Digital Commons Network^™

Evaluating The Spray Patterns Of Boomless Spray Nozzles At Increasing Application Speeds, Thomas Hayden Duncan

Theses and Dissertations

Boomless nozzles have been largely ignored in spray studies, resulting in limited understanding of their spray patterns and how they are affected by operating parameters. A study was conducted to evaluate the effect of application speed on the performance of four boomless nozzles. Dyed water was applied to Kromekote® paper to assess spray distribution based on coverage data at three speeds, and MSMA was applied to a mixed turf stand to evaluate the effect of speed on performance. Overlap simulations were done to evaluate how uniformity could be improved, and nozzle performance was compared to manufacturer claims. Spray patterns of …

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 ( …

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 …

Exploring The Biological Basis For Exercise Neuroprotection In Parkinson’S Disease: A Cross-Sectional Study Of Exercise And Physical Activity On Inflammatory Cytokines And Neurotrophins, Leah Isabelle P. Alegre, Jacob M. Brewer, Adeline Florschutz, Kate E. Hamiltonthompson

UNLV Theses, Dissertations, Professional Papers, and Capstones

Regular exercise and physical therapy are known to increase production of neurotrophins, including brain-derived neurotrophic factor (BDNF), and anti-inflammatory cytokines. These changes combine to theoretically protect and slow the progressive loss of neurons in Parkinson’s disease (PD). The purpose of this study was to examine the effect of exercise and physical activity on various anti-inflammatory and pro-inflammatory cytokines and neurotrophins in people with PD (PwP). This was a cross-sectional design involving PwP (n=37), aged 43-85 years, who participated in two 30-minute bouts of exercise (with brief rest breaks during and pre/post blood draws) separated by a week. Measures collected prior …

Postural And Load Dependent Modulation Of Lower Limb H-Reflex Excitability After Stroke, Daniel Bamiro, Matthew Berdiago, Ethan Hunter, Tia Nguyen

UNLV Theses, Dissertations, Professional Papers, and Capstones

Purpose/Hypothesis

Leg stiffness is regulated by reflexive, intrinsic, and passive mechanisms, which are influenced by posture, body weight loading, and motor task demands. After a stroke, the capacity to modulate these mechanisms is often compromised. The H-reflex is a widely used electrophysiological tool to assess the excitability of the Ia afferent pathway within spinal circuitry. Although prior studies in healthy individuals have examined limb loading effects, results have been variable, and the role of postural and loading changes during standing remains underexplored, particularly in individuals post-stroke. This study investigated how different postural and limb loading conditions, specifically prone, standing, and …

Effectiveness Of Cognitive Stimulation Therapy On The Quality Of Life Of Adults With Dementia: A Secondary Analysis, Evelyn Airam

UNLV Theses, Dissertations, Professional Papers, and Capstones

This secondary analysis study evaluated the effectiveness of Cognitive Stimulation Therapy (CST) on quality of life (QoL), depressive symptoms, and cognitive function in 108 community-dwelling older adults with cognitive impairments, including dementia. Outcomes involved Quality of Life (QoL) measured by the Quality of Life in Alzheimer’s Disease (QoL-AD), symptoms of depression by the Cornell Scale for Depression in Dementia (CSDD), and cognitive function using the Saint Louis University Mental Status (SLUMS). After the CST, significant improvements were observed in QoL (p = .004), depressive symptoms (p = .002), and cognitive function (p < .001), with small effect sizes. Additionally, a significant interaction between sex and dementia diagnosis status was found in predicting cognitive changes, suggesting that the relationship between dementia diagnosis and cognitive improvement differs by sex. No between-group differences were found for QoL or depression. Findings support CST as a multidimensional, non-pharmacological intervention that improves cognitive, psychological, and social outcomes. Although effects were small, consistent improvements are clinically meaningful given the progressive nature of dementia. This study extends existing literature by demonstrating CST’s effectiveness in a community-based setting and reinforces its alignment with occupational therapy’s emphasis on participation and holistic care. Results highlight the need for early intervention and expanded access to CST programs to enhance quality of life in this population.

Unknowing Sacrifices: Public Health And Radiation Illness In New Mexico And Nevada, 1940s-1960s, Beatriz Avila-Marquez

UNLV Theses, Dissertations, Professional Papers, and Capstones

The detonation of the first atomic bomb in the early morning of July 16, 1945, in New Mexico welcomed the atomic age that forever changed the world. After that day, thousands of lives were lost due to nuclear weapons, and hundreds of thousands more continued to suffer from the effects of atomic testing. The Atomic Energy Commission, fueled by the arms race of the Cold War, chose Nevada to continue the United States’ nuclear weapons testing. Knowledge of the dangers of radiation exposure, the effects of radiation, and techniques to prevent exposure are now available in part due to the …

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: …

Interpretable Deep Learning Models For Trustworthy Prediction Of Enzyme Functions, Louis Dumontet

UNLV Theses, Dissertations, Professional Papers, and Capstones

Trustworthy prediction of enzyme function from protein sequences remains a central challenge in computational biology, particularly when annotated data are limited, imbalanced, or incomplete. This dissertation develops interpretable deep learning methods for enzyme discovery and enzyme function prediction from amino acid sequences. First, it introduces PEPIC, an interpretable convolutional neural network for substrate-level prediction of hydrolytic plastic-degrading enzymes. Using curated and expanded sequence datasets, PEPIC improved predictive performance over benchmark methods, identified sequence regions aligned with catalytic and substrate-binding residues, and supported the discovery and experimental validation of a previously uncharacterized PET-degrading enzyme. Second, this dissertation investigates the integration of …

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 …

Methylation-Dependent Regulatory Pathway That Governs The Stability Of The Sox Family Proteins And Related Developmental Regulators, Keshari Gayathri Rajawasam

UNLV Theses, Dissertations, Professional Papers, and Capstones

The SRY (Sex-determining Region Y) protein is a transcription factor encoded on the Y chromosome and is the key regulator responsible for initiating male sex determination in mammals. During early embryonic development, SRY activates the genetic program that leads to testis formation by promoting the expression of downstream genes involved in male gonadal differentiation. Mutations or dysregulation of SRY can lead to disorders of sex development such as male-to-female sex conversion and hermaphroditism, highlighting its critical role in sex determination.

SRY belongs to the SOX (SRY-related HMG-box) family of transcription factors, which includes the proteins SOX1, SOX2 and SOX3. These …

From Flight To Hatching: Adult Sexual Dimorphism, Life History, And Egg-Stage Ecology Of Pseudocotalpa Giulianii, Mandylene Mountain

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Nevada endemic dune beetle Pseudocotalpa giulianii is currently known only from two dune systems in Amargosa Valley, Nevada, yet much of its life cycle occurs below the sand surface and remains poorly documented. This thesis addresses key gaps in adult-stage biology and egg-stage development that are relevant to understanding reproduction, vulnerability, and habitat requirements in this dunerestricted species.

To characterize adult sexual dimorphism and life history, I quantified morphological differences between males and females and measured sex-specific adult survival under laboratory conditions relative to the aboveground flight season. Males and females overlapped broadly in external body size, but tarsal …

Skin Of Frog And Scale Of Dragon: Nutritional Cues, Life Cycle Kinetics, And Secretome Dynamics In Batrachochytrium Dendrobatidis, Naomi C. Okada

UNLV Theses, Dissertations, Professional Papers, and Capstones

Nearly 50% of amphibian species are at risk of extinction, making them the most threatened group of vertebrates on the planet. A major driver of these declines is the pathogenic chytrid fungus Batrachochytrium dendrobatidis (Bd), which causes the fatal skin disease chytridiomycosis. Since its discovery in the late 1990s, Bd has been directly implicated in the extinction of 90 species of amphibians and the declines of hundreds more. Despite this devastating ecological impact, relatively little is known about its basic cellular biology.

Bd has a multi-stage asexual life cycle consisting of a motile and infectious zoospore, which encysts (into a …

Multiscale Modeling Of Chemoattractant-Guided Collective Cell Migration In The Drosophila Egg Chamber, Lara Scott, Bradford E. Peercy, Meghan Kwon, Michelle Starz-Gaiano

Biology and Medicine Through Mathematics Conference

No abstract provided.

Phase-Preserving Machine Learning Forecasting Of Nonlinear Predator–Prey Dynamics, Saira Batool, Muhammad Imran, Brett Mckinney

Biology and Medicine Through Mathematics Conference

No abstract provided.

Modeling Epidemic Dynamics With Renewal Processes And General Lifetime Distributions, Divine Wanduku, Divine Wanduku

Biology and Medicine Through Mathematics Conference

No abstract provided.

Remote Sensing To Detect Crop Damage By An Invasive Species, Cole Butler

Biology and Medicine Through Mathematics Conference

No abstract provided.

Dynamic Homeostasis In Relaxation And Bursting Oscillations, Christopher J. Ryzowicz

Biology and Medicine Through Mathematics Conference

No abstract provided.

Basics Of Forest Certification: A Primer For Forest Owners, Miah Maye Pormon, Joan U. Ureta, Marzieh Motallebi, Barry Graden

Forestry and Natural Resources

Forest certification promotes sustainable forest management, enhances market access for forest products, and improves ecosystem services. This article addresses forest owners’ hesitations in certifying their forest lands by providing information on the importance and requirements of the three biggest certification systems in the Southern U.S. This study can serve as a resource to raise awareness towards forest certification systems and encourage greater participation among forest landowners.

Dynamics For Complex Quadratic Networks, Templates And Mutations, Anca R. Radulescu, Eva Kaslik, Alexander Fikl, Sarah Muldoon, Johan Nakuci, Mark Comerford

Biology and Medicine Through Mathematics Conference

No abstract provided.

Delineating Differences In Firing Rate Estimates Of Healthy And Parkinsonian Single-Unit Basal Ganglia Recordings, Richard R. Foster, Cheng Ly

Biology and Medicine Through Mathematics Conference

No abstract provided.

Psychometric Framework For Coexistence With Large Carnivores, Benjamin Ghasemi, Gerard Kyle, Tara Teel, Rebeca Niemiec, Kevin Crooks, Jenny Anne Glikman, Neil H. Carter, John A. Vucetich, Michelle L. Lute, Stewart Breck, Beatrice Frank, Dana Hoag, Jonathan Salerno, Lily M. Van Eeden, Jeremy T. Bruskotter

Michigan Tech Publications

Human–carnivore coexistence is essential for biodiversity conservation, yet measuring the attitudes and behaviors that support it remains methodologically challenging. We developed psychometric scales to assess willingness to coexist with carnivores and the underlying beliefs of this coexistence through an iterative expert elicitation process grounded in risk perception theory and moral psychology to ensure strong content validity. The scales measure willingness to coexist and encompass individual and collective behaviors and their cognitive antecedents: perceived positive consequences, perceived negative consequences, and ethical considerations. We validated the scales based on three representative samples of Colorado residents (n = 434, 442, 433) focused on …

Thrombin-Induced Myofibroblast Differentiation Is Regulated By Myocardin And Novel Effector Genes In Ipf Fibroblasts, Christiana Okeke

Biotechnology Theses

Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial lung disease characterized by fibroblast activation, excessive extracellular matrix (ECM) deposition, and irreversible respiratory decline. In this study, we investigated the role of myocardin and its downstream effectors, RGS5, DLGAP5, and TAGLN, in thrombin-induced myofibroblast differentiation and ECM remodeling using primary human IPF fibroblasts. Myocardin knockdown significantly attenuated thrombin-induced expression of profibrotic genes, including FN1, COL1A1, PAI-1, ACTA2, and CNN1, as well as the novel effectors RGS5, DLGAP5, and TAGLN, confirming myocardin as a central regulator of fibrotic signaling. Silencing RGS5 produced minimal effects on gene and protein expression despite minor downward …

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). …

Environmental Dna (Edna) Assessment Of Fish And Decapod Diversity And Their Association With Cetacean Distribution In Matang Coastal Waters, Perak, Lim Chuan Hui

Student Works (2020-2029)

The estuarine and coastal regions of Matang, Perak, Peninsular Malaysia, are vital fishing grounds and recognised biodiversity hotspots, but are increasingly exposed to human activities. Understanding the biodiversity of marine fish and decapods is crucial for effective conservation efforts. Conventional biodiversity monitoring methods face several challenges, including invasiveness, inconsistencies in sampling techniques, reduced taxonomic accuracy, time-consuming processes, high costs, and often only providing approximate estimates. In this study, we evaluated the use of environmental DNA (eDNA) metabarcoding to assess marine fish and decapod diversity in Matang waters and to explore possible associations between fish assemblages and local cetacean occurrence. Water …

Care As Method: Sound, Duration, Relation In Contemporary Art Practice, Violet L. White

MFA in Visual Art

Abstract Care as Method: Sound, Duration, and Multispecies Relation in Contemporary Art Practice

This thesis proposes care as a method of artmaking, not a subject, theme, or aesthetic position, but the actual structural logic through which a body of work is built, sustained, and understood. Working at the intersection of ecological art practice and relational aesthetics, it asks what happens when the encounter at the center of the work is not between two people but between species, infrastructures, and histories of use and what obligations that encounter generates.

The argument is developed through six interconnected works: installations, sound compositions, sculptures, …

A Reassessment Of “Tityus” Tenuimanus Banks, 1910, As A Misidentified Leiurus Sp. (Scorpiones: Buthidae), Mohamed Mousaid, Ersen A. Yağmur, Zoe Flores, Alana Rivera, Aziza Lansari, Abdellah Bouazza

Euscorpius

This study re-examines the holotype of “Tityus” tenuimanus Banks, 1910, previously synonymized with Buthus atlantis Pocock, 1889 by Lourenço & Francke (1984). Our results indicate that the specimen is a misidentified representative of Leiurus Ehrenberg, 1828, as it exhibits the diagnostic characters of this genus: the central lateral and posterior median carinae of the carapace fused into a lyre-shaped configuration, and tergites I–II bearing five granular carinae (a character absent in the genus Buthus Leach, 1815). Moreover, the holotype lacks one of the most distinctive characters of the genus Tityus Koch, 1836, namely the presence of a subaculear tubercle. The …

The Dynamics Of Synchrony On Replicating Biological Populations, Montse Torres Garcia, Kevin Mcgoff, Francis Motta, Breschine Cummins, Steve Haase

Biology and Medicine Through Mathematics Conference

No abstract provided.

Computation Models Of The Primary Auditory Cortex, Jonathan Gonzalez Martinez, Quynh-Anh Nguyen

Biology and Medicine Through Mathematics Conference

No abstract provided.

Gap Junction Architecture And Synchronization Clusters In The Thalamic Reticular Nuclei, Alex Norwood

Biology and Medicine Through Mathematics Conference

No abstract provided.