Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 34

Full-Text Articles in Life Sciences

Investigating Potential Bioactive Compounds From Rhodococcus And Their Effects On Mcf7 Breast Cancer Cells, Megan N. Crabtree Dec 2013

Investigating Potential Bioactive Compounds From Rhodococcus And Their Effects On Mcf7 Breast Cancer Cells, Megan N. Crabtree

Electronic Theses and Dissertations

Many drugs used in the treatment of various cancers are derived from or influenced by compounds from nature. The soil bacterium Rhodococcus is of interest because of its identified secondary metabolic pathways and the production of novel natural antibiotics from several strains. In this study, a solid agar extraction method was used to collect compounds from strains of Rhodococcus. These bacterial compound extracts were then tested using a MTT assay in order to evaluate their effectiveness in augmenting MCF7 breast cancer cell death. The results of two way ANOVA analyses revealed 18 compound extracts from 15 strains of Rhodococcus that ...


Development Of In Vitro Chylomicron Assay Using Caco-2 Cells, Yuxi Sun Dec 2013

Development Of In Vitro Chylomicron Assay Using Caco-2 Cells, Yuxi Sun

Electronic Theses and Dissertations

Dietary fats are mainly transported by the intestine in lipoproteins: chylomicrons (CMs) and very low density lipoproteins (VLDLs). Unfortunately, studies of the intestinal absorption of dietary fat have been hampered by the lack of an adequate in vitro model system. As an in vitro model Caco-2 cells are able to secrete lipoproteins. We investigated the possible factors that may affect the secretion of CMs through the ultracentrifugation technique. The dose-dependent effects of oleic acid, mono-olein, egg lecithin, collagen matrix, and the effect of cell differentiation on CM secretion were then tested. We found that oleic acid, lecithin, and cell differentiation ...


Regulating Rsma Expression In Pseudomonas Aeruginosa, Sean D. Stacey Aug 2013

Regulating Rsma Expression In Pseudomonas Aeruginosa, Sean D. Stacey

Electronic Theses and Dissertations

Pseudomonas aeruginosa, a Gram-negative bacillus, commonly infects immunocompromised individuals and uses a variety of virulence factors to persist in these hosts. The posttranscriptional regulator, RsmA, plays a role in the expression of many virulence factors in P. aeruginosa. RsmA up regulates virulence factors used in colonizing hosts. However, regulation of rsmA is not well elucidated. Transposon mutagenesis was performed on P. aeruginosa containing a transcriptional rsmA-lacZ fusion to answer this question. Mutants were screened via β-galactosidase assay and transposon insertions identified via arbitrary PCR. A probable MFS transporter, we named mtpX, was one significant transposon mutant identified. A ΔmtpX mutant ...


Role Of Camkii In Pancreatic Alpha Cells, Brooke A. Buckland Aug 2013

Role Of Camkii In Pancreatic Alpha Cells, Brooke A. Buckland

Electronic Theses and Dissertations

Calcium/calmodulin-dependent protein kinase II (CaMKII) has been identified as an important modulator in controlling electrical activity in neurons and the heart; however, a role for CaMKII in pancreatic alpha cell signaling has not been previously reported. Upon activation by calcium/calmodulin, CaMKII phosphorylates proteins involved in intracellular calcium homeostasis by inducing downstream effects such as an increase in AMPA-receptor single channel conductance, potentiation of L-type voltage dependent calcium channels, and enhanced surface expression of inhibitory GABAA-receptors. In the pancreas, an increase in intracellular calcium drives secretion of glucagon from alpha cells within the Islets of Langerhans. α-cells ...


Evolution Of Xenopus Tropicalis Mc2r: Expression And Activation, Perry Victoria Davis Aug 2013

Evolution Of Xenopus Tropicalis Mc2r: Expression And Activation, Perry Victoria Davis

Electronic Theses and Dissertations

The structure and functional relationship between the melanocortin-2 receptor (MC2R) and adrenocorticotropic hormone (ACTH) is the most complex of the melanocortin gene family. Prior studies had been done on amniote tetrapod MC2Rs (e.g., mammals); this study analyzed the expression and activation of MC2R by an anamniote tetrapod, Xenopus tropicalis (xtMC2R). An immunofluorescence approach, done on the expression of xtMC2R in Chinese Hamster Ovary cells (CHO cells), indicated that the trafficking of xtMC2R to the plasma membrane required co-expression with a tetrapod MRAP1(melanocortin-1 receptor accessory protein). A cAMP-reporter assay was used to show that xtMC2R can activated by human ...


Vegetation Response After Invasive Tamarix Spp. Removal In The Riparian Zone And Semi-Arid Rangeland Ecosystems, Hisham Nagi El Waer Aug 2013

Vegetation Response After Invasive Tamarix Spp. Removal In The Riparian Zone And Semi-Arid Rangeland Ecosystems, Hisham Nagi El Waer

Electronic Theses and Dissertations

Removal of Tamarix spp. (a.k.a. tamarisk, saltcedar, Athel) invasion is often involved in restoration of Western, riparian habitat; however monitoring of vegetation after removal is often neglected and thus opportunity for adaptive management lost. To address this need, I have conducted three and half years of monitoring vegetation response after invasive Tamarix removal in twenty-five sites on the East and Western Colorado, starting fall 2009. I am also comparing six different methodologies: Point intercept, line transect, nearest neighbor, meter-square quadrats, nested Whittaker plots, and densitometer with the objective of developing monitoring protocols that can be used by scientists ...


Variations In Phenotypic Plasticity And Fluctuating Asymmetry Of Leaf Morphology Of Three Quercus (Oak) Species In Response To Environmental Factors, Joseph Kusi May 2013

Variations In Phenotypic Plasticity And Fluctuating Asymmetry Of Leaf Morphology Of Three Quercus (Oak) Species In Response To Environmental Factors, Joseph Kusi

Electronic Theses and Dissertations

Leaf morphology of Quercus (oak) species is highly variable and complicated confounded with phenotypic plasticity and fluctuating asymmetry (FA). However, the study of variation is mostly limited to leaf morphology. This study was extended to plasticity and FA variations in Q. alba (white oak), Q. palustris (pin oak), and Q. velutina (black oak). It was hypothesized that light exposure, individual trees, leaf position, and other leaf traits will influence variation in these species. Leaves were sampled from trees of these species and their morphological traits were measured. Absolute asymmetry of leaf width and area were determined and plasticity of each ...


Fossil Trachemys (Testudines: Emydidae) From The Late Hemphillian Of Eastern Tennessee And Its Implications For The Evolution Of The Emydidae, Steven E. Jasinski May 2013

Fossil Trachemys (Testudines: Emydidae) From The Late Hemphillian Of Eastern Tennessee And Its Implications For The Evolution Of The Emydidae, Steven E. Jasinski

Electronic Theses and Dissertations

Trachemys (Testudines: Emydidae) represents one of the most well-known turtles today. The evolution of Trachemys, while being heavily documented with various fossil representatives, is not well understood. Numerous fossils from the Gray Fossil Site in northeastern Tennessee are helping to elucidate the taxon’s evolution. The fossil Trachemys at the Gray Fossil Site represent a new species. A review of previously named Trachemys taxa reveals that a huge majority of them are not valid or have been previously misinterpreted. A phylogenetic analysis preformed on modern emydids and supposed fossil representatives of those genera also shows the evolution of a portion ...


In Vitro Cultivation Of The Microphallid Trematode Gynaecotyla Adunca, Jenna West Apr 2013

In Vitro Cultivation Of The Microphallid Trematode Gynaecotyla Adunca, Jenna West

Electronic Theses and Dissertations

It is important to study the cultivation of parasites in vitro for many reasons, such as to aid in developing antihelminthic drugs and vaccines, to eliminate the need for vertebrate hosts in parasite culture, and to more easily study the genetics and the biology of parasites. Trematodes have complex life cycles with multiple hosts which makes them difficult to grow in vitro. However, microphallid trematodes are excellent candidates for parasite in vitro cultivation because they are short lived and progenetic. The goal of my study was to optimize in vitro culture conditions for the microphallid trematode, Gynaecotyla adunca. I determined ...


Variation In Egg Components: A Study Of Maternal Investment And Resource Partitioning In The Nesting Loggerhead Sea Turtle; Estimating Genic Variation And Mapping Genetic Lineage Of A Rare Captive Helodermatid Population: Heloderma Horridum Charlesbogerti, Ketan V. Patel Apr 2013

Variation In Egg Components: A Study Of Maternal Investment And Resource Partitioning In The Nesting Loggerhead Sea Turtle; Estimating Genic Variation And Mapping Genetic Lineage Of A Rare Captive Helodermatid Population: Heloderma Horridum Charlesbogerti, Ketan V. Patel

Electronic Theses and Dissertations

Loggerhead sea turtles have the highest egg yields of any oviparous non-avian reptiles. Blood urea nitrogen levels increased as the season progressed while total blood albumen and total protein levels decreased. Wet egg mass (H = 1.7719 df = 2 p = 0.0375*) and albumen mass (H = 6.0507 df = 2 p = 0.0485*) significantly decreased across the nesting season however, wet yolk did not. Analysis of dried egg components showed that dry yolk and albumen did not differ across the nesting season. In addition on no seasonal change in dried egg components, hatchling size was conserved across the nesting season ...


Assortative Mating In Ixodes Scapularis (Acari: Ixodidae) Ticks? And Ixodes Scapularis Infest Male Deer More Often Than Female Deer At Savannah River Site, (Aiken, Sc), Jenny Dickson Apr 2013

Assortative Mating In Ixodes Scapularis (Acari: Ixodidae) Ticks? And Ixodes Scapularis Infest Male Deer More Often Than Female Deer At Savannah River Site, (Aiken, Sc), Jenny Dickson

Electronic Theses and Dissertations

In this study we explored the hypothesis that the mitochondrial genetic diversity observed in Ixodes Scapularis ticks in the Southeastern United States is maintained through assortative mating. The study of 319 couples of ticks collected in copula from deer at the Savannah River Site (Aiken, SC) showed that ticks assigned to mitochondrial (12SrDNA and d-loop genes) phylogenetic monophyletic clades do not chose their mating partner based on genetic similarity or genetic diversity. The genetic composition of couples did not differ significantly from random choice. Our data indicate that if genetic diversity is maintained in this tick population, this cannot be ...


Relating Climate Change To The Nesting Phenology And Nest Environment Of Marine Turtles, Monette Schwoerer Jan 2013

Relating Climate Change To The Nesting Phenology And Nest Environment Of Marine Turtles, Monette Schwoerer

Electronic Theses and Dissertations

Ectotherms (including marine turtles) being especially sensitive to climate, are at risk to the accelerated rate of human-driven climate change. This study addresses two concerns associated with marine turtles and climate change – the relationship between the timing of marine turtle nesting and sea surface temperature; and the concern over the feminization of marine turtle populations due to rising sand temperatures. Previous studies of loggerhead sea turtles (Caretta caretta) and green sea turtles (Chelonia mydas) have documented the relationship between sea surface temperatures and nesting phenology. Earlier nesting behaviors in both species have been associated with warmer sea surface temperatures. Also ...


Population Dynamics And Environmental Factors Influencing Herbs In Intact And Degraded Florida Rosemary Scrub, Elizabeth Stephens Jan 2013

Population Dynamics And Environmental Factors Influencing Herbs In Intact And Degraded Florida Rosemary Scrub, Elizabeth Stephens

Electronic Theses and Dissertations

Species have complex and contextual relationships with their environment; both the relative contributions of life-history stages to population growth and the effect of environmental factors on each stage can be different among co-existing species. Timing and extent of reproduction, survival, and mortality determine population growth, species distributions, and assemblage patterns. I evaluate the role of habitat (intact, degraded) and microsite (shrub, leaf litter, bare sand) on population dynamics of Florida scrub herbs. Isolated overgrown shrubs and extensive bare sand areas in degraded scrub were expected to decrease seed predation, reduce competition of herbs with shrubs, and provide larger habitat for ...


Biogeography And Systematics Of The Nerodia Clarkii/Nerodia Fasciata Clade In Florida, Gregory Territo Jan 2013

Biogeography And Systematics Of The Nerodia Clarkii/Nerodia Fasciata Clade In Florida, Gregory Territo

Electronic Theses and Dissertations

Biogeography provides a window into the evolutionary history of populations, and helps explain the diversity and distribution of life through time. Viewed from a systematic perspective, biogeographic studies generate convincing arguments to explain the relationships among organisms and categorize them into useful taxonomies. When taxonomies do not reflect evolutionary histories, inaccurate representations of biodiversity confound future studies and conservation efforts. Two thamnophiine snakes, Nerodia clarkii and Nerodia fasciata, harbor unique morphological and ecological adaptations that obscured natural groupings, leading to controversial taxonomic delimitations. Additionally, population declines documented in N. clarkii compressicauda and N. clarkii taeniata led managers to list N ...


Sex Ratios Of Juvenile Green Turtles (Chelonia Mydas) In Three Developmental Habitats Along The Coast Of Florida, Cheryl Sanchez Jan 2013

Sex Ratios Of Juvenile Green Turtles (Chelonia Mydas) In Three Developmental Habitats Along The Coast Of Florida, Cheryl Sanchez

Electronic Theses and Dissertations

The concept of temperature dependent sex determination (TSD) has been somewhat of an evolutionary enigma for many decades and has had increased attention with the growing predictions of a changing climate, particularly in species that are already threatened or endangered. TSD taxa of concern include marine turtles, which go through various life stages covering a range of regions. This, in turn, creates difficulties in addressing basic demographic questions. Secondary sex ratios (from life stages post-hatchling) were investigated by capturing juvenile green turtles (Chelonia mydas), 22.6-60.9 cm in straight carapace length (SCL), from three developmental areas along the east ...


Juvenile Ornamentation: Its Evolution, Genetic Basis, And Variation Across Habitats, Angela Tringali Jan 2013

Juvenile Ornamentation: Its Evolution, Genetic Basis, And Variation Across Habitats, Angela Tringali

Electronic Theses and Dissertations

Ornamental traits are considered honest advertisements of fitness, and their evolution is usually explained in terms of sexual selection. This explanation remains unsatisfactory in some instances, for example, juvenile birds whose plumage is molted prior to adulthood and breeding. I first evaluate whether juvenile plumage reflectance signals dominance status in the Federally Threatened Florida scrub-jay (Aphelocoma coerulescens) using a combination of observational and experimental methods. Then I estimate the heritability, non-genetic maternal and environmental effects, and strength of selection on juvenile plumage reflectance using archived feather samples and a pedigree constructed from historical nest records. Finally, I compare plumage reflectance ...


Modeling Survival Of Immature Loggerheads (Caretta Caretta) And Green Turtles (Chelonia Mydas) From 10 Years Of Mark-Recapture Data At The Florida Power And Light St. Lucie Plant, Andrew Sterner Jan 2013

Modeling Survival Of Immature Loggerheads (Caretta Caretta) And Green Turtles (Chelonia Mydas) From 10 Years Of Mark-Recapture Data At The Florida Power And Light St. Lucie Plant, Andrew Sterner

Electronic Theses and Dissertations

Loggerheads (Caretta caretta) are listed as Threatened and green turtles (Chelonia mydas) are listed as Endangered under the United States Endangered Species Act. While green turtle nest production in Florida has increased markedly in recent years, loggerhead nest production has followed a more tenuous path. Reasons for these differences are unknown. Limited demographic information is available for these species of conservation concern. I used Barker models, which incorporated mark-recapture, live-resight and dead recovery data, implemented in Program MARK. These models were used to estimate apparent survival for immature loggerhead (


Habitat Use And Feeding Ecology Of Delphinids Inferred From Stable Isotopes And Fatty Acid Signatures, Nicole Browning Jan 2013

Habitat Use And Feeding Ecology Of Delphinids Inferred From Stable Isotopes And Fatty Acid Signatures, Nicole Browning

Electronic Theses and Dissertations

Prey availability, directly or indirectly, affects all aspects of a predator’s life history and is a primary factor influencing habitat selection and movements. This is especially true for delphinid species where it has been documented that the behaviors and movements of dolphins are strongly influenced by food availability. Unfortunately, the feeding ecology and habitat use patterns of many of these species are poorly understood. Many methodologies that have been employed to explore these facets of dolphin ecology have limitations and constraints or are logistically infeasible. Stable isotope and fatty acid signature analyses have been used extensively on a wide ...


Disturbance-Based Management And Plant Species Change In Massachusetts Sandplain Heathlands Over The Past Two Decades, Kirsten Martin Jan 2013

Disturbance-Based Management And Plant Species Change In Massachusetts Sandplain Heathlands Over The Past Two Decades, Kirsten Martin

Electronic Theses and Dissertations

Massachusetts sandplain heathlands are habitats of conservation concern, harboring many rare plant species and providing habitat for animals that depend on openlands. These heathlands are threatened by human development, shrub encroachment in the absence of disturbance, and potentially increasing soil nutrient levels. Sandplain heathlands are managed with prescribed fire, in order to maintain their open structure and maintain species diversity. In order to assess how past management was correlated with species change, I used a data set that spanned twenty years from three different heathlands in Massachusetts. I looked for correlations between management and species change. Correlations between species change ...


Assessing The Effectiveness Of Living Shoreline Restoration And Quantifying Wave Attenuation In Mosquito Lagoon, Florida, Jennifer Manis Jan 2013

Assessing The Effectiveness Of Living Shoreline Restoration And Quantifying Wave Attenuation In Mosquito Lagoon, Florida, Jennifer Manis

Electronic Theses and Dissertations

Coastal counties make up only 17% of the land area in the continental United States, yet 53% of the nation’s population resides in these locations. With sea level rise, erosion, and human disturbances all effecting coastal areas, researchers are working to find strategies to protect and stabilize current and future shorelines. In order to maintain shoreline stability while maintaining intertidal habitat, multipurpose living shorelines have been developed to mimic natural shoreline assemblages while preventing erosion. This project determined the effectiveness of a living shoreline stabilization containing Crassostrea virginica (eastern oyster) and Spartina alterniflora (smooth cordgrass) in the field and ...


Florida Local Government Conservation Planning: Variability, Drivers, And Policy Implications, Pamela Pannozzo Jan 2013

Florida Local Government Conservation Planning: Variability, Drivers, And Policy Implications, Pamela Pannozzo

Electronic Theses and Dissertations

This study examined the quality of Florida county government conservation planning. To assess conservation planning quality, a theoretical model of conservation planning as prescribed by the conservation science literature was first developed. A plan evaluation coding protocol was applied to local comprehensive plan Conservation Elements to determine the extent to which county-level conservation planning met the theoretical model. A high degree of variability in conservation planning quality was found. Highest quality conservation planning occurred in the Gulf coast counties of southwest Florida. Lowest conservation planning quality occurred in the Florida Panhandle counties. The quality of conservation planning of coastal counties ...


Mitochondrial Glutathione Transport: Implications For Bcl-2 And Neuronal Survival, Heather Marie Wilkins Jan 2013

Mitochondrial Glutathione Transport: Implications For Bcl-2 And Neuronal Survival, Heather Marie Wilkins

Electronic Theses and Dissertations

Oxidative stress is a contributing factor to many neurodegenerative diseases. In particular, mitochondria are a key source of oxidative stress due to electron leakage at the level of the electron transport chain. To combat the endogenous production of reactive oxygen and reactive nitrogen species mitochondria are equipped with several redox-cycling systems, such as glutathione (GSH). Mitochondrial GSH has been shown to be a critical reservoir of this antioxidant, where selective depletion of mitochondrial GSH can induce apoptosis in several systems. Many studies have intricately linked Bcl-2 to cellular GSH status and it has been previously shown that Bcl-2 is a ...


A Role For Dynamin-Dependent Endocytosis During Drosophila Gastrulation, Marissa Kay Kuhl Jan 2013

A Role For Dynamin-Dependent Endocytosis During Drosophila Gastrulation, Marissa Kay Kuhl

Electronic Theses and Dissertations

Gastrulation, a process conserved among many higher organisms, is the directed migration of cells into layers that will establish various tissues targeted to become anatomical structures. This process is accomplished through another conserved morphogenetic event, known as cell intercalation. Early in development, this movement of cells within an organized tissue leads to unique cellular arrangements where neighboring cells contract their shared interfaces in order to meet at a shared vertex. In this thesis, I present work that demonstrates a requirement for Dynamin-dependent endocytosis during these contraction events. Using quantitative analysis, I have identified varied cell behaviors during experiments which knockdown ...


Evolution Of Melanocortin-2 Receptor Activations: Studies On A Mammal And A Fish, Liang Liang Jan 2013

Evolution Of Melanocortin-2 Receptor Activations: Studies On A Mammal And A Fish, Liang Liang

Electronic Theses and Dissertations

The structure and function relationship between melanocortin-2 receptor (MC2R) and ACTH are the most complicated in melanocortin receptor gene family. A comparative study on the activation of human and rainbow trout MC2R will provide a useful model system for understanding how ACTH emerged as the sole ligand for the MC2R of bony vertebrates. This dissertation will discuss how studies utilizing analogs of hACTH(1-24) have revealed two critical amino acid motifs in this ligand (HFRW and KKRRP) which are required for the activation of MC2R. In addition, the KKRRP motif functioned as the unique binding site for MC2R that directly ...


Wetland Diversity In A Disturbance-Maintained Landscape: Effects Of Fire And A Fire Surrogate On Aquatic Amphibian Survival And Species Depauperateness., Joyce Klaus Jan 2013

Wetland Diversity In A Disturbance-Maintained Landscape: Effects Of Fire And A Fire Surrogate On Aquatic Amphibian Survival And Species Depauperateness., Joyce Klaus

Electronic Theses and Dissertations

Disturbance is one of the central concepts explaining how diversity arises and is perpetuated in ecological time. A good model system for testing hypotheses related to disturbance is the longleaf pine ecosystem in the southeastern U.S. because in this ecosystem frequent, low-severity fires acts as a disturbance that maintains a unique vegetation structure and high species richness. Vegetation structure influences animal distributions; in fire-dependent ecosystems many animals rely on open-structured, fire-maintained vegetation but shrubs and trees encroach into fire-dependent ecosystems where fire has been excluded. Prescribed burning and mechanical removal are commonly used as restoration tools to control encroachment ...


Testing For Indirect Benefits Of Polyandry In The Florida Green Turtle, Christopher Long Jan 2013

Testing For Indirect Benefits Of Polyandry In The Florida Green Turtle, Christopher Long

Electronic Theses and Dissertations

Behavioral studies in the green turtle (Chelonia mydas) have indicated that promiscuous mating is commonplace. Though it has been shown that there is much variation in the rate of polyandry (females mating with multiple males), the drivers behind polyandry in this species are unknown. It has been speculated, but never demonstrated, that indirect benefits (fitness benefits resulting from offspring genetic diversity) play a role. However, previous tests of this hypothesis have limited scope of inference due to lack of environmental control. In this thesis, I attempted to study the indirect benefits of polyandry in Archie Carr National Wildlife Refuge (ACNWR ...


Estimated Diets, Diet Overlap, And Winter Habitat Associations Of Four Grassland Sparrows In Florida Dry Prairie, Marianne Korosy Jan 2013

Estimated Diets, Diet Overlap, And Winter Habitat Associations Of Four Grassland Sparrows In Florida Dry Prairie, Marianne Korosy

Electronic Theses and Dissertations

North American grassland birds show long-term population declines that generally exceed the declines of other bird groups. Efforts to conserve grassland birds require knowledge of diet and habitat requirements during both the breeding and nonbreeding periods of annual life cycles. This dissertation investigated sparrow habitat associations within two defined plant communities of the dry prairie ecosystem, the dry-mesic and wet-mesic prairie, for four prescribed fire treatments over two consecutive winters. Grasshopper and Henslow’s sparrows showed higher relative abundance in wet-mesic prairie and Bachman’s Sparrows were more abundant in dry-mesic prairie across all fire treatments. Abundances of Grasshopper and ...


Effects Of Site Preparation, Seed Germination, And Harvest Maturity On Wiregrass Restoration Efforts At Fort Stewart, Ga, Nickey Garrett Anderson Jan 2013

Effects Of Site Preparation, Seed Germination, And Harvest Maturity On Wiregrass Restoration Efforts At Fort Stewart, Ga, Nickey Garrett Anderson

Electronic Theses and Dissertations

Wiregrass (Aristida stricta Michx.) was once the dominant ground cover species within the Atlantic Coastal Plain longleaf pine (Pinus palustris Mill.) ecosystem. Less than 1 million hectares of intact longleaf pine-wiregrass communities remain, due primarily to anthropogenic activities. Wiregrass is a keystone species in the longleaf pine ecosystem, as its presence facilitates the natural fire regime, a critical component in the perpetuation of these communities. Therefore, there is increased interest in wiregrass restoration in both existing longleaf pine communities and future longleaf pine restoration sites. Many restoration sites are on tracts that have been cleared of all vegetation. Removal of ...


Individual And Population Responses Of The Caribbean Sponge, Aplysina Cauliformis, To Natural And Anthropogenic Stressors, Cole Gregory Easson Jan 2013

Individual And Population Responses Of The Caribbean Sponge, Aplysina Cauliformis, To Natural And Anthropogenic Stressors, Cole Gregory Easson

Electronic Theses and Dissertations

Coral reefs are under increasing threat from a diversity of stressors. These reefs have undergone a phase shift from coral-dominated to algal-dominated ecosystems, and in many cases other functional groups such as sponges are now the predominant organisms on many reefs. This dissertation investigated the responses of a common branching sponge, Aplysina cauliformis, to algal contact, eutrophication, hurricanes, and disease. The effects of algal competition, anthropogenic nutrients and a combination of these stressors on A. cauliformis were examined using factorial designed field experiments on Bahamian reefs. These experiments demonstrated a complex interaction between sponge and alga, in which the green ...


Linking The Functional Diversity Of Ectomycorrhizal Fungal Species To Soil Carbon And The Genetics Of A Foundational Tree Species, Nicole Marie Hergott Jan 2013

Linking The Functional Diversity Of Ectomycorrhizal Fungal Species To Soil Carbon And The Genetics Of A Foundational Tree Species, Nicole Marie Hergott

Electronic Theses and Dissertations

Carbon dioxide in the atmosphere continues to increase, leading to an enhanced interest in the potential for ecosystems to sequester carbon. Soil could have a high potential to store carbon in these forests, but there is still a great deal to learn about how carbon storage in soils is influenced by ectomycorrhizal fungi. In this symbiosis, the plant host provides the vast majority of C for fungal growth. As a consequence, ECM fungi may provide one of the major pathways for C from trees to soils. Ectomycorrhizal fungal species produce extracellular enzymes that may degrade soil carbon and may differ ...