Physical Sciences and Mathematics Commons^™

The Relation Of Dietary Patterns To Future Survival, Health, And Cardiovascular Events In Older Adults, Paula Diehr

Paula Diehr

BACKGROUND: There have been few long-term follow-up studies of older adults who follow different dietary patterns. METHODS: We cluster-analyzed data on dietary fat, fiber, protein, carbohydrate, and calorie consumption from the U.S. Cardiovascular Health Study (mean age=73), and examined the relationship of the dietary clusters to outcomes 10 years later. RESULTS: The five clusters were named "Healthy diet" (relatively high in fiber and carbohydrate and low in fat), "Unhealthy diet" (relatively high in protein and fat, relatively low in carbohydrates and fiber); "High Calorie," "Low Calorie," and "Low 4," which was distinguished by higher alcohol consumption. The clusters were strongly …

Modeling The Optimum Duration Of Antibiotic Prophylaxis In An Anthrax Outbreak, Ron Brookmeyer, Elizabeth Johnson, Robert Bollinger

Ron Brookmeyer

A critical consideration in effective and measured public health responses to an outbreak of inhalational anthrax is the optimum duration of antibiotic prophylaxis. We develop a competing-risks model to address the duration of antibiotic prophylaxis and the incubation period that accounts for the risks of spore germination and spore clearance. The model predicts the incubation period distribution, which is confirmed by empirical data. The optimum duration of antibiotic prophylaxis depends critically on the dose of inhaled spores. At high doses, we show that exposed persons would need to remain on antibiotic prophylaxis for at least 4 months, and considerable morbidity …

Statistical Models And Bioterrorism: Application To The U.S. Anthrax Outbreak, Ron Brookmeyer, Natalie Blades

Ron Brookmeyer

In the fall of 2001 an outbreak of inhalational anthrax occurred in the United States that was the result of bioterrorism. Letters contaminated with anthrax spores were sent through the postal system. In response to the outbreak, public health officials treated over 10,000 persons with antibiotic prophylaxis in the hopes of preventing further morbidity and mortality. No persons receiving the antibiotics subsequently developed disease. The question arises as to how many cases of disease may actually have been prevented by the public health intervention of antibiotic prophylaxis. A statistical model is developed to answer this question by relating to the …

Assessment Of Model Development Techniques And Evaluation Methods For Binary Classification In The Credit Industry, Satish Nargundkar, Jennifer Priestley

Jennifer L. Priestley

We examine and compare the most prevalent modeling techniques in the credit industry, Linear Discriminant Analysis, Logistic Analysis and the emerging technique of Neural Network modeling. K-S Tests and Classification Rates are typically used in the industry to measure the success in predictive classification. We examine those two methods and a third, ROC Curves, to determine if the method of evaluation has an influence on the perceived performance of the modeling technique. We found that each modeling technique has its own strengths, and a determination of the “best” depends upon the evaluation method utilized and the costs associated with misclassification.

Absorptive Capacity, Causal Ambiguity And Outcome Ambiguity: The Network Effect And Knowledge Transfer Difficulty Among Four Network Forms, Subhashish Samaddar, Jennifer Priestley

Jennifer L. Priestley

No abstract is currently available.

Rejoinder To "“Wavelet-Based Nonparametric Modeling Of Hierarchical Functions In Colon Carcinogenesis.”, Jeffrey S. Morris, Marina Vannucci, Philip J. Brown, Raymond J. Carroll

Jeffrey S. Morris

No abstract provided.

Quality Control And Peak Finding For Proteomics Data Collected From Nipple Aspirate Fluid Using Surface Enhanced Laser Desorption And Ionization., Jeffrey S. Morris, Kevin R. Coombes, Herbert A. Fritsche, Charlotte Clarke, Jeng-Neng Chen, Keith A. Baggerly, Lian-Chun Xiao, Mien-Chie Hung, Henry M. Kuerer

Jeffrey S. Morris

Background: Recently, researchers have been using mass spectroscopy to study cancer. For use of proteomics spectra in a clinical setting, stringent quality-control procedures will be needed.

Methods: We pooled samples of nipple aspirate fluid from healthy breasts and breasts with cancer to prepare a control sample. Aliquots of the control sample were used on two spots on each of three IMAC ProteinChip® arrays (Ciphergen Biosystems, Inc.) on 4 successive days to generate 24 SELDI spectra. In 36 subsequent experiments, the control sample was applied to two spots of each ProteinChip array, and the resulting spectra were analyzed to determine how …

Imputation Of Missing Longitudinal Data: A Comparison Of Methods, Paula Diehr, Jean Mundahl Engels

Paula Diehr

BACKGROUND AND OBJECTIVES: Missing information is inevitable in longitudinal studies, and can result in biased estimates and a loss of power. One approach to this problem is to impute the missing data to yield a more complete data set. Our goal was to compare the performance of 14 methods of imputing missing data on depression, weight, cognitive functioning, and self-rated health in a longitudinal cohort of older adults. METHODS: We identified situations where a person had a known value following one or more missing values, and treated the known value as a "missing value." This "missing value" was imputed using …

Nullificatory Juries, David A. Hoffman, Kaimipono D. Wenger

David A Hoffman

In this Article, we argue that current debates on the legitimacy of punitive damages would benefit from a comparison with jury nullification in criminal trials. We discuss critiques of punitive damages and of jury nullification, noting the surprising similarities in the arguments scholars use to attack these (superficially) distinct outcomes of the jury guarantee. Not only are the criticisms alike, the institutions of punitive damages and jury nullification also turn out to have many similarities: both are, we suggest, examples of what we call "nullificatory juries." We discuss the features of such juries, and consider recent behavioral data relating to …

Exact Multiplicity For Periodic Solutions Of Duffing Type, Hongbin Chen, Yi Li, Xiaojie Hou

Yi Li

In this paper, we study the following Duffing-type equation: x″+cx′+g(t,x)=h(t),

where g(t,x) is a 2π-periodic continuous function in t and concave–convex in x, and h(t) is a small continuous 2π-periodic function. The exact multiplicity and stability of periodic solutions are obtained.

Comparison Between Analytical Probabilistic And Computer Simulation Models, Using Current Design Examples, Barry A. Palynchuk Phd

Barry A. Palynchuk PhD

Closed form analytical expressions have been developed to solve several basic problems related to the hydrologic design of storm water management facilities. The collection of these analytical expressions is referred to as the Analytical Probabilistic Storm Water Models (APSWM). APSWM can be used as an alternative to the design storm simulation models in the design and analysis of storm water management facilities. In this paper, a comparison is made between APSWM and design storm simulation models as applied to an actual design case. Conventional outputs such as runoff volume, peak discharge, and peak discharge from detention ponds are reviewed and …

Wavelet-Based Nonparametric Modeling Of Hierarchical Functions In Colon Carcinogenesis., Jeffrey S. Morris, Marina Vannucci, Philip J. Brown, Raymond J. Carroll

Jeffrey S. Morris

In this article we develop new methods for analyzing the data from an experiment using rodent models to investigate the effect of type of dietary fat on O6-methylguanine-DNA-methyltransferase (MGMT), an important biomarker in early colon carcinogenesis. The data consist of observed profiles over a spatial variable contained within a two-stage hierarchy, a structure that we dub hierarchical functional data. We present a new method providing a unified framework for modeling these data, simultaneously yielding estimates and posterior samples for mean, individual, and subsample-level profiles, as well as covariance parameters at the various hierarchical levels. Our method is nonparametric in that …

Trajectories Of Health For Older Adults Over Time: Accounting Fully For Death, Paula Diehr

Paula Diehr

The process of healthy aging can best be described by plotting the trajectory of health-related variables over time. Unfortunately, graphs including data only from survivors may be misleading because they may confuse patterns of mortality with patterns of change in health. Two approaches for creating graphs that account for death in such situations are 1) to incorporate a category or value for death into the longitudinal health variable and 2) to measure time in years before death or some other event. The first approach has been applied to self-rated health (excellent to poor) and the 36-Item Short-Form Health Survey (SF-36). …

A Comprehensive Approach To The Analysis Of Maldi-Tof Proteomics Spectra From Serum Samples., Keith A. Baggerly, Jeffrey S. Morris, Jing Wang, David Gold, Lian-Chun Xiao, Kevin R. Coombes

Jeffrey S. Morris

For our analysis of the data from the First Annual Proteomics Data Mining Conference, we attempted to discriminate between 24 disease spectra (group A) and 17 normal spectra (group B). First, we processed the raw spectra by (i) correcting for additive sinusoidal noise (periodic on the time scale) affecting most spectra, (ii) correcting for the overall baseline level, (iii) normalizing, (iv) recombining fractions, and (v) using variable- width windows for data reduction. Also, we identified a set of polymeric peaks (at multiples of 180.6 Da) that is present in several normal spectra (B1–B8). After data processing, we found the intensities …

The Global Dynamics Of Isothermal Chemical Systems With Critical Nonlinearity, Yi Li, Yuanwei Qi

Yi Li

In this paper, we study the Cauchy problem of a cubic autocatalytic chemical reaction system u_1,t = u_1,xx − u^α₁ u^β₂, u_2,t = du_2,xx+ u^α₁ u^β₂ with non-negative initial data, where the exponents α,β satisfy 1<α,β<2, α+β = 3 and the constant d>0 is the Lewis number. Our purpose is to study the global dynamics of solutions under mild decay of initial data as |x|→∞. We show the exact large time behaviour of solutions which is universal.

Development Of A Regression Model For Estimating The Effects Of Assumption Violations On Type I Error Rates In The Student's T Test: Implications For Practitioners, John Fraas, Isadore Newman, Rosalie J. Hall

John W. Fraas

No abstract provided.

Bayesian Shrinkage Estimation Of The Relative Abundance Of Mrna Transcripts Using Sage, Jeffrey S. Morris, Keith A. Baggerly, Kevin R. Coombes

Jeffrey S. Morris

Serial analysis of gene expression (SAGE) is a technology for quantifying gene expression in biological tissue that yields count data that can be modeled by a multinomial distribution with two characteristics: skewness in the relative frequencies and small sample size relative to the dimension. As a result of these characteristics, a given SAGE sample may fail to capture a large number of expressed mRNA species present in the tissue. Empirical estimators of mRNA species’ relative abundance effectively ignore these missing species, and as a result tend to overestimate the abundance of the scarce observed species comprising a vast majority of …

Ordinary Least Squares Regression, Discriminant Analysis,And Logisitic Regression: Questions Researchers And Practioners Should Address When Selecting An Analytic Technique, John Fraas, Isadore Newman

John W. Fraas

No abstract provided.

The Press For Help Project Concept, Program And Working Paper Of Emmanuel Mario B Santos And His Marc Guerrero Communications Inc., Emmanuel Mario B. Santos Aka Marc Guerrero

Emmanuel Mario B Santos aka Marc Guerrero

FORETHOUGHT. DECLARATION OF IDEAOLOGY AND PRINCIPLES. VISION. MISSION. VALUES. GOALS. BASIC HELP project. EDUCATIONAL HELP project. MEDICAL HELP project. LEGAL HELP project. EMERGENCY HELP project. LIVELIHOOD HELP project. SPIRITUAL and CULTURAL HELP project. ENVIRONMENTAL HELP project. REENGINEERING HELP project. INTERNATIONAL HELP project. QUADRO CREDO Matthew 5.1-12, the Jerusalem Bible. The Universal Filipino Beatitudes. SALIN SA FILIPINO. DESIDERATA. AFTERTHOUGHT.

Oil And Product Price Dynamics In International Petroleum Markets, Alessandro Lanza, Matteo Manera, Massimo Giovannini

Matteo Manera

In this paper we investigate crude oil and products price dynamics. We present a comparison among ten price series of crude oils and fourteen price series of petroleum products, considering four distinct market areas (Mediterranean, North Western Europe, Latin America and North America) over the period 1994-2002. We provide first a complete analysis of crude oil and product price dynamics using cointegration and error correction models. Subsequently we use the error correction specification to predict crude oil prices over the horizon January 2002-June 2002.The main findings of the paper can be summarized as follows: a) differences in quality are crucial …

Star-Garch Models For Stock Market Interactions In The Pacific Basin Region, Japan And Us, Giorgio Busetti, Matteo Manera

Matteo Manera

We investigate the financial interactions between countries in the Pacific Basin region (Korea, Singapore, Malaysia, Hong Kong and Taiwan), Japan and US. The originality of the paper is the use of STAR-GARCH models, instead of standard correlationcointegration techniques. For each country in the Pacific Basin region, we find statistically adequate STAR-GARCH models for the series of stock market daily returns, using Nikkei225 and S&P500 as alternative threshold variables. We provide evidence for the leading role of Japan in the period 1988-1990 (pre-Japanese crisis years), whereas our results suggest that the Pacific Basin region countries are more closely linked with the …

Modelling The Load Curve Of Aggregate Electricity Consumption Using Principal Components, Matteo Manera, Angelo Marzullo

Matteo Manera

Since oil is a non-renewable resource with a high environmental impact, and its most common use is to produce combustibles for electricity, reliable methods for modelling electricity consumption can contribute to a more rational employment of this hydrocarbon fuel. In this paper we apply the Principal Components (PC) method to modelling the load curves of Italy, France and Greece on hourly data of aggregate electricity consumption. The empirical results obtained with the PC approach are compared with those produced by the Fourier and constrained smoothing spline estimators. The PC method represents a much simpler and attractive alternative to modelling electricity …

Perturbation Of Global Solution Curves For Semilinear Problems, Philip Korman, Yi Li, Tiancheng Ouyang

Yi Li

We revisit the question of exact multiplicity of positive solutions for a class of Dirichlet problems for cubic-like nonlinearities, which we studied in 161. Instead of computing the direction of bifurcation as we did in [6], we use an indirect approach, and study the evolution of turning points. We give conditions under which the critical (turning) points continue on smooth curves, which allows us to reduce the problem to the easier case of f (0) = 0. We show that the smallest root of f (u) does not have to be restricted.

Multiple Solutions For An Inhomogeneous Semilinear Elliptic Equation In Rn, Yinbin Deng, Yi Li, Xuejin Zhao

Yi Li

No abstract provided.

Bayesian Modelling And Forecasting Of Intra-Day Electricity Load, Remy Cottet, Michael Smith

Michael Stanley Smith

With the advent of wholesale electricity markets there has been renewed focus on intra-day electricity load forecasting. This paper employs a multi-equation regression model with a diagonal first order stationary vector autoregresson (VAR) for modeling and forecasting intra-day electricity load. The correlation structure of the disturbances to the VAR and the appropriate subset of regressors are explored using Bayesian model selection methodology. The full spectrum of finite sample inference is obtained using a Bayesian Markov chain Monte Carlo sampling scheme. This includes the predictive distribution of load and the distribution of the time and level of daily peak load, something …

Long-Run Models Of Oil Stock Prices, Alessandro Lanza, Matteo Manera, Massimo Giovannini, Margherita Grasso

Matteo Manera

The identification of the forces that drive oil stock prices is extremely important given the size of the Oil&Gas industry and its links with the energy sector and the environment. In the next decade oil companies will have to deal with international policies to contrast climate change. This issue is likely to affect companies’ shareholder values. In this paper we focus on the long-run financial determinants of the stock prices of six major oil companies (Bp, Chevron-Texaco, Eni, Exxon-Mobil, Royal Dutch Shell, Total-Fina-Elf) using multivariate cointegration techniques and vector error correction models. Weekly oil stock prices are analyzed together with …