Doctor of Philosophy, University of Akron, 2024, Chemistry

Cell communication is crucial for regulating cell growth, proliferation, survival, and function. The process of cell communication and cell signaling involves the recognition of exogenous or endogenous signaling molecules by receptors expressed on the surface of the plasma membrane. The activation of surface receptors such as enzyme-linked receptors results in the activation of the receptor's intracellular domain, which might have an intrinsic kinase activity like receptor tyrosine kinase (RTK). The activation of RTK triggers multiple downstream signaling pathways that regulate cell proliferation, angiogenesis, apoptosis, motility, adhesion, and metastasis. Therefore, a thorough understanding of RTK activation mechanisms and subsequent signaling events is crucial to provide insights into the control of RTK activity. The work presented in this dissertation is studying two different receptors from two subfamilies of RTKs, c-KIT, and EGFR/HER receptors family. The first project in this dissertation is focused on studying the SCF-mediated c-KIT signaling in mast cells (MCs) and the role of the underlying mechanisms in modulating mast cell viability and proliferation. The number of MCs in tissues usually remains constant, inflammation and asthma disturb this homeostasis, leading to proliferation of MCs. Understanding the signaling events behind this proliferative response could lead to the development of novel strategies for better management of allergic diseases. MC survival, proliferation, differentiation, and migration are all maintained by a MC growth factor, stem cell factor (SCF) via its receptor, KIT. Here, we explored how protein kinase C (PKC) redundancy influences MC proliferation in bone marrow-derived MC (BMMC). We found that SCF activates PKCα and PKCβ isoforms, which in turn modulates KIT phosphorylation and internalization. Further, PKCα and PKCβ activate p38 mitogen-activated protein kinase (MAPK), and this axis subsequently regulates SCF-induced MC cel (open full item for complete abstract)

Committee: Yilin Liu (Advisor); Christopher J. Ziegler (Committee Chair); Jordan Renna (Committee Member); Aliaksei Boika (Committee Member); Chrys Wesdemiotis (Committee Member) Subjects: Biochemistry; Chemistry; Physical Chemistry

Master of Science, Miami University, 2024, Electrical and Computer Engineering

Vehicular Ad-Hoc Networks (VANETs) are regarded as a leading technology that enhances the effectiveness and security of contemporary transportation networks. The development of intelligent transportation systems will greatly benefit from the implementation of VANETs. The primary objectives of VANET include enhanced traffic flow, delay tolerance, entertainment, time-sensitive safety applications, and more. The speed of the vehicles presents several types of technical challenges, including frequent handovers, resource allocation, security, delay constraints, availability, and scalability. These issues become prominent with the increasing number of vehicles in the network. In order to achieve network scalability, we investigated in this paper how to implement Scalable Cell-Free Massive Multiple Input Multiple Output (SCF massive MIMO) in VANET. The major focus of the analysis was to maximize the Spectral Efficiency (SE) considering a vehicle goes through pilot contamination and meets a certain threshold of Signal to Noise plus Interference Ratio (SINR). We adopted fractional power allocation to meet the power constraint of the system and chose the Linear Partial Minimum Mean Square Error (LP-MMSE) combining technique to maximize SE considering the scalability of the system. We completed the required calculations for the uplink and downlink transmission, channel estimation, pilot signal, SINR, and SE calculation while taking into account several vehicles in a pilot sequence. We performed simulations for both sparse and dense networks. We have analyzed the system for different numbers of vehicles and roadside units. We compared both uplink and downlink performance for the sparse and dense networks with conventional massive MIMO. The simulation results of the proposed system consistently outperformed the conventional approach.

Committee: Mark Scott (Advisor); Miao Wang (Committee Member); Bryan Van Scoy (Committee Member); Chi-Hao Cheng (Committee Member) Subjects: Communication; Electrical Engineering

Doctor of Philosophy, The Ohio State University, 2014, Human Ecology: Family Resource Management

With increasing income uncertainty during the Great Recession, many households might have had difficulty in projecting future income changes. Ideally, a household should consider lifetime wealth and the distinction between transitory and permanent income changes in making saving decisions, but during the Great Recession it was probably very difficult for households to identify which income changes were transitory. Gain-loss utility based on prospect theory assumes that household inter-temporal decisions are determined not only by current or permanent income but also by their own expectations or assessment about income and income uncertainty in the first period. In this study, how households' perception of their past and future income compared to reference points in the first period and how households' perception of their income uncertainty change affect saving decisions in the second period and between the periods were examined with estimates of future income change. Saving decisions were tested based on relative gain and loss utility using loss aversion theory of consumption and a two period model. Possible asymmetric saving responses between positive and negative changes in reference dependent income and uncertainty were also analyzed. The 2007 and 2009 Survey of Consumer Finances (SCF) panel dataset was used. Both total and subsamples were analyzed based on the expected income change measure to identify possible asymmetry of saving in response to a set of reference dependent income and uncertainty variables, such as deviation from normal income, expected income change, and income uncertainty change, as well as the effect on saving measured in two ways, savings between 2007 and 2009 and whether or not saved in 2009. This study found a set of reference dependent income and uncertainty variables had significant effects on saving decisions of households and asymmetric saving responses between negative and positive changes in those variables. H (open full item for complete abstract)

Committee: Kathryn Stafford (Advisor); Sherman Hanna (Committee Member); Robert Scharff (Committee Member) Subjects: Home Economics

Master of Science in Engineering (MSEgr), Wright State University, 2010, Electrical Engineering

This research develops and evaluates several different methods for multi-user signal classification via cyclic spectral analysis. The first method uses the spectral correlation function (SCF) through temporal smoothing with the use of higher order cyclic statistics (HOCS) to allow for modulation classification. The second method uses the cyclic temporal cumulant function (CTCF) and the spectral coherence function (SOF) through frequency smoothing. Using a feature-based pattern recognition technique with the SOF can not only determine the number of signals present in the received signal, but can also give signal parameter estimation and group classification performance. The last method conducts further modulation classification by using second and fourth order Cyclic Cumulants. Cyclostationary processing is the foundation of this research and requires no a priori information about the incoming signal parameters; including but not limited to symbol rate, carrier frequency and phase offset. Monte Carlo simulations completed in MATLAB and performance results are given for all aforementioned methods.

Committee: Zhiqiang Wu PhD (Advisor); Yao Ma PhD (Committee Member); Vasu Chakravarthy PhD (Committee Member) Subjects: Electrical Engineering; Engineering

Doctor of Philosophy, The Ohio State University, 2009, Family Resource Management

This is a study of the decision to use a financial planner in saving and investing decisions. Satterthwaite's (1979) improvements upon Stigler's (1961) model of the economics of information were used to define the practice of financial planning as a reputation good. The theory of the economics of information was used to model the likelihood of married couple households to prefer the services of a financial planner over other sources of information. In addition to search theory, seminal and current help-seeking articles revealed a need to place significant emphasis on the differences between men and women in their external search efforts for a financial professional. The objective of this study was to examine the predisposition of women to ask for help in financial affairs over men. An unweighted sample of 2,691 married couple households from the 2004 Survey of Consumer Finances was used to obtain the data necessary to achieve this objective. The respondent of the survey was the spouse who was most familiar with the household's finances. Each household was instructed to select the financially most knowledgeable spouse as the respondent for the survey. Within the sample of married couple households and only among those who used a financial planner, a weighted 23% of households had husband respondents who used a planner and 24% of households had wife respondents who used a planner. An initial logit model revealed that compared to male respondents in a married couple household, being a female respondent was positively associated with the likelihood of choosing a financial planner for saving and investment advice; having household income in the 10% and 15% tax bracket in 2004 was negatively associated with using a financial planner compared to households in the 25% bracket; having greater than or equal to $100,000 in financial assets was positively associated with using a financial planner; and being willing to take financial risks was negatively associated with using (open full item for complete abstract)

Committee: Jonathan Fox PhD (Advisor); Sherman Hanna (Committee Member); Catherine Montalto (Committee Member) Subjects: Behaviorial Sciences; Demographics; Economics; Families and Family Life; Finance; Gender; Home Economics; Womens Studies

Master of Science, The Ohio State University, 1993, Chemistry

Committee: Russell Pitzer (Advisor) Subjects:

Doctor of Philosophy, The Ohio State University, 2004, Family Resource Management

Risk tolerance is a key factor in household portfolio decisions, and understanding the determinants of financial risk tolerance is an important contribution of this dissertation. This study focuses on the Survey of Consumer Finances (SCF) risk tolerance question, which asks respondents to select either substantial, above-average, average, or no risk when making investments. Using all SCF cross-sectional datasets conducted between 1983 and 2001, this dissertation is the first study to analyze risk tolerance changes over an 18-year period. Multivariate cumulative logits were run with the SCF risk tolerance variable as the dependent variable. Controlling for other characteristics, risk tolerance generally increased from 1992 until 1998, then dropped slightly but not significantly in 2001. In 1998, respondents were 1.7 times as likely as those in 1992 to have substantial or above-average risk tolerance. In addition to analyzing trends in risk tolerance over time, this research reports on demographic effects. Many of the effects of demographic variables were statistically significant because of the large sample size resulting from the combined dataset. The dataset also allows for robust estimates of differences between demographic groups. The probability of taking some risk and substantial or above-average risk increased strongly with education. Generally, age had a negative effect on risk tolerance, with those under 30 being 4.7 times as likely as those age 75 or over to have substantial or above-average risk tolerance, and twice as likely as respondents between age 55 and 59 to have some risk tolerance. This study is unique in differentiating by gender of the respondent in married couple households. Married females were shown to be less risk tolerant than married males, and single males were more risk tolerant than single females and married respondents. Non-Hispanic Whites were much more likely to take some financial risk than otherwise similar respondents from other (open full item for complete abstract)

Committee: Sherman Hanna (Advisor) Subjects: