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Full-Text Articles in Physical Sciences and Mathematics

Exact One-Sided Confidence Limits For The Difference Between Two Correlated Proportions, Chris Lloyd, Max V. Moldovan Nov 2007

Exact One-Sided Confidence Limits For The Difference Between Two Correlated Proportions, Chris Lloyd, Max V. Moldovan

Chris J. Lloyd

We construct exact and optimal one-sided upper and lower confidence bounds for the difference between two probabilities based on matched binary pairs using well-established optimality theory of Buehler (1957). Starting with five different approximate loer and upper limits, we adjust them to have coverage probability exactly equal to the desired nominal level and then compare the resulting exact limits by their mean size. Exact limits based on the signed root likelihood ratio statistic are preferred and recommended for practical use.


Correction: Using Participatory Design To Develop (Public) Health Decision Support Systems Through Gis, S. Michelle Driedger, Anita Kothari, Jason Morrison, Michael Sawada, Eric J. Crighton, Ian D. Graham Nov 2007

Correction: Using Participatory Design To Develop (Public) Health Decision Support Systems Through Gis, S. Michelle Driedger, Anita Kothari, Jason Morrison, Michael Sawada, Eric J. Crighton, Ian D. Graham

Anita Kothari

Background: Organizations that collect substantial data for decision-making purposes are often characterized as being 'data rich' but 'information poor'. Maps and mapping tools can be very useful for research transfer in converting locally collected data into information. Challenges involved in incorporating GIS applications into the decision-making process within the non-profit (public) health sector include a lack of financial resources for software acquisition and training for nonspecialists to use such tools. This on-going project has two primary phases. This paper critically reflects on Phase 1: the participatory design (PD) process of developing a collaborative web-based GIS tool.

Methods: A case study …


Functional Principal Component Regression And Functional Partial Least Squares, Philip T. Reiss, R. Todd Ogden Aug 2007

Functional Principal Component Regression And Functional Partial Least Squares, Philip T. Reiss, R. Todd Ogden

Philip T. Reiss

Regression of a scalar response on signal predictors, such as near-infrared (NIR) spectra of chemical samples, presents a major challenge when, as is typically the case, the dimension of the signals far exceeds their number. Most solutions to this problem reduce the dimension of the predictors either by regressing on components--e.g. principal component regression (PCR) and partial least squares (PLS)--or by smoothing methods which restrict the coefficient function to the span of a spline basis. This paper introduces functional versions of PCR and PLS, which combine both of the above dimension reduction approaches. Two versions of functional PCR are developed, …


Meta-Analysis Evidence Of A Differential Risk Of The Fcrl3 -169t->C Polymorphism In White And East Asian Rheumatoid Arthritis Patients, Steven J. Schrodi, Begovich Ann, Chang Monica Jul 2007

Meta-Analysis Evidence Of A Differential Risk Of The Fcrl3 -169t->C Polymorphism In White And East Asian Rheumatoid Arthritis Patients, Steven J. Schrodi, Begovich Ann, Chang Monica

Steven J Schrodi

Association between a functional promoter polymorphism (rs7528684) in the Fc receptor-like gene, FCRL3, and rheumatoid arthritis (RA) has been observed in 3 independent Japanese case-control sample sets ([1][2]). Studies examining the role of this polymorphism in risk of RA in 9 independent white sample sets, however, have yielded conflicting results ([3-8]). Further, a large study of Korean subjects failed to demonstrate association of this single-nucleotide polymorphism (SNP) with RA ([9]). Although the precise function of FCRL3, which has strong structural homology with the classic Fc receptors, is unknown, the existing data are consistent with the hypothesis that it may influence …


A Large-Scale Rheumatoid Arthritis Genetic Study Identifies Association At Chr 9q33.2, Steven J. Schrodi May 2007

A Large-Scale Rheumatoid Arthritis Genetic Study Identifies Association At Chr 9q33.2, Steven J. Schrodi

Steven J Schrodi

No abstract provided.


High-Loading Nanosized Micelles Of Copoly(Styrene-Maleic Acid)-Zinc Protoporphyrin For Targeted Delivery Of A Potent Heme Oxygenase Inhibitor., Arun Iyer Mar 2007

High-Loading Nanosized Micelles Of Copoly(Styrene-Maleic Acid)-Zinc Protoporphyrin For Targeted Delivery Of A Potent Heme Oxygenase Inhibitor., Arun Iyer

Arun Iyer

Amphiphilic styrene-maleic acid (SMA) copolymer efficiently formed micelles with a potent heme oxygenase inhibitor-zinc protoporphyrin (ZnPP). The micelles were constructed by subtle pH adjustments to form non-covalent interaction between the hydrophobic ZnPP and amphiphilic SMA. The micelles (SMA-ZnPP) thus formed were nanoparticles with narrow size distribution in water (mean diameter 176.5nm), having tunable loading (from 15% to 60% w/w of ZnPP) with remarkable aqueous solubility. SMA-ZnPP had an average molecular size of 144kDa as determined by size-exclusion chromatography (SEC), this size is a marked increase from the molecular weight of free ZnPP (626.03Da), suggesting the formation of micellar structure. The …


Raokandro Malagasy (Medicinal Plants Of Madagascar), Nat Quansah Dec 2006

Raokandro Malagasy (Medicinal Plants Of Madagascar), Nat Quansah

Nat Quansah

No abstract provided.


Software To Forecast The Global Burden Of Alzheimer's Disease, Ron Brookmeyer, Elizabeth Johnson, Kathryn Ziegler-Graham, H. Michael Arrighi Dec 2006

Software To Forecast The Global Burden Of Alzheimer's Disease, Ron Brookmeyer, Elizabeth Johnson, Kathryn Ziegler-Graham, H. Michael Arrighi

Ron Brookmeyer

Software was developed to forecast the global burden of Alzheimer’s disease and evaluate the potential impact of interventions that delay disease onset and progression. The output includes 50 year projections of Alzheimer's disease prevalence by stage of disease and region of the world. The methods are based on a stochastic multi-state model The software incorporates U.N. worldwide population forecasts and data from epidemiological studies on risks of Alzheimer’s disease. The user can also supply their own population projections, and modify input parameters for the model including the disease incidence rates, effects of interventions on disease onset and progression, and stages …


Confidence Intervals For Biomarker-Based Human Immunodeficiecny Virus Incidence Estimates And Differences Using Prevalent Data, Ron Brookmeyer, S Cole, H Chu Dec 2006

Confidence Intervals For Biomarker-Based Human Immunodeficiecny Virus Incidence Estimates And Differences Using Prevalent Data, Ron Brookmeyer, S Cole, H Chu

Ron Brookmeyer

Prevalent biological specimens can be used to estimate human immunodeficiency virus (HIV) incidence using a two-stage immunologic testing algorithm that hinges on the average time, say T, between testing HIV positive on highly and less sensitive enzyme immunoassays. Common approaches to confidence interval (CI) estimation for this incidence measure have included (1) ignoring the random error in T or (2) employing a Bonferroni adjustment to the box method. The authors present alternative Monte Carlo-based CIs for this incidence measure, as well as CIs for the biomarker-based incidence difference; standard approaches to CIs are typically appropriate for the incidence ratio. Using …


Effects Of Support On The Initiation And Duration Of Breastfeeding, Sara L. Gill, Elizabeth Reifsnider, Joseph F. Lucke Dec 2006

Effects Of Support On The Initiation And Duration Of Breastfeeding, Sara L. Gill, Elizabeth Reifsnider, Joseph F. Lucke

Joseph Lucke

Researchers attempted to increase the initiation of breastfeeding and its duration to 6 months among a group of low-income, Hispanic women through an intervention program which included prenatal education and home based postpartum support. All participants were telephoned after delivery to determine infant feeding method. Duration of breastfeeding was determined by counting the number of days from initiation to the last day the baby was put to the breast. The Bayesian approach was used for the statistical analyses. In the intervention group, the propensity to initiate breastfeeding exceeded that of the control group. Results indicate the intervention group had twice …


Controlled Language: The Next Big Thing In Translation?, Uwe Muegge Dec 2006

Controlled Language: The Next Big Thing In Translation?, Uwe Muegge

Uwe Muegge

Many global organizations are beginning to see the productivity indicators for their translation and localization processes reach a plateau. That’s an inevitable fact even for those organizations that use what’s currently billed as the latest and greatest in translation technology, such as translation memory with automated workflow components or globalization management systems. Even with these tools in place, making content available in multiple languages remains a very expensive and time-consuming proposition. For those looking for ways to reduce the cost of translation to the point where almost all materials that should be translation actually can be translated, controlled language may …


Modeling The Effect Of Alzheimer's Disease On Mortality, Elizabeth Johnson, Ron Brookmeyer, Kathryn Ziegler-Graham Dec 2006

Modeling The Effect Of Alzheimer's Disease On Mortality, Elizabeth Johnson, Ron Brookmeyer, Kathryn Ziegler-Graham

Ron Brookmeyer

Mortality rate ratios and the associated proportional hazards models have been used to summarize the effect of Alzheimer's disease on longevity. However, the mortality rate ratios vary by age and therefore do not provide a simple parsimonious summary of the effect of the disease on lifespan. Instead, we propose a new parameter that is defined by an additive multistate model. The proposed multistate model accounts for different stages of disease progression. The underlying assumption of the model is that the effect of disease on mortality is to add a constant amount to death rates once the disease progresses from an …


Predicting Breast-Feeding Attrition: Adapting The Breast-Feeding Attrition Prediction Tool, Elizabeth Reifsnider, Sarah L. Gill, Joseph F. Lucke, Angela R. Mann Dec 2006

Predicting Breast-Feeding Attrition: Adapting The Breast-Feeding Attrition Prediction Tool, Elizabeth Reifsnider, Sarah L. Gill, Joseph F. Lucke, Angela R. Mann

Joseph Lucke

CONTEXT: Current breast-feeding rates fall short of the recommendations set forth in Health People 2010. The Breast-feeding Attrition Prediction Tool (BAPT), administered in the postpartum period, has been useful in predicting breast-feeding attrition. However, assessing a woman's intention to breast-feed prior to birth would identify women at risk for breast-feeding attrition.

PURPOSE: The purpose of this study was to describe a revised BAPT, administered antepartally that measures intention to breast-feed.

METHODS: The BAPT, comprising 94 items on a 6-point Likert-type scale, was translated into Spanish and back-translated for accuracy. The BAPT was then revised by reducing the number of items …


A Practical Illustration Of The Importance Of Realistic Individualized Treatment Rules In Causal Inference, Oliver Bembom, Mark J. Van Der Laan Dec 2006

A Practical Illustration Of The Importance Of Realistic Individualized Treatment Rules In Causal Inference, Oliver Bembom, Mark J. Van Der Laan

Oliver Bembom

The effect of vigorous physical activity on mortality in the elderly is difficult to estimate using conventional approaches to causal inference that define this effect by comparing the mortality risks corresponding to hypothetical scenarios in which all subjects in the target population engage in a given level of vigorous physical activity. A causal effect defined on the basis of such a static treatment intervention can only be identified from observed data if all subjects in the target population have a positive probability of selecting each of the candidate treatment options, an assumption that is highly unrealistic in this case since …