Digital Commons Network^™

Elevated Temperatures Disrupt Wolbachia-Induced Feminisation And Reshape Microbial Community Dynamics Across Generations In A Spider Host, Virginija Mackevicius-Dubickaja, Jennifer A. White, Ellen E. Williams, Eyal Klement, Yuval Gottlieb, Matthew R. Doremus

Entomology Faculty Publications

Longitudinal microbial interactions within a host are challenging to study, leading to a focus on constructed microbial communities in vitro settings. Here, we take advantage of a naturally defined microbial community within a spider host to study how elevated temperatures influence microbial dynamics and phenotypes across host generations. The spider Mermessus fradeorum hosts up to five endosymbionts, including a Wolbachia strain, W1, which induces feminisation, causing genetic males to develop as phenotypic females, skewing sex ratios and promoting symbiont spread. Despite this, Wolbachia 1 persists at intermediate frequencies in wild populations. We hypothesised that elevated temperatures might reduce penetration of …

Evolutionary Transitions In Social Behavior Are Associated With Convergent And Partially Reversible Expansions Of Transcription Factor Binding Sites, Savanna G. Ploessl, Beryl M. Jones

Entomology Faculty Publications

The evolution of sociality involves shifts in physiology and behavior, most notably the emergence of a reproductive division of labor. Within social colonies, these distinct behavioral phenotypes arise from differential regulation of a shared genome. Changes in transcription factor (TF) binding motifs are one potential mechanism underpinning this plasticity, with prior studies suggesting that social species exhibit expansions in TF binding sites. However, it remains unclear whether motif expansions are reversed when sociality is lost. Here we analyze predicted TF motif occurrences across gene promoters in 42 bee species spanning millions of years of evolutionary divergence and multiple independent gains …

Hall Current And Nth Order Chemical Reaction Effects On Unsteady 3d Mhd Williamson Nanofluid Flow With Thermophoresis And Brownian Motion Over An Inclined Stretching Sheet, Polavarapu Sudheer, Ramachandra Reddy Vaddemani, Raghunath Kodi

Mansoura Engineering Journal

This study examines the influence of Hall current and nth-order chemical reaction on unsteady three-dimensional magnetohydrodynamic (MHD) Williamson nanofluid flow over an inclined stretching sheet. The model incorporates thermal radiation, heat source, Brownian motion, and thermophoresis effects. The governing nonlinear partial differential equations are transformed into a system of ordinary differential equations using similarity transformations and solved numerically using the shooting method with a fourth-order Runge–Kutta scheme. The results indicate that an increase in the magnetic parameter significantly reduces velocity profiles while enhancing temperature and concentration distributions. The Hall parameter reduces surface drag and improves heat transfer, while decreasing mass …

Evaluating Matching Frontier Methods For Crash Modification Factor Estimation, Usama Elrawy Shahdah, Eman K . Ali, Sania Reyad Elagamy

Mansoura Engineering Journal

This study evaluates "matching frontier" methods against conventional approaches for estimating Crash Modification Factors (CMFs). Thirty-four method-model combinations were tested, including 16 frontier variants, 8 propensity-score-matching algorithms with negative binomial and mixed-effects models, and two benchmarks (empirical Bayes and cross-sectional), across multiple sample sizes and three true CMF values (0.80, 1.00, and 1.30). Of these, 30 converged successfully; 4 mixed-effects models with replacement-based matching failed due to duplicate control observations. Each scenario was evaluated across 10 Monte Carlo replications to quantify performance uncertainty.

Synthetic crash data were generated with known treatment effects, examining scenarios ranging from ideal (386 treated, 21,000 …

Remote Sensing-Based Rice Detection: Novel Indices From Optical And Sar Synergy, Kaifi Chomani

Mansoura Engineering Journal

Accurate rice mapping is challenging due to the lack of a simple, efficient approach and the complexity and limited ability of existing methods to distinguish rice fields from non-rice fields. This study proposes two novel indices: the Multispectral Rice Detection Index (MRDI), which utilises optical imagery, and the OptiRadar Rice Index (ORRI), which incorporates both optical and Synthetic Aperture Radar (SAR) data. Ground-truth data from the Cropland Cropping Systems (CROS) were used to assess the performance of both indices. The findings indicated that MRDI achieved an overall accuracy of 97.97% with perfect recall (100%) but lower precision (78.65%). However, the …

An Iterative & Analytical Hybrid Deep Learning Framework For Enhanced Brain Tumor Detection And Segmentation In Mri Video Scans, Swati V. Sakhare

Mansoura Engineering Journal

The critical need for accurate and robust brain tumor detection in MRI video scans is for early diagnosis and treatment planning operations. However, the existing methods suffer from several limitations, such as not being able to capture spatio-temporal features, handling class imbalances, and generalizing across datasets with diverse characteristics. To address these challenges, I propose a hybrid deep learning framework that integrates multiple advanced techniques to enhance the detection and segmentation of brain tumors. My approach starts by using the 3D CNN-LSTM (ResNet3D-LSTM) to extract spatio-temporal feature, which utilizes ResNet3D for spatial detail extraction and LSTM for temporal coherence across …

Optimizing The Lightweight Steel Fibre Reinforced Bacterial Concrete With Nano-Silica And Coconut Shell Aggregates Using Taguchi Method, Damodaran Pooja, Mayilsamy Yuvaperiyasamy

Mansoura Engineering Journal

Concrete is essential for construction due to its high strength and durability. It supports most modern infrastructure globally. Cement production is a major source of CO₂ emissions, posing serious environmental concerns. Additionally, the rising demand for concrete is straining the limited supply of essential raw materials, such as aggregates. Researchers are examining alternative materials to improve Sustainability while maintaining structural strength to address these issues. This research aims to improve concrete performance by enhancing cement durability with nano-silica. Coconut shell, an agricultural by-product, functions as an eco-friendly alternative to conventional coarse aggregates, alleviating their scarcity. Microbiologically induced calcium carbonate precipitation …

The Underappreciated Role Of Rifampin In Shaping The Epidemiology Of Rt027-Like Clostridioides Difficile Lineages, Isabella A. Tickler, Richard V. Goering, Fred Tenover

Biology Faculty Publications

The global emergence and dissemination of epidemic Clostridioides difficile ribotype 027 (RT027) and related lineages illustrate the role of antimicrobial pressure in shaping the epidemiology of this pathogen. We propose a hierarchical model in which fluoroquinolones (FQs) served as the dominant selective force underlying the worldwide expansion of RT027-related strains, with rifampin and rifamycins acting as secondary modifiers that promoted persistence and regional dominance. ©

Postfire Habitat Use And Density Of Pacific Martens (Martes Caurina) In Lassen National Forest, California, Deirdre L. Replinger

Cal Poly Humboldt theses and projects

Increasing frequency, size, and severity of wildfires in western North America threatens forest-dependent wildlife species. The Pacific marten (Martes caurina) has historically been associated with mature, structurally complex forest throughout most of its range. Recently, martens have been detected in forests burned at high severity by the 2021 Dixie Fire—the largest recorded single fire in California state history. I used non-invasive remote camera traps and hair snares (n = 166 sites) to assess marten habitat use and density using spatial occupancy and spatial capture-recapture models. I detected martens across the burn severity gradient (unburned to high-severity) at …

Multiple Burn And Forest Characteristics Affect Gray Fox (Urocyon Cinereoargenteus) Occurrence Following A California Megafire, Amida Zohar Verhey

Cal Poly Humboldt theses and projects

In western North American forests, predator communities are faced with changing fire regimes and increased fire severity and size, particularly with megafires (>10,000 ha). As some wildlife communities may restructure following the loss of apex consumers, understanding post-fire space use of mid-trophic carnivores may inform species composition in these forests. I compared gray fox (Urocyon cinereoargenteus) occupancy in and around the 2021 Dixie Fire, the largest single-ignition fire in California state history, to examine which spatially variable burn and forest characteristics affected the space use of a widespread generalist mesopredator. Using 210 camera traps placed in 2023, …

Following The Water: Tree Water Sources In Coastal Northern California Forests, Kaitlyn Briggs

Cal Poly Humboldt theses and projects

Increasing drought intensity and declining summer water availability in Mediterranean- climate forests raise concerns about forest resilience and streamflow persistence. This study evaluated how tree water sources vary with hillslope position, season, species, and watershed context across three coastal northern California forests. Stable isotopes of hydrogen (δD) and oxygen (δ18O), soil moisture time series, linear mixed-effects models, and site-specific Bayesian mixing models (MixSIAR) were used to estimate proportional contributions of shallow soil, deep soil, stream-associated, and fog water to tree xylem water. Across sites, xylem water isotopic signatures overlapped primarily with soil water, indicating dominant reliance on subsurface sources, while …

Foundations For Trojan-Y Chromosome Development In Sacramento Pikeminnow (Ptychocheilus Grandis): A Novel Strategy For Invasive Species Management In The Eel River, Ca, Raven Mcadams

Cal Poly Humboldt theses and projects

The Sacramento Pikeminnow (Ptychocheilus grandis), an invasive predator in California’s Eel River, contributes to predation pressure on native salmonid populations despite ongoing suppression programs. This study assessed the feasibility of hormonal sex reversal as an initial step toward implementing the Trojan Y Chromosome (TYC) strategy as a novel tool for managing invasive Sacramento Pikeminnow populations in the Eel River, CA. Objectives were to 1) determine the size when gonadal differentiation occurs 2) identify an effective estradiol dosage for producing phenotypic XY females, and 3) identify sex-reversed fish using a sex-specific genetic marker.  Histological examination of juvenile fish was …

Effects Of Conifer Encroachment On Oregon White Oak Crown Structure And Nonvascular Epiphyte Communities, Courtney Jonell Copper

Cal Poly Humboldt theses and projects

Oregon white oak (Quercus garryana, QUGA) is an ecologically and culturally important broadleaf tree species native to northern California and the Pacific Northwest. Fire suppression and subsequent encroachment by Douglas-fir (Pseudotsuga menziesii, PSME) and other conifers have made QUGA woodlands among the most threatened habitat types in the region. This study examines the influence of conifer encroachment on QUGA crown structure and nonvascular epiphyte (NVE) communities using ground- and crown-based sampling techniques.

Twenty-four trees were sampled across four sites in northern California along a gradient of conifer encroachment that was quantified as PSME basal area (BA). A …

Long-Term Relationships Between Tree Growth And Climate In The Trinity Alps Wilderness, Klamath Mountains, California, Usa, Emma R. Knepp

Cal Poly Humboldt theses and projects

The Trinity Alps Wilderness is a unique setting for evaluating late-Holocene climate variability because former glaciers occupied comparatively low elevations in a region influenced by both coastal and interior climate patterns. Tree-ring chronologies were developed from four conifer species—Shasta red fir (Abies magnifica var. shastensis), western white pine (Pinus monticola), Brewer’s spruce (Picea breweriana), and mountain hemlock (Tsuga mertensiana)—sampled at high elevations (1950 - 2300 m) near Emerald and Grizzly Lakes in the Trinity Alps Wilderness in northern California. The final chronologies included 12 Shasta red fir trees, 12 western white pine …

Assessing A Half-Century Of Change In Understory Plant Range And Frequency In The Klamath Mountains Of California, Emily Jean Jackson

Cal Poly Humboldt theses and projects

The effects of climate change have and will continue to impact plant communities, including by potentially shifting species’ ranges towards topographically sheltered, cooler locations or higher elevations. In 2024, I resampled 140 vegetation plots established in 1969 in the Klamath Mountains of Northern California to assess range shifts of 46 understory species over a 55-year period. During this time, the elevational distribution of all species has increased significantly by an average of 26.9 m, but this increase was slower than necessary to track historic temperature niches given regional warming (215-311 m). Despite this overall increase, only four species exhibited significant …

Evidence Of Personality And Movement Syndromes In A Mobile Predator: How Individual Hunting Strategy Shapes Ecosystem Service Potential By Barn Owls (Tyto Furcata) In An Agroecosystem, Lauren M. Jackson

Cal Poly Humboldt theses and projects

Animal-mediated ecosystem services are delivered through the behavior of individuals, yet most studies evaluate service-providing species at the population level. We tested whether individual variation in plumage, behavior, and movement predicted hunting behavior and vineyard habitat use by adult male American barn owls (Tyto furcata) nesting in winegrape vineyards in Lodi, California, USA. We fitted GPS-accelerometer tags to 42 breeding males, quantified breast-plumage traits, measured neophobia using repeated novel object tests, and derived nightly movement metrics from GPS tracks and hidden Markov model-classified hunting locations. Several behavioral traits were repeatable, but movement traits showed the clearest repeatable individual …

Symmetry In Affiliative Interactions Of North American River Otters (Lontra Canadensis) In A Northern California Estuary, Charlotte E. Norman

Cal Poly Humboldt theses and projects

Patterns of participation in affiliative behaviors may reflect underlying social dynamics. Two affiliative behaviors, allogrooming and social play, were assessed for their symmetry, or relative participation of participants, in a wild group of North American river otters. Behavioral observations were conducted over five months at the Little River estuary in northern California using video recordings and all-occurrence sampling. Observations included all-adult groups, a family group consisting of a breeding female and two pups, and an extended family group with one or two helpers, indicative of cooperative breeding. Individuals engaged in allogrooming and social play were classified by their group membership, …

Multi-Omics Analysis Of Immune-Metabolic Adaptation To Direct-Fed Microbial Supplementation In Newly Weaned Beef Steers, Adekunle Odunayo Ajiboye

Graduate Theses, Dissertations, and Problem Reports (ETD)

Immune and metabolic disruption during weaning represents a major challenge to health and productivity in beef cattle. This dissertation tested the hypothesis that supplementation with multi-strain direct-fed microbials (DFMs) modulates immune regulation and metabolic pathways associated with adaptation to weaning stress. To address this, whole-blood transcriptomics and plasma metabolomics were used to evaluate molecular and metabolic responses in newly weaned beef steers during the receiving period. Transcriptomic analysis identified differential expressions of genes associated with immune signaling and inflammatory regulation, indicating modulation of immune-related pathways without changes in growth performance. Metabolomic analysis revealed alterations in circulating metabolites related to amino …

Exploring The Interplay Of Operational Conditions, Microbial Communities, And Water Quality In Drinking Water Ozone-Biofiltration, Kara Yvonne Cunningham

Graduate Theses, Dissertations, and Problem Reports (ETD)

Ensuring reliable access to safe drinking water is a growing global challenge as water utilities face variable source water quality driven by population growth, land‑use change, and climate change impacts. To address these challenges, utilities are implementing advanced treatment technologies designed to improve reliability under variable source water conditions. Ozone-biofiltration has emerged as a treatment approach that can reduce a wide range of natural and anthropogenic contaminants. However, despite its increased use, there is limited insight into the biological processes shaping filter function or how they respond to operational and environmental changes. Advances in molecular microbiology and high-throughput sequencing now …

Hyperglycemia Detection From Sigle - Lead Ecg Using A Hybrid Cnn & Transformer Model, Adam Ayomikun Ogunjembola

Graduate Theses, Dissertations, and Problem Reports (ETD)

Abstract
Hyperglycemia Detection from Single-Lead ECG using a Hybrid CNN & Transformer Model
Adam Ogunjembola

Diabetes Mellitus is known as high blood glucose. This high blood glucose level happens when the body has a problem with producing or using insulin. Insulin is a very important hormone that the pancreas makes to control how much glucose gets into the bloodstream and cells. Diabetes Mellitus has an effect on the body if it is not treated, such as damaging the blood vessels and nerves which can lead to stroke, kidney failure, heart attack and permanent loss of vision. Since people with diabetes …

Swarm Of One: Self-Organization In Multicellular Robots, Trevor Riley Smith

Graduate Theses, Dissertations, and Problem Reports (ETD)

Designing robots traditionally relies on centralized, top-down methods that constrain adaptability and resiliency, producing systems optimized for specific tasks. However, such systems often fail in complex environments, such as extraterrestrial, disaster, or natural settings, where designers cannot foresee every scenario a robot may encounter. Achieving autonomy in these contexts requires robots that are resilient and capable of adapting to the unknown. Multicellular organisms exhibit this adaptability through self-organization, where complex structures and behaviors emerge from local interactions among their cells. Such organisms can be viewed simultaneously as a single entity and a swarm of cooperating cells, i.e., a Swarm-of-One.

This …

Studying The Mechanism For Ricin-Induced Growth Suppression, Daniel Judge

Graduate Theses, Dissertations, and Problem Reports (ETD)

This study focuses on ribosome-inactivating proteins (RIPs), a class of potent toxins that includes ricin, α-sarcin, and shiga toxin, which irreversibly damage large subunit rRNA. Although the catalytic activity of ricin toxin A chain (RTA) is well characterized, the precise mechanisms linking ribosome damage to altered cellular morphology remain poorly understood. In this study, we engineered a tetracycline-regulatable expression system to express RTA in Saccharomyces cerevisiae. We characterized the effects of RTA expression on yeast growth, viability, and reproductive potential. We demonstrated that our expression system produced rapid and robust RTA expression and ribosome depurination within less than one …

New Fossil Mygalomorph Spiders (?Idiopidae, Pycnothelidae) From The Lower Cretaceous Crato Formation Of Brazil, Elis Maria Gomes Santana

Graduate Theses, Dissertations, and Problem Reports (ETD)

The infraorder Mygalomorphae represents one of the earliest-diverging lineages of spiders, but its fossil record remains sparse relative to the modern diversity of the group. This is a reflection of both ecological and preservational biases, such as the predominantly fossorial habits of many mygalomorphs and the strong bias of the spider fossil record toward amber deposits. Compression fossils from rock deposits are therefore especially important for documenting the evolutionary history of the group. Here, two new mygalomorph fossils from the Lower Cretaceous Crato Formation, Araripe Basin (Brazil) are described. The first specimen is tentatively referred to ?Idiopidae based on male …

Population Dynamics And Future Viability Of The Eastern Massasauga Rattlesnake (Sistrurus Catenatus) In Southwest Michigan, Matthew John Klein

Graduate Theses, Dissertations, and Problem Reports (ETD)

Managing at-risk species or populations requires understanding the demographic and genetic drivers of long-term population trends. The eastern massasauga rattlesnake (Sistrurus catenatus) is a federally threatened species facing multiple interacting threats across its range. Habitat loss from wetland drainage and agricultural land conversion has caused range contractions and geographic isolation of populations. Because remaining populations are often small and widely separated, most are now genetically isolated, threatening their long-term viability. Reversing these declines requires understanding population dynamics, quantifying extinction risk, identifying drivers of long-term viability, and assessing the effects of inbreeding and the potential for genetic rescue to …

Improving Antibiotic Prescribing For Urinary Tract Infections In Urgent Care Centers, Alexis Alastanos

Graduate Theses, Dissertations, and Problem Reports (ETD)

Introduction: Urinary tract infections (UTIs) are one of the most common infections that require antibiotic therapy. Providers working in three urgent care clinics located in Eastern West Virginia diagnosis and treat UTIs based on their clinical judgement. Variability in clinical judgement results in inappropriate antibiotic use which has implications on antibiotic resistance and the financial burden of the patients as well as the entire organization.

Evidence Review: A total of 10 articles were evaluated to support the implementation of antibiotic stewardship initiatives that provide guidance in caring for this population. Interventions include electronic health record enhancements, provider education, and tracking …

Survival, Cause-Specific Mortality, Resource Selection, Movement Rates, And Population Dynamics Of White-Tailed Deer (Odocoileus Virginianus) In West Virginia, Usa, Brett P. Skelly

Graduate Theses, Dissertations, and Problem Reports (ETD)

White-tailed deer (Odocoileus virginianus) are one of the most culturally and economically important big game species in the United States. At the turn of the 20th century white-tailed deer were almost extirpated due to market hunting and unsustainable forestry practices that destroyed habitat. The creation of game laws that eliminated market hunting and created seasons and bag limits for deer hunting along with restocking efforts by sportsmen’s groups and state wildlife agencies aided in deer population recovery. These efforts have led to the abundant deer populations that are currently enjoyed by hunters and wildlife viewers. Deer populations require …

An Assessment Of Disease Risks, Population Genetics, And Spatial Ecology Of Appalachian Cottontails (Sylvilagus Obscurus) And Snowshoe Hares (Lepus Americanus) In West Virginia, Usa, Madison Leigh Miller

Graduate Theses, Dissertations, and Problem Reports (ETD)

Snowshoe hares (Lepus americanus) occupy a large range across the United States and Canada. While snowshoe hare populations are generally considered stable in the interior of their range, populations along range edges are experiencing declines, possibly driven by climate-related factors such as seasonal coat color mismatch. West Virginia represents one of the southernmost extents of the species’ range, yet little is known about the population genetic status or population sizes of snowshoe hares in the state. Appalachian cottontails (Sylvilagus obscurus) are another lagomorph species found in West Virginia. This species experienced a historical decline and currently …

Technology-Driven Approaches For Invasive Species Detection And Management, Kushal Naharki

Graduate Theses, Dissertations, and Problem Reports (ETD)

Invasive species pose significant ecological, economic, and management challenges globally. Purple loosestrife (Lythrum salicaria), Japanese knotweed (Fallopia japonica), tree of heaven (Ailanthus altissima), and mile-a-minute (Persicaria perfoliata) are widespread invasive plants across the eastern United States and present persistent challenges, particularly in remote and inaccessible landscapes. Effective management of these species requires an integrated approach that combines early detection, targeted intervention, public engagement, and spatial modeling. This dissertation used emerging technologies to improve invasive species detection, monitoring, and management.

Unmanned aerial vehicle (UAV)-based platforms equipped with optical sensors were used to establish …

Surrogate-Based Approaches For Evaluating Post-Harvest Food Safety Interventions In Fresh Produce, Md Shafiul Islam Rion

Graduate Theses, Dissertations, and Problem Reports (ETD)

Pathogenic bacteria are still a threat to human beings worldwide as their presence is often unknown even if they are already present in fresh produces. This in turn resulted in several outbreaks and recalls across the United States. This dissertation investigated the survival of pathogenic bacteria and their potential non-pathogenic surrogates after antimicrobial interventions in different modes of applications on the surface of cantaloupes, butternut squash, and fresh cilantro. In the first study, peroxyacetic acid (PAA) was applied in three separate doses on nalidixic acid resistant Salmonella Typhimurium, Listeria monocytogenes, Enterococcus faecium, and Listeria innocua inoculated cantaloupe surfaces …

Evaluating Source Material And Seed Propagation Techniques For Spartina Alterniflora To Enhance Salt Marsh Restoration In Coastal Georgia, Maygan Palacios

College of Graduate Studies: Theses & Dissertations

Salt marshes provide critical ecosystem services, including carbon sequestration, flood attenuation, and habitat for diverse aquatic and terrestrial species. Despite their ecological importance, these habitats are increasingly threatened by anthropogenic activities and rising sea levels. To protect and restore salt marshes and their ecosystem services, restoration efforts using living shorelines (LS) have become more common. Along the Eastern and Gulf coasts of the United States, the native grass Spartina alterniflora is commonly used in LS installations for its key role in salt marsh food webs, resilience to abiotic stress, and ability to stabilize and build sediment. Previous studies have documented …