Physical Sciences and Mathematics Commons^™

Sodium And Potassiumvapor Faraday Filters Re-Visited: Theory And Applications, S. D. Harrell, C. Y. She, Tao Yuan, D. A. Krueger, H. Chen, S. Chen, Z. L. Hu

All Physics Faculty Publications

A complete theory describing the transmission of atomic vapor Faraday filters is developed. The dependence of the filter transmission on atomic density and external magnetic field strength, as well as the frequency dependence of transmission, are explained in physical terms. As examples, applications of the computed results to ongoing research to suppress sky background, thus allowing Na lidar operation under sunlit conditions, and to enable measurement of the density of mesospheric oxygen atoms are briefly discussed.

Temperature Dependence Of Radiation Induced Conductivity In Insulators, John R. Dennison, Jodie Gillespie, Joshua Hodges, Rc Hoffman, J. Abbott, Alan W. Hunt, Randy Spalding

All Physics Faculty Publications

Thisstudy measures Radiation Induced Conductivity (RIC) of Low Density Polyethylene(LDPE) over temperatures ranging from ~110 K to ~350 K. RIC occurswhen incident ionizing radiation deposits energy and excites electrons intothe conduction band of insulators. Conductivity was measured when avoltage was applied across vacuum-baked, thin film LDPE polymer samplesin a parallel plate geometry. RIC was calculated as thedifference in sample conductivity under no incident radiation and underan incident ~4 MeV electron beam at low incident fluxes of10⁻⁴–10⁻¹ Gr/sec. The steady-state RIC was found to agree well withthe standard power law relation, _RIC = k_{RI …}

The Noctilucent Cloud (Nlc) Display During The Ecoma/Mass Sounding Rocket Flights On 3 August 2007: Morphology On Global To Local Scales, G. Baumgarten, J. Fiedler, K. H. Fricke, M. Gerding, M. Hervig, P. Hoffmann, N. Müller, Pierre-Dominique Pautet, M. Rapp, C. Robert, D. Rusch, C. Von Savigny, W. Singer

Publications

During the ECOMA/MASS rocket campaign large scale NLC/PMC was observed by satellite, lidar and camera from polar to mid latitudes. We examine the observations from different instruments to investigate the morphology of the cloud. Satellite observations show a planetary wave 2 structure. Lidar observations from Kühlungsborn (54° N), Esrange (68° N) and ALOMAR (69° N) show a highly dynamic NLC layer. Under favorable solar illumination the cloud is also observable by ground-based cameras. The cloud was detected by cameras from Trondheim (63° N), Juliusruh (55° N) and Kühlungsborn. We investigate planetary scale morphology and local scale gravity wave structures, important …

Characteristics Of Convective Sources Of Gravity Waves And Sprites Present In Satellite Ir Images During The Spreadfex 2005 Campaign, F. T. São Sabbas, V. T. Rampinelli, J. Santiago, P. Stamus, S. L. Vadas, D. C. Fritts, Michael J. Taylor, Pierre-Dominique Pautet, G. Dolif Neto, O. Pinto

All Physics Faculty Publications

We developed a technique to identify and estimate the size, intensity, and Tropopause overshoot of thunderstorm convective cores expected to be significant sources of gravity waves. The work was based on GOES IR images of South America on the night of 30 September to 1 October and 25–26 October 2005, as part of the Spread F Experiment (SpreadFEx) in Brazil in 2005. We also characterized, for the first time, the convective activity of three small TLE producing thunderstorms that yielded 11 TLEs on 25–26 October 2005. The campaign occurred during the dry to wet season transition in central Brazil, marked …

Quiet Variability Of Equatorial E × B Drifts During A Sudden Stratospheric Warning Event, J. L. Chau, Bela G. Fejer, L. P. Goncharenko

Bela G. Fejer

[1] We present strong evidence that during the January 2008 minor sudden stratospheric warming (SSW) event, the equatorial vertical E × B drifts exhibit a unique and distinctive daytime pattern. We do not think one event causes the other, however both events might be related through the global effects of planetary waves. The drifts were measured by the Jicamarca Incoherent scatter radar located under the magnetic equator. We have observed an anomalous temporal variation of the vertical E × B drifts during the minor SSW event, showing a semidiurnal variation with very large amplitudes lasting for several days. Large differences …

Lisa: Seeing The Cosmos In Low Frequency Gravitational Waves, Shane L. Larson

Colloquia and Seminars

No abstract provided.

Traveling-Wave Electrophoresis For Microfluidic Separations, Boyd F. Edwards, A. T. Timperman, R. Lloyd Carroll, K. Jo, J. M. Mease, J. E. Schiffbauer

All Physics Faculty Publications

Models and microfluidic experiments are presented of an electrophoretic separation technique in which charged particles whose mobilities exceed a tunable threshold are trapped between the crests of a longitudinal electric wave traveling through a stationary viscous fluid. The wave is created by applying periodic potentials to electrode arrays above and below a microchannel. Predicted average velocities agree with experiments and feature chaotic attractors for intermediate mobilities.

Characteristics Of Mesospheric Gravity Waves Near The Magnetic Equator, Brazil, During The Spreadfex Campaign, Michael J. Taylor, Pierre-Dominique Pautet, A. F. Medeiros, R. Buriti, J. Fechine, D. C. Fritts, S. L. Vadas, H. Takahashi, F. T. São Sabbas

All Physics Faculty Publications

As part of the SpreadFEx campaign, coordinated optical and radio measurements were made from Brazil to investigate the occurrence and properties of equatorial Spread F, and to characterize the regional mesospheric gravity wave field. All-sky image measurements were made from two sites: Brasilia and Cariri located ~10° S of the magnetic equator and separated by ~1500 km. In particular, the observations from Brasilia provided key data in relatively close proximity to expected convective sources of the gravity waves. High-quality image measurements of the mesospheric OH emission and the thermospheric OI (630 nm) emission were made during two consecutive new moon …

Methods To Quantify Variable Importance: Implications For Theanalysis Of Noisy Ecological Data, Kim Murray, Mary M. Conner

Wildland Resources Faculty Publications

Determining the importance of independent variables is of practical relevance to ecologists and managers concerned with allocating limited resources to the management of natural systems. Although techniques that identify explanatory variables having the largest influence on the response variable are needed to design management actions effectively, the use of various indices to evaluate variable importance is poorly understood. Using Monte Carlo simulations, we compared six different indices commonly used to evaluate variable importance; zero-order correlations, partial correlations, semipartial correlations, standardized regression coefficients, Akaike weights, and independent effects. We simulated four scenarios to evaluate the indices under progressively more complex circumstances …

Phenomena Induced By Powerful Hf Pumping Towards Magnetic Zenith With A Frequency Near The F-Region Critical Frequency And The Third Electron Gyro Harmonic Frequency, N. F. Blagoveshchenskaya, Herbert C. Carlson, V. A. Kornienko, T. D. Borisova, M. T. Rietveld, T. K. Yeoman, A. Brekke

Faculty publications

Multi-instrument observational data from an experiment on 13 October 2006 at the EISCAT/HEATING facility at Tromsø, Norway are analysed. The experiment was carried out in the evening hours when the electron density in the F-region dropped, and the HF pump frequency fH was near and then above the critical frequency of the F2 layer. The distinctive feature of this experiment is that the pump frequency was just below the third electron gyro harmonic frequency, while both the HF pump beam and UHF radar beam were directed towards the magnetic zenith (MZ). The HF pump-induced phenomena were diagnosed with several instruments: …

Logistic Models With Missing Categorical Covariates, Jeremiah Rounds

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

We present an EM based solution to missing categorical covariates in Binomial models with logit links using an assumption that experimental units are drawn from a Multinomial population of infinite size. We further address the problem of separation of points inducing large variances on parameter estimates by the use of a novel score-modification based on Firth's bias-reduction score-modification. We simulate to address questions about estimate bias, distribution, and appropriate parameter coverage by Wald intervals.

Approaches To Promote Active, Conceptual Learning In A Pedagogically Hybrid Introductory Statistics Course, Brittany L. Allred

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

Statistics education is an active area of research where discovery-based learning is becoming more prominent. This project reviews how the USEI and GAISE recommendations can be implemented in the statistics classroom. Further, the project describes the creation of a library of classroom materials for an introductory statistics course. The results are also discussed from implementing various library materials, along with the student response to hands-on learning techniques.

Intermediate-Complexity Biological Modeling Framework For Nutrient Cycling In Lakes Based On Physical Structure, Michael Clay Rigley

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

Mathematical models for the change in concentration of total dissolved nitrogen (TDN) in mountain lakes are developed based on the dynamics of coupled, well-mixed containers. Each includes a stratified lake structure without the complexity of a full fluid model. A lake is divided into a suite of compartments based on physical structure: warm upper layer (epilimnion), cold inflow and insertion layer (metalimnion), cold lower layer (hypolimnion), and a warm shallow shelf. With the compartments as the framework and literature values for uptake rates, death rates, half-saturation constants, and sinking rates, systems of equations are written for three models. The first …

The Statistical Evaluation Of Collective Risk Models With Various Distributional Assumptions, Chang Li

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

Our thesis includes 2 sections. In section 1, we mainly discuss the distribution function and the empirical simulation of the total claims amount for a portfolio with multiple distributional assumptions, under the collective risk model for a single period.

In section 2, we discuss the collective risk model for an extended period, which mainly deals with the amount of surplus over several periods of time. Let Un denote the surplus at time n, then we interested in the probability of ruin, that is, the probability that there exists an n such that Un< O. In this section, we put forward an algorithm for the probability of ruin (both theoretical and empirical) using this model, with various distributional assumptions, and compare the theoretical and empirical results.

The reference of this project is Actuarial …

Probe-Level Statistical Models For Differential Expression Of Genes In Bovine Nt Studies, Jason L. Bell

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

A brief introduction of microarray technology and its uses is given. This technology is commonly used in agricultural research, including research in nuclear transfer, which motivated this study. There are 3 classes of statistical models compared: probeset-level, weighted probeset-level and probe-level.

Different statistical mod els are compared on 3 spike-in experiments to assess the relative performance in identifying differentially expressed genes . A novel nested factorial model was found to outperform all other models compared in this study in one spike-in experiment, and was found to be competitive in its performance relative to the other models on the other spike-in …

Comparison Of Random Forests And Cforest: Variable Importance Measures And Prediction Accuracies, Rong Xia

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

Random forests are ensembles of trees that give accurate predictions for regression, classification and clustering problems. The CART tree, the base learn er employed by random forests, has been criticized because of bias in the selection of splitting variables. The performance of random forests is suspect due to this criticism. A new implementation of random forests, Cforest, which is claimed to outperform random forests in both predictive power and variable importance measures , was developed based on Ctree, an implementation of conditional inference trees.

We address the underlying mechanism of random forests and Cforest in this report. Comparison of random …

Folklore And The Internet: Vernacular Expression In A Digital World, Trevor J. Blank

All USU Press Publications

Folklore and the Internet is a pioneering examination of the folkloric qualities of the World Wide Web, e-mail, and related digital media. It shows that folk culture, sustained by a new and evolving vernacular, has been a key, since the Internetýs beginnings, to language, practice, and interaction online. Users of many sorts continue to develop the Internet as a significant medium for generating, transmitting, documenting, and preserving folklore. In a set of new, insightful essays, contributors Trevor J. Blank, Simon J. Bronner, Robert Dobler, Russell Frank, Gregory Hansen, Robert Glenn Howard, Lynne S. McNeill, Elizabeth Tucker, and William Westerman showcase …

Landscaping On The New Frontier: Waterwise Design For The Intermountain West, Susan E. Meyer, Roger K. Kjelgren, Darrel G. Morrison, William A. Varga

All USU Press Publications

A practical volume for the home or business owner on landscaping with native, drought-tolerant plants in the Rocky Mountain West. Filled with color illustrations, photos, and design sketches, over 100 native species are described, while practical tips on landscape design, water-wise irrigation, and keeping down the weeds are provided. In this book you will learn how to use natural landscapes to inspire your own designed landscape--around your business or home and yard. Included are design principles, practical ideas, and strong examples of what some homeowners have already done to convert traditional "bluegrass" landscapes into ones that are more expressive of …

Gathering Leadership Momentum Across Great Distances: Creating An Online Community Of Practice, Erin L. Davis, Danielle Theiss-White

Erin Davis

At the 2007 Mountain Plains Library Association Leadership (MPLA) Institute, held in New Mexico, USA, eight academic librarians formed an online multi-state, multigenerational community of practice. MPLA is a twelve-state library association within the United States. Using Google Groups™, the members formed an online environment called the MPLA Community of Practice for continuing development of the leadership skills presented at the Institute. These early-career librarians represent diverse educational backgrounds and work in libraries serving varied populations with differing disciplinary emphases.

The group meets monthly with each member preparing and facilitating online discussions, complete with personal assessments, topical readings, and questions. …

Applications Of Modern Classification Methods To Predict Occurrences Of Rare And Invasive Plant Species, Stacey Reynolds

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

Statistical classification methods are among the most widely used statistical procedures in ecology. Applications include vegetation mapping by remote sensing (Steele 2000), discrimination of subspecies using morphological measurements (Fisher 1936, 1938; Conner and Schenk 2003), and species distribution modelling (Guisan and Zimmerman 2000). Examples of the last application abound in the ecological literature and include predicting the distribution or characteristics of plant species (see, e.g., Austin et al. 1990), predicting presence and absence aquatic biota in streams (Hawkins et al. 2000), and habit at relationships of terrestrial animal species (Welch and MacMahon 2005). Over the last 20 years two mainstays …

Heritability Of Cognition Subscales In The Cache County Memory Study Cohort And Methods For Estimating Heritability, Colette Kelly Childs

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

The rapid improvement of genotyping technology holds the promise of better understanding the genetic causes of complex disease. While traits of interest often include the presence or absence of disease, there is growing interest in intermediate phenotypes (or so-called endophenotypes) that may yield more information about disease onset or course. In particular, changes over time with respect to an investigative ordinal measure often contain significant predictive power, and rate-of-change phenotypes are becoming important in their own right when studying genetic association. Initial steps in assessing the potential genetic determinants of a continuous trait often involve estimating the degree of the …

Cow Insurance Vs. Human Insurance: A Comparison Study, Corlan Fawcett

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

This paper will compare the premiums to insure cows and humans for n-year term, n-year endowment, and whole life insurance. It will go into more depth for whole life premium s that would be charged, such that the insurance company is 95 percent confident that they will not lose money. In particular the paper will look at how the variance affects the premiums for an insurance company insuring 100 cows.

Evaluating The Effectiveness Of A Probability Applet, Chelsa Green Tuddenham

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

The purpose of this project was to develop and examine a computerized interactive probability applet designed to teach basic concepts of probability. The applet design was intended to be a user-friendly way to encourage understanding of basic probability concepts such as, rules of probability, probabilities of mutually exclusive events, and the multiplication rule. Thirty participants were recruited from Utah State University and were asked to participate in the evaluation process of the probability applet. The evaluation of the probability applet consisted of three parts: First, a group of participants were video recorded and asked to voice any and all thoughts …

Comparison Of Exact Methods For Analyzing Family-Based Samples, Abbie Lundgreen

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

Family-based association tests are used to identify genes that increase the risk of developing a disease, while controlling for spurious associations caused by population structure. The exact family-based association test, exact FBAT, is a unified approach which can be app lied to tests of different genetic models, sampling designs, null hypotheses , and missing parental information.

The purpose of this report is to compare the power of the exact FBAT with two other tests, exact conditional logistic regression (CLR) and the exact trend test for clustered data (QEM). Pedigrees of sibships were simulated based upon a variety of different parameters, …

The Classification Of Simple Lie Algebras In Maple, D. Russell Sadler

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

Lie algebras are invaluable tools in mathematics and physics as they enable us to study certain geometric objects such as Lie groups and differentiable manifolds. The computer algebra system Maple has several tools in its Lie Algebras package to work with Lie algebras and Lie groups. The purpose of this paper is to supplement the existing software with tools that are essential for the classification of simple Lie algebras over C.

In particular, we use a method to find a Cartan subalgebra of a Lie algebra in polynomial time. From the Cartan subalgebra we can compute the corresponding root system. …

Gathering Leadership Momentum Across Great Distances: Creating An Online Community Of Practice, Erin Dini-Davis, Danielle Theiss-White

Library Faculty & Staff Publications

At the 2007 Mountain Plains Library Association Leadership (MPLA) Institute, held in New Mexico, USA, eight academic librarians formed an online multi-state, multigenerational community of practice. MPLA is a twelve-state library association within the United States. Using Google Groups™, the members formed an online environment called the MPLA Community of Practice for continuing development of the leadership skills presented at the Institute. These early-career librarians represent diverse educational backgrounds and work in libraries serving varied populations with differing disciplinary emphases. The group meets monthly with each member preparing and facilitating online discussions, complete with personal assessments, topical readings, and questions. …

Nutrient Limitation Of Phytoplankton By Nitrogen And Phosphorus: Erosion Of The Phosphorus Paradigm, Wayne A. Wurtsbaugh, William M. Lewis Iii

Watershed Sciences Faculty Publications

No abstract provided.

Freshwater Responses To Nitrogen And Phosphorus Pollution And A Case Study Of Cutler And Dingle Marsh Wetlands, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

No abstract provided.

Extreme Eutrophication And Cyanotoxin Levels In Farmington Bay, A Polluted Embayment Of The Great Salt Lake, Utah, Wayne A. Wurtsbaugh, Amy M. Marcarelli, Gregory Boyer

Watershed Sciences Faculty Publications

The Great Salt Lake of Utah is surrounded on its eastern and southern shores by 1.4 million people, with projections of 5 million by 2050. Agricultural, industrial and particularly secondary-treated domestic wastes from this population flow primarily into Farmington Bay, a 280 km2 shallow "estuary" with a mean depth near 0.5 m. Fish are rare but bird use is extensive and massive mortalities of waterfowl and shorebirds have occurred in the bay. Phosphorus loading rates of >2 g m-2yr-1 cause hypereutrophic conditions: Secchi depths are usually 0.6 mg/L, mean Chl. a is 179 ug/L and the combined trophic state index …

Evaluating The Effectiveness Of Grassbed Treatments As Habitat For Juvenile Black Bass In A Drawdown Reservoir, D. R. Ratcliff, Wayne A. Wurtsbaugh, J. Zustak

Watershed Sciences Faculty Publications

Many reservoirs in arid regions experience highly variable water levels caused by seasonal inflow fluctuations and designated outflow requirements. At Shasta Lake, California, managers plant cereal-grain grassbeds on exposed drawdown shorelines to increase juvenile fish habitat, localize productivity, and increase invertebrate fish prey. To determine the efficacy of these plantings, the abundance of juvenile black basses Micropterus spp. (20–55 mm standard length) and the amount of periphyton and macroinvertebrate prey were compared among three treatment types: (1) planted grassbeds of cereal barley Hordeum vulgare; (2) artificial rope grassbeds, which eliminated physical deterioration and nutrient release; and (3) nonplanted control sites …