Life Sciences Commons^™

Bioactive Potential Of Microbial Isolates From Yoluja Cave And Jepirramüin Rock Shelter, Cabo De La Vela (Colombia), Juan Sebastián López Caro, Virginia Patricia Roa Angulo, Alex Alberto González Vargas

International Journal of Speleology

Subterranean environments harbor diverse microbial communities with significant potential for the production of bioactive compounds. This study evaluated the antimicrobial and antioxidant potential of microbial isolates obtained from Yoluja Cave and the Jepirramüin rock shelter, located in the coastal region of La Guajira, Colombia. Field sampling was conducted during three campaigns in July, September, and November 2025, including soil and surface samples collected along environmental gradients within each site. Microorganisms were isolated using selective culture media and identified through morphological and biochemical characterization. Selected strains were subjected to liquid fermentation and organic solvent extraction to obtain crude metabolites. Analysis of …

Engineering Fsh-Cer T Cells To Enhance Response To Epithelial Ovarian Cancer, Nolan J. Beatty

USF Tampa Graduate Theses and Dissertations

Ovarian cancer remains a significant cause of cancer-related mortality, with epithelial ovarian cancer (EOC) being the most common subtype. Despite advances in treatment, the 5-year survival rate for late-stage EOC remains low due to factors such as tumor heterogeneity and an immunosuppressive tumor microenvironment (TME). This study investigates the therapeutic potential of chimeric endocrine receptor (CER) T cells engineered to express follicle stimulating hormone (FSH) in a syngeneic mouse model of EOC expressing follicle stimulating hormone receptor (ID8-FSHR). We compared two different co-stimulatory domains—CD28ζ and 4-1BBζ—in FSH-CER T cells and found that FSH-CD28ζ CER T cells exhibited enhanced cytotoxicity, proliferation, …

Vertebrate Diversity In Cave Systems Of Colombia: An Approach Based On Environmental Dna Metabarcoding Analysis, Rita Daniela Martinelli Marín, Carlos Andres Lasso, Francesco Sauro, Susana Josefina Caballero

International Journal of Speleology

There is currently limited knowledge of the biological communities inhabiting cave ecosystems in South America. This study examines the vertebrate community composition of 21 caves across diverse subterranean ecosystems in Colombia using environmental DNA (eDNA) analysis. Water was collected from water bodies inside caves and subterranean systems in six of the eight speleological regions of Colombia in eight departments. Water was filtered manually through a 0.8 m pore size filter and preserved with Longmire solution. A 170-base pair (bp) fragment of the 12s mitochondrial gene specific for vertebrate identification was amplified by PCR and sequenced by Illumina (metabarcoding). Data corresponding …

Nanoscale Morphological Perturbations Of Lipid Membranes Induced By Membrane Active Peptides, Yasith Sandeepa Indigahawela Gamage

USF Tampa Graduate Theses and Dissertations

Membrane-active peptides (MAPs) are a diverse group of biologically relevant molecules that induce nanoscale modulations during their interactions with cell membranes. Understanding the precise mechanism by which these MAPs perturb or modulate the cell membranes is a cornerstone of membrane biophysics, as it facilitates rational design of useful therapeutics. That is, if we have the knowledge to determine what the peptide can do, how selective it is, or how toxic it might be, we can optimize them and design new peptide therapeutics such as for antimicrobial, anticancer, or drug-delivery applications. In general, MAPs can be categorized into two classes based …

Light-Driven Zonation And Community Structure Of Aerophytic Microalgae In A Tropical Limestone Cave (Gua Tempurung, Malaysia), Wan Maznah Wan Omar, Mohammad Basri Eshak, Luthfiana Aprilianita Sari, Zulaihat Hamza Abdullahi, Yusuf Abdullahi

International Journal of Speleology

Cave ecosystems host specialized phototrophic biofilms structured primarily by light availability, yet quantitative assessments of aerophytic microalgal community organization in tropical limestone caves remain limited. This study investigated spatial variation in the structure of aerophytic microalgal communities across four ecologically distinct zones (entrance, transition, penetration, and low light) of Gua Tempurung, Malaysia. Stratified sampling was conducted during three seasonal periods. Dominant phototrophic morphospecies were identified using microscopy, and community composition was analyzed in relation to key environmental variables. Twenty-three dominant microalgal morphospecies were recorded across the cave gradient. Cyanobacteria constituted the major component of both richness and abundance, followed by …

Exploring Staphylococcus Aureus Host-Pathogen Interaction Using Proteomic Technologies, Emilee Marlene Elizabeth Mustor

USF Tampa Graduate Theses and Dissertations

Staphylococcus aureus deploys an arsenal of virulence effectors to remodel the host environment during infection, while simultaneously the host mounts an immune response to contain and eliminate this bacterium. This dynamic interplay defines the host-pathogen interface and shapes infection outcome. In this context, the secreted proteases represent a major arm of S. aureus pathogenesis, promoting bacterial persistence in the host by dismantling immune defenses, cleaving host signaling molecules and reshaping the host proteome. However, traditional substrate-by-substrate characterization cannot reveal the full scope of proteolytic activity occurring during infection. To address this, we developed Terminal Amine-Guanidination of Substrates-Charge Reversal (TAGS-CR), a …

House Sparrow Invasion Success Across Ecological, Immunological, And Molecular Scales, Kailey Marie Mccain

USF Tampa Graduate Theses and Dissertations

Biological invasions offer natural experiments for studying how organisms cope with ecological novelty. Although invasion success is often attributed to enemy release, introduced organisms do not enter enemy-free environments. Instead, they enter heterogeneous landscapes in which some familiar enemies are absent, others remain, and entirely novel enemies may be encountered. The question, then, is how invaders (hereafter non-natives) are poised to respond to these threats? This dissertation examines whether successful invasions in house sparrows (Passer domesticus) is associated with shifts in pathogen exposure, immune dynamics in blood, gut physiology, and gene co-expression network structure.

Chapter 1 is at the population/ecological …

Association Of Social Isolation, Loneliness, Social Strain And Support With Cancer Onset, And Frailty And All-Cause Mortality In People With Cancer, Joanne Elayoubi

USF Tampa Graduate Theses and Dissertations

Cancer is the second leading cause of death both in the United States and globally and for individuals over sixty-five. In 2026, approximately 2,114,850 new cancer cases are projected to emerge according to the National Center for Health Statistics (Siegel et al., 2026). Cancer incidence is increasing, making older adults sixty-five and older at risk of frailty and mortality following cancer. Although social isolation, loneliness, lack of social support, and social strain have been found to be risk factors for poor health and mortality, it is not clear the extent to which social relationships are associated with incident cancer, and …

Reproductive Trends Of Male Atlantic Spotted Dolphins (Stenella Frontalis) Following Two Hurricanes In The Bahamas, Tara Southerland Pedersen

USF Tampa Graduate Theses and Dissertations

Marine mammals are impacted by hurricanes that may influence reproductive success and genetic diversity. Understanding how populations respond to demographic change is increasingly important as extreme weather events become more frequent. A population of Atlantic spotted dolphins (Stenella frontalis) on Little Bahama Bank in the Bahamas has been observed continuously since 1985. In 2004, two hurricanes struck the region within one month, resulting in the loss of approximately 36% of the population. Population declines can alter the operational sex ratio (OSR), social structure, and encounter rates among potential mates, potentially influencing patterns of reproductive success. Previous molecular studies showed that …

From Cardiovascular Safety Assessment To Peptide Hemolytic Activity Prediction: Integrative Computational Analyses For Drug Evaluation And Discovery, Xinran Zhu

USF Tampa Graduate Theses and Dissertations

This thesis applied integrative computational approaches to two major areas of drug evaluation and discovery: cardiovascular safety assessment and peptide hemolytic activity prediction. First, pharmacovigilance data from the FDA Adverse Event Reporting System (FAERS), electronic health records (EHRs) from TriNetX, and transcriptomic analyses were combined to evaluate anesthetic-associated cardiac rhythm adverse drug events. Among propofol, ketamine, dexmedetomidine, and midazolam, dexmedetomidine showed the strongest association with bradycardia across both FAERS and propensity score-matched EHR analyses. Stratified analyses further suggested substantially higher bradycardia prevalence among older patients and a modestly increased risk among male patients. Drug-drug interaction analyses identified risperidone and albuterol …

“He’S Got The Whole World In His Hands”: Seed Sovereignty And Agricultural Decision Making In Southeastern Kenya, Caroline Stahley

USF Tampa Graduate Theses and Dissertations

Increasing corporate control of the global seed supply and restrictions to local exchange threaten the autonomy of smallholder farmers and Indigenous communities. This project contributes to agricultural sovereignty movements by examining the decisions farmers make to address climate uncertainty, market volatility, and development agendas. Specifically, how is seed saving practiced and understood in relation to sovereignty? It reimagines what global food systems might look like if investment were directed to producers rather than intermediaries, arguing that cultivators lack support, not knowledge or capacity. Across these domains, seeds act as a motif to describe the concerns, innovations, and visions of farmers.

House Sparrows Reveal Hidden Reservoirs Of Antimicrobial Resistance, Nathan Dowling

USF Tampa Graduate Theses and Dissertations

Antimicrobial resistance (AMR) is a growing global health threat, yet surveillance for antimicrobial resistance genes (ARGs) remains concentrated in clinical and livestock systems, leaving environmental and wildlife reservoirs comparatively understudied. The objective of this study was to evaluate whether one synanthropic bird species integrates landscape-level antimicrobial resistance pressures across socioeconomic gradients and to identify the predictors most strongly associated with cross-national variation in ARG prevalence. We examined ARG occurrence in the globally distributed house sparrow (Passer domesticus), sampling 205 individuals across eight countries spanning large gradients in economic development, antimicrobial use, and governance structure. Using targeted molecular screening of gastrointestinal …

Amending Planting Media With Typha-Derived Biochar For Sustainable Horticulture, Elissa Touma

USF Tampa Graduate Theses and Dissertations

Constructed wetlands are widely used to improve water quality by removing excess nutrients from wastewater and stormwater. Nutrients are stored within wetland vegetation, particularly in fast-growing plants such as Typha. Harvesting vegetation provides an opportunity to permanently remove these nutrients while generating biomass suitable for beneficial reuse. Converting harvested biomass into value-added products such as compost and biochar can support nutrient recovery and sustainable biomass management. In addition, increasing concerns regarding the environmental impacts of peat extraction have created interest in renewable alternatives for horticultural growing media. Therefore, the objective of this study was to evaluate the potential of harvested …

Assessment Of Artificial Oyster Reef Health Based On Water Quality, Oyster Recruitment, And Perkinsosis Infection In Tampa Bay, Christian J. Goldman

USF Tampa Graduate Theses and Dissertations

Providing nursey habitat, regulating nutrients, stabilizing shorelines, increasing biological diversity, improving water quality, and creating three-dimensional environments are some of the ecosystem services of oyster reefs. Oyster reefs are threatened by overharvesting, changes in water quality, pollution, and disease. The Eastern oyster, Crassostrea virginica, is the primary oyster species along Florida’s Gulf coast. This study aimed to evaluate the relationship between multiple parameters on artificial reefs and how they influence the health of these reefs. Here, young (less than five years old) artificial oyster reefs were monitored for one year across three sites in Tampa Bay, FL: Lassing Park (LAS), …

Quantitative Determination Of Nano Delivered Kras Sirna, Axel S. Deraspe

USF Tampa Graduate Theses and Dissertations

This study focuses on the development and validation of analytical methods for the detection of therapeutic KRAS-targeting siRNA in biological systems. Physicochemical characterization showed that p5RHH-formulated siRNA nanoparticles exhibit a controlled nanoscale size distribution, moderate polydispersity, and a negative zeta potential, suggesting colloidal stability and potential suitability for cellular uptake. Scanning electron microscopy confirmed a predominantly spherical morphology with a relatively uniform size distribution, consistent with dynamic light scattering measurements.

To enable accurate siRNA quantification, stem–loop reverse transcription (SL-RT) coupled with SYBR Green–based quantitative Polymerase Chain Reaction (qPCR) was optimized. Key parameters, including a primer concentration of 100 nM and …

Polygenic Risk Scores, Sex, And Socioeconomic Factors As Predictors Of Age Of Onset For Major Depressive Disorder, Kaitlyn M. Nowak

USF Tampa Graduate Theses and Dissertations

Major Depressive Disorder (MDD) is a heterogeneous psychiatric condition influenced by genetic, sociodemographic, and environmental factors, yet the extent to which these factors jointly shape the timing of disease onset remains unclear. This study evaluated the effects of polygenic risk scores (PRS), sex, and socioeconomic status (SES) on age of onset for MDD across two independent cohorts: the Pharmacogenomics Research Network Antidepressant Medication Pharmacogenomics Study (PGRN-AMPS) (N = 486) and the All of Us Research Program (N = 8,014). Analyses were restricted to individuals of European genetic ancestry, and PRS were constructed using both European-ancestry (EA) and multi-ancestry (MA) genome-wide …

Combating Β-Lactamase Resistance: From Inhibitor Design To Substrate Evolution, Lian M.C. Jacobs

USF Tampa Graduate Theses and Dissertations

β-lactamase production by bacteria is a major mechanism of antibiotic resistance. These enzymes hydrolyze β-lactam antibiotics, preventing them from binding to and inhibiting PBPs. Although new β-lactam scaffolds and inhibitors are continually introduced into the clinic, resistance often emerges within a few years. Therefore, the development of cross-class inhibitors with novel scaffolds is critical to mitigate this resistance. In parallel, a deeper understanding of the structural and mechanistic basis of β-lactamase resistance is essential. Together, these approaches provide an effective strategy for combating antibiotic resistance.

The first project addressed the need of effective cross-class β-lactamase inhibitors capable of targeting SBL …

The Heterogeneous Response Of Astrocytes In Different Brain Regions Under Metabolic Stress, Pawan Kumar Thapaliya

USF Tampa Graduate Theses and Dissertations

Astrocytes play a central role in maintaining ionic homeostasis, neurotransmitter clearance, and brain en-ergy metabolism. Their excitability, reflected in activity-evoked intracellular sodium (Na+, [Na+]i) and calcium (Ca2+,[Ca+]i) dynamics, is increasingly recognized as a critical determinant of neuronal function and vulnerability, particularly under metabolic stress. Despite their importance, the mechanisms underlying astrocytic ionic signaling and its regional heterogeneity remain incompletely understood. In this thesis, I developed detailed computational and biophysical models to investigate astrocytic Na+ and Ca2+ dynamics, their bioenergetic consequences, and the roles of key ion transporters under physiological and metabolically stressed conditions, validating the models against experi- mental data. …

Assessing The Impact Of Lampenflora Growth On Invertebrate Distribution And Food Resource Use In Ryusen-Do Cave, Japan, Kazuhide Nakajima, Kanato Ando, Shuji Watanabe, Masuo Komukai

International Journal of Speleology

Subterranean spaces, such as caves with openings to the surface, represent unique environments characterized by limited resources derived from photosynthetic primary production. Consequently, organic inputs from organisms inhabiting above- and belowground habitats, such as bats, play a crucial role in maintaining cave ecosystems. However, in show caves converted into tourist attractions, environmental changes have progressed without sufficient ecological assessment. One important factor is the impact of photosynthetic organisms colonizing around artificial lights, known as lampenflora, on cave ecosystems. Lampenflora growth may influence invertebrate distribution and resource use; however, its impact on both aspects has been poorly evaluated. In this study, …

The Molecular Determinants Of Deglycation And Substrate Specificity In Fructosamine Kinases, Jenet Matlack

USF Tampa Graduate Theses and Dissertations

Protein glycation is a universal, non-enzymatic modification that occurs when a sugar covalently attaches to a primary amine. These spontaneous modifications may have deleterious or regulatory effects on protein function, and their removal is mediated by the conserved metabolic kinase fructosamine-3-kinase (FN3K). Despite its crucial role in protein repair, we currently have a poor understanding of how FN3K engages or phosphorylates its substrates. Additionally, the molecular basis for the distinct yet overlapping substrate specificities of FN3K and its paralog, ketosamine-3 kinase (KT3K), remains unresolved. By integrating structural biology, biochemistry, and ancestral protein reconstruction (APR), this thesis elucidates the catalytic mechanism …

Invasion Risk Of Regal Demoiselle Following Lionfish Invasion In The Western Atlantic Ocean, Gulf Of Mexico, Bahamas, And Greater Caribbean, Shea L. Volkel

USF Tampa Graduate Theses and Dissertations

Indo-Pacific lionfish (Pterois volitans and P. miles) and regal demoiselle(Neopomacentrus cyanomos) are reef-associated fishes that have invaded the Western Atlantic Ocean, Gulf of Mexico, Bahamas, and Greater Caribbean. While invasive lionfish are established mesopredators with documented impacts on native reef communities, regal demoiselle are at an earlier stage of invasion, and their ecological risks are unclear. Because lionfish consume regal demoiselle in their invaded range, interactions between these species, particularly predation, may influence regal demoiselle invasion success. This dissertation assessed the invasion risk of regal demoiselle, focusing on predator-prey interactions among these species. The objectives were to 1) identify areas …

Genetic Testing Motivations Among Men With A History Of Prostate Cancer: A Judgment-Based Analysis, Maximilian Junge

USF Tampa Graduate Theses and Dissertations

Identifying individuals at increased hereditary cancer risk through genetic testing can improve early detection, inform treatment decisions, and enhance outcomes for patients and their families. While prior research has largely focused on women, less is known about factors that motivate men with prostate cancer to pursue genetic testing. This study examined components of visual messaging that may influence motivation to undergo genetic testing among men with a self-reported history of prostate cancer. Participants completed a survey in which they viewed eight visual messages that systematically varied across three components: image type (family-focused vs. individualized treatment-focused), written content (familial risk-focused vs. …

Assessing Capability, Opportunity, And Motivation In Relation To Guideline Adherence For Inherited Cancer Risk, Cecilia L. Delisanti

USF Tampa Graduate Theses and Dissertations

Introduction: Although National Comprehensive Cancer Network (NCCN) guidelines provide cancer screening or risk reduction recommendations for individuals with germline pathogenic and likely pathogenic variants (GPVs) in actionable hereditary cancer genes, guideline adherence remains inconsistent, and the behavioral contributors to this gap remain understudied. To identify behavioral factors related to adherence across inherited cancer risk genes, this study used the COM-B model, which posits that capability, opportunity, and motivation shape health behaviors.

Methods: IMPACT study participants, all with GPVs in a variety of actionable genes, completed surveys (N=575). Minimal adherence was based on gene-specific NCCN guidelines. COM-B constructs (capability, opportunity, motivation) …

Dual-Modal Tumor Imaging Using Functionalized Iron-Oxide Nanoparticles For Mri And Fluorescence, Kevin Secades

USF Tampa Graduate Theses and Dissertations

Accurate tumor imaging is essential for early cancer detection and treatment monitoring [1]. Technetium-99m (Tc-99m) is a commonly used radioisotope for medical imaging, but its reliance on gamma-ray emission poses challenges related to safety, accessibility, and regulatory constraints[2-5]. This research proposes the development of a dual-modal imaging approach by functionalizing iron-oxide nanoparticles (IONPs) with the fluorescent chromophore Cy5, enabling both MRI contrast enhancement and optical imaging for improved tumor specificity. IONPs provide strong T2-weighted MRI contrast [6], while conjugated near-infrared (NIR) chromophores allow for high-resolution fluorescence imaging [7], making this proposed system adaptable for both in vitro and in vivo …

Impact Of Statin Medication Use On Glycemic Control And Complications In Type 1 Diabetes, Ryan Bailey

USF Tampa Graduate Theses and Dissertations

Introduction: Hydroxymethylglutaryl-CoA enzyme inhibitors (statins) are frequently used to prevent cardiovascular events in individuals at high risk for cardiovascular diseases, including individuals with diabetes. Prior research has indicated that statins may increase the risk of developing type 2 diabetes (T2D) and may increase hyperglycemia among those previously diagnosed with T2D. To date, little research has investigated the impact of statins on glycemic control and diabetic complications associated with poor glycemic control in those with type 1 diabetes (T1D). The objective of this dissertation is to investigate the association between statin use and measures of glycemic control including hemoglobin A1c (HbA1c), …

Aging In The Shadows: Szekler Cemeteries And The Case For Recognizing Elderly Populations In Bioarchaeology, Katie M. Mcgrath

USF Tampa Graduate Theses and Dissertations

The study of aging in past populations lies at the intersection of bioarchaeology and paleodemography, offering insight into both biological processes and lived social experience. Despite this potential, older adults are often rendered “invisible” in skeletal assemblages due to methodological and cultural biases. This thesis addresses this gap through a rare, community-based study of aging among the Székely population of Transylvania. By integrating osteological analysis of individuals (11th–19th centuries) from the archaeological Papdomb church cemetery with demographic data derived from the modern cemetery headstones (ca.1850–present), this research examines patterns of aging, longevity, and elder visibility across a culturally and spatially …

Targeting Cancer With T Cells: Preclinical And In Silico Insights To Improve Immunotherapies, Nina Obertopp

USF Tampa Graduate Theses and Dissertations

T-cell–based immunotherapies are often constrained by limited trafficking and persistence in tumors and by functional exhaustion under chronic antigen exposure. This dissertation addresses these barriers through two distinct strategies: (i) preclinical studies testing how radiation therapy modulates tumor-infiltrating lymphocytes (TIL) therapy, and (ii) agent based modeling (ABM) to optimize treatment day treatment-free intervals (TFI) in T-cell engager (TCE) therapy. (i) In a human papillomavirus–positive (HPV⁺) head-and-neck cancer (HNC) model, a single local-dose of RT (8 Gy) delivered five days before tumor harvest increased the success and functional quality of ex vivo TIL outgrowth from tumor fragments, enriching polyfunctional CD8⁺ subsets. …

Lymphatic Malformations With Activating Kras Mutations Impair Lymphatic Valve Development Through Matrix Metalloproteinases, Diandra M. Mastrogiacomo

USF Tampa Graduate Theses and Dissertations

Lymphatic malformations (LMs) are lesions that can be due to inherited or somatic mutations, and they lead to a defective lymphatic vasculature. Activating KRAS mutations have been identified recently in LM patients with lymphedema, chylous ascites, or life-threatening chylothorax. In a LM mouse model, KRAS mutations are associated with a loss of lymphatic valves, which has been proposed to cause chylothorax via retrograde lymph flow into the pleural space. However, the mechanisms underlying the loss of lymphatic valves are unknown. To investigate the mechanisms leading to valve loss, we combined the lymphatic-specific and tamoxifen-inducible Flt4CreERT2 with Kras-loxP-stop-loxP-G12D (Kras+/G12D) mice and …

The Role Of Fkbp51 In The Regulation Of Reproductive Aging And Prenatal Stress-Impaired Ovarian Function And Development, Monica C. Moore

USF Tampa Graduate Theses and Dissertations

FK506-binding protein 51 (FKBP51) is an immunophilin that acts as a co-chaperone with heat shock protein 90 that negatively regulates transcriptional activity of glucocorticoid receptor (GR) and progesterone receptor (PR), and FKBP51 levels are increased by stress conditions. Our previous studies demonstrate that Fkbp5 gene depletion was protective against maternal re-strained stress-induced preterm birth (PTB), fetal growth restriction (FGR), and maternal stress-induced age-related decline in live births. We hypothesize that FKBP51 contributes to impaired ovarian development and folliculogenesis induced by prenatal stress (PNS). Timed-pregnant Fkbp5+/+ (wild-type) and Fkbp5−/− (knockout) mice were randomly assigned to either the undis-turbed (nonstress) or PNS …

Microplastic Contamination In Longfin Squid (Doryteuthis Pealeii) From The Florida Gulf Coast: Evidence Of Marine Based Pollution, Jordan Kleinschmidt Dilena

USF Tampa Graduate Theses and Dissertations

Microplastic contamination is a pervasive global issue, yet its impact on ecologically significant cephalopod populations remains poorly understood. This study quantified microplastic prevalence and distribution in longfin squid (Doryteuthis pealeii), a key trophic link in the Gulf of Mexico. Following hydrogen peroxide digestion of digestive tract and mantle tissues, microplastics were isolated via vacuum filtration and characterized using microscopy. Fourier-transform infrared (FTIR) spectroscopy confirmed polymer identities. Microplastic contamination was exceptionally high, with 96.4% of individuals containing particles (mean = 36.6 ± 20.0 particles per individual, range = 0–94, n = 110 squid). From 4,072 total particles analyzed, fragments dominated (98.3%), …