Biology Commons^™

Geographic Variation In Post-Mating Immune Gene Expression In Drosophila Melanogaster, Cheryl Ann Pinzone

Electronic Theses and Dissertations

An organism's immune response may vary due to pathogen pressure in its environment, as well as due to interactions with other organisms. These factors, along with geographic rules (i.e. Gloger's rule) may influence the geographic distribution of the immune response within populations of a species. Here we use real-time quantitative PCR to measure the immune gene expression in six populations collected along the eastern U.S. of Drosophila melanogaster after mating. Antimicrobial genes did not show significant differences in expression due to location, whereas we did observe differences in anti-fungal and pro-phenoloxidase (anti-macromolecule) related genes. These differences in anti-macromolecule resistance are …

Estimating Diet And Food Selectivity Of The Lower Keys Marsh Rabbit Using Stable Isotope Analysis, Matthew James Gordon

Electronic Theses and Dissertations

Understanding the effect of food abundance on feeding behavior can benefit conservation efforts in many ways, such as to determine whether impacted environments need food supplementation, whether different locations of threatened species contain different food abundances, or whether reintroduction sites are missing key components of a species’ diet. I studied the relationship between feeding behavior and food abundance in the Lower Keys marsh rabbit (Sylvilagus palustris hefneri), an endangered subspecies endemic to the lower Florida Keys. Specifically, my study set out to measure the relative abundance of the primary plants within the natural habitat of the Lower Keys marsh rabbit …

The Role Of The Feral Pig (Sus Scrofa) As A Disturbance Agent And Seed Disperser In Central Florida's Natural Lands, Camille Rose Brescacin

Electronic Theses and Dissertations

Feral pigs (Sus scrofa) are considered to be among the world’s worst invasive species due to their successful invasion and ecological and economic impact to native and agricultural plants and animals around the world. Feral pigs are significant disturbance agents that destroy plant communities, change soil characteristics, alter nutrient cycling, and create open sites for colonization of both native and non-native plant species through their foraging behavior called rooting. In contrast to native animal disturbances, rooting is a striking feature in the landscape that varies in space, seasonal timing, frequency (number of times rooted), and intensity (depth of rooting). During …

Effects Of Participation In Inquiry Science Workshops And Follow-Up Activities On Middle School Science Teachers' Content Knowledge, Teacher-Held Misconceptions, And Classroom Practices, Linda F. Cepeda

Electronic Theses and Dissertations

An important aspect of developing science literacy for all students is developing science-literate teachers. With the implementation of the No Child Left Behind Act, many middle school teachers found themselves in a position where they were no longer qualified to teach middle school science. This study was designed to help science teachers increase their science content knowledge, identify and resolve misconceptions/errors they may have, and assist them in their teaching by providing strategies for inquiry-based teaching, science laboratory exercises, and science equipment.

Teachers enrolled in biology courses offered by the Rocky Mountain Middle School Math and Science Partnership participated in …

Quantifying Soil And Groundwater Chemistry In Areas Invaded By Tamarix Spp. Along The Middle Rio Grande, New Mexico, Michelle Kelly Ohrtman

Electronic Theses and Dissertations

Tamarix spp. (a.k.a. saltcedar, tamarisk) invasion is considered a major ecological threat at both national and global levels, with supposed impacts on soil and water chemistry. One of the most often cited mechanisms of ecosystem change by Tamarix is through its ability to deposit salty exudates and salt-rich leaf litter. The degree to which Tamarix relates to elevated soil and groundwater salinity, however, has not been adequately quantified, especially in the context of environmental factors that may also influence salinity. If Tamarix does elevate localized salinity by means of uptake, concentration and exudation by plant tissues, then we might expect …

Structure-Function Analysis Of Endoproteolytic Cleavage: Site-Directed Mutagenesis Studies Of The Α-Msh Cleavage Site In Silurana Tropicalis Pomc, Quinn Kun Chen

Electronic Theses and Dissertations

The maturation process of many prohormone molecules typically requires endoproteolytic cleavage C-terminal of dibasic residues, such as the K¹⁴¹R¹⁴²↓ site N-terminal of the α-melanocyte stimulating hormone (α-MSH) sequence in Silurana tropicalis proopiomelanocortin (POMC). In order to determine the absolute requirement of basic amino acid residues in the cleavage process, site-directed mutagenesis was employed to substitute alanine for the wild-type residues in the frog POMC open reading frame. Specifically, the following underlined residues were individually targeted for alanine substitution: R ¹³⁷ Q ¹³⁸ E ¹³⁹ N ¹⁴⁰ K ¹⁴¹ R ¹⁴²↓. The mouse pancreatic αTC1.9 cell …

Role Of Pro-Apoptotic Bcl2-Homology-3 Domain (Bh3)-Only Proteins In The Mutant Sod1 Mouse Model Of Als, Anna George Andrianakos

Electronic Theses and Dissertations

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease involving rapid degeneration of motor neurons in the spinal cord and retraction of their axonal projections to the neuromuscular junctions. Several known mutations linked to some familial cases of ALS have been linked to mutations in Cu/Zn superoxide dismutase (SOD1), resulting in mitochondrial oxidative stress and intrinsic apoptosis. Transgenic mice expressing a G93A mutant of SOD1 provide an in vivo model to investigate motor neuron death during disease progression. The principal regulators of intrinsic apoptosis are the Bcl-2 family proteins. While some members of this family are pro-survival, the Bcl-2 homology-3 …

Assessing Crosstalk Between Calcium And Camp In Pancreatic Alpha Cells, Julianne Michelle Imseis

Electronic Theses and Dissertations

Blood glucose levels are regulated by the interactions between insulin and glucagon. Pancreatic alpha cells release glucagon in response to a drop in blood sugar. Pancreatic alpha cells appear to be regulated through multiple signaling pathways. One potential method of regulation occurs from α-MSH or epinephrine stimulated production of the intracellular messenger cyclic AMP. Exocytosis of dense core vesicles containing glucagon ultimately requires an increase in cytosolic calcium. This study focused on the link between cyclic AMP and calcium in pancreatic alpha cells which allows alpha cell regulation. Interactions between calcium and cyclic AMP in pancreatic alpha cells consists of …

Factors Affecting Predation Of Marine Turtle Eggs By Raccoons And Ghost Crabs On Canaveral National Seashore, Fl, Justin Brown

Electronic Theses and Dissertations

Changes in abundance of interactive species can have cascading, community-wide effects (Soule et al. 2003). Raccoons (Procyon lotor) prey on a competitor for marine turtle eggs, the Atlantic ghost crab (Ocypode quadrata). Conservation of marine turtles often includes managing raccoons-the most obvious egg predator-which may have broader ecological effects, and unknown effects on egg predation. Neither the relationship between raccoons and ghost crab density nor the effects of ghost crab density on egg predation are well understood. I studied raccoon-ghost crab interactions and the effects of environmental variation on their activity during the 2007 marine turtle nesting season on Canaveral …

Amino Acid Residues Implicated In The Interaction Of Melanocortin Ligands And Their Receptors: A Study Of Mc2r Selectivity, Kristopher D. Veo

Electronic Theses and Dissertations

Melanocortin receptor ligand selectivity has been a question not easily answered. The inability to functionally express melanocortin 2 receptor (MC2R) has inhibited the study of why MC2R is only stimulated by ACTH, a melanocortin hormone. With the recent discovery of the MC2R accessory protein (MRAP), creating a heterologous system is now feasible. Using a general cell line like CHO-K1 cells, which do not express endogenous MCRs, we were able to create a heterologous expression system and test the selectivity of MC2R using analog variants of ACTH(1-24). Our results indicate an amino acid requirement in the C-terminal portion of ACTH(1-24) for …

Factors Affecting Breeding Territory Size And Placement Of The Florida Grasshoper Sparrow (Ammodramus Savannarum Floridanus), Jill Aldredge

Electronic Theses and Dissertations

For most taxa, maximizing fitness depends on maintaining access to adequate resources. Territories provide exclusive use of resources for an individual or a family group, thus facilitating successful reproduction. The economic defensibility of a territory depends on the quality, abundance, and distribution of its resources as well as the amount of competition that an individual must endure to maintain exclusive access. The benefits of defense must outweigh the costs for territoriality to be profitable. Territory owners may benefit from territories with high quality resources, but they also may incur greater costs defending these resources from competitors. In contrast, territories with …

Habitat Use By The Southeastern Beach Mouse (Peromyscus Polionotus Niveiventris) At Cape Canaveral Air Force Station, Florida, Kathryn Simmons

Electronic Theses and Dissertations

Successful recovery of the federally threatened southeastern beach mouse (Peromyscus polionotus niveiventris) depends in part on an understanding of their habitat requirements. I studied habitat use by beach mice at Cape Canaveral Air Force Station, Florida from March 2005 until March 2006. I livetrapped six grids, three on coastal dunes and three within scrub located inland from the coast. On each grid and trap station, I quantified the extent of bare ground, woody vegetation, non-woody vegetation, height of vegetation, and percentage of coarse sand in the surface soil. I assessed trap success relative to these habitat variables using linear and …

Reintroduction Of Bison (Bison Bison) On Reservations In South Dakota: Four Case Studies, Trudy M. Ecoffey

Electronic Theses and Dissertations

This research explored and documented issues of sustainability associated with the reintroduction of bison in four different bison herds on Reservations in South Dakota. The four herds were managed by: a tribal family cooperative, an individual tribal member, a tribal university and a tribal fish and wildlife agency. The objectives were to identify management practices associated with the sustainability of bison introduction by American Indians; to explore the role of American Indian culture in the management of bison for sustainability; and to investigate rangeland criteria that could be used to measure sustainability of bison reintroduced by American Indians. This project …

The Effects Of Urbanization On The Structure, Quality, And Diversity Of Cypress Plant Communities In Central Florida, Courtney Knickerbocker

Electronic Theses and Dissertations

The integrity of wetland ecosystems is largely determined by hydrological functionality, degree of connectivity to like ecosystems, and permeability to external influence. Land use changes in upland areas adjacent to wetland ecosystems may influence hydrology and connectivity while introducing novel biotic and abiotic materials. There is an increasing trend toward the use of remote assessment techniques to determine the degree of impact of external influences on adjacent wetlands. Remote assessment and predictive capabilities are provided by indices such as the Landscape Development Intensity Index (LDI) (Brown and Vivas 2005) which may be beneficial in determining site condition, and which have …

Native Fire Regime As A Reference For Establishing Management Practices, Brean Duncan

Electronic Theses and Dissertations

Our understanding of natural fire regimes in human-dominated landscapes is limited. Fire regimes operating in the pyrogenic ecosystems of Florida have been altered by fire suppression and fuel fragmentation. This is especially true of North Merritt Island, Florida, where human impacts have led to an incomplete knowledge of current fire regimes. We know that growing season fires frequently occurred within general return intervals and that many native terrestrial species require fire to remain viable. A 20-year plus period of fire suppression caused structural and compositional changes to vegetation/fuels that led to catastrophic fires and the decline of native species populations …

Understanding Plant Community Composition In Agricultural Welands: Context Dependent Effects And Plant Interactions, Elizabeth Boughton

Electronic Theses and Dissertations

Community composition results from an integrated combination of random processes, regional habitat spatial structure, local environmental conditions, and species interactions. For example, the outcome of plant interactions can change depending on local environmental conditions such as nutrient availability, land management, or herbivory intensity. In particular, plant interactions may vary between facilitation and competition depending on ecological context, with facilitation expected to be prevalent under stressful conditions. I present the results of four studies that address different aspects of the community assemblage and dynamics emphasizing the synergistic effect of different processes. In the first, I investigated the importance of habitat isolation …

Landcover Change And Population Dynamics Of Florida Scrub-Jays And Florida Grasshopper Sparrows, David Breininger

Electronic Theses and Dissertations

I confronted empirical habitat data (1994-2004) and population data (1988-2005) with ecological theory on habitat dynamics, recruitment, survival, and dispersal to develop predictive relationships between landcover variation and population dynamics. I focus on Florida Scrub-Jays, although one chapter presents a model for the potential influence of habitat restoration on viability of the Florida Grasshopper Sparrow. Both species are unique to Florida landscapes that are dominated by shrubs and grasses and maintained by frequent fires. Both species are declining, even in protected areas, despite their protected status. I mapped habitat for both species using grid polygon cells to quantify population potential …

Tissue Engineered Myelination And The Stretch Reflex Arc Sensory Circuit: Defined Medium Formulation, Interface Design And Microfabrication, John Rumsey

Electronic Theses and Dissertations

The overall focus of this research project was to develop an in vitro tissue-engineered system that accurately reproduced the physiology of the sensory elements of the stretch reflex arc as well as engineer the myelination of neurons in the systems. In order to achieve this goal we hypothesized that myelinating culture systems, intrafusal muscle fibers and the sensory circuit of the stretch reflex arc could be bioengineered using serum-free medium formulations, growth substrate interface design and microfabrication technology. The monosynaptic stretch reflex arc is formed by a direct synapse between motoneurons and sensory neurons and is one of the fundamental …

Purinergic Receptors In The Circumvallate Papillae Of Rats, Alana Marselle Montoya

Electronic Theses and Dissertations

P2X2 receptors and P2Y4 receptors are ATP-activated cell surface receptors that gate movement of K+, Na+, and Ca2+. We used immunocytochemistry for P2X2 and P2Y4 receptors as well as taste cell type markers to learn if P2X2 immunoreactivity (IR) is present in nerve processes in close apposition to Type II and/or Type III taste cells. We also tested to see if P2Y4 IR is present in Type II and/or Type III taste cells. Our results indicate that P2X2 is present only in intragemmal nerve processes. P2X2-LIR nerve processes form close contacts with Type II and Type III taste cells. P2Y4 …

Structure-Function Analysis Of The Drosophila Stubble Type Ii Transmembrane Serine Protease, Rachel Morgan

Electronic Theses and Dissertations

Hormonally-triggered regulatory hierarchies play a major role in organismal development. Disruption of a single member of such a hierarchy can lead to irregular development and disease. Therefore, knowledge of the members involved and the mechanisms controlling signaling through such pathways is of great importance in understanding how resulting developmental defects occur. Type II transmembrane serine proteases (TTSPs) make up a family of cell surface-associated proteases that play important roles in the development and homeostasis of a number of mammalian tissues. Aberrant expression of TTSPs is linked to several human disorders, including deafness, heart and respiratory disease and cancer. However, the …

Tmdl Bioassessment Sampling Of Benthic Macroinvertebrates For Lake Jesup And Lake Seminary, Gloria Eby

Electronic Theses and Dissertations

The objective of this study was to obtain a bioassessment using benthic macroinvertebrates to meet TMDL (Total Maximum Daily Load) criteria for an oligotrophic (Lake Seminary) and an eutrophic (Lake Jesup) freshwater system in Seminole County, Florida. Monthly sampling of the benthic macroinverterbrate communities provided important biological data necessary to construct TMDL protocol and trophic state. Since macroinvertebrates are near the base of the food chain, they not only provide a critical role in the natural flow of energy and cycling of nutrients through the food web, but also provide a good indication of water quality by their presence and …

Growth And Survival Of Bacteria In Simulated Martian Conditions, Bonnie Berry

Electronic Theses and Dissertations

Escherichia coli and Serratia liquefaciens, two common microbial spacecraft contaminants known to replicate under low atmospheric pressures of 25 mb, were tested for growth and survival in simulated martian conditions. Stressors of high salinity, low temperature, and low pressure were screened alone and in combination to determine how they might affect microbial activity. Growth and survival of E. coli and S. liquefaciens under low temperatures (30, 20, 10, or 5 °C) with increasing concentrations (0, 5, 10, or 20 %) of three salts believed to be present on the surface of Mars (MgCl2, MgSO4, NaCl) were monitored over 7 d. …

Cis-Regulatory Analysis Of The Pigment Cell Differentiation Gene Polyketide Synthase, David Rogers

Electronic Theses and Dissertations

The analysis of Gene Regulatory Networks (GRNs) is essential to understanding the complete process of embryo development. Elucidating every gene regulatory circuit from maternal regulatory inputs all the way to the activation of differentiation gene batteries is an important step in increasing our understanding of developmental biology. In this work I study the cis-regulatory architecture of a pigment cell differentiation gene, polyketide synthase (SpPks) in the sea urchin Strongylocentrotus purpuratus. SpPks encodes an enzyme that is responsible for the biosynthesis of the sea urchin pigment echinochrome in larval pigment cells. The analysis of the promoter of a differentiation gene will …

Hatching Asynchrony Occurs As A Byproduct Of Maintaining Egg Viability, Robert Aldredge

Electronic Theses and Dissertations

For many organisms, embryonic development begins directly after an egg (ovum) has been fertilized by sperm; however, some organisms delay the onset of embryonic development until conditions are favorable for raising young. This delayed onset of development could occur by delaying implantation of fertilized ovum on the uterine wall, as seen in many mammals. Birds delay embryonic development by laying a set of fertilized ova over a period of consecutive days. These fertilized ova are protected from the ambient environment by an exterior shell, and it is in this shell outside of the female s body that embryonic development occurs, …

The Distribution, Abundance, And Habitat Use Of The Big Cypress Fox Squirrel, (Sciurus Niger Avicennia)., Danielle Munim

Electronic Theses and Dissertations

Human population growth and development reduce the area and quality of natural communities and lead to a reduction of populations of the species associated with them. Certain species can be useful indicators or "focal species" for determining the quality of ecosystem remnants and the required management practices. Tree squirrels are good models for studies on the effects of fragmentation because they depend on mature forests. The Big Cypress fox squirrel, (Sciurus niger avicennia), a state-listed Threatened subspecies endemic to south Florida, appears sensitive to habitat fragmentation and fire regime. This research aims to assess the conservation status of the Big …

Using Stable Isotopes To Assess Population Structure And Feeding Ecology Of North Pacific Humpback Whales (Megaptera Novaeangliae), Briana Witteveen

Electronic Theses and Dissertations

The North Pacific humpback whale (Megaptera novaeangliae) is a wide-ranging baleen whale species with a complex life history and population structure. As seasonal migrants, humpback whales are known to inhabit cooler, high-latitude waters when foraging and low-latitudes for mating and calving. Beyond this general migratory pattern, a number of demographic characteristics including, abundance, distribution, seasonal occurrence, and prey preferences remain unknown or poorly described. A complete understanding of humpback whale ecology is therefore lacking. Many methods used to explore these aspects of cetacean ecology are either prohibitively expensive or limited in the scope of what can be learned from their …

Modeling Canopy Photosynthesis Of A Scrub-Oak Ecosystem Under Elevated Co2, Lori Jones

Electronic Theses and Dissertations

Rising atmospheric CO2 and the need to understand potential impacts on terrestrial ecosystems has become increasingly recognized. Models can play a beneficial part in this research to enhance understanding of ecosystem responses to changing conditions like elevated CO2. In this study, data from a long term elevated CO2 experiment in a native forested ecosystem in east central Florida were employed to assess the utility of a multi-layer canopy photosynthesis model as a tool to better understand the responses to elevated CO2 in this ecosystem. Model results compared satisfactorily with the canopy gas exchange measurements in this ecosystem for the period …

Recovery And Restoration Of The Seagrass Halodule Wrightii After Boat Propeller Scar Damage In A Pole-Troll Zone In Mosquito Lag, Katherine Grablow

Electronic Theses and Dissertations

This study combined documentation of four boat propeller scar types in Halodule wrightii seagrass beds in Mosquito Lagoon, Florida with manipulative field experiments to document scar recovery times with and without restoration. Scar types ranged from the most severe scar type (Type 1) with trench formation which had no roots or shoots in the trench, to the least severe (Type 4) scars that had no depth, intact roots and shoots shorter than the surrounding canopy. For 110 measured existing scars, the frequency of each scar type was 56% for Type 1, 10% for Type 2, 7% for Type 3, and …

Prevalence And Severity Of Fibropapillomatosis In Juvenile Green Turtles (Chelonia Mydas) In Three Habitats On Florida's Eas, Kelly Borrowman

Electronic Theses and Dissertations

Fibropapillomatosis (FP) is a tumor-forming disease mainly found in juvenile green turtles (Chelonia mydas) inhabiting Florida's east coast. Despite increased research on the herpes virus that putatively causes it, long-term assessment is still needed of the distribution and severity of FP. Using the decades-long database compiled by the University of Central Florida Marine Turtle Research Group, I determined FP severity and distribution at three different sites: Indian River Lagoon (IRL), Sabellariid Worm Reef (SWR) and Trident Submarine Basin (TSB). Fibropapillomatosis occurred in > 50% of IRL turtles, 18% of SWR turtles and <1% of TSB turtles. Regression of FP tumors was correlated with its prevalence, i.e. when and where FP was common, tumor regression was common. The probability of a turtle being non-afflicted or mildly afflicted increased with both increasing straight-line carapace length (SCL) and increasing relative body condition (residuals of log body mass versus log SCL). Mean annual growth rates of IRL and SWR turtles did not vary with FP severity; however, mean annual growth rates in IRL (1.10 cm/y) were significantly higher than in SWR (1.05 cm/y) and TSB (1.04 cm/y). Annual apparent survival estimates for IRL and TSB turtles were 0.72 and 0.73, respectively, and were constant over time. Even with increased prevalence of FP, annual apparent survival estimates were constant and similar to survival estimates of juvenile green turtles in areas without FP. In IRL, survival rates among FP Categories 0, 1 and 2 were similar (0.74, 0.74 and 0.81 respectively) and lower only for FP Category 3 (0.63). Thus, while FP occurred in > 50% of turtles in some Florida east coast populations, …

Control Of Stomatal Formation In Arabidopsis Thaliana Inflorescence Stem, Nalini Odapalli

Electronic Theses and Dissertations

Stomata are cellular structures that control water loss and gas exchange through the plant epidermis. Stomata arise from special stem cells called meristemoids through a series of programmed asymmetric divisions that are controlled by cell signaling, or via multitude of regulatory pathways and intercellular communication between epidermal cells. In Arabidopsis thaliana, stomata are spaced non-randomly in the epidermis by cell-cell signaling of the receptor-like protein TOO MANY MOUTHS (TMM) as well as other proteins. Point mutation of the TMM gene prevents the development of stomata in some tissues like inflorescence stems. Investigation of tmm mutant stems showed that self-renewing stem …