Life Sciences Commons^™

From Cranes To Clinics: Genomic Epidemiology At The Human-Animal Interface, Sarah Shrum

Biology ETDs

Emerging infectious diseases represent a significant, increasing threat to human life, economic stability, and global security. The One Health framework, which promotes human health and wellness through the understanding that animal, environmental, and human health are interwoven, is critical to understanding pathogen emergence and transmission. This is underscored by the fact that roughly 60% of all human pathogens and 75% of emerging infectious disease are zoonotic, meaning they are transmitted from animals to humans.

The work presented in this dissertation integrates genomic epidemiology, ecological analysis, and One Health Surveillance approaches to characterize cross-species circulation of opportunistic yeast pathogens (Candida …

Characterizing A Potential Cbp/P300 Histone Acetyltransferase Homolog In Tardigrade Germline Specification And Development, Brittney Michelle Hartshorn

Honors Projects

Germline specification is a fundamental process that ensures the proper development of germ cells. Germline specification occurs either through germ cell determinants maternally inherited through the mechanism of preformation or through induction, where cell interaction and epigenetic modifications direct specification. Determining how these mechanisms evolved and diverged remains an important question in developmental biology. Despite research on germline regulation in model organisms such as Caenorhabditis elegans or Drosophila melanogaster, such regulation remains poorly understood in many other animal groups. Tardigrades are an emerging model system for investigating developmental mechanisms due to their phylogenetic placement and experimentally tractable embryos. CBP/P300 is …

Investigating Changes In The Stable Isotopic Composition Of Juniperus Osteosperma Over 34,000 Years Of Climatic Shifts, Lisa S. Garcia

Biology ETDs

Isotopic compositions of plants from the past provides empirical evidence for paleoclimatic shifts and plants physiologically response. This study used Neotoma paleomiddens (fossilized debris piles) collected from Death Valley National Park, which contained preserved abundant plant materials. These middens range from modern to >35,000 years and capture different climatic events in Earth history. Employing Juniperus osteosperma (Utah Juniper) leaves found in middens, I investigated variation in carbon and nitrogen stable isotopic composition. To help interpret paleomidden results, we used modern field and herbaria samples of Juniperus from a spatial gradient stretching across their geographic range. Results showed δ ¹³C …

Reassembling Riparian Ecosystems: Stream Restoration Effects On Vegetation, Arthropods, And Aquatic-Terrestrial Connectivity, Katelyn P. Driscoll

Biology ETDs

Riparian areas exist at the aquatic-terrestrial interface and provide disproportionate ecosystem services, yet multiple stressors have degraded these zones globally. Stream restoration seeks to reverse degradation, but rigorous evaluation of treatment effectiveness remains limited. I conducted a before-after-control-impact (BACI) study in the southern Rocky Mountains to evaluate two stream restoration treatments—beaver dam analogs (BDAs) and plug-and-ponds (P&Ps)—across three dimensions of riparian ecosystem response. Using Bayesian analysis, I quantified treatment effects on functional diversity and composition of riparian plant communities. Using generalized linear mixed models, I evaluated restoration effects on riparian arthropod abundance, richness and guild composition across lateral gradients and …

Patterns Of Molecular Evolution Driving Reproductive And Genomic Processes In Sauropsids, Taylor Green

Theses and Dissertations

Sexual reproduction is an important driver of genetic diversity and speciation through such forces as selection, mutation, and drift. Sauropsids are an appropriate clade to study shared molecular drivers of sexual and genomic evolution due to their genome architecture, sex determination mechanism (SDM) plasticity, and large syntenous genomic regions. Using comparative phylogenetic methods, I identify predictable patterns of selection in meiotic recombination genes and clade-specific drivers of recombination rate evolution. Then, leveraging whole genome sequencing, I demonstrate that American alligator genomes are characterized by an ancient loss of genetic diversity driven by drift and historic inbreeding. I also generate a …

Reproductive Genetics Of Caenorhabditis Nematodes, Dharani U. Matharage

Theses and Dissertations

Variation in reproductive traits and genome evolution reflects the interaction between selection, environment, and life-history. In the genus Caenorhabditis, recombination rate and sperm size exhibit a striking variation between strains and species. Here, Iintegrate three projects investigating recombination rate variation and recombination plasticity in C. elegans and sperm size divergence across Caenorhabditis species. First, I quantify recombination rates in two genetically distinct strains, N2 and CB4856, with different levels of laboratory adaptation using fluorescent markers spanning across gene-rich and gene-poor regions of the chromosome IV. I identify significant differences in recombination rate between the two strains within both gene-rich and …

Increasing Evolution Acceptance Among Religious Adults Through Targeted Education, Jamie Jensen

ScholarsArchive Data

These data come from a study measuring the effectiveness of the Shareable Home Application for Reconciling Evolution (SHARE) tool, which consists of five short videos addressing the nature of science, compatibility between doctrine of the Church of Jesus Christ of Latter-day Saints and evolution, evolutionary mechanisms, and evidence for evolution, including human evolution.

From Miocene Origins To Ecological Diversification: Unraveling Evolutionary Dynamics Of North American Asters (Symphyotrichum), Sushil Dahal

Theses and Dissertations

Symphyotrichum, a plant genus traditionally treated within the genus Aster L., comprises >100 species of annual or perennial plants in the Compositae family Asteraceae. One of the most diverse genera in the southeastern US flora, the genus extends across the Americas, the Caribbean as well as eastern Eurasia. Despite its presence across the major American biomes and with distinctive floristic characteristics, several question regarding Symphyotrichum remains obscure. This research project focuses on exploring diverse aspects of Symphyotrichum systematics, biogeography and evolution. I tested three main hypotheses: (1a) Symphyotrichum originated ancestrally across Mexico and eastern North America in the Miocene ( …

Assessing Biotic And Abiotic Drivers Of Hybridization And Species Delimitation In A Highly Reticulate Syngameon, Nicholas John Engle-Wrye

Theses and Dissertations

Hybridization, or the flow of genetic materials between varieties or species, shapes evolution by generating novel genotypes, altering allele frequencies, and driving diversification. Yet, the rate at which hybridization occurs is heterogeneous across the tree of life and the ecological and evolutionary factors that govern its occurrence remain poorly understood. This dissertation examines how conserved biotic and abiotic niches influence hybridization and uses integrative methods to delimit species boundaries within Heuchera (Saxifragaceae), a genus notable for widespread interspecific gene flow and cryptic morphological diversity. Results reveal that hybridization is most frequent where pre- and postzygotic barriers are weak, as with …

Cortical Bone Density And Thickness Assessment Of Intraradicular Sites In Adolescent Patients Using Cbct Imaging, Sara Endo

UNLV Theses, Dissertations, Professional Papers, and Capstones

Background: The indications for the use of cone beam computed tomography (CBCT) in orthodontics has grown since it was first introduced and dentists are discovering new ways that 3D images enhance diagnosis and treatment planning. Evaluating bone quality and quantity can be measured as bone density and thickness in CBCT imaging and is helpful for temporary anchorage device (TAD) placement in orthodontic treatment. TADs rely on primary stability and are commonly used in orthodontic treatment to increase anchorage and expand the limit that nonsurgical orthodontics can provide.

Objectives: This study aims to assess the bone thickness and density at different …

A Tale Of Two Mammals: Tenrec Ecaudatus And Homo Sapiens, Debra Renee Kerr

UNLV Theses, Dissertations, Professional Papers, and Capstones

Most modern mammals maintain stable body temperatures (Tb) ~37ºC and high metabolic rates. Hibernators, like ground squirrels, are homeothermic during the active summer season, but are heterothermic during the hibernation season. During the hibernation season, ground squirrels follow a predictable pattern of torpor bouts interrupted by interbout arousals. Tenrecs are unusual because they are heterothermic and heterometabolic even during the active season. Previously, ground squirrel bile constituents were shown to be predictive of whether a squirrel is in the summer active or winter hibernation season. We found tenrec bile constituents were highly variable and not predictive of seasonal and metabolic …

Thermal Physiological Ecology Of The Relict Leopard Frog At Hot And Cold Springs, Robert P. Pelletier Iii

UNLV Theses, Dissertations, Professional Papers, and Capstones

The relict leopard frog (Rana onca) once ranged across drainages in southern Nevada, northwestern Arizona, and southwestern Utah. Following a decline, the species only persisted in a few geothermally influenced hot springs, which led to the perspective that hot springs were high-quality habitat. Rana onca has been under intensive, multiagency management and the species has been translocated to establish additional populations, including at cold-water sites. Three research studies are presented into the thermal physiological ecology of R. onca with the aim of informing conservation strategy. The research was focused at a thermally influenced hot spring and a cold-water spring to …

Junctional Actin As A Mechanical Hub For Supracellular Actomyosin Force Transmission During Apical Constriction, Jasneet Brar

UNLV Theses, Dissertations, Professional Papers, and Capstones

Apical constriction is a conserved morphogenetic mechanism that drives epithelial folding during development. During ventral furrow formation in Drosophila melanogaster, contractile actomyosin networks generate forces that reduce apical cell area resulting in tissue invagination. For these cell-scale forces to produce coordinated tissue-scale changes, contractile networks must be mechanically integrated across neighboring cells. Although adherens junctions are known to mediate this coupling, it is unclear how junctions are integrated into cortical actin cytoskeleton, which directly determines cell, and consequently tissue, shape. This thesis tests the hypothesis that supracellular actomyosin organization during apical constriction depends on distinct adherens junction based mechanical couplings: …

The Competition Between Splicing And 3′ Processing Shapes The Human Transcriptome, Lindsey V. Soles, Shuangyu Li, Liang Liu, Kristianna S.K. Sarkan, Erik G. Alvstad, Lusong Tian, Yoseop Yoon, Marielle Valdez, Ivan Marazzi, Yongsheng Shi

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Eukaryotic pre-mRNA processing steps, including splicing and 3′ processing, are tightly coordinated, yet the underlying mechanisms remain incompletely understood. U1 snRNP has been proposed to inhibit 3′ processing at intronic polyadenylation (IPA) sites through a splicing-independent mechanism termed telescripting. In contrast, we discovered that disrupting splicing by using six different methods—targeting various key components such as U1 snRNP, U2 snRNP, U2AF, and SF3b—activates 3′ processing at thousands of IPA sites. Notably, splicing inhibition, especially of U1 snRNP, induced widespread premature transcription termination within gene bodies through both IPA-coupled and IPA-independent mechanisms. Inhibition of different splicing factors activated overlapping and distinct …

First Recombinant Expression, Purification, And Film Formation Of A Single Solitary Bee Silk Protein From Osmia Lignaria, Oran Wasserman, Kristin K. Durrant, Jackson J. Morley, Paula E. Oliveira, Mallory R. Wootton, Brianne E. Bell, Ethon D. Van Noy, Randolph V. Lewis, Justin A. Jones

Biology Student Research

Solitary bees account for most described bee species worldwide, with many spinning silk fibers to form protective cocoons during development; however, solitary bee silk proteins remain largely unexplored in recombinant systems and biomaterial fabrication. Here, we report the first recombinant expression and biomaterial formation from a solitary bee silk protein. Osmia lignaria silk fibroin 2 (OligF2) was expressed in Escherichia coli BL21(DE3) using an expression and purification scheme adapted from a recombinant hagfish intermediate filament (rHIF) workflow, yielding 0.34 g/L at ~70% purity. The purified OligF2 protein was cast into films at 0.75% and 1% (w/v). …

Making (Heat)Waves: Intermittent Thermal Stress Effects On Beet Armyworm (Spodoptera Exigua) Growth To Eclosion, Shane Dreher, Swayamjit Ray

Research and Creative Works Expo

In this study, we demonstrated how application of heat stress, followed by rapid cooling, affected the rate at which beet armyworm caterpillars gained weight, entered pupation and exited their pupae as moths via eclosion.

Digging Deep Into Curation: A Guide To Creating A Local Fossil Museum, Syd Joheim, René Shroat-Lewis

Research and Creative Works Expo

In Arkansas, the dissemination of educational content related to evolution and natural history is often constrained by prevailing cultural dynamics. This has resulted in a significant gap in the exposure of primary and secondary school students to foundational concepts in natural history and physical sciences. Even the state’s most popular science and history museums often intentionally exclude exhibits that risk upsetting a large portion of their visitors, further exacerbating the issue. As a consequence, many children do not receive proper education on natural history and physical sciences.  To address this educational deficiency, researchers identified and cataloged specimens from a collection …

Influence Of Pollinator Island Patch Size On Forb Establishment And Pollinator Networks In Palouse Prairie Restoration, Yaelle Esther Reeve

2026 Symposium

The Palouse Prairie Ecoregion is one of North America’s most endangered grassland ecosystems, with less than 1% retaining native vegetation. Restoration efforts have struggled to re-establish ecologically important native forbs and the plant–pollinator interactions necessary for long-term community stability. Spatial configuration of floral resources is known to influence pollinator foraging behavior and interaction network structure, yet few studies have evaluated how planting scale affects both plant establishment and pollinator community assembly in early-stage prairie restoration. My research aims to evaluate how variations in the size (0.1, 1, and 10 m²) of grouped wildflower plantings (pollinator islands) affect native forb establishment, …

Survey Of Student Perceptions And Use Of Artificial Intelligence When Reading Primary Literature In The Biological Sciences, Erin L. Zimmer, Michael I. Zimmer

Biology Department Faculty Articles

Artificial intelligence (AI) tools are increasingly used by students in higher education, yet little is known about how they are applied when reading primary scientific literature. This study investigated how undergraduate biology students use AI while engaging with primary research articles and how such use influences confidence, engagement, and perceived learning. Using a mixed-methods design across two institutions, we collected pre-course surveys assessing prior AI experience and attitudes, weekly self-reported AI usage logs during a semester-long primary literature–based course, and post-course surveys evaluating changes in practices and perceptions. Students entered the course with broad familiarity with generative AI but expressed …

A Herpetological Survey Of The Catawba Nation, York County, South Carolina, Courtney Skeldon, Marvin Bouknight, Steven E. Fields

Journal of the South Carolina Academy of Science

No abstract provided.

Behavioral And Molecular Effects Of 2,4-Dichlorophenoxyacetic Acid Exposure In Planarians, Emily Pintilie

Graduate Student Dissertations, Theses, Capstones, and Portfolios

The widespread use of pesticides, such as 2,4-dichlorophenoxyacetic acid (2,4-D), raises serious concerns about their effects on non-target aquatic organisms. In vertebrates, 2,4-D has been associated with neurotoxic outcomes. Planarians offer a valuable system for toxicological studies because of their well-characterized nervous system, regenerative capacity, and measurable behavioral responses. This study investigated the neurotoxic effects of 2,4-D exposure in the planarian species Girardia dorotocephala, including the assessment of nociceptive behaviors, survival rate, phototactic responses, and DNA methylation. Worms were exposed to various concentrations of 2,4-D (0–100 mg/L) at multiple time points. Nociceptive responses, such as scrunching, C-shapes, and seizures, …

The Detection Of Forever Chemicals From Paper Cups Using Colorimetry, Sara Miller

Graduate Student Dissertations, Theses, Capstones, and Portfolios

Per- and polyfluoroalkyl substances (PFAS) are synthetic chemicals added to food packaging products to increase water-resistance and durability. PFAS are a growing concern due to their migration into beverages and foods and have been linked to cancer, immunotoxicity, and thyroid disturbances. The purpose of this study was to quantify PFAS migration from paper cups into water and evaluate toxic effects using planarians. PFAS detection was performed using a colorimetric assay, which forms a colored complex with PFAS, on: perfluorononanoic acid (PFNA), heptadeca fluorooctane sulfonic acid potassium salt (PFOS), perfluorooctanoic acid (PFOA). PFNA and PFOS showed absorbance at 640 nm, while …

Apoe Ε2 Potential Protection Against Long-Term Consequences Of Traumatic Brain Injury, Rebecca Faith Mesidort

Graduate Student Dissertations, Theses, Capstones, and Portfolios

Traumatic brain injury (TBI) can alter the quality of life, often resulting in cognitive decline, neurodegeneration, or death. There have been no biological advances to resolve the long-term consequences of TBI. The APOE ε2 gene is well known as a neuroprotectant against neurodegenerative diseases such as Alzheimer’s disease and Parkinson’s disease. However, the biological mechanisms of how APOE ε2 protects against neurodegeneration are unknown. The purpose of this study is to investigate APOE ε2’s response to an environmental stimulus that leads to neurodegeneration, TBI, and further investigate APOE ε2’s biological mechanisms. After inflicting blunt force trauma to our model organism, …

The Effects Of Water Quality On The Physiological Responses Of Daphnia Magna, Sara Al Shekha, Alexis Avila-Hernandez

COD Library Student Research and Award Symposium

After conducting research on the effects of water quality on the physiological response of Daphnia magna, a common freshwater invertebrate, the biological stress response significantly differed in heart rates among groups, which differed from the original hypothesis after exposing the invertebrates to various samples of local pond water.

Faculty Sponsor:  Professor Lynda Randa

Virtualizing Practical Science Education: A Sociological Analysis Of Undergraduate Teaching And Learning, Sina J. Fakoyede, Femi E. Babalola, Oluwatoyin T. Obateru, Oluwayemisi D. Akomolafe, Deborah O. Alabi, Stella K. Ekundayo

Higher Learning Research Communications

Objectives: The study aims to investigate the perspectives of university teachers and students on integrating practical science teaching with virtual learning in a multicultural and diverse society, specifically within the context of southwestern Nigeria.

Methods: A mixed-methods approach was employed, involving data collection from 100 university lecturers and 400 undergraduate students across 10 universities. Qualitative data were gathered through semi-structured interviews with lecturers and focus group discussions with students. Quantitative data were obtained via structured questionnaires, allowing for triangulation and comprehensive analysis.

Results: Findings revealed that certain lecturers showed preferential support influenced by students’ cultural backgrounds or academic behavior during …

Cell Cycle Inhibition: Illudin S And Its Effects On Cdk2 In Ewing Sarcoma, Stephanie Diez, Natalie Flores, Alexandria Hernandez, Viviana Palacios, Terry Jo Shackleford

Cell and Molecular Methods

Ewing Sarcomas are aggressive round cell mesenchymal neoplasmas that have a high occurrence in children and young adults. CDK2 is a protein that is involved in the G1 phase of the cell cycle, which promotes the transition to the S phase. CDK2 kinase activation is mainly observed in the G1/S-phase transition.3 CDK2 binds to Cyclin proteins is responsible for entry and progression, thereby leading to maximal apoptosis activity in the S-phase. Illudin S is a drug that has been known to target cancer-specific cells, such as leukemia. Illudin S, in general are a cytotoxic metabolite that comes from plants, specifically …

Yap1 Knockdown And Panobinostat Treatment Increase Apoptotic Response And Decrease Gene Expression In Ewing Sarcoma Cells, Luna Collazo-Garcia, Alejandra Favela Santos, Madeline Torres-Salazar, Isabella Toscano, Terry Jo Shackleford

Cell and Molecular Methods

Ewing sarcoma (EWS) is considered to be one of the most aggressive pediatric malignancies, often characterized by its dysregulated gene expression driven by oncogenic fusion proteins. The Hippo signaling effector Yes-associated protein 1 (YAP1) has been known in promoting cell proliferation, survival, and therapeutic resistance in multiple cancers. However, its role in Ewing sarcoma response to treatment remains unclear. This study investigated whether YAP1 knockdown enhances the sensitivity of Ewing sarcoma cells to the histone deacetylase inhibitor Panobinostat. Ewing sarcoma, ES8, cells were transfected with a YAP1-targeting siRNA (siYAP1) or a non-targeting control (siControl) and treated with DMSO, 0.1 μM, …

Everolimus Treatment Combined With Akt1 Knockdown Increased Apoptosis And Decreased Cell Proliferation In Ewing Sarcoma Cells, Arisha Arif, Alfie Barcenez, Sophia Ruter, Nicole Vanegas-Riddick, Terry Jo Shackleford

Cell and Molecular Methods

The purpose of this study is to use the gene AKT1, due to the interest in AKT1’s role in cancer cell proliferation, and the drug Everolimus, to determine if combined targeted therapy works as a more efficient therapeutic approach. Ewing Sarcoma has been connected to chromosomal translocations and is most common in pediatric patients. It is most often treated with chemotherapy and local treatments. It may be connected to the gene AKT1 due to how it regulates cell metabolism, growth, and proliferation. The gene mTOR is similarly connected to cell metabolism and proliferation, and is inhibited by the drug Everolimus. …

Sirna Knockdown Of Rptor Reduces Rptor Expression, Increases Brd4 Expression, And Alters Proliferation And Apoptosis In Ewing's Sarcoma Cells, Sergio Cipriano, David Leavitt, Michael Olivia, Liam Valdez, Terry Jo Shackleford

Cell and Molecular Methods

Ewing sarcoma is a highly aggressive cancer that primarily affects children and young adults. Although treatment options exist, many patients do not respond effectively, showing the need for improved targeted therapies. RPTOR is a key in mTORC1 complex which regulates cell growth, proliferation, and survival. LY2874455 is a selective pan-FGFR inhibitor that targets growth factor signaling pathways involved in tumor progression, and FGFR signaling interacts with pathways such as mTOR, making it a potential target for combination therapies. We hypothesized that silencing RPTOR in Ewing sarcoma cells would disrupt mTOR signaling and alter expression of genes linked to cell survival …

Everolimus And Sirna-Mediated Mtor Inhibition Reduces Proliferation And Promotes Apoptosis In Ewing Sarcoma Cells, Dylan Calvert, Malorie Martinez, Alexa Miner, Ellis Quiroga, Terry Jo Shackleford

Cell and Molecular Methods

Ewing Sarcoma (ES) is an aggressive pediatric bone cancer characterized by rapid cell proliferation and poor prognosis, making the identification of therapeutic targets critical. One of  the mechanistic targets is rapamycin (mTOR) signaling pathway, which is critical for regulating cell growth, proliferation, and survival. Abnormal activation of the mTOR signaling pathway has been linked to the progression of ES, as it drives uncontrolled cell growth and apoptosis resistance. Because mTOR represents a promising therapeutic target for ES treatment, we hypothesized that inhibiting mTOR activity through an siRNA-mediated knockdown or through Everolimus drug treatment, would reduce cell proliferation and promote ES …