Statistics and Probability Commons^™

Modeling Mayfly Nymph Length Distribution And Population Dynamics Across A Gradient Of Stream Temperatures And Stream Types, Jeremy Anthony, Jennifer Baccam, Imanuel Bier, Emily Gregg, Leif Halverson, Ryan Mulcahy, Emmanuel Okanla, Samira A. Osman, Adam R. Pancoast, Kevin C. Schultz, Alex Sushko, Jennifer Vorarath, Yia Vue, Austin Wagner, Emily Gaenzle Schilling, John Zobitz

Faculty Authored Articles

We analyze a process-based temperature model for the length distribution and population over time of mayfly nymphs. Model parameters are estimated using a Markov Chain Monte Carlo parameter estimation method utilizing length distribution data at five different stream sites. Two different models (a standard exponential model and a modified Weibull model) of mayfly mortality are evaluated, where in both cases mayfly length growth is a function of stream temperature. Based on model-data comparisons to the modeled length distribution and the Bayesian Information Criterion, we found that approaches that length distribution data can reliably estimate 2–3 model parameters. Future model development …

Mini Review: A Note On Nonoscillatory Solutions For Higher Dimensional Time Scale Systems, Elvan Akin, Ozkan Ozturk, Ismail Ugur Tiryaki, Gulsah Yeni

Mathematics and Statistics Faculty Research & Creative Works

In this paper, we focus on nonoscillatory solutions of two (2D) and three (3D) dimensional time scale systems and discuss nonexistence of such solutions.

The Generalized Hypergeometric Difference Equation, Martin Bohner, Tom Cuchta

Mathematics and Statistics Faculty Research & Creative Works

A difference equation analogue of the generalized hypergeometric differential equation is defined, its contiguous relations are developed, and its relation to numerous well-known classical special functions are demonstrated.

A Higher-Order Ensemble/Proper Orthogonal Decomposition Method For The Nonstationary Navier-Stokes Equations, Max Gunzburger, Nan Jiang, Michael Schneier

Mathematics and Statistics Faculty Research & Creative Works

Partial differential equations (PDE) often involve parameters, such as viscosity or density. An analysis of the PDE may involve considering a large range of parameter values, as occurs in uncertainty quantification, control and optimization, inference, and several statistical techniques. The solution for even a single case may be quite expensive; whereas parallel computing may be applied, this reduces the total elapsed time but not the total computational effort. In the case of flows governed by the Navier-Stokes equations, a method has been devised for computing an ensemble of solutions. Recently, a reduced-order model derived from a proper orthogonal decomposition (POD) …

Parametrization Of Scale-Invariant Self-Adjoint Extensions Of Scale-Invariant Symmetric Operators, Miron B. Bekker, Martin Bohner, Alexander P. Ugol'nikov, Hristo Voulov

Mathematics and Statistics Faculty Research & Creative Works

On a Hilbert space H, we consider a symmetric scale-invariant operator with equal defect numbers. It is assumed that the operator has at least one scale invariant self-adjoint extension in H. We prove that there is a one-to-one correspondence between (generalized) resolvents of scale-invariant extensions and solutions of some functional equation. Two examples of Dirac-type operators are considered.

A Preliminary Study Of Smithport Plain Bottle Morphology In The Southern Caddo Area, Robert Z. Selden Jr.

CRHR: Archaeology

This study expands upon a previous analysis of the Clarence H. Webb collection, which resulted in the identification of two discrete shapes used in the manufacture of the base and body of Smithport Plain bottles. The sample includes the Smithport Plain bottles from the Webb collection, and four new bottles: two previously repatriated specimens in the Pohler Collection, and two from the Mitchell site (41BW4) to test whether those specimens align morphologically with the Belcher Mound or Smithport Landing specimens. Results indicate significant allometry and a significant difference in Smithport Plain body and base shapes for bottles produced at the …

Power Calculation For Cross-Sectional Stepped Wedge Cluster-Randomized Trials With Variable Cluster Sizes, Linda J. Harrison, Tom Chen, Rui Wang

Harvard University Biostatistics Working Paper Series

Standard sample size calculation formulas for Stepped Wedge Cluster Randomized Trials (SW-CRTs) assume that cluster sizes are equal. When cluster sizes vary substantially, ignoring this variation may lead to an under-powered study. We investigate the relative efficiency of a SW-CRT with varying cluster sizes to equal cluster sizes, and derive variance estimators for the intervention effect that account for this variation under the assumption of a mixed effects model; a commonly-used approach for analyzing data from cluster randomized trials. When cluster sizes vary, the power of a SW-CRT depends on the order in which clusters receive the intervention, which is …

Preference Probability Based On Ranks - A New Approach Using Logistic Regression With Zero Intercept, Oluwagbenga David Agboola

Theses, Dissertations and Capstones

Many probability models have been proposed to describe rankings. One of these is the BradleyTerry model, which is based on observed pairwise preferences. For this study, we reverse the case and propose a new approach for estimating pairwise preference probabilities based on observed rankings. The new approach uses logistic regression with zero intercept as the statistical model that fits this situation. In order to implement the model, we first estimate the parameter using maximum likelihood estimation. Then we evaluate this estimation using numerical approximation procedures. We consider three such procedures: bisection method, Newton-Raphson method, and improved Newton’s method. Using simulated …

Crosstalk Among Lncrnas, Micrornas And Mrnas In The Muscle ‘Degradome’ Of Rainbow Trout, Bam Paneru, Ali Ali, Rafet Al-Tobasei, Brett Kenney, Mohamed Salem

Faculty & Staff Scholarship

In fish, protein-coding and noncoding genes involved in muscle atrophy are not fully characterized. In this study, we characterized coding and noncoding genes involved in gonadogenesis-associated muscle atrophy, and investigated the potential functional interplay between these genes. Using RNA- Seq, we compared expression pattern of mRNAs, long noncoding RNAs (lncRNAs) and microRNAs of atrophying skeletal muscle from gravid females and control skeletal muscle from age-matched sterile individuals. A total of 852 mRNAs, 1,160 lncRNAs and 28 microRNAs were differentially expressed (DE) between the two groups. Muscle atrophy appears to be mediated by many genes encoding ubiquitin- proteasome system, autophagy related …

X-Ray Spectroscopy Of Nio And Nanodiamond At Ssrl, Jackson Earl

STAR Program Research Presentations

The first aspect of this research project focuses on investigating the surface chemistry of high pressure high temperature (HPHT) nanodiamond by using X-ray spectroscopy techniques at the Stanford Synchrotron Radiation Lightsource (SSRL). HPHT nanodiamond is being examined as a biosensing tool for electric field detection based on the fluorescent nitrogen vacancy center hosted within diamond. With use of the transition edge spectrometer (TES), a state-of-the-art X-ray fluorescence detector, we are able to probe the surface and bulk properties of diamond. Preliminary work using density functional theory (DFT) has been done, offering insight into ground state energies and electronic structure. DFT …

Low Sucrose, Omega-3 Enriched Diet Has Region-Specific Effects On Neuroinflammation And Synaptic Function Markers In A Mouse Model Of Doxorubicin-Based Chemotherapy, Tonya S. Orchard, Monica M. Gaudier-Diaz, Panchita Phuwamongkolwiwat-Chu, Rebecca Andridge, Maryam B. Lustberg, Joshua Bomser, Rachel M. Cole, Martha A. Belury, Courtney A. Devries

Faculty & Staff Scholarship

Chemotherapeutic agents such as doxorubicin may negatively affect long-term brain functioning in cancer survivors; neuroinflammation may play a causal role. Dietary approaches that reduce inflammation, such as lowering sucrose and increasing eicosapentaenoic acid plus docosahexaenoic acid (EPA + DHA), may attenuate chemotherapy-induced neuroinflammation and synaptic damage, thereby improving quality of life. Ovariectomized, C57BL/6 mice were assigned to a chemotherapy (9 mg/kg doxorubicin + 90 mg/kg cyclophosphamide) or vehicle two-injection regimen, with injections two and four weeks after starting diets. In Study 1, mice received low sucrose diets with EPA + DHA or No EPA + DHA for four to six …

Nonparametric Density Estimation Based On The Scaled Laplace Transform Inversion, Fairouz Elmagbri, Robert M. Mnatsakanov

Faculty & Staff Scholarship

New nonparametric procedure for estimating the probability density function of a positive random variable is suggested. Asymptotic expressions of the bias term and Mean Squared Error are derived. By means of graphical illustrations and evaluating the Average of L2-errors we conducted comparisons of the finite sample performance of proposed estimate with the one based on kernel density method.

Waking Up Every Day In A Body That Is Not Yours: A Qualitative Research Inquiry Into The Intersection Between Eating Disorders And Pregnancy, Elizabeth A. Claydon, Danielle M. Davidov, Keith J. Zullig, Christa L. Lilly, Lesley Cattrell, Stephanie C. Zerwas

Faculty & Staff Scholarship

Background: Women with eating disorders are more likely to negatively react to finding out they are pregnant, although this difference in attitudes between women with eating disorders and controls disappears at 18-weeks’ gestation. Those with anorexia also are twice as likely to have an unplanned pregnancy and those with bulimia have a 30-fold increased chance compared with healthy controls. Therefore, due to these considerations, pregnancy and the transition to motherhood can be an extremely challenging time for these women both psychologically and physically. The purpose of this qualitative descriptive study was to understand the intersection between eating disorders and pregnancy …

Rubella Immunity And Serum Perfluoroalkyl Substances: Sex And Analytic Strategy, Courtney S. Pilkerton, Gerald R. Hobbs, Christa Lilly, Sarah S. Knox

Faculty & Staff Scholarship

Background

Perfluoroalkyl substances (PFASs) have been associated with decreased immunity to child- hood tetanus and diphtheria immunizations. If these vaccinations are vulnerable to influence from PFASs, questions arise about associations with other common inoculations.

Objective

To examine whether serum PFASs were associated with reduced immunity to rubella immu- nization, and whether interactions with sex or ethnicity warranted analytic stratification. Usually, toxicology analyses are calculated controlling for race and sex. However, sex differ- ences in immune function have been reported and a reduction of immunity to rubella in women could pose risks such miscarriage.

Methods

We analyzed a nationally representative sample …

Food Choice Priorities Change Over Time And Predict Dietary Intake At The End Of The First Year Of College Among Students In The U.S., Melissa J. Vilaro, Sarah E. Colby, Kristin Riggsbee, Wenjun Zhou, Carol Byrd-Bredbenner, Melissa D. Olfert, Tracey E. Barnett, Tanya Horacek, Morgan Sowers, Anne E. Matthews

Faculty & Staff Scholarship

This study assessed food choice priorities (FCP) and associations with consumption of fruits and vegetables (FV), fiber, added sugars from non-beverage sources, and sugar-sweetened beverages (SSB) among college students. Freshmen from eight U.S. universities (N = 1149) completed the Food Choice Priorities Survey, designed for college students to provide a way to determine the factors of greatest importance regarding food choices, and the NCI Dietary Screener Questionnaire. Changes in FCP and dietary intake from fall 2015 to spring 2016 were assessed. Multiple regression models examined associations between FCP and log-transformed dietary intake, controlling for sex, age, race, and BMI. Participant …

Genome-Wide Association Analysis With A 50k Transcribed Gene Snp-Chip Identifies Qtl Affecting Muscle Yield In Rainbow Trout, Mohamed Salem, Rafet Al-Tobasei, Ali Ali, Daniela Lourenco, Guangtu Gao, Yniv Palti, Brett Kenney, Timothy D. Leeds

Faculty & Staff Scholarship

Detection of coding/functional SNPs that change the biological function of a gene may lead to identification of putative causative alleles within QTL regions and discovery of genetic markers with large effects on phenotypes. This study has two-fold objectives, first to develop, and validate a 50K transcribed gene SNP-chip using RNA-Seq data. To achieve this objective, two bioinformatics pipelines, GATK and SAMtools, were used to identify ∼21K transcribed SNPs with allelic imbalances associated with important aquaculture production traits including body weight, muscle yield, muscle fat content, shear force, and whiteness in addition to resistance/susceptibility to bacterial cold-water disease (BCWD). SNPs ere …

Integrated Analysis Of Lncrna And Mrna Expression In Rainbow Trout Families Showing Variation In Muscle Growth And Fillet Quality Traits, Ali Ali, Rafet Al-Tobasei, Brett Kenney, Timothy D. Leeds, Mohamed Salem

Faculty & Staff Scholarship

Muscle yield and quality traits are important for the aquaculture industry and consumers. Genetic selection for these traits is difficult because they are polygenic and result from multifactorial interactions. To study the genetic architecture of these traits, phenotypic characterization of whole body weight (WBW), muscle yield, fat content, shear force and whiteness were measured in ~500 fish representing 98 families from a growth-selected line. RNA-Seq was used to sequence the muscle transcriptome of different families exhibiting divergent phenotypes for each trait. We have identified 240 and 1,280 differentially expressed (DE) protein-coding genes and long noncoding RNAs (lncRNAs), respectively, in fish …

Neck Circumference Positively Relates To Cardiovascular Risk Factors In College Students, Oluremi A. Famodu, Makenzie L. Barr, Sarah E. Colby, Wenjun Zhou, Ida Holaskova, Miriam P. Leary, Carol Bryd-Bredbenner, Anne E. Matthews, Melissa D. Olfert

Faculty & Staff Scholarship

The objective of this study was to determine the relationship between neck circumference (NC) and other anthropometric measures and examine cut-off points for males and females according to existing waist circumference cut-off levels in this age group. Across 8 universities, 1562 students underwent a physical assessment. Spearman rho correlations (ρ) were calculated to determine associations between NC and other continuous variables of health. Receiving operating characteristic curves were constructed to assess the optimal cut-off levels of NC of males and females with central obesity. Participants were predominantly Caucasian (67%), female (70%), and outside of Appalachia 2 (82%). Forty-one percent of …

Adverse Event Detection By Integrating Twitter Data And Vaers, Junxiang Wang, Liang Zhao, Yanfang Ye, Yuji Zhang

Faculty & Staff Scholarship

Background: Vaccinehasbeenoneofthemostsuccessfulpublichealthinterventionstodate.However,vaccines are pharmaceutical products that carry risks so that many adverse events (AEs) are reported after receiving vaccines. Traditional adverse event reporting systems suffer from several crucial challenges including poor timeliness. This motivates increasing social media-based detection systems, which demonstrate successful capability to capture timely and prevalent disease information. Despite these advantages, social media-based AE detection suffers from serious challenges such as labor-intensive labeling and class imbalance of the training data.

Results: Totacklebothchallengesfromtraditionalreportingsystemsandsocialmedia,weexploittheircomplementary strength and develop a combinatorial classification approach by integrating Twitter data and the Vaccine Adverse Event Reporting System (VAERS) information aiming to identify potential AEs after …

Method Overtness, Forensic Autopsy, And The Evidentiary Suicide Note: A Multilevel National Violent Death Reporting System Analysis, Ian R. H. Rockett, Eric D. Caine, Steven Stack, Hilary S. Connery, Kurt B. Nolte, Christa L. Lilly, Ted R. Miller, Lewis S. Nelson, Sandra L. Putnam, Paul S. Nestadt, Haomiao Jia

Faculty & Staff Scholarship

Objective

Higher prevalence of suicide notes could signify more conservatism in accounting and greater proneness to undercounting of suicide by method. We tested two hypotheses: (1) an evidentiary suicide note is more likely to accompany suicides by drug-intoxication and by other poisoning, as less violent and less forensically overt methods, than suicides by firearm and hanging/suffocation; and (2) performance of a forensic autopsy attenuates any observed association between overtness of method and the reported presence of a note.

Methods

This multilevel (individual/county), multivariable analysis employed a generalized linear mixed model (GLMM). Representing the 17 states participating in the United States …

The Complementary Health Approaches For Pain Survey (Chaps): Validity Testing And Characteristics Of A Rural Population With Pain, Termeh Feinberg, Dina L. Jones, Christa Lilly, Amna Umer, Kim Innes

Faculty & Staff Scholarship

Objectives

Little is known about patterns and correlates of Complementary Health Approaches (CHAs) in chronic pain populations, particularly in rural, underserved communities. This article details the development and implementation of a new survey instrument designed to address this gap, the Complementary Health Approaches for Pain Survey (CHAPS).

Design

Following pilot-testing using pre-specified criteria to assess quality and comprehension in our target population, and after feedback regarding face-validity from content experts and stakeholders, the final cross-sectional self-report survey required 10–12 minutes to com- plete. It contained 69 demographic, lifestyle and health-related factors, and utilized a Trans- theoretical Model (TTM) underpinning to …

Subclinical Atherosclerosis, Cardiovascular Health, And Disease Risk: Is There A Case For The Cardiovascular Health Index In The Primary Prevention Population?, Sarah S. Singh, Courtney S. Pilkerton, Carl D. Shrader Jr, Stephanie J. Frisbee

Faculty & Staff Scholarship

Background: Current primary prevention guidelines for cardiovascular disease (CVD) prioritize risk identification, risk stratification using clinical and risk scores, and risk reduction with lifestyle interventions and pharmacotherapy. Subclinical atherosclerosis is an early indicator of atherosclerotic burden and its timely recognition can slow or prevent progression to CVD. Thus, individuals with subclinical atherosclerosis are a priority for primary prevention. This study takes a practical approach to answering a challenge commonly faced by primary care practitioners: in patients with no known CVD, how can individuals likely to have subclinical atherosclerosis be easily identified using existing clinical data and/or information provided by the …

Multivariate Analysis Of The Cotton Seed Ionome Reveals A Shared Genetic Architecture, Duke Pauli, Greg Ziegler, Min Ren, Matthew A. Jenks, Douglas J. Hunsaker, Min Zhang, Ivan Baxter, Michael A. Gore

Faculty & Staff Scholarship

To mitigate the effects of heat and drought stress, a better understanding of the genetic control of physiological responses to these environmental conditions is needed. To this end, we evaluated an upland cotton (Gossypium hirsutum L.) mapping population under water-limited and well-watered con- ditions in a hot, arid environment. The elemental concentrations (ionome) of seed samples from the pop- ulation were profiled in addition to those of soil samples taken from throughout the field site to better model environmental variation. The elements profiled in seeds exhibited moderate to high heritabilities, as well as strong phenotypic and genotypic correlations between elements …

Brief Report: Exercise And Blood Pressure In Older Adults—An Updated Look, George A. Kelley, Kristi S. Kelley

Faculty & Staff Scholarship

Background/Objectives. Raised blood pressure is a major problem in older adults. Using a random-effects model, a recent meta- analysis reported statistically significant reductions in both resting systolic blood pressure (SBP) and diastolic blood pressure (DBP) as a result of aerobic, resistance, and combined aerobic and resistance exercise in adults ≥65 years. To provide more objective information regarding this nonpharmacologic approach, this study applied more robust methods to this data. Design. Meta-analysis of 41 randomized controlled trials representing 96 groups (52 exercise; 44 control). Setting. Any location where a randomized controlled trial could be conducted. Participants. Adults ≥65 years. Intervention. Trials …

Brief Report: Exercise And Anxiety In Adults With Arthritis And Other Rheumatic Diseases: Support For Evidential Value, George A. Kelley, Kristi S. Kelley, Leigh F. Callahan

Faculty & Staff Scholarship

Objective. Given the high prevalence of anxiety in adults with arthritis and other rheumatic diseases (AORD) and the subsequent need for interventions to reduce anxiety, this brief report sought to determine if evidential value exists to support the role of exercise for reducing anxiety in adults with AORD. Methods. Utilizing data from a prior meta-analysis, a recently developed approach, P- curve, was used to determine evidential value by assessing for publication bias and p-hacking. Binomial tests as well as the more robust Stouffer’s test were used to examine for evidential value. To examine the influence of selected studies on p-curve …

Effects Of Mantra Meditation Versus Music Listening On Knee Pain, Function, And Related Outcomes In Older Adults With Knee Osteoarthritis: An Exploratory Randomized Clinical Trial (Rct), Kim Innes, Terry Kit Selfe, Sahiti Kandati, Sijin Wen, Zenzi Huysmans

Faculty & Staff Scholarship

Objective. Disease-modifying treatments for OA remain elusive, and commonly used medications can have serious side effects. Although meditation and music listening (ML) have been shown to improve outcomes in certain chronic pain populations, research in OA is sparse. In this pilot RCT, we explore the effects of two mind-body practices, mantra meditation (MM) and ML, on knee pain, function, and related outcomes in adults with knee OA. Methods. Twenty-two older ambulatory adults diagnosed with knee OA were randomized to a MM (N=11) or ML program (N=11) and asked to practice 15-20 minutes, twice daily for 8 weeks. Core outcomes included …

Perfluoroalkyl Substances And Kidney Function In Chronic Kidney Disease, Anemia, And Diabetes, Baqiyyah N. Conway, Ashley N. Badders, Tina Costacou, John M. Arthur, Kim E. Innes

Faculty & Staff Scholarship

Background: Anemia often complicates chronic kidney disease (CKD), leading to insufficient tissue oxygenation and hypoxic injury, the factor thought to underlie progression from CKD to renal failure. Perfluorocarbons are potent oxygen transporters used in organ preservation and synthetic blood development. Data are scarce on their relationship with kidney function, especially in diabetes where anemia and hypoxia are more prevalent. We investigated the relationship of perfluoroalkyl acids (PFAS) with kidney function and variation by diabetes and anemia status.

Methods: Data on 53,650 adults (5,210 with diabetes) were obtained from the C8 Health Project. CKD was defined as an estimated glomerular filtration …

Discerning Suicide In Drug Intoxication Deaths: Paucity And Primacy Of Suicide Notes And Psychiatric History, Ian Rh Rockett, Eric D. Caine, Hilary S. Connery, Gail D'Onofrio, David J. Gunnell, Ted R. Miller, Kurt B. Nolte, Mark S. Kaplan, Nestor D. Kapusta, Christa L. Lilly, Lewis S. Nelson, Sandra L. Putnam, Steven Stack, Peeter Varnik, Lynne R. Webster, Haomiao Jia

Faculty & Staff Scholarship

Objective

A paucity of corroborative psychological and psychiatric evidence may be inhibiting detec- tion of drug intoxication suicides in the United States. We evaluated the relative importance of suicide notes and psychiatric history in the classification of suicide by drug intoxication versus firearm (gunshot wound) plus hanging/suffocation—the other two major, but overtly violent methods.

Methods

This observational multilevel (individual/county), multivariable study employed a general- ized linear mixed model (GLMM) to analyze pooled suicides and undetermined intent deaths, as possible suicides, among the population aged 15 years and older in the 17 states participating in the National Violent Death Reporting System …

Novel Caries Loci In Children And Adults Implicated By Genome-Wide Analysis Of Families, Manika Govil, Nandita Mukhopadhyay, Daniel E. Weeks, Eleanor Feingold, John R. Shaffer, Steven M. Levy, Alexandre R. Vieira, Rebecca L. Slayton, Daniel W. Mcneil, Robert J. Weyant, Richard J. Crout, Mary L. Marazita

Faculty & Staff Scholarship

Background: Dental caries is a common chronic disease among children and adults alike, posing a substantial health burden. Caries is affected by multiple genetic and environmental factors, and prior studies have found that a substantial proportion of caries susceptibility is genetically inherited.

Methods: To identify such genetic factors, we conducted a genome-wide linkage scan in 464 extended families with 2616 individuals from Iowa, Pennsylvania and West Virginia for three dental caries phenotypes: (1) PRIM: dichotomized as zero versus one or more affected primary teeth, (2) QTOT1: age-adjusted quantitative caries measure for both primary and permanent dentitions including pre-cavitated lesions, and …

Existing And Potential Statistical And Computational Approaches For The Analysis Of 3d Ct Images Of Plant Roots, Zheng Xu, Camilo Valdes, Jennifer Clarke

Department of Statistics: Faculty Publications

Scanning technologies based on X-ray Computed Tomography (CT) have been widely used in many scientific fields including medicine, nanosciences and materials research. Considerable progress in recent years has been made in agronomic and plant science research thanks to X-ray CT technology. X-ray CT image-based phenotyping methods enable high-throughput and non-destructive measuring and inference of root systems, which makes downstream studies of complex mechanisms of plants during growth feasible. An impressive amount of plant CT scanning data has been collected, but how to analyze these data efficiently and accurately remains a challenge. We review statistical and computational approaches that have been …