RANDOMIZATION-BASED INFERENCE ABOUT LATENT VARIABLES FROM COMPLEX SAMPLES: THE CASE OF TWO-STAGE SAMPLING

In large-scale assessments, such as the National Assessment of Educational Progress (NAEP), plausible values based on Multiple Imputations (MI) have been used to estimate population characteristics for latent constructs under complex sample designs. Mislevy (1991) derived a closed-form analytic solution for a fixed-effect model in creating plausible values assuming a classical test theory model and a stratified student sample and proposed an analogous solution for a random-effects model to be applied with a two-stage student sample design. The research reported here extends the discussion of this random-effects model under the classical test theory framework. Under the simplified assumption of known population parameters, analytical solutions are provided for multiple imputations in the case of the classical test theory measurement model and two-stage sampling and their properties are verified in reconstructing population properties for the unobservable latent variables. With the more practical assumptions of unknown population and cluster means, this study empirically examines the reconstruction of population attributes. Next, properties of sample statistics are examined. Specifically, this research explores the impact of the variance components and sample sizes on the sampling variance of the MI-based estimate for the population mean. Findings include significant predictors and influential factors. Last, the relationships between the sampling variance of the estimate of the population mean based on the imputations and those based on observations of the true score and the observed score are discussed. The sampling variance based on the imputed score is expected to be the higher boundary of that based on the observed score, which is expected to be the higher boundary of that based on the true score

Buddhism and Adolescent Alcohol Use in Thailand

A sample of 2019 Thai secondary school students in grades equivalent to U.S. 10 through 12 completed a 43-item alcohol expectancy questionnaire in June 2000. Factor analysis revealed four factors: (a) positive expectancies, (b) negative expectancies, (c) sex and power expectancies, and (d) religious expectancies. Practicing Buddhists were less likely to drink than nonpracticing Buddhists and had fewer positive and more negative expectancies about alcohol. Among students who did drink, Buddhist beliefs did not appear to influence whether or not they were binge drinkers. Buddhist beliefs may influence decisions to drink but not decisions related to drinking patterns

Buddhism and Adolescent Alcohol Use in Thailand

A sample of 2019 Thai secondary school students in grades equivalent to U.S. 10 through 12 completed a 43-item alcohol expectancy questionnaire in June 2000. Factor analysis revealed four factors: (a) positive expectancies, (b) negative expectancies, (c) sex and power expectancies, and (d) religious expectancies. Practicing Buddhists were less likely to drink than nonpracticing Buddhists and had fewer positive and more negative expectancies about alcohol. Among students who did drink, Buddhist beliefs did not appear to influence whether or not they were binge drinkers. Buddhist beliefs may influence decisions to drink but not decisions related to drinking patterns

Genomic data for 78 chickens from 14 populations

Background: Since the domestication of the red jungle fowls (Gallus gallus; dating back to~10 000 B.P.) in Asia, domestic chickens (Gallus gallus domesticus) have been subjected to the combined effects of natural selection and human-driven artificial selection; this has resulted in marked phenotypic diversity in a number of traits, including behavior, body composition, egg production, and skin color. Population genomic variations through diversifying selection have not been fully investigated. Findings: The whole genomes of 78 domestic chickens were sequenced to an average of 18-fold coverage for each bird. By combining this data with publicly available genomes of five wild red jungle fowls and eight Xishuangbanna game fowls, we conducted a comprehensive comparative genomics analysis of 91 chickens from 17 populations. After aligning ~21.30 gigabases (Gb) of high-quality data from each individual to the reference chicken genome, we identified ~6.44 million (M) single nucleotide polymorphisms (SNPs) for each population. These SNPs included 1.10 M novel SNPs in 17 populations that were absent in the current chicken dbSNP (Build 145) entries. Conclusions: The current data is important for population genetics and further studies in chickens and will serve as a valuable resource for investigating diversifying selection and candidate genes for selective breeding in chickens.Peer reviewedAnimal Scienc

Comparative transcriptomics of 5 high-altitude vertebrates and their low-altitude relatives

Abstract Background: Species living at high altitude are subject to strong selective pressures due to inhospitable environments (e.g., hypoxia, low temperature, high solar radiation, and lack of biological production), making these species valuable models for comparative analyses of local adaptation. Studies that have examined high-altitude adaptation have identified a vast array of rapidly evolving genes that characterize the dramatic phenotypic changes in high-altitude animals. However, how high-altitude environment shapes gene expression programs remains largely unknown. Findings: We generated a total of 910 Gb of high-quality RNA-seq data for 180 samples derived from 6 tissues of 5 agriculturally important high-altitude vertebrates (Tibetan chicken, Tibetan pig, Tibetan sheep, Tibetan goat, and yak) and their cross-fertile relatives living in geographically neighboring low-altitude regions. Of these, ∼75% reads could be aligned to their respective reference genomes, and on average ∼60% of annotated protein coding genes in each organism showed FPKM expression values greater than 0.5. We observed a general concordance in topological relationships between the nucleotide alignments and gene expression–based trees. Tissue and species accounted for markedly more variance than altitude based on either the expression or the alternative splicing patterns. Cross-species clustering analyses showed a tissue-dominated pattern of gene expression and a species-dominated pattern for alternative splicing. We also identified numerous differentially expressed genes that could potentially be involved in phenotypic divergence shaped by high-altitude adaptation. Conclusions: These data serve as a valuable resource for examining the convergence and divergence of gene expression changes between species as they adapt or acclimatize to high-altitude environments

Differential roles of nitric oxide synthase isozymes in cardiotoxicity and mortality following chronic doxorubicin treatment in mice

The roles of individual nitric oxide synthases (NOS) in anthracycline-related cardiotoxicity are not completely understood. We investigated the effects of a chronic treatment with doxorubicin (DOX) on knockouts of the individual NOS isozymes and on transgenic mice with myocardial overexpression of eNOS. Fractional shortening (FS) was reduced in untreated homozygous nNOS and iNOS knockouts as well as in eNOS transgenics. DOX-induced FS decrease in wild-type mice was attenuated only in eNOS knockouts, which were found to overexpress nNOS. No worsening of contractility was observed in DOX-treated eNOS transgenics and iNOS knockouts. Although the surviving DOX-treated nNOS knockouts exhibited no further impairment in contractility, most (70%) animals died within 7 weeks after treatment onset. In comparison to untreated wild-type hearts, the nitric oxide (NO) level was lower in hearts from DOX-treated wild-type mice and in all three untreated knockouts. DOX treatment had no effect on NO in the knockouts. These data indicate differential roles of the individual NOS in DOX-induced cardiotoxicity. Protection against DOX effects conferred by eNOS deletion may be mediated by a compensatory overexpression of nNOS. NOS inhibition-based prevention of anthracycline-induced cardiotoxicity should be eNOS-selective, simultaneously avoiding inhibiting nNOS

Alcohol Expectancies among a Sample of Thai High School Students

The objective of this study was to identify and describe the alcohol-related expectancies of a sample of Thai high school students. A convenience sample of 2,227 high school students in Chon Buri province completed an alcohol expectancy questionnaire. The initial factor analysis was done with data from 875 questionnaires and identified four factors. The four factors were cross-validated on two separate sets of 676 questionnaires. A relationship was found between expectancies and drinking behaviors. High school students who drank alcohol had significantly greater positive expectancies for alcohol and greater expectancies that alcohol would enhance sexual performance and power. Students who did not drink had significantly greater negative expectancies for alcohol and a greater expectancy that Buddhism viewed alcohol use negatively. Frequent drinkers and students who drank alcohol in large quantities had significantly greater positive expectancies for alcohol and were more likely to believe that alcohol enhanced sex and power than infrequent drinkers and students who drank smaller quantities of alcohol. The alcohol expectancies found in this sample of Thai high school students were similar to alcohol expectancies found for adolescents in the USA, with the exception of the expectancy regarding Buddhism