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Full-Text Articles in Physical Sciences and Mathematics

Organizational Values, Social Responsibility, And Corporate Citizenship: The Case Of Nevada State College, Grace S. Thomson Dec 2009

Organizational Values, Social Responsibility, And Corporate Citizenship: The Case Of Nevada State College, Grace S. Thomson

Dr. Grace S. Thomson

Organizational Values, Social Responsibility, and Corporate Citizenship Organizations contribute more than products and services to the society. The generation of jobs, creation of wealth and satisfaction of needs are only a portion of the influence that organizations have in a community. Likewise, organizations are increasingly engaging in social responsible initiatives to respond to the concerns of their various stakeholders (Aguilera, Rupp, Williams, & Ganapathi, 2007). Organizations with a genuine interest for social responsibility and citizenship possess value systems that articulate and integrate these social motives into their corporate strategy (Graber & Kilpatrick, 2008). Higher education institutions in the United States …


A Statistical Framework For The Analysis Of Chip-Seq Data, Pei Fen Kuan, Dongjun Chung, Guangjin Pan, James A. Thomson, Ron Stewart, Sunduz Keles Nov 2009

A Statistical Framework For The Analysis Of Chip-Seq Data, Pei Fen Kuan, Dongjun Chung, Guangjin Pan, James A. Thomson, Ron Stewart, Sunduz Keles

Sunduz Keles

Chromatin immunoprecipitation followed by sequencing (ChIP-Seq) has revolutionalized experiments for genome-wide profiling of DNA-binding proteins, histone modifications, and nucleosome occupancy. As the cost of sequencing is decreasing, many researchers are switching from microarray-based technologies (ChIP-chip) to ChIP-Seq for genome-wide study of transcriptional regulation. Despite its increasing and well-deserved popularity, there is little work that investigates and accounts for sources of biases in the ChIP-Seq technology. These biases typically arise from both the standard pre-processing protocol and the underlying DNA sequence of the generated data.

We study data from a naked DNA sequencing experiment, which sequences non-cross-linked DNA after deproteinizing and …


Integrative Analysis Of Cancer Genomic Data, Shuangge Ma Sep 2009

Integrative Analysis Of Cancer Genomic Data, Shuangge Ma

Shuangge Ma

In the past decade, we have witnessed a period of unparallel development in the field of cancer genomics. To address the same or similar biomedical questions, multiple cancer genomic studies have been independently designed and conducted. Cancer gene signatures identified from analysis of individual datasets often have low reproducibility. A cost-effective way of improving reproducibility is to conduct integrative analysis of datasets from multiple studies with comparable designs. To properly integrate multiple studies and conduct integrative analysis, we need to access various public data warehouses, retrieve experiment protocols and raw data, evaluate individual studies and select those with comparable designs, …


Modern Spectral Climate Patterns In Rhythmically Deposited Argillites Of The Gowganda Formation (Early Proterozoic), Southern Ontario, Canada, Gary B. Hughes, Robert Giegengack, Haralambos N. Kritikos Aug 2009

Modern Spectral Climate Patterns In Rhythmically Deposited Argillites Of The Gowganda Formation (Early Proterozoic), Southern Ontario, Canada, Gary B. Hughes, Robert Giegengack, Haralambos N. Kritikos

Gary B. Hughes

Rhythmically deposited argillites of the Gowganda Formation (ca. 2.0–2.5 Ga) probably formed in a glacial setting. Drop stones and layered sedimentary couplets in the rock presumably indicate formation in a lacustrine environment with repeating freeze–thaw cycles. It is plausible that temporal variations in the thickness of sedimentary layers are related to interannual climatic variability, e.g. average seasonal temperature could have influenced melting and the amount of sediment source material carried to the lake. A sequence of layer couplet thickness measurements was made from high-resolution digitized photographs taken at an outcrop in southern Ontario, Canada. The frequency spectrum of thickness measurements …


Multiple Loci Within The Major Histocompatibility Complex Confer Risk Of Psoriasis, Bing-Jian Feng, Liang-Dan Sun, Razieh Soltani-Arabshahi, Anne M. Bowcock, Rajan P. Nair, Philip Stuart, James T. Elder, Steven J. Schrodi, Ann B. Begovich, Goncalo R. Abecasis, Xue-Jun Zhang, Kristina P. Callis Duffin, Gerald G. Krueger, David E. Goldgar Jul 2009

Multiple Loci Within The Major Histocompatibility Complex Confer Risk Of Psoriasis, Bing-Jian Feng, Liang-Dan Sun, Razieh Soltani-Arabshahi, Anne M. Bowcock, Rajan P. Nair, Philip Stuart, James T. Elder, Steven J. Schrodi, Ann B. Begovich, Goncalo R. Abecasis, Xue-Jun Zhang, Kristina P. Callis Duffin, Gerald G. Krueger, David E. Goldgar

Steven J Schrodi

Psoriasis is a common inflammatory skin disease characterized by thickened scaly red plaques. Previously we have performed a genome-wide association study (GWAS) on psoriasis with 1,359 cases and 1,400 controls, which were genotyped for 447,249 SNPs. The most significant finding was for SNP rs12191877, which is in tight linkage disequilibrium with HLA-Cw*0602, the consensus risk allele for psoriasis. However, it is not known whether there are other psoriasis loci within the MHC in addition to HLA-C. In the present study, we searched for additional susceptibility loci within the human leukocyte antigen (HLA) region through in-depth analyses of the GWAS data; …


A Tale Of Two Streets: Incorporating Grouping Structure In High Dimensional Data Mining, Shuangge Ma Jun 2009

A Tale Of Two Streets: Incorporating Grouping Structure In High Dimensional Data Mining, Shuangge Ma

Shuangge Ma

No abstract provided.


Regression When The Predictors Are Images, Philip T. Reiss Apr 2009

Regression When The Predictors Are Images, Philip T. Reiss

Philip T. Reiss

No abstract provided.


Smoothing Parameter Selection For A Class Of Semiparametric Linear Models, Philip T. Reiss, R. Todd Ogden Mar 2009

Smoothing Parameter Selection For A Class Of Semiparametric Linear Models, Philip T. Reiss, R. Todd Ogden

Philip T. Reiss

Spline-based approaches to nonparametric and semiparametric regression, as well as to regression of scalar outcomes on functional predictors, entail choosing a parameter controlling the extent to which roughness of the fitted function is penalized. In this paper we demonstrate that the equations determining two popular methods for smoothing parameter selection, generalized cross-validation and restricted maximum likelihood, share a similar form that allows us to prove several results common to both, and to derive a condition under which they yield identical values. These ideas are illustrated by application of functional principal component regression, a method for regressing scalars on functions, to …


Ceo Pay-For-Performance Heterogeneity: Examples Using Quantile Regression, Kevin F. Hallock, Regina Madalozzo, Clayton G. Reck Mar 2009

Ceo Pay-For-Performance Heterogeneity: Examples Using Quantile Regression, Kevin F. Hallock, Regina Madalozzo, Clayton G. Reck

Kevin F Hallock

We provide some examples of how quantile regression can be used to investigate heterogeneity in pay–firm size and pay-performance relationships for U.S. CEOs. For example, do conditionally (predicted) high-wage managers have a stronger relationship between pay and performance than conditionally low-wage managers? Our results using data over a decade show, for some standard specifications, there is considerable heterogeneity in the returns to firm performance across the conditional distribution of wages. Quantile regression adds substantially to our understanding of the pay-performance relationship. This heterogeneity is masked when using more standard empirical techniques.


Quantile Regression, Roger Koenker, Kevin F. Hallock Mar 2009

Quantile Regression, Roger Koenker, Kevin F. Hallock

Kevin F Hallock

Quantile regression as introduced by Koenker and Bassett seeks to extend ideas of quantiles to the estimation of conditional quantile functions--models in which quantiles of the conditional distribution of the response variable are expressed as functions of observed covariates.


Correlation Using Spss, Durgesh Chandra Pathak Jan 2009

Correlation Using Spss, Durgesh Chandra Pathak

Durgesh Chandra Pathak

This is a class presentation that was used to train participants of SPSS-Training Programme.


A Comparison Among The Director Networks In The Main Listed Companies In France, Germany, Italy, And The United Kingdom, Paolo Santella, Carlo Drago, Andrea Polo, Enrico Gagliardi Jan 2009

A Comparison Among The Director Networks In The Main Listed Companies In France, Germany, Italy, And The United Kingdom, Paolo Santella, Carlo Drago, Andrea Polo, Enrico Gagliardi

Carlo Drago

The purpose of this paper is to contribute to the literature on director interlocks by illustrating and analysing the interlocking directorships among the Italian, French, German, UK and US listed Blue Chips. The comparison of the five countries considered shows that two national models stand out. On the one hand a model made of a high number of companies linked to each other through a small number of shared directors who serve on several company boards at the time (France, Germany, and Italy). On the other hand, in the UK much fewer companies are connected to each other essentially through …


Bootstrap P-Values In Discrete Models: Asymptotic And Non-Asymptotic Effects, Chris Lloyd Dec 2008

Bootstrap P-Values In Discrete Models: Asymptotic And Non-Asymptotic Effects, Chris Lloyd

Chris J. Lloyd

(This paper is a major revision of http://works.bepress.com/chris_lloyd/15/.) Standard first order P-values suffer from two important drawbacks. First, even for quite large sample sizes they can misrepresent the exact significance which depends on nuisance parameters unspecified under the null. For most discrete models is that accuracy is variable and breaks down completely at the boundary. Second, different test statistics can give practically different results.

The bootstrap P-value is the exact significance with the null maximum estimate (ML) of the nuisance parameter substituted. We show that bootstrap P-values based on different first order statistics differ to second order. We also show …


Bootstrap And Second Order Tests Of Risk Difference, Chris Lloyd Dec 2008

Bootstrap And Second Order Tests Of Risk Difference, Chris Lloyd

Chris J. Lloyd

Standard approximate tests of the difference of two probabilities have type 1 error that can differ significantly from nominal, even for quite large sample sizes. There are two modern methods of reducing type 1 error. One is to use so-called higher order asymptotics (Reid, 2003) to provide an explicit adjustment to the likelihood ratio statistic. The second is to replace the nuisance parameter in an exact calculation with a null estimate (Young and Lee, 2005), which is a kind of bootstrap. The purpose of this paper is to explain and evaluate these two methods, for testing whether a difference in …


Evaluation Of Heterogeneity In Pharmacotherapy Trials For Drug Dependence: A Bayesian Approach, Charles E. Green, F. G. Moeller, J. M. Schmitz, Joseph F. Lucke, S. D. Lane, A. C. Swann, Robert E. Lasky, Joseph P. Carbonari Dec 2008

Evaluation Of Heterogeneity In Pharmacotherapy Trials For Drug Dependence: A Bayesian Approach, Charles E. Green, F. G. Moeller, J. M. Schmitz, Joseph F. Lucke, S. D. Lane, A. C. Swann, Robert E. Lasky, Joseph P. Carbonari

Joseph Lucke

Difficulty identifying effective pharmacotherapies for cocaine dependence has led to suggestions that subgroup differences may account for some of the heterogeneity in treatment response. Well-attested methodologicalifficulties associated with these analyses recommend the use of Bayesian statistical reasoning for evaluation of salient interaction effects.

Methods: A secondary data analysis of a previously published, double-blind, randomized controlled trial examines the interaction of decision-making, as measured by the Iowa Gambling Task, and citalopram in increasing longest sustained abstinence from cocaine use.

Results: Bayesian analysis indicated that there was a 99% chance that improved decision-making enhances response to citalopram. Given the strong positive nature …


Bayesian Approach To Average Power Calculations For Binary Regression Models With Misclassified Outcomes, Dunlei Cheng, James D. Stamey, Adam J. Branscum Dec 2008

Bayesian Approach To Average Power Calculations For Binary Regression Models With Misclassified Outcomes, Dunlei Cheng, James D. Stamey, Adam J. Branscum

Dunlei Cheng

We develop a simulation-based procedure for determining the required sample size in binomial regression risk assessment studies when response data are subject to misclassification. A Bayesian average power criterion is used to determine a sample size that provides high probability, averaged over the distribution of potential future data sets, of correctly establishing the direction of association between predictor variables and the probability of event occurrence. The method is broadly applicable to any parametric binomial regression model including, but not limited to, the popular logistic, probit, and complementary log-log models. We detail a common medical scenario wherein ascertainment of true disease …


Syllabus Of Mathematics For Economists (Master's Course), Reza Moosavi Mohseni Dr. Dec 2008

Syllabus Of Mathematics For Economists (Master's Course), Reza Moosavi Mohseni Dr.

Reza Moosavi Mohseni

No abstract provided.


The Development Of Humans – A Study Including Languages, Cultures, Religions And Genetics, Dr. Erik Dahlquist, Dr. Allan Dahlquist Dec 2008

The Development Of Humans – A Study Including Languages, Cultures, Religions And Genetics, Dr. Erik Dahlquist, Dr. Allan Dahlquist

Dr. Erik Dahlquist

The book covers the development of culture, religion, language and genetics of the human population since prehistory. Four main cultures have spread around the globe: 1) Monosyllabic language people with ancestor cult 2) Austroasiatic people with sun worshipping and megalit graves. Counting with 20 as the base 3) Uralic speaking people with kings from the sky, and strong city states. Moon and mother godess. Don´t differentiate between male and female, he and she. 4) Inflectual language speaking people with sky gods and cattles. Indoeuropeans. Often endings differentiating he and she. Shows how original cultures are refelected in todays society.


Should Biomarker Estimates Of Hiv Incidence Be Adjusted?, Ron Brookmeyer Dec 2008

Should Biomarker Estimates Of Hiv Incidence Be Adjusted?, Ron Brookmeyer

Ron Brookmeyer

Objective: To evaluate adjustment procedures that have been proposed to correct HIV incidence rates derived from cross-sectional surveys of biomarkers (BED). These procedures were motivated by some reports that the biomarker BED approach overestimates incidence when compared to cohort studies.

Design: Considered the Hargrove and McDougal adjustment procedures that adjust biomarker estimates of HIV incidence rates for misclassification with respect to the timing of infections.

Methods: Performed mathematical and statistical analysis of the adjustment formulas. Evaluated sources of error in cohort studies of incidence that could also explain discrepancies between cohort and biomarker estimates.

Results: The McDougal adjustment has no …


The Effects Of Herd Immunity On The Power Of Vaccine Trials, Blake Charvat, Ron Brookmeyer, Jay Herson Dec 2008

The Effects Of Herd Immunity On The Power Of Vaccine Trials, Blake Charvat, Ron Brookmeyer, Jay Herson

Ron Brookmeyer

We evaluate the effects of herd immunity on the power of vaccine trials. We consider large-scale trials in which persons are individually randomized to either placebo or vaccine. We evaluate the adequacy of naive power calculations that ignore the effects of herd immunity such as those based on the comparison of two independent binomials. We developed a simulation design to evaluate the quantitative effects of herd immunity on power. The simulation design accounted for nonhomogeneous mixing. We found that naive power calculations that ignore the effects of herd immunity can seriously overestimate power. In fact, we found that as sample …


Genome-Wide Scan Reveals Association Of Psoriasis With Il-23 And Nf-B Pathways, Rajan P. Nair, Kristina C. Duffin, Cynthia Helms, Jun Ding, Philip E. Stuart, David Goldgar, Johann E. Gudjonsson, Yun Li, Trilokraj Tejasvi, Bing-Jiag Feng, Andreas Ruether, Stefan Schreiber, Michael Weichenthal, Dafna Gladman, Proton Rahman, Steven J. Schrodi, Sampath Prahalad, Stephen L. Guthery, Judith Fischer, Wilson Liao, Pui-Yan Kwok, Alan Menter, G Mark Lathrop, Carol A. Wise, Ann B. Begovich, John J. Voorhees, James T. Elder, Gerald G. Krueger, Anne M. Bowcock, Goncalo R. Abecasis Dec 2008

Genome-Wide Scan Reveals Association Of Psoriasis With Il-23 And Nf-B Pathways, Rajan P. Nair, Kristina C. Duffin, Cynthia Helms, Jun Ding, Philip E. Stuart, David Goldgar, Johann E. Gudjonsson, Yun Li, Trilokraj Tejasvi, Bing-Jiag Feng, Andreas Ruether, Stefan Schreiber, Michael Weichenthal, Dafna Gladman, Proton Rahman, Steven J. Schrodi, Sampath Prahalad, Stephen L. Guthery, Judith Fischer, Wilson Liao, Pui-Yan Kwok, Alan Menter, G Mark Lathrop, Carol A. Wise, Ann B. Begovich, John J. Voorhees, James T. Elder, Gerald G. Krueger, Anne M. Bowcock, Goncalo R. Abecasis

Steven J Schrodi

Psoriasis is a common immune-mediated disorder that affects the skin, nails and joints. To identify psoriasis susceptibility loci, we genotyped 438,670 SNPs in 1,409 psoriasis cases and 1,436 controls of European ancestry. We followed up 21 promising SNPs in 5,048 psoriasis cases and 5,041 controls. Our results provide strong support for the association of at least seven genetic loci and psoriasis (each with combined P < 5 10-8). Loci with confirmed association include HLA-C, three genes involved in IL-23 signaling (IL23A, IL23R, IL12B), two genes that act downstream of TNF- and regulate NF-B signaling (TNIP1, TNFAIP3) and two genes involved in the modulation of Th2 immune responses (IL4, IL13). Although the proteins encoded in these loci are known to interact biologically, we found no evidence for epistasis between associated SNPs. Our results expand the catalog of genetic loci implicated in psoriasis susceptibility and suggest priority targets for study in other auto-immune disorders.


Bayesian Statistics, Joseph F. Lucke Dec 2008

Bayesian Statistics, Joseph F. Lucke

Joseph Lucke

No abstract provided.


Characterization Of Unknown Genetic Modifications Using High Throughput Sequencing And Computational Subtraction, Torstein Tengs Dec 2008

Characterization Of Unknown Genetic Modifications Using High Throughput Sequencing And Computational Subtraction, Torstein Tengs

Dr. Torstein Tengs

Background

When generating a genetically modified organism (GMO), the primary goal is to give a target organism one or several novel traits by using biotechnology techniques. A GMO will differ from its parental strain in that its pool of transcripts will be altered. Currently, there are no methods that are reliably able to determine if an organism has been genetically altered if the nature of the modification is unknown.

Results

We show that the concept of computational subtraction can be used to identify transgenic cDNA sequences from genetically modified plants. Our datasets include 454-type sequences from a transgenic line of …


Are (The Log-Odds Of) Hospital Mortality Rates Normally Distributed In Ontario? Implications For Studying Variations In Outcomes Of Medical Care, Peter C. Austin Dec 2008

Are (The Log-Odds Of) Hospital Mortality Rates Normally Distributed In Ontario? Implications For Studying Variations In Outcomes Of Medical Care, Peter C. Austin

Peter Austin

Objective: Hierarchical regression models are used to examine variations in outcomes following the provision of medical care across providers. These models frequently assume a normal distribution for the provider-specific random effects. Poincaré said, “Everyone believes in the normal law, the experimenters because they imagine it a mathematical theorem, and the mathematicians because they think it an experimental fact”. Our objective was to examine the appropriateness of this assumption when examining variations in mortality.

Study design and setting: We used Bayesian model selection methods to compare hierarchical regression models in which the provider-specific random effects were either a normal distribution or …