Digital Commons Network^™

Common Challenges Faced By Early-Career Researchers In Latin American And Small U.S. Universities, Daniela Cejas, Fatima Rodriguez Acosta, Juan Rivera-Correa

Publications and Research

Early-career researchers from Spanish-speaking Latin American countries and small U.S. universities are underrepresented in international scientific databases. They have geographical importance, infectious disease endemicity, and exceptional researchers in microbiology, but these factors do not translate to representation in high-impact scientific publications. Many reasons could be involved, including financial burdens such as the inability to pay article processing charges. Additional teaching, institutional, and service responsibilities also highly influence their research productivity. Despite this, they are expected to publish high-impact articles, and their career development highly depends on it. There is an opportunity for global peer collaboration to tackle this inequity and …

Induced Cd8a Identifies Enhanced Human Nk Cell Il-15-Induced Proliferation And Metabolism And Modulates Nk Cell Activation, Celia Cubitt

Arts & Sciences Graduate Student Theses and Dissertations

Natural Killer (NK) cells are cytotoxic innate lymphoid cells that play an important role in the surveillance and elimination of virally-infected and malignantly-transformed cells. These primary effector functions are achieved by producing cytokines and chemokines which activate and recruit additional immune effectors, as well as direct cytotoxic killing via perforin and granzymes. NK cell function is tightly regulated by a balance of germ-line encoded activating, inhibitory, co-stimulatory, and cytokine receptors expressed at the cell surface. Through these activating and inhibitory receptors, NK cells recognize and kill targets without prior sensitization through the loss of self-identifying molecules such as major histocompatibility …

Disrupting Nrf2-Driven Cancer Biology Through One-Carbon Metabolism Inhibition, Julius Chembo

Arts & Sciences Graduate Student Theses and Dissertations

Cancer remains a leading cause of mortality worldwide, with treatment resistance and recurrence posing major barriers to long-term survival. Despite advancements in targeted therapies, many cancers develop resistance to chemotherapy, radiation, and immunotherapy, significantly limiting their effectiveness. One key driver of therapeutic resistance is nuclear factor erythroid 2-related factor 2 (NFE2L2/NRF2), a transcription factor that regulates antioxidant responses and drug detoxification. While NRF2 protects normal cells from oxidative stress, its aberrant activation in cancer promotes tumor progression, metabolic reprogramming, and resistance to standard treatments. Alarmingly, NRF2 hyperactivation is implicated in some of the most aggressive and refractory malignancies, yet no …

Examing The Role Of Complement Signaling In Viral Neuroinflammatory Responses, Marlene Kanmogne

Arts & Sciences Graduate Student Theses and Dissertations

The complement system is an ancient pathway that serves dual roles as a key regulator of neuroinflammation and a critical regulator of neural networks. Few studies have addressed how these two pathways may interact during infection of the central nervous system. While some components of complement are expressed in the healthy developing brain, complement component 3a receptor (C3aR) is a G protein coupled receptor that is expressed by astrocytes, microglia and infiltrating immune cells during inflammatory states. We previously found that C3aR is required for engulfment of synaptic material by activated microglia during neuroinvasive viral infection. Here, we used a …

Role Of The Small Intestinal Microbiota In The Pathogenesis Of Environmental Enteric Dysfunction In Undernourished Children And Mothers, Clara Kao

Arts & Sciences Graduate Student Theses and Dissertations

Undernutrition in women and its propagation in their children remains a major global health challenge. Worldwide, one in five children under five years of age manifests undernutrition as impaired linear growth, or stunting. Stunting, defined as having a length-for-age z-score (LAZ) <-2, is associated with poor developmental outcomes, including impaired neurodevelopment and immune responses. Furthermore, stunting and its long-term sequelae persist across generations, contributing to an intergenerational cycle of undernutrition. Existing nutritional interventions fail to substantially improve stunting, highlighting the need to (i) better understand other factors contributing to stunting and (ii) focus clinical efforts towards treating maternal undernutrition. Environmental enteric dysfunction (EED) is a subclinical inflammatory enteropathy of the small intestine proposed to contribute to stunting. EED is diagnosed histologically by blunted intestinal villi, epithelial barrier disruption and an immunoinflammatory infiltrate in the lamina propria. However, the pathophysiology of EED remains poorly defined. Furthermore, the small intestinal microbiota remains understudied due to difficulties in sampling. Evidence that the small intestinal microbiota contributes to EED pathogenesis comes in part from our collaborative work with colleagues at icddr,b (the International Centre for Diarrhoeal Disease Research, Bangladesh) who oversaw the Bangladesh EED (BEED) study. In this study children, aged 12-18 months residing in an urban slum in the Mirpur district of Dhaka who failed a nutritional intervention for their stunting, underwent esophago-gastroduodenoscopy (EGD) to obtain duodenal mucosal biopsies, aspirates of duodenal luminal fluid and plasma samples. A set of 14 bacteria taxa (defined by 16S rRNA amplicon sequencing) were identified in the duodenal microbiota of >80% of children with EED. Moreover, the absolute abundances of these ‘core taxa’ were positively correlated with duodenal mucosal and systemic inflammation in study participants and negatively correlated with linear growth. Our lab showed that introduction of a consortium of bacteria cultured from these duodenal aspirates, including these core taxa, produced small intestinal inflammation in young adult gnotobiotic, providing …

Unraveling The Antiviral Mechanisms Of Bat Cells: Processing Of Genomic Rnas By Dicer In Bat Cells Limits Sars-Cov-2 Replication, Iyanuoluwani Owolabi

Dissertations

Bats are reservoirs for numerous viruses that cause serious diseases in other animals and humans. Several mechanisms are proposed to contribute to the tolerance of bats to these pathogens. This study investigates the response of bat cells to double-stranded RNA generated by SARS-CoV-2 replication. Here, we found the involvement of Dicer in the processing of viral genomic RNAs during SARS-CoV-2 infection. Examining RNA sequencing of infected cells, small-interfering RNA (siRNA)-like fragments were found derived from viral RNAs. Depletion of Dicer showed a reduction in these RNAs and an increase in viral loads suggesting unlike other mammals, bats may use Dicer …

Genomic Analysis Of The Lyme Disease Vector Across Virginia’S Spatial Expansion Front, Amy Jablonski

Honors Theses

Lyme disease is the most common vector-borne disease in the United States and is expanding with rising incidence in Virginia . This study investigates populations of lxodes scapularis across Virginia using RAD-seq to analyze SNPs from ticks collected in seven Virginia counties and four U.S. states as references . Results show a clear genetic split between western and eastern Virginia ticks . These results follow previously noted patterns in regional differences in Lyme disease risk.

Hotter Days, Sleepless Nights: The Effects Of Climate Change On Sleep, Arianne Johnson

Celebrating Scholarship and Creativity Day (2018-)

This literature review explores the intersection between environmental changes and human health. It has been found that climate change through rising temperatures, extreme weather events, and poor air quality, disrupts human sleep. This lack of sleep is linked to many physical and mental health concerns in humans. By examining previous research on the topic, this review emphasizes the need to incorporate sleep health in climate adaptation and public health strategies

Arthroscopy And The Future Of Surgery: Personal And Public Health Benefits, Preston T. Koski

Honors Thesis

Arthroscopy focuses on operating on the body using probes and working through keyhole incisions on the skin. This rapidly evolving field has seen many innovations in its technology, aided by advances in optical and surgical capabilities. Moreover, it presents many advantages over traditional surgery that directly impact the patient. Shorter recovery time and lessened scarring, reduced postoperative pain and opioid dependence, and less risk of infection are key benefits over open surgery. These benefits can also be applied to areas of public health. Minimizing the burden on hospital resources, reducing the environmental impact of surgery, and improving cost-effectiveness in healthcare …

Recombinant Expression And Purification Of Porphyromonas Gingivalis Tyrosine Kinase 1 In Escherichia Coli., Laura K. Hanna

College of Arts & Sciences Senior Theses

The goal of this study was to optimize the expression and purification of Porphyromonas gingivalis Tyrosine Kinase 1 (Ptk1) in recombinant Escherichia coli containing the plasmids Gro_ESL and Ptk1, with a His₆ tag_, to obtain a highly pure protein sample. Various experimental conditions were tested to determine the most effective parameters for protein expression and purification, including adjustments in induction timing, buffer composition, and purification techniques.

Optimal protein expression was achieved when cells were induced at an optical density (OD) of 0.3 to 0.4. β-D-1-thiogalactopyranoside (IPTG), which activates the lac operon, was used to induce Ptk1 expression. A …

Antimicrobial Peptides Improve Antibiotic-Mediating Killing Of Methicillin-Resistant Staphylococcus Aureus (Mrsa) Biofilms, Alya R. Theriault

All Theses And Dissertations

Staphylococcus aureus can cause drug-resistant, biofilm-associated infections. These infections place methicillin-resistant S. aureus (MRSA) as one of the sixth leading bacterial pathogens associated with deaths due to antimicrobial resistance. Traditional antibiotics are no longer enough to treat these resistant infections and novel therapeutics are needed. Antimicrobial adjuvants are a potential strategy for improving efficacy of existing antibiotics, and antimicrobial peptides (AMPs) may have adjuvant activity. Recent reports showed that AMPs improve antibiotic activity against planktonic staphylococci, but whether AMPs might alter antibiotic efficacy against biofilm-resident staphylococcus is less clear. We tested the effect of nine AMPs on staphylococcal biofilm susceptibility …

The Effect Of Calorie Restriction On Humoral Responses Towards The Influenza Vaccine, Grayson Kobluk

Celebrating Scholarship and Creativity Day (2018-)

Calorie restriction (CR) - a reduction in caloric intake without malnutrition - has been widely studied for its impact on lifespan and the onset of age-related diseases. Emerging research indicates that CR also influences immune function, though its effects can vary depending on the degree of restriction, duration, and individual characteristics. This study examined how CR effects vaccine-specific antibody responses following influenza vaccination. Male and female mice were maintained on either a control diet or a calorie-restricted diet and vaccinated with an inactivated influenza virus vaccine. Antibody titers were measured 28 days post-vaccination to evaluate the magnitude of the humoral …

Genomic Diversity Of Salmonella Enterica Serotype Braenderup In New York State, Nicole Zac Soligno

Biological Sciences

The Gram-negative Salmonella enterica (family Enterobacteriaceae) is a common foodborne pathogen mainly isolated from foods of animal origin. Salmonella can be transmitted to humans, causing diverse symptoms, from self-limiting gastrointestinal diseases to more fatal typhoid fever. The young, elderly, and Individuals with weakened immune systems are especially at risk from salmonellosis. Salmonella is a concern to public health and the food industry throughout the world, and its severity depends largely on its serotype, a classification based on the unique combination of surface antigens. In this study, I aimed to elucidate the population structure and antimicrobial resistance determinants of S. enterica …

Impact Of Temperature And Microbial Infection On The Honey Bee Hemocytes, Michael E. Oeth

Master's Theses

Introduction

Honey bees (Apis mellifera) rely on hemocytes for immunity, wound healing, and hemolymph homeostasis. While 32°C reflects optimal hive conditions, suboptimal temperatures (22°C) and stressors like pathogens (Varroa destructor, bacteria) or pesticides impair hemocyte function. Using clodronate liposomes (CLD) to deplete hemocytes, we assessed how immune suppression interacts with these stressors.

Methods

Newly emerged (5-day-old) and older (15-day-old) bees were assigned to: CLD, control liposomes (LP), PBS, injection wound, or no treatment. Cohorts were exposed to 32°C (optimal) or 22°C (stressful for non-immunosuppressed bees). Fifteen-day-old bees were challenged with Escherichia coli or Staphylococcus aureus. Survival, hemolymph volume, and hemocyte …

Differential Progression Of Pancreatic Premalignancy In Geographically Distant Murine Transgenic Cohorts Uncovers Key Role Of Microbial Metabolites, Rian M. Howell

Dissertations and Theses (Open Access)

Cancer is a leading cause of death worldwide. Despite recent advances in diagnostic and therapeutic modalities, pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer that remains highly lethal. Efforts have been made to increase the understanding of the underlying mechanisms driving early stages of tumor development, when the cancer is most susceptible to intervention. To this end, genetically engineered mouse models (GEMMs) have been developed with the mutations most commonly seen in the patient population. Expression of these mutations in select cellular compartments has resulted in the ability to recapitulate characteristics of human pancreatic cancer such as the development of …

Adaptation Of Influenza A Virus Strains A/Anhui/1/2013 (H7n9) And A/Shanghai/1/2013 (H7n9) For Development Of Effective Mouse Models, Spencer T. Mullen

Undergraduate Honors Capstone Projects

The emergence of avian Influenza A (H7N9) virus strains in humans poses a significant threat to human health globally due to their pandemic potential, limited human immunity, and lack of virus-specific interventions. This capstone aims to address some of the limitations in antiviral research regarding Influenza A H7N9 virus by adapting two low-pathogenic virus strains A/Anhui/1/2013 (H7N9) and A/Shanghai/1/2013 (H7N9) to BALB/c mice through sequential passaging through lung tissue. Following 12 serial passages, increased virulence was observed as evidenced by increased virus replication, increased weight loss, and increased mortality in infected mice. Titration of the initial non-adapted virus isolates were …

Investigating Self-Healing Mechanisms In Host-Pathogen Interactions: A Literature Review Of Macrophage Functions In Tuberculosis, Blessing Savusa

Open Access Theses & Dissertations

Tuberculosis (TB) remains a leading cause of mortality, particularly in underdeveloped regions. Mycobacterium tuberculosis (Mtb) is regarded as one of the most successful pathogens due to its ability to evade host immunity and persist within granulomas. Macrophages are the first-line host defenders that engulf Mtb into phagosomes, which initiates lysosomal activity for degradation. However, the virulence factor of Mtb is able to inhibit phagolysosome fusion. The host immune system forms granulomas to contain the mycobacterium at the site of inflammation. This, in turn, causes a necrotic state and causes tissue damage from the prolonged inflammation. Studies suggest that the host's …

Variation In Stress Response Regulation Across Natural Isolates Of Saccharomyces Cerevisiae, Crystal Christine Crook

Graduate Theses and Dissertations

The stress response of Saccharomyces cerevisiae is a valuable area of study for understanding cellular adaptation mechanisms that govern survival in fluctuating environments. This dissertation investigates stress response regulation in yeast through the roles of Hog1 mitogen-activated protein kinase (MAPK) and the post-transcriptional regulator Mkt1, a key post-transcriptional regulator, in diverse wild yeast isolates. Hog1 is traditionally known for its central role in osmotic stress regulation in the high-osmolarity glycerol (HOG) pathway. This study expands the functional scope of Hog1 to include oxidative and ethanol-induced stress responses.

In parallel, we investigate post-transcriptional regulation of stress responses by the Mkt1 interactome, …

Parasitic Effects Of Amoebidium Appalachense On Daphnia Magna Heart Rate, Hopping Frequency, And Metabolic Rate, Vanessa Wise

Honors Program: Senior Projects (Public)

Daphnia magna are a crustacean that inhabits multiple different types of freshwater ecosystems and thus is plays a part in many different types of interspecies interactions, one of which is parasitism. Amoebidium appalachense is a Mesomycetozoean parasite of aquatic arthropods that colonizes the antenna of D. magna. Previous research has shown that A. appalachense infection will reduce the fecundity and increase mortality rate of D. magna but how it causes these effects is unknown. To determine if A. appalachense causes these effects on D. magna by either stealing nutrients inside the D. magna like a tick or by compromising …

Bibliometric Analysis Of Research Trends Related To Human Immunodeficiency Virus., Madyson E. Johnson, Kaitlyn R. Coffman, Valerie Rivas, Elizabeth Barrett

ATU Scholars Symposium

Human immunodeficiency virus poses major health burden across the globe including the United States of America and has its zoonotic origin from the Simian Immunodeficiency viruses of sooty mangabey monkey and chimpanzee in Africa. Epidemiological trends indicate that even though the mortality rates for HIV are falling globally, the rates of new cases have been rising since 2010 in several countries including the USA. An estimated 0.5% of the human population is currently infected with the virus with countries like USA, India, Nigeria and South Africa carrying the highest burden of the disease. Host receptors such as CD4 and coreceptors …

Comparing Parasitism And Resistance To Flow In Two Populations Of Elimia Virginica, Morgan G. Hicok, Abbie Tomba, Kate Green

Departmental Honors & Graduate Capstone Projects

Snails are important in freshwater ecosystems as primary consumers and are good indicators of the stability of a habitat. Trematodes are parasitic flatworms that infect freshwater snails and can cause changes in metabolic function and growth. Flow rates and water levels are now more variable due to climate change, increasing stress and dislodgment in the snail population. This study investigates how parasites, shell morphology, and native flow environment influence resistance to disturbance. Elimia populations were sampled for differences in parasitism, shell morphology, and ability to withstand high flow environments in two different rivers. Sample sites at the Potomac River were …

Passive Integrated Transponders: An Effective Marking Technique For Individual Identification Of Anaxyrus Fowleri?, Emily Leprell

Honors College Theses

With the rise of fungal disease such as Chytridiomycosis, known as chytrid, causing massive population declines for many species of frogs and toads (order Anura), specific conservation strategies are needed now more than ever. In many cases, being able to mark and identify individuals is a necessary step in developing an effective conservation plan. Individual identification allows researchers to obtain accurate population estimates, which are needed to test the progress and validity of conservation management decisions. However, due to their unique life history, including cutaneous respiration and a dichotomous lifestyle, anurans are among the most difficult wildlife species to …

Impacts Of Climate Change On Cannibalism And Disease Transmission In The Fall Armyworm, Kale Rougeau

LSU Master's Theses

Climate change may alter host-pathogen dynamics in terrestrial ecosystems due to rising global temperatures and carbon dioxide levels. Here, we examined cannibalism and disease transmission using the fall armyworm (Spodoptera frugiperda), an invasive agricultural pest, and its species-specific lethal baculovirus, Spodoptera frugiperda multiple nucleopolyhedrovirus (SfMNPV), under various potential challenges of climate change. We used three temperature treatments (cooler, optimal, warmer) based on the fall armyworm’s thermal performance curve to simulate a changing climate and four artificial diets with various protein-to-carbohydrate ratios (low, equal, high, standard) to manipulate resource quality from altered carbon dioxide levels. We found that higher …

Associations Between Linguistic Factors And Vaccine Attitudes In A Hispanic Immigrant Population In The United States, Jamie Jensen

ScholarsArchive Data

Data are results of a nationwide survey administered by Qualtrics to Hispanic Immigrants concerning HPV vaccine uptake and hesitancy factors.

Designing An Optimal Thermal Preference Arena For Southern Cricket Frog (Acris Gryllus) Juveniles, Eleanor E. Briggs, David M. Phillips Jr.

Honors Theses

Climate change has been altering ecosystems across the world at a substantial rate, disrupting the delicate ecophysiological relationships between ecosystems and the organisms that live in them. Ectotherms, such as amphibians, rely on external temperatures to behaviorally thermoregulate, making it especially imperative to study their thermal biology. Thermal preference, which assesses the environmental temperature an organism would seek out in the absence of external stimuli, provides valuable information about an amphibian’s thermal biology and can be used to predict the effects of climate change on a species or population. A commonly used method to measure thermal preference is an arena …

Early Detection Of Colon Cancer Through Colonoscopy: Analysis Of Tumor Size And Resection Length, Alyssa Haddock

Honors Theses

Colon cancer remains a leading cause of cancer-related deaths in the United States, with early detection critical for improved outcomes. Colonoscopy is a primary screening tool that can reduce incidence rates through the identification and removal of precancerous polyps. This study examines how undergoing a colonoscopy prior to diagnosis impacts two key surgical outcomes: tumor size and colon resection length. Data were collected from 70 de-identified patients who underwent colon resection for colon cancer between 2019 and 2024 at two regional hospitals in East Texas: Hunt Regional Medical Center and Mother Christus Frances Hospital. Using pathology reports, tumor size and …

Antimicrobial Resistance (Amr) Emergence In Sewage Wastewater: An Investigation Based On Advanced Genomics Methods, Shahana Seher Malik

Thesis/ Dissertation Defenses

Antimicrobial resistance (AMR) is a global health worry, which makes the treatment of infectious diseases difficult by compromising the effectiveness of antimicrobial medications. This issue got worsen by the use of antibiotics without proper prescription and care during the time of COVID-19. At that time more than 78% of patients were prescribed with the use of medications like azithromycin and cephalosporins. The urban wastewater systems like wastewater treatment plants (WWTPs), hospital effluents, and residential wastewater were found to be bursting with antibiotic-resistant bacteria (ARB) and resistance genes (ARGs). This research used advanced metagenomics and LC-MS/MS techniques for the examination of …

Understanding Strain-Level Dynamics In Gut Commensal-Pathogen-Host Interactions, Anna Louise Deveaux

Arts & Sciences Graduate Student Theses and Dissertations

The human gut microbiome is a consortium of trillions of bacteria, archaea, fungi, and viruses that colonizes the gastrointestinal tract and promotes health under homeostatic conditions. This microbial community trains the immune system, modulates inflammation and anticancer immunity, promotes cardiometabolic health, enables nutrient extraction, and prevents pathogen overgrowth. The latter function manifests through colonization resistance, in which microbes occupy spatial and nutritional niches thereby excluding pathogens from the community entirely, and through limiting pathogen population growth if colonization occurs. These roles are facilitated by complex host-microbe and microbe-microbe interactions that underlie differences in susceptibility to microbiome-mediated infectious diseases. The strain-level …

Silver Nanoparticles And Vanillin Can Inhibit Collagenase Activities Of Serratia Marcescens, Elaine Vanterpool, Mya St. Louis, Josel Bryant, Kennedi Ewan, Taylor Hall, Leah Marcelle, Mayah Seal

Student Posters

Serratia marcescens is a gram-negative, disease-causing agent that belongs to the Enterobacteriaceae family. This rod-shaped microbe causes many infectious diseases such as urinary and respiratory infections, wound infections, and peritonitis, which can result in fatal bacteremia. Collagenase is an enzyme that breaks down collagen, while also playing a key role in the extracellular matrix. Collagenase uses zinc to operate that helps it break down the peptide bonds in collagen. Testing Agents ❖ Metronidazole is an antimicrobial drug used to treat infections caused by different anaerobic bacteria, such as infections in the blood, liver, bones, joints, and meninges. ❖ Vanillin is …

Inflammasomes Primarily Restrict Cytosolic Salmonella Replication Within Human Macrophages, Marisa S. Egan, E. A. O'Rourke, S. Kumar Mageswaran, B. Zuo, I. Martynyuk, T. Demissie, E. N. Hunter, A. R. Bass, Y.-W. Chang, I. E. Brodsky, S. Shin

Biology Faculty Works

Salmonella enterica serovar Typhimurium is a facultative intracellular pathogen that utilizes its type III secretion systems (T3SSs) to inject virulence factors into host cells and colonize the host. In turn, a subset of cytosolic immune receptors respond to T3SS ligands by forming multimeric signaling complexes called inflammasomes, which activate caspases that induce interleukin-1 (IL-1) family cytokine release and an inflammatory form of cell death called pyroptosis. Human macrophages mount a multifaceted inflammasome response to Salmonella infection that ultimately restricts intracellular bacterial replication. However, how inflammasomes restrict Salmonella replication remains unknown. We find that caspase-1 is essential for mediating inflammasome responses …