Digital Commons Network^™

Brillouin Zone Center Phonon Modes In Znga2O4, Megan Stokey, Rafal Korlacki, Sean Knight, Matthew J. Hilfiker, Zbigniew Galazka, Klaus Irmscher, Vanya Darakchieva, Mathias Schubert

Department of Electrical and Computer Engineering: Faculty Publications

Infrared-active lattice mode properties of melt-grown high-quality single bulk crystals of ZnGa₂O₄ are investigated by combined spectroscopic ellipsometry and density functional theory computation analysis. The normal spinel structure crystals are measured by spectroscopic ellipsometry at room temperature in the range of 100 cm^–1–1200 cm^–1. The complex-valued dielectric function is determined from a wavenumber-by-wavenumber approach, which is then analyzed by the four-parameter semi-quantum model dielectric function approach augmented by impurity mode contributions. We determine four infrared-active transverse and longitudinal optical mode pairs, five localized impurity mode pairs, and the high frequency dielectric constant. All …

Using A College Curriculum To Integrate Informal Science Learning Opportunities For University And Middle School Students, Eileen Hebets, Patricia Wonch Hill, Ann Matthews, Kathie Phillips, Susan Weller, Cassidy Whitney, Tyler B. Corey

Department of Entomology: Faculty Publications

We used community partnerships to develop an integrated science-learning program focused on two groups of learners – university and middle school (MS) students – to increase students’ interest and confidence in science as well as motivation to pursue science. Key program elements include a university course for undergraduate and graduate students, university student-led weekly afterschool clubs held at local middle schools (mostly Title I), and a capstone museum science festival led by university and MS students. Across nine course offerings, 78 university students conducted 25 clubs at seven middle schools and engaged at least 240 MS students. The capstone science …

An Evaluation Of Bird And Bat Mortality At Wind Turbines In The Northeastern United States, Daniel Y. Choi, Thomas W. Wittig, Bryan M. Kluever

United States Department of Agriculture Wildlife Services: Staff Publications

Wind energy offers substantial environmental benefits, but wind facilities can negatively impact wildlife, including birds and bats. Researchers and managers have made major efforts to chronicle bird and bat mortality associated with wind facilities, but few studies have examined the patterns and underlying mechanisms of spatial patterns of fatalities at wind facilities. Understanding the horizontal fall distance between a carcass and the nearest turbine pole is important in designing effective search protocols and estimating total mortality. We explored patterns in taxonomic composition and fall distance of bird and bat carcasses at wind facilities in the Northeastern United States using publicly …

Estimation Of Wildlife Damage From Federal Crop Insurance Data, Sophie Mckee, Stephanie A. Shwiff, Aaron M. Anderson

United States Department of Agriculture Wildlife Services: Staff Publications

BACKGROUND: Wildlife damage to crops is a persistent and costly problem for many farmers in the USA. Most existing estimates of crop damage have relied on direct assessment methods such as field studies conducted by trained biologists or surveys distributed to farmers. In this paper, we describe a new method of estimating wildlife damage that exploits federal crop insurance data. We focused our study on four crops: corn, soybean, wheat, and cotton, chosen because of their economic importance and their vulnerability to wildlife damage.

RESULTS: We determined crop-raiding hot spots across the USA over the 2015–2019 period and identified the …

Climate Change And Market-Based Insurance Feedbacks, Eric R. Holley, Adam Liska, Cory Walters, Geoffrey C. Friesen, Michael Hayes, Max J. Rudolph, Donald A. Wilhite

Adam Liska Papers

Climatic events have accounted for 91% of $1.05 trillion in insured costs for global catastrophic events from 1980 to 2016. Costs are driven by socio-economic development and increased frequency and severity of climatic disasters driven by climate change. Government policies to reduce systemic risk (e.g., cap-and-trade, carbon tax) have been a predominant approach for mitigation and adaptation. Alternatively, market-based incentives for climate change adaptation and mitigation already operate via the insurance industry to lessen impacts on society. Insurance feedbacks include changes in 1) premiums and insurance policies, 2) non-coverage, and 3) policy making and litigation. Alongside government policies, insurance feedbacks …

Metagenomic, Viral And Host Genetic Analyses Of Congenital Tremor In Pigs, Kylee Marie Sutton

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

The Pestivirus genus contains several viral species having a major impact on the livestock species. While there were only four major pestiviral species for a time, recent metagenomic sequencing approaches identified additional species, such as atypical porcine pestivirus (APPV). Congenital tremor was first identified almost a hundred years ago and since still has an impact on swine health. There are two main types of congenital tremor, type A and B, with type A congenital tremor further subcategorized based on causative agent. Until recently, type A-II congenital tremor did not have a known cause. Recent viral sequencing of affected samples, including …

Effects Of Char On Nitrogen Management In Agricultural Soils Of Semi-Arid Western Nebraska, Dinesh Panday

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

Soils in western Nebraska are characterized by low soil organic C due to semi-arid environment in the region and further aggravated by disruption of soil aggregates and rapid C decomposition from intensive tillage, erosion, and frequent droughts. Proper management of soil C may improve soil properties, reduce N losses, and subsequently improve crop yields in this low C soil and low moisture condition. This dissertation focuses on C-rich coal char (henceforth “char”) as a potential strategy to overcome the existing problem of low C in semi-arid region. Char is an industrial by-product, resulting from inefficient coal burning during sugar beet …

Advancing The Science Of Dry-Aged Beef, Felipe Azevedo Ribeiro

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

In order to tightly control dry aging environmental conditions, we designed and built a computerized dry aging system that is capable of measuring and precisely controlling relative humidity (RH; ± 1%), temperature (± 0.5 °C), air flow (± 0.015m³/min), and mass loss (± 5 g). This dissertation addressed the effects of RH and ultimate pH on meat quality and sensory attributes of dry-aged beef. In study one, we learned that wet-aged steaks had higher L* (P = 0.01), a* (P = 0.03), and b* values (P < 0.001), lower discoloration scores (P < 0.05), and lower TBARS (thiobarbituric acid reactive substance) values (P = 0.03) than dry-aged treatments. Under prolonged …

Influence Of Strategic Supplementation And Genetic Potential For Milk Yield On Forage Digestibility, Amino Acid Utilization, And Livestock Production, Tasha M. King

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

When consuming low-quality forages or at times when nutrient demands are high, ruminants may be unable to meet these requirements resulting in a state of negative energy balance. With feed costs contributing a large portion of production costs, providing dietary nutrients to maintain energy balance must be done so strategically. Additionally, producers must ensure consistent reproductive performance and offspring weaned to maintain a successful livestock enterprise. The objective of these studies was to evaluate the effect of glucogenic precursor supplementation and milk yield on forage digestibility, amino acid utilization, and livestock production. In experiment 1, a metabolism study was conducted …

Educational Benefits And Cognitive Health Life Expectancies: Racial/Ethnic, Nativity, And Gender Disparities, Marc A. Garcia, Brian Downer, Chi-Tsun Chiu, Joseph L. Saenz, Kasim Ortiz, Rebeca Wong

Department of Sociology: Faculty Publications

Background and Objectives: To examine racial/ethnic, nativity, and gender differences in the benefits of educational attainment on cognitive life expectancies among older adults in the United States.

Design and Methods: We used data from the Health and Retirement Study (1998-2014) to estimate Sullivan-based life tables of cognitively healthy, cognitively impaired/no dementia (CIND), and dementia life expectancies by gender for older White, Black, U.S.-born and foreign-born Hispanic adults with less than high school, high school, and some college or more.

Results: White respondents lived a greater percentage of their remaining lives cognitive healthy than their minority Black or Hispanic counterparts, regardless …

A New Species Of Buprestis (S. Str.) Linnaeus, 1758 (Coleoptera: Buprestidae) From The Southwestern United States, Richard L. Westcott, Clint Burfitt

Insecta Mundi

A new species of Buprestis L., 1758, B. pinyoni Westcott and Burfitt (Coleoptera: Buprestidae), is described from Arizona, New Mexico, and Utah. It is compared to other species in the subgenus Buprestis.

New Distribution Records Of Asilidae (Insecta: Diptera) For Mexico, Alejandro Estrada, Jesús Romero Nápoles

Insecta Mundi

We provide new distribution records for 19 species of robber flies (Diptera: Asilidae) of Mexico based on the examination of 221 specimens from Mexican entomological collections.

Beetles (Coleoptera) In Cones Of Cycads (Cycadales) Of The Northern Hemisphere: Diversity And Evolution, William Tang, Guang Xu, Thomas Marler, Jibankumar Singh Khuraijam, Rita Singh, Anders J. Lindström, P. Radha, Stephen Rich, Khang Sinh Nguyen, Paul E. Skelley

Insecta Mundi

Three groups of beetles inhabit cones of cycads (Cycadales) in the northern hemisphere and are believed to be involved in their pollination. The primitive weevil subtribe Allocorynina (Coleoptera: Belidae) is restricted to the New World cycad genera Dioon Lindl. and Zamia L. One group of weevils (Curculionidae), found only in Cycas L., appears to be a relatively recent colonizer of northern hemisphere cycads. Members of the beetle subfamily Pharaxonothinae (Erotylidae) occur in all Asian and New World cycad genera. Phylogenetic trees of these beetles, based on DNA analysis and supported with morphological studies, are compared to patterns of continental drift …

First Record Of The Orchid Bee Euglossa Dilemma (Hymenoptera: Apidae) In Hispaniola, The Antilles, Julio A. Genaro, Ismael A. Hinojosa-Díaz, Lisa Mcdowell Johnson

Insecta Mundi

The occurrence of the orchid bee Euglossa dilemma Bembé and Eltz (Hymenoptera: Apidae) is recorded for the first time for the island of Hispaniola in the Greater Antilles. Males were observed visiting varieties of sweet basil plants (Ocimum basilicum Linnaeus (Lamiaceae)) to obtain fragrances used during courtship and reproduction. Our observations showed that the species is established in Hispaniola and that it does not require the presence of orchids for reproductive success, being able to adapt to new plant resources it finds in the areas it colonizes. These observations correspond to what was found in Florida, United States, where …

Notes, New Records, New Combinations, A New Genus And Three New Species In Hemilophini (Coleoptera: Cerambycidae: Lamiinae), Antonio Santos-Silva, Daniel Heffern, Juan Pablo Botero, Francisco E. De L. Nascimento

Insecta Mundi

The number of specimens in the type series of Hemilophus leuconotus Laporte, 1840 (= Cirrhicera leu­conota) is corrected. Cirrhicera leucronota Thomson, 1857 (Coleoptera: Cerambycidae: Lamiinae: Hemilophini), currently considered lapsus calami or an error to C. leuconotus, and the number of specimens in the type series is also corrected. Cirrhicera leuconota is recorded from Guatemala for the first time. The sex of the holotype of Lamacoscylus albatus Martins, Santos-Silva and Galileo, 2015, is corrected, and a new state record in Mexico is provided. The description of the antennae in females of Lamacoscylus Martins and Galileo, 1991 is discussed; Malacoscylus …

First Record Of Planchonia Stentae (Brain, 1920) (Hemiptera: Coccomorpha: Asterolecaniidae) On Asclepias Curassavica Linnaeus, 1753 (Gentianales: Asclepiadaceae) In Mexico, With Observations On Parasitic Encyrtidae, Hipolito Cortez-Madrigal, Arturo Ramírez-Cruz, Christof F. Stumpf

Insecta Mundi

In April 2018, specimens of an asterolecaniid were collected on infested wild plants of Asclepias curas­savica Linnaeus, 1753 (Gentianales: Asclepiadaceae) in Jiquilpan, Michoacan, Mexico. The collected specimens were identified as Planchonia stentae (Brain, 1920) (Hemiptera: Asterolecaniidae). In this paper, we record for the first time the presence of P. stentae infesting A. curassavica in Mexico.

Influence Of Cover Crop Management Practices On Rainfed Corn Production In Semi-Arid Western Nebraska, Alexandre Tonon Rosa

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

With the increased cover crop (CC) popularity, producers of semi-arid regions of western Nebraska are questioning whether they could successfully incorporate CC into their rainfed winter wheat (Triticum aestivum L.)-corn (Zea mays L.)-fallow rotations. The major concern is that CCs may deplete soil water affecting the subsequent crop. Therefore, three studies were established under rainfed conditions of western Nebraska to access the effects of CCs on soil water, soil compaction, nutrient cycling, weed demographics, residue coverage, and subsequent corn yield. The first study evaluated the influence of CC planting and termination times prior to corn establishment. Late termination …

Protease Oma1 Modulates Mitochondrial Bioenergetics And Ultrastructure Through Dynamic Association With Micos Complex, Martonio P. Viana

Department of Biochemistry: Dissertations, Theses, and Student Research

Remodeling of mitochondrial ultrastructure is a complex dynamic process that is critical for a variety of mitochondrial functions and apoptosis. Although the key regulators of this process - mitochondrial contact site and cristae junction organizing system (MICOS) and GTPase Optic Atrophy 1 (OPA1) have been characterized, the mechanisms behind this regulation remain incompletely defined. Here, we found that in addition to its role in mitochondrial division, metallopeptidase OMA1 is required for maintenance of contacts between the inner and outer membranes through a dynamic association with MICOS. This association is independent of OPA1, appears to be mediated via the MIC60 MICOS …

Spatial Ecology And Resource Selection Of Bighorn Sheep (Ovis Canadensis) Ewes In A Prairie Badlands Population, Erin Wood

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

The basic spatial ecology and habitat relationships of female bighorn sheep in Nebraska are poorly understood. Establishing seasonal patterns of space use and resource selection for this population at the margin of their historical and current range addresses a key knowledge gap and provides important baseline information for ongoing conservation efforts in Nebraska. We deployed GPS radio-collars on 56 adult ewes in western Nebraska to quantify seasonal space use, movements, and resource selection of ewes. To investigate spatial ecology, we quantified movements of ewes and the factors that influence home range size, seasonal use, and spatial stability across seasons. Home …

Using Return Intervals And Nutrient Spiraling To Examine The 2019 Nebraska Flood, Alexa Davis

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

In March of 2019, flooding levels in many parts of Nebraska was the worst that streams and rivers had in decades, and in some locations, on record. Theses historic floods present an optimal case study to examine how current technological resources can be used to enhance our understanding of floods and how these floods impact in situ stream ecosystem processes like nitrogen and phosphorus cycling. Currently, there are only a few resources available to quantify the extent of floods; for my thesis, I will focus on satellite imagery and in situ water level gages. Unfortunately, due to technical issues with …

Symptom Presentation Of Sexually Abused Youth: Associations With Abuse Attributions, Brittany Biles

Department of Psychology: Dissertations, Theses, and Student Research

Child sexual abuse (CSA) outcomes are heterogeneous. Some victims display a combination of externalizing behaviors (e.g., aggression) and internalizing symptoms (e.g., depression), while others present with minimal symptoms (Domhardt, Munzer, Fegert, & Goldbeck, 2015). Among the factors that have been explored as relating to CSA outcomes are child characteristics (e.g., age; Dube et al., 2005), abuse-specific variables (e.g., abuse severity; Stroebel et al., 2012), and family variables (e.g., familial social support; Ryan, Kilmer, Cause, Watanabe, & Hoyt, 2000). Although much of the literature supports these factors as contributing to outcomes following CSA, conclusions have been inconsistent. Research has begun to …

Pesticide Occurrence And Persistence Entering Recreational Lakes Residing In Watersheds Of Various Land Uses, Jessica Satiroff

Department of Environmental Engineering: Theses and Other Student Research

Common Use Pesticides (CUPs) are important for agricultural producers to sustain food production. As a result, regions with high rates of agricultural production, such as the Midwest, often have ubiquitous occurrences of pesticides in surface and groundwater ¹. Once pesticides are introduced into an ecosystem, pesticides have the potential for creating unwanted effects on non-target species and downstream environments ^2,3. However, pesticides do not come strictly from agricultural practices. Therefore, the research presented in this thesis focuses on the neonicotinoid and fungicide concentrations detected in recreational lakes as well as their persistence in these aquatic environments during the …

Reinstatement Of Carposina Ottawana Kearfott, 1907 (Lepidoptera: Carposinidae) As A Valid Species, James D. Young, James A. Robertson

Insecta Mundi

Carposina ottawana Kearfott, 1907 (Lepidoptera: Carposinidae), revised status, formerly considered a synonym of C. sasakii Matsumura, 1900, is returned to species status. Morphological features that separate the Asian species C. sasakii and C. niponensis Walsingham, 1900 from the North American C. ottawana are described and illustrated. A heuristic maximum likelihood (ML) analysis based on the mitochondrial gene cyto­chrome oxidase I (DNA barcode) further supports C. ottawana and C. sasakii as distinct taxa.

Biofiltration Of Volatile Organic Compounds Emitted At Ethanol Plants, Mitham Al-Faliti

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Ethanol is a major biofuel source of energy in the U.S. Ethanol production produces several harmful emissions from both fermentation tanks and dryers. CO₂ scrubbers control the emissions from the fermentation tanks, while the emissions from the dryers are controller by regenerative thermal oxidizers. These methods are expensive to operate. A potential alternative is bio-trickling filters. Bio-trickling filters are an inexpensive and environmentally friendly alternative. For this study, two parallel bio-trickling filters were operated one at 25°C called the mesophilic bio-trickling filter and one at 60°C called the thermophilic bio-trickling filter. The mesophilic bio-trickling filter simulates emissions from fermentation …

Formal Language Constraints In Deep Reinforcement Learning For Self-Driving Vehicles, Tyler Bienhoff

School of Computing: Dissertations, Theses, and Student Research

In recent years, self-driving vehicles have become a holy grail technology that, once fully developed, could radically change the daily behaviors of people and enhance safety. The complexities of controlling a car in a constantly changing environment are too immense to directly program how the vehicle should behave in each specific scenario. Thus, a common technique when developing autonomous vehicles is to use reinforcement learning, where vehicles can be trained in simulated and real-world environments to make proper decisions in a wide variety of scenarios. Reinforcement learning models, however, have uncertainties in how the vehicle acts, especially in a previously …

On-Farm Research And Student Engagement To Assess And Promote The Use Of Organic Amendments To Improve Agricultural Soil Health And Resilience Of Crop Production Systems In Nebraska, Agustin Jose Olivo

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

In nearly every production environment, there are opportunities to capture profits if waste streams can be further processed or enhanced to create “value added” products. On-farm research studies were initiated in 2019 at four locations across Nebraska to assess the impacts of livestock manure, cedar mulch from forestry management and coal char from sugar beet processing, on agricultural cropland. Study treatments included beef cattle manure (CM), beef cattle slurry (CS), coal char (CC), woody biomass (WB) CM+WB, CS+WB, CM+CC and control (CON; no organic amendment). Soil properties and corn yield were evaluated after a single growing season. Results indicate that …

Snowy Plover Activity In The Central Platte River Valley In May 2019, Bethany L. Ostrom, Andrew J. Caven, Jenna M. Malzahn, Alyx Vogel

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

During five of eight site visits between 14 and 27 May 2019 we detected up to four Snowy Plovers (Charadrius nivosus nivosus) in the Central Platte River Valley (CPRV) near Mormon Island, Hall County, Nebraska, and recorded their behavior using an instantaneous scan sampling approach. We recorded loafing (47%), foraging (43%), mating (4%), flying (4%), and external threat (1%) related behavior. Most notably, we documented a copulation event on 23 May. During the 10-day span from 14 to 23 May when Snowy Plovers were detected, river stage and discharge were near median levels, but from 23 to 27 …

Wavelength Decomposition Of Hybrid Additive Manufacturing Power Signals And Their Relationship With Surface Integrity, Xingtao Wang

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

Additive Manufacturing (AM) has been a promising manufacturing technology in industrial applications and gained a massive amount of attention from researchers all over the world. Directed Energy Deposition (DED) is an AM process in which focused thermal energy is used to fuse materials by melting as they are deposited. One of the most significant challenges involved in current metal AM processes is improving repeatability and consistency. Substantial effort has already been invested in this area of research.

In this dissertation, a milling tool not only played a role in subtractive manufacturing but also acted as a method of monitoring the …

His And Hers: Gender-Specific Design In Mid-Twentieth Century North America Through Film And Television, Morgan O'Shaughnessy

Architecture Masters of Science Program: Theses

The built environment exists as a variety of ‘spaces’ which are constructed by, and for, the people who occupy them. What is the relationship between social constructs of gender and our built environment in the 20^th century? How does film and television representing the mid-20^th century exemplify this relationship? The overall theme of this topic will include a positive relationship between social gender constructs and our built environment. Through the exploration of select film and television, this study attempts to answer the question of how gender-focused design reinforces traditional gender roles in North American society in mid-20^{th …}

Spatial And Temporal Patterns Of Bat Activity In A Southeast Nebraska Agricultural Landscape, Christopher Fill

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

Intensive agriculture is associated with biodiversity loss and species decline. Yet wild species, such as bats, may provide critical ecosystem services to agriculture, even in transformed landscapes. In the United States, bats have been estimated to save the agricultural industry billions of dollars per year. However, white-nose syndrome and habitat loss have led to the decline of many bat species in North America, including the federally threatened northern long-eared bat, Myotis septentrionalis.

To better evaluate the effectiveness of these pest-controlling services, and to increase understanding of bat foraging behavior in these extreme landscapes, I deployed 11 grids of 24 detectors, …