Physical Sciences and Mathematics Commons^™

Possible Isolation Number Of A Matrix Over Nonnegative Integers, Leroy B. Beasley, Young Bae Jun, Seok-Zun Song

Mathematics and Statistics Faculty Publications

Let ℤ₊ be the semiring of all nonnegative integers and A an m × n matrix over ℤ₊. The rank of A is the smallest k such that A can be factored as an m × k matrix times a k×n matrix. The isolation number of A is the maximum number of nonzero entries in A such that no two are in any row or any column, and no two are in a 2 × 2 submatrix of all nonzero entries. We have that the isolation number of A is a lower bound of the rank of …

Space Environment Effects: Payoffs Of Unsgc Research Infrastructure Awards, Jr Dennison, Elizabeth Vargis

Presentations

No abstract provided.

Water-Mediated Carbon–Oxygen Hydrogen Bonding Facilitates S-Adenosylmethionine Recognition In The Reactivation Domain Of Cobalamin-Dependent Methionine Synthase, Robert J. Fick, Mary C. Clay, Lucas Vander Lee, Steve Scheiner, Hashim M. Al-Hashimi, Raymond C. Trievel

Chemistry and Biochemistry Faculty Publications

The C-terminal domain of cobalamin-dependent methionine synthase (MetH) has an essential role in catalyzing the reactivation of the enzyme following the oxidation of its cobalamin cofactor. This reactivation occurs through reductive methylation of the cobalamin using S-adenosylmethionine (AdoMet) as the methyl donor. Herein, we examine the molecular recognition of AdoMet by the MetH reactivation domain utilizing structural, biochemical, and computational approaches. Crystal structures of the Escherichia coli MetH reactivation domain in complex with AdoMet, the methyl transfer product S-adenosylhomocysteine (AdoHcy), and the AdoMet analogue inhibitor sinefungin illustrate that the ligands exhibit an analogous conformation within the solvent-exposed substrate binding cleft …

Pooling Of Variances: The Skeleton In The Mixed Model Closet?, Philip M. Dixon

Conference on Applied Statistics in Agriculture and Natural Resources

I explore three related issues concerning pooling of error variances: when is it appropriate (or not) to pool, how best to evaluate equality of variances, and whether there is a cost to never pooling. I focus on pooling decisions in a combined analysis of a multi-site experiment. A-priori, sites should have different error variances. My primary question is whether an analysis that ignores unequal variances is wrong.

I find that ignoring heteroscedasticity between sites maintains, or provides slightly conservative, tests of average treatment effects and treatment-by-site interactions. Models with site-specific variances do provide more powerful tests when variances are different. …

Phonon Dynamics Of Alkali Metals In The Hcp Lattice Structure, Jake Christensen

Physics Capstone Projects

An Embedded-Atom-Method model that is successful at describing the vibrational properties of alkali metals in the BCC crystal structure is applied to the HCP structure. Phonon dispersion curves, density of states, and Debye temperatures are calculalated for Li, Na, K, Rb, and Cs. Comparison of BCC, FCC and HCP Debye temperatures show that BCC is the preferred structure at higher temperatures, which agrees with experiment.

Hydrodeoxygenation Of Pinyon-Juniper Catalytic Pyrolysis Oil Using Red Mud-Supported Nickel Catalysts, Hossein Jahromi, Foster Agblevor

Biological Engineering Faculty Publications

Red mud (RM) is an alkaline waste generated in the Bayer process of alumina production. In the present study red mud supported nickel catalysts (Ni/RM) were prepared at different concentrations of nickel (10, 20, 30, 40, 50, and 65 wt.%) and used to hydrodeoxygenate (HDO) pinyon-juniper (PJ) catalytic pyrolysis oil. Increasing the nickel content improved the activity of Ni/RM catalysts for HDO reactions. Maximum organic liquid yield (68.6%) was obtained when 40%Ni/RM was used. The upgraded oil had oxygen content of 1.35 wt.% and higher heating value of 45.77 MJ/kg compared to 24.88 wt.% and 28.41 MJ/kg, respectively, for the …

Woodland Caribou Habitat Selection Patterns In Relation To Predation Risk And Forage Abundance Depend On Reproductive State, Rebecca Viejou, Tal Avgar, Glen S. Brown, Brent R. Patterson, Doug E. B. Reid, Arthur R. Rodgers, Jennifer Shuter, Ian D. Thompson, John M. Fryxell

Wildland Resources Faculty Publications

The ideal free distribution assumes that animals select habitats that are beneficial to their fitness. When the needs of dependent offspring differ from those of the parent, ideal habitat selection patterns could vary with the presence or absence of offspring. We test whether habitat selection depends on reproductive state due to top‐down or bottom‐up influences on the fitness of woodland caribou (Rangifer tarandus caribou), a threatened, wide‐ranging herbivore. We combined established methods of fitting resource and step selection functions derived from locations of collared animals in Ontario with newer techniques, including identifying calf status from video collar footage and seasonal …

Sequential And Differential Interaction Of Assembly Factors During Nitrogenase Mofe Protein Maturation, Emilio Jimenez-Vicente, Zhi-Yong Yang, W. Keith Ray, Carlos Echavarri-Erasun, Valerie L. Cash, Luis M. Rubio, Lance C. Seefeldt, Dennis R. Dean

Chemistry and Biochemistry Faculty Publications

Nitrogenases reduce atmospheric nitrogen, yielding the basic inorganic molecule ammonia. The nitrogenase MoFe protein contains two cofactors, a [7Fe-9S-Mo-C-homocitrate] active-site species, designated FeMo-cofactor, and a [8Fe-7S] electron-transfer mediator called P-cluster. Both cofactors are essential for molybdenum-dependent nitrogenase catalysis in the nitrogen-fixing bacterium Azotobacter vinelandii. We show here that three proteins, NafH, NifW, and NifZ, copurify with MoFe protein produced by an A. vinelandii strain deficient in both FeMo-cofactor formation and P-cluster maturation. In contrast, two different proteins, NifY and NafY, copurified with MoFe protein deficient only in FeMo-cofactor formation. We refer to proteins associated with immature MoFe protein in …

Structure Of Frequency-Interacting Rna Helicase From Neurospora Crassa Reveals High Flexibility In A Domain Critical For Circadian Rhythm And Rna Surveillance, Yalemi Morales, Keith J. Olsen, Jacqueline M. Bulcher, Sean J. Johnson

Chemistry and Biochemistry Faculty Publications

The FRH (frequency-interacting RNA helicase) protein is the Neurospora crassa homolog of yeast Mtr4, an essential RNA helicase that plays a central role in RNA metabolism as an activator of the nuclear RNA exosome. FRH is also a required component of the circadian clock, mediating protein interactions that result in the rhythmic repression of gene expression. Here we show that FRH unwinds RNA substrates in vitro with a kinetic profile similar to Mtr4, indicating that while FRH has acquired additional functionality, its core helicase function remains intact. In contrast with the earlier FRH structures, a new crystal form of FRH …

Structural Characterization Of The P1+ Intermediate State Of The P-Cluster Of Nitrogenase, Stephen M. Keable, Oleg A. Zadvornyy, Lewis E. Johnson, Bojana Ginovska, Andrew J. Rasmussen, Karamatullah Danyal, Brian J. Eilers, Gregory A. Prussia, Axl X. Levan, Simone Raugei, Lance C. Seefeldt, John W. Peters

Chemistry and Biochemistry Faculty Publications

Nitrogenase is the enzyme that reduces atmospheric dinitrogen (N₂) to ammonia (NH₃) in biological systems. It catalyzes a series of single-electron transfers from the donor iron protein (Fe protein) to the molybdenum–iron protein (MoFe protein) that contains the iron–molybdenum cofactor (FeMo-co) sites where N₂ is reduced to NH₃. The P-cluster in the MoFe protein functions in nitrogenase catalysis as an intermediate electron carrier between the external electron donor, the Fe protein, and the FeMo-co sites of the MoFe protein. Previous work has revealed that the P-cluster undergoes redox-dependent structural changes and that the …

Investigation Of Alternatives For Migrating The One-Stop-Shop (Oss) Application To A Single, Web-Based Offering That Is Conducive For Both Desktop And Mobile Use., Sahiti Katragadda

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

The One-Stop-Shop (OSS) application provides real-time data which is helpful for travelers in the Western United States in planning their travel. Included is traditional information (routing, imagery, weather), as well as points of interest and other route-specific information (elevations, rest areas, etc.). The system displays real-time data streams in a web-based application and in a separate mobile web application, which are presented to end users in a user-friendly format.

OSS web application and OSS mobile web application features have been examined and the best design features for the mobile application have been identified. Along with that, additional design features are …

Supplementation And Community Involvement As Drivers Of Salmon Recovery: Summer Chum Salmon (Oncorhynchus Keta) Populations In Union And Tahuya Rivers, Washington, United States, Seth M. Elsen

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Between the 1970s and late 1990s, Summer Chum salmon abundance in the Hood Canal basin declined significantly to the point the population was listed as “threatened” under the Endangered Species Act (1999), with multiple subpopulations extirpated. The Hood Canal Salmon Enhancement Group, in partnership with the Washington Department of Fish and Wildlife, developed and implemented a supplementation program to increase spawner abundance in the Union River so that supplementation could eventually take place in the Tahuya River, where Summer Chum had been extirpated. The program, which is only possible with intense volunteer efforts, reduced extinction risks for the Union River …

Examining Quadratic Relationships Between Traits And Methods In Two Multitrait-Multimethod Models, Fredric A. Hintz

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Psychological researchers are interested in the validity of the measures they use, and the multitrait-multimethod design is one of the most frequently employed methods to examine validity. Confirmatory factor analysis is now a commonly used analytic tool for examining multitrait-multimethod data, where an underlying mathematical model is fit to data and the amount of variance due to the trait and method factors is estimated. While most contemporary confirmatory factor analysis methods for examining multi-trait multi-method data do not allow relationships between the trait and method factors, a few recently proposed models allow for the examination of linear relationships between traits …

Mindset, Attitudes, And Success In Statistics, Matthew Isaac

Undergraduate Honors Capstone Projects

Students in many disciplines are required to take an introductory statistics course while pursuing a college education. Despite the utility of statistical methods in future research and career pursuits, many students have negative views of statistics. We are interested in how students' mindsets and attitudes towards statistics impact their performance in an undergraduate statistics course. We administered a survey to students in several undergraduate statistics courses at Utah State University. This survey included questions addressing mathematics experience, attitudes towards statistics, mindset, and course performance. We observed that the majority of students indicated the presence of a growth mindset and positive …

Three Environmental Fluid Dynamics Papers, Eden Furtak-Cole

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Three papers are presented, applying computational fluid dynamics methods to fluid flows in the geosciences. In the first paper, a numerical method is developed for single phase potential flow in the subsurface. For a class of monotonically advancing flows, the method provides a computational savings as compared to classical methods and can be applied to problems such as forced groundwater recharge. The second paper investigates the shear stress reducing action of an erosion control roughness array. Incompressible Naiver-Stokes simulations are performed for multiple wind angles to understand the changing aerodynamics of individual and grouped roughness elements. In the third paper, …

A Series Of Papers On Detecting Examinees Who Used A Flawed Answer Key, Marcus W. Scott

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

One way that examinees can gain an unfair advantage on a test is by having prior access to the test questions and their answers, known as preknowledge. Determining which examinees had preknowledge can be a difficult task. Sometimes, the compromised test content that examinees use to get preknowledge has mistakes in the answer key. Examinees who had preknowledge can be identified by determining whether they used this flawed answer key. This research consisted of three papers aimed at helping testing programs detect examinees who used a flawed answer key.

The first paper developed three methods for detecting examinees who used …

Breeding Season Ecology And Demography Of Lesser Scaup (Aythya Affinis) At Red Rock Lakes National Wildlife Refuge, Jeffrey M. Warren

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

It is hypothesized that individuals make reproductive decisions based on current assessments of their physiological condition and environmental conditions. For female lesser scaup (Aythya affinis), breeding occurs after an energetically costly spring migration. Increasing fat reserves (i.e., ‘body condition’) prior to breeding allows a female to produce a larger clutch of eggs, but time spent gaining body condition is costly in terms of time allowed to raise ducklings before freezing conditions in the fall. In Chapter 2 I explored rate of pre-breeding body condition gain in female lesser scaup, and how that rate influenced clutch size. Spring phenology, …

Elucidating Molecular Interactions Of Shigella Type Three Secretion System Components Critical For Pathogenesis, R. Alan Burgess

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Shigella are pathogenic bacteria which commonly infect human hosts through the fecal-oral route. As the causative agent of shigellosis, a disease characterized by severe diarrhea, nausea, and vomiting, Shigella are responsible for an estimated 90 million infections and 100,000 deaths each year. With the emergence of antibiotic resistant strains of Shigella, the need for alternative treatments methods has become critical to fighting outbreaks of shigellosis and drug resistant strains. One such method is to target the infection system of the bacteria, called the type three secretion system (T3SS). The T3SS includes a complex needle and syringe-like apparatus that is …

Geometric Algorithms For Intervals And Related Problems, Shimin Li

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In this dissertation, we study several problems related to intervals and develop efficient algorithms for them. Interval problems have many applications in reality because many objects, values, and ranges are intervals in nature, such as time intervals, distances, line segments, probabilities, etc. Problems on intervals are gaining attention also because intervals are among the most basic geometric objects, and for the same reason, computational geometry techniques find useful for attacking these problems. Specifically, the problems we study in this dissertation includes the following: balanced splitting on weighted intervals, minimizing the movements of spreading points, dispersing points on intervals, multiple barrier …

A Model For Bioaugmented Anaerobic Granule, Amitesh Mahajan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In this study, we have created a simulation model which is concerned about digesting cellulose, as a major component of microalgae in a bioreactor. This model is designed to generate a computational model that simulates the process of granulation in anaerobic sludge and aims to investigate scenarios of possible granular bioaugmentation. Once a mature granule is formed, protein is used as an alternative substrate that will be supplied to a mature granule. Protein, being a main component of cyanobacteria, will promote growth and incorporation of a cell type that can degrade protein (selective pressure). The model developed in a cDynoMiCs …

Multi-Stop Routing Optimization: A Genetic Algorithm Approach, Abbas Hommadi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In this research, we investigate and propose new operators to improve Genetic Algorithm’s performance to solve the multi-stop routing problem. In a multi-stop route, a user starts at point x, visits all destinations exactly once, and then return to the same starting point. In this thesis, we are interested in two types of this problem. The first type is when the distance among destinations is fixed. In this case, it is called static traveling salesman problem. The second type is when the cost among destinations is affected by traffic congestion. Thus, the time among destinations changes during the day. In …

The Role Of Recoverable And Non-Recoverable Defects In Dc Electrical Aging Of Highly Disordered Insulating Materials, Allen Andersen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Electrical insulation under high voltage can eventually fail, causing critical damage to electronics. Such electrostatic discharge (ESD) is the primary source of anomalies or failures on spacecraft due to charged particles from the Sun or planetary radiation belts accumulating in spacecraft insulators. High-voltage direct current power distribution is another example of a growing industry that needs to estimate the operational lifetime of electrical insulation. My research compares laboratory tests of ESD events in common insulating materials to a physics-based model of breakdown. This model of breakdown is based on the approximation that there are two primary types of defects in …

Standard Machine Learning Techniques In Audio Beehive Monitoring: Classification Of Audio Samples With Logistic Regression, K-Nearest Neighbor, Random Forest And Support Vector Machine, Prakhar Amlathe

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Honeybees are one of the most important pollinating species in agriculture. Every three out of four crops have honeybee as their sole pollinator. Since 2006 there has been a drastic decrease in the bee population which is attributed to Colony Collapse Disorder (CCD). The bee colonies fail/ die without giving any traditional health symptoms which otherwise could help in alerting the Beekeepers in advance about their situation.

Electronic Beehive Monitoring System has various sensors embedded in it to extract video, audio and temperature data that could provide critical information on colony behavior and health without invasive beehive inspections. Previously, significant …

Modeling The Spread Of Alfalfa Stem Nematodes: Insights Into Their Dynamics And Control, Scott G. Jordan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Alfalfa is a major cash crop in the western United States, where fields that are infested with the alfalfa stem nematode (Ditylenchus dipsaci) can be found. With no nematicides available to control alfalfa stem nematode spread, growers can use nematode resistant varieties of alfalfa to manage nematode populations in a field. A deterministic, discrete-time, host-parasite model is presented that describes the spread of alfalfa stem nematodes on resistant hosts that was fit to experimental data obtained in Weber County, Utah. Numerical results obtained from simulations with the model are used to compare how varying levels of resistance can affect …

Calculating Redshift Via Astronomical Spectroscopy, Joshua Glatt

Physics Capstone Projects

The Doppler effect is a well-known physical phenomenon which results in a change of a wave’s frequency or wavelength due to the motion of its source. Celestial objects in space (stars, galaxies, etc.) also experience a Doppler effect on their emitted electromagnetic radiation called redshift. In this study, redshifts were observed in the spectrographic observations of various celestial objects. This was done using a high-resolution near ultra-violet spectrometer in conjunction with a 14-inch Celestron Schmidt-Cassegrain telescope. The spectrometer was used to measure the absorption spectrum of the bodies and then these absorption spectrums were compared against the Hydrogen emission spectrum. …

The Effects Of The Beta Transition On Dielectric Breakdown In Ldpe, Tyler Kippen

Physics Capstone Projects

The beta transition is a solid-state transition that occurs as part of the glass transition in amorphous polymers. The transition occurs at a temperature where above which the polymer is soft and rubbery and below the transition temperature the polymer is hard and brittle. The glass transition is thought to be caused by the increasingly coordinated movements of polymer chains as the temperature of the polymer increases. Once the temperature reaches the glass transition temperature, large scale motions of polymer chains occurs and there is a dramatic change in properties. In LDPE the glass transition occurs in the region between …

Atmospheric Gravity Wave Events Over Antarctica, America Wrobel

Physics Capstone Projects

This study used infrared (IR) image data obtained from McMurdo Station, Antarctica to investigate the properties of atmospheric gravity waves as they propagate into the upper mesosphere over Antarctica. The data were obtained as part of the international Antarctic Gravity Wave Instrument Network (ANGWIN). ANGWIN utilizes image data from several sites around Antarctica to investigate continent-wide propagation. This paper covers a study that reduced and analyzed two years of data from one particular site: McMurdo Station. An all-sky IR camera placed at McMurdo Station, Antarctica (77°83’ S, 166°61’ E) took one picture every ten seconds for the months of April …

Sodium Lidar For Mesopause Temperature And Wind Studies, Xiaoqi Xi

Physics Capstone Projects

In 1990 Dr. Chiao-Yao She developed a narrowband Na Temperature lidar in Colorado State University (CSU), it immediately became an important instrument to measure the temperature in mesopause region (80-105 km in altitude): the atmospheric layer between mesosphere and thermosphere [Krueger et al., 2015]. Led by Dr. Tao Yuan, this system was relocated to Utah State University (USU) in summer 2010 and has been continuing its exploration of upper atmosphere. This report will give a brief introduction to the theory and application of Sodium Lidar.

Characterization Of Programmable Arduino Sensors, Brett Mortenson

Physics Capstone Projects

Arduinos are increasing in usage and prevalence due to the ease in which they can be programmed. External sensors attached to the Arduinos are being used for various measurements, and many of them give raw data output such as voltage spikes or decibel readings. These readings were characterized so that one can interpret the readings relatively easily, and understand more completely, the environment which the sensors are in. The sensors utilized are as follows: photoresistor, vibrational, sound, temperature, pressure, and humidity.

Gravity Waves Over Antarctica, Vanessa Chambers

Physics Capstone Projects

As part of the international Antarctic Gravity Wave Instrument Network (ANGWIN) program, the Utah State University all sky IR imager has been operated at the British Antarctic Survey (BAS) Halley Station (75°36′ S, 26°12′ W) since 2012, obtaining valuable gravity wave information in the upper mesosphere and lower thermosphere region (~80 to 100 km). In this study, we have utilized a new 3D spectral analysis technique (Matsuda, et al., 2014) to quantify the horizontal phase velocity distributions of gravity waves over Antarctica. This new tool enables us to analyze extensive amounts of airglow imaging data in a relatively short time …