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A Descriptive Study Of Wild Bees (Hymenoptera: Apoidea: Apiformes) And Angiosperms In A Tallgrass Prairie Corridor Of Southeastern Nebraska, Katie Lamke

Department of Entomology: Dissertations, Theses, and Student Research

The presence of diverse bee communities in an ecosystem is vital for maintaining healthy plant communities, promoting habitat resilience, and supporting sustainable agricultural production and urbanization. Approximately 20,000 known species of bees exist worldwide and assist with the successful reproduction of nearly 80% of Earth’s flowering plants by providing pollination services. In the US, wild bee declines have led to increased monitoring efforts for bees but there remain critical data gaps in prairies of the Great Plains ecoregion. Specific to the Tallgrass prairie where only 1-3% remains in native vegetation, the Nebraska Wildlife Action Plan has identified the loss of …

Encapsulation Of Astaxanthin-Enriched Camelina Seed Oil Obtained By Ethanol-Modified Supercritical Carbon Dioxide Extraction, Liyang Xie

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

Astaxanthin is a high-value carotenoid widely used in the food, feed, nutraceutical, and pharmaceutical industries. Natural sources of astaxanthin are preferable to synthetic sources. However, current sources of natural astaxanthin are limited and fall short of global demand. In addition, effective extraction and stabilization strategies are needed before the utilization of natural astaxanthin in food applications. This work investigated 1) the feasibility of ethanol-modified supercritical carbon dioxide (SC-CO2) extraction of astaxanthin from engineered camelina seed, a potential source of natural astaxanthin, and 2) the potential of an emulsion-based system to protect astaxanthin after extraction. The physical properties of the emulsion …

Density And Mass Effect On The Development Of Phormia Regina, Brandon H. Strauss

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

Forensic entomology is the application of the study of arthropods to the criminal justice system. This is primarily done through the development of a post mortem interval (PMI) based the insect evidence present. A practitioner must be able to determine the age of the insect through temperature data. One factor influencing the temperature dependent development is gregarious behavior. Current literature describes a faster development rate due to an increase in feeding efficiency and temperatures produced by this aggregate. However, there is very little literature defining a minimum number needed to induce this effect and little to none on it for …

Detection Of Heteroplasmic Single Nucleotide Polymorphisms Using Melt Curve Analysis And Dual Labeled Fluorescent Probes, Emily Jezewski

Honors Program: Senior Projects (Public)

Plant mitochondrial genomes are strange – they are unusually large, consist of huge amounts of non-coding DNA, and contain of several overlapping regions throughout the genome. The genome is made of several different sized linear and circular molecules and different mitochondria within a cell will have different pieces of the genome. Even if multiple mitochondria contain the same region of the genome, these sequences can differ by single nucleotide polymorphisms (SNPS). This is known as heteroplasmy. Heteroplasmy has been documented in Arabidopsis thaliana using whole-genome sequencing data. While heteroplasmy is well-documented, its existence in the mitochondrial genome is unexpected and …

Development Of Nanomaterial Supports For The Study Of Affinity-Based Analytes Using Ultra-Thin Layer Chromatography, Allegra Pekarek

Department of Chemistry: Dissertations, Theses, and Student Research

Ultra-thin layer chromatography (UTLC) is a growing field in analytical separations. UTLC is a branch of planar and liquid chromatography that is related to thin layer chromatography. The main advantage of UTLC compared to other techniques is it uses much less material, allowing for faster and more sensitive separations to take place. The UTLC devices fabricated in this project used either silicon oxide or silicon nanopillars deposited on a glass slide using glancing angle deposition (GLAD). Even a thin layer of these nanopillars deposited on a glass slide provide a large surface area for the analyte to be separated. GLAD …

Analysis Of Drug–Protein Interactions During Diabetes By High-Performance Affinity Chromatography, Pingyang Tao

Department of Chemistry: Dissertations, Theses, and Student Research

High-performance affinity chromatography (HPAC) is a type of liquid chromatography in which solutes are separated based on their binding to a stationary phase that is a biologically-related agent. Sulfonylurea drugs have significant binding to proteins in blood, with most of this binding is believed to occur with human serum albumin (HSA). HSA is known to be modified as a result of the high serum levels of glucose that is present during diabetes, which may also alter the function of HSA as a binding agent for many drugs in circulation. Some modifications of HSA that can occur during diabetes involves early …

Ultrashort Cross-Correlation In The Middle Infrared: A Novel Approach To Standoff Detection, William Conner Thomas

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Lasers are a common tool in standoff detection because of their small divergence, large amount of power, and multiple wavelengths available for optical interaction. Optical signatures of targets can be composed of but are not limited to absorption, fluorescence, backscatter, polarization manipulation, and plasma spectra. This work was an investigation of a new signature phenomenon: Dispersion of middle infrared ultrashort laser pulses through gas and vapor phase molecules. Vibrational and rovibrational absorption lines of molecular species affect the spectral phase and spectral amplitude of ultrashort light pulses leading an inititally gaussian temporal profile to become distorted. This dissertation is an …

Modeling And Economic Analysis Of A Crop–Livestock Production System Incorporating Cereal Rye As A Forage, Eric R. Coufal

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

This thesis consists of two chapters using agent-based modeling for a crop-livestock production system incorporating human labor. The first chapter examines the principles used to develop a fundamental simulation pertaining to grazing cereal rye (Secale cereal L.) with calves. Within the software guidelines, the base model has the ability to capture diverse system interactions between livestock/plants and land management with human labor efficiency. AnyLogic incorporates agent-based modeling while combining with discrete event modeling and system dynamics. The purpose of the model was to find the economic returns of grazing cover crops relative to the area of Mead, Nebraska. In …

Field Obstacle Identification For Autonomous Tractor Applications, Caleb Lindhorst

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

New technologies are being developed to meet the growing demand for agricultural products. Autonomous tractors are one of the many solutions to address this demand. Obstacle detection and avoidance is an important consideration for safe operation of any autonomous machine. Three field obstacles were chosen to be identified in this thesis work: tractors, round bales, and center pivots. Limited research work was found on the identification of center pivot detection.

Feasibility of using low cost LIDARs was considered for the detection of tractors, bales, and agricultural center pivots. Performance of LIDARs in different lighting conditions, different colors of obstacles, accuracy …

Long-Term Use Of Antibiotics And Risk Of Colorectal Adenoma, Yin Cao, Kana Wu, Raaj Mehta, David A. Drew, Mingyang Song, Paul Lochhead, Long H. Nguyen, Jacques Izard, Charles S. Fuchs, Wendy S. Garrett, Curtis Huttenhower, Shuji Ogino, Edward L. Giovannucci, Andrew T. Chan

Department of Food Science and Technology: Faculty Publications

Objective: Recent evidence suggests that antibiotic use, which alters the gut microbiome, is associated with an increased risk of colorectal cancer. However, the association between antibiotic use and risk of colorectal adenoma, the precursor for the majority of colorectal cancers, has not been investigated.

Design: We prospectively evaluated the association between antibiotic use at age 20–39 and 40–59 (assessed in 2004) and recent antibiotic use (assessed in 2008) with risk of subsequent colorectal adenoma among 16,642 women aged ≥ 60 enrolled in the Nurses’ Health Study who underwent at least one colonoscopy through 2010. We used multivariate logistic …

The Ecological Niche Of Echinococcus Multilocularis In North America: Understanding Biotic And Abiotic Determinants Of Parasite Distribution With New Records In New Mexico And Maryland, United States, Sebastian Botero-Cañola, Altangerel Tsogtsaikhan Dursahinhan, Sara E. Rácz, Parker V. Lowe, John E. Ubelaker, Scott Lyell Gardner

Scott L. Gardner Publications

English abstract: Understanding the factors shaping the niche of parasites and its expression over geographical space and through time continues to be a modern scientific challenge with the results of research in this area directly influencing both theoretical and applied biology. This is especially important for proactive management of zoonotic parasites such as Echinococcus multilocularis, the etiologic agent of alveolar echinococcosis. Echinococcus multilocularis has a Holarctic distribution; with its geographic range and prevalence increasing recently in areas of the western Palearctic, while its distribution dynamics are poorly understood in the Nearctic. In this paper, we use an ecological niche …

Wheat Strip Effects On Microbial Transport Following Variable Applications Of Beef Cattle Manure, Lisa M. Durso, John E. Gilley, David B. Marx, Chance A. Thayer, Bryan L. Woodbury

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Vegetative filter strips (VFS) consisting of perennial vegetation have been successfully used to reduce the transport of contaminants in runoff from land application areas. The effectiveness of a winter wheat strip, which may be more acceptable to producers, in reducing microbial transport was examined in this study. A 1.4 m wheat strip was used to allow direct comparison with experimental results obtained in previous studies. Beef cattle manure was applied to 0.75 m wide by 4.0 m long plots established on an Aksarben silty clay loam located in southeast Nebraska. Manure was added at rates required to meet the 0- …

Nutrient Management Suggestions For Corn, Charles A. Shapiro, Richard Ferguson, Charles S. Wortmann, Bijesh Maharjan, Brian T. Krienke

Department of Agronomy and Horticulture: Faculty Publications

Fertilizer nutrient requirements for corn are based on expected yield and soil nutrient availability. The preplant nitrogen (N) recommendation equation, with adjustment for fertilizer cost and time of application, is retained from the previous edition of this publication. Suggestions for in-season nitrogen decisions are briefly outlined. The major change is providing a phosphorus (P) recommendation based on yield history with an implied intent to build and maintain soil test P above the critical level, which has not changed.

Plant Mitochondrial Genome Evolution And Structure Has Been Shaped By Double-Strand Break Repair And Recombination, Emily Wynn

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

Plant mitochondrial genomes are large but contain a small number of genes. These genes have very low mutation rates, but genomes rearrange and expand at significant rates. We propose that much of the apparent complexity of plant mitochondrial genomes can be explained by the interactions of double-strand break repair, recombination, and selection. One possible explanation for the disparity between the low mutation rates of genes and the high divergence of non-genes is that synonymous mutations in genes are not truly neutral. In some species, rps14 has been duplicated in the nucleus, allowing the mitochondrial copy to become a pseudogene. By …

Regulation Of Vaccinia Virus Replication: A Story Of Viral Mimicry And A Novel Antagonistic Relationship Between Vaccinia Kinase And Pseudokinase, Annabel T. Olson

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

Poxviruses employ sophisticated signaling pathways that thwart cellular defense mechanisms and simultaneously ensure viral factors are modulated properly. Yet, our understanding of these complex signaling networks are incomplete. For example, the vaccinia B1 kinase plays a vital role in inactivating the cellular antiviral factor BAF, and is suggested to orchestrate other pathways. B1 is highly conserved among poxviruses and exhibits a remarkable degree of similarity to VRKs, a family of cellular kinases, suggesting that the viral enzyme has evolved to mimic VRK activity. Indeed, B1 and VRKs have been demonstrated to target a shared substrate, the DNA binding protein BAF, …

The Effects Of Butyric Acid On Performance Parameters, Egg Quality And Nutrient Utilization In Young White Leghorn Hens, Dani-El Ruth Hanna

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

The objective of this study was to evaluate the effects of Prophorce butyric acid on the performance of White Leghorn laying hens. Hens (180) were placed in 60 conventional cages (3 hens/cage) using a completely randomized design with 30 replicate cages per treatment allowing 722.58cm²/hen. Hens were given the control or butyric acid. The trial spanned 40 weeks (35 weeks old at the start). Water was given ad libitum and hens were fed 110g/day. Egg production and mortality were recorded daily. Egg shell strength, weight, and mass were recorded biweekly; hen weights and egg components were measured monthly; …

The Effect Of Threat On Preferences For Male Versus Female Candidates, Marley Sandberg

Honors Program: Senior Projects (Public)

In the United States, there is a continuing question of why the political bodies of the government, (i.e. the Senate and the House of Representatives) lack descriptive representation for women (Paxton, Kunovich & Hughes, 2007). We have seen a growing body of research that tries to explain this lack of female politicians. While many explanations have been found that partially explain this, such as incumbent status favoring men, and fewer political role models for women (Paxton, Kunovich & Hughes, 2007), there still has been no definitive answer. There is reason to believe that threat may play a role in a …

Expanded Phenotypic Diagnoses For 24 Recently Named New Taxa Of Hesperiidae (Lepidoptera), Nick V. Grishin

The Taxonomic Report of the International Lepidoptera Survey

Expanded diagnoses by phenotypic characters for the 24 new taxa named in the article "Genomes of skipper butterflies reveal extensive convergence of wing patterns" by Li, W., Cong, Q., Shen, J., Zhang, J., Hallwachs, W., Janzen, D.H. and Grishin, N.V., 2019 and published in the Proceedings of the National Academy of Sciences of the United States of America on March 15, 2019 are provided and illustrated. More detailed diagnoses will help identifying these phylogenetic groups by their wing patterns and shapes and other morphological characters including the structures of antennae and genitalia using this single publication, instead of obtaining the …

Descriptions Of One New Genus And Seven New Species Of Rhinotragini (Coleoptera: Cerambycidae: Cerambycinae), James E. Wappes, Antonio Santos-Silva

Insecta Mundi

Descriptions of a new genus, Giesberticus Wappes and Santos-Silva, and seven new species in the Rhinotragini (Coleoptera: Cerambycidae: Cerambycinae) are included: Oxylymma soniae Wappes and Santos-Silva, from Bolivia; O. surinamensis Wappes and Santos-Silva, from Suriname; O. birai Wappes and Santos-Silva, from Brazil; Paraeclipta albopilosa Wappes and Santos-Silva, from Bolivia; P. vandenberghei Wappes and Santos- Silva, from Nicaragua; Odontocera elllanocarti Wappes and Santos-Silva, from Panama; and Giesberticus longiventris Wappes and Santos-Silva, from Bolivia. In addition, the holotype of Oxylymma gibbicollis Bates, 1873 is figured for the first time, Odontocera argenteolineata Santos-Silva and Bezark, 2016 is newly recorded for Guatemala and the …

Revisión Del Género Microogenius Gutiérrez (Coleoptera: Scarabaeidae: Rutelinae: Rutelini), Con Descripción De Dos Nuevas Especies Altoandinas, José Mondaca

Insecta Mundi

The genus Microogenius Gutiérrez (Coleoptera: Scarabaeidae: Rutelinae: Rutelini), endemic to the Andean biogeographic region, is revised and now includes six species: Microogenius arrowi (Ohaus) (Bolivia), Microogenius borealis sp. nov. (Peru), Microogenius gutierrezi Martínez (Bolivia), Microogenius lanterii (Soula) (Argentina), Microogenius martinezi Gutiérrez (Bolivia) and Microogenius puna sp. nov. (Bolivia, Chile, Peru). Redescription of the genus, individual diagnoses, identification keys and distribution records for all known species are provided. Additionally, photographs of adults and of diagnostic morphological characters are included. Eremophygus calvus Gutiérrez, based on the female holotype, is synonymized under Microogenius arrowi (Ohaus), based on the male lectotype. The genus Microogenius …

Two New Tiger Beetle Species Of The Genus Calochroa Hope, 1838 (Coleoptera: Cicindelidae) From Myanmar. 150. Contribution Towards The Knowledge Of The Cicindelidae, Jürgen Wiesner, Moe Hnin Phyu

Insecta Mundi

Calochroa horii Wiesner and Phyu, new species, and Calochroa fumikoae Wiesner and Phyu, new species (Coleoptera: Cicindelidae) are described from Myanmar. A key to all members of the genus known to occur in Myanmar is provided.

Amphicoma Gandhara, A New Species Of Glaphyridae (Coleoptera: Scarabaeoidea) From Swat District In Northern Pakistan, Milan Nikodým, Guido Sabatinelli

Insecta Mundi

Amphicoma gandhara Nikodým and Sabatinelli (Coleoptera: Scarabaeoidea: Glaphyridae), a new species from Swat District of northern Pakistan, is described and illustrated. The new species is compared with related taxa, in particular with the most similar species, A. schneideri Nikodým, 2005.

Flow Alteration-Ecology Relationships In Ozark Highland Streams: Consequences For Fish, Crayfish And Macroinvertebrate Assemblages, Dustin Thomas Lynch, Douglas R. Leasure, Daniel D. Magoulick

United States Geological Survey: Staff Publications

We examined flowalteration-ecology relationships in benthic macroinvertebrate, fish, and crayfish assemblages in Ozark Highland streams, USA, over two years with contrasting environmental conditions, a drought year (2012) and a flood year (2013). We hypothesized that: 1) there would be temporal variation in flow alteration-ecology relationships between the two years, 2) flow alteration-ecology relationshipswould be stronger during the drought year vs the flood year, and 3) fish assemblages would show the strongest relationships with flow alteration. We used a quantitative richest-targeted habitat (RTH) method and a qualitative multihabitat (QMH) method to collect macroinvertebrates at 16 USGS gaged sites during both years. …

Field-To-Farm Gate Greenhouse Gas Emissions From Corn Stover Production In The Midwestern U.S., C. Rebecca Locker, Sarah Torkamani, Ian J. Laurenzi, Virginia L. Jin, Marty Schmer, Douglas L. Karlen

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Measured field data were used to compare two allocation methods on life cycle greenhouse gas emissions from corn (Zea mays L.) stover production in the Midwest U.S. We used publicly-available crop yield, nitrogen fertilizer, and direct soil nitrous oxide emissions data from the USDA-ARS Resilient Economic Agricultural Practices research program. Field data were aggregated from 9 locations across 26 site-years for 3 stover harvest rates (no removal; moderate removal e 3.1Mg ha-1; high removal e 7.2Mg ha-1) and 2 tillage practices (conventional; reduced/no-till). Net carbon uptake by crops was computed from measured plant carbon content. Monte Carlo simulations sampled input …

Flow Alteration-Ecology Relationships In Ozark Highland Streams: Consequences For Fish, Crayfish And Macroinvertebrate Assemblages, Dustin T. Lynch, Douglas R. Easure, Daniel D. Magoulick

United States Geological Survey: Staff Publications

We examined flowalteration-ecology relationships in benthic macroinvertebrate, fish, and crayfish assemblages in Ozark Highland streams, USA, over two years with contrasting environmental conditions, a drought year (2012) and a flood year (2013). We hypothesized that: 1) there would be temporal variation in flow alteration-ecology relationships between the two years, 2) flow alteration-ecology relationshipswould be stronger during the drought year vs the flood year, and 3) fish assemblages would show the strongest relationships with flow alteration. We used a quantitative richest-targeted habitat (RTH) method and a qualitative multihabitat (QMH) method to collect macroinvertebrates at 16 USGS gaged sites during both years. …

Population Characteristics Of Co-Managed White Bass And Hybrid Striped Bass In Lake Mcconaughy, Nebraska, Benjamin J. Schall, Casey W. Schoenebeck, Keith D. Koupal

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

White Bass (Morone chrysops) and Hybrid Striped Bass (M. saxatillis × M. chrysops) populations often coexist in the same waterbody and are known to achieve different lengths, have differing reproductive success, and provide different opportunities for anglers. However, comparative population dynamics from systems where Moronids are managed with the same regulation is often lacking. This study aimed to assess the recruitment, mortality, and growth of these species from seasonal samples collected at Lake McConaughy in 2015 and fall 2016. White Bass demonstrated highly variable recruitment in Lake McConaughy despite stocking efforts (mean recruitment variability index = …

Status Of The Plains Harvest Mouse (Reithrodontomys Montanus Griseus) In Eastern Nebraska, Keith Geluso, Greg D. Wright

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

In eastern Nebraska, current status of the Plains Harvest Mouse (Reithrodontomys montanus griseus) is not well understood. Infrequent captures during the last century have led to a paucity of information regarding this taxon, and some researchers postulate that its distribution has contracted in the state. In 2008, we conducted a field survey for R. m. griseus in eastern Nebraska, amassed prior specimen records, and examined most of the specimens for this subspecies from the state to better understand its distribution, natural history, and subspecific status. In our field efforts, we only captured a single individual despite …

Predation On Stink Bugs (Hemiptera: Pentatomidae) In Cotton And Soybean Agroecosystems, Kacie J. Athey, John R. Ruberson, Dawn M. Olson, James D. Harwood

Department of Entomology: Faculty Publications

Stink bugs (Hemiptera: Pentatomidae) are significant pests of cotton and soybeans in the southeastern United States with annual control costs exceeding $14 million in these crops. Three of the most prominent stink bug pests are the southern green (Nezara viridula), brown (Euschistus servus) and green (Chinavia hilaris) stink bugs. To determine trophic linkages between generalist arthropod predators and these pests, species-specific 16S molecular markers were designed and used to detect the presence of prey DNA in predator gut-contents. Over 2700 predators were collected over two growing seasons in cotton and soybean in southern Georgia in 2011 and 2012 and screened …

Enzyme Kinetics Of Dutpase From The Planarian Dugesia Ryukyuensis, Shahanoor Alam, Hideaki Moriyama

School of Biological Sciences: Faculty Publications

Objective: Planarians including Dugesia ryukyuensis (Dr) have strong regenerative abilities that require enhanced DNA replication. Knockdown of the DUT gene in Dr, which encodes deoxyuridine 5′-triphosphate pyrophosphatase (dUTPase), promotes DNA fragmentation, inhibits regeneration, and eventually leads to death. dUTPase catalyzes the hydrolysis of dUTP to dUMP and pyrophosphate. dUTPase is known to prevent uracil misincorporation in DNA by balancing the intracellular ratio between dUTP and dTTP, and contributes to genome stability. Nevertheless, the catalytic performance of Dr-dUTPase has not been reported.

Results: To confirm the catalytic activity of Dr-dUTPase, we cloned and expressed Dr-DUT in E. coli. Then, we purified …

Microbial Community Of Saline, Alkaline Lakes In The Nebraska Sandhills Based On 16s Rrna Gene Amplicon Sequence Data, Nicole A. Fiore, David D. Dunigan, Julie J. Shaffer, Ryan Roberts, Sanjay Antony-Babu, Bradley A. Plantz, Kenneth W. Nickerson, Andrew K. Benson, Karrie A. Weber

School of Biological Sciences: Faculty Publications

The Nebraska Sandhills region contains over 1,500 geochemically diverse interdunal lakes, some of which are potassium rich, alkaline, and hypersaline. Here, we report 16S rRNA amplicon pyrosequencing data on the water and sediment microbial communities of eight alkaline lakes in the Sandhills of western Nebraska.