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1084 full-text articles. Page 1 of 27.

Penalized Nonparametric Scalar-On-Function Regression Via Principal Coordinates, Philip T. Reiss, David L. Miller, Pei-Shien Wu, Wen-Yu Hua 2016 New York University School of Medicine

Penalized Nonparametric Scalar-On-Function Regression Via Principal Coordinates, Philip T. Reiss, David L. Miller, Pei-Shien Wu, Wen-Yu Hua

Philip T. Reiss

A number of classical approaches to nonparametric regression have recently been extended to the case of functional predictors. This paper introduces a new method of this type, which extends intermediate-rank penalized smoothing to scalar-on-function regression. The core idea is to regress the response on leading principal coordinates defined by a relevant distance among the functional predictors, while applying a ridge penalty. Our publicly available implementation, based on generalized additive modeling software, allows for fast optimal tuning parameter selection and for extensions to multiple functional predictors, exponential family-valued responses, and mixed-effects models. In an application to signature verification data, the proposed ...


Potato Cultivar Differences Associated With Mealiness, Diane R. McComber, Harry T. Horner, Mark A. Chamberlin, David F. Cox 2016 Iowa State University

Potato Cultivar Differences Associated With Mealiness, Diane R. Mccomber, Harry T. Horner, Mark A. Chamberlin, David F. Cox

Harry Horner

Russet Burbank, Norchip, Pontiac, and LaSoda potato cultivars were examined for the parameters mealy and waxy. Russet Burbank was judged dry, hard and particulate, typifying mealiness. Using phase contrast microscopy and scanning electron microscopy, raw mealy cells were determined to be larger and more irregularly shaped than cells from waxy cultivars. Mealy cooked cells were engorged with gelatinized starch, cell walls were more polarized, and cell shapes were better retained after mashing, when compared to waxy cells. NMR-T2 bound water readings from Russet Burbank and Pontiac samples did not differ from each other. Starch granule sizes and shapes varied by ...


A Microscopic Study Of The Trichomes On Gynoecia Of Normal And Tetraploid Clark Cultivars Of Glycine Max And Seven Near Isogenic Lines, Rosaria A. Healy, Harry T. Horner, Theodore B. Bailey, Reid G. Palmer 2016 Iowa State University

A Microscopic Study Of The Trichomes On Gynoecia Of Normal And Tetraploid Clark Cultivars Of Glycine Max And Seven Near Isogenic Lines, Rosaria A. Healy, Harry T. Horner, Theodore B. Bailey, Reid G. Palmer

Harry Horner

The surfaces of gynoecia of Glycine max cultivars—normal Clark, a tetraploid Clark, and seven isolines—display variations in at least three types of trichomes. The normal Clark soybean gynoecium has at least three and possibly four types of trichomes: a two‐ to four‐celled, elongate, thick‐walled trichome (TWT), an elongate thin‐walled unicellular trichome (UCT), a secretory multicellular trichome (MCT), and an elongate thin‐walled bicellular trichome that we have interpreted as an immature TWT. All these types are present on the gynoecium by 1 d before anthesis. After fertilization, the UCT is rare, but the other types ...


Physiologic Effects Of Nasopharyngeal Administration Of Supplemental Oxygen At Various Flow Rates In Healthy Neonatal Foals, David M. Wong, Cody J. Alcott, Chong Wang, Bonnie L. Hay-Kraus, Benjamin R. Buchanan, Charles W. Brockus 2016 Iowa State University

Physiologic Effects Of Nasopharyngeal Administration Of Supplemental Oxygen At Various Flow Rates In Healthy Neonatal Foals, David M. Wong, Cody J. Alcott, Chong Wang, Bonnie L. Hay-Kraus, Benjamin R. Buchanan, Charles W. Brockus

Chong Wang

Objective—To evaluate the effects of various flow rates of oxygen administered via 1 or 2 nasal cannulae on the fraction of inspired oxygen concentration (Fio2) and other arterial blood gas variables in healthy neonatal foals.

Animals—9 healthy neonatal (3- to 4-day-old) foals.

Procedures—In each foal, a nasal cannula was introduced into each naris and passed into the nasopharynx to the level of the medial canthus of each eye; oxygen was administered at 4 flow rates through either 1 or both cannulae (8 treatments/foal). Intratracheal Fio2, intratracheal end-tidal partial pressure of carbon dioxide, and arterial ...


A Live-Attenuated And An Inactivated Chimeric Porcine Circovirus (Pcv)1-2 Vaccine Are Both Effective At Inducing A Humoral Immune Response And Reducing Pcv2 Viremia And Intrauterine Infection In Female Swine Of Breeding Age, Michelle Hemann, Nathan M. Beach, Xiang-Jin Meng, Chong Wang, Patrick G. Halbur, Tanja Opriessnig 2016 Iowa State University

A Live-Attenuated And An Inactivated Chimeric Porcine Circovirus (Pcv)1-2 Vaccine Are Both Effective At Inducing A Humoral Immune Response And Reducing Pcv2 Viremia And Intrauterine Infection In Female Swine Of Breeding Age, Michelle Hemann, Nathan M. Beach, Xiang-Jin Meng, Chong Wang, Patrick G. Halbur, Tanja Opriessnig

Chong Wang

The objective of this pilot study was to determine the efficacy of inactivated (1 or 2 dose) and live-attenuated chimeric porcine circovirus (PCV)1-2 vaccines in sows using the PCV2-spiked semen model. Thirty-five sows were randomly divided into 6 groups: negative and positive controls, 1 dose inactivated PCV1-2 vaccine challenged (1-VAC-PCV2), 2 dose inactivated PCV1-2 vaccine challenged (2-VAC-PCV2), 1 dose live-attenuated PCV1-2 vaccine unchallenged (1-LIVE-VAC), and 1 dose live-attenuated PCV1-2 vaccine challenged (1-LIVE-VAC-PCV2). The inactivated PCV1-2 vaccine induced higher levels of PCV2-specific antibodies in dams. All vaccination strategies provided good protection against PCV2 viremia in dams, whereas the majority of ...


Bacterial Isolates, Antimicrobial Susceptibility Patterns, And Factors Associated With Infection And Outcome In Foals With Septic Arthritis: 83 Cases (1998–2013), Kate L. Hepworth-Warren, David M. Wong, Caroline V. Fulkerson, Chong Wang, Yaxuan Sun 2016 Iowa State University

Bacterial Isolates, Antimicrobial Susceptibility Patterns, And Factors Associated With Infection And Outcome In Foals With Septic Arthritis: 83 Cases (1998–2013), Kate L. Hepworth-Warren, David M. Wong, Caroline V. Fulkerson, Chong Wang, Yaxuan Sun

Chong Wang

Objective—To determine clinical characteristics, clinicopathologic data, and bacterial culture and antimicrobial susceptibility results associated with septic arthritis in foals ≤ 180 days old.

Design—Retrospective case series.

Animals—83 foals with septic arthritis.

Procedures—Medical records at 2 teaching hospitals between 1998 and 2013 were searched to identify those for foals ≤ 180 days old with confirmed infection of ≥ 1 synovial structure. Data extracted from the records included signalment, clinicopathologic information, bacteriologic culture and antimicrobial susceptibility results, and outcome. Data were analyzed for all foals as a single population and for foals stratified into 3 age groups (≤ 7 days, 8 to ...


Effect Of Cold Compression Therapy On Postoperative Pain, Swelling, Range Of Motion, And Lameness After Tibial Plateau Leveling Osteotomy In Dogs, Kevin A. Drygas, Scott R. McClure, Robert L. Goring, Antonio Pozzi, Sheilah A. Robertson, Chong Wang 2016 Affiliated Veterinary Specialists

Effect Of Cold Compression Therapy On Postoperative Pain, Swelling, Range Of Motion, And Lameness After Tibial Plateau Leveling Osteotomy In Dogs, Kevin A. Drygas, Scott R. Mcclure, Robert L. Goring, Antonio Pozzi, Sheilah A. Robertson, Chong Wang

Chong Wang

Objective—To evaluate the effect of cold compression therapy (CCT) on postoperative pain, lameness, range of motion of the stifle joint, and swelling following tibial plateau leveling osteotomy (TPLO) in dogs. Design—Randomized, blinded, placebo-controlled clinical trial. Animals—34 client-owned dogs with unilateral deficiency of a cranial cruciate ligament undergoing TPLO. Procedures—Dogs were assigned to 2 groups. Group 1 (n = 17 dogs) received CCT in the 24-hour period following TPLO. Group 2 (n = 17 dogs) received no CCT. Degree of lameness, range of motion, and circumference of the stifle joint were measured before surgery and 1,14, and 28 ...


A Method To Quantify Infectious Airborne Pathogens At Concentrations Below The Threshold Of Quantification By Culture, Timothy D. Cutler, Chong Wang, Steven J. Hoff, Jeffrey J. Zimmerman 2016 Iowa State University

A Method To Quantify Infectious Airborne Pathogens At Concentrations Below The Threshold Of Quantification By Culture, Timothy D. Cutler, Chong Wang, Steven J. Hoff, Jeffrey J. Zimmerman

Chong Wang

In aerobiology, dose-response studies are used to estimate the risk of infection to a susceptible host presented by exposure to a specific dose of an airborne pathogen. In the research setting, host- and pathogen-specific factors that affect the dose-response continuum can be accounted for by experimental design, but the requirement to precisely determine the dose of infectious pathogen to which the host was exposed is often challenging. By definition, quantification of viable airborne pathogens is based on the culture of micro-organisms, but some airborne pathogens are transmissible at concentrations below the threshold of quantification by culture. In this paper we ...


Using A Data Quality Framework To Clean Data Extracted From The Electronic Health Record: A Case Study., Oliwier Dziadkowiec, Tiffany Callahan, Mustafa Ozkaynak, Blaine Reeder, John Welton 2016 University of Colorado, College of Nursing, Anschutz Medical Campus

Using A Data Quality Framework To Clean Data Extracted From The Electronic Health Record: A Case Study., Oliwier Dziadkowiec, Tiffany Callahan, Mustafa Ozkaynak, Blaine Reeder, John Welton

eGEMs (Generating Evidence & Methods to improve patient outcomes)

Objectives: Examine (1) the appropriateness of using a data quality (DQ) framework developed for relational databases as a data-cleaning tool for a dataset extracted from two EPIC databases; and (2) the differences in statistical parameter estimates on a dataset cleaned with the DQ framework and dataset not cleaned with the DQ framework.

Background: The use of data contained within electronic health records (EHRs) has the potential to open doors for a new wave of innovative research. Without adequate preparation of such large datasets for analysis, the results might be erroneous, which might affect clinical decision making or results of Comparative ...


Improving Precision By Adjusting For Baseline Variables In Randomized Trials With Binary Outcomes, Without Regression Model Assumptions, Jon Arni Steingrmisson, Daniel F. Hanley, Michael Rosenblum 2016 Johns Hopkins Bloomberg School of Public Health

Improving Precision By Adjusting For Baseline Variables In Randomized Trials With Binary Outcomes, Without Regression Model Assumptions, Jon Arni Steingrmisson, Daniel F. Hanley, Michael Rosenblum

Johns Hopkins University, Dept. of Biostatistics Working Papers

Background: A recent guideline issued by the the European Medicines Agency discusses adjustment for prognostic baseline variables to improve precision and power in randomized trials.They state ``in case of a strong or moderate association between a baseline covariate(s) and the primary outcome measure, adjustment for such covariate(s) generally improves the efficiency of the analysis and avoids conditional bias from chance covariate imbalance.'' A challenge is that there are multiple statistical methods for adjusting for baseline variables, and little guidance on which to use. We investigate the pros and cons of two such adjustment methods.

Methods: We compare ...


Propensity Score Methods : A Simulation And Case Study Involving Breast Cancer Patients., John Craycroft 2016 University of Louisville

Propensity Score Methods : A Simulation And Case Study Involving Breast Cancer Patients., John Craycroft

Electronic Theses and Dissertations

Observational data presents unique challenges for analysis that are not encountered with experimental data resulting from carefully designed randomized controlled trials. Selection bias and unbalanced treatment assignments can obscure estimations of treatment effects, making the process of causal inference from observational data highly problematic. In 1983, Paul Rosenbaum and Donald Rubin formalized an approach for analyzing observational data that adjusts treatment effect estimates for the set of non-treatment variables that are measured at baseline. The propensity score is the conditional probability of assignment to a treatment group given the covariates. Using this score, one may balance the covariates across treatment ...


Stochastic Optimization Of Adaptive Enrichment Designs For Two Subpopulations, Aaron Fisher, Michael Rosenblum 2016 Johns Hopkins University Bloomberg School of Public Health

Stochastic Optimization Of Adaptive Enrichment Designs For Two Subpopulations, Aaron Fisher, Michael Rosenblum

Johns Hopkins University, Dept. of Biostatistics Working Papers

An adaptive enrichment design is a randomized trial that allows enrollment criteria to be modified at interim analyses, based on preset decision rules. When there is prior uncertainty regarding treatment effect heterogeneity, these trials can provide improved power for detecting treatment effects in subpopulations. An obstacle to using these designs is that there is no general approach to determine what decision rules and other design parameters will lead to good performance for a given research problem. To address this, we present a simulated annealing approach for optimizing the parameters of an adaptive enrichment design for a given scientific application. Optimization ...


Cross-Validated Targeted Minimum-Loss-Based Estimation, Wenjing Zheng, Mark van der Laan 2016 University of California - Berkeley

Cross-Validated Targeted Minimum-Loss-Based Estimation, Wenjing Zheng, Mark Van Der Laan

Wenjing Zheng

No abstract provided.


Models For Hsv Shedding Must Account For Two Levels Of Overdispersion, Amalia Magaret 2016 University of Washington - Seattle Campus

Models For Hsv Shedding Must Account For Two Levels Of Overdispersion, Amalia Magaret

UW Biostatistics Working Paper Series

We have frequently implemented crossover studies to evaluate new therapeutic interventions for genital herpes simplex virus infection. The outcome measured to assess the efficacy of interventions on herpes disease severity is the viral shedding rate, defined as the frequency of detection of HSV on the genital skin and mucosa. We performed a simulation study to ascertain whether our standard model, which we have used previously, was appropriately considering all the necessary features of the shedding data to provide correct inference. We simulated shedding data under our standard, validated assumptions and assessed the ability of 5 different models to reproduce the ...


Open Access!: Review Of Online Statistics: An Interactive Multimedia Course Of Study By David Lane, Samuel L. Tunstall 2016 Michigan State University

Open Access!: Review Of Online Statistics: An Interactive Multimedia Course Of Study By David Lane, Samuel L. Tunstall

Numeracy

David M. Lane (project leader). Online Statistics Education: An Interactive Multimedia Course of Study (http://onlinestatbook.com/)
Also: David M. Lane (primary author and editor), with David Scott, Mikki Hebl, Rudy Guerra, Dan Osherson, and Heidi Zimmer. Introduction to Statistics. Online edition (http://onlinestatbook.com/Online_Statistics_Education.pdf), 694 pp.

It is rare that students receive high-quality textbooks for free, but David Lane's Online Statistics: An Interactive Multimedia Course of Study permits precisely that. This review gives an overview of the many features in Lane's online textbook, including the Java Applets, the textbook itself, and the resources available for ...


Empirical Likelihood And Differentiable Functionals, Zhiyuan Shen 2016 University of Kentucky

Empirical Likelihood And Differentiable Functionals, Zhiyuan Shen

Theses and Dissertations--Statistics

Empirical likelihood (EL) is a recently developed nonparametric method of statistical inference. It has been shown by Owen (1988,1990) and many others that empirical likelihood ratio (ELR) method can be used to produce nice confidence intervals or regions. Owen (1988) shows that -2logELR converges to a chi-square distribution with one degree of freedom subject to a linear statistical functional in terms of distribution functions. However, a generalization of Owen's result to the right censored data setting is difficult since no explicit maximization can be obtained under constraint in terms of distribution functions. Pan and Zhou (2002), instead ...


In-Shoe Plantar Pressure System To Investigate Ground Reaction Force Using Android Platform, Ahmed A. Mostfa 2016 Virginia Commonwealth University

In-Shoe Plantar Pressure System To Investigate Ground Reaction Force Using Android Platform, Ahmed A. Mostfa

Theses and Dissertations

Human footwear is not yet designed to optimally relieve pressure on the heel of the foot. Proper foot pressure assessment requires personal training and measurements by specialized machinery. This research aims to investigate and hypothesize about Preferred Transition Speed (PTS) and to classify the gait phase of explicit variances in walking patterns between different subjects. An in-shoe wearable pressure system using Android application was developed to investigate walking patterns and collect data on Activities of Daily Living (ADL). In-shoe circuitry used Flexi-Force A201 sensors placed at three major areas: heel contact, 1st metatarsal, and 5th metatarsal with a PIC16F688 microcontroller ...


Design & Analysis Of A Computer Experiment For An Aerospace Conformance Simulation Study, Ryan W. Gryder 2016 Virginia Commonwealth University

Design & Analysis Of A Computer Experiment For An Aerospace Conformance Simulation Study, Ryan W. Gryder

Theses and Dissertations

Within NASA's Air Traffic Management Technology Demonstration # 1 (ATD-1), Interval Management (IM) is a flight deck tool that enables pilots to achieve or maintain a precise in-trail spacing behind a target aircraft. Previous research has shown that violations of aircraft spacing requirements can occur between an IM aircraft and its surrounding non-IM aircraft when it is following a target on a separate route. This research focused on the experimental design and analysis of a deterministic computer simulation which models our airspace configuration of interest. Using an original space-filling design and Gaussian process modeling, we found that aircraft delay assignments ...


Improved Parameter Estimation Of The Log-Logistic Distribution With Applications, Joseph Reath 2016 Michigan Technological University

Improved Parameter Estimation Of The Log-Logistic Distribution With Applications, Joseph Reath

Dissertations, Master's Theses and Master's Reports

In this report, we work with parameter estimation of the log-logistic distribution. We first consider one of the most common methods encountered in the literature, the maximum likelihood (ML) method. However, it is widely known that the maximum likelihood estimators (MLEs) are usually biased with a finite sample size. This motivates a study of obtaining unbiased or nearly unbiased estimators for this distribution. Specifically, we consider a certain `corrective' approach and Efron's bootstrap resampling method, which both can reduce the biases of the MLEs to the second order of magnitude. As a comparison, we also consider the generalized moments ...


Ring Test Evaluation Of The Detection Of Influenza A Virus In Swine Oral Fluids By Real-Time Reverse-Transcription Polymerase Chain Reaction And Virus Isolation, Christa K. Goodell, Jianqiang Zhang, Erin Strait, Karen Harmon, Devi Patnayak, Tracy Otterson, Marie Culhane, Jane Christopher-Hennings, Travis Clement, Pamela Leslie-Steen, Richard Hesse, Joe Anderson, Kevin Skarbek, Amy Vincent, Pravina Kitikoon, Sabrina Swenson, Melinda Jenkins-Moore, Jodi McGill, Rolf Rauh, William Nelson, Catherine O'Connell, Rohn Shah, Chong Wang, Rodger Main, Jeffery J. Zimmerman 2016 Iowa State University

Ring Test Evaluation Of The Detection Of Influenza A Virus In Swine Oral Fluids By Real-Time Reverse-Transcription Polymerase Chain Reaction And Virus Isolation, Christa K. Goodell, Jianqiang Zhang, Erin Strait, Karen Harmon, Devi Patnayak, Tracy Otterson, Marie Culhane, Jane Christopher-Hennings, Travis Clement, Pamela Leslie-Steen, Richard Hesse, Joe Anderson, Kevin Skarbek, Amy Vincent, Pravina Kitikoon, Sabrina Swenson, Melinda Jenkins-Moore, Jodi Mcgill, Rolf Rauh, William Nelson, Catherine O'Connell, Rohn Shah, Chong Wang, Rodger Main, Jeffery J. Zimmerman

Veterinary Diagnostic and Production Animal Medicine Publications

The probability of detecting influenza A virus (IAV) in oral fluid (OF) specimens was calculated for each of 13 assays based on real-time reverse-transcription polymerase chain reaction (rRT-PCR) and 7 assays based on virus isolation (VI). The OF specimens were inoculated with H1N1 or H3N2 IAV and serially diluted 10-fold (10(-1) to 10(-8)). Eight participating laboratories received 180 randomized OF samples (10 replicates × 8 dilutions × 2 IAV subtypes plus 20 IAV-negative samples) and performed the rRT-PCR and VI procedure(s) of their choice. Analysis of the results with a mixed-effect logistic-regression model identified dilution and assay as variables ...


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