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Articles 2191 - 2220 of 7341

Full-Text Articles in Physical Sciences and Mathematics

Altitudinal Variability Of Quiet-Time Plasma Drifts In The Equatorial Ionosphere, Debrup Hui May 2015

Altitudinal Variability Of Quiet-Time Plasma Drifts In The Equatorial Ionosphere, Debrup Hui

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In the modern world, we increasingly depend on space-based systems for our communication, positioning, and navigation systems. These systems depend on electromagnetic waves propagating through the ionosphere. The ionosphere is the medium in the upper atmosphere where, due to presence of the charged atomic and molecular particles and electrons collectively known as plasma, it influences the traveling electromagnetic waves following laws of electrodynamics. Improved models for predicting space weather conditions require improved knowledge of the drifts of these plasmas in the ionosphere. This study is focused on climatology of the altitudinal variations of these plasma drifts in the equatorial latitudes. …


Statistical Dependence In Imputed High-Dimensional Data For A Colorectal Cancer Study, Anvar Suyundikov May 2015

Statistical Dependence In Imputed High-Dimensional Data For A Colorectal Cancer Study, Anvar Suyundikov

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The research objective of this dissertation was to provide novel statistical methods to fill potential gaps in the analyses of micro-ribonucleic acid (miRNA) data, and consequently to identify the miRNAs that contribute to cancer development. Mainly, this dissertation addressed the statistical issues raised by the statistical dependence of imputed (i.e., the missing data were replaced with substituted values) miRNA data in the colorectal cancer study. This dissertation presented a modified imputation method, the weighted KNN imputation accounting for dependence, that predicted the expression levels of missing normal samples with greater imputation accuracy than other imputation methods, and had moderate power …


Thermal Evidence Of Flat­-Slab Subduction Perturbations In The Western Us, Michael Berry May 2015

Thermal Evidence Of Flat­-Slab Subduction Perturbations In The Western Us, Michael Berry

Physics Capstone Projects

The Laramide Orogeny, a late Cretaceous mountain building event in the western United States, 1,2,3 has been postulated to result from flat­slab style subduction of the Farallon plate . Possible consequences of flat­slab style subduction on elevation, tectonism and volcanism associated with expected changes in temperature and hydration state of the mantle in the western U.S. has x1 been of considerable interest. However, the impact of flat­slab subduction on modern mantle temperature, water and tectonic stability remains poorly­understood. Here we show that thermal perturbation by Farallon flat slab subduction is still evident today in Moho temperatures of the Rocky Mountain …


Correlations Of Fault Rock Constitutive Properties Derived From Laboratory Retrieved Data Of The North-Eastern Block Of The Southern San Andreas Fault, Mecca Hills, Ca Via Computational Analysis., Ryan M. Lee May 2015

Correlations Of Fault Rock Constitutive Properties Derived From Laboratory Retrieved Data Of The North-Eastern Block Of The Southern San Andreas Fault, Mecca Hills, Ca Via Computational Analysis., Ryan M. Lee

Physics Capstone Projects

We aim to characterize fault-structure-related rocks via correlation between the various geophysical characteristics of samples retrieved from the southern San Andreas Fault (SSAF) near the Mecca Hills region in Southern California. Samples from this area were retrieved from the San Andreas Fault Observatory at Depth (SAFOD) near Parkfield, California at a depth of approximately 3km. Core samples of various lithologies were gathered from the borehole and analyzed using various geophysical methods. Emphasis was placed in possible correlations and relationships between varying lithologies and calculated values of unconfined compressional strength (UCS) and cohesion. Using retrieved data from the samples, as well …


Centrality Measures Of Graphs Utilizing Continuous Walks In Hilbert Space, Jarod P. Benowitz May 2015

Centrality Measures Of Graphs Utilizing Continuous Walks In Hilbert Space, Jarod P. Benowitz

Physics Capstone Projects

Centrality is most commonly thought of as a measure in which we assign a ranking of the vertices from most important to least important. The importance of a vertex is relative to the underlying process being carried out on the network. This is why there is a diverse amount of centrality measures addressing many such processes. We propose a measure that assigns a ranking in which interference is a property of the underlying process being carried out on the network.


Comparing Linear Mixed Models To Meta-Regression Analysis In The Greenville Air Quality Study, Lynsie M. Daley May 2015

Comparing Linear Mixed Models To Meta-Regression Analysis In The Greenville Air Quality Study, Lynsie M. Daley

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

The effect of air quality on public health is an important issue in need of better understanding. There are many stakeholders, especially in Utah and Cache Valley, where the poor air quality as measured by PM 2.5 levels and consequent inversions can sometimes be the very worst in the nation. This project focuses on comparing two statistical methods used to analyze an important air quality data set from the Greenville Air Quality Study, focusing on a lung function response variable. A linear mixed model, with a random factor for subject, gives slope estimates and their significance for predictor variables of …


Survival Analysis For Truncated Data And Competing Risks, Michael Steelman May 2015

Survival Analysis For Truncated Data And Competing Risks, Michael Steelman

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

The purpose of this project is to consider the problems of left truncation and competing risks in analyzing censored survival data, and to compare and contrast various approaches for handling these problems. The motivation for this work comes from an analysis of data from the Cache County Memory Study. Study investigators were interested in the association between early-life psychologically stressful events (e.g., parental or sibling death, or parental divorce, among others) and late-life risk of Alzheimer's disease (AD). While conventional methods for censored survival data can be applied, the presence of left truncation and competing risks (i.e., other adverse events …


Empowering Community Partners: A Case Study Motivating Environmentally Sustainable Behavioral Changes In Latino Migrant Agricultural Families, Jessica Ivy Thomson May 2015

Empowering Community Partners: A Case Study Motivating Environmentally Sustainable Behavioral Changes In Latino Migrant Agricultural Families, Jessica Ivy Thomson

Undergraduate Honors Capstone Projects

Environmental sustainability outreach programs can benefit significantly through adaptation that connects to and fosters change within the Spanish speaking community. This article demonstrates a case study in which the authors partnered with a local Latino organization through an undergraduate service-learning project. The goal of this project was to incorporate environmentally sustainable behaviors both with young Latino students in school and with their families at the household level.


Modeling Seed Dispersal And Population Migration Given A Distribution Of Seed Handling Times And Variable Dispersal Motility: Case Study For Pinyon And Juniper In Utah, Ram C. Neupane May 2015

Modeling Seed Dispersal And Population Migration Given A Distribution Of Seed Handling Times And Variable Dispersal Motility: Case Study For Pinyon And Juniper In Utah, Ram C. Neupane

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The spread of fruiting tree species is strongly determined by the behavior and range of fruit-eating animals, particularly birds. Birds either consume and digest seeds or carry and cache them at some distance from the source tree. These carried and settled seeds provide some form of distribution which generates tree spread to the new location. Firstly, we modal seed dispersal by birds and introduce it in a dispersal model to estimate seed distribution. Using this distribution, we create a population model to estimate the speed at which juniper and pinyon forest boundaries move.

Secondly, we introduce a fact that bird …


Fake And Spam Messages: Detecting Misinformation During Natural Disasters On Social Media, Meet Rajdev May 2015

Fake And Spam Messages: Detecting Misinformation During Natural Disasters On Social Media, Meet Rajdev

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

During natural disasters or crises, users on social media tend to easily believe contents of postings related to the events, and retweet the postings, hoping that the postings will be reached by many other users. Unfortunately, there are malicious users who understand the tendency and post misinformation such as spam and fake messages with expecting wider propagation. To resolve the problem, in this paper we conduct a case study of the 2013 Moore Tornado and Hurricane Sandy. Concretely, we (i) understand behaviors of these malicious users; (ii) analyze properties of spam, fake and legitimate messages; (iii) propose flat and hierarchical …


Tropical Arithmetics And Dot Product Representations Of Graphs, Nicole Turner May 2015

Tropical Arithmetics And Dot Product Representations Of Graphs, Nicole Turner

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In tropical algebras we substitute min or max for the typical addition and then substitute addition for multiplication. A dot product representation of a graph assigns each vertex of the graph a vector such that two edges are adjacent if and only if the dot product of their vectors is greater than some chosen threshold. The resultS of creating dot product representations of graphs using tropical algebras are examined. In particular we examine the tropical dot product dimensions of graphs and establish connections to threshold graphs and the threshold dimension of a graph.


Annotation Tools For Multivariate Gene Set Testing Of Non-Model Organisms, Russell K. Banks May 2015

Annotation Tools For Multivariate Gene Set Testing Of Non-Model Organisms, Russell K. Banks

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Microarray chip technology enables researchers to obtain measures of gene activity for essentially all genes in an organism. After grouping genes into biologically meaningful sets, researchers employ certain statistical tests to identify which gene sets (biological processes) show different levels of activity across different treatment groups. The idea is to identify which biological processes are significantly affected by a certain treatment/condition in a given organism.

Non-model organisms (such as sheep) are not widely studied so gene set membership information is not always readily accessible. This thesis work utilizes two microarray studies involving sheep to provide researchers with working examples of …


Relative Toxicity Of Select Dehydropyrrolizidine Alkaloids And Evaluation Of A Heterozygous P53 Knockout Mouse Model For Dehydropyrrolizidine Alkaloid Induced Carcinogenesis, Ammon W. Brown May 2015

Relative Toxicity Of Select Dehydropyrrolizidine Alkaloids And Evaluation Of A Heterozygous P53 Knockout Mouse Model For Dehydropyrrolizidine Alkaloid Induced Carcinogenesis, Ammon W. Brown

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Dehydropyrrolizidine alkaloids (DHPAs) are toxins produced by approximately 3% of the world’s flowering plants that can be present naturally or as contaminants in animal feed and the human food supply. Many of these compounds have been determined to cause cancer in animals and probably also cause cancer in humans. Due to the difficulty in obtaining sufficient amounts of pure DHPAs most toxicity research has been done via injection of a small amount into the abdomen of a rodent, although natural exposure is exclusively oral. For the same reason, cancer research is limited to a handful of the hundreds of known …


Digital Soil Mapping Using Landscape Stratification For Arid Rangelands In The Eastern Great Basin, Central Utah, Brook B. Fonnesbeck May 2015

Digital Soil Mapping Using Landscape Stratification For Arid Rangelands In The Eastern Great Basin, Central Utah, Brook B. Fonnesbeck

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In some parts of the western US there is limited publicly available soil information that can be used to make land management decisions on both public and private land. A goal of the USDI Bureau of Land Management (BLM) in Utah was to map an area in central Utah where such soil maps and value-added information was not available for management and restoration decisions following a wildfire. In 2007, the Milford Flat Fire had burned more than 363,000 acres, removing vegetation that was holding erosion-sensitive soils in place. Following inconsistent results from stabilization and restoration efforts, this study was funded …


Algorithmic Information Theory Applications In Bright Field Microscopy And Epithelial Pattern Formation, Hamid Mohamadlou May 2015

Algorithmic Information Theory Applications In Bright Field Microscopy And Epithelial Pattern Formation, Hamid Mohamadlou

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The incredible patterns of multicellular organisms emerge as a result of the operation of Gene Regulatory Networks (GRN) that work during development. Understanding how GRNs produce these complex multicellular patterns is a significant challenge in biology. The primary goal of this dissertation is to employ Algorithmic Information Theory (AIT), also known as Kolmogorov complexity, to unravel the information complexity of GRNs and the resultant multicellular patterns. To obtain a better understanding of Kolmogorov complexity performance, first we study an application in cell image segmentation.

There are an estimated 20,000-25,000 protein-coding genes in the human genome. The sheer size of the …


Sequence Stratigraphy, Depositional Environments And Geochemistry Of The Middle Cambrian Bloomington Formation In Northern Utah, Christopher Ryan Jensen May 2015

Sequence Stratigraphy, Depositional Environments And Geochemistry Of The Middle Cambrian Bloomington Formation In Northern Utah, Christopher Ryan Jensen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Bloomington Formation (~425 m thick) is a latest Middle Cambrian (~506.5-505 Ma.), mixed warm water, carbonate and shale unit on the Cordilleran passive margin in northern Utah and southern Idaho. The Hodges Shale and Calls Fort Shale Members are shale dominated and the Middle Limestone Member is a thick carbonate. Fossil diversity and abundance is surprisingly low for a Middle Cambrian carbonate/shale formation. Present, however, are 10-50 cm thrombolite mud mounds, associated with Girvanella oncoliths. These mud mounds represent shallow water carbonates that experienced a small flooding event that gives the mud mounds time and proper conditions to build …


Linking Form And Process In Braided Rivers Using Physical And Numerical Models, Alan Kasprak May 2015

Linking Form And Process In Braided Rivers Using Physical And Numerical Models, Alan Kasprak

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Braided rivers are characterized by their dynamic nature, and are often significantly reshaped during each flood capable of transporting sediment. Over time, they adjust in response to the frequency and magnitude of floods, along with the amount of sediment available for bar building. Factors such as climate change, dam construction, or land use alteration that change the amount of sediment or water available to braided rivers may subsequently affect channel form. One avenue toward understanding braided channel evolution is to develop simple relationships between channel form and sediment transport, and extrapolate those relationships over extended timescales. With funding from the …


Computational Modeling To Study Disease Development: Applications To Breast Cancer And An In Vitro Model Of Macular Degeneration, Qanita Bani Baker May 2015

Computational Modeling To Study Disease Development: Applications To Breast Cancer And An In Vitro Model Of Macular Degeneration, Qanita Bani Baker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

There have been several techniques developed in recent years to develop computer models of a variety of disease behaviors. Agent-based modeling is a discrete-based modeling approach used agents to represent individual cells that mechanically interact and secrete, consume or react to soluble products. It has become a powerful modeling approach, widely used by computational researchers. In this research, we utilized agent-based modeling to study and explore disease development, particularly in two applications, breast cancer and bioengineering experiments. We further proposed an error-minimization search approach and used it to estimate cellular parameters from multicellular in vitro data.

In this dissertation, in …


A Study Of The Dayside High-Latitude Ionospheric Electrodynamics During Extended Solar Minimum, Janelle V. Jenniges May 2015

A Study Of The Dayside High-Latitude Ionospheric Electrodynamics During Extended Solar Minimum, Janelle V. Jenniges

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research investigated how electric fields, currents, and charged particles in Earth's high-latitude ionosphere respond to changing input from the sun. The ionosphere surrounds the entire Earth, makes radio communication possible, and can significantly degrade satellite communications and geo-positioning (navigation) capabilities. Many satellites fly within the ionosphere where a solar storm can cause increased satellite drag or destroy onboard electronics. Therefore, understanding and correctly predicting the behavior of this environment is important, and the results from this research will be used to improve current ionospheric models.

A relationship between the level of magnetic activity on Earth due to changes in …


Classification Of Five-Dimensional Lie Algebras With One-Dimensional Subalgebras Acting As Subalgebras Of The Lorentz Algebra, Jordan Rozum May 2015

Classification Of Five-Dimensional Lie Algebras With One-Dimensional Subalgebras Acting As Subalgebras Of The Lorentz Algebra, Jordan Rozum

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Motivated by A. Z. Petrov's classification of four-dimensional Lorentzian metrics, we provide an algebraic classification of the isometry-isotropy pairs of four-dimensional pseudo-Riemannian metrics admitting local slices with five-dimensional isometries contained in the Lorentz algebra. A purely Lie algebraic approach is applied with emphasis on the use of Lie theoretic invariants to distinguish invariant algebra-subalgebra pairs. This method yields an algorithm for identifying isometry-isotropy pairs subject to the aforementioned constraints.


Ecologically Sustainable But Unjust? Negotiating Equity And Authority In Common-Pool Marine Resource Management, Sarah Klain May 2015

Ecologically Sustainable But Unjust? Negotiating Equity And Authority In Common-Pool Marine Resource Management, Sarah Klain

Environment and Society Faculty Publications

Under appropriate conditions, community-based fisheries management can support sound resource stewardship, with positive social and environmental outcomes. Evaluating indigenous peoples’ involvement in commercial sea cucumber and geoduck fisheries on the central coast of British Columbia, Canada, we found that the current social-ecological system configuration is relatively ecologically sustainable according to stock assessments. However, the current system also results in perceived inequities in decision-making processes, harvesting allocations, and socioeconomic benefits. As a result, local coastal resource managers envision a transformation of sea cucumber and geoduck fisheries governance and management institutions. We assessed the potential robustness of the proposed institutions using Elinor …


Langmuir Probes In A Microwave Generated Plasma, Wesley Rawlins Apr 2015

Langmuir Probes In A Microwave Generated Plasma, Wesley Rawlins

Physics Capstone Projects

In this work, we considered a microwave generated plasma, in a toroidal device. In this set up, we tend to meet the conditions for several known plasma instabilities. Not all the gas in the chamber was ionized. Using a Langmuir probe we were able to determine the population temperature and the plasma density in the chamber. The existence of a plasma was determined by measuring the strength of reflected microwaves. We varied the fill pressure in the chamber, as well as the strength of an externally imposed magnetic field. From this, we determined that the plasma temperature decreased with an …


Imaging The Brigham City Fault Segment Using Electrical Resistivity Tomography Techniques, Alex Barker Apr 2015

Imaging The Brigham City Fault Segment Using Electrical Resistivity Tomography Techniques, Alex Barker

Physics Capstone Projects

Geologic faults are a result of rock structures that have given away to tectonic compression, extension, or lateral tension. Because of a fault’s propensity to slip and cause earthquakes, they are of major concern to any populated area near by. The Wasatch Fault is a result of extensional stress that runs the entire length of Utah from north the south. It has been analyzed and broken up into several segments. By stratigraphic analysis, scientists have been able to estimate when each of these segments has last experienced a rupture. Out of all the segments that make up the Wasatch Fault, …


Pt401 Paint Process Development And Infrared Reflectance Measurements, Sariah Cassidy Apr 2015

Pt401 Paint Process Development And Infrared Reflectance Measurements, Sariah Cassidy

Physics Capstone Projects

Z302 became less obtainable when the manufacturer required expensive massive drums of the black specular paint as the minimum order. As they no longer accommodate customers with pint-sized needs, companies, such as the National Institute of Science and Technology (NIST), are searching for a replacement. PT401 has been used on previous projects with satisfactory results. In accordance to requirements from NIST, a process for painting with PT401 8-10mils thick will be developed, and adherence, durability and specular reflectance and diffuse properties in the infrared will be documented.


Catching Mesospheric Gravity Waves Over Bear Lake, Utah, Kelly Osborne Apr 2015

Catching Mesospheric Gravity Waves Over Bear Lake, Utah, Kelly Osborne

Physics Capstone Projects

The Utah State Mesospheric Temperature Mapper (MTM) is a high resolution CCD imager capable of remote sensing faint optical emissions from the night sky to determine mesospheric temperature and its variability at an altitude of ~87 km (or 50 miles). The MTM was operated at the Bear Lake Observatory (BLO) for a two year period (Jan 2012 – Dec 2013) to investigate the seasonal characteristics of temperature variability at mid-latitudes.

This study was to be done from March 2013 – April 2014 but due to issues with the data in late 2013 it was changed to January 2013 - December …


Linking Hematite (Uth)/He Dating With The Microtextural Record Of Seismicity In The Wasatch Fault Damagezone, Utah, Usa, Alexis K. Ault, Peter W. Reiners, James P. Evans, Stuart N. Thomson Apr 2015

Linking Hematite (Uth)/He Dating With The Microtextural Record Of Seismicity In The Wasatch Fault Damagezone, Utah, Usa, Alexis K. Ault, Peter W. Reiners, James P. Evans, Stuart N. Thomson

Geosciences Faculty Publications

Techniques directly dating fault slip are few, limiting the ability to interpret the rock record of seismicity. Hematite is commonly found in fault zones, amenable to (U-Th)/He dating, and slip surface hematite may be reset by shear heating events and/or recrystallization. Glossy hematite-coated fault surfaces in the Wasatch fault footwall damage zone, Utah (USA), exhibit evidence of hematite cataclasis and preserve Pliocene hematite (U-Th)/He dates. Apatite (U-Th)/He and fission track data from the host gneiss indicate footwall unroofing through ∼2 km by ca. 4.5 Ma. Internally reproducible but disparate hematite (U-Th)/He dates 4.5 Ma and younger from isolated locations on …


Observations Of Mesospheric Gravity Waves Over The Andes, Jonathan Pugmire, Michael Taylor, Yucheng Zhao Apr 2015

Observations Of Mesospheric Gravity Waves Over The Andes, Jonathan Pugmire, Michael Taylor, Yucheng Zhao

Student Research Symposium

Focusing on data from an imager and the SABER instrument aboard the TIMED satellite temperature variances are determined to quantify small-scale gravity waves. IDL software was used to extract all the temperature profile measurements that were measured by SABER within a limited geographical area, centered on our ground-based optical imager at Cerro Pachon, Chile (30.3°S, 70.7°S). Large-scale tidal waves, with wavenumbers 0-6, were removed from each profile revealing the gravity wave perturbations. Temperature variances reveal possible increased wave activity due to mountain waves. Mountain waves in the mesosphere are a relatively unexplored field in aeronomy. They are generated predominantly in …


Calibration Of Muon Detector For Coincidence Cathodoluminescence Experiments, Kenneth Zia, Jr Dennison Apr 2015

Calibration Of Muon Detector For Coincidence Cathodoluminescence Experiments, Kenneth Zia, Jr Dennison

Presentations

A muon scintillation detector has been calibrated by measuring the magnitude and angular dependence of high energy cosmic background radiation events. Optimizing dark current as a function of voltage across the photomultiplier tube (PMT) detector was essential for accurate counting of current pulses as narrow as the counts in the PMT. Measurements of the crosssection zenith angle were also optimized by sweeping the detector across the horizon and from the zenith to nadir angle. The detector is now operating within proper Poisson distribution statistics for counting particle experiments, and is ready for the next step in determining coincidence between the …


Electron Penetration Range For Every Body, Anne Starley, Lisa Montierth Phillipps, Jr Dennison Apr 2015

Electron Penetration Range For Every Body, Anne Starley, Lisa Montierth Phillipps, Jr Dennison

Presentations

The penetration range of an electron into diverse materials can be estimated using an approximation fit as a function of a single parameter, N y, which describes the effective number of valence electrons. This fit is found using the Continuous-Slow Down-Approximation (CSDA), which simplifies the process of estimating an expected penetration range of a given material by applying some of the material’s key characteristics. Using the CSDA, a simple composite analytical formula is created which estimates the range or maximum penetration depth of incident electrons. This formula generates an approximation to the range using the parameter, Nv . The range …


Electron Penetration Range For Diverse Materials, Anne C. Starley, Lisa M. Phillipps, Jr Dennison Apr 2015

Electron Penetration Range For Diverse Materials, Anne C. Starley, Lisa M. Phillipps, Jr Dennison

Posters

The penetration range of energetic electrons into diverse materials can be modeled approximately with a simple fit. This fit is a function of a single parameter, Nv, which describes the effective number of valence electrons. Using the Continuous-Slow-Down-Approximation (CSDA) for energy deposition in a material, a composite analytical formula has been developed which estimates the range or maximum penetration depth of incident electrons for energies from10 MeV with an uncertainty of