Biology Commons^™

Characterization Of A Putative Phospholipase D ´ Like Gene As A Lipid Signaling Modulator And Its Role In Salicylic Acid Mediated Defense Pathway In Nicotiana Tabacum, Phillip T. Dean

Electronic Theses and Dissertations

Plants are in a perpetual evolutionary arms race with a wide range of pathogens. Their sessile nature has led plants to evolve defense mechanisms that can quickly recognize a unique stressor and deploy a resistance tailored for a specific attack. The salicylic acid (SA) mediated defense pathway has been shown to be one of the major defense tactics plants can initiate to defend themselves against microbial pathogens. Following a pathogen attack high levels of methyl salicylate (MeSA) are produced that can be converted to SA by the enzyme salicylic acid binding protein 2 (SABP2). A yeast two-hybrid screening was performed …

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 …

Induced Phytoextraction Of Lead From Contaminated Urban Soil Through Manipulation Of Rhizosphere And Plant Biogeochemical Functions In Switchgrass (Panicum Virgatum), Deayne M. Johnson

Master of Science in Integrative Biology Theses

Contamination of soils with lead (Pb) continues to pose a risk to the health of humans especially in residential urban areas. Remediation of these soils is necessary to reduce the amount of Pb and alleviate risk to human health. Phytoextraction of Pb through chemically induced accumulation of Pb in the harvestable foliage and removal of contaminated plant material has great potential in offering a solution to this environmental problem. The effects of the combined application of a soil fungicide (benomyl), synthetic chelates (ethylenediamineteteraacetic acid, EDTA), and foliar-Fe supplement on lead (Pb) phytoextraction from contaminated soil by switchgrass (Panicum virgatum) was …

Genomic Characterization Of Polyps In Familial Adenomatous Polyposis Patients And Identification Of Candidate Chemopreventive Drugs, Francis A. San Lucas

Dissertations & Theses (Open Access)

Familial adenomatous polyposis (FAP) is an autosomal dominant disease characterized by APC germline mutations and the development of hundreds to thousands of premalignant adenomas in the gastrointestinal tract at a young age. If left untreated, these patients inevitably develop colon cancer (CRC) and small bowel tumors. We performed exome sequencing of samples from 12 FAP patients to characterize adenomas and to identify candidate genes of adenoma development that may serve as potential targets for chemoprevention drug development. From each patient, a blood and at least one polyp were sequenced with a total of 25 polyps analyzed. In some cases, normal …

Phenotypic Analysis Of The Regulatory Role Of The Leucine-Responsive Regulatory Protein (Lrppa) In Pseudomonas Aeruginosa, Stephanie D. Larson

Master of Science in Integrative Biology Theses

Nutrient acquisition is critical to survival and infection by the opportunistic bacterium Pseudomonas aeruginosa. This pathogen expresses a number of virulence factors that are a part of the starvation response and are important in host-pathogen interactions. Additionally, P. aeruginosa is resistant to a large number of antibiotics and has become difficult to treat once it has colonized a tissue. New pharmaceutical treatments are sought while the metabolism of this organism must be fully understood to select new targets for therapy. The leucine- responsive regulatory protein (Lrp) could be a promising target for treatment. The ortholog in Escherichia coli is …

The Role Of Sirtuin Inhibitors On The Proteomic Responses Of The Mussels Mytilus Galloprovincialis And Mytilus Trossulus To Menadione Induced Oxidative Stress, Hayley C. Chilton

Master's Theses

Global climate change imposes physiological constraints on marine ecosystems that can alter the distribution of intertidal organisms. In one such instance, the native cold-adapted mussel Mytilus trossulus is being replaced along its southern range by the invasive warm-adapted Mytilus galloprovincialis. These blue mussels occur throughout rocky intertidal zones where they are subjected to greatly varying environmental conditions known to induce oxidative stress. We hypothesize that while under acute stress, related Mytilus congeners undergo a shift in redox potential from NADH-fueled respiratory pathways to pathways producing NADPH as a way to decrease the production of reactive oxygen species (ROS) and …

Differences In The Communicative Behavior And Neurobiology Of Chimpanzees (Pan Troglodytes) And Bonobos (Pan Paniscus), Brittany Moore

Master of Science in Integrative Biology Theses

Chimpanzees and bonobos have distinctly different vocalizations, but it is unclear why these differences have evolved. We hypothesized that differences in habitat and feeding ecology have selected for bonobos to have an increased reliance on vocal communication compared to chimpanzees. To evaluate this hypothesis 1571 chimpanzee vocal events and 612 bonobo vocal events were analyzed. After analyzing and coding video of communicative interactions it was determined that chimpanzees are more likely than bonobos to utilize multimodal communication and to direct vocalizations to an individual conspecific. Bonobos were more likely than chimpanzees to produce a vocalization that was not bound to …

Structure-Function Analysis Of Zapc, An Ftsz-Ring Stabilizer, In Escherichia Coli Cytokinesis, Lukasz Tchorzewski

Dissertations and Theses

In Escherichia coli, cell division is defined by the polymerization and constriction of a cytokinetic ring (Z ring) formed by FtsZ, a tubulin-like GTPase, at midcell. Division also involves the formation of a multi-protein complex at midcell known as the divisome. Several divisome proteins promote the assembly/disassembly processes of FtsZ, thereby exercising spatiotemporal control over division. Among FtsZ regulatory proteins are the FtsZ ringassociated proteins (Zap), which either directly or indirectly stabilize the Z-ring by increasing lateral interactions amongst FtsZ protofilaments in the Z-ring. ZapA-D are recruited during early cytokinesis and have overlapping functions in stabilizing FtsZ at midcell, but …

Tactical Escape Behavior And Performance Of A Small Sceloporine Lizard In Two High Risk Habitats, Seth Parker

Electronic Theses and Dissertations

The negotiation of uneven and complex terrain has implications for many small terrestrial vertebrates. Variation in the running surface due to obstacles like woody debris or vegetation can alter escape paths and running performance. Additionally, these microhabitat features can influence behavioral tactics in complex environments. The ability to negotiate physical barriers in dense environments likely influences survivorship through important ecological tasks, such as finding mates, foraging, and evading predators. The Florida scrub lizard (Sceloporus woodi) is a small, rare species endemic to two distinct and structurally complex environments in Florida, i.e. sand-pine scrub and longleaf pine-wiregrass sand-hills. The …

The Effect Of Fluvastatin On Mast Cell Function: Genotype Dependence, Elizabeth M. Kolawole

Theses and Dissertations

Fluvastatin, the HMG-CoA reductase inhibitor known for its role in the treatment of hypercholesterolemia and cardiovascular disease, has more recently been shown to play a role in the immune response. Given the critical role that mast cells play in allergy and inflammatory diseases such as asthma, which effects one third of America’s population, we assessed the effect of fluvastatin on mast cell and basophils function. We demonstrate that fluvastatin downregulated IgE-mediated cytokine production. Additionally, in vivo studies showed that fluvastatin suppressed IgE-mediated anaphylaxis. Interestingly, the effects of fluvastatin showed dependence on genetic background, as C57BL/6 mast cells were sensitive, while …

"Mining" For A Reference Condition In Southern West Virginia Streams, Matthew Rouch

Theses and Dissertations

Quarterly samples were used to estimate assemblage-level (all species combined) fish production within three minimally-impacted, southern West Virginia streams. The total annual fish production estimate was highest in Slaunch Fork (37.52 kg∙ha^-1∙y^-1), a tributary of the Tug Fork River, and lowest in Cabin Creek (10.59 kg∙ha^-1∙y^-1), a Guyandotte River tributary. Creek Chub Semotilus atromaculatus, Mottled Sculpin Cottus bairdii and Blacknose Dace Rhinicthys atratulus were the most abundant species among sites, accounting for >90% of all sampled individuals. Reference condition criteria were also selected and metrics calculated for each of the three …

Genome Jigsaw: Implications Of 16s Ribosomal Rna Gene Fragment Position For Bacterial Species Identification, Jennifer Mitchell

Theses and Dissertations (Comprehensive)

The 16S rRNA gene is present within all bacteria, and contains nine variable regions interspersed within conserved regions of the gene. While conserved regions remain mostly constant over time, variable regions can be used for taxonomic identification purposes. Current methodologies for characterizing microbial communities, such as those used to study the human microbiome, involve sequencing short fragments of this ubiquitous gene, and comparing these fragments to reference sequences in databases to identify the microbes present. Traditionally, whole 16S rRNA sequences with more than 97% sequence identity (id) are assigned to a single operational taxonomic unit (OTUs); each OTU being a …

Comparative Analysis Of Selected Model Species Used In Intervertebral Disc Research, Lauren A. Monaco

Theses and Dissertations (Comprehensive)

Animal models are frequently used in place of human specimens to study the progression of injury and/or disease of the intervertebral disc (IVD). This project aimed to compare the geometry, hydration, histology, and mechanical properties of selected animal models: bovine (cow) tail, porcine (pig) lumbar, and ovine (sheep) lumbar IVDs. X-ray images were taken and used to determine the anterior, posterior, and lateral IVD and vertebral heights in order to calculate IVD: vertebral height ratios. Water content was determined by comparing IVD weight before (wet weight) and after (dry weight) 24 hours of incubation at 65°C. Mechanical properties …

Comparative Study Of Factors Influencing Seed Germination And Seedling Longevity In Cuscuta (Dodder, Convolvulaceae), Behrang Behdarvandi

Theses and Dissertations (Comprehensive)

Cuscuta (dodder), the only parasitic genus of Convolvulaceae family, is a significant plant from ecological, economical, and conservational point of views. The genus consists of c. 200 described species with wide ranges of ecological distributions. Cuscuta spp. are categorized as stem parasitic plants with reduced (or lost) photosynthesis-related genes. The filamentous coiled embryo, embedded in the endosperm, lacks cotyledons and is covered with a multiple-layered seed coat. The seedlings carry a vestigial root-like organ which is not considered a ‘true’ functional root. Members of the genus differ in their germination rate and seedling survival. It is known that seed …

Microbial Community Characterization And Pathogen Profiling Of Land-Based Aquaculture Systems Using Culture-Based And Molecular-Based Fingerprinting Techniques, Nicole S. Kteily

Theses and Dissertations (Comprehensive)

The growing worldwide demand for fish production has prompted research towards intensive aquaculture. Innovative system designs, such as recirculating and flow-through aquaculture systems, have been developed to improve the efficiency and sustainability of intensive aquaculture practices. These LBAS systems exhibit a wide range of spatial and temporal heterogeneity. Although such heterogeneity suggests the potential for culture water to support a diverse and spatially complex assortment of microorganisms, there is a lack of information regarding the overall diversity and composition of microbial communities (including pathogens) in the different compartments of these systems. To better understand the diversity and functionality of microbial …

Diversity And Evolution Of The Multicellular Protuberances In Cuscuta (Convolvulaceae) And The Function Of The Stomatiferous Protuberances In Cuscuta Subgenus Grammica, Courtney J. Clayson

Theses and Dissertations (Comprehensive)

Cuscuta (Convolvulaceae), also known as the dodders, is a holoparasitic genus comprised of ca. 200 species grouped into four subgenera: Monogynella, Cuscuta, Pachystigma, and Grammica. The presence of unique multicellular structures, referred to as stomatiferous protuberances (SPs), was reported on the stems of subgenus Grammica over a century ago and was forgotten until similar SPs were observed on the flowers of several new Grammica species. The stems and flowers were examined in 136 Cuscuta taxa, and SPs were discovered on all of the haustorial stems of the species in the subgenus Grammica, as well as …