Digital Commons Network^™

Spatial Heterogeneity And Temporal Trends Of California Extreme Heat Using High-Resolution Earth System Model Simulations, Eleni Konstantelos

Master's Theses

Extreme heat threatens California’s diverse landscapes and populations through intensifying and geographically shifting patterns. This study examined the temporal trend and spatial heterogeneities of California’s extreme heat for 1994–2015. The analysis was based on the fully coupled Energy Exascale Earth System Model version 2 (E3SMv2), specifically its 25-km regionally refined configuration. While the Desert/Inland region exhibited the highest number of days ≥ 35 °C and the highest heatwave severity, Central Valley showed the fastest increase in the number of days ≥ 35 °C and heatwave events, as well as the fastest increases of days exceeding various heat index thresholds over …

Interpretable Wellness Prediction From Passive Wearable Sensor Data Using Large Language Models, Cheng-Huan Yu

Master's Theses

This thesis presents a unified framework for multi-target wellness prediction using passive wearable sensor data and large language models (LLMs). The study integrates two complementary paradigms: prompt-based regression and representation-driven classification. In the first stage, structured wearable representations derived from daily physiological signals are used to prompt LLMs to predict stress, fatigue, sleep quality, and readiness. Two input representations are evaluated: statistical summaries and hybrid inputs combining statistical summaries with raw sensor values. To improve interpretability and prediction consistency, the second stage introduces a representation-centric classification framework in which wearable signals and wellness targets are discretized into categorical levels. Multiple …

Middle Management Diplomacy: An Examination Of Us Foreign Policy Analysis In Middle-Echelon Diplomatic Professionals, Isaac R. Silvino

Master's Theses

This study analyzes the role which managerial level U.S. military Foreign Area Officers and Foreign Service Officers play in shaping and implementing U.S. foreign policy. By analyzing the individual professional at the middle-echelons of an organizational hierarchy, we make an effort in dispelling ourselves from obscured perceptions of IR centered on character and state idealization driven narratives. Doing this may help bridge the foundational gap between academics and practitioners while shifting towards a paradigm of IR analysis focusing on human agency and decisions.

Result

Individual managerial echelon diplomats do not directly make policy, but rather play a crucial role in …

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.

The Impact Of Growth Hormone-Releasing Hormone Antagonist On Human Adipose-Derived Stem Cells, Jeanne Michelle Dugas

Master's Theses

Obesity is a condition that affects over 40% of American adults and contributes to numerous preventable health issues. This condition is caused by increased adipose tissue, which forms when stem cells transform into adipocytes. Mesenchymal stem cells, including human adipose-derived stem cells (hASC), are multipotent with the ability to differentiate into adipocytes, osteocytes, or chondrocytes. Many factors affect this transformation, including the peptide growth hormone-releasing hormone (GHRH). The main role of GHRH is to trigger the release of growth hormone, but it has also been found to play an important role in adipocyte metabolism. We expect that if the differentiation …

Characterization Of Cd11c-Expressing Gut-Associated T Cells, Ana Cvetkovic

Master's Theses

Our immune system is a remarkable defense network that protects our bodies from a range of threats. Its’ intricate machinery comprises of messenger and effector cells that work together to coordinate an effective immune response. Traditionally, T lymphocytes have been considered effectors: they receive instructions from messengers, known as Antigen Presenting Cells (APCs), that alter T-cell activation state and behavior. In the gut, Dendritic Cells (DCs) are the APCs that most often instruct T cells. To accomplish their messenger role, DCs express CD11c at high levels, a surface marker involved in cell-to-cell signaling and phagocytosis. As such, CD11c expression has …

Perturbation Based Decomposition For Motor Unit Number Estimation, Anna T. Pham

Master's Theses

Motor unit number estimation (MUNE) is of clinical significance because information associated with motor unit populations and the loss of motor units over time are crucial to the diagnosis and monitoring of neuromuscular disorders. The responses of individual motor units can be extracted through incremental stimulation of a muscle group of interest and further analyzed through various methods to compute the MUNE. In this work, the utility of the perturbation-based decomposition by Szlavik will be investigated for this application and compared to the original MUNE approach developed by McComas. Successful decomposition may suggest an alternative method for motor unit number …

Development Of An Angiogenic Tissue-On-A-Chip Microenvironment, Eric Stuehr

Master's Theses

Preclinical testing is necessary to investigate the safety and efficacy of novel therapeutics before moving to clinical trials, yet approximately 90% of these therapies fail once tested in humans. This has led to increased interest in developing robust preclinical models that accurately mimic the complex human in vivo physiology. Microfluidic devices that can introduce dynamic conditions to 3D cell/organoid cultures, also known as tissue-on-a-chip, have emerged as physiologically relevant in vitro preclinical models that can achieve high throughput screening of therapeutics. The research presented here aimed to develop an angiogenic environment within a novel microfluidic device to stimulate formation of …

Using Noninvasive Calibrated Cuff Plethysmography To Observe The Effects Of Cold-Water Immersion On Arterial Compliance, Rita M. Grigorian

Master's Theses

As the prevalence of cardiovascular diseases continues to exponentially grow in populations across the globe, the necessity of determining underlying factors, effective methods of diagnoses, and universally available preventive measures also grows. Early detection of endothelial dysfunction, a proven precursor of cardiovascular diseases, can be extremely impactful in encouraging preventative measures and early intervention before medical conditions become chronic. In recent years, ice plunging, a form of cryotherapy involving full body immersion in cold water, has gained popularity within circles of fitness and health practitioners, gaining the interest of people of all backgrounds. Certain parallels observed between the human physiological …

Subclinical Atherosclerosis Quantified Through Cumulative Shear Measurement, Margaret Lynne Papka

Master's Theses

With the high mortality rate of cardiovascular disease, it is important to study the early signs. The early detection of cardiovascular disease can lead to saved lives. Currently the most prevalent detection methods are the Framingham Risk Score and the carotid intima media thickness, both of which are insufficient. The necessary tool for early detection requires a uniform quantification system. The stimulus leading to endothelial dysfunction, the most significant predictor of a major adverse cardiovascular event (MACE)—and subsequently subclinical atherosclerosis—is reduced shear stress. Increased surface relative roughness affects the flow profile transition from laminar to turbulent resulting in reduced shear …

Examination Of Flow Patterns During Droplet Formation And In Venous Valve Mimic Using Μ-Piv, Vignesha Vijayananda

Master's Theses

In this work, particle image velocimetry (PIV) was used for fluid flow visualization in both continuous and segmented-flow microfluidics. Droplet microfluidics is known for its precise and consistent volume dispersion between microliters and picoliters in volume for application ranging from molecular synthesis, drug discover, and diagnostics. But the influence of junction geometry on the process of drop formation has not been investigated. In this study, µ-PIV was used to study the internal flow during the drop formation process in flow-focus microfluidic device with and without constriction. It was found that in case of flow-focus with constriction, the shear force on …

Studying The Efficacy Of An Injectable 3-Dimensional Fibrin Extracellular Matrix To Characterize The Effects Of Antitumor Agents On Sw620 Cells In A Microfluidic Device, Thèo Anastos

Master's Theses

Colorectal cancer is the third most common cancer in the United States and there is currently a lot of research going into new antitumor agents to kill the cancer. One method for replicating the tumor response to a drug in vivo is by creating an in vitro drug testing model to replicate the in vivo condition. This research project was conducted to determine the efficacy of testing tumor cultures in a microfluidic device as a way to provide accurate drug responses in vitro instead of using in vivo subjects in clinical trials. A total of four experiments were conducted with …

Biological Semantic Segmentation On Ct Medical Images For Kidney Tumor Detection Using Nnu-Net Framework, Andres Bergsneider

Master's Theses

Healthcare systems are constantly challenged with bottlenecks due to human-reliant operations, such as analyzing medical images. High precision and repeatability is necessary when performing a diagnostics on patients with tumors. Throughout the years an increasing number of advancements have been made using various machine learning algorithms for the detection of tumors helping to fast track diagnosis and treatment decisions. “Black Box” systems such as the complex deep learning networks discussed in this paper rely heavily on hyperparameter optimization in order to obtain the most ideal performance. This requires a significant time investment in the tuning of such networks to acquire …

Cost-Effectiveness Analysis Of Colorectal Cancer Screening Strategies Using Active Learning And Montecarlo Simulation, Amirhosein Fouladi

Master's Theses

Colorectal cancer (CRC) is one of the deadliest types of cancer in the US due to its high incidence and mortality rates. Detection of CRC in the early stages through available screening tests increases the patient's survival chances. In this study, we investigate the cost-effectiveness of a wide variety of multi-modal CRC screening policies. More specifically, we develop a Monte Carlo simulation framework to model the CRC natural history and preventive interventions. Age-specific and size-specific progression rates of adenomatous polyps are estimated using an innovative active learning method. Specifically, we develop a decision tree model to estimate size-specific and age-specific …

The Impact Of Shod Versus Unshod Walking On Center Of Pressure Variability, Zachary Barrons

Master's Theses

The purpose of the present investigation was to examine the influence of footwear on walking stability. Twenty healthy women walked at 1.3 m/s on an instrumented treadmill. One hundred steps (50-right, 50-left) were analyzed from two walking conditions (shod, unshod). The variability of the center of pressure (COP) for each step was calculated for quadrants of the contact period. Significant differences in variability were seen between shod and unshod conditions in all quadrants as well as differences between left and right feet in quadrants one and four. Restricted foot motion while shod may explain the differences seen in COP variability. …

An Investigation Of Enzymes Capable Of Activating Cannabinoid Prodrugs, Brittney J. Morgan

Master's Theses

The plant Cannabis sativa contains a class of terpenophenols called cannabinoids which, in their active form, have been shown to have antiproliferative, anti-metastatic, anti-angiogenic, and pro-apoptotic effects on several types of cancer cells both in vitro and in vivo. Cannabinoids have been shown to not exert this apoptotic activity in healthy cells and they do not elicit the usual side effects seen with conventional chemotherapies. However, naturally occurring prodrugs from Cannabis must first be converted into the active form to induce the apoptotic and other physiological activities. Although humans do not possess the enzyme(s) necessary for this conversion, several different …

An Ergonomics Investigation Of The Application Of Virtual Reality On Training For A Precision Task, Delaney M. Bales

Master's Theses

Virtual reality is rapidly expanding its capabilities and accessibility to consumers. The application of virtual reality in training for precision tasks has been limited to specialized equipment such as a haptic glove or a haptic stylus, but not studied for handheld controllers in consumer-grade systems such as the HTC Vive. A straight-line precision steadiness task was adopted in virtual reality to emulate basic linear movements in industrial operations and disability rehabilitation. This study collected the total time and the error time for the straight-line task in both virtual reality and a physical control experiment for 48 participants. The task was …

Effects Of Experimental Noise Exposure On Songbird Nesting Behaviors And Nest Success, Tracy I. Mulholland

Master's Theses

Anthropogenic noise is an increasingly prevalent global disturbance. Animals that rely on the acoustical environment, such as songbirds, are especially vulnerable to these sounds. Traffic noise, in particular, overlaps with the frequency range of songbirds, creating masking effects. We investigated the effects of chronic traffic noise on provisioning behaviors and breeding success of nesting western bluebirds (Sialia mexicana) and ash-throated flycatchers (Myiarchus cinerascens). Because anthropogenic noise exposure has the potential to interrupt parent-offspring communication and alter vigilance behaviors, we predicted that traffic noise would lead to changes in provisioning behaviors, such as fewer visits to the …

Effects Of Extended Spaceflight On The Mandible And Incisor Teeth Of Mice, Didem Dagdeviren

Master's Theses

No abstract provided.

Trust, Reciprocity, Fairness, And Mind Reading Under Stress, Charles Jia Yao Xie

Master's Theses

Some hypothesized that when stressed, females activate tend-and-befriend, a stress response that enhances social abilities. Yet, critics argued this stress response is not exclusive to females and others suggested that males and females have different stress responses associated with social skills. This study intended to address these criticisms by testing whether males exhibit prosocial responses to stress and if particular stress responses improved social skills. To do this, 70 healthy introductory psychology students from a large public university in northern California were recruited to participate. Using random assignment, half of these individuals were exposed to an acute stressor and another …

Screening Bioactive Molecules In Tetrahymena Thermophila Using Phagocytosis Determined By Flow Cytometry, Santosh Gummidipundi

Master's Theses

The evaluation of molecules that have potentially bioactive significance is an expanding field, but current screening assays are expensive and time consuming. Mammalian cell-based assays require aseptic techniques, complex media and long generation times. This thesis reports on an assay that incorporates Tetrahymena phagocytic ingestion and flow cytometry to evaluate several potentially bioactive molecules. Several factors that influenced optimal and reproducible results were analyzed. Seven potentially bioactive molecules (serotonin, norepinephrine, dopamine, morphine, colchicine, mexiletine and procainamide) were evaluated to determine their effect on phagocytosis by Tetrahymena. Assay results indicated that the phagocytic rate was unaffected by serotonin, norepinephrine, dopamine, and …

The Role Of Nitric Oxide In Skeletal Simulated Microgravity Response, Luan Tran

Master's Theses

Prolonged exposure to the space environment leads to bone loss. Using a ground-based model for microgravity (hind-limb unloading), it has been shown in rodents that proliferation and differentiation activity of osteoprogenitors are decreased with exposure to simulated microgravity (Kostenuik et al., 1997). Osteoblast mineralization activity has been shown to increase with nitric oxide supplementation (Afzal et al., 2004; Koyama et al., 2000). I hypothesized that the degenerative effects of microgravity exposure result from chronic changes in nitric oxide regulation in osteoprogenitors, and that supplementation with exogenous nitric oxide following exposure would ameliorate these changes. In 20 C57Bl/6 mice, hind-limb unloading …

The Effect Of Heat Acclimation On Hand Cooling Efficacy During Exercise Heat Stress, Elizabeth Adams

Master's Theses

The Effect of Heat Acclimation on Hand Cooling Efficacy During Exercise Heat Stress

Adams EL, Vandermark LW, Pryor JL, Pryor RR, Vanscoy RM, Denegar CR, Huggins RA, Armstrong LE, Casa DJ. Korey Stringer Institute, Department of Kinesiology, University of Connecticut, Storrs, CT.

CONTEXT: Heat acclimation (HA) and body cooling during exercise in the heat both help to mitigate the rise in body temperature; however, the effects of HA and hand cooling combined remain unexplored. OBJECTIVE: To determine the separate and combined effects of HA and hand cooling efficacy, during and after exercise in the heat. DESIGN: Randomized, counterbalanced, crossover design. …

The Effect Of Skeletal Muscle Mass On Basal Metabolic Rate In College-Age Males 2013, Chase Vaughn

Master's Theses

There are many misconceptions within the fitness community. One such misconception is that an increase in muscle mass will have a large increase in basal metabolic rate, yet this may not be the best way for successful weight loss. The purpose of this study was to determine the strength of the correlation between skeletal muscle mass and basal metabolic rate. The hypothesis tested was that basal metabolic rate is strongly correlated with skeletal muscle mass. The participants were college-aged males (n =17). Skeletal muscle mass (SMM) was estimated using the skin-fold circumference model (SFCM): SMM (kg) = Ht (0.00744 CAG2 …

Hydrogen/Deuterium Exchange Mass Spectrometry For The Study Of Methanol-Induced Conformational Transitions In Ubiquitin, Steven Raul Rocha

Master's Theses

In aqueous solutions with high concentrations of methanol at low pH, the global conformation of ubiquitin denatures to a structure of increased helical character at 50% methanol to a highly helical denatured structure at 90% methanol. Circular dichroism analysis and hydrogen/deuterium exchange mass spectrometry experiments have been reported for the monitoring of alcohol-induced conformational transitions of ubiquitin upon exposure to increasing concentrations of methanol. A bottom-up analysis of deuterium labeled ubiquitin was used in this study to examine the local conformational transitions of ubiquitin upon exposure to solutions of varying concentrations of methanol. Analysis of ubiquitin and nine peptide fragments, …

The Relationship Between Liv-1 And E-Cadherin (Cdh1) In Prostate Cancer Cells, Lei Cao

Master's Theses

BACKGROUND

The zinc importer LIV-1 is widely distributed, mainly in hormonally controlled tissues. Attention has focused on its role in breast cancer, especially its regulation by estrogen and epidermal growth factor (EGF) and its link to the Epithelial–Mesenchymal Transition (EMT) marker, E-cadherin (CDH1). EMT is important for tumor progression and metastasis. CDH1 expression is under complex control, including by two transcriptional repressors, Snail and Slug. Contrast to CDH1, elevated MMP-9 expression has been linked to increased metastasis and tumor stage.

METHODS

The role of LIV-1 in prostate cancer cell lines, LNCaP and DU145 was investigated. Cells were treated with or …

Preparation And Characterization Of Electrospun Poly(D, L-Lactide-Co-Glycolide) Scaffolds For Vascular Tissue Engineering And The Advancement Of An In Vitro Blood Brain Barrier Model, Deven Chandrakant Patel

Master's Theses

Developing an in vitro Blood Brain Barrier model that will replicate the physiological, anatomical, and functional characteristics of the native BBB has gained significant attention. Such a model would enable prediction of the penetration of CNS targeting drug candidates across the BBB, allow pre-screening and optimization strategies to be developed for new drugs and gene delivery formulations, and permit research groups to further understand how a dysfunctional BBB is involved in the pathogenesis of several neurological diseases.

The Tissue Engineering laboratory at the California Polytechnic State University, San Luis Obispo is currently in the process of developing a dynamic in …

Flying Qualities Built-In-Test For Unmanned Aerial Systems, Alton Pak-Hin Chiu

Master's Theses

This paper presents a flying qualities built-in-test for UAS application with the scope limited to the longitudinal axis. A doublet input waveform excites the AV and both α and q are used by EUDKF to estimate the A and B matrices which are short period approximations of the system. ζ, ω, GM, PM, observability, and controllability are calculated to determine flying qualities with the results displayed to the AVO in a color-coded, easy to interpret display.

While SID algorithms have been flying in vehicles with adaptive control schemes, vehicles with other schemes (such as classical feedback) lack this built-in self …

Ischemia Impairs Vasodilation In Skeletal Muscle Resistance Artery, Kyle Remington Struthers

Master's Theses

Functional vasodilation in arterioles is impaired with chronic ischemia. We sought to examine the impact of chronic ischemia and age on skeletal muscle resistance artery function. To examine the impact of chronic ischemia, the femoral artery was resected from young (2-3mo) and adult (6-7mo) mice and the profunda femoris artery diameter was measured at rest and following gracilis muscle contraction 14 days later using intravital microscopy. Functional vasodilation was significantly impaired in ischemic mice (14.4±4.6% vs. 137.8±14.3%, p<0.0001 n=8) and non-ischemic adult mice (103.0±9.4% vs. 137.8±14.3%, p=0.05 n=10). In order to analyze the cellular mechanisms of the impairment, a protocol was developed to apply pharmacological agents to the experimental preparation while maintaining tissue homeostasis. Endothelial and smooth muscle dependent vasodilation were impaired with ischemia, 39.6 ± 13.6% vs. 80.5 ± 11.4% and 43.0 ± 11.7% vs. 85.1 ± 10.5%, respectively. From this data, it can be supported that smooth muscle dysfunction is the reason for the observed impairment in arterial vasodilation.

Characterization And Implementation Of A Decellularized Porcine Vessel As A Biologic Scaffold For A Blood Vessel Mimic, Aubrey N. Smith

Master's Theses

Every 34 seconds, someone in the United States suffers from a heart attack.  Most heart attacks are caused by atherosclerotic build up in the coronary arteries, occluding normal blood flow.  Balloon angioplasty procedures in combination with a metal stent often result in successful restoration of normal blood flow.  However, bare metal stents often lead to restenosis and other complications.  To compensate for this problem, industry has created drug-eluting stents to promote healing of the artery wall post stenting.  These stents are continually advancing toward better drug-eluting designs and methods, resulting in a need for fast and reliable pre-clinical testing modalities. …