Life Sciences Commons^™

Assessment Of Genetic Diversity In Largetooth Sawfish, Pristis Pristis, Populations Over The 20th Century, Ann Fearing

Master's Theses

The Critically Endangered Largetooth Sawfish, Pristis pristis, experienced global declines in range and abundance over the past century and Australia is now their last stronghold. This research aimed to understand whether these declines have been accompanied by a reduction in levels of genetic diversity. Using P. pristis tissue samples sourced from natural history specimens, three fragments (616-bp, 386-bp, 141-bp) in the mitochondrial DNA (mtDNA) control region were PCR-amplified. At each fragment, significant genetic structure was found in P. pristis overall (Φ_ST=0.946, N=9; 0.813, N=54; 0.771, N=99). The Indo-West Pacific and Atlantic/Eastern Pacific each harbor genetically distinct lineages of …

Associative Nitrogen Fixation Linked With Three Perennial Bioenergy Grasses In Field And Greenhouse Experiments, Jayani J. Wewalwela, Yuan Tian, Janet R. Donaldson, Brian S. Baldwin, Jac J. Varco, Brett Rushing, Haoliang Lu, Mark A. Williams

Faculty Publications

© 2020 The Authors. Associative nitrogen (N₂)‐fixation (ANF) by bacteria in the root‐zone of perennial bioenergy grasses has the potential to replace or supplement N fertilizer and support sustainable production of biomass, but its application in marginal ecosystems requires further evaluation. In this study, we first combined both greenhouse and field experiments, to explore the N₂ fixation effects of three temperate feedstocks Miscanthus × giganteus (giant miscanthus, Freedom), Panicum virgatum (switchgrass, Alamo), and Saccharum sp. (energycane, Ho 02‐147). In field studies across three growing seasons, plant and soil pools of candidate feedstocks were partially composed of N …

Quantifying Species Traits Related To Oviposition Behavior And Offspring Survival In Two Important Disease Vectors, Donald A. Yee, William C. Glasgow, Nnaemeka F. Ezeakacha

Faculty Publications

Animals with complex life cycles have traits related to oviposition and juvenile survival that can respond to environmental factors in similar or dissimilar ways. We examined the preference-performance hypothesis (PPH), which states that females lacking parental care select juvenile habitats that maximize fitness, for two ubiquitous mosquito species, Aedes albopictus and Culex quinquefasciatus. Specifically, we examined if environmental factors known to affect larval abundance patterns in the field played a role in the PPH for these species. We first identified important environmental factors from a field survey that predicted larvae across different spatial scales. We then performed two experiments, …

Comparison Of Retention Rates Between Traditional On-Ground And Online Biology Laboratory Courses In The Community College Setting, Megan Davis Winborne

Dissertations

Community colleges provide vital educational resources to students across the nation. Online learning has become an integral part of the course offerings for community colleges. With regards to online learning, there is a lack of empirical evidence and research focused on community college offered biology laboratories, particularly concerning retention rates of these students. Means, Toyama, Murphy, and Bakia. (2013) found that even though there are copious amounts of studies dedicated to evaluation of evidence-based practices in online learning formats, many of them neglected to review retention rates associated with online educational courses.

The purpose of this study was to determine …

Discovery Of Exosomes From Tick Saliva And Salivary Glands Reveals Therapeutic Roles For Cxcl12 And Il-8 In Wound Healing At The Tick–Human Skin Interface, Wenshuo Zhou, Faizan Tahir, Joseph Che Yen Wang, Michael Woodson, Michael B. Sherman, Shahid Karim, Girish Neelakanta, Hameeda Sultana

Faculty Publications

© Copyright © 2020 Zhou, Tahir, Wang, Woodson, Sherman, Karim, Neelakanta and Sultana.Ticks secrete various anti-coagulatory, anti-vasoconstrictory, anti-inflammatory, and anti-platelet aggregation factors in their saliva at the bite site during feeding to evade host immunological surveillance and responses. For the first time, we report successful isolation of exosomes (small membrane-bound extracellular signaling vesicles) from saliva and salivary glands of partially fed or unfed ixodid ticks. Our data showed a novel role of these in vivo exosomes in the inhibition of wound healing via downregulation of C-X-C motif chemokine ligand 12 (CXCL12) and upregulation of interleukin-8 (IL-8). Cryo-electron microscopy (cryo-EM) analysis …

Light And Temperature Mediate Algal Simulation Of Heterotrophic Activity On Decomposing Leaf Litter, Cody A. Pope, Halvor M. Halvorson, Robert H. Findlay, Steven N. Francoeur, Kevin A. Kuehn

Faculty Publications

1. Recent evidence suggests that periphytic algae stimulate plant litter heterotrophs (fungi and bacteria) in the presence of light, but few studies have tested whether this stimulation varies across gradients of light, which may covary with temperature.
2. We exposed field‐conditioned Typha domingensis litter to fully‐crossed, short‐term gradients of temperature (15, 20, 25, and 30°C) and light (0, 25, 53, 123, and 388 µmol quanta m⁻² s⁻¹) and measured responses of litter‐associated algal, fungal, and bacterial production rates and β‐glucosidase, β‐xylosidase, and phenol oxidase enzyme activities in the laboratory.
3. Increased light stimulated algal production rates, from immeasurable production under …

Historical And Contemporary Variables Affecting The Range And Distribution Of Aedes Aegypti, The Yellow Fever Mosquito, In The United States, Nicole Mackey

Master's Theses

Aedes aegypti, the primary mosquito vector of the yellow fever virus, threatens global health by passing on this virus, as well as chikungunya, dengue, and Zika viruses. Through its natural tendency to live in highly urban areas and bite human hosts; understanding the factors that affect the historical and current range of the pest is invaluable (Gubler, 1998). Although these viruses are not normally found in the United States, lack of vaccinations and wide-spread presence of the mosquito could lead to these diseases being reintroduced with potentially devastating effects (Monath, 2001). To determine a partial historical range of A. aegypti …

The Effect Of Truncated Complement Constructs On Biofilm Formation, Protease Production, And Pigmentation, Cara L. Cothern

Honors Theses

The msaABCR operon regulates virulence factors in Staphylococcus aureus, a Gram-positive commensal organism that colonizes healthy individuals but can also be a human pathogen. These virulence factors include biofilm development, pigmentation, and extracellular protease production. The operon consists of the msaB gene, which produces a coding transcript, the msaA gene and the msaC gene, which produce noncoding RNAs, and msaR, which produces an antisense RNA. The latter three transcript regions of the operon are referred to as untranslated regions (UTRs) and are essential for the function of the operon, but only msaB encodes a protein. The mechanism of …

A Comparison Of Egg Desiccation Tolerance And Development Under Different Temperatures For Three Common Aedes Mosquitoes, Shelby A. Hosch

Honors Theses

With the rise in global temperatures, invasive mosquito species like Aedes albopictus may be able to reach regions that were previously inhospitable to these species. Therefore, if A. albopictus were to potentially reach Puerto Rico, it would come into contact with the species of Aedes aegypti and Aedes mediovittatus in local containers, and it is unclear how the tropical temperatures and precipitation patterns would affect the co-occurrence of these three species. Egg desiccation and temperature dependent growth among the species were measured to test how these species hatched and developed during different humidity and temperature. It was hypothesized that there …

Regional Differences In Wild North American River Otter (Lontra Canadensis) Behavior And Communication, Sarah Walkley

Dissertations

This study focuses on the vocalization repertoires of wild North American river otters (Lontra canadensis) in New York and California. Although they are the same species, these two established populations of river otters are separated by a significant distance and are distinct from one another. River otters are semi-aquatic social predators that can be found throughout North America. This is the first study to examine the vocalizations of wild river otters, and results are compared across field sites in the different regions. River otter vocalizations and behaviors in New York were recorded using Bushnell Aggressor trail cameras that …

An Investigation Of The Impacts Of Traditional, Virtual, And Hybrid Biological Laboratories On College Students’ Achievement And Motivation To Learn Biology, Shavonda Jackson

Dissertations

Virtual courses function in a different manner than traditional courses, therefore they require teaching methods and assessment techniques geared specifically to maximize this learning experience. Internet-based learning and distance-education are no longer new concepts in the science field. Because of this, many collegiate biology programs have created courses that can be taken virtual or hybrid. A number of experimental studies have had great influence in terms of the effects and impacts of educational technology in relation to virtual laboratories.

However, not many studies emphasize the impact of hybrid laboratories on student achievement or assess students’ motivation to learn in a …

Escherichia Coli Antimicrobial Resistance Variability In Water Runoff And Soil From A Remnant Native Prairie, And Improved Pasture, And A Cultivated Agricultural Watershed, Maitreyee Mukherjee, Terry Gentry, Heidi Mjelde, John P. Brooks, Daren Harmel, Lucas Gregory, Kevin Wagner

Faculty Publications

Although many previous studies have examined patterns of antimicrobial resistance (AMR) and multidrug resistance (MDR) from domestic animals and farm environments, comparatively little is known about the environmental sources and natural reservoirs of AMR and MDR. In this study, we collected stormwater runoff and soil samples from three watersheds in Texas. Escherichia coli (E. coli) were enumerated, isolated, and analyzed for resistance patterns. E. coli from all sites, irrespective of land use, displayed the presence of AMR/MDR. Higher levels of AMR/MDR were observed in water compared to soil. More isolates were resistant to cephalothin than other antibiotics. For …

Tanaidacea– Forty Years Of Scholarship, Version 3.0, Gary Anderson

Tanaidacea - Recent Scholarship

No abstract provided.

Gulf Coast Marine Laboratories Past, Present And Future, Donald F. Boesch

Gulf and Caribbean Research

I spent my nearly 50—year career in marine science working at marine laboratories, most of that as a chief executive officer. So, it is appropriate that my reflections are about marine laboratories, rather than my own science. After relating my career course, I turn my attention to the history and development of marine laboratories along the U.S. coast of the Gulf of Mexico (GOM). Surprisingly, the region’s first laboratory was actually constructed in 1903 at Cameron, LA, but operated less than a decade before closing. It was not until after World War II that the university—affiliated marine laboratories of today …