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Full-Text Articles in Physical Sciences and Mathematics

The Gaise College Report: The American Statistical Association Meets Sound Pedagogy In Central Virginia, Beverly Wood Nov 2018

The Gaise College Report: The American Statistical Association Meets Sound Pedagogy In Central Virginia, Beverly Wood

Beverly Wood

Research in undergraduate statistics education often centers on the introductory course required for a large percentage of college students. While acknowledging the diverse setting, audience, and purpose of introductory courses, existing research assumes that courses offered by different disciplines share the same goals and teaching practices. The purpose of this study is to examine the objectives for student outcomes and pedagogical delivery of introductory statistics courses in various academic departments to provide explicit evidence for this assumption. The American Statistical Association’s Guidelines for Assessment and Instruction in Statistics Education (GAISE) are meant to apply to all introductory courses. The College …


Guidelines For Assessment And Instruction In Statistics Education (Gaise) College Report 2016, Robert Carver, Michelle Everson, John Gabrosek, Nicholas Horton, Robin Lock, Megan Mocko, Allan Rossman, Ginger Holmes Roswell, Paul Velleman, Jeffrey Witmer, Beverly Wood Nov 2018

Guidelines For Assessment And Instruction In Statistics Education (Gaise) College Report 2016, Robert Carver, Michelle Everson, John Gabrosek, Nicholas Horton, Robin Lock, Megan Mocko, Allan Rossman, Ginger Holmes Roswell, Paul Velleman, Jeffrey Witmer, Beverly Wood

Beverly Wood

In 2005 the American Statistical Association (ASA) endorsed the Guidelines for Assessment and Instruction in Statistics Education (GAISE) College Report. This report has had a profound impact on the teaching of introductory statistics in two- and four-year institutions, and the six recommendations put forward in the report have stood the test of time. Much has happened within the statistics education community and beyond in the intervening 10 years, making it critical to re-evaluate and update this important report. For readers who are unfamiliar with the original GAISE College Report or who are new to the statistics education community, the full …


Updated Guidelines, Updated Curriculum: The Gaise College Report And Introductory Statistics For The Modern Student, Beverly Wood, Megan Mocko, Michelle Everson, Nicholas J. Horton, Paul Velleman Nov 2018

Updated Guidelines, Updated Curriculum: The Gaise College Report And Introductory Statistics For The Modern Student, Beverly Wood, Megan Mocko, Michelle Everson, Nicholas J. Horton, Paul Velleman

Beverly Wood

Since the 2005 American Statistical Association's (ASA) endorsement of the Guidelines for Assessment and Instruction in Statistics Education (GAISE) College Report, changes in the statistics field and statistics education have had a major impact on the teaching and learning of statistics. We now live in a world where "Statistics - the science of learning from data - is the fastest-growing science, technology, engineering, and math (STEM) undergraduate degree in the United States," according to the ASA, and where many jobs demand an understanding of how to explore and make sense of data. In light of these new reports and other …


A Math Research Project Inspired By Twin Motherhood, Tiffany N. Kolba Aug 2018

A Math Research Project Inspired By Twin Motherhood, Tiffany N. Kolba

Tiffany N Kolba

The phenomenon of twins, triplets, quadruplets, and other higher order multiples has fascinated humans for centuries and has even captured the attention of mathematicians who have sought to model the probabilities of multiple births. However, there has not been extensive research into the phenomenon of polyovulation, which is one of the biological mechanisms that produces multiple births. In this paper, I describe how my own experience becoming a mother to twins led me on a quest to better understand the scientific processes going on inside my own body and motivated me to conduct research on polyovulation frequencies. An overview of …


Excess Versions Of The Minkowski And Hölder Inequalities, Iosif Pinelis Jul 2018

Excess Versions Of The Minkowski And Hölder Inequalities, Iosif Pinelis

Iosif Pinelis

No abstract provided.


Inversion Copulas From Nonlinear State Space Models With An Application To Inflation Forecasting, Michael S. Smith, Worapree Ole Maneesoonthorn May 2018

Inversion Copulas From Nonlinear State Space Models With An Application To Inflation Forecasting, Michael S. Smith, Worapree Ole Maneesoonthorn

Michael Stanley Smith

We propose the construction of copulas through the inversion of nonlinear state space models. These copulas allow for new time series models that have the same serial dependence structure as a state space model, but with an arbitrary marginal distribution, and flexible density forecasts. We examine the time series properties of the copulas, outline serial dependence measures, and estimate the models using likelihood-based methods. Copulas constructed from three example state space models are considered: a stochastic volatility model with an unobserved component, a Markov switching autoregression, and a Gaussian linear unobserved component model. We show that all three inversion copulas …


Antedependence Models For Skewed Continuous Longitudinal Data, Shu-Ching Chang May 2018

Antedependence Models For Skewed Continuous Longitudinal Data, Shu-Ching Chang

Shu-Ching Chang, PhD, MS

This thesis explores the problems of fitting antedependence (AD) models and partial antecorrelation (PAC) models to continuous non-Gaussian longitudinal data. AD models impose certain conditional independence relations among the measurements within each subject, while PAC models characterize the partial correlation relations. The models are parsimonious and useful for data exhibiting time-dependent correlations.

Since the relation of conditional independence among variables is rather restrictive, we first consider an autoregressively characterized PAC model with independent asymmetric Laplace (ALD) innovations and prove that this model is an AD model. The ALD distribution previously has been applied to quantile regression and has shown promise …


Aggressive Diuresis And Severity-Adjusted Length Of Hospital Stay In Acute Congestive Heart Failure Patients., Muhammad U. Butt M.D. Apr 2018

Aggressive Diuresis And Severity-Adjusted Length Of Hospital Stay In Acute Congestive Heart Failure Patients., Muhammad U. Butt M.D.

Muhammad Umer Butt M.D., MSCRD

To see if aggressive diuresis in 1st 24 hours is associated with a comparable number of total days in the hospital as compared to non-aggressive diuresis.  In this retrospective cohort study, we compared the length of hospital stay of consecutive patients admitted in one year based on their diuresis during the first twenty-four hours of hospitalization: aggressive diuresis (group 1) i.e. >2400mL versus non-aggressive diuresis (group 2) i.e. ≤ 2400mL urine output. Patients were excluded if in cardiogenic shock, had creatinine level above 3 mg/dL on admission, or on dialysis. A total of 194 patients were enrolled (29 in group …


The Subject Librarian Newsletter, Statistics, Fall 2016, Sandy Avila Apr 2018

The Subject Librarian Newsletter, Statistics, Fall 2016, Sandy Avila

Sandy Avila

No abstract provided.


Data Analysis Basics – Part Ii, Judith A. Savageau Mar 2018

Data Analysis Basics – Part Ii, Judith A. Savageau

Judith A. Savageau

Blog post to AEA365, a blog sponsored by the American Evaluation Association (AEA) dedicated to highlighting Hot Tips, Cool Tricks, Rad Resources, and Lessons Learned for evaluators. The American Evaluation Association is an international professional association of evaluators devoted to the application and exploration of program evaluation, personnel evaluation, technology, and many other forms of evaluation. Evaluation involves assessing the strengths and weaknesses of programs, policies, personnel, products, and organizations to improve their effectiveness.


Data Analysis Basics – Part I, Judith A. Savageau Mar 2018

Data Analysis Basics – Part I, Judith A. Savageau

Judith A. Savageau

Blog post to AEA365, a blog sponsored by the American Evaluation Association (AEA) dedicated to highlighting Hot Tips, Cool Tricks, Rad Resources, and Lessons Learned for evaluators. The American Evaluation Association is an international professional association of evaluators devoted to the application and exploration of program evaluation, personnel evaluation, technology, and many other forms of evaluation. Evaluation involves assessing the strengths and weaknesses of programs, policies, personnel, products, and organizations to improve their effectiveness.


An Old Tool With Enduring Value: Using Excel To Prepare Data For Analysis, Gregory A. Smith Mar 2018

An Old Tool With Enduring Value: Using Excel To Prepare Data For Analysis, Gregory A. Smith

Gregory A. Smith

Microsoft Excel was first released on the Windows platform 30 years ago and has since become widely used. Although new tools for manipulating, analyzing, and visualizing data are constantly emerging, Excel remains a potent tool—and not just because of newer features. Simple functions such as TRIM, MID, SUBSTITUTE, FIND, ROUNDDOWN, and VLOOKUP can be used to manipulate data sets in powerful ways. This workshop applies selected functions to realistic library data sets. Demonstrations include: deriving time-series categories from date and time stamps pre-coding survey comments based on keywords dealing with messy data points such as call numbers and publisher names …


Multivariate Spectral Analysis Of Crism Data To Characterize The Composition Of Mawrth Vallis, Melissa Luna Mar 2018

Multivariate Spectral Analysis Of Crism Data To Characterize The Composition Of Mawrth Vallis, Melissa Luna

Melissa Luna

No abstract provided.


Global Stability For A 2n+1 Dimensional Hiv Aids Epidemic Model With Treatments, Olusegun M. Otunuga Mar 2018

Global Stability For A 2n+1 Dimensional Hiv Aids Epidemic Model With Treatments, Olusegun M. Otunuga

Olusegun Michael Otunuga

In this work, we derive and analyze a 2n+1-dimensional deterministic differential equation modeling the transmission and treatment of HIV (Human Immunodeficiency Virus) disease. The model is extended to a stochastic differential equation by introducing noise in the transmission rate of the disease. A theoretical treatment strategy of regular HIV testing and immediate treatment with Antiretroviral Therapy (ART) is investigated in the presence and absence of noise. By defining $R_{0,n}$, $R_{t,n}$ and $\mathcal{R}_{t,n}$ as the deterministic basic reproduction number in the absence of ART treatments, deterministic basic reproduction number in the presence of ART treatments and stochastic reproduction number …


Integrated Bioinformatics, Environmental Epidemiologic And Genomic Approaches To Identify Environmental And Molecular Links Between Endometriosis And Breast Cancer, Deodutta Roy, Marisa L. Morgan, Changwon Yoo, Alok Deoraj, Sandhya Roy, Vijay Kumar Yadav, Mohannad Garoub, Hamza Assaggaf, Mayur Doke Feb 2018

Integrated Bioinformatics, Environmental Epidemiologic And Genomic Approaches To Identify Environmental And Molecular Links Between Endometriosis And Breast Cancer, Deodutta Roy, Marisa L. Morgan, Changwon Yoo, Alok Deoraj, Sandhya Roy, Vijay Kumar Yadav, Mohannad Garoub, Hamza Assaggaf, Mayur Doke

Alok Deoraj

We present a combined environmental epidemiologic, genomic, and bioinformatics approach to identify: exposure of environmental chemicals with estrogenic activity; epidemiologic association between endocrine disrupting chemical (EDC) and health effects, such as, breast cancer or endometriosis; and gene-EDC interactions and disease associations. Human exposure measurement and modeling confirmed estrogenic activity of three selected class of environmental chemicals, polychlorinated biphenyls (PCBs), bisphenols (BPs), and phthalates. Meta-analysis showed that PCBs exposure, not Bisphenol A (BPA) and phthalates, increased the summary odds ratio for breast cancer and endometriosis. Bioinformatics analysis of gene-EDC interactions and disease associations identified several hundred genes that were altered by …


Predictors Of Neonatal Abstinence Syndrome In Buprenorphine Exposed Newborn: Can Cord Blood Buprenorphine Metabolite Levels Help?, Darshan Shah, Stacy Brown, Nick Hagemeier, Shimin Zheng, Amy Kyle, Jason Pryor, Nilesh Dankhara, Piyuesh Singh Feb 2018

Predictors Of Neonatal Abstinence Syndrome In Buprenorphine Exposed Newborn: Can Cord Blood Buprenorphine Metabolite Levels Help?, Darshan Shah, Stacy Brown, Nick Hagemeier, Shimin Zheng, Amy Kyle, Jason Pryor, Nilesh Dankhara, Piyuesh Singh

Nicholas E. Hagemeier

Background

Buprenorphine is a semi-synthetic opioid used for the treatment of opioid dependence. Opioid use, including buprenorphine, has been increasing in recent years, in the general population and in pregnant women. Consequently, there has been a rise in frequency of neonatal abstinence syndrome (NAS), associated with buprenorphine use during pregnancy. The purpose of this study was to investigate correlations between buprenorphine and buprenorphine-metabolite concentrations in cord blood and onset of NAS in buprenorphine exposed newborns.

Methods

Nineteen (19) newborns who met inclusion criteria were followed after birth until discharge in a double-blind non-intervention study, after maternal consent. Cord blood and …


The Fossilized Birth-Death Model For The Analysis Of Stratigraphic Range Data Under Different Speciation Modes, Tanja Stadler, Alexandra Gavryushkina, Rachel C. M. Warnock, Alexei J. Drummond, Tracy A. Heath Feb 2018

The Fossilized Birth-Death Model For The Analysis Of Stratigraphic Range Data Under Different Speciation Modes, Tanja Stadler, Alexandra Gavryushkina, Rachel C. M. Warnock, Alexei J. Drummond, Tracy A. Heath

Tracy Heath

A birth-death-sampling model gives rise to phylogenetic trees with samples from the past and the present. Interpreting “birth” as branching speciation, “death” as extinction, and “sampling” as fossil preservation and recovery, this model – also referred to as the fossilized birth-death (FBD) model – gives rise to phylogenetic trees on extant and fossil samples. The model has been mathematically analyzed and successfully applied to a range of datasets on different taxonomic levels, such as penguins, plants, and insects. However, the current mathematical treatment of this model does not allow for a group of temporally distinct fossil specimens to be assigned …


A Ten-Year Comparison Of Women Authorship In U.S. Dermatology Literature, 1999 Vs. 2009, Shali Zhang, Ha-Young Kim, Rachel E.S. Hill, Emir Veledar, Suephy C. Chen Jan 2018

A Ten-Year Comparison Of Women Authorship In U.S. Dermatology Literature, 1999 Vs. 2009, Shali Zhang, Ha-Young Kim, Rachel E.S. Hill, Emir Veledar, Suephy C. Chen

Emir Veledar

Women are entering medicine at increasing rates, particularly in dermatology. In this study, we compared women’s influence and status in academic dermatology with that of men by examining authorship roles in peer-reviewed dermatology literature.Weexamined the literature in2009 and compared that to10 years prior (1999).Atotal of 1399 articles were reviewed, 594 of whichmet study criteria andwere included in statistical analysis. There was amarked increase in senior female authorship over a decade (22% vs. 38%, p b 0.001). Female first authorship increased as well (41% vs. 51%, p b 0.001). In contrast, changes in male senior and first authorship were not statistically …


Some Applications Of Sophisticated Mathematics To Randomized Computing, Ronald I. Greenberg Jan 2018

Some Applications Of Sophisticated Mathematics To Randomized Computing, Ronald I. Greenberg

Ronald Greenberg

No abstract provided.


Educational Magic Tricks Based On Error-Detection Schemes, Ronald I. Greenberg Jan 2018

Educational Magic Tricks Based On Error-Detection Schemes, Ronald I. Greenberg

Ronald Greenberg

Magic tricks based on computer science concepts help grab student attention and can motivate them to delve more deeply. Error detection ideas long used by computer scientists provide a rich basis for working magic; probably the most well known trick of this type is one included in the CS Unplugged activities. This paper shows that much more powerful variations of the trick can be performed, some in an unplugged environment and some with computer assistance. Some of the tricks also show off additional concepts in computer science and discrete mathematics.


Time Series Copulas For Heteroskedastic Data, Ruben Loaiza-Maya, Michael S. Smith, Worapree Maneesoonthorn Dec 2017

Time Series Copulas For Heteroskedastic Data, Ruben Loaiza-Maya, Michael S. Smith, Worapree Maneesoonthorn

Michael Stanley Smith

We propose parametric copulas that capture serial dependence in stationary heteroskedastic time series. We suggest copulas for first-order Markov series, and then extend them to higher orders and multivariate series. We derive the copula of a volatility proxy, based on which we propose new measures of volatility dependence, including co-movement and spillover in multivariate series. In general, these depend upon the marginal distributions of the series. Using exchange rate returns, we show that the resulting copula models can capture
their marginal distributions more accurately than univariate and multivariate generalized autoregressive conditional heteroskedasticity models, and produce more accurate value-at-risk forecasts.


Implicit Copulas From Bayesian Regularized Regression Smoothers, Nadja Klein, Michael S. Smith Dec 2017

Implicit Copulas From Bayesian Regularized Regression Smoothers, Nadja Klein, Michael S. Smith

Michael Stanley Smith

We show how to extract the implicit copula of a response vector from a Bayesian regularized regression smoother with Gaussian disturbances. The copula can be used to compare smoothers that employ different shrinkage priors and function bases. We illustrate with three popular choices of shrinkage priors --- a pairwise prior, the horseshoe prior and a g prior augmented with a point mass as employed for Bayesian variable selection --- and both univariate and multivariate function bases. The implicit copulas are high-dimensional and unavailable in closed form. However, we show how to evaluate them by first constructing a Gaussian copula conditional on the regularization parameters, …


Stacked Generalization: An Introduction To Super Learning, Ashley Naimi, Laura Balzer Dec 2017

Stacked Generalization: An Introduction To Super Learning, Ashley Naimi, Laura Balzer

Laura B. Balzer

Stacked generalization is an ensemble method that allows researchers to combine several different prediction algorithms into one. Since its introduction in the early 1990s, the method has evolved several times into a host of methods among which is the ‘‘Super Learner’’. Super Learner uses V -fold cross-validation to build the optimal weighted combination of predictions from a library of candidate algorithms. Optimality is defined by a user-specified objective function, such as minimizing mean squared error or maximizing the area under the receiver operating characteristic curve. Although relatively simple in nature, use of Super Learner by epidemiologists has been hampered by …


Characterization Of Plasmodium Falciparum And Plasmodium Vivax Recent Exposure In An Area Of Significantly Decreased Transmission Intensity In Central Vietnam, Johanna Helena Kattenberg, Annette Erhart, Minh Hieu Truong, Eduard Rovira-Vallbona, Khac Anh Dung Vu, Thi Hong Ngoc Nguyen, Van Hong Nguyen, Van Van Nguyen, Melanie Bannister-Tyrrell, Michael Theisen, Adam Bennet, Andrew A. Lover, Thanh Duong Tran, Xuan Xa Nguyen, Anna Rosanas-Urgell Dec 2017

Characterization Of Plasmodium Falciparum And Plasmodium Vivax Recent Exposure In An Area Of Significantly Decreased Transmission Intensity In Central Vietnam, Johanna Helena Kattenberg, Annette Erhart, Minh Hieu Truong, Eduard Rovira-Vallbona, Khac Anh Dung Vu, Thi Hong Ngoc Nguyen, Van Hong Nguyen, Van Van Nguyen, Melanie Bannister-Tyrrell, Michael Theisen, Adam Bennet, Andrew A. Lover, Thanh Duong Tran, Xuan Xa Nguyen, Anna Rosanas-Urgell

Andrew Lover

Background
In Vietnam, malaria transmission has been reduced to very low levels over the past 20 years, and as a consequence, the country aims to eliminate malaria by 2030. This study aimed to characterize the dynamics and extent of the parasite reservoir in Central Vietnam, in order to further target elimination strategies and surveillance.
Methods
A 1-year prospective cohort study (n = 429) was performed in three rural communities in Quang Nam province. Six malaria screenings were conducted between November 2014 and November 2015, including systematic clinical examination and blood sampling for malaria parasite identification, as well as molecular and serological …


Malaria Elimination: Time To Target All Species, Andrew A. Lover, J. Kevin Baird, Roly Gosling, Ric N. Price Dec 2017

Malaria Elimination: Time To Target All Species, Andrew A. Lover, J. Kevin Baird, Roly Gosling, Ric N. Price

Andrew Lover

Important strides have been made within the past decade toward malaria elimination in many regions, and with this progress, the feasibility of eradication is once again under discussion. If the ambitious goal of eradication is to be achieved by 2040, all species of Plasmodium infecting humans will need to be targeted with evidence-based and concerted interventions. In this perspective, the potential barriers to achieving global malaria elimination are discussed with respect to the related diversities in host, parasite, and vector populations. We argue that control strategies need to be reorientated from a sequential attack on each species, dominated by Plasmodium …


Econometric Modeling Of Regional Electricity Spot Prices In The Australian Market, Michael S. Smith, Thomas S. Shively Dec 2017

Econometric Modeling Of Regional Electricity Spot Prices In The Australian Market, Michael S. Smith, Thomas S. Shively

Michael Stanley Smith

Wholesale electricity markets are increasingly integrated via high voltage interconnectors, and inter-regional
trade in electricity is growing. To model this, we consider a spatial equilibrium model of price formation, where constraints on inter-regional flows result in three distinct equilibria in prices. We use this to motivate an econometric model for the distribution of observed electricity spot prices that captures many of their unique empirical characteristics. The econometric model features supply and inter-regional trade cost functions, which are estimated using Bayesian monotonic regression smoothing methodology. A copula multivariate time series model is employed to capture additional dependence --- both cross-sectional and serial --- in …