Digital Commons Network^™

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 …

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 …

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 …

Pubertal Timing, Physical Activity, And Internalizing Symptoms In Adolescent Girls, Kirby Knapp

Master's Theses

Puberty brings marked changes in physical appearance, biological functioning, psychological well-being, and behavior, making it one of the most pivotal transitions in adolescence. Those who experience puberty earlier than their same-aged peers are at an elevated risk of psychological disorders and physical inactivity. Research shows that there are links between physical activity and psychological disorders, yet few have examined the directional relations between physical activity and internalizing symptoms or whether a certain amount of physical activity is necessary to prevent internalizing symptoms. Therefore, the current study examined (1) the directional relations between internalizing symptoms and physical activity, (2) the degree …

Growing Through Systemic Adversity: Evaluation Of Developmental Trauma Assessment Among Black And/Or Latiné Adolescents With Adhd, Victoria Grant O'Daniel

Master's Theses

Black and Latiné youth are disproportionately impacted by targeted harm and trauma exposure, which is further exacerbated by stigma, biases, and punitive actions towards youth with attention deficit/hyperactive disorder (ADHD). This presents an urgent public health concern, as frequent exposure to trauma across development can lead to difficulties with behavior regulation, interpersonal relationships, impulse control, emotion regulation, and attention and cognition. Developmental trauma disorder (DTD) was proposed to capture the adverse developmental outcomes experienced by youth exposed to chronic trauma; however, there is a dearth of research on how to assess DTD. Thus, the current study aimed to establish support …

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) …

“Being An Arab Is Like Fighting For Your Joy”: Exploring Bicultural Identity, Racialization, And Psychological Well-Being Among Us-Born Arab Americans, Hisham Nsier

Master's Theses

Bicultural identity development in Arab Americans, who must manage sometimes conflicting cultural expectations, is understudied. Even less is known about Arab Americans born in the United States (US-born AA), who are American by birth yet are alienated from society due to differences between their ‘white’ racialization and their cultural identities. The current study aimed to examine the relationship between bicultural identity, racialization, and psychological well-being at the intersection of US-born AA’s co-existing identities. Eight adult US-born AAs (Mage = 28 years, SD = 4) were recruited from professional Listservs and WhatsApp affinity groups. Qualitative semi-structured interviews were conducted and analyzed …

City Farm Slo: A Case Study Of Nonprofit Regenerative Agriculture, Carver Tunnell

Master's Theses

The focus of this thesis is to create a case study on City Farm SLO, a nonprofit based in San Luis Obispo, California, that has engaged in education and regenerative agriculture on City owned land since 2013. This case study is intended for use in undergraduate agribusiness and natural resource management courses, to encourage thoughtful discussion surrounding nonprofit and regenerative agricultural systems. The case presents the nonprofit at a time of relative success, having recently secured a lease renewal, extending stewardship 40 years into the future. However, the reliance on grants and donations threatens the security of the operation going …

Dot Product Engine Based Neuromorphic Hardware For Continuous-Time Biomedical Signal Classification, Sanjeev Srinivasan

Master's Theses

Accurate diagnosis of pathological conditions from biomedical signals, such as electrocardiograms (ECGs) is often performed offline, making it time-consuming, costly, and inefficient, especially when abnormal patterns are rare and long-term monitoring generates large amounts of data. To address this, this work proposes a compact, scalable, and programmable neuromorphic system designed for real-time preliminary arrhythmia detection and classification using ECG signals, that can be extended to other biomedical signals. The proposed design processes ECG signals using a delta modulation-based spike encoder, followed by classification with a dot-product engine (DPE) based spiking neural network (SNN) processor and winner-take-all (WTA) circuit. The architecture …

Independent And Combined Effects Of Early-Life Iron Deficiency And Antibiotic Exposure On Growth And Hematological Outcomes In A Piglet Model, Ginger M. Fitzpatrick

Master's Theses

Iron deficiency (ID) affects over 2 billion individuals globally. Children under 5 are at increased risk of ID due to rapid growth and are especially vulnerable to its negative consequences because of iron’s essential role in cognitive development and immune maturation. ID is the leading cause of iron deficiency anemia (IDA), with IDA affecting approximately 40% of children in this age group. Antibiotic (abx) exposure is also prevalent during early life and may disrupt growth and through gut dysbiosis, with increasing use posing additional risk in younger populations. Geographically, there is overlap in regions with high anemia prevalence and those …

Large Scale Kmer-Based Proteomic Analysis: An Application Towards Evolutionary Constraint Discovery, Matthew Chak

Master's Theses

Large protein databases now make it possible to study short peptides across natural protein sequence space at unprecedented scale, but exhaustively counting k-mers across billions of protein sequences remains computationally difficult. This thesis develops an exact amino-acid k-mer counting method based on direct addressing, in which fixed-length amino-acid strings are encoded as base-20 integers and updated with a sliding-window recurrence. By avoiding key storage and collision resolution, this approach removes overhead inherent to hash-map-based methods when the k-mer space is sufficiently dense. A memory analysis shows when direct addressing is preferable to open-addressing hash tables, and expected-saturation calculations motivate its …

Structured Dynamic Factor Analysis Of Environmental Time Series With Application To Morro Bay Estuary, Jose Garcia

Master's Theses

This thesis develops a structured dynamic factor analysis (sDFA) framework for decomposing multivariate environmental time series into latent biological and physical components. The methodology is applied to five years of high-resolution passive monitoring data collected from two sites in Morro Bay, California from 2020 through 2024. Relative contribution indices are developed based on the structured DFA that measure how much each latent process contributes to each observed variable at any given time. Structured DFA models fit to the application data suggest site-specific patterns in how biological and physical processes affect water quality variables. At the bay mouth location, physical processes …

Exploring Regenerative Vegetable Systems On The Central Coast Of California, Una S. O'Connell

Master's Theses

As climate change and current agricultural practices place pressure on the long term sustainability and resilience of food production systems, there is growing interest in whether existing agricultural systems can adapt to maintain productivity while improving environmental outcomes.

This study evaluated the effects of regenerative versus standard organic vegetable production systems on yield, insect communities, and weed suppression across three field trials conducted on California's Central Coast. In addition, I collected baseline soil health data for all trials. Trials 1 and 2 were carried out at the Cal Poly San Luis Obispo Organic Farm using cabbage and broccoli as cash …

Discovering Differentially Correlated Sets Across Multiple Treatments, Tyler J. Stoen

Master's Theses

When comparing data sampled under several different conditions, we often want to study not only the overall treatment effect but also how treatments influence the relationships among variables. Differential Correlation Mining (DCM) is an existing method for identifying groups of variables whose average pairwise correlation differs significantly between exactly two sampling conditions. We extend this framework to the setting of three or more treatments, where the goal is to identify variable sets whose pairwise correlation structure varies across all conditions simultaneously. Our proposed method, VSAT for three or more treatments, generalizes the DCM search procedure using a multi-treatment hypothesis test …

The Effects Of Maceration And Enzymes On The Chemical Characteristics Of Hard Apple Cider, Manou De Pelsmaeker

Master's Theses

The purpose of this study was to analyze the effects of maceration and pectinase enzymes on the base chemical, polyphenolic, and volatile characteristics of cider. The apples (Fuji) were milled and macerated for 0, 4, 12, 24, or 36 hours, both with and without an enzymatic pectinase addition. While base chemical characteristics such as sugar content and ABV were unaffected, the acidity of cider was influenced maceration and enzymes. Extended maceration time resulted in lower concentrations of malic acid, and enzymes resulted in a lower pH compared to the control. Polyphenols were extracted during maceration time, resulting in higher concentrations …

Deep Learning For Affect Recognition: A Comparative Study Of Physiological Sensor-Based And Facial Image-Based Approaches, Ravi Panchal, Ravi Panchal

Master's Theses

This thesis investigates deep learning approaches for affect recognition using wearable physiological signals and facial image data. The sensor-based component evaluates stress and affect recognition on the WESAD dataset using wrist-based physiological windows and examines multiple temporal modeling strategies, including convolutional, recurrent, hybrid CNN-LSTM, attention-based, ensemble, and time-frequency approaches.

The image-based component evaluates hard-label facial expression recognition on AffectNet+ using pre-trained ResNet-50, EfficientNet-B3, and ConvNeXt-Tiny architectures across Easy, Challenging, and Difficult subsets representing different levels of expression ambiguity.

Experimental results show that the proposed Multi-Branch Attention CNN-BiLSTM (MBA-CNN-BiLSTM) model achieves the strongest wearable stress- and affect-recognition performance among the evaluated …

An Evaluation Of Road Network Structure As A Predictor Of Traffic Volume, Colin M. Mcdonald

Master's Theses

This thesis evaluates the relationships between various graph theory metrics and taxi traffic volume for the cities of San Francisco, California and Porto, Portugal. We also evaluate a modified betweenness centrality metric which incorporates the count of distinct origin-destination pairs from the taxi data as the weight function. This thesis extends a paper by Pengyao Ye, Bo Wu, and Wenbo Fan by reducing circularity through a temporal train-test split and by comparing both line-graph and primal-graph formulations of betweenness centrality.

We found that past traffic volume is almost perfectly correlated with future traffic volume and that the modified betweenness centrality …

Sustainable Management Of Soilborne Pathogens In Strawberry Production Through Host Resistance And Sanitation Practices, Maria G. Alvarez Arredondo

Master's Theses

Strawberry production in California is significantly impacted by soilborne pathogens that reduce plant productivity and increase management costs. This research addressed management of these pathogens through two independent approaches: evaluation of host resistance in strawberry cultivars and assessment of sanitation practices for reducing pathogen movement between fields.

Macrophomina root rot, caused by Macrophomina phaseolina, was evaluated over two growing seasons (2024–2025 and 2025–2026) using field trials at California Polytechnic State University, San Luis Obispo. In Year 1, disease incidence varied widely among genotypes, with mortality ranging from 1.3% to 88.8% and an average mortality of 26.4%. Area under the …

Evaluation Of Alternative Solvents For Electrospinning Occluded Scaffolds To Model Intracranial Atherosclerotic Disease In Blood Vessel Mimics, Olivia D. Rankin

Master's Theses

Intracranial atherosclerotic disease (ICAD) is characterized by a buildup of fatty plaque within the walls of arteries supplying the brain, resulting in vessel narrowing, restricted blood flow, and increased risk of ischemic stroke. While various treatments exist for ICAD, most are accompanied by high recurrent stroke rates and other adverse events, highlighting the need for further investigation and models for pre-clinical testing. Tissue engineered Blood Vessel Mimics (BVMs), consisting of a polymer scaffold sodded with human vascular cells, serve as physiologically relevant in vitro models for vascular device testing. This thesis focused on the application of alternative solvents to a …

Electrically Evoked Emg Decomposition Using The Perturbative Generalized Series Expansion, William R. Walker

Master's Theses

Electrically evoked electromyography records the muscle's response to nerve stimulation and has been used for clinical assessment of neuromuscular function, as well as treatments such as functional electrical stimulation or stroke rehabilitation. In every muscular contraction, an electrical signal is generated. These signals come from the summation of simultaneously recruited motor units, enabling decomposition techniques to reveal information about motor unit recruitment.  By improving the ability to decompose and analyze these signals, clinical treatments involving neuromuscular electrical stimulation can be optimized and better understood. Much of the research on EMG analysis focuses on voluntary EMG, leaving a gap in the …

Chemical And Sensory Consequences Of Oxidative And Reductive Handling Of White Wines, Amelia Pargellis

Master's Theses

In the 2024 and 2025 vintage four experiments were performed each with a different varietal, namely Albariño, Grenache blanc, Loureiro, and Vermentino. These experiments investigated the effects of hyperoxygenation, reductive winemaking techniques, while monitoring the oxidation-reduction potential.

Albariño grapes were made following two juice protocols, control/reductive (Reductive Control) and oxidative (HyOx). Reductive Control received antioxidants (50 ppm SO₂, 160 mg/L ascorbic acid) and CO₂ blanketing, and HyOx underwent hyperoxygenation at approximately 700 mL/L/h of air for two hours through a stainless-steel sparging stone with 10-µm pores. Juice was cold-settled and racked. Reductive Control juice was split into …

Computational Modeling To Evaluate Bipolar Flexible Electrode Designs For Use In Sciatic Nerve Stimulation, Krystyna S. Allman

Master's Theses

Peripheral nerve stimulation is clinically used to manage pain, rehabilitate motor function, and promote nerve regeneration. The sciatic nerve is often studied for stimulation due to its accessibility and clinical relevance. A conventional nerve cuff electrode is the least invasive method for nerve stimulation, but the mismatch of mechanical properties of the electrode with the nerve tissue can cause damage to the nerve and the electrode itself. This study investigated a novel bipolar, gold nanowire-based cuff electrode design and its ability to selectively activate fibers in the rat sciatic nerve at varying interelectrode spacings. In COMSOL, A finite element model …

Object Detection And Classification For Man-Made Structures To Aid In Search And Rescue (Sar), Mio A. Nakagawa

Master's Theses

This project explores the use of various object detection and classification models to identify permanent man-made structures, specifically cell towers, water towers, watch towers as well as its corresponding shadows (attributes), from aerial imagery. The goal is to evaluate those models and test the feasibility of current models to detect man-made structures in aerial images, in an effort to support search and rescue operations as well as update network infrastructure databases. Multiple object detection models, as well as classification models, including YOLOv8 and VGG19 are implemented and trained on annotated aerial images to determine the presence or absence of man-made …

Empirical Comparsion Of Traveling Salesperson Approximation Algorithms, Shayan Daijavad

Master's Theses

The traveling salesperson problem deals with optimizing the route a traveling sales- person might take to visit a set of places exactly once and return back to their starting point. The problem is NP-hard, and it is hard to approximate in general, but special cases have many approximation algorithms, which come with tradeoffs. In this thesis we compare the runtime, approximation ratio, and overall implementation complexity of two approximation algorithms for the Euclidean version of the problem, a classical 2-approximation algorithm and the multifragment heuristic. We run both algorithms on randomly generated point sets and real world data from TSPLIB. …

Effects Of Irrigation And Nitrogen Management On Yield And Leaching Risk In Organic And Conventional Broccoli Fields, Shane Egerstrom

Master's Theses

Under regulatory pressures to reduce groundwater contamination by nitrate from fertilizer, such as those posed by the Central Coast Regional Water Quality Control Board’s Agricultural Order 4.0, a need exists to better understand interactions between irrigation and nitrogen (N) management. To increase N use efficiency (NUE), growers are encouraged to account for additional sources of N in their management plans, such as irrigation water N and preplant soil N. The availability of these N sources for plant uptake and how it is affected by other management conditions is not yet well documented. We conducted 6 field trials, 3 organic and …

Assessing Nitrogen Leaching Risk In Organic Vegetable Production, Megan Widle

Master's Theses

Nitrogen (N) leaching is the primary driver of groundwater contamination in agricultural regions. On California’s Central Coast, Agricultural Order 4.0 regulates this risk by constraining field-level N balances (N applied minus N removed). However, the assumption that unrecovered N is lost via leaching may not hold in organic and regenerative systems that promote soil organic matter accumulation. This study evaluated whether measured N leaching aligns with estimates derived from partial N budgets in organic systems, and whether management practices (intercrops, cover crops, and reduced tillage) can mitigate leaching risk. Four field trials were conducted to investigate N dynamics in organic …

Evaluating The Commercial Aquaculture Potential Of The Native Pacific Littleneck Clam (Leukoma Staminea) As A Climate Resilient Alternative To The Non-Native Manila Littleneck Clam (Ruditapes Philippinarum)., Skylar M. Wuelfing

Master's Theses

The California shellfish industry’s near-exclusive reliance on the non-native Manila littleneck clam (Ruditapes philippinarum) creates an economic vulnerability to climate-driven disturbances, which can cause mortality events that eradicate up to 80% of stocks. This singular reliance on an introduced species highlights a need for the evaluation of native alternatives like the Pacific littleneck clam (Leukoma staminea). Our goal was to assess the feasibility of using the native Pacific littleneck in commercial aquaculture by comparing their performance to the non-native Manila littlenecks across the following conditions: 1) a five-month field outplant trial at high and low intertidal …

Synthesis And Characterization Of A Graphene Oxide-Zif-8 Composite For Enhanced Post-Combustion Carbon Capture, Sydney Cooper

Master's Theses

Carbon dioxide (CO₂) emissions from fossil fuel combustion are a major contributor to climate change and its associated environmental impacts. The current standard technology for post-combustion carbon capture, aqueous amine scrubbing, is effective but requires significant regeneration energy and has high operational costs. As a result, solid sorbents have been investigated as lower-energy alternatives. Metal-organic frameworks (MOFs) are a promising class of porous nanomaterials due to their high surface area, tunable pore structures, and adjustable surface chemistry. Among them, zeolitic imidazolate framework-8 (ZIF-8) has high thermal and chemical stability, hydrophobicity, and favorable adsorption properties. However, conventional synthesis methods often rely …