Life Sciences Commons^™

Phase Speciation Of Carbohydrates And Dioxins In Rivers And Coastal Waters In The Northern Gulf Of Mexico, Kusumica Mitra

Master's Theses

Dissolved carbohydrates (d-CHO), including monosaccharide (MCHO) and polysaccharides (PCHO), and particulate carbohydrates (p-CHO) are major components of natural organic matter and play an important role in biogeochemical cycles of carbon and other trace elements in marine environments. This study aimed to examine the abundance and partitioning of CHO between dissolved and particulate phases and their seasonal variations in the Mississippi Sound/Bight and Lake Pontchartrain. Laboratory mixing experiments were also carried out to examine the behaviour of CHO species along a salinity gradient. The phase partitioning of dioxin among three different phases, i.e., colloidal organic matter, particulate organic matter and sediments, …

Determining The Trophic Role Of Gulf Menhaden (Brevoortia Patronus) Using Carbon And Nitrogen Stable Isotopes, Zachary Olsen

Master's Theses

Gulf menhaden (Brevoortia patronus) play multiple roles in the Gulf of Mexico coastal ecosystem as filter feeders and as an important food source for many recreationally and economically important finfish. Gulf menhaden also support a large commercial fishery, and little is known about the impact of fishing on the role of this species as a filter feeder in the food web. This study examines the spatial, temporal and ontogenetic dynamics of food selectivity and trophic role observed in Gulf menhaden. The most important dietary item for juvenile fish was found to be phytoplankton (75.7% dietary composition) while that of subadults …

Anode Material Testing For Marine Sediment Microbial Fuel Cells, Andrew John Quaid

Master's Theses

Research on the power production of the microbial fuel cell has increased in the past decade. The sediment microbial fuel cell is a type of fuel cell that uses the environment of submerged sediments to provide a natural voltage difference. The fuel cell is comprised of an anode buried in the sediment and a cathode that is held in the overlying water column. The process of electron transfer to the anode is catalyzed by anaerobic bacteria in the sediment. The anaerobic bacteria have that are able to catalyze the electron transfer have been termed exoelectrogenic. The increase in scientific research …

Immunostimulatory And Cellular Toxic Effects Of Single-Stranded Rna On Cancer Cells, Chengwen Teng

Master's Theses

Whether 5'-triphosphate-single-stranded-RNA (5 '-ppp-ssRNA) is immunostimulatory was controversial in the literature. In order to clarify the immunostimulatory effect of 5'-ppp-ssRNA, we synthesized ssRNAs and tested the IFNp (interferon-beta) level and cellular toxicity of ssRNAs in SKOV3 cells. In this work, we confirmed that 5'-ppp-ssRNA (~ 60nt) was immunostimulatory and toxic in SKOV3 cells. 5'-ppp-ssRNA (~ 60nt) led to IFN-P induction and apoptosis in SKOV3 cells. Longer 5' ppp- ssRNA tended to have a higher immunostimulatory effect and cellular toxicity than shorter 5'-ppp-ssRNA. 5'-ppp-ssRNA was more immunostimulatory and toxic than 5'- 0H-ssRNA. If the incubation time of ssRNAs increased, the toxicity …

Experimental Evidence For The Interplay Of Exogenous And Endogenous Factors On The Movement Ecology Of A Migrating Songbird, Emily B. Cohen, Frank R. Moore, Richard A. Fischer

Faculty Publications

Movement patterns during songbird migration remain poorly understood despite their expected fitness consequences in terms of survival, energetic condition and timing of migration that will carry over to subsequent phases of the annual cycle. We took an experimental approach to test hypotheses regarding the influence of habitat, energetic condition, time of season and sex on the hour-by-hour, local movement decisions of a songbird during spring stopover. To simulate arrival of nocturnal migrants at unfamiliar stopover sites, we translocated and continuously tracked migratory red-eyed vireos (Vireo olivaceus) throughout spring stopover with and without energetic reserves that were released in two replicates …

Were Multiple Stressors A "Perfect Storm" For Northern Gulf Of Mexico Bottlenose Dolphins (Tursiops Truncatus) In 2011?, Ruth H. Carmichael, William M. Graham, Allen Aven, Graham Worthy, Stephan D. Howden

Faculty Publications

An unusual number of near term and neonatal bottlenose dolphin (Tursiops truncatus) mortalities occurred in the northern Gulf of Mexico (nGOM) in 2011, during the first calving season after two well documented environmental perturbations; sustained cold weather in 2010 and the Deepwater Horizon oil spill (DWHOS). Preceding the stranding event, large volumes of cold freshwater entered the nGOM due to unusually large snowmelt on the adjacent watershed, providing a third potential stressor. We consider the possibility that this extreme cold and freshwater event contributed to the pattern of perinatal dolphin strandings along the nGOM coast. During the 4-month period starting …

Survival, Growth And Reproduction Of Non-Native Nile Tilapia Ii: Fundamental Niche Projections And Invasion Potential In The Northern Gulf Of Mexico, Michael R. Lowe, Wei Wu, Mark S. Peterson, Nancy J. Brown-Peterson, William T. Slack, Pamela J. Schofield

Faculty Publications

Understanding the fundamental niche of invasive species facilitates our ability to predict both dispersal patterns and invasion success and therefore provides the basis for better-informed conservation and management policies. Here we focus on Nile tilapia (Oreochromis niloticus Linnaeus, 1758), one of the most widely cultured fish worldwide and a species that has escaped local aquaculture facilities to become established in a coastal-draining river in Mississippi (northern Gulf of Mexico). Using empirical physiological data, logistic regression models were developed to predict the probabilities of Nile tilapia survival, growth, and reproduction at different combinations of temperature (14 and 30°C) and salinity …

Evolution Of A Sexually Dimorphic Trait In A Broadly Distributed Topminnow (Fundulus Olivaceus), Jacob F. Schaefer, David D. Duvernell, Brian R. Kreiser, Charles Champagne, Scott R. Clark, Melissa Gutierrez, Laura K. Stewart, Chazz Coleman

Faculty Publications

Understanding the interaction between sexual and natural selection within variable environments is crucial to our understanding of evolutionary processes. The handicap principle predicts females will prefer males with exaggerated traits provided those traits are indicators of male quality to ensure direct or indirect female benefits. Spatial variability in ecological factors is expected to alter the balance between sexual and natural selection that defines the evolution of such traits. Male and female blackspotted topminnows (Fundulidae: Fundulus olivaceus) display prominent black dorsolateral spots that are variable in number across its broad range. We investigated variability in spot phenotypes at 117 sites …

Impacts Of Upstream Drought And Water Withdrawals On The Health And Survival Of Downstream Estuarine Oyster Populations, Laura E. Petes, Alicia J. Brown, Carley R. Knight

Faculty Publications

Increases in the frequency, duration, and severity of regional drought pose major threats to the health and integrity of downstream ecosystems. During 2007-2008, the U.S. southeast experienced one of the most severe droughts on record. Drought and water withdrawals in the upstream watershed led to decreased freshwater input to Apalachicola Bay, Florida, an estuary that is home to a diversity of commercially and ecologically important organisms. This study applied a combination of laboratory experiments and field observations to investigate the effects of reduced freshwater input on Apalachicola oysters. Oysters suffered significant disease-related mortality under high-salinity, drought conditions, particularly during the …

Concurrent Effects Of Resource Pulse Amount, Type, And Frequency On Community And Population Properties Of Consumers In Detritus-Based Systems, Donald A. Yee, Steven A. Juliano

Faculty Publications

Episodic resource inputs (i.e., pulses) can affect food web properties and community dynamics, but detailed mechanistic understanding of such effects remain elusive. Natural aquatic microsystems (e.g., tree holes, human-made containers) are colonized by invertebrates that form complex food webs dependent on episodic and sometimes sizeable inputs of allochthonous detritus from adjacent terrestrial environments. We investigated how variation in pulse frequency, amount, and resource type interacted to affect richness, abundance, composition, and population sizes of colonizing invertebrates in water-filled tires and tree hole analogs in a forest habitat. Different container types were used to assess the generality of effects across two …

Synthesis Of A Glutathione Analogue Using 2-Α-Methyl-Β-Cysteine, Nathan Freeman

Honors Theses

Inhibitors of glutathione reductase (GR) have been synthesized and studied in order to reverse an increasing trend in resistance to common malaria treatments. Analogues of glutathione (GSH) are being synthesized in order to increase resistance to proteolysis, thereby acting as an inhibitor of GR. Through the use of unnatural amino acids, solution-phase synthesis of GSH can be easily performed using modified cysteine (Cys) residues. A modified Cys residue, 2-α-methyl-β-cysteine, has been successfully synthesized, and coupling of this residue with the other required residues of GSH, glycine (Gly) and glutamic acid (Glu), has the potential to be successfully synthesized in good …

Exploring The Interaction Between Human Granulin-A (Hgrn-A) And Amyloid-Β (Aβ) Peptide, Michael Samel

Honors Theses

Alzheimer’s disease (AD) is the most common form of dementia affecting people over the age of 60, yet a detailed understanding of the molecular changes involved in AD remains a significant challenge to modern medicine. The hallmarks of an AD brain include the presence of senile plaques formed by a protein called amyloid-β (Aβ), along with inflammation of the brain. Aβ self-associates to form clumps of protein called “aggregates” which are known to be the primary toxic agents in AD pathology; however, several other proteins have also been implicated in this pathology. One such protein called progranulin (PGRN), which under …

Molecular And Functional Characterization Of Tick Salivary Vti Protein Family, Ashley Villarreal

Honors Theses

Tick salivary glands serves as the organ of osmoregulation in ticks and are critical to the biological success of ticks both during extended period off the host and also during the feeding periods on the host. The salivary glands are the sites of pathogen development and saliva is the route of transmission. The importance of multifunctional salivary glands to tick survival and vector competency makes the glands a potential target for intervention. The complex process by which tick salivary gland proteins exit the glands and enter the host has been extensively studied, in what is called the SNARE hypothesis, soluble …

Determining The Diversity Of Wetland Fungi Through Molecular-Based Species Identification, Kimberly Chesteen

Honors Theses

This study used molecular techniques to examine the diversity of fungal species inhabiting leaf and stem litter of the freshwater emergent macrophyte, Typha angustifolia, during decomposition. Because morphological identification of fungal species is frequently inaccurate and underestimates the number of fungal species present, molecular techniques involving rRNA genes such as ITS regions (internal transcribed spacer regions) are used to better determine specific fungal species within a sample. In this study, samples of decaying leaf and stems litter of Typha angustifolia were obtained from Independence Lake, Michigan over the span of a year. DNA from litter samples obtained from the months …

The Effects Of An Informal Science Education Setting On Students’ Attitudes Towards Learning Science, Lauren Finley

Honors Theses

Informal science education is becoming increasingly popular in today’s classrooms, and for this reason, it is important to understand the effects of informal science education on students. In this study, the Children’s Attitude Survey (Wulf, Mayhew, & Finkelstein, 2009) was used to measure the effects of informal science education on students’ attitude toward science. Questionnaires were administered to two sample sets, and results indicated a slight decrease in attitude after participating in an informal science field trip. Continuing research in this area will provide more insight into why these effects were seen, and how informal science education can be best …

Television’S Effects On Speech And Language: The Parent’S Perspective, Hillary Fortenberry

Honors Theses

Purpose: This study focuses on an area seldom studied, the parent’s perception of television’s influence on their speech and language disordered child’s receptive and expressive skills. Understanding the parent’s perspective on specific effects television has on speech and language development can be valuable by providing educators and child caretakers with answers as to why parents allow their children to watch television. With this knowledge, parents can be educated as to what type of programming and to what extent viewing should be allowed for children to gain positive speech and language outcomes from their television viewing experience.

Method: .This study gathered …

A Phylogeny Of Samydaceae Based On Nuclear Gbssi And Emb2765 Dna Sequences, Chelsa Williams

Honors Theses

Samydaceae are a tropical family of woody flowering plants, poorly known because they were once included in the ‘dustbin’ family Flacourtiaceae and because there are few economically important species. The family has recently been studied using DNA sequence data, but most of the data were from plastid DNA and some relationships had low statistical support. For this study, two nuclear regions, EMB2765 and GBSSI, were sequenced in order to affirm or refute the relationships inferred from plastid DNA and in order to find stronger statistical support for relationships. The data collected mostly affirm previously collected data from plastid DNA.

The Identification Of Arachnid Species In The Cockscomb Basin Wildlife Sanctuary, Lauren Auer

Honors Theses

Despite the known diversity of arachnids in neotropical ecozones there has been little considerable movement towards creating a collective means for identification of arachnids in Belize. Previous studies on ecotourism indicate positive trends between biodiversity education and conservation concern. This study was conducted to engage in a field-based study of arachnids in the Cockscomb Basin Wildlife Sanctuary to determine the most frequently encountered arachnid species. For this study, four separate locations were surveyed within the Sanctuary: three trail sites and the main camp area. Each site was surveyed during two alternate time periods to account for diurnal and nocturnal species. …

Spiders Of Riparian Communities In The Cockscomb Basin Wildlife Sanctuary, Belize, Megan Chevis

Honors Theses

Currently there is little literature on what arachnids inhabit the tropics of Central America, especially within the country of Belize. This study aimed to find which spider species are found in riparian areas within the Cockscomb Basin Wildlife Sanctuary in central Belize and to distinguish trends among spiders and the microhabitats in which they live. Nocturnal samples were predicted to have greater diversity than diurnal samples at all sites. Pisauridae, Salticidae, and Lycosidae were predicted to be the most common spider families collected. Specimens were collected from three riparian sites located on trails within Cockscomb. Diurnal and nocturnal samples were …

The Role Of Midline And Pexin10 In Regulating Drosophila Eye Development, John Forstall

Honors Theses

The Drosophila midline (mid) transcription factor gene encodes a highly conserved invertebrate ortholog of the mammalian Tbx20 gene essential for regulating the development of diverse tissues including the central nervous system (CNS), epidermis and heart. Decreasing mid transcript levels within larval eye discs using RNAi (mid- RNAi) results in poorly organized IPCs and in adult eyes, interommatidal bristles derived from sensory organ precursors are significantly reduced in number within the ventral eye field. We also observe gross abnormalities in bristle polarity, ommatidial organization, cellular adhesion and pigmentation in adult mid-RNAi flies. By combining a classical …

Differences In Race And/Or Gender In Attitudes And Beliefs Towards Obesity Among Students At The University Of Southern Mississippi, Erick Brown

Honors Theses

Overweight and obesity have been described by various experts as critical problems in populations around the world, especially in the United States. These issues are so characterized because they affect numerous facets of life in this society. Researchers in the medical community have repeatedly described the health-related risks associated with obesity rates, asserting that higher risks of debilitating or fatal disease are tied to one’s level of obesity. They also say that obesity rates of populations are related to other disease rates, and many imply or clearly state that obesity is the cause and therefore the problem to be contested. …

Flora Of The Gopher Farm Sandhill, Wayne County, Mississippi, Shira Brittany Nicholson

Honors Theses

This study documents the vascular plants and common lichens of the Gopher Farm sandhill, Wayne County, Mississippi. The Gopher Farm sandhill is located within the Chickasawhay Ranger District of the DeSoto National Forest and is one of the most northerly located sandhills in the Coastal Plain of Mississippi. The sandhill was surveyed 11 times from the spring of 2011 to the spring of 2012, primarily during the spring and fall. The survey resulted in 180 species, including 15 lichens, 1 fern, 2 gymnosperms, and 162 flowering plants. Collections included two rare species (Carex tenax and Rhynchospora megalocarpa) and …

Genetic Variation In Potentially Virulent Vibrio Parahaemolyticus From The Northern Gulf Of Mexico, Nicholas Felix Noriea Iii

Dissertations

Vibrio parahaemolyticus (V_p) is a gram-negative bacterium found naturally in marine and estuarine environments. V_p is found in oysters including those which are later consumed by the public. Sub-populations of potentially virulent Vp contain specific virulence factors and are relevant human pathogens capable of causing gastroenteritis, wound infection, and death. The tdh and trh genes, both encoding hemolysins, have been correlated with the majority of clinical V_p isolates but have not been shown to be the definitive virulence factors.

A total of 146 V_p isolates from the northern Gulf of Mexico were collected and probed …

Effects Of Hypoxia And 4-Tert-Octylphenol On Gene Expression Profiles Of The Sheepshead Minnow (Cyprinodon Variegatus), Arthur Alan Karels

Dissertations

Hypoxia occurs in estuaries of northern Gulf of Mexico and world-wide, with increasing frequency/severity via eutrophication and anthropogenic influences. Hypoxia inducible factors (HIFs) form transcriptional complex and bind DNA at hypoxia responsive elements (HREs) in promoter regions of genes needed for systemic and cellular adaptation of fish to low dissolved oxygen (hypoxia, DO <2.0 mg/ml). Hypoxia-induced activation of HIF-αs can lead to a cascade of downstream activation, such as erythropoietin (EPO). Return to normal DO levels (normoxia), prolyl hydroxylases (PHDs) are activated to degrade HIF-αs back to baseline. Fish are affected by environmental estrogen mimics, like 4-tert-octylphenol (4tOP), binding estrogen receptor alpha (ERα) at estrogen responsive elements (EREs) and activating genes vitellogenin (VTG). Previous research showed overlap or crosstalk between these two mechanistic pathways. Hypoxia triggers unknown factors regulating ERE-mediated ERα signaling pathway, and stressor combinations could increase/decrease hypoxic or endocrine pathway. Research examined molecular/physiological effects of hypoxia (acute and chronic, moderate and severe) and 4tOP (~60μg/L)on adult male and/or female sheepshead minnow (Cyprinodon variegatus). Three genes identified, cloned, and sequenced (HIF-1α, HIF-2α, and PHD3), plus previously identified genes EPO and VTG, were examined in liver/testes exposed to hypoxia and/or 4tOP for cellular/physiological changes. Endpoints examined included mRNA expression from real-time PCR of HIF-1α, HIF-2α, PHD3, EPO, and VTG using cDNA from total RNA extracts, and microarray analyses of genes expressed during the transition from hypoxia back to normoxia. Phylogenetic analyses confirmed isolation of two HIF-α isofoms (HIF-1α and HIF-2α) and the PHD3 isoform. Significant up-regulation of PHD3 occurred within 10 hrs of chronic hypoxia, and persisted when severe (1.5 mg/L) and declined when moderate (~2.5mg/L). Significant up-regulation of HIF-1α and EPO occurred within 30 minutes to 2 hours of onset of acute severe and very severe (~1.08mg/L) hypoxia. Hypoxia acted similar to an estrogen mimic, with huge up-regulation of VTG gene expression in males, and increased VTG levels (additive effect) when hypoxia was combined with 4tOP. Microarray analyses showed 125 genes with significant transcriptional change, with up- or down-regulation from transitions of: (1) hypoxia (72 hrs) to normoxia (74 hrs) and (2) hypoxia+4tOP (72 hrs) to normoxia+4tOP (74 hrs).

Clam (Corbicula Fluminea) As A Potential Sentinel Of Human Norovirus Contamination In Freshwater, Xunyan Ye

Dissertations

The purpose of this study was to evaluate and validate the use of the clam Corbicula fluminea as a sentinel of human noroviruses (HuNoV) contamination in freshwater. The first specific aim was to develop a new method to extract HuNoV RNA from contaminated bivalves (e.g. oysters, clams) that would be much faster than existing methods. The procedure developed includes an initial total RNA extraction using TRI Reagent, followed by HuNoV RNA concentration and purification using biotinylated probe-capture technology. HuNoV RNA is finally detected by real-time RT-PCR. Using bivalve homogenates spiked with HuNoV, 100 PCR detection units of the virus was …

Application Of A Hybrid 3d-Var Data Assimilation System In The Monterey Bay To Study Regional Dynamics Of The California Current System, Chudong Pan

Dissertations

A data assimilation system combining 3-dimensional variational scheme and Navy Coastal Ocean Model was applied to the Monterey Bay area to assimilate temperature and salinity glider data collected in August 2003. The hybrid background error covariance model in the present 3-dimensional variational system incorporates both the static and the flow-dependent background error covariance. To explore the impact of high temporal resolution on the overall skill of the assimilation system, the intended data assimilation interval was set to 1 hour in the present study. A Floating Temporal Window approach is designed to keep the computational efficiency of the scheme and to …

Personality Assessment In African Elephants (Loxodonta Africana), Kristina Marie Horback

Dissertations

The following study assessed personality in twelve African elephants using both observational behavior coding and standardized trait rating methods, thus demonstrating consistent individual differences across time and contexts. During the summer of 2010 and 2011, over 640 hours of behavioral data were collected onsite at the San Diego Zoo Safari Park in Escondido, CA. Four coding-based personality traits were determined after analysis: PLAYFUL, CURIOUS, TOLERANT, and, AGGRESSIVE. This data was then compared to survey ratings completed by the animal keeper staff during both summers. Four rating-based personality traits resulted from this analysis: PLAYFUL, CURIOUS, TIMID, and, AGGRESSIVE. All eight composite …

Diversity Of Tanaidacea (Crustacea: Peracarida) In The World's Oceans - How Far Have We Come?, Gary Anderson, Magdalena Blazewicz-Paszkowycz, Roger Bamber

Faculty Publications

Tanaidaceans are small peracarid crustaceans which occur in all marine habitats, over the full range of depths, and rarely into fresh waters. Yet they have no obligate dispersive phase in their life-cycle. Populations are thus inevitably isolated, and allopatric speciation and high regional diversity are inevitable; cosmopolitan distributions are considered to be unlikely or non-existent. Options for passive dispersion are discussed. Tanaidaceans appear to have first evolved in shallow waters, the region of greatest diversification of the Apseudomorpha and some tanaidomorph families, while in deeper waters the apseudomorphs have subsequently evolved two or three distinct phyletic lines. The Neotanaidomorpha has …

Caprg: Sequence Assembling Pipeline For Next Generation Sequencing Of Non-Model Organisms, Arun Rawat, Mohamed O. Elasri, Kurt A. Gust, Glover George, Don Pham, Leona D. Scanlan, Chris Vulpe, Edward J. Perkins

Faculty Publications

Our goal is to introduce and describe the utility of a new pipeline “Contigs Assembly Pipeline using Reference Genome” (CAPRG), which has been developed to assemble “long sequence reads” for non-model organisms by leveraging a reference genome of a closely related phylogenetic relative. To facilitate this effort, we utilized two avian transcriptomic datasets generated using ROCHE/454 technology as test cases for CAPRG assembly. We compared the results of CAPRG assembly using a reference genome with the results of existing methods that utilize de novo strategies such as VELVET, PAVE, and MIRA by employing parameter space comparisons (intra-assembling comparison). CAPRG performed …

An Evaluation Of Mississippi Barrier Islands As A Spawning And Nesting Habitat For The American Horseshoe Crab, Limulus Polyphemus, With Implications For Island Restoration, Richard Fulford, Rebecca A. Haehn

Gulf and Caribbean Research

The American horseshoe crab (HSC), Limulus polyphemus, is an economically and ecologically important species in the coastal ecosystem. Horseshoe crabs inhabit the continental shelf and estuaries from Maine to the central Gulf Coast and the Yucatán Peninsula. Although the presence of horseshoe crabs in southern Mississippi is known locally, there are limited data specific to the area and population, particularly regarding spawning and nesting habitat. Surveys of HSC presence, habitat use, and behavior on Mississippi barrier islands were conducted between March and November 2007 to 2009. These data, combined with habitat surveys of the barrier islands, were used to …