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Full-Text Articles in Life Sciences

Ecological Stoichiometry: What Role Does It Play In The Competition And Spatial Distribution Patterns Of Aedes Albopictus And Aedes Aegypti?, James Deerman Dec 2018

Ecological Stoichiometry: What Role Does It Play In The Competition And Spatial Distribution Patterns Of Aedes Albopictus And Aedes Aegypti?, James Deerman

Master's Theses

Ecological stoichiometry is the balance of chemical substances within animal bodies through interactions and processes within their ecosystem. Though relatively underexplored, it provides a wealth of information linking interactions across different levels of organization. Detritus is the base of the food web within the small aquatic ecosystems occupied by the mosquitoes Aedes albopictus and Aedes aegypti. Nutrient content of detritus varies, but it can have a negative effect on mosquito growth and survival if nutrient thresholds are not met. I investigated nutrient environments and species abundance in cemetery vases in New Orleans, LA to assess detrital heterogeneity and its …


Coastal Wetland Dynamics Under Sea-Level Rise And Wetland Restoration In The Northern Gulf Of Mexico Using Bayesian Multilevel Models And A Web Tool, Tyler Hardy Aug 2018

Coastal Wetland Dynamics Under Sea-Level Rise And Wetland Restoration In The Northern Gulf Of Mexico Using Bayesian Multilevel Models And A Web Tool, Tyler Hardy

Master's Theses

There is currently a lack of modeling framework to predict how relative sea-level rise (SLR), combined with restoration activities, affects landscapes of coastal wetlands with uncertainties accounted for at the entire northern Gulf of Mexico (NGOM). I developed such a modeling framework – Bayesian multi-level models to study the spatial pattern of wetland loss in the NGOM, driven by relative RSLR, vegetation productivity, tidal range, coastal slope, and wave height – all interacting with river-borne sediment availability, indicated by hydrological regimes. These interactions have not been comprehensively investigated before. I further modified this model to assess the efficacy of restoration …


Spatial Distribution And Stock-Recruitment Analysis Of The Atlantic Surfclam, Spisula Solidissima, In The Mid-Atlantic Bight And On Georges Bank, Jeremy Timbs Aug 2018

Spatial Distribution And Stock-Recruitment Analysis Of The Atlantic Surfclam, Spisula Solidissima, In The Mid-Atlantic Bight And On Georges Bank, Jeremy Timbs

Master's Theses

Atlantic surfclams, Spisula solidissima, are long-lived bivalve molluscs with dispersive larval stages. Surfclam patchiness throughout the U.S. Exclusive Economic Zone (EEZ) has declined from the 1980’s to the present in all assessed regions (Delmarva, New Jersey, Long Island, Southern New England, and Georges Banks). Warming of Mid-Atlantic bottom waters is driving the surfclam stock into new habitat and extirpating the surfclams from nearshore areas. Based on a species distribution function model, the small surfclams appear to inhabit a greater area than the large market-size surfclams across the entire stock. The wider distribution of recent recruits relative to the fishable …


Creating Renewable Energy Through The Pairing Of Wastewater Remediation And Biofuel Production With Two Species Of Microalgae, Laura Brown Aug 2018

Creating Renewable Energy Through The Pairing Of Wastewater Remediation And Biofuel Production With Two Species Of Microalgae, Laura Brown

Master's Theses

In this study, two species of microalgae, Scenedesmus sp. isolated locally and Chlorella sorokiniana (UTEX 1230) were grown in municipal wastewater collected from Stennis Space Center, MS in order to assess whether or not the microalgae could remediate the wastewater into a clean and usable form while also producing the biomaterials necessary for fuel and other useful byproducts. Each species was cultured in 16 ˚C and 30 ˚C to assess functional variabilities at different times of the year. The microalgae’s ability to decrease nutrient concentrations in the wastewater and produce lipids and protein was assessed at three different growth stages: …


The Role And Contribution Of Saprotrophic Fungi During Standing Litter Decomposition Of Two Perennial Grass Species, Schizachyrium Scoparium And Schizachyrium Tenerum, Matthew Lodato May 2018

The Role And Contribution Of Saprotrophic Fungi During Standing Litter Decomposition Of Two Perennial Grass Species, Schizachyrium Scoparium And Schizachyrium Tenerum, Matthew Lodato

Master's Theses

In terrestrial ecosystems, most of the plant biomass produced enters the detrital pool, where microbial decomposers colonize, enzymatically degrade, and assimilate plant litter carbon and nutrients in amounts sufficient to bring about the decomposition of plant litter. Here, I estimated the biomass and production of fungi and microbial respiration associated with decaying Schizachyrium scoparium and Schizachyrium tenerum leaf litter, and constructed a partial organic matter budget estimating C flow into and through fungal decomposers. Significant losses in S. scoparium (57%) and S. tenerum (68%) leaf mass was observed during litter decomposition along with concomitant increases in fungal biomass, which reached …


Life-History Characteristics And Fishery Dynamics Of Red Drum (Sciaenops Ocellatus), In The North-Central Gulf Of Mexico, Corbin Bennetts May 2018

Life-History Characteristics And Fishery Dynamics Of Red Drum (Sciaenops Ocellatus), In The North-Central Gulf Of Mexico, Corbin Bennetts

Master's Theses

Red Drum (Sciaenops ocellatus) are highly targeted recreationally in the Gulf of Mexico, and support a small commercial fishery in Mississippi. Despite their popularity, the stock is assessed using data limited approaches that necessitate accurate life history information. I estimated the year-specific and year-aggregated escapement rates for the Mississippi stock (years 2004 to 2015), which were sensitive to mortality estimation methods; year-aggregated estimates were 6.9 to 28.2 % depending on the method, but temporal patterns were consistent. I then addressed concerns with previously estimated life-history characteristics by describing the sex-specific growth and reproductive dynamics. The three-parameter von Bertalanffy …


Vocalizations Of North American River Otters (Lontra Canadensis) In Two Human Care Populations, Sarah Walkley May 2018

Vocalizations Of North American River Otters (Lontra Canadensis) In Two Human Care Populations, Sarah Walkley

Master's Theses

There is a dearth of information regarding the vocal repertoire of North American river otters (Lontra canadensis). This indicator species is cosmopolitan yet elusive, making recordings methodologically difficult in the wild. Therefore, this exploratory study uses video and audio recordings of two populations of North American river otters in human care to broaden the known vocal repertoire of river otters in various social contexts. The populations consist of a male-female pair at the Stamford Museum and Nature Center and a male-male pair at The Maritime Aquarium at Norwalk. This study is the first to examine the vocalizations produced …


Regional Variation In Migratory Behavior And Reproductive Output Of The Gulf Of Mexico Blue Crab Spawning Stock, Adam Kemberling May 2018

Regional Variation In Migratory Behavior And Reproductive Output Of The Gulf Of Mexico Blue Crab Spawning Stock, Adam Kemberling

Master's Theses

The overarching goal of this research was to better understand the structure and boundaries of the blue crab stock(s) in the Gulf of Mexico, focusing on large-scale movements of spawning female crabs. Because spawning location is a primary determinant of larval transport pathways, understanding spawning locations and offshore movements of female blue crabs can inform stock identification and potentially clarify the somewhat conflicting population genetic information available for blue crabs. A large-scale mark-recapture study was conducted through the partnership of state/federal management agencies, the commercial fishing industry, recreational fisherman, tourists, and numerous academic institutions to shed light on the timing …


Detection, Activity Measurement And Phylogeny Of Ureolytic Bacteria Isolated From Elasmobranch Tissue, Yimu Yang May 2018

Detection, Activity Measurement And Phylogeny Of Ureolytic Bacteria Isolated From Elasmobranch Tissue, Yimu Yang

Master's Theses

Free-ranging marine elasmobranch tissue-associated micro-organisms were cultured from free-ranging Atlantic stingray (Dasyatis sabina) and Atlantic sharpnose sharks (Rhizoprionodon terraenovae). 16S rRNA gene phylogeny indicated bacteria community structure in both elasmobranchs were under phylum Proteobacteria, Firmicutes and Actinobacteria. By conducting split-plot ANOVA, we found the microbial richness is significantly different (P=0.0814) between two superorders of elasmobranch, which may largely due to their preferred habitats and feeding habits. Urease presentence and activity was detected in phylogenetically diverse bacterial strains. Species with high urea-hydrolyzing ability, such as Micrococcus luteus (shark blood isolate: 46.84 mU/mg protein; stingray blood isolate: 24.36 …


Spatial Variation In Basal Resources And Trophic Position Of Selected Fishes Of The North-Central Gulf Of Mexico, Christopher Fleming May 2018

Spatial Variation In Basal Resources And Trophic Position Of Selected Fishes Of The North-Central Gulf Of Mexico, Christopher Fleming

Master's Theses

The North-central Gulf of Mexico is a complex hydrologic environment with freshwater influx that varies on spatial and temporal scales. Freshwater input exerts influence on the isotope values of organisms living in coastal ecosystems. The objectives of this study were to determine relationships between total length and isotope value, estimate basal resource usage and trophic position of target species from Mississippi Sound, reef, and pelagic environments, and identify differences and similarities in spatial patterns of collection. Muscle tissue samples were collected from October 2014 through September 2015. Stable isotope analysis identified a trophic gradient extending from nearshore to offshore, with …


Impact Of Prolonged Sitting On Central Hemodynamics: Role Of Intermittent Pneumatic Compression Therapy, Anna Kayleigh Downey May 2018

Impact Of Prolonged Sitting On Central Hemodynamics: Role Of Intermittent Pneumatic Compression Therapy, Anna Kayleigh Downey

Master's Theses

Prolonged sitting (3-6 hours) negatively impacts peripheral vascular health. Whether sitting similarly impacts central cardiovascular hemodynamics and vascular stiffness is unknown. Purpose: Determine if prolonged sitting increases central blood pressure, aortic pulse wave reflection and vascular stiffness. Methods: In 10 subjects (Age=22±2 yrs, BMI=28±4kg/m2, 3 females), brachial artery pulse wave analysis was performed before (baseline-BL), during, and after 3 hours of sitting. Aortic pulse wave velocity (PWV) was examined before and after sitting using carotid applanation tonometry coupled with oscillometry performed on left upper-thigh. For mechanistic insight, intermittent pneumatic compression (IPC) was applied during sitting (i.e., 3, 120 …


Factors Affecting The Regrowth Of Ilex Glabra In A Routinely Burned Longleaf Forest, Jaybus Price May 2018

Factors Affecting The Regrowth Of Ilex Glabra In A Routinely Burned Longleaf Forest, Jaybus Price

Master's Theses

This study examines the effects of historical management by use of prescribed fire on Ilex glabra stems/m2 and factors affecting the regrowth of I. glabra after a prescribed burn to gain beneficial knowledge for management purposes. Environmental factors and morphological parameters of I. glabra were sampled before and after a prescribed burn of the Longleaf Trace Nature Preserve in September 2016. The study site is located in Lamar County, Mississippi, just west of Hattiesburg, MS. Stem densities of I. glabra were collected once before the prescribed burn and twice after the prescribed burn at 2 month and 9 month …


Linkages Between Marsh Fragmentation, Prey Availability, And Blue Crab (Callinectes Sapidus) Abundance And Mortality, Lennah Shakeri May 2018

Linkages Between Marsh Fragmentation, Prey Availability, And Blue Crab (Callinectes Sapidus) Abundance And Mortality, Lennah Shakeri

Master's Theses

Coastal marshes are important nursery habitats for many commercially important invertebrate species, yet these marshes are being lost worldwide at an unprecedented rate due to subsidence, erosion, climate change, and human activity. As marsh is lost, it creates the opportunity for submerged aquatic vegetation (SAV) colonization and establishment in newly created open water areas. Blue crabs, Callinectes sapidus, use both marsh edge and SAV habitat during the juvenile stages and support one of the largest fisheries in the Gulf of Mexico, worth over $70 million in 2015. This thesis studied the linkages between habitat type, SAV cover, benthic prey …


Interplay Of Dgat1, Pdat1 And Dgat2 Enzymes In Plant Triacylglycerol Assembly, Anushobha Regmi May 2018

Interplay Of Dgat1, Pdat1 And Dgat2 Enzymes In Plant Triacylglycerol Assembly, Anushobha Regmi

Master's Theses

Acyl-CoA:diacylglycerol acyltransferase (DGAT) catalyzes the transesterification of fatty acid from acyl-CoA to diacylglycerol (DAG) forming triacylglycerol (TAG, a.k.a oils and fats). Most plants have at least two unrelated DGAT genes, DGAT1 and DGAT2. Plants predominantly express only one during oil synthesis; the reason, however is not clear. A few studies have indicated that each enzyme prefers DAG and acyl-CoA substrates with different fatty acid compositions. Industrially desirable seed oil composition can be obtained through genetic engineering by replacing the endogenous enzyme with one that has different substrate selectivity. In Arabidopsis thaliana, DGAT1 and another unrelated enzyme PDAT1 are essential …