Engineering Commons^™

Tissue-Specific Roles Of Transforming Growth Factor Beta Ligands In Cardiac Outflow Tract Malformations And Calcific Aortic Valve Disease, Nadia Al-Sammarraie

Theses and Dissertations

Congenital heart defects and adult calcific aortic valve disease are two of the leading causes of morbidity and mortality worldwide. To date, there is no medical cure and surgical intervention is the main option of treatment. The cardiac outflow tract is the major site for these abnormalities, which are triggered by genetic and/or environmental factors that alter development and/or homeostasis. Recently, significant roles of TGFβ signaling in development of cardiovascular disorders have become more evident in humans, however, the specific requirement of individual TGFβ ligands on the pathogenesis of OFT malformations and diseases remains elusive. In the present work, three …

Wireless Rf Induced Energy Absorption And Heating Of Lanthanum-Nickel Alloy In The Near-Field, Michael Dillon Lindsay

Theses and Dissertations

This thesis will investigate whether and how a synthetic metal-magnetic alloy absorbs enough near-field electromagnetic (EM) radiation for heating. Although resistive elements could be used for indirect heating, a wireless radio frequency (RF) method is explored because of its advantages in its non-intrusive nature and its ability to direct or focus energy within a specific area. For our case, the RF heating process relies on the materials ability to absorb sufficient RF energy due to the induced currents. We expect there to be significant surface resistance due to the conductivity and magnetic permeability of the material and thus heat. This …

Astrocyte Sensitivity To Dopamine In Culture And Ex Vivo, Ashley L. Galloway

Theses and Dissertations

Dopamine is critical for processing of reward and etiology of drug addiction. Astrocytes throughout the brain express dopamine receptors, but consequences of astrocytic dopamine receptor signaling are not well established. This thesis illustrates effects of dopamine on cultured astrocytes and astrocytes in brain slices (ex vivo). In striatal cultures, extracellular dopamine triggered changes in astrocytic Ca²⁺ signaling and rapid concentration-dependent stellation of astrocytic processes that was not a result of dopamine oxidation, but instead relied on both cAMP-dependent and cAMP-independent dopamine receptor signaling. To isolate possible mechanisms underlying these structural and functional changes, whole-genome RNA sequencing was …

Role Of Epigenetic, Molecular And Cellular Pathways In The Regulation Of Inflammation, William James Becker

Theses and Dissertations

Dysregulated inflammation is at the heart of countless human diseases. Graft rejection is the process by which an organ from an incompatible donor is rejected by the recipient whose immune cells attack the foreign tissue. Colitis is an inflammatory disorder caused by undue chronic inflammation in the colon and rectum that can progress to cancer. Colitis incidence is on the rise, especially in developing nations and Asia; and the list of patients who need organ transplants grow by the day. Therapies for both graft rejection and colitis are limited to immunosuppressive drugs that leaves patients vulnerable to infection, heart disease, …

Dc Bus Stabilization And Dynamic Performance Improvement Of A Multi-Converter System, Silvia Arrua

Theses and Dissertations

Evolution of semiconductor devices is allowing to implement power electronics technology in a variety of applications, moving traditional AC systems to more efficient and reliable DC systems. Some examples are shipboard power distribution systems, DC microgrids, electric vehicles and more electric aircrafts. Even though these types of systems offer significant advantages that make them attractive in different areas, the interconnection of feedback-controlled power converters leads to emergent dynamic behavior that a system designer must take into account to ensure proper operation of the system. Additionally, system reconfiguration is very likely to happen in applications such as a shipboard power distribution, …

The Contribution Of Adipose Tissue From Ovariectomized Mice To Colon Cancer, Meredith Smith Carson

Theses and Dissertations

Obesity is considered a major public health concern worldwide due to the increased incidences of metabolic dysfunction and cancer risk. The obese state is, in part, attributable to the overconsumption of calorie-dense foods commonly seen in a standard Western diet, which aids in the progression of chronic, lowgrade inflammation. The role of estrogen varies depending on menopausal status, where estrogen deficiency coupled with increased visceral fat associated with post-menopause leads to increased secretions of pro-inflammatory adipokines and cytokines. However, the presence of estrogen in a premenopausal state has been shown to attenuate the pro-inflammatory response, which has been demonstrated when …

Fractional Order And Virtual Variable Sampling Design Of Repetitive Control For Power Converters, Zhichao Liu

Theses and Dissertations

With the growth of electricity demand and renewable energy power source, power converter becomes a more and more significant component in electrical power systems. The requirement of the power converter controller is to produce an accurate and low-distorted voltage or current under different load conditions. Although the conventional controller can meet the requirement of some applications, it requires accurate knowledge of the system model and cannot provide a satisfactory result especially under nonlinear loads or sudden load change. Repetitive control (RC) presents an attractive solution to achieve excellent steady-state tracking error and low total harmonic distortion for periodic signals, and …

Curbside Antenna To Vehicle Path Loss Measurements And Modeling In Three Frequency Bands, Patrick Murphy

Theses and Dissertations

V2V and V2I systems have been an increasingly important topic of study in recent years. Future V2I systems could involve antennas near or on the curb at intersections or on the ground along highways. To this end the curbside antenna to vehicle channel has not been studied very much. The scope of this thesis is to develop initial models for the path loss for examples of this channel. This was done through a measurement campaign where the transmitting antenna is located on the ground near the road and the receiver is in a vehicle driving towards the transmitter. The vehicle …

Effect Of Tcdd, An Environmental Contaminant, On Activation Of Ahr Leading To Induction Of Myeloid Derived Suppressor Cells (Mdscs) And The Ability Of Resveratrol, A Botanical, To Neutralize This Effect, Wurood Hantoosh Neamah

Theses and Dissertations

Aryl hydrocarbon receptor (AhR), is a ligand-activated transcription factor that integrates environmental, dietary, microbial and metabolic cues to control various cellular processes, such as the cell cycle, epithelial barrier function, cell migration and immune function. AhR was discovered as the receptor that binds with high affinity to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and leads to numerous of toxicological outcomes. In the current study, we discovered a critical role played by AhR, following activation by TCDD, in modulating a variety of immunological functions through regulation of epigenetic and microbial pathways. Our data demonstrated that AhR activation triggers MDSC mobilization from bone marrow to peritoneal …

Epigenetic And Purinergic Regulation Of Mast Cells Mediator Release, Zahraa Abdulmohsin Mohammed

Theses and Dissertations

Mast cells (MCs) are well known for their implications in allergic reactions. They are also known to have multiple functions in the innate and adaptive immune system. Their activation plays an essential role in many aspects of physiological and pathological conditions. Allergies are considered chronic conditions that affect more than 60 million people in the U.S. These diseases are driven by the activation of MCs in response to IgE-mediated antigen, rendering these cells as targets for the management of allergies and asthma. Therefore, this research considers the understanding of their activation and the regulation of their response to be an …

Interdependent Mechanisms Of Stress Susceptibility, Julie Elaine Finnell

Theses and Dissertations

Social stress is a significant risk factor for the emergence of psychiatric disorders including depression and anxiety. While there are a number of commercially available therapeutic options for the treatment of these disorders, these treatments require weeks of continuous use to produce behavioral efficacy. It has also been suggested that these traditional therapies are only marginally effective in producing complete remission, suggesting that our understanding as it pertains to the mechanisms underlying stressinduced behavioral dysfunction is still in its infancy. In the last few years, inflammation has become a major focus in the field of stress and depression as clinical …

Multimodal Emotion Classification, Anurag Illendula, Amit Sheth

Publications

Most NLP and Computer Vision tasks are limited to scarcity of labelled data. In social media emotion classification and other related tasks, hashtags have been used as indicators to label data. With the rapid increase in emoji usage of social media, emojis are used as an additional feature for major social NLP tasks. However, this is less explored in case of multimedia posts on social media where posts are composed of both image and text. At the same time, w.e have seen a surge in the interest to incorporate domain knowledge to improve machine understanding of text. In this paper, …

Knowledge-Aware Assessment Of Severity Of Suicide Risk For Early Intervention, Manas Gaur, Amanuel Alambo, Joy Prakash Sain, Ugur Kursuncu, Krishnaprasad Thirunarayan, Ramakanth Kavuluru, Amit Sheth, Randon S. Welton, Jyotishman Pathak

Publications

Mental health illness such as depression is a significant risk factor for suicide ideation, behaviors, and attempts. A report by Substance Abuse and Mental Health Services Administration (SAMHSA) shows that 80% of the patients suffering from Borderline Personality Disorder (BPD) have suicidal behavior, 5-10% of whom commit suicide. While multiple initiatives have been developed and implemented for suicide prevention, a key challenge has been the social stigma associated with mental disorders, which deters patients from seeking help or sharing their experiences directly with others including clinicians. This is particularly true for teenagers and younger adults where suicide is the second …

Three-Dimensional Plasma Cell Survival Microniche In Multiple Myeloma, Katrina A. Harmon

Theses and Dissertations

Multiple myeloma (MM) is an incurable malignancy characterized by the uncontrolled proliferation of long-lived plasma cells (PCs) in the bone marrow (BM), which constitute at least 10% of BM cellularity. Normally, long-lived plasma cells make up less than 1% of BM cells. Plasma cells become neoplastic when a clonal PC population produces a monoclonal immunoglobulin protein. A diagnosis of monoclonal gammopathy of undetermined significance (MGUS) is made when there is an increase in monoclonal PCs within the BM, but less than 10%, and the patient does not present with end-organ damage, which is associated with active MM. Though not considered …

Low Frequency Injection As A Method Of Low-Level Dc Microgrid Communication, Matthew Davidson

Theses and Dissertations

In the last ten years, DC microgrid approaches have gained more popularity for the interconnection of distributed energy resources (DERs) and prosumers. The devices (generation, storage, and load) connected to the network may contain operational parameters that have the ability to be adjusted in real-time as to optimize the operation of the microgrid. In this thesis, a simple unidirectional global communication scheme is defined, implemented, and tested. The proposed approach relies on low frequency sinusoidal components that are injected into the DC microgrid power lines. Using the proposed communication approach, multiple parameters can be transmitted to the devices connected to …

Fabrication And Characterization Of Thin Films For Heterojunction Solar Cells And Radiation Detectors, Towhid A. Chowdhury

Theses and Dissertations

The dissertation study has undertaken research in two areas: (1) development of Cu2ZnSnS4 (CZTS) thin film photo-absorber using low-cost fabrication technique for roll- to-roll commercial production for photovoltaic application, and (2) development of enriched lithium-doped amorphous selenium alloy film, a new solid-state detector material for neutron detection.

In this study CZTS thin film was developed by employing low-cost, high- throughput spray pyrolysis technique, followed by sulfurization under a 5% H2S flow at 550°C. Characterization of deposited films revealed better structural, compositional, and optical properties for sulfurized film compared to as-deposited film. The ‘sulfurized’ CZTS films deposited at 380°C substrate temperature …

Beneficial Effects Of Resveratrol Against Colitis And Colorectal Cancer Mediated By The Host Microbiome, Epigenome, And Immune Response, Haider Rasheed Daham Alrafas

Theses and Dissertations

Resveratrol, a natural polyphenol compound found in red wine, the skins of grapes, and other plant products, has been used as a traditional medicine for thousands of years throughout human history, but current research has revealed this natural component is capable of modulating a variety of immunological, microbial, and epigenetic mechanisms to improve overall health and well-being of hosts that consume it. Colitis, an inflammatory bowel disease characterized by chronic inflammation in the colon and rectum, which has been associated with colon cancer. This cancer incidence is rising in younger adults in the US. Thus, newer approaches to prevent colitis …

Modeling And Loss Analysis Of Sic Power Semiconductor Devices For Switching Converter Applications, Soheila Eskandari

Theses and Dissertations

Since its inception, power electronics has been to a large extent driven by the available power semiconductor devices. Switching power converter topologies, modes of operation, switching frequencies, passive filtering elements are chosen based on the switching and conduction characteristics of power semiconductor devices. In recent times new wide bandgap power semiconductor devices, such as SiC MOSFETs, are emerging with superior performance as compared to conventional silicon devices.

In switching power converter design, power losses of the power semiconductor de- vices play a crucial role in determining the physical characteristics of power converter systems in terms of size, weight, efficiency and, …

Path Loss Models For Two Small Airport Indoor Environments At 31 Ghz, Alexander L. Grant

Theses and Dissertations

Path loss modeling plays a fundamental role in the design of fixed and mobile communication systems for a range of applications. Another term for path loss is channel attenuation, or reduction in signal power from transmitter to receiver. Work here was in support of a NASA project for advanced air traffic management (ATM) applications, specifically for improving the efficiency of airports. Measurements in the millimeter wave (mmWave) band were conducted at 31 GHz in indoor settings at a small municipal airport, the Jim Hamilton–L.B. Owens Airport, in Columbia, SC. Some measurements were also taken at 5 GHz for comparison. A …

Constrained Consensus In Continuous-Time Multi-Agent Systems, Zheqing Zhou

Theses and Dissertations

Since the consensus problem is getting popular in recent researches and the applications based on it are expanding in current years! the consensus problem under the condition that constraints exist on agents’ state in continuous-time in a multi-agent system has been studied here. This work combines the projection operator method in a general consensus algorithm to avoid the violation of state on its individual constraint set. When the projection operator works in the general consensus algorithm, the constraint region is divided into the projection-operator working region and the non-projection region. The boundary between these two regions is a circular line. …

Finite Element Electromagnetic (Em) Analyses Of Induction Heating Of Thermoplastic Composites, Ankit Patel

Theses and Dissertations

Thermoplastic composites are in great demand for current and future manufacturing of aircraft and automotive industries. Induction heating and welding of thermoplastic composite laminates is of great significance. The non-contact method of heating and welding is being adopted in aircraft parts, engine parts, and turbine parts manufacturing among many other things. This thesis performs simulations and analyses of Electromagnetic (EM) induction heating of thermoplastic composites materials.

The induction heating and welding of thermoplastic composites in the presence of a susceptor alloy (called Monel) consisting of 67% nickel and 27% copper is studied using a Finite Element Analysis (FEA) software. A …

Three-Dimensional Plasma Cell Survival Microniche In Multiple Myeloma, Katrina A. Harmon

Theses and Dissertations

Multiple myeloma (MM) is an incurable malignancy characterized by the uncontrolled proliferation of long-lived plasma cells (PCs) in the bone marrow (BM), which constitute at least 10% of BM cellularity. Normally, long-lived plasma cells make up less than 1% of BM cells. Plasma cells become neoplastic when a clonal PC population produces a monoclonal immunoglobulin protein. A diagnosis of monoclonal gammopathy of undetermined significance (MGUS) is made when there is an increase in monoclonal PCs within the BM, but less than 10%, and the patient does not present with end-organ damage, which is associated with active MM. Though not considered …

Biophysical Analyses Of Left Ventricular Remodeling Secondary To Myocardial Infarction And Left Ventricular Pressure Overload, William Manuel Torres

Theses and Dissertations

Left ventricular (LV) remodeling is nominally an adaptive process that restores biomechanical function following myocardial injury and/or sustained alterations in loading conditions. This remodeling can materialize as changes in myocardial geometry, composition, and mechanical properties. When these changes fail to restore LV biomechanical function, remodeling is termed maladaptive. It is generally accepted that maladaptive LV remodeling underlies the progression to heart failure in various forms of heart disease. The central hypothesis of this study is that we can leverage echocardiographic imaging techniques to non-invasively quantify changes in biomechanical function and mechanical properties in a serial manner throughout the progression towards …

Identifying Key Topics Bearing Negative Sentiment On Twitter: Insights Concerning The 2015-2016 Zika Epidemic, Ravali Mamidi, Michele Miller, Tanvi Banerjee, William Romine, Amit Sheth

Publications

Background To understand the public sentiment regarding the Zika virus, social media can be leveraged to understand how positive, negative, and neutral sentiments are expressed in society. Specifically, understanding the characteristics of negative sentiment could help inform federal disease control agencies’ efforts to disseminate relevant information to the public about Zika-related issues.

Objective The purpose of this study was to analyze the public sentiment concerning Zika using posts on Twitter and determine the qualitative characteristics of positive, negative, and neutral sentiments expressed.

Methods Machine learning techniques and algorithms were used to analyze the sentiment of tweets concerning Zika. A supervised …

Determination Of Personalized Asthma Triggers From Multimodal Sensing And A Mobile App: Observational Study, Revathy Venkataramanan, Krishnaprasad Thirunarayan, Utkarshani Jaimini, Dipesh Kadariya, Hong Yung Yip, Maninder Kalra, Amit Sheth

Publications

Background: Asthma is a chronic pulmonary disease with multiple triggers. It can be managed by strict adherence to an asthma care plan and by avoiding these triggers. Clinicians cannot continuously monitor their patients’ environment and their adherence to an asthma care plan, which poses a significant challenge for asthma management.

Objective: In this study, pediatric patients were continuously monitored using low-cost sensors to collect asthma-relevant information. The objective of this study was to assess whether kHealth kit, which contains low-cost sensors, can identify personalized triggers and provide actionable insights to clinicians for the development of a tailored asthma care plan. …