Digital Commons Network^™

Review Of Dr. Adelina A. Barrion’S Contributions To Basic Studies On The Asian Corn Borer And A Tribute To An Outstanding Entomologist, Ireneo L. Lit Jr., Merdelyn T. Caasi-Lit, John David C. Cortez, Aimee Lynn A. Barrion-Dupo

The Philippine Agricultural Scientist

The previous works of the late Dr. Adelina A. Barrion, a distinguished Filipino insect geneticist, on the Asian corn borer (ACB), Ostrinia furnacalis (Guenee), were retrieved. The works were reviewed and highlighted in relation to the recently funded project entitled “Basic studies on the Asian corn borer, Ostrinia furnacalis (Guenee),” funded by the Biotechnology Coalition of the Philippines in collaboration with various players in the corn seed industry. The unpublished papers of Dr. Barrion from the 1981 PCARR project entitled “Breeding for Corn Borer Resistance” were important milestones in basic studies on the ACB. Several studies conducted by her team …

Non-Target Organisms And Terrestrial Arthropod Biodiversity In The Corn Agroecosystem: Bt Corn Beyond Acb Pest Management [Review Article], Ireneo L. Lit Jr., Merdelyn T. Caasi-Lit, Kristine O. Abenis

The Philippine Agricultural Scientist

Assessments of risks of modern biotechnology products to non-target organisms (NTOs) are required before a product can be registered and allowed for commercial production. For Bt-engineered plants, data from such studies become part of environmental risk or impact assessments that are reviewed before a hybrid can be registered and allowed for commercial planting. The approaches and methods vary among countries and researchers. Consequently, the choice of species and groups of organisms or guilds that are monitored or studied may range from narrow to broad and encompassing. The inevitability of adverse changes in agroecosystems, including those that involve the corn crop, …

Basic Studies On The Asian Corn Borer, Ostrinia Furnacalis (Guenée), Are Crucial For Insect Resistance Management For Bt Corn In The Philippines, Merdelyn T. Caasi-Lit, Aimee Lynn A. Barrion-Dupo

The Philippine Agricultural Scientist

The Philippines is considered to be “at the forefront of biotech research and commercialization in Southeast Asia and a model for science-based and thorough regulatory policy in the region” (ISAAA 2016). This is evident in the country's pioneering adoption of Bt corn technology in Asia and in the effective handling and implementation of rules and regulations on biosafety and the application of transgenic crops through the regulatory function of the Bureau of Plant Industry (BPI) under the Department of Agriculture.

Age-Dependent Reproductive Fitness And Behavioral Dynamics Of The Asian Corn Borer, Ostrinia Furnacalis (Guenée) (Lepidoptera:Crambidae), Marcela M. Navasero, Randolph N. Candano, Maricon Dp Javier, Jethro M. Navasero, Wilson N. De Panis

The Philippine Agricultural Scientist

This study evaluated the effects of parental age of the Asian corn borer (ACB), Ostrinia furnacalis (Guenée), on fecundity, egg hatchability, adult longevity, and the duration of pre-oviposition, oviposition, and post-oviposition periods using arranged mating pairs aged 1 to 5 days old. Mating behavior was also observed and documented. The highest fecundity, measured by the number of egg masses and total eggs produced, was recorded in pairings of 1-day-old males and females, indicating a positive effect of young parental age. In contrast, pairings involving 5-day-old males and females resulted in the lowest egg production, demonstrating an inverse relationship between parental …

Characterization Of Adult Emergence Pattern And Eclosion Behavior Of The Asian Corn Borer, [Ostrinia Furnacalis (Guenée)] (Lepidoptera: Crambidae), Under Laboratory And Field Conditions In The Philippines, Marcela M. Navasero, Gelyn D. Sapin, Merdelyn T. Caasi-Lit, Wilson N. De Panis, Randolph N. Candano, Maricon Dp Javier, Jethro M. Navasero, Meijei T. Bangangao

The Philippine Agricultural Scientist

This study focuses on understanding the emergence pattern of Asian Corn Borer (ACB), Ostrinia furnacalis (Guenee), in the Philippines vital in crafting integrated pest management schemes, including insect resistance management against pesticides and Bt protein. Although ACB adults are known to be nocturnal and primarily emerge at night, identifying critical windows of emergence for targeted management actions is essential. In the experiments conducted, the scotophase period is the preferred time for adult emergence under laboratory conditions with 248 adults (80.52%) and 60 adults (19.48%) in the photophase period. A similar trend was also observed under field cage conditions with ACB …

Temporal Decline And Spatial Heterogeneity Of Cry1ab Susceptibility In Asian Corn Borer, Ostrinia Furnacalis (Guenée), Populations In The Philippines: A Review And Synthesis Of Monitoring Data (2015–2024) [Review Article], Edwin P. Alcantara

The Philippine Agricultural Scientist

Transgenic corn expressing the insecticidal Cry1Ab protein has been widely utilized in the Philippines to control the Asian corn borer (ACB), Ostrinia furnacalis (Guenée). Continuous, long-term monitoring is critical to detect shifts in baseline susceptibility and mitigate the risk of field-evolved resistance. This study evaluated the spatiotemporal dynamics of ACB susceptibility to Cry1Ab over nine years (2015–2024). Bioassay data were collected from 12 geographically distinct field populations across the Philippines, alongside a susceptible laboratory reference strain (UPLB). To account for spatial hierarchy and temporal variance, data were analyzed using a Bayesian hierarchical multilevel model with a logit link. Baseline assessments …

Movement Of The Different Larval Stages Of Asian Corn Borer, Ostrinia Furnacalis (Guenée), On Conventional Corn Hybrid Under Field Caged Conditions, Merdelyn T. Caasi-Lit, Mark Bryan A. Lontoc, Victor V. Alpuerto, Abigail P. De Leon, Jenifer Bigkas-Naungayan, John David C. Cortez, Edwin A. Benigno

The Philippine Agricultural Scientist

Larval dispersal is crucial in pest population establishment in crop fields. The movement of Ostrinia furnacalis (ACB) larvae within corn plots was observed to determine which factors affect larval dispersal in the field. Conventional corn plots (3 rows, 0.70 m apart x 9 plants, 0.20 m apart) were artificially infested with different combinations of larval age and pest density. The distributions of larvae were recorded through destructive sampling at 4, 8, 12, and 16 days after infestation (DAI). The behavior of ACB from the time the hatching larvae break open the egg mass shell to ballooning to start actual movement …

Modeling And Analysis Of Electric Signal In Neurons, Kevin J. Roberts

All Graduate Reports and Creative Projects, Fall 2023 to Present

Neurons in humans and other species transmit information by sending electric signals via axons. This process relies on the generation and propagation of action potentials—rapid changes in the membrane potential of the axon. Understanding the mechanisms of action potentials, including how they are generated and influenced by the axon geometry and material parameters, is crucial for gaining insight into neurological diseases such as Alzheimer’s and Multiple Sclerosis (diseases highly correlated to demyelination). In this work, we review and summarize mathematical models for signal transmission–including the classical Hodgkin-Huxley model, the Single Cable (SC) model, and the Double Cable (DC) model. We …

Advancing The Virus Diagnostic Toolkit: Development Of Accurate And Reliable Artificial Virus-Mimicking Positive Controls And Crispr-Based Detection, Habeeb Yinka Atanda

Graduate Theses and Dissertations

Accurate and reliable detection of plant viruses is critical for protecting berries and other economically important crops. Yet diagnostic programs face persistent challenges with positive control availability, biosafety concerns, and specificity limitations. This thesis advances the diagnostic toolkit for berry viruses through three complementary innovations that address fundamental gaps in current detection methodologies. First, this research developed and validated virus-mimicking artificial positive controls (ViMAPCs) for diverse viruses affecting berry crops for endpoint PCR applications. ViMAPCs incorporate size differentiation, which enables immediate visual gel band discrimination between control and natural infection signals. Amplification efficiency analysis demonstrated close correspondence with true-positive controls …

Integrated Pest Management Adoption, Pesticide Handling And Knowledge Gaps Among Cotton Farmers In Tanzania: Implications For Human And Environmental Health, Sospeter Jibunge Charles

Journal of Humanities and Social Sciences

The global demand for cotton has risen significantly due to its extensive use in the textile and manufacturing industries, making it one of the most valuable cash crops worldwide. However, this growing demand for cotton production is severely threatened by the currently emerging pests which are intensified by the occurring of climate change and variability. As a result, many smallholder farmers have increasingly turned to chemical pesticides use to control the pests and maintain cotton production. But, while pesticides are effective in controlling pests and improving yields, their improper use and mismanagement pose serious risks to human health and the …

Functional Characterization Of The Hssb1 K94q Mutation, Isaiah Singleton

All Theses

Genome stability depends on precise DNA repair pathways such as homologous recombination (HR), where human single-stranded DNA-binding protein 1 (hSSB1) stabilizes single-stranded DNA (ssDNA) intermediates and recruits repair complexes. Post-translational modifications, including acetylation, are known to regulate hSSB1 activity, but their molecular effects remain poorly defined. This study examined the role of lysine 94 (K94) acetylation using a glutamine substitution mutant (K94Q) that mimics the acetylated state. Recombinant hSSB1 wild type (WT) and hSSB1_K94Q were expressed in Escherichia coli and purified using Ni–NTA affinity chromatography. Biochemical analyses, including electrophoretic mobility shift assays (EMSA), single-strand annealing assays, and displacement loop …

Plant Community Responses To Wildfire, Timber Thinning, And Bison Reintroduction On The Northern Great Plains, Ethan H. Van-Derpoel

All Theses

The Northern Great Plains (NGP) is one of the largest intact grasslands remaining in the world. These two studies examine a few of the ecological concerns on the NGP today. First, the woody encroachment of conifers into grasslands and the effects of wildfires. Second, the effects of bison (Bison bison) reintroduction on plant communities. In Chapter 1, this study aims to examine the effects of wildfire and mechanical timber thinning, using a two-by-two factorial design, on plant community responses and forage quality in the Bull Mountains area of central Montana, USA. We found that our treatments had varying …

Patch Mow Grazing: Investigating The Effects Of Mowing On Forage Nutritive Value, The Biomass–Nutritive Value Relationship, And Herbivore Selection, Trace R. Stauble

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Herbivore foraging behavior plays a critical role in shaping grassland structural heterogeneity, with selection often driven by forage biomass and nutritive value. Currently, it is thought that herbivores primarily select areas that are greater in nutritive value, and low in biomass. More specifically, disturbances like fire and grazing have been thoroughly studied showing that recently burned and grazed areas are not only higher in nutritive value but disproportionately selected by herbivores in comparison to undisturbed areas. However, most studies address only narrow ranges of defoliation, comparing intensely defoliated sites (< 10 cm) to those that are either not defoliated or have experienced a much longer time since defoliation, thereby decreasing grazing pressure as biomass increases. However, one of the most widely used methods of defoliation in grasslands, mowing, hasn’t been thoroughly studied for its effects on nutritive value, and how it impacts herbivore selection. Our study aimed to (1) evaluate how mowing treatments—i.e., short (5 cm), medium (18 cm), and tall (>30 cm, unmown)—affect nutritive value and herbivore selection, (2) assess …

Cover Crop Influence On Arthropod Biodiversity And Soil–Water Dynamics In A Semi-Arid Maize–Soybean Sequence Of The Nebraska High Plains, Carlos Eduardo De Oliveira Martins

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

With the expansion of cover crop (CC) use in semi-arid regions, producers in the Nebraska High Plains are increasingly interested in understanding how CCs influence both beneficial arthropods and soil-water within maize-soybean (Zea mays L., Glycine max [L.] Merr.) rotations. Integrating CCs in these systems can enhance soil water availability and beneficial insect activity, but potential trade-offs include higher early-season water use by CCs and the risk of increasing potential pest populations. This thesis addresses these questions through two complementary studies conducted under field conditions near Brule, Nebraska. The first study evaluated the effects of a multi-species CC mixture …

Post-Fire Soil Health Assessment Of The Grasslands And Woodlands In The Semi-Arid Nebraska Sandhills, Stephanie M. Lugo

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Grasslands in the Nebraska Sandhills are shaped by natural wildfires, which help maintain the structure and function of native grasslands. In recent decades, afforestation with ponderosa pine and eastern redcedar has introduced new woodlands that altered the region’s fire dynamics and raised important questions about the effects of wildfire on different vegetation types. As wildfires become more frequent, understanding their impacts on soil health in grasslands and woodlands becomes increasingly important. This study examines the short-term effects of the 2022 Bovee Fire on physical, chemical, and biological soil properties in native grasslands and ponderosa pine and eastern redcedar afforested woodlands. …

Impact Of Polystyrene Nanoplastics On Oncogenic Signaling Pathways In Prostate Cells, Luis Alfonso Adel-Alvarez

Open Access Theses & Dissertations

Prostate cancer (PC) remains the most prevalent malignant disease among the male population worldwide, with a dramatic increase observed in the European Union from the 1980s to the 2000s. The etiology of PC is attributed to both hereditary factors and environmental pollutants. Among these, endocrine disruptors and polystyrene nanoparticles (PSNPs) interact with the prostate gland via the circulatory system, inducing intense oxidative stress. This study aims to characterize, for the first time, the pathobiological effects of PSNPs in both non-malignant (RWPE1) and malignant (22RV1) prostate cell lines. The objective was to elucidate the mechanisms by which environmental pollutants, such as …

Enduring Efffects Of Juvenile Fluoxetine Exposure On Serotonin Transporter Expression Within The Hippocampus And Prefrontal Cortex Of Male C57bl/6 Mice, Daniel Eduardo Calvo

Open Access Theses & Dissertations

Prescription rates of fluoxetine, the most dispensed selective serotonin reuptake inhibitor, have been rising among the juvenile population. Since adolescence is a critical developmental period in which the brain undergoes pruning, chronic increases in serotonin levels may lead to long-term neurobiological changes in brain regions responsible for emotional regulation. Thus, using mice as a model system, this thesis evaluated how adolescent fluoxetine exposure (AFE) influences the expression of serotonin transporters (SERT) in the adult hippocampus and prefrontal cortex. To do this, postnatal day (PD)-35 male C57BL/6 mice were administered with fluoxetine (250 mg/l in their drinking water) for 15 consecutive …

Age, Growth, Diet And Reproduction Of African Pompano (Alectis Ciliaris), Clinton J. Moran, Jonathan Tucker, Callie H. Crawford

Biology

Understanding the life history traits of ecologically and economically important fish species is critical for effective management. This study provides the first detailed analysis of age, growth, diet and reproductive characteristics of African pompano (Alectis ciliaris) from the southeastern United States, expanding upon prior work from the Western Arabian Gulf. A total of 54 specimens were collected off the coasts of Georgia and South Carolina when they were available during the 2024 fishing season (May–October). Age was determined via otolith sectioning, and growth was modelled using the von Bertalanffy growth function (L∞ = 96.61 cm, K = 0.689, t0 = …

Fisheries Research Report No. 363 : South-West Freshwater Angling: Estimates Of Participation, Effort And Catch For 2024/25, Claire B. Smallwood, Karina L. Ryan, Eva Lai

Fisheries Research Reports

South-West Freshwater Angling (SWFA) in Western Australia is a licensed fishery primarily targeting the Brown Trout (Salmo trutta) and Rainbow Trout (Oncorhynchus mykiss), which are stocked in selected dams and rivers, as well as the introduced Redfin Perch (Perca fluviatilis) and the native Freshwater Cobbler (Tandanus bostocki). Since 2000/01, annual phone-recall surveys have been undertaken using the SWFA licence database as the sampling frame. This monitoring provides information to understand the fishery and support future management decisions. For the first time, data are reported by basin for different waterbody types (public dams, rivers) as well as for specific key fishing …

Visualizing The Fretboard: Arpeggiated Patterns, Muscle Memory, And Neurocognitive Strategies For The 5-String Electric Bass, Matthew Alexander Woisin

Electronic Theses and Dissertations

Proficient navigation of the 5-string electric bass requires a comprehensive mastery of various techniques and a solid understanding of music theory. This includes a detailed grasp of arpeggios, chord extensions, and the development of deeply ingrained muscle memory for precise execution. This thesis introduces a structured methodology that refines existing fretboard visualization techniques and applies a unique manner of fretboard mapping, offering a more precise framework for comprehending and unlocking the full range of the instrument. By drawing insights from music theory, music education, cognitive science, neuroscience, and technology this approach is achieved by synthesizing research on visual pattern recognition, …

Forage Preference In Two Geographically Co-Occurring Fungus Gardening Ants: A Dietary Dna Approach, Matthew Richards-Perhatch V, Elizabeth Boshers, Matthew Greenwold, Jon N. Seal

Biology Faculty Publications and Presentations

Traditional methods of forage identification are impractical with non-leafcutting fungus gardening ants, making diet-related ecological and life history questions difficult to study. To address this limitation, we utilized dietary DNA metabarcoding on excavated ant fungus gardens to generate forage diversity metrics for the two co-occurring species Trachymyrmex septentrionalis and Mycetomoellerius turrifex. Ten fungus garden samples from each species were collected from a 60x70 m plot in East Texas. Each of the colonies we sampled was paired with a colony from the other species within 3 m of it. Plant forage diversity was assessed with chloroplast trnL primers, and insect frass …

Defining The Causal Contribution Of The Gut Microbiota To Cardiomyopathy Pathogenesis As A Basis For Developing Microbiome-Targeted Therapies, Xu Shi

Department of Food Science and Technology: Dissertations, Theses, and Student Research

Heart failure (HF) is a leading cause of morbidity and mortality worldwide, placing substantial clinical and economic burdens on society. Although advances in therapy have improved patient outcomes, the biological mechanisms that drive HF onset and progression remain incompletely understood. Increasing evidence suggests that the gut microbiota, the trillions of microorganisms residing in the gastrointestinal tract, plays a key role in some forms of heart disease, especially cardiovascular disease. Moreover, gut microbial dysbiosis has been associated with systemic inflammation, metabolic imbalance, and immune dysregulation, all of which contribute to the pathophysiology of HF. Cardiomyopathy, a primary disorder of the heart …

An Integrated Modeling Framework To Evaluate Circularity Of The Corn–Water–Ethanol–Beef Nexus, Heydi Han

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

This dissertation examines the transition from conventional linear agricultural and food bioenergy systems toward more circular, resilient, and resource-efficient configurations. Prior research indicates that spatial and temporal variability in soil, weather, animal biological responses, and management decisions strongly influences productivity, nutrient-use efficiency, and profitability. Studies have also shown that a diversified circular system can buffer these sources of variability, improving stability and adaptive capacity. Building on these insights, the central focus of this work is to develop an integrated modeling framework to evaluate circularity within the Corn-Water-Ethanol-Beef (CWEB) nexus and explore how climate variability and management choices shape system-wide performance. …

Evaluating Fall And Spring Planted Cover Crops For Integrated Management Of Herbicide Resistant Palmer Amaranth And Effect On Soil Health, Vipin Kumar

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

Herbicide-resistant Palmer amaranth (Amaranthus palmeri S. Watson) pose a severe threat to agronomic crop productivity in the United States, including corn and soybean production in Nebraska. Therefore, there is an urgent need for diversified and sustainable management approaches. Integrating cover crops (CCs) with herbicide programs represents a promising strategy to achieve Palmer amaranth suppression, sustain crop yields, and contribute to long-term soil health in irrigated corn–soybean production systems in Nebraska.

A meta-analysis of 41 studies and 595 paired observations demonstrated that CCs reduced Amaranthus spp. density and biomass by 37–59% depending on the growing season, with grasses and mixtures …

Assessing Crop Rotation Productivity, Soil Health, And Fertility, And Economic Performance, To Enhance Semi-Arid High Plains Cropping Systems Sustainability, Ezequiel Maria Villamil

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

Sustainable crop production in the semi-arid High Plains of Nebraska faces challenges from limited precipitation, high interannual variability, and economic risk. This dissertation investigates the long-term productivity, water use, soil health, and economic sustainability of dryland crop rotations, with emphasis on the role of pulses as alternatives to fallow.

Chapter 1 analyzes nearly three decades (1995–2023) of on-farm data from the High Plains Agricultural Laboratory (Sidney, Nebraska) to compare seven crop rotations, including wheat, corn, millet, sunflower, and field peas. Results showed that wheat–corn–fallow (W–C–F) consistently outperformed traditional wheat–fallow (W–F) and more intensified four-year rotations, providing the highest grain yields, …

Development Of Databases For Glycan Utilization And Anti-Prokaryotic Defense In Microbiomes, Yuchen Yan

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

Microbiomes in humans, animals, plants, and other environments are necessary components of the biosphere for global nutrient cycling and maintaining ecosystem balance. In particular, the gut microbiome plays an essential role in modulating human health through glycan utilization. Carbohydrate-active enzymes (CAZymes), CAZyme gene clusters (CGCs), and polysaccharide utilization loci (PULs) are key genomic features that determine microbial capacities for carbohydrate metabolism. Meanwhile, the arms race between phages and prokaryotes has led to the evolution of various anti-prokaryotic immune systems (APIS) in phages to counteract prokaryotic immune systems (PIS).

As bioinformatics methods used to analyze microbiome information advance rapidly, there is …

The Role Of Peroxisomal Acot4 And Acot8 In Modulating Lipid Metabolism And Stress Pathways In Steatotic Hepatocytes, Sylwia Miekus

Department of Nutrition and Health Sciences: Dissertations, Theses, and Student Research

Metabolic dysfunction-associated steatotic liver disease (MASLD) is characterized by excessive lipid accumulation in hepatocytes and the development of lipotoxic stress that disrupts cellular homeostasis. Peroxisomal lipid metabolism plays an important role in maintaining acyl-CoA balance during fatty acid overload, yet the contribution of peroxisomal acyl-CoA thioesterases to early lipotoxic responses remains insufficiently understood. The aim of this study was to investigate the functional involvement of the peroxisomal enzymes acyl-CoA thioesterase 4 (ACOT4) and acyl-CoA thioesterase 8 (ACOT8) in hepatocyte lipid handling under acute lipotoxic conditions. An in vitro model of steatosis was established in AML12 cells through exposure to a …

Characterizing The Relationship Between Parturition In Beef Cattle And The Lunar Phase And Meteorological Factors., Caroline E. Chambers

Honors College Theses

For beef cattle, parturition is one of the most critical stages in the reproductive process. It is crucial that farmers understand the factors that may influence the timing of parturition. There is a persistent preconception that the onset of parturition is influenced by the lunar phase and weather factors. The objective of this study is to characterize the association between parturition in beef cattle, the lunar phase, and/or different weather factors such as barometric pressure and temperature. Cattle records were obtained from Chambers Family Farm in Cumberland Furnace, TN. Data was collected from 142 calvings from January 2017 to October …

Root Analysis Of Glechoma Hederacea, Austin Z. Shiner

Theses/Capstones/Creative Projects

Glechoma hederacea, or commonly referred to as ground ivy, is a weed that can be found in many places such as parks, yards, and landscapes. A mutant genotype of Glechoma hederacea that was exhibiting virescence was collected from a single mutant branch of the wildtype ground ivy. The collected mutant has delayed chloroplast development, and this appears to impact plastidial terpenoid synthesis resulting in damage to leaf tissue. Since a range of plant hormones include isoprene units, altered IPP synthesis may have visible impacts beyond the green tissues of the plant, so this study aimed at addressing this question. …

Exploring Life History Trade-Offs In The Facultative Eusocial Bee Megalopta Genalis, Ana Gutiérrez Zuluaga

All Graduate Theses and Dissertations, Fall 2023 to Present

Organisms face many trade-offs in how to invest in these traits. One example is the trade-off between reproduction and longevity. Queens of social insects seem to escape this trade-off, producing thousands of eggs daily, despite having a longer lifespan than their workers. Some hypotheses have been proposed to explain this phenomenon, such as an evolutionary change in the molecular pathways that regulate queen investment in maintenance, growth, and reproduction. An alternative hypothesis suggests that the tradeoffs are rarely observed in queens due to the extensive resources provided by the help of workers. While these hypotheses have supporting evidence, they have …