Digital Commons Network^™

Is There A Difference In Bird Diversity Among Prairie And Lake Habitats In Central Minnesota?, Emmi Edel, Morgan Cromwell, Maddy Fuller, Preston Mcgraw

Celebrating Scholarship and Creativity Day (2018-)

Biodiversity plays an essential role in ecosystem stability. Habitat changes from human activities also threaten this role. Our study examined how habitat type and urbanization affect the number of birds and bird diversity across two campuses in central Minnesota. The first campus is rural Saint John’s University (SJU), and the second is suburban College of Saint Benedict (CSB). We predicted that more bird species would be in habitats with water than habitats without water bodies. We also predicted that bird species numbers would be more significant on SJU, which has a large natural area, which CSB lacks. Observations were conducted …

Positive Impact Of Mangroves On Periwinkle Snail (Littoraria Angulifera) Population Size, Anna Jones, Eva Kolbow, Lucy Petschel, Morgan Stone

Celebrating Scholarship and Creativity Day (2018-)

Mangroves play a crucial role as shoreline aquatic nurseries and provide infrastructure along bodies of water to protect inland areas from extreme weather and storm surges. Mangroves also provide a secure habitat for animals, and trap and filter pollutants. Their stilt roots provide shelter for fish species and are critical to the survival of many small species that use this ecosystem. We investigated mangrove periwinkle snail populations on the red mangrove species (Rhizophora mangle). Data was collected along Pigeon Creek, San Salvador Island, Bahamas in March 2025. We hypothesized that there is a relationship between mangrove density and snail population …

The Effect Of Anthropogenic Sound On Foraging Behavior In Bluegill Sunfish (Lepomis Macrochirus), Dayna Wiley

Celebrating Scholarship and Creativity Day (2018-)

Anthropogenic noise can have adverse effects on fish populations. High-amplitude noise can cause hearing damage and interfere with essential behaviors, including feeding, migration, and reproduction. Studies suggest that fish regularly exposed to boat noise in lakes exhibit different behavioral responses compared to populations in quieter environments. Bluegill sunfish (Lepomis macrochirus) were collected via angling from a “Quiet Lake” (Lake Sagatagan, Collegeville, MN) with no motor use, and a “Loud Lake” (Upper Spunk Lake, Avon, MN) with frequent motor use. Bluegill foraging behavior was examined in response to daily playback of motorboat traffic. Bluegill (n = 5 individuals per trial; n …

Sympatric Behavior Of Tree Squirrels In An Urban Environment, Ryan L. Snyder

Undergraduate Honors Thesis Collection

The eastern gray squirrel (Sciurus carolinensis) and fox squirrel (Sciurus niger) are ubiquitous in urban ecosystems like university campuses despite the habitat loss and fragmentation often associated with urbanization. While populations of both species usually do not overlap in their native geographic ranges, gray and fox squirrels are sometimes forced into coexistence in urban habitats where fewer green spaces are available. The coexistence of both species at Butler University in Indianapolis, Indiana refutes the competitive exclusion principle, and niche partitioning is likely necessary for them to coexist. This study assessed the activity patterns of fox and gray squirrels at Butler …

Neuronal Tol-1 Integrates Microbial And Metabolic Cues To Modulate Feeding And Aversion In C. Elegans, Gursimran Singh Gujral

Theses, Dissertations and Culminating Projects

Toll-like receptors (TLRs) are key mediators of innate immunity, but emerging evidence suggests that they also play critical roles in the functioning of the central nervous system. This thesis explores the function of TOL-1, the Caenorhabditis elegans homolog of mammalian TLRs, in sensory neurobiology and behavioral responses to nutritive food. In particular, carbon dioxide and ethanol are commonly encountered in microbial environments and can signal metabolically active food sources or potential pathogens. Using tol-1 loss-of-function mutants, neuronal rescue lines, and a combination of molecular, tissue imaging, and behavioral assays, we demonstrate that TOL-1 functions in chemosensory neurons to regulate feeding …

The Effects Of Prenatal Cigarette Smoke Exposure On Developmental Milestones, Megan Jacobs

College of Arts & Sciences Senior Theses

In Kentucky, a reported 12.7% of mothers smoke cigarettes during pregnancy. Nicotine readily crosses the placental and blood-brain barriers, with fetal blood concentrations reaching 15% higher than maternal levels. By stimulating and desensitizing nicotinic acetylcholine receptors in the autonomic nervous system, nicotine disrupts uteroplacental blood flow, potentially altering fetal growth and development.

To investigate the effects of prenatal cigarette smoke exposure (CSE) on developmental milestones, C57Bl6 mice were exposed to either cigarette smoke (CSE, n = 30) or filtered room air (Sham, n = 20) for 3 hours daily from two days before mating until the day before birth. Offspring …

Don’T Be A Big Baby: Phenotypic Novelty In The Facultative Paedomorph Ambystoma Talpoideum., Andrew S. Kanes

All Theses

This thesis explores the relationship between heterokairy and the skin microbiota of amphibians, specifically focusing on the facultatively paedomorphic salamander, Ambystoma talpoideum. Heterokairy refers to variations in developmental timing that generate phenotypic novelty within life stages. The first chapter investigates how reordering metamorphosis relative to sexual maturation affects the skin microbiota in this species. By sampling different life stages—larval, paedomorphic, and metamorphic—results show the emergence of novel microbial combinations, resulting from both microbial gain and loss in the heterokairic paedomorphic stage. These findings suggest that changes in microbial communities may lead to phenotypic novelty and have broader eco-evolutionary implications. …

Effects Of Common Herbicides On Organismal Interactions, Robert Chamberlin

All Theses

Pesticides are applied to agricultural lands to prevent undesirable weeds, animal pests, and fungi from harming crops and reducing crop yields. Pesticides are used in croplands at increasing rates around the world and have become an essential component of farming in recent decades. Often, rain, wind, and soil permeation move pesticides from farmlands to natural environments. Such contamination of natural environments by pesticides may threaten species by altering their behaviors, bodily functions, and the ways in which individuals interact. Atrazine and glyphosate are among the most widely used herbicides around the world and are useful in eliminating weeds, primarily in …

Variation In Stress Response Regulation Across Natural Isolates Of Saccharomyces Cerevisiae, Crystal Christine Crook

Graduate Theses and Dissertations

The stress response of Saccharomyces cerevisiae is a valuable area of study for understanding cellular adaptation mechanisms that govern survival in fluctuating environments. This dissertation investigates stress response regulation in yeast through the roles of Hog1 mitogen-activated protein kinase (MAPK) and the post-transcriptional regulator Mkt1, a key post-transcriptional regulator, in diverse wild yeast isolates. Hog1 is traditionally known for its central role in osmotic stress regulation in the high-osmolarity glycerol (HOG) pathway. This study expands the functional scope of Hog1 to include oxidative and ethanol-induced stress responses.

In parallel, we investigate post-transcriptional regulation of stress responses by the Mkt1 interactome, …

Movement Ecology Of Sandhills Chub, A Carolina Endemic, Zachary Adam Ramsey

Electronic Theses and Dissertations

Fish movement studies have traditionally focused on species that support commercial and recreational fisheries, but recently more focus has been given to non-game, stream fishes because of their recognized importance in maintaining biodiversity within these ecosystems. Stream fish movement is described as being “restricted” and following a leptokurtic distribution via diffusive spread related to environmental and biological factors. Many studies of stream fish movement ecology in North America have occurred in high-gradient streams with coarse substrate in mountains or in streams of the interior plains. Sandhills streams of the southeastern USA are characterized as warm-water, low gradient, and dominated by …

Flow Field Surrounding Bluegill (Lepomis Macrochirus) During Suction-Feeding, Jensine Caroline Coggin

Electronic Theses and Dissertations

Suction-feeding is a common method for capturing prey by aquatic organisms and contributed to the diversification of fishes by enabling them to consume a wide range of prey. Suction-feeding is a complex fish-fluid interaction governed by various hydrodynamic forces: inertia, unsteady, viscous, and pressure gradients. These forces are described by the coupling between the flow physics equations (Navier-Stokes) and the dynamic behavior of the fish (motion and forces). However, the distribution of the pressure field that drives this process, and the extent to which suction-feeding is three-dimensional, remain underexplored. I estimated the pressure within the flow field surrounding the mouth …

Advancing Mitochondrial Dna Visualization And Dynamics In Plants: Application Of The Mt-Hi-Ness Fluorescent Marker, Madeleine H. Faber

Honors Program: Senior Projects (Public)

Mitochondrial DNA (mtDNA) plays a crucial role in cellular energy production and inheritance, yet its dynamics and exchange remain poorly understood in plant systems due to limitations in visualization techniques. Traditional visualization methods such as exogenous DNA stains and fluorescent protein markers present challenges in specificity and live-cell imaging. To address this challenge, we adapted the MT-HI-NESS fluorescent marker, originally developed for mammalian cells, for use in plant mitochondrial studies. Using Arabidopsis thaliana as a model system, we employed mitochondrial targeting sequences (IVD and AOX) to ensure accurate localization and to confirm mtDNA binding specificity. The validation process included fluorescence-based …

Effects Of Cadmium And Diet On Metal Accumulation And Kidney Cell Death Pathways., Justin Xu

College of Arts & Sciences Senior Theses

Cadmium (Cd) is a non-biodegradable environmental toxin and accumulates in the body with an estimated half-life of 30-45 years. Humans can be exposed to Cd through diet, drinking water, tobacco smoking, and industrial pollution. Cd can especially accumulate in the kidney due to the release of Cd from protein-metal complexes when filtering blood in the tubules causing oxidative stress and inducing kidney injury. Obesity is another risk factor for kidney disease therefore we examined the dual effects of Cd and obesity on the accumulation of essential metals in mouse kidneys. Starting in utero and continuing until 24 weeks postweaning, male/female …

Understanding The Properties Of Repair Protein P26 For Dry-State Preservation Of Biological Materials., Hannah Skaggs

College of Arts & Sciences Senior Theses

The preservation of complex biological materials in the frozen state has been well established and plays a critical role in the advancement of clinical applications and the pharmaceutical industry. Cryopreservation of complex biological materials has several clinical applications, including vaccine preservation, bone marrow transplants, cell therapeutics, and increasing the shelf life of red blood cells (RBCs) for transfusion. However, many challenges are present, including the use of toxic protective agents and the financial burden of maintaining extremely low temperatures between 193.15 and – 77.6 K (Parihar, Kumar et al. 2023). Lyophilization, or freeze-drying, presents an opportunity to mitigate such challenges. …

Ghrelin And Decision-Making: Exploring Its Role In Food Reward, Novelty-Seeking, And Cost Valuation, Serina A. Batson

Open Access Theses & Dissertations

When low energy levels are detected, Ghrelin, a peptide hormone, is produced in the fundus of the stomach. Referred to as the "hunger hormone", Ghrelin is traditionally associated with increased food intake and blood sugar levels. A key modulator in the gut-brain interaction, Ghrelin's growth hormone secretagogue receptor can be found widely across the cortico-striosomal circuit. Critical for decision-making, Ghrelin-based manipulation of this circuit can directly affect reward and cost valuation. While Ghrelin is uniformly considered to increase the valuation of food-based rewards, little research has explored its impact on non-food-based rewards or its effects on cost valuation. Therefore, to …

Development Of A Behavioral Paradigm To Monitor Seizure Susceptibility And Severity In A Zebrafish Model Of Cblx Syndrome, Claudia Berenice Gil

Open Access Theses & Dissertations

Methylmalonic acidemia and homocysteinemia cblX type (cblX) (MIM#309541) is a rare, X-linked recessive disorder caused by a mutation in the HCFC1 gene. This disorder is characterized by multiple congenital anomalies which include intellectual disability, brain malformations, intractable epilepsy, microcephaly, and facial dysmorphia. The most severe symptom of cblX is intractable epilepsy which is 100% penetrant. Our lab developed a zebrafish model with a mutation in the zebrafish hcfc1a ortholog to study the mechanisms underlying seizure phenotypes in cblX. Our laboratory previously showed that mutation of hcfc1a results in increased number and proliferation of neural precursor cells (NPCs) and an increase …

Regulation Of Ccr7 Signaling Events By G-Protein-Coupled Receptor Kinases 2 And 3, Anahi Sanchez

Open Access Theses & Dissertations

G protein-coupled receptors (GPCR) can bind multiple ligands, leading to differential signaling events termed biased signaling. C-C chemokine receptor 7 (CCR7) is a GPCR known to have biased signaling between the two ligands it binds to, CCL19 and CCL21. Binding of C-C Chemokine Ligand 19 (CCL19) promotes a high level of CCR7 phosphorylation, while CCL21 leads to a much lower level of CCR7 phosphorylation; findings observed in HEK and dendritic cells. GPCR kinases (GRKs), which can control the phosphorylation patterns of a GPCR, are hypothesized to regulate biased signaling of a receptor. GRK expression differs between cell lines and cell …

Investigating Self-Healing Mechanisms In Host-Pathogen Interactions: A Literature Review Of Macrophage Functions In Tuberculosis, Blessing Savusa

Open Access Theses & Dissertations

Tuberculosis (TB) remains a leading cause of mortality, particularly in underdeveloped regions. Mycobacterium tuberculosis (Mtb) is regarded as one of the most successful pathogens due to its ability to evade host immunity and persist within granulomas. Macrophages are the first-line host defenders that engulf Mtb into phagosomes, which initiates lysosomal activity for degradation. However, the virulence factor of Mtb is able to inhibit phagolysosome fusion. The host immune system forms granulomas to contain the mycobacterium at the site of inflammation. This, in turn, causes a necrotic state and causes tissue damage from the prolonged inflammation. Studies suggest that the host's …

The Expression Of Intestinal Tight Junction Proteins Induced By 1,25-Dihydroxyvitamin D3-Glycosides Supplementation To Reduce Bacterial Chondronecrosis With Osteomyelitis Lameness In Broilers, Kennedy M. Hicks

Biological Sciences Undergraduate Honors Theses

Bacterial Chondronecrosis with Osteomyelitis (BCO) is a leading cause of lameness in broiler chickens, impacting animal welfare and commercial poultry production. Supplementation using organic trace minerals, vitamin D, probiotics, and prebiotics has been studied to mitigate BCO lameness incidences in broiler chickens. Our previous study demonstrated that feeding Panbonis®-G-1,25(OH)₂D₃ from Solanum glaucophyllum, containing 1 µg/kg G-1,25(OH)₂D₃, to broilers for the first 28 days of their production cycle reduced BCO lameness by approximately 50%. In this study, we investigated the impact of 1,25-dihydroxy vitamin D₃ supplementation on the expression of tight junction …

Immune Function Modulation By Temperature On Isolated Rainbow Trout Macrophages, Abby Hunter

Biological Sciences Undergraduate Honors Theses

Fever is an evolutionary mechanism that enhances immune function, yet the molecular and metabolic responses to fever temperatures in ectothermic species remain poorly understood. In this study, we investigated how fever temperatures (19° C) influence macrophage function and metabolic activity in rainbow trout (Oncorhynchus mykiss), rather than normal temperatures (16° C). Using a rainbow trout monocytic cell line, RTS11, and primary head kidney-derived macrophages (HKCs), we examined the effects of fever temperatures on nitric oxide (NO) production, gene expression, protein synthesis, and energy metabolism. We found that fever temperatures increased NO production in both cell types, with further …

The Effects Of Pfos Exposure On Zebrafish Dopaminergic Neurodevelopment, Allison G. Fletcher

Departmental Honors & Graduate Capstone Projects

Per- and polyfluoroalkyl substances (PFAS) are a group of environmental contaminants that cause disruptions to the nervous and endocrine systems. Perfluorooctanesulfonate (PFOS) is considered one of the most disruptive PFAS to the nervous system, and may disrupt neurodevelopment of the dopaminergic system, which has been linked to neurodevelopmental disorders like Attention Deficit/Hyperactivity Disorder (ADHD) in humans. I hypothesized that early life PFOS exposure disrupts the development of the dopaminergic system. To test this hypothesis, I exposed zebrafish to 0.05, 0.5, and 5.0 mg/L PFOS through 5 days of embryonic and larval development. To assess acute effects of PFOS on the …

Analyzing Microalgae-Bacteria Population Changes In Response To Environmental Parameters For Improved Wastewater Treatment, Amanda M. Moravek

All Graduate Theses and Dissertations, Fall 2023 to Present

Microalgae are incredible organisms that have a variety of uses such as wastewater treatment, fertilizer, livestock feed, and bio-compound production. Microalgae require a light source and minimal nutrients space to proliferate, making them an environmentally friendly and sustainable option for such processes. The Sustainable Wastes-to-Bioproducts Engineering Center at Utah State University is developing and implementing a Rotating Algae Biofilm Reactor (RABR) to remove total nitrogen and phosphorous from the Central Valley Wastewater Reclamation Facility wastewater effluent. Harmful compounds such as nitrates and phosphates are metabolized by the microalgae and converted into useful bioproducts, resulting in a circular economy. These RABRs …

Uv-A Light And Heat-Activated Antimicrobial And Biodegradable Materials For Food Packaging And Preservation, Michael J. Bodily

All Graduate Theses and Dissertations, Fall 2023 to Present

Current food packaging materials are often non-biodegradable and harmful for ingestion, which poses a threat to the environment and public health. Thus far, the dangers of microbial contamination of food on human health have outweighed the risks associated with using these conventional packaging plastics. A possible solution to these issues is to use a combination of innovative materials and microbial inactivation methods that can potentially both reduce plastic waste and combat harmful microorganisms. In this study, two antimicrobial, biodegradable composites were developed and tested for their ability to inactivate two types of bacterium, Escherichia coli K12 and Listeria innocua, …

Regulation Of The Hypothalamic-Pituitary-Adrenal Axis Through Corticotropin-Releasing Factor Receptor 2 Activation And Androgens Acting On Androgen Receptors In Mice Exposed To Repeat Stress Conditions, David Reilly

Biological Sciences

The hypothalamic-pituitary adrenal (HPA)-axis is the body’s main neuroendocrine mechanism for regulating stress. It has been shown in both animal and human models that anxiety and depression like behavior is more prevalent in females compared to males. Studies have shown evidence that suggests there are sex differences in the HPA-axis that likely contribute to the observed sex difference. It has been shown that anxiety related behavior and HPA-axis responsiveness is correlated with androgens acting on androgen receptors (AR). The role of androgens acting on AR has a more unclear role in stress behavior and HPA-axis regulation when subjected to chronic …

Investigating The Effects Of Sod1 Knockout On Oxidative Stress And Stress Coping Styles In Zebrafish Using Crispr Technology, Tai Prauner, Ryan Wong

Theses/Capstones/Creative Projects

Reactive oxygen species are byproducts of cellular metabolism that, when not efficiently neutralized, can damage DNA, proteins, and lipids. Superoxide dismutase 1 (SOD1) is an antioxidant enzyme that converts superoxide radicals into less harmful molecules. While its molecular function is well documented, the role of SOD1 in shaping stress-related behavior remains underexplored. This project aimed to establish foundational tools for studying the behavioral impact of SOD1 knockout across proactive and reactive stress-coping styles in zebrafish.

To support future gene-editing experiments, microinjection and breeding protocols were refined across wildtype AB, proactive, and reactive zebrafish lines. No embryos were injected with CRISPR-Cas9 …

Ghosts In Glass: Ghost Crabs As Judges Of Glass Sand For Coastal Restoration, Emily Parrish

Honors Theses

Over 60% of the Gulf of Mexico coastline is actively eroding, which has resulted in thousands of miles of lost coastline over the last 100 years. This drastic loss of coastal land highlights the dire need for coastal restoration across the entirety of the Gulf Coast. A vital aspect of restoring these eroded areas is replenishing eroded substrate, traditionally conducted through offshore dredging of substrates which comes with high economic and ecological costs. Recycled glass sand may be able to fill this role and reduce our reliance on dredging while lowering the amount of glass waste entering landfills each year. …

A Genetic And Spatial Analysis Of The Last Megafaunal Species (Tapirus Terrestris) In The Paraguayan Dry Chaco Forest, Emily Bowers

LSU New Orleans Theses and Dissertations

No abstract provided.

Investigating Evolution Through The Lens Of Ai-Driven Protein Exploration And Phylogenetic Modeling, Mataya Duncan

Graduate Theses and Dissertations

Recent advances in computational biology, artificial intelligence, and sequencing technologies have enabled new perspectives for addressing longstanding questions in evolutionary biology. Increased computational power has made large-scale simulations feasible for investigating diverse aspects of evolutionary and phylogenetic modeling. Similarly, deep learning algorithms now allow for the prediction of reasonably accurate tertiary protein structures, unlocking the potential for investigating diversity and evolution of protein structure across a broad range of organisms. This thesis presents two studies that target different aspects of evolutionary inference from unique perspectives. Yet, the share an overarching goal of presenting new perspectives on the evolutionary basis of …

Substrate Complexity Is Not Correlated With Skin Pattern Complexity In Callistoctopus Furvus, Emily Lekas

Honors Theses

Callistoctopus furvus is an understudied, nocturnal octopus that inhabits shallow, subtropical waters in the western Atlantic. This species relies on camouflage to blend in to diverse environments to escape predators. To understand the relationship between substrate and skin patterning in this species, we used second-by-second analysis of video data recorded in the field. We compared frequencies of four substrate types (sand, rock, algae, and seagrass) ranked by contrast across ten skin patterns displayed by C. furvus. Chi-squared analyses showed significant results that the four substrates were unevenly represented in every skin pattern. However, the data did not support our hypothesis …

A Cross-Taxa Comparison Of Avian Telomere Dynamics, Age, And Lifespan, Benjamin Konigsberg

Honors Theses

When eukaryotes replicate cells throughout their life, the end regions of chromosomes naturally degrade as a result of the 5' to 3' directionality of DNA polymerase. There is a point when the chromosome is too damaged to provide normal cellular functions, so the cell will die. Telomeres act as a buffer by providing repetitive sequences of non-coding nucleotides. While telomeres do shorten during replication events, the enzyme telomerase can extend telomeres to prevent senescence. Telomere lengths vary between individuals based on different stressor and stress mitigation. Telomeric rate of change is a metric that can capture telomerase activity by measuring …