Digital Commons Network^™

Connecting The Dots: Understanding Migration In The Context Of Other Periods Of The Annual Cycle, Kristina Lee Paxton

Dissertations

Migration is a fundamental characteristic of the life history of many organisms. Large-scale seasonal movements expose migratory species to an array of differing environmental conditions such that the ecology, behavior, and life history strategies of migratory species must balance selection pressures associated with each phase of the annual cycle. Therefore, scientists increasingly realize that to understand the ecology of a migratory species in any one phase of the annual cycle requires an understanding of how other phases may interact with and influence the period of interest. That said, following individuals throughout the year poses a serious challenge.

The focus of …

Role Of Msa In Immune Evasion, Persistence, And Protease Regulation In The Human Pathogenic Strains Of Staphylococcus Aureus, Maria Deepa Basco

Dissertations

Opportunistic pathogens like Staphylococcus aureus on entering the host can stay colonized at the foci of infection or evade the immune system to disseminate to other sites. In this study we investigated the regulatory influence of the modulator of sarA (msa) on immune evasion and host persistence, employing the hospital-acquired strain S. aureus UAMS-1 and community-acquired strain S. aureus USA300 LAC. In the murine sepsis model, mutation of the msa gene in LAC showed no change in dissemination of infection; however, in UAMS-1 a decrease in microbial load was observed in the lungs. Differential regulation by the msa gene was …

Comparative Analysis Of Antiviral Responses In Mouse Embryonic Stem Cells And In Mesenchymal Stem Cells, Jundi Wang

Master's Theses

Embryonic stem cells (ESCs) are cells that have unlimited capacity for selfrenewal and differentiation. These properties make ESCs a great cell source for application in regenerative medicine. When used for cell therapy, ESC-derived cells could be placed in a wounded area that is likely to be exposed to various pathogens. However, it is not well-understood whether ESCs and ESC-derived cells have active antiviral responses against infectious agents from the environment. To answer this important question, I comparatively analyzed the antiviral responses of ESCs and mesenchymal stem cells (MSCs, C3H10Tl/2 cell line) to infectious agents. Using the expression of type I …

An Insight Into The Microbial Diversity And Expression Of Cysteine Protease Inhibitors (Cystatin) In Rickettsia Parkeri Infected Amblyomma Maculatum, Khemraj Budachetri

Master's Theses

Amblyomma maculatum (Gulf Coast tick) is an emerging tick species of public health significance in United States. It is a competent vector of Rickettsia parkeri, an etiological agent of a human rickettsiosis. In this study, we investigated the spotted fever group of rickettsial diversity in A. maculatum based on rickettsial ompA gene PCR. Our results showed A. maculatum harbors R. parkeri, R. amblyommii, and R. endosymbiont of A. maculatum. While only R. parkeri was detected in female salivary glands which suggest its ability to traffic from midgut to salivary glands via hemocoel. The presence of R. parkeri was further …

Science Fair: Is It Worth The Work? A Qualitative Study On Deaf Students' Perceptions And Experiences Regarding Science Fair In Primary And Secondary School, Vivian Lee Smith

Dissertations

Science fairs have a long history in American education. They play an important role for establishing inquiry-based experiences in a science classroom. Students may be more motivated to learn science content when they are allowed to choose their own science fair topics. The purpose of this study was to examine Deaf college students’ perceptions and experiences regarding science fair participation during primary and/or secondary school and determine the influence of science fair involvement on the development of language skills, writing skills, and higher order thinking skills as well as its impact on choice of a STEM major.

This study examined …

Developmental Expression Profile Of Bric Á Brac 2, Midline And H15 In The Developing Eye And Central Nervous System Of Drosophila Melanogaster, Petra Visic

Honors Theses

Aberrant activity of a single gene can lead towards development of cancerous cells. Drosophila melanogaster is a useful model system to study cancer because there is high degree of evolutionary conservation in signaling pathways between humans and flies that play major roles in regulating cell proliferation and growth (Miles et al., 2011). At The University of Southern Mississippi (USM), Dr. Leal’s lab has gathered evidence suggesting that bab1 and bab2 interact with the T-box gene midline (mid) and its paralog H15, while the early developmental function of bab1 and bab2 remains unknown. That is why elucidating the early …

Characterization Of Whole Pine Tree Substrates For Adventitious Rooting Of Cuttings And Initial Growth Of Seedlings, Anthony Lynn Witcher

Dissertations

Processed whole pine (Pinus taeda L.) trees have been extensively evaluated to supplement peatmoss and pine bark usage in container substrates for greenhouse and nursery crop production. The suitability of whole pine tree (WPT) substrates for crop propagation has not been investigated. Demonstrating the versatility of WPT substrates is essential to expanding their commercial availability and use.

The objective of this work was to evaluate WPT substrates for stem cutting and seed propagation of ornamental crops, and to identify factors affecting root development. Stem cutting and seedling root development was evaluated in WPT and traditional (peatmoss and pine bark) …

Interrelationships Between Testosterone, Aggression, And Parental Care Of A Temperate-Zone, Resident Songbird, The Northern Cardinal (Cardinalis Cardinalis), Margaret Susan Devries

Dissertations

Interrelationships among testosterone (T), aggression, and parental care have received much investigative attention. Within birds, many studies have focused on examining such relationships using species characterized by relatively brief periods of territoriality and breeding. Few have investigated links between circulating T and reproductive behavior in birds that are year-round territorial residents and have lengthy breeding seasons, such as the Northern Cardinal (Cardinalis cardinalis). The following six chapters report and discuss findings from this dissertation’s examination of aspects of T production and potential interconnections with circulating T, aggression, and parental care in male and female cardinals. This work suggests …

Community Metrics And Trophic Dynamics In Tidal Creeks In An Anthropogenically Fragmented, Coastal Landscape, Michael Robert Lowe

Dissertations

Salt marsh landscapes are among the most anthropogenically altered ecosystems in the world. Urbanization (i.e., accumulation of impervious cover and man made structrues) of the coastal landscape can disrupt the delivery of numerous ecosystem services. Among the many services provided by salt marsh habitats, they serves as the primary habitats for distinct macroinfauna (i.e., benthic and epibenthic macrofauna) and nekton (i.e., fish and decapod crustaceans) assemblages. In this dissertation, I used a number of metrics to test the overarching hypothesis that coastal urbanization has negative consequences for salt marsh faunal assemblages. Chapter I uses a landscape ecology approach to show …

A Bird In The Binoculars: Understanding Birdwatchers' Potential To Contribute To Sustainable Development And Biological Conservation, Sheri Lynn Glowinski

Dissertations

The three studies comprising this research drew from local economic development and environmental sociology to understand aspects of human dynamics that influence the conservation of birds. Using survey data collected from birdwatchers visiting coastal Alabama, the first study examined the local economic impact of birdwatching tourism and the factors that participants deemed important with respect to their recreation. Birdwatchers spent $103,305 during the four month study period. The total annual economic impact of this recreation on the area was estimated at $937,470, producing a multiplier of 1.48 and the equivalent of 20.3 full time jobs. Infrastructural variables (parking, bathrooms, site …

Interactions Between Protozoan Prey (Phylum Protista) And Their Mosquito Predators (Order Diptera, Family Cuclicidae) Prey Size And Predator Behavior Effects, Jeffrey Jay Skiff

Master's Theses

Mosquitoes (Diptera. Culicidae) are insects that are medically important as adults as they vector numerous diseases. Yet, understanding the ecology of the larval stage can lead to surveillance and control of adult populations. Aedes albopictus, Aedes triseriatus, Cu/ex corona/or, and Culex quinquefasciatus are four species of mosquito that co-occur in discarded automobile tires. Mosqui-to larvae feed on microorganisms (including protozoans) and particulate organic matter Most larval feeding experiments. howt:ver, have dealt exclusively with bacteria, fungi , and particulate organic matter Although bactena and fungi are important sources of nitrogen and lipids, they may be 111sufficient sources of carbon, which may …

Effects Of Food Dispersion On Dominance Related Behaviors In Garnett's Bushbaby (Otolemur Garnettii)?, Kyle Daniel Edens

Dissertations

Socio-ecological theorists tie primate social structure diversity to variations in habitats within which primate species reside. This premise permits laboratory researchers to investigate specific factors that influence or relate to social structure formation and maintenance. The focus of the current investigation was three fold. We first aimed to determine the relationships between traditional and non-traditional behavioral measures of dominance, then evidence for dominance hierarchy formation was examined, and various hypotheses were tested to discern if adjustments in the foraging context altered social behaviors in Garnett’s bushbaby (Otolemur garnettii). It was determined that animals likely to displace conspecifics were …

Investigating The Function Of The Mold Specific Gene M46, In The Pathogenic Dimorphic Fungus Histoplasma Capsulatum, Davida Lashaundra Crossley

Dissertations

Histoplasma capsulatum (Hc) is a dimorphic fungus that is the etiologic agent for the respiratory infection histoplasmosis. The fungus is found in the environment in contaminated soils of birds and bat excreta as a multi-cellular saprophytic mold. Once the soil is disturbed, spores are released and are inhaled into the lungs. In the lungs, the fungus converts to uni-cellular parasitic yeast (Maresca & Kobayashi, 1989). The conversion from mold to yeast is a requirement for pathogenesis. Previously, several mold specific genes have been isolated by our laboratory from a subtracted cDNA library. One such gene, is M46. M46 is a …

Evaluation Of Human Fecal Pollution In Mississippi Coastal And Creek Waters Using Library Independent Markers, Christopher John Flood

Dissertations

The objective of this study was to determine whether statistically valid correlations could be elucidated between standard indicator bacteria (enterococci and fecal coliforms) from coastal creek and marine samples and the presence of four library independent molecular markers that are human or sewage specific. Eight hundred and nineteen samples were collected between August 2007 and July 2010 to determine enterococcal and fecal coliform counts and the presence of genetic markers for sewage indicator organisms Methanobrevibacter smithii, human specific Bacteroides sp., Bacteroides thetaiotaomicron, and Fecalibacterium sp. During the course of this study environmental parameters were measured and statistically analyzed to determine …

Accessing Learning In The Adult Zebrafish With A Novel Associative Learning Task, David Joseph Jouandot Ii

Dissertations

The zebrafish (Danio rerio) is accepted in the developmental and genomic communities as a model organism. However, the capacity for the zebrafish as a behavioral model has yet to be fully acknowledged. The research presented provides evidence validating the novel task, aids in gaining a better understanding of the learning processes, and identifies individual differences. The novel associative learning task differs from any present well established behavioral model and lends itself to future development. The task provides the zebrafish community with a high output behavioral task which is readily replicated and allows one researcher to test between eight …