Physical Sciences and Mathematics Commons^™

Net Reclassification Indices For Evaluating Risk Prediction Instruments: A Critical Review, Kathleen F. Kerr, Zheyu Wang, Holly Janes, Robyn Mcclelland, Bruce M. Psaty, Margaret S. Pepe

UW Biostatistics Working Paper Series

Background Net Reclassification Indices (NRI) have recently become popular statistics for measuring the prediction increment of new biomarkers.

Methods In this review, we examine the various types of NRI statistics and their correct interpretations. We evaluate the advantages and disadvantages of the NRI approach. For pre-defined risk categories, we relate NRI to existing measures of the prediction increment. We also consider statistical methodology for constructing confidence intervals for NRI statistics and evaluate the merits of NRI-based hypothesis testing.

Conclusions Investigators using NRI statistics should report them separately for events (cases) and nonevents (controls). When there are two risk categories, the …

Optimization Of A Boundary Element Approach To Electromagnet Design With Application To A Host Of Current Problems In Magnetic Resonance Imaging, Chad T. Harris

Electronic Thesis and Dissertation Repository

Magnetic resonance imaging (MRI) has proven to be a valuable methodological approach in both basic research and clinical practice. However, significant hardware advances are still needed in order to further improve and extend the applications of the technique. The present dissertation predominantly addresses gradient and shim coil design (sub-systems of the MR system).

A design study to investigate gradient performance over a set of surface geometries ranging in curvature from planar to a full cylinder using the boundary element (BE) method is presented. The results of this study serve as a guide for future planar and pseudo-planar gradient systems for …

2013 Annual Meeting Program

Journal of the South Carolina Academy of Science

No abstract provided.

2013 Tsu Undergraduate Research Program, David Owerbach

Office of Research Institutional Research and Scholarship

No abstract provided.

Place Events Fall 2013, Place

PLACE Historical Documents

This document describes PLACE events at Linfield College for fall 2013.

Using The Inverse Transform To Specify Contrasts In Regression And Latent Curve Structural Equation Models, Thomas N. Templin

Nursing Faculty Research Publications

A simple yet general method for specifying contrasts to test hypotheses in regression and latent curve structural equation models is presented. The traditional qualitative variable coding schemes used in multiple regression (e.g., dummy coding) have a more general formulation. Five matrices are involved: The coding scheme, A. The matrix which gives the distribution and ordering of cases, W; WA = X; X is the design matrix. The contrast coefficient matrix C; and C^-1 = A. In practice, only C, C^-1, and A are necessary because the statistical software generates the design matrix. This method has great generality …

Juxtaposing Nasa’S Aeronet Aod With Carb Pm Data Over The San Joaquin Valley To Facilitate Multi-Angle Imaging Spectroradiometer (Misr) Pm Pollution Research, John Kanemoto

STAR Program Research Presentations

Airborne particulate matter (PM) has been shown to increase the risk for asthma, chronic bronchitis, cardiopulmonary complications, and respiratory cell membrane damage/infection/leakage. PM levels are currently analyzed from two perspectives: stationary land-based monitoring (LBM) sites and total Aerosol Optical Depth (AOD) atmospheric column measurements. Both perspectives often leave miles of space between measuring locations and will have a continually increasing cost from introducing/maintaining sites. The Multi-angle Imaging SpectroRadiometer (MISR) satellite team hopes to begin investigating/archiving PM levels comprehensively via inputting MISR AOD measurements into a function/model which predicts the amount of ground level PM.

In the future, multivariable spatial correlations …

The Unseen And Untold Issues Of Clinical Trials And Research Ethics In Pakistan., Shahan Waheed, Emaduddin Siddiqui

Department of Emergency Medicine

No abstract provided.

Renal Cryoablation: Investigation Of Periprocedural Visualization Tools And Treatment Response Quantification, Katherine L. Dextraze

Dissertations & Theses (Open Access)

Cryoablation for small renal tumors has demonstrated sufficient clinical efficacy over the past decade as a non-surgical nephron-sparing approach for treating renal masses for patients who are not surgical candidates. Minimally invasive percutaneous cryoablations have been performed with image guidance from CT, ultrasound, and MRI. During the MRI-guided cryoablation procedure, the interventional radiologist visually compares the iceball size on monitoring images with respect to the original tumor on separate planning images. The comparisons made during the monitoring step are time consuming, inefficient and sometimes lack the precision needed for decision making, requiring the radiologist to make further changes later in …

Successful Aging And Creativity : An Investigation On Functional Status And Psychological Wellbeing In Older Adults, Mirie E. Levy

Loma Linda University Electronic Theses, Dissertations & Projects

Objectives: While the literature supports the maintenance of functional status as integral to successful aging, the relationship of creativity on functional status has received little attention. Creativity has been associated with health and aging in the research but only a small number of studies have examined creativity interventions to enhance functional status and boost psychological wellbeing.

Methods: A pretest-posttest quasi-experimental design was used to investigate an 8-week creativity intervention on functional status and psychological wellbeing in older adults. Sample subjects were 92 men and women all over age 60. A series of two-way mixed ANOVAs measured differences between treatment and …

Polysaccharide-Based Nanocarriers For Improved Drug Delivery, Nan Zhang

Dissertations - ALL

The field of drug delivery has provided a solution to the limited efficacy and high toxicity of many drugs. Nano-sized drug carriers are popular because their size allows for selective accumulation in the diseased area. Polysaccharides are non-toxic and biodegradable natural polymers that can serve as the basis for these nano-sized carriers. Polysialic acid (PSA) is such a polysaccharide with strong hydrophilicity that may reduce uptake by the reticuloendothelial system and prolong drug circulation. In this study, we developed PSA-based nanocarriers, specifically micelles and nanoparticles, for improved drug delivery with improved efficacy and minimized toxicity. PSA-based micelle systems were developed …

Ionic Conductivity In Non-Ionic Compounds, Usha Kranthi Avala

Masters Theses & Specialist Projects

The main objective of this work is to investigate the ionic conductivity of the drugs under certain conditions and also to compare the ionic conductivities of drugs determined by single surface sensors and parallel plate sensors. The ionic conductivity of various materials at their pre-melt and melt states are studied in order to further study a recently discovered phenomenon. Polar solids like Lidocaine, Ketoconazole, Procainamide and Nifedipine were examined in this study. Experimental studies show an increase in ionic conductivity in both pre-melt (20 -30 °C below melting temperature) and melt transition regions. Results of ionic conductivity of both parallel …

Biophysical Understanding Of Novel Synthetic Amyloid-Β (Aβ) Prions In Alzheimer's Disease, Amit Kumar

Dissertations

Oligomers of amyloid-β (Aβ) peptide are the primary toxic agents that play a pivotal role in the pathogenesis of Alzheimer’s disease (AD). Oligomers are the intermediates formed during the Aβ aggregation process leading up to insoluble fibrils. It is important to know that oligomers can also be formed via pathways that do not lead to fibril formation. Such ‘off-pathway’ oligomers would have significantly longer half-lives than the ‘on-pathway’ ones, which may result in prolonged toxicity to neuronal cells. Furthermore, neither the mechanism of neurotoxicity nor the potential mechanisms of propagation and proliferation to neighboring cells are well understood. Moreover, recent …

Single Step Synthesis Of Antibiotic Kanamycin Embedded Gold Nanoparticles For Efficient Antibacterial Activity, Shravan Gavva

Masters Theses & Specialist Projects

Nanotechnology has become the most advanced type of drug delivery system within the last decade. This advancement shifted the focus on small carriers to increase the efficiency of the drugs. Among these, gold nanoparticles (GNPs) were found to have profound biomedical applications. In current research, kanamycin embedded GNPs were prepared in a single step, single phase, and bio-friendly (green synthesis) procedure. The synthesized Kanamycin-GNPs (Kan-GNPs) were spherical in shape and had a size range of 15 ± 3 nm. The chosen kanamycin is an aminoglycosidic antibiotic that is isolated from Streptomyces kanamyceticus. These special antibiotic GNPs are further characterized using …

Correlates Of Hiv Acquisition In A Cohort Of Black Men Who Have Sex With Men In The United States: Hiv Prevention Trials Network (Hptn) 061, Beryl A. Koblin, Kenneth H. Mayer, Susan H. Eshleman, Lei Wang, Sharon B. Mannheimer, Carlos Del Rio, Steve Shoptaw, Manya Magnus, Susan Buchbinder, Leo Wilton, Ting-Yuan Liu, Vanessa Cummings, Estelle Piwowar-Manning, Sheldon D. Fields, Sam Griffith, Vanessa Elharrar, Darrell Wheeler

Epidemiology Faculty Publications

Background

Black men who have sex with men (MSM) in the United States (US) are affected by HIV at disproportionate rates compared to MSM of other race/ethnicities. Current HIV incidence estimates in this group are needed to appropriately target prevention efforts.

Methods

From July 2009 to October 2010, Black MSM reporting unprotected anal intercourse with a man in the past six months were enrolled and followed for one year in six US cities for a feasibility study of a multi-component intervention to reduce HIV infection. HIV incidence based on HIV seroconversion was calculated as number of events/100 person-years. Multivariate proportional …

Attributing Effects To Interactions, Tyler J. Vanderweele, Eric J. Tchetgen Tchetgen

Harvard University Biostatistics Working Paper Series

A framework is presented which allows an investigator to estimate the portion of the effect of one exposure that is attributable to an interaction with a second exposure. We show that when the two exposures are independent, the total effect of one exposure can be decomposed into a conditional effect of that exposure and a component due to interaction. The decomposition applies on difference or ratio scales. We discuss how the components can be estimated using standard regression models, and how these components can be used to evaluate the proportion of the total effect of the primary exposure attributable to …

Developing Thyronamine Analog Pharmaceuticals Targeting Taar1 To Treat Methamphetamine Addiction, Troy Andrew Wahl

Dissertations and Theses

As a part of the overall program in the Grandy laboratory at Oregon Health & Science University (OHSU), studying the underlying chemical biology of methamphetamine (Meth) addiction, this dissertation reports on the development of six new thyronamine analogs which were synthesized and assayed against trace amine associated receptor 1 (TAAR1), giving preliminary results consistent with the analogs being inverse agonists. Due to highly variable TAAR1 expression levels in the assays, based on inter-assay response to control Meth stimulation as well as other possible factors, kinetic models were developed to qualitatively explain the assay results. The models set approximate limits on …

Natural History Of Concentric Left Ventricular Geometry In Community-Dwelling Older Adults Without Heart Failure During Seven Years Of Follow-Up, Ravi Desai, Mustafa Ahmed, Marjan Mujib, Inmaculada Aban, Michael Zile, Ali Ahmed

Ravi V Desai MD

No abstract provided.

Absence Of Obesity Paradox In Patients With Chronic Heart Failure And Diabetes Mellitus: A Propensity-Matched Study, Chris Adamopoulos, Philippe Meyer, Ravi Desai, Kyparissi Karatzidou, Fernando Ovalle, Michel White, Inmaculada Aban, Thomas Love, Prakash Deedwania, Stefan Anker, Ali Ahmed

Ravi V Desai MD

No abstract provided.

Relation Of Baseline Systolic Blood Pressure And Long-Term Outcomes In Ambulatory Patients With Chronic Mild To Moderate Heart Failure, Maciej Banach, Vikas Bhatia, Margaret Feller, Marjan Mujib, Ravi Desai, Mustafa Ahmed, Jason Guichard, Inmaculada Aban, Thomas Love, Wilbert Aronow, Michel White, Prakash Deedwania, Gregg Fonarow, Ali Ahmed

Ravi V Desai MD

No abstract provided.

Warfarin Use And Outcomes In Patients With Advanced Chronic Systolic Heart Failure Without Atrial Fibrillation, Prior Thromboembolic Events, Or Prosthetic Valves, Marjan Mujib, Abu-Ahmed Rahman, Ravi Desai, Mustafa Ahmed, Margaret Feller, Inmaculada Aban, Tomas Love, Michel White, Prakash Deedwania, Wilbert Aronow, Gregg Fonarow, Ali Ahmed

Ravi V Desai MD

No abstract provided.

Influence Of Co-Existing Atrial Fibrillation On The Efficacy Of Atorvastatin Treatment In Patients With Dilated Cardiomyopathy: A Pilot Study, Agata Bielecka-Dabrowa, Jan Goch, Jacek Rysz, Marek Maciejewski, Ravi Desai, Wilbert Aronow

Ravi V Desai MD

No abstract provided.

Rheumatic Heart Disease And Risk Of Incident Heart Failure Among Community-Dwelling Older Adults: A Prospective Cohort Study, Marjan Mujib, Ravi Desai, Mustafa Ahmed, Jason Guichard, Margaret Feller, O Ekundayo, Prakash Deedwania, Mahboob Ali, Inmaculada Aban, Thomas Love, Michel White, Wilbert Aronow, Shahbudin Rahimtoola, Robert Bonow, Ali Ahmed

Ravi V Desai MD

No abstract provided.

Relationship Between Left And Right Ventricular Ejection Fractions In Chronic Advanced Systolic Heart Failure: Insights From The Best Trial, Ravi Desai, Philippe Meyer, Mustafa Ahmed, Marjan Mujib, Chris Adamopoulos, Michel White, Inmaculada Aban, Ami Iskandrian, Ali Ahmed

Ravi V Desai MD

No abstract provided.

Design And Rationale Of Studies Of Neurohormonal Blockade And Outcomes In Diastolic Heart Failure Using Optimize-Hf Registry Linked To Medicare Data, Yan Zhang, Meredith Kilgore, Tarun Arora, Marjan Mujib, O. Ekundayo, Inmaculada Aban, Margaret Feller, Ravi Desai, Thomas Love, Richard Allman, Gregg Fonarow, Ali Ahmed

Ravi V Desai MD

No abstract provided.

A Propensity-Matched Study Of The Association Of Diabetes Mellitus With Incident Heart Failure And Mortality Among Community-Dwelling Older Adults, Brita Roy, Pushkar Pawar, Ravi Desai, Gregg Fonarow, Marjan Mujib, Yan Zhang, Margaret Feller, Fernando Ovalle, Inmaculada Aban, Thomas Love, Ami Iskandrian, Prakash Deedwania, Ali Ahmed

Ravi V Desai MD

No abstract provided.

Heart Failure Is A Risk Factor For Incident Driving Cessation Among Community-Dwelling Older Adults: Findings From A Prospective Population Study, Richard Sims, Marjan Mujib, Gerald Mcgwin, Yan Zhang, Mustafa Ahmed, Ravi Desai, Inmaculada Aban, Patrick Sawyer, Stefan Anker, Ali Ahmed

Ravi V Desai MD

No abstract provided.

Managed Care, Hospice Use, Site Of Death, And Medical Expenditures In The Last Year Of Life, Ezekiel Emanuel, Arlene Ash, Wei Yu, Gail Gazelle, Norman Levinsky, Olga Saynina, Mark Mcclellan, Mark Moskowitz

wei yu

BACKGROUND: We examined deaths of Medicare beneficiaries in Massachusetts and California to evaluate the effect of managed care on the use of hospice and site of death and to determine how hospice affects the expenditures for the last year of life.

METHODS: Medicare data for beneficiaries in Massachusetts (n = 37 933) and California (n = 27 685) who died in 1996 were merged with each state's death certificate files to determine site and cause of death. Expenditure data were Health Care Financing Administration payments and were divided into 30-day periods from the date of death back 12 months.

RESULTS: …

Characterization By Nmr Of Reactants And Products Of Hydrofluoroether Isomers, Cf3(Cf2)3och3 And (Cf3)2c(F)Cf2och3, Reacting With Isopropyl Alcohol, Howard Knachel, Vladimir Benin, William E. Moddeman, Janine C. Birkbeck, Thomas A. Kestner, Tayna L. Young

Chemistry Faculty Publications

The 3M Company product Novec™ 71IPA DL, a mixture of methoxyperfluorobutane, methoxyperfluoroisobutane and 4.5 wt.% isopropyl alcohol, has been found to be very stable at ambient temperature, producing fluoride at the rate of ~1 ppm/year. Our earlier kinetic and theoretical studies have identified the reaction mechanism. This paper identifies the ¹H and ¹⁹F NMR chemical shifts, multiplicities, and coupling constants of reactants and the major products that result from aging the mixture in sealed Pyrex NMR tubes for periods up to 1.8 years at temperatures from 26 °C to 102 °C. Chemical shifts and coupling constants of fluorine …

Cardiovascular Outcome Trials In Type 2 Diabetes And The Sulphonylurea Controversy: Rationale For The Active-Comparator Carolina Trial, Julio Rosenstock, Nikolaus Marx, Steven E. Kahn, Bernard Zinman, John J. Kastelein, John M. Lachin, Erich Bluhmki, Sanjay Patel, Odd-Erik Johansen, Hans-Jurgen Woerle

Epidemiology Faculty Publications

Sulphonylureas (SUs) are widely used glucose-lowering agents in type 2 diabetes mellitus (T2DM) with apparent declining efficacy over time. Concerns have been raised from observational retrospective studies on the cardiovascular (CV) safety of SUs but there are few long-term data on CV outcomes from randomized controlled trials (RCTs) involving the use of this class of agents. Most of the observational studies and registry data are conflicting and vary with study population and methodology used for analyses. To address the SU controversy, we reviewed the recently published literature (until end of the year 2011) to evaluate the impact of SUs on …