Biology Commons^™

Long-Term Stimulant Use Is Associated With Normalized White Matter Integrity In The Vta-Nacc Pathway In Adolescents, Isaac T. Arsenault

Biological Sciences Undergraduate Honors Theses

Medical practitioners are diagnosing Attention-Deficit/Hyperactivity Disorder (ADHD) at a high and ever-increasing rate. The use of stimulant medication to treat ADHD is also increasing and is associated with changes in the brain. Past research found that children with ADHD have lower volume in reward neurocircuitry, such as the ventral tegmental area (VTA) and the nucleus accumbens (NAcc). Research has also found that stimulant usage in those with ADHD might “normalize” the reward circuits. However, few longitudinal studies have directly tested the long-term effects of stimulant medication on brain development. Here we tested whether long-term stimulant use is associated with changes …

Exploring Student Sensemaking During A Collaborative Biology Lab, Rebecca Kollipara

School of Natural Resources: Dissertations, Theses, and Student Research

Collaborative learning environments offer valuable opportunities for students to construct scientific understanding through dialogue, yet the conditions that support sustained conceptual reasoning in group settings remain incompletely understood. While prior research has identified discourse moves associated with productive collaboration, less attention has been paid to how those moves function together across turns and conceptual boundaries, or how individual student characteristics shape their emergence. This thesis examines collaborative sensemaking in an undergraduate General Biology II course, drawing on two complementary analyses of student discourse during a bryophyte life-cycle modeling activity.

Chapter 1 investigates how student groups participated in sensemaking and how …

Bio 23 Human Anatomy & Physiology I Syllabus, Rujin Tian

Open Educational Resources

The syllabus for BIO 23 contains a course description, course objectives, course readings divided by week and a link to an OER textbook.

Bio 24 Human Anatomy And Physiology Ii, Rujin Tian

Open Educational Resources

The syllabus for BIO 24 contains a course description, course objectives, course readings divided by week and a link to an OER textbook.

Optimizing Citriculture In South Texas With Endemic Hlb, Ruth Lilia Galan

Theses and Dissertations

The Texas citrus industry has a long history of resilience, rebounding from environmental and economic disasters. Over the last decade it has endured several hurricanes, freezes, pests and diseases. Huanglongbing (HLB), a graft-transmissible disease caused by Gram-negative bacterium Candidatus Liberibacter asiaticus which is vectored by the Asian citrus psyllid (ACP) (Diaphorina citri Kuwayama), is an endemic citrus disease posing serious threat to the long-term viability of the industry. Rapid production of high quality nursery trees and effective protection of young citrus transplants from HLB are critical for long term sustainability of citriculture in this region. Studies were performed to improve …

The Effect Of Drought On Avian Migratory Patterns And Stopover Through Texas And Louisiana, Ian Becker

Theses and Dissertations

Extreme weather events pose a massive threat for native ecosystems. As precipitation and temperature patterns are altered due to climate change, drought may become an incredibly severe event on the landscape. Drought directly impacts resources that migratory birds need during stopover en route to breeding and non-breeding grounds. Here, I quantify the impacts of drought on migration through Texas and Louisiana using 26 years of weather surveillance radar data. To understand how drought interacts with the local environment to impact migration, I tested 4 hypotheses displaying drought’s ability to impact migrants in conjunction with climatic and habitat level characteristics. Fall …

Developing A Qpcr Method For Evaluating Parasitoid Wasps As A Potential Means Of Control Of The Southern Cattle Fever Tick Rhipicephalus (Boophilus) Microplus In South Texas, Abbey Abalos

Theses and Dissertations

Ixodiphagus spp. wasps are natural enemies of ticks that have been reported to cause mortality in multiple tick species. Parasitoid wasps may represent a potential biocontrol alternative to traditional chemical tick control methods, which are challenged by non-target toxicity and the development of pesticide resistance in species of concern such as Rhipicephalus microplus, a pest of livestock that causes billions of dollars in loss to the livestock industry worldwide. Rhipicephalus sanguineus s.l. is a congeneric species of R. microplus, and parasitism of R. sanguineus by Ixodiphagus sp. in areas of co-occurrence has been observed. It is unknown if R. microplus …

The Impact Of Nutrition On Insecticide Resistance And Gene Expression In Aedes Aegypti, Esmeralda Guadalupe Rosas

Theses and Dissertations

The development of insecticide resistance in Aedes aegypti, a major vector of dengue and Zika viruses, threatens vector control efforts, particularly in endemic regions such as South Texas. Insecticides remain widely used; however, their overuse has accelerated metabolic resistance mediated by cytochrome P450 enzymes. Environmental factors such as larval nutrition may influence mosquito physiology and resistance-associated gene expression, yet this relationship remains poorly understood. This study examines how larval nutritional conditions affect the expression of cytochrome P450 genes linked to pyrethroid resistance in Aedes aegypti. Larvae were reared under five dietary treatments differing in lipid and protein ratios, and adults …

Resource Allocation Trade-Offs Between Longevity And Reproduction In Daphnia Magna, Amelia Pearson

Electronic Theses and Dissertations

Although trade-offs between longevity and reproduction have been described for a long time, the genetic mechanisms by which organisms modulate allocation of resources between these two essential processes remain poorly understood, due to their complex nature and their modification by existing nutritional states and environmental cues. Daphnia magna represents a valuable model for investigation in this area due to their moderate lifespan and cyclic parthenogenetic mode of reproduction, allowing for the easy study of gene by environment interactions. This dissertation first investigates the change in mortality, reproduction, activity, and gene expression when fully fed Daphnia and calorically restricted Daphnia are …

Can Carpobrotus Edulis Cause Significant Changes To The Soil Microbiome?, Samantha J. Cowan

Electronic Theses, Projects, and Dissertations

Invasive species cause significant damage to ecosystem biodiversity and can cost billions of dollars to restore native species (Van der Wal et al, 2008; Diagne et al., 2021).  In certain instances, even if the invasive species are removed, they can leave legacy effects on the environment that make restoration more challenging (Conser and Connor, 2008; Elgersma et al., 2011). Carpobrotus edulis is an invasive species of plant that is known to cause changes to its environment such as affecting the soil nitrogen cycle and the pH, potentially leading to persistent changes in the soil microbiome and causing native species to …

Wrky Transcription Factors: Integral Regulators Of Defence Responses To Biotic Stress In Crops, Dongjiao Wang, Ruize Zhang, Wenhui Zou, Yuanyuan Zhang, Wanying Zhao, Tingting Sun, Qibin Wu, Zheng Qing Fu, Youxiong Que

Faculty Publications

Crops are continually challenged by biotic stresses, including fungal, bacterial and viral pathogens and insect pests, which cause substantial yield and quality losses worldwide. WRKY transcription factors constitute a plant-specific and functionally diverse family that is central to immune regulation. Recent advances in genomic resources and multi-omics approaches have accelerated the identification and functional characterisation of WRKYs in crops. This review summarises the structural features and classification of WRKY genes and their genome-wide distribution across crop species. It also synthesises WRKY-centred regulatory modules that mediate resistance to major classes of biotic stress. In antifungal defence, WRKYs reinforce pattern- and effector-triggered …

From Antigen Presentation To Tumor Control: Mechanisms Of Type I Conventional Dendritic Cell-Based Cancer Vaccines, Josue E. Pineda

Dissertations and Theses (Open Access)

Type 1 conventional dendritic cells (cDC1s) are important for generating and sustaining antitumor immunity. Accordingly, the abundance of cDC1s in human tumors correlates with improved outcomes in cancer. Capitalizing on this role, we previously demonstrated that vaccination with in vitro-derived murine cDC1s elicits durable tumor control in multiple preclinical models; however, the immunological mechanisms underlying the efficacy of cDC1 vaccination remain unclear. Here, we examined whether in vitro-derived cDC1s resemble tumor-infiltrating DC populations and whether MHC-I and MHC-II antigen presentation contribute to cDC1-mediated tumor control following vaccination in melanoma.

As expected, MHC-I- or MHC-II-deficiency had minimal impact on …

Prediabetes Prediction Before Disease Onset Using Multimodal Health Data: A Machine Learning Approach, Luisa Veronica Gracia Mazuca

Open Access Theses & Dissertations

Prediabetes is a critical health condition that increases the risk of developing type 2 diabetes. The hemoglobin A1c (HbA1c) test diagnoses patients with prediabetes, but the disease has already caused metabolic alterations. Early detection is essential for timely interventions, and machine learning models offer a promising approach to identify prediabetic individuals through the analysis of biomarkers such as cytokines. We compared four classifiers-logistic regression, decision tree, random forest, and k-nearest neighbors - using cytokines (TNF-α, MCP-1, IL-1β, IL-6, IFN-γ), age, BMI, and waist-to-hip ratio (WHR). Models were evaluated using stratified 5-fold cross-validation and ROC-AUC. K-Nearest Neighbors (k-NN) achieved the highest …

Drug Repurposing Against Giardia Targeting Lipid Rafts, Extracellular Vesicles, And Sphingolipid Synthesis, Breanna Chantal Pence

Open Access Theses & Dissertations

Giardia lamblia is a protozoan parasite responsible for the intestinal disease giardiasis worldwide. Giardia is one of the major intestinal parasites in the world, with over 500,000 new cases annually. Symptoms of giardiasis include diarrhea, abdominal pain, and nausea. Children are particularly vulnerable to giardiasis, with cases of malnutrition, stunted growth, and cognitive impairment in countries where the disease is endemic. Giardia consists of two morphologic forms: an infective cyst which transmits the disease and a motile trophozoite which attaches to the epithelium of the small intestine during infection. Metronidazole is a common treatment for giardiasis, but cases of toxicity …

Determining Zap-70 Signaling Pathways Mediated By Ccr7 In Tcr T Cell Activation, Vivian Torres

Open Access Theses & Dissertations

Activation of T lymphocytes is the main event that occurs in the adaptive immune response after engagement of the T cell receptor (TCR) with the peptide of the major histocompatibility complex (pMHC) molecules that are demonstrated by antigen presenting cells [1]. A key step in this process is the recruitment and activation of the zeta chain associated protein of 70 kDa (ZAP-70). ZAP-70 couples TCR engagement to downstream intracellular signaling pathways through phosphorylation of tyrosine residues within intracellular tyrosine activation motifs (ITAMs) [2]. Although there have been extensive studies on the signaling response through TCR activation, the regulatory influence of …

Mitogenomic And Physiological Comparison Between Wild And Domesticated Congeners, Nicholas Enriquez

Open Access Theses & Dissertations

Domestication is a process in which wild populations are morphologically and/or behaviorally manipulated through selective breeding to become optimized for living in captivity. Consequently, many traits become quickly and significantly diverged from their ancestral, wild lineages, a process known as part of domestication syndrome. Captive breeding of mallards (Anas platyrhynchos) was one of the last major successful domestication events resulting in dozens of recognized breeds today. Many breeds were optimized for either ornamental or agricultural purposes (i.e., meat and/or egg production), but the game-farm mallard was specifically bred for sport hunting. In North America, the use of game-farm mallards to …

High-Resolution Mapping Of Brainstem Feeding Circuits: A Framework For Targeted Neuroscience Tools, Geronimo Tapia

Open Access Theses & Dissertations

The neural control of energy balance is mediated in part by distributed brainstem circuits that integrate metabolic, visceral, and hormonal signals to coordinate appropriate motivated behaviors and autonomic responses. Despite extensive study, the precise neuroanatomical architecture regulating metabolism remains incompletely defined within standardized atlas frameworks. This work addresses that gap through complementary studies examining an acute glycemic challenge methodology known to stimulate feeding, the acute delivery of an anorexigenic-associated neurohormone, and the chemoarchitecture of a major feeding-related region, the parabrachial nucleus. First, utilizing 2-deoxy-D-glucose (2-DG) induced glucoprivation, we map the rapid response of dorsal medullary neuronal populations with high spatial …

Characterization Of The Antiviral Activity Of Mouse Schlafen Proteins, Wendy Paola Alvarez Leal

Open Access Theses & Dissertations

The goal of this work was to characterize the anti-viral role of mouse Schlafen8 and Schlafen9. Expression of these proteins is induced by type I interferon in response to viral infections. Importantly, their human functional orthologs exhibit anti-viral functions, and the structural element required for these activities are conserved in Schlafen8 and Schlafen9. Therefore, it is expected that these proteins will also impair viral replication. An important limitation in this field is that the anti-viral function of human SLFNs has been evidenced only in in vitro cellular models. No informative mutations have been described in human populations so far. Thus, …

Enhancing Walleye (Ogaa) Recruitment: Evaluating Assisted Reproduction As A Mitigation Strategy, Douglass Keiser

Biology Graduate Theses

Over the past several decades, cold- and cool-water fish populations across the Upper Midwest, including Minnesota and Wisconsin, have shown troubling signs of decline. Among the most affected is the walleye/Ogaa (Sander vitreus), a species deeply embedded in the ecological balance, cultural identity, and economic vitality of the region, and central to the lifeways, treaty-reserved rights, and resource stewardship of Tribal Nations, including Ojibwe communities across the Upper Midwest. Despite ongoing stocking efforts and harvest regulations, many lake systems have experienced persistent declines in natural recruitment, prompting resource agencies to investigate the underlying causes. One such system is …

Decomposition Study Using Pigs In Southeastern Nebraska During The Fall And Winter Seasons, Ryan Bodine

Department of Anthropology: Theses and Student Research

When an individual is found deceased, one of the tools used in the identification process is estimating the post-mortem interval (PMI). This estimate is used to determine how long an individual has been deceased once their remains are found. To estimate an accurate PMI, knowing how decomposition is affected by external factors is key. The transition period from fall to winter in southeastern Nebraska consists of fluctuating temperatures as the seasons transfer from fall to winter. This thesis investigates how decomposition is affected during this transition period while also looking at two different environments that are common in Nebraska, prairies …

Exploring The Biocultural Profile Of The Undocumented Populations Of The Sonoran Corridor: A Skeletal Assessment Of The Prevention Through Deterrence Strategy, Mary A. Vaughn

Department of Anthropology: Theses and Student Research

Over the last thirty years the mortality rate of the undocumented population at the US-Mexico border has risen, requiring methods distinguishing US-born individuals from immigrants to improve the likelihood of identification and repatriation through foreign consulates. Forensic anthropologists with the Pima County Office of the Medical Examiner (PCOME) have advocated for the use of the biocultural profile, combining the biological profile with factors including oral health, osteological stress, and personal effects. The biocultural profile serves two purposes, functioning both as a tool for identification and with which to document structural inequality within communities of origin.

This study examines changes in …

Nadh Flim Reveals Cellular Bioenergetics And Mitochondrial Morphology During Drosophila Convergent Extension, Maria Espana Pena

Graduate Theses and Dissertations

Mitochondria are dynamic organelles that can fragment or fuse to support different bioenergetic demands and cellular processes, although the role of mitochondrial fission and fusion during embryonic development is not well understood. Fluorescence lifetime imaging (FLIM) of the mitochondrial cofactor NADH can be used to visualize mitochondrial networks and infer aspects of cellular bioenergetics in a label-free manner. We used NADH FLIM to test whether germband cells undergo changes in cellular metabolism during Drosophila convergent extension (CE)––a process in which hundreds of epithelial cells undergo coordinated intercalation to elongate the embryo. Contrary to our expectations, we did not observe significant …

Genomic Surveillance Of Guillain–Barré Syndrome-Associated Genes In Campylobacter Jejuni Across Human And Non-Human Reservoirs, Emma Doughty

Biological Sciences

Campylobacter jejuni is a leading cause of foodborne illness and a major trigger of Guillain–Barré Syndrome (GBS), an autoimmune neuropathy caused by molecular mimicry between bacterial lipooligosaccharides (LOS) and host nerve gangliosides. While prior genomic studies have focused primarily on human clinical isolates, the prevalence and distribution of GBS-associated genes in non-human reservoirs remain poorly characterized. This study used genomic datasets derived from analyses of human and non-human C. jejuni isolates to assess the distribution of GBS-associated genes, with a focus on the neuABC sialylation pathway. Results demonstrate that these genes are present in both host types, across multiple geographic …

Alternative Abl1 Isoform Expression In Oncogenic Translocations: Implications For Cancer Progression, Jessica Teague

Biological Sciences

Abstract (also on poster): Previous studies in our lab show that an alternate isoform of Bruton’s tyrosine kinase, BTK-C, is required for the survival of several epithelial-derived cancer cells. BTK-C is transcribed from an alternative promoter and includes a 34-amino-acid N- terminal extension with a palmitoylation sequence that alters its subcellular localization. Nine other human kinases have similar alternative N-termini (ANT), often producing palmitoylated or non-palmitoylated isoforms from different transcriptional start sites. Among these, ABL1 is a known oncogenic kinase and key drug target. Translocation mutations at the 5′ end of ABL1 are a major cause of adult leukemias. This …

Examining Pathogenic Vibrio Abundance And Environmental Controls Across Macroalgae, Sediment, And Oysters, Alexandra H. Geisser, Abigail K. Scro, Roxanna Smolowitz, Robinson W. Fulweiler

Arts & Sciences Faculty Publications

Climate change is accelerating the geographic spread and abundance of pathogenic Vibrio species in coastal waters, posing growing threats to ecosystems and human health. We investigated the abundance and pathogenic gene presence of V. vulnificus and V. parahaemolyticus across three common estuarine substrates (macroalgae, sediment, and oysters) in a temperate estuary. Macroalgae consistently harbored the highest Vibrio counts in conjunction with elevated pathogenic gene frequencies, while oysters contained the lowest. Environmental conditions related to Vibrio abundance were substrate and Vibrio species specific. Temperature and salinity were most closely related to pathogenic Vibrio abundance in oysters. In contrast, pathogenic Vibrio abundance …

Biohybrid Robotic Jellyfish For Swimming-Enhanced Vertical Ocean Profiling, Kelsi M. Rutledge, Sean Colin, John H. Costello, Noa Yoder, Simon R. Anuszczyk, Kelly R. Sutherland, Brad L. Gemmell, John O. Dabiri

Arts & Sciences Faculty Publications

Ocean monitoring is essential for understanding climate change and marine ecosystem dynamics, yet achieving comprehensive global coverage remains a challenge in oceanography. Current technologies face limitations in cost, power, hardware, and depth capacity that restrict widespread monitoring capabilities. Here we show that biohybrid robotic jellyfish (Aurelia aurita) can serve as autonomous vertical ocean profilers by integrating microcontrollers with positively buoyant sensor payloads, achieving controlled vertical-profiling capabilities. Laboratory experiments demonstrated repeatable up–down trajectories, quantified force balance limits, and identified predictable, size-dependent descent swimming speeds. Field deployments in Massachusetts coastal waters and the open ocean off the Florida Keys demonstrated field operation …

Vitaltitration Predicts Fermentation Performance Of Phylogenetically Distinct Saccharomyces Cerevisiae Yeast Strains, Samantha White Ms

All Student Scholarship

Accurate assessment of yeast physiological health is essential for achieving consistent, efficient, and predictable beer fermentations. Although yeast vitality is more predictive of fermentation performance than viability alone, no universally adopted vitality assay currently exists in the brewing industry. This thesis investigates vitaltitration (VT) as a rapid, robust, and brewery-feasible method for quantifying yeast vitality and predicting fermentation performance. We hypothesize that VT provides a reliable measure of metabolic competence that correlates with fermentation kinetics across brewery-relevant yeast strains. To test this hypothesis, VT was evaluated alongside Acidification Power (AP) in structured serial-fermentation experiments in two phylogenetically distinct brewing yeasts: …

Body Size Variation And Floral Associations Of The American Bumble Bee, Bombus Pensylvanicus, In East Texas, Sabekun Nahar

Electronic Theses and Dissertations

The American bumble bee, Bombus pensylvanicus, is an important pollinator species that was once widespread in much of North America but has experienced population declines in recent decades in some regions. As a species of conservation concern, it is important to understand how body size varies in response to environmental conditions and to identify the key floral resources that support this species. I examined body size variation in East Texas and floral resource use of B. pensylvanicus across Texas. In the first chapter, body size variation among queens, workers, and males was quantified using thorax width and size variation …

A Series Of Investigations On The L. Cornutus Host System And Bivesiculid Sp. Cercariae, Briana K. Zaffiro

All HCAS Student Capstones, Theses, and Dissertations

Rising global temperatures are likely modulating parasite-host interactions, yet the direction and magnitude of these changes remain uncertain. Rarely are these interactions viewed from both a host and parasite perspective. Using both CT_max, or Critical Thermal Maximum, and Clark-type polarographic oxygen microelectrodes, the physiological metabolic effects are investigated. CT_max is examined in Common Shiners, Luxilis cornutus, and is shown to be modulated by parasitism: uninfected fish had the highest CT_max average of 37.0°C, whereas heavily infected fish had decreased CT_max averaging 35°C. Prior to the parasite metabolic investigation, a suitable medium was determined, as …

Investigating The Ability Of Foxo1 To Maintain Stem Cells, Stella Aime Rios

Theses and Dissertations

Forkhead box O (Foxo) transcription factors are key regulators of stem cell identity and tumor aggressiveness. Prior work from our group and others demonstrates that Foxo factors maintain stem-like states across diverse biological systems; however, the mechanisms by which Foxo1 suppresses differentiation remain poorly defined.

Using C2C12 myoblasts as a model, we investigated whether Foxo1 preserves stem-like programs through regulation of the nuclear pore protein Nup210. RNA interference was used to generate Foxo1 knockdown cells, followed by qRT-PCR, RNA-sequencing, and fluorescence microscopy. Transcriptomic analysis revealed widespread gene expression changes involving metabolic, mitochondrial, and transcriptional pathways. Notably, Nup210 expression was significantly …