Digital Commons Network^™

Salinity Adaption And Toxicity Of Harmful Algal Blooms In Three Bays Of Great Salt Lake (Usa), W. A. Wurtsbaugh, Malin Olofsson, Gregory L. Boyer, Amy Marcarelli

Michigan Tech Publications

Cyanobacterial blooms can be harmful to animals and humans exposed to their toxins; however, their environmental drivers and boundaries still need to be elucidated. Salinity has been demonstrated to be an important driver of community composition that sets boundaries of species migration and survival. The filamentous cyanobacteria Nodularia spumigena forms dense blooms in estuaries around the world, produces the hepatotoxin nodularin, and has been thought to not survive or fix nitrogen (N) in high salinities. From 2005–2009 we studied three bays of Great Salt Lake (USA), two of which are estuaries with salinities ranging from 0 to >90 g L …

Effects Of Maternal Hypoxia On Developmental Plasticity, Matilda Powell

The Plymouth Student Scientist

Developmental plasticity enables organisms to adjust phenotypes to environmental cues, yet the transgenerational consequences of maternal effects remain unclear. Hypoxia, intensified by climate change and eutrophication, triggers taxon-specific plastic responses. Daphnia magna exhibits plasticity dependence, making it a critical model species for studying environmental responses. While maternal hypoxia (MH) influences generational plasticity, its long-term impacts on reproductive and physiological traits across generations remain insufficiently explored, limiting predictions of species resilience to environmental change. This study employed a controlled two-generation design: gravid F0 adults were exposed to moderate hypoxia (40% air saturation) or normoxia (100% AS) for 8 days, with reproductive …

Comparing The Effect Of Marine Aquarium Salts And Sodium Chloride On Vicia Faba Stress Response, Bethany Smerdon

The Plymouth Student Scientist

Soil salinity is a major abiotic stressor limiting agricultural productivity. Many salt stress studies rely solely on sodium chloride (NaCl) solutions, despite not accurately representing natural saline conditions. This study investigated the stress response of Vicia faba to NaCl and marine aquarium salt (MAS) solutions to assess the impact of a more complex ionic composition on plant physiology. Plants were cultivated in a controlled greenhouse and treated with either NaCl, MAS, or rainwater (control) for up to 55 days. Growth parameters, water status, proline accumulation, chlorophyll content, and root nodule weight were measured to evaluate stress responses. The results indicate …

Assessing Jasmonic Acid Seed Priming In Brassica Napus: Impacts On Aphid Herbivory Resistance And Seedling Fitness Trade-Offs, Daisy Stradling

The Plymouth Student Scientist

Jasmonic acid (JA) is a key phytohormone involved in plant defence, offering a potential sustainable alternative to conventional chemical pesticides. While JA seed priming has been explored as a strategy to enhance herbivore resistance in certain plant families, its potential fitness trade-offs remain poorly understood. This study investigates the effects of JA seed priming on Brassica napus (oilseed rape), a key agricultural crop, focusing on seedling fitness and resistance to Brevicoryne brassicae (mealy cabbage aphid), a major agricultural pest. To assess potential fitness trade-offs, seeds were primed with 75 µM JA, and multiple seedling fitness parameters were measured. Germination monitoring …

Characterizing The Germination Process And Establishing Best Practices For Seed Propagation Of Tamaulipan Thornscrub Species For Habitat Restoration, Saroj Dhakal

Theses and Dissertations

Tamaulipan thornscrub is an imperiled plant community of southern Texas and northeastern Mexico. Given its importance for biodiversity conservation, stakeholders have been involved in restoration programs using seedlings grown from wild seeds. However, stakeholders often report that insufficient seedling supply is a challenge. To address knowledge gaps in seed germination behavior limiting seedling production, this study was conducted on 18 Tamaulipan thornscrub species, identified by growers as difficult to germinate. Seeds of all studied species are orthodox except Amyris texana, which have recalcitrant properties. Nine species have physical dormancy that was successfully addressed with mechanical and/or chemical scarification. Other species …

Determination Of An Effective Natural Boxelder Bug (Boisea Trivittata) Repellent, Reyna Chavez

Theses and Dissertations

This study investigates the use of ecofriendly repellant alternatives to pest management to control boxelder bugs (Boisea trivittata). This bug gathers by the thousands on warm surfaces of exterior suburban homes during early fall and late spring. I determined bug repellency to turmeric oil (Curcuma longa), catnip (Nepeta cataria), citronella (Cymbopogon nardus), and lavender (Lavandula angustifolia). The treatments consisted of essential oils containing 20% methanol. All treatments demonstrated repellency of Boxelder bugs. Citronella was the most effective and had the highest level of repellency range of 90-99%. Catnip was the least effective with a repellency range of 63-82%.

Seagrass Preference Among Pinfish In The Lower Laguna Madre, Nathaniel Garza

Theses and Dissertations

Pinfish (Lagodon rhomboides) is a common estuarine fish species found from Massachusetts to the Yucatan, Mexico. As juveniles, pinfish spend a significant portion of their life in coastal seagrasses which provide both shelter from predators and food. Along the Texas coast, there are three major species of seagrass- turtle grass (Thalassia testudinum), manatee grass (Syringodium filiforme) and shoal grass (Halodule wrightii) that differ in structural complexity. The goal of this study was to determine if pinfish associate more with one seagrass species than the others. A year-long field study was completed using twelve sample sites in the Lower Laguna Madre, …

Bacillus Subtilis: A Bacterium That Can Potentially Degrade Low-Density Polyethylene (Ldpe) And Polyethylene Terephthalate (Pet), Migdalia Flores

Theses and Dissertations

The widespread application and disposal of plastics, such as low-density polyethylene (LDPE) and polyethylene terephthalate (PET), have raised significant environmental health concerns. Because of each plastic’s stability and durability, these plastics exhibit limited natural degradation in the environment. Recently, the environmentally friendly biodegradation of plastics by living microorganisms has attracted more attention, as they can assist in the natural degradation process. In this study, the bacterial strain Bacillus subtilis ATCC6051 was used to degrade LDPE and PET for 60 days. To measure the degradation of low-density (LDPE) and polyethylene terephthalate (PET), the dry weight was taken, and physical characteristics were …

Population Structure Of Red Drum (Sciaenops Ocellatus (Linnaeus, 1766)) In Two Systems In The Northwestern Gulf Of Mexico, Sandra Antonia Leal

Theses and Dissertations

Red drum (Sciaenops ocellatus) are an economically significant species of fish inhabiting the Gulf of Mexico. There are limited studies assessing S. ocellatus population structure focused on the southern coast of Texas. A total of 1,008 fish were collected over one year on a quarterly basis at South Bay (SB) and Holly Beach (HB) in the Lower Laguna Madre (LLM) of Texas to assess population structure. Juvenile S. ocellatus utilize the water systems of the LLM as a nursery ground and were more abundant at SB (n = 718) than HB (n = 290). The most abundant age classes were …

Applicability Of Cementochronology To Estimate Season-Of-Death In Humans: Insights From Modern Documented Collections, Olga Ibarra-Sanchez

Theses and Dissertations

Dental cementum is characterized by lifelong deposition of alternating opaque annuli in fall/winter and translucent bands in spring/summer. This study aims to test the applicability of cementochronology to estimate season-of-death, by observing the properties of the last layer, with direct implications for forensic anthropology and bioarchaeology. The sample includes canine teeth from 146 adults (84 males, 62 females), age-at-death ranging from 20-97 years (mean=61.7 years, SD=18.6 years), from two contemporary skeletal collections. Of these individuals, 78 (53.4%) died in spring/summer and 68 (46.6%) died in fall/winter. Overall accuracy was low at 64.4% (94/146). Accuracy was higher for spring/summer deaths 100.0% …

Ontogenetic Analysis Of Parasaurolophus Braincases (Ornithischia, Hadrosauridae) From The Kaiparowits Formation (Upper Cretaceous) Of Utah, Usa: Comparing Juvenile And Adult Morphology, Amanda "Billie" C. Guerrero

Electronic Theses, Projects, and Dissertations

This study documents the ontogenetic development of the braincase in Parasaurolophus, a lambeosaurine hadrosaurid dinosaur known for its distinctive cranial crest. Whereas the crest has been extensively examined for its roles in communication and display, the braincase remains less understood, despite its structural and functional relationship with the crest. This research compares the braincase morphology of a juvenile specimen (RAM 14000, "Baby Joe"), a subadult specimen (RAM 17000), and an adult P. tubicen (NMMNH P-25100), to investigate how developmental changes influenced sensory systems, neurocranial architecture, and biomechanical adaptations across ontogeny.

Detailed morphological analysis reveals progressive changes from juvenile to …

Bricks, Bushes, And Bones: Urbanization Influence On Western Fence Lizard (Sceloporus Occidentalis) Morphology And Performance, Daisy P. Xiong

Electronic Theses, Projects, and Dissertations

With increasing urbanization due to rising human populations, organisms may be forced to adapt rapidly to changing environments. Urbanization is replacing natural surfaces with more impervious substrates which can result in morphological changes affecting organismal locomotion, then also impact fitness. This study compares urban and natural habitat impact on Western Fence Lizards (Sceloporus occidentalis) and their adaptations in such settings. We captured lizards from three locations in inland Southern California with both urbanized and natural habitats in order to compare the morphological differences between lizards, and then measured their performance to determine the possible impacts from their morphology. …

Population Observations And Microhabitat Use Of Isthmohyla Tica (Anura: Hylidae) In San Ramón, Costa Rica, Pablo Marin Pacheco, Jerson Santamaria Martinez, Jose Manuel Mora, Jennifer L. Stynoski, Randall Arguedas

Biology Faculty Publications and Presentations

Isthmohyla tica, the Tica Frog, is a critically endangered species endemic to Costa Rica and supposedly Panama that has only been seen in a few sites in recent decades. To aid in its conservation, we assessed the population status and microhabitat preferences of this frog in a section of the Danta stream at Rancho Alegre farm, San Ramón, Costa Rica. We conducted 18 nocturnal surveys and collected data on perch types, vegetation associations, stream characteristics, and environmental variables for each sighting of the Tica Frog. To identify potential microhabitat preferences, we compared these features between sites with or without frogs …

Life History And Distribution Of Two Species Of Cownose Ray, Rhinoptera Bonasus And Rhinoptera Brasiliensis, In Mississippi Coastal Waters, Anna Millender

Master's Theses

Historically, the American Cownose Ray (Rhinoptera bonasus) was considered the only rhinopterid residing in the northern Gulf of Mexico (GOM); however, recent studies have confirmed the presence of the Brazilian Cownose Ray (Rhinoptera brasiliensis) throughout this region. The current study investigated the life history and distribution of both species within Mississippi waters, an area that previously represented a data gap for both species. From April 2016 – July 2025, 193 R. bonasus and 94 R. brasiliensis were analyzed to describe the reproductive biology. Reproductive timing, mating, gestation length, and parturition were similar among species. Although more …

Spotted Seal Coastal Haul Out Behavior In Arctic Alaska, Maeghan Connor

Biological Sciences

Hauling out - the act of exiting the water to rest, molt, breed, and pup on solid surfaces - is a key behavior of pinnipeds worldwide. Unlike other ice seals (i.e., ice-associated phocid species), spotted seals (Phoca largha) in Alaska frequently use terrestrial substrates to haul out during the summer and fall open-water period in the Chukchi and Beaufort Seas. Despite being a core aspect of spotted seal ecology, their terrestrial haul out behavior remains understudied. To address this, we analyzed data collected from 2020 - 2022 near two known haul out sites in Dease Inlet, Alaska, including time-lapse camera …

Benthic Infaunal Responses To Shoreline Restoration, Jessica Lauren Cline

Theses and Dissertations

In the age of increasing urban coastal sprawl, natural shorelines are being replaced by hard armoring structures, which result in the loss of valuable ecosystem services. Hybrid living shorelines, areas that include limited and less intensive armoring strategies paired with the integration of plants and other natural materials, present an opportunity to marry the need for more aggressive stabilization with the continued preservation of ecosystem functions and biological communities. This project uses benthic infauna to evaluate the success of a living shoreline installation in Palm Bay, Florida. The deployment features experimental treatments of breakwaters and red mangroves to explore how …

Comparative Assessment Of Lower Limb Neuromusculoskeletal Activation And Joint Kinematics In Normal And Impaired Gait, Jack Ryan Schule

Theses and Dissertations

This thesis evaluates whether accessible and affordable technologies can provide clinically significant, quantifiable gait analysis comparable to traditional marker-based motion capture systems. Modern high-end systems offer excellent accuracy but remain financially and logistically inaccessible to many clinicians and researchers. To address this gap, a framework was developed using markerless pose estimation using the model, MediaPipe, inertial measurement units (IMUs) processed through an Extended Kalman Filter (EKF), and surface electromyography (sEMG) to measure joint kinematics and neuromuscular activity during gait. An experiment was performed where data was collected from participants with both normal gait and pathologies including: Osgood–Schlatter disease, Plica Band …

An Investigation Of The Characteristics And Uses Of School Farms In California Ffa’S Superior Region, Emily R. Fuller, Jessica M. Toombs

Journal of Research in Technical Careers

This study investigates the characteristics and uses of school farms within Northern California, focusing on their role in school-based agricultural education (SBAE). The research aims to determine the structural and operational attributes of these facilities and to identify their primary uses as experiential learning tools. Utilizing a descriptive survey design, data were collected from 74 agricultural educators. Findings reveal that school farms, averaging 21.27 acres, are predominantly managed by agriculture teachers and are primarily used for housing market animals, supporting Supervised Agricultural Experience (SAE) projects. The study highlights the need for diversified school farm facilities to enhance experiential learning across …

Context Dependent Regulation Of Dicer Function During Oocyte-To-Embryo Transition, Nick A. Newkirk

Dissertations and Theses (Open Access)

Over two decades ago, Dicer was discovered as the primary enzyme responsible for the generation of small RNAs known as the microRNAs (miRNAs) and short interfering RNAs (siRNAs). Spatiotemporal regulation of Dicer-dependent small-RNA biogenesis affects many aspects of biology, including aging, disease progression, fertility, and cancer. Interestingly, a distinct population of Dicer-dependent small RNAs, known as the endogenous siRNAs (endo-siRNAs), are uniquely abundant in the germ cells and gametes, and are critical for normal fertility. Despite their function regulating new life, the mechanisms controlling their biogenesis and subsequent germ cell functions remain poorly defined. Work to parse these mechanisms in …

Capsinoids, Non-Pungent Trpv1 Agonists, Induce A Mild Hypothermia That Provides Short- And Long-Term Neuroprotection After Ischemic Stroke, Alexander Andersohn, Alexander Andersohn

Dissertations and Theses (Open Access)

Therapeutic hypothermia (TH) has demonstrated neuroprotection in instances of cardiac arrest and neonatal hypoxia/ischemia but faces different challenges in application to stroke due to the activation of cold defense mechanisms in conscious patients. This dissertation examines the efficacy and specificity of capsinoids (a purified mixture of capsiate and dihydrocapsiate) to induce a sustained mild hypothermia in conscious mice that is neuroprotective after stroke. Capsinoids function as TRPV1 agonists. However, unlike capsaicin, capsinoids are vulnerable to esterase-mediated breakdown, thus significantly restricting their action to the site of delivery. We showed that capsinoids delivered intraperitoneally (IP) to mice induced a TRPV1-dependent drop …

Neural Dynamics Supporting Flexible Cognition, Meredith J. Mccarty

Dissertations and Theses (Open Access)

Flexible cognition enables humans to adapt their behavior to changing circumstances by prioritizing relevant information and filtering out distractions. This process is thought to be supported by the integration of ongoing behavioral goals with incoming sensory information, but how this integration is realized in the human brain remains unclear. It is unknown how high-order sensory cortices can balance specialized processing with flexible integration of changing behavioral goals. In the following investigations, we use intracranial EEG (iEEG) recordings in humans to study the neural dynamics of flexible cognition during high-order sensory processing. First, we validated assumptions about the locality of iEEG …

A Mixed Methods Study Of The Weather And Climate Science Curriculum Pilot In South Carolina K-12 Schools, 4-H, And Agricultural Education Programs, Emily B. Hood

All Dissertations

Weather and climate science topics in K-12 education are more important now than ever due to extreme weather and climate events happening worldwide. Most U.S. science teachers included climate science in their courses, but they may not have a sufficient background in the topic which can hinder their efforts, or there is no explicit curriculum for the teacher to utilize. Research indicates that there is a need for innovation in the curriculum to help prepare children to become the next generation of leaders and address complex problems, such as issues related to weather and climate science. There are a few …

Mountain Communities During A Time Of War: A Case Study Of The Hutsul Region In The Carpathian Mountains Of Ukraine, Pavlo Rybaruk

Electronic Theses and Dissertations

This thesis investigates the ethno-ecological technologies employed by the Hutsul people within the highland agrarian economy of the Carpathian Mountains. Over centuries, the Hutsuls have developed ethno-ecological technologies that maintain ecological integrity while supporting community livelihoods.

The study addresses three primary research questions: What are the most important ethno-ecological technologies of the Hutsul highland economy? How might these traditional ethno-ecological practices be applied to economic, agricultural, and tourism development in the Hutsul region? How might these traditional ethno-ecological practices be combined with contemporary approaches to encourage sustainable development in the region?

The research explores the devastating impact of the Russian …

Taxonomy Of Endophytic Fungi Associated With Vallisneria Neotropicalis, Md. Arafat Rashid

Graduate Theses and Dissertations (2019 - present)

This study presents the first comprehensive taxonomic and ecological investigation of endophytic fungi (EF) associated with the submerged aquatic macrophyte Vallisneria neotropicalis in the southern United States. Over a 12 month period, from April 2023 to March 2024, leaf samples were collected from two distinct sites in Mobile Bay, Alabama a disturbed, brackish Causeway location and a cleaner, less impacted site at Meaher State Park. Using culture dependent methods, a total of 257 fungal endophytes were isolated from 1,200 leaf segments. All isolates belonged to the phylum Ascomycota, distributed across 3 classes, 6 orders, 10 families, and 19 taxa. The …

Improved Model For Neurodegeneration In C. Elegans, Jean-Pierre Arditi

Graduate Theses and Dissertations (2019 - present)

During Alzheimer's disease (AD), insoluble amyloid beta (AP) peptides accumulate to form extracellular aggregates (plaques). The direct cause of neuronal dysfunction observed in AD has been broadly investigated. The amyloid hypothesis states that AP plaques are neurotoxic, but recent studies support the AP oligomer hypothesis, which states that intracellular AP (iAP) is neurotoxic. To test this hypothesis, I used CRISPR-Cas9 gene editing to generate two transgenic Caenorhabditis elegans (C. elegans) strains. I generated a strain (RSLl 11) using the rab-3 promoter to co-express GFP in neurons, which showed no gross behavioral changes but had a 50% reduced egglaying rate. RSLl …

Twim #243: Beef And Bacillus, Sakiem Winston, Madison Wolford, Rebecca Seipelt-Thiemann, Angela Wilson

School of Medical Diagnostics & Translational Sciences Publications

Podcast annotation TWiM #243: Beef and Bacillus from the weekly podcast series "This Week in Microbiology" (TWiM), a podcast where experts in microbiology discuss academic papers in their field in an informal way.

Associations Between Feed Efficiency And Feeding Behavior In Yearling Angus Bulls In A Competitive Environment, Amelia Katz

Master's Theses

Feed efficiency in beef cattle is a complex trait shaped by physiological, behavioral, and social factors that influence how animals access and utilize feed resources. This study examined feed efficiency classification and how it is influenced by feeding behavior, competitive interactions, and bunk approach patterns in yearling Angus bulls housed in a drylot over two years. Bulls were grouped into high and low feed efficiency categories using residual feed intake and feed conversion ratio within pen and year (n = 40 per year; n = 40 per treatment). Continuous electronic monitoring quantified feeder visitation, feeding duration, intake, and rate. A …

Serum Concentrations Of Inflammatory Markers And Selected Nutrient Metabolites In Holstein And Jersey Cows Across The Transition Period, Avery Orr

Master's Theses

The transition period, spanning the weeks surrounding parturition, requires dairy cows to undergo synchronized metabolic, endocrine, and immunological adjustments that support the onset of lactation but also heighten disease susceptibility. Although individual inflammatory or metabolic biomarkers have been extensively studied, the integrated immunometabolic dynamics that occur across this period and the difference between breeds is not fully understood. The objective of this study was to characterize longitudinal patterns in key nutrient metabolites and inflammatory markers in Holstein and Jersey cows and assess how these systems interact across the transition period.

A total of 63 Holstein and Jersey cows were sampled …

Characterization Of A New Domestic Feline Macrophage Cell Line To Study Molecular Mechanisms Of Feline Coronavirus, Adam Espinoza

Electronic Theses, Projects, and Dissertations

Feline Coronavirus (FCoV) is a veterinary pathogen common in domestic cats. FCoV is transmitted via the fecal-oral route, results in mild enteric symptoms, and is considered feline enteric coronavirus (FECV). During infection the virus may transition from infecting host enteric epithelial cells to infecting host macrophages, resulting in a lethal systemic disease, and the virus is now considered feline infectious peritonitis virus (FIPV). FIPV arises in an infected individual, is not shed in the feces, and is not transmitted from cat to cat. There is limited research defining the host molecular mechanisms driving FCoV lethal outcomes, with few feline cell …

Factors Affecting Diet Selection In Sheep Fed Endophyte-Infected Toxic Fescue, Jordan Thomas

Animal Science Undergraduate Honors Theses

Tall fescue infected with endophyte‑producing fungi can induce fescue toxicosis in grazing ruminants, reducing performance and altering forage intake. Isoflavones—such as biochanin A, a major compound in red clover (Trifolium pratense)—have been proposed to mitigate these effects through improved palatability and vascular relaxation. This study examined whether inclusion of ground red clover (GRC)—either directly or combined with hydroxypropyl methylcellulose (HPMC) and polyethylene glycol (PEG)—affected voluntary diet selection in lambs offered toxic fescue.

Thirty‑two lambs were housed individually and assigned randomly to one of four diets: (1) toxic fescue silage (CONT), (2) silage + 5% GRC (RC5), (3) silage + 10% …