Digital Commons Network^™

Analysis Of Drought-Flood Abrupt Alternation Events And Their Impacts In Kenya, Betty Makena

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

Drought-Flood Abrupt Alternation (DFAA) is a compound disaster event that refers to the abrupt shift of extreme drought events to extreme floods resulting in exacerbated impacts on already vulnerable communities and hindering their coping abilities. This study aimed to analyze drought-flood abrupt alternation events and their impacts in Kenya. The first chapter aimed to understand historical drought events in the Greater Horn of Africa and their impacts, while drawing comparisons with the recent 2020-2022 drought period, referred to as the ‘triple dip La Niña’. Datasets used in this study include the Climate Hazards Group InfraRed Precipitation with Station (CHIRPS), Normalized …

Remotely Sensed Early Warning Of Algal Blooms In An Eastern Nebraska Reservoir: A Comparison Of Temporal And Spatial Indicators, Mercy Kipenda

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

Cyanobacterial harmful algal blooms (CyanoHABs) detrimentally affect human, animal, and ecosystem health. Remotely sensed early warning systems for cyanoHABs in inland lakes could contribute to more proactive water quality monitoring and help mitigate negative impacts. Advances in freely available remote sensing imagery, with finer spatial, temporal, and spectral resolutions, present new opportunities for the development and comparative analysis of methods to detect sudden deterioration in lake water quality. In this thesis, I compared and tested for temporal and spatial early warning signals of cyanoHABs in field-based and remotely sensed datasets from 2019 to 2023 in Pawnee Lake in southeast Nebraska, …

Impacts Of Invasive Carp And Their Population Dynamics On Fish Communities In The Missouri River, Joshua F. Kocik

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

Invasive Carp species: Silver Carp Hypophthalmichthys molitrix, Bighead Carp Hypophthalmichthys nobilis, Grass Carp Ctenopharyngodon idella, and Black Carp Mylopharyngodon piceus have both potential and realized abilities to negatively impact native species. Specifically, Bighead Carp and Silver Carp as filter feeders have been theorized to be detrimental not only to adult filter-feeding species, but to many fish which rely on plankton and algae in their early-life stages. The impact of Invasive Carp on the overall fish community remains underexplored. The fish communities below Gavins Point Dam (Invasive Carp present) and Fort Randall Dam (Invasive Carp absent) afford the …

Spatiotemporal Plasticity In Reproductive Readiness And Recruitment Of Ichthyoplankton Of Invasive Silver Carp Along A Western Invasion Front, Jessi L. Urichich

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

Individuals of invasive species at the edge of their invasion distribution may exhibit enhanced reproductive capacity and phenotypic plasticity leading to accelerated range expansion. Environmental conditions in highly fluctuating environments at distribution edges may either promote or hinder such reproductive readiness and phenotypic plasticity. Dynamic habitat conditions and periodic disturbances experienced in prairie streams, such as drought (e.g., low-flow, high water temperatures), may potentially reduce suitable spawning environments and ichthyoplankton recruitment of invasive Silver Carp, potentially slowing range expansion or enabling management strategies that reduce abundance in the absence of a reproducing population. Female Silver Carp batch fecundity, Gonadosomatic Index …

Assessing, Restoring, And Centering Social–Ecological Relationships For Advancing Social–Ecological Resilience In The Northern Great Plains Grasslands, Katia Pilar Carranza Bernal

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

The Northern Great Plains grasslands are social-ecological systems that were shaped by evolutionary and Indigenous social-ecological relationships. European colonization disrupted many of these interactions, including the coupling of fire and grazing, and degraded social-ecological resilience, shifting these grasslands to a new state. For those reasons, my research focused on assessing, restoring, and centering evolutionary and Indigenous social-ecological relationships for advancing social-ecological resilience in the Northern Great Plains grasslands. I first performed a study in the Nebraska Sandhillls assessing the potential of patch-burn grazing to support grassland resilience by comparing its effects to those of rotational grazing. Through vegetation and bird …

We're Swarming Again! Swarming, Collectivity, And Trope: The Case Of Extinction Rebellion, Tyler J. Behymer

Department of Communication Studies: Dissertations, Theses, and Student Research

This thesis explores the rhetoric of the eco-movement Extinction Rebellion, focusing on the use of swarming and nature tropes to mobilize collective action and revivify contemporary notions of collectivity. Drawing on rhetoric of social movement scholarship, cultural studies, and psychoanalysis, this essay theorizes swarming as a tropological economy that expands the conditions of propriety in the context of collectivity. Through an analysis of Extinction Rebellion’s discourse, this study demonstrates how the naturalization of swarming tropes works in various ways to rewild conventional political discourse, galvanize disruptive collective assembly, and challenge green neoliberalism.

Advisor: Casey Ryan Kelly

Integration Of Matlab And Machine Learning To Accelerate Evaluation Of Biological Activity In Agricultural Soils And Promote Soil Health Improvement Goals, Andrew Stiven Ortiz Balsero

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

Traditionally, assessments of soil biological activity have been confined to laboratory settings, creating a disconnect with practical in-field methods. To bridge this gap, cotton fabric degradation has been used to illustrate soil microbial activity under different management practices. While effective, these demonstrations are subjective and labor-intensive.

Researchers have explored using image processing software like ImageJ and Adobe Photoshop to streamline this process. Although these tools accurately quantified fabric degradation under varying soil conditions, the methods remained labor-intensive and complex. Consequently, these methods were still not ideal for on-farm use by agricultural practitioners.

To further address labor and complexity limitations, the …

Linking Risk Preference, Women’S Empowerment, Farm Investment And Household Well-Being, Samuel Olusesi Olumide

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

A nuanced understanding of intra-household dynamics can inform the design of more effective empowerment and agricultural investment policies. By integrating household risk preferences and empowerment dynamics, this work offers valuable insights into the complex mechanisms driving household welfare and provides a framework for future interventions to promote gender equality and economic development in rural settings. This thesis addresses three core hypotheses: first, that the spouses of risk-seeking male heads are more likely to be disempowered compared to those of risk-averse male heads; second, that households with risk-seeking male heads and disempowered spouses are likely to invest more in farming activities; …

Preschool Executive Control And Adolescent Dietary Outcomes: Highlighting The Role Of Context, Marla Lopez

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

Research has identified executive control (EC) as an important predictor of dietary outcomes among youth. Executive control in preschool age has been shown to predict important outcomes across development for youth, indicating that good, foundational EC abilities are associated with successful development in later life. Dietary outcomes across adolescence, an important transitional period for establishing healthy eating behaviors, are understudied. Therefore, the current study sought to link two critical developmental periods, examining how preschool EC is associated with dietary trajectories across adolescence. Further, the study aimed to identify how contextual factors, specifically indices of socio-economic status and the home and …

Applications Of Artificial Intelligence On Drought Impact Monitoring And Assessment, Beichen Zhang

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

Drought, a prevalent and consequential natural disaster, poses widespread, indirect challenges across environmental and societal dimensions. Despite considerable focus on monitoring meteorological and hydrological drought and studying their characteristics, there is a gap in assessing its multifaceted impacts, especially on societal sectors. The dissertation comprises three research essays utilizing artificial intelligence to quantitatively study multi-dimensional drought impacts. The first essay leveraged deep learning and natural language processing to predict multi-dimensional drought impacts from textual datasets, including social media, news media, and citizen scientist reports. The findings demonstrate superior performance over traditional methods and unveil the spatial and temporal heterogeneity of …

Investigating Associations Between Activity And Performance Traits Across Three Breeds Of Swine Using NuTrack, Dalton R. Obermier

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

Feed costs are the largest contributor towards the variable costs of pork production. To decrease feed cost while not sacrificing output requires an improvement in feed efficiency (FE). A potential approach to expand available phenotypes associated with FE is with activity tracking, yet the relationship between activity and performance is not well defined in swine. Therefore, the objective of this study was to quantify associations between activity and feed intake traits. Average daily feed intake (ADFI) was collected on 1,766 purebred boars of three genetic lines (Duroc, Landrace, and Yorkshire) using FIRE (Osborne Industries, Inc., Osborne, Kansas) at a testing …

Essays On Education And Labor Market Outcomes, Ishita Ahmed

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

This dissertation focuses on the labor market or educational outcomes using applied microeconomic methods. Chapter 1 investigates the impact of waiting an additional year to start kindergarten on the socioeconomic achievement gap in Nebraska using longitudinal administrative data from the Nebraska Department of Education. I utilize fuzzy regression discontinuity design to find the effect of waiting on test scores. I find waiting a year to improve the test score, and this impact fades away over time. This fading pattern shows a considerable amount of heterogeneity across different demographic groups, suggesting an acceleration of the achievement gap. The study also investigates …

"Huddled Masses:" The Immigration Act Of 1917 In Habeas Corpus, Chikamso Chijioke

Digital Legal Research Lab

Research poster titled "Huddled Masses:" The Immigration Act of 1917 in Habeas Corpus; presented via the Digital Legal Research Lab NSF REU Site, University of Nebraska–Lincoln, August 2024.

Introduction

Dr. Jagodinsky's Petitioning for Freedom is a collection of habeas corpus petitions in the American West and examines marginalized peoples’ use of habeas to challenge detention. This project explores the role of the Immigration Act of 1917 in these cases. The Immigration Act of 1917, passed due to xenophobic tensions surrounding WWI, restricted immigration of people from Asia and the Pacific while implementing an English literacy test for those over 16 …

Candida Albicans Farnesol Synthesis And Secretion, Daniel J. Gutzmann

School of Biological Sciences: Dissertations, Theses, and Student Research

Candida albicans is a polymorphic fungus and opportunistic commensal found primarily in the gastrointestinal and skin of healthy individuals. Several barriers prevent C. albicans from causing disease including a healthy immune system and microbiome. When these barriers become comprised, C. albicans can transition to a pathogen and disseminate through the intestinal mucosa leading to life-threatening bloodstream and invasive infections with mortality rates of up to 64%. Morphogenic plasticity is key to this transition and impacts virulence, adaptation to different host environments, and evasion of host immune responses. One regulator of morphogenesis is farnesol. Farnesol is a secondary metabolite of …

Praying To Tiktok, Seeking The Self: How Rhetoric Reveals And Conceals The World’S Most Powerful Guru Of The Postindustrial Age, Samantha L. Gillespie-Hoffman

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

Imagine a world where the most powerful leader is a wellness guru that runs an elaborate church with millions of followers. The guru is so powerful that everyone believes they can read minds and make ordinary people rich and famous. The guru controls forms of communication, media channels, consumer tastes, and what people eat, drink, say, and even think. What if this guru was not human but actually an algorithm? Does this sound like the plot of a science fiction novel? I argue that this scenario is closer to reality than most will admit. In this project, readers encounter a …

Developing A Comprehensive Genome-Scale Metabolic Model For The Arabidopsis Thaliana Root System, Lohani Esterhuizen

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

Arabidopsis thaliana (Arabidopsis) is the most well-established model plant to date. Being the first plant to have its genome mapped, studies on Arabidopsis have provided insurmountable insights into the physiological and biochemical nature of plants. Methods that allow us to computationally study the metabolism of organisms include the use of genome-scale metabolic models (GEMs). Despite its popularity, no GEM currently maps the metabolic activity in the root system of Arabidopsis, which is the first organ to face and respond to stress conditions in the soil. This work aims to develop and implement a comprehensive GEM of the Arabidopsis root system …

Smart Automatic Modal Hammer Predictor–Corrector Approach For Accurate Excitation Of Dynamical Systems, Mohammad Nasr

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

This research introduces an innovative solution that revolutionizes the study of linear and nonlinear dynamical systems—a smart automatic modal hammer. With its affordability and intelligent capabilities, this automatic modal hammer becomes an invaluable tool for research and industry, enabling repeatable strikes with precise force control. This system's significance becomes particularly evident when studying nonlinear systems, which heavily rely on the excitation level for their dynamics. By offering a cost-effective design this proposed system proves to be robust in accelerating research on nonlinear dynamics, providing researchers with an efficient and accessible means to delve deeper into these complex systems. The proposed …

Studies Of Exotic Electronic, Optical, And Electrochemical Properties In Nanoparticle Assembly And Graphene, Jay Min Lim

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

It is well known that exotic properties and phenomena emerge as structural dimensions shrink to nanoscales. We self-assembled one-dimensional chains of gold nanoparticles in solution and quantified the growth process by monitoring the redshift of localized surface plasmon resonance (LSPR). Curiously, the redshift stopped while the chains continued to rearrange as manifested by gradual reduction in the LSPR peak. Using electromagnetic simulations, we quantitatively explained the phenomena as a rapid “addition-polymerization” followed by a sharp transition to “condensation-process.” Next, recognizing the significant electric field enhancement in the interparticle gap, a photoluminescent-active Eu³⁺ ion was used to probe Surface-Enhanced Photoluminescence …

Understanding The Role Of The Microbiome In Infectious Disease, Developing Surveillance Tools, And Engineering Direct Fed Microbials To Improve Animal Health, Alison Clare (Bartenslager) Neujahr

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

With the ever-increasing demand for animal protein and the continual need for the assurance of proper animal welfare, investigations of preventative strategies for diseases is greatly needed. Specifically in the cattle industry, infectious bovine keratoconjunctivitis (IBK), commonly known as pinkeye, causes a large economic loss to the producer. However, effective mitigation strategies are lacking. Partly, this is due to the lack of studies investigating the ocular microbiome. Therefore, studies investigating the bovine ocular microbiome are greatly needed to better understand IBK disease etiology. To this end, we investigated the changes in the ocular microbiome in animals before, during and after …

Candida Albicans Farnesol Synthesis And Secretion, Daniel John Gutzmann

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

Candida albicans is a polymorphic fungus and opportunistic commensal found primarily in the gastrointestinal and skin of healthy individuals. Several barriers prevent C. albicans from causing disease including a healthy immune system and microbiome. When these barriers become comprised, C. albicans can transition to a pathogen and disseminate through the intestinal mucosa leading to life-threatening bloodstream and invasive infections with mortality rates of up to 64%. Morphogenic plasticity is key to this transition and impacts virulence, adaptation to different host environments, and evasion of host immune responses. One regulator of morphogenesis is farnesol. Farnesol is a secondary metabolite …

Information About Honey Fraud: Implications Of Information Choice For Consumer Behavior, Christopher R. Gustafson

Cornhusker Economics

The study highlights that standard research practice—exposing participants to information—may not capture what will happen outside of the lab when people have a choice about what to read, view, or do with their time. While we found that having participants read about honey fraud significantly shifted their willingness to pay for local and domestic versus imported honey, we did not find those changes when people were able to select a text to read.

The implications of these findings extend beyond the issue of honey fraud to broader contexts of food safety, nutrition, and production techniques. While people have preferences for …

Reviving Trade Justice: How Arbitration Is Saving Wto Dispute Resolution (For Now), Christine Mcdaniel

Yeutter Institute International Trade Policy Review

Yeutter Institute Non-Resident Fellow Christine McDaniel provides her thoughts about how arbitration is saving World Trade Organization dispute resolution for the time being. She suggests that the dispute mechanism and the appeal process are not fully functioning, although a temporary solution has emerged, namely, arbitration and a speedy appeals process. She covers recent cases and options facing WTO members who have a complaint.

Integrated Multi-Omics Analysis Of Cerebrospinal Fluid In Postoperative Delirium, Bridget A. Tripp, Simon T. Dillon, Min Yuan, John M. Asara, Sarinnapha M. Vasunilashorn, Tamara G. Fong, Sharon K. Inouye, Long H. Ngo, Edward R. Marcantonio, Zhongcong Xie, Towia A. Libermann, Hasan H. Otu

Department of Electrical and Computer Engineering: Faculty Publications

Preoperative risk biomarkers for delirium may aid in identifying high-risk patients and developing intervention therapies, which would minimize the health and economic burden of postoperative delirium. Previous studies have typically used single omics approaches to identify such biomarkers. Preoperative cerebrospinal fluid (CSF) from the Healthier Postoperative Recovery study of adults ≥ 63 years old undergoing elective major orthopedic surgery was used in a matched pair delirium case–no delirium control design. We performed metabolomics and lipidomics, which were combined with our previously reported proteomics results on the same samples. Differential expression, clustering, classification, and systems biology analyses were applied to individual …

Aposematic-Habitat Correlation In Nearctic Species Of Episyron Schiødte (Hymenoptera: Pompilidae: Pompilinae: Pompilini), Frank E. Kurczewski

Insecta Mundi

Three Nearctic species of Episyron Schiødte (Hymenoptera: Pompilidae: Pompilinae: Pompilini) were examined morphologically, geographically, and ecologically with intent to infer an aposematic correlation with habitat type, protarsal digging rake morphology, and host spider association. Episyron quinquenotatus quinquenotatus (Say) and E. conterminus cressoni (Dewitz), two subspecies with extensive aposematic markings and more and longer protarsal comb spines, were associated with bare or sparsely vegetated sandy soils near water courses. Episyron biguttatus biguttatus (Fabricius), with few aposematic markings and less and shorter protarsal comb spines, was associated with more densely vegetated terrain and gravelly and loamy soils. Three subspecies of Anoplius …

An Analysis Of The Genus Aleyrodes Latreille (Hemiptera: Sternorrhyncha: Aleyrodidae) In California, With Three Synonymies, Natalia Von Ellenrieder, Raymond J. Gill

Insecta Mundi

Abstract

Based on the examination of an extensive series of specimens and available type material, three out of the six species of Aleyrodes Latreille (Hemiptera: Sternorrhyncha: Aleyrodidae) described from California, A. diasemus Bemis, 1904, A. essigi Penny, 1922, and A. osmaroniae Sampson, 1945, are newly synonymized under A. spiraeoides Quaintance, 1900. The species of Aleyrodes reported from California are keyed and diagnosed based on characters from puparia and male genitalia, and character variability is documented and illustrated.

Resumen

Basado en el examen de una extensa serie de especímenes y material tipo disponible, tres de las seis …

Revision Of Trachyderines Related To Sphaenothecus From North America With Description Of Three New Genera, And New Species Of Lophalia Casey, 1912, Mannophorus Leconte, 1854, And Ischnocnemis Thomson, 1864 (Coleoptera: Cerambycidae: Cerambycinae: Trachyderini), Bryan K. Eya

Insecta Mundi

The genera Lophalia Casey, 1912, Mannophorus LeConte, 1854 and Ischnocnemis Thomas, 1864 (Coleoptera: Cerambycidae: Cerambycinae: Trachyderini) are recharacterized by providing additional morphological features to enhance the delineation of these genera. Two species, Lophalia cribricollis Bates, 1892 and Ischnocnemis luteicollis (Bates, 1885), are transferred to a new genus Lophaliamorpha Eya with Lophaliamorpha luteicollis (Bates) new combination as the type species. Ischnocnemis skillmani Chemsak and Hovore, 2010 is transferred to a new genus Paramannophorus Eya with Paramannophorus skillmani (Chemsak and Hovore) new combination as the type species. A new genus Microteroschema is created to accommodate two additional species from Mexico: Microteroschema parvum …

A New Species Of Gaindaphodius Král And Mencl From Nepal (Coleoptera: Scarabaeidae: Aphodiinae), Stefano Ziani

Insecta Mundi

A new species from Nepal, Gaindaphodius marigold (Coleoptera: Scarabaeidae: Aphodiinae), is described, illustrated and compared with G. gainda Král and Mencl, 2024, the only other species in the genus Gaindaphodius Král and Mencl, 2024.

Three Essays In Food Security And The U.S. Sugar Program, Jacob Michels

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

Chapter one devises an approach to adjust estimates of the number of food insecure for changes in sedentarism over time. Existing methodologies are biased upwards and date back several decades. We build a household model utilizing a Stone-Geary utility function, which rationalizes households shifting their labor decisions towards sedentary activities. Our comparative statics examine the impacts of changes in the productivities of sedentary types, as opposed to my physically demanding types, of activities and also their returns. Our empirical approach is informed by our theoretical model and comparative statics, in which we construct a unique pseudo-panel dataset. Sitting time serves …

Effect Of Beef Heifer Development Systems Utilizing Corn Residue And Late Summer Planted Cover Crops On Growth, Reproductive Performance, And Economics, Hannah F. Speer, Robert A. Cushman, Harvey Freetly, Jay Parsons, Jessica Windh, M. E. Drewnoski

Department of Agricultural Economics: Faculty Publications

The objective of this study was to evaluate growth and reproductive performance of heifers developed using 3 different winter systems in the midwestern U.S. Spring-born heifers (n = 1,156; 214 d of age; SD ± 17 d) were used in a 3-yr study to evaluate performance in winter development systems, which utilized cover crop (CC) and corn residue grazing. Heifers were assigned to 1 of 3 treatments: grazing corn residue with 0.77 kg/d dried distillers grains (CD) or 1.69 kg/d wheat midds (CW) supplementation followed by a grower ration in the drylot, or grazing late summer planted oat-brassica CC followed …

Exploring Chilling Stress And Recovery Dynamics In C4 Perennial Grass Of Miscanthus Sinensis, Karolina Sobańska, Monika Mokrzycka, Martyna Przewoźnik, Tomasz Pniewski, Katarzyna Glowacka

Department of Biochemistry: Faculty Publications

The increasing cultivation of perennial C4 grass known as Miscanthus spp. for biomass production holds promise as a sustainable source of renewable energy. Unlike the sterile triploid hybrid of M. × giganteus, which cannot reproduce through seeds, M. sinensis possesses attributes that could potentially address these limitations by effectively establishing itself through seed propagation. This study aimed to investigate how 18 genotypes of M. sinensis respond to chilling stress and subsequent recovery. Various traits were measured, including growth and biomass yield, the rate of leaf elongation, and a variety of chlorophyll fluorescence parameters, as well as chlorophyll …