Digital Commons Network^™

Electrically Induced Cancellation And Inversion Of Piezoelectricity In Ferroelectric Hf0.5Zr0.5O2, Haidong Lu, Dong-Jik Kim, Hugo Aramberri, Marco Holzer, Pratyush Buragohain, Sangita Dutta, Uwe Schroeder, Veeresh Deshpande, Jorge Íñiguez, Alexei Gruverman, Catherine Dubourdieu

Department of Physics and Astronomy: Faculty Publications

HfO2-based thin films hold huge promise for integrated devices as they show full compatibility with semiconductor technologies and robust ferroelectric properties at nanometer scale. While their polarization switching behavior has been widely investigated, their electromechanical response received much less attention so far. Here, we demonstrate that piezoelectricity in Hf_0.5Zr_0.5O₂ ferroelectric capacitors is not an invariable property but, in fact, can be intrinsically changed by electrical field cycling. Hf_0.5Zr_0.5O₂ capacitors subjected to ac cycling undergo a continuous transition from a positive effective piezoelectric coefficient d₃₃ in the pristine state to …

The Devil You Know And The Devil You Don’T: Current Status And Challenges Of Bovine Tuberculosis Eradication In The United States, Daniel J. O'Brien, Tyler C. Thacker, Liliana C.M. Salvador, Anthony G. Duffiney, Suelee Robbe‑Austerman, Mark S. Camacho, Jason E. Lombard, Mitchell V. Palmer

United States Department of Agriculture Wildlife Services: Staff Publications

Having entered into its second century, the eradication program for bovine tuberculosis (bTB, caused by Mycobacterium bovis) in the United States of America occupies a position both enviable and daunting. Excepting four counties in Michigan comprising only 6109 km2 (0.06% of US land area) classified as Modified Accredited, as of April 2022 the entire country was considered Accredited Free of bTB by the US Department of Agriculture for cattle and bison. On the surface, the now well-described circumstances of endemic bTB in Michigan, where white-tailed deer (Odocoileus virginianus) serve as a free-ranging wildlife maintenance host, may appear to be …

Universal Dna Methylation Age Across Mammalian Tissues, A. T. Lu, Jessica Lynn Petersen, Steve Horvath, Et Al.

Department of Animal Science: Faculty Publications

Aging, often considered a result of random cellular damage, can be accurately estimated using DNA methylation profiles, the foundation of pan-tissue epigenetic clocks. Here, we demonstrate the development of universal pan-mammalian clocks, using 11,754 methylation arrays from our Mammalian Methylation Consortium, which encompass 59 tissue types across 185 mammalian species. These predictive models estimate mammalian tissue age with high accuracy (r > 0.96). Age deviations correlate with human mortality risk, mouse somatotropic axis mutations and caloric restriction. We identified specific cytosines with methylation levels that change with age across numerous species. These sites, highly enriched in polycomb repressive complex 2-binding locations, …

Topological Hall Effect In Particulate Magnetic Nanostructure, Ahsan Ullah

Department of Physics and Astronomy: Dissertations, Theses, and Student Research

Conduction electrons change their spin direction due to the exchange interaction with the lattice spins. Ideally, the spins of the conduction electrons follow the atomic spin adiabatically, so that spins like S1, S2, and S3 can be interpreted as time-ordered sequences t1 < t2 < t3. Such spin sequences yield a quantum-mechanical phase factor in the wave function,  →ei, where  is known as the Berry phase. The corresponding spin rotation translates into a Berry curvature and an emergent magnetic field and subsequently, Hall-effect contribution known as the topological Hall-effect. This dissertation explores topological Hall-effect in particulate magnets, where noncollinear spins are stabilized by competition between different magnetic interactions. The topologically non-trivial spin textures in these nanostructures are flower states, curling states, vortex, and magnetic bubbles, which give rise to topological Hall-effect and have finite spin chirality and Skyrmion number Q. Topological Hall-effect is investigated in noninteracting nanoparticles, exchanges coupled centrosymmetric nanoparticles, exchanges coupled non-centrosymmetric nanoparticles which possess Dzyaloshinskii-Moriya interaction (DMI), and exchanged coupled Hard and soft magnetic films. Micromagnetic modeling, simulations, analytical calculations, and experimental methods are used to determine topological Hall-effect. In very small noninteracting nanoparticles, the reverse magnetic fields enhance Q due to the flower state until the reversal occurs, whereas, for particles with a radius greater than coherence radius, the Q jumps to a larger value at the nucleation field representing the curling state. The comparisons of magnetization patterns between experimental and computed magnetic force microscopy (MFM) measurements show the presence of spin chirality. Magnetic and Hall-effect measurements identify topological Hall-effect in the exchange-coupled Co and CoSi-nanoparticle films. The origin of the topological Hall-effect namely, the chiral domains with domain-wall chirality quantified by an integer skyrmion number in Co and chiral spins with partial skyrmion number in CoSi. These spin structures are different from the Skyrmions due to DMI in B-20 crystals and multilayered thin films with Cnv symmetry. In these films THE caused by cooperative magnetization reversal in the exchange-coupled Co-nanoparticles and peripheral chiral spin textures in CoSi-nanoparticles.

Advisor: Xiaoshan Xu

Functional Connectivity Varies Across Scales In A Fragmented Landscape, Kate I. T. Bird, Daniel R. Uden, Craig R. Allen

School of Natural Resources: Faculty Publications

Species of different sizes interact with the landscape differently because ecological structure varies with scale, as do species movement capabilities and habitat requirements. As such, landscape connectivity is dependent upon the scale at which an animal interacts with its environment. Analyses of landscape connectivity must incorporate ecologically relevant scales to address scale-specific differences. Many evaluations of landscape connectivity utilize incrementally increasing buffer distances or other arbitrary spatial delineations as scales of analysis. Instead, we used a mammalian body mass discontinuity analysis to objectively identify scales in the Central Platte River Valley (CPRV) of Nebraska, U.S.A. We implemented a graph-theoretic network …

Influence Of Ultrasound Machine Settings On Quantitative Measures Derived From Spatial Frequency Analysis Of Muscle Tissue, Scott K. Crawford, Stephanie A. Kliethermes, Bryan C. Heiderscheit, Greg Bashford

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Background Ultrasound is a powerful tool for diagnostic purposes and provides insight into both normal and pathologic tissue structure. Spatial frequency analysis (SFA) methods characterize musculoskeletal tissue organization from ultrasound images. Both sonographers in clinical imaging and researchers may alter a minimized range of ultrasound settings to optimize image quality, and it is important to know how these small adjustments of these settings affect SFA parameters. The purpose of this study was to investigate the effects of making small adjustments in a typical default ultrasound machine setting on extracted spatial frequency parameters (peak spatial frequency radius (PSFR), Mmax, Mmax%, and …

Machine Learning Techniques To Predict The Air Quality Using Meteorological Data In Two Urban Areas In Sri Lanka, Lakindu Mampitiya, Namal Rathnayake, Lee P. Leon, Vishwanadham Mandala, Hazi Md. Azamathulla, Sherly Shelton, Yukinobu Hoshino, Upaka Rathnayake

Department of Earth and Atmospheric Sciences: Faculty Publications

The effect of bad air quality on human health is a well-known risk. Annual health costs have significantly been increased in many countries due to adverse air quality. Therefore, forecasting air quality-measuring parameters in highly impacted areas is essential to enhance the quality of life. Though this forecasting is usual in many countries, Sri Lanka is far behind the state-of-the-art. The country has increasingly reported adverse air quality levels with ongoing industrialization in urban areas. Therefore, this research study, for the first time, mainly focuses on forecasting the PM₁₀ values of the air quality for the two urbanized areas …

Search For Higgs Boson Decay To A Charm Quark-Antiquark Pair In Proton-Proton Collisions At √S =13 Tev, A. Tumasyan

Department of Physics and Astronomy: Faculty Publications

A search for the standard model Higgs boson decaying to a charm quark-antiquark pair, H → c[], produced in association with a leptonically decaying V (W or Z) boson is presented. The search is performed with proton-proton collisions at √s = 13 TeV collected by the CMS experiment, corresponding to an integrated luminosity of 138 fb⁻¹. Novel charm jet identification and analysis methods using machine learning techniques are employed. The analysis is validated by searching for Z → c[] in VZ events, leading to its first observation at a hadron collider with a significance …

Communication In The Science-Policy Interface: Evidence From A Boundary Organization In Nebraska, Usa, Sechindra Vallury, Brian C. Chaffin, Samantha L. Hamlin, Craig R. Allen

School of Natural Resources: Faculty Publications

Boundary organizations have a crucial function in environmental governance by facilitating the processes through which scientists and decision-makers generate, exchange, evaluate, and utilize knowledge to identify societal problems, propose potential solutions, and make decisions on appropriate courses of action. This support for evidence-informed decision making is essential in addressing environmental challenges effectively. Despite the growing popularity of boundary organizations, there remains a significant challenge in designing information dissemination platforms to bridge the communication divide between scientific experts and non-experts. To address this gap, we used natural language processing tools to analyze the communication strategies of a specific boundary organization — …

Early Career Aquatic Scientists Forge New Connections At Eco-Das Xv, Olivia J. Graham, Alia Al-Haj, Eleanor C. Arrington, Emily R. Arsenault, Carolina C. Barbosa, Kadir Bice, Evie Brahmstedt, S. River D. Bryant, Xun Cai, Stacy Calhoun-Grosch, Joshua Culpepper, Katherine Dale, Derek J. Detweiler, Katlin D. Doughty, Kyle A. Emery, Kara Gadeken, Laura Griffiths, Atefeh Hosseini, Catriona Jones, Hadis Miraly, Alexander W. Mott, Karla Münzner, Igor Ogashawara, Carly R. Olson, Joseph S. Rabaey, Walter A. Rich, Phoenix A. Rogers, Meredith Evans Seeley, Lorena Selak, Qipei Shangguan, Kelsey J. Solomon, Xinyu Sun, Spencer J. Tassone, Audrey Thellman, John Tracey, Jilian Xiong, Tianfei Xue

School of Natural Resources: Faculty Publications

A sense of kuleana (personal responsibility) in caring for the land and sea. An appreciation for laulima (many hands cooperating). An understanding of aloha ’āina (love of the land). The University of Hawai’i at Manoa hosted the 2023 Ecological Dissertations in Aquatic Sciences (Eco-DAS) program, which fostered each of these intentions by bringing together a team of early career aquatic ecologists for a week of networking and collaborative, interdisciplinary project development (Fig. 1).

Seek And Classify: End-To-End Joint Multi-Signal Detection And Classification Using Deep Learning, Prashant Subedi

School of Computing: Dissertations, Theses, and Student Research

The rise in the use of wireless communication has led to the problem of spectrum scarcity in licensed bands. The popularity of Internet of Things (IoT) requires innovative solutions that maximize the use of available spectrum to support the increasing number of connected devices. This thesis tackles two significant problems in wireless communication: the need for efficient spectrum sensing techniques and the scarcity of large, diverse raw in-phase (I) and quadrature (Q) datasets.

The ability to detect and classify modulation of the signals efficiently can enable a cognitive radio to monitor the spectrum activity in real time and utilize unused …

Understanding The Factors Affecting Nebraskan Farmers’ And Landowners' Decision To Adopt Precision Agricultural Technologies And Programs, Corrin C. Winter

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

Advisors: Andrew Little, Christopher Chizinski

To gain insights into the challenges faced by Nebraska farmers and landowners when adopting precision agriculture technologies, I analyzed data collected from a 2022 survey involving 7,503 participants, consisting of producers and farmland owners from across the state of Nebraska. The primary objective was to provide valuable insights for agencies seeking to improve their precision agriculture and conservation outreach efforts for the benefit of conservation and Nebraskan farmers and landowners. This study aimed to understand key factors influencing adoption behaviors by evaluating the constraints to precision agriculture adoption, assessing the impact of producer and landowner …

Exploring Experimental Design And Multivariate Analysis Techniques For Evaluating Community Structure Of Bacteria In Microbiome Data, Kelsey Karnik

Department of Statistics: Dissertations, Theses, and Student Research

The gut microbiome plays a crucial role in human health, and by working collaboratively with microbiologists, we aim to further our understanding of the human gut and its impact on human health. Promoting a diverse microbiome is emphasized throughout microbiology literature, and involving a statistician in designing experiments to relate gut bacteria and some measured health outcome is crucial for ensuring valid and accurate results. By adopting new experimental design and analysis methods, researchers can begin to gain a deeper understanding of how the genetics of our food affect the composition of taxa within the gut microbiome. This dissertation is …

Positioning Undergraduate Learning Assistants In Instruction: A Case Study Of The La Role In Active Learning Mathematics Classrooms At The University Of Nebraska–Lincoln, Rachel Funk

Department of Mathematics: Dissertations, Theses, and Student Research

Research suggests learning assistant (LA) programs can be a change lever to support the institutionalization of active learning in postsecondary education. Some research suggests LAs offer unique benefits for STEM courses, independent from other change levers, but more research needs to be done to understand how LAs support active learning classrooms, specifically in mathematics. Research on mathematics instruction and the use of reform resources suggests that the successful implementation of reforms is impacted by perceptions individuals hold about that resource, such as the LA role. Yet, there is little research about the LA role in mathematics, particularly where the instructor …

Experimental Study Of Linux Flightsize Estimation, Mingrui Zhang

School of Computing: Dissertations, Theses, and Student Research

Transmission Control Protocol (TCP) is a fundamental Internet protocol responsible for controlling and coordinating the Internet traffic. As a result, TCP significantly influences the overall performance and stability of the Internet. One critical information required by a TCP connection to make decisions is FlightSize, which is the total amount of outstanding data contributed by the connection to the Internet. The FlightSize information is used by a TCP connection to determine its future sending rate and also avoid traffic congestion and collapse in the Internet. Consequently, an inaccurate estimation of FlightSize can result in degraded performance and instability of the Internet. …

Exploring The Presence Of Nonlinear Deterministic Dynamics In Commodity Prices, Sagar Dahal

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

Determining whether commodity prices (and volatility) are driven by linear stochastic processes or low-dimensional nonlinear deterministic dynamics (“chaos”) is crucial for policymaking, forecasting, production, storage, investment, risk management, and hedging decisions. Previous studies that used Lyapunov exponents and correlation dimensions to identify chaotic structures in price series may be unreliable in practical applications because these methods rely on asymptotic properties that require large, noiseless data which is often not available. We applied nonlinear time series analysis approaches to empirically detect the underlying market dynamics using the daily futures prices of ten agricultural commodities. We used phase space reconstruction to reconstruct …

Assessing Determinants Of Participation In Conservation Programs In The U. S., Manita Ale

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

The United States Department of Agriculture (USDA) has implemented conservation programs through Natural Resources Conservation Service (NRCS) and Farm Service Agency (FSA). Conservation Reserve Program (CRP), Conservation Stewardship Program (CSP), and Environmental Quality Incentives Program (EQIP) are some of them. These programs provide financial and technical assistance to farmers and ranchers to adopt land management practices that generate environmental benefits. In this study, we explore the determinants of participation in conservation programs (CRP, CSP, EQIP) in Iowa, Kansas, and Nebraska. For this, we use a unique survey-based data set comprising observations from row crop farmers in these states. We are …

Growth And Emergent Functionalities Of Oxide Thin Films Utilizing Interface Engineering, Detian Yang

Department of Physics and Astronomy: Dissertations, Theses, and Student Research

Complex oxide interfaces have offered intriguing novel emergent phenomena and multiple functionalities through interfacial reconstructions of spin, orbital, charge, and lattice degrees of freedom. Interface engineering via manipulating interfacial interaction, defects and multiple interfacial quantum charges and orders constitutes the essential method and technique to achieve desired functionalities in oxide heterostructures. In this thesis, shown are two examples of utilizing interfacial reconstruction and interfacial strain engineering to achieve intrinsic exchange bias and realize epitaxial growth of mixed-valence hexagonal manganite thin films, respectively.

Firstly, we demonstrated intrinsic exchange bias induced by interfacial reconstruction in Ni_xCo_yFe_3-x-yO …

Data-Driven Framework For Predicting And Scheduling Household Charging Of Evs, Ahmad Almaghrebi

Durham School of Architectural Engineering and Construction: Dissertations, Theses, and Student Research

The increasing prevalence of EV charging poses challenges for power grid stability and quality due to high charging load demands. Without effective energy management strategies for EV charging, the simultaneous power demand from numerous EVs can strain the electric grid, impacting power quality and the wholesale electricity market. To address these challenges, this dissertation presents a comprehensive framework comprising five critical tasks: analyzing EV charging behavior, optimizing charging schedules, developing predictive models, analyzing aggregated impacts, and evaluating implications of predicted user behavior on scheduling. By examining EV charging behavior at household and public charging stations, this study aims to understand …

Cooler Forests In Clean Air, Liang Chen

Department of Earth and Atmospheric Sciences: Faculty Publications

Improving air quality by reducing atmospheric aerosols can bring valuable health benefits, but also generally leads to warming. Now, research suggests that in cleaner air the local cooling effect of planting trees may be stronger in middle and low latitude regions.

Forests provide a substantial sink for atmospheric carbon and therefore have great potential for contributing to climate change mitigation globally.¹ Meanwhile, forests play an important role in local and regional climate through their effects on albedo, evapotranspiration, and surface roughness.² The biogeophysical mechanisms driving forest-climate feedback depend strongly on the local background climate. But it remains unclear …

Azimuthal Correlations Within Exclusive Dijets With Large Momentum Transfer In Photon-Lead Collisions, A. Tumasyan

Department of Physics and Astronomy: Faculty Publications

The structure of nucleons is multidimensional and depends on the transverse momenta, spatial geometry, and polarization of the constituent partons. Such a structure can be studied using high-energy photons produced in ultraperipheral heavy-ion collisions. The first measurement of the azimuthal angular correlations of exclusively produced events with two jets in photon-lead interactions at large momentum transfer is presented, a process that is considered to be sensitive to the underlying nuclear gluon polarization. This study uses a data sample of ultraperipheral lead-lead collisions at √s_NN = 5.02 TeV, corresponding to an integrated luminosity of 0.38 nb⁻¹, collected with …

Prairie Protector: Student Development Of Systems Thinking Habits In The Context Of Agroecosystems, Erin Ingram, Jennifer Keshwani

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Introduction: The Great Plains ecosystem offers an opportunity for young people to gain knowledge about intricate systems through practical learning. The spread of woody plants into grasslands, known as the “Green Glacier,” poses a risk to biodiversity and animal production. Although effective management strategies exist, some land managers are reluctant to use them. It is critical to cultivate a scientifically literate population that can think systematically and make informed decisions based on STEM principles to address such complex agroecosystem problems.

Methods: In this study, semi-structured focus group discussions with high school students were analyzed to determine whether Prairie …

Drinking Water Quality Management Progress In Ontario, Two Decades After Walkerton, Megan Fuller, Emma Wells, Laith Furatian, Ian Douglas, Kaycie Lane

Department of Civil and Environmental Engineering: Faculty Publications

Following the waterborne disease outbreak in Walkerton, Ontario, the province made significant efforts to implement recommendations of the public inquiry that resulted. As Ontario reformed its drinking water sector, other jurisdictions were advancing risk-based quality management frameworks for drinking water, including the World Health Organization (WHO) through its water safety plan (WSP) framework. Two decades after the Walkerton tragedy, this paper seeks to: (i) evaluate alignment of Ontario’s Drinking Water Quality Management Standard (DWQMS) with the WSP framework (ii) review readily available data for evidence that Ontario’s DWQMS implementation has improved drinking water safety and promoted a preventive approach through …

Differential Membrane Binding Of Α/Β-Peptide Foldamers: Implications For Cellular Delivery And Mitochondrial Targeting, Tzong-Hsien Lee, James W. Checco, Tess Malcolm, Chelcie H. Eller, Ronald T. Raines, Samuel H. Gellman, Erinna F. Lee, W. Douglas Fairlie, Marie-Isabel Aguilar

Department of Chemistry: Faculty Publications

The intrinsic pathway of apoptosis is regulated by the Bcl-2 family of proteins. Inhibition of the anti-apoptotic members represents a strategy to induce apoptotic cell death in cancer cells. We have measured the membrane binding properties of a series of peptides, including modified α/β-peptides, designed to exhibit enhanced membrane permeability to allow cell entry and improved access for engagement of Bcl-2 family members. The peptide cargo is based on the pro-apoptotic protein Bim, which interacts with all anti-apoptotic proteins to initiate apoptosis. The α/β-peptides contained cyclic β-amino acid residues designed to increase their stability and membrane-permeability. Dual polarisation interferometry was …

Leveraging Eco-Evolutionary Models For Gene Drive Risk Assessment, Matthew A. Combs, Andrew J. Golnar, Justin M. Overcash, Alun L. Lloyd, Keith R. Hayes, David A. O'Brochta, Kim M. Pepin

United States Department of Agriculture Wildlife Services: Staff Publications

Engineered gene drives create potential for both widespread benefits and irreversible harms to ecosystems. CRISPR-based systems of allelic conversion have rapidly accelerated gene drive research across diverse taxa, putting field trials and their necessary risk assessments on the horizon. Dynamic processbased models provide flexible quantitative platforms to predict gene drive outcomes in the context of system-specific ecological and evolutionary features. Here, we synthesize gene drive dynamic modeling studies to highlight research trends, knowledge gaps, and emergent principles, organized around their genetic, demographic, spatial, environmental, and implementation features. We identify the phenomena that most significantly influence model predictions, discuss limitations of …

Idempotent Completions Of Equivariant Matrix Factorization Categories, Michael K. Brown, Mark E. Walker

Department of Mathematics: Faculty Publications

We prove that equivariant matrix factorization categories associated to henselian local hypersurface rings are idempotent complete, generalizing a result of Dyckerhoff in the non- equivariant case.

Electron Scattering From 1-Methyl-5-Nitroimidazole: Cross-Sections Formodeling Electron Transport Through Potential Radiosensitizers, Ana I. Lozano, Lidia Álvarez, Adrián García-Abenza, Carlos Guerra, Fábris Kossoski, Jaime Rosado, Francisco Blanco, Juan Carlos Oller, Mahmudul Hasan, Martin Centurion, Thorsten Weber, Daniel S. Slaughter, Deepthy M. Mootheril, Alexander Dorn, Sarvesh Sarvesh, Paulo Limão-Vieira, Rafael Colmenares, Gustavo García

Department of Physics and Astronomy: Faculty Publications

In this study, we present a complete set of electron scattering cross-sections from 1-Methyl-5- Nitroimidazole (1M5NI) molecules for impact energies ranging from 0.1 to 1000 eV. This information is relevant to evaluate the potential role of 1M5NI as a molecular radiosensitizers. The total electron scattering cross-sections (TCS) that we previously measured with a magnetically confined electron transmission apparatus were considered as the reference values for the present analysis. Elastic scattering cross-sections were calculated by means of two different schemes: The Schwinger multichannel (SMC) method for the lower energies (below 15 eV) and the independent atom model-based screening-corrected additivity rule with …

Beef Color And Tenderness Response To Production Systems Utilizing Additive Combinations Of Growth-Promotant Technologies, Megan J. Webb, Janna J. Block, John R. Jaeger, R. Funston, Michael G. Gonda, Keith R. Underwood, Judson K. Grubbs, Kenneth C. Olson, Amanda D. Blair

West Central Research and Extension Center, North Platte

The objective of this study was to compare the influence of beef production systems using additive combinations of growth-promotant technologies on meat quality. Steer calves (n = 120) were assigned to 1 of 4 treatments: 1) no technology (NT; control), 2) antibiotic treated (ANT; NT plus therapeutic antibiotics, monensin, and tylosin), 3) implant treated (IMP; ANT plus a series of three implants), and 4) beta-agonist treated (BA; IMP plus ractopamine-HCl). Muscle biopsy samples from the longissimus lumborum were extracted from a subset (n = 4 per treatment) of steers to evaluate expression of calpain-1, calpain-2, and calpastatin using …

Crustal Structures Of Diebold Knoll And Adjacent Juan De Fuca Oceanic Crust From Integration Of Seismic, Gravity And Magnetic Data, Md Ariful Islam

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

Cascadia Subduction Zone (CSZ) has a long history of devastating earthquakes as the Juan de Fuca plate subducts beneath North America, where an imminent megathrust earthquake is expected. Compared to other subduction zones, CSZ exhibits unusually low seismic activity, particularly in the central region with respect to relatively high seismicity zones to the north and south. Some researchers attribute this behavior to subducted seamounts, although their impact on seismicity remains poorly understood and highly debated in the literature. Examining subducted seamounts is challenging due to complexity of the overburden strata. That is why this study focuses on an isolated not-yet-subducted …

Light Alters Leaf Breakdown Rates And Metabolic Activity In Anthropogenically Impacted Nebraska Streams, William Reilly Farrell

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

Algal growth influences carbon breakdown rates in aquatic ecosystems; however, the magnitude and direction of these effects differ based on ecosystem context. To explore algal priming effects on decomposition in anthropogenically impacted ecosystems, I conducted light manipulation experiments in three streams, each surrounded by different land uses (i.e., predominantly urban, row crop, or concentrated animal feeding operation) across Nebraska. I measured leaf breakdown rates, metabolic activity, fungal and algal biomass, and leaf percent carbon (C) and phosphorus (P) to assess the effect of light differences. These streams were impacted by sedimentation and turbidity over the course of the leaf incubation. …