Digital Commons Network^™

The Ecological Impacts Of Un-Protecting Forests: The Case Of Gold Mining In Ghana, Tate Alexander Barend

Master's Theses

This paper estimates the causal effect of Ghana’s Legislative Instrument 2462 (L.I. 2462) on deforestation in protected areas. The policy redefined the regulatory regime governing small-scale gold mining in protected areas, moving from prohibition to discretionary permitting. I exploit the implementation of L.I. 2462 as a policy shock and apply a difference-in-differences event-study framework to a propensity score–matched sample of pixels derived from high-resolution satellite images. Contrary to widespread concerns that the policy would accelerate deforestation, the results provide no evidence of large-scale vegetation loss in exposed protected areas following the policy change. Instead, protected area pixels located within 5 …

Comparing Online Versus In-Person Administration Of Cognitive Tasks And Evaluating Their Predictive Utility Of Inattention Symptoms And Related Behaviors, Cameron Pothoven

Master's Theses

Attention-Deficit/Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder associated with less developed working memory (WM) processes, theorized to be a core contributing factor in the development of ADHD and a predictor of ADHD symptom severity (Alderson et al., 2013; Rapport et al., 2008). Objective measures inclusive of working memory tasks, when used in conjunction with self-report measures, have been previously shown to increase the accuracy of diagnosing ADHD (Marshal et al., 2021. However, given that WM is typically assessed by a trained clinician, it is unclear how accurate and comparable online administration of adapted WM tasks are to their in-person counterparts. …

Blue Crab Reproductive Output And Phenology In A Changing Climate, Blaise Rohan

Master's Theses

Globally, ecosystems are experiencing rising temperatures due to climate change, with potential consequences for reproductive investment and timing in many species. Blue crabs, Callinectes sapidus, support valuable commercial fisheries throughout the U.S. Atlantic and Gulf coasts, and understanding variation in reproductive output has important management and conservation implications. This study examined two components of blue crab reproduction: (1) reproductive investment across populations spanning multiple latitudes (New York, New Jersey, North Carolina, Mississippi, and Texas), using a space-for-time substitution to assess the effects of varying thermal regimes on fecundity and egg quality, and (2) spawning phenology in North Carolina from …

Baseline Nutrition Knowledge And Feasibility Of A Whatsapp-Delivered Nutrition Education Intervention Among California Wildland-Urban Interface Firefighters, Lauren E. Anderson

Master's Theses

Wildland firefighters perform physically demanding work under challenging environmental conditions that place substantial demands on nutritional health and occupational performance. Despite the importance of nutrition in supporting physical performance, recovery, and long-term health, limited research has examined nutrition knowledge and dietary behaviors among California wildland firefighters or evaluated the feasibility of remotely delivered nutrition education interventions within this occupational population. Therefore, the purpose of this pilot study was to assess baseline nutrition knowledge, nutrition self-efficacy, and dietary behaviors while evaluating the feasibility of a 12-week WhatsApp-delivered nutrition education intervention among California wildland firefighters.

Twenty-four firefighters completed the baseline assessment and …

The Effect Of Specialty Malt On Dry-Hopping, Alexander Kivela

Master's Theses

Dry-Hopping is a modern and ever-increasing method to add hoppy flavors to beer. This is typically seen in pale ales and India Pale Ales (IPA’s). Most research has investigated the effect of dry-hopping only using pale malt, whereas most breweries used specialty malts to create a malty backbone to their beer.

The objectives of this research were to analyze the impact of specialty malts and their concentration on the efficacy of hop flavor and extraction, determined via gas chromatography and sensory analysis. Gas chromatography analysis was modeled after the ASBC Method Beer-48. Sensory analysis was performed via the 15cm line …

Determining The Role Of Maumee River Sediments In Microbial Nitrogen Transformations And Net Fluxes, Ashlyn Stanalonis

Master's Theses

The Maumee River watershed is the largest of any river feeding into the Laurentian Great Lakes and is primarily comprised of agricultural land uses. Most cultivated crops require fertilizer applications to sustain growth and productivity. Fertilizer runoff is a major source of nutrient loading to the river, and total nitrogen (N) and phosphorus (P) inputs contribute to eutrophication and cyanobacterial blooms in the western basin of Lake Erie. This study aimed to characterize Maumee River sediments as net N sinks or sources to the western basin and evaluate N removal efficiency (a valuable ecosystem service) to determine if river sediments …

Multidimensional Determinants Of Gait, Balance, And Softball Performance In Female Youth: Biomechanics, Resource Access, And Psychosocial Factors, Allie G. Mcauliffe

Master's Theses

Movement quality is a fundamental indicator of healthy childhood development and supports physical, emotional, psychosocial, and cognitive well-being. Movement quality is influenced by multiple biomechanical, environmental, and psychosocial factors, yet the relationships among them remain poorly understood in underrepresented populations such as female youth, particularly in softball. Previous studies have largely examined biomechanics, resource access, and psychosocial experience independently, and few have investigated how these factors interact in female youth softball players. To address this gap, this study compared gait and balance characteristics between softball (N = 34) and non-softball (N = 7) female youth, examined associations between resource access, …

A Genetic Analysis Of The Rare Endemic Astragalus Ripleyi Barneby, Juan Antonio Jaramillo-Chico

Master's Theses

Astragalus ripleyi Barneby is a rare endemic species found in the San Luis Valley of the southern portions of the Rocky Mountains in Colorado and New Mexico. Though not federally listed as endangered, the species is on the Bureau of Land Management’s Sensitive Species List, warranting protection and continued management. This study aims to provide information about the genetic health of the species to inform conservation efforts and provide updated management recommendations. A genetic health analysis was conducted investigating the levels of diversity present in the species, how genetic diversity is structured across the known range of the species and …

Fish Meal Serum Modulates Mitochondrial Membrane Potential In Steroidogenic Cells: Implications For Luteoprotection In Cattle, Tyra Marie Goodluck

Master's Theses

The bovine corpus luteum (CL) is a transient endocrine gland that forms after ovulation and produces progesterone, a hormone crucial for early pregnancy. The cattle industry faces tremendous losses annually due to early embryonic mortality within the first 100 days of gestation, where approximately 16% occur during a critical timeframe known as the maternal recognition of pregnancy (MRP). In a normal estrous cycle, if no viable embryo is present, the uterus secretes prostaglandin F2α (PGF2α) during the late luteal phase, triggering luteal regression. One key action of PGF2α is reducing luteal blood flow, leading to hypoxia. This hypoxic state induces …

The Acute Effect Of A Single Dose Of Berberine On Blood Glucose Response Following A Standardized Meal And 2-Mile Walk Performance In Healthy Adults, Victor Emmanuel Obaro

Master's Theses

It is clear that exercise improves overall health status, and it is possible that berberine (BR) may work through some similar mechanisms to improve health status as well.  Purpose: The purpose of this study was to explore the acute effects of a single dose of BR on health status following a standardized meal and a 2 mile walk treadmill protocol with outcomes including blood glucose (BG), blood pressure (BP), heart rate (HR), rate of perceived exertion (RPE), and a two-mile walk time trial performance. Methods: This study used a cross-over design where 14 healthy, young adults were given berberine (BBR) …

Developing A Rapid Urban Forest Assessment System For Sustainable City Greenification, Daniel Gonzalez

Master's Theses

This thesis presents the Rapid Urban Forest Assessment (RUFA) system, a web-based platform that integrates urban tree inventories and aerial tree detection to assess forest health across California’s census-designated places. RUFA combines inventoried tree records with coordinates detected from high-resolution multispectral imagery using convolutional neural networks, then computes a composite RUFA Score from four metrics: canopy cover percentage, trees per capita, tree diversity (TD-50), and tree evenness. The thesis addresses two engineering challenges in building the dashboard: querying and aggregating over seven million tree records in real time, and rendering spatial summaries at multiple zoom levels without recomputing cluster assignments …

Low-Cost Modular Transradial Prosthetic System, Caleb E. Barajas

Master's Theses

Upper-limb loss can significantly impact overall quality of life by limiting  a person's ability to perform activities of daily living (ADLs). Although prosthetic devices can help bridge the gap, many upper-limb prostheses are limited by high costs, discomfort, limited repairability, and accessibility barriers. Current commercial myoelectric prosthetic hands can provide high levels of functionality, but are often expensive and require specialized clinical access. In contrast, many current low-cost and open source prosthetic devices improve affordability but are limited in function or designed for partial hand applications rather than full transradial limb loss.

The purpose of this thesis was to design, …

Spatial And Hydrologic Effects Of Climate Change And Urbanization On Freshwater Fish Communities In North Georgia Watersheds, Mayuko Mizutani

Master's Theses

Urbanization and climate change are altering streamflow and land cover across the southeastern United States, threatening freshwater biodiversity in rivers already burdened by impoundments and habitat loss. I investigated how changes in streamflow and land cover might affect fish community biodiversity in the Etowah River watershed of North Georgia. By combining a dataset of fish collections from 1999 through 2019 with contemporaneous land use and daily streamflow, I was able to model fish community responses to urbanization and climate-driven hydrologic changes and then forecast fish community structure under multiple CMIP6 global climate models and greenhouse gas emissions scenarios (SSP2-4.5 and …

Development And Evaluation Of Alternative Mandrel Materials For The Fabrication Of In-House Silicone Vascular Models, Cole Capitani

Master's Theses

Dr. Kristen Cardinal’s Tissue Engineering Laboratory at California Polytechnic State University, San Luis Obispo develops tissue-engineered blood vessel mimics (BVMs) for preclinical testing of neurovascular devices. These BVMs are reliant on silicone vascular models that define the vessel geometry, support endothelial cell attachment, and allow devices to be evaluated in a controlled in vitro environment. Previous work in the lab established injection molding as a viable method for fabricating silicone vascular models and utilized acrylonitrile butadiene styrene (ABS) for sacrificial mandrels. However, this workflow relied on the use of acetone for mandrel dissolution, required single-use mandrels, had extended post-processing times, …

A Comparison Of Survival, Growth, And Stress Resilience In Three Different Lineages Of The Pacific Oyster (Crassostrea Gigas) Farmed On The California Central Coast, Victoria F. Hanshaw

Master's Theses

Aquaculture of Pacific oysters on the US West Coast is routinely impacted by seasonal unexplained mortality events. To better understand these large-scale mortality events in oyster aquaculture, shellfish growers and scientists in California have partnered together to conduct comparative, multi-estuary farm trials of discrete Pacific oyster (Crassostrea gigas) lineages. In this thesis we investigate how the more recently imported Midori lineage performs compared to the historically used Miyagi lineage, as well as a Hybrid (Midori x Miyagi) lineage. As part of a 7-month long field study from April-November of 2024 in Morro Bay and Tomales Bay, California, we evaluated …

Hardware-In-The-Loop Evaluation Of Sensor-Source Selection For Prosthetic Locomotion Intent Recognition, Victoria Asencio-Clemens

Master's Theses

Active lower-limb prostheses use intent-recognition systems to identify a user’s locomotion mode and select an appropriate control strategy, but sensor configurations that perform well offline may be unsuitable for resource-constrained embedded hardware. Existing sensor-selection methods generally prioritize classification accuracy without directly accounting for processing latency, memory usage, or other hardware-dependent requirements. To address this limitation, this thesis develops a hardware-in-the-loop source-selection framework for embedded classification of level walking, ramp ascent, ramp descent, stair ascent, and stair descent using multimodal biomechanical data from transtibial amputee participants. Subject-specific linear support vector machine classifiers were evaluated using trial-held-out validation, and candidate configurations from …

Predicting Student Belonging In Computing Education: A Multimodal Machine Learning Approach Using Eeg And Survey Data, Hannah Moshtaghi

Master's Theses

Measuring students’ sense of belonging, characterized by feelings of acceptance, inclusion, and encouragement from teachers, remains a significant challenge in computing education. Prior research has associated this multidimensional construct with positive academic outcomes and has identified instructors’ growth- and fixed-mindset messaging as a potential influence. However, belonging is a complex and deeply personal experience that is difficult to capture through direct observation alone. Current measurement methods rely on self-report surveys, which may not capture every aspect of an experience that can also involve emotional and cognitive responses.

This thesis investigates whether combining EEG data recorded during a belonging questionnaire with …

Biologically-Based Alternatives To Plastic Mulch Enrich Microbiome And Buffer Yield In Small-Scale Strawberry Production, Olivia L. Fragiacomo

Master's Theses

Much of commercial agriculture has used plastic mulch since the 1950s to contain fungicides and fertilizers, control weeds, retain soil moisture, and warm the top soil to start the growing season earlier. Research suggests that small-scale strawberry (Fragaria x ananassa) growers may be able to incorporate biological techniques, such as wheat straw mulch with microbial amendments, to reduce the use of single-use plastic mulch with a comparable yield. For this study, I carried out a randomized complete block comparison of five strawberry management techniques: plastic mulch (PM), straw mulch alone, and straw mulch inoculated with either arbuscular mycorrhizal fungi (AMF), …

Impacts Of Agricultural Microplastics On The Growth Of Marine Phytoplankton In Monterey Bay, Olivia A. Pawlyk

Master's Theses

Agricultural plastics are an emerging source of microplastics (MPs) to coastal marine environments, yet their effects on marine phytoplankton remain poorly understood. In coastal regions surrounding Monterey Bay (California, USA), plastic mulch used in agriculture can fragment into MPs during weathering and removal, entering marine waters via runoff and wind transport. This study investigated the effects of environmentally relevant concentrations of agricultural MPs on the growth and physiology of four marine phytoplankton species: two harmful algal bloom (HAB) taxa (Alexandrium sp. and Pseudo-nitzschia multiseries) and two non-HAB taxa (Thalassiosira sp. and Prorocentrum sp.). Each species was cultured independently and exposed …

Impacts Of Physical Extremes On The Reproductive Output And Dispersal Of Stephanocystis Osmundacea, Jessica J. Franks

Master's Theses

Population replenishment is vital for species survival and depends on reproductive output and recruitment success. Many marine organisms rely on both short- and long-distance dispersal to sustain and expand their populations. Marine dispersal involves microscopic or planktonic stages that are influenced by currents, physical processes, and biological traits such as planktonic duration and sinking behavior. Depth and light gradients affect primary producer growth, impacting reproduction, especially in morphologically plastic seaweeds. This study examined how depth-related factors influence reproductive morphology, reproductive output, and dispersal of the subtidal brown seaweed Stephanocystis osmundacea in central California. Using field, lab, and computational methods, depth-driven …

Investigating Learning In Immersive Virtual Reality, Andrew Negrette

Master's Theses

Students often struggle with learning challenging subjects throughout their education. This also tends to lead to lower enjoyment and science self-efficacy for learning. Some subjects may be better represented in 3-dimensional spaces utilizing immersive virtual reality (IVR). Recently, IVR headsets have become more accessible and affordable and therefore are in wider use. The purpose of this study was to investigate whether differences in science selfefficacy, enjoyment, presence and knowledge retention exist between IVR and controls on an ocean acidification lesson. I predicted that participants taking the lesson in IVR would score higher compared to a laptop on all measures, due …

Effects Of Variable Light On Sexual Competition In Kelp Species, Jaycee Lanza

Master's Theses

As foundation species, kelps significantly influence the structure and composition of their surrounding habitat by modifying environmental conditions, including light levels, currents, nutrient availability, sedimentation, and seawater chemistry. Light, in particular, is a critical resource that varies greatly within kelp forests, affecting kelp reproductive processes such as gametogenesis, fertilization, and recruitment, which are vital to population persistence. Biological factors, such as density-dependent competition for resources and sexual competition with other kelps, can also affect such processes. To understand how environmental variables influence kelp populations, it is crucial to recognize their combined effects. This study investigated the impacts of light levels …

The Characterization Of Bridging Waters And Ions In Protein-Rna Complexes, Leslie Duong

Master's Theses

Here we explore the role of bridging waters and ions in protein-RNA complexes. From an initial set of 33 high-resolution X-ray crystal structures, 17 were identified such that protein-RNA complex and component protein and RNA chains were found within 1 pH unit as indicated by crystallization conditions and their diffraction temperatures meeting one of two ranges: above or below freezing. To define an even more realistic set, 12 unbound-unbound and unbound-pseudo-unbound complexes from the 17-set were studied, showing the large fraction of complexes indicating more protein and RNA water hydrogen bonding in their actual interfacial regions as opposed to those …

Hydrus Modeling Of A Sahelian Agroforestry System: An Investigation Of Local Water Balance, Nicole A. Butler

Master's Theses

Effects of drought can devastate agricultural productivity in the West African Sahel. Climate complexities, such as lower-than-average rainfall and high winds, can lead to crop failure and low yields, thereby creating food security issues. Agriculture in the Sahel is primarily rainfed, and the rain is becoming increasingly unpredictable due to the changing climate. The method of intercropping groundnut (Arachis hypogea) and pearl millet (Pennisetum glaucum) with the shrub species Piliostigma reticulatum can combat the effects of climate change and restore degraded soil. Intercropping can increase water availability and crop yield when compared to crops grown in the absence of shrubs. …

Prepration And Characterization Of Alginate Biocomposite Films From Natural Seaweed Containing Glycerol And Silica, Bahareh Ebrahimi Mojaveri

Master's Theses

This study focuses on the development of sodium alginate, a seaweed-derived biopolymer, as a sustainable alternative to conventional food packaging films. The alginate is extracted from natural brown seaweed with a yield of 31% and is formed into alginate films by the solution casting method. This study discusses the alginate extraction and film formation techniques as well as the conditions that affect film properties. Additionally, it explores using composite formulations to enhance alginate properties through additives such as glycerol and silica. Glycerol, tested at different concentrations (15, 25, and 50 wt.%), works as a plasticizer to enhance the flexibility of …

Pick Up The Pieces: Multicultural Men’S Experiences Of Represenentation And Belonging In Higher Education, Lucion Armani Fuller

Master's Theses

To examine how multicultural students experience identity, representation, and belonging within U.S. higher education structured around monoracial classification systems, the present study interviewed six self-identified multicultural male college students. Drawing on Frantz Fanon’s concept of identity fragmentation and Critical Multiracial Theory, the study explored how institutional categorization and racialized perception shape lived experiences of identity formation and misrecognition. Using semi-structured interviews and reflexive thematic analysis informed by interpretive phenomenology, participant narratives were analyzed to understand how identity is negotiated within institutional spaces. The study has three themes. The first is experiencing imposed identity and racial misrecognition. The second is navigating …

Extracellular Vesicle-Mediated Transfer Of Gsdme-Nt Pores As A Mechanism Of Inflammation Propagation, Bifeng Xiao

Master's Theses

Inflammasomes are multiprotein complexes that initiate inflammatory signaling through activation of caspase-1, cytokine maturation, and cleavage of Gasdermin D (GSDMD). Cleaved GSDMD forms membrane pores that contribute to cytokine release and pyroptotic cell death. Recent evidence suggests that extracellular vesicles (EVs) may facilitate the intercellular transfer of inflammatory mediators. This study investigated whether GSDMD N-terminal fragment (GSDMD-NT) associates with EV-enriched fractions and contributes to inflammation propagation. Doxycycline-inducible HeLa cells expressing FLAG-tagged GSDMD-NT were used to generate EV-enriched fractions. Western blot analysis detected GSDMD-NT-associated material within EV fractions, while EV marker analysis supported successful enrichment of EV-associated material. Exposure of recipient …

Environmental Impact Of Preventative Fire-Retardant Products On Soil Chemistry, Elisabeth Kraycik

Master's Theses

Human-caused ignitions account for most wildfires in the United States, particularly along roadsides, utility corridors, and other high-risk infrastructure where fine fuels are abundant and ignition sources are concentrated. These settings are often embedded within grassland and shrubland ecosystems, where fires spread rapidly and can threaten nearby communities and assets. Preventative fire-retardant products (PFRPs) have emerged as a promising strategy for reducing ignition likelihood in these environments. Unlike traditional aerial retardants applied during active suppression, PFRPs are designed for annual, pre-season application to ignition-prone locations. Despite their growing use, the environmental consequences of repeated PFRP applications remain poorly understood, especially …

Evaluating Fungicide Programs For Grapevine Disease Management And Fungicide Sensitivity Monitoring, Abraham Ahumada

Master's Theses

Grapevine diseases, such as powdery mildew and Botrytis bunch rot, require repeated fungicide applications to maintain fruit quality and reduce yield losses. However, fungicide performance can vary among products, application programs, disease pressure, and pathogen sensitivity. This thesis evaluated fungicide programs for control of powdery mildew in ‘Chardonnay’ grapes and assessed fungicide sensitivity of Botrytis cinerea isolates collected from California vineyards.

Powdery mildew, caused by the fungal pathogen Erysiphe necator, is a major threat to the production of Vitis vinifera grapes worldwide. Because powdery mildew management relies heavily on fungicide applications, field evaluations are needed to compare the efficacy …

Evaluation Of A Sleep Health Composite: Changes In Sleep Over The Menarcheal Transition Among Girls, Julianna Adornetti

Master's Theses

Sleep undergoes a shift during puberty, increasing the risk for psychological and insomnia symptoms, particularly among girls. However, little research has examined how the onset of menarche may contribute to vulnerability in sleep and psychological functioning. The Sleep Health framework provides a standardized, multidimensional way to conceptualize sleep health (RU-SATED: satisfaction, alertness, timing, efficiency, duration, and regularity). Although prior studies have provided proof-of-concept for assessing sleep health using a composite score (SHc), its measurement properties have yet to be explored. The primary aims of this longitudinal study were to (1) evaluate the factor structure of a sleep health composite, (2) …