Physical Sciences and Mathematics Commons^™

Sequence Stratigraphy, Chemostratigraphy, And Biostratigraphy Of Lower Ordovician Units In Northeastern And Western Central Utah: Regional Implications, Colter R. Davis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Lower to Middle Ordovician Garden City Formation and Pogonip Group are mixed carbonate and sandy marine rocks deposited on the western margin of ancestral North America. The Garden City Formation was deposited in the Northern Utah Basin and the Pogonip Group was deposited in the Ibex Basin. These two basins experienced different rates of subsidence that resulting in significant thickness differences between rock units and different rock types related to sea level change. This study provides a unique opportunity to examine changes in rock types, rock chemistry, and fossil types as sea level changed within two separate basins in …

Spatio-Temporal History Of Fluid-Rock Interaction In The Hurricane Fault Zone, Jace Michael Koger

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Hurricane Fault is a 250-km long, west dipping, active Basin and Range-bounding normal fault in southwest Utah and northwest Arizona. There are multiple known hot springs along its 250-km length and multiple late Tertiary-Quaternary basaltic centers that broadly parallel the fault. Possible sources of hot spring fluids include deeply circulated meteoric water that experienced water-rock exchange at high temperatures (>100 °C) and deep-seated crustal fluids. Abundant damage zone veins, cements, and host rock alteration are present along strike, indicative of past fluid flow. Carbonate veins and cements are key features of the Hurricane Fault zone, and the primary …

The Influence Of Aspen Chemistry And The Nutritional Context On Aspen Herbivory, Kristen Y. Heroy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Consumption of aspen by herbivores is one major force causing aspen decline in North America. In this Dissertation, I aimed to determine why herbivores prefer browsing on certain aspen stands over others, and why they prefer consuming aspen that contains chemical defenses over understory forages like grasses, forbs, and shrubs. I explored the influence of nutrients and chemical defenses within aspen on aspen intake and preference by lambs in pen experiments. I also explored drivers of aspen preference on the landscape by looking at relationships between aspen herbivory, indicators of aspen health, amount of nutrients available in the understory, and …

Great Basin Bristlecone Pine Resistance To Mountain Pine Beetle: An Evaluation Of Dendroctonus Ponderosae Host Selection Behavior And Reproductive Success In Pinus Longaeva, Erika L. Eidson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The mountain pine beetle (Dendroctonus ponderosae) is a native bark beetle that attacks and kills most species of pines (Pinus) throughout its range in western North America. Due to the strong relationship between thermal conditions and mountain pine beetle population success, climate change-induced changes in mountain pine beetle outbreaks are a major concern for land managers. Over the past several decades, warmer than average temperatures allowed mountain pine beetle populations to reach epidemic levels across much of the western U.S. and Canada, including high elevations where outbreaks were previously limited by cool temperatures. Many high-elevation pine …

Sclerocactus Wetlandicus: Habitat Characterization, Seed Germination And Mycorrhizal Analysis, Kourtney T. Harding

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Uinta Basin hookless cactus (Sclerocactus wetlandicus) is a threatened species native to Eastern Utah. The cactus is found in a landscape highly disturbed by non-renewable energy production. To understand the environmental conditions that support natural growth of this cactus, we asked what types of plants were present in the same areas as the cactus, and if the types of plants were different in environments that were disturbed. From our assessment, we determined that the types of plants present in disturbed areas were drastically different from those present in undisturbed locations. Areas previously used for energy production are …

Conservative Tryptophan Mutations In Protein Tyrosine Phosphatase Ptp1b And Its Effect On Catalytic Rate And Chemical Reaction, Teisha Richan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Protein-tyrosine phosphatases (PTPs) catalyze the hydrolysis of phosphorylated tyrosines by a 2-step mechanism involving nucleophilic attack by cysteine and general acid catalysis by aspartic acid. In most PTPs the aspartic acid resides on a flexible protein loop, consisting of about a dozen residues, called the WPD loop. PTP catalysis rates span several orders of magnitude, and differences in WPD loop dynamics have recently been show to correlate with the rate of enzymatic catalysis. The rate of WPD loop motion could possibly be related to a widely conserved tryptophan residue on the WPD loop. Therefore, point mutants were made in PTP1B …

A Stochastic Model For Water-Vegetation Systems And The Effect Of Decreasing Precipitation On Semi-Arid Environments, Shannon A. Dixon

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Current climate change trends are affecting the magnitude and recurrence of extreme weather events. In particular, several semi-arid regions around the planet are confronting more intense and prolonged lack of precipitation, slowly transforming these regions into deserts. Many mathematical models have been developed for purposes of analyzing vegetation-water interactions, particularly in semi-arid landscapes. Most models are based on the average behavior of the system as a whole, and how it is influenced by external changes. These models may be termed "macro-scale" models. Other models have concerned themselves with the interactions between individuals, in this case the interactions between individual plants …

Microcontroller Survivability In Space Conditions, Windy Olsen

Senior Theses and Projects

No abstract provided.

Microcontroller Survivability In Space Conditions, Windy Olsen

Physics Capstone Projects

The Utah State University (USU) Materials Physics Group (MPG) is interested in the performance of Commercial Off the Shelf (COTS) microcontrollers in space conditions. Microcontrollers are commonly used on CubeSats, small relatively inexpensive satellites that are flown in Low Earth Orbit (LEO) at altitudes of ~160 km-2000 km. There is a large area of interest in COTS microcontrollers because they provide a more cost-effective on-board computer for CubeSats. This experiment focused on the functionality of an ATmega328 microcontroller on an Arduino Uno board inside the MPG’s Space Survivability Test (SST) Chamber. A diagnostic program was used to try to detect …

A Comparison Of Multiple Testing Adjustment Methods With Block-Correlation Positively-Dependent Tests, John R. Stevens, Abdullah Al Masud, Anvar Suyundikov

Mathematics and Statistics Faculty Publications

In high dimensional data analysis (such as gene expression, spatial epidemiology, or brain imaging studies), we often test thousands or more hypotheses simultaneously. As the number of tests increases, the chance of observing some statistically significant tests is very high even when all null hypotheses are true. Consequently, we could reach incorrect conclusions regarding the hypotheses. Researchers frequently use multiplicity adjustment methods to control type I error rates—primarily the family-wise error rate (FWER) or the false discovery rate (FDR)—while still desiring high statistical power. In practice, such studies may have dependent test statistics (or p-values) as tests can be dependent …

Assembly Of Effective Halide Receptors From Components. Comparing Hydrogen, Halogen, Tetrel Bonds, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

Receptors for halide anions are constructed based on the imidazolium unit, and then replacing the H-bonding C-H group firstby halogen-bonding C-I and then by tetrel-bonding C-SnH3 and C-SiF3.Attaching a phenyl ring to any of these species has little effect on its ability to bind a halide, but incorporation of a second imidazolium to the benzene connector, forming a bidentate dicationic receptor, greatly enhances the binding. Addition of electron-withdrawing F atoms to each imidazolium adds a further increment. F- consistently binds more strongly to the various receptor models than does Cl-. Whereas replacement of the H atom on the imidazolium groups …

Landscape-Level Wolf Space Use Is Correlated With Prey Abundance, Ease Of Mobility And The Distribution Of Prey Habitat, Andrew M. Kittle, Morgan Anderson, Tal Avgar, James A. Baker, Glen S. Brown, Jevon Hagens, Ed Iwachewski, Scott Moffatt, Anna Mosser, Brent R. Patterson, Douglas E. B. Reid, Arthur R. Rodgers, Jen Shuter, Garrett M. Street, Ian D. Thompson, Lucas M. Vander Vennen, John M. Fryxell

Wildland Resources Faculty Publications

Predator space use influences ecosystem dynamics, and a fundamental goal assumed for a foraging predator is to maximize encounter rate with prey. This can be achieved by disproportionately utilizing areas of high prey density or, where prey are mobile and therefore spatially unpredictable, utilizing patches of their prey's preferred resources. A third, potentially complementary strategy is to increase mobility by using linear features like roads and/or frozen waterways. Here, we used novel population-level predator utilization distributions (termed "localized density distributions") in a single-predator (Wolf), two-prey (moose and caribou) system to evaluate these space-use hypotheses. The study was conducted in contrasting …

Analysis Of Carbon And Nitrogen Stable Isotope Levels In Side-Blotched Lizards ( Uta Stansburiana ) Fed Varying Diets, Kati Mattinson

Physics Capstone Projects

When attempting to determine the diet of wild animals, a limited number of techniques currently exist. Often, biologists look at the stomach contents or feces of an animal, if they cannot observe what it is eating directly. However, these techniques often cannot be used with reptiles because they may not eat often or may have an empty stomach when the contents of their stomach are examined. Many ecologists have begun to use stable isotopes of carbon and nitrogen to determine what an animal has eaten. Stable isotopes are useful because unlike radioactive isotopes, stable isotopes do not decay and thus …

The Global Positioning System, Brendon Baker

Physics Capstone Projects

This research study explores the Global Positioning System (GPS), its history, and the process of discovery needed to create the most accurate GPS possible, as well as the contemporary applications of GPS technology. Starting with the first satellite in space, GPS has been a work in progress. Originally pursued by the military for improvements to military tactics, GPS has become integrated into the everyday lives of millions of people around the world. How GPS determines location is a dichotomy, with simplistic theory and complex application. Many factors go into GPS to provide a consistent, accurate location. The orbital planes the …

Reduction Of Radiation Effects In Polymers, Alexandra Hughlett, Tyler Kippen, Jr Dennison

Posters

No abstract provided.

An Adaptive Threshold Determination Method Of Feature Screening For Genomic Selection, Matthew D. Meng, Gang Wang, Aaron R. Brough

Mathematics and Statistics Faculty Publications

Background
Although the dimension of the entire genome can be extremely large, only a parsimonious set of influential SNPs are correlated with a particular complex trait and are important to the prediction of the trait. Efficiently and accurately selecting these influential SNPs from millions of candidates is in high demand, but poses challenges. We propose a backward elimination iterative distance correlation (BE-IDC) procedure to select the smallest subset of SNPs that guarantees sufficient prediction accuracy, while also solving the unclear threshold issue for traditional feature screening approaches.

Results
Verified through six simulations, the adaptive threshold estimated by the BE-IDC performed …

Solvation Enhances The Distinction Between Carboxylated Armchair And Zigzag Single-Wall Carbon Nanotubes (Swnt-Cooh), Tapas Kar, Upendra Adhikari, Steve Scheiner, Ajit K. Roy, Renato L. T. Parreira, Pedro A. De S. Bergamo, Giovanni F. Caramori, Felipe S. S. Schneider

Chemistry and Biochemistry Faculty Publications

The effect of various solvents on the structures and properties of carboxylated SWNTs has been explored using the Same Level Different Basis Set approach (SLDB), where B3LYP functional of density functional theory (DFT) was applied. Armchair (4,4) and zigzag (8,0) and (9,0) tubes were considered as the test bed. In order to simulate varying concentration of –COOH groups, one to five acids groups were placed at one end of these tubes. These samples were placed in different solvents (namely, CS2, THF and water) with varying polarity and results were compared with gas-phase properties. Similar to the gas-phase, zigzag tubes also …

Estimating Utilization Distributions From Fitted Step-Selectionfunctions, Johannes Signer, John Fieberg, Tal Avgar

Wildland Resources Faculty Publications

Habitat-selection analyses are often used to link environmental covariates, measured within some spatial domain of assumed availability, to animal location data that are assumed to be independent. Step-selection functions (SSFs) relax this independence assumption, by using a conditional model that explicitly acknowledges the spatiotemporal dynamics of the availability domain and hence the temporal dependence among successive locations. However, it is not clear how to produce an SSF-based map of the expected utilization distribution. Here, we used SSFs to analyze virtual animal movement data generated at a fine spatiotemporal scale and then rarefied to emulate realistic telemetry data. We then compared …

Dynamic Secondary Electron Emission In Dielectric/Conductor Mixed, Leandro Olano, Isabel Montero, María E. Dávila, A. Jacas, M. A. Rodriguez, Jr Dennison

Conference Proceedings

Secondary Emission Yield (SEY) of dielectric materials is of great importance for prediction and testing of the Multipaction discharge in RF components for space applications. An atypical behavior of the SEY of coatings composed by a mixture of conductor and dielectric microparticles was reported and modeled in [1]; in this original model, the interactions between dielectric and conductor particles were not taken into account, but an effective action of the surface voltage generated within the sample was included. The aim of the present contribution is to more accurately model the effect the electric fields between dielectric and conductor particles have …

Dynamic Secondary Electron Emission In Dielectric/Conductor Mixed Coatings, Leandro Olano, Isabel Montero, María E. Dávila, Jr Dennison

Presentations

An unexpected behavior of the Secondary Emission Yield (SEY) on coatings composed by a mixture of conductor and dielectric microparticles was reported and modeled in [1]. As a follow up, we measured for a fixed primary energy the dynamic evolution of the SEY in similar samples and proposed a charging-roughness coupled model to simulate the experimental results. Two different coatings were selected: 1) TMM and Al microparticles (type 1), and 2) zeolites and gold nanoparticles (type 2). Pulsed and continuous tests were used to obtain the SEY as a function of the primary energy.

In both types of samples extremely …

Temperature Dependence Of Electrostatic Discharge In Highly Disordered Insulating Polymers, Tyler Kippen, Allen Andersen, Jr Dennison

Posters

No abstract provided.

Accounting For Spatial And Temporal Variation In Macroinvertebrate Community Abundances When Measuring The Food Supply Of Stream Salmonids, Nicholas Weber, Nicolaas Bouwes, Chris Jordan

Watershed Sciences Faculty Publications

The goal of salmonid habitat monitoring programs is to measure habitat attributes linked to salmonid productivity based on protocols that have sufficient precision to detect environmental variation at relevant spatial and temporal scales. Benthic macroinvertebrate community composition often is evaluated as part of habitat monitoring and assessment protocols, despite a lack of direct relationships between benthic composition and salmonid production. Macroinvertebrate drift provides a direct measure of the food resources available to stream salmonids, but drift is rarely evaluated as part of habitat monitoring protocols. This reluctance may stem from the complex spatial and temporal variability inherent in macroinvertebrate drift …

Accounting For Spatial And Temporal Variation In Macroinvertebrate Community Abundances When Measuring The Food Supply Of Stream Salmonids, Nicholas Weber, Nicolaas Bouwes, Chris Jordan

Watershed Sciences Faculty Publications

The goal of salmonid habitat monitoring programs is to measure habitat attributes linked to salmonid productivity based on protocols that have sufficient precision to detect environmental variation at relevant spatial and temporal scales. Benthic macroinvertebrate community composition often is evaluated as part of habitat monitoring and assessment protocols, despite a lack of direct relationships between benthic composition and salmonid production. Macroinvertebrate drift provides a direct measure of the food resources available to stream salmonids, but drift is rarely evaluated as part of habitat monitoring protocols. This reluctance may stem from the complex spatial and temporal variability inherent in macroinvertebrate drift …

Accelerated Increase In The Arctic Tropospheric Warming Events Surpassing Stratospheric Warming Events During Winter, Shih-Yu (Simon) Wang, Yen-Heng Lin, Ming-Ying Lee, Jin-Ho Yoon, Jonathan D.D. Meyer, Philip J. Rasch

Plants, Soils, and Climate Faculty Publications

In January 2016, a robust reversal of the Arctic Oscillation (AO) took place associated with a rapid tropospheric warming in the Arctic region; this was followed by the occurrence of a classic sudden stratospheric warming in March-April. The succession of these two distinct Arctic warming events provides a stimulating opportunity to examine their characteristics in terms of similarities and differences. Historical cases of these two types of Arctic warming were identified and validated based upon tropical linkages with the Madden-Julian Oscillation and El Niño as well as those documented in previous studies. Our results indicate a recent and accelerated increase …

Logarithmic Corrections To Black Hole Entropy From Kerr/Cft, Abhishek Pathak, Achilleas P. Porfyriadis, Andrew Strominger, Oscar J. Varela

All Physics Faculty Publications

It has been shown by A. Sen that logarithmic corrections to the black hole area-entropy law are entirely determined macroscopically from the massless particle spectrum. They therefore serve as powerful consistency checks on any proposed enumeration of quantum black hole microstates. Sen’s results include a macroscopic computation of the logarithmic corrections for a five-dimensional near extremal Kerr-Newman black hole. Here we compute these corrections microscopically using a stringy embedding of the Kerr/CFT correspondence and find perfect agreement.

China: Avoiding Impediments To Successful Climate Change Mitigation, Molly Rose Van Engelenhoven

Undergraduate Honors Capstone Projects

This paper uses the Cultural Topography (CTOPs) methodology, an intelligence community standard which is used to avoid ethnocentric analysis and the dangerous practice of mirror imaging--projecting US culture on to another country rather than viewing the costs and benefits they face through their own cultural lens. CTOPs assess a country’s culture by examining four components of culture: identity, values, norms, and perceptual lens of an actor in conjunction with a specific issue of concern. This paper examines the internal culture of China, with the Chinese government as the key actor, to discover how to build effective policy to regulate air …

Regime Switching In Cointegrated Time Series, Bradley David Zynda Ii

Undergraduate Honors Capstone Projects

Volatile commodities and markets can often be difficult to model and forecast given significant breaks in trends through time. To account such breaks, regime switching methods allow for models to accommodate abrupt changes in behavior of the data. However, the difficulty often arises in beginning the process of choosing a model and its associated parameters with which to represent the data and the objects of interest. To improve model selection for these volatile markets, this research examines time series with regime switching components and argues that a synthesis of vector error correction models with regime switching models with ameliorate financial …

Algebraic And Topological Structures On Rational Tangles, Vida Milani, Seyed M.H. Mansourbeigi, Hossein Finizadeh

Computer Science Student Research

In this paper we present the construction of a group Hopf algebra on the class of rational tangles. A locally finite partial order on this class is introduced and a topology is generated. An interval coalgebra structure associated with the locally finite partial order is specified. Irrational and real tangles are introduced and their relation with rational tangles are studied. The existence of the maximal real tangle is described in detail.

Shrub Communities, Spatial Patterns, And Shrub-Mediated Tree Mortality Following Reintroduced Fire In Yosemite National Park, California, Usa, James A. Lutz, Tucker J. Furniss, Sara J. Germain, Kendall M. L. Becker, Erika M. Blomdahl, Sean M. A. Jeronimo, C. Alina Cansler, James A. Freund, Mark E. Swanson, Andrew J. Larson

Wildland Resources Faculty Publications

Shrubs contribute to the forest fuel load; their distribution is important to tree mortality and regeneration, and vertebrate occupancy. We used a method new to fire ecology—extensive continuous mapping of trees and shrub patches within a single large (25.6 ha) study site—to identify changes in shrub area, biomass, and spatial pattern due to fire reintroduction by a backfire following a century of fire exclusion in lower montane forests of the Sierra Nevada, California, USA. We examined whether trees in close proximity to shrubs prior to fire experienced higher mortality rates than trees in areas without shrubs. We calculated shrub biomass …

Mass Action In Two-Sex Population Models: Encounters, Mating Encounters And The Associated Numerical Correction, Katherine Snyder, Brynja R. Kohler, Luis F. Gordillo

Mathematics and Statistics Faculty Publications

Ideal gas models are a paradigm used in Biology for the phenomenological modelling of encounters between individuals of different types. These models have been used to approximate encounter rates given densities, velocities and distance within which an encounter certainly occurs. When using mass action in two-sex populations, however, it is necessary to recognize the difference between encounters and mating encounters. While the former refers in general to the (possibly simultaneous) collisions between particles, the latter represents pair formation that will produce offspring. The classical formulation of the law of mass action does not account this difference. In this short paper, …