Life Sciences Commons^™

Windows Of Developmental Susceptibility To Tetrahydrocannabivarin (Thcv) Reveal Stage-Dependent Morphological And Biological Effects, Mirielle Clayton

Honors Theses

Tetrahydrocannabivarin (THCV), a minor cannabinoid found in Cannabis sativa, is gaining attention for its potential therapeutic applications, yet its effects on early development remain poorly understood. This study investigated how the timing of THCV exposure influences morphological, behavioral, and bioaccumulation outcomes in zebrafish (Danio rerio) embryos. Embryos were exposed to 2 μM THCV during discrete developmental windows (6–30, 30–54, 54–78, 78–102) and continuous 6–102 hours post-fertilization (hpf), designed to model early stages of human gestation. Behavioral analysis using a larval photomotor response assay revealed significant reductions in locomotor activity during dark phases, with the strongest hypoactivity observed …

Evolution Of Nematode Prey Chemotaxis Behavior Across Different Environments, Hailey R. Smith

Honors Theses

Climatic conditions in the near future are projected to be warmer, with more frequent and intense weather events. This will substantially alter the environments in which organisms must integrate specific information to find essential resources. Many organisms rely upon chemical signals to orient towards attractive resources through a mechanism called chemotaxis. How different environmental conditions, like temperature, impact this process will be important to understand as environments change. I conducted a laboratory evolution experiment with the model nematode Caenorhabditis elegans to see how success in chemotaxis assays changes over time when selected under different temperature regimes (normal laboratory temperature, increased …

Photo Identification On Interactions Between Tursiops Trucatus And Humans To Promote The Importance Of Sustainability, Julia Bronneberg

Undergraduate University Honors Capstones

The Mediterranean Sea is one of the most biodiverse regions, and especially around the Maltese islands, a popular tourist destination where people come to enjoy the beautiful weather and blue waters. Because bottlenose dolphins (Tursiops truncatus) are the most common species people see in coastal areas, they are the primary focus of this research. We care about these bottlenose dolphins because they cannot protect themselves if we are the ones accidentally causing them harm. This study starts from the belief that if we cannot protect the ocean and marine life, then we cannot protect ourselves. We use many resources that …

Life Histories Of Two Sgcn Procambarus Species In East Texas, Mckenzie A. Adkins

Biology Theses

Within freshwater systems, crayfish play notable roles by shaping habitats and linking food web levels. Yet even with such influence, knowledge about numerous species is incomplete, which hinders protection strategies. Found only in the Neches River basin in eastern Texas, Procambarus nechesae and Procambarus nigrocinctus have different conservation statuses, mainly because data on their life history remains sparse. These two species are not closely related and are analyzed independently in this study. Research into traits tied to survival and environmental preferences was carried out so that informed decisions on conservation efforts can be made for these species. The goal of …

Teacher Shortages In Arkansas Rural School Districts: Employed Teacher’S Perceptions Of The Impact On Their Effectiveness, Carloss Guess

ATU Theses and Dissertations 2021 - Present

ABSTRACT

TEACHER SHORTAGES IN ARKANSAS RURAL SCHOOL DISTRICTS: EMPLOYED TEACHERS’ PERCEPTIONS OF THE IMPACT

ON THEIR EFFECTIVENESS

Carloss Guess

Teacher shortages in rural school districts remain a persistent challenge that affects instructional quality, teacher workload, and professional sustainability. The purpose of this qualitative phenomenological study was to explore how teachers in rural Arkansas perceive the impact of staffing shortages on their instructional roles, workload, and professional well-being. Data were collected through semi-structured interviews with 10 K–12 teachers representing elementary, middle, and high schools and across varying career stages. Interview transcripts were analyzed using an inductive qualitative approach and the constant …

Debriefing In Emergency Departments And Intensive Care Units To Combat Compassion Fatigue, Madison N. Chiolino

ATU Theses and Dissertations 2021 - Present

Compassion fatigue can be associated with nurses working in increased stressful environments such as the Intensive Care Unit (ICU) and Emergency Room (ER).  There is a gap in healthcare facilities, where structured interventions like debriefing tools are not implemented to address compassion fatigue. The purpose of this study was to determine if implementing a debriefing tool in areas where nurses are placed in high stress scenarios such as the intensive care unit and emergency department can aid in combating compassion fatigue. A piloted quantitative pre-and post-survey intervention design was used. Data was collected using the ProQOL 5 and PEARLS debriefing …

Impacts Of Salinity On Microbial Enzyme Activity In Coastal Waters, Natali Ariyoshi

Honors Theses

Microbial extracellular enzymes are critical for the breakdown of organic matter and nutrient cycling in aquatic ecosystems. Extracellular enzyme activity serves as an indicator of nutrient turnover rates, metabolic states, and nutrient limitations within an ecosystem. Coastal ecosystems are especially dynamic as the influx of freshwater from inland runoff or seawater intrusion from storm surges can lead to fluctuations in salinity which can restructure microbial communities and alter enzymatic activity. Despite the ecological significance of these changes, few studies have explored the effects of short-term salinity shifts on microbial extracellular enzyme activity in coastal waters. This study investigated the effects …

Effects Of Increased Salinity On Mississippi Coast Bacterial Community Composition And Diversity, Clifton C. Wade

Honors Theses

Bacterial communities are important to ecosystem function in coastal environments, but the response of these communities to short term increased salinity conditions is understudied. This study utilized a microcosm setup to investigate the response of coastal seawater bacterial communities to three treatments: an unamended seawater control, a reference treatment that received reverse osmosis (RO) water, and an elevated salinity treatment that received artificial seawater dissolved in RO water. Microcosms were sampled four times over a five-day period to analyze the effects of time under different salinity conditions on the seawater bacterial community. 16S rRNA gene sequencing was used to analyze …

Studying More, Not Less: Rethinking Test Anxiety In Undergraduate Biology Courses, Kailey E. Reeves

Honors Theses

This study investigates the relationships among test anxiety, study behaviors, and metacognitive evaluation in undergraduate biology courses. While prior research has established that study strategies and metacognition influence academic performance, less is known about how these factors interact with test anxiety in undergraduate Biology courses. Guided by the student approaches to learning (SAL) and metacognition frameworks, this study examines whether test anxiety is associated with the type and number of study strategies students use, as well as their ability to evaluate their own learning and preparedness. Using a convergent parallel mixed-methods design, data was collected from 205 students enrolled in …

Neurophysiological Signatures Of Perceived Control In The Human Brain: An Electroencephalography Study, Megan Staehling

Honors Theses

Perceived control is defined as the belief that one’s actions can influence the outcomes in the environment. It plays an important role in decision-making, motivation, and emotional regulation. Previous studies suggest that perceived control shapes how the brain processes both reward and punishment stimuli. However, the neural mechanisms underlying this process are still unclear. The present study examined the neurophysiological correlates of perceived control during a decision-making task. Electroencephalography (EEG) was used to record the neural activity of twenty-nine undergraduate students while they completed the Choice Task. Participants associated visual cues with different levels of control over trials involving monetary …

Bax Activation Through The N-Terminal Bh3-Like Domains Of Vdac1 And Vdac2, Autumn A. Peters

Honors Theses

Voltage-dependent anion channels (VDACs) are central to mitochondrial function by mediating metabolite diffusion across the mitochondrial outer membrane (MOM). Two isoforms­­­­­­­­­­­,­­­­­­­­­­­­­­­­­­­­­­­­­­­­ VDACs 1 and 2, are also implicated in apoptosis based on interactions with Bcl-2 family proteins that control this process, including Bax and Bcl-xL. Activation of the pro-apoptotic protein Bax by interaction with ‘BH3-only’ proteins, such as Bim or Bid, induces MOM permeabilization to signal apoptosis, yet accumulating evidence indicates VDACs 1 and 2 may also affect Bax. We discovered that the VDAC N-terminal domains contain high sequence similarity to the conserved BH3 domains within Bcl-2 family members that …

A Survey Of Lichen Native To Three Of Mississippi’S National Forests, William S. Granberry Iii

Honors Theses

Lichens are a major part of the environment for telling the air quality and the impact humans have on the environment. These signs go into how many species of lichen are present in a general area, and there has been a lack of a list of lichens that call Mississippi their home. The goal of this research is to help create this list through a survey of lichen in three of Mississippi’s National Forests: DeSoto, Homochitto, and Holly Springs. These three forests are ideal because they cover differing ecosystems and are in different parts of the state, heightening the chance …

Mechanisms Underlying Diversity In Bacterial Biofilms, Jacob David Holt

Dartmouth College Ph.D Dissertations

Bacteria commonly exist in natural environments as communities of multiple strains and species attached to surfaces and encased in an extracellular matrix of DNA, protein, and polysaccharides–termed biofilms. These biofilms contribute to diverse functions, from ocean carbon cycling via chitin degradation to pathogenic processes such as wound or implant colonization. The molecular mechanisms governing biofilm formation and composition have been well characterized in model pathogenic organisms, yet the extent to which aspects of biofilm formation contribute to the assembly and maintenance of diverse communities remains less well understood. Using microfluidics, confocal microscopy, and model biofilm-forming bacteria, this thesis details how …

Evaluating Uv-C Hormesis On Physiological, Biochemical And Molecular Responses In Two Tomato Cultivars, Wong Gwo Rong

Student Works (2020-2029)

The growing demand for nutrient-dense fruit and vegetables presents challenges due to population growth, global climate change, limited land resources, and increasing pathogen pressure. Tomatoes, a widely consumed and nutritious fruit crop, often require high inputs of fertilisers and pesticides, raising environmental and health concerns. Ultraviolet-C (UV-C) radiation (100-280 nm), long recognised for DNA-damaging and disinfecting properties, has shown promising hormetic effects at low dosage that can enhance plant growth and post-harvest shelf-life. However, the detailed understanding of UV-C effect on flower traits, fruit quality and on molecular responses underlying plant defence remains limited. In this study, a custom UV …

Functionalized Nanodiamonds As Binding Platforms For Single-Stranded Dna, Mallory A. Chapman

Honors Theses

Nanodiamonds (NDs) offer a promising platform for biomolecular applications due to their stability, biocompatibility, and three-dimensional structure. This study focused on developing a nanodiamond–DNA complex in which streptavidin-functionalized NDs would form a protective shell around biotinylated single-stranded DNA (ssDNA), creating a core–shell system like an “M&M” candy with DNA at the center and a protective coating on the outside. DNA has many uses in nanotechnology, including DNA origami, nanomachines, and drug delivery systems, but its degradation limits its practical use, making protective strategies essential.

ND–DNA conjugates were prepared using biotin–streptavidin interactions and analyzed using gel electrophoresis. Initial separation on agarose …

Community Composition Of Antibiotic-Resistant Bacteria On The Mississippi Gulf Coast, Marisa Martin, Colin Jackson

Honors Theses

The Mississippi Gulf Coast is an important resource for transportation, economic development, and recreation. Given its economic and cultural importance, it is crucial to maintain clean and safe conditions along the coast for public health, but other than routine beach monitoring, few studies have examined microbial contamination of coastal waters in this region. This study aimed to determine the quantity, composition, and distribution of bacteria resistant to six different antibiotics (Vancomycin, Kanamycin, Tetracycline, Ciprofloxacin, Erythromycin, or Amoxicillin) in seawater at seven public beaches along the Mississippi Gulf Coast. No bacteria resistant to Ciprofloxacin were detected, and bacteria resistant to Kanamycin …

From Stranger To Self: The Role Of Familiarity In Modulating The N170 And N250 Erp Components, Tabish Gul

Dissertations

This study investigated how varying levels of face familiarity modulate the N170 and N250 event-related potential (ERP) components, two neural markers of face perception and recognition. While the N250 is widely considered familiarity-sensitive, the N170 has traditionally been linked to the structural encoding stage of face perception. However, recent research suggests that face familiarity may also influence N170 amplitude and latency. While most previous studies have compared up to three familiarity levels, the present study examined five levels of familiarity: own face, friend’s face, famous face, experimentally familiar face, and unfamiliar face. Twenty-six participants viewed face images while completing a …

Brachial Macroparasite Loads In Estuarine Young-Of-Year Striped Mullet (Mugil Cephalus), Triston Rice

Honors Theses

Climate change is a growing threat to marine habitats globally. One ecological impact that warming water temperatures poses is the increased metabolic rate of many parasite species. Their promoted reproductive and feeding rates could pose a threat to the stability of many host populations. Parasites of the gills, or brachial parasites, are especially concerning to fish populations globally. As parasitism is not limited to a specific taxon and comprises a large diversity of ecomorphs and behaviors, geographically distinct areas may be differentially affected by the changing prevalence of parasites. This study aimed to survey current brachial parasite abundance and prevalence …

Neuroprotective Effects Of Estradiol And Genistein And Interactions With Aromatase Inhibitions Post Cerebellar Lesion In Male Zebra Finches, Grace E. Thompson, Anthony P. Irovic

Honors Theses

Across vertebrates, peripheral and brain-derived estradiol (E₂) promotes neuroplasticity. After injury, E₂ can be derived locally from testosterone via aromatase (AROM), an enzyme that is upregulated in glia at the site of neural injury. E₂disrupts testicular function and elevates cancer and stroke risk, primarily via binding to estrogen receptor alpha (ER α). Genistein (GEN), a phytoestrogen, is similar to E₂ but binds preferentially to estrogen receptor beta (ER β). It may offer neuroprotection without adverse effects of E₂. We used adult male zebra finches (ZF) to model neuroprotective effects of E_{2 …}

Unc-45b As A Potential Chaperone For The Transcription Factor, Gata-4, Kaylah Owings

Electronic Theses and Dissertations

The cardiac myosin–specific chaperone UNC-45B has been shown to physically interact with the cardiac myosin transcription factor GATA-4. Specifically, this interaction occurs within the chaperoning region of UNC-45B, known as the UCS domain. However, the precise nature of this interaction has not yet been fully elucidated. The present study was conducted to confirm earlier findings and to evaluate whether UNC-45B functions as a chaperone for GATA-4 using bioinformatic approaches. Analysis of the interaction using AlphaFold 3 modeling verified not only that binding occurs at the UCS (chaperoning) domain of UNC-45B, but also that the interaction is associated with an increase …

Ectomycorrhizal Fungal Identity Strongly Influences Soil Properties Relative To Pine Presence And Soil History In A Pine–Eucalyptus System, Braedan Watters

Honors Theses

Invasive Pinus radiata has increasingly spread into native ecosystems in the Southern Hemisphere, including Eucalyptus forests in Australia, where it forms novel hybrid forest systems in which invasive and native tree species coexist. The success of these invasions is closely tied to ectomycorrhizal fungi (EMF) such as Rhizopogon spp., yet the relative roles of pines versus their fungal symbionts in altering soil properties remain poorly understood. This study investigated the independent and interactive effects of soil history (Pinus or Eucalyptus), EMF identity, and pine presence on soil properties using a controlled factorial experiment. Soil from beneath either Pinus …

Beyond The Bug: How The Covid-19 Pandemic Exposed Longstanding Systemic Failures In The United States Workforce And Economy, Abbey M. Markley

Honors Theses

The purpose of this thesis is to investigate and discuss how longstanding systemic failures in the United States exacerbated the effects the COVID-19 pandemic had on the American economy, essential healthcare workers, and overall public trust in institutions. A review of the existing literature surrounding this topic and the subsequent results of various studies were used to compose this thesis. The United States has a painful lack of worker protections and tends to view members of its workforce as expendable, even in times such as pandemic when they are deemed essential. Healthcare workers in particular faced increasing threats to their …

Biochemical Characterization Of Luciferase In Omphalotus Olearius, James H. Martin

Honors Theses

The overall goal of this thesis was to investigate the genetic basis of bioluminescence in Omphalotus olearius, a bioluminescent mushroom. The project initially focused on growing fungal cultures under controlled laboratory conditions and using molecular techniques such as DNA extraction, PCR, and gel electrophoresis to identify the organism and isolate the gene responsible for light production. The main objective was to insert this gene into a bacterial system to confirm its function through observable bioluminescence. However, repeated difficulties in maintaining viable fungal cultures and errors in molecular procedures resulted in inconclusive results, preventing successful gene identification. Due to these …

Antibiotic Resistance Patterns In Bacterial Isolates From Mississippi Gulf Coastal Environments, Lawler F. Horn

Honors Theses

Coastal environments host diverse microbial communities that play essential ecological roles but may also serve as reservoirs for antibiotic-resistant bacteria. This study investigated patterns of antibiotic resistance in microbial isolates collected from public beaches along the Mississippi Gulf Coast. A total of 143 bacterial isolates exhibited growth and were included in antibiotic susceptibility screening. High levels of antibiotic resistance were observed, with 137 of 143 isolates showing growth on vancomycin, 124 on amoxicillin, and 102 on erythromycin. Resistance to kanamycin (19/143 isolates) and tetracycline (33/143) was less common. Multidrug resistance was widespread, with 101 isolates (70.6%) resistant to three or …

Invasive Macrofungi In The United States: A Mushrooming Crisis, Emily Torres

Student Theses 2015-Present

Globalization has accelerated the spread of invasive species, making them one of the largest contributors to biodiversity loss worldwide. While invasive macrofungi remain largely absent from scientific discourse on invasive species, they represent a growing ecological concern throughout the United States. Invasive macrofungi disrupt forest ecosystems, alter soil communities, and displace native fungi. Beyond these ecological impacts, their presence and establishment profoundly affect human-nature relationships, most notably mushroom foraging and cultivation practices. This paper adopts a multidisciplinary approach to examine the ecological, economic, and anthropogenic impacts of invasive macrofungi in the United States. Chapter 1 provides a quantitative overview of …

Optimization Of Refolding, Purification, And Analytical Characterization Of Proinsulin(F25d) Soluble Antigen Array Immunotherapy, Abigail Richardson

McKelvey School of Engineering Graduate Student Theses & Dissertations

Type 1 Diabetes (T1D) is characterized by autoreactive immune responses to insulin and its precursor, proinsulin. Soluble antigen arrays (SAgAs) displaying the metabolically inactive proinsulin variant, proinsulin(F25D), represent a promising antigen‑specific immunotherapy candidate for T1D. However, the production of these platforms is hindered by substantial practical challenges, including protein aggregation, inefficient refolding, and the lack of sensitive analytical tools to verify quality and dosage. This work establishes an integrated, scalable pipeline for the purification, conjugation, and quantification of a proinsulin(F25D) SAgA. First, we optimized the refolding of recombinant methionine-proinsulin(F25D) (M-PI(F25D)) from inclusion bodies using controlled buffer systems and created a …

The Effect Of Climate Change On California’S Agricultural Economy, Anmol Singh

Honors Capstones

This study examines the relationship between climate variability and agricultural production in California, focusing on major specialty crops including almonds, walnuts, pistachios, and grapes. Using annual data from 1993 to 2023, the analysis evaluates how temperature and precipitation influence agricultural output while controlling for differences across crop types. The study employs ordinary least squares regression models using the natural logarithm of crop production as the dependent variable. In addition to a baseline linear specification, an extended nonlinear model including squared temperature and precipitation terms is estimated to test for potential nonlinear climate effects.

The results indicate that temperature has a …

Quantifying Genetic Diversity In Nematode Feeding Rate, Jacob King

Honors Theses

Understanding how populations persist under changing environmental conditions is a central question in ecology and evolutionary biology. Variation in traits related to resource acquisition may play a key role in determining population survival when resources are limited or fluctuate over time. In this study, I investigated how variation in feeding-related traits influences population persistence using a combination of computational modeling and laboratory experiments. I developed a stochastic, individual-based consumer–resource model to simulate population dynamics across varying levels of trait variance and resource regimes. Across 60,000 simulated populations, increased trait variation consistently reduced extinction risk and extended persistence time, although the …

The Stress Of Competition: Assessing Cortisol Levels In University-Owned Horses Via Hair Sampling And Behavioral Observations, Zoey Horn

Undergraduate Theses and Capstone Projects

Stress in equine athletes looks very different from that in our human counterparts. There are behavioral signs of equine stress, such as flared nostrils, excess tail swishing, sweating, pawing, pacing, and many more. High levels of stress have been associated with weakened immune function in addition to the symptoms of ulcers, which include stomach perforation, chronic pain, and reduced performance. There are many methods to take cortisol sampling; however, the least invasive option is to do so via hair sampling. Cortisol is incorporated into hair, allowing identification of average cortisol levels over the last weeks or even months before the …

Teaching Exercise: A Survey On Educational Aids And Self-Efficacy, Joshua I. Eaton, Lucas Morgan, Matthew Hermes

Honors College Theses

HEPs are an important part of therapeutic treatment because they allow for greater exercise stimulus than can be achieved from supervised exercise alone. 94.7% of physical therapists reported prescribing HEPs to their patients. However, patient adherence to these plans can be as low as 35%. Lack of HEP adherence likely leads to sub-optimal clinical outcomes in physical therapy patients. Self-efficacy is improved in patients by supplementing HEPs with instructional aids, especially in the form of videos instead of pictures or descriptions, because they act as a form of vicarious experience. It is possible that improving self-efficacy through vicarious experience could …