Biology Commons^™

Patterns And Potential Mechanisms Of Phenotypic Changes In Urban Small Mammals, Leslie Lopez

Master's Theses

Urbanization is an example of human induced rapid environmental change that can have wide-reaching ecological effects, including habitat destruction, fragmentation, and alteration of local climates. Effects of urbanization have been shown to impact wildlife, as disturbances resulting from urbanization can create novel environments and selective pressures that could lead to changes in morphology, physiology, or both. Small mammals such as rodents are an ecologically important set of wildlife species because they are a key prey item for several predators, hold strong influence over plants as a primary consumer, and some species carry and transmit major human and animal diseases. Previous …

Controlled Radiation Capsule For Precision And Rapid Cancer Treatment, Hoseon Lee, Zsolt Kollar, Bailey R. White, Junia Nguyen, David Roque, Sowjanya Palagani

Symposium of Student Scholars

This research aims to transform cancer treatment through the optimization of brachytherapy, with a focus on reducing treatment duration, setup complexities, and financial burdens, all while emphasizing patient safety. Patients living at a distance from radiation clinics, particularly those undergoing extended Low Dose Radiation brachytherapy, often struggle with the formidable financial challenges associated with securing nearby accommodations. In response to these issues, the research introduces a radiation capsule designed to condense the conventional six-month treatment period to approximately just one week, thereby significantly reducing the duration of required accommodations. This capsule is especially relevant considering the construction cost of $40 …

Quantifying The Role Of Water Quality On Nitrogen Cycling In A Trophic Estuary, Kayla Gonzalez-Boy

Symposium of Student Scholars

Jobos Bay Estuary is an intertidal, tropical estuary located in southern Puerto Rico. The estuary covers about 12 km² and has a variety of habitats, such as seagrass beds, mangroves, mud flats, and coral reefs, which play important roles in sediment trapping and water quality maintenance. Seagrasses also serve as nursery and feeding grounds and provide shelter for macrofauna. Currently, the role of seagrasses and water quality on nitrogen (N) cycling in trophic estuaries is not well constrained. Understanding variations in sediment-based effects on N cycling rates and transformations, and how they are associated with water quality, is an …

Early Stage Or Curable Cancer Diagnoses In Minorities: A Journey Of Survivors, Lora Asberry

Master of Science in Integrative Biology Theses

Patients diagnosed with early-staged or curable forms of cancer experience physical, as well as, mental challenges associated with disease progression and treatment. Previous studies have demonstrated that minorities and underrepresented communities did not receive the same level of care in comparison to their non-minority counterparts. Previous studies have also demonstrated that health disparities among minorities affected their cancer journey. This study addressed: how medical disparities varied between minorities and non-minorities, the overall effects of the cancer diagnoses in minorities compared to non-minorities, whether these perspectives differed in male vs. female participants, and whether there were any possible communication barriers between …

Influence Of Woody Vegetation Composition And Structure On Fuels And Prescribed Fire In Mountain Longleaf Restoration, Collin J. Anderson

Master of Science in Integrative Biology Theses

Longleaf pine (LLP) ecosystems have experienced a widespread ecological state shift largely due to fire exclusion which has allowed mesophytes, i.e., shade-tolerant, often fire-sensitive species to encroach, reducing flammability and biodiversity through a process known as “mesophication.” Although prescribed fire is commonly used to reverse mesophication, fire behavior, and thus prescribed fire utility for this purpose, is poorly characterized in mixed pine-hardwood stands with mesophyte encroachment. This study aimed to identify mechanisms by which tree composition, structure, and fuels contribute to fire behavior, focusing on the understudied mountain longleaf pine (MLLP) ecoregion in northwest Georgia. I hypothesized that woody vegetation …

Variation In Salamander Life History And Community Composition Across An Urban Gradient In Atlanta, Georgia, Usa, Leah Rittenburg

Master of Science in Integrative Biology Theses

Urbanization threatens to alter stream systems in watersheds in the eastern United States. These highly disturbed systems may result in many local extirpations of sensitive salamander species. One group of organisms that often persists in urban streams is the Eurycea bislineata (Two-lined Salamander) species complex. Many aspects of Two-lined Salamander life history are linked to environmental factors, particularly stream temperature, prey abundance, and stream hydrology. Urbanization threatens to alter these environmental factors, potentially influencing Two-lined Salamander life history. At 14 sites spanning an urban gradient in Atlanta, GA, I investigated the variation in life history and phenology in the Southern …

The Manhattant: Identification, Natural History, And Nutritional Ecology Of A Recently Introduced Pest In New York City, Lasius Emarginatus (Hymenoptera: Formicidae), Samantha Kennett

Master of Science in Integrative Biology Theses

New York City is one of the oldest and largest cities in North America, and it is a center for global trade and shipping. As such, it has also been the site of introduction for some of North America’s most damaging invasive pests, from chestnut blight to the Asian long-horned beetle. Despite these cautionary examples, there has been no formal research on a newly introduced ant species that was tentatively identified as a European ant species, Lasius cf. emarginatus. Since its discovery in 2011, L. cf. emarginatus has become among the most common urban ant species in New York …

Measuring The Physiological Effects Of Methylobacterium Oryzae Foliar Inoculation Onto Salt-Stressed Tomatoes Grown In A Greenhouse Semi-Hydroponic System, Collin Dice

Master of Science in Integrative Biology Theses

Salinity stress has been shown to improve hydroponic produce quality such as that of tomato but at the trade-off of produce yield. In order to improve demand for hydroponic produce, techniques that improve salinity tolerance could offset declines in yield without altering the improved quality of produce. In two separate trials, we tested whether foliar inoculation of the ACC deaminase-producing bacteria Methylobacterium oryzae CBMB20 improved salt tolerance in tomatoes grown in a semi-hydroponic system using an indeterminate variety exposed to 26mM NaCl (Trial 1) and a determinate variety exposed to 17mM NaCl (Trial 2). We also tested how salinity and …

The City Blues Of An Iridescent Canary: Physiological, Behavioral, And Developmental Impacts Of Lead (Pb) On Songbirds Along An Urban-To-Rural Gradient, Michelle Ross

Master of Science in Integrative Biology Theses

Urbanization is rapidly changing the environment and creating new challenges in the lives of animals across the globe. Anthropogenic contaminants found commonly in old construction materials—including heavy metals like lead— persist within the environment for prolonged periods of time and present a widespread problem for all who live near contaminated areas. Despite the phase-out of lead usage, it continues to threaten the health of all organisms but especially those from urban areas where historical lead use was more common. Currently, the sub-lethal effects of lead on wildlife are not well understood, though lead is known to affect physiology and behavior …

Proximate Causes Of Alternative Reproductive Tactics In Blue Ridge Two-Lined Salamanders (Eurycea Cf. Wilderae), Yatin Kalki

Master of Science in Integrative Biology Theses

Alternative reproductive tactics (ARTs) refer to discrete variation in reproductive behavior between members of a sex and within a species. ARTs are present in Blue Ridge two-lined salamanders (Eurcyea cf. wilderae) in the form of male polymorphism. Two male morphs exist: “searching” males and “guarding” males. Each phenotype has a unique reproductive ecology and associated discrete morphological differences. Another trait that shows discrete variation in E. cf. wilderae is the larval period, which may be one or two years in length. This thesis explores the proximate causes of ARTs in a population of E. cf. wilderae from the …

Investigating Biometrics Of Perimyotis Subflavus In Traditional And Nontraditional Hibernacula In The Southeastern United States As It Relates To Susceptibility To White-Nose Syndrome., Makayla Ferrari

Master of Science in Integrative Biology Theses

Perimyotis subflavus, or tricolored bat, populations have declined significantly since the emergence of white-nose syndrome (WNS) and has been proposed for listing as “endangered” under the United States Endangered Species Act. Traditionally, bats use caves as hibernacula, but as anthropogenic impacts have increased so has the use of manmade structures like culverts and bridges for roosting by several bat species. The internal environment of these anthropogenic structures is influenced by external temperature and humidity differently than caves and may influence P. subflavus winter activity, and thus susceptibility to WNS. One of the most significant differences in P. subflavus roosting behavior …

Guano Among Bat Species From Two Regions Shows Influence Of Geography And Diet On Bacterial Community, Rahma Ahmed, Thomas Mcelroy, Shannon Whitney, Lydia Moore

Symposium of Student Scholars

Studies of bat guano have shown that the diversity and structure of associated microbial communities can be related to factors such as host phylogeny, life history and reproductive stage, geography, and diet. Many insectivorous bat species in the southeastern U.S. have generalist diets that may shift seasonally to take advantage of abundant prey species or maximize caloric intake. Seasonal shifts in prey availability or consumption should be reflected in a guano microbiome change. We also expected to detect distinct guano microbiomes within species. Within species, distinct microbial communities related to geography, and finally life history and reproductive stage. We compared …

Insect Availability And Parental Care Behavior In A Common Bird, Cole Bourque

Symposium of Student Scholars

Populations of aerially insectivorous birds are declining throughout North America. Urbanization may indirectly contribute to this decline through its negative effects on populations of insects, an important food source in insectivores' diets, where low insect availability may be especially challenging for birds during breeding. How fluctuations in insect populations impact various species at higher trophic levels is an important area of current study for future conservation biology. Here, we examine whether nestling provisioning, brooding and guarding behaviors in a breeding bird—the European starling (Sturnus vulgaris)—may be altered depending on the relative insect availability in the environment. We found …

Characterization Of Caenorhabditis Elegans F07a5.4, Human Ortholog Of Olfactomedin 1, Sade K. Thomas, Karunambigai Kalichamy, Martin Hudson

Symposium of Student Scholars

Accurate control of nervous system development is critical for normal brain patterning, and defects in this process can lead to neurological disorders such as schizophrenia and Autism Spectrum Disorder. The transcription factor neurogenin is necessary for the development of neural subtypes and is deeply conserved across species. However, the transcriptional targets of neurogenin are poorly understood, creating an imperative for further study. We have used the nematode Caenorhabditis elegans as a model to better understand ngn-1/neurogenin function. Previous work from our lab revealed that ngn-1 plays a role in nerve ring architecture, and neural cell fate specification. In addition, …

Chemically Induced Phytoextraction Of Lead (Pb) Contaminated Soil By Switchgrass (Panicum Virgatum L.), Assisted With Bap And Nta Applications, Genna Hart

Master of Science in Integrative Biology Theses

The accumulation of lead (Pb) deposits in soil is a growing global concern. Phytoextraction of Pb-contaminated soil can be enhanced by soil chelation to increase the bioavailability of Pb. In the initial study nitrilotriacetic acid (NTA) 5mM, the alkylpolyglucoside (APG) Triton X-100 (2%), and nano-silica were applied to switchgrass (Panicum virgatum L.) growing in 5L pots of Pb-contaminated soil. The second experiment used 10mM NTA, the alkylpolyglycoside Triton X-100 (2%), foliar application of the plant growth regulator 6-benzylaminopurine (BAP) twice per week, Triple-12® nutrients, and Infuse™ a soil fungicide which were applied to switchgrass Plants were grown in a controlled …

Heavy Metal Distribution Across Three Georgia Estuaries Using Coastal Sharks As Sentinel Species, Allyson Stiles

Master of Science in Integrative Biology Theses

Estuaries are transitional environments that play key roles in coastal ecosystem functioning by providing essential habitats to ecologically important plant and animal species. Estuaries are exposed to a number of anthropogenic impacts, including heavy metal contamination from human activities. However, few studies have examined heavy metal distribution within Georgia’s estuaries and how intact salt marsh ecosystems could play a role in filtering and sequestering contaminants, such as Mercury (Hg). This thesis examined blood total mercury (THg) concentrations of four coastal shark species and concentrations of five heavy metals (Hg, As, Cr, Cu, and Pb) within the water and sediments of …

The Effects On Soil Fungal Community Of Excluding Select Above-Ground Herbaceous Species In A Montane Longleaf Pine Savanna Restoration Area, Sean Davis

Master of Science in Integrative Biology Theses

Due to anthropogenic pressures, by the 1990s longleaf pine forests were at 3% its peak area. Restoration is difficult as vegetation communities constitute a mosaic across the longleaf range. Hence, vegetation description is important wherever longleaf pine communities exist. Vegetation strongly associates with specific soil fungi operational taxonomic units (OTUs) and description of longleaf pine ecosystems are incomplete without description of microbial taxa.

My goals were to begin describing soil fungal communities of the longleaf pine at Sheffield Wildlife Management Area (SWMA) and describe changes to the fungal community after the removal of dominant plants in a longleaf savanna. I …

Assessing The Indigenous Arbuscular Mycorrhizal Fungi (Amf) Community Associated With Sea Oats Along The Georgia Coast At Jekyll And Tybee Islands, Kylie Stover

Master of Science in Integrative Biology Theses

Coastal sand dunes are fragile ecosystems that serve as natural defenses to protect the adjacent mainland by absorbing the impacts and energy from severe storms. Different efforts have been taken to restore coastal sand dunes, focusing on foredunes. However, there are many strategies involved with coastal restoration and one superior technique has not been found to be the best. Arbuscular mycorrhizal fungi (AMF) supply a range of limiting nutrients (N, P, Fe, and Zn) to the host plant while improving dune stability. This study aimed to assess and compare the diversity of the indigenous AMF community associated with sea oats …

Connecting Above- And Belowground Effects Of Climate Warming On Bumble Bee Health, Francis Mullan

Master of Science in Integrative Biology Theses

Climate warming has been identified as one of the primary factors causing worldwide pollinator declines. One of the most at-risk groups of pollinators is bumble bees (Bombus spp.). Bumble bees are common, widespread, and key pollinators of a wide range of crops and wild plants. Although studies have examined the thermal physiological traits of individual bumble bees to understand how they may be impacted by climate warming, little to no studies have examined how climate warming may impact whole bumble bee colonies both in their ability to thermoregulate their nest for their brood or in their ability to forage …

Ant Cuticle Microsculpture: Diversity, Classification, Evolution, And Function, John Paul Hellenbrand

Master of Science in Integrative Biology Theses

My thesis covers the intricacies of ant microsculpture diversity, classification, evolution and function. To do this, the thesis is organized into two chapters. The first chapter is a review of ant cuticle and microsculpture diversity as well as including analyses examining the evolution and lability of microsculpture traits. I then review the literature for functional hypotheses related to ant microsculpture. The second chapter explores the relationship of microsculpture and important morphological, physiological, and ecological traits to evaluate support for functional hypotheses.

The Evolution Of Honeycomb, Grace Cope

Master of Science in Integrative Biology Theses

The regular cells of honeycomb nests have fascinated scholars and mathematicians for millennia. In 36BC, the Roman scholar Marcus Terentius Varro first proposed the “honeycomb conjecture,” in which he postulated that bees build their comb using hexagons because it is the shape that requires the least amount of material to divide space into equal portions. Since this time, honeycomb has been used by engineers in applications that range from skyscraper supports to impact absorbers inside the feet of the lunar lander during the first moon missions, but mysteries remain about the biological origins of honeycomb and the mechanical properties of …

Noxious Cellular Injury Triggers An Oxidative Stress Gene Response, Shawyun Khoshneviszadeh

Master of Science in Integrative Biology Theses

Wound and regeneration involves a series of complex processes that can induce oxidative stress by elevating intracellular reactive oxygen species (ROS) levels. In this study, we used RNA-seq and qPCR to examine the molecular signature of Human Embryonic Kidney cells (HEK-293T) stimulated with Crotalus atrox (CA) venom. NGS data was assembled and annotated utilizing the Illumina paired-end RNA-seq approach with software packages HISAT2 and StringTie. Results showed 243 genes were differentially expressed (106 upregulated, 137 downregulated) between CA venom stimulated and non-stimulated cells (p<0.05). HEK-293T stimulated with CA venom for 4 hours showed an increase in the expression of oxidative stress response genes (e.g., TOMM6, EGR (1,2,3), HSP70 (1A, 1B), SPRY4, ETV5, and EMP1) (Fold-Change (fc) >2.0). Significantly downregulated genes were associated with many novel transcripts/proteins such as AC117378, AD000671, and AC023509. …

Studying Tissue Specific Diversity Of Splicing Regulator Muscleblind, Davron Hanley

Master of Science in Integrative Biology Theses

The muscleblind (mbl) family of RNA-binding proteins regulates alternative splicing, determining mRNA transcript composition for various types of tissue, and has been implicated in myotonic dystrophy. The mbl gene is subject to alternative splicing in Drosophila, leading to multiple isoforms, and has several paralogs in humans. Mbl proteins vary significantly in length, although the significance of such diversity and the role of specific isoforms have not been fully explored. Using immunofluorescence microscopy and polyclonal serum, we analyzed Mbl protein expression across adult Drosophila tissues. Mbl was detected in various locations, including the brain, gonads, muscle, and gut epithelium. Skeletal muscles …

Physiological Costs Of Total Cholesterol In European Starlings Across An Urban To Rural Gradient, Courtney Linkous

Master of Science in Integrative Biology Theses

Urban areas—characterized by high human densities and associated buildings and impermeable surfaces—are increasing globally and represents a leading threat to wildlife that is drastically altering the natural resources they are accustomed to. Prior studies suggest that living in urban habitats can cause wildlife to show increased cholesterol levels; in biomedical research, elevated cholesterol is linked to disease, but the consequence of elevated cholesterol in wildlife remains unclear. We measured total cholesterol in European starlings (Sturnus vulgaris)—an urban adapted species—across an urban and a rural site. We ask: (1) do urban starlings have elevated cholesterol, (2) does elevated cholesterol …

A Neuromuscular Look Into Genetics Of Muscle Aging, Christina Talley

Master of Science in Integrative Biology Theses

As individuals age throughout their life, they experience muscle tissue loss that impacts their quality of life such as a decrease in their physical capabilities and sometimes even their mental capacity. The process of muscle aging is the key point of this study. This involves the individual’s muscles and the motor neurons that control them. Skeletal muscles are used daily to maintain posture, stand, walk, etc. Throughout a lifetime these muscles undergo damage and need to be repaired. When the muscles are repaired, they express physical changes. The tissue shrinks in size and eventually the composition of the tissue is …

Fire And Periodical Cicadas: Impacts On Soil Nutrients And Understory Plant Germination, Andrea Gamache

Master of Science in Integrative Biology Theses

Purpose

A compound disturbance, composed of a prescribed fire and a periodical cicada emergence, occurred in northern Georgia in the summer of 2021. Independently these disturbances have substantial effects on the surrounding ecosystems. This study investigated the collective impact on soil composition and seed germination.

Methods

Through the soil analysis of cicada turrets, burned soil, and unburned soil, we hope to understand the composition of each soil type. Additionally, a 2 x 2 factorial study was performed with those same samples, providing insight into the impact on seed germination these disturbances have. The two factors were between burned and unburned …

New Ant In The Big City: Known Natural History Of Lasius Cf. Emarginatus In Its Native Range And Potential Impacts Of Recent Us Introduction, Samantha M. Kennett, Clint A. Penick

Symposium of Student Scholars

New York City has been the site of introduction for some of North America’s most damaging invasive pests, from chestnut blight to the Asian long-horned beetle. Despite these cautionary examples, there has been no formal tracking of a newly introduced ant species, Lasius cf. emarginatus, which has quickly become among the most common species in the city. Sometime between the first ant diversity survey of New York City in 2006 and the second in 2011,L. cf. emarginatus was introduced and quickly became established in the most urban habitats with the highest human contact. In contrast to other urban …

Pseudomonas Aeruginosa Evades Predation By Myxococcus Xanthus, Sarah Joie Beauvais

Symposium of Student Scholars

Multidrug-resistant Pseudomonas aeruginosa causes an estimated 32,600 hospital-acquired-infections and 2,700 estimated deaths in the US in 2017(CDC). Myxococcus xanthus is a strain of myxobacteria that preys on Pseudomonas sp, through the production of antibiotics and digestive enzymes. In previous experiments, P. aeruginosa evaded predation, through an unknown mechanism. Using confocal microscopy, this research investigates if quorum sensing, a cell density-dependent signaling pathway, could be a factor in motility and evasion of M. xanthus. Liquid suspensions of log-phase PA01 were dyed with two fluorescent dyes: SYTO 9 for marking live cells and Propidium iodide (PI) for marking dead cells. …

Microbial Diversity And Community Structure In Sediments Associated With The Seagrass (Thallassia Testudinum) In Apalachicola Bay, Florida, Rahma Ahmed, Thomas Mcelroy, Troy Mutchler

Symposium of Student Scholars

Seagrass is an angiosperm which provides many ecosystem services in coastal areas, such as providing food, shelter and nurseries for many species, and decreasing the impact of waves on shorelines. A global assessment reported that 29% of known seagrass meadows are in a state of decline due to the effects of human activity. Seagrass is commonly found in shallow marine waters where they form meadows containing a microbiome that plays an important role in providing nutrients for seagrass growth, though little is known about the microorganisms within the seagrass meadow sediments. Our project collected sediments from seagrass meadows and adjacent …

Sex Ratios And The City: Is Parental Corticosterone A Mediator Of The Relationship Between Urbanization And Offspring Sex Allocation?, Denyelle Kilgour

Master of Science in Integrative Biology Theses

The Trivers-Willard hypothesis states that mothers can adjust their offspring sex ratios according to their own condition and the environmental conditions they face during breeding. Past tests of this hypothesis in avian species have focused on how natural variation shapes sex allocation trade-offs. However, urbanization also influences individual condition and presents animals with novel challenges in optimizing their brood sex ratio. One likely mediator of the relationship between environmental conditions, parental condition, and sex ratios is corticosterone (CORT), the primary glucocorticoid in birds. However, no research has examined the links between urbanization, individual condition, CORT, and adaptive sex allocation within …