Biology Commons^™

Quantifying The Effects Of Boat Wakes On Intertidal Oyster Reefs In A Shallow Estuary, Donna Campbell

Electronic Theses and Dissertations

There have long been concerns about the negative impacts of recreational boating activity in the Indian River Lagoon system (IRL), especially in Mosquito Lagoon (ML), the northernmost part of the IRL. My research is focused on the impacts of boat wakes on intertidal reefs formed by the eastern oyster, Crassostrea virginica. There has been a 24% loss of oyster habitat in ML since 1943, where natural oyster reefs have been replaced by dead oyster reefs which do not serve the same ecological function. While there is anecdotal and correlative evidence that this loss is a result of boat wakes, no …

Adaptive Movements And Thermoregulation In Big-Eared Bats, Cody Jordan

Electronic Theses and Dissertations

There are a variety of (non-exclusive) reasons to explain the presence of group-living, but clustering or huddling is especially important for small endotherms with high surface-area-to-volume ratios. Clustering is interesting because variations within clustering are seldom investigated despite anecdotal evidence that bat clustering varies widely. I studied a colony of Rafinesque's big-eared bats (Corynorhinus rafinesquii) to learn more about clustering behavior using infrared video. I predicted that temperature would be the primary driver of how and when bats cluster while roosting. The actual relationship was not as predicted by an energetic model. High density clusters of bats were comacross a …

Effects Of Benzo[A]Pyrene And Cyp19a1b Knockdown On Zebrafish Development, Khalid M. Alharthy

Electronic Theses and Dissertations

Benzo[a]pyrene (BaP) is a ubiquitous environmental contaminant that is both an endocrine disruptor and a carcinogen. Aromatase (CYP19) is a key enzyme in steroidogenesis playing a key role in the hypothalamus-pituitary-gonad feedback loop. We hypothesized that BaP would negatively impact cyp19a1b expression in zebrafish, in turn, adversely affecting development and physiology. Here, we consider whether the toxicities observed following BaP exposure are comparable to those following a transient morpholino (MO)-mediated CYP19a1b knockdown or exposure to an aromatase inhibitor (fadrozole) during early development. One-cell zebrafish embryos were injected with a CYP19a1b-MO or control-MO. Other non-injected embryos were exposed to nominal waterborne …

Autoregulation Of The Glial Gene Reversed Polarity In Drosophila Melanogaster, Jamie L. Wood

Electronic Theses and Dissertations

During development, cells of the nervous system begin as unspecified precursors and proceed along one of two developmental paths to become either neurons or glia. I seek to understand more about the genes that control this process, focusing on the lesser understood of the cell types, glial cells. Using Drosophila melanogaster as a model system, previous work from my lab and others has established the role of the master regulatory transcription factor Gcm in directing neuronal precursor cells to assume a lateral glial fate. Gcm acts on many target genes, one of which is reversed polarity (repo). repo is necessary …

Birdie See, Birdie Do: Zebra Finch Observational Learning In Three Cognitive Domains With Discussion Of Cerebellar Involvement, Amy Hribar

Electronic Theses and Dissertations

Observational learning is a cognitive ability that allows individuals to acquire information or skills through watching others. Examples of observational learning can be seen in all major vertebrate groups and some invertebrates. Observational learning may confer a selective advantage to animals due to improvements in decision-making and increased behavioral flexibility. While studies of animals’ observational learning capabilities and the types of information acquired have been examined in many species, multiple types of observational learning have rarely been examined in non-rodent species in controlled laboratory experiments. Additionally, only recently have the neural mechanisms that support observational learning been examined. I sought …

Modeling And Analysis Of A Three-Species Food Web With Facilitated And Intraguild Predation, Joshua Castro

Electronic Theses and Dissertations

Biotic interactions are known to shape natural community assemblages and biodiversity. Positive interactions such as facilitation have recently received attention in ecological food webs. Mechanistic models have improved our understanding of these complex food web interactions. Here, focus is given to a three-species food web system with a beach dune natural community in mind. In the last decade, there has been a series of studies investigating intraguild predation between two major loggerhead sea turtle nest predators, North American raccoons and Atlantic ghost crabs. Studies have also highlighted that ghost crab predation assists raccoons in finding nests (i.e., facilitated predation). However, …

Gene Expression In The Choanoderm, Jesús Federico Peña

Electronic Theses and Dissertations

The body plan of sponges (phylum Porifera) is an outlier among modern animals and is thought to have special evolutionary significance. Sponges lack muscles, nerves and a gut. Instead, they are composed of few cell types and simple tissues that function to pump water through an internal canal network where bacterial prey are filtered by a specialized tissue called the choanoderm. The choanoderm is composed of cells with striking similarity to choanoflagellates, the unicellular relatives of animals. Thus, the traditional view is that the sponge choanoderm is a useful model of the first animal epithelial tissues. Using the freshwater sponge …

Testing For Isolation In Florida Raccoons (Procyon Lotor) Using Phylogenetics And Population Genetic Structure, Alexa Trujillo

Electronic Theses and Dissertations

Molecular data are useful in determining if populations are isolated and for species delimitation. Researchers and managers currently recognize five subspecies of raccoons (Procyon lotor) in Florida, based largely on perceived geographic isolation due to the island ranges of four subspecies. In this study, I provide the first estimate of phylogenetic relationships and population divergences within Florida raccoons using a molecular dataset. I analyze the mitochondrial control region, cytochrome b gene, and eight nuclear microsatellite loci to test two hypotheses: 1) the five, morphologically and geographically-defined subspecies of raccoon in Florida represent genetically distinct populations and (2) due to differing …

Does The Journey Matter More Than The Destination? The Contribution Of Geospatial And Local Conditions To Invasive Pomacea Maculata Distribution Across Ranchland Wetlands, Steffan Pierre

Electronic Theses and Dissertations

Geospatial characteristics such as isolation and avenues of connectivity influence an invader's pattern of dispersal and distribution. However many examinations of invasion success ignore the contribution of dispersal to patterns of invasion and focus only on the local environmental/habitat factors. This study examines the interaction of geospatial characteristics, that may influence dispersal, and local environmental factors, that may govern successful occupation, on the likelihood of invasion (invasability) of wetlands within an agriculturally modified landscape. I examined the current invasion of seasonal wetlands in south-central Florida ranchland by non-native apple snails (Pomacea maculata (Ampullariidae)) as a model system for understanding this …

Development Of Human And Rodent Based In Vitro Systems Toward Better Translation Of Bench To Bedside In Vivo Results, Bonnie Berry

Electronic Theses and Dissertations

Prospective medicinal compounds progress through multiple testing phases before becoming licensed drugs. Testing of novel compounds includes a preclinical phase where the potential therapeutic is tested in vitro and/or in animal models in vivo to predict its potential efficacy and/or toxicity in humans. The failure of preclinical models to accurately predict human drug responses can lead to potentially dangerous compounds being administered to humans, or potentially beneficial compounds being kept in development abeyance. Moreover, inappropriate choice in model organism for studying disease states may result in pushing forward inappropriate drug targets and/or compounds and wasting valuable time and resources in …

Identifying Inundation-Driven Effects Among Intertidal Crassostrea Virginica In A Commercially Important Gulf Of Mexico Estuary, Joshua Solomon

Electronic Theses and Dissertations

Sea level rise and changing storm frequency and intensity resulting from climate change create tremendous amounts of uncertainty for coastal species. Intertidal species may be especially affected since they are dependent on daily inundation and exposure. The eastern oyster Crassostrea virginica is an economically and biologically important sessile intertidal species ranging from Canada to the Gulf of Mexico. Declines and changes in distribution of oyster populations has forced commercial harvesting to spread from subtidal to intertidal reefs. We investigated the potential responses of intertidal C. virginica to sea level rise, and the response of larval settlement to sedimentation which is …

A Socio-Economic Assessment Of Marine Turtle Eco-Tourism, Kendra Cope

Electronic Theses and Dissertations

Marine turtles have historically contributed to economic activity through consumptive harvest for food, tools, and decorative objects. Only recently have they begun to benefit humans economically through non-consumptive roles, primarily as a focal point of educational eco-tourism. In recent years, the annual number of turtle walks conducted around the Archie Carr National Wildlife Refuge (ACNWR) has risen. This expansion contributed to a statistically significant increase in attendance from 2,162 in 2001 to 3,047 participants in 2014. I examined the regional economic impacts of marine turtle eco-tourism around the ACNWR using social surveys and an economic impact analysis tool. IMPLAN, an …

The Impact Of Photopollution On Nesting Loggerhead Sea Turtles (Caretta Caretta) Along The Grand Strand, South Carolina, Ryan Bonner

Electronic Theses and Dissertations

Photopollution present along heavily developed coastlines is known to have a significant negative impact on nesting sea turtle populations by damaging nesting habitat quality, but few studies have explored this relationship on broad spatial scales. The purpose of this study was to characterize the onshore light field along a developed stretch of South Carolina coastline and to quantify how photopollution intensity affects regional loggerhead sea turtle (Carretta carretta) nesting density using historical nesting data. Light measurements were collected using a portable low-light photometer at 74 sites spaced at approximately one km intervals across the study area. At each site, the …

The Fish Kill Mechanism Of The Harmful Raphidophyte Chattonella Subsalsa, Amy E. Grogan

Electronic Theses and Dissertations

Harmful algae blooms (HABs) and toxins associated with HAB species are a significant threat to the health of marine species and coastal environments. In the South Carolina coastal zone, HABs have proliferated with intensified anthropogenic eutrophication in coastal waters. The raphidophyte species Chattonella subsalsa is a prominent cause of algal blooms resulting in fish kills in South Carolina. Though C. subsalsa is a known ichthyotoxic alga, the fish kill mechanism of this species remains unidentified. C. subsalsa is likely to elicit fish mortality via one of two mechanisms: (1) gill damage induced by cell contact irritation or (2) the production …

The Vascular Flora Of Steele Creek Park And A Quantitative Study Of Vegetation Patterns In Canopy Gaps, Sullivan County, Tennessee, Phillip C. Klahs

Electronic Theses and Dissertations

An inventory of vascular plants was conducted in Steele Creek Park in Sullivan County, Tennessee from March 2013 to September 2014. The park covers an area of 892 ha and lies within the Ridge and Valley Province. The inventory of vascular plants documented 547 species of 323 genera and 101 families. Two hundred sixteen taxa were newly reported for Sullivan County. Tennessee Special Concern Species included Cardamine rotundifolia, Castanea dentata, Lonicera dioica, Allium tricoccum, Cypripedium acaule, and Panax quinquefolius. A single species, Juglans cinerea L., is considered a Tennessee Threatened Species. Vegetation patterns were studied quantitatively by installing 10 …

Biochemical Characterization Of Sbip-470 And Its Role In Sa-Mediated Signaling In Plants, Danda P. Chapagai

Electronic Theses and Dissertations

Salicylic acid binding protein 2 (SABP2) is known to play a key role in Salicylic acid mediated defense pathway. SBIP-470 is SABP2 interacting protein that might be putatively involved in transfer of lipids. SBIP-470 was cloned without the signal peptide and expressed in E. coli. In vitro lipid binding assay using recombinant SBIP-470 failed to detect lipid binding. In vitro lipid transfer assay showed recombinant SBIP-470 does not transfer phospholipid. Study has shown that SBIP-470 is highly inducible upon infection with viral as well as bacterial pathogens. Induction of SBIP-470 expression upon the TMV infection most likely depends upon …

Cloning And Expression Of A Tobacco Stearoyl-Acp Desaturase Gene Sbip24 And Its Interaction With Sabp2 In Sa Pathway, Amin J. Ferdous

Electronic Theses and Dissertations

Salicylic acid binding protein 2 (SABP2) that converts methyl salicylate to salicylic acid (SA) plays an obligatory role in the SA-mediated disease resistance pathway in plants. SABP2 interacts with SBIP24 in a yeast two-hybrid screening. SBIP24 belongs to the stearoyl-acyl carrier protein-desaturase protein family. To biochemically characterize the SBIP24, it was cloned from tobacco leaves using RT-PCR and expressed in E. coli. Recombinant SBIP24 was affinity purified using Ni-NTA chromatography. RT-PCR was performed to determine the role of SABP2 in modulating the expression SBIP24. TMV infected transgenic C3 (control tobacco plant containing empty silencing vector) and 1-2 (SABP2-silenced) …

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 …

Identification, Cloning, And Expression Of Tobacco Responsive To Dehydration Like Protein (Rd22), Sbip-355 And Its Role In Sabp2 Mediated Sa Pathway In Plant Defense, Hanadi Abdulaali Almazroue

Electronic Theses and Dissertations

Abscisic acid (ABA) induces RD22, responsive to dehydration stress gene. Salicylic acid (SA) has been the focus of research due to its role against pathogens and abiotic stress. Interaction between ABA and SA signaling pathways is still poorly understood. SA-Binding Protein 2 (SABP2) converts methyl salicylate to SA. An attempt was made to identify proteins that interact with SABP2 using a yeast 2-hybrid screening. Several interactors were identified. One of them, SA-Binding Protein 2 Interacting Protein-355 (SBIP-355), showed high homology to RD22. Bioinformatic approaches showed that SBIP-355 contains a BURP domain. Phylogenetic analysis reveals that SBIP-355 clustered into the …

Earthworm, Microbial Biomass, And Leaf Litter Decay Responses After Invasive Honeysuckle Shrub Removal From Urban Woodlands., Robert Preston Pipal

Electronic Theses and Dissertations

Invasive species are one of the leading causes of biodiversity loss and their presence can significantly impact the structure and function of native ecosystems. In this dissertation, the impacts of the invasive honeysuckle shrub, Lonicera maackii, on exotic earthworm populations, leaf litter decay responses, and inorganic and organic nutrient pools in an urban woodland park are assessed. Chapter 1 provides a brief review of honeysuckle's effects on forest ecosystems. Chapter 2 describes honeysuckle’s effects on exotic earthworm populations and the seasonal importance of macroinvertebrates to leaf litter decomposition in urban woodlands. This study revealed that L. maackii promoted higher exotic …

Development And Testing Of A Rapid Multiplex Assay For The Identification Of Biological Stains, Kevin M. Legg

Electronic Theses and Dissertations

While DNA profiling makes it possible to individualize biological stains, the identification of the stain itself can present forensic serologists with a significant challenge. Current antibody- and enzyme activity-based assays used by forensic practitioners for biological stain identification yield only presumptive results. Positive results with non-target body fluids or cross-reactivity with non-human sources has also been well documented. Some tests can consume unacceptable quantities of precious evidence while for some body fluids (vaginal fluid and menstrual blood) there are simply no available tests at all.

This research presented here aims to develop and rigorously test a fast, accurate, and sensitive …

Production Of An Antibiotic-Like Activity By Streptomyces Sp. Couk1 Under Different Growth Conditions, Olaitan G. Akintunde

Electronic Theses and Dissertations

Streptomyces are known to produce a large variety of antibiotics and other bioactive compounds with remarkable industrial importance. Streptomyces sp. COUK1 was found as a contaminant on a plate in which Rhodococcus erythropolis was used as a test strain in a disk diffusion assay and produced a zone of inhibition against the cultured R. erythropolis. The identity of the contaminant was confirmed as Streptomyces through 16S rRNA sequencing. This Streptomyces produces a strong inhibitory compound in different growth media. A culture extract from inorganic salts starch agar was found to be very active; producing a large zone of inhibition …

An Agent-Based Model Of Ant Colony Energy And Population Dynamics: Effects Of Temperature And Food Fluctuation, Guo Xiaohui

Electronic Theses and Dissertations

The ant colony, known as a self-organized system, can adapt to the environment by a series of negative and positive feedbacks. There is still a lack of mechanistic understanding of how the factors, such as temperature and food, coordinate the labor of ants. According to the Metabolic Theory of Ecology (MTE), the metabolic rate could control ecological process at all levels. To analyze self-organized process of ant colony, we constructed an agent-based model to simulate the energy and population dynamics of ant colony. After parameterizing the model, we ran 20 parallel simulations for each experiment and parameter sweeps to find …

Northern Saw-Whet Owl (Aegolius Acadicus) Abundance And Distribution In The Southern Appalachian Mountains Of Northeast Tennessee, John P. Mccormick

Electronic Theses and Dissertations

Little is known about the distribution, abundance, or life histories of the Northern Saw-whet Owl (Aegolius acadicus) in the Southern Appalachian Mountains of Northeast Tennessee. This study relied upon the Pennsylvania Protocol of audio playback of a Northern Saw-whet Owl call to monitor for owl presence at various areas above 3,500 feet in elevation. Owls were found at multiple areas in Northeast Tennessee, including Roan Mountain, Unaka Mountain, Rocky Fork, and the Pond Mountain Area. Statistical analysis revealed that these owls were not limited by habitat, showing equal presence in Hardwood habitats along with Spruce and/or Fir habitats. …

Neogene Climate Change In Eastern North America: A Quantitative Reconstruction, Kyrie A. Baumgartner

Electronic Theses and Dissertations

Though much is known of the global paleoclimate during the Neogene, little is understood about eastern North America at that time. During the Neogene the global paleoclimate was transitioning from the warm temperatures and higher levels of precipitation of the Paleogene to the cooler temperatures and lower levels of precipitation during the Pleistocene. Eleven fossil sites from Neogene eastern North America were analyzed using the Coexistence Approach: Pollack Farm, Brandon Lignite, Legler Lignite, Alum Bluff, Bryn Mawr, Big Creek on Sicily Island, Brandywine, Gray Fossil Site, Citronelle, Peace Creek, and Ohoopee River Dune Field. Analyses showed a general trend that …

Paleozoic Seed Bank And Their Ecological Significance, Petra Seka Yehnjong

Electronic Theses and Dissertations

Soil seed banks are a reservoir of viable seeds present in the soil in plant communities. They have been studied and characterized in various ways in different habitats. However, these studies are limited to modern seed banks. This study extends seed bank studies to the Paleozoic Era. It was hypothesized that size distribution and seed density in Paleozoic seed banks exhibit similar patterns as in modern seed banks. Seed sizes and seed density of fossil seed from Wise Virginia were estimated. Modern seed bank information was obtained from published data. Data were analyzed using one-way ANOVA and Kruskal-Wallis test. The …

Adaptive Strategies For Foraging And Their Implications For Flower Constancy, Or: Do Honey Bees Multitask?, Ashley E. Wagner

Electronic Theses and Dissertations

Classical experiments on honey bee time-memory showed that foragers trained to collect food at a fixed time of day return the following day with remarkable time-accuracy. Previous field experiments revealed that not all foragers return to a food source on unrewarded test days. Rather, there exist 2 subgroups: “persistent” foragers reconnoiter the source; “reticent” foragers wait in the hive for confirmation of source availability. To examine how these foragers contribute to a colony’s ability to reallocate foragers across sources with rapidly changing availabilities, foragers were trained to collect sucrose during a restricted window for several days and observed over 3 …

Subcloning, Expression And Purification Of Functional E. Coli Nucleotide Excision Repair Protein Uvra Using Impact-Cn System, Cathy W. Lin Mrs

Electronic Theses and Dissertations

DNA in cells is constantly damaged by both endogenous and exogenous genotoxic agents. DNA repair is a cellular machinery that counters DNA damage and thus preserve genome integrity. Nucleotide excision repair (NER) in Escherichia coli (E. coli) is one of the DNA repair systems that recognizes and removes a variety of DNA damage such as pyrimidine dimers, bulky chemical adducts, DNA intrastrand cross-links, etc. The genes responsible for E. coli NER incisions are UvrA, UvrB, and UvrC. As the first step of E. coli NER, DNA damage recognition is achieved through the UvrA₂B …

Invasive Plants As Drivers And Passengers Of Community Change In A Disturbed Urban Forest., Jeffery A. Masters

Electronic Theses and Dissertations

Invasive species can impact local ecosystems by decreasing biodiversity and local abundances of native species. Invasive species also frequently establish in disturbed habitats. An invasive species may dominate a habitat because the introduced species is a superior competitor (driver model) for resources or because the introduced species is more tolerant of noncompetitive processes such as anthropogenic disturbance that reduces the diversity and abundance of native species (passenger model). Ranunculus ficaria (Ranunculaceae) is an invasive plant species in the northeastern United States, and can be especially dense in urban riparian habitats. It emerges early and forms thick mats of vegetation that …

Character Evolution And Microbial Community Structure In A Host-Associated Grasshopper, Tyler Raszick

Electronic Theses and Dissertations

The spotted bird grasshopper, Schistocerca lineata Scudder (Orthoptera: Acrididae), is a widely distributed species found throughout most of the continental United States and southern Canada. This species is known to be highly variable in morphology, with many distinct ecotypes across its native range. These ecotypes display high levels of association with type-specific host plants. Understanding the evolutionary relationships among different ecotypes is crucial groundwork for studying the process of ecological differentiation. I examine four ecotypes from morphological and phylogeographic perspectives, and look for evidence of distinct evolutionary lineages within the species. I also begin to explore the potential role of …