Physical Sciences and Mathematics Commons^™

Leaf Optical And Indirect Lai Measurements In Wheat And Alfalfa At Maciv: Agmet Progress Report 89-4, E. A. Walter-Shea, B. L. Blad

School of Natural Resources: Documents and Reviews

No abstract provided.

Inferred Areal Extent Of The Oligocene (White River Group) Chadron Basal Sand, Conservation And Survey Division

Conservation and Survey Division

No abstract provided.

Pre-Tertiary Subcrop Rocks In The Nebraska Panhandle, Conservation Annd Survey Division

Conservation and Survey Division

No abstract provided.

Configuration Of The Base Of The Principal Aquifer, Conservation And Survey Division

Conservation and Survey Division

No abstract provided.

Climate Smart Agriculture, J. David Aiken

Cornhusker Economics

There are several programs encouraging producers to reduce their carbon intensity, including United States Department of Agriculture climate-smart agriculture programs, the 2024 Nebraska Climate Action Plan, and the 2024 Nitrogen Reduction Incentive Act. The hope is that producers with lower carbon intensity (CI) scores will receive a premium for their products. Producers would be well advised to learn more about these programs, as reducing carbon intensity in agriculture seems to be an emerging agricultural policy trend that will be with us for some time to come.

Institutional Data Repositories Are Vital, Jen Darragh, Mikala R. Narlock, Halle Burns, Peter A. Cerda, Wind Cowles, Leslie M. Delserone, Seth Erickson, Joel Herndon, Heidi Imker, Lisa R. Johnston, Sherry Lake, Michael Lenard, Alicia Hofelich Mohr, Jennifer Moore, Jonathan Petters, Brandie Pullen, Shawna Taylor, Briana Wham

UNL Libraries: Faculty Publications

As funding agencies and publishers reiterate research data sharing expectations (1), many higher-education institutions have demonstrated their commitment to the long-term stewardship of research data by connecting researchers to local infrastructure, with dedicated staffing, that eases the burden of data sharing. Institutional repositories are an example of this investment (2). They provide support for researchers in sharing data that might otherwise be lost: data without a disciplinary repository, data from projects with limited funding, or data that are too large to sustainably store elsewhere. The staffing and technical infrastructure provided by institutional repositories ensures responsible access to information while considering …

How Much Green To Keep The Garden Clean? An Analysis Of The Willingness To Pay (Wtp) Of Home Gardeners For Biowrap Technology, Gengchen Kai, Kanji Fatema, Karina Schoengold

Cornhusker Economics

A research team from the University of Nebraska-Lincoln, Kansas State University, and South Dakota School of Mines are working on creating an alternative product that would use locally available materials to create a spray-on, biodegradable polymer that can suppress weeds and will biodegrade in a timeframe that is amenable to crop production. We broadly refer to this technology as BioWRAP (Bioplastics with Regenerative Agricultural Properties).

Our results show that the home garden market is potentially a significant one for a BioWRAP product. Continued work in the development of the BioWRAP technology is necessary to determine what the cost of a …

Ponca State Park Vascular Plant Species List, Robert F. Steinauer

Nebraska Game and Parks Commission: White Papers, Conference Presentations, and Manuscripts

A list of vascular plant species found in Ponca State Park. Arranged by plant family and then species name. Also included are descriptions of locations where the species is commonly found.

Wildcat Hills Rare Plant Survey Final Report, Steven B. Rolfsmeier

Nebraska Game and Parks Commission: White Papers, Conference Presentations, and Manuscripts

This survey report summarizes fifteen days of field work in eleven sites scattered across the Wildcat Ridge that were completed between May and August of 1996. Forty-five occurrences of 15 plant species on the Nebraska Natural Heritage element list were found. Ten tracts of high quality (or otherwise noteworthy) native communities were identified. Included in the report are site descriptions and element occurrences.

Groundwater Modeling Of The Ogallala Aquifer: Use Of Machine Learning For Model Parameterization And Sustainability Assessment, Tewodros Aboret Tilahun

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

Addressing groundwater depletion problems in heterogeneous aquifer systems is a challenge. The heterogeneous Ogallala Aquifer, a critical source of groundwater in the central United States, has undergone decades of decline in water levels due to pumping. This project aims to build a robust groundwater model to evaluate optimal scenarios for sustainable use of the groundwater resource within a section of the Ogallala aquifer located in the Middle Republican Natural Resources District (MRNRD). This study follows a comprehensive approach involving parameterization, construction, and optimization. The model is parametrized using hydraulic conductivity and recharge values obtained from a random forest-based machine learning …

The Feasibility Of Utilizing The Open Dynamic Interaction Network (Odin) App To Assess Rema Data Across 30 Days Among Those Recovering From Alcoholism, Dennis E. Mcchargue, Bilal Khan, Jesscia Phelps, Patrick Duryea, Kimberly A. Tyler, Arthur Andrews, Ellie Reznicek, Lucy Napper, Mohamed Saad, Hsuan-Wee Lee

Department of Psychology: Faculty Publications

About ~4 million people with an alcohol use disorder receive treatment annually, and frequent relapse has produced a rapid revolving door between recovery and use. This paper presents preliminary data from a prospective micro-longitudinal study (30 days) that examines co-evolution of relapse risk processes of people with alcohol use disorders who entered a short-term residential substance use treatment. The primary goal of the current data was to assess the feasibility of using the open dynamic interaction network (ODIN) responsive ecological momentary assessment (rEMA). rEMA collected daily estimates on affect, urges, sober-support engagement, and use. The ODIN app administered twelve questions …

Conservation Decision Making And Agricultural Land Leasing - An Experimental Investigation Of The Role Of Gender, Diya Ganguly, Simanti Banerjee, Christopher Gustafson

Cornhusker Economics

This research investigated the impact of landowner gender and of the different types of contract leases offered by them to a male tenant, on the conservation (or non-conservation) choice made by the tenant. Specifically, we investigate if a) female and male landowners offer different rental contracts and b) whether tenants choose different actions based on the landowner’s gender. For this purpose, we implemented a controlled, gender-context-loaded economic experiment with university students, in which we tested contract and land use choice under different treatments for three types of rental contracts – fixed rent, fixed rent with penalty, and fixed rent with …

Fourier Transform Ion Cyclotron Resonance Mass Spectrometry Applications For Metabolomics, Darcy Cochran, Robert Powers

Robert Powers Publications

Metabolomics is an interdisciplinary field that aims to study all metabolites < 1500 Da that are ubiquitously found within all organisms. Metabolomics is experiencing exponential growth and commonly relies on high-resolution mass spectrometry (HRMS). Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) is a form of HRMS that is particularly well suited for metabolomics research due to its exceptionally high resolution (10⁵–10⁶) and sensitivity with a mass accuracy in parts per billion (ppb). In this regard, FT-ICR-MS can provide valuable insights into the metabolomics analysis of complex biological systems due to unique capabilities such as the easy separation of isobaric and isomeric species, isotopic fine structure analysis, spatial resolution of metabolites in cells and tissues, and a high confidence (error) in metabolite identification. Alternatively, the large and complex data sets, long acquisition times, high cost, and limited access mainly through national mass spectrometry facilities may impede the …

A Measurement Of The Differential Drell-Yan Cross Section As A Function Of Invariant Mass In Proton–Proton Collisions At √ S = 13 Tev, William Robert Tabb

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

The Drell-Yan process, a crucial mechanism for producing lepton pairs in highenergy hadron collisions, serves as an essential probe for testing the Standard Model of particle physics. This dissertation presents a comprehensive measurement of the differential cross section with respect to the invariant mass of the lepton pairs, utilizing data collected by the CMS experiment at CERN from 2016 to 2018. Cross sections are essential for refining our understanding of parton distribution functions and the underlying quantum chromodynamics processes, thereby providing constraints on theoretical predictions. In this analysis, the cross sections are compared to theoretical models and simulations, offering new …

Exploring Intraplate Seismicity In The Midwest, Alexa Fernández

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

Intraplate seismicity represents a notable occurrence within the stable North American Craton. This research explores the potential sources of stresses that could reactivate older faults and influence seismic activity within this region. Among these sources, the enduring impact of the last glacial period is considered, which includes continued glacial isostatic adjustments (GIA). During GIA the lithosphere rebounds due to the retreating ice, and the forebulge caused by far-field flexure in response to the glacial load, collapses. This results in significant faulting, fracturing, and seismic activity associated with the deglaciation phase. The adjustment of the lithosphere manifests as both near surface …

Sensitivity Of Present And Future Seasonal Precipitation Over Central United States To The Representation Of Rocky Mountain Topography, Ranasinghe Disanayakalage Sherly Shelton Ranathunga

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

Precipitation change across the Central United States (USA) is of great interest to the research community. Studies using global climate simulations suggest that the “100^th-Meridian”, which separates the “dry west” from the “moist east” will shift to the east as the climate responds to future emissions pathways. However, these simulations are run at relatively coarse resolutions, which do not accurately represent topography. Here, we perform regional simulations using the Weather Research and Forecasting (WRF) model to explore the sensitivity of present and future precipitation patterns across the central USA to the representation of the Rocky Mountains (RM). We …

Occurrence, Inputs, And Ecological Significance Of Antibiotics And Pharmaceuticals In Western Nebraska Streams, Katelyn F. Glause

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

Few emerging environmental contaminants are as concerning as antibiotics. Human and animal health benefits greatly from the prudent use of antibiotics, yet we give little thought to environmental release of these biologically active compounds. Environmental occurrence of these and other pharmaceutical compounds must be measured in different environmental compartments such as municipal wastewater and in the vicinity of large animal feeding operations to understand potential effects. This study reports the results of a monitoring study in western Nebraska, with a large population of livestock and smaller but more concentrated population of humans, comparing the relative environmental concentrations and loading from …

Applying Circuit Theory To Describe Changes In Structural Landscape Connectivity In Response To Wildfire, Christian Ross Nielsen

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

Understanding and conserving ecological connectivity is critical to the preservation of vulnerable landscapes. Circuit theory, in which landscapes are imagined as circuit boards with varying resistances to the flow of current, is being increasingly used to model spatially explicit connectivity of landscapes and to inform land management and conservation decision-making. Utilizing continuous, quantitative estimates of percent cover by five land cover functional groups to create a conductance surface, this study expanded upon an established application of circuit theory that used the open-source software Circuitscape to model species-agnostic, omnidirectional connectivity. This model was automated using Python to create time-series connectivity maps …

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 …

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 …

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 …

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 Biological Systems Engineering: Dissertations and Theses

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 …

Making Sandwiches: A Novel Invariant In D-Module Theory, David Lieberman

Department of Mathematics: Dissertations, Theses, and Student Research

Say I hand you a shape, any shape. It could be a line, it could be a crinkled sheet, it could even be a the intersection of a cone with a 6-dimensional hypersurface embedded in a 7-dimensional space. Your job is to tell me about the pointy bits. This task is easier when you can draw the shape; you can you just point at them. When things get more complicated, we need a bigger hammer.

In a sense, that “bigger hammer” is what the ring of differential operators is to an algebraist. Then we will say some things and stuff …

A Study On The Vanishing Of Ext, Andrew J. Soto Levins

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

This thesis has two goals. The first is to study an Ext analog of the rigidity of Tor, and the second is to study Auslander bounds.

In Chapter 2 we show that if R is an unramified hypersurface, if M and N are finitely generated R-modules, and if the nth Ext modules of M against N is zero for some n less than or equal to the grade of M, then the ith Ext module of M against N is zero for all i less than or equal to n. A corollary of this says that if …

Spreads And Transversals And Their Connection To Geproci Sets, Allison Joan Ganger

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

Spreads of [set of prime numbers]³ over finite fields can yield geproci sets. We study the existence of transversals to such spreads, proving that spreads with two transversals exist for all finite fields, before further considering the groupoids coming from spreads when transversals do or do not exist. This is further considered for spreads of higher dimensional projective spaces. We also consider how certain spreads might generalize to characteristic zero and the connection to the previously known geproci sets coming from the root systems D₄ and F₄.

Advisor: Brian Harbourne

On Regularity Of Graph C*-Algebras, Gregory Joseph Faurot

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

We prove that for any countable directed graph E with Condition (K), the corresponding graph C*-algebra C*(E) has nuclear dimension at most two. We also prove that the nuclear dimension of certain extensions is at most one, which can be applied to certain graphs to achieve the optimal upper bound of one. Finally, we generalize some previous results for O_∞ -stability of graph algebras, and prove some partial results for Z-stability.

Advisor: Christopher Schafhauser

Transforming Grassland Conservation: Challenges And Opportunities Across Law, Policy, And Human Dimensions, Conor D. Barnes

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

Great Plains social-ecological systems are facing growing pressure from complex, ‘wicked’ problems. Addressing these problems will require integrating ecological resilience and complex systems thinking concepts into our legal framework in order to better reflect the changing ecological reality of the Great Plains and promote flexibility and adaptability in the face of that change. In this dissertation, I examine how past and present policy priorities have affected social-ecological systems on the Great Plains, and how ecological resilience and complex systems thinking might be applied to grassland management policy. In Chapter 2, I examine the rapid progress made in the adoption of …

Gevrey Class Estimates Towards Null Controllability Of A Fluid Structure Interaction System, Dylan Mcknight

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

Fluid-Structure Interaction concerns the interaction of parabolic fluids and hyperbolic elastic structures via numerous mechanisms such as boundary coupling and pressure. These models find application in blood flow, fluid flow in the eye, and air flow over plane wings. Parabolic equations are well known for “infinite speed of propagation,” which manifests itself via a uniform bound on the resolvent of the infinitesimal generator of the associated strongly continuous semigroup. Qualitatively, a solution of a parabolic pde with rough initial data is immediately smooth for any positive time. A priori, it is not clear whether a fluid structure interaction inherits any …

Phylogenetic And Biogeographic Patterns Of Devonian Proetid Trilobites, Katherine Jane Jordan

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

Ecological disruption events such as mass extinctions can result in the permanent alteration in clades and ecosystems. A pivotal time of change during the history of life on Earth can be seen in the Devonian Period. During this time, major transitions in marine and terrestrial system resulted in a different world at the end of the period in comparison to the beginning. One such group most heavily impacted were trilobites. Trilobites were reduced to one order by the end of the Devonian: Proetida. My dissertation focuses on phylogenetic, biogeographic, and paleocommunity patterns of this group, known as the last of …