Digital Commons Network^™

Practical Recommendations For Mixed Methods Sampling In Psychological Intervention Research: A Mixed Methods Case Study, Analay Perez

College of Education and Human Sciences: Dissertations, Theses, and Student Research

Sampling is integral to the research process and, if not appropriately addressed, can affect the meta-inferences of the mixed methods study. Sampling is also closely related to recruitment, retention, and additional methodological components. Sampling issues are magnified in social and health sciences intervention research due to the temporal placement of data collection and analysis. Limited research has examined sampling based on researchers’ rationales and decision-making across mixed methods psychological intervention research. This study explored this phenomenon to develop and refine a list of practical recommendations for sampling in mixed methods that were tested using content validity.

Using an exploratory sequential …

Examining Potential Trade-Offs Between Pest Management And Pollination To Sunflower Production In Nebraska, Luis Ochoa Cadena

Department of Entomology: Dissertations, Theses, and Student Research

Sunflower (Helianthus annuus) is cultivated for oil and seed production worldwide, and the United States produces 2.5% of the world’s oilseed sunflower primarily grown in the Great Plains. In 2022, oilseed and confectionary U.S. sunflower production increased by 48 and 44%, respectively, compared to last year's records. However, sunflower production can be seriously compromised by insect pests. The red sunflower seed weevil (Smicronyx fulvus LeConte) is considered the most serious pests in North America and causes severe economic damage yearly. On the other hand, native bees contribute substantially to sunflower yield. Currently, insecticide applications are the primary tool to suppress …

Understanding The Factors Affecting Nebraskan Farmers’ And Landowners' Decision To Adopt Precision Agricultural Technologies And Programs, Corrin C. Winter

School of Natural Resources: Dissertations, Theses, and Student Research

Advisors: Andrew Little, Christopher Chizinski

To gain insights into the challenges faced by Nebraska farmers and landowners when adopting precision agriculture technologies, I analyzed data collected from a 2022 survey involving 7,503 participants, consisting of producers and farmland owners from across the state of Nebraska. The primary objective was to provide valuable insights for agencies seeking to improve their precision agriculture and conservation outreach efforts for the benefit of conservation and Nebraskan farmers and landowners. This study aimed to understand key factors influencing adoption behaviors by evaluating the constraints to precision agriculture adoption, assessing the impact of producer and landowner …

Exploring Experimental Design And Multivariate Analysis Techniques For Evaluating Community Structure Of Bacteria In Microbiome Data, Kelsey Karnik

Department of Statistics: Dissertations, Theses, and Student Research

The gut microbiome plays a crucial role in human health, and by working collaboratively with microbiologists, we aim to further our understanding of the human gut and its impact on human health. Promoting a diverse microbiome is emphasized throughout microbiology literature, and involving a statistician in designing experiments to relate gut bacteria and some measured health outcome is crucial for ensuring valid and accurate results. By adopting new experimental design and analysis methods, researchers can begin to gain a deeper understanding of how the genetics of our food affect the composition of taxa within the gut microbiome. This dissertation is …

Adverse Childhood Experiences Among Adolescent Girls In Residential Treatment: Relationship With Trauma Symptoms, Substance Use, And Delinquency, Akemi E. Mii

Department of Psychology: Dissertations, Theses, and Student Research

Adverse childhood experiences (ACEs) refer to negative events during childhood or adolescence including abuse, maltreatment, and exposure to household dysfunction (Kalmakis & Chandler, 2014). ACEs are associated with negative outcomes including mental and behavioral health concerns and offending (Fox et al., 2015). The risk of negative outcomes associated with ACEs increases when an individual experiences polyvictimization (experiencing multiple types of adverse events; Felitti et al., 1998; Finkelhor et al., 2011). A majority of adolescents served by residential treatment programs (RTPs) have experienced polyvictimization (Briggs et al., 2013). Research examining juvenile offending and youth delinquency has focused on boys. Thus, research …

Assessment Of Integrated Nutrient Management Practices On Soil Health And Nitrogen Efficiency In Cropping Systems, María José Oviedo Ventura

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Groundwater quality in Nebraska is threatened by non-point source contributions of nitrate-nitrogen, primarily by agricultural systems. Intensive crop and livestock production that neglects the value of manure in crop fertility plans can contribute to soil degradation and natural resource impairment. The purpose of this study is to evaluate opportunities to improve agricultural nutrient management throughout Nebraska by quantifying opportunities for manure distribution, evaluating soil health implications of organic and inorganic soil amendments, and assessing nutrient management practices focused on reducing nitrate leaching in agricultural soils.

This study described in Chapter 2 provides a spatial illustration of nitrogen and phosphorus balances …

Lunchbox Hydroponics, Stacy A. Adams

Department of Agronomy and Horticulture: Faculty Publications

Growing plants with hydroponics is less complicated than it may appear when the fundamentals of the system are understood. This publication provides instruction on the construction of a simple hydroponic prototype suitable for school or youth education programs. The fundamentals of hydroponics, basic design of a solution system, seed starting, creating a nutrient solution, and plant care are explored through this engaging project. This prototype can successfully be used to grow small edible and herb plants in the classroom or at home.

Assessing Determinants Of Participation In Conservation Programs In The U. S., Manita Ale

Department of Agricultural Economics: Dissertations, Theses, and Student Research

The United States Department of Agriculture (USDA) has implemented conservation programs through Natural Resources Conservation Service (NRCS) and Farm Service Agency (FSA). Conservation Reserve Program (CRP), Conservation Stewardship Program (CSP), and Environmental Quality Incentives Program (EQIP) are some of them. These programs provide financial and technical assistance to farmers and ranchers to adopt land management practices that generate environmental benefits. In this study, we explore the determinants of participation in conservation programs (CRP, CSP, EQIP) in Iowa, Kansas, and Nebraska. For this, we use a unique survey-based data set comprising observations from row crop farmers in these states. We are …

Wild Bee Utilization Of Engineered Pollinator Habitat In Eastern Nebraska Agroecosystems, Shianne Lindsay

Department of Entomology: Dissertations, Theses, and Student Research

Habitat loss is a leading cause of biodiversity decline globally. Further, loss of natural and semi-natural habitat is a major factor contributing to declines in wild pollinator populations. Among intensive agroecosystems in the Midwestern United States, corn, soy, and small grain fields dominate the landscape and leave limited space available for forb-rich habitat that supports diverse pollinator assemblages to exist and thrive. There are numerous barriers and challenges to integrating pollinator habitat into such agroecosystems and quantitative assessments of impacts on pollinator communities are largely lacking. The establishment of high-quality pollinator habitat can provide both high flower abundance and species …

The Perceptions Of Psycap Growth Among College Student Leaders Who Mentor, James Lee

Department of Agricultural Leadership, Education, and Communication: Dissertations, Theses, and Student Research

The purpose of this cross-sectional study is to examine the perceptions of Psychological Capital (PsyCap) growth among college student leaders who mentor. Recent research documented a positive association between mentoring and the mentee’s PsyCap growth, yet little is known about how mentoring impacts the mentor’s PsyCap. Additionally, though PsyCap has been researched considerably in the last decade, little is known about both the antecedents of PsyCap and the social mechanisms that contribute to the growth of PsyCap. This study addresses these gaps and examines the influence of mentoring for leadership development on the mentors’ perceptions of PsyCap growth. There are …

Framework Development For Evaluating The Impacts Of Nursing Home Acoustics On Older Adults, Brian J. Puckett

Durham School of Architectural Engineering and Construction: Dissertations, Theses, and Student Research

Nursing homes are complex, multi-faceted environments which provide necessary medical supervision and housing for older adults in need of long-term care. With cognitive and sensory impairments being common adversities faced throughout the aging process, research is needed to better understand characteristics of the built environment which may contribute to difficulties for nursing home residents. Noise, in particular, has been shown to be problematic for nursing home residents in a variety of ways including disrupting sleep, associating with behavioral and psychological symptoms of dementia, and leading to increased readmission to hospitals due to verbal communication misunderstandings. As the older adult population …

Gender-Neutral Bathrooms On Campus: A Multicampus Study Of Cisgender And Transgender And Gender Diverse College Students, Merle Huff, Katie Edwards, Victoria Mauer, Heather Littleton, Stephanie Lim, Kayla E. Sall

Department of Educational Psychology: Faculty Publications

Objective: This study examined cisgender and transgender and gender diverse (TGD) college students’ perceptions of gender-neutral bathroom availability across eight U.S. campuses, TGD students’ fear of harassment related to (lack of) availability of gender-neutral bathrooms, and the relation between fear of harassment and TGD students’ psychological distress.

Methods: Participants were 4,328 college students (4,195 cisgender, 30 binary transgender, 103 gender diverse) from eight U.S. institutions of higher education.

Results: The majority (84.2%) of TGD students and 34.6% of cisgender students perceived there were too few gender-neutral bathrooms on their campus. Further, TGD students’ fear of harassment related to a lack …

Cooler Forests In Clean Air, Liang Chen

Department of Earth and Atmospheric Sciences: Faculty Publications

Improving air quality by reducing atmospheric aerosols can bring valuable health benefits, but also generally leads to warming. Now, research suggests that in cleaner air the local cooling effect of planting trees may be stronger in middle and low latitude regions.

Forests provide a substantial sink for atmospheric carbon and therefore have great potential for contributing to climate change mitigation globally.¹ Meanwhile, forests play an important role in local and regional climate through their effects on albedo, evapotranspiration, and surface roughness.² The biogeophysical mechanisms driving forest-climate feedback depend strongly on the local background climate. But it remains unclear …

Prairie Protector: Student Development Of Systems Thinking Habits In The Context Of Agroecosystems, Erin Ingram, Jennifer Keshwani

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Introduction: The Great Plains ecosystem offers an opportunity for young people to gain knowledge about intricate systems through practical learning. The spread of woody plants into grasslands, known as the “Green Glacier,” poses a risk to biodiversity and animal production. Although effective management strategies exist, some land managers are reluctant to use them. It is critical to cultivate a scientifically literate population that can think systematically and make informed decisions based on STEM principles to address such complex agroecosystem problems.

Methods: In this study, semi-structured focus group discussions with high school students were analyzed to determine whether Prairie …

Drinking Water Quality Management Progress In Ontario, Two Decades After Walkerton, Megan Fuller, Emma Wells, Laith Furatian, Ian Douglas, Kaycie Lane

Department of Civil and Environmental Engineering: Faculty Publications

Following the waterborne disease outbreak in Walkerton, Ontario, the province made significant efforts to implement recommendations of the public inquiry that resulted. As Ontario reformed its drinking water sector, other jurisdictions were advancing risk-based quality management frameworks for drinking water, including the World Health Organization (WHO) through its water safety plan (WSP) framework. Two decades after the Walkerton tragedy, this paper seeks to: (i) evaluate alignment of Ontario’s Drinking Water Quality Management Standard (DWQMS) with the WSP framework (ii) review readily available data for evidence that Ontario’s DWQMS implementation has improved drinking water safety and promoted a preventive approach through …

Differential Membrane Binding Of Α/Β-Peptide Foldamers: Implications For Cellular Delivery And Mitochondrial Targeting, Tzong-Hsien Lee, James W. Checco, Tess Malcolm, Chelcie H. Eller, Ronald T. Raines, Samuel H. Gellman, Erinna F. Lee, W. Douglas Fairlie, Marie-Isabel Aguilar

Department of Chemistry: Faculty Publications

The intrinsic pathway of apoptosis is regulated by the Bcl-2 family of proteins. Inhibition of the anti-apoptotic members represents a strategy to induce apoptotic cell death in cancer cells. We have measured the membrane binding properties of a series of peptides, including modified α/β-peptides, designed to exhibit enhanced membrane permeability to allow cell entry and improved access for engagement of Bcl-2 family members. The peptide cargo is based on the pro-apoptotic protein Bim, which interacts with all anti-apoptotic proteins to initiate apoptosis. The α/β-peptides contained cyclic β-amino acid residues designed to increase their stability and membrane-permeability. Dual polarisation interferometry was …

Leveraging Eco-Evolutionary Models For Gene Drive Risk Assessment, Matthew A. Combs, Andrew J. Golnar, Justin M. Overcash, Alun L. Lloyd, Keith R. Hayes, David A. O'Brochta, Kim M. Pepin

United States Department of Agriculture Wildlife Services: Staff Publications

Engineered gene drives create potential for both widespread benefits and irreversible harms to ecosystems. CRISPR-based systems of allelic conversion have rapidly accelerated gene drive research across diverse taxa, putting field trials and their necessary risk assessments on the horizon. Dynamic processbased models provide flexible quantitative platforms to predict gene drive outcomes in the context of system-specific ecological and evolutionary features. Here, we synthesize gene drive dynamic modeling studies to highlight research trends, knowledge gaps, and emergent principles, organized around their genetic, demographic, spatial, environmental, and implementation features. We identify the phenomena that most significantly influence model predictions, discuss limitations of …

Identification And Assessment Of Lameness In Sows Through The Utilization Of NuTrack And Gaitfour Systems, Lexi M. Ostrand

Department of Animal Science: Dissertations, Theses, and Student Research

Lameness is a financial concern for producers and a welfare concern for the animals. Utilizing both the GAITFour and NUtrack systems, gilts’ natural tendencies and gait were analyzed to better understand the onset of lameness and what indicators can be identified in a commercial setting. Beginning at 20 weeks of age, video on replacement gilts was collected for 9 consecutive days and processed using the NUtrack System to identify individual gilts’ distance travelled (m), avg speed (m/s), angle rotated (degrees), and time standing (s), sitting (s), eating (s), and laying (s). NUtrack is a deep learning-based multi-object …

Consequences Of Cow–Calf Production With Limited Perennial Forage Grazing, Hannah Fae Speer

Department of Animal Science: Dissertations, Theses, and Student Research

Conversion of perennial grasslands to cropland and rising land prices prompts a need to evaluate alternative beef cow-calf production systems. A 3-yr study was conducted comparing beef cow-calf performance between two August-calving cow systems: perennial forage and corn residue grazing; or summer drylot, fall grazing of late-summer-planted cover crop, and corn residue grazing. Cow body condition score differed between systems, but condition of cows in both systems never fell below adequate. There were no differences in pregnancy rates between systems. Calf weaning weights differed between systems each year; differences are attributed to feedstuff quantity, quality, and type available to calves …

Transcriptional Regulation Of The Synthesis And Secretion Of Farnesol In The Fungus Candida Albicans: Examination Of The Homann Transcription Regulator Knockout Collection, Daniel Gutzmann, Jaxon J. Kramer, Brigid M. Toomey, Cory Honsinger Thomas Boone, Audrey L. Atkin, Kenneth Nickerson

School of Biological Sciences: Faculty Publications

Candida albicans is an efficient colonizer of human gastrointestinal tracts and skin and is an opportunistic pathogen. C. albicans exhibits morphological plasticity, and the ability to switch between yeast and filamentous morphologies is associated with virulence. One regulator of this switch is the quorum sensing molecule farnesol that is produced by C. albicans throughout growth. However, the synthesis, secretion, regulation, and turnover of farnesol are not fully understood. To address this, we used our improved farnesol assay to screen a transcription regulator knockout library for differences in farnesol accumulation in whole cultures, pellets, and supernatants. All screened mutants …

Transcriptional Regulation Of The Synthesis And Secretion Of Farnesol In The Fungus Candida Albicans: Examination Of The Homann Transcription Regulator Knockout Collection, Daniel Gutzmann, Jaxon J. Kramer, Brigid M. Toomey, Cory Honsinger Thomas Boone, Audrey L. Atkin, Kenneth Nickerson

School of Biological Sciences: Faculty Publications

Candida albicans is an efficient colonizer of human gastrointestinal tracts and skin and is an opportunistic pathogen. C. albicans exhibits morphological plasticity, and the ability to switch between yeast and filamentous morphologies is associated with virulence. One regulator of this switch is the quorum sensing molecule farnesol that is produced by C. albicans throughout growth. However, the synthesis, secretion, regulation, and turnover of farnesol are not fully understood. To address this, we used our improved farnesol assay to screen a transcription regulator knockout library for differences in farnesol accumulation in whole cultures, pellets, and supernatants. All screened mutants produced …

Performance Fatigability And Neuromuscular Responses Are Not Joint Angle Specific Following A Sustained Isometric Forearm Flexion Task Anchored To A High Perceptual Intensity In Women, Jocelyn E. Arnett, Robert W. Smith, Tyler J. Neltner, John Paul V. Anders, Dolores G. Ortega, Terry J. Housh, Richard J. Schmidt, Glen O. Johnson

Department of Nutrition and Health Sciences: Faculty Publications

Objectives: To examine the effects of joint angle (JA) on maximal voluntary isometric contractions (MVIC) and neuromuscular responses following a sustained, isometric forearm flexion task anchored to a rating of perceived exertion (RPE) of 8 (RPE=8). Methods: Nine women (age: 20.7±2.9 yrs; height: 168.8±7.2 cm; body mass: 66.3±6.8 kg) performed 2,3s forearm flexion MVICs at JAs of 75°, 100°, and 125° prior to and following a sustained, isometric forearm flexion task anchored to RPE=8 to task failure (torque reduced to zero) at JA100. Electromyographic (EMG) and mechanomyographic (MMG) signals were recorded from the biceps brachii. Results: The …

Beef Color And Tenderness Response To Production Systems Utilizing Additive Combinations Of Growth-Promotant Technologies, Megan J. Webb, Janna J. Block, John R. Jaeger, R. Funston, Michael G. Gonda, Keith R. Underwood, Judson K. Grubbs, Kenneth C. Olson, Amanda D. Blair

West Central Research and Extension Center, North Platte

The objective of this study was to compare the influence of beef production systems using additive combinations of growth-promotant technologies on meat quality. Steer calves (n = 120) were assigned to 1 of 4 treatments: 1) no technology (NT; control), 2) antibiotic treated (ANT; NT plus therapeutic antibiotics, monensin, and tylosin), 3) implant treated (IMP; ANT plus a series of three implants), and 4) beta-agonist treated (BA; IMP plus ractopamine-HCl). Muscle biopsy samples from the longissimus lumborum were extracted from a subset (n = 4 per treatment) of steers to evaluate expression of calpain-1, calpain-2, and calpastatin using …

Critical Factors And Individual Decision Making In Earthquake And Tsunami Preparedness Among Coastal Communities In Oregon U.S.A., Shelley Olds

School of Natural Resources: Dissertations, Theses, and Student Research

Earthquakes and tsunamis are natural hazards that cause considerable loss of life, destruction of property and infrastructure, and economic damage. Preparedness is critical in regions of significant earthquake and tsunami risk. A key challenge for organizations that manage hazard preparedness and response is mobilizing earthquake preparedness among individuals and families. This dissertation provides an examination of individual earthquake and tsunami preparedness from both a global and regional perspective. It comprises two publications that explore various aspects of disaster preparedness.

Chapter One provides an overview of global seismic and tsunami hazards, along with potential impacts, and addresses the challenges in promoting …

Increasing Rye Cover Crop Biomass Production After Corn Residue Removal To Balance Economics And Soil Health, Sabrina J. Ruis, Humberto Blanco-Canqui, Paul J. Jasa, Glen Slater, Richard B. Ferguson

Department of Agronomy and Horticulture: Faculty Publications

Low or variable cover crop (CC) biomass production could limit CC benefits. Longer CC growing periods via late termination could increase CC benefits, especially under limited crop residue return. We studied whether early (2–3 wk before planting)- or late (at planting)-terminated winter rye (Secale cereale L.) CC maintains soil properties, crop yields, and farm income under 0%, 25%, 50%, 75%, and 100% corn (Zea mays L.) residue removal in rainfed and irrigated no-till in the U.S. Great Plains after 6 yr. Early-terminated CCs produced < 1 Mg ha^-1 of biomass while late-terminated CCs averaged 1.6 Mg ha^-1 at the rainfed …

Distribution Of The Soft Tick Carios Vespertilionis In Lowlands And Low Mountain Regions Of Germany, Anja Fritzsche, Stefan Zaenker, Jannis Gottwald, Renate Keil, Christian Zaenker, Michael Bröker, Lidia Chitimia-Dobler

Harold W. Manter Laboratory of Parasitology: Library Materials

In Germany, the knowledge about ticks infesting bats is limited, and is restricted only to a few studies, most of them dating back decades. To further improve our knowledge on ticks parasitising bats, healthy and sick bats in central Germany were examined for ticks. In total 519 larvae and one nymph of Carios vespertilionis were collected from nine bat species: Eptesicus nilssonii, Eptesicus serotinus, Myotis daubentonii, Myotis myotis, Nyctalus leisleri, Pipistrellus nathusii, Pipistrellus pygmaeus, Pipistrellus pipistrellus, and Vespertilio murinus. Either the presence of C. vespertilionis was new for some areas or it was confirmed in some federal states in …

Investigating The Physiological Mechanisms Between Resistance Training And Pain Relief In The Cancer Population: A Literature Review, Yvonne Jiang, Peter C. Angeletti, Amy J. Hoffman

Nebraska Center for Virology: Faculty Publications

This literature review examines the mechanisms of how exercise, specifically in the form of resistance training, may lead to pain relief in the cancer population. Primary data from three different cancer populations: breast, prostate, and lung, will be examined. A number of experimental studies have been conducted to confirm the effectiveness of resistance training on pain relief as well as the biochemical pathways that relate to this process. In this review, we will examine 5 randomized controlled trials. For the purposes of this review, pain is defined as physical suffering or discomfort associated with illness. Pain is the body’s natural …

Nebraska Extension: Supporting The Well-Being Of Farmers And Ranchers, Jessica Groskopf

Cornhusker Economics

Nebraska Extension is a proud member of the North Central Farm and Ranch Stress Assistance Center. A regional center funded by USDA NIFA, it delivers farm and ranch stress and mental health resources and services in 12 states, including Nebraska.

Since 2021, several programs delivered by Nebraska Extension and its partners have been supported with these funds. This article will review the key programs supported in Nebraska.

Harnessing Autoimmunity With Dominant Self-Peptide: Modulating The Sustainability Of Tissue-Preferential Antigen-Specific Tregs By Governing The Binding Stability Via Peptide Flanking Residues, Youwei Lin, Shun Sakuraba, Chandirasegaran Massilamany, Jayagopala Reddy, Yoshimasa Tanaka, Sachiko Miyake, Takashi Yamamura

School of Veterinary and Biomedical Sciences: Faculty Publications

Sensitization to self-peptides induces various immunological responses, from autoimmunity to tumor immunity, depending on the peptide sequence; however, the underlying mechanisms remain unclear, and thus, curative therapeutic options considering immunity balance are limited. Herein, two overlapping dominant peptides of myelin proteolipid protein, PLP136-150 and PLP139-151, which induce different forms of experimental autoimmune encephalomyelitis (EAE), monophasic and relapsing EAE, respectively, were investigated. Mice with monophasic EAE exhibited highly resistant to EAE re-induction with any encephalitogenic peptides, whereas mice with relapsing EAE were susceptible, and progressed, to EAE re-induction. This resistance to relapse and reinduction in monophasic EAE mice was associated with …

Combining Host And Rumen Metagenome Profiling For Selection In Sheep: Prediction Of Methane, Feed Efficiency, Production, And Health Traits, Melanie K. Hess, Larissa Zetouni, Andrew S. Hess, Juliana Budel, Ken G. Dodds, Hannah M. Henry, Rudiger Brauning, Alan F. Mcculloch, Sharon M. Hickey, Patricia L. Johnson, Sara Elmes, Janine Wing, Brooke Bryson, Kevin Knowler, Dianne Hyndman, Hayley Baird, Kathryn M. Mcrae, Arjan Jonker, Peter H. Janssen, John C. Mcewan, Suzanne J. Rowe

Department of Animal Science: Faculty Publications

Background Rumen microbes break down complex dietary carbohydrates into energy sources for the host and are increasingly shown to be a key aspect of animal performance. Host genotypes can be combined with microbial DNA sequencing to predict performance traits or traits related to environmental impact, such as enteric methane emissions. Metagenome profiles were generated from 3139 rumen samples, collected from 1200 dual purpose ewes, using restriction enzyme-reduced representation sequencing (RE-RRS). Phenotypes were available for methane (CH4) and carbon dioxide (CO2) emissions, the ratio of CH4 to CH4 plus CO2 (CH4Ratio), feed efficiency (residual feed intake: RFI), liveweight at the time …