Organisms Commons^™

Phytochemical And In-Vitro Cytotoxic Analyses Of Flavonoid Species Isolated From Chromolaena Leivensis, Luke A. Bryant

Electronic Theses and Dissertations

As a leading cause of death worldwide, cancer and its treatments remain a primary source of interest among researchers. Modern studies are looking into bioselective cytotoxicity to create new chemotherapies that do not have the same harsh side effects as those we use today. Natural product research has a promising future for the development of such treatments. Specifically, polar flavonoids may be the key to a bioselective treatment. Such flavonoid species are native to plants, often within flower petals or within the body. A natural antioxidant, they are designed not to harm healthy cells. This study focuses on the plant …

Regulation Of Müllerian Duct Mesenchyme Transcription During Mammalian Sex Differentiation, Haowen Li, Richard R Behringer, Rachel D Mullen

Dissertations and Theses (Open Access)

Sp7/Osterix (Osx) encodes a zinc-finger transcription factor of the Specificity-protein family discovered by Nakashima et al. at the MD Anderson Cancer Center. While primarily recognized for its role in osteogenesis, Osx has also been implicated in mammalian reproductive development, particularly in male sex differentiation, where Müllerian Duct (MD) regression occurs, mediated by anti-Müllerian hormone (AMH) signaling. AMH-induced regression signals are transduced by the mesenchymal tissue surrounding the ductal structure, known as the Müllerian Duct mesenchyme (MDM). It was discovered that AMH signaling is necessary and sufficient for driving Osx expression in MDM. A previous transgenic mouse reporter …

The Gut Microbiome, The Gut-Brain Axis, And College Student Well-Being, Idi Mckay

University Honors Theses

This literature review examines how diet, stress, environmental exposure, and food accessibility may influence college students' mental health and academic performance through the gut microbiome and the Gut-Brain Axis (GBA). Current microbiome research often focuses on early childhood development, clinical disease populations, or older adults, while overlooking college-age students who experience significant social, environmental, and biological transitions. College students frequently face food insecurity, irregular eating patterns, chronic stress, inconsistent sleep schedules, and reduced access to nutrient-dense foods, all of which may influence microbial diversity and overall gut health.

This thesis explores how modern campus environments and lifestyle factors may contribute …

Rhythms Of Hippocampal Function And Memory After Moderate Prenatal Alcohol Exposure, Lilliana May Sanchez

Psychology ETDs

Fetal Alcohol Spectrum Disorders involve morphologic and neurobiological abnormalities in offspring subjected to prenatal alcohol exposure. Although not as well studied as high exposure, moderate prenatal alcohol exposure represents the most common and undetected form in humans. While learning and memory deficits have been well characterized at the behavioral level in humans with Fetal Alcohol Spectrum Disorders and in animal models of moderate prenatal alcohol exposure, few studies have determined the circuit or systems level mechanisms of the behavioral deficits. A complete understanding of the neural bases of memory deficits after moderate prenatal alcohol exposure is needed to ultimately identify …

Quality Improvement (Qi) Project Aimed At Reducing Unnecessary Antibiotic Usage Among Older Adult Patients By Addressing Inappropriate Antibiotic Prescribing In Primary And Long-Term Care Settings, Pamela M. Thomas

Seton Hall University Dissertations and Theses (ETDs)

Antibiotic overuse among older adults remains a significant patient safety and public health concern. Recent national data indicate that approximately 30%–50% of outpatient antibiotic prescriptions may be unnecessary, particularly for viral or self-limiting conditions (Chua et al., 2021). Antimicrobial resistance has been associated with more than 1.27 million deaths globally (Murray et al., 2022). This quality improvement project evaluated a multifaceted antimicrobial stewardship intervention in primary and long-term care settings. Baseline review of 167 antibiotic cases revealed 37.1% were inappropriate or questionable, and 28.7% lacked adequate diagnostic documentation. The intervention incorporated provider education, electronic health record decision-support tools, audit and …

Testing The In Vitro Effectiveness Of Protease Inhibitors Against Histomonas Meleagridis, Evy Belle Hafer

Animal Science Undergraduate Honors Theses

Histomonas meleagridis is a protozoal parasite able to exist in a flagellated or amoeboid form that infects gallinaceous birds, particularly turkeys, and causes significant mortality. There is currently no effective treatment for this disease. The purpose of this study was to assess the anti-histomonal activity of commercially available protease inhibitors, leupeptin, bestatin, and antipain, using an established in vitro model. Three protease inhibitors, leupeptin, bestatin, and antipain, were evaluated across five assays. Treatment groups included: 1) non-treated control, 2) leupeptin 100 µM, 3) bestatin hydrochloride 100 µM, and 4) antipain dihydrochloride 100 µM. Histomonads were enumerated using a hemocytometer after …

Comparative Investigation Of Bacterial Adhesion On Medical Device Thermoplastics, Dev V. Mehta

Honors Theses

This project will focus on determining if differences in bacterial cell wall composition influences adhesiveness to thermoplastic materials used to construct patient orthotic splints. Bacteria with decreased adhesion are unable to remain bonded to orthotic splints, increasing its ability to transfer to a patient’s wound, leading to an infection. Antibiotic resistant bacteria used in this investigation included gram-positive cocci vancomycin-resistant (VRE) Enterococcus faecalis, methicillin-resistant Staphylococcus aureus (MRSA), and gram-negative rods extended-spectrum beta-lactamase (ESBL) Escherichia coli and Pseudomonas aeruginosa. Each test bacterium is a major pathogen causing healthcare-associated infections (HAIs). Saline, artificial perspiration, and ascites fluids were used to determine the …

Metabolic And Replicative Constraints On Pathogen Virulence: Isoleucine Catabolism In Shigella And Comparative Tanapoxvirus Replication In Cell Cultures, Benecia Angelica

Masters Theses

Pathogens survive by balancing metabolic demands with environmental challenges that shape their virulence and adaptability. Shigella flexneri, a highly infectious human pathogen responsible for severe diarrheal disease worldwide, utilizes branched-chain amino acid (BCAA) metabolism to withstand stress conditions encountered within the host environment. In this study, we explored the Shigella isoleucine catabolism pathway by knocking out four genes in the S. flexneri isoleucine catabolic pathway (ilvE, fadA, fadD, and acnB) and examining their metabolism and virulence. We found that the ilvE and acnB mutants displayed reduced metabolic activity and smaller plaque size, while the fadD mutant showed decreased invasion. In …

Mississippi Coastal Bacterial Community Response To Lowered Salinty, Jackson C. Sues

Honors Theses

Microbial communities are essential to the function of coastal ecosystems; however, few studies have examined their response to short-term reductions in salinity. This study used a microcosm approach to examine how decreased salinity over five days affected seawater bacterial community composition, diversity, and richness. Microcosms were assigned to three treatments: unmanipulated seawater (control) collected from the Mississippi coast, seawater amended with natural freshwater, and seawater amended with sterilized freshwater. Length of time bacteria spent in the microcosms was found to have the strongest effect on bacterial community composition, while salinity effects were weaker but still statistically significant. All treatments shifted …

Geographical And Anatomical Microbiome Variation In Invasive Green Iguanas (Iguana Iguana), Amanda A. Diaz

All HCAS Student Capstones, Theses, and Dissertations

The common green iguana (Iguana iguana) was introduced to South Florida in 1965 and has since been an especially pernicious threat both environmentally and economically. This highly invasive species is also expanding in range and populations at an astonishing rate. Understanding how this reptile is able to adapt and thrive in novel environments is of imperative need in order to begin managing their disruptive populations. Notwithstanding their negative impacts and significance, the microbiome of wild populations has not yet been characterized. Here, using 16S ribosomal RNA gene sequencing, this study is the first to characterize the microbiome composition …

Identifying Major Sources Of Leptospira Interrogans In San Juan Bay And Río Grande De Loíza Estuaries Of Puerto Rico, Logan Mccullers, Dave Bachoon

Biology Theses

This study evaluated the presence of pathogenic Leptospira interrogans, potential carriers, and environmental factors influencing their occurrence in the San Juan Bay Estuary (SJBE) and Río Grande de Loíza (RGDL) watersheds of Puerto Rico from 2024–2025. Detection of this pathogen from water samples was performed using the lipL32 PCR assay. The likely hosts of L. interrogans were determined using fecal source tracking (FST) assays for human (HF-183), canine (BacCan-UCD), equine (HoF597), and rat mitochondrial DNA NADH dehydrogenase subunit 2 gene (RatMt) markers. In 2024, 91 samples were collected (March: 50; June: 41), and in 2025, 124 samples were collected …

Surveillance Of A Novel Vesivirus Discovered In An Urban Mephitis Mephitis Population, Amanda E. Diggins

Honors Theses and Capstones

Caliciviridae is a family of non-enveloped, positive-sense, single stranded RNA viruses, including eleven defined genera that contain important pathogens of humans and animals. Within the Caliciviridae family, the genus Vesiviridae includes feline calicivirus, a leading cause of upper respiratory disease in cats, and vesicular exanthema of swine virus, a historical disease of domestic swine that has now been implicated in several marine mammal vesicular diseases, one of which has been confirmed zoonotic. Urban landscapes create a unique environment for rapid intra- and interspecies transmission of viruses. Clustered resources attract high-density populations of synanthropic wildlife species, increasing spatial overlap and heightening …

Invasion Of Microplastics Into The Reproductive Tissues Of Feral And Domestic Felines, Emma K. Quade

Honors Undergraduate Theses

Although plastics have many useful properties in modern society, once these materials are introduced into the environment, they can cause extensive damage. Following degradation into microplastics (MP), plastic particles less than 5 mm in size, these contaminants can make their way into a variety of different environments and organisms. There are many studies that have investigated the prevalence of MP in marine environments, but fewer studies have looked into terrestrial systems, and even less that have focused on contamination in companion animals. This study sought to investigate the invasion of MP into the reproductive tissues of felines, Felis catus, …

The Structure, Dynamics, And Impact Of An Interbacterial Weapon Encoded By Human Gut Bacteria, Casey John Latario

Dartmouth College Ph.D Dissertations

The human gut is densely colonized by diverse bacteria. Over a human’s growth, the GI tract becomes a dynamic community that is subjected to a continual in-flow of nutrients and would-be colonizers and an out-flow of microbes and waste products. Despite these dynamics, the bacterial community often displays stability, with particular strains persisting over decades. These stable colonizers have evolved mechanisms to bolster their colonization, resist disruption by other microbes, and persist through environmental flux.

Both interbacterial competition and horizontal gene transfer (HGT) contribute to colonization and survival within the GI tract. A major mechanism for interbacterial competition is the …

Adaptive Compulsion, Amanda A. Santos

Electronic Theses, Projects, and Dissertations

Adaptive

Adjective

Adap.tive ( ə-ˈdap-tiv)

of, relating to, or being a heritable trait that serves a specific function and improves an organism's fitness or survival

Compulsion

Noun

Com.pul.sion (kəm-ˈpəl-shən)

a repetitive behavior or mental act that a person feels driven to perform to alleviate the anxiety and distress caused by an unwanted thought or urge, known as an obsession.

For years we have lived in unprecedented times. From the worldwide quarantine in 2020 resulting from the pandemic, to our current US political crisis. The constant barrage of events is overwhelming and demoralizing.

The work in this gallery is a display …

Increasing Pediatric Hpv Vaccination Rates, Brooke A. Nicholas

Dissertations

Increasing Pediatric HPV Vaccination Rates

Abstract

Problem: The human papillomavirus (HPV) is a sexually transmitted infection that affects more than 80% of the population within the United States (Eisenhauer et al., 2020). HPV can develop into cervical, anogenital, and oropharyngeal cancers (Eisenhauer et al., 2020). About 4,000 individuals die from cervical cancer alone each year (O’Leary, 2022). The HPV vaccine, though recommended by the ACIP and AAP, is below national vaccination rates in comparison to other vaccines (O’Leary, 2022).

Methods: This quality improvement project is a non-randomized controlled trial that observed HPV vaccine dose completion rates for patients aged 9-14 …

Transcriptomic And Epigenomic Profiling Of Immune Cells Responses To Simian Immunodeficiency Virus Infection In The Brain, Xiaoke Xu

Theses & Dissertations

Human immunodeficiency virus type 1 (HIV-1) is an enveloped retrovirus that significantly impairs the human immune system. A common complication of HIV-1 infection is HIV-associated neurocognitive disorder (HAND), which, prior to the introduction of antiretroviral therapy (ART), led to considerable morbidity and mortality due to untreated neuropsychiatric manifestations. Although ART has substantially reduced the incidence of HIV-associated dementia (HAD), approximately 50% of people living with HIV (PLWH) continue to experience milder forms of HAND. The CNS is seeded by HIV during the acute phase of infection. Once in the brain, HIV targets and activates resident immune cells, primarily microglia and …

Chemical And Physical Characterization Of Verbenaceae Essential Oils Using Modern Analytical Methods And Chemometrics, Aleksandra N. Hilliard

Master's Theses

Essential oils have been used for generations to treat various health issues, including mitigating insomnia, reducing stress, inflammation, and preserving foods, to mention a few. Essential oils have complex chemistry, which defines the essence of the host plant. Recently, increased commercial uses of essential oils have prompted attention at the governmental level to monitor the chemical, physical, or biological activity of essential oils. This study is an attempt to add new information for consumers to the understanding of the composition of essential oils.

Modern analytical techniques including FTIR-ATR, GC-MS, LC-MS-MS, multivariate analysis statistics, and physio-chemical techniques (electrochemistry, DPPH, TRC, and …

Field Journal: The Excluded Middle, Carrie E. Kouts

Masters Theses

What does it look like to engage with organisms and landscapes at the periphery of anthropocentric value structures? How does one break the internalized myth that the “built” environment is excluded from the natural world? When does a hyper-mobile and hyper-commodified society confront the exponential crisis of animal death? Within this series of journal entries, field notes, collection observations, weird prose, and sensory musings, one will find questions on the nature of being human and the complex narratives of care we encounter in a world shared with more-than-humans. Each handwritten vignette and photograph from daily life weaves a non-linear and …

A Modified Sir Model Used To Investigate The Relationship Between Congenital And Adult Syphilis, Kaleesta R. Waysman

Honors Thesis

A complex SIR model integrating the relationship between adult and congenital syphilis was developed. The goal of the project was to determine the specific population(s) or control strategies that should be enforced, altered, or removed to decrease the number of children experiencing clinical sequelae due to congenital syphilis. Early clinical sequelae include hydrops fetalis, preterm birth, central nervous system infection, hepatosplenomegaly, hyperbilirubinemia, cholestasis, hemolytic anemia, snuffles, osteochondritis, and lesions or rashes in the palms and soles. Late clinical sequelae include interstitial keratitis, hearing loss, Hutchinson teeth, saber shins, Clutton joints, mulberry molars, and saddle nose. After implementing real-world data into …

Justification For The Biological Foundation Of Methane On Mars: Methanogens’ Capacity To Metabolize On Montmorillonite Clay And Basalt, Ashley Ezeldin

Biological Sciences Undergraduate Honors Theses

The possibility of extraterrestrial life, particularly on Mars, remains a compelling question in astrobiology. Mars' harsh atmospheric conditions, dominated by carbon dioxide and extreme cold, prevent the survival of aerobic species. However, it still leaves the possibility of methanogens, an anaerobic species that can survive in extreme conditions, to inhabit this planet. Due to the discovery of methane on Mars, it is possible that methanogens may live and grow in the subsurface of this planet.

For this experiment, basalt and montmorillonite clay were chosen as substrates because they are believed to be found in the composition of Mars's subsurface. Methane, …

Elucidating The Multi-Omics Of Early-Onset Colorectal Cancer, Jumanah Alshenaifi

Dissertations and Theses (Open Access)

The incidence and mortality rates of sporadic early-onset colorectal cancer have increased in recent decades, but there is no clear etiological basis for this trend. EOCRC is commonly defined as colon and rectal cancers diagnosed before the age of 50 years. The rising incidence of EOCRC has made it the second most common cancer and the third leading cause of cancer death in this age group. The rising incidence of EOCRC is also documented internationally in more than 20 countries across different continents. Clinically, EOCRC has a distinct, more aggressive clinical profile than LOCRC. While approximately 15% of EOCRC cases …

Investigating Prefrontal Cortex Neuronal Signatures Of Opioid-Induced Risk-Taking Behavior, Cana Quave

Dissertations and Theses (Open Access)

Opioid use disorder occurs alongside impaired risk-related decision-making, but the underlying neural correlates are unclear. We developed an approach-avoidance conflict task using a modified conditioned place preference procedure to study neural signals of risky opioid seeking in the prefrontal cortex, a region implicated in executive decision-making. Following morphine conditioned place preference, rats underwent a conflict test in which fear-inducing cat odor was introduced in the previously drug-paired side of the apparatus. While the saline-exposed control group avoided cat odor, the morphine group included two subsets of rats that either maintained a preference for the paired side despite the presence of …

Determining The Bioaccumulation Of Minor Cannabinoids In Zebrafish Larvae, Kamdyn A. Holt

Honors Theses

Due to the increasing prevalence of cannabis product availability and usage in the modern United States, particularly among pregnant individuals, evaluating the bioaccumulation of minor cannabinoids to further understand the adverse effects of cannabinoids during early development is critical. This study quantitated the uptake of eight minor cannabinoids ((∆8-tetrahydrocannabinol (∆8-THC), ∆9-THC, ∆10-THC, cannabidiol (CBD), cannabigerol (CBG), cannabinol (CBN), tetrahydrocannabivarin (THCV), and hexahydrocannabinol (HHC)) in zebrafish larvae following water-borne 2 µM exposures from 6 to 96 hours post fertilization (hpf). Larvae were homogenized at 96 hpf and analyzed using a gas chromatography- mass spectrometry (GC-MS) method developed in this study. Bioconcentration …

An Exploration Of Behavioral Sex Differences Due To A Parkinsonian Gene, Pdr-1, In C. Elegans., Adriana Mulet Miranda, Mary B. Kroetz, Paul J. Kiser

Undergraduate Theses

Parkinson’s disease is a debilitating neurodegenerative disease of the central nervous system classified by the loss of dopaminergic neurons. Males and females exhibit different symptoms however, the cause remains unknown. Through the use of a model organism, C. elegans, we will investigate an ortholog of a Parkinsonian gene, pdr-1, to explore whether or not there are statistical differences between the hermaphrodites and males through known behavioral assays such as Swimming Induced Paralysis and Basal Slowing Rate. In order to compare gender differences, we successfully conducted CRISPR, where we inserted the him-8 mutation, resulting in an increased population …

The Role Of Horizontal Gene Transfer In Antibiotic Resistance Amidst Prevalent Community And Healthcare-Associated Mrsa Rates, Gabrielle Nascimento

Honors College Theses

In recent decades, cases of community-acquired MRSA (CA-MRSA) and healthcare-associated MRSA (HA-MRSA) have been on the rise. The ability of antibiotic resistance to transfer between microorganisms greatly expands its threat to the effective treatment and containment of bacterial infections. The mecA gene is found on a mobile cassette within the Staphylococcal cell and encodes for PBP2a, an alternate version of penicillin-binding protein (PBP) with less binding affinity for β-lactam antibiotics, increasing resistance to the effects of antibiotics. The goal of this research is to investigate the horizontal transfer of the mecA gene between various Staphylococcus species as well as to …

Investigating Regulation And The Regulome Of The Nucleic Acid Binding Protein Spovg Within Borrelia Burgdorferi, Timothy C. Saylor

Theses and Dissertations--Medical Sciences

Prior studies indicated Borrelia burgdorferi SpoVG protein was regulated, SpoVG binds specifically to a number of nucleic acids, and SpoVG binds to the non-variable section of the major virulence factor vlsE. Although a direct transcriptional activator or inhibitor was not elucidated, it is shown that SpoVG is regulated based on cell culture density independent of the growth rate of B. burgdorferi, indicating that SpoVG regulation is outside the scope of the alternative sigma factor RpoS. Using a dCas9 CRISPRi construct to target SpoVG resulted in protein expression trending towards upregulation of the BosR-RpoS regulon, and a marked decrease …

Gene Expression In Relation To Bone Fractures In Throughbred Racehorses, Anna M. Rauber-Ramos

Theses and Dissertations--Veterinary Science

Evidence that fractures in Thoroughbred racehorses are outcomes of chronic bone microdamage has led to extensive research into identifying horses at increased risk of fracture. This includes the use of biomarkers and messenger RNA (mRNA) as a measure of bone turnover. Previous research has found expression differences in horses with fractures compared to controls. Utilizing pre-race whole blood samples collected over an 18-month period from Thoroughbred racehorses in Southern California, RNA-sequencing was conducted on horses with bone fractures and race-matched controls to identify differences in gene expression. Focusing on third metacarpal (MC3) and proximal sesamoid bone (PSB) fractures, differentially expressed …

Contact Pathway Factors As Potential Modifiers Of Bleeding Related To Factor Xi Deficiency, Ivy R. Han, Leah Rosenfeldt, Courtney Young, Bal Krishan Phd, Rachel Cantrell Phd, Cassie Sprague, Mousa Kharnaf, William Abplanalp, Joseph Palumbo Md

Williams Honors College, Honors Research Projects

Factor XI (FXI) deficiency, also known as Hemophilia C, is characterized by mild to moderate bleeding symptoms. However, the factors that modify bleeding severity in FXI deficiency are not fully understood. In this study, we investigated whether components of the contact activation pathway can act as modifiers of bleeding in the context of FXI deficiency. Using a tail vein transection (TVT) model in rats, we assessed bleeding in four experimental groups: wild-type Sprague-Dawley rats, Prekallikrein knockout (PKK^-/-) rats, rats treated with a FXI-inhibiting antibody, and PKK-/- rats treated with the FXI antibody.

Under anesthesia, each rat underwent a …

Development Of A Streptococcus Mutans Biofilm Model On A Typodont Platform To Investigate Its Dynamics In Orthodontics, Hibah Chughtai

Theses & Dissertations

Introduction: Biofilm formation plays a significant role in dental health, resulting in plaque accumulation, which can lead to caries and oral diseases. Streptococcus mutans (S. mutans) is a key bacterium involved in this process. The goal of this study was to establish a protocol for the development of an S. mutans biofilm on dental typodont teeth to analyze the effects of orthodontic brackets on biofilm formation. Understanding these dynamics is critical for developing strategies to mitigate biofilm accumulation during orthodontic treatment. Methods: S. mutans biofilms were cultivated under three conditions: 96-well tissue culture plates, S. mutans inoculated non-bracketed …