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Florida's Pillar Coral (Dendrogyra Cylindrus): The Roles Of The Holobiont Partners In Bleaching, Recovery, And Disease Processes, Cynthia Fairbank Lewis Dec 2018

Florida's Pillar Coral (Dendrogyra Cylindrus): The Roles Of The Holobiont Partners In Bleaching, Recovery, And Disease Processes, Cynthia Fairbank Lewis

FIU Electronic Theses and Dissertations

The iconic pillar coral, Dendrogyra cylindrus, is one of five Caribbean species listed in 2014 under the US Federal Endangered Species Act because of its extreme low abundance and continued decline in US waters. Until recently, little was known about the demographics or genetic diversity of Florida’s D. cylindrus population. This study represents the first time two holobiont partners (coral animal and associated photosynthetic algal endosymbionts) have been closely examined, spatially and temporally, in this little-studied species. The aim was to explore the influences of coral animal genotypes, mutualistic photosynthetic algal strains, and hyperthermal stress on bleaching and …


Factors Affecting Green Turtle Foraging Ecology Across Multiple Spatial Scales, Elizabeth Rose Whitman Oct 2018

Factors Affecting Green Turtle Foraging Ecology Across Multiple Spatial Scales, Elizabeth Rose Whitman

FIU Electronic Theses and Dissertations

The hierarchical levels at which resource selection occurs can have important consequences for individual and population energy budgets and structure the impacts of a forager on its ecosystem. Assessing factors affecting resource selection of large marine herbivores across scales is important because of their potentially large impacts on seagrass community dynamics and historical and current changes in their population sizes and those of their potential predators. I explored the factors (predation risk, resource abundance, quality and identity) affecting resource use of large marine herbivores (green turtles, Chelonia mydas) from the scale of habitat patches to forage species within patches. …


Novel Role Of Pseudomonas Aeruginosa Lptd Operon, Sundar Pandey Jun 2018

Novel Role Of Pseudomonas Aeruginosa Lptd Operon, Sundar Pandey

FIU Electronic Theses and Dissertations

Pseudomonas aeruginosais an opportunistic pathogen that infects cystic fibrosis (CF) patients contributing to their high morbidity and mortality. P. aeruginosaundergoes a phenotypic conversion in the CF lung, from nonmucoid to mucoid, by constitutively producing a polysaccharide called alginate. These mucoid strains often revert to nonmucoid in vitrodue to second-site suppressor mutations. We hypothesized that mapping these mutations would lead to the identification of novel genes involved in alginate production. In a previous study, a mucoid strain, PDO300 (PAOmucA22), was used to isolate suppressors of alginate phenotype (sap). One of the uncharacterized nonmucoid revertants, …


Spatial And Temporal Patterns Of Arctic Nearshore Fish Community And Food Web Structures, Mark B. Barton Jun 2018

Spatial And Temporal Patterns Of Arctic Nearshore Fish Community And Food Web Structures, Mark B. Barton

FIU Electronic Theses and Dissertations

Climate change and increasing anthropogenic activities are causing rapid changes to environmental and ecological processes in the Arctic Ocean. To better understand these changes, scientists have increased research efforts in these regions, but to date the number of studies on Arctic nearshore habitats are lacking. My dissertation responds to the paucity of information and investigates patterns in Arctic nearshore fish communities and food webs to gain insight to how these ecosystems may shift as these changes continue. I used multivariate statistical analysis to examine patterns in community structure and composition to determine that Arctic nearshore fish communities are largely driven …


Quantitative Spatial Upscaling Of Categorical Data In The Context Of Landscape Ecology: A New Scaling Algorithm, Daniel Gann Jun 2018

Quantitative Spatial Upscaling Of Categorical Data In The Context Of Landscape Ecology: A New Scaling Algorithm, Daniel Gann

FIU Electronic Theses and Dissertations

Spatially explicit ecological models rely on spatially exhaustive data layers that have scales appropriate to the ecological processes of interest. Such data layers are often categorical raster maps derived from high-resolution, remotely sensed data that must be scaled to a lower spatial resolution to make them compatible with the scale of ecological analysis. Statistical functions commonly used to aggregate categorical data are majority-, nearest-neighbor- and random-rule. For heterogeneous landscapes and large scaling factors, however, use of these functions results in two critical issues: (1) ignoring large portions of information present in the high-resolution grid cells leads to high and …


Saltwater Intrusion And Vegetation Shifts Drive Changes In Carbon Storage In Coastal Wetlands, Sean Patrick Charles Jun 2018

Saltwater Intrusion And Vegetation Shifts Drive Changes In Carbon Storage In Coastal Wetlands, Sean Patrick Charles

FIU Electronic Theses and Dissertations

Coastal wetlands protect coastlines through efficient storage of organic carbon (OC) that decreases wetland vulnerability to sea level rise (SLR). Accelerated SLR is driving saltwater intrusion and altering vegetation communities and biogeochemical conditions in coastal wetlands with uncertain implications. We quantified changes in OC stocks and fluxes driven by 1) saltwater and phosphorous intrusion on freshwater and brackish marshes, 2) vegetation along an experimental saltmarsh to mangrove gradient, 3) saltwater intrusion and vegetation change across a marsh to mangrove ecotone, and 4) vegetation change and mangrove forest development along a marsh to mangrove ecotone. Increasing salinity in freshwater marshes decreased …


Evolutionary And Population Dynamics Of Crustaceans In The Gulf Of Mexico, Laura Timm Jun 2018

Evolutionary And Population Dynamics Of Crustaceans In The Gulf Of Mexico, Laura Timm

FIU Electronic Theses and Dissertations

Evolution occurs and can be conceptualized along a spectrum, bounded on one extreme by the relationships between deep lineages – such as phyla, classes, and orders – and on the other by the molecular dynamics of operational taxonomic units within a species, defined as population genetics. The purpose of this dissertation was to better understand the evolutionary and population dynamics of crustaceans within the Gulf of Mexico. In the second chapter of my dissertation, I provide a guide to best phylogenetic practice while reviewing infraordinal relationships within Decapoda, including the promise held by next-generation sequencing (NGS) approaches such as Anchored …


Regulation Of Juvenile Hormone Synthesis By 20-Hydroxyecdysone In The Yellow-Fever Mosquito, Aedes Aegypti, Maria Areiza May 2018

Regulation Of Juvenile Hormone Synthesis By 20-Hydroxyecdysone In The Yellow-Fever Mosquito, Aedes Aegypti, Maria Areiza

FIU Electronic Theses and Dissertations

In Aedes aegypti, development and reproduction are regulated by juvenile hormone III (JH). This master regulatory hormone is synthesized by the corpora allata (CA), a pair of endocrine glands with neural connections to the brain. JH titers are largely determined by the rate of biosynthetic activity of the CA and are regulated by inhibitory and stimulatory factors. Like JH, the ecdysteroid 20-hydroxyecdysone (20E) is a key hormonal regulator and has been proposed as an allatoregulator in other insects. However, its part in the regulation of JH biosynthesis of mosquitoes was unknown. The specific aims of this dissertation were to …


The Adaptive Evolution Of Herbivory In Freshwater Systems, Jessica Lynn Sanchez Montelongo May 2018

The Adaptive Evolution Of Herbivory In Freshwater Systems, Jessica Lynn Sanchez Montelongo

FIU Electronic Theses and Dissertations

Herbivory is thought to be nutritionally inefficient relative to carnivory and omnivory. But, herbivory evolved from carnivory in many lineages, suggesting that there are advantages to eating plants. To understand the adaptive significance of the transition from carnivory to herbivory, I proposed five hypotheses for the adaptive evolution of herbivory and reviewed the current freshwater literature to identify conditions where eating plants might be adaptive over eating animals. I tested three of these ideas (Suboptimal Habitat, Heterotroph Facilitation, and Lipid Allocation) using the herbivorous Sailfin Molly (Poecilia latipinna)and identified each as a potential mechanism for the evolution of …


The Evolution And Domestication Genetics Of The Mango Genus, Mangifera (Anacardiaceae), Emily Warschefsky Apr 2018

The Evolution And Domestication Genetics Of The Mango Genus, Mangifera (Anacardiaceae), Emily Warschefsky

FIU Electronic Theses and Dissertations

Domesticated species are vital to global food security and have also been foundational to the formulation and advancement of evolutionary theory. My dissertation employs emerging molecular genomic tools to provide an evolutionary context for crop improvement. I begin by providing a contemporary perspective on two components of domestication biology that have long been used to improve crop production: wild relatives of crop species and grafted rootstocks. First, I propose a method to systematically introgress crop wild relative diversity into crop breeding programs. Then, I explore rootstocks, the lesser-known half of the perennial crop equation, documenting prevalence and diversity, cataloging rootstock …


Diatoms As Tools For Inferring Changing Environmental Gradients In Coastal, Freshwater Wetlands Threatened By Saltwater Intrusion, Viviana Mazzei Mar 2018

Diatoms As Tools For Inferring Changing Environmental Gradients In Coastal, Freshwater Wetlands Threatened By Saltwater Intrusion, Viviana Mazzei

FIU Electronic Theses and Dissertations

Saltwater intrusion alters the natural salinity and phosphorus (P) gradients in the oligotrophic, freshwater wetlands located near coastlines of the Caribbean Basin with important consequences to the structure and function of key ecosystem components, including plants, soil microbes, and periphyton. Periphyton communities, particularly diatoms, are extremely sensitive to water quality changes and can serve as excellent bioindicators; however, little is known about their use in detecting novel rates of saltwater intrusion into coastal, freshwater wetlands. I examined the individual and combined effects of elevated salinity and P on periphyton functional processes and diatom composition by conducting transect surveys along salinity …


A Confluence Of Invasion, Behavioral, And Theoretical Ecology: What Drives Ephemeral Metacommunity Re-Assembly?, Jesse Ryan Blanchard Mar 2018

A Confluence Of Invasion, Behavioral, And Theoretical Ecology: What Drives Ephemeral Metacommunity Re-Assembly?, Jesse Ryan Blanchard

FIU Electronic Theses and Dissertations

Metacommunity theory has been particularly useful in understanding the way spatially structured communities assemble. Both niche and neutral processes are known to influence metacommunity assembly, and the relative influence of each depends on the level of dispersal-limitation. Contemporary trait-based analyses of metacommunity assembly have enhanced our understanding of these processes. Of the traits investigated, individual personalities have received the least attention, but have been suggested to be drivers of metacommunity assembly model parameters, such as dispersal tendencies and patch density. I address this topic from three angles, three chapters, in this dissertation. First, I used a three-year field survey of …


Sab Concentration Determines The Chemotherapeutic Efficacy In Gynecological Cancer, Iru Paudel Mar 2018

Sab Concentration Determines The Chemotherapeutic Efficacy In Gynecological Cancer, Iru Paudel

FIU Electronic Theses and Dissertations

The American Cancer Society predicts there will be 110,070 new cases and 32,120 deaths due to gynecological malignancies in 2018. A major contributing factor to the high mortality associated with gynecological cancers is the recurrence of treatment-resistant tumors. Ovarian cancer (OC) remains the most lethal gynecological malignancy, yet the mechanisms responsible for regulating tumor resistance and vulnerability are largely unknown or undruggable. Therefore, the goal of this research is to identify mechanisms responsible for therapeutic resistance in gynecological cancers and discover innovative approaches to circumvent these molecular alterations. Our efforts began in OC where secondary analysis of gene expression data …


Patterns Of Carbon Metabolism, Storage, And Remineralization In Seagrass Ecosystems, Jason Lee Howard Mar 2018

Patterns Of Carbon Metabolism, Storage, And Remineralization In Seagrass Ecosystems, Jason Lee Howard

FIU Electronic Theses and Dissertations

Coastal marine sediments have recently been identified as globally important stocks of organic carbon (Corg) that, if compromised, could significantly exacerbate global greenhouse gas emissions. While resource managers and policy makers are eager to incorporate this ecosystem service into seagrass ecosystem valuation frameworks, similar to those already in existence for terrestrial forests, there has been insufficient information regarding how environmental conditions and seagrass ecology control carbon storage. These include the influence of the seagrass to the production and preservation of soil organic matter, the fate of stored carbon following conversion of coastal wetlands, and the interactions between organic …


Recovery Of Amphibian And Reptile Communities During Tropical Secondary Forest Succession, Michelle E. Thompson Mar 2018

Recovery Of Amphibian And Reptile Communities During Tropical Secondary Forest Succession, Michelle E. Thompson

FIU Electronic Theses and Dissertations

The extensive clearing and modification of natural systems from anthropogenic activities is a pressing global concern. Forest habitats and animal communities within forests are among the most highly impacted, globally. Forest destruction has been repeatedly documented as a driver of biodiversity loss. However, little is known about how animal communities respond when altered landscapes are abandoned and left to regenerate into secondary forests. It is thought that the regrowth of secondary forests may help reverse biodiversity loss by restoring habitats to similar conditions as prior to land conversion. Of the forest cover that remains, over half is secondary forest, and …


Drivers And Mechanisms Of Peat Collapse In Coastal Wetlands, Benjamin J. Wilson Mar 2018

Drivers And Mechanisms Of Peat Collapse In Coastal Wetlands, Benjamin J. Wilson

FIU Electronic Theses and Dissertations

Coastal wetlands store immense amounts of carbon (C) in vegetation and sediments, but this store of C is under threat from climate change. Accelerated sea level rise (SLR), which leads to saltwater intrusion, and more frequent periods of droughts will both impact biogeochemical cycling in wetlands. Coastal peat marshes are especially susceptible to saltwater intrusion and changes in water depth, but little is known about how exposure to salinity affects organic matter accumulation and peat stability. I investigated freshwater and brackish marsh responses to elevated salinity, greater inundation, drought, and increased nutrient loading. Elevated salinity pulses in a brackish marsh …