Engineering Commons^™

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 …

Biomechanical And Psychophysical Underpinnings Of Balance Dysfunction In Individuals With Traumatic Brain Injury, Naphtaly Ehrenberg

Dissertations

Falls are a major burden on healthcare infrastructure, especially in older adults and even more so in older individuals that are living in institutions. According to data from the Centers for Disease Control and Prevention (CDC), from 2010 to 2020, unintentional falls were the leading cause of nonfatal emergency department visits for all age groups except among individuals from 15-24 years of age, where unintentional falls ranked a very close second to being unintentionally struck by or against. Among older individuals living in the community, approximately 30-35% fall at least once in a given year, and around three times as …

Re-Engineering Cardio-Oncology Testing Using Biomimetic Heart Slice Cultures., Jessica Miller

Electronic Theses and Dissertations

28% of drug withdrawal from the market are due to unforeseen disruptions in cardiomyocyte contractility and electrophysiology. The most commonly used platforms for drug testing are in vivo animal models and in vitro cell culture models. While both have been of paramount importance for the discovery and detection of many cardiotoxicities and mechanisms of action, they lack the ability to model an intact human myocardium. This work aims to establish cardiac tissue slices, which are 300-micron thin tissue sections taken from the left ventricular myocardium, as an alternative platform for cardio-oncology studies, specifically cardiotoxicity testing. Additionally, this work aims to …

Establishing The Efficacy Of Non-Cellular Components Of Adipose-Derived Stromal Vascular Fraction In Promoting Angiogenesis., Daniel Benson

Electronic Theses and Dissertations

Microvascular disease is hallmarked by pathophysiological conditions such as endothelial senescence, intimal thickening which impairs vasodilation, and regression of the capillary beds causing tissue ischemia in the myocardium or in peripheral vascular networks. Adipose-derived stromal vascular fraction (SVF) has previously demonstrated the ability to revascularize tissue. Increasing evidence shows that regenerative cells elicit their therapeutic benefit by paracrine mechanisms, leaving open extracellular vesicles (EVs) as a potential crux of the cell therapy paradigm. To test this idea, three types of gelatin methacrylate hydrogels were employed: SVF gels, EV gels derived from SVF, and blank control gels, which were used in-vitro …

Integrative Physiology-Coupled Pilot-Centered Flight Simulation, Shawn C. Harrison

Electrical & Computer Engineering Theses & Dissertations

Maintaining the pilot’s physiological performance envelope within the limits of human capabilities may be crucial for avoiding hazardous physiological episodes in fighter aircraft that compromise safety. The main physiological episode of interest is impaired pilot respiration, better known as hypoxia caused by a high fraction of inspired oxygen (FiO₂) at high altitudes and variation in accelerative gravitational forces (g-forces). Integrated into fighter aircraft is an Onboard Oxygen Generating System (OBOGS) developed to mitigate the necessity of gaseous and liquid oxygen cannisters [1]. OBOGS act as a life support in hypoxic environments by providing oxygen-rich air, thereby oxygenating the …

Frontiers In The Self-Assembly Of Charged Macromolecules, Khatcher O. Margossian

Doctoral Dissertations

The self-assembly of charged macromolecules forms the basis of all life on earth. From the synthesis and replication of nucleic acids, to the association of DNA to chromatin, to the targeting of RNA to various cellular compartments, to the astonishingly consistent folding of proteins, all life depends on the physics of the organization and dynamics of charged polymers. In this dissertation, I address several of the newest challenges in the assembly of these types of materials. First, I describe the exciting new physics of the complexation between polyzwitterions and polyelectrolytes. These materials open new questions and possibilities within the context …

Functionality Of The Gracilis Collateral Is Impaired Following Arteriogenesis And Cell Transplantation, Ada A. Tadeo

Biomedical Engineering

Peripheral Arterial Disease involves narrowed arteries, reducing blood flow to limbs. Increasing blood flow to those extremities is possible by redirecting the blood to flow through natural bypasses (i.e. collateral arteries), which can enlarge via arteriogenesis to maintain blood supply once the prominent arteries have become occluded. This study aims to investigate how arteriogenesis affects collateral function, if myoblast transplantation can stimulate collateral growth, and how that in turn may affect collateral function. Femoral artery ligation was performed to mimic the blockage that occurs in patients with ischemic diseases on lean mice and mice with diet induced obesity (DIO). A …

Engineering Of Ideal Systems For The Study And Direction Of Stem Cell Asymmetrical Division And Fate Determination, Martina Zamponi

Biomedical Engineering Theses & Dissertations

The cellular microenvironment varies significantly across tissues, and it is constituted by both resident cells and the macromolecules they are exposed to. Cues that the cells receive from the microenvironment, as well as the signaling transmitted to it, affect their physiology and behavior. This notion is valid in the context of stem cells, which are susceptible to biochemical and biomechanical signaling exchanged with the microenvironment, and which plays a fundamental role in establishing fate determination and cell differentiation events. The definition of the molecular mechanisms that drive stem cell asymmetrical division, and how these are modulated by microenvironmental signaling, is …

Regression Analysis Of Pacing When Running A Marathon, Hawkin Starke

Industrial Engineering Undergraduate Honors Theses

Regression analysis can be an effective way of examining performance in the marathon event. By splitting up the race into segments or in runner terminology “splits” the significance of each segment as it relates to the total finish time can be explored. Because the idea of splits is already ingrained into the minds of runners, it makes intuitive sense to use these as the metrics to define a race. Additionally, marathons generally make participant age and gender date publicly available which can then be used to find trends within specific demographics. This tailors trends to smaller groups of people, making …

Deterministic Model Of The Voltage Dependent Anion Channel (Vdac) Kinetics, Viren Shah

Theses and Dissertations

The voltage-dependent anion channel (VDAC) is a voltage gated channel residing on the outer mitochondrial membrane (OMM) that facilitates the flow of metabolites between the cytosol and mitochondria. The channel is regulated through conformational changes driven by electrostatic effects along with numerous regulatory mechanisms. The aim of this study is to mechanistically model kinetics of substrate flow through VDAC and incorporate them into existing mechanistic computational models of mitochondrial function. The resulting model is used in two ways: 1) to establish mitochondrial bioenergetics (conductance, permeability, and current/flux) under physiological conditions, and 2) to conduct perturbations simulating the effect of altered …

Investigatin Actin-Myosin Mechanics To Model Heart Disease Using Fluorescence Microscopy And Optical Trapping, Justin Edward Reynolds

Honors Theses

Hypertrophic cardiomyopathy (HCM) is a hereditary disease in which the myocardium becomes hypertrophied, making it more difficult for the heart to pump blood. HCM is commonly caused by a mutation in the β-cardiac myosin II heavy chain. Myosin is a motor protein that facilitates muscle contraction by converting chemical energy from ATP hydrolysis into mechanical work and concomitantly moving along actin filaments. Optical tweezers have been used previously to analyze single myosin biophysical properties; however, myosin does not work as a single unit within the heart. Multiple myosin interacts to displace actin filaments and do not have the same properties …

Quantitative Optical Imaging Of Metabolic And Structural Biomarkers In Rodent Injury Models, Shima Mehrvar

Theses and Dissertations

The assessment of organ metabolic function using optical imaging techniques is an overgrowing field of disease diagnosis. The broad research objective of my PhD thesis is to detect quantitative biomarkers by developing and applying optical imaging and image processing tools to animal models of human diseases. To achieve this goal, I have designed and implemented an optical imaging instrument called in vivo fluorescence imager to study wound healing progress. I have also developed a 3-dimensional (3D) vascular segmentation technique that uses intrinsic fluorescence images of whole organs.

Intrinsic fluorophores (autofluorescence signals) provide information about the status of cellular bioenergetics in …

Flexible Electrochemical Lactate Sensor, Peyton Miesse

Biomedical Engineering Theses & Dissertations

Lactic acid is a vital indicator for shock, trauma, stress, and exercise intolerance. It is a key biomarker for increases in stress levels and is the primary metabolically produced acid responsible for tissue acidosis that can lead to muscle fatigue and weakness. During intensive exercise, the muscles go through anerobic metabolism to produce energy. This leads to decreases in the blood flow of nutrients and oxygen to the muscles and increases in lactate production, which in turn cause lactic acidosis. Currently, changes in blood lactate concentrations are monitored by sensors that can be invasive via blood or wearable based sensors …

Early Detection Of Asthma Via Enhanced Resolution Of Small Airways Using Ultra-Low Frequency Impulse Oscillometry, Christopher M. Aguilar

Open Access Theses & Dissertations

Examination of lung function for diagnosis and monitoring of diseases such as chronic obstructive pulmonary disease (COPD) and asthma can be performed with a variety of pulmonary function testing (PFT) techniques. The most commonly prescribed of these procedures are spirometry and whole-body plethysmography. However, these active participation tests depend on forced breathing maneuvers, may be physically exhausting, might not produce enough information, and are susceptible to being subject-dependent. In contrast, passive PFT approaches such as the forced oscillation technique (FOT) and the impulse oscillometry system (IOS) are increasingly being utilized for measuring lung mechanics because they require only minimal participation, …

Evaluation Of Novel Hemocompatible Surface Coatings For Extracorporeal Life Support: A Biocompatible Alternative To Systemic Anticoagulation, Teryn Rose Roberts

USF Tampa Graduate Theses and Dissertations

Extracorporeal life support (ECLS) is a class of technologies used to support or replace the function of failing organs. During ECLS, blood is withdrawn from systemic circulation and circulated through an artificial organ or “treatment membrane” that performs the function of the failing organ, prior to return to systemic circulation. While ECLS provides life-saving therapy to wide patient populations from pre-term infants to combat-wounded soldiers, this therapy is limited due to secondary thrombotic and bleeding complications that result from: 1) exposure of blood to the foreign surfaces in the device circuit and 2) administration of anticoagulant drugs to prevent clot …

Radical Social Ecology As Deep Pragmatism: A Call To The Abolition Of Systemic Dissonance And The Minimization Of Entropic Chaos, Arielle Brender

Student Theses 2015-Present

This paper aims to shed light on the dissonance caused by the superimposition of Dominant Human Systems on Natural Systems. I highlight the synthetic nature of Dominant Human Systems as egoic and linguistic phenomenon manufactured by a mere portion of the human population, which renders them inherently oppressive unto peoples and landscapes whose wisdom were barred from the design process. In pursuing a radical pragmatic approach to mending the simultaneous oppression and destruction of the human being and the earth, I highlight the necessity of minimizing entropic chaos caused by excess energy expenditure, an essential feature of systems that aim …

Human Optimization And Performance Enhancement In Flight Via Real-Time Biofeedback (Project Have Hope), Michael S. Fritts

Theses and Dissertations

A four-phase, chronological, and build-up approach was implemented that commenced with basic hardware testing in a centrifuge and culminated in flights augmented by real-time biofeedback displays. A prototype Portable Electrocardiogram Unit (PECGU) was designed and proven to accurately measure heart rate (HR) and display percent heart rate reserve (%HRR). Results showed that %HRR was not a sole predictor of cognitive state. Cognitive responses indicated some correlation with %HRR, but were influenced by environment (centrifuge vs. flight). Subjective perceived exertion levels did not show statistically significant changes during test with biofeedback. A G-tracking task was evaluated during centrifuge and flight tests. …

Can A Comprehensive Transition Plan To Barefoot Running Be The Solution To The Injury Epidemic In American Endurance Runners?, Michael A. Scarlett

CMC Senior Theses

Fossils belonging to the genus Homo, dating as far back as two million years ago, exhibit uniquely efficient features suggesting that early humans had evolved to become exceptional endurance runners. Although they did not have the cushion or stability-control features provided in our modern day running shoes, our early human ancestors experienced far less of the running-related injuries we experience today. The injury rate has been estimated as high as 90% annually for Americans training for a marathon and as high as 79% annually for all American endurance runners. There is an injury epidemic in conventionally shod populations that …

The Vibe, Sarah P. Douglass

Capstones

The Vibe is a long-form narrative about where tech is taking the female orgasm. The piece concludes that physiological research is a required next step when creating the climax of the future.

http://sarahpdouglass.com

Removal Of Endocrine Disrupting Compounds Using Membrane Bioreactor, Mohanad Ali Abdulsahib Kamaz

Graduate Theses and Dissertations

The presence of endocrine disrupting compounds (EDCs) and pharmaceutically active compounds (PhAC) such as pesticides, personal care products, antibiotics and pharmaceutical compounds, in sewage, industrial, and domestic waters has extensively become the major concern for health and environmental organizations. These compounds have the ability to interact with mammalian endocrine system and disrupting their functions. The traditional activated sludge processes are designed to degrade solids, organic carbon and nitrogen loading. Although several treatment steps in a wastewater treatment plant can contribute to partial removal of EDCs, effective removal has been a challenge due to their resistant chemical and biological degradation and …

Role Of Trpv4 In Astrocyte Extracellular Matrix Production, Abby Terlouw

Biomedical Engineering Undergraduate Honors Theses

Traumatic Brain Injury (TBI) is an alteration of brain pathology following damage of the central nervous system (CNS) by an external force. In the CNS, glial scar formation often occurs following TBI, and astrocytes are widely believed to contribute to this scar formation. While the role of astrocytes in extracellular matrix (ECM) production is known, the exact mechanism(s) for this event remain unclear. One possible method is the activation of transient receptor potential vanilloid 4 (TRPV4). TRPV4 is a channel protein found in the astrocyte membrane which has been shown to generate intracellular calcium ions following mechanical stimulation. Previous research …

Neural Representation Of Vocalizations In Noise In The Primary Auditory Cortex Of Marmoset Monkeys, Ruiye Ni

McKelvey School of Engineering Theses & Dissertations

Robust auditory perception plays a pivotal function in processing behaviorally relevant sounds, particularly when there are auditory distractions from the environment. The neuronal coding enabling this ability, however, is still not well understood. In this study we recorded single-unit activity from the primary auditory cortex of alert common marmoset monkeys (Callithrix jacchus) while delivering conspecific vocalizations degraded by two different background noises: broadband white noise (WGN) and vocalization babble (Babble).

Noise effects on single-unit neural representation of target vocalizations were quantified by measuring the response similarity elicited by natural vocalizations as a function of signal-to-noise ratio (SNR). Four consistent response …

Modulation Of Whole Cell Currents In Human Neuroblastoma Cells Via The Hormone Aldosterone: An In Vitro Study, Harish Kumar Chittam

USF Tampa Graduate Theses and Dissertations

Ion channels play a critical role in maintaining homeostasis by moving various ions in and out of cells. The Na⁺-K⁺-2Cl^- or NKCC1 ion channel is involved in the regulation of Na⁺, K⁺, and Cl^- across cell membranes, and plays a key role in many forms of cellular physiology. In the cochlea, NKCC1 is involved in endolymph production and maintenance of the endocochlear potential. Our hypothesis is that blocking NKCC1 channels should directly impact auditory sensitivity causing hearing loss. Our lab has also shown that the hormone aldosterone (ALD) can upregulate …

An Analysis Of Plasticity In The Rat Respiratory System Following Cervical Spinal Cord Injury And The Application Of Nanotechnology To Induce Or Enhance Recovery Of Diaphragm Function, Janelle Lorien Walker

Wayne State University Dissertations

Second cervical segment spinal cord hemisection (C2Hx) results in ipsilateral hemidiaphragm paralysis. However, the intact latent crossed phrenic pathway can restore function spontaneously over time or immediately following drug administration.

WGA bound fluorochromes were administered to identify nuclei associated with diaphragm function in both the acute and chronic C2Hx models. WGA is unique in that it undergoes receptor mediated endocytosis and is transsynaptically transported across select physiologically active synapses. Comparison of labeling in the acutely injured to the chronically injured rat provided an anatomical map of spinal and supraspinal injury induced synaptic plasticity. The plasticity occurs over time in the …

Development And Application Of Gadolinium Free Cardiac Magnetic Resonance Fibrosis Imaging For Multiscale Study Of Heart Failure In Patients With End Stage Renal Disease, Tori A. Stromp

Theses and Dissertations--Physiology

Cardiac magnetic resonance (CMR) is a powerful tool to noninvasively image ventricular fibrosis. Late gadolinium enhancement (LGE) CMR identifies focal and, with T1 mapping, diffuse fibrosis. Despite prevalent cardiac fibrosis and heart failure, patients with end stage renal disease (ESRD) are excluded from LGE. Absence of a suitable diagnostic has limited the understanding of heart failure and obstructed development of therapies in the setting of ESRD. A quantitative, gadolinium free fibrosis detection method could overcome this critical barrier, propelling the advancement of diagnostic, monitoring, and therapy options. This project describes the development of a gadolinium free CMR technique and application …

Smooth Muscle Cell Organization In The Stem Region Of The Gracilis Collateral Circulation, Amanda Krall

Biomedical Engineering

Many patients who suffer from the ischemic Peripheral Arterial Occlusive Disease (PAOD) experience intermittent claudication, which can be attributed to impaired vasodilation. Collateral vessels are the primary site of resistance to blood flow downstream; therefore maximizing vasodilation in collaterals is crucial for efficient circulation. Collaterals function as natural bypasses around the occluded arteries and the increase in flow into these vessels causes them to outwardly remodel into conduit vessels. However, functional vasodilation in the stem region of collateral vessels is impaired at day 7 following femoral ligation, which can be attributed to smooth muscle cell malfunction. However, the increase in …

The Effects Of Ocean Acidification And Eutrophication On The Growth, Lipid Composition And Toxicity Of The Marine Raphidophyte Heterosigma Akashiwo., Julia Rose Matheson

Electronic Thesis and Dissertation Repository

Anthropogenic forcing, such as ocean acidification caused by rising carbon dioxide emissions, and eutrophication due to increased nutrient loadings in run-off, are causing major changes to the biogeochemistry of the oceans. As a consequence, coastal phytoplankton are susceptible to altered biogeochemical environments. This study examined the effect of a lower pH and increased levels of nutrients on the common coastal harmful alga, Heterosigma akashiwo. Growth rates, maximal cell yields, neutral lipid accumulation and toxicity of cells grown under various pH and nutrients regimes were measured. H. akashiwo growth was near maximal when grown at lower pH levels. There was …

Investigation Of Cardiac Electrophysiology In Human Ventricular Tissue, Kathleen Brownson

Theses and Dissertations--Biomedical Engineering

Individuals with cardiomyopathy are at higher risk to die from sudden cardiac arrest than those with non-failing (NF) hearts. This study examined the differences in electrical properties of failing and NF human hearts in terms of cardiac memory through explicit control of diastolic intervals in a sinusoidal fashion, restitution of action potential duration (APD) through standard and dynamic pacing protocols, maximum rate of depolarization and APD alternans. Recordings of transmembrane potentials were made in tissues extracted from patients with heart failure and one donor NF heart. Computational simulations were performed using the O’Hara Rudy model for generating surrogates of control …

Enabling Sum Frequency Spectroscopy And Fluorescence Correlation Spectroscopy Of Model Cellular Membranes, Sarah M. Sterling

Electronic Theses and Dissertations

The majority of proteins secreted from cells contain a signal peptide sequence that is required for secretion mediated by the endoplasmic reticulum and Golgi apparatus. However, many proteins lack the essential signal peptide sequence, yet still undergo secretion. Such proteins are known to regulate cell proliferation, differentiation, and migration. Fibroblast growth factor 1 (FGF-1) is one protein which undergoes non-classical protein transport. The role of its interactions with the cellular membrane during non-classical protein transport is not fully understood, although FGF-1 has shown preferential destabilizing effects on artificial membranes composed of acidic phospholipids. In the present work, physiologically relevant model …

The Effects Of Hydrostatic Pressure On Early Endothelial Tubulogenic Processes, Ryan M. Underwood

Theses and Dissertations--Biomedical Engineering

The effects of mechanical forces on endothelial cell function and behavior are well documented, but have not been fully characterized. Specifically, fluid pressure has been shown to elicit physical and chemical responses known to be involved in the initiation and progression of endothelial cell-mediated vascularization. Central to the process of vascularization is the formation of tube-like structures. This process—tubulogenesis—is essential to both the physiological and pathological growth of tissues. Given the known effects of pressure on endothelial cells and its ubiquitous presence in the vasculature, we investigated pressure as a magnitude-dependent parameter for the regulation of endothelial tubulogenic activity. To …