Life Sciences Commons^™

The Vascular Flora Of Wayne County, Mississippi, Daniel M. Mcnair

Master's Theses

The vascular flora of Wayne County, Mississippi, was surveyed from 2013–2015, and the species of native and naturalized plants are listed. In total, 1,135 species were identified from field collections, previously collected herbarium specimens, and field observations. These belong to 556 genera and 165 families. Four of these species represent first recorded occurrences in the state of Mississippi: Blyxa aubertii Rich., Gomphrena serrata Pav. ex Moq., Isoetes valida (Engelm.) Clute, and Polypogon interruptus Kunth. GPS coordinates are given for important collection sites representing the diversity of plant communities in the county. All voucher specimens from the survey are deposited in …

Are Large Dogs Smarter Than Small Dogs? Investigating Within Species Differences In Large And Small Dogs: Spatial Memory, Megan S. Broadway

Master's Theses

The study of canine cognition can be useful in understanding the ontology and selective pressures that affect the development of cognitive abilities. Dogs have undergone intensive artificial selection yielding distinctive breeds which differ both phenotypically and behaviorally. Breed based cognitive differences have not been found but some studies suggest there may be differences in broader categories such as working disposition and sex. The influence of size on canine cognition has not been thoroughly addressed despite the fact that large dogs are often perceived to be ‘smarter’ than small dogs. This preconception has only recently been addressed and supported in one …

Same-Sex Socio-Sexual Interactions Among A Group Of Captive Bottlenose Dolphins (Tursiops Truncatus), Natalia Botero Acosta

Master's Theses

Bottlenose dolphins (Tursiops truncatus) frequently engage in non-reproductive sexual behavior, including homosexual encounters. In order to better understand the nature and function of these interactions, a longitudinal study of the patterns of association and the dynamics of initiator/recipient role exchange was conducted. Underwater video footage of a colony of bottlenose dolphins housed at the Roatan Institute for Marine Sciences (RIMS), collected between March of 2010 and May of 2013, was analyzed. Associations occurring during homosexual interactions were transitory for most individuals. Nonetheless, subsequent analyses allowed the rejection of the null hypothesis of random association, suggesting the existence of …

Management Strategy Evaluation For The Atlantic Surfclam, Spisula Solidissima, Using A Fisheries Economics Model, Kelsey M. Kuykendall

Master's Theses

The Atlantic surfclam, Spisula solidissima, is an economically valuable bivalve harvested along the northeastern United States. The surfclam’s range has contracted and the center of the stock’s distribution has shifted north driven by warmer bottom water temperatures. Declining landings per unit effort (LPUE) in the Mid-Atlantic Bight (MAB) is one result. Declining stock abundance and LPUE suggest that overfishing may be occurring off New Jersey. The objective of this project is to perform a management strategy evaluation (MSE) for Spisula solidissima. The terminal goal is to identify a preferred management option that promotes enhanced surfclam productivity in the …

High Resolution Melt Analysis Of Samples With Differential Dna Methylation To Identify Tissue Source Of Origin, Stephanie M. Ledgerwood

Master's Theses

In Forensic Science casework, identifying the source of a tissue can assist in crime scene reconstruction. Currently, presumptive testing methods to identify tissue type are utilized in crime scene laboratories, but there is a need for a more reliable confirmatory test for tissue type identification. High Resolution Melt (HRM) analysis is an innovative technology that has the potential to determine tissue types through variations in DNA methylation patterns. Recently, DNA methylation patterns have been found to correspond with specific tissue types in particular regions of DNA. Two markers, B_SPTB_03 and DDX4 have been effective in differentiating sperm from other tissue …

Maternal Effects And Offspring Behavior: Potential Contributors To The Lack Of Recruitment In Mississippi Gopher Tortoises (Gopherus Polyphemus), Aaron L. Holbrook

Master's Theses

Federally threatened in Mississippi, gopher tortoise (Gopherus polyphemus) populations within the state have strongly variable recruitment and are generally in decline. Hatching success is significantly lower in Mississippi than in any other part of the species’ range , and most hatchlings die within the first year. There are few refuges where survival and hatching success is high. Here I compare two populations that differ in recruitment and offspring survival for differences in corticosterone. Corticosterone is a hormone that influences both energy availability and is released in elevated levels during stressful events, like living in poor quality habitat. Prolonged corticosterone elevation …

Territorial Defense Strategies In The Northern Cardinal (Cardinalis Cardinalis): Who Is The Bigger Threat?, Kaylee M. Gentry

Master's Theses

This thesis examines the use of defensive strategies in relation to territories year round in the northern cardinal (Cardinalis cardinalis). Responses to recorded neighbor song and stranger song playback from the middle of a focal male’s territory were measured. This allowed for an estimation of aggression in both the winter and spring seasons. Each focal male was subjected to both treatments (stranger song and neighbor song). Males were more responsive over-all to neighbor song playback, however in the winter months, persistence of response to neighbor song playback increased. It was also shown that southeastern United States cardinals show …

Does Gut Microbiota Affect The Diet Preference In Anurans?, Jordan A. Rice

Honors Theses

Gut microbiota is a community of bacteria that live in the digestive track of a host. These microbes assist in the breakdown of indigestible materials as food passes through the alimentary canal. Metabolites from bacteria may play a role cell to cell communication with their host and thus gut microbiota may affect the diet preference of the animal host. Southern Leopard frogs (Rana sphenocephala) and Green Tree frogs (Hyla cinerea) were used as focal species to test whether gut microbiota affect their diet preference. Three groups of tadpoles were tested. The control group was fed a …

Characterization Of Embryonic Stem Cell-Differentiated Cells As Mesenchymal Stem Cells, Rachael N. Kuehn

Honors Theses

Embryonic stem cells (ESCs), due to their ability to differentiate into different cell types while still maintaining a high proliferation capacity, have been considered as a potential cell source in regenerative medicine. However, current ESC differentiation methods are low yielding and create heterogeneous cell populations. If transplanted in the human body, differentiated ESCs could be rejected by the immune system, form tumors, or may not function normally within the human body. On the other hand, mesenchymal stem cells (MSCs), a type of adult stem cell typically derived from bone marrow, have proved to be excellent candidates in clinical applications due …

Hospital Practices Related To Breastfeeding In Mississippi: A Socio-Ecological Approach, Amir Alakaam

Dissertations

Mississippi continues to have one of the lowest rates and the weakest support in respect to breastfeeding in the nation (Centers for Disease Control and Prevention, 2014a). Hospital practices supporting breastfeeding such as the Ten Steps to Successful Breastfeeding (TSSB) can dramatically increase breastfeeding rates and duration (Rosenberg, Stull, Adler, Kasehagen, & Crivelli-Kovach, 2008). The aim of this study was to explore breastfeeding practices in Mississippi hospitals based on two levels of the Socio-Ecological Model: the organizational level (phase I) examined the hospital practices based on the level of implementation of the TSSB; the individual level (phase II) examined knowledge …

Macrobenthic Communities In The Northern Gulf Of Mexico Hypoxic Zone: Testing The Pearson-Rosenberg Model, Shivakumar Shivarudrappa

Dissertations

The Pearson and Rosenberg (P-R) conceptual model of macrobenthic succession was used to assess the impact of hypoxia (dissolved oxygen [DO] ≤ 2 mg/L) on the macrobenthic community on the continental shelf of northern Gulf of Mexico for the first time. The model uses a stress-response relationship between environmental parameters and the macrobenthic community to determine the ecological condition of the benthic habitat. The ecological significance of dissolved oxygen in a benthic habitat is well understood. In addition, the annual recurrence of bottom-water hypoxia on the Louisiana/Texas shelf during summer months is well documented.

The P-R model illustrates the decreasing …

Environmental Impacts And Carry-Over Effects In Complex Life Cycles: The Role Of Different Life History Stages, Nnaemeka F. Ezeakacha

Dissertations

A challenge faced by organisms with complex life cycles is how environmental factors experienced at an earlier life stage affect the fitness at that stage or are carried over to subsequent life stages. I used container-inhabiting mosquitoes: Aedes albopictus, Aedes aegypti, Aedes triseriatus and Culex quinquefasciatus to study the interactions and performance of life history stages under specific environmental factors. I investigated the effects of egg-desiccation tolerance on egg viability and larval performance in the Aedes mosquitoes. I found increase in egg hatch rate with relative humidity and interaction between relative humidity and egg storage period. Larval performance …

Investigating The Impact Of Reflexive Practices On College Students In A Science Laboratory Course, Chandrani Mishra

Dissertations

Emphasis on professional practices to develop students’ professionalism is currently a major focus of higher education. Studies have shown the benefits of reflexive practices in classroom to facilitate the development of students’ professional attitude or identity in some fields. Reflexive practices involve students in self-reflection where he/she reflects on his/her own actions. Little investigation about the benefits of reflexive practices in the development of students’ scientific identity in a science class led to my investigation. Development of a scientific identity of students and their overall interest and motivation in science is deemed essential for retaining students in STEM fields.

My …

Influence Of Benagene Supplementation In Conjunction With High Intensity Cycling Exercise, Wilson P. Simmons

Honors Theses

High intensity aerobic performance is determined by the body’s maximal ability to match lactate production and clearance rates, defined as the lactate threshold (LaTh). Intensities performed above the LaTh result in accumulation of lactate causing fatigue. In a double-blind experiment, using trained cyclists and triathletes, we investigated skeletal muscle adaptations that occurred following 28-days of Benagene supplementation (oxaloacetate). The testing protocol consisted of an initial cycle test (T1) to measure VO₂max, LaTh, respiratory exchange ratio (RER), power output (PO) and heart rate (HR). Testing began after a 15-min warm-up at 75W, beginning at 100W, increasing 30W each 3-min …

Loss Of Glycosaminoglycan Receptor Binding After Mosquito Cell Passage Reduces Chikungunya Virus Infectivity, Dhiraj Acharya, Amber M. Paul, John F. Anderson, Faqing Huang, Fengwei Bai

Faculty Publications

Chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus that can cause fever and chronic arthritis in humans. CHIKV that is generated in mosquito or mammalian cells differs in glycosylation patterns of viral proteins, which may affect its replication and virulence. Herein, we compare replication, pathogenicity, and receptor binding of CHIKV generated in Vero cells (mammal) or C6/36 cells (mosquito) through a single passage. We demonstrate that mosquito cell-derived CHIKV (CHIKV_mos) has slower replication than mammalian cell-derived CHIKV (CHIKV_vero), when tested in both human and murine cell lines. Consistent with this, CHIKV_mos infection in both cell lines …

An Insight Into The Functional Role Of Thioredoxin Reductase, A Selenoprotein, In Maintaining Normal Native Microbiota In The Gulf Coast Tick (Ambylomma Maculatum), Khemraj Budachetri, Shahid Karim

Faculty Publications

Tick selenoproteins have been associated with antioxidant activity in ticks. Thioredoxin reductase (TrxR), also a selenoprotein, belongs to the pyridine nucleotide‐disulphide oxidoreductase family of proteins and is an important antioxidant. Molecular interactions between native microbiota and tick hosts have barely been investigated to date. In this study, we determined the functional role of TrxR in tick feeding and in maintenance of the native microbial community. TrxR transcript levels remained high and microbial load was reduced throughout tick attachment to the vertebrate host. RNA interference (RNAi) showed that depletion of TrxR activity did not interfere with tick haematophagy or phenotype but …

Testosterone Might Not Be Necessary To Support Female Aggression In Incubating Northern Cardinals, M. Susan Devries, Caitlin P. Winters, Jodie M. Jawor

Faculty Publications

Testosterone's (T) influence on male aggression has been well established in many vertebrate species, but the impact of T on female aggressive behaviour is poorly understood. Among birds, a link between T and female aggression is plausible, as females of many species exhibit a seasonal peak in T concentrations at the onset of breeding when social instability is greatest and they may have circulating T through much of the breeding season. However, investigations examining the relationship between T and female aggression are few and have yielded conflicting results, with experimentally or endogenously elevated T supporting aggressive behaviour in females of …

Functional, Sub-100 Nm Polymer Nanoparticles Via Thiol-Ene Miniemulsion Photopolymerization, Douglas Amato, Dahlia Amato, Alex S. Flynt, Derek L. Patton

Faculty Publications

In this work, sub-100 nm crosslinked polythioether nanoparticles were synthesized via thiol–ene photopolymerization in miniemulsion using high-energy homogenization. The effects of the miniemulsion formulation and homogenization parameters – including inhibitor concentration, surfactant concentration, organic weight fraction, ultrasonication time and amplitude – on nanoparticle size and size distribution were investigated. Thiol–ene nanoparticles with a mean particle diameter of 46 nm were obtained under optimized conditions for the current system at 2.5 wt% organic fraction and 20 mM surfactant concentration. In an effort to demonstrate potential utility of thiol–ene nanoparticles, we exploit the step-growth radical mechanism of thiol–ene photopolymerization under non-stoichiometric conditions …

How Diverse Detrital Environments Influence Nutrient Stoichiometry Between Males And Females Of The Co-Occurring Container Mosquitoes Aedes Albopictus, Ae. Aegypti, And Culex Quinquefasciatus, Donald A. Yee, Michael G. Kaufman, Nnaemeka F. Ezeakacha

Faculty Publications

Allocation patterns of carbon and nitrogen in animals are influenced by food quality and quantity, as well as by inherent metabolic and physiological constraints within organisms. Whole body stoichiometry also may vary between the sexes who differ in development rates and reproductive allocation patterns. In aquatic containers, such as tree holes and tires, detrital inputs, which vary in amounts of carbon and nitrogen, form the basis of the mosquito-dominated food web. Differences in development times and mass between male and female mosquitoes may be the result of different reproductive constraints, which could also influence patterns of nutrient allocation. We examined …

Forensic Autopsy. The Particularities Of Consent For Research, Sorin Hostiuc

Journal of Health Ethics

Forensic autopsy has as its main goal to find out the truth about the causes and circumstances of death, when there is a reasonable suspicion to be caused by a violent act. As the legal guardian cannot refuse a forensic autopsy, the forensic physician is free to perform any procedures considered to be necessary for finding out the truth (in order to answer to the objectives asked by the authority). However the use of biological samples or data in research is limited and needs an additional consent, from the legal guardian, which can lead to difficulties in the interpretation of …

Assessing Biogeochemical Impacts And Environmental Conditions Associated With Cross-Shelf High Chlorophyll Plumes In The Northern Gulf Of Mexico, Erin Brooke Jones

Dissertations

The northern Gulf of Mexico is a complex marine system subject to episodic physical phenomena such as loop current eddies. Flow fields generated by these eddies can result in cross-shelf exchanges between riverine influenced shelf waters and the offshore water column. This study considers the impacts of high chlorophyll plumes (HCPs) resulting from cross-shelf exchanges to the bio-optical properties of affected waters and how these plumes are influenced by their environment. The seasonal, interannual and decadal chlorophyll cycles of the Gulf of Mexico and the northern Gulf of Mexico are described to provide context for evaluating the ecological effects of …

Latitudinal Variation In Thermal Tolerance And Preference Of Fundulus Notatus And F. Olivaceus: Implications For Temperature Mediated Reproductive Isolation, Laura Kristin Stewart

Master's Theses

Temperature is one of the most pervasive and influential abiotic factors affecting the life histories of fish, regulating a host of physiological processes and influencing behavioral thermoregulation. Fundulus notatus, the blackstripe topminnow, and F. olivaceus, the blackspotted topminnow, are widely distributed species located in drainages along the northern part of Gulf of Mexico (30°N latitude) and as far north as southern Illinois (39°N latitude). However, F. notatus has a much broader range reaching up into the Great Lakes (43°N latitude). Due to their broad geographical range, these populations inhabit a wide range of thermal regimes, thus …

Ichthyoplankton Composition In The Loop Current And Sargassum Habitats In The Northern Gulf Of Mexico, Stephanie Morgan Taylor

Master's Theses

Ichthyoplankton in the Gulf of Mexico (GOM) aggregate in two different habitats that serve to provide refuge and concentrate prey in an otherwise oligotrophic environment: the Loop Current (LC) a mesoscale oceanographic feature characterized by the transition of environmental conditions of the water mass between the GOM and Caribbean; and Sargassum, a two species assemblage of floating brown algae that is habitat for many larval and juvenile obligate and associated fishes. The objectives of this study were to characterize the density and community composition of ichthyoplankton within these habitats using multivariate analysis. I identified three unique assemblages of ichthyoplankton …

Habitat Selection Of Gulf-Strain Striped Bass, Morone Saxatilis: Relationships To Dynamic Abiotic Environmental Characteristics Within The Biloxi River, Mississippi, Jennifer Lynne Green

Master's Theses

The purpose of this project was to provide insights about the short- and long-term patterns of habitat selection of Gulf-strain Striped Bass, Morone saxatilis, based on spatially and seasonally variable abiotic environmental characteristics (water temperature, dissolved oxygen (DO), salinity, specific conductivity, and pH) in the Biloxi River, MS system. Juvenile hatchery-reared and feral adult Gulf-strain Striped Bass were acoustically-tagged and continuously monitored via active and passive telemetry from November 2012 – June 2014. Each month the available abiotic environmental characteristics of 40 random locations within the Biloxi River, along with sub-habitat conditions occupied by acoustically-tagged Gulf-strain Striped Bass, were …

Naturalists’ Perspectives On The Use Of Mobile Technology During A Nature Hike, Aubin Marishka Radzewicz St. Clair

Master's Theses

Naturalists act as our link between scientific knowledge and the public’s understanding of natural history and conservation efforts. In order for them to succeed, they need access to reference materials as well as up-to-date information (Mankin, Warner, & Anderson, 1999). Incorporating mobile technology (i.e. tablets) into naturalists’ endeavors in natural history and environmental education can be used as supportive and educational tools. My project investigated how newly trained naturalists used tablet technology while leading groups of children on nature hikes. I investigated naturalists’ views on the use of mobile technology as a tool during the hikes. My research was guided …

Evaluation Of The Protein Recognition Properties Of Peptide Nucleic Acids, Crystal Cox Serrano

Master's Theses

The objective is to evaluate the ability of aminoacyl-tRNA synthetases (aaRS) to recognize the non-standard nucleic acid, PNA (peptide nucleic acid). PNA has immense potential in biomedical applications due to its increased thermostability and nuclease resistance over natural nucleic acids. PNA represents a superior alternative to natural nucleic acids in many biomedical applications due to its specificity, strong binding, and nuclease resistance. This study is the initial data set that indicates PNA are recognized by translation enzymes.

Analyses Of Indices Of Abundance For Important Groundfish Species In The Northern Gulf Of Mexico From 1987-2009, Relative To Shrimp Bycatch; With Age And Growth Of Three Sciaenid Species, Allison Renee Odom

Master's Theses

Bycatch in the shrimp fishery became of particular concern in the 1980s during the peak of shrimp harvest in the northern Gulf of Mexico. Shrimp bycatch is of major importance because the majority of catch in the fishery is not intended target species of commercial shrimp, and most of the additional bycatch is returned to the sea dead or dying, inducing higher rates of mortality. This study was developed to assess the potential ecosystem effects of shrimp harvest on thirty selected species/species groups commonly encountered within the shrimp fishery as bycatch. Delta-lognormal modeling (DLM) was used to determine the relative …

Elucidating The Molecular Function Of Reprolysin Metalloproteases In Tick-Host-Pathogen Interaction, Jaclyn Bo Williams

Master's Theses

Ticks are ectoparasites that attach to their host for many days to weeks, feeding to engorgement and continuing their species life cycle. The mechanisms behind the successful feeding and manipulation of host immune responses have been associated with the secretion of their specialized saliva. Tick saliva includes a variety of modulatory molecules that must disrupt and counteract defense mechanisms, including a variety of proteases. Reprolysin Metalloproteases, in the Zn²⁺ dependent family, is secreted as a proenzyme and is shown to have proteolytic activity, degrading fibrinogen and gelatinase activity, as well as disturbing homeostasis¹². Previous work with …

Regulation Of Vancomycin Resistance And Stress Response By The Msaabcr Operon In Staphylococcus Aureus, Dhritiman Samanta

Dissertations

Staphylococcus aureus is the predominant cause of public health problems around the world. Vancomycin has been an important antibiotic against Methicillin Resistant Staphylococcus aureus (MRSA) infections. However, Vancomycin Intermediate S. aureus (VISA) strains have been reported. These strains are characterized by thick cell walls, reduced autolytic rate, reduced PBP4 activity, and increased amount of D-Ala-D-Ala termini in the cell wall. In this study, we show that the msaABCR operon regulates vancomycin resistance in two clinical VISA strains. Deletion of the msaABCR operon in strains Mu50 and HIP6297 resulted in a significant decrease in the minimum inhibitory concentration (MIC) for vancomycin. …

An Insight Into The Sialome Of The Lone Star Tick, Ambylomma Americanum, With A Glimpse On Its Time Dependent Gene Expression, Shahid Karim, José M.C. Ribeiro

Faculty Publications

Hard ticks feed for several days or weeks on their hosts. Blood feeding is assisted by tick saliva, which is injected in the host skin regularly, alternating with blood ingestion. Tick saliva contains hundreds or thousands of different peptides and other bioactive compounds that assist feeding by inhibiting their hosts’ blood clotting, platelet aggregation, vasoconstriction, as well as pain and itching. Immunomodulatory and antimicrobial peptides are also found in tick saliva. Molecular characterization of tick salivary compounds, or its sialome (from the Greek sialos = saliva), helps identification of possible antigens that might confer anti-tick immunity, as well as identifying …