. Urban gardeners are responding to the need to adapt to new climate conditions while sustaining their food sources and cultural practices. Many have adapted thanks to local interventions led by the government and non-profit agencies. For this study, I partnered with La Mesa Verde (LMV), a gardening and food justice program that works with low-income Latinx families in San José, and I documented the contributions of experienced Latinx gardeners, especially those with agricultural backgrounds, to climate-resilient gardening in San …

Comparison Of Stem Student Reflections Of Their Undergraduate Research Experiences: Cures Vs. Apprentice Model, Chazzidy Harper

Master's Theses

Undergraduate research is widely recognized as a high-impact educational practice that promotes engagement and academic success in STEM. However, limited research has examined how different research formats, particularly course-based undergraduate research experiences (CUREs) and the apprentice model, shape student experiences. This study investigates undergraduate research (UR) course characteristics and student reflections across STEM disciplines at Kennesaw State University (KSU), focusing on differences between CURE and apprentice experiences. A mixed-methods analysis was conducted on 809 student reflections and 169 course syllabi spanning biology, chemistry, physics, and mathematics, computing, data science, software engineering, and information technology, psychological science, and engineering. Demographic data …

How Effective Are Engineered And Non-Engineered Riparian Forest Restoration Projects In Providing Salmonid-Quality Habitat In The San Francisco Bay Area?, Alexander Ivanov

Master's Theses

Streams and their riparian zones in the San Francisco Bay Area have been degraded, severely harming salmonid populations in the region. Ecological restoration is a common approach to return stream function. Such restoration projects vary widely in intensity, from low-impact vegetation removal/planting to highly engineered projects involving structures and grading. This research investigated the effectiveness of streams restored using engineered versus non-engineered solutions in supporting salmonid habitat viability in San Francisco Bay Area streams. Fourteen streams, seven from each of the two types of restoration, were sampled in the wet and dry season in 2024, three times each season. Data …

Replicating Vignoles Et Al. Results On Multidimensional Self-Construal: Comparing The United States, East Asia, Southeast Asia, And Latin America, Jon Lorenz A. Lim

Master's Theses

Contemporary research on self-construal indicates that people define and perceive themselves either as independent or interdependent. Self-construal scales have become the most common method to quantitatively measure both types of self-construal across the United States, East Asia, Southeast Asia, and Latin America. Multidimensional measures of the self tend to be more accurate in defining the self than earlier dichotomous scales. In general, European Americans and Latin Americans perceived themselves as independent and East and Southeast Asians as interdependent. In the current study, undergraduate European American, East Asian American, Southeast Asian American, and Latin American students from San Jose State University …

Abalone And Seaweed Co-Culture: Growth And Shell Biomineralization Of An Iconic California Gastropod, Noah R. Kolander

Master's Theses

Climate change threatens shellfish aquaculture worldwide, with ocean acidification (OA) accelerating shell dissolution and reducing calcification, hindering growth. This study addressed the negative impacts of OA on juvenile red abalone (Haliotis rufescens), a life stage that is particularly susceptible to climate stressors, and the ability of the red seaweed, dulse (Devaleraea mollis), to mitigate these effects. I tested the hypothesis that Integrated Multi-Trophic Aquaculture (IMTA), with abalone and seaweed grown in co-culture, can raise seawater pH through photosynthesis to yield more favorable conditions for abalone growth and shell construction. A 5-month experiment was conducted to determine the benefits of IMTA …

An Interpretative Phenomenological Analysis Of Black Female Swimmers' Experiences Of Belonging, Felicity E. Passon

Master's Theses

Although swimming participation has grown in the United States, the experiences of Black female swimmers remain significantly underrepresented in academic literature. This study addresses that gap by exploring the lived experiences of Black women participating in Division 1 (D1) college swimming. Using Interpretative Phenomenological Analysis (IPA) and Black feminist thought, the research explored how Black female D1 swimmers experienced belonging in this underrepresented sport. Semi-structured interviews were conducted with nine D1 Black female swimmers, and six major themes illustrate the varied factors that shaped their experiences of belonging. Even with racially gendered barriers to inclusion, they identified strategies to foster …

Fluid-Structure Interaction Comsol Model For Unsteady Flow Through A 3d Bi-Leaflet Mechanical Heart Valve, Aya Zaky

Master's Theses

In this study, we developed a 3D Fluid-Structure Interaction (FSI) model using COMSOL© to analyze the unsteady flow through a bi-leaflet mechanical heart valve. The model incorporates sufficient complexity to test various factors, such as leaflet angle rotation, material selection for rigid components, fluid properties, and different simulation modes. Simultaneously, the model maintains a simplified structure and is developed using a single software platform, facilitating ease of modification and expansion by other researchers or developers. The mechanical heart valve (MHV) design was created using St. Jude’s geometric parameters as a reference. The input and output pressure waveforms are derived from …

Unmanned Aerial Systems (Uass) In Rangeland Ecosystem Management: Assessing Grazing Impacts At Willits, California, Pramil Khanal

Master's Theses

California's rangelands, vital for biodiversity and cattle production, face threats from land use changes and climate changes, necessitating robust management strategies. While overgrazing has been studied extensively, the effects of light rotational grazing on vegetation have seldom been assessed. This study used Unmanned Aerial Systems (UASs) and multispectral imagery to assess the seasonal impacts of light rotational grazing on vegetation health and coverage in wetland mitigation areas near Willits, California. Data were collected in May (spring) and November (fall) 2024 using a DJI M3M drone and MicaSense camera capturing RGB and Near-Infrared (NIR) bands. Green Chromatic Coordinate (GCC) and Normalized …

Chemical And Physical Characterization Of Verbenaceae Essential Oils Using Modern Analytical Methods And Chemometrics, Aleksandra N. Hilliard

Master's Theses

Essential oils have been used for generations to treat various health issues, including mitigating insomnia, reducing stress, inflammation, and preserving foods, to mention a few. Essential oils have complex chemistry, which defines the essence of the host plant. Recently, increased commercial uses of essential oils have prompted attention at the governmental level to monitor the chemical, physical, or biological activity of essential oils. This study is an attempt to add new information for consumers to the understanding of the composition of essential oils.

Modern analytical techniques including FTIR-ATR, GC-MS, LC-MS-MS, multivariate analysis statistics, and physio-chemical techniques (electrochemistry, DPPH, TRC, and …

Regulation Of Spermatogenesis By The Notch Signaling Pathway, Emma O'Flaherty

Master's Theses

The Notch signaling pathway plays a significant role in gonad development and spermatogenesis, but little is known about its specific targets in the testis. The Drosophila testis contains two populations of stem cells: germline stem cells and cyst stem cells, which give rise to differentiating germline and somatic cyst cells, respectively. Notch signaling is activated in the somatic cyst cells by the Delta ligand from the germline in a region of the testes coined the “transition zone”, where somatic cyst cells progress from early cyst cells surrounding gonialblasts and 2-cell germline cysts to late cyst cells surrounding 16-cell spermatocyte cysts. …