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The Conservation Genetics Of Two Emydid Turtles: Emydoidea Blandingii And Malaclemys Terrapin, Charlotte Lizana Petre

Master's Theses

Conservation of turtles is complicated by their sensitivity to habitat degradation and overexploitation. I used microsatellites and standard population genetic analyses to explore genetic diversity, population structure, paternity and demographic history in two emydid turtles that are currently experiencing threats to their survival. The Blanding’s turtle, Emydoidea blandingii, has experienced habitat fragmentation throughout its range, and this study focuses on a population in Massachusetts where hatchlings from one population are being translocated to establish a new population. I found evidence of multiple paternity within clutches and found no significant reduction in genetic diversity when comparing the source population and …

Clarification Of The Systematics Of The Haploporoidea (Trematoda) With Descriptions Of New Genera And Species, Michael Jay Andres

Dissertations

The superfamily Haploporoidea Nicoll, 1914 comprises two families, the Atractotrematidae Yamaguti, 1939 and the Haploporidae Nicoll, 1914, and the subfamily Cadenatellinae Gibson et Bray, 1982. All members are parasites of the alimentary tract or gall bladder of marine, estuarine, and freshwater herbivorous fishes. Overstreet and Curran (2005a) provided a review of the Haploporidae and recognized four subfamilies, the Chalcinotrematinae Overstreet et Curran, 2005, Haploporinae Nicoll, 1914, Megasoleninae Manter, 1935, and Waretrematinae Srivastava, 1937. In a series of five publications, Blasco-Costa et al. (2009a-e) revised the Haploporinae and erected a fifth subfamily, the Forticulcitinae Blasco-Costa, Balbuena, Kostadinova, et Olson, 2009. The …

Fungal Contribution To Carbon And Nutrient Cycling In A Subtropical Freshwater Marsh, Rong Su

Dissertations

Despite the well-known occurrence of emergent standing litter in freshwater marshes, very little quantitative data is available concerning the functional role and contribution of fungal decomposers to litter decomposition or their impact on ecosystem scale carbon and nutrient cycling. In the present study, microbial respiration and seasonal biomass and production rates of fungal decomposers associated with standing plant litter were examined to assess the quantitative contribution of fungi to both fine scale litter decay processes and large-scale ecosystem carbon flow pathways in a subtropical Typha domingensis and mixed Cladium jamaicense/Juncus roemarianus freshwater marsh, respectively. In addition, the growth …

Online Versus Face-To-Face Biology: A Comparison Of Student Transactional Distance, Approach To Learning, And Knowledge Outcomes, Mary Erin Riggins

Dissertations

Community colleges are among many other institutions increasing course offerings online, but there is still some concern about the quality of online learning. Educator concerns, a lack of empirical evidence on biology courses offered online, and the need for an equal opportunity for education support the need for clarification of the quality of distance education in biology, especially in the community college setting. Student attitudes, approaches to learning, and performance should all be studied in order to formulate a better evaluation of the quality and effectiveness of online courses (Svirko & Mellanby, 2008).

The purpose of this study was to …

Identification And Characterization Of Msab Gene Involved In Biofilm Formation And Virulence In Staphylococcus Aureus, Amelsaad Elbarasi

Master's Theses

Staphylococcus aureus is an important human pathogen that causes a wide variety of life-threatening infections ranging from minor skin and oral infections to severe infections, such as bacteremia, pneumonia, osteomyelitis, or endocarditis due to the presence and secretion of a large number of virulence factors that are controlled by global virulence regulators in complex networks. Furthermore, S. aureus infections have become a threat to public health because of their high potential to form biofilm, and their ability to resist a wide range of antibiotics has exacerbated further. Therefore, understanding the regulatory networks and developing a drug targeting these networks has …

Characterizing Populations Of Non-Coding Rnas In Karenia Brevis At Different Times Of The Diel Cycle, Scott Boyd Anglin

Master's Theses

Karenia brevis is a mixotrophic, marine dinoflagellate found in the Gulf of Mexico that generates periodic, if not annual, harmful algal blooms (also known as “red tides”) in certain coastal areas. In an effort to better understand the biology of this organism, a functional genomics project has been initiated. As part of that project, it has been determined that a significant number of natural antisense transcripts (NATs) as well as double-stranded RNA (dsRNA) molecules exist within the transcriptome of K. brevis. I hypothesize that the non-coding NATs, similar to microRNAs (miRNAs) in other organisms play a role in regulating …

Role Of Msaa Gene In Regulation Of The Msaabcr Operon And Biofilm Development In Staphylococcus Aureus, Ahmed Alzuway

Master's Theses

Staphylococcus aureus is an important human pathogen that causes wide variety of diseases ranging from chronic biofilm associated infection to acute life threatening infection such as bacteremia, pneumonia, osteomyelitis, or endocarditis, despite the progress with antibiotics used in the treatment of bacterial infections. Furthermore, increased use of prosthetic and indwelling devices in modern medical practices has led to increased infections due to S. aureus. Treating S. aureus infections have become difficult owing to its ability to resist most of the antibiotics; this problem is further exacerbated by ability of MRSA strains to form biofilms. Emergence of community-acquired methicillin resistance …

The Ontogeny Of Whistle Production In Infant Atlantic Bottlenose Dolphins (Tursiops Truncatus) During The First Thirty Days Of Life, Brittany Leigh Jones

Master's Theses

The manner in which dolphin calves acquire their whistle repertoire is largely unknown. This paper focuses on whistle development in four bottlenose dolphin calves during the first thirty days of life in order to increase our understanding of the early emergence of whistles and whistle-like vocalizations. The acoustic parameters of whistle-type vocalizations (i.e., whistles and whistlesquawks) that coincided with a bubblestream emission from the focal calf and/or its mother were analyzed, as were the behavioral states of the mother-calf pair during the emission of such vocals. Mother and calf whistle rates are inversely related, with the mother whistling more often …

Taxonomy, Diversity, And Distribution Patterns Of Portunid Crab Megalopae In The Northern Gulf Of Mexico During Fall Of 2003, Carley Rain Knight

Master's Theses

The field of zooplankton biology contributes to more accurate stock assessments as well as to a greater understanding of the marine food web. However, adequate information for the invertebrate component of zooplankton is lacking compared to the ichthyoplankton component. In this thesis, identification of Portunidae (Crustacea: Decapoda) megalopae collected during the fall of 2003 from a NOAA SEAMAP cruise revealed 7 species and 11 morphs with 90% of the total density comprised of Callinectes sapidus, Achelous gibbesii, Callinectes similis, Achelous spinicarpus, and Achelous sp.I. Keys and detailed descriptions are provided along with photographs and morphological drawings for each morph to …

Differences In Consumption Rates Between Juvenile And Adult Laccophilus Fasciatus Rufus (Coleoptera: Dytiscidae) On Larval Culex Quinquefasciatus (Diptera: Culicidae), Carmen E. Bofill

Honors Theses

With the increase of global temperature and human populations, prevalence of vector-borne diseases is becoming an issue for public health. Over the years these vectors have been notorious for developing resistance to human regulated insecticides. Thus, other forms of control, including the use of natural predators, have become an important topic in research. Research on member of the family of predaceous diving beetles (Dytiscidae) and their predatory ability to decrease aquatic mosquito larvae populations has been of recent interest. The purpose of this study is to 1) quantify consumption rates of the dytiscid Laccophilus fasciatus rufus juvenile and adults on …

Regulation Of Gene Expression In Karenia Brevis, Skylar C. Rodgers

Honors Theses

Karenia brevis is species of dinoflagellate responsible for most of the harmful algal blooms that occur in the Gulf of Mexico. These blooms can be detrimental to the environment and the economy of a coastal region due to the brevetoxins produced by Karenia brevis. Currently, the cause of these blooms, as well as the mechanisms of associated toxin production, are unknown. Efforts to characterize Karenia brevis at a molecular level are ongoing. However, based on genomic findings, researchers have hypothesized that regulation of gene expression occurs post-transcriptionally. In many organisms, non-coding RNAs, such as natural antisense transcripts (NATs), play …

Role Of Il-17 In Cd8+ T Cell Mediated Clearance Of West Nile Virus, Jordan E. Lowery

Honors Theses

West Nile virus (WNV), a positive sense single stranded RNA flavivirus, is prevalent in many countries worldwide and is a growing threat in the United States. Some patients infected with WNV develop severe neuroinvasive disease including meningitis or encephalitis which may lead to death. The recently characterized cytokine interleukin-17 (IL-17) has been implicated in several autoimmune diseases, neuroinflammatory conditions, and immune responses to various microbial infections. Previous research has indicated that a known contributor to IL-17 production, interleukin-23, is produced in response to WNV infection, but the role of IL-17 during WNV infection has not been studied before. This study …

Population Genetics And Microbial Communities Of The Gopher Tortoise (Gopherus Polyphemus), Daniel Lyle Gaillard

Dissertations

The gopher tortoise, Gopherus polyphemus, is an endangered species living in the southeastern United States. The recent and drastic decline in tortoise numbers has resulted in a multi-faceted approach to conserve this species. I used a population genetic approach to determine the population structure, genetic diversity and barriers to gene flow at a broad, regional and local scale. Tortoises are divided into five distinct genetic populations at the broad scale, the central populations have the highest levels of genetic diversity and the Tombigbee, Mobile, Apalachicola, Suwannee and St. John’s Rivers appear to be barriers to gene flow. At the regional …

The Delivery, Speciation, And Fate Of Trace Elements In St. Louis Bay, Mississippi, Gopal Bera

Dissertations

Estuaries are dynamic regions in which there can be significant modification of the riverine flux of trace elements to the open ocean due to various geochemical, physical, and biological processes. Additionally, estuaries are often subject to anthropogenic inputs of trace elements. The first portion of this study investigated the source, behavior, and sediment interaction of anthropogenic stable cesium (Cs) in St. Louis Bay (SLB), MS. A consistent increase in stable Cs concentration was noticed in sediment cores starting from a period when a titanium dioxide refinery on SLB started operations. Weak correlation between Cs and clay percentage and strong correlations …

Three-Dimensional Reconstruction Of Marine Clay Nano- And Microstructure By Transmission Electron Microscopy: Analysis Of Fabric And Pore Network, Jessica Rae Gardner Douglas

Master's Theses

Three-dimensional reconstructions of marine fine-grained sediment open a new dimension for studying nano- and microscale organo-clay fabric important to improving and advancing organic matter (OM) sequestration and fluid flow dynamics modeling. I created 3-D reconstructions of clay fabric and pore pathways from serial sections and photographic mosaics obtained using transmission electron microscopy. These reconstructions show aggregations of clay domains, surrounding OM, and pore networks. I examined a Model sample (laboratory consolidated) with 1% OM and a Natural sample (polychaete fecal pellet) with high levels of OM. Three-dimensional reconstructions were segmented into 300 nm cube subsamples to make highly localized qualitative …