Physical Sciences and Mathematics Commons^™

Understanding Sportsperson Retention And Reactivation Through License Purchasing Behavior, Matthew P. Hinrichs, Nathaniel B. Price, Matthew P. Gruntorad, Kevin L. Pope, Joseph J. Fontaine, Christopher J. Chizinski

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Most state and provincial fish and wildlife agencies have access to important information about patterns in sportsperson participation through their license databases. Using transaction data from Nebraska Game and Parks Commission’s electronic hunting and fishing license system, we tracked license purchases of Nebraska, USA, resident license holders in 2010 through 2017. We categorized sportspersons by gender and yearly purchases as hunting only (Hunter), fishing only (Angler), a combination of hunting and fishing (Hunter–Angler), or no purchases (Inactive). The probability of movement among active sportsperson groups was limited and varied little based on initial group participation. The Angler group had the …

Spatial And Temporal Behavioral Differences Between Angler-Access Types, Derek Kane, Mark A. Kaemingk, Christopher J. Chizinski, Kevin L. Pope

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Recreational angler surveys typically collect information on how anglers access a fishery. Yet, it is unclear how this information is useful for fisheries management and conservation. The objective of this study was to compare behavior (e.g., party size, time fished, and numbers of fish released and harvested) of bank and boat anglers, representing two angler-access types. Bank and boat anglers were surveyed across 29 Nebraska waterbodies from April through October, 2007–2017. We documented behavioral differences between bank and boat anglers that varied as a function of waterbody size and season. Patterns of party size, time fished, and numbers of fish …

Exact Distribution Of Linkage Disequilibrium In The Presence Of Mutation, Selection, Or Minor Allele Frequency Filtering, Jiayi Qu, Stephen D. Kachman, Dorian Garrick, Rohan L. Fernando, Hao Cheng

Department of Statistics: Faculty Publications

Linkage disequilibrium (LD), often expressed in terms of the squared correlation (r2) between allelic values at two loci, is an important concept in many branches of genetics and genomics. Genetic drift and recombination have opposite effects on LD, and thus r2 will keep changing until the effects of these two forces are counterbalanced. Several approximations have been used to determine the expected value of r2 at equilibrium in the presence or absence of mutation. In this paper, we propose a probability-based approach to compute the exact distribution of allele frequencies at two loci in a finite population at any generation …

Comparative Physiology Of Honey Bees (Apis Mellifera L.) Exposed To Chlorantraniliprole, Jennifer Williams

Department of Entomology: Dissertations, Theses, and Student Research

One outstanding threat to the honey bee, Apis mellifera L., is the unintended exposure of these pollinators to agricultural pesticides. Anthranilic diamides, such as chlorantraniliprole, work in target pests through activation of the ryanodine receptor causing rapid feeding cessation, lethargy, paralysis, and eventual death. Chlorantraniliprole exhibits low acute toxicity to honey bees but relatively little information exists regarding effects of chlorantraniliprole exposure beyond mortality. The acute toxicity and metabolic detoxification enzyme activities following oral exposure were determined in the honey bee and the model crop pest, the fall armyworm (Spodoptera frugiperda, J.E. Smith). Additionally, chlorantraniliprole effects on honey bee …

Transect Survey Biases And Correction Methods In Southern Africa, Erika Swenson, Larkin Powell

UCARE Research Products

In southern Africa, transect surveys and distance-based analyses are often used to obtain density and population estimates for species in large reserves or management zones. However, these estimates may be biased by unnaturally large concentrations of animals at waterholes that are on or near the path of the transect. We used empirical survey data from the Namibrand Nature Reserve in southwest Namibia to parameterize spatial simulations in which we distributed gemsbok (Oryx gazella) on a grid along a 50-kilometer transect. We created multiple simulations with and without waterholes to determine how the proportion of animals clumped at the …

Crystallization At Droplet Interfaces For The Fabrication Of Geometrically Programmed Synthetic Magnetosomes, Matthew Gromowsky, Michael Stoller, Maddee Rauhauser, Marcus Judah, Abhiteja Konda, Christopher Jurich, Stephen Morin

UCARE Research Products

Many organisms rely on the precise growth, assembly, and/or organization of inorganic crystals to achieve vital functions, for example, three-dimensional structural support (i.e., skeletal systems based on calcite) or environmental sensing (i.e., magnetosomes based on magnetite). Mimicking the production of the complex products observed in these biomineralization processes, synthetically, remains challenging. Herein, a method for the synthesis of artificial magnetosomes with programmable magnetic domains was developed. Specifically, precursors were compartmentalized inside different surfactant-stabilized aqueous-phase droplets suspended in oil and microfluidic technologies were implemented to control their interactions precisely. When reactive droplets were brought into contact with one another, a lipid …

Impacts Of Human Recreation On Nutrient Availability And Periphyton Abundance On The Niobrara River, Matthew Chen, Jessica Corman, Sydney Kimnach, Kayla Vondracek

UCARE Research Products

In freshwater ecosystems, eutrophication can create many problems. Excess nutrients, like nitrogen or phosphorus, promote algal or cyanobacterial growth. This growth also leads to increased organic matter production and decomposition, a process that can reduce oxygen concentration in the water. When this happens, species diversity declines, transparency of the water declines, and anoxia may lead to fish kills . Of particular concern is the possibility of cyanobacteria blooms that create compounds toxic for humans. Many of the waters across Nebraska receive excessive nutrients from human activities, largely related to agriculture (Dickey 1982). However, there is one river, the Niobrara River, …

Modeling Predator-Prey Interaction In A Two Patch System, Marc Wade

UCARE Research Products

In this study we examine predator-prey relationships in the context of a two patch system. What is meant by a two patch system is that prey live in a habitat that consists of type 1 patches with an abundance of food and type 2 patches with no food. In our study, we will be assuming that predators cannot enter the first type of patch. We combine three well-established ecological theories: migration theory, optimal foraging theory, and the standard predator-prey model in order to answer the motivating question: "Under what environmental conditions is a predator population stable when predation can only …

Using Electrocoagulation To Remove Perfluoroalkyl And Polyfluoroalkyl Substances (Pfas) From Contaminated Water, Amy Yanagida

UCARE Research Products

Perfluoroalkyl and Polyfluoroalkyl substances (PFAS) are a family of manmade chemicals that are used to improve the quality of several commercial products by making them resistant to heat, oil, stains, grease and water. Unfortunately, the chemical properties that make PFAS useful from an industrial perspective also make them mobile and recalcitrant once released into the environment. We used electrocoagulation to run a direct current through contaminated water to generate a zinc floc to precipiate PFAS out of water.

Explainable Deep Learning For Medical Image Analysis, Brennan Rhoadarmer

UCARE Research Products

Explainable Deep Learning for Medical Image Analysis is a project focused on improving the ability for deep learning models to explain the reasoning behind their classification in order to improve their viability in the medical field, where explanations of decisions is critical for the care of patients. In order to explore this topic, we work to implement GradCAM, which is a new method of determining the cause classification in models by tracing back through the model layers to the input.

Talking Trash In The Big Apple: Mitigating Bird Strikes Near The North Shore Marine Transfer Station, Stephan J. Beffre, Brian E. Washburn

United States Department of Agriculture Wildlife Services: Staff Publications

Anthropogenic activities that concentrate wildlife near airports increases the risk of wildlife–aircraft collisions. Placing waste management facilities, natural areas, golf courses, and other landscape features near airports have the potential to attract wildlife hazardous to aviation. We conducted a 3-year study (March 2013–February 2016) to determine if the implementation of a Wildlife Hazard Mitigation Program (WHMP) would influence the bird use of a waste transfer station located near LaGuardia Airport, New York City, New York, USA. We conducted wildlife surveys during 3 phases: (1) no mitigation program and no waste transfer station, (2) active mitigation and no waste transfer station, …

Collective Effect Of Landfills And Landscape Composition On Bird–Aircraft Collisions, Morgan Pfeiffer, Bradley F. Blackwell, Travis L. Devault

United States Department of Agriculture Wildlife Services: Staff Publications

Ninety-three percent of all reported bird strikes occur below 1,067 m, which based on the typical approach and departure angles of aircraft is within 8–13 km of an airport. Concomitantly, the Federal Aviation Administration and the International Civil Aviation Organization recommend that any feature that would attract hazardous wildlife to the approach and departure airspace be restricted. Thus, preventing the establishment of wildlife attractants, such as municipal solid waste landfills (MSWLFs) within 8 km or 13 km extents (U.S. and international recommendations, respectively) of airports, has been recommended to mitigate the risk of bird–aircraft collisions (strikes). However, robust evidence linking …

Got Science? Club, Nora Husein, Randa Ismail

Honors Expanded Learning Clubs

Got Science? Club allows students to learn about the science that can be found in our daily lives using everyday items such as food and school supplies. Students will learn about these sciences through hands-on experiments, allowing them to truly experience the science around them.

Environmental Activism, Ellen Dexter, Lydia Dexter

Honors Expanded Learning Clubs

An after school book club that follows Greta Thunberg's book of speeches No One is Too Small to Make a Difference , as well as uses hands-on activities to teach the importance of environmental activism.

Periodic Table Club, Makayla Gill, Kailynn Jensen

Honors Expanded Learning Clubs

This club is dedicated to teaching the generation of future scientists the periodic table. This is designed to be a unique take on a STEM club that uses the periodic table as a backbone for a solid foundation in chemistry.

Maize Growth, Yield, Water Productivity And Evapotranspiration Response To Different Irrigation Methods And Amounts And Different Timing And Methods Of Nitrogen Applications, Ali T. Mohammed

Department of Biological Systems Engineering: Dissertations and Theses

Declining the quantity and quality of freshwater resources in many parts of the world, including Midwestern USA, especially in the light of rapidly growing world’s population and changing climate, imposes significant and, in some cases imminent, challenges for producers, policy- and decision-makers to produce more yield with less water and other inputs, particularly in water scarcity regions.

There is not comprehensive previous research has quantified and evaluated coupled impacts of irrigation rates and nitrogen timing management strategies and their interactions on maize (Zea mays L.) productivity and its various attributed efficiency index metrics under different irrigation methods under the same …

An Anns Based Failure Detection Method For Onos Sdon Controller, Shideh Yavary Mehr

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

Network reachability is an important factor of an optical telecommunication network. In a wavelength-division-muliplexing (WDM) optical network, any failure can cause a large amount of loss and disruptions in network. Failures can occur in network elements, link, and component inside a node or etc. Since major network disruptions can caused network performance degradations, it is necessary that operators have solutions to prevent such those failures. This work examines a prediction model in optical networks and propose a protection plan using a Machine Learning (ML) algorithm called Artificial Neural Networks (ANN) using Mininet emulator. ANN is one of the best method …

Group Testing Identification: Objective Functions, Implementation, And Multiplex Assays, Brianna D. Hitt

Department of Statistics: Dissertations, Theses, and Student Work

Group testing is the process of combining items into groups to test for a binary characteristic. One of its most widely used applications is infectious disease testing. In this context, specimens (e.g., blood, urine) are amalgamated into groups and tested. For groups that test positive, there are many algorithmic retesting procedures available to identify positive individuals. The appeal of group testing is that the overall number of tests needed is significantly less than for individual testing when disease prevalence is small and an appropriate algorithm is chosen. Group testing has a number of applications beyond infectious disease testing, such as …

Nebraska Statewide Groundwater-Level Monitoring Report 2019, Aaron R. Young, Mark E. Burbach, Leslie M. Howard, Sue Olafsen Lackey, Robert Matthew Joeckel

Conservation and Survey Division

The term “groundwater” has come to be all but synonymous with Nebraska. Nearly three-quarters of the total volume of the High Plains Aquifer lies beneath the State. Groundwater maintains our streams, our ecosystems, our people, and our vitally important agricultural economy. Nebraska’s total groundwater resource is vast, yet it is also vulnerable to natural and anthropogenic changes, necessitating a long-term commitment to wise management through informed decision making. Monitoring, studying, and reporting form the essential basis for such management and, ultimately, for meeting the myriad challenges presented by change.

The personnel of the Conservation and Survey Division (CSD) are proud …

Assessment Of An Automated Calibration Of The Sebal Algorithm To Estimate Dry-Season Surface-Energy Partitioning In A Forest–Savanna Transition In Brazil, Leonardo Laipelt, Anderson Luis Ruhoff, Ayan Santos Fleischmann, Rafael Henrique Bloedow Kayser, Elisa De Mello Kich, Humberto Ribeiro Da Rocha, Christopher Michael Usher Neale

Daugherty Water for Food Global Institute: Faculty Publications

Evapotranspiration (ET) provides a strong connection between surface energy and hydrological cycles. Advancements in remote sensing techniques have increased our understanding of energy and terrestrial water balances as well as the interaction between surface and atmosphere over large areas. In this study, we computed surface energy fluxes using the Surface Energy Balance Algorithm for Land (SEBAL) algorithm and a simplified adaptation of the CIMEC (Calibration using Inverse Modeling at Extreme Conditions) process for automated endmember selection. Our main purpose was to assess and compare the accuracy of the automated calibration of the SEBAL algorithm using two different sources of meteorological …

Weather And Exposure Period Affect Coyote Detection At Camera Traps, Anastasia E. Madsen, Lucia Corral Hurtado, Joseph J. Fontaine

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Abstract Camera traps are an increasingly popular means to monitor wildlife populations. However, like other techniques for measuring populations, camera traps are subject to sources of error that may bias population estimates. Past studies accounting for detection error have failed to account for a simple but potentially widely pervasive source of environmental error: weather conditions. Using 5,108,416 photographs from 804 scent‐lured camera traps deployed in western Nebraska, USA, during spring and autumn of 2014 and 2015, we analyzed the relationship between weather conditions (barometric pressure, wind speed, precipitation, and temperature) and coyote (Canis latrans) detection probability. Using binomial …

Testing A Key Assumption Of Using Drones As Frightening Devices: Do Birds Perceive Drones As Risky?, Conor C. Egan, Bradley Blackwell, Esteban Fernández-Juricic, Page E. Klug

United States Department of Agriculture Wildlife Services: Staff Publications

Wildlife managers have recently suggested the use of unmanned aircraft systems or drones as nonlethal hazing tools to deter birds from areas of human-wildlife conflict. However, it remains unclear if birds perceive common drone platforms as threatening. Based on field studies assessing behavioral and physiological responses, it is generally assumed that birds perceive less risk from drones than from predators. However, studies controlling for multiple confounding effects have not been conducted. Our goal was to establish the degree to which the perception of risk by birds would vary between common drone platforms relative to a predator model when flown at …

A Polarimetric Radar Analysis Of Cold- And Warm-Based Supercells, Timothy J. Gunkel

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Polarimetric analyses of supercell thunderstorms have been increasingly common within the past decade, since operational polarimetric radar data became available in 2013. Although polarimetric signatures within supercell thunderstorms are well known, few have investigated variability in these signatures in differing environments. Polarimetric signatures can provide vital information regarding the microphysical characteristics and processes in supercell thunderstorms. Specific polarimetric signatures of interest are the differential reflectivity (Z_DR) column, the low-level polarimetrically inferred hail core, and the Z_DR arc. These signatures provide information regarding updraft characteristics, hailfall characteristics, and size sorting processes in the storm- relative inflow. Previous studies …

Communicating Computing Limitations Through Kinesthetic Pedagogy, Michael Mason

Honors Theses

Abstract concepts, such as those in advanced Computer Science and Mathematics, can be extremely difficult to understand fundamentally without an existing background in a similar subject. Recent research has shown that raw visualizations without learner interaction are not particularly effective at communicating complex information because they allow the learner to ignore the example (Lauer 2006, Naps 2002). Forcing somebody to interact with an example ensures that they can grasp the visualization. This paper describes a six step technique to demonstrate the limitations of computing through kinesthetic pedagogy, then offers an example exercise utilizing the method. The six proposed steps are: …

A Mathematical Model Of Speeding, Jared Ott, Xavier Pérez Giménez

Honors Theses

Crime is often regarded as nonsensical, impulsive, and irrational. These conjectures are pointed, though conversation about the pros and cons of crime does not happen often. People point to harsh fines, jail times, and life restrictions as their reason for judgement, stating that the trade-offs are far too unbalanced to participate in illicit activity. Yet, everyday people commit small crimes, sometimes based on hedonistic desires, other times based on a rational thought process.

Speeding seems to be one of those that almost all people commit at least once during their life. Our work hopes to make an incremental improvement on …

Evaluation Of The Potential Geological And Socioeconomic Impacts Of The Imminent Cascadia Megathrust Earthquake, Matthew Pritchard

Honors Theses

The Cascadia Subduction Zone on the northwest coast of the United States poses the threat of a devastating megathrust earthquake and subsequent tsunami damaging coastal populations. This paper synthesizes literature to analyze the geologic and socioeconomic effects of this natural disaster, as well as examines the existing warning system infrastructure, and makes recommendations to mitigate the damage. In order to assess the geologic effects of a megathrust earthquake, I investigate the tectonic history, the role of episodic tremor and slip (ETS) in stress buildup, crustal architecture of the subduction zone, and analogous subduction zones such as Chile and Japan. This …

The Emergence Of The Local Moment Molecular Spin Transistor, Guanhua Hao, Ruihua Cheng, Peter Dowben

Peter Dowben Publications

Local moment molecular systems have now been used as the conduction channel in gated spintronics devices, and some of these three terminal devices might even be considered molecular spin transistors. In these systems, the gate voltage can be used to tune the molecular level alignment, while applied magnetic fields have an influence on the spin state, altering the magnetic properties, and providing insights to the magnetic anisotropy. More recently, the use of molecular spin crossover complexes, as the conduction channel, has led to devices that are both nonvolatile and have functionality at higher temperatures. Indeed, some devices have now been …

Friendship At The Feeding Station, Anisha Pokharel

Zea E-Books Collection

A young steppe eagle and his mother fly to Nepal from Mongolia, where Griffy, a Himalayan griffon, chases the hungry Steppe from the feeding station, but Garuda, a white-rumped vulture, intervenes and becomes Steppe's friend. Steppe's mother is angered at first, but learns the lesson that each species has its role to play.

Designed by Breanna Epp with Maeve Lausch

Characterization Of A Trochoidal Electron Monochromator, Jesse Kruse

Honors Theses

This thesis presents a quantitative study of a trochoidal electron monochromator and attempts to observe the 2p^53p^2 resonance in neon. A detailed description of the experimental apparatus, including the electron beam system, the vacuum system, and the light analysis system, is presented first. Then, we discuss the theory of how the electron beam is monochromatized, how we measured monochomatization, and how we analyze the light being emitted from the collision cell. The light analysis system is capable of accurately measuring the relative Stokes parameters for any polarization of light, and the electron beam system is capable of producing electron beams …

Acoustically Advertising Male Harbour Seals In Southeast Alaska Do Not Make Biologically Relevant Acoustic Adjustments In The Presence Of Vessel Noise, Leanna P. Matthews, Michelle E.H. Fournet, Christine Gabriele, Holger Klinck, Susan E. Parks

United States National Park Service: Publications

Aquatically breeding harbour seal (Phoca vitulina) males use underwater vocalizations during the breeding season to establish underwater territories, defend territories against intruder males, and possibly to attract females. Vessel noise overlaps in frequency with these vocalizations and could negatively impact breeding success by limiting communication space. In this study, we investigated whether harbour seals employed anti-masking strategies to maintain communication in the presence of vessel noise in Glacier Bay National Park and Preserve, Alaska. Harbour seals in this location did not sufficiently adjust source levels or acoustic parameters of vocalizations to compensate for acoustic masking. Instead, for every 1 dB …