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The Ecological Role Of Cassiopea In Shallow Mangrove Habitats, David Marcel Durieux

USF Tampa Graduate Theses and Dissertations

Upside-down jellyfish, Cassiopea sp., can be locally abundant in shallow mangrove habitats throughout the tropics and subtropics. Unlike other jellyfish, Cassiopea sp. are epibenthic. Due to this unique lifestyle and their ability to achieve high population densities, an understanding is needed of their ecological impacts both individually and in aggregations, particularly given that Cassiopea sp. ranges are expanding poleward due to global climate change. We quantified the fluid flow produced by Cassiopea sp. feeding currents and found that an average-sized Cassiopea sp. can transport over 200 l/h of water in the vertical excurrent jet of their feeding current. Populations of …

Mechanistic Insight Into Β-Lactamase Catalysis, Inhibitor Design And Resistance, Michael Trent Kemp

USF Tampa Graduate Theses and Dissertations

The emergence of antibiotic resistance and spread of Gram negative bacteria poses a very real health threat to the public. The main mode of resistance within Gram negative bacteria is the production of β-lactamase enzymes that catalyze the breakdown of β-lactam antibiotics through a hydrolysis mechanism. Once the β-lactam ring is hydrolyzed and opened, the drug loses its efficacy, which allows for the bacteria to grow and proliferate uninhibited. These β-lactamase enzymes are organized into four categories based on the Ambler classification, with classes A, C and D being denoted as serine-based β-lactamase enzymes. Class B is composed of metalloenzymes …

Learning Connections Inventory© Validation Using A Physician Assistant Training Program, Roberta Worsham

USF Tampa Graduate Theses and Dissertations

The purpose of this study was to validate the Learning Connections Inventory for use with the military Physician Assistant students at the Interservice Physician Assistant Program at Fort Sam Houston, TX. The 61 participants in this study completed both a demographic survey and the Learning Connections Inventory (LCI©). The results of the demographic questionnaire depicted the characteristics of the participants and the LCI© described the learning patterns of each participant.

Research Questions one, confirmation of the current LCI© model, and two, the instructor assessment and the current model agreement, were answered using confirmatory factor analysis (CFA) and construct validity. The …

Efficient Management Of Nitrogen And Phosphorus At Centralized Water Reclamation Facilities, Helene Kassouf

USF Tampa Graduate Theses and Dissertations

A variety of process configurations are employed at municipal water reclamation facilities (WRFs), such as 5-stage Bardenpho, oxidation ditch, modified Ludzack-Ettinger (MLE) process, and sidestream recycle. However, all of these configurations face certain challenges in achieving optimum treatment of nitrogen and phosphorus. In this dissertation, the driving objectives were to: (1) quantitatively assess the fate of nitrogen and phosphorus (mass fluxes) at a treatment facility that employs biological nutrient removal, aerobic digestion, and sidestream recycle, (2) evaluate the performance of a microbial fuel cell (MFC) as a technology to remove nitrogen from sidestreams at a treatment plant that employs that …

The Role Of Cpeb2 Alternative Splicing In Tnbc Metastasis, Shaun C. Stevens

USF Tampa Graduate Theses and Dissertations

Breast cancer is the second leading cause of cancer-related deaths for women in the U.S. Although the overall 5-year survival rate for breast cancer is 90%, this rate drops substantially for triple-negative breast cancer (TNBC) due to its high metastatic potential. Furthermore, there is a lack of targeted therapeutics for TNBC, and clinical trials have been largely unsuccessful. These characteristics validate the need for identifying novel therapeutic targets for the treatment of TNBC. The study of alternative splicing (AS) has emerged as a powerful tool to elucidate the molecular underpinnings driving cancer.

Our lab has identified cytoplasmic polyadenylation element-binding protein …

Revisiting Darwin’S Little Pond As A Method To Liberate Phosphorus From Apatite Under Prebiotic Hadean Earth Conditions, Jennifer Lago

USF Tampa Graduate Theses and Dissertations

Phosphorus is an essential element for life as we know it. Phosphorus, mainly in the form of phosphate, is key to biologic functions such as genetic material, energy production, and cellular framework. As phosphorus is key to so many important biological functions it is of no wonder the question of how phosphorus was incorporated into life initially is a fundamental question in how life began.

During this time a prebiotic phosphorus source would need to have originated in rock, as phosphorus has not volatile source on Earth. The most prevalent mineral source on a prebiotic Earth would likely have been …

Unraveling The Role Of Novel G5 Peptidase Family Proteins In Virulence And Cell Envelope Biogenesis Of Staphylococcus Aureus, Stephanie M. Marroquin

USF Tampa Graduate Theses and Dissertations

Virulence factors and the bacterial cell envelope are two important components in S. aureus pathogenesis and survival. More importantly, understanding the regulation of these cellular processes is crucial to further understanding and combating this successful pathogen. To date, numerous factors have been identified as playing a role in the regulation of Agr activity in S. aureus, including transcription factors, antisense RNAs, and host elements. Herein we investigate the product of SAUSA300_1984 (termed MroQ), a transmembrane G5 peptidase family protein, as a novel effector of this system. Using a USA300 mroQ mutant we observed a drastic reduction in proteolysis, hemolysis, and …

The Photophysical Studies Of Transition Metal Polyimines Encapsulated In Metal Organic Frameworks (Mof’S), Jacob M. Mayers

USF Tampa Graduate Theses and Dissertations

Light harvesting systems provide a platform that converts solar energy into other forms of energy. One of the most common examples of photon capturing and conversion into chemical energy is observed in photosynthetic organisms in both Eurkaroyic and Prokaryotic domains. Nature provides a model for successful light harvesting platforms which includes the compartmentalization of antenna complexes that contain separated donor and acceptor pairs that participate in efficient electron transfer processes. In order to mimic such systems, crystalline porous materials that exhibits regular cavities and pore dimensions provides an excellent starting place. Metal organic frameworks (MOFs) are a class of porous …

Shortcut Nitrogen Removal In Photo-Sequencing Batch Reactor, Experiments, Dynamic Model And Full-Scale Design, Sahand Iman Shayan

USF Tampa Graduate Theses and Dissertations

Nitrogen is one of the essential elements for life; however, inefficient use of nitrogen creates major environmental problems. Nitrogen-rich streams from urban areas, farms, and wastewater treatment plants (WWTPs) lead to surface and groundwater contamination, resulting in eutrophication, hypoxia, and notable environmental, public health and economic damage. Ammonia is a form of nitrogen that can be created during industrial or biological nitrogen fixation or decomposition of biomass. Anaerobic digesters (ADs) in WWTP generate biogas from collected sludge from primary and secondary clarifiers to achieve energy recovery in the plant. However, sidestream effluent from dewatering AD sludge contains high concentrations of …

Ecological Genomics Of Two Coastal Foundation Plant Species, Jeannie Mounger

USF Tampa Graduate Theses and Dissertations

I was born and raised in rural Florida on a tributary of the Withlacoochee River. “Withlacoochee” comes from a series of Muscogee Creek words that together mean “big little water,” possibly owing to the seasonal fluctuations in the breadth and flow of the river or to the chain of lakes that in part form it. The name contains within it an understanding of the capacity of land and water to undergo great shifts. It conjures images of mutable boundaries, of water covering and receding across the landscape over and over again. Many of my clearest memories from childhood are related …

The Relationship Between Motivation And Professional Learning For Teachers In Makkah, Saudi Arabia, Yassir Alzahrani

USF Tampa Graduate Theses and Dissertations

Even though, there are many studies on teacher professional learning and many studies on teacher motivation, there is a lack of research to examine the relationship between teacher professional learning and motivation. This study examined the relationship between teacher motivation and professional learning in Makkah, Saudi Arabia.

This study was conducted using two instruments. The first instrument was the Education Participation Scale (EPS) originally developed by Boshier (1991). However, the researcher used the most recent version of EPS by Richter et al. (2019). The EPS determines what factors most motivate teachers to participate in professional development. These factors are personal …

Exercise Prescription Practices In University Counseling Centers: Testing The Information-Motivation-Behavioral Skills Model, A'Naja M. Newsome

USF Tampa Graduate Theses and Dissertations

The co-occurence of physical inactivity and poor mental health in the college student population can lead to chronic health issues that have negative short-term (e.g., academic success and weight gain) and long-term (e.g., obesity, serious mental illness, and premature mortality) impacts. Integrating exercise prescription into the mental health treatment plan of college students could enhance the holistic care model described by The American College Health Association (ACHA) and Healthy Campus task force. Understanding the knowledge, attitudes, and skills that mental health professionals (MHPs) hold regarding exercise prescription is important for policy formation and program development for college student health. The …

Examining The Effects Of Hydrology And Reclaimed Water Application On Nutrient Retention In Wetlaculture Mesocosms In Southwest Florida, Andrew Wilson

USF Tampa Graduate Theses and Dissertations

The substantial increase among agricultural and urban land use over the past century is widely regarded as the leading cause in a variety of negative environmental impacts, particularly regarding eutrophication of both salt and fresh surface waters. Usage of both synthetic and natural fertilizers on agricultural fields and residential lawns has increased significantly in order to achieve maximum crop yield and green lawns. The nitrogen and phosphorus in these fertilizers inevitably run off the landscape and into downstream surface waters. The geographic scale of this issue makes it a challenge to overcome, as targeting specific sources/polluters is nearly impossible. Landscape-scale …

A System Architecture For Water Distribution Networks, Noha Abdel-Mottaleb

USF Tampa Graduate Theses and Dissertations

This dissertation examines structure-function relationships of water distribution networks (WDNs), with focus on improving the decision-making process for water utilities. WDNs are lifeline infrastructure systems, necessary for the functioning of cities. Yet water utilities around the world struggle with emerging challenges that include but are not limited to aging infrastructure components, limited budgets, increased interdependencies between infrastructure systems, increased rates of urbanization, and increasing extreme weather conditions. This is why enhancing the performance of WDNs is a priority for water utilities around the world. This research begins to delineate a system architecture for WDNs and evaluates the use of various …

Metastatic Mat Phenotype Driven By Noncanonical Epha2 Signaling In Melanoma, Chao Zhang

USF Tampa Graduate Theses and Dissertations

Acquired BRAF/MAPK/extracellular signal‒regulated kinase inhibitor resistance in melanoma results in a new transcriptional state associated with an increased risk of metastasis. In this study, we identified noncanonical ephrin receptor (Eph) EphA2 signaling as a driver of the resistance-associated metastatic state. We used mass spectrometry‒based proteomic and phenotypic assays to demonstrate that the expression of active noncanonical EphA2-S897E in melanoma cells led to a mesenchymal-to-amoeboid transition driven by Cdc42 activation. The induction of mesenchymal-to-amoeboid transition promoted melanoma cell invasion, survival under shear stress, adhesion to endothelial cells under continuous-flow conditions, increased permeability of endothelial cell monolayers, and stimulated melanoma transendothelial cell …

Ecology And Diversity Of Boletes Of The Southeastern United States, Arian Farid

USF Tampa Graduate Theses and Dissertations

The boletes are conspicuous stipito-pileate macrofungi that are generally defined by their tubulose hymenophores. Molecular phylogenetic analyses have informed extensive taxonomic revisions across the boletes. Despite this, the boletes in the southeastern USA have been largely absent from the literature. This dissertation seeks to understand the microbiome inhabiting the tuberculate ectomycorrhizae of the bolete Hemileccinum rubropunctum, and addresses taxonomic revisions of boletes found in the Boletaceae and Suillaceae. The introduction provides a brief background on boletes, as well as our understanding of tuberculate ectomycorrhizae. The second chapter seeks to understand the composition of the microbiome tuberculate ectomycorrhizae of H. rubropunctum …

Spin Coupling In Magnetic Core - Shell Nanoparticles, Corisa Kons

USF Tampa Graduate Theses and Dissertations

Magnetic nanoparticles (NPs) have garnered much interest due to the unique properties that emergewhen compared to their bulk counterparts. In particular, core-shell (CS) NPs offer the ability to tailor the magnetic properties of the system through careful selection of core and shell constituent materials. In this work, the magnetic ordering of CS NPs with contrast in core/shell features (moment, anisotropy, coercivity, etc.) have been investigated using a combination of X-ray magnetic circular dichroism spectroscopy (XMCD) and polarized small angle neutron scattering (SANS). First, temperature-dependent analyses of XMCD and SANS studies were carried out for CS NPs featuring a core composed …

Riverine And Estuarine Co2-System Studies On The West Coast Of Florida, Christopher S. Moore

USF Tampa Graduate Theses and Dissertations

Coastal and estuarine acidification impacts ecosystem health and economic resources and has both natural and anthropogenic components (Cai et al., 2021). Riverine input is one of several important factors that can influence acidification in coastal ecosystems. Rivers disgorging into coastal environments can create strong gradients, both spatial and temporal, that make accurate CO2-system characterization challenging. The work described in this thesis provides a baseline CO2-system study of four major rivers that flow into Tampa bay with an emphasis on seasonal change. As a second objective, this thesis examines the effects of HgII additions on CO2-system measurements in organic-rich estuarine waters. …

Advice As Metadiscourse: On The Gendering Of Women's Leadership In Advice-Giving Practices, Amaly Santiago

USF Tampa Graduate Theses and Dissertations

This dissertation is about advice as social practice. Specifically, I examine leadership discourse as communicatively constituted and advice-giving as creating a metadiscourse of gendered abilities and leadership asymmetries. In the light of the growing number of initiatives created for women to improve their status as leaders, this project examines leadership, not as a quality, but as discourse: as a communicative dynamic. This is in line with how organizations see leadership when they create leadership programs, for these programs are designed to advise or teach women to be different and better leaders. My purpose is to encourage inclusiveness and contribute to …

Machine Learning For Species Habitat Analysis, Abigail Lavallin

USF Tampa Graduate Theses and Dissertations

Management and conservation initiatives will always be controlled by finite resources, whether financialor temporal. Understanding a species’ spatial ecology, and how its requirements vary across habitats and locations is key to a successful species management plan. During recent decades, it has been noted how many species populations have declined, despite conservation practices working to increase their numbers. The most prevalent impacts affecting fauna populations have come from anthropogenic change in the form of habitat loss and destruction, along with fragmentation, and global climate change. There is a clear need for management practices to now operate on an entire landscape instead …

Evolutionary Mechanisms For Host Resistance To Tumor Growth And Subsequent Cancer Cell Counter-Adaptations, Arig Ibrahim Hashim

USF Tampa Graduate Theses and Dissertations

Cancer is well-recognized as an evolutionary system, as first proposed by Cairns and Nowell more than 60 years ago. In an evolutionary context, cancers growing in vivo typically consist of heterogeneous subpopulations of cells that interact with each other and with host cells through selection forces operating at many temporal and spatial scales. Moreover, the tumor environment comprises more than just cancer cells; it includes a rich cancer stroma and cancer-driving molecules such as cytokines and metabolites. The tumor’s environment comprises intratumoral heterogeneity that often leads to therapy resistance attributed to the essential roles of many genetic and nongenetic mechanisms. …

Investigation Of Immobilized Enzymes In Confined Environment Of Mesoporous Host Matrices, Xiaoliang Wang

USF Tampa Graduate Theses and Dissertations

Enzyme immobilization in metal-organic frameworks (MOFs) as a promising strategy, is attracting the interest of scientists from different disciplines with the expansion of MOF’s development. Different from other traditional host materials, their unique strengths of high surface areas, large yet adjustable pore sizes, functionalizable pore walls, and diverse architectures make MOFs an ideal platform to investigate hosted enzymes, which is critical to the industrial and commercial process. In addition to the protective function of MOFs, the extensive roles of MOFs in the enzyme immobilization are being well-explored by making full use of their remarkable properties like well-defined structure, high porosity, …

Microbial Dark Matter: Culturing The Uncultured In Search Of Novel Chemotaxonomy, Sarah J. Kennedy

USF Tampa Graduate Theses and Dissertations

Although <1% of environmental isolates can be cultured, insights into the culturable fraction refine future techniques to unlock the cryptic biodiversity. This cryptic biodiversity is omnipresent within culture-independent surveys of environmental bacterial populations. Subsequently, these elusive organisms are termed “microbial dark matter” due to the intrigue surrounding their potential taxonomic and biosynthetic impacts. To this end of investigating bacterial-specific dark matter, we employed high-throughput culturing techniques to examine Gulf of Mexico sediments and sponges for chemotaxonomically important bacteria. Through stepwise implementation of permissive and selective recovery techniques, we succeeded in recovering over 150 unique bacterial isolates. We observed several isolates that pose as chemotaxonomically interesting, including several strains that belong to critical bioremediation taxa. In addition to these biotechnological-amenable isolates, we have also succeeded in culturing taxa historically attributed with antibacterial discoveries. One such isolate was a previously sponge-associated organism belonging to the rarely cultured Verrucosispora genus. Through extensive comparative genomics, we identified it as a novel species and subsequently named it Verrucosispora sioxanthis sp. nov. with the published genome serving as a resource for continued microbial dark matter investigations. Following continued passaging of the organism, we observed improved growth, biomass, and liquid growth dispersal within each increasingly sub-passaged generation of the isolate. As such, the laboratory attenuation, or domestication, of the organism warranted in-depth whole genomic analyses to generate insight into the increased laboratory sustainability. Through phenotypically-guided bioinformatics, we determined that the domestication was mediated through genome-wide selective pseudo- or non-pseudogenization of genes. As the previously sponge-associated organism evolved with the selection pressures of the static laboratory, we demonstrate that isolate effectively underwent genomic atrophy to resolve into a largely stable, sustainable laboratory-domesticated strain. Collectively, our chemotaxonomic discovery pipeline expands on the culturable bacterial biodiversity and ultimately provides a previously uncultured model organism for initial forays into resolving the microbial dark matter knowledge gap.

An Ecology Of Learning: Secondary Mathematics Teacher Candidate Learning While Co-Teaching In Early Clinical Practice, Cynthia A. Castro-Minnehan

USF Tampa Graduate Theses and Dissertations

Researchers have called for more empirical research exploring better ways to organize clinical practice around teacher candidate (TC) learning and the coursework-fieldwork gap. This study responds to their call by exploring secondary mathematics TC learning in early clinical placements that use co-teaching. Further, this study views co-teaching in clinical practice through the lens of an activity system. An activity system conceptualizes co-teaching in clinical practice as a complex learning environment or a learning ecology. This study uses a convergent mixed methods design. Findings reveal evidence of TC learning of eight key practices associated with co-teaching in their early clinical placements. …

Use Of Biochar And Zeolite For Landfill Leachate Treatment: Experimental Studies And Reuse Potential Assessment, Thanh Thieu Lam

USF Tampa Graduate Theses and Dissertations

Leachate is a highly colored liquid waste product of landfills that contains high concentrations of ammonia nitrogen (NH4+-N), refractory organic matter, and heavy metals. It is commonly disposed to local publicly owned treatment works (POTWs). With these potent characteristics, it interferes with the physical, biological, and chemical treatment processes within POTWs. Sequencing batch biofilm reactors (SBBR) and hybrid subsurface flow constructed wetlands (CW) have been used in the past to treat landfill leachate, but their design and performance can still be optimized. Addition of low-cost adsorbent materials to SBBRs and CWs, such as biochar and zeolite, have the potential to …

Application Of Gold Nanoshells For Photothermal Therapy In Lung Cancer Cells, Yva K. Luc

USF Tampa Graduate Theses and Dissertations

Lung cancer is the leading cause of cancer deaths in the world. For the year 2020, it was estimated 1.8 million deaths were due to lung cancer alone, making it more lethal than breast cancer and prostate cancer combined. For the year 2021, it is estimated 235,760 new cases of lung cancer and 50% will lead to death. The primary cause of lung cancer is due to cigarette smoking, which accounts for 80% of all lung cancer deaths. Lung cancer screening relies on only different methods, biopsy, bronchoscopy, ultrasound, chest x-ray film, and sputum cytology. These techniques are used to …

Investigation Of An Alternative Protocol For The Production Of Sars-Cov-2 Antigenic Proteins, Nichole Ninaltowski

USF Tampa Graduate Theses and Dissertations

With the COVID-19 pandemic showing no signs of slowing down, large-scale antigenic protein production is still needed for surveillance using serologic assays. From screening to vaccines to biotherapeutics, being able to produce the proteins for these assays is essential; however, the current gold standard method for producing SARS-CoV-2 spike proteins is prohibitively expensive for most research groups.

Alternative methods of transfecting mammalian cells to produce recombinant proteins that are relatively inexpensive have been used for years. Unlike the expensive, commercially available lipid-based methods, other established methods such as polyethyleneimine (PEI), are considerably easier, and cheaper to meet the needs of …

A Functional Characterization Of The Omega (Ω) Subunit Of Rna Polymerase In Staphylococcus Aureus, Shrushti B. Patil

USF Tampa Graduate Theses and Dissertations

In bacteria, RNA polymerase (RNAP) is a well-characterized and highly conserved multi-subunit enzyme complex responsible for transcription of DNA into RNA. The ω subunit (rpoZ/RpoZ), one of the smaller accessory subunits of RNAP, is often overlooked and under-studied, however, particularly in Gram-positive species. We have previously shown that deleting ω impacts the integrity of RNA polymerase in S. aureus, especially the β' subunit, and alters preference of the core enzyme for sigma factors, skewing heavily towards σB instead of the housekeeping σ factor. Consequently, this causes deregulation of myriad transcriptional processes, strongly rewiring gene expression circuits, and ultimately impairing the …

Evaluating Daily Systemic Betaine Delivery In Alleviating Dry-Amd Pathophysiology, Dawin Khiev

USF Tampa Graduate Theses and Dissertations

MnSod (Sod2) deletion in the retinal pigment epithelium (RPE) of Sod2flox/floxVMD2-cre mice leads to oxidative stress-induced apoptosis of the RPE and photoreceptor cells that show salient features of dry-AMD. The purpose of this study was to investigate the potential antioxidant effect of betaine in protecting retinal health in Sod2flox/floxVMD2-cre mice. Betaine low dose (50mg/Kg Body Weight) and high dose (500mg/kg Body Weight, n=9) were administered intraperitoneally to 8-weeks old male and female Sod2flox/floxVMD2-cre mice daily for four months, while the control group (Sod2flox/floxVMD2-cre mice; n=9) received saline. We used spectral-domain optical coherence tomography (SD-OCT), retinal outer nuclear layer (ONL) thickness …

Seasonality In Competence To Transmit West Nile Virus For A Widespread Reservoir, Kyle L. Koller

USF Tampa Graduate Theses and Dissertations

All organisms face a central conflict; a limited supply of resources must beoptimally allocated to competing biological functions. Utilizing robust immune defenses can be energetically costly;, thus, immune function is often diminished when other processes, such as reproduction, molt, or migration demand energy. As wild animals residing in temporally dynamic environments face seasonal patterns in resource availability, infectious disease risk, and environmental suitability, many species have evolved endogenous biological rhythms so that the performance of reproduction, molt, or migration and the associated trade-off with immune function be completed when doing so best promotes fitness. In turn, this demand to optimize …