Digital Commons Network^™

Biomaterials With Diverse Physical & Chemical Signals For Tissue Engineering Applications, Mohammed Mehdi Benmassaoud

Theses and Dissertations

Cells within natural tissues are exposed to a myriad of biochemical and biophysical cues, and it is challenging to recapitulate these signals in vitro. The goal of this dissertation is to create materials with distinct biophysical and biochemical signals as platforms that induce controllable yet diverse cellular responses. To evaluate the effects of heterogeneous biophysical cues on cell behavior, cells were encapsulated in porous scaffold-hydrogel composites, and it was found that cellular metrics (morphology, matrix mechanosensing) varied within soft (hydrogel) and rigid (scaffold) composite regions. To create soft materials with spatially defined biochemical signals, hydrogels that can be subsequently photopatterned …

Asymmetry Of Gains And Losses In Human Decision-Making And Choice: Behavioral Correlates Of Loss Aversion, Money, Food, And The Menstrual Cycle, Marcia Mackley Ventura

Theses and Dissertations

The purpose of this research is to determine if loss aversion is replicable as an overt behavioral response to potential gains and losses in complex, recurring, uncertain, and risky choice with real gains and losses of money and food. Cognitive methods used to determine the effect of loss have primarily measured verbal response to hypothetical choice scenarios in which participants cognitively predict their behavior in a series of bets or situations involving imagined monetary gains and losses. Less has been done using behavioral methods that measure overt behavioral response to gains and losses of actual commodities. The present study uses …

Examining The Influence Of Argument Driven Inquiry Instructional Approach On Female Students Of Color In Sixth Grade Science: Its Impact On Classroom Experience, Interest, And Self-Efficacy In Science, Written Argumentation Skills, And Scientific Voice, Paul Duggan

Theses and Dissertations

Four of the eight Engineering Standards in the Next Generation Science Standards (NGSS, 2013) focus on authentic science communication: “asking questions (science) and defining problems (engineering), analyzing and interpreting data, constructing explanations (for science) and designing solutions (for engineering), engaging in argument from evidence, obtaining, evaluating and communicating information” (Sampson et al., 2010, p. 218). Authentic science communication is supported in NGSS through cross-cutting concepts (Driver et al., 2000) that integrate the structure and function of science concepts together with communication strategies that include reading, writing, and peer critique. These cross-cutting concepts include reading strategies that focus on reading informational …

Nutrition Facts Label Use Among U.S. Adolescents, Jennifer Beth Mandelbaum

Theses and Dissertations

Despite the promise of Nutrition Facts label (NFL) use as a population-level intervention with broad reach, few studies have examined determinants of adolescents’ NFL use, and how this label use may be associated with nutrition behaviors. This study used data from the International Food Policy Study, an online cross-sectional survey of trends in dietary patterns and policy-relevant behaviors in the U.S. and five other countries. First, this study examined 1) whether NFL use was associated with healthy eating efforts and 2) whether there were sociodemographic differences in NFL use among U.S. adolescents. Results demonstrated that NFL use was positively associated …

A Multiple-Case Study: Motivating Students With Disabilities In Personalized Literacy Instruction, Courtney Kozelski

Theses and Dissertations

Adolescents often experience a decline in motivation, yet support for basic psychological needs can prevent such a decline. Individuals with disabilities face particularly high motivational obstacles, placing them at the center of this action research study. This study took place within a special education classroom during one school year. The intervention unfolded over the course of the year, using personalized learning to support students’ basic psychological needs and provide sources of self-efficacy. The findings lend support to previous studies, indicating literacy motivation can be promoted through implementation of a needs-supportive personalized learning intervention that builds upon both self-efficacy and self-determination …

Investigating The Impact Of Endothelial Dysfunction And Aging On Vascular Remodeling Using Mouse Models, Liya Du

Theses and Dissertations

Endothelial dysfunction, characterized by a reduction in the bioavailability of nitric oxide (NO), is a major factor in the initiation and progression of atherosclerosis, an age-related chronic inflammatory process in the arterial wall and the leading cause of mortality and morbidity globally. A better understanding of alterations in vascular structure and function associated with endothelial dysfunction can facilitate the early detection of atherosclerosis and the development of potential pharmaceutical interventions. This study aims to clarify the impact of endothelial dysfunction in conjunction with aging on the microstructure of aortic extracellular matrix (ECM) and to elucidate the relationship between microstructural adaptation …

The Use Of Social Justice Socioscientific Issues In Secondary Biology Classes: An Action Research, Stephanie Marilyn Bailey

Theses and Dissertations

The U.S. Education system is founded on a Eurocentric focus of curriculum, and students of color are not achieving as high as white students on the National Assessment for Education Progress in science. This research aims to repay the education debt owed to students of color by decolonizing science curriculum through the implementation of lessons centered around socioscientific issues grounded in social justice. An action research study was implemented in which 9 ^th grade Biology students participated in three instructional units centered on social justice issues. Data was collected through surveys, focus group interviews, student work, and journal reflections from …

Helpful Or Harmful: The Impact Of Shame And Guilt On Concealment In Adulthood Following Childhood Trauma, Xiomara Vanessa Senior

Theses and Dissertations

The current study aimed to examine the moderating role of shame and guilt in the associations between types of childhood maltreatment and levels of self-concealment. Childhood maltreatment has been linked to emotions such as shame and guilt that elicit schemas of self-doubt, incompetence, and failure (Cohen et al., (2011). When an individual internalizes these thoughts and emotions, they may act in maladaptive ways such as avoidance, fear, dissociation, and possible concealment within adulthood (Dorahy & Clearwater, 2012, Smetana et al., 2019). De Seve et al. (2020) recently found that shame proved to be a mediator in the relationship between self-concealment …

Examining Executive Dysfunction In Dementia: Vascular Etiology As A Contributor To Greater Impairment, Julianne Szemko

Theses and Dissertations

Objective: The present study examines executive functioning and overall neuropsychological functioning within a memory disorder clinic population with a specific focus on examining performance on the Modified Wisconsin Card Sorting Test (M-WCST) among individuals with and without cerebrovascular disease. Method: This study utilized test data collected between 2018-2022 from the research database at the Health First Memory Disorder Clinic (HFMDC) in Melbourne, Florida. Participants were included if they completed a brief neuropsychological evaluation (BNE) at the HFMDC with the M-WCST, Trail Making Test - Form B (TMT-B), and Color/Word subtest of the Golden Stroop as part of their battery and …

The Effects Of Trauma And Statelessness On Refugee Employment Outcomes, Seth Hershberger

Theses and Dissertations

An empirical study, this paper examines the relationship of pre-resettlement refugee characteristics on their respective economic outcomes post-resettlement. In particular, it places special focus on the correlation that a refugee’s level of trauma and duration of statelessness, or time spent in a temporary country of asylum, have with that refugee’s real wages, probability of being employed at 180 days post-resettlement, and duration of initial unemployment in the country of final resettlement. Through the development of three sets of models, this paper finds a quadratic relationship between the length of a refugee’s statelessness and real wages post-resettlement, where increases in duration …

Association Of Prior Periodontal Disease With Cancer – Exploring Epidemiologic Evidence Of Periodontal Exudate-Exposed Site Cancer Risk Versus Remote Gastrointestinal Sites, Asma Alzahrani

Theses and Dissertations

Background: Periodontal disease, a chronic bacterial infection of the gums, if untreated, causes chronic inflammation over years and eventual tooth loss. The associations between periodontal disease (measured by missing teeth) and certain sites of cancer have been established, in epidemiological studies, and attributed to systemic inflammatory impacts causing carcinogenic change over decades. Because periodontal exudates are toxic, containing locally bioactive bacteria and toxins, this study hypothesized and studied the potential higher cancer risk of anatomic sites exposed to oral exudates (exudate-exposed site cancers (EEC); head and neck, oral, pharynx, larynx, esophagus, stomach). The study studied the risk of exudate exposed …

Deciphering The Molecular Circuitry That Controls Iron Regulation In Non-Pathogenic Yeast, Debolina Hati

Theses and Dissertations

The trace metal iron is essential for the survival of almost all living organisms. It is a co-factor for many proteins involved in a variety of vital functions such as respiration, nitrogen fixation, and DNA biosynthesis, to name a few. Iron homeostasis in non-pathogenic fungi such as Schizosaccharomyces pombe has been extensively studied over the past few decades to better understand how intracellular iron is regulated under different environmental conditions. Iron regulation in S. pombe is controlled by two Fe-responsive transcriptional repressors known as Php4 and Fep1. Both rely on iron-sulfur (Fe-S) clusters as signals to balance iron acquisition, storage, …

Histomechanical Compatibility Of Coronary Artery Bypass Grafts, Colton J. Kostelnik

Theses and Dissertations

Coronary artery disease is a localized form of atherosclerosis that can severely restrict blood flow to the heart often requiring a surgical intervention known as coronary artery bypass grafting (CABG) to reestablish perfusion to this essential circulation. To some extent, the selection of the autograft tissue is at the surgeon’s discretion with factors such as stenosis location and the existing tissue’s pathological state contributing to a choice that could be deterministic in surgical outcomes. Many post-operative complications and premature graft failures originate from graft-target tissue incompatibilities and altered blood flow patterns. We hypothesize that mechanical mismatching between the graft material …

Uncovering The Diverse Roles Of The Human Cst (Ctc1-Stn1-Ten1) Complex In Resolving Genomic Stress, Percy Logan Schuck

Theses and Dissertations

The CST (CTC1-STN1-TEN1) complex is a heterotrimeric single-stranded DNA binding protein known to stimulate polymerase α-primase (Pol α) and promote telomere length regulation, genome-wide DNA replication and double strand break repair. However, much of its cellular function remains unknown. The focus of my dissertation work was to uncover novel roles of CST in DNA stress response pathways. In particular, my work relates to understanding the function of CST in sister chromatid cohesion (SCC) and base excision repair (BER) as well as characterizing CST protein interactions. SCC is established following DNA replication by loading of the cohesion complex, which encircles replicated …

Changes In The Regulation Of The Unfolded Protein Response During Aging In Peromyscus, Elham Soltanmohammadi

Theses and Dissertations

Endoplasmic reticulum (ER) stress has been linked to various metabolic pathologies, neurodegeneration, and aging. Although various mechanistic aspects of the resulting unfolded protein response (UPR) have been elucidated, its regulation in genetically diverse populations remains elusive. In the present study we evaluated the expression of chaperones BiP/GRP78, GRP94 and calnexin (CANX) in the lungs, liver, and brain of 7 months old and 2–3 years old outbred deer mice P. maniculatus and P. leucopus. Chaperones’ _expression was highly variable between species, tissues and ages suggesting that levels of expression of individual chaperones do not change consistently during aging. Despite this variation, …

Genomic Analysis Workflows To Identify Mutational Signatures And Structural Variations In Ovcar8 Cells And Rad51d-Deficient Mouse Embryonic Fibroblasts, Manli Yang

Theses and Dissertations

Specific genomic profiles associated with exposure to DNA damaging agents have been identified in cancer related genes, revealing that mutational patterns can be carcinogen- specific. However, there have been limited efforts to demonstrate similar clear relationships for endogenous mutational processes. One endogenous source of mutations is contamination of the deoxynucleotide pool with damaged bases that, if incorporated into DNA, cause mutations.

The Catalog of Somatic Mutations In Cancer (COSMIC) represents an international effort to characterize mutations in cancer. A mutational signature is the pattern of mutations generated by a mutational process. Each mutational process contains two parts: DNA damage and …

Monitoring Titanium Dioxide Engineered Particles In Rural And Urban Surface Waters, Md Mahmudun Nabi

Theses and Dissertations

Quantifying and characterizing engineered particles in environmental systems is key for assessing their risk but remains challenging and requires the distinction between natural and engineered particles. The Ph.D. dissertation research described in this thesis contributes to the current attempts to improve environmental nanoparticle analysis and better understand nanoparticle behavior in natural systems, with the focus being on natural streams, and the application of single particle inductively coupled plasma-time of flight-mass spectrometry (SP-ICP-TOF-MS) for distinguishing and tracing the origins of environmental nanoparticles. The objective of this dissertation is to characterize and quantify the concentrations of titanium dioxide engineered particles in urban …

Fabrication Of Asymmetrical Hollow Fiber-Supported Thin Film Membranes, Stack Assembly, And Accelerated Long-Term Stability Test For Oxygen Production From Air, Myongjin Lee

Theses and Dissertations

Air separation is a widely used process for oxygen production. Several separation technologies have been developed for air separation, including cryogenic distillation, swing adsorption, redox process of metal oxides, and electrochemical process. Among these technologies, electrochemical permeation process stands out as a cost-effective and simple process for pure oxygen production from air. The electrochemical permeation process employs a gas-tight membrane to permeate and separate oxygen from air directly, where the membrane conducts both ions and electrons simultaneously. Different membrane designs have been studied to obtain the improved performance for oxygen permeation, typically planar and tubular designs. Among these membrane configurations, …

Tropical Cyclone And Ocean-Atmosphere Interactions In The Gulf Of Mexico, Emily Nichole Eley

Theses and Dissertations

The Gulf of Mexico (GoM) is historically a favorable region for the formation, maintenance and intensification of tropical cyclones that frequently evolve into powerful hurricanes. These natural disasters threaten the basin’s innate habitat and wildlife diversity, and the expansive coastal economies and communities. The dominant ocean circulation feature in the GoM is the Loop Current System (LCS) which includes the Loop Current (LC) and its associated mesoscale eddy field. The LC originates at the Yucatán Channel, loops anticyclonically into the basin, and ends at the Florida Straits; further it produces both anticyclonic and cyclonic eddies. The existence of the LCS …

Mechanistic Insights Into An Iron-Responsive Repressor, Fep1, From Schizosaccharomyces Pombe, Allison Nicole Kimsey

Theses and Dissertations

Iron is an essential metal cofactor required for a variety of biochemical pathways in most living organisms. In recent years, the nonpathogenic fungi Schizosaccharomyces pombe has been used to study iron regulation and uncover the molecular mechanisms for controlling intracellular iron levels. Some of these regulation pathways are conserved with those of pathogenic fungi, making these studies applicable for the future development of antifungals that target iron homeostasis. In S. pombe, the GATA-type transcriptional repressor Fep1 is responsible for repressing iron uptake genes during times of iron abundance. Previous reports have proposed that the binding of an iron-sulfur (Fe-S) …

Novel Dietary Index For Gut Microbiota And Associations With Colorectal Cancer And Breast Cancer Risk, Bezawit Eyob Kase

Theses and Dissertations

Introduction: Diet serves as a driving force for shaping the gut microbiome. Understanding how diet may modify gut microbiota and subsequently may be associated with chronic disease is critical to public health prevention efforts. Aims: We aimed to develop a novel dietary index that captures the quality of diet with respect to attaining beneficial composition and function of gut microbiota. We then examined the relationship between the dietary index and two gut microbiota-related cancers, i.e., colorectal and breast cancers.

Methods: We conducted a systematic review of studies that examined the effect of foods on gut microbiota in adult populations. Dietary …

Development Of Peptidomimetic Inhibitors Targeting The Polo Box Domain Of Plk1 As Potential Cancer Therapeutics, Jessy Mariam Stafford

Theses and Dissertations

PLK1 overexpression has shown to be associated with tumor progression and an unfavorable prognosis in a wide variety of cancer types. Interfering with PLK1 genetically and chemically induces apoptotic cell death in cancer cells thus confirming PLK1 as a validated anticancer target. From a drug discovery perspective, PLK1 offers two functionally distinct, essential, and interconnected target sites in one molecule. These are the ATP binding kinase domain (KD) and the unique Polo Box Domain (PBD), where the interplay between these results in dynamic structural regulation of catalytic activity and sub cellular localization. Since the KD is conserved among kinases and …

Characterization Of The Interaction Between Grx4-Bol2 And The Iron-Responsive Transcription Factor Aft1 In Candida Glabrata, Evan A. Talib

Theses and Dissertations

Iron is an indispensable protein cofactor that plays a critical role in biological functions such as cellular respiration. However, excess iron causes cellular damage via the generation of reactive oxygen species. To obtain optimal intracellular iron levels, eukaryotic cells have developed mechanisms to tightly regulate iron levels. The molecular mechanism for iron regulation in the pathogenic yeast Candida glabrata has not yet been explored, although this yeast bears iron regulation pathways that are very similar to the model yeast Saccharomyces cerevisiae. Understanding how C. glabrata regulates iron levels is critical for the treatment of infections caused by this opportunistic …

Identifying Racial Differences In Colorectal Polyp Profile At Screening Colonoscopy Using Traditional Regression And Machine Learning Approaches, Yuqi Wu

Theses and Dissertations

Background

Colorectal cancer (CRC), the second leading cause of cancer and cancer deaths in the United States, can largely be prevented by screening the age-appropriate adult population with colonoscopy to remove precancerous lesions. However, despite the encouraging annual, population-wide decline in CRC incidence and mortality in recent decades, and widespread adoption of screening colonoscopy since 2000 (~60% population coverage rate), the Black population has consistently suffered higher CRC incidence and mortality than Whites, currently 20% and 40% respectively, little changed from the 2000 rats of 26% and 52%.

The reason for this is thought to be that the Black population …

Sleep Challenges And Temperament Among Infants At Elevated Likelihood Of Autism Spectrum Disorder, Miranda Hope Foster

Theses and Dissertations

The current study used parent report in a prospective longitudinal design to examine the relationship between early sleep difficulties and temperament among infants with an older sibling diagnosed with ASD (EL-ASIB, n = 32), those born pre-term (EL-PT, n = 24) and those with no familial history of ASD (LL, n = 28) across the first year of life. At 3, 4, 6 and 12 months, caregivers completed the Short Form of the Infant Behavior Questionnaire-Revised (IBQ-R) (Putnam et al., 2014). To understand how sleep difficulties are related to temperament, a new scale of Sleep Challenges was created with items …

“Even The Little Things Matter:” A Phenomenological Study On Factors Impacting Student Motivation During And After Covid-Related Disruptions In Education, Jennifer Ferris-Crisafulli

Theses and Dissertations

The COVID-19 pandemic brought about unprecedented disruptions in education, as schools were forced to make a rapid transition to virtual learning in March 2020. Students’ motivation seemed to decline significantly during and after this virtual learning period, which ranged from months to over a year in various areas of the United States. This study seeks to understand the factors impacting student motivation during and after this virtual learning period.

This action research study was conducted using a qualitative, phenomenological approach. Data was collected from open-ended surveys and semi-structured interviews during Spring 2021 and Spring 2022. Data was analyzed through the …

Implementing A Technology-Based Instructional Module In An Introduction To Engineering Course: The Impact On Student’S Vocabulary Retention And Attitudes Towards Learning, Robin T. Amick

Theses and Dissertations

The purpose of this study was to evaluate the academic impact of a technology-based instructional module for content vocabulary instruction in the Project Lead the Way (PLTW) Introduction to Engineering course. The goal of the study was to answer two key questions: 1) How does implementing a technology-based instructional module impact Engineering vocabulary academic gains for students taking the Introduction to Engineering course? and 2) What is the effect of implementing a technology-based instructional model on attitudes towards learning Engineering vocabulary for students taking the Introduction to Engineering course? This study was conducted with Introduction to Engineering students (N …

Natural Variation Of Fructose-1,6-Bisphosphatase In Colias Butterflies, Andrea Blair Stokes

Theses and Dissertations

In a process known as the evolutionary recursion, it is possible to follow how adaptation affects natural selection at successive stages of a species’ life cycle. Through studying allele and genotype frequencies of enzymes in glycolysis, a central metabolic pathway, it is possible to document how polymorphisms can shift the evolving functionality of enzymes within or among species. Fructose-1,6-bisphosphatase (FBPase) is an enzyme in gluconeogenesis that converts fructose-1,6-bisphosphate to fructose 6- phosphate. It is also known to convert the unused amino acid carbon skeletons of glycolysis into glycogen storage. Appearing to play a vital role in the acquisition, storage, and …

Use Of Dic Measurements With Finite Element Models For Direct Heterogeneous Material Property Determination And Wrinkle Formation During Automated Fiber Placement, Sreehari Rajan Kattil

Theses and Dissertations

In this work, application of DIC in combination with finite element modeling is demonstrated for efficient material characterization for complex heterogeneous materials and tow wrinkle formation during automated fiber placement.

The first part of the work describes the integration of DIC measurements with finite element models for direct property identification in heterogeneous material systems. The material property identification is based on solving partial differential equations (PDE) of equilibrium for unknown elastic material properties with known boundary conditions and full field strain data (Eg. DIC). The PDEs are solved numerically using Petrov-Galerkin finite element procedure. The classical Bubnov-Galerkin method is shown …

Applications Of Machine Learning For Improved Patient Selection And Therapy Recommendations, Brendan Elochukwu Odigwe

Theses and Dissertations

The public health domain continues to battle with illness and the growing need for continuous advancement in our approach to clinical care. Individuals experiencing certain conditions undergo tried and tested therapies and medications, practices that have become the mainstay and standard of care in clinical medicine. As with all therapies and medications, they don't always work the same way and do not work for everyone. Some Treatment regimens, like Hydroxyurea medication, which is commonly administered to Sickle cell anemia patients, come with some adverse side effects due to the chemotherapeutic nature of the drug. This would be particularly disappointing if …