Physical Sciences and Mathematics Commons^™

Orb-Web Spider Argiope (Araneidae) As Indigenous Arrow Poison Of G/Ui And G//Ana San Hunters In The Kalahari, Tharina L. Bird, Smith Moeti, Robert K. Hitchcock, Melinda C. Kelly, Lefang L. Chobolo, Nonofo Gotcha, Kgosi K. Moatlhodi, Leungo D. Mukoka, Emmanuel K. Sekopo, Caroline Simmrita Chaboo

Publications of UNSM Staff and Affiliates

Hunting has been crucial in early human evolution. Some San (Bushmen) of southern Africa still practice their indigenous hunting. The use of poisons is one remarkable aspect of their bow-and-arrow hunting but the sources, taxonomic identifications of species used, and recipes, are not well documented. This study reports on fieldwork to investigate recent indigenous hunting practices of G/ui and G//ana San communities in the Central Kalahari Game Reserve (CKGR), Botswana. Here we discuss their use of spider poison. The hunters use the contents of the opisthosoma (‘abdomen’) of a spider as sole ingredient of the arrow poison and discard the …

Holocene Variations In Lake Titicaca Water Level And Their Implications For Sociopolitical Developments In The Central Andes, Stéphane Guédron, Christophe Delaere, Sherilyn C. Fritz, Julie Tolu, Pierre Sabatier, Anne-Lise Devel, Carlos Heredia, Claire Vérin, Eduardo Q. Alves, Paul A. Baker

Papers in the Earth and Atmospheric Sciences

Holocene climate in the high tropical Andes was characterized by both gradual and abrupt changes, which disrupted the hydrological cycle and impacted landscapes and societies. High-resolution paleoenvironmental records are essential to contextualize archaeological data and to evaluate the sociopolitical response of ancient societies to environmental variability. Middle-to-Late Holocene water levels in Lake Titicaca were reevaluated through a transfer function model based on measurements of organic carbon stable isotopes, combined with high-resolution profiles of other geochemical variables and paleoshoreline indicators. Our reconstruction indicates that following a prolonged low stand during the Middle Holocene (4000 to 2400 BCE), lake level rose rapidly …

Demographic Groups Differ In Urban Recreational Behavior, Brandon Barlow

Dissertations & Theses in Natural Resources

Urban recreational behavior is an essential component to understanding both how our recreational opportunities will be utilized and how they can be further improved. By improving recreational opportunities, we can ensure safe and reliable emotional and physical outlets for users. As urban areas continue to expand both in geographic area and in population size, urban recreational opportunities will also see growth in the number of recreational users. Demographics provide the opportunity to further understand and predict recreational behavior, producing a variety of decision management tools. Our goal was to understand differences in urban recreational behavior among demographic groups. To address …

Sturgeon Chub Distributional Patterns And Habitat Use And Benthic Fish Assemblage Structure In Missouri River Tributaries Of South Dakota, Mitchell R. Magruder

Dissertations & Theses in Natural Resources

Native species of the Missouri River drainage inhabiting benthic habitats dominate state and federal lists of species at risk. Sicklefin Chub Macrhybopsis meeki and Sturgeon Chub Macrhybopsis gelida are two native Missouri River benthic minnows that are currently under review for federal listing under the Endangered Species Act (ESA) due to extensive population declines and local extirpations within their native range. Substantial alterations to the Missouri River threaten Macrhybopsis spp. and other benthic fishes; however, large, less impacted tributaries in South Dakota may act as refugia for native species. The extent of Sicklefin Chub and Sturgeon Chub populations is largely …

An Empirical Study On The Classification Of Python Language Features Using Eye-Tracking, Jigyasa Chauhan

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

Python, currently one of the most popular programming languages, is an object-
oriented language that also provides language feature support for other programming
paradigms, such as functional and procedural. It is not currently understood how
support for multiple paradigms affects the ability of developers to comprehend that
code. Understanding the predominant paradigm in code, and how developers classify
the predominant paradigm, can benefit future research in program comprehension as
the paradigm may factor into how people comprehend that code. Other researchers
may want to look at how the paradigms in the code interact with various code smells.
To investigate how …

One Health In Action: Flea Control And Interpretative Education At Badlands National Park, David Eads, Lindsey Buehler, Anne Esbenshade, Jason Fly, Evan Miller, Holly Redmond, Emily Ritter, National Park Service, Sasha Wittmann, Paul Roghair, Eddie Childers

USGS Staff -- Published Research

No abstract provided.

Learnfca: A Fuzzy Fca And Probability Based Approach For Learning And Classification, Suraj Ketan Samal

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

Formal concept analysis(FCA) is a mathematical theory based on lattice and order theory used for data analysis and knowledge representation. Over the past several years, many of its extensions have been proposed and applied in several domains including data mining, machine learning, knowledge management, semantic web, software development, chemistry ,biology, medicine, data analytics, biology and ontology engineering.

This thesis reviews the state-of-the-art of theory of Formal Concept Analysis(FCA) and its various extensions that have been developed and well-studied in the past several years. We discuss their historical roots, reproduce the original definitions and derivations with illustrative examples. Further, we provide …

Attention In The Faithful Self-Explanatory Nlp Models, Mostafa Rafaiejokandan

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

Deep neural networks (DNNs) can perform impressively in many natural language processing (NLP) tasks, but their black-box nature makes them inherently challenging to explain or interpret. Self-Explanatory models are a new approach to overcoming this challenge, generating explanations in human-readable languages besides task objectives like answering questions. The main focus of this thesis is the explainability of NLP tasks, as well as how attention methods can help enhance performance. Three different attention modules are proposed, SimpleAttention, CrossSelfAttention, and CrossModality. It also includes a new dataset transformation method called Two-Documents that converts every dataset into two separate documents required by the …

Bevers: A General, Simple, And Performant Framework For Automatic Fact Verification, Mitchell Dehaven

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

Fact verification has become an important process, primarily done manually by humans, to verify the authenticity of claims and statements made online. Increasingly, social media companies have utilized human effort to debunk false claims on their platforms, opting to either tag the content as misleading or false, or removing it entirely to combat misinformation on their sites. In tandem, the field of automatic fact verification has become a subject of focus among the natural language processing (NLP) community, spawning new datasets and research. The most popular dataset is the Fact Extraction and VERification (FEVER) dataset. In this thesis an end-to-end …

Sequence-Based Bioinformatics Approaches To Predict Virus-Host Relationships In Archaea And Eukaryotes, Yingshan Li

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

Viral metagenomics is independent of lab culturing and capable of investigating viromes of virtually any given environmental niches. While numerous sequences of viral genomes have been assembled from metagenomic studies over the past years, the natural hosts for the majority of these viral contigs have not been determined. Different computational approaches have been developed to predict hosts of bacteria phages. Nevertheless, little progress has been made in the virus-host prediction, especially for viruses that infect eukaryotes and archaea. In this study, by analyzing all documented viruses with known eukaryotic and archaeal hosts, we assessed the predictive power of four computational …

The North Platte River Valley: The Intersectionality Between Water Quality And People, Anni Poetzl

Dissertations & Theses in Natural Resources

The North Platte River (NPR) Valley of western Nebraska is a semi-arid watershed with row crop production, livestock production, and urban land use activity and has a population of diverse stakeholders. These land use activities contribute to the enrichment of surface waters, such as streams, which can affect human and ecosystem health, as well as economic development and recreational activities. The project objectives are to: (1) quantify the movement of dissolved inorganic nutrients from the land within the NPR Valley to the NPR via tributaries and canals, (2) identify spatiotemporal variability of nutrient limitation of periphyton growth within the NPR, …

Human And Hydrologic Influences On Nebraska's Endangered Rainwater Basin Wetlands, Sarah Thompson

Dissertations & Theses in Earth and Atmospheric Sciences

Over half of wetlands in North America have been lost or degraded. Rainwater Basin (RWB) wetlands, located in south-central Nebraska, are a primary example of such loss; an estimated 90% have been destroyed by land conversion for agriculture. Remaining RWB wetlands are often embedded in row-crop fields, where they are threatened by altered surface water runoff flow, drainage features, and excess sediment inputs. Efforts at the state and federal level have been made to preserve this wetland complex due to the critical stopover habitat these wetlands provide for migratory birds. Land managers work to maintain sufficient water levels during migratory …

A Pipeline To Generate Deep Learning Surrogates Of Genome-Scale Metabolic Models, Achilles Rasquinha

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

Genome-Scale Metabolic Models (GEMMs) are powerful reconstructions of biological systems that help metabolic engineers understand and predict growth conditions subjected to various environmental factors around the cellular metabolism of an organism in observation, purely in silico. Applications of metabolic engineering range from perturbation analysis and drug-target discovery to predicting growth rates of biotechnologically important metabolites and reaction objectives within dierent single-cell and multi-cellular organism types. GEMMs use mathematical frameworks for quantitative estimations of flux distributions within metabolic networks. The reasons behind why an organism activates, stuns, or fluctuates between alternative pathways for growth and survival, however, remain relatively unknown. GEMMs …

Computer Engineering Education, Marilyn Wolf

CSE Conference and Workshop Papers

Computer engineering is a rapidly evolving discipline. How should we teach it to our students?

This virtual roundtable on computer engineering education was conducted in summer 2022 over a combination of email and virtual meetings. The panel considered what topics are of importance to the computer engineering curriculum, what distinguishes computer engineering from related disciplines, and how computer engineering concepts should be taught.

An Interactive Simulation And Visualization Tool For Conventional And Aberration-Corrected Transmission Electron Microscopy, Xingzhong Li

Faculty Publications from Nebraska Center for Materials and Nanoscience

Contrast transfer function (CTF) is a vital function in transmission electron microscopy (TEM). It expresses to what extent amplitudes converted from the phase changes of the diffracted waves contribute to the TEM image, including the effects of lens aberrations. Simulation is very helpful to understand the application of the function thoroughly. In this work, we develop the CTFscope as a component in the Landyne software suite, to calculate the CTF with temporal and spatial dumping envelopes for conventional TEM and to extend it to various aberrations (up to fifth order) for aberration-corrected (AC)- TEM. It also includes effects on the …

A Long-Term Vision For An Ecologically Sound Platte River, Andrew J. Caven, Melissa M. Mosier, Kristal Stoner, Bill Taddicken, Brice Krohn, Ashley Gramza, Craig R. Allen, Mike Carter, Michelle Koch, Kirk D. Schroeder, Sarah Bailey, Rich Walters, Brian C. Chaffin, Erica Gnuse, Amy Jones, Kate Bird

Zea E-Books Collection

The Platte River extends about 310 mi (499 km) from North Platte, Nebraska, to its terminus at the Missouri River confluence near Plattsmouth, Nebraska. The Platte River Valley is a continentally significant ecosystem that serves as a major stopover for migratory waterbirds in the Central Flyway including the endangered Whooping Crane (Grus americana) and >1 million Sandhill Cranes (Antigone canadensis) at the peak of spring migration. However, the Platte River Valley also supports a great diversity of avifauna including grassland breeding birds, native stream fish, vascular plants, herpetofauna, mammals, pollinators, and aquatic macroinvertebrates. Despite ongoing conservation …

Remote Surface Optical Phonon Scattering In Ferroelectric Ba0.6Sr0.4Tio3 Gated Graphene, Hanying Chen, Tianlin Li, Yifei Hao, Anil Rajapitamahuni, Zhiyong Xiao, Stefan Schoeche, Mathias Schubert, Xia Hong

Xia Hong Publications

We report the effect of remote surface optical (RSO) phonon scattering on carrier mobility in monolayer graphene gated by ferroelectric oxide. We fabricate monolayer graphene transistors back-gated by epitaxial (001) Ba0.6Sr0.4TiO3 films, with field effect mobility up to 23,000 cm² V⁻¹ s⁻¹ achieved. Switching ferroelectric polarization induces nonvolatile modulation of resistance and quantum Hall effect in graphene at low temperatures. Ellipsometry spectroscopy studies reveal four pairs of optical phonon modes in Ba_0.6Sr_0.4TiO₃, from which we extract RSO phonon frequencies. The temperature dependence of resistivity in graphene can be well accounted for …

Population Health Metrics During The Early Stages Of The Covid-19 Pandemic: Correlative Pilot Study, Marie A. Severson, David A. Cassada, Victor C. Huber, Daniel D. Snow, Lisa M. Mcfadden

Faculty Publications from The Water Center

Background: COVID-19 has caused nearly 1 million deaths in the United States, not to mention job losses, business and school closures, stay-at-home orders, and mask mandates. Many people have suffered increased anxiety and depression since the pandemic began. Not only have mental health symptoms become more prevalent, but alcohol consumption has also increased during this time. Helplines offer important insight into both physical and mental wellness of a population by offering immediate, anonymous, cheap, and accessible resources for health and substance use disorders (SUD) that was unobstructed by many of the mandates of the pandemic. Further, the pandemic also …

Comparative Behavioral Ecotoxicology Of Inland Silverside Larvae Exposed To Pyrethroids Across A Salinity Gradient, Sara J. Hutton, Samreen Siddiqui, Emily I. Pedersen, Christopher Y. Markgraf, Amelie Segarra, Michelle L. Hladik, Richard E. Connon, Susanne M. Brander

USGS Staff -- Published Research

Pyrethroids, a class of commonly used insecticides, are frequently detected in aquatic environments, including estuaries. The influence that salinity has on organism physiology and the partitioning of hydrophobic chemicals, such as pyrethroids, has driven interest in how toxicity changes in saltwater compared to freshwater. Early life exposures in fish to pyrethroids cause toxicity at environmentally relevant concentrations, which can alter behavior. Behavior is a highly sensitive endpoint that influences overall organism fitness and can be used to detect toxicity of environmentally relevant concentrations of aquatic pollutants. Inland Silversides (Menidia beryllina), a commonly used euryhaline model fish species, were exposed …

Using Active Source Seismology To Image The Palos Verdes Fault Damage Zone As A Function Of Distance, Depth, And Geology, Travis Alongi, Emily E. Brodsky, Jared Kluesner, Daniel Brothers

USGS Staff -- Published Research

Fault damage zones provide a window into the non-elastic processes of an earthquake. Geological and seismic tomography methods have been unable to measure damage zones at depth with sufficient spatial sampling to evaluate the relative influence of depth, distance, and lithological variations. Here, we identify and analyze the damage zone of the Palos Verdes Fault offshore southern California using two 3D seismic reflection datasets. We apply a novel algorithm to identify discontinuities attributed to faults and fractures in large seismic volumes and examine the spatial distribution of fault damage in sedimentary rock surrounding the Palos Verdes Fault. Our results show …

Evaluating Dimensionality Reduction For Genomic Prediction, Vamsi Manthena, Diego Jarquín, Rajeev K. Varshney, Manish Roorkiwal, Girish Prasad Dixit, Chellapilla Bharadwaj, Reka Howard

Faculty Publications, Department of Statistics

The development of genomic selection (GS) methods has allowed plant breeding programs to select favorable lines using genomic data before performing field trials. Improvements in genotyping technology have yielded high-dimensional genomic marker data which can be difficult to incorporate into statistical models. In this paper, we investigated the utility of applying dimensionality reduction (DR) methods as a pre-processing step for GS methods. We compared five DR methods and studied the trend in the prediction accuracies of each method as a function of the number of features retained. The effect of DR methods was studied using three models that involved the …

Coastal Wetland Area Change For Two Freshwater Diversions In The Mississippi River Delta, John R. White, Brady Couvillion, John W. Day

USGS Staff -- Published Research

Coastal systems around the globe are being re-integrated with adjacent river systems to restore the natural hydrologic connection to riparian wetlands. The Mississippi River sediment diversions or river reconnections are one such tool to combat high rates of wetland loss in coastal Louisiana, USA by providing freshwater, sediment, and nutrients. There has been some disagreement in the published literature whether re-establishing river reconnection is slowing or contributing to coastal wetland loss. This issue is due to the difficulties in the application of remote sensing in low-relief environments where water level changes could indicate either land loss or simply temporary submergence. …

Observations On Late Cretaceous Micrampulla (Corethrales, Bacillariophyceae) From The Campbell Plateau (Zealandia), Southwest Pacific Ocean, Kenta Abe, David M. Harwood, Richard W. Jordan

Papers in the Earth and Atmospheric Sciences

Late Cretaceous (late Campanian) diatom assemblages from the Campbell Plateau (Zealandia), southwest Pacific Ocean, obtained from Deep Sea Drilling Project (DSDP) Leg 29 Site 275, contain well-preserved specimens of two enigmatic diatom species currently assigned to the genus Ktenodiscus; Micrampulla parvula originally described from the Maastrichtian-age Moreno Shale, California, and Pterotheca cretacea from DSDP Site 275. In general, the two species share a number of common features with modern Corethron (domed valves, probable heterovalvate frustules, T-shaped serrated articulated spines, marginal sockets), but differ in the location of the sockets (i.e. vertically at the base of the valve dome and …

Evidence For The ~ 1.4 Ga Picuris Orogeny In The Central Colorado Front Range, Asha A. Mahatma, Yvette D. Kuiper, Christopher S. Holm-Denoma

USGS Staff -- Published Research

We present the first evidence for sedimentation and new evidence for penetrative deformation and metamorphism in the central Colorado Front Range associated with the ~ 1.48–1.35 Ga Picuris orogeny. This orogeny has recently been recognized in New Mexico, Arizona and southern Colorado and may be part of a larger active accretionary margin that includes the ~ 1.51–1.46 Ga Pinware and Baraboo events, in eastern Canada and central US respectively, that preceded the amalgamation of the Rodinian supercontinent. We demonstrate that in addition to ~ 1.4 Ga reactivation of northeast-trending Paleoproterozoic shear zones, regional folding occurred in an area south of …

A Tem Study Of Fe3+X Co3-XTi2 (X = 0, 1, 2, 3) Intermetallic Alloys, Xingzhong Li, Anandakumar Sarella, B. Balasubramanian, Shah R. Valloppilly

David Sellmyer Publications

A TEM study has been carried out on crystal structures in the rare-earth-free intermetallic alloys, Fe_3+xCo_3-xTi₂ (x = 0, 1, 2, 3). These alloys have been demonstrated to have potentially high magnetic anisotropy. In these alloys, the main intermetallic compound was recently reported as a new hexagonal phase with a space group of P-6 m2. The present study reveals that the main compound belongs to Laves C14 variant surrounded by α-Fe type crystal as secondary phase in the Fe_3+xCo_3-xTi₂ (x = 0, 1, 2, 3) alloys, in agreement with the …

Level And Pattern Of Overstory Retention Shape The Abundance And Long-Term Dynamics Of Natural And Created Snags, Charles B. Halpern, Allison K. Rossman, Joan C. Hagar

USGS Staff -- Published Research

Standing dead trees, or snags, serve myriad functions in natural forests, but are often scarce in forests managed for timber production. Variable retention (VR), the retention of live and dead trees through harvest, has been adopted globally as a less intensive form of regeneration harvest. In this study, we explore how two key elements of VR systems — level (amount) and spatial pattern of live-tree retention — affect the carryover and post-harvest dynamics of natural and artificially created snags. We present nearly two decades of data from the DEMO Study, a regional-scale experiment in VR harvests of Douglas-fir-dominated forests in …

Bayesian Analysis For The Lomax Model Using Noninformative Priors, Daojiang He, Dongchu Sun, Qing Zhu

Faculty Publications, Department of Statistics

The Lomax distribution is an important member in the distribution family. In this paper, we systematically develop an objective Bayesian analysis of data from a Lomax distribution. Noninformative priors, including probability matching priors, the maximal data information (MDI) prior, Jeffreys prior and reference priors, are derived. The propriety of the posterior under each prior is subsequently validated. It is revealed that the MDI prior and one of the reference priors yield improper posteriors, and the other reference prior is a second-order probability matching prior. A simulation study is conducted to assess the frequentist performance of the proposed Bayesian approach. Finally, …

Hydrogen Isotope Behavior During Rhyolite Glass Hydration Under Hydrothermal Conditions, Michael R. Hudak, Ilya N. Bindeman, James M. Watkins, Jacob B. Lowenstern

USGS Staff -- Published Research

The diffusion of molecular water (H₂O_m) from the environment into volcanic glass can hydrate the glass up to several wt% at low temperature over long timescales. During this process, the water imprints its hydrogen isotope composition (δD_H2O) to the glass (δD_gl) offset by a glass-H₂O fractionation factor (ΔD_gl-H2O = δD_gl – δD_H2O) which is approximately -33‰ at Earth surface temperatures. Glasses hydrate much more rapidly at higher, sub-magmatic temperatures as they interact with H₂O during eruption, transport, and emplacement. To aid in the interpretation …

Timber Rattlesnake (Crotalus Horridus): A Species Conservation Assessment For The Nebraska Natural Legacy Project, Melissa J. Panella, Dan Fogell, Colleen Rothe-Groleau

Nebraska Game and Parks Commission Publications

The primary goal in the development of at-risk species conservation assessments is to compile biological and ecological information that may assist conservation practitioners in making decisions regarding the conservation of species of interest. The Nebraska Natural Legacy Project recognizes the timber rattlesnake (Crotalus horridus) as a Tier 1 at-risk species. Provided here are general management recommendations regarding timber rattlesnakes. Conservation practitioners will need to use their professional judgment for management decisions based on objectives, location, and site-specific conditions. Based on the body of literature and available data, this species conservation assessment provides an overview of our current knowledge of timber …

2022 Academic Program Review

School of Natural Resources: Documents and Reviews

No abstract provided.