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Modeling Longitudinal Change In Cervical Length Across Pregnancy, Hope M. Wolf, Shawn J. Latendresse, Jerome F. Strauss III, Timothy P. York 2021 Virginia Commonwealth University

Modeling Longitudinal Change In Cervical Length Across Pregnancy, Hope M. Wolf, Shawn J. Latendresse, Jerome F. Strauss Iii, Timothy P. York

Graduate Research Posters

Introduction: A short cervix (cervical length < 25 mm) in the mid-trimester (18 to 24 weeks) of pregnancy is a powerful predictor of spontaneous preterm delivery (gestational age at delivery < 37 weeks). Although the biological mechanisms of cervical remodeling have been the subject of extensive investigation, very little is known about the rate of change in cervical length over the course of a pregnancy, or the extent to which rapid cervical shortening increases maternal risk for spontaneous preterm delivery.

Methods: A cohort of 5,160 unique women carrying 5,971 singleton pregnancies provided two or more measurements of cervical length during pregnancy. Cervical length was measured in millimeters using a transvaginal 12-3 MHz ultrasound endocavity probe (SuperSonic Imagine). Maternal characteristics, including relevant medical history and birth outcome data, were collected for each participant. Gestational age at delivery was measured from the first day of each woman’s last menstrual period and confirmed by ultrasound. Repeated measurements of cervical length during pregnancy were modeled as a longitudinal, multilevel growth curve in MPlus. A three-level ...


Joint Modeling Of Distances And Times In Point-Count Surveys, Adam Martin-Schwarze, Jarad Niemi, Philip Dixon 2021 University of Michigan

Joint Modeling Of Distances And Times In Point-Count Surveys, Adam Martin-Schwarze, Jarad Niemi, Philip Dixon

Statistics Publications

Removal and distance modeling are two common methods to adjust counts for imperfect detection in point-count surveys. Several recent articles have formulated models to combine them into a distance-removal framework. We observe that these models fall into two groups building from different assumptions about the joint distribution of observed distances and first times to detection. One approach assumes the joint distribution results from a Poisson process (PP). The other assumes an independent joint (IJ) distribution with its joint density being the product of its marginal densities. We compose an IJ+PP model that more flexibly models the joint distribution and ...


Neither “Post-War” Nor Post-Pregnancy Paranoia: How America’S War On Drugs Continues To Perpetuate Disparate Incarceration Outcomes For Pregnant, Substance-Involved Offenders, Becca S. Zimmerman 2021 Pitzer College

Neither “Post-War” Nor Post-Pregnancy Paranoia: How America’S War On Drugs Continues To Perpetuate Disparate Incarceration Outcomes For Pregnant, Substance-Involved Offenders, Becca S. Zimmerman

Pitzer Senior Theses

This thesis investigates the unique interactions between pregnancy, substance involvement, and race as they relate to the War on Drugs and the hyper-incarceration of women. Using ordinary least square regression analyses and data from the Bureau of Justice Statistics’ 2016 Survey of Prison Inmates, I examine if (and how) pregnancy status, drug use, race, and their interactions influence two length of incarceration outcomes: sentence length and amount of time spent in jail between arrest and imprisonment. The results collectively indicate that pregnancy decreases length of incarceration outcomes for those offenders who are not substance-involved but not evenhandedly -- benefitting white pregnant ...


Projected Changes In Temperature And Precipitation Over The United States, Central America, And The Caribbean In Cmip6 Gcms, Mansour Almazroui, M. Nazrul Islam, Fahad Saeed, Sajjad Saeed, Muhammad Ismail, Muhammad Azhar Ehsan, Ismaila Diallo, Enda O’Brien, Moetasim Ashfaq, Daniel Martínez-Castro, Tereza Cavazos, Ruth Cerezo-Mota, Michael K. Tippett, William J. Gutowski Jr., Eric J. Alfaro, Hugo G. Hidalgo, Alejandro Vichot-Llano, Jayaka D. Campbell, Shahzad Kamil, Irfan Ur Rashid, Mouhamadou Bamba Sylla, Tannecia Stephenson, Michael Taylor, Mathew Barlow 2021 King Abdulaziz University

Projected Changes In Temperature And Precipitation Over The United States, Central America, And The Caribbean In Cmip6 Gcms, Mansour Almazroui, M. Nazrul Islam, Fahad Saeed, Sajjad Saeed, Muhammad Ismail, Muhammad Azhar Ehsan, Ismaila Diallo, Enda O’Brien, Moetasim Ashfaq, Daniel Martínez-Castro, Tereza Cavazos, Ruth Cerezo-Mota, Michael K. Tippett, William J. Gutowski Jr., Eric J. Alfaro, Hugo G. Hidalgo, Alejandro Vichot-Llano, Jayaka D. Campbell, Shahzad Kamil, Irfan Ur Rashid, Mouhamadou Bamba Sylla, Tannecia Stephenson, Michael Taylor, Mathew Barlow

Geological and Atmospheric Sciences Publications

The Coupled Model Intercomparison Project Phase 6 (CMIP6) dataset is used to examine projected changes in temperature and precipitation over the United States (U.S.), Central America and the Caribbean. The changes are computed using an ensemble of 31 models for three future time slices (2021–2040, 2041–2060, and 2080–2099) relative to the reference period (1995–2014) under three Shared Socioeconomic Pathways (SSPs; SSP1-2.6, SSP2-4.5, and SSP5-8.5). The CMIP6 ensemble reproduces the observed annual cycle and distribution of mean annual temperature and precipitation with biases between − 0.93 and 1.27 °C and − 37.90 ...


A Bayesian Hierarchical Mixture Model With Continuous-Time Markov Chains To Capture Bumblebee Foraging Behavior, Max Thrush Hukill 2021 Bowdoin College

A Bayesian Hierarchical Mixture Model With Continuous-Time Markov Chains To Capture Bumblebee Foraging Behavior, Max Thrush Hukill

Honors Projects

The standard statistical methodology for analyzing complex case-control studies in ethology is often limited by approaches that force researchers to model distinct aspects of biological processes in a piecemeal, disjointed fashion. By developing a hierarchical Bayesian model, this work demonstrates that statistical inference in this context can be done using a single coherent framework. To do this, we construct a continuous-time Markov chain (CTMC) to model bumblebee foraging behavior. To connect the experimental design with the CTMC, we employ a mixture model controlled by a logistic regression on the two-factor design matrix. We then show how to infer these model ...


An Updated Method For Correcting Batch Effect, Yonghui Huo 2021 Iowa State University

An Updated Method For Correcting Batch Effect, Yonghui Huo

Creative Components

Abstract

I propose a novel variation (Pro-SVA) on iteratively reweighted surrogate variable analysis (IRW-SVA) for detecting and measuring batch effects in high dimensional gene expression data. Specifically, I propose to use the matrix-free high dimensional factor analysis (HDFA) algorithm instead of singular value decomposition (SVD) in the IRW-SVA iterations. HDFA efficiently provides the maximum likelihood estimates of the error variances and batch loadings, which can subsequently be used to estimate the batch factors. To evaluate the performance of Pro-SVA, I simulated 100 samples of 1,000 genes with batch effects and (1) no biological effects, (2) biological effects for half ...


Effects Of Farrowing Stall Layout And Number Of Heat Lamps On Sow And Piglet Behavior, Suzanne M. Leonard, Hongwei Xin, Tami M/ Brown-Brandl, Brett C. Ramirez, Anna K. Johnson, Somak Dutta, Gary A. Rohrer 2021 Iowa State University

Effects Of Farrowing Stall Layout And Number Of Heat Lamps On Sow And Piglet Behavior, Suzanne M. Leonard, Hongwei Xin, Tami M/ Brown-Brandl, Brett C. Ramirez, Anna K. Johnson, Somak Dutta, Gary A. Rohrer

Animal Science Publications

Farrowing stalls are used in the United States swine industry to reduce pre-weaning piglet mortality, enable efficient individual animal management, and decrease facility construction and operating costs. The quantity and quality of space provided for sows and piglets in farrowing stalls are important economic and welfare considerations. To further explore the impacts of farrowing stall space allocation, a large-scale field study was conducted to compare sow and piglet behavior when housed in three farrowing stall layouts (TSL – traditional stall layout, ECSL – expanded creep area stall layout, ESCSL – expanded sow and creep area stall layout) with either one or two heat ...


Modeling And Inference For Mixtures Of Simple Symmetric Exponential Families Of P-Dimensional Distributions For Vectors With Binary Coordinates, Abhishek Chakraborty, Stephen B. Vardeman 2021 Lawrence University

Modeling And Inference For Mixtures Of Simple Symmetric Exponential Families Of P-Dimensional Distributions For Vectors With Binary Coordinates, Abhishek Chakraborty, Stephen B. Vardeman

Statistics Publications

We propose tractable symmetric exponential families of distributions for multivariate vectors of 0's and 1's in dimensions, or what are referred to in this paper as binary vectors, that allow for nontrivial amounts of variation around some central value . We note that more or less standard asymptotics provides likelihood-based inference in the one-sample problem. We then consider mixture models where component distributions are of this form. Bayes analysis based on Dirichlet processes and Jeffreys priors for the exponential family parameters prove tractable and informative in problems where relevant distributions for a vector of binary variables are clearly not ...


Information Prioritization: A Comparison Between Utility Maximizers And Probability Matchers, Yusuf Ismaeel 2021 Claremont Colleges

Information Prioritization: A Comparison Between Utility Maximizers And Probability Matchers, Yusuf Ismaeel

CMC Senior Theses

This thesis examines the differences between probability matchers and utility maximizers in their preferences for information sources in a lab environment. In this paper, we consider the best source of information to be the most connected one. We conducted several linear probability model type regressions along with logit regressions. Furthermore, we also attempted to control and fix any potential misclassifications in classifying the cognitive strategy by using instrumental variables. The results show that utility maximizers will almost always choose the most informed node. Probability matchers, on the other hand, do not exhibit such a behavior as the probability matching strategy ...


Hyperbolic Quadrature Method Of Moments For The One-Dimensional Kinetic Equation, Rodney O. Fox, Frédérique Laurent 2021 Iowa State University

Hyperbolic Quadrature Method Of Moments For The One-Dimensional Kinetic Equation, Rodney O. Fox, Frédérique Laurent

Chemical and Biological Engineering Publications

A solution is proposed to a longstanding open problem in kinetic theory, namely, 5 given any set of realizable velocity moments up to order 2n, a closure for the moment of order 2n+1 is 6 constructed for which the moment system found from the free-transport term in the one-dimensional 7 (1-D) kinetic equation is globally hyperbolic and in conservative form. In prior work, the hyperbolic 8 quadrature method of moments (HyQMOM) was introduced to close this moment system up to fourth 9 order (n ≤ 2). Here, HyQMOM is reformulated and extended to arbitrary even-order moments. The 10 HyQMOM closure ...


A Transdisciplinary Analysis Of Just Transition Pathways To 100% Renewable Electricity, Adewale Aremu Adesanya 2021 Michigan Technological University

A Transdisciplinary Analysis Of Just Transition Pathways To 100% Renewable Electricity, Adewale Aremu Adesanya

Dissertations, Master's Theses and Master's Reports

The transition to using clean, affordable, and reliable electrical energy is critical for enhancing human opportunities and capabilities. In the United States, many states and localities are engaging in this transition despite the lack of ambitious federal policy support. This research builds on the theoretical framework of the multilevel perspective (MLP) of sociotechnical transitions as well as the concept of energy justice to investigate potential pathways to 100 percent renewable energy (RE) for electricity provision in the U.S. This research seeks to answer the question: what are the technical, policy, and perceptual pathways, barriers, and opportunities for just transition ...


Evaluation Of A Random Forest Model To Identify Invasive Carp Eggs Based On Morphometric Features, Katherine Goode, Michael J. Weber, Aaron Matthews, Clay L. Pierce 2021 Iowa State University

Evaluation Of A Random Forest Model To Identify Invasive Carp Eggs Based On Morphometric Features, Katherine Goode, Michael J. Weber, Aaron Matthews, Clay L. Pierce

Natural Resource Ecology and Management Publications

Three species of invasive carp—Grass Carp Ctenopharyngodon idella, Silver Carp Hypophthalmichthys molitrix, and Bighead Carp H. nobilis—are rapidly spreading throughout North America. Monitoring their reproduction can help to determine establishment in new areas but is difficult due to challenges associated with identifying fish eggs. Recently, random forest models provided accurate identification of eggs based on morphological traits, but the models have not been validated using independent data. Our objective was to evaluate the predictive performance of egg identification models developed by Camacho et al. (2019) for classifying invasive carp eggs by using an independent data set. When invasive ...


Lengthening Of Maize Maturity Time Is Not A Widespread Climate Change Adaptation Strategy In The Us Midwest, Lori J. Abendroth, Fernando E. Miguez, Michael J. Castellano, Paul R. Carter, Carlos D. Messina, Philip M. Dixon, Jerry L. Hatfield 2021 Iowa State University

Lengthening Of Maize Maturity Time Is Not A Widespread Climate Change Adaptation Strategy In The Us Midwest, Lori J. Abendroth, Fernando E. Miguez, Michael J. Castellano, Paul R. Carter, Carlos D. Messina, Philip M. Dixon, Jerry L. Hatfield

Agronomy Publications

Increasing temperatures in the US Midwest are projected to reduce maize yields because warmer temperatures hasten reproductive development and, as a result, shorten the grain fill period. However, there is widespread expectation that farmers will mitigate projected yield losses by planting longer season hybrids that lengthen the grain fill period. Here, we ask: (a) how current hybrid maturity length relates to thermal availability of the local climate, and (b) if farmers are shifting to longer season hybrids in response to a warming climate. To address these questions, we used county‐level Pioneer brand hybrid sales (Corteva Agriscience) across 17 years ...


Influence Of Some Climatic Elements On Radon Concentration In Saeva Dupka Cave, Bulgaria, Peter Nojarov, Petar Stefanov, Karel Turek 2020 National Institute of Geophysics, Geodesy and Geography, Bulgarian Academy of Sciences

Influence Of Some Climatic Elements On Radon Concentration In Saeva Dupka Cave, Bulgaria, Peter Nojarov, Petar Stefanov, Karel Turek

International Journal of Speleology

This study reveals the influence of some climatic elements on radon concentration in Saeva Dupka Cave, Bulgaria. The research is based mainly on statistical methods. Radon concentration in the cave is determined by two main mechanisms. The first one is through penetration of radon from soil and rocks around the cave (present all year round, but has leading role during the warm half of the year). The second one is through thermodynamic exchange of air between inside of the cave and outside atmosphere (cold half of the year). Climatic factors that affect radon concentration in the cave are temperatures (air ...


Development Of A Statistical Model To Predict Materials’ Unit Prices For Future Maintenance And Rehabilitation In Highway Life Cycle Cost Analysis, Changmo Kim, Ghazan Khan, Brent Nguyen, Emily L. Hoang 2020 University of California, Davis

Development Of A Statistical Model To Predict Materials’ Unit Prices For Future Maintenance And Rehabilitation In Highway Life Cycle Cost Analysis, Changmo Kim, Ghazan Khan, Brent Nguyen, Emily L. Hoang

Mineta Transportation Institute Publications

The main objectives of this study are to investigate the trends in primary pavement materials’ unit price over time and to develop statistical models and guidelines for using predictive unit prices of pavement materials instead of uniform unit prices in life cycle cost analysis (LCCA) for future maintenance and rehabilitation (M&R) projects. Various socio-economic data were collected for the past 20 years (1997–2018) in California, including oil price, population, government expenditure in transportation, vehicle registration, and other key variables, in order to identify factors affecting pavement materials’ unit price. Additionally, the unit price records of the popular pavement ...


Incorporating Shear Resistance Into Debris Flow Triggering Model Statistics, Noah J. Lyman 2020 California Polytechnic State University, San Luis Obispo

Incorporating Shear Resistance Into Debris Flow Triggering Model Statistics, Noah J. Lyman

Master's Theses

Several regions of the Western United States utilize statistical binary classification models to predict and manage debris flow initiation probability after wildfires. As the occurrence of wildfires and large intensity rainfall events increase, so has the frequency in which development occurs in the steep and mountainous terrain where these events arise. This resulting intersection brings with it an increasing need to derive improved results from existing models, or develop new models, to reduce the economic and human impacts that debris flows may bring. Any development or change to these models could also theoretically increase the ease of collection, processing, and ...


Quantifying The Simultaneous Effect Of Socio-Economic Predictors And Build Environment On Spatial Crime Trends, Alfieri Daniel Ek 2020 University of Arkansas, Fayetteville

Quantifying The Simultaneous Effect Of Socio-Economic Predictors And Build Environment On Spatial Crime Trends, Alfieri Daniel Ek

Theses and Dissertations

Proper allocation of law enforcement agencies falls under the umbrella of risk terrainmodeling (Caplan et al., 2011, 2015; Drawve, 2016) that primarily focuses on crime prediction and prevention by spatially aggregating response and predictor variables of interest. Although mental health incidents demand resource allocation from law enforcement agencies and the city, relatively less emphasis has been placed on building spatial models for mental health incidents events. Analyzing spatial mental health events in Little Rock, AR over 2015 to 2018, we found evidence of spatial heterogeneity via Moran’s I statistic. A spatial modeling framework is then built using generalized linear ...


Gene Set Testing By Distance Correlation, Sho-Hsien Su 2020 University of Arkansas, Fayetteville

Gene Set Testing By Distance Correlation, Sho-Hsien Su

Theses and Dissertations

Pathways are the functional building blocks of complex diseases such as cancers. Pathway-level studies may provide insights on some important biological processes. Gene set test is an important tool to study the differential expression of a gene set between two groups, e.g., cancer vs normal. The differential expression of a gene set could be due to the difference in mean, variability, or both. However, most existing gene set tests only target the mean difference but overlook other types of differential expression. In this thesis, we propose to use the recently developed distance correlation for gene set testing. To assess ...


Statistical Methods With A Focus On Joint Outcome Modeling And On Methods For Fire Science, Da Zhong Xi 2020 The University of Western Ontario

Statistical Methods With A Focus On Joint Outcome Modeling And On Methods For Fire Science, Da Zhong Xi

Electronic Thesis and Dissertation Repository

Understanding the dynamics of wildfires contributes significantly to the development of fire science. Challenges in the analysis of historical fire data include defining fire dynamics within existing statistical frameworks, modeling the duration and size of fires as joint outcomes, identifying the how fires are grouped into clusters of subpopulations, and assessing the effect of environmental variables in different modeling frameworks. We develop novel statistical methods to consider outcomes related to fire science jointly. These methods address these challenges by linking univariate models for separate outcomes through shared random effects, an approach referred to as joint modeling. Comparisons with existing approaches ...


Stochastic Analysis And Statistical Inference For Seir Models Of Infectious Diseases, Andrés Ríos-Gutiérrez, Viswanathan Arunachalam, Anuj Mubayi 2020 PRECISIONheor

Stochastic Analysis And Statistical Inference For Seir Models Of Infectious Diseases, Andrés Ríos-Gutiérrez, Viswanathan Arunachalam, Anuj Mubayi

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.


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