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Theses/Dissertations

Life Sciences

2014

ETD

Articles 1 - 18 of 18

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Sessile Invertebrate Colonization On Rocky Outcrops At Gray's Reef National Marine Sanctuary, Brittany Poirson Jan 2014

Sessile Invertebrate Colonization On Rocky Outcrops At Gray's Reef National Marine Sanctuary, Brittany Poirson

Electronic Theses and Dissertations

Documenting patterns of sessile invertebrate community development is important for predicting recovery patterns after disturbance and designing effective marine reserves. In the South Atlantic Bight, invertebrate assemblages can differ significantly from one rocky outcrop to another, but the factors driving these differences are not well understood. I tracked community development for fourteen months at four rocky outcrops at Gray’s Reef National Marine Sanctuary (GRNMS) to address the predictions that (i) developing sessile invertebrate communities in this system do not exhibit a predictable pattern of succession and (ii) recolonization patterns for small patches of open space that become available are influenced …


Epistasis In Predator-Prey Relationships, Iuliia Inozemtseva Jan 2014

Epistasis In Predator-Prey Relationships, Iuliia Inozemtseva

Electronic Theses and Dissertations

Epistasis is the interaction between two or more genes to control a single phenotype. We model epistasis of the prey in a two-locus two-allele problem in a basic predator- prey relationship. The resulting model allows us to examine both population sizes as well as genotypic and phenotypic frequencies. In the context of several numerical examples, we show that if epistasis results in an undesirable or desirable phenotype in the prey by making the particular genotype more or less susceptible to the predator or dangerous to the predator, elimination of undesirable phenotypes and then genotypes occurs.


Tactical Escape Behavior And Performance Of A Small Sceloporine Lizard In Two High Risk Habitats, Seth Parker Jan 2014

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 …


Effects Of Organic And Conventional Agricultural Practices On Soil Microbial Communities And Molecular Detection Of Soil Borne Disease, Holli K. Milner Jan 2014

Effects Of Organic And Conventional Agricultural Practices On Soil Microbial Communities And Molecular Detection Of Soil Borne Disease, Holli K. Milner

Electronic Theses and Dissertations

Agricultural practices affect soil microbial communities and health through the input of pesticides, herbicides, fertilizers, and cycling of crop rotation. By examining the microbial community structure, we analyzed how microbial species respond to the environment that individual farms create. Early detection of soil borne disease is essential for agricultural success. However, monitoring incidence of disease based on plant growth response to pathogenic inoculation may not reveal the amount of pathogenic DNA in soil. A comparative study of tomato production systems was conducted by analysis of soil microbial community structure from four farms in Southeast Georgia for the years 2012 and …


Phenology Of A Relict Population Of The Pitcher Plant Mosquito, Wyeomyia Smithii (Diptera: Culicidae), In Tattnall Co., Ga, Rachel L. Morreale Jan 2014

Phenology Of A Relict Population Of The Pitcher Plant Mosquito, Wyeomyia Smithii (Diptera: Culicidae), In Tattnall Co., Ga, Rachel L. Morreale

Electronic Theses and Dissertations

Wyeomyia smithii Coquillett lives only within the pitchers of the purple pitcher plant, Sarracenia purpurea L. An isolated population of Wy. smithii occurs in Tattnall Co., GA isolated from other populations by over 300 km in all directions. In order to monitor the stability, phenology, and behavior of this population, fluctuations of the larval and pupal abundances (number/pitcher) were monitored over time. The density (number/mL) of Wy. smithii larvae present within pitchers was recorded from June 2012 until April 2014. Fluid volume contained in pitchers had a strong positive effect on larval abundance within the pitcher (r2 = 0.624). …


An Examination Of Behavioral And Temporal Consistency Of Pre-Performance Routines In Ncaa Division I Basketball Free Throw Shooting – A Naturalist Observational Investigation, Jacob Blumberg Jan 2014

An Examination Of Behavioral And Temporal Consistency Of Pre-Performance Routines In Ncaa Division I Basketball Free Throw Shooting – A Naturalist Observational Investigation, Jacob Blumberg

Electronic Theses and Dissertations

Research has shown that pre-performance routines positively influence performance of closed and self-paced skills (Boutcher & Crews, 1987; Cohn, 1990; Otto et al., 2011). Boutcher and Crews (1987) suggested that pre-performance routines improve performance by helping reduce anxiety along with helping athletes’ retain mental sharpness and focus. Furthermore, several quantitative studies have examined the influence of both behavioral and temporal consistency of pre-performance routines on the success of a skill, yielding inconsistent results (Boutcher & Crews, 1987; Lobmeyer & Wasserman, 1986; Lonsdale & Tam, 2008; Jackson, 2003). However, research examining this phenomenon from a qualitative and naturalistic observational perspective is …


Phenotypic Variation In Native North American And Invasive Chinese Populations Of Plantago Virginica, Teresa E. Popp Jan 2014

Phenotypic Variation In Native North American And Invasive Chinese Populations Of Plantago Virginica, Teresa E. Popp

Electronic Theses and Dissertations

Alien plant species can cause significant economic and biological destruction by invading new environments and outcompeting native species. Through experimental research, the mechanisms by which these species invade can be better understood and applied to their management. Plantago virginica is a perennial herb, native to North America that has recently invaded China. It has been known to reduce crop growth and harbor diseases in the introduced range. A common garden study was conducted at the Georgia Southern University greenhouse, comparing twenty populations of P. virginica from both the native North American and invasive Chinese ranges. I examined if there were …


Molecular Phylogenetic Relationships Of North American Dermacentor Ticks Using Mitochondrial Gene Sequences, Kayla L. Perry Jan 2014

Molecular Phylogenetic Relationships Of North American Dermacentor Ticks Using Mitochondrial Gene Sequences, Kayla L. Perry

Electronic Theses and Dissertations

Dermacentor is a recently evolved genus of hard ticks (Family Ixodiae) that includes 36 known species worldwide. Despite the importance of Dermacentor species as vectors of human and animal disease, the systematics of the genus remain largely unresolved. This study focuses on phylogenetic relationships of the eight North American Nearctic Dermacentor species: D. albipictus, D. variabilis, D. occidentalis, D. halli, D. parumapertus, D. hunteri, and D. andersoni, and the recently re-established species D. kamshadalus, as well as two of the Neotropical Dermacentor species D. nitens and D. dissimilis (both formerly Anocentor). We sequenced portions of the mitochondrial …


Temporal Patterns Of Aquatic Macroinvertebrate Communities And Organic Matter Standing Stock Availability In A Coastal Floodplain (Altamaha River, Georgia), Erica L. Johnson Jan 2014

Temporal Patterns Of Aquatic Macroinvertebrate Communities And Organic Matter Standing Stock Availability In A Coastal Floodplain (Altamaha River, Georgia), Erica L. Johnson

Electronic Theses and Dissertations

River floodplain habitats of the Southeastern United States are sites of high biological productivity that rely on a predictable flooding event as a keystone process. This study took place in a river-floodplain area of the Altamaha River, an unimpounded large-order river in the Coastal Plains region of the US. This study aims to investigate how aquatic macroinvertebrate communities changed over the course of the annual flood pulse. I predicted that the communities would be different and that the differences would be driven by hydrology at the main stem and organic matter standing stock availability. I took quantitative samples of benthic …


The Effects Of Beaver Dams On The Structure And Function Of Invertebrate Communities In A Southeastern Coastal Plain Stream, Damon L. Mullis Jan 2014

The Effects Of Beaver Dams On The Structure And Function Of Invertebrate Communities In A Southeastern Coastal Plain Stream, Damon L. Mullis

Electronic Theses and Dissertations

Beaver were at the brink of extinction in the early 20th century, but over the past century populations have been rebounding. This increase in range and population size has raised new concerns over possible impacts on aquatic ecosystems. Beaver are considered ecosystem engineers because they change the physical structure of aquatic systems through the construction of dams, which turn naturally flowing sections of rivers and streams into standing water. Such changes are known to influence habitat heterogeneity, influence organic matter transport and storage, and consequentially influence biological diversity. To my knowledge, no studies of the effects of beaver impoundments …


Soil Microbial Community Distributions And Disease Suppressiveness In The Coastal Plain Of Georgia, Michael J. Sabula Jan 2014

Soil Microbial Community Distributions And Disease Suppressiveness In The Coastal Plain Of Georgia, Michael J. Sabula

Electronic Theses and Dissertations

This study compared the soil microbial communities of three vegetation types in the coastal plain of Georgia: 1. crop land actively in use for agricultural production, 2. transitional grassland in early stages of secondary succession, and 3. pristine unmanaged forest land. Microbial species diversity and quantities of microbial DNA were determined from each of these vegetation types at three separate locations near Statesboro, Georgia. Length heterogeneity PCR(LH-PCR) methods and subsequent analysis of fungal, bacterial, and metazoan communities by analysis of similarity (ANOSIM) revealed high within-group similarity by vegetation type, indicating land management intensity and vegetation cover is a strong determining …


Water And Nutrient Reuse Within Closed Hydroponic Systems, Emerson Christie Jan 2014

Water And Nutrient Reuse Within Closed Hydroponic Systems, Emerson Christie

Electronic Theses and Dissertations

Currently, little research exists on the maintenance of individual nutrient balance within the nutrient solutions of closed hydroponic systems and how this maintenance may result in reductions in water and nutrient consumption. In this study, a nutrient solution management procedure was developed to maintain outputs while minimizing inputs. Lactuca sativa (lettuce) crops were grown in six closed hydroponic systems utilizing the nutrient film technique. Electrical conductivity was used as the primary indicator of nutrient solution quality and determined if the nutrient solution was discarded and replaced (control systems) or restored (test systems). Restorations in test systems were made individually to …


The Prevalence And Effect Of Wolbachia Infection On The Brown Widow Spider (Latrodectus Geometricus), Brittany Dane' Arrington Jan 2014

The Prevalence And Effect Of Wolbachia Infection On The Brown Widow Spider (Latrodectus Geometricus), Brittany Dane' Arrington

Electronic Theses and Dissertations

Wolbachia was recently identified in the Brown Widow Spider (Latrodectus geometricus). This symbiont has not previously been found in this genus, therefore the consequences on the host’s population dynamics are unknown. The frequency of endosymbiont infection can provide insight into the population dynamics of the host as this bacteria is known to alter host life history. In my 1st chapter I determine the prevalence of Wolbachia pipentis infection in in the Brown Widow Spider (Latrodectus geometricus) from five locations in the Southeastern United States. Infection frequency differed significantly among sampling locations, ranging from 20% to …


Cellular Coping Mechanisms To Hypoxia In The Longhorn Sculpin (Myoxocephalus Octodecemspinosus) Brain, Kelly Heino Jan 2014

Cellular Coping Mechanisms To Hypoxia In The Longhorn Sculpin (Myoxocephalus Octodecemspinosus) Brain, Kelly Heino

Electronic Theses and Dissertations

The loss of neurological function due to hypoxia remains to be a challenge in many species due to the lack of knowledge and understanding of cellular responses. To investigate cellular responses and survival strategies of the brain during hypoxia and post-hypoxia recovery in a moderate hypoxia-tolerant species, with the hopes of identifying possible therapeutic remedies, thirty Longhorn sculpin, Myoxocephalus octodecimspinosus, were challenged with acute hypoxia (40% O2 saturation for 1 h) and twelve additional sculpin were used as controls (~90% O2 saturation). Fish were sampled at each of the following time points: control/normoxic conditions (T=0 h); hypoxic conditions …


Microbial Communities Colonizing Leaves During Early Decomposition Stages, Stephanie Harper Jan 2014

Microbial Communities Colonizing Leaves During Early Decomposition Stages, Stephanie Harper

Electronic Theses and Dissertations

Microbial communities associated with decaying leaves play an important role in the cycling of nutrients in stream ecosystems. In headwater streams that are deemed as heterotrophic, bacteria and fungi are main drivers of organic matter decomposition and thus partly responsible for facilitating the cycling of nutrients from leaves that fall into the stream. The main objective of this study was to compare microbial community composition between different leaf types during breakdown in stream ecosystems. To achieve this objective, I used a combination of field and laboratory trials. Field experiments were performed at the Luquillo Experimental Forest using Dacryodes excelsa and …


Antecedents Of Athletes’ Achievement Goal Orientations, Matthew Lachman Jan 2014

Antecedents Of Athletes’ Achievement Goal Orientations, Matthew Lachman

Electronic Theses and Dissertations

Theorized by Nicholls (1984), achievement goal theory describes the interaction of one’s perceived ability and two goal orientations, known as “task” and “ego,” that an athlete employs when setting goals. These goal orientations are what athletes employ when playing their sport. The result of this interaction is an athlete’s achievement behavior. Previous research has examined this theory extensively (Newton & Duda, 1999; Chin, Khoo, & Low, 2012; Smoll, Smith, & Cumming, 2007; White & Zellner, 1996). However, few studies have solely looked at factors that predict one’s achievement goal orientations. The purpose of this study is to address which demographic …


Water Column Ammonium Concentration And Salinity Influence Nitrogen Uptake And Growth Of Spartina Alterniflora, Rachel Mactavish Jan 2014

Water Column Ammonium Concentration And Salinity Influence Nitrogen Uptake And Growth Of Spartina Alterniflora, Rachel Mactavish

Electronic Theses and Dissertations

Salt marsh macrophytes, such as Spartina alterniflora, play a critical role in uptake and transformation of inorganic nitrogen before it reaches coastal waters, thereby reducing the potential for eutrophication. Although nitrogen availability typically limits S. alterniflora growth, it may be possible to exceed the nitrogen uptake capacity of S. alterniflora. Increasing either nitrogen concentrations or salinity are key factors regulating S. alterniflora nitrogen uptake. Investigating the effects of nutrients and salinity on S. alterniflora is important given that increases in inorganic nitrogen supply to surface waters from agriculture and urbanization occur simultaneously with freshwater withdrawals that reduce flow and increase …


The Effects Of Herbicide On The Endangered Herb Baptisia Arachnifera And Preliminary Nutrient Survey Of Leaf Tissue And Soil, Ruth Ann C. Steinbrecher Jan 2014

The Effects Of Herbicide On The Endangered Herb Baptisia Arachnifera And Preliminary Nutrient Survey Of Leaf Tissue And Soil, Ruth Ann C. Steinbrecher

Electronic Theses and Dissertations

Baptisia arachnifera (Hairy Rattleweed) is an endangered herbaceous legume that only occurs in Wayne and Brantley Counties of Georgia, United States. Many of the remaining populations exist in areas now managed for timber. This study investigated the effects of Imazapyr, an herbicide commonly used in timber management, on health and vitality of B. arachnifera under both field and greenhouse conditions. This study also analyzed leaf and soil samples from six populations of B. arachnifera to determine the nutrient content of the leaves. A recensus of a B. arachnifera population was also conducted in a site without commercial timber management. In …