Physical Sciences and Mathematics Commons^™

Procedures For Assessment Of The Marine Carbon System And Evaluation Of Access And Ocean Acidification Literacy In The Deaf Community, Loraine Martell-Bonet

USF Tampa Graduate Theses and Dissertations

One major goal of this dissertation addresses the need for improved laboratory procedures to measure chemical changes in seawater caused by the uptake of atmospheric CO2, especially in coastal environments. Due to the proximity of anthropogenic stressors in the coastal zone, the biogeochemical complexity of the CO2 system is more dynamic than the open ocean. My principal research objectives were addressed by developing methods for (1) improving the accuracy of pH measurements over a wide range of salinities and (2) investigating the acid-base properties of natural organics in the coastal ocean.

The accuracy of pH electrode calibrations is affected when …

Deep Learning-Based Automatic Stereology For High- And Low-Magnification Images, Hunter Morera

USF Tampa Graduate Theses and Dissertations

Quantification of the true number of stained cells in specific brain regions is an important metric in many fields of biomedical research involving cell degeneration, cytotoxicology, cellular inflammation, and drug development for a wide range of neurological disorders and mental illnesses. Unbiased stereology is the current state-of-the-art method for collecting the cell count data from tissue sections. These studies require trained experts to manually focus through a z-stack of microscopy images and count (click) on a hundred or more cells per case, making this approach time consuming (~1 hour per case) and prone to human error (i.e., inter-rater variability). Thus, …

Developing New Strategy Toward Ruthenium And Gold Redox Catalysis, Chenhuan Wang

USF Tampa Graduate Theses and Dissertations

This dissertation mainly contains three parts: 1) The discovery of triazole-modified Ru carbene catalysts for alkene metathesis and dynamic covalent chemistry; 2) The study of ligand assisted gold oxidative addition toward aryl iodide to achieve the alkene difunctionalization; 3) Gold redox catalysis via chiral P,N-chelating ligands. In the first part, the 1,2,3-triazole coordinated ruthenium carbene complexes (TA-Ru) were reported for the first time as a new class of modified Grubbs catalyst to achieve challenging olefin metathesis at higher temperatures without catalyst decomposition. With this new TA-Ru catalyst, cross-metathesis (CM), ring-closing metathesis (RCM) and dynamic covalent chemistry (DCvC) were achieved. The …

Booker Creek: Wet Season Water Quality Trends In A Florida Urban Stream, Alexandra M. Shostak

USF Tampa Graduate Theses and Dissertations

Booker Creek, a 1.9-mile stream with a 4.9-mi2 watershed, flows southeast through highly urbanized St. Petersburg, Florida, and empties into Bayboro Harbor, which connects with Tampa Bay. This study collected and analyzed water quality data for several parameters (TN, TP, nitrate-nitrite, ammonia, orthophosphate, chl-a, fecal coliform, dissolved oxygen, pH, turbidity, temperature, and salinity) every two weeks, at four different sites, during the 2022 wet season to characterize the current state and geographic variability of Booker Creek. Current creek sampling regimes, though consistent, do not sample at multiple sites along the creek. Urban streams do not display uniform water quality along …

Water Chemistry Variability In Peacock Springs Cave System And Spring Basin: Impacts On Continuous Monitoring Of Karst Aquifers, Mahnoor Kamal

USF Tampa Graduate Theses and Dissertations

The Upper Floridan Aquifer (UFA) is a highly transmissive and heterogeneous karst aquifer that makes it acutely susceptible to pollution. Rapid and extensive water quality changes in nutrients at springs draining the UFA have prompted intensive monitoring at several priority springs, including continuous and discrete water quality sampling. Springs, however, are a discrete discharge point of an often-expansive phreatic cave network that can intersect different land uses and thus drain distinct geographic areas of a springshed. The extensive network contains convergent passages from deep and shallow aquifer regions and may contribute to varying water chemistry across passages resulting in water …

Affordances And Limitations Of Molecular Representations In General And Organic Chemistry, Ayesha Farheen

USF Tampa Graduate Theses and Dissertations

Molecular representations that show chemical bonding are ubiquitous in general and organic chemistry. These help in communicating chemistry concepts that are fundamental to understanding how and why molecules interact. The goal of this dissertation work is to offer an evidence-based report on the affordances and limitations of the variety of molecular representations by chemistry topic. The variety of representations investigated are chemical formula, Lewis dot structure, line-angle diagram, ball and stick, space filling, and electrostatic potential maps. Five studies were conducted with general and organic chemistry students and three key findings emerged. First, affordances and limitations of molecular representations are …

Labile Dissolved Nickel (Ni) Concentrations In The North Pacific, Calyn M. Crawford

USF Tampa Graduate Theses and Dissertations

Nickel (Ni) is an important micronutrient for phytoplankton and bacteria that serves as a required co-factor in several metalloenzymes. Despite these known biological uses, total dissolved Ni concentrations remain elevated in global surface waters, in contrast to the surface depletion commonly observed for macronutrients and other nutrient-type trace elements. A prevailing hypothesis for the muted depletion of dissolved Ni concentrations in surface waters is that dissolved Ni in seawater is not in a bioavailable form. The chemical lability of Ni in seawater provides insight into Ni speciation and bioavailability, but few measurements have been made in the open ocean to …

Understanding Controls On Spring Hydrographs In An Eogenetic Karst Aquifer In North-Central Florida, Ryan Almeqhem

USF Tampa Graduate Theses and Dissertations

Florida has one of the largest karst aquifers in the United States, with a significant portion of its water resources originating from the eogenetic karst system in north central Florida. Despite the importance of this system, eogenetic karst still needs to be studied compared to telogenetic karst. The hydrological behavior of karst aquifers is complex, with numerous factors influencing the timing, magnitude, and shape of spring hydrographs. One hypothesis, by Florea and Vacher (2006), suggests that matrix permeability is the primary control of spring hydrographs in karst systems. However, this thesis challenges this hypothesis by presenting evidence that the recharge …

Time-Series Analysis Of Coral Reef And Reef-Fish Biodiversity In The Florida Keys National Marine Sanctuary, Cara L. Estes

USF Tampa Graduate Theses and Dissertations

The general decline in coral-reef ecosystem health throughout the Caribbean between the 1970’s and late 1990’s seems to have slowed down or stopped, with only slight decreases in coral reef cover observed in the 2000’s through 2019. The earlier decline can be attributed to many different local and regional stressors that have acted together, and include naturally occurring (hurricanes, diseases) and anthropogenic pressures (increased sedimentation, fishing). These ecosystems provide a range of services to people, including food and protection from storms, with an annual benefit of billions of dollars. This has driven a desire to better understand these ecosystems. The …

Mining Multibeam Transit Data For Deep Ocean Polymetallic Nodules: Case Study In Se Pacific Ocean, Mark E. Mussett

USF Tampa Graduate Theses and Dissertations

Occurrences of nodules on the seafloor represent benthic habitats and present potential deposits of economically important metals. Better understanding their extent throughout Earth’s oceans will aid in resource management and determining different factors which influence their formative factors and respective local characteristics. Multibeam bathymetry and backscatter data, along with auxiliary data suggest an area of seafloor near the Foundation Seamount chain in the southern Pacific Ocean, centered around -36.84° latitude, -119.75° longitude, contains a previously uncharted polymetallic nodule occurrence. Our analysis of Simrad EM12 DUAL (12 kHz) multibeam data, collected during a 1997 transit, shows an area of strong backscatter …

Discovery Of Small-Molecule Inhibitors For The Β-Catenin/B-Cell Lymphoma 9 Protein-Protein Interaction., Zilu Li

USF Tampa Graduate Theses and Dissertations

The Wnt/β-catenin signaling pathway is associated with activating genes that support cell proliferation, differentiation, and survival. Excessive activation of Wnt/β‐catenin signaling has been associated with development of several types of cancer and activation of stem-like cancer cells. Direct targeting of β‐catenin, the central hub in this signaling pathway, is a promising strategy to suppress the hyperactive β‐catenin signaling but has proven to be highlychallenging. Substantial efforts have been made to discover compounds that bind with β‐catenin, block β‐catenin mediated protein–protein interactions (PPIs) and suppress β‐catenin signaling. β‐catenin/BCL9 PPI has a smaller contacting area (1450 Å2) and a moderate binding affinity …

Tree Planting As An Adaptive Management Tool For Climate Change In Morocco, Stephanie J. Robinson

USF Tampa Graduate Theses and Dissertations

The practice of planting fruit trees to combat climate change impacts in Morocco has been growing in popularity with support from the Moroccan government and non-profit organizations. Although it is often considered a successful adaptive management tool, tree planting initiatives (TPIs) in arid lands have not been thoroughly analyzed, their management is unstandardized, and these initiatives can cause harm when trees are planted in areas that cannot support them. To implement tree planting better these TPIs need to find areas where the trees they are introducing have the best chance of survival without negatively impacting the surrounding ecosystem and human …

Evaluating Methods For Improving Dnn Robustness Against Adversarial Attacks, Laureano Griffin

USF Tampa Graduate Theses and Dissertations

Deep learning has become more widespread as advances in the field continue. As aresult, making sure deep learning is safe has become a priority. A seemingly normal image with intentional pixel changes can cause a well-trained model to misclassify the image with high confidence. Those kinds of images are called adversarial attacks. Adversarial training has been developed to defend against adversarial attacks. This thesis evaluates different adversarial training methods against a variety of adversarial attacks. The key metrics for evaluation are classification accuracy and training time. This thesis also experiments with an improvement on an existing adversarial training method, the …

Chemical Analysis Of Metabolites From Mangrove Endophytic Fungus, Sefat E Munjerin

USF Tampa Graduate Theses and Dissertations

Natural products hold a significant place in drug discovery for their abundant and unique secondary metabolites. These secondary metabolites which encompass a range of organic compounds such as alkaloids, phenols, peptides, flavonoids, polyketides, and terpenoids, can easily be exploited for drug development. Endophytic fungi, residing harmoniously with its host, have emerged as generous producers of bioactive secondary metabolites, displaying efficacy against a wide array of human pathogens, including the challenging ESKAPE pathogens.

The research explores endophytic fungi and their prospective for drug discovery and development through the synthesis of distinctive secondary metabolites. Endophytic fungus, HM13-26C-2B, collected from Honeymoon Island, Florida …

Use Of Silica Dust And Lunar Simulants For Assessing Lunar Regolith Exposure, Layzamarie Irizarry-Colon

USF Tampa Graduate Theses and Dissertations

The utilization of the lunar regolith holds immense potential for future space exploration, but the potential health risks associated with lunar regolith are a significant concern. This literature review seeks to critically assess the use of silica and lunar simulants standards and permissible exposure limits (PELs) to evaluate the adverse health effects of lunar regolith. The literature review covers an extensive analysis of existing research, health risks, toxicological properties, and physical and chemical composition associated with silica, lunar simulants, and lunar regolith by using three main sources: regulations, scholarly articles, and Kennedy Space Center (KSC) discussion. This comprehensive analysis forms …

Stable Isotope Analysis On Yellowfin And Blackfin Tuna Eye Lenses Reveals Life History Patterns In The Gulf Of Mexico, Kylee M. Rullo

USF Tampa Graduate Theses and Dissertations

Spatial geography, ontogenetic movement, and trophic patterns of mobile species are key elements of effective marine resource management. A number of methods are currently available for tracking movements of pelagic migratory species, including the use of conventional and electronic tags. However, tagging campaigns can take years to provide useful data, can be expensive, and only capture a portion of a fish’s lifetime. For this project, I used stable-isotopic ratios of nitrogen (δ15N) and carbon (δ13C) in metabolically inert, chronologically-layered fish-eye lenses to explore lifetime movement and trophic patterns of yellowfin tuna (Thunnus albacares) and blackfin tuna (Thunnus atlanticus) in the …

A Psychometric Analysis Of Natural Language Inference Using Transformer Language Models, Antonio Laverghetta Jr.

USF Tampa Graduate Theses and Dissertations

Large language models (LLMs) are poised to transform both academia and industry. But the excitement around these generative AIs has also been met with concern for the true extent of their capabilities. This dissertation helps to address these questions by examining the capabilities of LLMs using the tools of psychometrics. We focus on analyzing the capabilities of LLMs on the task of natural language inference (NLI), a foundational benchmark often used to evaluate new models. We demonstrate that LLMs can reliably predict the psychometric properties of NLI items were those items administered to humans. Through a series of experiments, we …

Entanglements Of Teenage Food Security Within High School Pantries In Pinellas County, Florida, Karen T. Díaz Serrano

USF Tampa Graduate Theses and Dissertations

Food insecurity has the ability to shape an individual’s or a family’s everyday life and take emotional, psychological, and physical tolls. Among adolescents, not having access to nutritious food could lead to physical effects during growth and development. Moreover, the stress and anxiety of not knowing where their next meal is coming from and the social stigma associated with being food insecure can have negative effects on mental health. A recent solution to these issues is locating food pantries in high schools. Purpose: This exploratory study examined how high school students in Pinellas County, Florida perceive the use of a …

Development Of Bioactive Peptidomimetics, Lei Wang

USF Tampa Graduate Theses and Dissertations

In the past two decades, a lot of different peptidomimetics, such as β-peptides, oligoureas, azapeptides, peptoids, aromatic oligoamides, and others, have been developed. These peptidomimetics with distinctive scaffolds have shown potential in protein surface recognition and mimicry, PPI regulation, catalysis, etc. Moreover, these bioactive peptidomimetics demonstrate much better bioavailability and biostability than the bioactive peptides. To expand the application of peptidomimetics, our group have developed a new sequence-specific peptidomimetics- γ-AApeptide, which is derived from chiral γ-PNA. It shows excellent advantages including highly resistant to various proteolytical degradations and has the potential to increase chemodiversity. γ-AApeptide also exhibits remarkable biomedical applications, …

Development Of Antiviral Peptidomimetics, Songyi Xue

USF Tampa Graduate Theses and Dissertations

Protein-protein interactions (PPIs) are essential for biological processes and are associated with a number of diseases, including cancer, infectious diseases, and neurodegenerative diseases. As a result, modulation of PPIs has been recognized as one of the most promising strategies to develop the novel drugs. Peptide modulators always exhibit higher specificity and affinities with targets than small compounds or monoclonal antibodies, but their broad medicinal effectiveness is constrained by their poor bioavailability and biostability. Peptidomimetics, which have been developed to mimic the structure as well as function of bioactive peptides and proteins, have shown excellent potential in protein surface mimicry and …

Synthesis Of Small Molecule Modulators Of Non-Traditional Drug Targets, Jamie Nunziata

USF Tampa Graduate Theses and Dissertations

This work details the effort toward structure-activity-relationship (SAR) studies and synthesis of the small molecule modulators of two non-traditional drug targets. The first part of this manuscript (chapters 1–2) will discuss the collaborative work and synthesis of an inhibitor of Slingshot Homology 1 (SSH1) with the potential therapeutic application toward Alzheimer’s Disease (AD) treatment. The second part (chapters 3–6) will discuss the synthetic efforts toward modulation of a protein target known as STING, or stimulator of interferon genes, with the therapeutic application toward autoimmune disease or anti-tumor activity.

AD is a progressive and degenerative illness that holds the title of …

Synthesis Of Tools For The Investigation And Treatment Of Infectious Diseases, Grant Lawrence

USF Tampa Graduate Theses and Dissertations

Modern medicine’s ability to treat a wide array of diseases is due mainly to the development of small-molecule drug discovery. Thousands of years of traditional medicines have been dwarfed in less than a hundred years. In addition, drug discovery has becoming a more consistent process with the introduction of the clinical trials process as well.Plasmodium is a genus of tropical parasites that have the potential to wreak havoc on billions of people globally. Current methods of drug discovery aimed at defeating these parasites require expensive assays that use radioactive material. By using an alkyne-labeled agent instead of a tritium-labeled agent, …

Exposure Characteristics Of Environmental Chemicals By Life Stages, Nisha Vijayakumar

USF Tampa Graduate Theses and Dissertations

Environmental chemicals are ubiquitous and can contribute to human exposure. These exposures can result in long-term health consequences if they occur in early life. However, exposures to environmental chemicals are not evenly distributed throughout childhood. As a result, there exists variation in the levels of chemical exposure depending on the developmental stages, pathways of exposure, and broader systemic factors. However, in early life, limited research exists on exposures to environmental chemicals, particularly phthalates, pesticides, and polycyclic aromatic hydrocarbons (PAHs). In addition, environmental exposures to phthalates, pesticides, and PAHs, considering life stages, have not been fully explored. Hence it is imperative …

Machine Learning Approach For Static Ransomware Analysis, Aldin Vehabovic

USF Tampa Graduate Theses and Dissertations

Ransomware is a form of malware which uses encryption methods to make data inaccessible to legitimate users. This cyberthreat has emerged as one of the most serious security challenges today, and a wide range of ransomware families have been developed and deployed, causing immense damage to governments, corporations, and private users. As this malware type continues to expand, governments across the world are taking serious steps to limit its reach. In addition, researchers have proposed a range of ransomware detection and attribution schemes, most of which use advanced machine learning (ML) techniques to process and analyze real-world empirical data from …

Meta-Analysis Of United States Seabird Populations Based On Ocean Biodiversity Information System (Obis) Records (1965–2018), Savannah Hartman

USF Tampa Graduate Theses and Dissertations

Understanding the distribution of organisms is an important priority for society as we live through ecosystem transformations that threaten the well-being of all organisms. I have approached the dynamic and complex issue of studying biodiversity by using open-access seabird data collected along the Americas since the 1960s. I explained how these data have changed over time and space, how certain species populations could have shifted over time, and possible correlations between this potential geographic change and select environmental variables.

In Chapter 2 I evaluated the suitability of the open-access data archive Ocean Biodiversity Information System (OBIS) for supporting detailed inquiry …

Exploring The Impact Of Eddies On Southern Ocean Biogeochemical Structure Using Bgc-Argo Float Observations, Nicola J. Guisewhite

USF Tampa Graduate Theses and Dissertations

The Southern Ocean plays a crucial role in global ocean circulation, and global heat and nutrient transport. However, this region is both distant and dangerous and is therefore largely under-sampled and understudied. Methods to fill in biogeochemical data-gaps include using limited in-situ data in models to output biogeochemical property estimates, but a number of recent studies have raised concerns about how most Southern Ocean models do not resolve eddies. Eddies are known to impact biogeochemistry around the globe but little is known about their impact in the Southern Ocean. This study examines temperature, salinity, oxygen, nitrate, and dissolved inorganic carbon …

Optimizing The Membrane-Assisted Recovery Of Solids (Mars) Technology For Nutrient Removal And Recovery From Concentrated Waste Streams, Ben Yamin Hoque

USF Tampa Graduate Theses and Dissertations

The effective management of nutrients, such as nitrogen and phosphorus, in decentralizedwastewater treatment environments is a pressing challenge. These nutrients pose significant risks to the environment and public health when discharged into water bodies, while their recovery and reuse can help alleviate nutrient shortages in various industries, including agriculture. Conventional biological treatment methods used in centralized facilities are not suitable for decentralized systems due to operational complexities and space limitations. Chemical treatment mechanisms, such as adsorption, ion exchange, precipitation, and air-stripping, offer potential solutions but are accompanied by challenges like high costs and logistical issues. Therefore, finding a sustainable and …

Enhancing And Securing Wireless Medical Technology For Diagnosis And Treatment Of Lower Urinary Tract Dysfunction, Farhath Zareen

USF Tampa Graduate Theses and Dissertations

Lower urinary tract dysfunction (LUTD) is a debilitating medical condition that affects millions of individuals worldwide. Urodynamics is the current gold standard for diagnosing LUTD but uses non-physiologically fast, retrograde cystometric filling to obtain a brief snapshot of bladder function. Current state-of-the-art research in bladder monitoring includes ambulatory urodynamics using wireless implantable devices to evaluate bladder function during natural filling for long-term monitoring. However, there are various challenges and limitations to this multi-sensor approach. This research focuses on developing frameworks for automated event detection, data analysis, and optimization of long-term bladder recordingsto improve the diagnosis and treatment of LUTD. In …

Optimization Techniques For Machine Learning Inference And Near Memory Image Processing In Hardware For Highly Constrained Iot Edge Nodes, Rajeev Joshi

USF Tampa Graduate Theses and Dissertations

The growing demand for fast and energy-efficient hardware for resource-constrained Internet of Things (IoT) edge devices has highlighted the limitations of conventional computing architectures. This research focuses on addressing the demand for fast, optimized, and energy-efficient machine learning inference engines as well as image processing in IoT edge applications. In this work, we address three challenging research problems and devise efficient solutions. Our investigation involved comprehensive exploration and analysis, leading to the proposal of effective approaches for overcoming these demanding issues. Through our work, we contribute novel solutions that offer improved efficiency and effectiveness in handling these research problems.

First, …

Multimodal Assessment Of Human Behavior With Applications In Analysis Of Autism Spectrum Disorder, Sk Rahatul Jannat

USF Tampa Graduate Theses and Dissertations

Human behavior analysis is an important application area of artificial intelligence. Usingdata collected from sensors (e.g., cameras), human behavior including, but not limited to, emotions, expressions, body movement, and eye gaze are analyzed. This analysis is useful in applications in diverse fields ranging from healthcare, defense, education, and marketing. Considering this, in this dissertation, we have proposed new approaches to emotion and expression recognition, subject identification, and classification of autism spectrum disorder. More specifically, this dissertation has the following contributions: 1) A new approach for multimodal ubiquitous emotion recognition is proposed; 2) Investigation into the impact of large expression variations …