Life Sciences Commons^™

Nesting Population Trend Of The Leatherback Sea Turtle In Bocas Del Toro Province And Comarca Ngäbe-Buglé, Panama For The Period 2002–2022, Sonia Gutiérrez Parejo, Susan E. Piacenza, Raúl García, Cristina Ordóñez, Roldán A. Valverde

School of Earth, Environmental, & Marine Sciences Faculty Publications

Sea turtle biologists have made sustained efforts to understand the global status of leatherback sea turtle populations. However, despite progress in assessments, demographics, and ecology, key uncertainties persist in tracking leatherback population trends. Trend analyses have historically focused on nesting beaches, with nest counts providing a widely used index for population abundance. Here, we analysed 20 years of annual nest abundance at four main nesting beaches (Soropta, Bluff, Playa Larga and Chiriquí) in Bocas del Toro province and the Comarca Ngäbe-Buglé, Panama, which constitute the largest nesting leatherback sea turtle population in Central America. We conducted daily nest counts during …

Interfacing Neural Models: Biocompatibility And Fabrication Of A Flexible, Self-Folding Microelectrode Array, Fernando A. Pesantez Torres

Electronic Theses & Dissertations (2024 - present)

Neurodegenerative diseases pose a formidable challenge in modern medicine, necessitating the development of advanced research tools that can elucidate their complex pathophysiology. Recent advancements in neurodegenerative disease research have led to the development of three-dimensional (3D) neurodegenerative organoids using human induced pluripotent stem cells (hiPSCs). These organoids closely mimic human brain architecture and functionality, providing a valuable tool for understanding complex diseases. Additionally, the ability to generate and study brain organoids consistently and in large quantities holds potential for a controlled in vitro setting and high-throughput drug screening. However, these models are complex systems requiring specialized maintenance, analysis, and manipulation …

Elucidating The Effects Of Environmental And Physiological Conditions On Stem Cell Regulation In Vivo, Nimmy John

Electronic Theses & Dissertations (2024 - present)

The Notch signaling pathway is a highly conserved intercellular signaling pathway that any dysregulation can lead to a variety of human diseases. These diseases are further exacerbated by various environmental, pathological and genetic conditions. Previous studies have shown that these conditions have been known to affect the Notch transcriptional response. However, the molecular mechanisms by which such conditions influence Notch signaling remained largely unknown. Moreover, most Notch studies have relied on in vitro systems and indirect reporters, which can miss the dynamic and contextual nature of Notch signaling. Here, we systematically analyzed the effects of these conditions with single molecule …

Characterization Of Corticotropin Releasing Factor Receptor 2 In Stress-Regulating Regions Of The Mouse Brain, Jennifer J. Lafrican

Electronic Theses & Dissertations (2024 - present)

Sex differences in the morphology of the brain are thought to underlie the sex differences we see in anxiety and depression, where women are twice as likely to be diagnosed when compared to men. Stress, or a disruption to homeostasis, can exacerbate these mood disorders. Corticotropin releasing factor (CRF), and its receptors, play an important role in regulating the stress response. Binding of CRF with CRFR2 has been shown to reduce behavioral and neuroendocrine stress responses, yet whether there are sex differences in CRFR2 expressing neurons and stress-induced activation of these neurons in mice is unknown, in part due to …

Doves And Symbiotic Bacteria: Whole-Genome Assembly And Phylogenomic Inference, Mariam Topchyan

Theses and Dissertations

Part 1

I examined a potential source of variation in phylogenetic inference, investigating whether handling single-nucleotide polymorphisms (SNPs) through different methods during reference-guided genome assembly of pigeon and dove species impacts phylogenetic reconstruction and inference. Specifically, I created a custom consensus base calling tool that handles allelic variation through two different approaches, either ignoring heterozygous sites by denoting them as an ambiguous character “N,” or using a pseudo-random choice between supported base variants. Through reference-guided assembly of 108 dove species, I generated two datasets of alignments using both consensus calling methods, created two trees from both datasets via supermatrix and …

Targeting The Achilles’ Heel Of Lung Cancer Induced By Oncogenic P53, Brandon G. Velasco

Theses and Dissertations

Mutations of the tumor suppressor gene, TP53, are the most prevalent oncogenic mutations in lung cancer, occurring in up to 70% of human non-small cell lung cancer (NSCLC). The majority of mutations in p53 are missense mutations that cause not only a loss of tumor suppressor function, but also gain of oncogenic functions, like tumorigenicity, immune suppression, and chemoresistance. Previous studies have shown that the depletion of gain-of-function (GOF) p53 or disruption of its ability to transactivate the expression of genes related to oncogenesis eliminates its tumorigenic properties indicating a dependency of human lung cancer cells expressing GOF p53 …

Linking Disturbance & Macrophyte Colonization–Extinction Dynamics To Invasion Success & Community Assembly: Integrating Population, Community, & Landscape Perspectives, Joshua T. Armstrong

Theses and Dissertations

Aquatic plants, macrophytes, are foundational components of freshwater ecosystems, influencing abiotic conditions, providing habitat structure, and shaping biodiversity and community assembly processes. Their role is particularly critical in dynamic systems where disturbance regimes and colonization processes interact to shape community patterns and species distributions. Despite their ecological importance, macrophytes remain underrepresented in theoretical and applied studies of metacommunity dynamics and invasion ecology, especially in natural systems experiencing frequent environmental fluctuations. Here we aim to elucidate how macrophytes influence and respond to spatial and temporal variation in aquatic ecosystems, with a particular focus on colonization-extinction dynamics, invasion success, and community assembly. …

Prevalence Of Insecticide Resistance Gene In Aedes Albopictus Populations Of Central Illinois, Merylann Akinyi Ochieng

Masters Theses

The Asian tiger mosquito, Aedes albopictus, is a significant vector for diseases such as Dengue, Chikungunya, and Zika. Its increasing resistance to insecticides poses a critical challenge for vector control efforts. This study investigates knockdown resistance (kdr) mutations in the voltage-gated sodium channel (VGSC) genes, specifically V1016G and F1534C, which are associated with pyrethroid resistance. Aedes albopictus populations from Central Illinois were analyzed using allele-specific PCR techniques to address three primary objectives: (1) determining whether V1016G and F1534C mutations are present in these populations, (2) determining which mutation is more widespread, and (3) investigating how resistance gene …

Enhancing Sunflower Regeneration: Molecular And Genetic Insights From Helianthus Eggertii, Owen West

Masters Theses

In vitro plant regeneration, particularly through organogenesis and somatic embryogenesis, is essential for plant transformation and crop improvement, especially in recalcitrant species like sunflower. In this study, we explore the genetic and molecular mechanisms underlying regeneration in Helianthus eggertii, a wild sunflower species with high regeneration potential. Global gene expression profiling, conducted using Oxford Nanopore sequencing across multiple time points and genotypes, identified sixty-three core differentially expressed genes (DEGs) critical to regeneration. These DEGs are associated with critical biological processes such as cell proliferation, transcriptional regulation, and photosynthesis. Among them, a sunflower WUSCHEL-related homeobox transcription factor (WOX4) showed preferential expression …

Spatiotemporal Variability In Invasive Carp Spawning Activity In Two Midwestern River Basins, Braden A. Whisler

Masters Theses

Across the United States, fisheries managers and agencies continue to battle the spread of invasive bigheaded carp (Hypophthalmichthys spp.). Although previous research has identified environmental parameters such as temperature and flow to be triggers of spawning activity, many of these studies focus on larger rivers, rarely focusing on the specific thresholds or timing of when a spawning event takes place. I utilized the differing hydrology of the Illinois and Wabash Rivers and their tributaries to examine the differences in environmental parameters needed to trigger bigheaded carp reproduction. Three mainstem sites and three tributaries of both basins were sampled …

Assessing Ecological And Food Web Responses To Small-Scale Stream Restorations In Urban And Agricultural Streams, Sydney Mcandrews

Masters Theses

Urban and agricultural streams across the Midwestern United States are vulnerable to elevated pollution, eutrophication, habitat simplification, and losses of sensitive species. Instream habitat restoration is increasingly used to mitigate the impacts of rapid land-use change. This study synthesizes habitat and biological responses from a 2020 urban stream restoration in the Saline Branch (Urbana, Illinois) and evaluates food web responses from both the Saline Branch and a 2010 restoration in Kickapoo Creek (Charleston, Illinois), an agricultural stream. In the Saline Branch, four years of fish and three years of habitat and macroinvertebrate pre-restoration surveys were compared to three years of …

Allodus Podophylli: The Infection Cycle Of Mayapple Rust, W. John Hayden

Biology Faculty Publications

This article addresses the parasitic fungus, Allodus podophylli, that causes Mayapple Rust. This disease is extremely common throughout the entire geographic range of Mayap-ple, Podophyllum peltatum, the 2025 VNPS Wildflower of the Year.

Wildflower Of The Year; Mayapple (Podophyllum Peltatum), W. John Hayden

Biology Faculty Publications

Mayapples are perennial herbaceous plants with thick fibrous roots that arise from a creeping rhizome.

L-Theanine Modulates Stress Physiology And Immunology In Nile Tilapia, Sammie Miller, Lindee Mason, Shah Sumaiya Khaled, Elena Deng, Ahmed Mustafa

Mansoura Veterinary Medical Journal

Background: Fish are a prominent food source within the growing aquaculture industry, particularly within recirculating aquaculture systems, to alleviate global hunger demands. Diminishing detrimental stress conditions such as overcrowding prevalence and chemical toxins remain a primary goal. Nutraceuticals, particularly L-theanine, pose a natural alternative solution to alleviate these conditions. The amino acid L-theanine was scrutinized as a potential nutraceutical additive within commercial feed within the diet of Nile tilapia, Oreochromis niloticus, subjected to stress and unstressed in-vivo conditions.

Methods: To accomplish this, both 0.004% of body weight of L-theanine and 0.01% of body weight of hydrocortisone were implemented into feed …

Pharmacological Safety Profiling Of Nigella Sativa (Ns) And Hibiscus Sabdariffa (Hs) Extracts In Zebrafish (Danio Rerio) Embryos: An Integrative Vet-Pharmacotoxicological Evaluation Of Lc₅₀, Teratogenicity, And Developmental Outcomes, Ahmed E. A. Mostafa

Mansoura Veterinary Medical Journal

Herbal medicines are deeply rooted in Egyptian and Middle Eastern traditions, with Nigella sativa (NS) and Hibiscus sabdariffa (HS) being among the most widely consumed remedies. Despite extensive pharmacological evidence of their therapeutic benefits, systematic safety validation remains limited. Conventional toxicity assessments predominantly rely on rodents and higher vertebrates, which are costly, time-consuming, and ethically challenging. This gap necessitates alternative models that align with the 3R principles (Reduction, Replacement, Refinement). In this study, the zebrafish (Danio rerio) embryo model was employed to evaluate the developmental toxicity and median lethal concentration (LC50) of NS and HS aqueous extracts. Zebrafish embryos at …

Mental Fatigue Effect On Joint Repositioning, Collin Kehrwald

Dissertations and Theses

Mental fatigue influences both cognitive and physical performance, but its specific effects on proprioception have not been widely explored. This study aimed to examine how mental fatigue affects shoulder and knee joint repositioning senses. A joint repositioning task was used to assess proprioception in 18 college-aged males, with measurements taken for both shoulder and knee joint angles before and after a mental fatigue-inducing intervention. The Stroop task was employed to induce mental fatigue between the conditions. Results showed a significant increase in shoulder flexion variable error (p = 0.01, pre-Stroop = 2.79 ± 1.31 degrees, post-Stroop = 4.97 ± 3.20 …

Blattella Germanica As A Vector Of Salmonella Typhimurium, Matthew Turner

Dissertations and Theses

The following investigates the role of the German cockroach (Blattella germanica) as a vector of the bacterium Salmonella enterica subspecies enterica serovar Typhimurium (S. Typhimurium). As such, this work examines various host-pathogen-microbiome interactions that define the vectorial capacity of the German cockroach for Salmonella. To date, the majority of literature focuses on the general association of the German cockroach with various human pathogens, claiming any dissemination to be carried out via passive mechanical transmission. This project recognizes those claims, while expanding to include the possibility of biological transmission, involving active and complex host-pathogen interactions, including mechanisms like replication within the …

Small Mammal Diet As An Indicator Of Lyme Disease And The Road To Endemicity In Michigan’S Upper Peninsula, Jacqueline E. Suits

Dissertations, Master's Theses and Master's Reports

Lyme disease is expanding in the Upper Midwest due to climate change, forest degradation, and shifting wildlife communities. Small mammals are key reservoir hosts, and their foraging behavior offers insight into environmental conditions that sustain pathogen transmission. We used DNA metabarcoding to investigate small mammal diets across seasonal, spatial, and infection gradients in Michigan’s Upper Peninsula. We identified dominant dietary plant and arthropod taxa, seasonal shifts, and slight variation by species, site, and Lyme infection status. Taxa associated with Lyme-positive individuals were primarily linked to moist, edge, and disturbed habitats, areas that also support ticks and disease spread. These results …

Rotten Through The Cores: What Decomposition Can Tell Us About Carbon Cycling, Eileen C. Reeves

Dissertations, Master's Theses and Master's Reports

Sequestration of carbon (C) in forests means that the C is stored in the ecosystem and not emitted to the atmosphere, thus slowing the accumulation of greenhouse gases and mitigating the acceleration of manmade climate change. Quantifying the pools and fluxes of C in forests is therefore of considerable interest to landowners, policy makers, and scientists.

Decomposition is an ecological process central to the movement of C through ecosystems. This dissertation uses several techniques to help determine the factors influencing the speed of decomposition and long-term fate of decomposed plant material. In Chapter Two, phospholipid fatty acid analysis was used …

Understanding Trends In Zostera Research, Stressors, And Response Variables, Hannah R. Lyford, Emma Guerrini Romano, Shayna A. Sura, Sarah Joy Bittick

Biology Faculty Works

Background. Seagrass meadows are ecologically significant habitats that are globally threatened. Thus, there is increased interest in conservation of seagrasses as they face widespread decline. Biotic and abiotic factors that influence seagrass can be classified as stressors, such as rising temperature and eutrophication. Our study met an imminent need to consolidate data from previous studies to discern knowledge gaps and identify trends in studies, stressors, species, and geographic origination of research for the genus Zostera. For our systematic review, the objectives were to (A) qualitatively assess and summarize the current state of literature focused on seagrass species within the Zostera …

A Comprehensive Embryonic Staging Series Of The Turtle Trachemys Scripta, Christina M. Noravian, Perla G. Rand, Amira Mahomed, Maxellende Ezin, Annie Rickard, Oscar D. Juvera, Maria Elena De Bellard

Biology Faculty Works

Background: Turtles hold a unique place in vertebrate evolutionary history, making them critical assets in embryology research. Yet, they remain understudied as potential model organisms in the field. Here, to support experimental manipulations with turtle embryos, we have created a complete normal table of development for comprehensive embryonic staging of Trachemys scripta, one of the most common invasive turtle species worldwide.

Results: The development of T. scripta embryos from 0 days post-oviposition (DPO) to hatching (~60 DPO) was described from approximately 300 viable eggs collected at California State University, Northridge during the 2021–2024 nesting seasons. Thirty-one stages between oviposition and …

Nature, Nurture, And Serial Murder: A Biocriminological Analysis Of Jeffrey Dahmer And Aileen Wuornos, Dori W. Jal

Honors Thesis

In recent years, there has been an increase in public fascination with serial killers, however current criminological explanations continue to focus on social and psychological factors, lacking commentary on potential biological implications. This thesis addresses a gap in the literature by examining how biological processes, specifically epigenetic, neurobiological, and endocrinological mechanisms, interact with environmental stressors to shape serial homicidal behavior. The goal is to determine whether serial murder can be more effectively understood through a biosocial framework that integrates biological vulnerability with lived experience, rather than relying on singular explanatory models.

Using a qualitative multiple-case study methodology, this research analyzes …

Investigating Mitochondrial Stress Response Mechanisms In Aging, Aileigh E. Daniel

Theses and Dissertations

Mitochondrial dysfunction is widely recognized as a key contributor to aging and age-related diseases. The concept of mitohormesis suggests that low levels of ROS can activate stress-responsive transcription factors, promoting adaptive mechanisms that enhance longevity. We hypothesized that changes in protein abundance under conditions of mild mitochondrial stress reflect an adaptive response, and that commonly altered proteins across diverse genetic backgrounds of mitochondrial stress can help identify key regulators of stress resilience and aging. Our study identified conserved mitochondrial stress response pathways and highlighted candidate regulators for further investigation. These regulators appear to impair mitochondrial energy production by downregulating ATP …

Unleashing Serine Palmitoyltransferase In Test Tubes And Mice, Matthew W. Peart

Theses and Dissertations

Canonically known both for structural contributions to lipid bilayers and roles in cell signaling, the sphingolipids comprise a dynamic, multifaceted class of molecules which are studied to understand homeostatic cell biology as well as pathophysiology. Sphingolipids contribute to tissue-specific structures such as myelin, a multilayer membrane that allows for rapid conduction of action potentials along neuronal axons. All sphingolipids are downstream products of the rate-limiting and initiating enzyme in the de novo sphingolipid synthesis pathway, Serine palmitoyltransferase (SPT). Demonstrative of its status as the enzyme that catalyzes a crucial step in a biochemical pathway, SPT activity is strictly regulated. This …

Climate Change-Induced Shifts In Mediterranean Fungal Fruiting Phenology And Productivity, Rachel Demay

Theses and Dissertations

We used a 29-year dataset of mushroom fruiting from the Pinar Grande forest in northern Spain to investigate the effects of climate change on the phenology, productivity, and diversity of mycorrhizal and saprotrophic mushrooms. We investigated the long-term trends in fruiting season length, yield (by count, total weight, and average weight), and genus richness. Additionally, we identified associations between monthly temperature and monthly precipitation with these fungal responses across functional groups: mycorrhizal, saprotrophic, litter-decaying saprotrophic, and wood-decaying saprotrophic mushrooms, and the economically-important edible genera Boletus and Lactarius. We found that autumnal season length in the Pinar Grande has shortened over …

Molecular Mechanisms Of Kynurenine-Mediated Lifespan Regulation In Yeast, Ryan E. Counterman Jobb

Theses and Dissertations

The kynurenine pathway is a highly conserved pathway that acts as the primary pathway for tryptophan catabolism and has been found to be involved in lifespan regulation across many diverse organisms. Caloric restriction (CR) is the only known dietary intervention to date that both increases the mean lifespan and the health span of multiple organisms, although the molecular mechanisms of these effects are not fully understood. There are known and sometimes contradictory relationships between the kynurenine pathway activity and the life- extending effect of CR but the crosstalk between the two is not well characterized. Understanding these relationships could lead …

Evaluation Of The Impact Of Secondhand E-Cigarette Aerosols On Ros-Mediated Alterations Of Epigenetic Events: Implications For Copd Pathogenesis And Assessment Of The Efficacy Of Cold Atmospheric Plasma In Degrading Organophosphate Pesticides On Kevlar Materials, Ta-Chun Lin

Masters Theses

"We explored 1) the toxicological impacts of e-cigarette aerosols and 2) the decontamination efficacy of Cold Atmospheric Plasma (CAP) technology over organophosphates. In examining the effects of firsthand and secondhand e-cigarette aerosol exposure on A549 and BEAS-2B lung cells, we observed significant cytotoxicity, increased ROS levels, and epigenetic modifications, including heightened DNA methylation and downregulation of histone deacetylases (HDACs). These molecular alterations may contribute to chronic respiratory conditions, such as COPD, underscoring the health risks of e-cigarette exposure.

We investigated CAP’s effectiveness in degrading organophosphate pesticide (OP) residues on fabric surfaces, revealing that CAP treatment effectively decomposes OPs such as …

Bacteria-Engineered Vesicles For Cancer Immunotherapy: From Immunomodulation In Vitro To Anti-Tumor Effects In Melanoma Models, Lan Li

Theses and Dissertations--Chemistry

Bacterial vesicles hold immense potential in various biomedical fields. Among these, outer membrane vesicles (OMVs) produced by Gram-negative bacteria are the most extensively studied. While the exact mechanism of OMV production remains unclear, numerous environmental factors have been shown to influence both their yield and composition. In this study, we investigated the effect of three different antimicrobial families on OMV production by E. coli. Interestingly, antimicrobials within the same family did not provide the same effects on OMV yield, suggesting that OMV production may not directly correlate with the antimicrobial mechanism of action. OMVs have demonstrated tumor-inhibitory activity in multiple …

Functional And Structural Impacts Of Bison Grazing Intensity On Plant Communities, Samantha Lynn Berk

Graduate Research Theses & Dissertations

The reintroduction of grazing disturbance has become an increasingly popular tool in grassland restoration to build and maintain diverse and functioning ecosystems, but our understanding of how grazers like bison (Bison bison) shape plant communities is limited by binary grazing treatments and unanswered calls for in-depth and mechanistic examinations of community function and structure. Little research has focused on how natural variations in bison grazing intensity impact the function and structure of restored tallgrass prairie; whereby functional diversity is purely defined by changes in trait expression according to plant responses to grazing, and examining both vegetation structure and ecosystem function …

"On The Mat They Will Get Treated The Same": Male High School Wrestlers' Attitudes Towards Female Opponents, Emily Ann Kaht

Graduate Research Theses & Dissertations

Wrestling has historically been considered a male sport. Until recently, so few girls wrestled that those who did had no choice but to take on male opponents. Media reports and the literature indicate that those girls faced a wide range of attitudes from their opponents. While some women reported feeling supported by their male teammates, others reported hostility. Some stakeholders have, in the past, argued that wrestling is inherently unsuitable for girls, and some girls had trouble securing matches due to widespread refusal of boys to wrestle against them. Reasons given for boys forfeiting against girls have included a fear …