Life Sciences Commons^™

Evaluating Environmental Enrichment As A Preventative Treatment In A Zebrafish (Danio Rerio) Model Of Alzheimer's Disease, Ainsley Craddock

Undergraduate Honors Theses

Alzheimer’s Disease (AD) is a progressive neurodegenerative disorder that leads to several cognitive deficits, including impairments in spatial memory (Alzheimer’s Association, “What is Alzheimer’s Disease?,” 2024). This is thought to occur due to atrophy in the hippocampus and cholinergic system (Ferreira-Vieira et al., 2016). Acetylcholine receptor antagonists, such as scopolamine, can mimic the effects of AD by decreasing acetylcholine activity at muscarinic receptors in the hippocampus. Scopolamine is an antiemetic that is FDA approved to treat certain kinds of nausea, but it has become a popular pharmacological model for studying the cognitive impairments associated with AD (Bajo et al., 2015). …

Ecology And Conservation Of Diamondback Terrapins In Virginia, Cypress Ambrose

Undergraduate Honors Theses

The diamondback terrapin (Malaclemys terrapin) is the only turtle species native to North America with specific morphological and physiological adaptations to estuarine environments. Along with many other pressures contributing to population declines, terrapins frequently become trapped and drown as bycatch in crab pots used in the commercial and recreational blue crab (Callinectes sapidus) fishery. A wealth of evidence supports the use of inexpensive bycatch reduction devices (BRDs) that can be attached to the entrances of these traps, which leads to a marked decrease in terrapin bycatch while not reducing crab catch dramatically. Virginia is the only …

Life History Of Two Goatfishes In Hawaii And Alternative Methodologies In Life History Research, Duncan Campbell

Undergraduate Honors Theses

Data-driven management of fisheries requires information on the life history of the species being managed. I provide new information on the life histories of two goatfish species in Hawaiʻi, Parupeneus insularis and Parupeneus cyclostomus. Fish were collected using spearfishing from the reefs of Oʻahu between 2020 and 2023. Macroscopic and microscopic methods of assigning maturity and reproductive stage were used to estimate size at maturity and seasonality. Parapeneus insularis females are estimated to reach 50% maturity at 188 mm fork length (95% CI: 177mm, 197mm), and 95% maturity at 245 mm FL (95% CI: 226mm, 287mm). P. cyclostomus females reach …

Fecal Pellet Production By North Atlantic Zooplankton, Michael Gibson

Undergraduate Honors Theses

Fecal pellet carbon (FPC) production by zooplankton is a significant component of the ocean’s biological carbon pump: the suite of biological processes that mediate export of carbon to the deep ocean, ultimately leading to the sequestration of atmospheric carbon dioxide in the ocean. In this study, mesozooplankton (zooplankton 0.2 mm to ~2 cm) were collected from the epipelagic zone in the temperate North Atlantic Ocean during day and night in May 2021. Zooplankton were live separated into five size fractions and incubated on board ship in natural surface seawater to measure fecal pellet production rate of the mixed mesozooplankton community. …

The Effects Of Loss Of Orexin Neurons On Attention, Alejandra Eceizabarrena Sainz

Undergraduate Honors Theses

Attention is the ability to process stimuli in the environment and select relevant cues amongst distractors. It is a crucial aspect of the nervous system that engages multiple brain circuits. Neurons that release the neuropeptide orexin are implicated in attention. These neurons originate in the lateral hypothalamus and send projections widely throughout the brain. Evidence suggests orexins modulate attentional mechanisms through interactions with ascending neuromodulatory systems such as the basal forebrain. Experiments manipulating orexin receptors have found a subsequent effect on attention-demanding tasks, with infusions of orexin A enhancing attention in the presence of distractors. In contrast, the blockade of …

Aggression In And Out Of The Surrounding Space, Marissa Incer

Undergraduate Honors Theses

Social isolation is a type of punishment used to address misbehavior in individuals, such as children with time-outs and prisoners in solitary confinement. It was thought to be an effective method for teaching good behavior or alleviating tense situations. However, this type of punishment may worsen the punished individual’s aggression depending on the environment of isolation. The current study was divided into two experiments. In the first experiment, participants were isolated in a small (2x2 feet) or large (6x6 feet) space to observe if the space alone affected their aggression. In the second experiment, a frustration-inducing task was given to …

Synthesis And Biological Testing Of Small-Molecule Mitochondrial Complex I Inhibitors, Willough Sloan

Undergraduate Honors Theses

This thesis delineates two main projects: the first outlines the structure elucidation efforts toward a Diels-Alder adduct of a novel reaction for the synthesis of chimaphilin, a naphthoquinone-based natural product with apoptotic or antiproliferative activity in certain cancer cells^1,2. The structure elucidation extends to derivatives of chimaphilin synthesized by the same cyclization reaction. While Diels-Alder reactions are usually regioselective, ¹H-NMR and ¹³C-NMR of the adducts was inconclusive and indicated the possibility of regioisomer presence, with one regioisomer being chimaphilin (or derivatives). A multitude of crystallization methods were carried out in order to be able to analyze …

Carrying Capacity Of Cultured Bivalves In Cherrystone Inlet, Va, And The Implications Of Spatial Distribution And Environmental Change, Sophia Chirico

Undergraduate Honors Theses

Aquaculture is a growing industry internationally. In the United States, aquaculture of bivalves occurs throughout the Chesapeake Bay. Cherrystone Inlet, a tidal inlet on the Virginia Eastern Shore, is the location of intensive hard clam culture, and recently oyster aquaculture has become common there as well. Given the intensive culture in Cherrystone and similar systems in the Chesapeake, it is important to understand the carrying capacity of the respective bivalves and how they can be grown together. Carrying capacity is defined here as the largest population of individuals that can be supported that allows individuals to reach a harvestable size …

Relating Occupancy Patterns To Multi-Life-History Scales For Pond-Breeding Anurans In Eastern Virginia, Patrick A. Hardner

Undergraduate Honors Theses

Amphibians are experiencing population declines worldwide due to a multitude of factors, including habitat loss. Therefore, assessments of breeding habitat occupancy are important to determine which environmental characteristics are crucial for conservation of amphibians. While most research assesses habitat conditions at the breeding site (i.e., pond or wetland), for many species this misrepresents annual habitat use as many migrate to terrestrial habitats once breeding is completed. To provide a comprehensive assessment of annual habitat use, we evaluated how anuran (i.e., frog and toad) breeding site occupancy related to three life-history scales: breeding, migration and dispersal. Basically, the three scales define …

Using Deep Learning With Satellite Imagery To Estimate Deforestation Rates, Maeve Naughton-Rockwell

Undergraduate Honors Theses

Previous studies have used Convolutional Neural Networks for regional detection of deforestation breaks. However, there is limited research into the capability of deep neural networks to identify sudden shifts in global forest cover from satellite imagery. Additionally, many deforestation detection models are trained on region specific data and need manual input thresholds. In this work, we develop a deep learning model to predict the percent of deforestation in a region between two points in time, trained on globally sourced data. Using the before and after satellite images of a deforestation event as inputs, we implemented a two input Convolutional Neural …

Investigating The Effect Of Longhorned Milkweed Beetle Larval Root Feeding On Resprouting In Common Milkweed, Margaret Donnan

Undergraduate Honors Theses

Clonal reproduction is an important form of reproduction for many plants, and plants can grow clonally through a variety of methods, such as belowground stems, specialized organs, or adventitious buds on their roots (Herben and Klimešová 2020). In plants that reproduce via buds on their roots, researchers have shown that damage to roots can stimulate bud production and sprouting (Bartušková and Klimešová 2010). Common milkweed (Asclepias syriaca) is a root- sprouting perennial plant that receives yearly damage to its roots via the feeding of the larvae of the specialist longhorned milkweed beetle (Tetraopes tetrophthalmus) (Erwin et al. 2013). In this …

Student Sleep Patterns When Exposed To Mindfulness Reminders, Zeyanna Dhalla

Undergraduate Honors Theses

University students are plagued with increased levels of stress and anxiety which can lead to poor sleep quality and quantity. Breathing techniques have demonstrated counteractive effects to the chronic stresses that the population encounters on an everyday basis. Wearable technology, such as Apple Watches, contain a mindfulness feature that encourages its users to pause throughout the day and engage in mindfulness through resonant breathing. Wearable technology has become increasingly accessible and is also growing in accuracy to measure different biometrics such as sleep quality and quantity. The purpose of the present study was to examine if the mindfulness reminders initiated …

Using A Machine Learning Model To Predict Plant Inflorescences Based Upon Its Soil Microbiome, Luke Denoncourt

Undergraduate Honors Theses

The UN estimates that the global population could reach 9.7 billion by 2050 (United Nations). As a result, the amount of food required to feed humanity is thought to double by 2050 (Ray et al., 2012). Humanity must find a way to increase crop production without increasing fertilizer usage and eutrophication, which can be done using the soil microbiome. Using potted plants with soils inoculated with Pseudomonas alcaligenes, Pseudomonas denitrificans, Bacillus polymyxa, and Mycobacterium phlei, both the shoot and root growth of pea and cotton plants was significantly increased (Egamberdieva & Höflich, 2004). In this study, utilizing a random forest …

The Cognitive & Educational Implications Of Color Use In Drawing To Learn, Juliana F.M. Cantarutti

Undergraduate Honors Theses

Drawing to Learn (D2L) is a learning aid that encourages STEM students to interact with abstract concepts in STEM by sketching. D2L is not an intuitive skill, and researchers strive to provide students with guidelines on how to master this method. One potential way to enhance the D2L method for students is by incorporation of visual cues, specifically color. While many students choose to incorporate color into their models without explicit instruction to do so, we have found no research on: a) why students use color in sketching, b) its effects on D2L. This study used interviews, surveys, and course …

The Characterization Of The Type I Dna Methyltransferase Hsdm1 (Hp0463) In Helicobacter Pylori, Elise Zimmerman

Undergraduate Honors Theses

Helicobacter pylori is a gram-negative spiral-shaped bacterium that colonizes the gastric epithelium and is the leading cause of gastric adenocarcinoma globally. For both H. pylori and many other bacterial species, there is an increasing body of evidence that methylation by restriction-modification systems regulates gene expression in addition to its traditional role in genome protection. The study aimed to further elucidate the mechanisms through which H. pylori achieves methylome plasticity. We demonstrated that the Type I DNA methyltransferase hsdM1 (HP0463) is regulated by the main acid sensing mechanism of H. pylori, the two-component system (TCS) ArsRS. ArsRS induces hsdM1 …

Climate Change And Conservation Of Milkweed: Evidence Of Extensive Admixture Between Common Milkweed And Poke Milkweed, Elizabeth Davies

Undergraduate Honors Theses

Global climate change can drive many changes in species interactions. One primary way it affects species is by changing climates, causing species to expand their ranges and allowing them to interact with species from whom they were previously isolated. In plants, new species interactions can result in hybridization – the creation of hybrid offspring between two separate species. This hybridization can increase gene flow between the species and lead to introgression, the transfer of genetic material from one species to another through hybrid backcrossing with the parent species. My thesis investigates hybridization in the model system Asclepias (milkweed) by analyzing …

Modeling And Analyses Of Mechanisms Underlying Network Synaptic Dynamics In Two Neural Circuits, Linda Ma

Undergraduate Honors Theses

In systems neuroscience, circuit models of cortical structures can be used to deconstruct mechanisms responsible for spike patterns that generate a variety of behaviors observed in the brain. In particular, mathematical simulations of these circuits can replicate complex dynamical behaviors that mirror not only macroscopically patterns observed in the brain, but also a significant amount of experimentally characterized minutiae. These models are capable of analyzing neural mechanisms by explicitly deconstructing connectivities between populations of neurons in ways that tend to be empirically inaccessible. This work presents two such models; one in the rat somatosensory barrel cortex, responsible for processing sensory …

Honey As A Biomonitor For Air Pollutant Deposition In The Eastern United States Using Ion Chromatography And Scanning Electron Microscopy, Cole Cochran

Undergraduate Honors Theses

Anthropogenic activities generate metal, acid, and particulate air pollutants which negatively impact human and ecological health. In the United States, power plant, industrial, and vehicle emissions are leading causes of air pollution, however, the measurement of air pollution at high-resolution spatial regimes remains a challenge. Honey has emerged as a powerful biomonitoring tool to effectively quantify contaminants without the need for a large array of monitoring instruments. I hypothesized that honey could be used to effectively measure and map modern air pollutant spatiotemporal relationships over the Eastern U.S. Using ion chromatography with sulfate as an indicator for air pollution and …

A Mathematical Model Of Vagus Nerve Stimulation In Alzheimer's Disease, Julianne Miranda

Undergraduate Honors Theses

Alzheimer’s Disease is a neurodegenerative condition characterized by cognitive decline as a result of brain atrophy. The exact cause of Alzheimer’s is unknown but current theories involve the aggregation of amyloid beta plaques as well as neurofibrillary tangles. Inflammation is emerging as central to the progression of the disease, with increased amyloid beta plaques and neurofibrillary tangles associated with the Nuclear Factor Kappa B pathway. This project presents a mathematical model of the impact of vagus nerve stimulation in Alzheimer’s Disease, as seen through the Nuclear Factor Kappa B (NFKB) pathway. The model examines several factors involved in the inflammatory …

Analysis Of Edna To Assess Effects Of Water Quality On Freshwater Fungal Diversity In A Virginia Coastal Watershed, Lauren French

Undergraduate Honors Theses

Freshwater fungi comprise a phylogenetically and functionally diverse group which contributes to wide-ranging ecosystem processes in aquatic systems. Saprotrophic fungi convert detritus into nutrient-rich food sources for fish and invertebrates, whereas pathogenic and parasitic fungi can cause disease and population declines of other aquatic organisms. With their diverse and important roles, changes in freshwater fungal community structure may have far-reaching impacts on ecosystems. To understand how natural and anthropogenic stressors to freshwater systems impact fungal-mediated ecosystem processes, a greater understanding of the taxonomic and functional composition of freshwater fungal communities is needed. We assessed relationships among freshwater habitat types, water …

Characterizing The Microbiome Of Floral Nectar Of Asclepias Syriaca And Other Asclepias Species, Heather Natterer

Undergraduate Honors Theses

In recent decades, Danaus plexippus (the monarch butterfly) has experienced a drastic decrease in population size due to urbanization, climate change, and habitat loss. The primary habitat and food source of D. plexippus is plant species that are within the genus Asclepias (milkweed). The preservation and propagation of Asclepias spp. is necessary to combat D. plexippus’s population declines. A plant’s reproductive success is dependent upon its ability to attract pollinators, which is linked to the plant’s nectar qualities. We propose that, in turn, these nectar qualities may be influenced by the nectar microbiome. This study aims to better understand the …

Welcoming The Game Changer Of Human Society: A Defense Of The Moral Permissibility And Obligations Of Human Genetic Engineering, Yongkang Li

Undergraduate Honors Theses

In 2018, a Chinese scientist, Jiankun He, announced the birth of two HIV-resistant babies through his experiment of human genetic engineering. This incidence has soon shocked the entire scientific community and invoked public outrage towards He’s corrupt moral integrity.

However, this event should also act as a harbinger to the human society that the technique of human genetic engineering is rapidly approaching maturity. In that case, how should we respond?

This thesis focuses on the moral issues surrounding human genetic engineering and advertises an accepting moral attitude to this booming technology. This thesis will first discuss the types of human …

Attentional Dysfunction In Schizophrenia: The Effects Of Dual Orexin Receptor Blockade On An Nmda Receptor Hypofunction Model, Paige Little

Undergraduate Honors Theses

Hypofunctionality at the N-Methyl-D-aspartic acid receptor (NMDAR) is a commonly used model of the neurodevelopmental disorder schizophrenia due to the complex circuitry changes that follow NMDAR blockade. While these animal models are very popular for modeling the cognitive deficits seen in schizophrenia, actual treatments for this disorder remain sparse. Orexins (hypocretins) are neuropeptides that are capable of modulating activity along pathways relevant to attention, but are rarely tested for their efficacy in attenuating attentional dysfunction. This study was conducted to determine if systemic administration of the dual orexin receptor antagonist filorexant (MK-6096) was able to attenuate sustained attentional dysfunction induced …

Rapid Morphological Divergence In Three Introduced Cichlid Species, Khalil Russell

Undergraduate Honors Theses

Cichlids are well-known for their capacity to exploit trophic niches in their environments through rapid speciation and morphological diversification; the best-documented case of such diversification in cichlids occurred in the African Rift Valley. With numerous species established in Florida, the purpose of this study was to explore how members of the family Cichlidae have managed to invade so successfully by focusing on morphological differences between native and non-native (Floridian) populations of three cichlid species: Pelmatolapia mariae, Mayaheros urophthalmus, and Parachromis managuensis. Using both linear measurements and 2D landmark geometric morphometry, I found that all three species have diverged in …

Effects Of Gamete Age On Development In Asterias Forbesi, Amanda Yeo

Undergraduate Honors Theses

For broadcast spawning organisms like echinoderms, the timing of the union of gametes is essential for successful fertilization. However, the release of gametes is not always synchronous and the success of fertilization is highly dependent upon a number of factors including: the number and distribution of spawning adults, the timing of gamete release, the dispersal of gametes, the interaction of gametes within the water column, turbulence in the water column, and the phenotypic properties (e.g. size) of the gametes themselves. Previous studies have shown that the longer sperm is in the water column the greater their mobility decreases and they …

Three Centuries Of Vegetation Change In The William & Mary College Woods Reconstructed Using Phytoliths, Timothy Terlizzi

Undergraduate Honors Theses

The College Woods, west of William & Mary’s campus, consists of ~900 acres of protected southern mixed hardwood forest. The woods surround Lake Matoaka, a former millpond established in ~1700. Despite the rich history of the area, little is known about how the dominant vegetative landcover has shifted over the last 300 years. This study set out to quantify the modern vegetation within the College Woods via the phytolith assemblages within the soil and identify shifts in the assemblages since the creation of Lake Matoaka and whether these changes are distinct from the vegetation that existed in the area before …

Effects Of Xanomeline On Attention In Rats, Grace Smith

Undergraduate Honors Theses

The cholinergic system plays a large role in regulating attentional processing. Diseases such as Alzheimer’s Disease are known to degrade cholinergic neurons and deactivate cholinergic M1 receptors. Dysfunction in the cholinergic system results in a wide range of cognitive deficits, including a decrease in attention. The cholinergic system has been a focus of drug research to help modulate acetylcholine levels in order to relieve AD symptoms. Xanomeline is a drug previously used in this endeavor that works via agonism of acetylcholine M1 and M4 receptors. Cognitive improvements of Xanomeline administration in AD are thought to be due to agonism of …

Cacna1g Transcript Knockdown Analysis Via In Situ Hybridization, Jennifer (Shih-En) Chen

Undergraduate Honors Theses

The pedunculopontine nucleus (PPN) comprises the mesencephalic locomotor region (MLR) of the midbrain. It contains glutamatergic, cholinergic, and GABAergic interneurons, but only glutamatergic neurons influence locomotion, which is our focus here. The PPN receives upstream and downstream input from the basal ganglia. It projects to the reticular formation of the brainstem, which connects to the spinal cord. The PPN is involved in a wide range of physiological and behavioral processes, but our focus is locomotion. We hypothesize that the PPN influences the reticular activating system (RAS) of the medulla and thus the central pattern generators (CPG) in the spinal cord …

Proteomic Analysis Of Mycobacteriophage Crimd, William Moeller

Undergraduate Honors Theses

Bacteriophages represent a large portion of the biomatter on our planet, and many of them have yet to be fully characterized. Here we discuss the proteomic analysis of a particular Bacteriophage, Mycobacteriophage CrimD. This phage was discovered on the Campus of William & Mary and has had its genome characterized. We took the next logical step of proteomic analysis.

In our analyses we made use high pressure liquid chromatography paired with linear ion trap mass spectrometry to analyze the proteome of CrimD at specific time points after the infection of its host, Mycobacterium smegmatis. Additionally, we used nanospray ionization with …

Mysteries And Uncertainties In Tracing Cryptic Viral Infections, Melaina Jacoby

Undergraduate Honors Theses

Viruses are the most abundant biological entities on Earth. Viral impacts are evident from the level of individual cells and population all the way up to ecosystems and global elemental cycles. Since bacteriophages (viruses that infect bacteria) were first identified in the early twentieth century, the study of these fascinating entities has shown how viral dynamics within ecosystems can influence microbially-mediated processes at a large scale. Viral infections can impact hosts and host-mediated processes in in multiple ways, one of which is through cryptic infections. This state, in which a bacterium may harbor a cryptic phage infection, is known as …