Digital Commons Network^™

Microplastic In Water And Wastewater, Dounia Elkhatib

Open Access Dissertations

This thesis addresses three challenges related to the microplastic contamination in water and wastewater treatment plants. The first challenge is the multiple methodologies used to collect, quantify, and characterize microplastics in both wastewater and drinking water. Our study shows a lack of consensus regarding the techniques used at all of the stages (from collection to characterization) required for the quantification of microplastics in urban water systems. This represents a barrier to accurately determine the loads of microplastic contamination and to the comparison of the results obtained among different studies. Our results indicate large discrepancies in the concentrations reported in both …

Confirmatory Factor Analysis Of The Wisc-Iv With A Trinidad Referred Sample, Cherisse Rambarose

Open Access Dissertations

There has been an extensive amount of research in the intelligence-assessment literature on the structure of the Wechsler Intelligence Scale for Children, fourth edition (WISC-IV; 2003a). Numerous studies show that the test’s general factor structure replicates across normative and referred groups, in the U.S. and globally. Thus far, few studies have been done examining the factor structure of this, and other intelligence tests with Caribbean samples. The current study adds to this body of literature by examining the factor structure of the WISC-IV with a referred sample from Trinidad. This study utilized archival data from a sample accessed through private …

Investigating Nat Products & Pharmaceuticals Targeting Inflammation In Neurodegenerative Diseases, Shelby L. Johnson

Open Access Dissertations

Alzheimer’s and Parkinson’s disease (AD and PD, respectively) are the two most common neurodegenerative diseases. Currently, no interventions have been successful in stopping the progression of these diseases. Here, we utilize two independent strategies: the use of natural products and repurposed pharmaceuticals to target neuroinflammation in models of neurodegeneration.

Natural products have been used for their medicinal properties for centuries in traditional eastern medicine practices. Mucuna pruriens (Mucuna) is a well-known natural source of levodopa, typically prescribed in Ayurveda for PD. A novel levodopa reduced seed extract exhibited protective effects against oxidative stress and PD specific toxic agents, both in …

Chemical Investigation Of Bacterial Interactions Involving Pathogens, Hilary Joan Grant Ranson

Open Access Dissertations

Chemical communication mediates the vast majority of collective bacterial behaviors, orchestrating gene expression and community functions. A fundamental understanding of how pathogens are able to do this underlies the philosophy of natural product chemistry, providing insights into novel mechanisms for controlling pathogenic bacterial infections. To increase the effectiveness of antibiotics, alternative therapeutic approaches can be used that target bacterial phenotypes associated with infections, including swarming motility and quiescence. This dissertation explores molecules that interfere with such phenotypes in two different pathogens: uropathogenic Escherichia coli (UPEC) and Vibrio parahaemolyticus. Increased understanding of how bacterial behaviors can be modulated in pathogens …

Making Energetic Materials Safer, Michelle D. Gonsalves

Open Access Dissertations

Canine (K9) units and scientists developing explosives trace detection devices (ETDs) work with and are exposed to energetic materials when imprinting the dog or building instrument libraries. However, access to extremely hazardous materials, such as explosives, is limited, with a great need for training aids that provide a safe-handling and long shelf-life material. In order to address these needs, encapsulation of energetic materials, such as triacetone triperoxide (TATP), erythritol tetranitrate (ETN) and trinitrotoluene (TNT) in a polymer matrix have been developed, and extensively characterized to ensure explosive desensitization, controlled released, clean background odor and delivery of the pure explosive as …

Beyond The Negative Lens: A Strength-Based Approach To Understanding Sexual Minority Women’S Health, Angela Darosh

Open Access Dissertations

Introduction: It is well-documented that, compared to their heterosexual counterparts, sexual minority women (SMW) are at an increased risk for a variety of negative mental health outcomes, including depression, non-suicidal self-injury (NSSI), suicidal ideation, and suicide attempts. According to the minority stress model, lesbian, gay, and bisexual individuals are at an increased risk for adverse health outcomes because they experience excess stress as a result of belonging to a stigmatized group. In particular, sexual minority stress may be mediated by LGB-specific stressors including discrimination and victimization as a result of one’s sexual orientation, internalized homophobia, and concealment. The majority …

Reorienting The Female Gothic: Curiosity And The Pursuit Of Knowledge, Jenna Guitar

Open Access Dissertations

This dissertation investigates the mode of the Female Gothic primarily by examining how texts utilize the role of curiosity and the pursuit of knowledge, paying close attention to how female characters employ these attributes. Existing criticism is vital to understanding the Female Gothic and in presenting the genealogy of feminist literary criticism, and yet I argue, this body of criticism often produces elements of essentialism. In an attempt to avoid and expose the biases that essentialism produces, I draw from Sara Ahmed’s theory of queer phenomenology to investigate the connections between the way that women pursue and circulate knowledge through …

The Impact Of A Curricular Change On Undergraduate Human Anatomy And Physiology Students’ Academic Behavior And Performance, Jessica A. Adams

Open Access Dissertations

This dissertation explores learning in context. Undergraduate introductory human anatomy and human physiology courses are either taught as discipline-specific or integrated anatomy and physiology (A&P) sequences. These courses are critically important to future health care professionals yet a consensus is lacking on the optimal course approach. Our institution underwent a curricular revision to change pedagogical methodologies from discipline-specific human anatomy and human physiology to an integrated A&P I and II sequence. Thus, providing a unique opportunity to study the potential impact of contextual learning. Specifically, over three years the effects integrating physiological concepts had on anatomy education were explored as …

Assessing Treatment Performance Of Advanced Nitrogen-Removal Onsite Wastewater Treatment Systems, Bianca Noelle Ross

Open Access Dissertations

Wastewater is a major source of nitrogen (N) to groundwater and coastal waterbodies, threatening both environmental and public health. Advanced N-removal onsite wastewater treatment systems (OWTS) are used to reduce effluent N concentration through biological N removal (BNR). Despite the important role that these systems play in treating nutrient- and pathogen-rich wastewater, few studies have targeted the mechanisms involved in N removal, their capacity to produce effluent to meet regulatory standards, or their impact on the atmosphere.

I evaluated effluent total N (TN) concentration, the structure and composition of N-removing microbial communities, and greenhouse gas fluxes of advanced N-removal OWTS …

Molecularly Targeted Treatments For Urothelial And Renal Cell Carcinomas, Andre R. Jordan

Open Access Dissertations

Bladder cancer (BCa) is the 4th most common cancer in men, and more often presents as advanced disease in women. Management of BCa is complicated and costly due to high rates of recurrence and progression, multifocality, and heterogeneity of tumors. The hyaluronic acid-HYAL-1 system is a molecular driver of BCa. Tumor cell-derived hyaluronidase, HYAL-1, degrades hyaluronic acid (HA) into angiogenic fragments (AGF: 10-12 disaccharides). AGF support tumor growth and progression. In preclinical models of BCa, we evaluated whether o-sulfated AGF (sHA-F) inhibits HYAL-1 HAase activity and has antitumor activity. At IC50 for HAase activity inhibition (5-20 µg/ml [0.4-1.7 µM]), sHA-F …

Understanding The Role Of Idh Mutation In Chondrosarcoma, Luyuan Li

Open Access Dissertations

Chondrosarcomas constitute a heterogeneous group of malignant bone tumors that produce hyaline cartilaginous matrix. Chondrosarcomas are generally resistant to conventional chemotherapy and radiotherapy, leaving surgery as the only curative treatment option for most localized tumors. In the absence of effective systemic therapy, metastatic disease is nearly uniformly fatal. Therefore, better therapy for patients with unresectable or metastatic disease is urgently needed. Mutations in isocitrate dehydrogenase 1/2 (IDH1/2) enzymes were recently described in several malignancies including conventional and dedifferentiated chondrosarcomas. These mutations represent a novel genetic abnormality in chondrosarcoma, indicating a potential role for aberrant IDH function in the pathogenesis of …

A Role For The Hypoxia-Inducible Factor 1 Alpha In Murine Gammaherpesvirus 68 (Mhv68) Lytic Replication And Reactivation From Latency, Darlah Michelle López-Rodríguez

Open Access Dissertations

The hypoxia inducible factor 1 alpha (HIF1α) protein and the hypoxic microenvironment are critical for infection and pathogenesis by the oncogenic gammaherpesviruses (γHV) such as Kaposi' Sarcoma-associated Herpes Virus (KSHV) and Epstein-Barr virus (EBV). However, understanding the role of HIF1α during the virus life cycle and its biological relevance in the context of host pathogenesis has been challenging due to the lack of animal models for human γ HV. To study the role of HIF1α we employed the murine gammaherpesvirus 68 (MHV68), a rodent pathogen that readily infects laboratory mice. We show that MHV68 infection induces HIF1α protein and HIF1α-responsive …

Infection Of Mitochondria In Damselfish Neurofibromatosis: Impacts On Mitochondrial Function And Dna Levels, Merly Laura Ovares

Open Access Dissertations

Damselfish neurofibromatosis (DNF) is a type of cancer affecting Stegastes partitus (Bicolor damselfish) on Florida reefs. The agent which causes the disease, termed the damselfish virus-like agent (DVLA), is the only known agent to replicate within mitochondria of animal cells. Determining the effects DVLA has on mitochondrial function and DNA levels are of importance to further understand DNF, as well as which mechanisms of mitochondrial function are directly affected by DVLA which may cause cancer. Experiments analyzed DNA levels of both DVLA and mitochondria (mtDNA), as well as mitochondrial-mediated metabolism on healthy and tumor tissues. Cell lines were also analyzed …

Nucleus Pulposus Of The Intervertebral Disc: The Effect Of Environmental Factors On Metabolic Activity, Lukas M. Jaworski

Open Access Dissertations

Lower back pain is a major socioeconomic concern in developed nations. Moreover, it is a condition which a majority of people will experience an episode within their lifetime, with a portion becoming chronically afflicted. Degeneration of the intervertebral disc (IVD) is believed to play a critical role in initiating lower back pain. Poor nutrient supplies are implicated as a one of the root causes of this degeneration and much effort has been spent to better elucidate the behavior of IVD cells. The IVD is the largest avascular structure within the body, relying on diffusion to migrate nutrients in and clear …

Exploring Myosin Rlc Phosphorylation As A Potential Novel Therapeutic Target For Hypertrophic Cardiomyopathy, Sunil Yadav

Open Access Dissertations

Background: Hypertrophic Cardiomyopathy (HCM) is one of the most prevalent heart diseases characterized by ventricular and septal hypertrophy, myocardial fibrosis and myofibrillar disarray. Genetic forms of HCM are mainly caused by mutations in major sarcomeric proteins such as β-myosin heavy chain (β-MHC), myosin protein binding C (MyBP-C), regulatory and essential light chains (RLC/ELC), troponin, tropomyosin and actin. My Ph.D. proposal focuses on myosin RLC and two RLC mutations: Arginine-to-Glutamine, R58Q, and Aspartic acid-to-Valine, D166V, that cause HCM and strives to provide insight into the importance of human cardiac myosin RLC phosphorylation site at Ser-15 for normal heart function and its …

Functional Significance Of The Hexosamine Biosynthesis Pathway In Pancreatic Cancer, Nikita Satish Sharma

Open Access Dissertations

Pancreatic cancer is a notoriously lethal disease. Late detection, lack of effective biomarkers, presence of a treatment refractory population of cells, an impermeable stroma, metastasis and tumor recurrence are some of the factors contributing to the dismissal 5-year survival rate of 8% for this disease. Hexosamine Biosynthesis Pathway (HBP) is a unique node in cancer metabolism. Its end product, UDP-GlcNAc is used by both tumor cells and the extracellular matrix component Hyaluronan for signaling, proliferation and metastasis of pancreatic cancer cells. While there have been reports examining the significance of HBP in individual factors contributing to tumor aggressiveness, a comprehensive …

The Diverse Roles Of Mitochondrial Dynamics In Retinal Ganglion Cell Maturation, Disease, And Regeneration, Alexander Kreymerman

Open Access Dissertations

Mitochondria maintain a diversity of roles central to the array of neuronal functions and survival, as implied by the ubiquitous evidence of mitochondrial roles in neuronal developmental, aging, and disease progression. The canonical function of mitochondria is to produce ATP, a critical and dominant molecule used by cells for energy requiring activities. However, since their discovery more than a century ago, mitochondria have been implicated in a vast collection of cellular processes, largely driven by their expanded function beyond metabolism, including secondary messenger signaling, cytoplasmic Ca2+ signaling, fatty acid oxidation, reactive oxygen species (ROS) production, and protein scaffolding. More recently, …

A Comprehensive Investigation Of Mth1 As A Novel Therapeutic Target In Ras-Driven Cancers., Govindi Jayanika De Alwis Samaranayake

Open Access Dissertations

The nucleotide pool is significantly more susceptible to oxidative damage induced by reactive oxygen species (ROS) compared to genomic DNA, due to DNA being more protected by the double helix and nucleosome packing. The NUDIX pyrophosphatase, MutT Homolog 1 (MTH1), maintains nucleotide pool integrity by hydrolyzing oxidized purines thus preventing their genomic incorporation. If incorporated into DNA the accumulation of these oxidized purines can lead to DNA strand breaks, genomic instability, and ultimately cell death. Our prior work has shown that MTH1 is critical in facilitating multiple pro-tumorigenic phenotypes in oncogenic RAS-mutated cancer cells, with its depletion leading to decreased …

The Ecophysiology Of Photosynthetic Heat Tolerances In Tropical Plants, Timothy More Perez

Open Access Dissertations

Temperature governs several biological processes from molecular to macroecological scales. Underlying many ecological processes is the assumption that fitness is constrained by the physiological limits of species’ metabolic function. The thermal limits of metabolic function, termed thermal tolerances, are often assumed to directly translate into the environmental conditions that define species’ abiotic thermal niches. When species exceed their physiological thermal tolerances, it is expected to negatively impact fitness, and may therefore provide a basis for understanding the environmental constraints on species distributions. Given the rising temperatures caused by climate change, heat tolerances are of particular interest for understanding these constraints. …

Induction Of Beta-Cell Regeneration By Activin-Like Kinase 3 Stimulation, Mirza Muhammad Fahd Qadir

Open Access Dissertations

Glucose homeostasis is maintained and tightly regulated via production of key hormones that control the uptake and metabolism of glucose. β-cells, which secrete insulin, are the subject of autoimmune destruction in type 1 diabetes. From a developmental standpoint, Bone Morphogenetic Protein receptors (BMPRs) have a key role in multiple cell processes, including proliferation and differentiation. Targeting these receptors to identify and induce the proliferation of progenitor cells could have therapeutic applications. Previous studies have shown the conversion of the exocrine compartment of the pancreas to form insulin-producing cells. In this context, we have identified a cell residing in the pancreatic …

The Effect Of A High Intensity Interval Exercise Bout On Addictive Behaviors In Overweight/Obese Adults, Sarah Zaldivar

Open Access Dissertations

Addictive snacking can contribute to excessive caloric intake having an adverse effect on body weight and the obesity pandemic. Studies have reported that moderate intensity exercise decreases chocolate consumption. However, the effect of high intensity interval exercise (HIIE) on addictive snacking is unknown. This study aimed to investigate the effects of a brief HIIE bout on cravings, affect (affective valence and affective activation), and attentional bias to chocolate. Twelve regular chocolate eaters (10 premenopausal females; 2 males; mean age: 30.5 ± 7.37 years, mean BMI: 28.67 ± 4.5 kg/m2) abstained from chocolate consumption for 24 h prior to evaluation. Participants …

Contemporary Central American Imaginaries Under (Re)Construction: Landings In A Postwar Cultural Landscape, Rosario Catalina Ramírez

Open Access Dissertations

My dissertation maps contemporary Central American cultural production in literature, music and grassroots networks for culture. It is focused on the postwar period in the region, from the signing of the Peace Accords in the 1990s onwards. I focus on emergent cultural narratives in order to analyze the reconstruction of isthmian imaginaries through a constructive lens. Cultural texts and discursive imaginaries are analyzed from a perspective grounded in local histories versus the grand homogenizing narratives that have historically defined the Central America isthmus, such as mestizaje and the revolutionary as paradigm. Through the analytical constructs of aterrizaje and descendencia, …

Genomic Analyses Reveal The Evolutionary Dynamics Of Speciation In Two Tropical Avian Systems, Sarah Alison Cowles

Open Access Dissertations

The process of speciation is long and complex, and takes place in multiple stages, with a variety of potential outcomes. Studying lineages at different stages in the speciation process can lend insight into the evolutionary factors that generate and maintain biodiversity. For my dissertation, I used two genomic datasets generated from field-collected DNA samples in two tropical avian systems to examine the early and late stages of the speciation process. I studied the initial stages of speciation in the Amazilia Hummingbird (Amazilia amazilia) subspecies complex. Found across Ecuador and Peru, this species is split into six phenotypically differentiated …

The Effects Of Environmental Variables And Anthropogenic Pollutants On The Physiology And Behavior Of Marine Fishes, Lela S. Schlenker

Open Access Dissertations

In the face of rapidly changing environmental conditions due to human mediated climate change and large-scale pollution events such as the Deepwater Horizon oil spill, it is critical to understand the relationship between environmental stimuli and the behavior of marine fishes. Sustainable management of commercially important and highly migratory fish species, such as mahi-mahi (Coryphaena hippurus), as well as unfished reef species, like the bicolor damselfish (Stegastes partitus), depend upon our understanding of their physiology and behavior in response to changing habitat conditions. Olfaction is critical for fish to detect environmental cues and triggers behaviors that …

Investigating Novel Compounds In The Treatment Of Cardiac Arrhythmia, Briana Marie Bohannon

Open Access Dissertations

Cardiac arrhythmia leads to 325,000 cases of sudden cardiac death annually in adults alone (Clinic 2017). Long QT Syndrome (LQTS) is an arrhythmogenic disorder that is caused by mutations (or channelopathies) in voltage-gated ion channels expressed in the cardiomyocyte. Polyunsaturated fatty acids (PUFAs) have emerged as a potential therapeutic for the treatment of LQTS because they modulate the activity of voltage-gated ion channels involved in LQTS pathology. PUFAs are amphipathic molecules with a hydrophilic head group, as well as long, polyunsaturated hydrophobic tail. In this work, we demonstrate that the position of the double bonds in the hydrophobic tail influence …

Leveraging Admixture In United States Minority Populations To Elucidate The Genetic Underpinnings Of Multiple Sclerosis, Ashley Harris Beecham

Open Access Dissertations

Notable progress has been made towards unraveling the genetic architecture of multiple sclerosis (MS) within ancestral European populations; with 200 confirmed variants outside of the Major Histocompatibility Complex (MHC) explaining ~19% of the genetic predisposition to MS, and the MHC alone explaining ~20%. However, the genetics of MS in Hispanics and African Americans remains largely understudied. I proposed to examine the role of the previously confirmed non-MHC MS risk loci in United States patient populations of Hispanics and African Americans and to identify novel loci. In Hispanics, I proposed to extend these analyses; both to characterize the MHC and to …

Cervical Cancer Prevention And Control In Haitian Women Living In South Florida And The Central Plateau Of Haiti, Rhoda K. Moise

Open Access Dissertations

The cervical cancer burden in Haiti is among the highest in the world, despite being a largely preventable disease through primary (i.e., vaccination against Human papillomavirus (HPV), the principal cause of cervical cancer), and secondary (i.e., routine cervical cancer screening) prevention strategies. Haitian women likely face multiple barriers to disease prevention though knowledge of these barriers remains limited, particularly from a multilevel, transnational orientation. This dissertation aims to fill this gap. Guided by the PEN-3 model and the tenets of Community Engaged Research, the three associated papers rely on mixed methodologies to articulate the complex interplay between socio-cultural, environmental, political, …

Air-Sea Interaction Dynamics Under Hurricane Wind Conditions, Sanchit Mehta

Open Access Dissertations

Understanding turbulent fluxes of momentum, mass, and energy across the air-sea boundary are fundamental to our ability to model and parameterize a number of multidimensional geophysical processes, such as wind-wave generation, oceanic circulation, and air-sea gas transfer. The physical nature of the near surface boundary layer remains less known, especially under high winds due to the development of an intermediate substrate layer of large spray droplets known as spume, between the atmosphere and ocean surface. Presence of these spume droplet effects the aerodynamic resistance of the prevailing winds over the surface and thus the behavior of surface drag coefficient. The …

Engineering A Compartmentalized Hydrogel Platform For In Vitro Assembly Of Neuromuscular Junctions, Rachel Besser

Open Access Dissertations

This study reports the first hydrogel based compartmentalized in vitro platform for neuromuscular junction (NMJ) formation. The study was performed in three parts including the fabrication of a biomimetic substrate adhesive to both cell types involved in NMJ formation, optimizing the media formulation for these cells, and designing and testing a compartmentalized hydrogel system. A laminin coated gelatin (GEL-LN) hydrogel was fabricated and used to assess C2C12 mouse skeletal muscle cells, primary rat Schwann cells, and human induced pluripotent stem cell derived spinal spheroid (SpS). The GEL- LN substrate increased maturation and improved morphology when used to culture C2C12 cells …

High Rate Quasi-Steady-State Pattern Visual Evoked Potentials For Brain-Computer Interface, Ibrahim Kaya

Open Access Dissertations

Visual Evoked Potentials (VEPs) are electrophysiological signals recorded from occipital areas of the scalp in response to visual stimulation. VEPs are used for clinical monitoring of diseases and Brain-Computer Interfaces (BCIs). Depending on the stimulation rate, there are two types of VEPs, transient (low stimulation rates < 3Hz) and Steady-State (higher stimulation rates >5Hz). However, a novel VEP stimulation paradigm was developed at the University of Miami, Neurosensory Laboratory. This paradigm generates low jittered VEPs similar to Steady-State VEP (SSVEP) and called Quasi-Steady State VEPs (QSS-VEPs). QSS paradigm has proven itself in the fast acquisition of Auditory Brainstem Responses (ABRs) and Pattern Electroretinograms (PERGs). One major advantage …