Digital Commons Network^™

History & Evolution Of Plastic Mulching Technology: An Ethnography Of California Strawberry Plasticulture, Kalea Conrad

Master's Theses

This ethnography draws on key informant interviews and participant observation to produce a case study about plastic mulching as an important industry standard in specialty crop production. It documents the historic adoption and present role of plastic mulching technology in California strawberry production and addresses the characteristics of commercial standard management that inhibit the adoption of alternative mulching practices. It complements extensive research on strawberry pathology and fumigation, breeding innovations, fertilizer and pesticide treatments, and maximization of yields to incorporate participants’ lived experiences and knowledge of mulch origins, the technology adoption process, mulch benefits and drawbacks, the state of agricultural …

Dual Base Sige Is-Hbt For Use In Biosensing Applications, Liam Stephen Hayes

Master's Theses

The proposed research is for a novel SiGe-based Ion-Sensitive Dual Hetero-junction Bipolar Transistor (IS-HBT) to be used in both trans-dermal biological sensing as well as Lab-on-Chip (LOC) applications. The end goals for the device designed are two: For one, the research done for this work will be used to substantiate the claims made by Zafar et al. [1] that an HBT-style structure is better suited for biosensing application rather than a conventional Field Effect Transistor (FET) based geometries. Secondly, it provides the final element to be integrated along with a selectivity membrane, as well as with a reverse-iontophoresis system to …

Design And Implementation Of An Inverted Short Baseline Acoustic Positioning System, Jakob Frabosilio

Master's Theses

This document details the design, implementation, testing, and analysis of an inverted short baseline acoustic positioning system. The system presented here is an above-water, air-based prototype for an underwater acoustic positioning system; it is designed to determine the position of remotely-operated underwater vehicles (ROVs) and autonomous underwater vehicles (AUVs) in the global frame using a method that does not drift over time.

A ground-truth positioning system is constructed using a stacked hexapod platform actuator, which mimics the motion of an AUV and provides the true position of an ultrasonic microphone array. An ultrasonic transmitter sends a pulse of sound towards …

Validation Of Mobile Devices In Arbitrary Locations Against Force Plate Standard For Balance Assessment, German J. Ellsworth

Master's Theses

With balance assessment being essential to the prediction of fall risk and detection and assessment of motor disorders, increasing clinical accessibility to objective balance metrics is essential. Work has been done validating center of mass (COM) acceleration metrics against well regarded force plate center of pressure (COP) position standards for mobile device data acquisition systems, but most research is restricted to devices being close to the COM or strapped in a harness configuration. Through the use of rigid body kinematics and the inverted pendulum model, this study develops novel methodology for calculating COM acceleration using mobile devices in arbitrary positions, …

Dynamic Maze Puzzle Navigation Using Deep Reinforcement Learning, Luisa Shu Yi Chiu

Master's Theses

The implementation of deep reinforcement learning in mobile robotics offers a great solution for the development of autonomous mobile robots to efficiently complete tasks and transport objects. Reinforcement learning continues to show impressive potential in robotics applications through self-learning and biological plausibility. Despite its advancements, challenges remain in applying these machine learning techniques in dynamic environments. This thesis explores the performance of Deep Q-Networks (DQN), using images as an input, for mobile robot navigation in dynamic maze puzzles and aims to contribute to advancements in deep reinforcement learning applications for simulated and real-life robotic systems. This project is a step …

Representation Theory Arising From Groups In Physics, Jaxon Green

Master's Theses

A representation is a group homomorphism whose image is a group of invertible matrices. Representations and their associated matrices are analyzed through well-established techniques from linear algebra. We characterize representations by a unique decomposition into irreducible representations just as we characterize the decomposition of matrices into their eigenspaces. Through the study of these representations, we uncover mathematical relationships that underlie groups with physical applications. Due to physical symmetries, we study how the irreducible representations of groups that embody the actions of even the most basic rotations are utilized in the computation of irreducible representations groups that reflect more complicated mechanics, …

Of Geese And Grass: Investigating Impacts Of Brant Grazing On Eeelgrass, Dakota L. Osborne

Master's Theses

Grazing pressure is important in structuring plant communities, particularly in aquatic environments. Eelgrass (Zostera marina), a keystone species in estuaries across North America, is experiencing widespread population declines. As a keystone species, eelgrass provides numerous important functions, including: 1) water filtration, 2) sediment stabilization, 3) providing refuge and nursery habitat for numerous species, and 4) carbon sequestration. Benefits which could be lost if eelgrass beds continue to diminish. California has experienced some of the greatest eelgrass declines, and Morro Bay, CA experienced a 96% decrease in eelgrass from 2007 to 2017. Most studies to date have examined bottom-up …

Development Of Extruded Puffed Snack Utilizing Carrot Pomace, Bean Flour, And Rice Starch As Primary Ingredients, Julia Zoe

Master's Theses

Every year, the carrot industry worldwide wastes up to 50% of carrots as raw material due to processing (Šeregelj et al., 2020). When carrots are juiced, the remaining fibrous pulp is often discarded as carrot pomace. In order to redirect this food waste, the first objective of this research was to optimize formulations for an extruded puffed snack that is most similar to commercially available puffed snacks, utilizing baby lima bean flour and carrot pomace

Hardness (kg), cross-sectional expansion ratio, bulk density (g/cm³), moisture content (%), water activity, specific mechanical energy (kJ/kg), carotenoid concentration (ppm), and total dietary …

The Post-Closet Home: Queer Domesticity, Enclosure, And Queer Southern Gothicism In Lee Mandelo's "Summer Sons", Andrew Dylan Dampier

Master's Theses

In current discussions of queer theory, terms such as “post-gay” leave room for misrepresentation. The premise behind this term serves a primarily cisgenderheterosexual agenda by promising the assimilation of queer individuals into the dominant society. For this reason, I prefer to align the term “post-closet” with the queer person’s journey towards, and past, such societal barriers while maintaining the significance of foundational queer theories. In his novel Summer Sons, Lee Mandelo depicts Andrew Blur’s journey through the grief-ridden confines of the closet as he seeks a new identity following the death of his best friend. Mandelo accomplishes this by juxtaposing …

Assessment Of Mediterranean Diet Adherence Using The Kidmed Diet 2.0 Tool: College Student Questionnaire, Nakia Cyrice Hilton

Master's Theses

The Mediterranean Diet has garnered increasing popularity due to its multifaceted health benefits. The MedDiet enhances well-being across all age groups, emphasizing high consumption of fruits, vegetables, legumes, nuts, olive oil, and whole grains and moderate fish, poultry, and dairy intake. Recent research underscores the significant impact of Mediterranean diet adherence on college students' physical and mental health. The diet's emphasis on nutrient-dense foods rich in vitamins, minerals, and antioxidants supports cognitive function, which is pivotal for academic performance. Moreover, the abundant presence of healthy fats, particularly from olive oil and fatty fish, may contribute to improved mood regulation, potentially …

Supervised Classification Modeling On Louisiana Medicaid Data: A Comparative Study, Yead Rahman

Master's Theses

This thesis systematically optimizes and compares state-of-the-art supervised classification models for Louisiana Medicaid data targeting clinical services, COVID-19 infection, and tobacco use. These target variables are critically important as they represent key health outcomes and behaviors among Medicaid enrollees in Louisiana, a population often characterized by poverty and limited access to education. This study applies advanced machine learning techniques to identify the best model for multinomial and binary classification tasks. These include models such as Logistic Regression, XGBoost, AdaBoost, Random Forest, Decision Tree, Artificial Neural Networks, and Naïve Bayes. Extensive tuning of the hyperparameters and optimization of each classifier were …

Adherence To Mediterranean Diet Principles In Minority College Students, Bridgette Lorraine Barbre

Master's Theses

Every year, millions of young adults attend college. The Centers for Disease Control and Prevention (CDC) lists heart disease and diabetes as the top health concerns for minority Americans. African American and Hispanic/Latino communities could see a reduction in illness risk by promoting physical activity and healthy eating habits such as the Mediterranean Diet. Research indicates that young adults may benefit significantly from taking charge of their eating habits at the crucial point in their transition from high school to college. By determining the dietary patterns of minority college students, as related to the Mediterranean diet principles, this study intends …

Division I Collegiate Baseball Pitching Performance In Relation To Forearm Kinematics And Kinetics, Christopher W. Watson

Master's Theses

This thesis investigates physical and anthropometric factors influenced by forearm rotation biases associated with supination and pronation on pitch characteristics among Division I college baseball pitchers. The study involved twenty-two participants who underwent comprehensive physical assessments, including measures of forearm strength, range of motion, and grip strength, as well as finger and hand length measurements. Ball flight metrics were collected during intrasquad scrimmages using advanced radar tracking technology. Results revealed significant relationships between distinct physical biases of strength in pronation and supination, pinch strength, anthropometrics such as middle finger length, and specific pitch characteristics. This study lays the groundwork for …

Robotic Odor Source Localization Using Vision And Olfaction Sensing, Sunzid Hassan

Master's Theses

Robotic Odor Source Localization (ROSL) technology allows autonomous agents like robots to find an odor source in unknown environments. A successful odor source location depends crucially on an effective navigation algorithm that directs the robot towards the odor source. This thesis is a combination of three projects. First, we detail development of a versatile multi-modal robotic platform for ROSL real-world ROSL experimentation and discussed real-world validation of a traditional olfactionbased ROSL algorithm. Secondly, we introduced vision in ROSL by proposing a fusion navigation algorithm that integrates deep-learning enabled vision and olfaction-based navigation. This hybrid approach tackles challenges such as turbulent …

Development Of A Urothelial Cell Line Expressing A Caspase-1 Biosensor To Measure Cellular Inflammatory Responses To Potential Uropathogens, Nikita Riya Kesav

Master's Theses

Urinary tract infections are one of the most common bacterial infections, historically implicating Escherichia coli as the causative pathogen. However, it is now known that there are a variety of bacteria that exist within the urinary tract, acting as either beneficial uroprotectives or opportunistic uropathogens. Furthermore, there are significant gaps in our understanding as to how these bacteria interact with the urothelium and what role each plays in maintaining or disrupting homeostasis. Research has shown that Toll-like receptor 4 (TLR4) signaling and Nod-like Receptor Protein 3 play a role in inflammasome activation during infection, triggering caspase-1 activation and inducing release …

Evolutionary Patterns Of Anolis Lizard Skulls: An Investigation In Geometric Morphometrics And An Educational Exploration Of Structure And Function, Katherine Beyer Starr

Master's Theses

This study explores the evolutionary patterns of Anolis lizard skulls and integrates findings into a curriculum focused on elucidating the structure and function of a lizard's head. The first objective was to develop an understanding of how the evolutionary patterns, of an extraordinary group of lizards (Anolis) compares to their relatives. Most of the prior research on Anolis morphology has focused on the post-cranium because of its significance towards subdivision of the arboreal habitat. But the group’s remarkable diversity in head shape has been seriously under-investigated. By performing geometric morphometric analysis of skull shape across a large sample of anoles …

Development Of Targeted, Statin Loaded Nanoparticle Delivery Systems, Stephanie Judkins

Master's Theses

Statins lower endogenous production of cholesterol through their inhibition of the mevalonate pathway. Lipophilic statins in particular exhibit anti-inflammatory effects at supraphysiological doses by preventing downstream signaling through small molecule GTPases. Interest lies in development of statins as anti-inflammatory therapeutics, however, achieving effective doses locally incurs serious off-target effects. Our goal was to develop and optimize a targeted delivery system to traffic these drugs to inflamed sites and unload the drug at effective concentrations while avoiding systemic exposure. Lipophilic statins (lovastatin, simvastatin, and atorvastatin) were incorporated into polymeric nanoparticles (NPs) due to their hydrophobicity. We have shown that statins released …

The Anti-Inflammatory Properties Of Exopolysaccharide From Bacillus Subtilis, Nikolay Todorov

Master's Theses

Commensal microorganisms can be used therapeutically to ameliorate a variety of diseases. The laboratory of Dr. Katherine L. Knight studies these therapeutic properties in the commensal microorganism known as Bacillus subtilis. Previously, the Knight lab has demonstrated that B. subtilis can protect against colitis caused by Citrobacter rodentium suggesting that B. subtilis possesses anti-inflammatory properties. These properties are specific to the polysaccharide capsule of the microorganism known as exopolysaccharide or EPS. EPS can be produced and purified for study. EPS has been demonstrated to be protective in a variety of diseases such as allergic eosinophilia, sepsis, Graft versus Host disease, …

Absolute Quantification Of Human Myosin And Titin Isoforms In Disease By A Mass Spectrometry Approach, Nitha Aima Muntu

Master's Theses

Heart failure (HF) is the leading cause of death worldwide and produces an immense economic burden. Dilated cardiomyopathy (DCM), characterized by contractile weakness and chamber dilation, is a significant cause of HF. The sarcomeric proteins play a crucial role in regulating the contractile properties of the heart. As the primary motor protein, the expression of cardiac myosin isoforms (α-MHC and β-MHC) dictates the performance and cardiac energy utilization of the sarcomere. Titin is the giant spring protein in the sarcomere, and titin isoform expression impacts the passive stiffness of the myocardium. Small changes in the α-MHC/β-MHC and titin isoform ratios …

Sport And Environmental Issues: Ncaa Division I Student-Athletes’ Personal Experiences, Ivanna M. Anderson-Villela

Master's Theses

While sport ecology is a growing category in sport management literature, there is a lack of research exploring athletes’ experiences regarding environmental issues, and the impacts environmental issues have on student-athletes. The present study qualitatively explored the personal lived experiences of eight NCAA Division I student-athletes regarding environmental issues with the aim of identifying potential influences on values and beliefs through social norms and understanding the student-athlete perspective. Thematic analysis identified 152 raw data themes and 19 higher order themes, which were organized into four central themes: awareness, care and concern from athletic departments, implications, and advocacy. Generally, student-athletes perceived …

A Qualitative Evaluation Of Speech Sound Disorder Treatment Apps For Children, Rachel G. Barnett

Master's Theses

This research examined 20 speech sound disorder (SSD) treatment apps’ features and costs as related to the feature matching process within speech-language therapy. Methods included the development of a 67-item SSD checklist and sorted into 9 categories, including linguistic levels, speech models, software customization, cost, game types, image types, technical elements, feedback types, and engagement and manipulation. Two independent reviewers applied the checklist to randomly selected contemporary apps available on both iPhones and iPads. App cost was capped at $25. Results indicated that app cost was not a good predictor of feature quantity and contemporary apps had some relevant feature …

Single-Caregiver Families: Using Lived Experiences To Build Effective Resilience And Protect Future Children Against Negative Outcomes, Andrew Chakalian

Master's Theses

Among many cited risk factors that disproportionately affect children who grow up in a single-caregiver family, adverse childhood experiences (ACEs) and related behavioral and health outcomes are some of the most significant. Comparatively, there has been a substantial gap in the research exploring protective factors that support healthy development for children with this family composition. The present study used a phenomenological methodology to explore how nine participants aged 18-25 viewed their childhood in a single-caregiver family. Through the use of semi-structured interviews, participants shared their experiences; analysis yielded four themes: (1) further dysfunction in the social system exacerbating the effects …

Beyond ‘Manning Up’: The Impact Of Hegemonic Masculinity & Gender Norms On Mental Health Help-Seeking Among College Men, Joslyn Barragan

Master's Theses

This narrative inquiry study was conducted to explore college men's conceptualization of masculinity and gender norms and their relationship with mental health-related help-seeking behaviors. Through semi-structured interviews with seven men, I gathered their perceptions of mental health support and the obstacles they encountered in accessing it. Drawing from Connell's conceptualization of masculinities, this study locates their narratives within the broader framework of societal expectations, highlighting the complexities of men's attitudes and behaviors toward mental health counseling. Ultimately, five critical narratives were discovered: a) Initial models of masculinity emerge through socialization; b) Men encounter barriers to mental health care from all …

Remote Sensing With Airborne Infrared Thermography For Assessment Of Landscape Scale Wildfire Spread And Intensity, Christopher C. Giesige

Master's Theses

Wildland fire is one of the most complex environmental physical processes to quantify. The way in which we observe and measure wildland fire is critical in understanding how these processes drive fire dynamics. Fire behavior can be observed in several ways including the use of ground sensors and remote sensing packages aboard aircraft and satellites. Airborne sensors provide high spatial resolution and can provide high temporal resolution. Infrared thermography takes advantage of radiant heat transfer allowing for the study of fire characteristics such as fire spread and intensity. Aircraft observations utilizing infrared cameras have been a well-established method of fire …

Analyzing Live And Dead Fuel Moisture In California: Insights For Wildfire Management Decisions, Jack R. Drucker

Master's Theses

This study investigates trends in fuel moisture content (FMC) across California from 2000 to 2021. It utilizes two distinct sources of FMC data: the Fuel Moisture Repository, which integrates live fuel moisture content (LFMC) observations, and a novel dead fuel moisture content (DFMC) reanalysis product which provides spatial fuel moisture maps by integrating dead fuel moisture observations and a fuel moisture model driven by gridded weather data. The analysis uncovered a general downtrend in FMC across California, with the exception of LFMC in the Northernmost regions and coarse DFMC. Despite the differing long-term FMC trends, all the regions experienced a …

The Relationship Among Meditation Frequency, Mindfulness, Emotional Regulation, And Happiness, Emily Inlow

Master's Theses

High levels of happiness and well-being are important for many reasons including health, relationships, and work-life balance. Understanding what can increase happiness and well-being levels may be beneficial to create a happy, healthy life. Recently, meditation has become a popular practice to increase happiness and overall well-being. The purpose of this study was to investigate the relationships between meditation frequency and mindfulness, emotional regulation, happiness, and overall well-being. To add to existing literature meditation frequency and emotional regulation were each assessed in two ways: average meditation frequency per week, average meditation session length, expressive suppression, and cognitive reappraisal. It was …

On The Colorability Of The Sphere Complex, Bennett Haffner

Master's Theses

One of the most prominently studied groups in geometric group theory is the outer automorphism group of the free group Out(F). The sphere complex provides a topological model for Out(F). We demonstrate the chromatic number of the sphere complex is finite.

Observations Of Currents, Waves, And Turbulence Within A Giant Kelp Forest In Stillwater Cove, Carmel, California, Logan A. Grady

Master's Theses

Nutrient distribution and propagule dispersal within Giant kelp (Macrocystis pyrifera) forests are significantly influenced by turbulence. In-situ measurements of turbulence within giant kelp forests are limited and driving mechanisms are primarily informed by controlled-flume experiments. This study investigates relationships between currents, surface gravity waves, and turbulence within a kelp forest through deployment of moored instrumentation and kelp surveys in Stillwater Cove, California during summer of 2022. Oceanographic conditions were primarily driven by coastal upwelling and a semi-diurnal internal tide, which was associated with cooling events and enhanced onshore velocity within the kelp forest during rising tides. Estimates of gradient Richardson …

Online Trolling, Harassment, Misinformation: The Psychological Predictors Of Dark Participation, Randy Kim

Master's Theses

This study aims to examine the reasons why certain individuals engage in “dark participation”, antisocial social participation online involving behavior such as trolling, hate speech, harassment, and spreading disinformation. Online toxicity has increasingly destabilized our ability to engage in socially important discourse online, and trolling has such a strong effect on our environment to the point where the 2016 presidential election was, in part, influenced by online trolls. We theorize that dark participation (DP) will be predicted by high levels of moral disengagement (MD), need for chaos (NFC), and meaninglessness in life (MLN) and self concept clarity (SCC). A series …

Flora And Fauna Lexical Indicators Of Prehistoric Movement Of Yuman Peoples, Adam Ingwerson

Master's Theses

Amyloid fibrils are locally ordered protein aggregates characterized by a filamentous morphology held together by a hydrogen bonding motif known as cross-β structure whereby hydrogen bonds form between backbone amide bond moieties across separate protein segments. The most notable medical significance of amyloid fibrils is their central role in the etiology of Alzheimer’s disease, type 2 diabetes, and other human diseases. Although amyloid fibrils have been studied extensively, the mechanism of their formation is still not fully understood. X-ray crystallography is a leading experimental technique for resolving amyloid fibril structures from crystallized proteins; however, inherent limitations leave open the possibility …