Digital Commons Network^™

Modern Estimation Problems In Group Testing, Md Shamim Sarker

Theses and Dissertations

In the simplest form of group testing, pools are formed by compositing a fixed number of individual specimens (e.g., blood, urine, swab, etc.) and then the pools are tested for a binary characteristic, such as presence or absence of a disease. Group testing is commonly used to screen for a variety of sexually transmitted diseases in epidemiological applications where the main goal is to increase testing efficiency. In this dissertation, we study three estimation problems that are motivated by real-life applications. We propose new methods to model group testing data for both single and multiple infections. In the first problem, …

Semiparametric Joint Dynamic Modeling Of A Longitudinal Marker, Recurrent Competing Risks, And A Terminal Event, Piaomu Liu

Theses and Dissertations

The joint modeling framework has found extensive applications in cancer and other biomedical research. For example, recent initiatives and developments in precision medicine call for appropriate prognostic tools to assist individualized or personalized approaches in cancer diagnosis and treatment. Data generated by clinical trials and medical research often include correlated longitudinal marker measurements and time- to-event information, which are possibly a recurrent event, competing risks, and a survival outcome. Primary interests of joint modeling include the association between the longitudinal marker measurements and time-to-event data, as well as predictions of survival probabilities of new observational units from the same population. …

A Qualitative Study Of How Communities Think About And Act Upon Hunger In The Presence Of A Food Banking System, Eliza Miriam Fishbein

Theses and Dissertations

Hunger is often addressed by providing food directly to those experiencing symptoms of food insecurity and hunger. Even with the availability of government food assistance programs, food insecurity and hunger rates continue to rise. Many local community organizations (e.g., small food banks, faith-based organizations, schools) across the country have come together to create and implement a variety of nongovernment food programs. Although there is no evidence these programs lower food insecurity and hunger rates, community organizations appear to be strongly committed to sustaining these programs. Little is known about the basis for this commitment, i.e., “ the will to act …

Spending Someone Else’S Money: The Impact Of Inheritances On Charitable Giving, Jacob Martin

Theses and Dissertations

Experimental literature has documented a ‘house money effect’, in which subjects using unearned endowments are less risk averse and more willing to consume than when they use an endowment they have not earned. I use Panel Study of Income Dynamics (PSID) data to test for this effect outside the laboratory by estimating the impact of inherited money on charitable giving. When I control for differences between individuals, I find that the impact of inheritances is significantly reduced. My results indicate that the correlation observed in previous econometric analyses is largely driven by non-random allocation of inheritances to individuals predisposed to …

Implementation Processes And Impacts Of School Store Policies In South Korea, Seul Ki Choi

Theses and Dissertations

With the concern of unhealthy school food environments, the South Korean government enacted two school nutrition policies to reduce unhealthy foods in school stores. The first policy banned on soft drinks sales in school stores enacted in 2007. The second policy restricted energy-dense nutrient-poor (EDNP) food sales in school stores enacted in 2009. This study aims to examine the changes in adolescents’ food intake and foods sold in school stores due to the two policies and to understand the policy implementation processes.

The Korea National Health and Nutrition Examination Surveys were used to examine trends in adolescents’ energy intake from …

Promoting Positive Academic Beliefs And Performance: Exploring The Impact Of An Academic Enrichment Program, Melanie Avery

Theses and Dissertations

First generation and low income college students experience unique achievementrelated barriers not typically experienced by their counterparts whose parents attended college and/or are of higher socioeconomic status (Hahs-Vaugn, 2004; Kahlenberg, 2004; Mortensen, 2003; Prospero & Vohra-Gupta, 2007). Academic enrichment programs that target first generation and low income college youth are one strategy that has helped to address these concerns. To extend literature in this area, the current study sought to identify factors that may be promotive of and/or barriers to first generation and low income youths’ achievement-related outcomes. Furthermore, this investigation sought to explore whether an academic enrichment program, namely …

Spatio-Temporal Analysis Of The Occupational Fatal Victimization Of Law Enforcement Officers In The Us, Xueyi Xing

Theses and Dissertations

The models with constant coefficients of the covariates across space and time are commonly used in spatio-temporal analyses. However, the associations between risk factors and the outcome could have locally differential temporal trends in many cases. In this study, a Bayesian latent cluster modeling strategy is employed to identify potential spatial clusters in which locally specific sets of temporally varying coefficients of covariates are allowed. A state-level panel data of police officers occupational fatal victimization for the years 1979-2010 is used. To accommodate overdisperson and excess zeros, a negative binomial model and zero-inflated Poisson/negative binomial models are also utilized. A …

Investigating Cross Talk Between The High And Low Iron Sensors In Saccharomyces Cerevisiae, John S. Hepburn

Theses and Dissertations

Iron is essential for nearly all life on earth. Cells must maintain sufficient levels of this important nutrient due its function as a central co-factor for many cellular processes. Although iron is extremely plentiful, its poor solubility requires specialized import. On the other side, too much iron inside the cell can lead to the generation of reactive oxygen species (ROS), which have deleterious effects on many cellular functions and have been implicated in a wide variety of diseases such as cancer and Alzheimer’s disease. Using the model eukaryote Saccharomyces cerevisiae, or budding yeast, our research group has accomplished much in …

Regression Models For Count Data Based On The Double Poisson Distribution, Rebecca Wardrop

Theses and Dissertations

This paper explores the double Poisson distribution. The probability mass function and the difficulties associated with derivative-based optimization for this distribution are discussed. Stata software developed for estimation of double Poisson regression is detailed. Simulations are used to test the software. Data which are over-, under-, and equidispersed relative to the Poisson are generated and the software is utilized to estimate a regression model, a zero-inflated model, and a marginalized zero-inflated model all based on the double Poisson distribution. The estimated power of the test for φ = 1 for the double Poisson models are compared to the power of …

Life-Cycle Analysis Of A Cement Manufacturing Plant Co-Firing Hazardous Waste In The Usa, Stephen P. Holt

Theses and Dissertations

The purpose of this work was to determine the overall environmental impacts associated with the co-firing hazardous waste by burning in a cement kiln to replace the use of coal in the cement manufacturing process. This environmental assessment was conducted using LCA methodology. Understanding the environmental impacts associated with burning hazardous waste in a cement factory could help shape national environmental policy, regulations and the need for site specific human health risk assessments in the environmental regulatory permitting processes. Accordingly, the primary objective of this study was to evaluate the environmental impacts from the hazardous waste burning for energy recovery …

The Roots Of Perspective In The American Context: News Media Discourse And Stakeholder Perspectives About The Supplemental Nutrition Assistance Program, Nicholas Younginer

Theses and Dissertations

The Supplemental Nutrition Assistance Program serves 46 million people but is controversial. The media is positioned to influence political and public opinions about SNAP policy. This study identifies the SNAP media discourse and investigates perspectives of SNAP participants and frontline workers about the program.

I employed a mixed-methods design with two aims. Aim 1 gathered 295 articles across six news outlets, semi-inductively coding the articles for characters, assignment of responsibility, and framing of the article. I then ran chi-square tests for difference between employed frame and responsibility and employed frame and political ideology.

Aim 2 collected a sample of 20 …

Deserts Will Bloom: Atomic Agriculture And The Promise Of Radioactive Redemption, Chris Fite

Theses and Dissertations

This paper examines the rhetorical and visual strategies used in marketing atomic agriculture to the American public from the 1940s to the 1960s. The term “atomic agriculture” refers to various agricultural research programs that used radioactive materials, particularly radioisotope tracing and mutation breeding. In print and on screen, atomic boosters from government and industry offered the promise of a better world made possible by applying atomic energy to agriculture. I argue that the proponents of atomic agriculture combined futurism and nostalgia to create a techno-pastoral vision. They hearkened back to the nineteenth century while simultaneously imagining a bright postwar future. …

Healthcare Utilization And Expenditure Patterns Among Older Adults With Functional And Medical Decline, Ashley Shields Robertson

Theses and Dissertations

Purpose. As the aged population of this country grows, the U.S. healthcare system will face increased pressure to provide long-term care services and supports to increasing numbers of elderly Medicare beneficiaries. Studies have indicated that unmet long-term care need can lead to increased, unnecessary utilization of the healthcare system, thus further taxing the Medicare system. Little is known about how type of long-term care, as well as how long-term care policies—specifically payment policies—affect health care utilization. The objective of this original dissertation research was to examine the effects of place of residence (community versus residential long-term care facility) and …

Examing Supine-To-Stand As A Measure Of Functional Motor Competence And Health Across The Lifespan, Danielle Rene Nesbitt

Theses and Dissertations

A person’s ability to rise from the floor to a standing position is seen as a precursor for establishing and maintaining physical independence. It also is an important primer for the development of other fundamental movement skills (FMS) and is associated with functional capacity in later life. Thus, the potential importance of developing this movement capability early in life and understanding how it may relate to global function (i.e., motor competence-MC and health-related fitness-HRF) across the lifespan may be underestimated. Limited research has examined components or performance (i.e., time) of supine-to-stand (STS) in children to young adults. Further, no previous …

Essays On Retirement, Labor Supply, And Living Arrangements, Anudeep Gill

Theses and Dissertations

Three changes in the U.S. Social Security program affected recent cohorts of older individuals: repeal of the earnings test, increases in the normal retirement age, and increases in the delayed retirement credit. All three policy changes were expected to affect work decisions for those eligible for social security benefits. The first two chapters of my dissertation assess the impact of these policy changes. In the first chapter, using data from the Survey of Income Program and Participation (SIPP) for the years 1996-2013, I study the influence of the three policy changes on the retirement and benefit-claiming decisions of older men …

Help-Seeking And Intimate Partner Violence Re-Victimization Of Sexual Minority And Heterosexual College Students, Andrew T. Schramm

Theses and Dissertations

Recent estimates indicate that 18.5% of heterosexual college students and 30.3% of sexual minority college students are victims of physical intimate partner violence (IPV; Edwards, Sylaska, Barry, et al., 2015). Research among adult women in oppositesex relationships has shown that once an individual is victimized by IPV she is subsequently at high risk for future IPV victimization. Re-victimization is associated with more severe physical and mental health consequences of IPV. No prior study has assessed the rate of re-victimization among sexual minority adults. Help-seeking behavior, which refers to accessing a range of sources of support (e.g., family and friends, law …

Physics Based Modeling Of Guided Waves For Detection And Characterization Of Structural Damage In Nde And Shm, Banibrata Poddar

Theses and Dissertations

Guided waves based damage detection techniques are popular for their ease of generation and detection along with their ability to travel long distances. Accurate and efficient modeling is a key for successful implementation of guided waves for NDE/SHM. However, efficient prediction of scattering from various damage is challenging due to the complex nature of these guided waves.

This dissertation presents as physics based efficient and accurate modeling techniques to predict ultrasonic wave propagation and their interaction with various damage. Detection and characterization of damage in structures can typically be divided into two categories, active and passive. This research is aimed …

Nursing Attitudes Towards Suicidal Patients In The Emergency Department: Assessment Interview Training, Belinda Beaver

Theses and Dissertations

This project sought evidence for the effectiveness of pedagogy in professional nursing continuing education and its effect on emergency department nurse attitudes towards patients seeking crisis intervention for suicide. Approximately 12 million emergency department (ED) visits annually were for patients suffering with mental illness and/or suicidal ideation. Emergency department staffs were often not adequately prepared to manage these problems. The purpose of this project was to examine the impact of an educational initiative on nurses’ attitudes about patients expressing suicidal ideation in the emergency departments 2 rural southeastern towns.

The project question was; in two different rural community emergency departments …

High-Throughput Sequencing-Based Approaches For The Identification And Development Of Molecular Targets For Cancer Therapy, David Joel Oliver

Theses and Dissertations

Effective cancer treatment depends on the development of therapeutics that efficiently eliminate the disease without significant reduction to quality of life. Targeted therapeutics achieve these goals, but their long-term efficacy is limited by the ability of cancers to become resistant to these therapies over time. The identification of new therapeutic targets is crucial for the future of cancer treatment. In this work we present functional identification and characterization of novel targets for cancer therapy.

Loss-of-function screens are a well-founded approach for the functional identification of new therapeutic targets, and, in combination with high-throughput sequencing technology, can now be performed at …

Relationships Of Chronotype, Social Jetlag, Sleep, Physical Activity And Diet With Mood, Perceived Stress, Obesity, Blood Pressure And Prostate Cancer, Daria M. Mcmahon

Theses and Dissertations

Background: Chronotype, social jetlag, poor sleep, proinflammatory diet, and low physical activity have been associated with increased risk of chronic diseases: obesity, diabetes, cardiovascular disease, depression and cancer. Yet the relationships between these factors have not been extensively investigated in prospective studies.

Methods: Two studies were conducted. The first study followed 390 healthy men and women ages 21-35 for two years. Social jetlag [SJL] and sleep measures (total sleep time [TST], sleep onset latency [SOL], wake after sleep onset [WASO]), sleep efficiency [SE]), were derived from physical activity personal (armband) monitoring. The participants wore the armband for 4-10 …

Ndt And Shm Methods Of Damage Detection In Welded Structures, Saad Mohammed

Theses and Dissertations

There has been an increasing demand for Nondestructive Testing (NDT) and Structural Health Monitoring (SHM) techniques to continuously monitor during all processes of a structure to prevent catastrophic failure and reduce maintenance costs. NDT and SHM are inspection processes which form part of the quality assurance/quality control (QA/QC) scheme. Among NDT and SHM methods, ultrasonic and guided wave techniques are the most commonly and widely used in industry. Ultrasonic methods provide the advantage of accurately locating and dimensioning defects within structures. Most of these structures consist of welded joints because welding is an economical and efficient method for obtaining a …

Using Synthetic Lectins To Investigate Metastatic Potential In Colon Cancer, Erin E. Gatrone

Theses and Dissertations

Cancer is a disease that affects millions of people each year and it is well established that early diagnosis is a key factor towards improving survival rate, with that in mind there is a great need for better diagnostics. From the earliest onset of cancer, changes can be detected in the type and amount of carbohydrates expressed by the cancer cells, i.e., aberrant glycosylation. This process results in differing glycosylation patterns that can be used to detect cancer. Aberrant glycosylation can also greatly affect the potential of cancer cells to metastasize and can be used to stage the disease as …

Exploration Of Appropriate And Inappropriate E-Disclosure: A Qualitative Investigation Of The Decision-Making Process Of Counselors In Training, Katherine H. Dewitt

Theses and Dissertations

This study explored how counseling students in CACREP accredited counselor education program made meaning of and categorize appropriate and inappropriate self-disclosure in the digital age. In particular, how do future counselors consider and apply ethical codes to personal behavior on social media? Utilizing a qualitative design, the researcher explored student decision making and understanding of ethical considerations in the personal use of social media. A vital component to the professionalism of counseling is the constancy of the presentation-of-self in all identities (public, private, in-person, or online) of the counselor. The researcher asserts that there is an ethical obligation of all …

The Effect Of Arsenic On Type 2 Diabetes And Inflammation, Kayla Penta

Theses and Dissertations

Arsenic, a ubiquitous environmental contaminant, has been shown to cause a number of health effects. At high concentrations the inorganic form is a well-known toxin, but at lower concentrations the effects range from various cancers, to cardiovascular disease and type 2 diabetes. At higher concentrations of arsenic (500- 1000μg/L) there have been epidemiological studies conducted demonstrating an increased risk in the development of type 2 diabetes with this exposure. At lower levels of arsenic exposure (<500 μg/L) the epidemiological results are inconclusive. Arsenic is also an immunotoxicant, meaning that it will cause changes in the immune response. The changes in the immune response will vary depending on a number of variables, including amount of arsenic exposure, forms of exposure and route of exposure. We wanted to determine if arsenic could modulate the immune system, and if this change could lead to an increase in susceptibility to type 2 diabetes development. We chose to examine this in C57BL/6 and db/+ mice – two non-susceptible strains. After 8 weeks (4 weeks old to 12 weeks old) of low dose inorganic arsenic exposure (50 μg/kg or 500 μg/kg) we evaluated changes in body composition, glucose tolerance and immune response. We saw that there were differences based on sex, genotype and treatment group present after the 8-week treatment period in body composition, while there were minimal changes in glucose tolerance. Finally, the immune response showed great variability depending on sex, genotype and treatment group. This project has demonstrated that while we are trying to compare differences in in vivo and epidemiological studies to find a link between arsenic and type 2 diabetes, there may be deeper levels of complications based on individual variability to arsenic exposure.

Public Perceptions Of Genetically Modified Food On Social Media: A Content Analysis Of Youtube Comments On Videos, Nanlan Zhang

Theses and Dissertations

Controversy about genetically modified (GM) food prevails on social media. Discussion about GM food includes the implementation of mandatory labeling as well as public concerns about potential health hazards posed by GM food. Previous studies mainly focus on traditional press and broadcast media, few investigate such controversial topics on social media. Interested in public opinion about this issue and possible influences of social media on public opinion, this study uses quantitative content analysis to examine the characteristics of user comments on a specific social media platform, YouTube. The purpose of the study is to investigate YouTube comments from several aspects, …

Semiparametric Estimation Methods For Complex Accelerated Failure Time Model, Yinding Wang

Theses and Dissertations

The proportional hazards (PH) model and the accelerated failure time (AFT) model are the two most popular survival models in fitting the right-censored data. The AFT model is a useful alternative to the PH model, particularly when the PH assumption is not satisfied. Usually, the linear association is assumed with logarithm of survival time in the AFT model. However, the nonlinear association may exist in practice. The first project aims to handle the nonlinear component in the AFT model, which is called the semiparametric additive partial accelerated failure time (AP-AFT) model. Two estimation methods based on the rank-smooth method and …

Sustainability Of Food And Nutrition Security Policies During Presidential Transitions: Integrating Socio-Political And Nutritional Sciences, Jessica Liana Escobar-Alegría

Theses and Dissertations

Presidential transitions are uncertain periods in which relationships among power, accountability, and electoral support of a democratic process do not hold. Transitions challenge collaboration towards implementing policies contributing to food and nutrition security (FNSP). Sustaining these policies during transitions is critical for reaching long-term goals. Knowledge gaps remain on how to perform strategic multisectoral work during transitions to maximize FNSP sustainability.

This study aimed to examine what determines FNSP sustainability during presidential transitions and responded to the questions: How do policy actors define sustainability? What are the mechanisms determining policy sustainability? What are the implications of terminal logic behavior (TLB) …

Evaluation Of Concrete Degradation Using Acoustic Emission: Data Filtering And Damage Detection, Marwa A. Abdelrahman

Theses and Dissertations

The prevalence of aging and deteriorating infrastructure in the U.S. has raised concerns regarding its level of serviceability, reliability, and vulnerability to natural disasters. This issue has gained attention recently and efforts are being conducted to accelerate the delivery of enhanced nondestructive testing (NDT) and structural health monitoring (SHM) methods. Acoustic emission (AE) is a strong candidate for these applications due to its high sensitivity and potential for damage detection in different materials. However, several challenges associated with the technique hinder the development of automated, reliable, real-time SHM using AE.

This study aims to advance the use of AE for …

Contextualizing Multilayered Sexual Subjectivities Of Heterosexual Black Female Undergraduate Students At A Predominantly White Institution In The South, Amarachi Rossana Anakaraonye

Theses and Dissertations

This study uses an intersectional theoretical framework to examine Black college women’s sexual health by focusing on how they engage in sexual decision making within their social contexts. This qualitative study analyzed 20 individual in-depth interviews of Black female undergraduate students, ages 18-22, who attend a predominantly white institution (PWI) in the Southeastern United States. The themes that emerged from qualitative data analysis include Black female undergraduate students’ perceptions of the sexual culture of their campus and the protective strategies they employ to navigate the sexual culture in order to achieve and/or maintain physical, emotional, and social well-being. Key findings …

Ashley's Sister, Christina Phillips

Theses and Dissertations

This nonfiction project is a memoir, constructed in sections, about my relationship with my sister with an intellectual disability.