Digital Commons Network^™

Characterizing The Ethanol Sensitivity Of The Planar Cell Polarity Pathway In Endoderm Morphogenesis And Jaw Development., Raéden Omneil C. C. Rolle Gray

Electronic Theses and Dissertations

Fetal Alcohol Spectrum Disorders (FASD) describes a large range of developmental defects due to prenatal alcohol exposure. It is characterized by neural and facial defects, including jaw hypoplasia. Many factors contribute to the susceptibility of ethanol-induced facial defects, including genetics, yet the genes involved, and the cell events they regulate, are poorly understood. Zebrafish have a large number of tools for genetic manipulation available, share 70% of genes with humans, are fertilized externally and are translucent during embryogenesis, making them great models to study FASD. Previous studies show that two members of the Planar Cell Polarity (PCP) pathway, zebrafish vangl2 …

Structure And Function Studies On Trna Splicing Endonuclease, Justin G. Underwood

Dissertations and Theses (Open Access)

A subset of eukaryotic pre-tRNAs have introns that must be spliced out to become mature molecules capable of functioning in translation. This essential processing step is performed by tRNA splicing endonuclease (TSEN), a highly conserved heterotetramer with two catalytic and two structural subunits. In addition to this conserved function, archaeal TSEN also processes pre-rRNA and yeast TSEN cleaves some mRNAs that encode mitochondrial proteins to initiate mRNA degradation. Interestingly, single amino acid mutations in TSEN cause the human Mendelian disease pontocerebellar hypoplasia (PCH) by an unknown mechanism. Recently, several groups have determined the structure of human TSEN, revealing similarities and …

Host-Intrinsic Factors Determine Anti-Tumor Efficacy Of Exercise In Pancreatic Ductal Adenocarcinoma, Sumedha Pareek

Dissertations and Theses (Open Access)

Pancreatic Ductal Adenocarcinoma (PDAC) is the third leading cause of cancer-related deaths with a low 5-year relative survival rate of approximately 13.3% for all stages combined. We have previously shown that exercise can improve quality of life and enhance functional capacity among patients with PDAC. Exercise induces a variety of changes in the tumor microenvironment with beneficial effects in several tumor types. However, our understanding of the clinical effects of exercise and the mechanisms that mediate anti-tumor effects are limited in pancreatic cancer.

In this project, using C57BL/6 mice from Taconic Biosciences (Tac) and Jackson Laboratories (Jax), we established a …

A Randomized Controlled Trial Combining House Screening And Insecticide-Treated Nets Reduces Malaria Transmission In Northwestern Ethiopia, Aklilu K. Belay, Abebe Asale, Catherine L. Sole, Abdullahi A. Yusuf, Baldwyn Torto, Zewdu Abro, Menale Kassie, Clifford M. Mutero, David P. Tchouassi

All Peer-Reviewed Publications

House screening (HS) of doors, eaves, and windows using wire-mesh has demonstrated potential in the integrated vector management of malaria. However, limited epidemiological data are available to guide its implementation across different ecological settings. In a 16-month randomized controlled trial (follow-up period) conducted across three agroecological areas (dry mountain, plateau highland, and semi-arid) in Jabi Tehnan district, northwestern Ethiopia, treatment houses were equipped with HS combined with insecticide-treated nets (ITNs), while control houses received ITNs only. The intervention led to a significant 2.3-fold reduction in indoor malaria vector density, the primary entomologic outcome, largely influenced by An. gambiae s.l. mosquitoes. …

Nutrient Utilization Efficiency And Antioxidant Profile Of Bc2 Abaca (Musa Textilis Née) Hybrids, Roberto Barba Jr, Antonio Lalusin

The Philippine Agricultural Scientist

Abaca (Musa textilis Née) is an important fiber crop widely recognized for its superior tensile strength, yet its productivity remains constrained by nutrient inefficiency, poor cropping management, and climatic stresses under manual production systems. Efficient nutrient utilization and an understanding of antioxidant compositions are practically relevant to the productivity of the abaca fiber crop. However, despite the crop’s economic importance, limited studies have examined nutrient uptake dynamics and internal utilization efficiency related to fiber synthesis. This study aimed to demonstrate the nutrient utilization efficiency and antioxidant profiles of BC₂ abaca hybrids in relation to fiber yield and quality. Fiber …

Prevalence Of Shiga Toxin Producing Escherichia Coli In Illinois Bison Herds, Adam M. Baldocchi

Honors Capstones

Shiga toxin-producing Escherichia coli (STEC) represents an important group of zoonotic pathogens that pose ongoing risks to public health through foodborne outbreaks and environmental transmission. This project evaluated the prevalence and genetic distribution of stx1 and stx2 toxin genes in fecal samples collected from Illinois bison Bison bison) managed under either commercial or preservation conditions. A total of 320 fecal samples were screened for STEC presence by performing enrichment culturing and confirmed by Polymerase Chain Reaction (PCR) for stx1, stx2, and uidA, which confirmed E. coli identity. Of all tested samples, 28.4% were STEC-positive, with stx2 (21.3%) …

Characterization Of Mitochondrial Dna Repair Components And Repair Choices At Targeted Double-Strand Breaks In Arabidopsis Thaliana, Moira Rodriguez

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Plant mitochondrial genomes are complex when compared to most other eukaryotic mitochondrial genomes. They are large and variable in size, expand and rearrange frequently, abundant in non-tandem repeats, but maintain a very low synonymous substitution rate in the remaining coding regions. Many of these complexities can be explained by the increased use of double-strand break repair for DNA damage. To advance the understanding of mitochondrial genome dynamics as it relates to double-strand break repair, we performed a forward genetics screen to identify proteins involved in DNA repair in plant mitochondrial genomes. Through this screen, we identified an RNA/DNA helicase, Suv3, …

Proso Millet In Us High Plains Dryland Agriculture: Systems Resilience, Phenology, And Consumer Preferences For Alternative Grains, Pratiksha Baishya

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Dryland crop production in Nebraska's semi-arid High Plains faces challenges from fluctuating weather impacts of climate change, including extreme temperatures, short growing seasons, and recurring droughts. Proso millet is an alternative crop used to build a more robust three-year rotation in the region, rather than the traditional two-year wheat-fallow cycle. This dissertation provides a systems-level assessment of proso millet, a climate-resilient crop with great potential to support sustainable cropping systems in the US High Plains. Using a field-to-consumer approach, it highlights its agronomic and environmental advantages in dryland rotations, develops a phenological framework to aid future research on production, crop …

Recovery And Characterization Of Moraxella Species From Bovine Specimens, Laura G. Leger

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

The family Moraxellaceae is made up of a diverse group of 24 named species that fall into three phylogenetic groups. While most Moraxella spp. act as commensal respiratory and/or ocular flora of mammals, some are associated with disease. One of these diseases, infectious bovine keratoconjunctivitis (IBK), has significant welfare and economic impacts to both cattle and cattle producers. Moraxella bovis is the only experimentally determined cause of IBK, however, an association of Moraxella bovoculi with disease has been proposed. Currently, available vaccines do not have high levels of efficacy in the field. Culture based methods are the gold standard for …

Pfos And Lung Injury: A Review Of Human And Experimental Evidence, Farzana Hakim

Theses and Dissertations

Human epidemiological research has shown the adverse health consequences of long-term accumulation of per- and polyfluoroalkyl substances (PFAS) in human tissue. Specifically, this review will examine the relationship between PFAS exposure, impaired immune system functioning, and an elevated risk of respiratory disease using both human and experimental data. Research on human populations indicates that children exposed to PFAS have lower levels of antibodies to vaccines; those children prenatally exposed to PFAS are more susceptible to upper respiratory infections; and that adult humans have a higher incidence of chronic obstructive pulmonary disease (COPD). Additionally, experimental studies demonstrate that PFOS and PFOA …

Monte Carlo Simulations Of Geometric Deformation Of Harrison-Anderson-Mick Applicators Used In Intraoperative Radiation Therapy, Benjamin Insley, Brett Bocian, Sam Beddar, Reza Reiazi, Patrick James Jensen, Rachael M Martin-Paulpeter, Joshua Scott Niedzielski, David Flint, Gabriel Oliveira Sawakuchi, Luis Augusto Perles

Faculty, Staff and Student Publications

Background: The Harrison-Anderson-Mick (HAM) applicator is a high-dose-rate intraoperative radiotherapy (HDR-IORT) applicator used to position Ir-192 brachytherapy sources over surgically-accessed tumor volumes or post-resection tumor beds. Because of the lack of a 3D imaging system, dwell times are optimized pre-surgery by a TG-43-based treatment planning system (TPS) that assumes a perfectly flat applicator surface surrounded by an infinite water phantom. These assumed conditions are disparate from typical treatment conditions, especially in the pelvic regions, which often involve uneven patient surfaces and superficial irradiations with little to no backscatter material.

Purpose: Develop and validate a Monte Carlo (MC) model of HDR-IORT …

Dynamics, Predictability And Impacts Of Multi-Year La Niña Event, Nahid A. Hasan

All Graduate Theses and Dissertations, Fall 2023 to Present

This dissertation investigates the dynamics, predictability, and impacts of multi-year La Niña events. Multi-year La Niña events are referred to as extended periods of unusually cooler tropical Pacific that persist for two or more consecutive winters. These prolonged events can increase the risk of natural hazards such as droughts, floods, and heatwaves in the western US and around the world. Despite their worldwide significance, questions remain about the mechanisms driving their initiation, their predictability, and regional hydroclimate impacts.

The first chapter of the dissertation introduces what scientists currently believe causes them, and how well different types of climate models can …

Shifting Grounds: Knowledge, Power, And Place In Changing Western Rangelands, Molly C. Levy

Boise State University Theses and Dissertations

Public rangelands in the American West are sites of enduring contestation, where ecological change, competing values, and institutional complexity converge. Long-standing debates over livestock grazing, wildlife conservation, and land stewardship highlight fundamental questions of whose knowledge counts, whose authority is legitimate, and how resource use should adapt under shifting social and ecological conditions. This dissertation examines the intersections of knowledge, power, and land use in collaborative governance of contested landscapes. Using the Thunder Basin ecoregion (TBER) in northeastern Wyoming as a case study, I adopt a mixed-methods approach that integrates qualitative interviews, participant observation, archival research, and quantitative analysis of …

Exploring The Path To Sustainable Firm Performance: The Role Of Leadership, Learning, And Procurement In Smes, Manar Fawzi Bani Mfarrej, Imane Belyamani, Syed Zamberi Ahmad, Abdul Rahim Abu Bakar

All Works

This study explores how sustainability leadership influences sustainable firm performance in small and medium-sized enterprises (SMEs), with a particular focus on the mediating roles of sustainable procurement and organizational learning. Anchored in the dynamic capabilities view (DCV), the research proposes leadership, learning, and procurement practices as dynamic capabilities that enable firms to adapt, transform, and thrive amid sustainability-related challenges. Data were collected from 476 SMEs across the United Arab Emirates (UAE), including middle- and senior-level managers, owners, and CEOs. The proposed hypotheses were tested using partial least squares structural equation modeling (PLS-SEM). The findings reveal that the direct effect of …

Efficacy Of Zinc Oxide Nanoaciculates As Antagonists Against Meloidogyne Javanica On Phaseolus Abyssinicus, Manar Fawzi Bani Mfarrej, Faheem Ahmad, Amir Khan, Mohd Sajid Ali, Hamad A. Al-Lohedan, Arshad Iqbal, Khalid Umar, Gulam Rabbani, Mohd Farhan Khan

All Works

This work investigates the synthesis of zinc oxide nanoaciculates (ZNA) using the Sol–gel method and their potential as a long-term bio-control agent against Meloidogyne javanica, a root-knot nematode that causes severe damage to Phaseolus abyssinicus. The produced ZNA were evaluated using SEM–EDS, X-ray diffraction (XRD), and UV–Vis spectroscopy to ensure precise evaluation of their nanoscale characteristics. Bio-efficacy assays were carried out at four concentrations (125, 250, 375, and 500 mg/L) to evaluate nematicidal activity on juvenile nematodes (J2) and M. javanica egg masses. The results showed that ZNA had significant toxicity at all doses, with the highest efficacy observed at …

Characterization And Recycling Of Waste Gabbro Stone Powder As A Sustainable Cement Replacement, Jad Bawab, Hilal El-Hassan, Hassan Al Zagha, Maisa El Gamal

All Works

Cement production significantly contributes to climate change due to its high carbon emissions and resource-intensive processes. With traditional cement alternatives dwindling, exploring underutilized resources is crucial. This study investigates gabbro stone powder (GSP), an abundant byproduct in the United Arab Emirates (UAE), as a partial cement replacement in blended pastes. The characteristics of GSP were determined using standardized procedures. Then, it was incorporated into mixes at 0 %, 5 %, 10 %, and 20 % cement replacement levels with water-to-binder (w/b) ratios of 0.30, 0.35, and 0.40. Characterization revealed GSP as a siliceous-aluminous material with limited hydraulic activity. Experimental results …

Linking Training To Confidence: A Literature Review On Advancing Nutrition Environments In Child Care Programs, Jeanne M. Vanorsdal

Capstone Experience: Master of Public Health

This comprehensive literature review examined child care nutrition training interventions using the Health Belief Model (HBM) to understand how to increase providers’ ability to serve nutritious food. By analyzing HBM constructs such as perceived severity, benefits, and barriers, the review assessed how training influences provider abilities and identified barriers and facilitators to consistently offering healthy meals and snacks. Studies were 1) published in English; 2) research conducted in the United States; 3) population involved home-based or center-based child care providers caring for children from birth to age 5; 4) articles published from January 1, 2015, to October 5, 2025; 5) …

Fast & Forensic: Rapid Detection & Quantitation Of 30 + Emerging Novel Psychoactive Substances In Hair Using Lc-Ms/Ms, Seokjin Hwang

Student Theses

The continuous emergence of novel psychoactive substances (NPS) poses a significant challenge for forensic and clinical toxicologists, due to their structural diversity, rapid turnover on the illicit drug market, and limited toxicological information. Hair is a powerful matrix for retrospective drug exposure assessment and monitoring NPS worldwide. Not only does it provide a broad window of detection but also a simple sample exchange amongst laboratories. However, the extraction of multi-class NPS in a single method remains an analytical challenge. Therefore, there is an urgent need for extraction techniques and analytical methods that are both rapid and capable of multi-class quantitation …

Microplastic Accumulation In A Mixed Species Seagrass Bed In The Tamar Estuary, Torpoint, Cornwall, Uk, Hannah G. Phillips

The Plymouth Student Scientist

Microplastic pollution is a major threat to UK seagrass habitats, which provide essential ecosystem services by supporting biodiversity and economically valuable fish species. Seagrass beds, acting as long-term ‘sinks’ for microplastics due to their dense canopies face a high risk of degradation. This study investigated microplastic accumulation in the sediment of a mixed species (Zostera marina and Nanozostera noltei) seagrass bed in the Tamar Estuary, Southwest England, considering the effect of sediment particle size. Microplastics were extracted by density separation using Sodium Bromide (NaBr) and sediment particle size analysis was used to investigate the seagrass bed sediment. FT-IR …

Effects Of Maternal Hypoxia On Developmental Plasticity, Matilda Powell

The Plymouth Student Scientist

Developmental plasticity enables organisms to adjust phenotypes to environmental cues, yet the transgenerational consequences of maternal effects remain unclear. Hypoxia, intensified by climate change and eutrophication, triggers taxon-specific plastic responses. Daphnia magna exhibits plasticity dependence, making it a critical model species for studying environmental responses. While maternal hypoxia (MH) influences generational plasticity, its long-term impacts on reproductive and physiological traits across generations remain insufficiently explored, limiting predictions of species resilience to environmental change. This study employed a controlled two-generation design: gravid F0 adults were exposed to moderate hypoxia (40% air saturation) or normoxia (100% AS) for 8 days, with reproductive …

All Rivers Reach The Sea: Can We Improve Ocean Conservation Through Improving Public Understanding Of The Connections Between Marine And Terrestrial Systems?, Lauren Hind

The Plymouth Student Scientist

With marine environments facing growing threats and their connections to terrestrial environments often disregarded, understanding public perceptions of these connections is crucial for effective ocean conservation. This study aimed to assess public understanding of the interconnectedness of marine and terrestrial environments and its influence on ocean conservation efforts. To achieve this, two questionnaires (N=560) were distributed among over 18’s (N=301) and under 18’s (N=259) evaluating their knowledge on the connections between marine and terrestrial environments, engagement with conservation and views on education and responsibility. The results indicated a limited understanding and awareness of marine-terrestrial connections, particularly among under 18’s. Current …

From Sea To Shore: Wind-Driven Aerosolization Of Harmful Algal Bloom Toxins In Qingdao, China, During The Winter Of 2019, Madeleine K. Martin

The Plymouth Student Scientist

In Qingdao, China, harmful algal blooms (HABs) are a known hazard to coastal communities. Aerosolization is a mechanism by which HAB toxins can be transported from the sea surface into the air when wind speeds exceed 5 m/s. Previous studies have analysed the composition of aerosolized marine biotoxins (AMBs) in the breathable air surrounding Qingdao, but the role of the onshore winds in transporting them there would benefit from further research. Ciguatoxin is one such AMB, and this study analyses the role of onshore winds in aerosolizing and transporting toxins inland from a ciguatoxin bloom in Aoshan Bay, Qingdao during …

Comparing The Effect Of Marine Aquarium Salts And Sodium Chloride On Vicia Faba Stress Response, Bethany Smerdon

The Plymouth Student Scientist

Soil salinity is a major abiotic stressor limiting agricultural productivity. Many salt stress studies rely solely on sodium chloride (NaCl) solutions, despite not accurately representing natural saline conditions. This study investigated the stress response of Vicia faba to NaCl and marine aquarium salt (MAS) solutions to assess the impact of a more complex ionic composition on plant physiology. Plants were cultivated in a controlled greenhouse and treated with either NaCl, MAS, or rainwater (control) for up to 55 days. Growth parameters, water status, proline accumulation, chlorophyll content, and root nodule weight were measured to evaluate stress responses. The results indicate …

Evaluating The Impacts Of The Invasive Macrophyte, Crassula Helmsii, On Macroinvertebrate Assemblages At Small Spatial Scales In Lentic Ecosystems, Keivan Rakhshani

The Plymouth Student Scientist

Freshwater ecosystems cover only three percent of the Earth’s surface yet support approximately ten percent of global biodiversity. These systems play a crucial role in maintaining native biodiversity across spatial and temporal scales but are increasingly threatened by anthropogenic stressors, including habitat modification, pollution, and biological invasions. The introduction of non-native macrophytes can fundamentally alter community structure by modifying habitat complexity, resource availability, and competitive interactions. This study assesses the impact of the invasive macrophyte Crassula helmsii on macroinvertebrate assemblages at small spatial scales within partially invaded ponds in Dartmoor National Park, southwest England. Three ponds with varying degrees of …

Assessing Jasmonic Acid Seed Priming In Brassica Napus: Impacts On Aphid Herbivory Resistance And Seedling Fitness Trade-Offs, Daisy Stradling

The Plymouth Student Scientist

Jasmonic acid (JA) is a key phytohormone involved in plant defence, offering a potential sustainable alternative to conventional chemical pesticides. While JA seed priming has been explored as a strategy to enhance herbivore resistance in certain plant families, its potential fitness trade-offs remain poorly understood. This study investigates the effects of JA seed priming on Brassica napus (oilseed rape), a key agricultural crop, focusing on seedling fitness and resistance to Brevicoryne brassicae (mealy cabbage aphid), a major agricultural pest. To assess potential fitness trade-offs, seeds were primed with 75 µM JA, and multiple seedling fitness parameters were measured. Germination monitoring …

Collective Agency And Community Resilience Among Farmworkers In The Lower Rio Grande Valley, Angel Velazquez

Theses and Dissertations

This research assesses how farmworkers in the Lower Rio Grande Valley of Texas use everyday practices to build resilience and adapt to changes in their lives. I apply two interconnected theories, White’s (2017, 2019) framework of collective agency and community resilience and Castro and Sen’s (2022) framework of everyday adaptation actions, to study these practices. I conducted 19 semi-structured interviews with Latino farmworkers and professionals who work with local farmworker organizations in the Rio Grande Valley (RGV) of Texas. Interview transcripts were analyzed to determine if and how Latino farmworkers in the RGV can work towards community resilience and implement …

Determination Of An Effective Natural Boxelder Bug (Boisea Trivittata) Repellent, Reyna Chavez

Theses and Dissertations

This study investigates the use of ecofriendly repellant alternatives to pest management to control boxelder bugs (Boisea trivittata). This bug gathers by the thousands on warm surfaces of exterior suburban homes during early fall and late spring. I determined bug repellency to turmeric oil (Curcuma longa), catnip (Nepeta cataria), citronella (Cymbopogon nardus), and lavender (Lavandula angustifolia). The treatments consisted of essential oils containing 20% methanol. All treatments demonstrated repellency of Boxelder bugs. Citronella was the most effective and had the highest level of repellency range of 90-99%. Catnip was the least effective with a repellency range of 63-82%.

Clustering 24-Hour Ambulatory Blood Pressure Time Series With Dynamic Time Warping And Time Warp Edit Distance, John Knight

Theses and Dissertations

Ambulatory blood pressure monitoring (ABPM) captures dynamic circadian changes in blood pressure (BP) that are not reflected in static clinic readings. This study applied time-series clustering with two elastic distance measures—Dynamic Time Warping (DTW) and Time Warp Edit Distance (TWED)—to identify distinct phenotypes in 2,155 24-hour ABPM time series from participants in the Maracaibo Aging Study. DTW and TWED both yielded three clusters corresponding to non-dipping, moderate-dipping, and strong-dipping patterns. The non-dipping group showed elevated nighttime BP, associated with greater cardiovascular and cognitive risk, while the strong-dipping group was associated with higher education and younger age in baseline clinic measurements. …

Bacillus Subtilis: A Bacterium That Can Potentially Degrade Low-Density Polyethylene (Ldpe) And Polyethylene Terephthalate (Pet), Migdalia Flores

Theses and Dissertations

The widespread application and disposal of plastics, such as low-density polyethylene (LDPE) and polyethylene terephthalate (PET), have raised significant environmental health concerns. Because of each plastic’s stability and durability, these plastics exhibit limited natural degradation in the environment. Recently, the environmentally friendly biodegradation of plastics by living microorganisms has attracted more attention, as they can assist in the natural degradation process. In this study, the bacterial strain Bacillus subtilis ATCC6051 was used to degrade LDPE and PET for 60 days. To measure the degradation of low-density (LDPE) and polyethylene terephthalate (PET), the dry weight was taken, and physical characteristics were …

Applicability Of Cementochronology To Estimate Season-Of-Death In Humans: Insights From Modern Documented Collections, Olga Ibarra-Sanchez

Theses and Dissertations

Dental cementum is characterized by lifelong deposition of alternating opaque annuli in fall/winter and translucent bands in spring/summer. This study aims to test the applicability of cementochronology to estimate season-of-death, by observing the properties of the last layer, with direct implications for forensic anthropology and bioarchaeology. The sample includes canine teeth from 146 adults (84 males, 62 females), age-at-death ranging from 20-97 years (mean=61.7 years, SD=18.6 years), from two contemporary skeletal collections. Of these individuals, 78 (53.4%) died in spring/summer and 68 (46.6%) died in fall/winter. Overall accuracy was low at 64.4% (94/146). Accuracy was higher for spring/summer deaths 100.0% …