Digital Commons Network^™

Microbial Community Structure In Global Soils, Matthew Jabro

CMC Senior Theses

Soil harbors the most diverse microbial communities on Earth, yet whether predictable community types exist across biomes and whether taxonomic composition encodes habitat of origin remain open questions at global scale. This thesis addresses both questions by applying unsupervised clustering and supervised classification to transformed 16S ribosomal RNA (rRNA) amplicon profiles from two independent datasets: the global topsoil survey of Bahram et al. (193 samples) and the Earth Microbiome Project (EMP) soil subset of Thompson et al. (2,209 samples). Application of a sample clustering method based on a mixture of Gaussian Graphical Models (MixGGM) identified 19 clusters in the topsoil …

Neuroimaging Correlates Of Differences In Learning From Repeated Probabilistic Outcomes, Allison E. Rudolph

CMC Senior Theses

Learning from experience requires integrating feedback over time, yet individuals vary widely in how effectively they extract structure from probabilistic environments. This study examined how such variability relates to neural responses in the ventral striatum (vStr), caudate nucleus, hippocampus, and medial prefrontal cortex (mPFC). Seventy-four participants across childhood, adolescence, and adulthood completed a modified Iowa Gambling Task during fMRI scanning, choosing whether to play or pass on four machines differing in expected value and variance. Behavioral learning slopes, calculated across six runs for each machine, were used to classify participants as learners or non-learners. Learners showed clearer improvement over time …

An Intuitionistic Fuzzy Hypergraph Model Enhanced ‎By Forest-Of-Walks Dynamics For Medical Image ‎Segmentation, Brinthaguru Thangaraj, Karthick Palanisamy

Mansoura Engineering Journal

The process of accurately segmenting Urolithiasis and pulmonary nodules from medical images presents significant difficulties because of three main factors which include nonuniform intensity distribution and the presence of weak object borders and the uncertainty caused by anatomical structure overlaps. The study introduces F-Zinhger as a solution to these problems through its application of the Forest of Walks technology. The method uses superpixels as fundamental elements which form a multi-scale hypergraph that establishes hyperedges through three criteria: intensity similarity, spatial proximity, and Z-intuitionistic fuzzy hesitation to capture complex contextual connections. The system incorporates a random walk-based label propagation system. The …

Cross-Domain Antimicrobial Resistance In Poultry Farming: A One Health Assessment Of Antimicrobial Use And Multidrug Resistance In Kiambu County, Kenya, Ann Kangai Munene, Peter Muiruri Mwangi, Lilly Caroline Bebora, Christine Minoo Mbindyo, John Muthini Maingi

All Peer-Reviewed Publications

Background and Aim: Antimicrobial resistance (AMR) has emerged as a major One Health threat driven by inappropriate antimicrobial use (AMU) in humans, animals, and the environment. Poultry production is recognized as a key reservoir of antimicrobial-resistant bacteria, yet few studies in Kenya examine AMU and AMR across interconnected human–animal–environment domains. This study assessed AMU patterns among poultry farmers in Kiambu County and characterized phenotypic resistance in Escherichia coli and Enterococcus spp. isolated from humans, chickens, and chicken environments. Materials and Methods: A cross-sectional study was conducted from May to September 2024, involving 102 poultry farms. Farm demographics and AMU data …

Mapping Robusta Coffee (Coffea Canephora) Cropping Systems In Uganda: A Two-Step Pixel And Sub-Pixel Based Approach With Sentinel-2 Data, Getachew Kebede, Bester Tawona Mudereri, Onisimo Mutanga, Tobias Landmann, John Odindi, Natacha Motisi, Fabrice Pinard, Henri E.Z. Tonnang, Elfatih M. Abdel-Rahman

All Peer-Reviewed Publications

Coffee is a highly valued commodity and a widely consumed beverage, playing an important role in global trade. However, coffee farming landscapes are increasing transitioning into smaller-scale agricultural setups. This transformation highlights the critical need for accurate classification and mapping of coffee cropping systems (CS), especially in countries like Uganda, where dense vegetation and complex terrain present substantial challenges to traditional land survey methods. Moreover, understanding the spatial distribution of Robusta coffee (Coffea canephora) CS is essential for developing site-specific management strategies, guiding extension services, and informing evidence-based policy decisions. To address this gap, the present study aimed to enhance …

Roles Of Cytokines In Modulating Trypanosoma Brucei Rhodesiense Infection Outcomes In Vervet Monkeys, Clarah Jebet, John Kibuthu Thuita, Daniel Masiga, Benedict Owino Orindi, John Oidho, Mark C. Field, Enock Matovu, Vincent Owino Adung’A

All Peer-Reviewed Publications

Introduction:

Human African trypanosomiasis (HAT), caused by Trypanosoma brucei rhodesiense, is categorized as acute due to rapid disease progression but presents varying clinical outcomes. Although the mechanisms underpinning differential clinical progression are poorly understood, both host and parasite factors are implicated. Therefore, we sought to elucidate roles of primate host factors in mediating varying T. b. rhodesiense infection outcomes.

Methods:

Here, we assessed the roles of selected host cytokines in disease progression using a tsetse-mediated infection in a non-human primate (NHP) vervet monkey model that closely mimics HAT and natural infection. We quantified eight cytokines, including TNF-α, IFN-γ, IL-10, IL-6, …

Impact Of Environmental Microparticles On Insect Olfaction, Steve B.S. Baleba, Danube K.N. Wandji, Yves H. Tchiechoua, Komi Mensah Agboka, Iman B. Hassaballa, Victor O. Omondi, Beatrice T. Nganso, Saliou Niassy, Souleymane Diallo, Merid N. Getahun

All Peer-Reviewed Publications

Terrestrial insects underpin key ecosystem services, including pollination, herbivory regulation, decomposition, nutrient cycling, and disease control. These functions depend on chemical communication that guides insects to food, mates, hosts, shelters, and oviposition sites while helping them avoid threats. Environmental microparticles, such as micro- and nanoplastics, tyre wear particles, soot, mineral dust, and agricultural residues, are now widespread across air, soil, vegetation, and indoor environments, exposing insects through contact, deposition, and ingestion. Growing evidence shows that these particles disrupt insect olfaction by adsorbing volatile compounds, blocking antennal sensilla, and interfering with receptor and neuronal processes. These disruptions impair foraging, mating, oviposition, …

A Systematic Review And Meta-Analysis Of Mosquito Arboviral Infections Detected Through Xenosurveillance In Africa: A Focus On West Nile, Rift Valley Fever, And Chikungunya Virus Infections, Mxolisi Mgongoma, Armanda Bastos, Abel Ramoelo, David P. Tchouassi

All Peer-Reviewed Publications

This systematic review and meta-analysis comprehensively evaluated the mosquito arboviral infections with West Nile virus (WNV), Rift Valley fever virus (RVFV), and chikungunya virus (CHIV), detected through xenosurveillance, reported in mosquito vectors across Africa in the last 25 years (2000–2024). The study analysed xenosurveillance data from 45 studies conducted with over 115,000 mosquito specimens, and incorporated moderator analyses to assess the influence of trap type, seasonality, regional location, settlement type, and screening methods on virus detection rates. The estimated pooled prevalence of WNV was 1.18% (95% CI: 0.60–3.43%), with higher rates observed in Culex quinquefasciatus and Culex pipiens, particularly in …

Effects Of Temperature On The Life-History Traits Of Myzus Persicae And Its Efficiency In Transmitting Potato Virus Y (Pvy) In Potato Crops, Bonoukpoè M. Sokame, Henri E. Tonnang, Heidy Gamarra, Pablo Carhuapoma, Jan Kreuze, Leah R. Johnson, Ali Arab, Peter A. Armbruster, Oswaldo C. Villena

All Peer-Reviewed Publications

Aphids are highly sensitive to temperature changes and play a crucial role in transmitting plant viruses, accounting for the transmission of more than 50% of viruses that cause disease in crops. Among them, Myzus persicae is a major global pest, affecting over 400 plant species and transmitting more than 100 plant viruses, including potato virus Y (PVY), which poses a severe threat to potato crops. This study examines how temperature influences the life-history traits of M. persicae and its efficiency in transmitting PVY. Our research revealed that temperature significantly affects developmental duration, survival, and fecundity of M. persicae. The aphids …

Reframing Sexual Assault And Intimate Partner Violence Through A Maternal And Child Health Lens: Implications For Integrated Prevention, Policy, And Practice, Daija C. Gibson

Theses and Dissertations

Sexual assault and intimate partner violence remain persistent public health concerns in the United States, with significant consequences for individual health, family stability, and population well-being. Although these forms of violence are frequently addressed through criminal justice and behavioral health frameworks, less attention has been given to their implications within maternal and child health, where relational dynamics, life course development, and intergenerational outcomes are central. This study reframed SA and IPV as core MCH issues to examine how integrated, systems-based approaches can strengthen prevention efforts. A structured literature review and systematic synthesis of peer-reviewed studies published between 2015 and 2026 …

Evaluation Of Valley Healthcare System Inc. School-Based Health Clinic/Center At Dorothy I. Heights Elementary School In Columbus, Georgia, Nakia Ford

Theses and Dissertations

School-Based Health Centers (SBHCs) are an important strategy for addressing health disparities and improving educational outcomes among underserved students. In Columbus, Georgia, barriers such as limited insurance, transportation challenges, and provider shortages contribute to unmet health needs, which are linked to increased absenteeism. To address these issues, Valley Healthcare System, Inc. (VHCS) implemented a School-Based Health Clinic (SBHC) at Dorothy I. Heights Elementary School. This study evaluates the effectiveness of the SBHC in improving student attendance outcomes. A quasi-experimental, difference-in-differences design compared Dorothy I. Heights Elementary School (treatment group) before and after SBHC implementation (2021–2022 and 2022–2023) with a similar …

Trident-Bladder: A Resolution-Aware Multimodal System For Robust, Calibrated Bladder Cancer Diagnosis Across Endoscopy, Histopathology, And Liquid Biopsy, K. Sankar, S. Venkata Lakshmi, Gummadi Reshma, V. Gokula Krishnan, M. Ganesan, V. Vijayaraja

Mansoura Engineering Journal

Bladder cancer diagnosis demands the integration of cystoscopy, histopathology, and biomarker testing, yet the majority of AI systems continue to be modality, specific and sensitive to acquisition variations. TRIDENT, Bladder is a resolution, aware multimodal framework that we have developed to address this issue. The method combines cystoscopic lesion segmentation, whole, slide image (WSI) molecular subtype prediction, and urine miRNAclinical data through reliability, weighted fusion and a utility, aware decision policy. The endoscopic branch features a quality, gated super, resolution component, resulting in mDice 87.5, sensitivity 92.1%, precision 91.4%, boundary, F1 85.3%, and ECE 0.023 at 32 FPS. mDice on …

Evaluating Soil And Plant Health In A Wide-Row Maize (Zea Mays L.) Production System Integrated With Perennial Cover Crops And Turkey (Meleagris Gallopavo), Sovika Bhattarai

All Graduate Theses, Dissertations, and Other Capstone Projects

In regions dominated by intensive maize (Zea mays L.) production systems, such as the US Midwest, sustainable agricultural practices such as cover crops and livestock integration are gaining interest for their potential to improve soil, plant, and environmental health. Traditionally, annual cover cropping systems (ACCs) have been used to maintain soil quality and crop performance without compromising ecosystem services. However, the high establishment and management costs of ACCs highlight the need for alternative approaches, such as perennial cover crops (PCCs). Grown as companion crops with maize, PCCs provide extended soil cover and can improve soil biochemical properties (e.g., total C …

Retention Time Of Microplastics In The Purple Sea Urchin (Arbacia Punctulata), Alexandra Shore

Honors Theses and Capstones

Marine ecosystems around the world are facing the problem of plastic pollution. Large pieces of plastic eventually degrade into smaller microplastics that are suspended in the water column and sink to the seabed. Sea urchins are exposed to microplastics as they graze on the sea floor and can accidentally consume these pollutants. Sea urchins are ecologically important animals because they physically alter their ecosystem via grazing and are integral part of marine food webs. To better understand how sea urchins interact with microplastics, purple sea urchins were exposed to microfibers and microspheres in a laboratory setting, and the retention time …

Exploring The Relationships Between Social Influence, Vaping Behaviors, And Susceptibility Across Grade Levels In Kentucky, Raphael Adesiyan, Odunayo O. Omotilewa, Saber Feizy, Melinda J. Ickes

Kinesiology and Health Promotion Faculty Publications

Purpose: This study explored the relationships between social influence, vaping behavior, and susceptibility across different grade levels.   Design: The study design was cross-sectional. Data were collected from middle and high school students who voluntarily participated between September 2022 and April 2023.   Sample: A convenience sample of students in 6^th to 12^th grades in Kentucky (N = 4677).   Measures: Demographic information, including age, grade level, school location, and race/ethnicity, was collected. The outcome variables included social influence, susceptibility, and vaping behavior.   Analysis: Logistic regression analysis was used to explore the relationships between social influence, vaping behavior, and susceptibility.   Results: …

Impacts Of Management Practices And Soil Properties On Free-Living Nitrogen Fixation In Eastern South Dakota, Laura Galvan Nuevo

Electronic Theses and Dissertations

Free-living nitrogen (N) fixation (FLNF) may represent a sustainable pathway to supplement crop N demand in agroecosystems, yet edaphic and management factors regulating this process under field conditions remain poorly understood in the Northern Great Plains. Using 15N2 direct method to quantify potential FLNF (pFLNF) and baseline FLNF (bFLNF), this thesis investigates how crop rotations (2-, 3-, and 4-year systems), tillage management (conventional vs. no-till), cover cropping, and soil properties affect the potential of free-living diazotrophs to supply N via FLNF in a long-term no-till corn-based system in Southeastern South Dakota. A two-year field study evaluated pFLNF across four growing …

Immune Suppression And Epigenetic Reprogramming In Epithelial-Mesenchymal Transition, Hanxu Lu

Dartmouth College Ph.D Dissertations

Epithelial-mesenchymal transition (EMT) is increasingly recognized as a dynamic spectrum of cellular programthat contributes to tumor progression, metastasis, and therapeutic resistance. Rather than existing as discrete epithelial or mesenchymal phenotypes, tumor cells undergo intermediate EMT states in which epithelial and mesenchymal features are partially and variably expressed. In this thesis, I studied EMT state heterogeneity through two complementary and integrated dimensions: tumor-immune interactions and the dynamic remodeling of epigenetic programs across the EMT spectrum. Using a clonal EMT model derived from the murine triple-negative 4T1 mammary carcinoma cell line, including epithelial, intermediate, and mesenchymal states that are stably maintained in …

Colorectal Cancers With Distinct Metastatic Potential Trigger Divergent Early T Cell Responses, Marwa Ahmed Saad

Student Theses and Dissertations

The intestinal mucosa harbors the largest immune compartment in the mammalianbody, where resident and recruited immune cells must maintain tolerance to commensal and dietary antigens while preserving their ability to mount effective responses against pathogens and malignant transformation. Uncontrolled epithelial proliferation leads to colorectal cancer (CRC), the second leading cause of cancer-related deaths worldwide. More than 85% of human CRC cases arise from accumulating sporadic or hereditary mutations in the tumor suppressor genes Apc, Tp53, Smad4, and the oncogene Kras. Although immune checkpoint blockade has transformed the treatment of certain solid tumors, most CRCs, particularly those with a proficient mismatch …

Investigating Primary Motor Cortex Involvement In Mouse Vocal Communication, Elena N. Duryea Waidmann

Student Theses and Dissertations

Vocal communication is used to transmit a range of information to other individuals. While many vocalizations are innate, some species can learn to change their vocal output. This is termed vocal-learning, and it is a rare trait and a necessary building block for human spoken language and songbird song. Comparative work in humans and songbirds suggests that convergent genetic and neural specializations may drive these learned vocal behaviors. Two key features of these advanced vocal learners are: i) specialized primary motor regions in the forebrain with activity tied to vocalization; and ii) dense monosynaptic projections from the primary motor cortex …

Noncanonical Roles Of Hepatitis B Virus Precore Rna In Reverse, Mengyin Zhang

Student Theses and Dissertations

Hepatitis B virus (HBV) is a partially double-stranded DNA virus that replicates through reverse transcription. Transcription from the HBV core promoter generates two genome-length RNAs: pregenomic RNA (pgRNA) and precore RNA (pcRNA). pcRNA contains the entire pgRNA sequence plus an additional 32 nucleotides at its 5’ end that include the precore start codon, enabling translation of the precore protein, the precursor of the secreted HBV e antigen (HBeAg). Whereas pgRNA is translated to produce core and polymerase and serves as the template for reverse transcription by cis-acting HBV polymerase, pcRNA has long been considered unable to support HBV DNA synthesis. …

Astrocyte Identity And Function Acquisition During Nervous System Development In C. Elegans, Simin Liu

Student Theses and Dissertations

Astrocytes are essential regulators of nervous system development, homeostasis, and function. Beyond their well-established roles in synapse formation, metabolic support, and neural circuit modulation, astrocytes are increasingly recognized as dynamic participants in behavior regulation and neurological disease. Despite their importance, the developmental logic by which astrocytes acquire their identity and functional properties remains incompletely understood. In particular, how distinct developmental programs coordinate to establish astrocyte identity, and how immature glial cells transition into fully functional astrocytes, are central unresolved questions in neurobiology. In this thesis, I investigate the developmental mechanisms that establish astrocyte identity and function using the astrocyte-like Caenorhabditis …

Utilizing Plethodontid Occupancy To Assess Initial Ecosystem Responses To Invasive Plant Control Treatment In The Central Hardwoods, Maree Guinevere Dieterich

Graduate Theses, Dissertations, and Problem Reports (ETD)

Invasive plants are a growing concern for land managers, impacting ecosystem resilience and outcompeting native vegetation. To combat this, invasive plant control treatments can assist in reducing the impacts and spread of damaging, non-native plant species. However, intensive treatments completed at large scales have the potential to negatively impact ecosystem services as well. To monitor these impacts, I utilized a well-known indicator in the Central Applachian region, Plethodontid salamanders, to assess impacts of invasive plant control treatments in the Central Hardwood forests. I completed 12 visual samples across 60 sites in West Virginia, USA during Spring and Fall of 2025 …

Evaluation Of Brook Trout (Salvelinus Fontinalis) Thermal Tolerance And Projected Climate Change Effects On Headwater Brook Trout Population Persistence, Cory Bauerlien

Graduate Theses, Dissertations, and Problem Reports (ETD)

Climate change has been identified as one of the greatest threats to global biota in recorded human history. Consequences are expected to be more pronounced in ectotherms because most of their physiology is controlled by external temperature conditions. Predicting how ectotherms may respond to increasing global temperatures necessitates information about thermal limits of thermal sensitive species and how increasing temperatures may affect individual and population-level fitness. Therefore, the objectives of this research were aimed at gaining a better understanding of the mechanisms that underpin thermal tolerance limits of fish and how those mechanisms may affect fitness and population persistence under …

Design, Syntheses And Biological Applications Of Fluorescent Probes For Nad(P)H, Hsa And Cellular Microenvironment Sensing, Adenike M. Olowolagba

Dissertations, Master's Theses and Master's Reports

Fluorescent probes have emerged as powerful tools for investigating complex biological processes due to their high sensitivity, selectivity, and capability for real-time, non-invasive imaging. In particular, the detection of key biomolecules such as NAD(P)H, viscosity-related parameters, human serum albumin (HSA), and pH is essential for understanding cellular metabolism, redox homeostasis, and disease progression. In Chapter 2, three coumarin-based fluorescent probes (A–C) were designed, synthesized, and characterized for monitoring NAD(P)H levels in living cells. Probes A and B feature coumarin–cyanine hybrid structures linked via vinyl and thiophene bridges to 3-quinolinium acceptors, respectively, while probe C incorporates a dicyano moiety to replace …

Spatiotemporal Patterns Of Migratory Songbird Habitat Use: An Analysis Of Environmental Drivers At The Net Level, Garrett Kucharski

Dissertations, Master's Theses and Master's Reports

Many eastern North American migratory songbirds are declining at alarming rates, and growing evidence suggests that events occurring away from the breeding grounds, particularly during migration, can be major drivers of these trends. Stopover sites are a key component of migration because they are where birds rest, refuel, and recover before continuing long-distance movements, yet the ecological factors that shape how broadly different species use stopover habitat remain unresolved. From both an applied perspective, identifying habitat attributes associated with use by the greatest diversity of migrants will help land managers prioritize and restore stopover sites, actions that may contribute to …

Fluctuation Of Organochlorine Concentrations In Bull Sharks At Different Life Stages, Mackenzie R. Phillips

Dissertations, Master's Theses and Master's Reports

For Carcharhinid species such as the bull shark (Carcharhinus leucas), the maternal offloading of nutrients is essential for pup development and growth, however, significant amounts of OCs are also transferred. As a top predator in aquatic food webs, bull sharks can potentially bioaccumulate high concentrations of pollutants such as dichloro-diphenyl-trichloroethane (DDT) that biomagnify through aquatic food webs. These pollutants are also hydrophobic and fat soluble and therefore pose toxicity risks to developing young bull sharks. In this study, liver tissues collected from juvenile bull sharks inhabiting Florida’s coastal waters were analyzed for a suite of organochlorine pesticides (OCs) …

Computational And Ai Frameworks For Identifying Key Regulatory Genes And Their Target Genes In Plants And Humans, Md Khairul Islam

Dissertations, Master's Theses and Master's Reports

This dissertation presents computational and AI-driven frameworks for identifying key regulatory genes and their downstream targets across plant and human biological systems. Three studies address distinct challenges in genomic regulation using advanced machine learning and bioinformatics approaches.

The first study introduces DyGAF (Dynamic Gene Attention Focus), a dual-attention transformer framework that identifies and ranks disease-relevant biomarker genes by simultaneously modeling independent molecular responses and interdependent regulatory network behavior. Two attention models provide complementary perspectives on gene importance and are fused through a novel combination metric. Applied to COVID-19 nasopharyngeal swab profiles, the attention-weighted representations achieved 94.23% classification accuracy, high sensitivity, …

Exploring Fructose Mimetics As Chemotherapeutic Potentiators: Impact On Glut5-Mediated Cancer Cell Vulnerability, Vedant Buwa

Dissertations, Master's Theses and Master's Reports

Metabolic reprogramming toward increased sugar uptake is a hallmark of cancer, and fructose-specific uptake through the facilitative transporter GLUT5 is selectively upregulated in several adenocarcinomas, including breast and lung cancer. This dissertation develops and characterizes a panel of fluorescent fructose mimetics – the coumarin-based ManCou probes and the quinolinone-based ManQuin probes – as GLUT5-targeted reporters, cytotoxic effectors, and chemosensitization adjuvants, and establishes the boundaries within which each role holds.

The central experimental strategy pairs each GLUT5-targeted glycoconjugate with its sugar-free aglycone control, isolating transporter-mediated cytotoxicity from cytotoxicity intrinsic to the fluorophore itself. In luminal (MCF7) and triple-negative (MDA-MB-231) breast carcinoma, …

Public Perception Of Environmental Contamination And Its Implications For Fish And Community Health In West Bengal, India, Libia Hazra

Dissertations, Master's Theses and Master's Reports

In West Bengal, India, the highest fish-consuming state in the country, fish are woven into everyday life, including ceremonies of birth and marriage, prayers offered during harvesting and the cultural memory of communities whose identities are inseparable from aquatic life. However, the rivers, wetlands, and ponds that sustain these fish-human relationships are increasingly threatened by environmental contamination resulting from industrial discharge, agricultural runoff, and inadequate environmental management. Understanding how communities perceive these environmental changes is essential for developing effective conservation and public health strategies.

In collaboration between the Indian Institute of Technology (ITT) Kharagpur, India, and Michigan Technological University (USA), …

Physicochemical Characterization Of Small Extracellular Vesicles: Effects Of Immobilization, Isolation, And Disease State, Bianca M. Mercado Velez

Dissertations, Master's Theses and Master's Reports

Cancer treatments and survival outcomes have improved significantly in the last couple of decades, with survival rates increasing in the U.S. Despite improvements in treatment outcomes, early detection and treatment are crucial for improving cancer prognosis and survival rates. The standard cancer diagnostic procedure of tissue biopsy is highly invasive, leading to the further spread of cancer in some cases. Alternatively, the extraction of biofluids from cancer patients, also called a liquid biopsy, is increasingly popular because it is less invasive and more representative of the tumor microenvironment, which contains cancer cells, tumor genetic material, and extracellular vesicles, including small …