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Functional Morphology And Feeding Mechanics Of Billfishes, María Laura Habegger

USF Tampa Graduate Theses and Dissertations

Billfishes (marlins, spearfishes, sailfishes and swordfish) are one of the fastest and largest marine apex predators, and perhaps their most recognizable attribute is their bill or rostrum. The proposed function for this novel structure has ranged from hydrodynamic enhancement to defensive weaponry. However, the most supported hypothesis for its function has been linked to feeding. Billfishes have been observed to subdue their prey with their rostrum, either stunning or cutting them into pieces before ingestion. Due to their large body sizes and pelagic lifestyles a thorough investigation of the function of this structure has been logistically challenging. The goal of …

Influences Of Yard Management Intensity On Urban Soil Biogeochemistry, Viviana Penuela Useche

USF Tampa Graduate Theses and Dissertations

Soils are critical to ecosystem function as they provide essential nutrients for primary producers, habitat and organic energy for decomposers, and storage of organic matter. Irrigation with reclaimed water is an increasingly popular water conservation strategy; yet its high salinity and nutrient content potentially affect soil properties. In this study, set in a residential neighborhood of Tampa (U.S.). I tested whether there are distinct lawn system management strategies characterized by systematic differences in reclaimed water usage and irrigation and fertilization practices. I then investigated whether soil biogeochemistry responds to lawn system management strategy.

My results indicated that amendment strategy, which …

Development Of An Efficient Human Hepatocyte Culture Platform For Assessing Novel Therapeutic Efficacy Against Plasmodium Liver Parasites, Steven Patrick Maher

USF Tampa Graduate Theses and Dissertations

Malaria is a critical and global public health problem, affecting over 200 million people every year, resulting in over 500,000 deaths. A vaccine is not currently available and only one drug, primaquine, is effective against the dormant stages of Plasmodium vivax. Preclinical assessment of novel therapeutic drugs and vaccines is hampered by the lack of an in vitro liver model for P. falciparum and P. vivax. To provide a stable human hepatocyte-based culture platform for parasite development, we engineered a microfluidic bilayer device capable of both simple and complex culture methods, including perfusion and co-culture, to better understand the requirements …

A Multi-Scale Approach To Study Predator-Prey Interactions And Habitat Use Of Pinfish, Lagodon Rhomboids, Dinorah Helena Chacin

USF Tampa Graduate Theses and Dissertations

Biological processes like species interactions and patterns such as abundance and distribution observed in nature can vary depending on the scale at which the subject of interest is evaluated. Knowing that there is no single natural scale at which systems should be studied, in this thesis, I conducted a series of basic and applied ecological approaches in order to examine the phenomena that can occur at different scales of space, time, and ecological organization.

Species abundances can vary over large spatial and temporal scales. By studying the habitat use of an abundant species, which uses a wide range of habitats, …

Feeding Performance Of King Mackerel, Scomberomorus Cavalla, Amber Rose Ferguson

USF Tampa Graduate Theses and Dissertations

Although bite force is a commonly used metric of feeding performance, other factors such as bite pressure and strike speed are also likely to affect prey capture. Therefore, this study investigated static bite force, dynamic speeds, and predator and prey forces resulting from ram strikes, as well as bite pressure of the king mackerel, Scomberomorus cavalla, in order to examine their relative contributions to overall feeding performance. Theoretical posterior bite force ranged from 14.0-318.7 N. Ram speed, recorded with a rod and reel incorporated with a line counter and video camera, ranged from 3.3-15.8 BL/s. Impact forces on the …

Manipulating The Tumor Microenvironment For Therapeutic Benefit, Kate M. Bailey

USF Tampa Graduate Theses and Dissertations

The physical tumor microenvironment contributes significantly to carcinogenesis, cancer progression and metastatic dissemination. Two main components of the tumor microenvironment, hypoxia and acidosis, are present in nearly every solid tumor and act as powerful selection forces against the tumor. Hypoxia and acidosis promote tumor heterogeneity and contribute to chemotherapy and radiotherapy resistance. This dissertation interrogates methods to target the tumor microenvironment including two novel studies describing mechanisms of buffer therapy resistance and targeting tumor hypoxia with vasodilators to enhance the efficacy of a hypoxia activated prodrug, TH-302.

In the first study, mechanisms of buffer therapy resistance were identified and detailed. …

Rna Detection Technology For Applications In Marine Science: Microbes To Fish, Robert Michael Ulrich

USF Tampa Graduate Theses and Dissertations

The accurate identification of taxa from mixed assemblages using genetic analysis remains an important field of molecular biology research. The common principle behind the development of numerous documented genetic detection technologies is to exploit specific nucleotide sequences inherent to each taxon. This body of work focuses on practical applications of real-time nucleic acid sequence-based amplification (RT-NASBA) in marine science, and is presented in four case studies. Each study represents novel work in the genetic identification of respective taxa of interest using RT-NASBA. Two case studies documented the development of an assay targeting mitochondrial 16S rRNA to discern legally salable grouper …

Early Developmental Impacts On Male Traits And Female Preference In Zebra Finches (Taeniopygia Guttata), Martyna Boruta

USF Tampa Graduate Theses and Dissertations

Some male sexually selected traits are sensitive to stressors early in life and provide females with information to discriminate among males with different developmental experiences. Moreover, female early life experiences could also impact which males they choose. Females might either choose honest traits indicative of male quality, no matter their own experiences, or they might choose mates to match or compensate for their own experiences. To determine how developmental stressors alter male sexually-selected traits and female preference thereof, I exposed zebra finches (Taeniopygia guttata, ZEFI) to i) lipopolysaccharide (LPS), an immunogenic, Gram-negative bacterial component, ii) corticosterone (CORT), an avian stress …

From Co2 To Cell: Energetic Expense Of Creating Biomass Using The Calvin-Benson-Bassham And Reductive Citric Acid Cycles Based On Genomic Data, Mary Ann Mangiapia

USF Tampa Graduate Theses and Dissertations

Abstract

The ubiquity of the Calvin-Benson-Bassham cycle (CBB) amongst autotrophic organisms suggests that it provides an advantage over a wide range of environmental conditions. However, in some habitats, such as hydrothermal vents, the reductive citric acid cycle (rCAC) is an equally predominant carbon fixation pathway. It has been suggested that the CBB cycle poses a disadvantage under certain circumstances due to being more energetically demanding compared to other carbon fixation pathways. The purpose of this study was to compare the relative metabolic cost of cell biosynthesis by an autotrophic cell using either the CBB cycle or the rCAC. For both …

Craniometric Ancestry Proportions Among Groups Considered Hispanic: Genetic Biological Variation, Sex-Biased Asymmetry, And Forensic Applications, Meredith L. Tise

USF Tampa Graduate Theses and Dissertations

Today, groups considered Hispanic in the United States consist of populations whose complex genetic structures reflect intermixed diverse groups of people who came in contact during Spanish colonization in Latin America. After coming in contact and wiping out most of the Native Americans who occupied North and Latin America, the Spanish also introduced West African individuals for labor to begin developing crops to be shipped back to Europe, resulting in the Trans-Atlantic African slave trade. These migration events and differential gene flow among males and females that occurred throughout Latin America have led to populations that have been genetically transformed …

Host-Parasite Interactions In An Invasive Songbird, Courtney A.C. Coon

USF Tampa Graduate Theses and Dissertations

Introduced species are the greatest threat to biodiversity after habitat loss. Understanding the processes that permit organisms to become successful invaders may provide opportunities to prevent or limit their dispersal and establishment and thereby alleviate some of their harmful effects. The goal of my dissertation research has been to investigate whether invasive species have distinctive interactions with parasites, and some of the mechanisms that may underlie that variation. I used one of the world's most successful vertebrate invaders as a case study: the house sparrow (Passer domesticus; Introduction).

Previous research in the house sparrow suggested that loss of …

An Investigation Into The Habitat, Behavior And Opportunistic Feeding Strategies Of The Protected Goliath Grouper (Epinephelus Itajara), Angela Collins

USF Tampa Graduate Theses and Dissertations

Groupers (Epinephelidae: Epinephelinae) are apex predators within many reef communities worldwide. Grouper landings contribute significantly to global fisheries, and many populations are suffering from unsustainable levels of exploitation. The large size, site specificity and catchability of most groupers increase susceptibility to fishing pressure, and a large number of grouper species throughout the world are currently overfished. Multiple species are listed as endangered or threatened, and many have suffered local extirpations across their range. Removal of these upper level predators can significantly alter community structure and result in second order effects that may have critical ecological implications. The economic and ecological …

Transcriptional Control Of Toxoplasma Development, Joshua Byran Radke

USF Tampa Graduate Theses and Dissertations

Toxoplasma gondii is an obligate intracellular protozoan parasite of animals and man. The asexual life cycle of Toxoplasma involves three very distinct, but tightly coordinated developmental stages. In nature, the sporozoite (contained within an oocyst) and bradyzoite (contained within a tissue cyst) initiate infection of the intermediate host, followed by rapid differentiation into the actively replicating tachyzoite. When countered by an effective host response, the tachyzoite differentiates back into the latent bradyzoite and this unique ability of Toxoplasma to interconvert between the replicating tachyzoite and the latent bradyzoite within a single host is the cause of life long infection. The …

Testing The Feasibility Of Bioacoustic Localization In Urban Environments, Blaire O'Neal

USF Tampa Graduate Theses and Dissertations

Bioacoustics is a relatively new field of research focused on studying the acoustic signals of vocal animal species. The field has been a topic of interest for many years due its passive approach and avoidance of species-level limitations, such as tracking rare or nocturnal species. It has been used to locate birds in terrestrial environments; however, localization in urban environments remains unstudied. This research aims to fill the gap by attempting to estimate the location of 30 discrete calls in eight unique, urban environments. Sites represented two distinct traffic scenarios: moderate traffic and high traffic. Three system arrays of three …

Student Identity Considerations And Implications Associated With Socioscientific Issues Instruction, Mitchel James Ruzek

USF Tampa Graduate Theses and Dissertations

The purpose of this investigation was to explore how aspects of identity, perceived levels of controversy, and the strength of a student's attachment to their controversial identity relate to conceptual understanding and knowledge acquisition during socioscientific issues (SSI) based instruction in a biology classroom. The knowledge gained from this study will have the capacity to enhance our understanding of the role that attachment to identity plays during SSI negotiation. Additionally, insight was gained into the role played by aspects of identity in conceptual understanding of scientifically controversial topics during SSI based instruction.

This study contributed to the existing knowledge base …