WorldWideScience

Sample records for two-locus epistasis tests

  1. Further investigations of the W-test for pairwise epistasis testing [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Richard Howey

    2017-07-01

    Full Text Available Background: In a recent paper, a novel W-test for pairwise epistasis testing was proposed that appeared, in computer simulations, to have higher power than competing alternatives. Application to genome-wide bipolar data detected significant epistasis between SNPs in genes of relevant biological function. Network analysis indicated that the implicated genes formed two separate interaction networks, each containing genes highly related to autism and neurodegenerative disorders. Methods: Here we investigate further the properties and performance of the W-test via theoretical evaluation, computer simulations and application to real data. Results: We demonstrate that, for common variants, the W-test is closely related to several existing tests of association allowing for interaction, including logistic regression on 8 degrees of freedom, although logistic regression can show inflated type I error for low minor allele frequencies,  whereas the W-test shows good/conservative type I error control. Although in some situations the W-test can show higher power, logistic regression is not limited to tests on 8 degrees of freedom but can instead be taylored to impose greater structure on the assumed alternative hypothesis, offering a power advantage when the imposed structure matches the true structure. Conclusions: The W-test is a potentially useful method for testing for association - without necessarily implying interaction - between genetic variants disease, particularly when one or more of the genetic variants are rare. For common variants, the advantages of the W-test are less clear, and, indeed, there are situations where existing methods perform better. In our investigations, we further uncover a number of problems with the practical implementation and application of the W-test (to bipolar disorder previously described, apparently due to inadequate use of standard data quality-control procedures. This observation leads us to urge caution in

  2. Genome-wide survey in African Americans demonstrates potential epistasis of fitness in the human genome.

    Science.gov (United States)

    Wang, Heming; Choi, Yoonha; Tayo, Bamidele; Wang, Xuefeng; Morris, Nathan; Zhang, Xiang; Broeckel, Uli; Hanis, Craig; Kardia, Sharon; Redline, Susan; Cooper, Richard S; Tang, Hua; Zhu, Xiaofeng

    2017-02-01

    The role played by epistasis between alleles at unlinked loci in shaping population fitness has been debated for many years and the existing evidence has been mainly accumulated from model organisms. In model organisms, fitness epistasis can be systematically inferred by detecting nonindependence of genotypic values between loci in a population and confirmed through examining the number of offspring produced in two-locus genotype groups. No systematic study has been conducted to detect epistasis of fitness in humans owing to experimental constraints. In this study, we developed a novel method to detect fitness epistasis by testing the correlation between local ancestries on different chromosomes in an admixed population. We inferred local ancestry across the genome in 16,252 unrelated African Americans and systematically examined the pairwise correlations between the genomic regions on different chromosomes. Our analysis revealed a pair of genomic regions on chromosomes 4 and 6 that show significant local ancestry correlation (P-value = 4.01 × 10 -8 ) that can be potentially attributed to fitness epistasis. However, we also observed substantial local ancestry correlation that cannot be explained by systemic ancestry inference bias. To our knowledge, this study is the first to systematically examine evidence of fitness epistasis across the human genome. © 2016 WILEY PERIODICALS, INC.

  3. Sign epistasis caused by hierarchy within signalling cascades

    NARCIS (Netherlands)

    Nghe, Philippe; Kogenaru, Manjunatha; Tans, S.J.

    2018-01-01

    Sign epistasis is a central evolutionary constraint, but its causal factors remain difficult to predict. Here we use the notion of parameterised optima to explain epistasis within a signalling cascade, and test these predictions in Escherichia coli. We show that sign epistasis arises from the

  4. Fixation Probability in a Two-Locus Model by the Ancestral Recombination–Selection Graph

    Science.gov (United States)

    Lessard, Sabin; Kermany, Amir R.

    2012-01-01

    We use the ancestral influence graph (AIG) for a two-locus, two-allele selection model in the limit of a large population size to obtain an analytic approximation for the probability of ultimate fixation of a single mutant allele A. We assume that this new mutant is introduced at a given locus into a finite population in which a previous mutant allele B is already segregating with a wild type at another linked locus. We deduce that the fixation probability increases as the recombination rate increases if allele A is either in positive epistatic interaction with B and allele B is beneficial or in no epistatic interaction with B and then allele A itself is beneficial. This holds at least as long as the recombination fraction and the selection intensity are small enough and the population size is large enough. In particular this confirms the Hill–Robertson effect, which predicts that recombination renders more likely the ultimate fixation of beneficial mutants at different loci in a population in the presence of random genetic drift even in the absence of epistasis. More importantly, we show that this is true from weak negative epistasis to positive epistasis, at least under weak selection. In the case of deleterious mutants, the fixation probability decreases as the recombination rate increases. This supports Muller’s ratchet mechanism to explain the accumulation of deleterious mutants in a population lacking recombination. PMID:22095080

  5. Estimating directional epistasis

    Science.gov (United States)

    Le Rouzic, Arnaud

    2014-01-01

    Epistasis, i.e., the fact that gene effects depend on the genetic background, is a direct consequence of the complexity of genetic architectures. Despite this, most of the models used in evolutionary and quantitative genetics pay scant attention to genetic interactions. For instance, the traditional decomposition of genetic effects models epistasis as noise around the evolutionarily-relevant additive effects. Such an approach is only valid if it is assumed that there is no general pattern among interactions—a highly speculative scenario. Systematic interactions generate directional epistasis, which has major evolutionary consequences. In spite of its importance, directional epistasis is rarely measured or reported by quantitative geneticists, not only because its relevance is generally ignored, but also due to the lack of simple, operational, and accessible methods for its estimation. This paper describes conceptual and statistical tools that can be used to estimate directional epistasis from various kinds of data, including QTL mapping results, phenotype measurements in mutants, and artificial selection responses. As an illustration, I measured directional epistasis from a real-life example. I then discuss the interpretation of the estimates, showing how they can be used to draw meaningful biological inferences. PMID:25071828

  6. Sign epistasis caused by hierarchy within signalling cascades.

    Science.gov (United States)

    Nghe, Philippe; Kogenaru, Manjunatha; Tans, Sander J

    2018-04-13

    Sign epistasis is a central evolutionary constraint, but its causal factors remain difficult to predict. Here we use the notion of parameterised optima to explain epistasis within a signalling cascade, and test these predictions in Escherichia coli. We show that sign epistasis arises from the benefit of tuning phenotypic parameters of cascade genes with respect to each other, rather than from their complex and incompletely known genetic bases. Specifically, sign epistasis requires only that the optimal phenotypic parameters of one gene depend on the phenotypic parameters of another, independent of other details, such as activating or repressing nature, position within the cascade, intra-genic pleiotropy or genotype. Mutational effects change sign more readily in downstream genes, indicating that optimising downstream genes is more constrained. The findings show that sign epistasis results from the inherent upstream-downstream hierarchy between signalling cascade genes, and can be addressed without exhaustive genotypic mapping.

  7. Inferring Demographic History Using Two-Locus Statistics.

    Science.gov (United States)

    Ragsdale, Aaron P; Gutenkunst, Ryan N

    2017-06-01

    Population demographic history may be learned from contemporary genetic variation data. Methods based on aggregating the statistics of many single loci into an allele frequency spectrum (AFS) have proven powerful, but such methods ignore potentially informative patterns of linkage disequilibrium (LD) between neighboring loci. To leverage such patterns, we developed a composite-likelihood framework for inferring demographic history from aggregated statistics of pairs of loci. Using this framework, we show that two-locus statistics are more sensitive to demographic history than single-locus statistics such as the AFS. In particular, two-locus statistics escape the notorious confounding of depth and duration of a bottleneck, and they provide a means to estimate effective population size based on the recombination rather than mutation rate. We applied our approach to a Zambian population of Drosophila melanogaster Notably, using both single- and two-locus statistics, we inferred a substantially lower ancestral effective population size than previous works and did not infer a bottleneck history. Together, our results demonstrate the broad potential for two-locus statistics to enable powerful population genetic inference. Copyright © 2017 by the Genetics Society of America.

  8. Replication and explorations of high-order epistasis using a large advanced intercross line pedigree.

    Directory of Open Access Journals (Sweden)

    Mats Pettersson

    2011-07-01

    Full Text Available Dissection of the genetic architecture of complex traits persists as a major challenge in biology; despite considerable efforts, much remains unclear including the role and importance of genetic interactions. This study provides empirical evidence for a strong and persistent contribution of both second- and third-order epistatic interactions to long-term selection response for body weight in two divergently selected chicken lines. We earlier reported a network of interacting loci with large effects on body weight in an F(2 intercross between these high- and low-body weight lines. Here, most pair-wise interactions in the network are replicated in an independent eight-generation advanced intercross line (AIL. The original report showed an important contribution of capacitating epistasis to growth, meaning that the genotype at a hub in the network releases the effects of one or several peripheral loci. After fine-mapping of the loci in the AIL, we show that these interactions were persistent over time. The replication of five of six originally reported epistatic loci, as well as the capacitating epistasis, provides strong empirical evidence that the originally observed epistasis is of biological importance and is a contributor in the genetic architecture of this population. The stability of genetic interaction mechanisms over time indicates a non-transient role of epistasis on phenotypic change. Third-order epistasis was for the first time examined in this study and was shown to make an important contribution to growth, which suggests that the genetic architecture of growth is more complex than can be explained by two-locus interactions only. Our results illustrate the importance of designing studies that facilitate exploration of epistasis in populations for obtaining a comprehensive understanding of the genetics underlying a complex trait.

  9. Two-locus linkage analysis in multiple sclerosis (MS)

    Energy Technology Data Exchange (ETDEWEB)

    Tienari, P.J. (National Public Health Institute, Helsinki (Finland) Univ. of Helsinki (Finland)); Terwilliger, J.D.; Ott, J. (Columbia Univ., New York (United States)); Palo, J. (Univ. of Helsinki (Finland)); Peltonen, L. (National Public Health Institute, Helsinki (Finland))

    1994-01-15

    One of the major challenges in genetic linkage analyses is the study of complex diseases. The authors demonstrate here the use of two-locus linkage analysis in multiple sclerosis (MS), a multifactorial disease with a complex mode of inheritance. In a set of Finnish multiplex families, they have previously found evidence for linkage between MS susceptibility and two independent loci, the myelin basic protein gene (MBP) on chromosome 18 and the HLA complex on chromosome 6. This set of families provides a unique opportunity to perform linkage analysis conditional on two loci contributing to the disease. In the two-trait-locus/two-marker-locus analysis, the presence of another disease locus is parametrized and the analysis more appropriately treats information from the unaffected family member than single-disease-locus analysis. As exemplified here in MS, the two-locus analysis can be a powerful method for investigating susceptibility loci in complex traits, best suited for analysis of specific candidate genes, or for situations in which preliminary evidence for linkage already exists or is suggested. 41 refs., 6 tabs.

  10. Epistasis analysis using artificial intelligence.

    Science.gov (United States)

    Moore, Jason H; Hill, Doug P

    2015-01-01

    Here we introduce artificial intelligence (AI) methodology for detecting and characterizing epistasis in genetic association studies. The ultimate goal of our AI strategy is to analyze genome-wide genetics data as a human would using sources of expert knowledge as a guide. The methodology presented here is based on computational evolution, which is a type of genetic programming. The ability to generate interesting solutions while at the same time learning how to solve the problem at hand distinguishes computational evolution from other genetic programming approaches. We provide a general overview of this approach and then present a few examples of its application to real data.

  11. Fixation probability in a two-locus intersexual selection model.

    Science.gov (United States)

    Durand, Guillermo; Lessard, Sabin

    2016-06-01

    We study a two-locus model of intersexual selection in a finite haploid population reproducing according to a discrete-time Moran model with a trait locus expressed in males and a preference locus expressed in females. We show that the probability of ultimate fixation of a single mutant allele for a male ornament introduced at random at the trait locus given any initial frequency state at the preference locus is increased by weak intersexual selection and recombination, weak or strong. Moreover, this probability exceeds the initial frequency of the mutant allele even in the case of a costly male ornament if intersexual selection is not too weak. On the other hand, the probability of ultimate fixation of a single mutant allele for a female preference towards a male ornament introduced at random at the preference locus is increased by weak intersexual selection and weak recombination if the female preference is not costly, and is strong enough in the case of a costly male ornament. The analysis relies on an extension of the ancestral recombination-selection graph for samples of haplotypes to take into account events of intersexual selection, while the symbolic calculation of the fixation probabilities is made possible in a reasonable time by an optimizing algorithm. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Epistasis × environment interactions among Arabidopsis thaliana glucosinolate genes impact complex traits and fitness in the field.

    Science.gov (United States)

    Kerwin, Rachel E; Feusier, Julie; Muok, Alise; Lin, Catherine; Larson, Brandon; Copeland, Daniel; Corwin, Jason A; Rubin, Matthew J; Francisco, Marta; Li, Baohua; Joseph, Bindu; Weinig, Cynthia; Kliebenstein, Daniel J

    2017-08-01

    Despite the growing number of studies showing that genotype × environment and epistatic interactions control fitness, the influences of epistasis × environment interactions on adaptive trait evolution remain largely uncharacterized. Across three field trials, we quantified aliphatic glucosinolate (GSL) defense chemistry, leaf damage, and relative fitness using mutant lines of Arabidopsis thaliana varying at pairs of causal aliphatic GSL defense genes to test the impact of epistatic and epistasis × environment interactions on adaptive trait variation. We found that aliphatic GSL accumulation was primarily influenced by additive and epistatic genetic variation, leaf damage was primarily influenced by environmental variation and relative fitness was primarily influenced by epistasis and epistasis × environment interactions. Epistasis × environment interactions accounted for up to 48% of the relative fitness variation in the field. At a single field site, the impact of epistasis on relative fitness varied significantly over 2 yr, showing that epistasis × environment interactions within a location can be temporally dynamic. These results suggest that the environmental dependency of epistasis can profoundly influence the response to selection, shaping the adaptive trajectories of natural populations in complex ways, and deserves further consideration in future evolutionary studies. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  13. Conclusion of LOD-score analysis for family data generated under two-locus models.

    Science.gov (United States)

    Dizier, M H; Babron, M C; Clerget-Darpoux, F

    1996-06-01

    The power to detect linkage by the LOD-score method is investigated here for diseases that depend on the effects of two genes. The classical strategy is, first, to detect a major-gene (MG) effect by segregation analysis and, second, to seek for linkage with genetic markers by the LOD-score method using the MG parameters. We already showed that segregation analysis can lead to evidence for a MG effect for many two-locus models, with the estimates of the MG parameters being very different from those of the two genes involved in the disease. We show here that use of these MG parameter estimates in the LOD-score analysis may lead to a failure to detect linkage for some two-locus models. For these models, use of the sib-pair method gives a non-negligible increase of power to detect linkage. The linkage-homogeneity test among subsamples differing for the familial disease distribution provides evidence of parameter misspecification, when the MG parameters are used. Moreover, for most of the models, use of the MG parameters in LOD-score analysis leads to a large bias in estimation of the recombination fraction and sometimes also to a rejection of linkage for the true recombination fraction. A final important point is that a strong evidence of an MG effect, obtained by segregation analysis, does not necessarily imply that linkage will be detected for at least one of the two genes, even with the true parameters and with a close informative marker.

  14. Conclusions of LOD-score analysis for family data generated under two-locus models

    Energy Technology Data Exchange (ETDEWEB)

    Dizier, M.H.; Babron, M.C.; Clergt-Darpoux, F. [Unite de Recherches d`Epidemiologie Genetique, Paris (France)

    1996-06-01

    The power to detect linkage by the LOD-score method is investigated here for diseases that depend on the effects of two genes. The classical strategy is, first, to detect a major-gene (MG) effect by segregation analysis and, second, to seek for linkage with genetic markers by the LOD-score method using the MG parameters. We already showed that segregation analysis can lead to evidence for a MG effect for many two-locus models, with the estimates of the MG parameters being very different from those of the two genes involved in the disease. We show here that use of these MG parameter estimates in the LOD-score analysis may lead to a failure to detect linkage for some two-locus models. For these models, use of the sib-pair method gives a non-negligible increase of power to detect linkage. The linkage-homogeneity test among subsamples differing for the familial disease distribution provides evidence of parameter misspecification, when the MG parameters are used. Moreover, for most of the models, use of the MG parameters in LOD-score analysis leads to a large bias in estimation of the recombination fraction and sometimes also to a rejection of linkage for the true recombination fraction. A final important point is that a strong evidence of an MG effect, obtained by segregation analysis, does not necessarily imply that linkage will be detected for at least one of the two genes, even with the true parameters and with a close informative marker. 17 refs., 3 tabs.

  15. The Red Queen lives: Epistasis between linked resistance loci.

    Science.gov (United States)

    Metzger, César M J A; Luijckx, Pepijn; Bento, Gilberto; Mariadassou, Mahendra; Ebert, Dieter

    2016-02-01

    A popular theory explaining the maintenance of genetic recombination (sex) is the Red Queen Theory. This theory revolves around the idea that time-lagged negative frequency-dependent selection by parasites favors rare host genotypes generated through recombination. Although the Red Queen has been studied for decades, one of its key assumptions has remained unsupported. The signature host-parasite specificity underlying the Red Queen, where infection depends on a match between host and parasite genotypes, relies on epistasis between linked resistance loci for which no empirical evidence exists. We performed 13 genetic crosses and tested over 7000 Daphnia magna genotypes for resistance to two strains of the bacterial pathogen Pasteuria ramosa. Results reveal the presence of strong epistasis between three closely linked resistance loci. One locus masks the expression of the other two, while these two interact to produce a single resistance phenotype. Changing a single allele on one of these interacting loci can reverse resistance against the tested parasites. Such a genetic mechanism is consistent with host and parasite specificity assumed by the Red Queen Theory. These results thus provide evidence for a fundamental assumption of this theory and provide a genetic basis for understanding the Red Queen dynamics in the Daphnia-Pasteuria system. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

  16. A survey about methods dedicated to epistasis detection

    Directory of Open Access Journals (Sweden)

    Clément eNiel

    2015-09-01

    Full Text Available During the past decade, findings of genome-wide association studies (GWAS improved our knowledge and understanding of disease genetics. To date, thousands of SNPs have been associated to diseases and other complex traits. Statistical analysis typically looks for association between a phenotype and a SNP taken individually via single-locus tests. However, geneticists admit this is an oversimplified approach to tackle the complexity of underlying biological mechanisms. Interaction between SNPs, namely epistasis, must be considered. Unfortunately, epistasis detection gives rise to analytic challenges since analyzing every SNP combination is at present impractical at a genome-wide scale. In this review, we will present the main strategies recently proposed to detect epistatic interactions, along with their operating principle. Some of these methods are exhaustive, such as multifactor dimensionality reduction, likelihood ratio-based tests or receiver operating characteristic curve analysis; some are non-exhaustive, such as machine learning techniques (random forests, Bayesian networks or combinatorial optimization approaches (ant colony optimization, computational evolution system.

  17. FHSA-SED: Two-Locus Model Detection for Genome-Wide Association Study with Harmony Search Algorithm.

    Directory of Open Access Journals (Sweden)

    Shouheng Tuo

    Full Text Available Two-locus model is a typical significant disease model to be identified in genome-wide association study (GWAS. Due to intensive computational burden and diversity of disease models, existing methods have drawbacks on low detection power, high computation cost, and preference for some types of disease models.In this study, two scoring functions (Bayesian network based K2-score and Gini-score are used for characterizing two SNP locus as a candidate model, the two criteria are adopted simultaneously for improving identification power and tackling the preference problem to disease models. Harmony search algorithm (HSA is improved for quickly finding the most likely candidate models among all two-locus models, in which a local search algorithm with two-dimensional tabu table is presented to avoid repeatedly evaluating some disease models that have strong marginal effect. Finally G-test statistic is used to further test the candidate models.We investigate our method named FHSA-SED on 82 simulated datasets and a real AMD dataset, and compare it with two typical methods (MACOED and CSE which have been developed recently based on swarm intelligent search algorithm. The results of simulation experiments indicate that our method outperforms the two compared algorithms in terms of detection power, computation time, evaluation times, sensitivity (TPR, specificity (SPC, positive predictive value (PPV and accuracy (ACC. Our method has identified two SNPs (rs3775652 and rs10511467 that may be also associated with disease in AMD dataset.

  18. A simple route to maximum-likelihood estimates of two-locus

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Genetics; Volume 94; Issue 3. A simple route to maximum-likelihood estimates of two-locus recombination fractions under inequality restrictions. Iain L. Macdonald Philasande Nkalashe. Research Note Volume 94 Issue 3 September 2015 pp 479-481 ...

  19. Epistasis × environment interactions among Arabidopsis thaliana glucosinolate genes impact complex traits and fitness in the field

    DEFF Research Database (Denmark)

    Kerwin, Rachel E.; Feusier, Julie; Muok, Alise

    2017-01-01

    (GSL) defense chemistry, leaf damage, and relative fitness using mutant lines of Arabidopsis thaliana varying at pairs of causal aliphatic GSL defense genes to test the impact of epistatic and epistasis × environment interactions on adaptive trait variation. We found that aliphatic GSL accumulation...

  20. Functional regression method for whole genome eQTL epistasis analysis with sequencing data.

    Science.gov (United States)

    Xu, Kelin; Jin, Li; Xiong, Momiao

    2017-05-18

    Epistasis plays an essential rule in understanding the regulation mechanisms and is an essential component of the genetic architecture of the gene expressions. However, interaction analysis of gene expressions remains fundamentally unexplored due to great computational challenges and data availability. Due to variation in splicing, transcription start sites, polyadenylation sites, post-transcriptional RNA editing across the entire gene, and transcription rates of the cells, RNA-seq measurements generate large expression variability and collectively create the observed position level read count curves. A single number for measuring gene expression which is widely used for microarray measured gene expression analysis is highly unlikely to sufficiently account for large expression variation across the gene. Simultaneously analyzing epistatic architecture using the RNA-seq and whole genome sequencing (WGS) data poses enormous challenges. We develop a nonlinear functional regression model (FRGM) with functional responses where the position-level read counts within a gene are taken as a function of genomic position, and functional predictors where genotype profiles are viewed as a function of genomic position, for epistasis analysis with RNA-seq data. Instead of testing the interaction of all possible pair-wises SNPs, the FRGM takes a gene as a basic unit for epistasis analysis, which tests for the interaction of all possible pairs of genes and use all the information that can be accessed to collectively test interaction between all possible pairs of SNPs within two genome regions. By large-scale simulations, we demonstrate that the proposed FRGM for epistasis analysis can achieve the correct type 1 error and has higher power to detect the interactions between genes than the existing methods. The proposed methods are applied to the RNA-seq and WGS data from the 1000 Genome Project. The numbers of pairs of significantly interacting genes after Bonferroni correction

  1. RATES OF FITNESS DECLINE AND REBOUND SUGGEST PERVASIVE EPISTASIS

    Science.gov (United States)

    Perfeito, L; Sousa, A; Bataillon, T; Gordo, I

    2014-01-01

    Unraveling the factors that determine the rate of adaptation is a major question in evolutionary biology. One key parameter is the effect of a new mutation on fitness, which invariably depends on the environment and genetic background. The fate of a mutation also depends on population size, which determines the amount of drift it will experience. Here, we manipulate both population size and genotype composition and follow adaptation of 23 distinct Escherichia coli genotypes. These have previously accumulated mutations under intense genetic drift and encompass a substantial fitness variation. A simple rule is uncovered: the net fitness change is negatively correlated with the fitness of the genotype in which new mutations appear—a signature of epistasis. We find that Fisher's geometrical model can account for the observed patterns of fitness change and infer the parameters of this model that best fit the data, using Approximate Bayesian Computation. We estimate a genomic mutation rate of 0.01 per generation for fitness altering mutations, albeit with a large confidence interval, a mean fitness effect of mutations of −0.01, and an effective number of traits nine in mutS− E. coli. This framework can be extended to confront a broader range of models with data and test different classes of fitness landscape models. PMID:24372601

  2. Polymorphism in the two-locus Levene model with nonepistatic directional selection.

    Science.gov (United States)

    Bürger, Reinhard

    2009-11-01

    For the Levene model with soft selection in two demes, the maintenance of polymorphism at two diallelic loci is studied. Selection is nonepistatic and dominance is intermediate. Thus, there is directional selection in every deme and at every locus. We assume that selection is in opposite directions in the two demes because otherwise no polymorphism is possible. If at one locus there is no dominance, then a complete analysis of the dynamical and equilibrium properties is performed. In particular, a simple necessary and sufficient condition for the existence of an internal equilibrium and sufficient conditions for global asymptotic stability are obtained. These results are extended to deme-independent degree of dominance at one locus. A perturbation analysis establishes structural stability within the full parameter space. In the absence of genotype-environment interaction, which requires deme-independent dominance at both loci, nongeneric equilibrium behavior occurs, and the introduction of arbitrarily small genotype-environment interaction changes the equilibrium structure and may destroy stable polymorphism. The volume of the parameter space for which a (stable) two-locus polymorphism is maintained is computed numerically. It is investigated how this volume depends on the strength of selection and on the dominance relations. If the favorable allele is (partially) dominant in its deme, more than 20% of all parameter combinations lead to a globally asymptotically stable, fully polymorphic equilibrium.

  3. A two-locus model of spatially varying stabilizing or directional selection on a quantitative trait.

    Science.gov (United States)

    Geroldinger, Ludwig; Bürger, Reinhard

    2014-06-01

    The consequences of spatially varying, stabilizing or directional selection on a quantitative trait in a subdivided population are studied. A deterministic two-locus two-deme model is employed to explore the effects of migration, the degree of divergent selection, and the genetic architecture, i.e., the recombination rate and ratio of locus effects, on the maintenance of genetic variation. The possible equilibrium configurations are determined as functions of the migration rate. They depend crucially on the strength of divergent selection and the genetic architecture. The maximum migration rates are investigated below which a stable fully polymorphic equilibrium or a stable single-locus polymorphism can exist. Under stabilizing selection, but with different optima in the demes, strong recombination may facilitate the maintenance of polymorphism. However usually, and in particular with directional selection in opposite direction, the critical migration rates are maximized by a concentrated genetic architecture, i.e., by a major locus and a tightly linked minor one. Thus, complementing previous work on the evolution of genetic architectures in subdivided populations subject to diversifying selection, it is shown that concentrated architectures may aid the maintenance of polymorphism. Conditions are obtained when this is the case. Finally, the dependence of the phenotypic variance, linkage disequilibrium, and various measures of local adaptation and differentiation on the parameters is elaborated. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  4. A two-locus DNA sequence database for typing plant and human pathogens within the Fusarium oxysporum species complex

    DEFF Research Database (Denmark)

    O'Donnell, Kerry; Gueidan, C; Sink, S

    2009-01-01

    We constructed a two-locus database, comprising partial translation elongation factor (EF-1alpha) gene sequences and nearly full-length sequences of the nuclear ribosomal intergenic spacer region (IGS rDNA) for 850 isolates spanning the phylogenetic breadth of the Fusarium oxysporum species compl...... of the IGS rDNA sequences may be non-orthologous. We also evaluated enniatin, fumonisin and moniliformin mycotoxin production in vitro within a phylogenetic framework....

  5. Epistasis can accelerate adaptive diversification in haploid asexual populations.

    Science.gov (United States)

    Griswold, Cortland K

    2015-03-07

    A fundamental goal of the biological sciences is to determine processes that facilitate the evolution of diversity. These processes can be separated into ecological, physiological, developmental and genetic. An ecological process that facilitates diversification is frequency-dependent selection caused by competition. Models of frequency-dependent adaptive diversification have generally assumed a genetic basis of phenotype that is non-epistatic. Here, we present a model that indicates diversification is accelerated by an epistatic basis of phenotype in combination with a competition model that invokes frequency-dependent selection. Our model makes use of a genealogical model of epistasis and insights into the effects of balancing selection on the genealogical structure of a population to understand how epistasis can facilitate diversification. The finding that epistasis facilitates diversification may be informative with respect to empirical results that indicate an epistatic basis of phenotype in experimental bacterial populations that experienced adaptive diversification. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  6. Accelerating epistasis analysis in human genetics with consumer graphics hardware

    Directory of Open Access Journals (Sweden)

    Cancare Fabio

    2009-07-01

    Full Text Available Abstract Background Human geneticists are now capable of measuring more than one million DNA sequence variations from across the human genome. The new challenge is to develop computationally feasible methods capable of analyzing these data for associations with common human disease, particularly in the context of epistasis. Epistasis describes the situation where multiple genes interact in a complex non-linear manner to determine an individual's disease risk and is thought to be ubiquitous for common diseases. Multifactor Dimensionality Reduction (MDR is an algorithm capable of detecting epistasis. An exhaustive analysis with MDR is often computationally expensive, particularly for high order interactions. This challenge has previously been met with parallel computation and expensive hardware. The option we examine here exploits commodity hardware designed for computer graphics. In modern computers Graphics Processing Units (GPUs have more memory bandwidth and computational capability than Central Processing Units (CPUs and are well suited to this problem. Advances in the video game industry have led to an economy of scale creating a situation where these powerful components are readily available at very low cost. Here we implement and evaluate the performance of the MDR algorithm on GPUs. Of primary interest are the time required for an epistasis analysis and the price to performance ratio of available solutions. Findings We found that using MDR on GPUs consistently increased performance per machine over both a feature rich Java software package and a C++ cluster implementation. The performance of a GPU workstation running a GPU implementation reduces computation time by a factor of 160 compared to an 8-core workstation running the Java implementation on CPUs. This GPU workstation performs similarly to 150 cores running an optimized C++ implementation on a Beowulf cluster. Furthermore this GPU system provides extremely cost effective

  7. Accelerating epistasis analysis in human genetics with consumer graphics hardware.

    Science.gov (United States)

    Sinnott-Armstrong, Nicholas A; Greene, Casey S; Cancare, Fabio; Moore, Jason H

    2009-07-24

    Human geneticists are now capable of measuring more than one million DNA sequence variations from across the human genome. The new challenge is to develop computationally feasible methods capable of analyzing these data for associations with common human disease, particularly in the context of epistasis. Epistasis describes the situation where multiple genes interact in a complex non-linear manner to determine an individual's disease risk and is thought to be ubiquitous for common diseases. Multifactor Dimensionality Reduction (MDR) is an algorithm capable of detecting epistasis. An exhaustive analysis with MDR is often computationally expensive, particularly for high order interactions. This challenge has previously been met with parallel computation and expensive hardware. The option we examine here exploits commodity hardware designed for computer graphics. In modern computers Graphics Processing Units (GPUs) have more memory bandwidth and computational capability than Central Processing Units (CPUs) and are well suited to this problem. Advances in the video game industry have led to an economy of scale creating a situation where these powerful components are readily available at very low cost. Here we implement and evaluate the performance of the MDR algorithm on GPUs. Of primary interest are the time required for an epistasis analysis and the price to performance ratio of available solutions. We found that using MDR on GPUs consistently increased performance per machine over both a feature rich Java software package and a C++ cluster implementation. The performance of a GPU workstation running a GPU implementation reduces computation time by a factor of 160 compared to an 8-core workstation running the Java implementation on CPUs. This GPU workstation performs similarly to 150 cores running an optimized C++ implementation on a Beowulf cluster. Furthermore this GPU system provides extremely cost effective performance while leaving the CPU available for other

  8. Maternal-Zygotic Epistasis and the Evolution of Genetic Diseases

    Directory of Open Access Journals (Sweden)

    Nicholas K. Priest

    2010-01-01

    Full Text Available Many birth defects and genetic diseases are expressed in individuals that do not carry the disease causing alleles. Genetic diseases observed in offspring can be caused by gene expression in mothers and by interactions between gene expression in mothers and offspring. It is not clear whether the underlying pattern of gene expression (maternal versus offspring affects the incidence of genetic disease. Here we develop a 2-locus population genetic model with epistatic interactions between a maternal gene and a zygotic gene to address this question. We show that maternal effect genes that affect disease susceptibility in offspring persist longer and at higher frequencies in a population than offspring genes with the same effects. We find that specific forms of maternal-zygotic epistasis can maintain disease causing alleles at high frequencies over a range of plausible values. Our findings suggest that the strength and form of epistasis and the underlying pattern of gene expression may greatly influence the prevalence of human genetic diseases.

  9. Simple genomes, complex interactions: Epistasis in RNA virus

    Science.gov (United States)

    Elena, Santiago F.; Solé, Ricard V.; Sardanyés, Josep

    2010-06-01

    Owed to their reduced size and low number of proteins encoded, RNA viruses and other subviral pathogens are often considered as being genetically too simple. However, this structural simplicity also creates the necessity for viral RNA sequences to encode for more than one protein and for proteins to carry out multiple functions, all together resulting in complex patterns of genetic interactions. In this work we will first review the experimental studies revealing that the architecture of viral genomes is dominated by antagonistic interactions among loci. Second, we will also review mathematical models and provide a description of computational tools for the study of RNA virus dynamics and evolution. As an application of these tools, we will finish this review article by analyzing a stochastic bit-string model of in silico virus replication. This model analyzes the interplay between epistasis and the mode of replication on determining the population load of deleterious mutations. The model suggests that, for a given mutation rate, the deleterious mutational load is always larger when epistasis is predominantly antagonistic than when synergism is the rule. However, the magnitude of this effect is larger if replication occurs geometrically than if it proceeds linearly.

  10. FAM-MDR: a flexible family-based multifactor dimensionality reduction technique to detect epistasis using related individuals.

    Directory of Open Access Journals (Sweden)

    Tom Cattaert

    Full Text Available We propose a novel multifactor dimensionality reduction method for epistasis detection in small or extended pedigrees, FAM-MDR. It combines features of the Genome-wide Rapid Association using Mixed Model And Regression approach (GRAMMAR with Model-Based MDR (MB-MDR. We focus on continuous traits, although the method is general and can be used for outcomes of any type, including binary and censored traits. When comparing FAM-MDR with Pedigree-based Generalized MDR (PGMDR, which is a generalization of Multifactor Dimensionality Reduction (MDR to continuous traits and related individuals, FAM-MDR was found to outperform PGMDR in terms of power, in most of the considered simulated scenarios. Additional simulations revealed that PGMDR does not appropriately deal with multiple testing and consequently gives rise to overly optimistic results. FAM-MDR adequately deals with multiple testing in epistasis screens and is in contrast rather conservative, by construction. Furthermore, simulations show that correcting for lower order (main effects is of utmost importance when claiming epistasis. As Type 2 Diabetes Mellitus (T2DM is a complex phenotype likely influenced by gene-gene interactions, we applied FAM-MDR to examine data on glucose area-under-the-curve (GAUC, an endophenotype of T2DM for which multiple independent genetic associations have been observed, in the Amish Family Diabetes Study (AFDS. This application reveals that FAM-MDR makes more efficient use of the available data than PGMDR and can deal with multi-generational pedigrees more easily. In conclusion, we have validated FAM-MDR and compared it to PGMDR, the current state-of-the-art MDR method for family data, using both simulations and a practical dataset. FAM-MDR is found to outperform PGMDR in that it handles the multiple testing issue more correctly, has increased power, and efficiently uses all available information.

  11. JBASE: Joint Bayesian Analysis of Subphenotypes and Epistasis.

    Science.gov (United States)

    Colak, Recep; Kim, TaeHyung; Kazan, Hilal; Oh, Yoomi; Cruz, Miguel; Valladares-Salgado, Adan; Peralta, Jesus; Escobedo, Jorge; Parra, Esteban J; Kim, Philip M; Goldenberg, Anna

    2016-01-15

    Rapid advances in genotyping and genome-wide association studies have enabled the discovery of many new genotype-phenotype associations at the resolution of individual markers. However, these associations explain only a small proportion of theoretically estimated heritability of most diseases. In this work, we propose an integrative mixture model called JBASE: joint Bayesian analysis of subphenotypes and epistasis. JBASE explores two major reasons of missing heritability: interactions between genetic variants, a phenomenon known as epistasis and phenotypic heterogeneity, addressed via subphenotyping. Our extensive simulations in a wide range of scenarios repeatedly demonstrate that JBASE can identify true underlying subphenotypes, including their associated variants and their interactions, with high precision. In the presence of phenotypic heterogeneity, JBASE has higher Power and lower Type 1 Error than five state-of-the-art approaches. We applied our method to a sample of individuals from Mexico with Type 2 diabetes and discovered two novel epistatic modules, including two loci each, that define two subphenotypes characterized by differences in body mass index and waist-to-hip ratio. We successfully replicated these subphenotypes and epistatic modules in an independent dataset from Mexico genotyped with a different platform. JBASE is implemented in C++, supported on Linux and is available at http://www.cs.toronto.edu/∼goldenberg/JBASE/jbase.tar.gz. The genotype data underlying this study are available upon approval by the ethics review board of the Medical Centre Siglo XXI. Please contact Dr Miguel Cruz at mcruzl@yahoo.com for assistance with the application. anna.goldenberg@utoronto.ca Supplementary data are available at Bioinformatics online. © The Author 2015. Published by Oxford University Press.

  12. Both Epistasis and Diversifying Selection Drive the Structural Evolution of the Ebola Virus Glycoprotein Mucin-Like Domain.

    Science.gov (United States)

    Ibeh, Neke; Nshogozabahizi, Jean Claude; Aris-Brosou, Stéphane

    2016-06-01

    Throughout the last 3 decades, Ebola virus (EBOV) outbreaks have been confined to isolated areas within Central Africa; however, the 2014 variant reached unprecedented transmission and mortality rates. While the outbreak was still under way, it was reported that the variant leading up to this outbreak evolved faster than previous EBOV variants, but evidence for diversifying selection was undetermined. Here, we test this selection hypothesis and show that while previous EBOV outbreaks were preceded by bursts of diversification, evidence for site-specific diversifying selection during the emergence of the 2014 EBOV clade is weak. However, we show strong evidence supporting an interplay between selection and correlated evolution (epistasis), particularly in the mucin-like domain (MLD) of the EBOV glycoprotein. By reconstructing ancestral structures of the MLD, we further propose a structural mechanism explaining how the substitutions that accumulated between 1918 and 1969 distorted the MLD, while more recent epistatic substitutions restored part of the structure, with the most recent substitution being adaptive. We suggest that it is this complex interplay between weak selection, epistasis, and structural constraints that has shaped the evolution of the 2014 EBOV variant. The role that selection plays in the emergence of viral epidemics remains debated, particularly in the context of the 2014 EBOV outbreak. Most critically, should such evidence exist, it is generally unclear how this relates to function and increased virulence. Here, we show that the viral lineage leading up to the 2014 outbreak underwent a complex interplay between selection and correlated evolution (epistasis) in a protein region that is critical for immune evasion. We then reconstructed the three-dimensional structure of this domain and showed that the initial mutations in this lineage deformed the structure, while subsequent mutations restored part of the structure. Along this mutational path, the

  13. Use of rbcL and trnL-F as a two-locus DNA barcode for identification of NW-European ferns: an ecological perspective

    NARCIS (Netherlands)

    Groot, de G.A.; During, H.J.; Maas, J.W.; Schneider, H.; Erkens, R.H.J.

    2011-01-01

    Although consensus has now been reached on a general two-locus DNA barcode for land plants, the selected combination of markers (rbcL + matK) is not applicable for ferns at the moment. Yet especially for ferns, DNA barcoding is potentially of great value since fern gametophytes—while playing an

  14. Direct and indirect genetic effects of sex-specific mitonuclear epistasis on reproductive ageing

    DEFF Research Database (Denmark)

    Immonen, Elina; Collet, Marie; Goenaga, Julieta

    2016-01-01

    Mitochondria are involved in ageing and their function requires coordinated action of both mitochondrial and nuclear genes. Epistasis between the two genomes can influence lifespan but whether this also holds for reproductive senescence is unclear. Maternal inheritance of mitochondria predicts sex...... to slower senescence relative to novel mitonuclear combinations. We found no evidence for mitonuclear coadaptation in males. Mitonuclear epistasis not only affected age-specific ejaculate weight, but also influenced male age-dependent indirect effects on traits expressed by their female partners (fecundity...... beetle Callosobruchus maculatus, using introgression lines harbouring distinct mitonuclear genotypes. Our results reveal both direct and indirect sex-specific effects of mitonuclear epistasis on reproductive ageing. Females harbouring coadapted mitonuclear genotypes showed higher lifetime fecundity due...

  15. Discovering epistasis in large scale genetic association studies by exploiting graphics cards.

    Science.gov (United States)

    Chen, Gary K; Guo, Yunfei

    2013-12-03

    Despite the enormous investments made in collecting DNA samples and generating germline variation data across thousands of individuals in modern genome-wide association studies (GWAS), progress has been frustratingly slow in explaining much of the heritability in common disease. Today's paradigm of testing independent hypotheses on each single nucleotide polymorphism (SNP) marker is unlikely to adequately reflect the complex biological processes in disease risk. Alternatively, modeling risk as an ensemble of SNPs that act in concert in a pathway, and/or interact non-additively on log risk for example, may be a more sensible way to approach gene mapping in modern studies. Implementing such analyzes genome-wide can quickly become intractable due to the fact that even modest size SNP panels on modern genotype arrays (500k markers) pose a combinatorial nightmare, require tens of billions of models to be tested for evidence of interaction. In this article, we provide an in-depth analysis of programs that have been developed to explicitly overcome these enormous computational barriers through the use of processors on graphics cards known as Graphics Processing Units (GPU). We include tutorials on GPU technology, which will convey why they are growing in appeal with today's numerical scientists. One obvious advantage is the impressive density of microprocessor cores that are available on only a single GPU. Whereas high end servers feature up to 24 Intel or AMD CPU cores, the latest GPU offerings from nVidia feature over 2600 cores. Each compute node may be outfitted with up to 4 GPU devices. Success on GPUs varies across problems. However, epistasis screens fare well due to the high degree of parallelism exposed in these problems. Papers that we review routinely report GPU speedups of over two orders of magnitude (>100x) over standard CPU implementations.

  16. Discovering epistasis in large scale genetic association studies by exploiting graphics cards

    Directory of Open Access Journals (Sweden)

    Gary K Chen

    2013-12-01

    Full Text Available Despite the enormous investments made in collecting DNA samples and generating germline variation data across thousands of individuals in modern genome wide association studies (GWAS, progress has been frustratingly slow in explaining much of the heritability in common disease. Today’s paradigm of testing independent hypotheses on each SNP marker is unlikely to adequately reflect the complex biological processes in disease risk. Alternatively, modeling risk as an ensemble of SNPs that act in concert in a pathway, and/or interact non-additively on log risk for example, may be a more sensible way to approach gene mapping in modern studies. Implementing such analyses genome-wide can quickly become intractable due to the fact that even modest size SNP panels on modern genotype arrays (500k markers pose a combinatorial nightmare, require tens of billions of models to be tested for evidence of interaction. In this article, we provide an in-depth analysis of programs that have been developed to explicitly overcome these enormous computational barriers through the use of processors on graphics cards known as Graphics Processing Units (GPU. We include tutorials on GPU technology, which will convey why they are growing in appeal with today’s numerical scientists. One obvious advantage is the impressive density of microprocessor cores that are available on only a single GPU. Whereas high end servers feature up to 24 Intel or AMD CPU cores, the latest GPU offerings from nVidia feature over 2,600 cores. Each compute node may be outfitted with up to 4 GPU devices. Success on GPUs varies across problems. However epistasis screens fare well due to the high degree of parallelism exposed in these problems. Papers that we review routinely report GPU speedups of over two orders of magnitude (>100x over standard CPU implementations.

  17. Evolution and polymorphism in the multilocus Levene model with no or weak epistasis.

    Science.gov (United States)

    Bürger, Reinhard

    2010-09-01

    Evolution and the maintenance of polymorphism under the multilocus Levene model with soft selection are studied. The number of loci and alleles, the number of demes, the linkage map, and the degree of dominance are arbitrary, but epistasis is absent or weak. We prove that, without epistasis and under mild, generic conditions, every trajectory converges to a stationary point in linkage equilibrium. Consequently, the equilibrium and stability structure can be determined by investigating the much simpler gene-frequency dynamics on the linkage-equilibrium manifold. For a haploid species an analogous result is shown. For weak epistasis, global convergence to quasi-linkage equilibrium is established. As an application, the maintenance of multilocus polymorphism is explored if the degree of dominance is intermediate at every locus and epistasis is absent or weak. If there are at least two demes, then arbitrarily many multiallelic loci can be maintained polymorphic at a globally asymptotically stable equilibrium. Because this holds for an open set of parameters, such equilibria are structurally stable. If the degree of dominance is not only intermediate but also deme independent, and loci are diallelic, an open set of parameters yielding an internal equilibrium exists only if the number of loci is strictly less than the number of demes. Otherwise, a fully polymorphic equilibrium exists only nongenerically, and if it exists, it consists of a manifold of equilibria. Its dimension is determined. In the absence of genotype-by-environment interaction, however, a manifold of equilibria occurs for an open set of parameters. In this case, the equilibrium structure is not robust to small deviations from no genotype-by-environment interaction. In a quantitative-genetic setting, the assumptions of no epistasis and intermediate dominance are equivalent to assuming that in every deme directional selection acts on a trait that is determined additively, i.e., by nonepistatic loci with

  18. Of Mice and Men: Empirical Support for the Population-Based Social Epistasis Amplification Model (a Comment on ).

    Science.gov (United States)

    Sarraf, Matthew Alexandar; Woodley Of Menie, Michael Anthony

    2017-01-01

    This commentary article offers new perspective on recent research investigating the behavioral and social ecological effects of a mutation related to autism spectrum disorders in mice. The authors explain the consistency of this research on mice with predictions advanced by a theory of the role of mutations in altering interorganismal gene-gene interactions (social epistasis) in social species including humans, known as the social epistasis amplification model. The potential significance of the mouse research for understanding contemporary human behavioral trends is explored.

  19. Nonparametric method for genomics-based prediction of performance of quantitative traits involving epistasis in plant breeding.

    Directory of Open Access Journals (Sweden)

    Xiaochun Sun

    Full Text Available Genomic selection (GS procedures have proven useful in estimating breeding value and predicting phenotype with genome-wide molecular marker information. However, issues of high dimensionality, multicollinearity, and the inability to deal effectively with epistasis can jeopardize accuracy and predictive ability. We, therefore, propose a new nonparametric method, pRKHS, which combines the features of supervised principal component analysis (SPCA and reproducing kernel Hilbert spaces (RKHS regression, with versions for traits with no/low epistasis, pRKHS-NE, to high epistasis, pRKHS-E. Instead of assigning a specific relationship to represent the underlying epistasis, the method maps genotype to phenotype in a nonparametric way, thus requiring fewer genetic assumptions. SPCA decreases the number of markers needed for prediction by filtering out low-signal markers with the optimal marker set determined by cross-validation. Principal components are computed from reduced marker matrix (called supervised principal components, SPC and included in the smoothing spline ANOVA model as independent variables to fit the data. The new method was evaluated in comparison with current popular methods for practicing GS, specifically RR-BLUP, BayesA, BayesB, as well as a newer method by Crossa et al., RKHS-M, using both simulated and real data. Results demonstrate that pRKHS generally delivers greater predictive ability, particularly when epistasis impacts trait expression. Beyond prediction, the new method also facilitates inferences about the extent to which epistasis influences trait expression.

  20. Nonparametric method for genomics-based prediction of performance of quantitative traits involving epistasis in plant breeding.

    Science.gov (United States)

    Sun, Xiaochun; Ma, Ping; Mumm, Rita H

    2012-01-01

    Genomic selection (GS) procedures have proven useful in estimating breeding value and predicting phenotype with genome-wide molecular marker information. However, issues of high dimensionality, multicollinearity, and the inability to deal effectively with epistasis can jeopardize accuracy and predictive ability. We, therefore, propose a new nonparametric method, pRKHS, which combines the features of supervised principal component analysis (SPCA) and reproducing kernel Hilbert spaces (RKHS) regression, with versions for traits with no/low epistasis, pRKHS-NE, to high epistasis, pRKHS-E. Instead of assigning a specific relationship to represent the underlying epistasis, the method maps genotype to phenotype in a nonparametric way, thus requiring fewer genetic assumptions. SPCA decreases the number of markers needed for prediction by filtering out low-signal markers with the optimal marker set determined by cross-validation. Principal components are computed from reduced marker matrix (called supervised principal components, SPC) and included in the smoothing spline ANOVA model as independent variables to fit the data. The new method was evaluated in comparison with current popular methods for practicing GS, specifically RR-BLUP, BayesA, BayesB, as well as a newer method by Crossa et al., RKHS-M, using both simulated and real data. Results demonstrate that pRKHS generally delivers greater predictive ability, particularly when epistasis impacts trait expression. Beyond prediction, the new method also facilitates inferences about the extent to which epistasis influences trait expression.

  1. Estimation and interpretation of genetic effects with epistasis using the NOIA model.

    Science.gov (United States)

    Alvarez-Castro, José M; Carlborg, Orjan; Rönnegård, Lars

    2012-01-01

    We introduce this communication with a brief outline of the historical landmarks in genetic modeling, especially concerning epistasis. Then, we present methods for the use of genetic modeling in QTL analyses. In particular, we summarize the essential expressions of the natural and orthogonal interactions (NOIA) model of genetic effects. Our motivation for reviewing that theory here is twofold. First, this review presents a digest of the expressions for the application of the NOIA model, which are often mixed with intermediate and additional formulae in the original articles. Second, we make the required theory handy for the reader to relate the genetic concepts to the particular mathematical expressions underlying them. We illustrate those relations by providing graphical interpretations and a diagram summarizing the key features for applying genetic modeling with epistasis in comprehensive QTL analyses. Finally, we briefly review some examples of the application of NOIA to real data and the way it improves the interpretability of the results.

  2. What?s Downstream? A Set of Classroom Exercises to Help Students Understand Recessive Epistasis ?

    OpenAIRE

    Knight, Jennifer K.; Wood, William B.; Smith, Michelle K.

    2013-01-01

    Undergraduate students in genetics and developmental biology courses often struggle with the concept of epistasis because they are unaware that the logic of gene interactions differs between enzymatic pathways and signaling pathways. If students try to develop and memorize a single simple rule for predicting epistatic relationships without taking into account the nature of the pathway under consideration, they can become confused by cases where the rule does not apply. To remedy this problem,...

  3. Genecentric: a package to uncover graph-theoretic structure in high-throughput epistasis data

    OpenAIRE

    Gallant, Andrew; Leiserson, Mark DM; Kachalov, Maxim; Cowen, Lenore J; Hescott, Benjamin J

    2013-01-01

    Background New technology has resulted in high-throughput screens for pairwise genetic interactions in yeast and other model organisms. For each pair in a collection of non-essential genes, an epistasis score is obtained, representing how much sicker (or healthier) the double-knockout organism will be compared to what would be expected from the sickness of the component single knockouts. Recent algorithmic work has identified graph-theoretic patterns in this data that can indicate functional ...

  4. Translational regulation of ribosomal protein S15 drives characteristic patterns of protein-mRNA epistasis.

    Science.gov (United States)

    Mallik, Saurav; Basu, Sudipto; Hait, Suman; Kundu, Sudip

    2018-04-21

    Do coding and regulatory segments of a gene co-evolve with each-other? Seeking answers to this question, here we analyze the case of Escherichia coli ribosomal protein S15, that represses its own translation by specifically binding its messenger RNA (rpsO mRNA) and stabilizing a pseudoknot structure at the upstream untranslated region, thus trapping the ribosome into an incomplete translation initiation complex. In the absence of S15, ribosomal protein S1 recognizes rpsO and promotes translation by melting this very pseudoknot. We employ a robust statistical method to detect signatures of positive epistasis between residue site pairs and find that biophysical constraints of translational regulation (S15-rpsO and S1-rpsO recognition, S15-mediated rpsO structural rearrangement, and S1-mediated melting) are strong predictors of positive epistasis. Transforming the epistatic pairs into a network, we find that signatures of two different, but interconnected regulatory cascades are imprinted in the sequence-space and can be captured in terms of two dense network modules that are sparsely connected to each other. This network topology further reflects a general principle of how functionally coupled components of biological networks are interconnected. These results depict a model case, where translational regulation drives characteristic residue-level epistasis-not only between a protein and its own mRNA but also between a protein and the mRNA of an entirely different protein. © 2018 Wiley Periodicals, Inc.

  5. Compensatory mutations cause excess of antagonistic epistasis in RNA secondary structure folding

    Directory of Open Access Journals (Sweden)

    Adami Christoph

    2003-02-01

    Full Text Available Background The rate at which fitness declines as an organism's genome accumulates random mutations is an important variable in several evolutionary theories. At an intuitive level, it might seem natural that random mutations should tend to interact synergistically, such that the rate of mean fitness decline accelerates as the number of random mutations is increased. However, in a number of recent studies, a prevalence of antagonistic epistasis (the tendency of multiple mutations to have a mitigating rather than reinforcing effect has been observed. Results We studied in silico the net amount and form of epistatic interactions in RNA secondary structure folding by measuring the fraction of neutral mutants as a function of mutational distance d. We found a clear prevalence of antagonistic epistasis in RNA secondary structure folding. By relating the fraction of neutral mutants at distance d to the average neutrality at distance d, we showed that this prevalence derives from the existence of many compensatory mutations at larger mutational distances. Conclusions Our findings imply that the average direction of epistasis in simple fitness landscapes is directly related to the density with which fitness peaks are distributed in these landscapes.

  6. Compensatory mutations cause excess of antagonistic epistasis in RNA secondary structure folding.

    Science.gov (United States)

    Wilke, Claus O; Lenski, Richard E; Adami, Christoph

    2003-02-05

    The rate at which fitness declines as an organism's genome accumulates random mutations is an important variable in several evolutionary theories. At an intuitive level, it might seem natural that random mutations should tend to interact synergistically, such that the rate of mean fitness decline accelerates as the number of random mutations is increased. However, in a number of recent studies, a prevalence of antagonistic epistasis (the tendency of multiple mutations to have a mitigating rather than reinforcing effect) has been observed. We studied in silico the net amount and form of epistatic interactions in RNA secondary structure folding by measuring the fraction of neutral mutants as a function of mutational distance d. We found a clear prevalence of antagonistic epistasis in RNA secondary structure folding. By relating the fraction of neutral mutants at distance d to the average neutrality at distance d, we showed that this prevalence derives from the existence of many compensatory mutations at larger mutational distances. Our findings imply that the average direction of epistasis in simple fitness landscapes is directly related to the density with which fitness peaks are distributed in these landscapes.

  7. What’s Downstream? A Set of Classroom Exercises to Help Students Understand Recessive Epistasis

    Directory of Open Access Journals (Sweden)

    Jennifer K. Knight

    2013-08-01

    Full Text Available Undergraduate students in genetics and developmental biology courses often struggle with the concept of epistasis because they are unaware that the logic of gene interactions differs between enzymatic pathways and signaling pathways. If students try to develop and memorize a single simple rule for predicting epistatic relationships without taking into account the nature of the pathway under consideration, they can become confused by cases where the rule does not apply. To remedy this problem, we developed a short pre-/posttest, an in-class activity for small groups, and a series of clicker questions about recessive epistasis in the context of a signaling pathway that intersects with an enzymatic pathway. We also developed a series of homework problems that provide deliberate practice in applying concepts in epistasis to different pathways and experimental situations. Students show significant improvement from pretest to posttest, and perform well on homework and exam questions following this activity. Here we describe these materials, as well as the formative and summative assessment results from one group of students to show how the activities impact student learning.

  8. Reciprocal sign epistasis between frequently experimentally evolved adaptive mutations causes a rugged fitness landscape.

    Directory of Open Access Journals (Sweden)

    Daniel J Kvitek

    2011-04-01

    Full Text Available The fitness landscape captures the relationship between genotype and evolutionary fitness and is a pervasive metaphor used to describe the possible evolutionary trajectories of adaptation. However, little is known about the actual shape of fitness landscapes, including whether valleys of low fitness create local fitness optima, acting as barriers to adaptive change. Here we provide evidence of a rugged molecular fitness landscape arising during an evolution experiment in an asexual population of Saccharomyces cerevisiae. We identify the mutations that arose during the evolution using whole-genome sequencing and use competitive fitness assays to describe the mutations individually responsible for adaptation. In addition, we find that a fitness valley between two adaptive mutations in the genes MTH1 and HXT6/HXT7 is caused by reciprocal sign epistasis, where the fitness cost of the double mutant prohibits the two mutations from being selected in the same genetic background. The constraint enforced by reciprocal sign epistasis causes the mutations to remain mutually exclusive during the experiment, even though adaptive mutations in these two genes occur several times in independent lineages during the experiment. Our results show that epistasis plays a key role during adaptation and that inter-genic interactions can act as barriers between adaptive solutions. These results also provide a new interpretation on the classic Dobzhansky-Muller model of reproductive isolation and display some surprising parallels with mutations in genes often associated with tumors.

  9. The Integration of Epistasis Network and Functional Interactions in a GWAS Implicates RXR Pathway Genes in the Immune Response to Smallpox Vaccine.

    Directory of Open Access Journals (Sweden)

    Brett A McKinney

    Full Text Available Although many diseases and traits show large heritability, few genetic variants have been found to strongly separate phenotype groups by genotype. Complex regulatory networks of variants and expression of multiple genes lead to small individual-variant effects and difficulty replicating the effect of any single variant in an affected pathway. Interaction network modeling of GWAS identifies effects ignored by univariate models, but population differences may still cause specific genes to not replicate. Integrative network models may help detect indirect effects of variants in the underlying biological pathway. In this study, we used gene-level functional interaction information from the Integrative Multi-species Prediction (IMP tool to reveal important genes associated with a complex phenotype through evidence from epistasis networks and pathway enrichment. We test this method for augmenting variant-based network analyses with functional interactions by applying it to a smallpox vaccine immune response GWAS. The integrative analysis spotlights the role of genes related to retinoid X receptor alpha (RXRA, which has been implicated in a previous epistasis network analysis of smallpox vaccine.

  10. Mapping epistasis and environment × QTX interaction based on four -omics genotypes for the detected QTX loci controlling complex traits in tobacco

    Directory of Open Access Journals (Sweden)

    Liyuan Zhou

    2013-12-01

    Full Text Available Using newly developed methods and software, association mapping was conducted for chromium content and total sugar in tobacco leaf, based on four -omics datasets. Our objective was to collect data on genotype and phenotype for 60 leaf samples at four developmental stages, from three plant architectural positions and for three cultivars that were grown in two locations. Association mapping was conducted to detect genetic variants at quantitative trait SNP (QTS loci, quantitative trait transcript (QTT differences, quantitative trait protein (QTP variability, and quantitative trait metabolite (QTM changes, which can be summarized as QTX locus variation. The total heritabilities of the four -omics loci for both traits tested were 23.60% for epistasis and 15.26% for treatment interaction. Epistasis and environment × treatment interaction had important impacts on complex traits at all -omics levels. For decreasing chromium content and increasing total sugar in tobacco leaf, six methylated loci can be directly used for marker-assisted selection, and expression of ten QTTs, seven QTPs and six QTMs can be modified by selection or cultivation.

  11. A developmental systems perspective on epistasis: computational exploration of mutational interactions in model developmental regulatory networks.

    Directory of Open Access Journals (Sweden)

    Jayson Gutiérrez

    2009-09-01

    Full Text Available The way in which the information contained in genotypes is translated into complex phenotypic traits (i.e. embryonic expression patterns depends on its decoding by a multilayered hierarchy of biomolecular systems (regulatory networks. Each layer of this hierarchy displays its own regulatory schemes (i.e. operational rules such as +/- feedback and associated control parameters, resulting in characteristic variational constraints. This process can be conceptualized as a mapping issue, and in the context of highly-dimensional genotype-phenotype mappings (GPMs epistatic events have been shown to be ubiquitous, manifested in non-linear correspondences between changes in the genotype and their phenotypic effects. In this study I concentrate on epistatic phenomena pervading levels of biological organization above the genetic material, more specifically the realm of molecular networks. At this level, systems approaches to studying GPMs are specially suitable to shed light on the mechanistic basis of epistatic phenomena. To this aim, I constructed and analyzed ensembles of highly-modular (fully interconnected networks with distinctive topologies, each displaying dynamic behaviors that were categorized as either arbitrary or functional according to early patterning processes in the Drosophila embryo. Spatio-temporal expression trajectories in virtual syncytial embryos were simulated via reaction-diffusion models. My in silico mutational experiments show that: 1 the average fitness decay tendency to successively accumulated mutations in ensembles of functional networks indicates the prevalence of positive epistasis, whereas in ensembles of arbitrary networks negative epistasis is the dominant tendency; and 2 the evaluation of epistatic coefficients of diverse interaction orders indicates that, both positive and negative epistasis are more prevalent in functional networks than in arbitrary ones. Overall, I conclude that the phenotypic and fitness effects of

  12. Epistasis among Drosophila persimilis factors conferring hybrid male sterility with D. pseudoobscura bogotana.

    Directory of Open Access Journals (Sweden)

    Audrey S Chang

    2010-10-01

    Full Text Available The Bateson-Dobzhansky-Muller model posits that hybrid incompatibilities result from genetic changes that accumulate during population divergence. Indeed, much effort in recent years has been devoted to identifying genes associated with hybrid incompatibilities, often with limited success, suggesting that hybrid sterility and inviability are frequently caused by complex interactions between multiple loci and not by single or a small number of gene pairs. Our previous study showed that the nature of epistasis between sterility-conferring QTL in the Drosophila persimilis-D. pseudoobscura bogotana species pair is highly specific. Here, we further dissect one of the three QTL underlying hybrid male sterility between these species and provide evidence for multiple factors within this QTL. This result indicates that the number of loci thought to contribute to hybrid dysfunction may have been underestimated, and we discuss how linkage and complex epistasis may be characteristic of the genetics of hybrid incompatibilities. We further pinpoint the location of one locus that confers hybrid male sterility when homozygous, dubbed "mule-like", to roughly 250 kilobases.

  13. Epistasis increases the rate of conditionally neutral substitution in an adapting population.

    Science.gov (United States)

    Draghi, Jeremy A; Parsons, Todd L; Plotkin, Joshua B

    2011-04-01

    Kimura observed that the rate of neutral substitution should equal the neutral mutation rate. This classic result is central to our understanding of molecular evolution, and it continues to influence phylogenetics, genomics, and the interpretation of evolution experiments. By demonstrating that neutral mutations substitute at a rate independent of population size and selection at linked sites, Kimura provided an influential justification for the idea of a molecular clock and emphasized the importance of genetic drift in shaping molecular evolution. But when epistasis among sites is common, as numerous empirical studies suggest, do neutral mutations substitute according to Kimura's expectation? Here we study simulated, asexual populations of RNA molecules, and we observe that conditionally neutral mutations--i.e., mutations that do not alter the fitness of the individual in which they arise, but that may alter the fitness effects of subsequent mutations--substitute much more often than expected while a population is adapting. We quantify these effects using a simple population-genetic model that elucidates how the substitution rate at conditionally neutral sites depends on the population size, mutation rate, strength of selection, and prevalence of epistasis. We discuss the implications of these results for our understanding of the molecular clock, and for the interpretation of molecular variation in laboratory and natural populations.

  14. Epistasis among Drosophila persimilis factors conferring hybrid male sterility with D. pseudoobscura bogotana.

    Science.gov (United States)

    Chang, Audrey S; Bennett, Sarah M; Noor, Mohamed A F

    2010-10-27

    The Bateson-Dobzhansky-Muller model posits that hybrid incompatibilities result from genetic changes that accumulate during population divergence. Indeed, much effort in recent years has been devoted to identifying genes associated with hybrid incompatibilities, often with limited success, suggesting that hybrid sterility and inviability are frequently caused by complex interactions between multiple loci and not by single or a small number of gene pairs. Our previous study showed that the nature of epistasis between sterility-conferring QTL in the Drosophila persimilis-D. pseudoobscura bogotana species pair is highly specific. Here, we further dissect one of the three QTL underlying hybrid male sterility between these species and provide evidence for multiple factors within this QTL. This result indicates that the number of loci thought to contribute to hybrid dysfunction may have been underestimated, and we discuss how linkage and complex epistasis may be characteristic of the genetics of hybrid incompatibilities. We further pinpoint the location of one locus that confers hybrid male sterility when homozygous, dubbed "mule-like", to roughly 250 kilobases.

  15. Epistasis modifies the dominance of loci causing hybrid male sterility in the Drosophila pseudoobscura species group.

    Science.gov (United States)

    Chang, Audrey S; Noor, Mohamed A F

    2010-01-01

    Speciation, the evolution of reproductive isolation between populations, serves as the driving force for generating biodiversity. Postzygotic barriers to gene flow, such as F(1) hybrid sterility and inviability, play important roles in the establishment and maintenance of biological species. F(1) hybrid incompatibilities in taxa that obey Haldane's rule, the observation that the heterogametic sex suffers greater hybrid fitness problems than the homogametic sex, are thought to often result from interactions between recessive-acting X-linked loci and dominant-acting autosomal loci. Because they play such prominent roles in producing hybrid incompatibilities, we examine the dominance and nature of epistasis between alleles derived from Drosophila persimilis that confer hybrid male sterility in the genetic background of its sister species, D. pseudoobscura bogotana. We show that epistasis elevates the apparent dominance of individually recessive-acting QTL such that they can contribute to F(1) hybrid sterility. These results have important implications for assumptions underlying theoretical models of hybrid incompatibilities and may offer a possible explanation for why, to date, identification of dominant-acting autosomal "speciation genes" has been challenging.

  16. A two-locus global DNA barcode for land plants: the coding rbcL gene complements the non-coding trnH-psbA spacer region.

    Science.gov (United States)

    Kress, W John; Erickson, David L

    2007-06-06

    A useful DNA barcode requires sufficient sequence variation to distinguish between species and ease of application across a broad range of taxa. Discovery of a DNA barcode for land plants has been limited by intrinsically lower rates of sequence evolution in plant genomes than that observed in animals. This low rate has complicated the trade-off in finding a locus that is universal and readily sequenced and has sufficiently high sequence divergence at the species-level. Here, a global plant DNA barcode system is evaluated by comparing universal application and degree of sequence divergence for nine putative barcode loci, including coding and non-coding regions, singly and in pairs across a phylogenetically diverse set of 48 genera (two species per genus). No single locus could discriminate among species in a pair in more than 79% of genera, whereas discrimination increased to nearly 88% when the non-coding trnH-psbA spacer was paired with one of three coding loci, including rbcL. In silico trials were conducted in which DNA sequences from GenBank were used to further evaluate the discriminatory power of a subset of these loci. These trials supported the earlier observation that trnH-psbA coupled with rbcL can correctly identify and discriminate among related species. A combination of the non-coding trnH-psbA spacer region and a portion of the coding rbcL gene is recommended as a two-locus global land plant barcode that provides the necessary universality and species discrimination.

  17. Genecentric: a package to uncover graph-theoretic structure in high-throughput epistasis data.

    Science.gov (United States)

    Gallant, Andrew; Leiserson, Mark D M; Kachalov, Maxim; Cowen, Lenore J; Hescott, Benjamin J

    2013-01-18

    New technology has resulted in high-throughput screens for pairwise genetic interactions in yeast and other model organisms. For each pair in a collection of non-essential genes, an epistasis score is obtained, representing how much sicker (or healthier) the double-knockout organism will be compared to what would be expected from the sickness of the component single knockouts. Recent algorithmic work has identified graph-theoretic patterns in this data that can indicate functional modules, and even sets of genes that may occur in compensatory pathways, such as a BPM-type schema first introduced by Kelley and Ideker. However, to date, any algorithms for finding such patterns in the data were implemented internally, with no software being made publically available. Genecentric is a new package that implements a parallelized version of the Leiserson et al. algorithm (J Comput Biol 18:1399-1409, 2011) for generating generalized BPMs from high-throughput genetic interaction data. Given a matrix of weighted epistasis values for a set of double knock-outs, Genecentric returns a list of generalized BPMs that may represent compensatory pathways. Genecentric also has an extension, GenecentricGO, to query FuncAssociate (Bioinformatics 25:3043-3044, 2009) to retrieve GO enrichment statistics on generated BPMs. Python is the only dependency, and our web site provides working examples and documentation. We find that Genecentric can be used to find coherent functional and perhaps compensatory gene sets from high throughput genetic interaction data. Genecentric is made freely available for download under the GPLv2 from http://bcb.cs.tufts.edu/genecentric.

  18. Variance heterogeneity in Saccharomyces cerevisiae expression data: trans-regulation and epistasis.

    Science.gov (United States)

    Nelson, Ronald M; Pettersson, Mats E; Li, Xidan; Carlborg, Örjan

    2013-01-01

    Here, we describe the results from the first variance heterogeneity Genome Wide Association Study (VGWAS) on yeast expression data. Using this forward genetics approach, we show that the genetic regulation of gene-expression in the budding yeast, Saccharomyces cerevisiae, includes mechanisms that can lead to variance heterogeneity in the expression between genotypes. Additionally, we performed a mean effect association study (GWAS). Comparing the mean and variance heterogeneity analyses, we find that the mean expression level is under genetic regulation from a larger absolute number of loci but that a higher proportion of the variance controlling loci were trans-regulated. Both mean and variance regulating loci cluster in regulatory hotspots that affect a large number of phenotypes; a single variance-controlling locus, mapping close to DIA2, was found to be involved in more than 10% of the significant associations. It has been suggested in the literature that variance-heterogeneity between the genotypes might be due to genetic interactions. We therefore screened the multi-locus genotype-phenotype maps for several traits where multiple associations were found, for indications of epistasis. Several examples of two and three locus genetic interactions were found to involve variance-controlling loci, with reports from the literature corroborating the functional connections between the loci. By using a new analytical approach to re-analyze a powerful existing dataset, we are thus able to both provide novel insights to the genetic mechanisms involved in the regulation of gene-expression in budding yeast and experimentally validate epistasis as an important mechanism underlying genetic variance-heterogeneity between genotypes.

  19. Relevance Epistasis Network of Gastritis for Intra-chromosomes in the Korea Associated Resource (KARE Cohort Study

    Directory of Open Access Journals (Sweden)

    Hyun-hwan Jeong

    2014-12-01

    Full Text Available Gastritis is a common but a serious disease with a potential risk of developing carcinoma. Helicobacter pylori infection is reported as the most common cause of gastritis, but other genetic and genomic factors exist, especially single-nucleotide polymorphisms (SNPs. Association studies between SNPs and gastritis disease are important, but results on epistatic interactions from multiple SNPs are rarely found in previous genome-wide association (GWA studies. In this study, we performed computational GWA case-control studies for gastritis in Korea Associated Resource (KARE data. By transforming the resulting SNP epistasis network into a gene-gene epistasis network, we also identified potential gene-gene interaction factors that affect the susceptibility to gastritis.

  20. Mapping the fitness landscape of gene expression uncovers the cause of antagonism and sign epistasis between adaptive mutations.

    Directory of Open Access Journals (Sweden)

    Hsin-Hung Chou

    2014-02-01

    Full Text Available How do adapting populations navigate the tensions between the costs of gene expression and the benefits of gene products to optimize the levels of many genes at once? Here we combined independently-arising beneficial mutations that altered enzyme levels in the central metabolism of Methylobacterium extorquens to uncover the fitness landscape defined by gene expression levels. We found strong antagonism and sign epistasis between these beneficial mutations. Mutations with the largest individual benefit interacted the most antagonistically with other mutations, a trend we also uncovered through analyses of datasets from other model systems. However, these beneficial mutations interacted multiplicatively (i.e., no epistasis at the level of enzyme expression. By generating a model that predicts fitness from enzyme levels we could explain the observed sign epistasis as a result of overshooting the optimum defined by a balance between enzyme catalysis benefits and fitness costs. Knowledge of the phenotypic landscape also illuminated that, although the fitness peak was phenotypically far from the ancestral state, it was not genetically distant. Single beneficial mutations jumped straight toward the global optimum rather than being constrained to change the expression phenotypes in the correlated fashion expected by the genetic architecture. Given that adaptation in nature often results from optimizing gene expression, these conclusions can be widely applicable to other organisms and selective conditions. Poor interactions between individually beneficial alleles affecting gene expression may thus compromise the benefit of sex during adaptation and promote genetic differentiation.

  1. Age- and gender-specific epistasis between ADA and TNF-α influences human life-expectancy.

    Science.gov (United States)

    Napolioni, Valerio; Carpi, Francesco M; Giannì, Paola; Sacco, Roberto; Di Blasio, Luca; Mignini, Fiorenzo; Lucarini, Nazzareno; Persico, Antonio M

    2011-11-01

    Aging is a complex phenotype with multiple determinants but a strong genetic component significantly impacts on survival to extreme ages. The dysregulation of immune responses occurring with increasing age is believed to contribute to human morbidity and mortality. Conversely, some genetic determinants of successful aging might reside in those polymorphisms for the immune system genes regulating immune responses. Here we examined the main effects of single loci and multi-locus interactions to test the hypothesis that the adenosine deaminase (ADA) and tumor necrosis factor alpha (TNF-α) genes may influence human life-expectancy. ADA (22G>A, rs73598374) and TNF-α (-308G>A, rs1800629; -238G>A, rs361525) functional SNPs have been determined for 1071 unrelated healthy individuals from Central Italy (18-106 years old) divided into three gender-specific age classes defined according to demographic information and accounting for the different survivals between sexes: for men (women), the first class consists of individuals88 years old (>91 years old). Single-locus analysis showed that only ADA 22G>A is significantly associated with human life-expectancy in males (comparison 1 (age class 2 vs. age class 1), O.R. 1.943, P=0.036; comparison 2 (age class 3 vs. age class 2), O.R. 0.320, P=0.0056). Age- and gender-specific patterns of epistasis between ADA and TNF-α were found using Generalized Multifactor Dimensionality Reduction (GMDR). In comparison 1, a significant two-loci interaction occurs in females between ADA 22G>A and TNF-α -238G>A (Sign Test P=0.011). In comparison 2, both two-loci and three-loci interaction are significant associated with increased life-expectancy over 88 years in males. In conclusion, we report that a combination of functional SNPs within ADA and TNF-α genes can influence life-expectancy in a gender-specific manner and that males and females follow different pathways to attain longevity. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Epistasis between QTLs for bone density variation in Copenhagen × dark agouti F2 rats

    Science.gov (United States)

    Liu, Lixiang; Alam, Imranul; Sun, Qiwei; Econs, Michael J.; Foroud, Tatiana; Turner, Charles H.

    2010-01-01

    The variation in several of the risk factors for osteoporotic fracture, including bone mineral density (BMD), has been shown to be strongly influenced by genetic differences. However, the genetic architecture of BMD is complex in both humans and in model organisms. We previously reported quantitative trait locus (QTL) results for BMD from a genome screen of 828 F2 progeny of Copenhagen and dark agouti rats. These progeny also provide an excellent opportunity to search for epistatic effects, or interaction between genetic loci, that contribute to fracture risk. Microsatellite marker data from a 20-cM genome screen was analyzed along with weight-adjusted bone density (DXA and pQCT) phenotypic data using the R/qtl software package. Genotype and phenotype data were permuted to determine genome-wide significance thresholds for the full model and epistasis (interaction) LOD scores corresponding to an alpha level of 0.01. A novel locus on chromosome 15 and a previously reported chromosome 14 QTL demonstrated a strong epistatic effect on BMD at the femur by DXA (LOD = 5.4). Two novel QTLs on chromosomes 2 and 12 were found to interact to affect total BMD at the femur midshaft by pQCT (LOD = 5.0). These results provide new information regarding the mode of action of previously identified QTL in the rat, as well as identifying novel loci that act in combination with known QTL or with other novel loci to contribute to BMD variation. PMID:19153792

  3. Epistasis between QTLs for bone density variation in Copenhagen x dark agouti F2 rats.

    Science.gov (United States)

    Koller, Daniel L; Liu, Lixiang; Alam, Imranul; Sun, Qiwei; Econs, Michael J; Foroud, Tatiana; Turner, Charles H

    2009-03-01

    The variation in several of the risk factors for osteoporotic fracture, including bone mineral density (BMD), has been shown to be strongly influenced by genetic differences. However, the genetic architecture of BMD is complex in both humans and in model organisms. We previously reported quantitative trait locus (QTL) results for BMD from a genome screen of 828 F2 progeny of Copenhagen and dark agouti rats. These progeny also provide an excellent opportunity to search for epistatic effects, or interaction between genetic loci, that contribute to fracture risk. Microsatellite marker data from a 20-cM genome screen was analyzed along with weight-adjusted bone density (DXA and pQCT) phenotypic data using the R/qtl software package. Genotype and phenotype data were permuted to determine genome-wide significance thresholds for the full model and epistasis (interaction) LOD scores corresponding to an alpha level of 0.01. A novel locus on chromosome 15 and a previously reported chromosome 14 QTL demonstrated a strong epistatic effect on BMD at the femur by DXA (LOD = 5.4). Two novel QTLs on chromosomes 2 and 12 were found to interact to affect total BMD at the femur midshaft by pQCT (LOD = 5.0). These results provide new information regarding the mode of action of previously identified QTL in the rat, as well as identifying novel loci that act in combination with known QTL or with other novel loci to contribute to BMD variation.

  4. OncoSimulR: genetic simulation with arbitrary epistasis and mutator genes in asexual populations.

    Science.gov (United States)

    Diaz-Uriarte, Ramon

    2017-06-15

    OncoSimulR implements forward-time genetic simulations of biallelic loci in asexual populations with special focus on cancer progression. Fitness can be defined as an arbitrary function of genetic interactions between multiple genes or modules of genes, including epistasis, restrictions in the order of accumulation of mutations, and order effects. Mutation rates can differ among genes, and can be affected by (anti)mutator genes. Also available are sampling from simulations (including single-cell sampling), plotting the genealogical relationships of clones and generating and plotting fitness landscapes. Implemented in R and C ++, freely available from BioConductor for Linux, Mac and Windows under the GNU GPL license. Version 2.5.9 or higher available from: http://www.bioconductor.org/packages/devel/bioc/html/OncoSimulR.html . GitHub repository at: https://github.com/rdiaz02/OncoSimul. ramon.diaz@iib.uam.es. Supplementary data are available at Bioinformatics online. © The Author 2017. Published by Oxford University Press.

  5. Epistasis between dopamine regulating genes identifies a nonlinear response of the human hippocampus during memory tasks.

    Science.gov (United States)

    Bertolino, Alessandro; Di Giorgio, Annabella; Blasi, Giuseppe; Sambataro, Fabio; Caforio, Grazia; Sinibaldi, Lorenzo; Latorre, Valeria; Rampino, Antonio; Taurisano, Paolo; Fazio, Leonardo; Romano, Raffaella; Douzgou, Sofia; Popolizio, Teresa; Kolachana, Bhaskar; Nardini, Marcello; Weinberger, Daniel R; Dallapiccola, Bruno

    2008-08-01

    Dopamine modulation of neuronal activity in prefrontal cortex maps to an inverted U-curve. Dopamine is also an important factor in regulation of hippocampal mediated memory processing. Here, we investigated the effect of genetic variation of dopamine inactivation via catechol-O-methyltransferase (COMT) and the dopamine transporter (DAT) on hippocampal activity in healthy humans during different memory conditions. Using blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI) in 82 subjects matched for a series of demographic and genetic variables, we studied the effect of the COMT valine (Val)(158)methionine (Met) and the DAT 3' variable number tandem repeat (VNTR) polymorphisms on function of the hippocampus during encoding of recognition memory and during working memory. Our results consistently demonstrated a double dissociation so that DAT 9-repeat carrier alleles modulated activity in the hippocampus in the exact opposite direction of DAT 10/10-repeat alleles based on COMT Val(158)Met genotype during different memory conditions. Similar results were evident in ventrolateral and dorsolateral prefrontal cortex. These findings suggest that genetically determined dopamine signaling during memory processing maps to a nonlinear relationship also in the hippocampus. Our data also demonstrate in human brain epistasis of two genes implicated in dopamine signaling on brain activity during different memory conditions.

  6. Cost-effective GPU-grid for genome-wide epistasis calculations.

    Science.gov (United States)

    Pütz, B; Kam-Thong, T; Karbalai, N; Altmann, A; Müller-Myhsok, B

    2013-01-01

    Until recently, genotype studies were limited to the investigation of single SNP effects due to the computational burden incurred when studying pairwise interactions of SNPs. However, some genetic effects as simple as coloring (in plants and animals) cannot be ascribed to a single locus but only understood when epistasis is taken into account [1]. It is expected that such effects are also found in complex diseases where many genes contribute to the clinical outcome of affected individuals. Only recently have such problems become feasible computationally. The inherently parallel structure of the problem makes it a perfect candidate for massive parallelization on either grid or cloud architectures. Since we are also dealing with confidential patient data, we were not able to consider a cloud-based solution but had to find a way to process the data in-house and aimed to build a local GPU-based grid structure. Sequential epistatsis calculations were ported to GPU using CUDA at various levels. Parallelization on the CPU was compared to corresponding GPU counterparts with regards to performance and cost. A cost-effective solution was created by combining custom-built nodes equipped with relatively inexpensive consumer-level graphics cards with highly parallel GPUs in a local grid. The GPU method outperforms current cluster-based systems on a price/performance criterion, as a single GPU shows speed performance comparable up to 200 CPU cores. The outlined approach will work for problems that easily lend themselves to massive parallelization. Code for various tasks has been made available and ongoing development of tools will further ease the transition from sequential to parallel algorithms.

  7. Epistasis Analysis for Estrogen Metabolic and Signaling Pathway Genes on Young Ischemic Stroke Patients

    Science.gov (United States)

    Hsieh, Yi-Chen; Jeng, Jiann-Shing; Lin, Huey-Juan; Hu, Chaur-Jong; Yu, Chia-Chen; Lien, Li-Ming; Peng, Giia-Sheun; Chen, Chin-I; Tang, Sung-Chun; Chi, Nai-Fang; Tseng, Hung-Pin; Chern, Chang-Ming; Hsieh, Fang-I; Bai, Chyi-Huey; Chen, Yi-Rhu; Chiou, Hung-Yi; Jeng, Jiann-Shing; Tang, Sung-Chun; Yeh, Shin-Joe; Tsai, Li-Kai; Kong, Shin; Lien, Li-Ming; Chiu, Hou-Chang; Chen, Wei-Hung; Bai, Chyi-Huey; Huang, Tzu-Hsuan; Chi-Ieong, Lau; Wu, Ya-Ying; Yuan, Rey-Yue; Hu, Chaur-Jong; Sheu, Jau- Jiuan; Yu, Jia-Ming; Ho, Chun-Sum; Chen, Chin-I; Sung, Jia-Ying; Weng, Hsing-Yu; Han, Yu-Hsuan; Huang, Chun-Ping; Chung, Wen-Ting; Ke, Der-Shin; Lin, Huey-Juan; Chang, Chia-Yu; Yeh, Poh-Shiow; Lin, Kao-Chang; Cheng, Tain-Junn; Chou, Chih-Ho; Yang, Chun-Ming; Peng, Giia-Sheun; Lin, Jiann-Chyun; Hsu, Yaw-Don; Denq, Jong-Chyou; Lee, Jiunn-Tay; Hsu, Chang-Hung; Lin, Chun-Chieh; Yen, Che-Hung; Cheng, Chun-An; Sung, Yueh-Feng; Chen, Yuan-Liang; Lien, Ming-Tung; Chou, Chung-Hsing; Liu, Chia-Chen; Yang, Fu-Chi; Wu, Yi-Chung; Tso, An-Chen; Lai, Yu- Hua; Chiang, Chun-I; Tsai, Chia-Kuang; Liu, Meng-Ta; Lin, Ying-Che; Hsu, Yu-Chuan; Chen, Chih-Hung; Sung, Pi-Shan; Chern, Chang-Ming; Hu, Han-Hwa; Wong, Wen-Jang; Luk, Yun-On; Hsu, Li-Chi; Chung, Chih-Ping; Tseng, Hung-Pin; Liu, Chin-Hsiung; Lin, Chun-Liang; Lin, Hung-Chih; Hu, Chaur-Jong

    2012-01-01

    Background Endogenous estrogens play an important role in the overall cardiocirculatory system. However, there are no studies exploring the hormone metabolism and signaling pathway genes together on ischemic stroke, including sulfotransferase family 1E (SULT1E1), catechol-O-methyl-transferase (COMT), and estrogen receptor α (ESR1). Methods A case-control study was conducted on 305 young ischemic stroke subjects aged ≦ 50 years and 309 age-matched healthy controls. SULT1E1 -64G/A, COMT Val158Met, ESR1 c.454−397 T/C and c.454−351 A/G genes were genotyped and compared between cases and controls to identify single nucleotide polymorphisms associated with ischemic stroke susceptibility. Gene-gene interaction effects were analyzed using entropy-based multifactor dimensionality reduction (MDR), classification and regression tree (CART), and traditional multiple regression models. Results COMT Val158Met polymorphism showed a significant association with susceptibility of young ischemic stroke among females. There was a two-way interaction between SULT1E1 -64G/A and COMT Val158Met in both MDR and CART analysis. The logistic regression model also showed there was a significant interaction effect between SULT1E1 -64G/A and COMT Val158Met on ischemic stroke of the young (P for interaction = 0.0171). We further found that lower estradiol level could increase the risk of young ischemic stroke for those who carry either SULT1E1 or COMT risk genotypes, showing a significant interaction effect (P for interaction = 0.0174). Conclusions Our findings support that a significant epistasis effect exists among estrogen metabolic and signaling pathway genes and gene-environment interactions on young ischemic stroke subjects. PMID:23112845

  8. THE EVOLUTION OF CANALIZATION AND THE BREAKING OF VON BAER'S LAWS: MODELING THE EVOLUTION OF DEVELOPMENT WITH EPISTASIS.

    Science.gov (United States)

    Rice, Sean H

    1998-06-01

    Evolution can change the developmental processes underlying a character without changing the average expression of the character itself. This sort of change must occur in both the evolution of canalization, in which a character becomes increasingly buffered against genetic or developmental variation, and in the phenomenon of closely related species that show similar adult phenotypes but different underlying developmental patterns. To study such phenomena, I develop a model that follows evolution on a surface representing adult phenotype as a function of underlying developmental characters. A contour on such a "phenotype landscape" is a set of states of developmental characters that produce the same adult phenotype. Epistasis induces curvature of this surface, and degree of canalization is represented by the slope along a contour. I first discuss the geometric properties of phenotype landscapes, relating epistasis to canalization. I then impose a fitness function on the phenotype and model evolution of developmental characters as a function of the fitness function and the local geometry of the surface. This model shows how canalization evolves as a population approaches an optimum phenotype. It further shows that under some circumstances, "decanalization" can occur, in which the expression of adult phenotype becomes increasingly sensitive to developmental variation. This process can cause very similar populations to diverge from one another developmentally even when their adult phenotypes experience identical selection regimes. © 1998 The Society for the Study of Evolution.

  9. The sex-specific associations of the aromatase gene with Alzheimer's disease and its interaction with IL10 in the Epistasis Project.

    Science.gov (United States)

    Medway, Christopher; Combarros, Onofre; Cortina-Borja, Mario; Butler, Helen T; Ibrahim-Verbaas, Carla A; de Bruijn, Renée F A G; Koudstaal, Peter J; van Duijn, Cornelia M; Ikram, M Arfan; Mateo, Ignacio; Sánchez-Juan, Pascual; Lehmann, Michael G; Heun, Reinhard; Kölsch, Heike; Deloukas, Panos; Hammond, Naomi; Coto, Eliecer; Alvarez, Victoria; Kehoe, Patrick G; Barber, Rachel; Wilcock, Gordon K; Brown, Kristelle; Belbin, Olivia; Warden, Donald R; Smith, A David; Morgan, Kevin; Lehmann, Donald J

    2014-02-01

    Epistasis between interleukin-10 (IL10) and aromatase gene polymorphisms has previously been reported to modify the risk of Alzheimer's disease (AD). However, although the main effects of aromatase variants suggest a sex-specific effect in AD, there has been insufficient power to detect sex-specific epistasis between these genes to date. Here we used the cohort of 1757 AD patients and 6294 controls in the Epistasis Project. We replicated the previously reported main effects of aromatase polymorphisms in AD risk in women, for example, adjusted odds ratio of disease for rs1065778 GG=1.22 (95% confidence interval: 1.01-1.48, P=0.03). We also confirmed a reported epistatic interaction between IL10 rs1800896 and aromatase (CYP19A1) rs1062033, again only in women: adjusted synergy factor=1.94 (1.16-3.25, 0.01). Aromatase, a rate-limiting enzyme in the synthesis of estrogens, is expressed in AD-relevant brain regions ,and is downregulated during the disease. IL-10 is an anti-inflammatory cytokine. Given that estrogens have neuroprotective and anti-inflammatory activities and regulate microglial cytokine production, epistasis is biologically plausible. Diminishing serum estrogen in postmenopausal women, coupled with suboptimal brain estrogen synthesis, may contribute to the inflammatory state, that is a pathological hallmark of AD.

  10. Two-locus maximum lod score analysis of a multifactorial trait: joint consideration of IDDM2 and IDDM4 with IDDM1 in type 1 diabetes.

    Science.gov (United States)

    Cordell, H J; Todd, J A; Bennett, S T; Kawaguchi, Y; Farrall, M

    1995-10-01

    To investigate the genetic component of multifactorial diseases such as type 1 (insulin-dependent) diabetes mellitus (IDDM), models involving the joint action of several disease loci are important. These models can give increased power to detect an effect and a greater understanding of etiological mechanisms. Here, we present an extension of the maximum lod score method of N. Risch, which allows the simultaneous detection and modeling of two unlinked disease loci. Genetic constraints on the identical-by-descent sharing probabilities, analogous to the "triangle" restrictions in the single-locus method, are derived, and the size and power of the test statistics are investigated. The method is applied to affected-sib-pair data, and the joint effects of IDDM1 (HLA) and IDDM2 (the INS VNTR) and of IDDM1 and IDDM4 (FGF3-linked) are assessed with relation to the development of IDDM. In the presence of genetic heterogeneity, there is seen to be a significant advantage in analyzing more than one locus simultaneously. Analysis of these families indicates that the effects at IDDM1 and IDDM2 are well described by a multiplicative genetic model, while those at IDDM1 and IDDM4 follow a heterogeneity model.

  11. Two-locus maximum lod score analysis of a multifactorial trait: Joint consideration of IDDM2 and IDDM4 with IDDMI in type 1 diabetes

    Energy Technology Data Exchange (ETDEWEB)

    Cordell, H.J.; Todd, J.A.; Bennett, S.T. [Univ. of Oxford (United Kingdom)] [and others

    1995-10-01

    To investigate the genetic component of multifactorial diseases such as type 1 (insulin-dependent) diabetes mellitus (IDDM), models involving the joint action of several disease loci are important. These models can give increased power to detect an effect and a greater understanding of etiological mechanisms. Here, we present an extension of the maximum lod score method of N. Risch, which allows the simultaneous detection and modeling of two unlinked disease loci. Genetic constraints on the identical-by-descent sharing probabilities, analogous to the {open_quotes}triangle{close_quotes} restrictions in the single-locus method, are derived, and the size and power of the test statistics are investigated. The method is applied to affected-sib-pair data, and the joint effects of IDDM1 (HLA) and IDDM2 (the INS VNTR) and of IDDM1 and IDDM4 (FGF3-linked) are assessed with relation to the development of IDDM. In the presence of genetic heterogeneity, there is seen to be a significant advantage in analyzing more than one locus simultaneously. Analysis of these families indicates that the effects at IDDM1 and IDDM2 are well described by a multiplicative genetic model, while those at IDDM1 and IDDM4 follow a heterogeneity model. 17 refs., 9 tabs.

  12. Imaging oxytocin x dopamine interactions: An epistasis effect of CD38 and COMT gene variants influences the impact of oxytocin on amygdala activation to social stimuli

    Directory of Open Access Journals (Sweden)

    Carina eSauer

    2013-04-01

    Full Text Available Although oxytocin (OT has become a major target for the investigation of positive social processes, it can be assumed that it exerts its effects in concert with other neurotransmitters. One candidate for such an interaction is dopamine (DA. For both systems, genetic variants have been identified that influence the availability of the particular substance. A variant of the gene coding for the transmembrane protein CD38 (rs3796863, which is engaged in OT secretion, has been associated with OT plasma level. The common catechol-O-methyltransferase (COMT val158met polymorphism is known to influence COMT activity and therefore the degradation of DA. The present study aimed to investigate OTxDA interactions in the context of an OT challenge study. Hence, we tested the influence of the above mentioned genetic variants and their interaction on the activation of different brain regions (amygdala, VTA, ventral striatum and fusiform gyrus during the presentation of social stimuli. In a pharmacological cross-over design 55 participants were investigated under OT and placebo (PLA by means of fMRI.Brain imaging results revealed no significant effects for VTA or ventral striatum. Regarding the fusiform gyrus, we could not find any effects apart from those already described in (Sauer et al., 2012. Analyses of amygdala activation resulted in no gene main effect, no gene x substance interaction but a significant gene x gene x substance interaction. While under PLA the effect of CD38 on bilateral amygdala activation to social stimuli was modulated by the COMT genotype, no such epistasis effect was found under OT. Our results provide evidence for an OTxDA interaction during responses to social stimuli. We postulate that the effect of central OT secretion on amygdala response is modulated by the availability of DA. Therefore, for an understanding of the effect of social hormones on social behavior, interactions of OT with other transmitter systems have to be taken

  13. Genetics of hybrid male sterility between drosophila sibling species: a complex web of epistasis is revealed in interspecific studies.

    Science.gov (United States)

    Palopoli, M F; Wu, C I

    1994-10-01

    To study the genetic differences responsible for the sterility of their male hybrids, we introgressed small segments of an X chromosome from Drosophila simulans into a pure Drosophila mauritiana genetic background, then assessed the fertility of males carrying heterospecific introgressions of varying size. Although this analysis examined less than 20% of the X chromosome (roughly 5% of the euchromatic portion of the D. simulans genome), and the segments were introgressed in only one direction, a minimum of four factors that contribute to hybrid male sterility were revealed. At least two of the factors exhibited strong epistasis: males carrying either factor alone were consistently fertile, whereas males carrying both factors together were always sterile. Distinct spermatogenic phenotypes were observed for sterile introgressions of different lengths, and it appeared that an interaction between introgressed segments also influenced the stage of spermatogenic defect. Males with one category of introgression often produced large quantities of motile sperm and were observed copulating, but never inseminated females. Evidently these two species have diverged at a large number of loci which have varied effects on hybrid male fertility. By extrapolation, we estimate that there are at least 40 such loci on the X chromosome alone. Because these species exhibit little DNA-sequence divergence at arbitrarily chosen loci, it seems unlikely that the extensive functional divergence observed could be due mainly to random genetic drift. Significant epistasis between conspecific genes appears to be a common component of hybrid sterility between recently diverged species of Drosophila. The linkage relationships of interacting factors could shed light on the role played by epistatic selection in the dynamics of the allele substitutions responsible for reproductive barriers between species.

  14. Epistasis between 5-HTTLPR and ADRA2B polymorphisms influences attentional bias for emotional information in healthy volunteers.

    Science.gov (United States)

    Naudts, Kris H; Azevedo, Ruben T; David, Anthony S; van Heeringen, Kees; Gibbs, Ayana A

    2012-09-01

    Individual differences in emotional processing are likely to contribute to vulnerability and resilience to emotional disorders such as depression and anxiety. Genetic variation is known to contribute to these differences but they remain incompletely understood. The serotonin transporter (5-HTTLPR) and α2B-adrenergic autoreceptor (ADRA2B) insertion/deletion polymorphisms impact on two separate but interacting monaminergic signalling mechanisms that have been implicated in both emotional processing and emotional disorders. Recent studies suggest that the 5-HTTLPR s allele is associated with a negative attentional bias and an increased risk of emotional disorders. However, such complex behavioural traits are likely to exhibit polygenicity, including epistasis. This study examined the contribution of the 5-HTTLPR and ADRA2B insertion/deletion polymorphisms to attentional biases for aversive information in 94 healthy male volunteers and found evidence of a significant epistatic effect (pbias for aversive information was attenuated by possession of the ADRA2B deletion variant whereas in the absence of the s allele, the bias was enhanced. These data identify a cognitive mechanism linking genotype-dependent serotonergic and noradrenergic signalling that is likely to have implications for the development of cognitive markers for depression/anxiety as well as therapeutic drug effects and personalized approaches to treatment.

  15. iLOCi: a SNP interaction prioritization technique for detecting epistasis in genome-wide association studies

    Directory of Open Access Journals (Sweden)

    Piriyapongsa Jittima

    2012-12-01

    Full Text Available Abstract Background Genome-wide association studies (GWAS do not provide a full account of the heritability of genetic diseases since gene-gene interactions, also known as epistasis are not considered in single locus GWAS. To address this problem, a considerable number of methods have been developed for identifying disease-associated gene-gene interactions. However, these methods typically fail to identify interacting markers explaining more of the disease heritability over single locus GWAS, since many of the interactions significant for disease are obscured by uninformative marker interactions e.g., linkage disequilibrium (LD. Results In this study, we present a novel SNP interaction prioritization algorithm, named iLOCi (Interacting Loci. This algorithm accounts for marker dependencies separately in case and control groups. Disease-associated interactions are then prioritized according to a novel ranking score calculated from the difference in marker dependencies for every possible pair between case and control groups. The analysis of a typical GWAS dataset can be completed in less than a day on a standard workstation with parallel processing capability. The proposed framework was validated using simulated data and applied to real GWAS datasets using the Wellcome Trust Case Control Consortium (WTCCC data. The results from simulated data showed the ability of iLOCi to identify various types of gene-gene interactions, especially for high-order interaction. From the WTCCC data, we found that among the top ranked interacting SNP pairs, several mapped to genes previously known to be associated with disease, and interestingly, other previously unreported genes with biologically related roles. Conclusion iLOCi is a powerful tool for uncovering true disease interacting markers and thus can provide a more complete understanding of the genetic basis underlying complex disease. The program is available for download at http://www4a.biotec.or.th/GI/tools/iloci.

  16. Genetic Interaction Mapping in Schizosaccharomyces pombe Using the Pombe Epistasis Mapper (PEM) System and a ROTOR HDA Colony Replicating Robot in a 1536 Array Format.

    Science.gov (United States)

    Roguev, Assen; Xu, Jiewei; Krogan, Nevan

    2018-02-01

    This protocol describes an optimized high-throughput procedure for generating double deletion mutants in Schizosaccharomyces pombe using the colony replicating robot ROTOR HDA and the PEM (pombe epistasis mapper) system. The method is based on generating high-density colony arrays (1536 colonies per agar plate) and passaging them through a series of antidiploid and mating-type selection (ADS-MTS) and double-mutant selection (DMS) steps. Detailed program parameters for each individual replication step are provided. Using this procedure, batches of 25 or more screens can be routinely performed. © 2018 Cold Spring Harbor Laboratory Press.

  17. Survival dimensionality reduction (SDR: development and clinical application of an innovative approach to detect epistasis in presence of right-censored data

    Directory of Open Access Journals (Sweden)

    Beretta Lorenzo

    2010-08-01

    Full Text Available Abstract Background Epistasis is recognized as a fundamental part of the genetic architecture of individuals. Several computational approaches have been developed to model gene-gene interactions in case-control studies, however, none of them is suitable for time-dependent analysis. Herein we introduce the Survival Dimensionality Reduction (SDR algorithm, a non-parametric method specifically designed to detect epistasis in lifetime datasets. Results The algorithm requires neither specification about the underlying survival distribution nor about the underlying interaction model and proved satisfactorily powerful to detect a set of causative genes in synthetic epistatic lifetime datasets with a limited number of samples and high degree of right-censorship (up to 70%. The SDR method was then applied to a series of 386 Dutch patients with active rheumatoid arthritis that were treated with anti-TNF biological agents. Among a set of 39 candidate genes, none of which showed a detectable marginal effect on anti-TNF responses, the SDR algorithm did find that the rs1801274 SNP in the FcγRIIa gene and the rs10954213 SNP in the IRF5 gene non-linearly interact to predict clinical remission after anti-TNF biologicals. Conclusions Simulation studies and application in a real-world setting support the capability of the SDR algorithm to model epistatic interactions in candidate-genes studies in presence of right-censored data. Availability: http://sourceforge.net/projects/sdrproject/

  18. Histone Variant HTZ1 Shows Extensive Epistasis with, but Does Not Increase Robustness to, New Mutations

    Science.gov (United States)

    Richardson, Joshua B.; Uppendahl, Locke D.; Traficante, Maria K.; Levy, Sasha F.; Siegal, Mark L.

    2013-01-01

    Biological systems produce phenotypes that appear to be robust to perturbation by mutations and environmental variation. Prior studies identified genes that, when impaired, reveal previously cryptic genetic variation. This result is typically interpreted as evidence that the disrupted gene normally increases robustness to mutations, as such robustness would allow cryptic variants to accumulate. However, revelation of cryptic genetic variation is not necessarily evidence that a mutationally robust state has been made less robust. Demonstrating a difference in robustness requires comparing the ability of each state (with the gene perturbed or intact) to suppress the effects of new mutations. Previous studies used strains in which the existing genetic variation had been filtered by selection. Here, we use mutation accumulation (MA) lines that have experienced minimal selection, to test the ability of histone H2A.Z (HTZ1) to increase robustness to mutations in the yeast Saccharomyces cerevisiae. HTZ1, a regulator of chromatin structure and gene expression, represents a class of genes implicated in mutational robustness. It had previously been shown to increase robustness of yeast cell morphology to fluctuations in the external or internal microenvironment. We measured morphological variation within and among 79 MA lines with and without HTZ1. Analysis of within-line variation confirms that HTZ1 increases microenvironmental robustness. Analysis of between-line variation shows the morphological effects of eliminating HTZ1 to be highly dependent on the line, which implies that HTZ1 interacts with mutations that have accumulated in the lines. However, lines without HTZ1 are, as a group, not more phenotypically diverse than lines with HTZ1 present. The presence of HTZ1, therefore, does not confer greater robustness to mutations than its absence. Our results provide experimental evidence that revelation of cryptic genetic variation cannot be assumed to be caused by loss of

  19. Histone variant HTZ1 shows extensive epistasis with, but does not increase robustness to, new mutations.

    Directory of Open Access Journals (Sweden)

    Joshua B Richardson

    Full Text Available Biological systems produce phenotypes that appear to be robust to perturbation by mutations and environmental variation. Prior studies identified genes that, when impaired, reveal previously cryptic genetic variation. This result is typically interpreted as evidence that the disrupted gene normally increases robustness to mutations, as such robustness would allow cryptic variants to accumulate. However, revelation of cryptic genetic variation is not necessarily evidence that a mutationally robust state has been made less robust. Demonstrating a difference in robustness requires comparing the ability of each state (with the gene perturbed or intact to suppress the effects of new mutations. Previous studies used strains in which the existing genetic variation had been filtered by selection. Here, we use mutation accumulation (MA lines that have experienced minimal selection, to test the ability of histone H2A.Z (HTZ1 to increase robustness to mutations in the yeast Saccharomyces cerevisiae. HTZ1, a regulator of chromatin structure and gene expression, represents a class of genes implicated in mutational robustness. It had previously been shown to increase robustness of yeast cell morphology to fluctuations in the external or internal microenvironment. We measured morphological variation within and among 79 MA lines with and without HTZ1. Analysis of within-line variation confirms that HTZ1 increases microenvironmental robustness. Analysis of between-line variation shows the morphological effects of eliminating HTZ1 to be highly dependent on the line, which implies that HTZ1 interacts with mutations that have accumulated in the lines. However, lines without HTZ1 are, as a group, not more phenotypically diverse than lines with HTZ1 present. The presence of HTZ1, therefore, does not confer greater robustness to mutations than its absence. Our results provide experimental evidence that revelation of cryptic genetic variation cannot be assumed to be

  20. Evidence for complete epistasis of null mutations in murine Fanconi anemia genes Fanca and Fancg.

    Science.gov (United States)

    van de Vrugt, Henri J; Koomen, Mireille; Bakker, Sietske; Berns, Mariska A D; Cheng, Ngan Ching; van der Valk, Martin A; de Vries, Yne; Rooimans, Martin A; Oostra, Anneke B; Hoatlin, Maureen E; Te Riele, Hein; Joenje, Hans; Arwert, Fré

    2011-12-10

    Fanconi anemia (FA) is a heritable disease characterized by bone marrow failure, congenital abnormalities, and cancer predisposition. The 15 identified FA genes operate in a molecular pathway to preserve genomic integrity. Within this pathway the FA core complex operates as an ubiquitin ligase that activates the complex of FANCD2 and FANCI to coordinate DNA repair. The FA core complex is formed by at least 12 proteins. However, only the FANCL subunit displays ubiquitin ligase activity. FANCA and FANCG are members of the FA core complex for which no other functions have been described than to participate in protein interactions. In this study we generated mice with combined null alleles for Fanca and Fancg to identify extended functions for these genes by characterizing the double mutant mice and cells. Double mutant a(-/-)/g(-/-) mice were born at near Mendelian frequencies without apparent developmental abnormalities. Histological analysis of a(-/-)/g(-/-) mice revealed a Leydig cell hyperplasia and frequent vacuolization of Sertoli cells in testes, while ovaries were depleted from developing follicles and displayed an interstitial cell hyperplasia. These gonadal aberrations were associated with a compromised fertility of a(-/-)/g(-/-) males and females. During the first year of life a(-/-)/g(-/-) did not develop malignancies or bone marrow failure. At the cellular level a(-/-)/g(-/-), Fanca(-/-), and Fancg(-/-) cells proved equally compromised in DNA crosslink and homology-directed repair. Overall the phenotype of a(-/-)/g(-/-) double knockout mice and cells appeared highly similar to the phenotype of Fanca or Fancg single knockouts. The lack of an augmented phenotype suggest that null mutations in Fanca or Fancg are fully epistatic, making additional important functions outside of the FA core complex highly unlikely. 2011 Elsevier B.V. All rights reserved.

  1. A high-resolution gene expression atlas of epistasis between gene-specific transcription factors exposes potential mechanisms for genetic interactions.

    Science.gov (United States)

    Sameith, Katrin; Amini, Saman; Groot Koerkamp, Marian J A; van Leenen, Dik; Brok, Mariel; Brabers, Nathalie; Lijnzaad, Philip; van Hooff, Sander R; Benschop, Joris J; Lenstra, Tineke L; Apweiler, Eva; van Wageningen, Sake; Snel, Berend; Holstege, Frank C P; Kemmeren, Patrick

    2015-12-23

    Genetic interactions, or non-additive effects between genes, play a crucial role in many cellular processes and disease. Which mechanisms underlie these genetic interactions has hardly been characterized. Understanding the molecular basis of genetic interactions is crucial in deciphering pathway organization and understanding the relationship between genotype, phenotype and disease. To investigate the nature of genetic interactions between gene-specific transcription factors (GSTFs) in Saccharomyces cerevisiae, we systematically analyzed 72 GSTF pairs by gene expression profiling double and single deletion mutants. These pairs were selected through previously published growth-based genetic interactions as well as through similarity in DNA binding properties. The result is a high-resolution atlas of gene expression-based genetic interactions that provides systems-level insight into GSTF epistasis. The atlas confirms known genetic interactions and exposes new ones. Importantly, the data can be used to investigate mechanisms that underlie individual genetic interactions. Two molecular mechanisms are proposed, "buffering by induced dependency" and "alleviation by derepression". These mechanisms indicate how negative genetic interactions can occur between seemingly unrelated parallel pathways and how positive genetic interactions can indirectly expose parallel rather than same-pathway relationships. The focus on GSTFs is important for understanding the transcription regulatory network of yeast as it uncovers details behind many redundancy relationships, some of which are completely new. In addition, the study provides general insight into the complex nature of epistasis and proposes mechanistic models for genetic interactions, the majority of which do not fall into easily recognizable within- or between-pathway relationships.

  2. Replication by the Epistasis Project of the interaction between the genes for IL-6 and IL-10 in the risk of Alzheimer's disease

    Science.gov (United States)

    Combarros, Onofre; van Duijn, Cornelia M; Hammond, Naomi; Belbin, Olivia; Arias-Vásquez, Alejandro; Cortina-Borja, Mario; Lehmann, Michael G; Aulchenko, Yurii S; Schuur, Maaike; Kölsch, Heike; Heun, Reinhard; Wilcock, Gordon K; Brown, Kristelle; Kehoe, Patrick G; Harrison, Rachel; Coto, Eliecer; Alvarez, Victoria; Deloukas, Panos; Mateo, Ignacio; Gwilliam, Rhian; Morgan, Kevin; Warden, Donald R; Smith, A David; Lehmann, Donald J

    2009-01-01

    Background Chronic inflammation is a characteristic of Alzheimer's disease (AD). An interaction associated with the risk of AD has been reported between polymorphisms in the regulatory regions of the genes for the pro-inflammatory cytokine, interleukin-6 (IL-6, gene: IL6), and the anti-inflammatory cytokine, interleukin-10 (IL-10, gene: IL10). Methods We examined this interaction in the Epistasis Project, a collaboration of 7 AD research groups, contributing DNA samples from 1,757 cases of AD and 6,295 controls. Results We replicated the interaction. For IL6 rs2069837 AA × IL10 rs1800871 CC, the synergy factor (SF) was 1.63 (95% confidence interval: 1.10–2.41, p = 0.01), controlling for centre, age, gender and apolipoprotein E ε4 (APOEε4) genotype. Our results are consistent between North Europe (SF = 1.7, p = 0.03) and North Spain (SF = 2.0, p = 0.09). Further replication may require a meta-analysis. However, association due to linkage disequilibrium with other polymorphisms in the regulatory regions of these genes cannot be excluded. Conclusion We suggest that dysregulation of both IL-6 and IL-10 in some elderly people, due in part to genetic variations in the two genes, contributes to the development of AD. Thus, inflammation facilitates the onset of sporadic AD. PMID:19698145

  3. A two-locus molecular characterization of Paramecium calkinsi.

    Science.gov (United States)

    Przyboś, Ewa; Tarcz, Sebastian; Potekhin, Alexey; Rautian, Maria; Prajer, Małgorzata

    2012-03-01

    Paramecium calkinsi (Ciliophora, Protozoa) is a euryhaline species which was first identified in freshwater habitats, but subsequently several strains were also collected from brackish water. It is characterized by clockwise spiral swimming movement and the general morphology of the "bursaria type." The present paper is the first molecular characterization of P. calkinsi strains recently collected in distant regions in Russia using ITS1-5.8S- ITS2-5'LSU rDNA (1100bp) and COI (620bp) mtDNA sequenced gene fragments. For comparison, our molecular analysis includes P. bursaria, exhibiting a similar "bursaria morphotype" as well as species representing the "aurelia type," i.e., P. caudatum, P. multimicronucleatum, P. jenningsi, and P. schewiakoffi, and some species of the P. aurelia species complex (P. primaurelia, P. tetraurelia, P. sexaurelia, and P. tredecaurelia). We also use data from GenBank concerning other species in the genus Paramecium and Tetrahymena (which used as an outgroup). The division of the genus Paramecium into four subgenera (proposed by Fokin et al. 2004) is clearly presented by the trees. There is a clear separation between P. calkinsi strains collected from different regions (races). Consequently, given the molecular distances between them, it seems that these races may represent different syngens within the species. Copyright © 2011 Elsevier GmbH. All rights reserved.

  4. A new strategy for estimating two-locus recombination fractions ...

    Indian Academy of Sciences (India)

    2011-08-19

    Aug 19, 2011 ... based on data of backcross family in the framework of some natural and necessary parameter .... received from the heterozygous parent, respectively, and the ..... the impact of ignoring the higher ordered terms in the Taylor.

  5. Selection in one- and two-locus systems

    CERN Document Server

    Nagylaki, Thomas

    1977-01-01

    Most of these notes were presented as part of a two-quarter course on theoretical population genetics at The University of Chicago. Almost all the students were either undergraduates in mathematics or graduate students in the biological sciences. The only prerequisites were calculus and matrices. As is done in these notes, biological background and additional mathematical techniques were covered when they were required. I have included the relevant problems assigned in the course. My aim in these notes is to formulate the various models fairly generally, making the biological assumptions quite explicit, and to perform the analyses relatively rigorously. I hope the choice and treatment of topics will enable the reader to understand and evaluate detailed analyses of specific models and applications in the literature. No attempt has been made to review the literature or to assign credit. Most of the references are to papers directly germane to the subjects and approaches covered here. Frequency of reference is n...

  6. Variability in working memory performance explained by epistasis vs polygenic scores in the ZNF804A pathway

    DEFF Research Database (Denmark)

    Nicodemus, Kristin K; Hargreaves, April; Morris, Derek

    2014-01-01

    disorder, major depressive disorder, and other psychosis). MAIN OUTCOMES AND MEASURES: Participants completed a neuropsychological assessment battery designed to target the cognitive deficits of schizophrenia including general cognitive function, episodic memory, working memory, attentional control......, and social cognition. RESULTS: Higher polygenic scores were associated with poorer performance among patients on IQ, memory, and social cognition, explaining 1% to 3% of variation on these scores (range, P = .01 to .03). Using a narrow psychosis training set and independent test sets of narrow phenotype...... psychosis (schizophrenia and schizoaffective disorder), broad psychosis, and control participants (n = 89), the addition of 2 interaction terms containing 2 SNPs each increased the R2 for spatial working memory strategy in the independent psychosis test sets from 1.2% using the polygenic score only to 4...

  7. Examination of Csr regulatory circuitry using epistasis analysis with RNA-seq (Epi-seq) confirms that CsrD affects gene expression via CsrA, CsrB and CsrC.

    Science.gov (United States)

    Potts, Anastasia H; Leng, Yuanyuan; Babitzke, Paul; Romeo, Tony

    2018-03-29

    The Csr global regulatory system coordinates gene expression in response to metabolic status. This system utilizes the RNA binding protein CsrA to regulate gene expression by binding to transcripts of structural and regulatory genes, thus affecting their structure, stability, translation, and/or transcription elongation. CsrA activity is controlled by sRNAs, CsrB and CsrC, which sequester CsrA away from other transcripts. CsrB/C levels are partly determined by their rates of turnover, which requires CsrD to render them susceptible to RNase E cleavage. Previous epistasis analysis suggested that CsrD affects gene expression through the other Csr components, CsrB/C and CsrA. However, those conclusions were based on a limited analysis of reporters. Here, we reassessed the global behavior of the Csr circuitry using epistasis analysis with RNA seq (Epi-seq). Because CsrD effects on mRNA levels were entirely lost in the csrA mutant and largely eliminated in a csrB/C mutant under our experimental conditions, while the majority of CsrA effects persisted in the absence of csrD, the original model accounts for the global behavior of the Csr system. Our present results also reflect a more nuanced role of CsrA as terminal regulator of the Csr system than has been recognized.

  8. In vivo Modeling Implicates APOL1 in Nephropathy: Evidence for Dominant Negative Effects and Epistasis under Anemic Stress.

    Directory of Open Access Journals (Sweden)

    Blair R Anderson

    2015-07-01

    Full Text Available African Americans have a disproportionate risk for developing nephropathy. This disparity has been attributed to coding variants (G1 and G2 in apolipoprotein L1 (APOL1; however, there is little functional evidence supporting the role of this protein in renal function. Here, we combined genetics and in vivo modeling to examine the role of apol1 in glomerular development and pronephric filtration and to test the pathogenic potential of APOL1 G1 and G2. Translational suppression or CRISPR/Cas9 genome editing of apol1 in zebrafish embryos results in podocyte loss and glomerular filtration defects. Complementation of apol1 morphants with wild-type human APOL1 mRNA rescues these defects. However, the APOL1 G1 risk allele does not ameliorate defects caused by apol1 suppression and the pathogenicity is conferred by the cis effect of both individual variants of the G1 risk haplotype (I384M/S342G. In vivo complementation studies of the G2 risk allele also indicate that the variant is deleterious to protein function. Moreover, APOL1 G2, but not G1, expression alone promotes developmental kidney defects, suggesting a possible dominant-negative effect of the altered protein. In sickle cell disease (SCD patients, we reported previously a genetic interaction between APOL1 and MYH9. Testing this interaction in vivo by co-suppressing both transcripts yielded no additive effects. However, upon genetic or chemical induction of anemia, we observed a significantly exacerbated nephropathy phenotype. Furthermore, concordant with the genetic interaction observed in SCD patients, APOL1 G2 reduces myh9 expression in vivo, suggesting a possible interaction between the altered APOL1 and myh9. Our data indicate a critical role for APOL1 in renal function that is compromised by nephropathy-risk encoding variants. Moreover, our interaction studies indicate that the MYH9 locus is also relevant to the phenotype in a stressed microenvironment and suggest that consideration of

  9. Major histocompatibility complex harbors widespread genotypic variability of non-additive risk of rheumatoid arthritis including epistasis.

    Science.gov (United States)

    Wei, Wen-Hua; Bowes, John; Plant, Darren; Viatte, Sebastien; Yarwood, Annie; Massey, Jonathan; Worthington, Jane; Eyre, Stephen

    2016-04-25

    Genotypic variability based genome-wide association studies (vGWASs) can identify potentially interacting loci without prior knowledge of the interacting factors. We report a two-stage approach to make vGWAS applicable to diseases: firstly using a mixed model approach to partition dichotomous phenotypes into additive risk and non-additive environmental residuals on the liability scale and secondly using the Levene's (Brown-Forsythe) test to assess equality of the residual variances across genotype groups per marker. We found widespread significant (P 5e-05) vGWAS signals within the major histocompatibility complex (MHC) across all three study cohorts of rheumatoid arthritis. We further identified 10 epistatic interactions between the vGWAS signals independent of the MHC additive effects, each with a weak effect but jointly explained 1.9% of phenotypic variance. PTPN22 was also identified in the discovery cohort but replicated in only one independent cohort. Combining the three cohorts boosted power of vGWAS and additionally identified TYK2 and ANKRD55. Both PTPN22 and TYK2 had evidence of interactions reported elsewhere. We conclude that vGWAS can help discover interacting loci for complex diseases but require large samples to find additional signals.

  10. Test

    DEFF Research Database (Denmark)

    Bendixen, Carsten

    2014-01-01

    Bidrag med en kortfattet, introducerende, perspektiverende og begrebsafklarende fremstilling af begrebet test i det pædagogiske univers.......Bidrag med en kortfattet, introducerende, perspektiverende og begrebsafklarende fremstilling af begrebet test i det pædagogiske univers....

  11. Testing Testing Testing.

    Science.gov (United States)

    Deville, Craig; O'Neill, Thomas; Wright, Benjamin D.; Woodcock, Richard W.; Munoz-Sandoval, Ana; Gershon, Richard C.; Bergstrom, Betty

    1998-01-01

    Articles in this special section consider (1) flow in test taking (Craig Deville); (2) testwiseness (Thomas O'Neill); (3) test length (Benjamin Wright); (4) cross-language test equating (Richard W. Woodcock and Ana Munoz-Sandoval); (5) computer-assisted testing and testwiseness (Richard Gershon and Betty Bergstrom); and (6) Web-enhanced testing…

  12. Low genetic diversity of Pneumocystis jirovecii among Cuban population based on two-locus mitochondrial typing.

    Science.gov (United States)

    de Armas, Yaxsier; Friaza, Vicente; Capó, Virginia; Durand-Joly, Isabelle; Govín, Anamays; de la Horra, Carmen; Dei-Cas, Eduardo; Calderón, Enrique J

    2012-05-01

    Genotypes of two different loci of the Pneumocystis jirovecii mitochondrial gene were studied in specimens from a total of 75 Pneumocystis pneumonia patients in Spain, France and Cuba. A new genotype of the mitochondrial small subunit rRNA gene of P. jirovecii (160A/196T) was identified, which was revealed to be the most common in these three countries, especially in Cuba where its proportion reached 93.8%. Our data imply that the new genotype might be circulating worldwide and also suggests that the distribution of P. jirovecii genotypes could be narrower in islands such as Cuba.

  13. A simple route to maximum-likelihood estimates of two-locus ...

    Indian Academy of Sciences (India)

    ulation study of their proposed algorithm, and apply it to a dataset given by Clemens .... complicated routes to MLEs are sometimes used in genetic applications when a simpler ... computing, version 3.1.2. R Foundation for Statistical Comput-.

  14. Empirical Statistical Power for Testing Multilocus Genotypic Effects under Unbalanced Designs Using a Gibbs Sampler

    Directory of Open Access Journals (Sweden)

    Chaeyoung Lee

    2012-11-01

    Full Text Available Epistasis that may explain a large portion of the phenotypic variation for complex economic traits of animals has been ignored in many genetic association studies. A Baysian method was introduced to draw inferences about multilocus genotypic effects based on their marginal posterior distributions by a Gibbs sampler. A simulation study was conducted to provide statistical powers under various unbalanced designs by using this method. Data were simulated by combined designs of number of loci, within genotype variance, and sample size in unbalanced designs with or without null combined genotype cells. Mean empirical statistical power was estimated for testing posterior mean estimate of combined genotype effect. A practical example for obtaining empirical statistical power estimates with a given sample size was provided under unbalanced designs. The empirical statistical powers would be useful for determining an optimal design when interactive associations of multiple loci with complex phenotypes were examined.

  15. Evolutionary and functional properties of a two-locus β-globin polymorphism in Indian house mice

    DEFF Research Database (Denmark)

    Runck, Amy M; Weber, Roy E.; Fago, Angela

    2010-01-01

    exceeded neutral expectations, and reconstructed haplotype networks for both β-globin paralogs revealed extensive allele sharing with several other closely related species of Mus. However, despite this suggestive evidence for balancing selection, O2-equilibrium curves revealed no discernible functional......Electrophoretic surveys of hemoglobin (Hb) polymorphism in house mice from South Asia and the Middle East have revealed that two alternative β-globin haplotypes, Hbbd and Hbbp, are often present at intermediate frequencies in geographically disparate populations. Both haplotypes harbor two......) are distinguished by two amino acid substitutions. To investigate the possible adaptive significance of the Hbbd/Hbbp polymorphism we conducted a population genetic analysis of the duplicated β-globin genes of Indian house mice (Mus castaneus) in conjunction with experimental studies of Hb function in inbred...

  16. Epistasis between neurochemical gene polymorphisms and risk for ADHD

    Science.gov (United States)

    Segurado, Ricardo; Bellgrove, Mark A; Manconi, Francesca; Gill, Michael; Hawi, Ziarah

    2011-01-01

    A number of genes with function related to synaptic neurochemistry have been genetically associated with attention deficit/hyperactivity disorder. However, susceptibility to the development of common psychiatric disorders by single variants acting alone, can so far only explain a small proportion of the heritability of the phenotype. It has been postulated that the unexplained ‘dark heritability' may at least in part be due to epistatic effects, which may account for the small observed marginal associations, and the difficulties with replication of positive findings. We undertook a comprehensive exploration of pair-wise interactions between genetic variants in 24 candidate genic regions involved in monoaminergic catabolism, anabolism, release, re-uptake and signal transmission in a sample of 177 parent-affected child trios using a case-only design and a case–pseudocontrol design using conditional logistic regression. Marker-pairs thresholded on interaction odds ratio (OR) and P-value are presented. We detected a number of interaction ORs >4.0, including an interesting correlation between markers in the ADRA1B and DBH genes in affected individuals, and several further interesting but smaller effects. These effects are no larger than you would expect by chance under the assumption of independence of all pair-wise relations; however, independence is unlikely. Furthermore, the size of these effects is of interest and attempts to replicate these results in other samples are anticipated. PMID:21368917

  17. Intramolecular epistasis and the evolution of a new enzymatic function.

    Directory of Open Access Journals (Sweden)

    Sajid Noor

    Full Text Available Atrazine chlorohydrolase (AtzA and its close relative melamine deaminase (TriA differ by just nine amino acid substitutions but have distinct catalytic activities. Together, they offer an informative model system to study the molecular processes that underpin the emergence of new enzymatic function. Here we have constructed the potential evolutionary trajectories between AtzA and TriA, and characterized the catalytic activities and biophysical properties of the intermediates along those trajectories. The order in which the nine amino acid substitutions that separate the enzymes could be introduced to either enzyme, while maintaining significant catalytic activity, was dictated by epistatic interactions, principally between three amino acids within the active site: namely, S331C, N328D and F84L. The mechanistic basis for the epistatic relationships is consistent with a model for the catalytic mechanisms in which protonation is required for hydrolysis of melamine, but not atrazine.

  18. Test Architecture, Test Retrofit

    Science.gov (United States)

    Fulcher, Glenn; Davidson, Fred

    2009-01-01

    Just like buildings, tests are designed and built for specific purposes, people, and uses. However, both buildings and tests grow and change over time as the needs of their users change. Sometimes, they are also both used for purposes other than those intended in the original designs. This paper explores architecture as a metaphor for language…

  19. Testing Significance Testing

    Directory of Open Access Journals (Sweden)

    Joachim I. Krueger

    2018-04-01

    Full Text Available The practice of Significance Testing (ST remains widespread in psychological science despite continual criticism of its flaws and abuses. Using simulation experiments, we address four concerns about ST and for two of these we compare ST’s performance with prominent alternatives. We find the following: First, the 'p' values delivered by ST predict the posterior probability of the tested hypothesis well under many research conditions. Second, low 'p' values support inductive inferences because they are most likely to occur when the tested hypothesis is false. Third, 'p' values track likelihood ratios without raising the uncertainties of relative inference. Fourth, 'p' values predict the replicability of research findings better than confidence intervals do. Given these results, we conclude that 'p' values may be used judiciously as a heuristic tool for inductive inference. Yet, 'p' values cannot bear the full burden of inference. We encourage researchers to be flexible in their selection and use of statistical methods.

  20. Seismic testing

    International Nuclear Information System (INIS)

    Sollogoub, Pierre

    2001-01-01

    This lecture deals with: qualification methods for seismic testing; objectives of seismic testing; seismic testing standards including examples; main content of standard; testing means; and some important elements of seismic testing

  1. Schirmer test

    Science.gov (United States)

    Tear test; Tearing test; Dry eye test; Basal secretion test; Sjögren - Schirmer; Schirmer's test ... used when the eye doctor suspects you have dry eye. Symptoms include dryness of the eyes or excessive ...

  2. Pinworm test

    Science.gov (United States)

    Oxyuriasis test; Enterobiasis test; Tape test ... diagnose this infection is to do a tape test. The best time to do this is in ... lay their eggs at night. Steps for the test are: Firmly press the sticky side of a ...

  3. Ultrasonic Testing

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyeong Jun; Kuk, Jeong Han

    2002-02-15

    This book introduces ultrasonic testing, which tells of outline of ultrasonic testing, principle of ultrasonic testing, prosperities of ultrasonic waves, radiographic test and ultrasonic test, basic theory on ultrasonic testing, mode conversion, transmission and diffraction, ultrasonic flaw detection and probe, standard test piece and reference test piece, like KS(JIS) ASME and ASTM, classification and properties of ultrasonic testing, straight beam method, angle beam method, ASME SEC.V.Art.5 ASTMA 388 and KS B 0817 Korean industrial standard.

  4. Trichomonas Testing

    Science.gov (United States)

    ... Genetic Tests for Targeted Cancer Therapy Glucose Tests Gonorrhea Testing Gram Stain Growth Hormone Haptoglobin hCG Pregnancy ... With some NAATs, samples collected for testing of gonorrhea and chlamydial infections can also be used to ...

  5. Coombs test

    Science.gov (United States)

    Direct antiglobulin test; Indirect antiglobulin test; Anemia - hemolytic ... No special preparation is necessary for this test. ... There are 2 types of the Coombs test: Direct Indirect The direct ... that are stuck to the surface of red blood cells. Many diseases ...

  6. Ham test

    Science.gov (United States)

    Acid hemolysin test; Paroxysmal nocturnal hemoglobinuria - Ham test; PNH - Ham test ... BJ. In: Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures . 6th ed. Philadelphia, PA: Elsevier ...

  7. Magnesium Test

    Science.gov (United States)

    ... PF4 Antibody Hepatitis A Testing Hepatitis B Testing Hepatitis C Testing HER2/neu Herpes Testing High-sensitivity C-reactive Protein (hs-CRP) Histamine Histone Antibody HIV Antibody and HIV Antigen (p24) HIV Antiretroviral Drug Resistance Testing, Genotypic HIV Viral Load HLA Testing HLA- ...

  8. Lipase Test

    Science.gov (United States)

    ... PF4 Antibody Hepatitis A Testing Hepatitis B Testing Hepatitis C Testing HER2/neu Herpes Testing High-sensitivity C-reactive Protein (hs-CRP) Histamine Histone Antibody HIV Antibody and HIV Antigen (p24) HIV Antiretroviral Drug Resistance Testing, Genotypic HIV Viral Load HLA Testing HLA- ...

  9. Rubella Test

    Science.gov (United States)

    ... PF4 Antibody Hepatitis A Testing Hepatitis B Testing Hepatitis C Testing HER2/neu Herpes Testing High-sensitivity C-reactive Protein (hs-CRP) Histamine Histone Antibody HIV Antibody and HIV Antigen (p24) HIV Antiretroviral Drug Resistance Testing, Genotypic HIV Viral Load HLA Testing HLA- ...

  10. Mono Test

    Science.gov (United States)

    ... PF4 Antibody Hepatitis A Testing Hepatitis B Testing Hepatitis C Testing HER2/neu Herpes Testing High-sensitivity C-reactive Protein (hs-CRP) Histamine Histone Antibody HIV Antibody and HIV Antigen (p24) HIV Antiretroviral Drug Resistance Testing, Genotypic HIV Viral Load HLA Testing HLA- ...

  11. AMA Test

    Science.gov (United States)

    ... PF4 Antibody Hepatitis A Testing Hepatitis B Testing Hepatitis C Testing HER2/neu Herpes Testing High-sensitivity C-reactive Protein (hs-CRP) Histamine Histone Antibody HIV Antibody and HIV Antigen (p24) HIV Antiretroviral Drug Resistance Testing, Genotypic HIV Viral Load HLA Testing HLA- ...

  12. Neuropathy Tests

    Science.gov (United States)

    ... LD) Lactoferrin Lactose Tolerance Tests LDL Cholesterol LDL Particle Testing (LDL-P) Lead Legionella Testing Leptin Levetiracetam Lipase ... tests, such as computed tomography (CT) scans or magnetic resonance imaging ... suspected, additional testing may be performed to evaluate heart rate, blood ...

  13. Pharmacogenomic Testing

    Science.gov (United States)

    ... your family Plan for the future Insurance and financial planning Transition for children Emergency preparedness Testing & Services Testing ... Support Genetic Disease Information Find a Support Group Financial Planning Who Should I Tell? Genetic Testing & Counseling Compensation ...

  14. Predictive Testing

    Science.gov (United States)

    ... your family Plan for the future Insurance and financial planning Transition for children Emergency preparedness Testing & Services Testing ... Support Genetic Disease Information Find a Support Group Financial Planning Who Should I Tell? Genetic Testing & Counseling Compensation ...

  15. Syphilis Test

    Science.gov (United States)

    ... Genetic Tests for Targeted Cancer Therapy Glucose Tests Gonorrhea Testing Gram Stain Growth Hormone Haptoglobin hCG Pregnancy ... treated for another sexually transmitted disease , such as gonorrhea Is pregnant, during the first prenatal visit and ...

  16. Randomization tests

    CERN Document Server

    Edgington, Eugene

    2007-01-01

    Statistical Tests That Do Not Require Random Sampling Randomization Tests Numerical Examples Randomization Tests and Nonrandom Samples The Prevalence of Nonrandom Samples in Experiments The Irrelevance of Random Samples for the Typical Experiment Generalizing from Nonrandom Samples Intelligibility Respect for the Validity of Randomization Tests Versatility Practicality Precursors of Randomization Tests Other Applications of Permutation Tests Questions and Exercises Notes References Randomized Experiments Unique Benefits of Experiments Experimentation without Mani

  17. Test chamber

    NARCIS (Netherlands)

    Leferink, Frank Bernardus Johannes

    2009-01-01

    A test chamber for measuring electromagnetic radiation emitted by an apparatus to be tested or for exposing an apparatus to be tested to an electromagnetic radiation field. The test chamber includes a reverberation chamber made of a conductive tent fabric. To create a statistically uniform field in

  18. Tensile testing

    CERN Document Server

    2004-01-01

    A complete guide to the uniaxial tensile test, the cornerstone test for determining the mechanical properties of materials: Learn ways to predict material behavior through tensile testing. Learn how to test metals, alloys, composites, ceramics, and plastics to determine strength, ductility and elastic/plastic deformation. A must for laboratory managers, technicians, materials and design engineers, and students involved with uniaxial tensile testing. Tensile Testing , Second Edition begins with an introduction and overview of the test, with clear explanations of how materials properties are determined from test results. Subsequent sections illustrate how knowledge gained through tensile tests, such as tension properties to predict the behavior (including strength, ductility, elastic or plastic deformation, tensile and yield strengths) have resulted in improvements in materals applications. The Second Edition is completely revised and updated. It includes expanded coverage throughout the volume on a variety of ...

  19. Test quality

    International Nuclear Information System (INIS)

    Hartley, R.S.; Keller, A.E.

    1992-01-01

    Inservice testing of safety-related components at nuclear power plants is performed under the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (the Code). Subsections IWP and IWV of Section 11 of the Code state test method and frequency requirements for pumps and valves, respectively. Tests vary greatly in quality and frequency. This paper explores the concept of test quality and its relationship with operational readiness and preventive maintenance. This paper also considers the frequencies of component testing. Test quality is related to a test's ability to detect degradation that can cause component failure. The quality of the test depends on several factors, including specific parameters measured, system or component conditions, and instrument accuracy. The quality of some currently required tests for check valves, motor-operated valves, and pumps is also discussed. Suggestions are made to improve test quality by measuring different parameters, testing valves under load, and testing positive displacement pumps at high pressure and centrifugal pumps at high flow rate conditions. These suggestions can help to improve the level of assurance of component operational readiness gained from testing

  20. Test quality

    International Nuclear Information System (INIS)

    Hartley, R.S.; Keller, A.E.

    1992-01-01

    This document discusses inservice testing of safety-related components at nuclear power plants which is performed under the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (the Code). Subsections IWP and IWV of Section XI of the Code state test method and frequency requirements for pumps and valves respectively. Tests vary greatly in quality and frequency. This paper explores the concept of test quality and its relationship with operational readiness and preventive maintenance. This paper also considers the frequencies of component testing. Test quality is related to a test's ability to detect degradation that can cause component failure. The quality of the test depends on several factors, including specific parameters measured, system or component conditions, and instrument accuracy. The quality of some currently required tests for check valves, motor-operated valves, and pumps is also discussed. Suggestions are made to improve test quality by measuring different parameters, testing valves under load, and testing positive displacement pumps at high pressure and centrifugal pumps at high flow rate conditions. These suggestions can help to improve the level of assurance of component operational readiness gained from testing

  1. Randomization tests

    National Research Council Canada - National Science Library

    Edgington, Eugene S

    1980-01-01

    .... This book provides all the necessary theory and practical guidelines, such as instructions for writing computer programs, to permit experimenters to transform any statistical test into a distribution-free test...

  2. Laboratory Tests

    Science.gov (United States)

    ... Medical Devices Radiation-Emitting Products Vaccines, Blood & Biologics Animal & ... What are lab tests? Laboratory tests are medical devices that are intended for use on samples of blood, urine, or other tissues ...

  3. Triglycerides Test

    Science.gov (United States)

    ... K. Brunner & Suddarth's Handbook of Laboratory and Diagnostic Tests. 2 nd Ed, Kindle. Philadelphia: Wolters Kluwer Health, Lippincott Williams & Wilkins; c2014. Triglycerides; 491–2 p. Lab Tests ...

  4. Lactate Test

    Science.gov (United States)

    ... Plasma Free Metanephrines Platelet Count Platelet Function Tests Pleural Fluid Analysis PML-RARA Porphyrin Tests Potassium Prealbumin ... ency/article/000391.htm . (2002 January, Updated). Lactate (Liquid) Reagent Set. Pointe Scientific, Inc. [On-line Reagent ...

  5. Electrolytes Test

    Science.gov (United States)

    ... Plasma Free Metanephrines Platelet Count Platelet Function Tests Pleural Fluid Analysis PML-RARA Porphyrin Tests Potassium Prealbumin ... of potassium is found in the plasma , the liquid portion of the blood. Monitoring potassium is important ...

  6. Ferritin Test

    Science.gov (United States)

    ... normal" values. By comparing your test results with reference values, you and your healthcare provider can see if ... along with other iron tests , when a routine complete blood count (CBC) shows that a person's hemoglobin and hematocrit ...

  7. Cholesterol Test

    Science.gov (United States)

    ... artery disease. Other names for a cholesterol test: Lipid profile, Lipid panel What is it used for? If you ... Clinic [Internet]. Mayo Foundation for Medical Education and Research; c1998-2017.Cholesterol Test: Overview; 2016 Jan 12 [ ...

  8. Gonorrhea Test

    Science.gov (United States)

    ... Links Patient Resources For Health Professionals Subscribe Search Gonorrhea Testing Send Us Your Feedback Choose Topic At ... Sources Ask Us Also Known As GC Test Gonorrhea NAAT or NAT Neisseria gonorrhoeae Nucleic Acid Amplification ...

  9. Susceptibility Testing

    Science.gov (United States)

    ... Marker Bicarbonate (Total CO2) Bilirubin Blood Culture Blood Gases Blood Ketones Blood Smear Blood Typing Blood Urea ... hours depending on the method used. There are commercial tests available that offer rapid susceptibility testing and ...

  10. Nationale test

    DEFF Research Database (Denmark)

    2009-01-01

    Professor Sven Erik Nordenbo og centerleder Niels Egelund, begge DPU, i samtale om nationale test.......Professor Sven Erik Nordenbo og centerleder Niels Egelund, begge DPU, i samtale om nationale test....

  11. Nationale Test

    DEFF Research Database (Denmark)

    2009-01-01

    Hvad er egentlig formålet med de nationale test? Bliver eleverne klogere af at blive testet? Og er der en sammenhæng mellem bandekrig og nationale test? Fysisk medie: dpu.dk/tv......Hvad er egentlig formålet med de nationale test? Bliver eleverne klogere af at blive testet? Og er der en sammenhæng mellem bandekrig og nationale test? Fysisk medie: dpu.dk/tv...

  12. VDRL test

    Science.gov (United States)

    ... confirmed with another blood test to make the diagnosis of syphilis. Normal value ranges may vary slightly among different ... broken) Alternative Names Venereal disease research ... laboratory test (VDRL) – serum. In: Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures . 6th ed. St Louis, MO: Elsevier Saunders; ...

  13. Drug Testing

    Science.gov (United States)

    ... testing, substance abuse testing, toxicology screen, tox screen, sports doping tests What is it used for? Drug screening is used to find out whether or not a person has taken a certain drug or drugs. It ... Sports organizations. Professional and collegiate athletes usually need to ...

  14. HIV Testing

    Science.gov (United States)

    ... Abroad Treatment Basic Statistics Get Tested Find an HIV testing site near you. Enter ZIP code or city Follow HIV/AIDS CDC HIV CDC HIV/AIDS See RSS | ... All Collapse All Should I get tested for HIV? CDC recommends that everyone between the ages of ...

  15. Nondestructive Testing

    Energy Technology Data Exchange (ETDEWEB)

    Berger, Harold [Argonne National Laboratory

    1969-01-01

    A nondestructive test is an examination of an object in any manner which will not impair the future usefulness of the object. This booklet discusses a few basic methods of nondestructive testing, and some of their characteristics. In addition, it discusses possible future methods for nondestructive testing by taking a quick look at some of the methods now under study.

  16. Ultrasonic testing

    Energy Technology Data Exchange (ETDEWEB)

    Song, Sung Jin [Sungkwunkwan Univ., Seoul (Korea, Republic of); Jeong, Hyun Jo [Wonkwang Univ., Iksan (Korea, Republic of)

    2004-02-15

    For the proper performance of ultrasonic testing of steel welded joints, and anisotropic material it is necessary to have sound understanding on the underlying physics. To provide such an understanding, it is beneficial to have simulation tools for ultrasonic testing. In order to address such a need, we develop effective approaches to simulate angle beam ultrasonic testing with a personal computer. The simulation is performed using ultrasonic measurement models based on the computationally efficient multi-Gaussian beams. This reach will describe the developed ultrasonic testing models together with the experimental verification of their accuracy.

  17. Troponins Test

    Science.gov (United States)

    ... lab's website in order to provide you with background information about the test(s) you had performed. You will need to return ... C, Banfi G, Guidi GC. Influence of a half-marathon run on NT-proBNP and troponin ... MedlinePlus Medical Encyclopedia [On-line information]. Available online ...

  18. Insulin Test

    Science.gov (United States)

    ... hours before blood is collected, but occasionally a health practitioner may do testing when fasting is not possible, such as when a glucose tolerance test (see Glucose ) is done. In some cases, the health practitioner may request that a person fast longer ...

  19. Genetic Testing

    Science.gov (United States)

    ... is often the only way to determine if symptoms could possibly be related to celiac disease. For a person who faces this situation, a negative gene test would indicate that symptoms are not the result of celiac disease. A positive gene test, however, does not diagnose ...

  20. Potassium test

    Science.gov (United States)

    ... hyperkalemia ) may be due to: Addison disease (rare) Blood transfusion Certain medicines Crushed tissue injury Hyperkalemic periodic paralysis ... released. This may cause a falsely high result. Alternative Names Hypokalemia test; K+ Images Blood test References Mount DB. Disorders of potassium balance. ...

  1. Nationale test

    DEFF Research Database (Denmark)

    Bundsgaard, Jeppe; Puck, Morten Rasmus

    Nationale test skubber undervisning i en forkert retning. Det er lærerne og skolelederne enige om. Men særligt skolelederne ser også muligheder for at bruge testen til at få viden om elevernes faglige kompetencer og om undervisningen. Det kommer til udtryk i rapporten Nationale test: Danske lærere...

  2. Oedometer Tests

    DEFF Research Database (Denmark)

    Thorsen, Grete

    1996-01-01

    The paper describes the results of oedometer tests carried out with samples from Eemian fresh-water deposits and the methods used to determine the preconsolidation pressure from the test results. The influence of creep in the material on the apparent preconsolidation pressure is estimated from...

  3. TORCH Test

    Science.gov (United States)

    ... Parietal Cell Antibody Partial Thromboplastin Time (PTT, aPTT) Parvovirus B19 Pericardial Fluid Analysis Peritoneal Fluid Analysis Pertussis Tests ... enterovirus, Epstein-Barr virus , varicella-zoster virus , and parvovirus B19 . How is the sample collected for testing? A ...

  4. Automating Test Activities: Test Cases Creation, Test Execution, and Test Reporting with Multiple Test Automation Tools

    OpenAIRE

    Loke Mun Sei

    2015-01-01

    Software testing has become a mandatory process in assuring the software product quality. Hence, test management is needed in order to manage the test activities conducted in the software test life cycle. This paper discusses on the challenges faced in the software test life cycle, and how the test processes and test activities, mainly on test cases creation, test execution, and test reporting is being managed and automated using several test automation tools, i.e. Jira, ...

  5. A replication study for association of ITPKC and CASP3 two-locus analysis in IVIG unresponsiveness and coronary artery lesion in Kawasaki disease.

    Directory of Open Access Journals (Sweden)

    Ho-Chang Kuo

    Full Text Available Single-nucleotide polymorphisms (SNPs in inositol 1,4,5-trisphosphate 3-kinase C (ITPKC, rs28493229 and caspase-3 (CASP3, rs113420705 are associated with susceptibility to KD in Japanese and Taiwanese populations. This study was conducted to investigate the involvement of these 2 SNPs in the risk for intravenous immunoglobulin (IVIG resistance and coronary artery lesion (CAL in Taiwanese population. A total of 340 KD patients were subjected to assess by the identification of 2-locus genes model. A combinatorial association between ITPKC (rs28493229 and CASP3 (rs113420705 was found in CAL formation (P = 0.0227, OR: 3.06. KD patients with high-risk genotype had a trend of overrepresentation in IVIG resistance compared with individual SNPs. Our findings suggest the existence of genetic factors affecting patients' risk for CAL formation and IVIG responsiveness in a Taiwanese population.

  6. Trypsinogen test

    Science.gov (United States)

    ... care provider about the meaning of your specific test results. What Abnormal Results ... vary in size, so it may be harder to get a blood sample from one person than another. Other risks associated with having ...

  7. Just testing

    International Nuclear Information System (INIS)

    Robinson, D.

    1985-01-01

    In the 1950s, most of the men who witnessed Britain's nuclear tests at Christmas Island in the Pacific were national servicemen, aged 19 or 20. Some revelled in sun and swimming, some were bored, some were too busy to be bored. How many of the twenty thousand servicemen involved in the tests suspected that they might be exposed to radiation that would reveal itself a generation later in blood and bone cancers, sterility, cataracts, or deformities in their children. The Ministry of Defence insists nobody was in danger. This book tells a different story, in the words of the servicemen, and of their medical reports, about secrets which are no longer Official. It is important not only to the victims of a government's extraordinary reluctance to face up to the tragic consequences of a programme of nuclear tests on Christmas Island and in Australia, but to anyone concerned with the damage that nuclear testing is still doing in the world today. (author)

  8. Test Ship

    Data.gov (United States)

    Federal Laboratory Consortium — The U. S. Navy dedicated the decommissioned Spruance Class destroyer ex-PAUL F. FOSTER (EDD 964), Test Ship, primarily for at sea demonstration of short range weapon...

  9. Injection Tests

    CERN Document Server

    Kain, V

    2009-01-01

    The success of the start-up of the LHC on 10th of September was in part due to the preparation without beam and injection tests in 2008. The injection tests allowed debugging and improvement in appropriate portions to allow safe, efficient and state-of-the-art commissioning later on. The usefulness of such an approach for a successful start-up becomes obvious when looking at the problems we encountered before and during the injection tests and could solve during this period. The outline of the preparation and highlights of the different injection tests will be presented and the excellent performance of many tools discussed. A list of shortcomings will follow, leading to some planning for the preparation of the run in 2009.

  10. Fungal Tests

    Science.gov (United States)

    ... Wu, A. (2006). Tietz Clinical Guide to Laboratory Tests, Fourth Edition. Saunders Elsevier, St. Louis, Missouri. Pp 1569, 1570, 1532, 1616. Forbes, B. et. al. (© 2007). Bailey & Scott's Diagnostic Microbiology, Twelfth Edition: Mosby Elsevier Press, St. Louis, Missouri. ...

  11. PTH Test

    Science.gov (United States)

    ... Gregory C. Sephel PhD FACB MT(ASCP). Lab Tests Online adjunct board member. Director Clinical Pathology, VA TN Valley Healthcare System; Associate Professor Pathology, Microbiology, Immunology, Vanderbilt University School of Medicine. Sources Used ...

  12. Phosphorus Test

    Science.gov (United States)

    ... be seen with increased intake of the mineral, hypocalcemia , and with kidney dysfunction. Someone with a mild ... usually detected because of the relationship with and effect on calcium levels . Calcium is routinely tested as ...

  13. Procalcitonin Test

    Science.gov (United States)

    ... normal" values. By comparing your test results with reference values, you and your healthcare provider can see if ... g., blood culture , urine culture ), lactate , blood gases , complete blood count (CBC) , and cerebrospinal fluid (CSF) analysis . When is ...

  14. RSV Test

    Science.gov (United States)

    ... Sex Hormone Binding Globulin (SHBG) Shiga toxin-producing Escherichia coli Sickle Cell Tests Sirolimus Smooth Muscle Antibody (SMA) ... University Medical Center, LAB Letter [On-line newsletter]. PDF available for download at http://www.stanfordhospital.com/ ...

  15. Prenatal Tests

    Science.gov (United States)

    ... tests are considered routine — that is, almost all pregnant women receiving prenatal care get them. They include things like checking urine (pee) levels for protein, sugar, or signs of infection. Other non-routine ...

  16. Progesterone Test

    Science.gov (United States)

    ... replacement therapy, or help diagnose the cause of abnormal uterine bleeding When To Get Tested? At specific times during ... receiving progesterone replacement therapy; when a woman has abnormal uterine bleeding Sample Required? A blood sample drawn from a ...

  17. Testosterone Test

    Science.gov (United States)

    ... Testing Triglycerides Troponin Tryptase Tumor Markers Uric Acid Urinalysis Urine Albumin and Albumin/Creatinine Ratio Urine Culture ... 2010) 2536–259. Centers for Disease Control Hormone Standardization website(HoST). Available online at http://www.cdc. ...

  18. Pertussis Tests

    Science.gov (United States)

    ... of Conditions Not Listed? Not Listed? Acidosis and Alkalosis Adrenal Insufficiency and Addison Disease Alcoholism Allergies Alzheimer ... tested? Pertussis, commonly called whooping cough, is a respiratory infection caused by the bacteria Bordetella pertussis . These ...

  19. Tests computarizados

    Directory of Open Access Journals (Sweden)

    R. Fernando Prialé Z.

    1983-12-01

    Full Text Available En primer lugar, se considera el impacto de las microcomputadoras en la actualidad, viéndolo como un hecho social destinado a traer profundos cambios: nos orientamos hacia una cultura informática cuyo signo es la posibilidad de tratar grandes cantidades de información. En segundo lugar; se analiza brevemente la importancia de los tests en el desarrollo de la psicología. Finalmente, se discute la posibilidad de aplicar la informática a la psicometría con el ejemplo del test de BARSIT.   The impact of microcomputers is discussed as a cultural fact that will bring profound changes in the near future: a society with an ubiquous capacity for treating big amounts of information. The importance of tests for the development of psychology is then analysed. Finaly, the possibility of applying microcomputers to psychometry is discussed trough a concrete example: The BARSIT test.

  20. VMA Test

    Science.gov (United States)

    ... spasms and rapid eye movements referred to as "dancing eyes, dancing feet." The VMA test may also be ordered ... a pheochromocytoma or neuroblastoma? People with a family history of multiple endocrine neoplasia (MEN2), a genetic condition ...

  1. Neuropsychological testing.

    Science.gov (United States)

    Zucchella, Chiara; Federico, Angela; Martini, Alice; Tinazzi, Michele; Bartolo, Michelangelo; Tamburin, Stefano

    2018-06-01

    Neuropsychological testing is a key diagnostic tool for assessing people with dementia and mild cognitive impairment, but can also help in other neurological conditions such as Parkinson's disease, stroke, multiple sclerosis, traumatic brain injury and epilepsy. While cognitive screening tests offer gross information, detailed neuropsychological evaluation can provide data on different cognitive domains (visuospatial function, memory, attention, executive function, language and praxis) as well as neuropsychiatric and behavioural features. We should regard neuropsychological testing as an extension of the neurological examination applied to higher order cortical function, since each cognitive domain has an anatomical substrate. Ideally, neurologists should discuss the indications and results of neuropsychological assessment with a clinical neuropsychologist. This paper summarises the rationale, indications, main features, most common tests and pitfalls in neuropsychological evaluation. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  2. Testing theories

    International Nuclear Information System (INIS)

    Casten, R F

    2015-01-01

    This paper discusses some simple issues that arise in testing models, with a focus on models for low energy nuclear structure. By way of simplified examples, we illustrate some dangers in blind statistical assessments, pointing out especially the need to include theoretical uncertainties, the danger of over-weighting precise or physically redundant experimental results, the need to assess competing theories with independent and physically sensitive observables, and the value of statistical tests properly evaluated. (paper)

  3. Testing the utility of matK and ITS DNA regions for discrimination of Allium species

    Science.gov (United States)

    Molecular phylogenetic analysis of the genus Allium L. has been mainly based on the nucleotide sequences of ITS region. In 2009 matK and rbcL were accepted as a two-locus DNA barcode to classify plant species by the Consortium for the Barcode of Life (CBOL) Plant Working Group. MatK region has been ...

  4. Allergy testing - skin

    Science.gov (United States)

    Patch tests - allergy; Scratch tests - allergy; Skin tests - allergy; RAST test; Allergic rhinitis - allergy testing; Asthma - allergy testing; Eczema - allergy testing; Hayfever - allergy testing; Dermatitis - allergy testing; Allergy testing; ...

  5. Adaptive test

    DEFF Research Database (Denmark)

    Kjeldsen, Lars Peter; Eriksen, Mette Rose

    2010-01-01

    Artikelen er en evaluering af de adaptive tests, som blev indført i folkeskolen. Artiklen sætter særligt fokus på evaluering i folkeskolen, herunder bidrager den med vejledning til evaluering, evalueringsværktøjer og fagspecifkt evalueringsmateriale.......Artikelen er en evaluering af de adaptive tests, som blev indført i folkeskolen. Artiklen sætter særligt fokus på evaluering i folkeskolen, herunder bidrager den med vejledning til evaluering, evalueringsværktøjer og fagspecifkt evalueringsmateriale....

  6. Tests computarizados

    OpenAIRE

    Prialé Z., R. Fernando

    1983-01-01

    En primer lugar, se considera el impacto de las microcomputadoras en la actualidad, viéndolo como un hecho social destinado a traer profundos cambios: nos orientamos hacia una cultura informática cuyo signo es la posibilidad de tratar grandes cantidades de información. En segundo lugar; se analiza brevemente la importancia de los tests en el desarrollo de la psicología. Finalmente, se discute la posibilidad de aplicar la informática a la psicometría con el ejemplo del test de BARSIT.   The im...

  7. Testing Hubbert

    International Nuclear Information System (INIS)

    Brandt, Adam R.

    2007-01-01

    The Hubbert theory of oil depletion, which states that oil production in large regions follows a bell-shaped curve over time, has been cited as a method to predict the future of global oil production. However, the assumptions of the Hubbert method have never been rigorously tested with a large, publicly available data set. In this paper, three assumptions of the modern Hubbert theory are tested using data from 139 oil producing regions. These regions are sub-national (United States state-level, United States regional-level), national, and multi-national (subcontinental and continental) in scale. We test the assumption that oil production follows a bell-shaped curve by generating best-fitting curves for each region using six models and comparing the quality of fit across models. We also test the assumptions that production over time in a region tends to be symmetric, and that production is more bell-shaped in larger regions than in smaller regions

  8. Prealbumin Test

    Science.gov (United States)

    ... T. J. (© 2007). Mosby's Diagnostic and Laboratory Test Reference 8th Edition: Mosby, Inc., Saint Louis, MO. Pp 755-756. Clarke, W. and Dufour, D. R., Editors (© 2006). Contemporary Practice in Clinical Chemistry: AACC Press, Washington, DC. Pp 197. Banh, L. ( ...

  9. Genomic Testing

    Science.gov (United States)

    ... this database. Top of Page Evaluation of Genomic Applications in Practice and Prevention (EGAPP™) In 2004, the Centers for Disease Control and Prevention launched the EGAPP initiative to establish and test a ... and other applications of genomic technology that are in transition from ...

  10. Fibrinogen Test

    Science.gov (United States)

    ... thrombotic episode ) As a follow-up to an abnormal bleeding disorder test ( prothrombin time, PT or partial thromboplastin time, ... to help diagnose disseminated intravascular coagulation (DIC) or abnormal ... status of a progressive disease (such as liver disease ) over time or, rarely, ...

  11. (stress) testing

    African Journals Online (AJOL)

    However, maximal HR was significantly higher in all groups during their sporting activities than during stress testing in the laboratory (P < 0.01). Conclusions. Maximal HR in veteran athletes during specific sporting activities was significantly higher than that attained during a routine sECG. This finding was not sport-specific, ...

  12. Trypsinogen Test

    Science.gov (United States)

    ... exocrine.html. UPCMD (1998 – 2002). Cystic Fibrosis. University Pathology Consortium, LLC [On-line information]. Available online at http://www.upcmd.com/dot/examples/00218/description.html. Sainato, D., (2002, March). Genetic Testing for CF Going Mainstream? Clinical Laboratory ...

  13. Chymotrypsin Test

    Science.gov (United States)

    ... exocrine.html. UPCMD (1998 – 2002). Cystic Fibrosis. University Pathology Consortium, LLC [On-line information]. Available online at http://www.upcmd.com/dot/examples/00218/description.html. Sainato, D., (2002, March). Genetic Testing for CF Going Mainstream? Clinical Laboratory ...

  14. Radiographic Test

    Energy Technology Data Exchange (ETDEWEB)

    Lee, H.J; Yang, S.H. [Korea Electric Power Research Institute, Taejon (Korea)

    2002-07-01

    This report contains theory, procedure technique and interpretation of radiographic examination and written for whom preparing radiographic test Level II. To determine this baseline of technical competence in the examination, the individual must demonstrate a knowledge of radiography physics, radiation safety, technique development, radiation detection and measurement, facility design, and the characteristics of radiation-producing devices and their principles of operation. (author) 98 figs., 23 tabs.

  15. Testing Understanding and Understanding Testing.

    Science.gov (United States)

    Pedersen, Jean; Ross, Peter

    1985-01-01

    Provides examples in which graphs are used in the statements of problems or in their solutions as a means of testing understanding of mathematical concepts. Examples (appropriate for a beginning course in calculus and analytic geometry) include slopes of lines and curves, quadratic formula, properties of the definite integral, and others. (JN)

  16. Credibility test; Vertrauens-Test

    Energy Technology Data Exchange (ETDEWEB)

    Fuhs, Michael

    2009-07-01

    Solar wafer producers must prove their quality standards. Q-Cells has started a marketing office and opened their test center to journalists. They are aware that adherence to standards is going only half the way of quality assurance. The other half consists in gaining the customers' trust. (orig.)

  17. Knowledge Test

    DEFF Research Database (Denmark)

    Sørensen, Ole Henning

    1998-01-01

    The knowledge test is about competing temporal and spatial expressions of the politics of technological development and national prosperity in contemporary society. The discussion is based on literature of national systems of innovation and industrial networks of various sorts. Similarities...... and differences in the disparate theories are discussed through a critical perspective on metaphor, time, space, agency and technology. It is asserted that the process of globalization is leading to a new production of space-time perceptions and practices where localization and globalization is becoming...... increasingly important. National space is being contested and nation states need to perform differently....

  18. QTL identification of grain protein concentration and its genetic ...

    Indian Academy of Sciences (India)

    culated using the statistical software package SPSS 12.0. (SPSS, Chicago, USA). ... Joint QTL analysis for PC and GWP/SC was carried out according to the multiple interval ..... testing for epistasis: an application in maize. Theor. Appl. Genet.

  19. Testing SUSY

    CERN Document Server

    Cassel, S; Ross, G G

    2010-01-01

    If SUSY provides a solution to the hierarchy problem then supersymmetric states should not be too heavy. This requirement is quantified by the Barbieri-Giudice fine tuning measure that provides a quantitative test of SUSY as a solution to the hierarchy problem. The measure is useful in correlating the impact of the various experimental measurements relevant to the search for supersymmetry and also in identifying the most sensitive measurements for testing SUSY. In this paper we apply the measure to the CMSSM, computing it to two-loop order and taking account of current experimental limits and the constraint on dark matter abundance. Using this we determine the present limits on the CMSSM parameter space and identify the measurements at the LHC that are most significant in covering the remaining parameter space. Without imposing the LEP Higgs mass bound we show that the smallest fine tuning (1:14.5) consistent with a saturation of the relic density within the 1$\\sigma$ WMAP bounds corresponds to a Higgs mass o...

  20. Heart failure - tests

    Science.gov (United States)

    CHF - tests; Congestive heart failure - tests; Cardiomyopathy - tests; HF - tests ... the best test to: Identify which type of heart failure (systolic, diastolic, valvular) Monitor your heart failure and ...

  1. Nuclear stress test

    Science.gov (United States)

    ... Persantine stress test; Thallium stress test; Stress test - nuclear; Adenosine stress test; Regadenoson stress test; CAD - nuclear stress; Coronary artery disease - nuclear stress; Angina - nuclear ...

  2. Computer-Based Testing: Test Site Security.

    Science.gov (United States)

    Rosen, Gerald A.

    Computer-based testing places great burdens on all involved parties to ensure test security. A task analysis of test site security might identify the areas of protecting the test, protecting the data, and protecting the environment as essential issues in test security. Protecting the test involves transmission of the examinations, identifying the…

  3. Mononucleosis spot test

    Science.gov (United States)

    Monospot test; Heterophile antibody test; Heterophile agglutination test; Paul-Bunnell test; Forssman antibody test ... The mononucleosis spot test is done when symptoms of mononucleosis are ... Fatigue Fever Large spleen (possibly) Sore throat Tender ...

  4. Coccidioides precipitin test

    Science.gov (United States)

    Coccidioidomycosis antibody test; Coccidioides blood test; Valley fever blood test ... There is no special preparation for the test. ... The precipitin test is one of several tests that can be done to determine if you are infected with coccidioides, which ...

  5. Myoglobin urine test

    Science.gov (United States)

    Urine myoglobin; Heart attack - myoglobin urine test; Myositis - myoglobin urine test; Rhabdomyolysis - myoglobin urine test ... The test involves only normal urination, which should cause no discomfort.

  6. A chromosome 5q31.1 locus associates with tuberculin skin test reactivity in HIV-positive individuals from tuberculosis hyper-endemic regions in east Africa.

    Directory of Open Access Journals (Sweden)

    Rafal S Sobota

    2017-06-01

    Full Text Available One in three people has been infected with Mycobacterium tuberculosis (MTB, and the risk for MTB infection in HIV-infected individuals is even higher. We hypothesized that HIV-positive individuals living in tuberculosis-endemic regions who do not get infected by Mycobacterium tuberculosis are genetically resistant. Using an "experiment of nature" design that proved successful in our previous work, we performed a genome-wide association study of tuberculin skin test positivity using 469 HIV-positive patients from prospective study cohorts of tuberculosis from Tanzania and Uganda to identify genetic loci associated with MTB infection in the context of HIV-infection. Among these individuals, 244 tested were tuberculin skin test (TST positive either at enrollment or during the >8 year follow up, while 225 were not. We identified a genome-wide significant association between a dominant model of rs877356 and binary TST status in the combined cohort (Odds ratio = 0.2671, p = 1.22x10-8. Association was replicated with similar significance when examining TST induration as a continuous trait. The variant lies in the 5q31.1 region, 57kb downstream from IL9. Two-locus analyses of association of variants near rs877356 showed a haplotype comprised of rs877356 and an IL9 missense variant, rs2069885, had the most significant association (p = 1.59x10-12. We also replicated previously linked loci on chromosomes 2, 5, and 11. IL9 is a cytokine produced by mast cells and TH2 cells during inflammatory responses, providing a possible link between airway inflammation and protection from MTB infection. Our results indicate that studying uninfected, HIV-positive participants with extensive exposure increases the power to detect associations in complex infectious disease.

  7. Underground Nuclear Testing Program, Nevada Test Site

    International Nuclear Information System (INIS)

    1975-09-01

    The Energy Research and Development Administration (ERDA) continues to conduct an underground nuclear testing program which includes tests for nuclear weapons development and other tests for development of nuclear explosives and methods for their application for peaceful uses. ERDA also continues to provide nuclear explosive and test site support for nuclear effects tests sponsored by the Department of Defense. This Supplement extends the Environmental Statement (WASH-1526) to cover all underground nuclear tests and preparations for tests of one megaton (1 MT) or less at the Nevada Test Site (NTS) during Fiscal Year 1976. The test activities covered include numerous continuing programs, both nuclear and non-nuclear, which can best be conducted in a remote area. However, if nuclear excavation tests or tests of yields above 1 MT or tests away from NTS should be planned, these will be covered by separate environmental statements

  8. Test Review: TestDaF

    Science.gov (United States)

    Norris, John; Drackert, Anastasia

    2018-01-01

    The Test of German as a Foreign Language (TestDaF) plays a critical role as a standardized test of German language proficiency. Developed and administered by the Society for Academic Study Preparation and Test Development (g.a.s.t.), TestDaF was launched in 2001 and has experienced persistent annual growth, with more than 44,000 test takers in…

  9. Tests Related to Pregnancy

    Science.gov (United States)

    ... to learn. Search form Search Tests related to pregnancy You are here Home Testing & Services Testing for ... to Genetic Counseling . What Are Tests Related to Pregnancy? Pregnancy related testing is done before or during ...

  10. Design Driven Testing Test Smarter, Not Harder

    CERN Document Server

    Stephens, M

    2010-01-01

    The groundbreaking book Design Driven Testing brings sanity back to the software development process by flipping around the concept of Test Driven Development (TDD) - restoring the concept of using testing to verify a design instead of pretending that unit tests are a replacement for design. Anyone who feels that TDD is "Too Damn Difficult" will appreciate this book. Design Driven Testing shows that, by combining a forward-thinking development process with cutting-edge automation, testing can be a finely targeted, business-driven, rewarding effort. In other words, you'll learn how to test

  11. Learning software testing with Test Studio

    CERN Document Server

    Madi, Rawane

    2013-01-01

    Learning Software Testing with Test Studio is a practical, hands-on guide that will help you get started with Test Studio to design your automated solution and tests. All through the book, there are best practices and tips and tricks inside Test Studio which can be employed to improve your solution just like an experienced QA.If you are a beginner or a professional QA who is seeking a fast, clear, and direct to the point start in automated software testing inside Test Studio, this book is for you. You should be familiar with the .NET framework, mainly Visual Studio, C#, and SQL, as the book's

  12. Dominant Epistasis Between Two Quantitative Trait Loci Governing Sporulation Efficiency in Yeast Saccharomyces cerevisiae

    Science.gov (United States)

    Bergman, Juraj; Mitrikeski, Petar T.

    2015-01-01

    Summary Sporulation efficiency in the yeast Saccharomyces cerevisiae is a well-established model for studying quantitative traits. A variety of genes and nucleotides causing different sporulation efficiencies in laboratory, as well as in wild strains, has already been extensively characterised (mainly by reciprocal hemizygosity analysis and nucleotide exchange methods). We applied a different strategy in order to analyze the variation in sporulation efficiency of laboratory yeast strains. Coupling classical quantitative genetic analysis with simulations of phenotypic distributions (a method we call phenotype modelling) enabled us to obtain a detailed picture of the quantitative trait loci (QTLs) relationships underlying the phenotypic variation of this trait. Using this approach, we were able to uncover a dominant epistatic inheritance of loci governing the phenotype. Moreover, a molecular analysis of known causative quantitative trait genes and nucleotides allowed for the detection of novel alleles, potentially responsible for the observed phenotypic variation. Based on the molecular data, we hypothesise that the observed dominant epistatic relationship could be caused by the interaction of multiple quantitative trait nucleotides distributed across a 60--kb QTL region located on chromosome XIV and the RME1 locus on chromosome VII. Furthermore, we propose a model of molecular pathways which possibly underlie the phenotypic variation of this trait. PMID:27904371

  13. Epistasis between QTLs for bone density variation in Copenhagen × dark agouti F2 rats

    OpenAIRE

    Koller, Daniel L.; Liu, Lixiang; Alam, Imranul; Sun, Qiwei; Econs, Michael J.; Foroud, Tatiana; Turner, Charles H.

    2009-01-01

    The variation in several of the risk factors for osteoporotic fracture, including bone mineral density (BMD), has been shown to be strongly influenced by genetic differences. However, the genetic architecture of BMD is complex in both humans and in model organisms. We previously reported quantitative trait locus (QTL) results for BMD from a genome screen of 828 F2 progeny of Copenhagen and dark agouti rats. These progeny also provide an excellent opportunity to search for epistatic effects, o...

  14. Cytonuclear Epistasis Controls the Density of Symbiont Wolbachia pipientis in Nongonadal Tissues of Mosquito Culex quinquefasciatus.

    Science.gov (United States)

    Emerson, Kevin J; Glaser, Robert L

    2017-08-07

    Wolbachia pipientis , a bacterial symbiont infecting arthropods and nematodes, is vertically transmitted through the female germline and manipulates its host's reproduction to favor infected females. Wolbachia also infects somatic tissues where it can cause nonreproductive phenotypes in its host, including resistance to viral pathogens. Wolbachia -mediated phenotypes are strongly associated with the density of Wolbachia in host tissues. Little is known, however, about how Wolbachia density is regulated in native or heterologous hosts. Here, we measure the broad-sense heritability of Wolbachia density among families in field populations of the mosquito Culex pipiens , and show that densities in ovary and nongonadal tissues of females in the same family are not correlated, suggesting that Wolbachia density is determined by distinct mechanisms in the two tissues. Using introgression analysis between two different strains of the closely related species C. quinquefasciatus , we show that Wolbachia densities in ovary tissues are determined primarily by cytoplasmic genotype, while densities in nongonadal tissues are determined by both cytoplasmic and nuclear genotypes and their epistatic interactions. Quantitative-trait-locus mapping identified two major-effect quantitative-trait loci in the C. quinquefasciatus genome explaining a combined 23% of variance in Wolbachia density, specifically in nongonadal tissues. A better understanding of how Wolbachia density is regulated will provide insights into how Wolbachia density can vary spatiotemporally in insect populations, leading to changes in Wolbachia -mediated phenotypes such as viral pathogen resistance. Copyright © 2017 Emerson, Glaser.

  15. Beyond the single gene: How epistasis and gene-by-environment effects influence crop domestication.

    Science.gov (United States)

    Doust, Andrew N; Lukens, Lewis; Olsen, Kenneth M; Mauro-Herrera, Margarita; Meyer, Ann; Rogers, Kimberly

    2014-04-29

    Domestication is a multifaceted evolutionary process, involving changes in individual genes, genetic interactions, and emergent phenotypes. There has been extensive discussion of the phenotypic characteristics of plant domestication, and recent research has started to identify the specific genes and mutational mechanisms that control domestication traits. However, there is an apparent disconnect between the simple genetic architecture described for many crop domestication traits, which should facilitate rapid phenotypic change under selection, and the slow rate of change reported from the archeobotanical record. A possible explanation involves the middle ground between individual genetic changes and their expression during development, where gene-by-gene (epistatic) and gene-by-environment interactions can modify the expression of phenotypes and opportunities for selection. These aspects of genetic architecture have the potential to significantly slow the speed of phenotypic evolution during crop domestication and improvement. Here we examine whether epistatic and gene-by-environment interactions have shaped how domestication traits have evolved. We review available evidence from the literature, and we analyze two domestication-related traits, shattering and flowering time, in a mapping population derived from a cross between domesticated foxtail millet and its wild progenitor. We find that compared with wild progenitor alleles, those favored during domestication often have large phenotypic effects and are relatively insensitive to genetic background and environmental effects. Consistent selection should thus be able to rapidly change traits during domestication. We conclude that if phenotypic evolution was slow during crop domestication, this is more likely due to cultural or historical factors than epistatic or environmental constraints.

  16. Dynamic QTL and epistasis analysis on seedling root traits in upland ...

    Indian Academy of Sciences (India)

    2014-04-21

    Apr 21, 2014 ... phenotypic values at the time t conditional on the pheno- typic values ...... root, which directly determines drought tolerance and yield potential of ..... Talents of the Ministry of Education (NCET-06-0106) to J. Hua. References.

  17. Genetics of reproductive isolation in the Drosophila simulans clade: complex epistasis underlying hybrid male sterility.

    Science.gov (United States)

    Cabot, E L; Davis, A W; Johnson, N A; Wu, C I

    1994-05-01

    We have analyzed the sterility associated with introgressions of the distal one-fourth of the X chromosome from either Drosophila mauritiana or Drosophila sechellia into the genome of Drosophila simulans using a series of visible and DNA markers. Because in Drosophila hybrids, male sterility is usually complete and is often tightly linked with each of several markers used in crosses, a simple genetic basis has generally been assumed. In our low resolution mapping experiment, we were not able to reject the null hypothesis that a single gene, introgressed from either D. mauritiana or D. sechellia, is the cause of male sterility. High resolution mapping, however, reveals a much more complex picture. At least three distinct factors from D. mauritiana, or two from D. sechellia, were identified that need to be jointly present to confer full sterility. Each individual factor by itself is relatively ineffective in causing sterility, or even a partial spermatogenic defect. Moreover, there appear to be more sterility factors on comparable introgressions from D. mauritiana than from D. sechellia. On the basis of these observations, we propose a model which suggests that multilocus weak allele interactions are a very common cause of reproductive incompatibility between closely related species. We also present theoretical argument and empirical evidence against extrapolating the results of within-species analysis to interpret the genetic basis of species differences. The implications of this model on the theories of evolution of species differences and the attempt to understand the mechanisms of hybrid sterility/inviability at the molecular level are discussed.

  18. Engine Test Facility (ETF)

    Data.gov (United States)

    Federal Laboratory Consortium — The Air Force Arnold Engineering Development Center's Engine Test Facility (ETF) test cells are used for development and evaluation testing of propulsion systems for...

  19. Thyroid Function Tests

    Science.gov (United States)

    ... Home » Thyroid Function Tests Leer en Español Thyroid Function Tests FUNCTION HOW DOES THE THYROID GLAND FUNCTION? ... Cancer Thyroid Nodules in Children and Adolescents Thyroid Function Tests Resources Thyroid Function Tests Brochure PDF En ...

  20. CEA (Carcinoembryonic Antigen) Test

    Science.gov (United States)

    ... Gene Mutations Testing Cytomegalovirus (CMV) Tests D-dimer Dengue Fever Testing Des-gamma-carboxy prothrombin (DCP) DHEAS ... Glance Why Get Tested? Primarily to monitor cancer treatment, including response to therapy and recurrence; as an ...

  1. Blood Test: Bilirubin

    Science.gov (United States)

    ... Videos for Educators Search English Español Blood Test: Bilirubin KidsHealth / For Parents / Blood Test: Bilirubin What's in ... liver or kidneys) is working. What Is a Bilirubin Test? A bilirubin test measures how much bilirubin ...

  2. Catecholamine blood test

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003561.htm Catecholamine blood test To use the sharing features on this page, ... measured with a urine test than with a blood test. How the Test is Performed A blood sample ...

  3. Anthrax blood test

    Science.gov (United States)

    Anthrax serology test; Antibody test for anthrax; Serologic test for B. anthracis ... This test may be performed when the health care provider suspects you have anthrax infection. The bacteria that cause ...

  4. Myoglobin blood test

    Science.gov (United States)

    Serum myoglobin; Heart attack - myoglobin blood test; Myositis - myoglobin blood test; Rhabdomyolysis - myoglobin blood test ... too high, it can damage the kidneys. This test is ordered when your health care provider suspects ...

  5. Blood sugar test

    Science.gov (United States)

    ... sugar; Blood sugar level; Fasting blood sugar; Glucose test; Diabetic screening - blood sugar test; Diabetes - blood sugar test ... The test may be done in the following ways: After you have not eaten anything for at least 8 ...

  6. Ketones urine test

    Science.gov (United States)

    Ketone bodies - urine; Urine ketones; Ketoacidosis - urine ketones test; Diabetic ketoacidosis - urine ketones test ... Urine ketones are usually measured as a "spot test." This is available in a test kit that ...

  7. Lactose tolerance tests

    Science.gov (United States)

    Hydrogen breath test for lactose tolerance ... Two common methods include: Lactose tolerance blood test Hydrogen breath test The hydrogen breath test is the preferred method. It measures the amount of hydrogen ...

  8. Test techniques for fracture mechanics testing

    International Nuclear Information System (INIS)

    Schwalbe, K.H.

    1980-01-01

    Test methods for fracture mechanics tests are described. Two groups of techniques are distinguished: Those for measurement of stable crack growth and those for determination of the loading parameters. (orig.) [de

  9. To test or not to test

    DEFF Research Database (Denmark)

    Rochon, Justine; Gondan, Matthias; Kieser, Meinhard

    2012-01-01

    Background: Student's two-sample t test is generally used for comparing the means of two independent samples, for example, two treatment arms. Under the null hypothesis, the t test assumes that the two samples arise from the same normally distributed population with unknown variance. Adequate...... control of the Type I error requires that the normality assumption holds, which is often examined by means of a preliminary Shapiro-Wilk test. The following two-stage procedure is widely accepted: If the preliminary test for normality is not significant, the t test is used; if the preliminary test rejects...... the null hypothesis of normality, a nonparametric test is applied in the main analysis. Methods: Equally sized samples were drawn from exponential, uniform, and normal distributions. The two-sample t test was conducted if either both samples (Strategy I) or the collapsed set of residuals from both samples...

  10. Materials testing 1985

    International Nuclear Information System (INIS)

    1985-01-01

    The following subjects were dealt with at the meeting: Testing with vibration loads; Hardness testing; Calibration of test devices and equipment; Test technique for compound materials; Vibration strength testing and expense of experiments; Solving problems in introducing forces into samples and components and process of ambulant materials testing. There are 17 separate abstracts from among 43 lectures. (orig./PW) [de

  11. 5-HIAA Test

    Science.gov (United States)

    ... PF4 Antibody Hepatitis A Testing Hepatitis B Testing Hepatitis C Testing HER2/neu Herpes Testing High-sensitivity C-reactive Protein (hs-CRP) Histamine Histone Antibody HIV Antibody and HIV Antigen (p24) HIV Antiretroviral Drug Resistance Testing, Genotypic HIV Viral Load HLA Testing HLA- ...

  12. Uric Acid Test

    Science.gov (United States)

    ... PF4 Antibody Hepatitis A Testing Hepatitis B Testing Hepatitis C Testing HER2/neu Herpes Testing High-sensitivity C-reactive Protein (hs-CRP) Histamine Histone Antibody HIV Antibody and HIV Antigen (p24) HIV Antiretroviral Drug Resistance Testing, Genotypic HIV Viral Load HLA Testing HLA- ...

  13. Direct Antiglobulin Test

    Science.gov (United States)

    ... PF4 Antibody Hepatitis A Testing Hepatitis B Testing Hepatitis C Testing HER2/neu Herpes Testing High-sensitivity C-reactive Protein (hs-CRP) Histamine Histone Antibody HIV Antibody and HIV Antigen (p24) HIV Antiretroviral Drug Resistance Testing, Genotypic HIV Viral Load HLA Testing HLA- ...

  14. CK-MB Test

    Science.gov (United States)

    ... PF4 Antibody Hepatitis A Testing Hepatitis B Testing Hepatitis C Testing HER2/neu Herpes Testing High-sensitivity C-reactive Protein (hs-CRP) Histamine Histone Antibody HIV Antibody and HIV Antigen (p24) HIV Antiretroviral Drug Resistance Testing, Genotypic HIV Viral Load HLA Testing HLA- ...

  15. Understanding Your Tests

    Science.gov (United States)

    ... PF4 Antibody Hepatitis A Testing Hepatitis B Testing Hepatitis C Testing HER2/neu Herpes Testing High-sensitivity C-reactive Protein (hs-CRP) Histamine Histone Antibody HIV Antibody and HIV Antigen (p24) HIV Antiretroviral Drug Resistance Testing, Genotypic HIV Viral Load HLA Testing HLA- ...

  16. Myasthenia Gravis Tests

    Science.gov (United States)

    ... PF4 Antibody Hepatitis A Testing Hepatitis B Testing Hepatitis C Testing HER2/neu Herpes Testing High-sensitivity C-reactive Protein (hs-CRP) Histamine Histone Antibody HIV Antibody and HIV Antigen (p24) HIV Antiretroviral Drug Resistance Testing, Genotypic HIV Viral Load HLA Testing HLA- ...

  17. Citric acid urine test

    Science.gov (United States)

    Urine - citric acid test; Renal tubular acidosis - citric acid test; Kidney stones - citric acid test; Urolithiasis - citric acid test ... No special preparation is necessary for this test. But the results ... test is usually done while you are on a normal diet. Ask your ...

  18. From Test Takers to Test Makers

    Science.gov (United States)

    Smith, Kari

    2009-01-01

    As a classroom teacher, Kari Smith realized that traditional objective tests don't always assess what students actually know. But tests are so deeply embedded in the education system that it would be difficult to do away with them entirely. Smith decided to make tests into learning tools. In this article, Smith describes three strategies for…

  19. CANFLEX fuel bundle strength tests (test report)

    International Nuclear Information System (INIS)

    Chang, Seok Kyu; Chung, C. H.; Kim, B. D.

    1997-08-01

    This document outlines the test results for the strength tests of the CANFLEX fuel bundle. Strength tests are performed to determine and verify the amount of the bundle shape distortion which is against the side-stops when the bundles are refuelling. There are two cases of strength test; one is the double side-stop test which simulates the normal bundle refuelling and the other is the single side-stop test which simulates the abnormal refuelling. the strength test specification requires that the fuel bundle against the side-stop(s) simulators for this test were fabricated and the flow rates were controlled to provide the required conservative hydraulic forces. The test rig conditions of 120 deg C, 11.2 MPa were retained for 15 minutes after the flow rate was controlled during the test in two cases, respectively. The bundle loading angles of number 13- number 15 among the 15 bundles were 67.5 deg CCW and others were loaded randomly. After the tests, the bundle shapes against the side-stops were measured and inspected carefully. The important test procedures and measurements were discussed as follows. (author). 5 refs., 22 tabs., 5 figs

  20. Test design requirements: Thermal conductivity probe testing

    International Nuclear Information System (INIS)

    Heath, R.E.

    1985-01-01

    This document establishes the test design requirements for development of a thermal conductivity probe test. The thermal conductivity probe determines in situ thermal conductivity using a line source transient heat conduction analysis. This document presents the rationale for thermal conductivity measurement using a thermal conductivity probe. A general test description is included. Support requirements along with design constraints are detailed to allow simple design of the thermal conductivity probe and test. The schedule and delivery requirements of the responsible test designer are also included. 7 refs., 1 fig

  1. Irradiation effects test series test IE-1 test results report

    International Nuclear Information System (INIS)

    Quapp, W.J.; Allison, C.M.; Farrar, L.C.; Mehner, A.S.

    1977-03-01

    The report describes the results of the first programmatic test in the Nuclear Regulatory Commission Irradiation Effects Test Series. This test (IE-1) used four 0.97m long PWR-type fuel rods fabricated from previously irradiated Saxton fuel. The objectives of this test were to evaluate the effect of fuel pellet density on pellet-cladding interaction during a power ramp and to evaluate the influence of the irradiated state of the fuel and cladding on rod behavior during film boiling operation. Data are presented on the behavior of irradiated fuel rods during steady-state operation, a power ramp, and film boiling operation. The effects of as-fabricated gap size, as-fabricated fuel density, rod power, and power ramp rate on pellet-cladding interaction are discussed. Test data are compared with FRAP-T2 computer model predictions, and comments on the consequences of sustained film boiling operation on irradiated fuel rod behavior are provided

  2. The Stimulus test stand

    International Nuclear Information System (INIS)

    Christofek, L.; Rapidis, P.; Reinhard, A.; Fermilab

    2005-01-01

    The Stimulus Test Stand was originally constructed and assembled for testing the SVX2 ASIC readout and then upgraded for SVX3 ASIC prototyping and testing. We have modified this system for SVX4 ASIC [1] prototype testing. We described the individual components below. Additional details for other hardware for SVX4 testing can be found in reference [2]. We provide a description of the Stimulus Test Stand used for prototype testing of the SVX4 chip

  3. CSF-VDRL test

    Science.gov (United States)

    ... test - CSF; Neurosyphilis - VDRL Images CSF test for syphilis References Chernecky CC, Berger BJ. Venereal disease research laboratory test (VDRL), test, cerebrospinal fluid – specimen. In: Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures . 6th ed. St Louis, MO: Elsevier Saunders; ...

  4. CO2 blood test

    Science.gov (United States)

    Bicarbonate test; HCO3-; Carbon dioxide test; TCO2; Total CO2; CO2 test - serum; Acidosis - CO2; Alkalosis - CO2 ... Many medicines can interfere with blood test results. Your health ... need to stop taking any medicines before you have this test. DO ...

  5. Tonopah Test Range - Index

    Science.gov (United States)

    Capabilities Test Operations Center Test Director Range Control Track Control Communications Tracking Radars Photos Header Facebook Twitter YouTube Flickr RSS Tonopah Test Range Top TTR_TOC Tonopah is the testing range of choice for all national security missions. Tonopah Test Range (TTR) provides research and

  6. Rail Impact Testing. Test Operations Procedure (TOP)

    Science.gov (United States)

    2008-09-15

    impact test. The rail impact test is used to verify structural integrity of the test item and the adequacy of the tie-down system and tie-down...strength of provisions, connection and supporting structural frame, paragraph 5.2.3 ** Superscript...parts, to include outriggers and booms) without advanced approval by SDDCTEA. Torque nuts on wire rope clips to their correct value. Torque cable

  7. Tractor accelerated test on test rig

    Directory of Open Access Journals (Sweden)

    M. Mattetti

    2013-09-01

    Full Text Available The experimental tests performed to validate a tractor prototype before its production, need a substantial financial and time commitment. The tests could be reduced using accelerated tests able to reproduce on the structural part of the tractor, the same damage produced on the tractor during real life in a reduced time. These tests were usually performed reproducing a particular harsh condition a defined number of times, as for example using a bumpy road on track to carry out the test in any weather condition. Using these procedures the loads applied on the tractor structure are different with respect to those obtained during the real use, with the risk to apply loads hard to find in reality. Recently it has been demonstrated how, using the methodologies designed for cars, it is possible to also expedite the structural tests for tractors. In particular, automotive proving grounds were recently successfully used with tractors to perform accelerated structural tests able to reproduce the real use of the machine with an acceleration factor higher than that obtained with the traditional methods. However, the acceleration factor obtained with a tractor on proving grounds is in any case reduced due to the reduced speed of the tractors with respect to cars. In this context, the goal of the paper is to show the development of a methodology to perform an accelerated structural test on a medium power tractor using a 4 post test rig. In particular, several proving ground testing conditions have been performed to measure the loads on the tractor. The loads obtained were then edited to remove the not damaging portion of signals, and finally the loads obtained were reproduced in a 4 post test rig. The methodology proposed could be a valid alternative to the use of a proving ground to reproduce accelerated structural tests on tractors.

  8. Color vision test

    Science.gov (United States)

    ... present from birth) color vision problems: Achromatopsia -- complete color blindness , seeing only shades of gray Deuteranopia -- difficulty telling ... Vision test - color; Ishihara color vision test Images Color blindness tests References Bowling B. Hereditary fundus dystrophies. In: ...

  9. Kidney function tests

    Science.gov (United States)

    Kidney function tests are common lab tests used to evaluate how well the kidneys are working. Such tests include: ... Oh MS, Briefel G. Evaluation of renal function, water, electrolytes ... and Management by Laboratory Methods . 23rd ed. Philadelphia, ...

  10. Liver Function Tests

    Science.gov (United States)

    ... digest food, store energy, and remove poisons. Liver function tests are blood tests that check to see ... as hepatitis and cirrhosis. You may have liver function tests as part of a regular checkup. Or ...

  11. Home blood sugar testing

    Science.gov (United States)

    Diabetes - home glucose testing; Diabetes - home blood sugar testing ... Usual times to test your blood sugar are before meals and at bedtime. Your provider may ask you to check your blood sugar 2 hours after a meal or ...

  12. Teratology testing under REACH.

    Science.gov (United States)

    Barton, Steve

    2013-01-01

    REACH guidelines may require teratology testing for new and existing chemicals. This chapter discusses procedures to assess the need for teratology testing and the conduct and interpretation of teratology tests where required.

  13. Celiac Disease Tests

    Science.gov (United States)

    ... diet When To Get Tested? When you have symptoms suggesting celiac disease, such as chronic diarrhea, abdominal pain, anemia , and ... Celiac tests are usually ordered for people with symptoms suggesting celiac disease, including anemia and abdominal pain. Sometimes celiac testing ...

  14. Aviation Flight Test

    Data.gov (United States)

    Federal Laboratory Consortium — Redstone Test Center provides an expert workforce and technologically advanced test equipment to conduct the rigorous testing necessary for U.S. Army acquisition and...

  15. Mark 1 Test Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Mark I Test Facility is a state-of-the-art space environment simulation test chamber for full-scale space systems testing. A $1.5M dollar upgrade in fiscal year...

  16. Growth hormone suppression test

    Science.gov (United States)

    ... Acromegaly - blood test; Gigantism - blood test Images Blood test References Kaiser U, Ho KKY. Pituitary physiology and diagnostic evaluation. In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM, eds. Williams Textbook of Endocrinology . 13th ed. Philadelphia, PA: Elsevier; ...

  17. Lactose Tolerance Tests

    Science.gov (United States)

    ... Plasma Free Metanephrines Platelet Count Platelet Function Tests Pleural Fluid Analysis PML-RARA Porphyrin Tests Potassium Prealbumin ... of these, the person tested is given a liquid to drink that contains a standard amount of ...

  18. Thyroid Diseases Tests

    Science.gov (United States)

    ... Gene Mutations Testing Cytomegalovirus (CMV) Tests D-dimer Dengue Fever Testing Des-gamma-carboxy prothrombin (DCP) DHEAS ... newborn blood screening programs since early detection and treatment can minimize long-term damage. Hashimoto thyroiditis : the ...

  19. What Is Diagnostic Testing?

    Science.gov (United States)

    ... your family Plan for the future Insurance and financial planning Transition for children Emergency preparedness Testing & Services Testing ... Support Genetic Disease Information Find a Support Group Financial Planning Who Should I Tell? Genetic Testing & Counseling Compensation ...

  20. Tests for H. pylori

    Science.gov (United States)

    ... ulcers and many cases of stomach inflammation (chronic gastritis). How the Test is Performed There are several ... treating bleeding, or making sure there is no cancer. Why the Test is Performed Testing is most ...

  1. BUN - blood test

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003474.htm BUN - blood test To use the sharing features on this page, ... for the Test Many medicines can interfere with blood test results. Your health care provider will tell you ...

  2. Porphyrins - blood test

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003372.htm Porphyrins blood test To use the sharing features on this page, ... blood or the urine . This article discusses the blood test. How the Test is Performed A blood sample ...

  3. Renin blood test

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003698.htm Renin blood test To use the sharing features on this page, ... renin test measures the level of renin in blood. How the Test is Performed A blood sample is needed . How ...

  4. Prolactin blood test

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003718.htm Prolactin blood test To use the sharing features on this page, ... test measures the amount of prolactin in the blood. How the Test is Performed A blood sample is needed . How ...

  5. Large Rotor Test Apparatus

    Data.gov (United States)

    Federal Laboratory Consortium — This test apparatus, when combined with the National Full-Scale Aerodynamics Complex, produces a thorough, full-scale test capability. The Large Rotor Test Apparatus...

  6. Ketones blood test

    Science.gov (United States)

    Acetone bodies; Ketones - serum; Nitroprusside test; Ketone bodies - serum; Ketones - blood; Ketoacidosis - ketones blood test ... fat cells break down in the blood. This test is used to diagnose ketoacidosis . This is a ...

  7. Dexamethasone suppression test

    Science.gov (United States)

    DST; ACTH suppression test; Cortisol suppression test ... During this test, you will receive dexamethasone. This is a strong man-made (synthetic) glucocorticoid medicine. Afterward, your blood is drawn ...

  8. Bone mineral density test

    Science.gov (United States)

    BMD test; Bone density test; Bone densitometry; DEXA scan; DXA; Dual-energy x-ray absorptiometry; p-DEXA; Osteoporosis - BMD ... need to undress. This scan is the best test to predict your risk of fractures, especially of ...

  9. Assessment and Testing.

    Science.gov (United States)

    Clapham, Caroline

    2000-01-01

    Explores the term "applied linguistics" and discusses the role of language testing within this discipline, the relationship between testing and teaching, and the relationship between testing and assessment (Author/VWL)

  10. Tips on Blood Testing

    Science.gov (United States)

    ... Test Pain, Discomfort and Anxiety Tips to Help Children through Their Medical Tests Tips to Help the Elderly through Their Medical Tests Find Us On Social Media: Facebook Twitter Google Plus Footer Menu Home About ...

  11. Blood Test: Testosterone

    Science.gov (United States)

    ... Test: Estradiol Precocious Puberty Understanding Puberty Endocrine System Male Reproductive System Getting a Blood Test (Video) All About Puberty Blood Test (Video) Male Reproductive System View more About Us Contact Us Partners Editorial ...

  12. Structural Test Facility

    Data.gov (United States)

    Federal Laboratory Consortium — Provides a wide variety of testing equipment, fixtures and facilities to perform both unique aviation component testing as well as common types of materials testing...

  13. SPECT quality control tests

    International Nuclear Information System (INIS)

    Robilotta, C.C.; Rebelo, M.F.S.; Oliveira, M.A.; Abe, R.

    1987-01-01

    Quality control tests of tomographic system composed by a rotatory chamber (CGR Gammatomome T-9000) and a microcomputer are presented. Traditional quality control tests for scintilation chambers and specific tests for tomographic systems are reported. (M.A.C.) [pt

  14. Irradiation effects test Series Scoping Test 1: test results report

    International Nuclear Information System (INIS)

    Quapp, W.J.; Allison, C.M.; Farrar, L.C.

    1977-09-01

    The report describes the results of the first scoping test in the Irradiation Effects Test Series conducted by the Thermal Fuels Behavior Program, which is part of the Water Reactor Research Program of EG and G Idaho, Inc. The research is sponsored by the United States Nuclear Regulatory Commission. This test used an unirradiated, three-foot-long, PWR-type fuel rod. The objective of this test was to thoroughly evaluate the remote fabrication procedures to be used for irradiated rods in future tests, handling plans, and reactor operations. Additionally, selected fuel behavior data were obtained. The fuel rod was subjected to a series of preconditioning power cycles followed by a power increase which brought the fuel rod power to about 20.4 kW/ft peak linear heat rating at a coolant mass flux of 1.83 x 10 6 lb/hr-ft 2 . Film boiling occurred for a period of 4.8 minutes following flow reductions to 9.6 x 10 5 and 7.5 x 10 5 lb/hr-ft 2 . The test fuel rod failed following reactor shutdown as a result of heavy internal and external cladding oxidation and embrittlement which occurred during the film boiling operation

  15. Small test SDHW systems

    DEFF Research Database (Denmark)

    Vejen, Niels Kristian

    1999-01-01

    Three small test SDHW systems was tested in a laboratory test facility.The three SDHW systems where all based on the low flow principe and a mantle tank but the design of the systems where different.......Three small test SDHW systems was tested in a laboratory test facility.The three SDHW systems where all based on the low flow principe and a mantle tank but the design of the systems where different....

  16. Textiles Performance Testing Facilities

    Data.gov (United States)

    Federal Laboratory Consortium — The Textiles Performance Testing Facilities has the capabilities to perform all physical wet and dry performance testing, and visual and instrumental color analysis...

  17. Electromagnetic Interface Testing Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Electromagnetic Interface Testing facilitysupports such testing asEmissions, Field Strength, Mode Stirring, EMP Pulser, 4 Probe Monitoring/Leveling System, and...

  18. FOOD SAFETY TESTING LABORATORY

    Data.gov (United States)

    Federal Laboratory Consortium — This laboratory develops screening assays, tests and modifies biosensor equipment, and optimizes food safety testing protocols for the military and civilian sector...

  19. Thyroxine (T4) Test

    Science.gov (United States)

    ... K. Brunner & Suddarth's Handbook of Laboratory and Diagnostic Tests. 2 nd Ed, Kindle. Philadelphia: Wolters Kluwer Health, Lippincott Williams & Wilkins; c2014. Thryoxine, Serum 485 p. Lab Tests ...

  20. Laboratory for filter testing

    Energy Technology Data Exchange (ETDEWEB)

    Paluch, W.

    1987-07-01

    Filters used for mine draining in brown coal surface mines are tested by the Mine Draining Department of Poltegor. Laboratory tests of new types of filters developed by Poltegor are analyzed. Two types of tests are used: tests of scale filter models and tests of experimental units of new filters. Design and operation of the test stands used for testing mechanical properties and hydraulic properties of filters for coal mines are described: dimensions, pressure fluctuations, hydraulic equipment. Examples of testing large-diameter filters for brown coal mines are discussed.

  1. Mobile Test Capabilities

    Data.gov (United States)

    Federal Laboratory Consortium — The Electrical Power Mobile Test capabilities are utilized to conduct electrical power quality testing on aircraft and helicopters. This capability allows that the...

  2. GPS Test Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Global Positioning System (GPS) Test Facility Instrumentation Suite (GPSIS) provides great flexibility in testing receivers by providing operational control of...

  3. Hot Ground Vibration Tests

    Data.gov (United States)

    National Aeronautics and Space Administration — Ground vibration tests or modal surveys are routinely conducted to support flutter analysis for subsonic and supersonic vehicles. However, vibration testing...

  4. Test Control Center (TCC)

    Data.gov (United States)

    Federal Laboratory Consortium — The Test Control Center (TCC) provides a consolidated facility for planning, coordinating, controlling, monitoring, and analyzing distributed test events. ,The TCC...

  5. Moisture related test protocols for HVS testing

    CSIR Research Space (South Africa)

    Denneman, E

    2008-10-01

    Full Text Available outcomes of HVS tests where the moisture condition of the pavement or specific layers in the pavement is under investigation for a specific test. Practical guidance is then provided on the potential systems (how to manage the moisture – hardware) as well...

  6. Integrated Test and Evaluation Flight Test 3 Flight Test Plan

    Science.gov (United States)

    Marston, Michael Lawrence

    2015-01-01

    The desire and ability to fly Unmanned Aircraft Systems (UAS) in the National Airspace System (NAS) is of increasing urgency. The application of unmanned aircraft to perform national security, defense, scientific, and emergency management are driving the critical need for less restrictive access by UAS to the NAS. UAS represent a new capability that will provide a variety of services in the government (public) and commercial (civil) aviation sectors. The growth of this potential industry has not yet been realized due to the lack of a common understanding of what is required to safely operate UAS in the NAS. NASA's UAS Integration into the NAS Project is conducting research in the areas of Separation Assurance/Sense and Avoid Interoperability, Human Systems Integration (HSI), and Communication to support reducing the barriers of UAS access to the NAS. This research is broken into two research themes namely, UAS Integration and Test Infrastructure. UAS Integration focuses on airspace integration procedures and performance standards to enable UAS integration in the air transportation system, covering Sense and Avoid (SAA) performance standards, command and control performance standards, and human systems integration. The focus of Test Infrastructure is to enable development and validation of airspace integration procedures and performance standards, including the integrated test and evaluation. In support of the integrated test and evaluation efforts, the Project will develop an adaptable, scalable, and schedulable relevant test environment capable of evaluating concepts and technologies for unmanned aircraft systems to safely operate in the NAS. To accomplish this task, the Project will conduct a series of Human-in-the-Loop and Flight Test activities that integrate key concepts, technologies and/or procedures in a relevant air traffic environment. Each of the integrated events will build on the technical achievements, fidelity and complexity of the previous tests and

  7. Test report for core drilling ignitability testing

    International Nuclear Information System (INIS)

    Witwer, K.S.

    1996-01-01

    Testing was carried out with the cooperation of Westinghouse Hanford Company and the United States Bureau of Mines at the Pittsburgh Research Center in Pennsylvania under the Memorandum of Agreement 14- 09-0050-3666. Several core drilling equipment items, specifically those which can come in contact with flammable gasses while drilling into some waste tanks, were tested under conditions similar to actual field sampling conditions. Rotary drilling against steel and rock as well as drop testing of several different pieces of equipment in a flammable gas environment were the specific items addressed. The test items completed either caused no ignition of the gas mixture, or, after having hardware changes or drilling parameters modified, produced no ignition in repeat testing

  8. Digface characterization test plan (remote testing)

    International Nuclear Information System (INIS)

    Croft, K.; Hyde, R.; Allen, S.

    1993-08-01

    The objective of the Digface Characterization (DFC) Remote Testing project is to remotely deploy a sensor head (Mini-Lab) across a digface to determine if it can characterize the contents below the surface. The purpose of this project is to provide a robotics technology that allows removal of workers from hazards, increases speed of operations, and reduces life cycle costs compared to alternate methods and technologies. The Buried Waste Integrated Demonstration (BWID) is funding the demonstration, testing, and evaluation of DFC. This document describes the test plan for the DFC remote deployment demonstration for the BWID. The purposes of the test plan are to establish test parameters so that the demonstration results are deemed useful and usable and perform the demonstration in a safe manner and within all regulatory requirements

  9. Irradiation effects test series, test IE-5. Test results report

    International Nuclear Information System (INIS)

    Croucher, D.W.; Yackle, T.R.; Allison, C.M.; Ploger, S.A.

    1978-01-01

    Test IE-5, conducted in the Power Burst Facility at the Idaho National Engineering Laboratory, employed three 0.97-m long pressurized water reactor type fuel rods, fabricated from previously irradiated zircaloy-4 cladding and one similar rod fabricated from unirradiated cladding. The objectives of the test were to evaluate the influence of simulated fission products, cladding irradiation damage, and fuel rod internal pressure on pellet-cladding interaction during a power ramp and on fuel rod behavior during film boiling operation. The four rods were subjected to a preconditioning period, a power ramp to an average fuel rod peak power of 65 kW/m, and steady state operation for one hour at a coolant mass flux of 4880 kg/s-m 2 for each rod. After a flow reduction to 1800 kg/s-m 2 , film boiling occurred on one rod. Additional flow reductions to 970 kg/s-m 2 produced film boiling on the three remaining fuel rods. Maximum time in film boiling was 80s. The rod having the highest initial internal pressure (8.3 MPa) failed 10s after the onset of film boiling. A second rod failed about 90s after reactor shutdown. The report contains a description of the experiment, the test conduct, test results, and results from the preliminary postirradiation examination. Calculations using a transient fuel rod behavior code are compared with the test results

  10. Irradiation Effects Test Series: Test IE-3. Test results report

    International Nuclear Information System (INIS)

    Farrar, L.C.; Allison, C.M.; Croucher, D.W.; Ploger, S.A.

    1977-10-01

    The objectives of the test reported were to: (a) determine the behavior of irradiated fuel rods subjected to a rapid power increase during which the possibility of a pellet-cladding mechanical interaction failure is enhanced and (b) determine the behavior of these fuel rods during film boiling following this rapid power increase. Test IE-3 used four 0.97-m long pressurized water reactor type fuel rods fabricated from previously irradiated fuel. The fuel rods were subjected to a preconditioning period, followed by a power ramp to 69 kW/m at a coolant mass flux of 4920 kg/s-m 2 . After a flow reduction to 2120 kg/s-m 2 , film boiling occurred on the fuel rods. One rod failed approximately 45 seconds after the reactor was shut down as a result of cladding embrittlement due to extensive cladding oxidation. Data are presented on the behavior of these irradiated fuel rods during steady-state operation, the power ramp, and film boiling operation. The effects of a power ramp and power ramp rates on pellet-cladding interaction are discussed. Test data are compared with FRAP-T3 computer model calculations and data from a previous Irradiation Effects test in which four irradiated fuel rods of a similar design were tested. Test IE-3 results indicate that the irradiated state of the fuel rods did not significantly affect fuel rod behavior during normal, abnormal (power ramp of 20 kW/m per minute), and accident (film boiling) conditions

  11. Displacement compressors - acceptance tests

    CERN Document Server

    International Organization for Standardization. Geneva

    1996-01-01

    ISO 1217:2009 specifies methods for acceptance tests regarding volume rate of flow and power requirements of displacement compressors. It also specifies methods for testing liquid-ring type compressors and the operating and testing conditions which apply when a full performance test is specified.

  12. Refactoring test code

    NARCIS (Netherlands)

    A. van Deursen (Arie); L.M.F. Moonen (Leon); A. van den Bergh; G. Kok

    2001-01-01

    textabstractTwo key aspects of extreme programming (XP) are unit testing and merciless refactoring. Given the fact that the ideal test code / production code ratio approaches 1:1, it is not surprising that unit tests are being refactored. We found that refactoring test code is different from

  13. Load testing circuit

    DEFF Research Database (Denmark)

    2009-01-01

    A load testing circuit a circuit tests the load impedance of a load connected to an amplifier. The load impedance includes a first terminal and a second terminal, the load testing circuit comprising a signal generator providing a test signal of a defined bandwidth to the first terminal of the load...

  14. SAP crm integration testing

    OpenAIRE

    Černiavskaitė, Marija

    2017-01-01

    This Bachelor's thesis presents SAP CRM and integration systems testing analysis: investigation in SAP CRM and SAP PO systems, presentation of relationship between systems, introduction to third-party system (non-SAP) – Network Informational System (NIS) which has integration with SAP, presentation of best CRM testing practises, analysis and recommendation of integration testing. Practical integration testing is done in accordance to recommendations.

  15. 1968 Prototype Diagnostic Test.

    Science.gov (United States)

    Veterans Administration Hospital, Bedford, MA.

    This true-false diagnostic test was used for pretesting of employees at a Veterans Administration Hospital. The test is comprised of 20 items. An alternate test--Classification Questionnaire--was used for testing after remedial training. (For related document, see TM 002 334.) (DB)

  16. Liquid Rocket Engine Testing

    Science.gov (United States)

    Rahman, Shamim

    2005-01-01

    Comprehensive Liquid Rocket Engine testing is essential to risk reduction for Space Flight. Test capability represents significant national investments in expertise and infrastructure. Historical experience underpins current test capabilities. Test facilities continually seek proactive alignment with national space development goals and objectives including government and commercial sectors.

  17. Nationale test i naturfag

    DEFF Research Database (Denmark)

    Andreasen, Karen Egedal; Jensen, Lars Bang

    2015-01-01

    Kapitlet rummer en analyse og diskussion af test inden for naturfagsområdet og de fagforståelser de afspejler med fokus på de nationale test.......Kapitlet rummer en analyse og diskussion af test inden for naturfagsområdet og de fagforståelser de afspejler med fokus på de nationale test....

  18. Numeracy Tests For Dummies

    CERN Document Server

    Beveridge, Colin

    2012-01-01

    The easy way to get practice and excel at numeracy tests Whether you're looking for a new job, applying to certain university courses, or attempting to join the military, you're increasingly likely to face a numeracy test as part of the screening process. And the only way to prepare for a numeracy test is practise. Numeracy Tests For Dummies is an accessible one-stop guide to pass these test. Featuring expert advice, instruction, review, and plenty of practise, Numeracy Tests For Dummies will help you succeed. Numeracy Tests For Dummies contains instruction and revision on:Basic mathematical k

  19. Dtest Testing Software

    Science.gov (United States)

    Jain, Abhinandan; Cameron, Jonathan M.; Myint, Steven

    2013-01-01

    This software runs a suite of arbitrary software tests spanning various software languages and types of tests (unit level, system level, or file comparison tests). The dtest utility can be set to automate periodic testing of large suites of software, as well as running individual tests. It supports distributing multiple tests over multiple CPU cores, if available. The dtest tool is a utility program (written in Python) that scans through a directory (and its subdirectories) and finds all directories that match a certain pattern and then executes any tests in that directory as described in simple configuration files.

  20. ITER test programme

    International Nuclear Information System (INIS)

    Abdou, M.; Baker, C.; Casini, G.

    1991-01-01

    ITER has been designed to operate in two phases. The first phase which lasts for 6 years, is devoted to machine checkout and physics testing. The second phase lasts for 8 years and is devoted primarily to technology testing. This report describes the technology test program development for ITER, the ancillary equipment outside the torus necessary to support the test modules, the international collaboration aspects of conducting the test program on ITER, the requirements on the machine major parameters and the R and D program required to develop the test modules for testing in ITER. 15 refs, figs and tabs

  1. Pancreatic exocrine function testing

    International Nuclear Information System (INIS)

    Goff, J.S.

    1981-01-01

    It is important to understand which pancreatic function tests are available and how to interpret them when evaluating patients with malabsorption. Available direct tests are the secretin stimulation test, the Lundh test meal, and measurement of serum or fecal enzymes. Indirect tests assess pancreatic exocrine function by measuring the effect of pancreatic secretion on various nutrients. These include triglycerides labeled with carbon 14, cobalamin labeled with cobalt 57 and cobalt 58, and para-aminobenzoic acid bound to a dipeptide. Of all these tests the secretin stimulation test is the most accurate and reliable if done by experienced personnel. However, the indirect tests are simpler to do and appear to be comparable to the secretin test at detecting pancreatic exocrine insufficiency. These indirect tests are becoming clinically available and clinicians should familiarize themselves with the strengths and weaknesses of each

  2. Blanket testing in NET

    International Nuclear Information System (INIS)

    Chazalon, M.; Daenner, W.; Libin, B.

    1989-01-01

    The testing stages in NET for the performance assessment of the various breeding blanket concepts developed at the present time in Europe for DEMO (LiPb and ceramic blankets) and the requirements upon NET to perform these tests are reviewed. Typical locations available in NET for blanket testing are the central outboard segments and the horizontal ports of in-vessel sectors. These test positions will be connectable with external test loops. The number of test loops (helium, water, liquid metal) will be such that each major class of blankets can be tested in NET. The test positions, the boundary conditions and the external test loops are identified and the requirements for test blankets are summarized (author). 6

  3. Functional Testing Airborne Radars

    Science.gov (United States)

    1981-03-27

    recorded, and presented in accordance with this TOP? Yes No Comment : 2. Were the facilities, test equipment, instrumentation, and support accommo- dations...adequate to accomplish the test objectives? Yes No Comment : 3. Have all data collected been reviewed for correctness and completeness? Yes No ... Comment : 4. Were the test results compromised in any way due to insufficient test planning? Yes No . Comment : 5. Were the test results compromised in any

  4. Testing Aircraft Instruments.

    Science.gov (United States)

    1981-02-11

    1. Have test data been collected, recorded, and presented in accordance with this TOP? Yes No Comment : 2. Were the facilities, test equipment...instrumentation, and support accommodations adequate to accomplish the test objectives? Yes No Comment : 3. Have all data collected been reviewed for...correctness and completeness? Yes No Comment : 4. Were the test results compromised in any way due to insufficient test planning? Yes No Comment : 5. Were the

  5. Pancreatic Exocrine Function Testing

    OpenAIRE

    Berk, J. Edward

    1982-01-01

    It is important to understand which pancreatic function tests are available and how to interpret them when evaluating patients with malabsorption. Available direct tests are the secretin stimulation test, the Lundh test meal, and measurement of serum or fecal enzymes. Indirect tests assess pancreatic exocrine function by measuring the effect of pancreatic secretion on various nutrients. These include triglycerides labeled with carbon 14, cobalamin labeled with cobalt 57 and cobalt 58, and par...

  6. Testing experience with fast flux test facility

    International Nuclear Information System (INIS)

    Noordhoff, B.H.; McGough, C.B.; Nolan, J.E.

    1975-01-01

    Early FFTF project planning emphasized partial and full-scale testing of major reactor and plant prototype components under expected environmental conditions, excluding radiation fields. Confirmation of component performance during FFTF service was considered essential before actual FFTF startup, to provide increased assurance against FFTF startup delays or operational difficulties and downtime. Several new sodium facilities were constructed, and confirmation tests on the prototype components are now in progress. Test conditions and results to date are reported for the primary pump, intermediate heat exchanger, sodium-to-air dump heat exchanger, large and small sodium valves, purification cold trap, in-vessel handling machine, instrument tree, core restraint, control rod system, low-level flux monitor, closed loop ex-vessel machine, refueling equipment, and selected maintenance equipment. The significance and contribution of these tests to the FFTF and Liquid Metal Fast Breeder Reactor (LMFBR) program are summarized. (U.S.)

  7. Antimicrobials Products Tested or Pending Testing

    Science.gov (United States)

    The agency has completed testing of the majority of registered hospital disinfectants and tuberculocide products. The list of products can assist users in making informed choices regarding infection control in their facilities.

  8. The hardness test: a real mechanical test

    International Nuclear Information System (INIS)

    Rezakhanlou, R.

    1993-02-01

    During the service life, the mechanical properties of the PWR components change. It is necessary to determine precisely this evolution, but it is not always possible to draw a sample with the adequate size for the characterization. For this latter case we intend to calculate the stress-strain curve of a material from a hardness test results, because it is appropriate for testing on site and do not need any particular sample shape. This paper is the first bibliographical part of a larger study on the relation between the values measured during a hardness test (applied load, indentation diameter) and the mechanical properties of a solid obtained by a traction test. We have treated the problem within the general setting of two solids in contact. Thus, we expose general elastic, elasto-plastic and plastic models describing the indentation of a solid by a rigid indenter

  9. Test plan for core drilling ignitability testing

    International Nuclear Information System (INIS)

    Witwer, K.S.

    1996-01-01

    The objective of this testing is to determine if ignition occurs while core drilling in a flammable gas environment. Drilling parameters are chosen so as to provide bounding conditions for the core sampling environment. If ignition does not occur under the conditions set forth in this test, then a satisfactory level of confidence will be obtained which would allow field operations under the normal drilling conditions

  10. TESTING TESTS ON ACTIVE GALACTIC NUCLEI MICROVARIABILITY

    International Nuclear Information System (INIS)

    De Diego, Jose A.

    2010-01-01

    Literature on optical and infrared microvariability in active galactic nuclei (AGNs) reflects a diversity of statistical tests and strategies to detect tiny variations in the light curves of these sources. Comparison between the results obtained using different methodologies is difficult, and the pros and cons of each statistical method are often badly understood or even ignored. Even worse, improperly tested methodologies are becoming more and more common, and biased results may be misleading with regard to the origin of the AGN microvariability. This paper intends to point future research on AGN microvariability toward the use of powerful and well-tested statistical methodologies, providing a reference for choosing the best strategy to obtain unbiased results. Light curves monitoring has been simulated for quasars and for reference and comparison stars. Changes for the quasar light curves include both Gaussian fluctuations and linear variations. Simulated light curves have been analyzed using χ 2 tests, F tests for variances, one-way analyses of variance and C-statistics. Statistical Type I and Type II errors, which indicate the robustness and the power of the tests, have been obtained in each case. One-way analyses of variance and χ 2 prove to be powerful and robust estimators for microvariations, while the C-statistic is not a reliable methodology and its use should be avoided.

  11. Trends in software testing

    CERN Document Server

    Mohanty, J; Balakrishnan, Arunkumar

    2017-01-01

    This book is focused on the advancements in the field of software testing and the innovative practices that the industry is adopting. Considering the widely varied nature of software testing, the book addresses contemporary aspects that are important for both academia and industry. There are dedicated chapters on seamless high-efficiency frameworks, automation on regression testing, software by search, and system evolution management. There are a host of mathematical models that are promising for software quality improvement by model-based testing. There are three chapters addressing this concern. Students and researchers in particular will find these chapters useful for their mathematical strength and rigor. Other topics covered include uncertainty in testing, software security testing, testing as a service, test technical debt (or test debt), disruption caused by digital advancement (social media, cloud computing, mobile application and data analytics), and challenges and benefits of outsourcing. The book w...

  12. Pragmatics of Testing

    Directory of Open Access Journals (Sweden)

    İsmail Fırat ALTAY

    2007-10-01

    Full Text Available Teaching of a language is a very complicated issue and testing is anindispensable part of this matter. Thanks to testing teachers can assess efficiency ofteaching and learning atmosphere, and can get feedback about their learners. In order torealize this, a test should have some qualifications. One of these qualifications is aboutpragmatics. This paper aims at explaining what makes a test pragmatic and howpragmatic tests can be formed. So, examples of pragmatic tests of different types arepresented with explanations. Their pragmatic components and nature are focused on bygiving example test items on the problematic area of test questions prepared. Finally,the writer states his last words by making further comments and explanations onpragmatics of testing in the conclusion part.

  13. Relay test program

    International Nuclear Information System (INIS)

    Bandyopadhyay, K.K.; Kunkel, C.; Shteyngart, S.

    1994-02-01

    This report presents the results of a relay test program conducted by Brookhaven National Laboratory (BNL) under the sponsorship of the US Nuclear Regulatory Commission (NRC). The program is a continuation of an earlier test program the results of which were published in NUREG/CR-4867. The current program was carried out in two phases: electrical testing and vibration testing. The objective was primarily to focus on the electrical discontinuity or continuity of relays and circuit breaker tripping mechanisms subjected to electrical pulses and vibration loads. The electrical testing was conducted by KEMA-Powertest Company and the vibration testing was performed at Wyle Laboratories, Huntsville, Alabama. This report discusses the test procedures, presents the test data, includes an analysis of the data and provides recommendations regarding reliable relay testing

  14. Nondestructive testing of materials

    International Nuclear Information System (INIS)

    NUKEM has transferred know-how from reactor technology to materials testing. The high and to a large extent new quality standards in the nuclear industry necessitate reliable measuring and testing equipment of the highest precision. Many of the tasks presented to us could not be solved with the equipment available on the market, for which reason we have developed our own measuring, testing and control systems. We have therefore acquired considerable experience in dealing with specific measuring, testing and control tasks and can handle even out-of-the-way problems that are submitted to us from a wide variety of fields. Our mechanical systems for the checking of close-tolerance gaps, the automatic determination of pellet dimensions and the measurement of absolute lengths and absolute velocities are in use in many different industrial fields. We have succeeded in solving unusual testing and sorting problems with the aid of automated surface testing equipment working on optical principles. Our main activities in the field of non-destructive testing have been concentrated on ultrasonic and eddy current testing and, of late, acoustic emission analysis. NUKEM ultrasonic systems are notable for their high defect detection rate and testing accuracy, combined with high testing speed. The equipment we supply includes ultrasonic rotary systems for the production testing of quality tubes, ultrasonic immersion systems for the final testing of reactor cladding tubes, weld testing equipment, and test equipment for the bonds in multi-layer plates. (orig./RW) [de

  15. Gas Test Loop Booster Fuel Hydraulic Testing

    International Nuclear Information System (INIS)

    Gas Test Loop Hydraulic Testing Staff

    2006-01-01

    The Gas Test Loop (GTL) project is for the design of an adaptation to the Advanced Test Reactor (ATR) to create a fast-flux test space where fuels and materials for advanced reactor concepts can undergo irradiation testing. Incident to that design, it was found necessary to make use of special booster fuel to enhance the neutron flux in the reactor lobe in which the Gas Test Loop will be installed. Because the booster fuel is of a different composition and configuration from standard ATR fuel, it is necessary to qualify the booster fuel for use in the ATR. Part of that qualification is the determination that required thermal hydraulic criteria will be met under routine operation and under selected accident scenarios. The Hydraulic Testing task in the GTL project facilitates that determination by measuring flow coefficients (pressure drops) over various regions of the booster fuel over a range of primary coolant flow rates. A high-fidelity model of the NW lobe of the ATR with associated flow baffle, in-pile-tube, and below-core flow channels was designed, constructed and located in the Idaho State University Thermal Fluids Laboratory. A circulation loop was designed and constructed by the university to provide reactor-relevant water flow rates to the test system. Models of the four booster fuel elements required for GTL operation were fabricated from aluminum (no uranium or means of heating) and placed in the flow channel. One of these was instrumented with Pitot tubes to measure flow velocities in the channels between the three booster fuel plates and between the innermost and outermost plates and the side walls of the flow annulus. Flow coefficients in the range of 4 to 6.5 were determined from the measurements made for the upper and middle parts of the booster fuel elements. The flow coefficient for the lower end of the booster fuel and the sub-core flow channel was lower at 2.3

  16. Gas Test Loop Booster Fuel Hydraulic Testing

    Energy Technology Data Exchange (ETDEWEB)

    Gas Test Loop Hydraulic Testing Staff

    2006-09-01

    The Gas Test Loop (GTL) project is for the design of an adaptation to the Advanced Test Reactor (ATR) to create a fast-flux test space where fuels and materials for advanced reactor concepts can undergo irradiation testing. Incident to that design, it was found necessary to make use of special booster fuel to enhance the neutron flux in the reactor lobe in which the Gas Test Loop will be installed. Because the booster fuel is of a different composition and configuration from standard ATR fuel, it is necessary to qualify the booster fuel for use in the ATR. Part of that qualification is the determination that required thermal hydraulic criteria will be met under routine operation and under selected accident scenarios. The Hydraulic Testing task in the GTL project facilitates that determination by measuring flow coefficients (pressure drops) over various regions of the booster fuel over a range of primary coolant flow rates. A high-fidelity model of the NW lobe of the ATR with associated flow baffle, in-pile-tube, and below-core flow channels was designed, constructed and located in the Idaho State University Thermal Fluids Laboratory. A circulation loop was designed and constructed by the university to provide reactor-relevant water flow rates to the test system. Models of the four booster fuel elements required for GTL operation were fabricated from aluminum (no uranium or means of heating) and placed in the flow channel. One of these was instrumented with Pitot tubes to measure flow velocities in the channels between the three booster fuel plates and between the innermost and outermost plates and the side walls of the flow annulus. Flow coefficients in the range of 4 to 6.5 were determined from the measurements made for the upper and middle parts of the booster fuel elements. The flow coefficient for the lower end of the booster fuel and the sub-core flow channel was lower at 2.3.

  17. Metamorphic Testing for Cybersecurity.

    Science.gov (United States)

    Chen, Tsong Yueh; Kuo, Fei-Ching; Ma, Wenjuan; Susilo, Willy; Towey, Dave; Voas, Jeffrey; Zhou, Zhi Quan

    2016-06-01

    Testing is a major approach for the detection of software defects, including vulnerabilities in security features. This article introduces metamorphic testing (MT), a relatively new testing method, and discusses how the new perspective of MT can help to conduct negative testing as well as to alleviate the oracle problem in the testing of security-related functionality and behavior. As demonstrated by the effectiveness of MT in detecting previously unknown bugs in real-world critical applications such as compilers and code obfuscators, we conclude that software testing of security-related features should be conducted from diverse perspectives in order to achieve greater cybersecurity.

  18. Theory of nonparametric tests

    CERN Document Server

    Dickhaus, Thorsten

    2018-01-01

    This textbook provides a self-contained presentation of the main concepts and methods of nonparametric statistical testing, with a particular focus on the theoretical foundations of goodness-of-fit tests, rank tests, resampling tests, and projection tests. The substitution principle is employed as a unified approach to the nonparametric test problems discussed. In addition to mathematical theory, it also includes numerous examples and computer implementations. The book is intended for advanced undergraduate, graduate, and postdoc students as well as young researchers. Readers should be familiar with the basic concepts of mathematical statistics typically covered in introductory statistics courses.

  19. Metamorphic Testing for Cybersecurity

    Science.gov (United States)

    Chen, Tsong Yueh; Kuo, Fei-Ching; Ma, Wenjuan; Susilo, Willy; Towey, Dave; Voas, Jeffrey

    2016-01-01

    Testing is a major approach for the detection of software defects, including vulnerabilities in security features. This article introduces metamorphic testing (MT), a relatively new testing method, and discusses how the new perspective of MT can help to conduct negative testing as well as to alleviate the oracle problem in the testing of security-related functionality and behavior. As demonstrated by the effectiveness of MT in detecting previously unknown bugs in real-world critical applications such as compilers and code obfuscators, we conclude that software testing of security-related features should be conducted from diverse perspectives in order to achieve greater cybersecurity. PMID:27559196

  20. Comparative Test Case Specification

    DEFF Research Database (Denmark)

    Kalyanova, Olena; Heiselberg, Per

     This document includes a definition of the comparative test cases DSF200_3 and DSF200_4, which previously described in the comparative test case specification for the test cases DSF100_3 and DSF200_3 [Ref.1]....... This document includes a definition of the comparative test cases DSF200_3 and DSF200_4, which previously described in the comparative test case specification for the test cases DSF100_3 and DSF200_3 [Ref.1]....

  1. Proficiency Testing in Nondestructive Testing (NDT)

    International Nuclear Information System (INIS)

    Amry Amin Abbas; Suhairy Sani; Mohamad Pauzi Ismail; Abd Nassir Ibrahim

    2014-01-01

    Department of Standard Malaysia (DSM) launched myPTP programme on 31 December 2013 in accordance to ISO/IC 17043. The standard states the requirements for Proficiency Testing. The provider of these services is called Proficiency Testing Provider (PTP). The role of PTP is to compare the proficiency level between inspection bodies or laboratories. With the assistance of expert panel, the PTP will determine the assigned value as reference to be compared to the values obtained from the inspection bodies or laboratories. Quality wise, this services is important as participation will improve wuality of the inspection quality continuously and increase confidence level of client and improve safety level. Requirement of PT in NDT is mentioned in SC1.5- Specific Criteria for Accreditation of Mechanical Testing and Non-Destructive Testing (NDT) for MS ISO/IEC17025 and MTR2- MIBAS Technical Requirements for Accreditation of NDT. This paper explains and discusses the result of this proficiency test done on a number of NDT companies that participated. (author)

  2. Irradiation Effects Test Series: Test IE-2. Test results report

    International Nuclear Information System (INIS)

    Allison, C.M.; Croucher, D.W.; Ploger, S.A.; Mehner, A.S.

    1977-08-01

    The report describes the results of a test using four 0.97-m long PWR-type fuel rods with differences in diametral gap and cladding irradiation. The objective of this test was to provide information about the effects of these differences on fuel rod behavior during quasi-equilibrium and film boiling operation. The fuel rods were subjected to a series of preconditioning power cycles of less than 30 kW/m. Rod powers were then increased to 68 kW/m at a coolant mass flux of 4900 kg/s-m 2 . After one hour at 68 kW/m, a power-cooling-mismatch sequence was initiated by a flow reduction at constant power. At a flow of 2550 kg/s-m 2 , the onset of film boiling occurred on one rod, Rod IE-011. An additional flow reduction to 2245 kg/s-m 2 caused the onset of film boiling on the remaining three rods. Data are presented on the behavior of fuel rods during quasiequilibrium and during film boiling operation. The effects of initial gap size, cladding irradiation, rod power cycling, a rapid power increase, and sustained film boiling are discussed. These discussions are based on measured test data, preliminary postirradiation examination results, and comparisons of results with FRAP-T3 computer model calculations

  3. Visual acuity test

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003396.htm Visual acuity test To use the sharing features on this page, please enable JavaScript. The visual acuity test is used to determine the smallest ...

  4. Learning Python testing

    CERN Document Server

    Arbuckle, Daniel

    2014-01-01

    This book is ideal if you want to learn about the testing disciplines and automated testing tools from a hands-on, conversational guide. You should already know Python and be comfortable with Python 3.

  5. EMI Test Facility

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Supports electromagnetic interference/radio frequency interference (EMI/RFI) testing of flight hardware. It is also used to support custom RF testing up to...

  6. Urine specific gravity test

    Science.gov (United States)

    ... medlineplus.gov/ency/article/003587.htm Urine specific gravity test To use the sharing features on this page, please enable JavaScript. Urine specific gravity is a laboratory test that shows the concentration ...

  7. Ballistic Test Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Ballistic Test Facility is comprised of two outdoor and one indoor test ranges, which are all instrumented for data acquisition and analysis. Full-size aircraft...

  8. Ultrasonic testing X gammagraphy

    International Nuclear Information System (INIS)

    Mello Campos, A.M. de

    1989-01-01

    The experience of 10 years for substituting gammagraphy tests by ultrasonic tests is related. A comparative evaluation of data obtained from both techniques applied to welded butt joints is presented. (author)

  9. Extraocular muscle function testing

    Science.gov (United States)

    ... medlineplus.gov/ency/article/003397.htm Extraocular muscle function testing To use the sharing features on this page, please enable JavaScript. Extraocular muscle function testing examines the function of the eye muscles. ...

  10. Platelet Function Tests

    Science.gov (United States)

    ... Patient Resources For Health Professionals Subscribe Search Platelet Function Tests Send Us Your Feedback Choose Topic At ... Also Known As Platelet Aggregation Studies PFT Platelet Function Assay PFA Formal Name Platelet Function Tests This ...

  11. Variable Attitude Test Stand

    Data.gov (United States)

    Federal Laboratory Consortium — The Variable Attitude Test Stand designed and built for testing of the V-22 tilt rotor aircraft propulsion system, is used to evaluate the effect of aircraft flight...

  12. Insensitive Munitions Testing

    Data.gov (United States)

    Federal Laboratory Consortium — Insensitive Munitions Testing at RTC is conducted (IAW MILSTD-2105) at Test Area 4. Our engineers and technicians obtain data for hazards classification and safety...

  13. Lab and Imaging Tests

    Science.gov (United States)

    ... tests to help detect (diagnose) a blood cancer (leukemia, lymphoma, myeloma, myelodysplastic syndromes or myeloproliferative disease). You may need to undergo additional tests to confirm your diagnosis. Once your diagnosis is confirmed, your doctor may ...

  14. Learning Android application testing

    CERN Document Server

    Blundell, Paul

    2015-01-01

    If you are an Android developer looking to test your applications or optimize your application development process, then this book is for you. No previous experience in application testing is required.

  15. Genetic Testing for ALS

    Science.gov (United States)

    ... genetic counselor can help you work through the pros and cons of genetic testing based on your ... showing symptoms or what their progression will be. Technology is changing rapidly and costs of testing are ...

  16. Atlantic Test Range (ATR)

    Data.gov (United States)

    Federal Laboratory Consortium — ATR controls fully-instrumented and integrated test ranges that provide full-service support for cradle-to-grave testing. Airspace and surface target areas are used...

  17. The Danish National Tests

    DEFF Research Database (Denmark)

    Beuchert, Louise Voldby; Nandrup, Anne Brink

    In 2010, the Danish National Tests were implemented in the public compulsory schools as a mean of evaluating the performance of the public school system. The extensive test program consists of ten mandatory tests in six subjects in grades 2 through 8. In this paper, we share our insights from wor...... characteristics as well as pupils' 9th grade examination marks. We document a stable test score gap across grade levels and socio economic background and discuss the prospects of the national test data for future research....... within each test and argue that this is often a more feasible measure for data analyses compared to the transformed test score presented to pupils and teachers. We provide the reader with preliminary analyses of the relation between pupils' national test results and a wide range of pupil background...

  18. Uric acid test (image)

    Science.gov (United States)

    Uric acid urine test is performed to check for the amount of uric acid in urine. Urine is collected over a 24 ... for testing. The most common reason for measuring uric acid levels is in the diagnosis or treatment of ...

  19. Ethylene glycol blood test

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003564.htm Ethylene glycol blood test To use the sharing features ... enable JavaScript. This test measures the level of ethylene glycol in the blood. Ethylene glycol is a ...

  20. hs-CRP Test

    Science.gov (United States)

    ... the sample? No test preparation is needed; however, fasting for 9-12 hours before the blood sample ... such as colon cancer , complications of diabetes , and obesity. I have had cholesterol tests but never an ...

  1. Understanding Laboratory Tests

    Science.gov (United States)

    ... and Drug Administration (FDA) regulates the development and marketing of all laboratory tests that use test kits ... Cancer.gov en español Multimedia Publications Site Map Digital Standards for NCI Websites POLICIES Accessibility Comment Policy ...

  2. Corrosion Testing Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Corrosion Testing Facility is part of the Army Corrosion Office (ACO). It is a fully functional atmospheric exposure site, called the Corrosion Instrumented Test...

  3. Rocketball Test Facility

    Data.gov (United States)

    Federal Laboratory Consortium — This test facility offers the capability to emulate and measure guided missile radar cross-section without requiring flight tests of tactical missiles. This facility...

  4. PT and INR Test

    Science.gov (United States)

    ... Plasma Free Metanephrines Platelet Count Platelet Function Tests Pleural Fluid Analysis PML-RARA Porphyrin Tests Potassium Prealbumin ... and vitamin K (either in a multivitamin or liquid nutrition supplement) may decrease PT. Certain foods, such ...

  5. Helicobacter pylori Test

    Science.gov (United States)

    ... Plasma Free Metanephrines Platelet Count Platelet Function Tests Pleural Fluid Analysis PML-RARA Porphyrin Tests Potassium Prealbumin ... collected and then the person is given a liquid to drink. Another breath sample is collected at ...

  6. Static Loads Test Facility

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Provides the capability to perform large-scale structural loads testing on spacecraft and other structures. Results from these tests can be used to verify...

  7. Antidiuretic hormone blood test

    Science.gov (United States)

    ... medlineplus.gov/ency/article/003702.htm Antidiuretic hormone blood test To use the sharing features on this page, please enable JavaScript. Antidiuretic blood test measures the level of antidiuretic hormone (ADH) in ...

  8. Gastrin blood test

    Science.gov (United States)

    Peptic ulcer - gastrin blood test ... A blood sample is needed . ... in the stomach, gastrin is released into the blood. As the acid ... provider may order this test if you have signs or symptoms of a ...

  9. HCG blood test - qualitative

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003509.htm HCG blood test - qualitative To use the sharing features on this page, please enable JavaScript. A qualitative HCG blood test checks if there is a hormone called human ...

  10. ACE blood test

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003567.htm ACE blood test To use the sharing features on this page, ... Alternative Names Serum angiotensin-converting enzyme; SACE Images Blood test References Carty RP, Pincus MR, Sarafraz-Yazdi E. ...

  11. LDH isoenzyme blood test

    Science.gov (United States)

    ... medlineplus.gov/ency/article/003499.htm LDH isoenzyme blood test To use the sharing features on this page, ... Names LD; LDH; Lactic (lactate) dehydrogenase isoenzymes Images Blood test References Carty RP, Pincus MR, Sarafraz-Yazdi E. ...

  12. Phosphorus blood test

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003478.htm Phosphorus blood test To use the sharing features on this page, please enable JavaScript. The phosphorus blood test measures the amount of phosphate in the blood. ...

  13. CEA blood test

    Science.gov (United States)

    Carcinoembryonic antigen blood test ... doing so for a short time before the test. ... When the needle is inserted to draw blood, some people feel ... may be some throbbing or a slight bruise. This soon goes away.

  14. Methylmalonic acid blood test

    Science.gov (United States)

    ... medlineplus.gov/ency/article/003565.htm Methylmalonic acid blood test To use the sharing features on this page, please enable JavaScript. The methylmalonic acid blood test measures the amount of methylmalonic acid in the ...

  15. TBG - blood test

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003374.htm TBG - blood test To use the sharing features on this page, please enable JavaScript. The TBG blood test measures the level of a protein that moves ...

  16. Calcitonin blood test

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003699.htm Calcitonin blood test To use the sharing features on this page, please enable JavaScript. The calcitonin blood test measures the level of the hormone calcitonin in ...

  17. Calcium blood test

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003477.htm Calcium blood test To use the sharing features on this page, please enable JavaScript. The calcium blood test measures the level of calcium in the blood. ...

  18. Aldolase blood test

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003566.htm Aldolase blood test To use the sharing features on this page, ... risk any time the skin is broken) Images Blood test References Berridge BR, Van Vleet JF, Herman E. ...

  19. Glucagon blood test

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003716.htm Glucagon blood test To use the sharing features on this page, please enable JavaScript. A glucagon blood test measures the amount of a hormone called glucagon ...

  20. Leucine aminopeptidase blood test

    Science.gov (United States)

    ... medlineplus.gov/ency/article/003559.htm Leucine aminopeptidase blood test To use the sharing features on this page, ... Alternative Names Serum leucine aminopeptidase; LAP - serum Images Blood test References Chernecky CC, Berger BJ. Leucine aminopeptidase (LAP) - ...

  1. Pyruvate kinase blood test

    Science.gov (United States)

    ... medlineplus.gov/ency/article/003357.htm Pyruvate kinase blood test To use the sharing features on this page, ... energy when oxygen levels are low. How the Test is Performed A blood sample is needed. In the laboratory, white blood ...

  2. Ammonia blood test

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003506.htm Ammonia blood test To use the sharing features on this page, ... Encephalopathy - ammonia; Cirrhosis - ammonia; Liver failure - ammonia Images Blood test References Chernecky CC, Berger BJ. Ammonia (NH3) - blood ...

  3. Antithrombin III blood test

    Science.gov (United States)

    ... medlineplus.gov/ency/article/003661.htm Antithrombin III blood test To use the sharing features on this page, ... a protein that helps control blood clotting. A blood test can determine the amount of AT III present ...

  4. Fibrinopeptide A blood test

    Science.gov (United States)

    ... medlineplus.gov/ency/article/003373.htm Fibrinopeptide A blood test To use the sharing features on this page, ... measure the level of this substance in your blood. How the Test is Performed A blood sample is needed. How ...

  5. Tularemia blood test

    Science.gov (United States)

    Tularemia test; Serology for Francisella tularensis ... This blood test is done when tularemia is suspected. ... Elsevier; 2017:chap 44. Chernecky CC, Berger BJ. Tularemia agglutinins - serum. In: Chernecky CC, Berger BJ, eds. ...

  6. RBC urine test

    Science.gov (United States)

    ... measurement for a result of this test. Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your provider ...

  7. Mantoux Tuberculin Skin Test

    Centers for Disease Control (CDC) Podcasts

    Learn how to evaluate people for latent TB infection with the Mantoux tuberculin skin test. This podcast includes sections on administering and reading the Mantoux tuberculin skin test, the standard method for detecting latent TB infection since the 1930s.

  8. Large scale reflood test

    International Nuclear Information System (INIS)

    Hirano, Kemmei; Murao, Yoshio

    1980-01-01

    The large-scale reflood test with a view to ensuring the safety of light water reactors was started in fiscal 1976 based on the special account act for power source development promotion measures by the entrustment from the Science and Technology Agency. Thereafter, to establish the safety of PWRs in loss-of-coolant accidents by joint international efforts, the Japan-West Germany-U.S. research cooperation program was started in April, 1980. Thereupon, the large-scale reflood test is now included in this program. It consists of two tests using a cylindrical core testing apparatus for examining the overall system effect and a plate core testing apparatus for testing individual effects. Each apparatus is composed of the mock-ups of pressure vessel, primary loop, containment vessel and ECCS. The testing method, the test results and the research cooperation program are described. (J.P.N.)

  9. Test Preparation: Your Role

    Science.gov (United States)

    ... eating cooked meat may be required since some studies have shown that eating cooked meat prior to testing can temporarily increase the level of creatinine. Fecal occult blood test : certain food and/or medication restrictions may be required. Urine ...

  10. Testing for HIV

    Science.gov (United States)

    ... Medical Devices Radiation-Emitting Products Vaccines, Blood & Biologics Animal & Veterinary Cosmetics Tobacco Products Vaccines, Blood & Biologics Home Vaccines, Blood & Biologics Safety & Availability (Biologics) HIV Home Test Kits Testing for HIV Share Tweet Linkedin Pin it More ...

  11. Radiated Emissions Test Approach

    Science.gov (United States)

    2015-10-02

    1. Draft Department of Transportation (DOT) Test Plan to Develop : Interference Tolerance Masks for GNSS Receivers in the L1 : Radiofrequency Band (1559 1610 MHz) provides high level : overview of radiated emissions test setup : 2. Presenta...

  12. HPV DNA test

    Science.gov (United States)

    ... test; Cancer of cervix - HPV DNA test References Hacker NF. Cervical dysplasia and cancer. In: Hacker NF, Gambone JC, Hobel CJ, eds. Hacker and Moore's Essentials of Obstetrics and Gynecology . 6th ...

  13. Cross cultural usability testing

    DEFF Research Database (Denmark)

    Clemmensen, Torkil; Goyal, Shivam

    2005-01-01

    In this paper, we present the results of a pilot study in Denmark of cross cultural effects on Think Aloud usability testing. We provide an overview of previous research on cross cultural usability evaluation with a special focus on the relationship between the evaluator and the test user....... This relation was studied in an experiment with usability testing of a localized clipart application in which eight participants from Denmark and India formed pairs of evaluator-test user. The test users were asked to think aloud and the evaluators' role were to facilitate the test users thinking aloud...... and hereby identify usability problems with the clipart application. Data on the evaluators' and test users' behaviour were recorded and analyzed by coding and summarizing statistics on these behavioural events. The results show that Think Aloud Usability Test of a localized application is most effectively...

  14. Environmental Test Facility (ETF)

    Data.gov (United States)

    Federal Laboratory Consortium — The Environmental Test Facility (ETF) provides non-isolated shock testing for stand-alone equipment and full size cabinets under MIL-S-901D specifications. The ETF...

  15. The first PANDA tests

    International Nuclear Information System (INIS)

    Dreier, J.; Huggenberger, M.; Aubert, C.

    1996-01-01

    The PANDA test facility at PSI in Switzerland is used to study the long-term Simplified Boiling Water Reactor (SBWR) Passive Containment Cooling System (PCCS) performance. The PANDA tests demonstrate performance on a larger scale than previous tests and examine the effects of any non-uniform spatial distributions of steam and non-condensables in the system. The PANDA facility has a 1:1 vertical scale, and 1:25 ''system'' scale (volume, power, etc.). Steady-state PCCS condenser performance tests and extensive facility characterization tests have been completed. Transient system behavior tests were conducted late in 1995; results from the first three transient tests (M3 series) are reviewed. The first PANDA tests showed that the overall global behavior of the SBWR containment was globally repeatable and very favorable; the system exhibited great ''robustness.''

  16. Growth hormone stimulation test

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003377.htm Growth hormone stimulation test To use the sharing features on this page, please enable JavaScript. The growth hormone (GH) stimulation test measures the ability of ...

  17. USA Hire Testing Platform

    Data.gov (United States)

    Office of Personnel Management — The USA Hire Testing Platform delivers tests used in hiring for positions in the Federal Government. To safeguard the integrity of the hiring processes and ensure...

  18. Shock resistance testing

    International Nuclear Information System (INIS)

    Pouard, M.

    1984-03-01

    In the framework of mechanical tests and to answer the different requests for tests, the T.C.R (Transport Conditionnement et Retraitement) laboratory got test facilities. These installations allow to carry out tests of resistance to shocks, mainly at the safety level of components of nuclear power plants, mockups of transport casks for fuel elements and transport containers for radioactive materials. They include a tower and a catapult. This paper give a decription of the facilities and explain their operation way [fr

  19. Tests in Print II: An Index to Tests, Test Reviews, and the Literature on Specific Tests.

    Science.gov (United States)

    Buros, Oscar K., Ed.

    Tests in Print II is a comprehensive, annotated bibliography of all in-print tests published as separates for use with English-speaking subjects. The 1,155 two-column pages list 2,467 tests in print as of early 1974; 16,574 references through 1971 on specific tests; a reprinting of the 1974 APA-AERA-NCME Standards for Educational andPsychological…

  20. Liquid Rocket Engine Testing

    Science.gov (United States)

    2016-10-21

    Briefing Charts 3. DATES COVERED (From - To) 17 October 2016 – 26 October 2016 4. TITLE AND SUBTITLE Liquid Rocket Engine Testing 5a. CONTRACT NUMBER...298 (Rev. 8-98) Prescribed by ANSI Std. 239.18 Liquid Rocket Engine Testing SFTE Symposium 21 October 2016 Jake Robertson, Capt USAF AFRL...Distribution Unlimited. PA Clearance 16493 Liquid Rocket Engine Testing • Engines and their components are extensively static-tested in development • This

  1. Probe tests microweld strength

    Science.gov (United States)

    1965-01-01

    Probe is developed to test strength of soldered, brazed or microwelded joints. It consists of a spring which may be adjusted to the desired test pressure by means of a threaded probe head, and an indicator lamp. Device may be used for electronic equipment testing.

  2. Language Testing in Japan.

    Science.gov (United States)

    Brown, James Dean, Ed.; Yamashita, Sayoko Okada, Ed.

    Papers on second language testing in Japan include: "Differences Between Norm-Referenced and Criterion-Referenced Tests" (James Dean Brown); "Criterion-Referenced Test Construction and Evaluation" (Dale T. Griffe); "Behavioral Learning Objectives as an Evaluation Tool" (Judith A. Johnson); "Developing Norm-…

  3. [Memory Checking Tests].

    Science.gov (United States)

    Hart, Joseph T.

    Two basic tests for checking memory skills are included in these appendices. The first, the General Information Test, uses the same 150 items for each of its two versions. One version is a completion-type test which measures recall by requiring the examinee to supply a specific response. The other version supplements each of the 150 items with…

  4. Get Tested for HIV

    Science.gov (United States)

    ... AIDS: What is HIV/AIDS? Women and HIV/AIDS Next section ... Tested? Why do I need to get tested for HIV? The only way to know if you have HIV is to get tested. Many people with HIV don’t have any symptoms. In the United States, about 1 in 7 ...

  5. Testing Backbone.js

    CERN Document Server

    Roemer, Ryan

    2013-01-01

    This book is packed with the step by step tutorial and instructions in recipe format helping you setup test infrastructure and gradually advance your skills to plan, develop, and test your backbone applications.If you are a JavaScript developer looking for recipes to create and implement test support for your backbone application, then this book is ideal for you.

  6. Automation of radiometric testing

    International Nuclear Information System (INIS)

    Chekalin, A.S.; Temnik, A.K.; Butakova, G.E.; Goncharov, V.I.

    1983-01-01

    The main prerequisites for creation of automatic systems of radiometric testing as the means to increase the testing objectivity and quality have been considered, principles of their design being developed. The operating system is described for testing complex configuration products using RD-10R gamma flow detector as a sensor of initial information

  7. Estradiol blood test

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003711.htm Estradiol blood test To use the sharing features on this page, ... of estrogens. How the Test is Performed A blood sample is needed . How to Prepare for the Test Your health care provider may tell you to ...

  8. Nuclear Test Personnel Review

    Science.gov (United States)

    FOIA Electronic Reading Room Privacy Impact Assessment DTRA No Fear Act Reporting Nuclear Test Personnel Review NTPR Fact Sheets NTPR Radiation Dose Assessment Documents US Atmospheric Nuclear Test History Documents US Underground Nuclear Test History Reports NTPR Radiation Exposure Reports Enewetak

  9. 2017 Census Test

    Science.gov (United States)

    /Programs Latest Information Are you in a Survey? 2020 Census 2018 Census Test 2010 Census American Information Surveys/Programs Main Are you in a Survey? 2020 Census 2018 Census Test If you have received a Census. Latest Information The 2018 Census Test will take place in Pierce County, Wash.; Providence

  10. Usability testing for dummies

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    Usability testing seems complicated and time-consuming. Is it though? In fact, it is the best way to understand how real users experience your product. In this interactive session, we will do a live usability test and you will get advice on how to conduct your own usability tests.

  11. Barron's SAT subject test

    CERN Document Server

    Jansen, MA, Robert

    2016-01-01

    Includes one diagnostic test and three complete tests, all questions answered and explained, self-assessment guides, and subject reviews. Also features test strategies, QR codes to short instructional videos, and a detailed appendix with equations, physical constants, and a basic math review.

  12. Toroid magnet test facility

    CERN Multimedia

    2002-01-01

    Because of its exceptional size, it was not feasible to assemble and test the Barrel Toroid - made of eight coils - as an integrated toroid on the surface, prior to its final installation underground in LHC interaction point 1. It was therefore decided to test these eight coils individually in a dedicated test facility.

  13. Dismantling the Mantel tests

    DEFF Research Database (Denmark)

    Guillot, Gilles

    The simple and partial Mantel tests are routinely used in many areas of evolutionary biology to assess the significance of the association between two or more matrices of distances relative to the same pairs of individuals or demes. Partial Mantel tests rather than simple Mantel tests are widely...

  14. Dismantling the Mantel tests

    DEFF Research Database (Denmark)

    Guillot, Gilles; Rousset, François

    2012-01-01

    1. The simple and partialMantel tests are routinely used in many areas of evolutionary biology to assess the significance of the association between two ormorematrices of distances relative to the same pairs of individuals or demes. Partial Mantel tests rather than simple Mantel tests are widely...

  15. A test management approach for structured testing

    NARCIS (Netherlands)

    Veenendaal, van E.P.W.M.; Pol, M.; Veenendaal, van E.P.W.M.; McMullan, J.

    1997-01-01

    Despite encouraging results with various quality improvement approaches, the IT industry is still far from achieving zero defect software. Testing will remain an important activity within software development and maintenance, often taking more than 30 - 40% of the total budget. Both the increasing

  16. Grimsel Test Site: heat test, final report

    International Nuclear Information System (INIS)

    Schneefuss, J.; Glaess, F.; Gommlich, G.; Schmidt, M.

    1989-05-01

    The Swiss concept for the storage of radioactive waste consists in placing it in compact, dense rock formations. An experiment 'Heat Test' carried out by the 'Gesellschaft fuer Strahlen- und Umweltforschung' in Nagra's Grimsel rock laboratory simulated the heat production of stored radioactive waste. The aim was to evaluate processes for the demonstration of the suitability of a final repository for heat-producing radioactive waste in cristalline rock, to investigate the thermic, mechanic and hydraulic reactions to an artificial heat source, and to develop corresponding calculating models. The duration of the tests was about 3 years. In this report the measured thermic, mechanic and hydraulic reactions are documented and discussed in detail. A simple, rotation symmetrical FEM-model was used for the preparatory and experiment-accompanying modelling of the thermomechanical conditions in the heat test. The test showed that suitable measuring methods for the surveillance of the geomechanics of a final repository are available and that the reactions of the crystalline host rock to the heat source remain locally limited and can be modelled with relatively small effort. 29 refs., 33 figs., 10 tabs

  17. Toroidal simulation magnet tests

    International Nuclear Information System (INIS)

    Walstrom, P.L.; Domm, T.C.

    1975-01-01

    A number of different schemes for testing superconducting coils in a simulated tokamak environment are analyzed for their merits relative to a set of test criteria. Two of the concepts are examined in more detail: the so-called cluster test scheme, which employs two large background field coils, one on either side of the test coil, and the compact torus, a low-aspect ratio toroidal array of a small number of coils in which all of the coils are essentially test coils. Simulation of the pulsed fields of the tokamak is discussed briefly

  18. 100 statistical tests

    CERN Document Server

    Kanji, Gopal K

    2006-01-01

    This expanded and updated Third Edition of Gopal K. Kanji's best-selling resource on statistical tests covers all the most commonly used tests with information on how to calculate and interpret results with simple datasets. Each entry begins with a short summary statement about the test's purpose, and contains details of the test objective, the limitations (or assumptions) involved, a brief outline of the method, a worked example, and the numerical calculation. 100 Statistical Tests, Third Edition is the one indispensable guide for users of statistical materials and consumers of statistical information at all levels and across all disciplines.

  19. Testing of abrasion materials

    International Nuclear Information System (INIS)

    Hummert, G.

    1983-01-01

    A method of abrasion testing according to ASTM C 704-76 a is presented for steel fibre concrete mortar, fusion-cast basalt and a surface coating material and results of practical interest are mentioned. Due to the high technical demands on these materials and their specific fields of application, the very first test already supplied interesting findings. From the user's point of view, the method is an interesting alternative to the common test methods, e.g. according to DIN 52 108 (wheel test according to Boehme). In English-speaking countries, testing according to ASTM is often mandatory in the refractory industry in order to assure constant quality of refractory materials after setting. The method is characterized by good comparability and high accuracy of measurement. Only the test piece is exchanged while the test conditions remain constant, so that accurate information on the material studied is obtained. (orig.) [de

  20. Earthquake likelihood model testing

    Science.gov (United States)

    Schorlemmer, D.; Gerstenberger, M.C.; Wiemer, S.; Jackson, D.D.; Rhoades, D.A.

    2007-01-01

    INTRODUCTIONThe Regional Earthquake Likelihood Models (RELM) project aims to produce and evaluate alternate models of earthquake potential (probability per unit volume, magnitude, and time) for California. Based on differing assumptions, these models are produced to test the validity of their assumptions and to explore which models should be incorporated in seismic hazard and risk evaluation. Tests based on physical and geological criteria are useful but we focus on statistical methods using future earthquake catalog data only. We envision two evaluations: a test of consistency with observed data and a comparison of all pairs of models for relative consistency. Both tests are based on the likelihood method, and both are fully prospective (i.e., the models are not adjusted to fit the test data). To be tested, each model must assign a probability to any possible event within a specified region of space, time, and magnitude. For our tests the models must use a common format: earthquake rates in specified “bins” with location, magnitude, time, and focal mechanism limits.Seismology cannot yet deterministically predict individual earthquakes; however, it should seek the best possible models for forecasting earthquake occurrence. This paper describes the statistical rules of an experiment to examine and test earthquake forecasts. The primary purposes of the tests described below are to evaluate physical models for earthquakes, assure that source models used in seismic hazard and risk studies are consistent with earthquake data, and provide quantitative measures by which models can be assigned weights in a consensus model or be judged as suitable for particular regions.In this paper we develop a statistical method for testing earthquake likelihood models. A companion paper (Schorlemmer and Gerstenberger 2007, this issue) discusses the actual implementation of these tests in the framework of the RELM initiative.Statistical testing of hypotheses is a common task and a

  1. Teacher Test Accountability.

    Directory of Open Access Journals (Sweden)

    Larry H. Ludlow

    2001-02-01

    Full Text Available Given the high stakes of teacher testing, there is no doubt that every teacher test should meet the industry guidelines set forth in the Standards for Educational and Psychological Testing. Unfortunately, however, there is no public or private business or governmental agency that serves to certify or in any other formal way declare that any teacher test does, in fact, meet the psychometric recommendations stipulated in the Standards. Consequently, there are no legislated penalties for faulty products (tests nor are there opportunities for test takers simply to raise questions about a test and to have their questions taken seriously by an impartial panel. The purpose of this article is to highlight some of the psychometric results reported by National Evaluation Systems (NES in their 1999 Massachusetts Educator Certification Test (MECT Technical Report, and more specifically, to identify those technical characteristics of the MECT that are inconsistent with the Standards. A second purpose of this article is to call for the establishment of a standing test auditing organization with investigation and sanctioning power. The significance of the present analysis is twofold: a psychometric results for the MECT are similar in nature to psychometric results presented as evidence of test development flaws in an Alabama class-action lawsuit dealing with teacher certification (an NES-designed testing system; and b there was no impartial enforcement agency to whom complaints about the Alabama tests could be brought, other than the court, nor is there any such agency to whom complaints about the Massachusetts tests can be brought. I begin by reviewing NES's role in Allen v. Alabama State Board of Education, 81-697-N. Next I explain the purpose and interpretation of standard item analysis procedures and statistics. Finally, I present results taken directly from the 1999 MECT Technical Report and compare them to procedures, results, and consequences of

  2. Fracture evaluation tests

    International Nuclear Information System (INIS)

    Robinson, G.C.

    1991-01-01

    In this report period, efforts have concentrated on defining the requirements for shallow-flaw beam testing. Analyses have been made to envelope the significant parameters for both deep- and shallow-flaw beams for three-point loading; that is, load to initiation of a frangible flaw, load to plastic collapse, LLD, and CMOD. An assessment was made of facilities capable of performing the tests identified by the parametric analyses discussed above. Two testing machines were identified for performing the scoped test series, the first a 550-kip Instron machine assigned to the Pressure Vessel Technology Section located in Building 9204-1 at the Y-12 Plant and the second a 220-kip MTS machine assigned to a mechanical testing group located at the K-25 Site. An existing bend test fixture previously used in the HSST clad plate test series is being modified for use in testing beams under other sponsorship but will be available for shared usage with the HSST shallow-flaw beam testing activities. To prevent the shared usage from having an adverse impact on the logistics of the HSST Program, the decision was made to procure a bend test fixture tailored specifically to serve the shallow flaw beam test series. A specification was prepared and procurement initiated. A survey is in progress for determining sources and costs of displacement-measuring instrumentation from both foreign and domestic sources. It appears that existing direct current displacement transducers available to the HSST Program may be adequate for the LLD measurements. These devices will be employed in the shakedown tests that are planned. A safety and environmental survey assessment for the beam testing conforming to the revised DOE rules has been prepared and approved

  3. Test Results for CSTR Test 4

    International Nuclear Information System (INIS)

    Lee, D.D.

    2001-01-01

    One of the 3 technologies currently being developed for the Savannah River Salt Waste Processing Program is the Small-Tank Tetraphenylborate Process (STTP). This process uses sodium tetraphenylborate to precipitate and remove radioactive Cs from the waste and monosodium titanate to sorb and remove radioactive Sr and actinides. ORNL is demonstrating this process at the 1:4000 scale using a 20-liter continuous-flow stirred tank reactor (CSTR) system. The primary goal of Test 4 was to verify that the STTP process could achieve and maintain the necessary Cs decontamination while TPB was actively decomposing. Even with TPB being decomposed by the off-normal conditions of this test, the decontaimination factor for 137 Cs obtained for the filtrate from the Slurry Concentrating Tank ranged from 47,000 to 646,000, exceeding the WAC standard

  4. Hot ductility testing and weld simulation tests

    International Nuclear Information System (INIS)

    Weber, G.; Schick, M.

    1999-01-01

    The objective of the project was to enhance the insight into the causes of intergranular cracks detected in austenitic circumferential welds at BWR pipes. The susceptibility of a variety of austenitic pipe materials to hot cracking during welding and in-service intergranular crack corrosion was examined. The assumption was cracking in the root area of the HAZ of a multiple-layer weld. Hot-ductility tests and weld simulation tests specifically designed for the project were performed with the austenitic LWR pipe materials 1.4553 (X6 CrNiNb 18 10 S), 1.4550 (X10 CrNiNb 18 9), 1.4533 (X6 CrNiTi 18 9, two weld pools), and a non-stabilized TP 304 (X5 CrNi 18 10). (orig./CB) [de

  5. Standard Test Method for Sandwich Corrosion Test

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2009-01-01

    1.1 This test method defines the procedure for evaluating the corrosivity of aircraft maintenance chemicals, when present between faying surfaces (sandwich) of aluminum alloys commonly used for aircraft structures. This test method is intended to be used in the qualification and approval of compounds employed in aircraft maintenance operations. 1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information. 1.3 This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Specific hazard statements appear in Section 9.

  6. Testing of the structural evaluation test unit

    International Nuclear Information System (INIS)

    Ammerman, D.J.; Bobbe, J.G.

    1995-01-01

    In the evaluation of the safety of radioactive material transportation it is important to consider the response of Type B packages to environments more severe than that prescribed by the hypothetical accident sequence in Title 10 Part 71 of the Code of Federal Regulations (NRC 1995). The impact event in this sequence is a 9-meter drop onto an essentially unyielding target, resulting in an impact velocity of 13.4 m/s. The behavior of 9 packages when subjected to impacts more severe than this is not well known. It is the purpose of this program to evaluate the structural response of a test package to these environments. Several types of structural response are considered. Of primary importance is the behavior of the package containment boundary, including the bolted closure and 0-rings. Other areas of concern are loss of shielding capability due to lead slump and the deceleration loading of package contents, that may cause damage to them. This type of information is essential for conducting accurate risk assessments on the transportation of radioactive materials. Currently very conservative estimates of the loss of package protection are used in these assessments. This paper will summarize the results of a regulatory impact test and three extra-regulatory impact tests on a sample package

  7. Test, dannelse og faglighed

    DEFF Research Database (Denmark)

    Schou, Lotte Rahbek

    2013-01-01

    Erfaringer fra blandt andet USA viser, at indførelse af obligatoriske nationale test får stor betydning for, hvilke former for faglighed der bliver dominerende i skolens undervisning. Hensigten har været at styrke de former for viden, som faktisk kan testes – ikke på bekostning af andre vidensfor...... vidensformer og indsigter - men simpelthen for blot at blive bedre til de dele af fagligheden, som kan testes. Forskning peger dog på, at obligatoriske test ikke blot styrker dele af fagligheden, men snarere bliver fuldstændig determinerende for hele fagligheden.......Erfaringer fra blandt andet USA viser, at indførelse af obligatoriske nationale test får stor betydning for, hvilke former for faglighed der bliver dominerende i skolens undervisning. Hensigten har været at styrke de former for viden, som faktisk kan testes – ikke på bekostning af andre...

  8. Pilocarpine iontophoresis test

    DEFF Research Database (Denmark)

    Hjortskov, N; Jepsen, Leif; Nielsen, B

    1995-01-01

    The pilocarpine iontophoresis test (P-test) is used as a predictor of the capacity to produce sweat. Therefore, we studied the reproducibility of this test in 12 normal subjects on 10 consecutive days. Furthermore, we determined whether the P-test reflects whole-body and regional sweat secretion...... during exercise in the heat. Finally, we determined whether the P-test stimulates the eccrine sweat glands to maximal sweat secretion. Six growth hormone-deficient (GHD) patients who are known to have decreased sweating, and 11 healthy control subjects were studied. To induce maximal sweat secretion......, the patients exercised on a bicycle ergometer at a workload corresponding to 40% of their maximal aerobic power (VO2max). The 11 healthy subjects exercised at a workload of 150 W. All subjects exercised for 60 min in ambient air at 35 degrees C, with 50% relative humidity. The P-test showed a mean day...

  9. Test plans for availability

    International Nuclear Information System (INIS)

    Rise, J.L.; Bjoerklund, O.

    1978-12-01

    In this work is developed principles for statistical test plans for availability compliance tests. Failure terminated and time terminated fixed size plans are considered as well as sequential test plans without and with failure and time truncation. The suggested methods are evaluated with respect to some important characteristics, namely the average number of failures to termination, the duration of the test and the operating characteristic function. The methods used are based on the assumption that up- and down-times can be considered gamma distributed. Simulation studies indicate that the methods are robust against reasonable deviations in distribution assumptions for the down-times. In the work is also outlined technical conditions and prerequisites applicable to availability compliance tests in general. The approach choosen seems very promising and is worth further development. It is based on the same fundamental principles as present is used in International standardization of equipment reliability testing. (author)

  10. Large scale model testing

    International Nuclear Information System (INIS)

    Brumovsky, M.; Filip, R.; Polachova, H.; Stepanek, S.

    1989-01-01

    Fracture mechanics and fatigue calculations for WWER reactor pressure vessels were checked by large scale model testing performed using large testing machine ZZ 8000 (with a maximum load of 80 MN) at the SKODA WORKS. The results are described from testing the material resistance to fracture (non-ductile). The testing included the base materials and welded joints. The rated specimen thickness was 150 mm with defects of a depth between 15 and 100 mm. The results are also presented of nozzles of 850 mm inner diameter in a scale of 1:3; static, cyclic, and dynamic tests were performed without and with surface defects (15, 30 and 45 mm deep). During cyclic tests the crack growth rate in the elastic-plastic region was also determined. (author). 6 figs., 2 tabs., 5 refs

  11. The engineering test facility

    International Nuclear Information System (INIS)

    Steiner, D.; Becraft, W.R.; Sager, P.H.

    1981-01-01

    The vehicle by which the fusion program would move into the engineering testing phase of fusion power development is designated the Engineering Test Facility (ETF). The ETF would provide a test-bed for reactor components in the fusion environment. In order to initiate preliminary planning for the ETF decision, the Office of Fusion Energy established the ETF Design Center activity to prepare the design of the ETF. This paper describes the design status of the ETF. (orig.)

  12. Engineering test facility

    International Nuclear Information System (INIS)

    Steiner, D.; Becraft, W.R.; Sager, P.H.

    1981-01-01

    The vehicle by which the fusion program would move into the engineering testing phase of fusion power development is designated the Engineering Test Facility (ETF). The ETF would provide a test-bed for reactor components in the fusion environment. In order to initiate preliminary planning for the ETF decision, the Office of Fusion Energy established the ETF Design Center activity to prepare the design of the ETF. This paper described the design status of the ETF

  13. Test planning and performance

    International Nuclear Information System (INIS)

    Zola, Maurizio

    2001-01-01

    Testing plan should include Safety guide Q4 - Inspection and testing - A testing plan should be prepared including following information: General information (facility name, item or system reference, procurement document reference, document reference number and status, associated procedures and drawings); A sequential listing of all testing activities; Procedure, work instruction, specification or standard to be followed in respect of each operation and test; Acceptance criteria; Identification of who is performing tests; Identification of hold points; Type of records to be prepared for each test; Persons and organizations having authority for final acceptance. Proposed activities sequence is: visual, electrical and mechanical checks; environmental tests (thermal aging, vibrations aging, radioactive aging); performance evaluation in extreme conditions; dynamic tests with functional checks; final electrical and mechanical checks The planning of the tests should always be performed taking into account an interpretative model: a very tight cooperation is advisable between experimental people and numerical people dealing with the analysis of more or less complex models for the seismic assessment of structures and components. Preparatory phase should include the choice of the following items should be agreed upon with the final user of the tests: Excitation points, Excitation types, Excitation amplitude with respect to frequency, Measuring points. Data acquisition, recording and storage, should take into account the characteristics of the successive data processing: to much data can be cumbersome to be processed, but to few data can make unusable the experimental results. The parameters for time history acquisition should be chosen taking into account data processing: for Shock Response Spectrum calculation some special requirements should be met: frequency bounded signal, high frequency sampling, shock noise. For stationary random-like excitation, the sample length

  14. Nondestructive testing method

    International Nuclear Information System (INIS)

    Porter, J.F.

    1996-01-01

    Nondestructive testing (NDT) is the use of physical and chemical methods for evaluating material integrity without impairing its intended usefulness or continuing service. Nondestructive tests are used by manufaturer's for the following reasons: 1) to ensure product reliability; 2) to prevent accidents and save human lives; 3) to aid in better product design; 4) to control manufacturing processes; and 5) to maintain a uniform quality level. Nondestructive testing is used extensively on power plants, oil and chemical refineries, offshore oil rigs and pipeline (NDT can even be conducted underwater), welds on tanks, boilers, pressure vessels and heat exchengers. NDT is now being used for testing concrete and composite materials. Because of the criticality of its application, NDT should be performed and the results evaluated by qualified personnel. There are five basic nondestructive examination methods: 1) liquid penetrant testing - method used for detecting surface flaws in materials. This method can be used for metallic and nonmetallic materials, portable and relatively inexpensive. 2) magnetic particle testing - method used to detect surface and subsurface flaws in ferromagnetic materials; 3) radiographic testing - method used to detect internal flaws and significant variation in material composition and thickness; 4) ultrasonic testing - method used to detect internal and external flaws in materials. This method uses ultrasonics to measure thickness of a material or to examine the internal structure for discontinuities. 5) eddy current testing - method used to detect surface and subsurface flaws in conductive materials. Not one nondestructive examination method can find all discontinuities in all of the materials capable of being tested. The most important consideration is for the specifier of the test to be familiar with the test method and its applicability to the type and geometry of the material and the flaws to be detected

  15. Biodiesel Test Plan

    Science.gov (United States)

    2014-07-01

    Biodiesel Test Plan Distribution Statement A: Approved for Public Release; distribution is unlimited. July 2014 Report No. CG-D-07-14...Appendix C) Biodiesel Test Plan ii UNCLAS//Public | CG-926 R&DC | G. W. Johnson, et al. Public | July 2014 N O T I C E This...Development Center 1 Chelsea Street New London, CT 06320 Biodiesel Test Plan iii UNCLAS//Public | CG-926 R&DC | G. W. Johnson, et al

  16. Dryden Aeronautical Test Range

    Data.gov (United States)

    Federal Laboratory Consortium — Recently redesignated to honor Dr. Hugh L. Dryden, NASA's Dryden Aeronautical Test Range (DATR) supports aerospace flight research and technology integration, space...

  17. GRE physics test

    CERN Document Server

    Fakhrudin, Hasan

    2010-01-01

    Designed for students and professionals looking to advance their careers, our test prep gives you everything you need to succeed. Focused chapter reviews cover all the information tested on the GRE Physics exam. Each review chapter contains examples to reinforce key concepts. The book includes four full-length practice tests based on the most recent GRE Physics exam. Each test contains every type of question that can be expected on the GRE so you can “practice for real” and boost your confidence before taking the exam.

  18. Cable tray fire tests

    International Nuclear Information System (INIS)

    Klamerus, L.J.

    1978-01-01

    Funds were authorized by the Nuclear Regulatory Commission to provide data needed for confirmation of the suitability of current design standards and regulatory guides for fire protection and control in water reactor power plants. The activities of this program through August 1978 are summarized. A survey of industry to determine current design practices and a screening test to select two cable constructions which were used in small scale and full scale testing are described. Both small and full scale tests to assess the adequacy of fire retardant coatings and full scale tests on fire shields to determine their effectiveness are outlined

  19. Calcium in Urine Test

    Science.gov (United States)

    ... K. Brunner & Suddarth's Handbook of Laboratory and Diagnostic Tests. 2 nd Ed, Kindle. Philadelphia: Wolters Kluwer Health, Lippincott Williams & Wilkins; c2014. Calcium, Serum; Calcium and Phosphates, Urine; ...

  20. Main Test Floor (MTF)

    Data.gov (United States)

    Federal Laboratory Consortium — Purpose: The MTF is employed to validate advanced structural concepts and verify new analytical methodologies. Test articles range in size from subcomponent to full...

  1. Cable aging tests

    International Nuclear Information System (INIS)

    Hubbard, G.

    1993-01-01

    This paper describes the results from aging, condition monitoring, and loss-of-coolant accident (LOCA) testing of class 1E electrical cables, per NUREG/CR-5772. This test was designed to test the performance of cables which had been aged with simultaneous radiation and thermal exposure. The tested cables included crosslinked polyolefin cables, ethylene propylene rubber cables, and miscellaneous cable types. Cables were exposed to 20, 40, and 60 years equivalent aging, and then exposed to LOCA tests at the end of their qualified life to determine the minimum insulation thickness needed for survival of the test. Failures were found in a large number of the tested cables. As a result the NRC has sent information notices to the industry regarding potential insulation problems. The results have raised the question of whether the artificial aging methods provide adequate testing methods. As a result of this testing the NRC is reviewing the artificial aging procedures, the adequacy of environmental qualification requirements for cable safety, and reexamining data from condition monitoring of installed cables

  2. Pavement Testing Facility

    Data.gov (United States)

    Federal Laboratory Consortium — Comprehensive Environmental and Structural AnalysesThe ERDC Pavement Testing Facility, located on the ERDC Vicksburg campus, was originally constructed to provide an...

  3. Fire test database

    International Nuclear Information System (INIS)

    Lee, J.A.

    1989-01-01

    This paper describes a project recently completed for EPRI by Impell. The purpose of the project was to develop a reference database of fire tests performed on non-typical fire rated assemblies. The database is designed for use by utility fire protection engineers to locate test reports for power plant fire rated assemblies. As utilities prepare to respond to Information Notice 88-04, the database will identify utilities, vendors or manufacturers who have specific fire test data. The database contains fire test report summaries for 729 tested configurations. For each summary, a contact is identified from whom a copy of the complete fire test report can be obtained. Five types of configurations are included: doors, dampers, seals, wraps and walls. The database is computerized. One version for IBM; one for Mac. Each database is accessed through user-friendly software which allows adding, deleting, browsing, etc. through the database. There are five major database files. One each for the five types of tested configurations. The contents of each provides significant information regarding the test method and the physical attributes of the tested configuration. 3 figs

  4. Large coil test facility

    International Nuclear Information System (INIS)

    Nelms, L.W.; Thompson, P.B.

    1980-01-01

    Final design of the facility is nearing completion, and 20% of the construction has been accomplished. A large vacuum chamber, houses the test assembly which is coupled to appropriate cryogenic, electrical, instrumentation, diagnostc systems. Adequate assembly/disassembly areas, shop space, test control center, offices, and test support laboratories are located in the same building. Assembly and installation operations are accomplished with an overhead crane. The major subsystems are the vacuum system, the test stand assembly, the cryogenic system, the experimental electric power system, the instrumentation and control system, and the data aquisition system

  5. Repetitive Rockfall Trajectory Testing

    Directory of Open Access Journals (Sweden)

    Axel Volkwein

    2018-03-01

    Full Text Available Numerical simulations of rockfall trajectories are a standard procedure for evaluating rockfall hazards. For these simulations, corresponding software codes must be calibrated and evaluated based on field data. This study addresses methods of repeatable rockfall tests, and investigates whether it is possible to produce traceable and statistically analysable data. A testing series is described extensively covering how to conduct rockfall experiments and how certain elements of rockfall trajectories can be measured. The tests use acceleration and rotation sensors inside test blocks, a system to determine block positions over time, surveying measurements, and video recordings. All systems are evaluated regarding their usability in the field and for analyses. The highly detailed description of testing methods is the basis for sound understanding and reproducibility of the tests. This article serves as a reference for future publications and other rockfall field tests, both as a guide and as a basis for comparisons. First analyses deliver information on runout with a shadow angle ranging between 21 and 45 degrees for a slope consisting of homogeneous soft soil. A digital elevation model of the test site as well as point clouds of the used test blocks are part of this publication.

  6. Sodium blood test

    Science.gov (United States)

    ... medicines that may affect the test. These include: Antibiotics Antidepressants Some high blood pressure medicines Lithium Nonsteroidal anti-inflammatory drugs (NSAIDs) Water pills (diuretics) DO NOT stop ...

  7. Charcoal filter testing

    Energy Technology Data Exchange (ETDEWEB)

    Lyons, J. [Nuclear Regulatory Commission, Washington, DC (United States)

    1997-08-01

    In this very brief, informal presentation, a representative of the US Nuclear Regulatory Commission outlines some problems with charcoal filter testing procedures and actions being taken to correct the problems. Two primary concerns are addressed: (1) the process to find the test method is confusing, and (2) the requirements of the reference test procedures result in condensation on the charcoal and causes the test to fail. To address these problems, emergency technical specifications were processed for three nuclear plants. A generic or an administrative letter is proposed as a more permanent solution. 1 fig.

  8. Forensic DNA testing.

    Science.gov (United States)

    Butler, John M

    2011-12-01

    Forensic DNA testing has a number of applications, including parentage testing, identifying human remains from natural or man-made disasters or terrorist attacks, and solving crimes. This article provides background information followed by an overview of the process of forensic DNA testing, including sample collection, DNA extraction, PCR amplification, short tandem repeat (STR) allele separation and sizing, typing and profile interpretation, statistical analysis, and quality assurance. The article concludes with discussions of possible problems with the data and other forensic DNA testing techniques.

  9. Designing and testing prototypes

    NARCIS (Netherlands)

    Vereijken, P.; Wijnands, F.; Stol, W.

    1995-01-01

    This second progress report focuses on designing a theoretical prototype by linking parameters to methods and designing the methods in this context until they are ready for initial testing. The report focuses also on testing and improving the prototype in general and the methods in particular until

  10. Ultrasonic weld testing.

    Science.gov (United States)

    1970-12-01

    The study was broken down into two phases. Phase I consisted of a laboratory investigation of test specimens to determine the reliability of the ultrasonic equipment and testing procedure. Phase II was a field study where the knowledge, skills and ab...

  11. Coaxial test fixture

    Science.gov (United States)

    Praeg, Walter F.

    1986-01-01

    An assembly is provided for testing one or more contact material samples in a vacuum environment. The samples are positioned as an inner conductive cylinder assembly which is mounted for reciprocal vertical motion as well as deflection from a vertical axis. An outer conductive cylinder is coaxially positioned around the inner cylinder and test specimen to provide a vacuum enclosure therefor. A power source needed to drive test currents through the test specimens is connected to the bottom of each conductive cylinder, through two specially formed conductive plates. The plates are similar in form, having a plurality of equal resistance current paths connecting the power source to a central connecting ring. The connecting rings are secured to the bottom of the inner conductive assembly and the outer cylinder, respectively. A hydraulic actuator is also connected to the bottom of the inner conductor assembly to adjust the pressure applied to the test specimens during testing. The test assembly controls magnetic forces such that the current distribution through the test samples is symmetrical and that contact pressure is not reduced or otherwise disturbed.

  12. Poppering the Newell Test

    NARCIS (Netherlands)

    Taatgen, Niels A.

    2003-01-01

    The Newell Test as it is proposed by Anderson & Lebiere (A&L) has the disadvantage of being too positivistic, stressing areas a theory should cover, instead of attempting to exclude false predictions. Nevertheless, Newell's list can be used as the basis for a more stringent test with a stress on the

  13. Gastrin: The Test

    Science.gov (United States)

    ... lab's website in order to provide you with background information about the test(s) you had performed. You will need to return ... underlying condition. Although gastrinomas are rare, more than half of them are cancerous and can spread to other parts of your ... Helicobacter pylori , Gastric Acid Conditions: Endocrine Syndromes Elsewhere ...

  14. Testing as social practice

    DEFF Research Database (Denmark)

    Kousholt, Kristine

    2016-01-01

    In this article, the author challenges the implicit assumptions of tests as a neutral tool for measuring the individual’s learning achievement. Instead, testing is explored as a social practice which becomes part of children’s conduct of everyday life. The theoretical foundation for the analysis...

  15. Loglinear Rasch model tests

    NARCIS (Netherlands)

    Kelderman, Hendrikus

    1984-01-01

    Existing statistical tests for the fit of the Rasch model have been criticized, because they are only sensitive to specific violations of its assumptions. Contingency table methods using loglinear models have been used to test various psychometric models. In this paper, the assumptions of the Rasch

  16. Vocational Aptitude Test

    Directory of Open Access Journals (Sweden)

    Candiasa I Made

    2018-01-01

    Full Text Available Test for measuring vocational aptitude has been formulated and validated. There are three main constructs involved in vocational aptitude test, which are individual characteristics, activities that are likely to be selected, and professions that tend to be idolized. Individual characteristics indicate the individuals talents, whereas the activity that tends to be chosen leads to student interest in the activity, and the intended profession gives clues about the capability of themselves to pursue the profession. Content validity test with Lawse technique yields content validity ratio (CVR for all items are in the range 0.82-0.94 and content validity index (CVI = 0.88. The construct validity test yields comparative fit index (CFI = 0.918 and chi square coefficient (χ2 = 5.85 with significance (p = 0.002. These findings indicate that the test is valid either by content or construct. Furthermore, the reliability test with Alpha Cronbach found the alpha coefficient (α = 0.82. Finally, it can be concluded that vocational aptitude test can be utilized for early identification of student vocational aptitude. The hope, the test can help students to choose the appropriate vocational school, in order to obtain the better learning outcomes.

  17. Planter unit test stand

    Science.gov (United States)

    A planter test stand was developed to evaluate individual row-crop metering units in early 2013. This test stand provided the ability to quantify actual seed metering in terms of population, seed spacing, skips, and multiples over a range of meter RPMs and vacuum pressures. Preliminary data has been...

  18. Testing object Interactions

    NARCIS (Netherlands)

    Grüner, Andreas

    2010-01-01

    In this thesis we provide a unit testing approach for multi-purposes object-oriented programming languages in the style of Java and C#. Our approach includes the definition of a test specification language which results from extending the programming language with new designated specification

  19. Inspection- and test arrangement

    International Nuclear Information System (INIS)

    Weber, R.; Gallwas, J.

    1980-01-01

    The ultrasonic testing equipment is located on a wagon that can be moved on a circular rail fixed below the bottom of the cylindrical pressure vessel. To compensate thermal expansions between ground and rail, this rail is provided on its outside with radial sticks that are embedded in braces. The braces themselves are connected with the bottom that has to be tested. (DG) [de

  20. ALP - blood test

    Science.gov (United States)

    ... Tissues with higher amounts of ALP include the liver, bile ducts, and bone. A blood test can be done ... and the A.D.A.M. Editorial team. Bile Duct Diseases Read more Bone Diseases Read more Liver Function Tests Read more A.D.A.M., ...

  1. Follow-Up Testing

    Science.gov (United States)

    ... second should occur after 1 year on the gluten-free diet. After that, a celiac should receive follow-up ... test result is straightforward—a celiac on the gluten-free diet should have a negative test. The numerical value ...

  2. CLEAR test facility

    CERN Multimedia

    Ordan, Julien Marius

    2017-01-01

    A new user facility for accelerator R&D, the CERN Linear Electron Accelerator for Research (CLEAR), started operation in August 2017. CLEAR evolved from the former CLIC Test Facility 3 (CTF3) used by the Compact Linear Collider (CLIC). The new facility is able to host and test a broad range of ideas in the accelerator field.

  3. Preparing for CLIC tests

    CERN Multimedia

    Laurent Guiraud

    1999-01-01

    The Canon 5 undergoes first brazing for preparation in the CLIC study at the CLIC Test Facility 2 (CTF2). This will test injection for a proposed linear collider that will further explore discoveries made at the LHC. Electric fields in the canon will boost electrons into the acceleration fields of the collider.

  4. Proficiency tests, Evaluating

    NARCIS (Netherlands)

    Cofino, W.P.; Molenaar, J.; Torfs, P.J.J.F.

    2017-01-01

    Marine monitoring programs provide data that are essential for marine management. The reliability of such data is underpinned by proficiency tests. In the context of Quasimeme, a proficiency testing program for the marine environment, a statistical model has been developed in 2000 to evaluate data

  5. Vitamin A Test

    Science.gov (United States)

    ... was last reviewed on October 21, 2015. This article was last modified on June 29, 2018. At a Glance Why Get Tested? To detect vitamin A deficiency or toxicity When To Get Tested? When you have symptoms suggesting a vitamin A deficiency or excess, or are at risk for a deficiency Sample ...

  6. Hepatitis B Test

    Science.gov (United States)

    ... Links Patient Resources For Health Professionals Subscribe Search Hepatitis B Testing Send Us Your Feedback Choose Topic At ... Known As HBV Tests Hep B anti-HBs Hepatitis B Surface Antibody HBsAg Hepatitis B Surface Antigen HBeAg ...

  7. Testing confectionary products

    International Nuclear Information System (INIS)

    Kumar, M.; Smith, I.H.

    1983-01-01

    Cream-filled cakes are tested by passing a #betta#-ray from a #betta#-particle source to a detector and checking the #betta#-particle count to indicate if the cakes have been correctly filled with cream. The presence of a cake to be tested is sensed by an optical detector and incorrectly filled cakes are removed by a plunger. (author)

  8. Testing and Inclusive Schooling

    DEFF Research Database (Denmark)

    Morin, Anne; Hamre, Bjørn; Ydesen, Christian

    Testing and Inclusive Schooling provides a comparative on seemingly incompatible global agendas and efforts to include all children in the general school system, Thus reducing exclusion. With an examination of the international testing culture and the politics of inclusion currently permeating...

  9. SNL Abuse Testing Manual.

    Energy Technology Data Exchange (ETDEWEB)

    Orendorff, Christopher [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lamb, Joshua [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Steele, Leigh Anna Marie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-07-01

    This report describes recommended abuse testing procedures for rechargeable energy storage systems (RESSs) for electric vehicles. This report serves as a revision to the FreedomCAR Electrical Energy Storage System Abuse Test Manual for Electric and Hybrid Electric Vehicle Applications (SAND2005-3123).

  10. National HIV Testing Day

    Centers for Disease Control (CDC) Podcasts

    Dr. Kevin A. Fenton, Director of CDC's National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, discusses National HIV Testing Day, an annual observance which raises awareness of the importance of knowing one's HIV status and encourages at-risk individuals to get an HIV test.

  11. Test dig selv!

    DEFF Research Database (Denmark)

    Hølge-Hazelton, Bibi; Nielsen, Gregers; Langstrup, Henriette

    2011-01-01

    Teknologirådet omkring rapporten ”Test dig selv! – Vurderinger og anbefalinger vedrørende anvendelse medicinsk udstyr til selvtestning. Offentliggjort d. 25.10.11.......Teknologirådet omkring rapporten ”Test dig selv! – Vurderinger og anbefalinger vedrørende anvendelse medicinsk udstyr til selvtestning. Offentliggjort d. 25.10.11....

  12. Over the air test

    DEFF Research Database (Denmark)

    2015-01-01

    [1] This invention relates to over-the-air testing of a device in an anechoic chamber. In particular, the invention is suitable for simulating both uplink and downlink over-the-air communication with a device under test even when the anechoic chamber has different numbers of uplink and downlink...

  13. The scapular dyskinesis test

    DEFF Research Database (Denmark)

    Christiansen, David Høyrup; Møller, Anders Damgaard; Vestergaard, Jesper Medom

    2017-01-01

    tests with which to identify scapular dyskinesis. PURPOSE OF THE STUDY: To evaluate intrarater and interrater reliability and predictive value of the Scapular Dyskinesis Test (SDT) in patients with subacromial impingement syndrome. METHODS: Forty-five patients with subacromial impingement syndrome were...

  14. Testing of Mortar Systems

    Science.gov (United States)

    2010-03-11

    IEP /TDP) or Independent Assessment Plan (IAP), and the test item and the procedures as outlined in this TOP. The following must also be considered...Command DTIC = Defense Technical Information Center DTP = Detailed Test Plan IAP = Independent Assessment Plan IEP = Independent Evaluation Plan IPT

  15. Automate functional testing

    Directory of Open Access Journals (Sweden)

    Ramesh Kalindri

    2014-06-01

    Full Text Available Currently, software engineers are increasingly turning to the option of automating functional tests, but not always have successful in this endeavor. Reasons range from low planning until over cost in the process. Some principles that can guide teams in automating these tests are described in this article.

  16. Solenoid Testing Facility

    Data.gov (United States)

    Federal Laboratory Consortium — Current Configuration: Accommodate a device under test up to 2.8 m diameter, 0.7 m height and 15,000 lbs. weight. Up to 10 g/s, 4.5 K helium flow. Up to 250 A test...

  17. Robust test limits

    NARCIS (Netherlands)

    Albers, Willem/Wim; Kallenberg, W.C.M.; Otten, G.D.

    1997-01-01

    Because of inaccuracies of the measurement process inspection of manufactured parts requires test limits which are more strict than the given specification limits. Test limits derived under the assumption of normality for product characteristics turn out to violate the prescribed bound on the

  18. What Is Stress Testing?

    Science.gov (United States)

    ... would during exercise. You can then have the stress test. The medicine may make you flushed and anxious, but the effects go away as soon as the test is over. The medicine also may give you a headache. While you're exercising or getting medicine to ...

  19. Prematurely terminated slug tests

    International Nuclear Information System (INIS)

    Karasaki, K.

    1990-07-01

    A solution of the well response to a prematurely terminated slug test (PTST) is presented. The advantages of a PTST over conventional slug tests are discussed. A systematized procedure of a PTST is proposed, where a slug test is terminated in the midpoint of the flow point, and the subsequent shut-in data is recorded and analyzed. This method requires a downhole shut-in device and a pressure transducer, which is no more than the conventional deep-well slug testing. As opposed to slug tests, which are ineffective when a skin is present, more accurate estimate of formation permeability can be made using a PTST. Premature termination also shortens the test duration considerably. Because in most cases no more information is gained by completing a slug test to the end, the author recommends that conventional slug tests be replaced by the premature termination technique. This study is part of an investigation of the feasibility of geologic isolation of nuclear wastes being carried out by the US Department of Energy and the National Cooperative for the Storage of Radioactive Waste of Switzerland

  20. Chemical Reactivity Test (CRT)

    Energy Technology Data Exchange (ETDEWEB)

    Zaka, F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-12-13

    The Chemical Reactivity Test (CRT) is used to determine the thermal stability of High Explosives (HEs) and chemical compatibility between (HEs) and alien materials. The CRT is one of the small-scale safety tests performed on HE at the High Explosives Applications Facility (HEAF).

  1. Parent's Guide to Understanding Tests.

    Science.gov (United States)

    CTB / McGraw-Hill, Monterey, CA.

    This brief introduction to testing is geared to parents. Types of tests are defined, such as standardized tests, achievement tests, norm referenced tests, criterion referenced tests, and aptitude tests. Various types of scores (grade equivalent, percentile rank, and stanine are also defined, and the uses made of tests by administrators, teachers,…

  2. Thermal Testing Measurements Report

    Energy Technology Data Exchange (ETDEWEB)

    R. Wagner

    2002-09-26

    The purpose of the Thermal Testing Measurements Report (Scientific Analysis Report) is to document, in one report, the comprehensive set of measurements taken within the Yucca Mountain Project Thermal Testing Program since its inception in 1996. Currently, the testing performed and measurements collected are either scattered in many level 3 and level 4 milestone reports or, in the case of the ongoing Drift Scale Test, mostly documented in eight informal progress reports. Documentation in existing reports is uneven in level of detail and quality. Furthermore, while all the data collected within the Yucca Mountain Site Characterization Project (YMP) Thermal Testing Program have been submitted periodically to the Technical Data Management System (TDMS), the data structure--several incremental submittals, and documentation formats--are such that the data are often not user-friendly except to those who acquired and processed the data. The documentation in this report is intended to make data collected within the YMP Thermal Testing Program readily usable to end users, such as those representing the Performance Assessment Project, Repository Design Project, and Engineered Systems Sub-Project. Since either detailed level 3 and level 4 reports exist or the measurements are straightforward, only brief discussions are provided for each data set. These brief discussions for different data sets are intended to impart a clear sense of applicability of data, so that they will be used properly within the context of measurement uncertainty. This approach also keeps this report to a manageable size, an important consideration because the report encompasses nearly all measurements for three long-term thermal tests. As appropriate, thermal testing data currently residing in the TDMS have been reorganized and reformatted from cumbersome, user-unfriendly Input-Data Tracking Numbers (DTNs) into a new set of Output-DTNs. These Output-DTNs provide a readily usable data structure

  3. Testing for Chronic Diarrhea.

    Science.gov (United States)

    Raman, M

    Chronic diarrhea is a frequently encountered symptom in clinical practice. The etiologies for chronic diarrhea are diverse and broad with varying clinical implications. A useful method of categorizing chronic diarrhea to guide a diagnostic work-up is a pathophysiology-based framework. Chronic diarrhea may be categorized as malabsorptive, secretory, osmotic, and inflammatory or motility related. Frequently, overlap between categories may exist for any given diarrhea etiology and diagnostic testing must occur with an understanding of the differential diagnosis. Investigations to achieve a diagnosis for chronic diarrhea range from screening blood and stool tests to more directed testing such as diagnostic imaging, and endoscopic and histological evaluation. The pathophysiology-based framework proposed in this chapter will allow the clinician to select screening tests followed by targeted tests to minimize cost and complications to the patient, while providing a highly effective method to achieve an accurate diagnosis. © 2017 Elsevier Inc. All rights reserved.

  4. LHC synchronization test successful

    CERN Multimedia

    The synchronization of the LHC's clockwise beam transfer system and the rest of CERN's accelerator chain was successfully achieved last weekend. Tests began on Friday 8 August when a single bunch of a few particles was taken down the transfer line from the SPS accelerator to the LHC. After a period of optimization, one bunch was kicked up from the transfer line into the LHC beam pipe and steered about 3 kilometres around the LHC itself on the first attempt. On Saturday, the test was repeated several times to optimize the transfer before the operations group handed the machine back for hardware commissioning to resume on Sunday. The anti-clockwise synchronization systems will be tested over the weekend of 22 August.Picture:http://lhc-injection-test.web.cern.ch/lhc-injection-test/

  5. Equipment for hydraulic testing

    International Nuclear Information System (INIS)

    Jacobsson, L.; Norlander, H.

    1981-07-01

    Hydraulic testing in boreholes is one major task of the hydrogeological program in the Stripa Project. A new testing equipment for this purpose was constructed. It consists of a downhole part and a surface part. The downhole part consists of two packers enclosing two test-sections when inflated; one between the packers and one between the bottom packer and the bottom of the borehole. A probe for downhole electronics is also included in the downhole equipment together with electrical cable and nylon tubing. In order to perform shut-in and pulse tests with high accuracy a surface controlled downhole valve was constructed. The surface equipment consists of the data acquisition system, transducer amplifier and surface gauges. In the report detailed descriptions of each component in the whole testing equipment are given. (Auth.)

  6. Biocide patch tests

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Veien, Niels

    1985-01-01

    Routine patch testing with a series of 6 industrial biocides containing methylene-bis-thiocyanate (Cytox 3522), benzisothiazolin-3-one (BIT), chlorocresol (Preventol CMK), 2-n-octyl-4-isothiazolin-3-one (Kathon 893), polyhydroxymethylene monobenzylether (Preventol D2) or 1,3,5-tris (hydroxy......-ethyl) hexahydrotriazine (Grotan BK) was carried out in 6 Danish out-patient clinics to evaluate guinea pig allergy test results with the same compounds. A total of 1652 consecutive patients with dermatitis were tested. The usefulness of this patch test battery was limited. There were a few positive reactions to Cytox...... of male patients and atopics, but significant differences in the frequencies of occupational cases, hand eczemas, and leg ulcers/stasis dermatitis, indicating possible variations in referral patterns, use of patch tests, and/or environmental factors....

  7. Mechanical Testing of MLCCs

    Science.gov (United States)

    Teverovsky, Alexander A.

    2016-01-01

    Cracking of multilayer ceramic capacitors, MLCCs, remains a serious problem for space systems. This problem increases substantially for large size capacitors and in cases when manual soldering is involved or the system experiences mechanical shock or vibration. In any case, a fracture occurs when the sum of external and internal mechanical stresses exceeds the strength of the part. To reduce the probability of cracking, the level of stress should be reduced, e.g. by optimizing the assembly workmanship and rules for board design, and the strength of the parts increased by selecting the most mechanically robust capacitors. The latter might possibly be achieved by selecting MLCCs based on the in-situ measurements of mechanical characteristics using four types of tests: flexural strength, hardness, fracture toughness, and flex bend testing. Note that military specifications MIL-PRF-123 and MIL-PRF-55681 do not have requirements for mechanical testing of the parts. However, specifications for automotive industry components employ two types of mechanical tests: beam load (break strength) test per AEC-Q200-003 and board flex test per AEC-Q200-005. A recent military specification for thin dielectric capacitors, MIL-PRF-32535, has one mechanical test, board flex testing, that is similar to AEC-Q200-005. The purpose of this report was assessment of the efficiency of different mechanical tests for selection robust capacitors and comparison of mechanical characteristics of Base Metal Electrode (BME) and Precious Metal Electrode (PME) capacitors. The report has three parts related to the first three mechanical tests mentioned above.

  8. Flushable reagent stool blood test

    Science.gov (United States)

    Stool occult blood test - flushable home test; Fecal occult blood test - flushable home test ... This test is performed at home with disposable pads. You can buy the pads at the drug store without ...

  9. Repository simulation tests

    International Nuclear Information System (INIS)

    Wicks, G.G.; Bibler, N.E.; Jantzen, C.M.; Plodinec, M.J.

    1984-01-01

    The repository simulation experiments described in this paper are designed to assess the performance of SRP waste glass under the most realistic repository conditions that can be obtained in the laboratory. These tests simulate the repository environment as closely as possible and introduce systematically the variability of the geology, groundwater chemistry, and waste package components during the leaching of the waste glass. The tests evaluate waste form performance under site-specific conditions, which differ for each of the geologic repositories under consideration. Data from these experiments will aid in the development of a realistic source term that can describe the release of radionuclides from SRP waste glass as a component of proposed waste packages. Hence, this information can be useful to optimize waste package design for SRP waste glass and to provide data for predicting long-term performance and subsequent conformance to regulations. The repository simulation tests also help to bridge the gap in interpreting results derived from tests performed under the control of the laboratory to the uncertainity and variability of field tests. In these experiments, site-specific repository components and conditions are emphasized and only the site specific materials contact the waste forms. An important feature of these tests is that both actual and simulated waste glasses are tested identically. 7 figures, 2 tables

  10. Mathematics Admission Test Remarks

    Directory of Open Access Journals (Sweden)

    Ideon Erge

    2016-12-01

    Full Text Available Since 2014, there have been admission tests in mathematics for applicants to the Estonian University of Life Sciences for Geodesy, Land Management and Real Estate Planning; Civil Engineering; Hydraulic Engineering and Water Pollution Control; Engineering and Technetronics curricula. According to admission criteria, the test must be taken by students who have not passed the specific mathematics course state exam or when the score was less than 20 points. The admission test may also be taken by those who wish to improve their state exam score. In 2016, there were 126 such applicants of whom 63 took the test. In 2015, the numbers were 129 and 89 and in 2014 150 and 47 accordingly. The test was scored on scale of 100. The arithmetic average of the score was 30.6 points in 2016, 29.03 in 2015 and 18.84 in 2014. The test was considered to be passed with 1 point in 2014 and 20 points in 2015 and 2016. We analyzed test results and gave examples of problems which were solved exceptionally well or not at all.

  11. MXIbus data throughput tests

    International Nuclear Information System (INIS)

    Botlo, M.; Dunning, J.; Jagieski, M.; Miller, L.; Romero, A.

    1992-11-01

    A series of tests were conducted to evaluate data transfer rates using the MXIbus architecture. The tests were conducted by the DAQ group in the Physics Research Division. The MXIbus from National Instruments provides a multisystem extension interface bus. It allows multiple VME chassis to be networked. Other bus architectures that can participate in the network include VXIbus, IBM PC-AT bus, Sun Sbus, Mac NuBus and stand-alone instruments with the appropriate MXIbus adapter cards. From a functional standpoint the MXIbus provides the capability to enlarge the address space in a fashion that is transparent to the software application. The tests were designed to measure data throughput when using the MSIbus with other industry off-the-shelf hardware. This report contains discussions on: MXIbus architecture and general guidelines; the commercial hardware and software used in each set of tests; and a brief description of each set of tests, observations and guidelines; the commercial hardware and software used in each set of tests; and a brief description of each set of tests, observations and conclusions

  12. Invalid Permutation Tests

    Directory of Open Access Journals (Sweden)

    Mikel Aickin

    2010-01-01

    Full Text Available Permutation tests are often presented in a rather casual manner, in both introductory and advanced statistics textbooks. The appeal of the cleverness of the procedure seems to replace the need for a rigorous argument that it produces valid hypothesis tests. The consequence of this educational failing has been a widespread belief in a “permutation principle”, which is supposed invariably to give tests that are valid by construction, under an absolute minimum of statistical assumptions. Several lines of argument are presented here to show that the permutation principle itself can be invalid, concentrating on the Fisher-Pitman permutation test for two means. A simple counterfactual example illustrates the general problem, and a slightly more elaborate counterfactual argument is used to explain why the main mathematical proof of the validity of permutation tests is mistaken. Two modifications of the permutation test are suggested to be valid in a very modest simulation. In instances where simulation software is readily available, investigating the validity of a specific permutation test can be done easily, requiring only a minimum understanding of statistical technicalities.

  13. Eco-Test at Vehicle Testing Centres

    Directory of Open Access Journals (Sweden)

    Nada Štrumberger

    2003-09-01

    Full Text Available Following the world conference on sustainable developmentof ecology, the care for the environment has to be strictlycomplied with, and this should be the task both of every individualand of the society as an organised whole. The work presentsconcrete measurements from practice and the indicators of thesituation regarding motor vehicles in Croatia. The EGO-TESThas been performed in Croatia according to the European Uniondirectives; first on the vehicles with petrol engines. Now, it isstarting to be applied on the vehicles with Diesel engines as well.Compliance with the EGO TEST regarding motor vehicles inCroatia will take into consideration the guidelines provided bythe European Union and thus reduce the harm from exhaustgases and noise pollution, and increase the possibility of usingmotor vehicles in order to reduce the danger and increase thesafety on the roads by excluding old vehicles from traffic.

  14. Parallelize Automated Tests in a Build and Test Environment

    OpenAIRE

    Durairaj, Selva Ganesh

    2016-01-01

    This thesis investigates the possibilities of finding solutions, in order to reduce the total time spent for testing and waiting times for running multiple automated test cases in a test framework. The “Automated Test Framework”, developed by Axis Communications AB, is used to write the functional tests to test both hardware and software of a resource. The functional tests that tests the software is considered in this thesis work. In the current infrastructure, tests are executed sequentially...

  15. Software Testing as Science

    Directory of Open Access Journals (Sweden)

    Ingrid Gallesdic

    2013-06-01

    Full Text Available The most widespread opinion among people who have some connection with software testing is that this activity is an art. In fact, books have been published widely whose titles refer to it as art, role or process. But because software complexity is increasing every year, this paper proposes a new approach, conceiving the test as a science. This is because the processes by which they are applied are the steps of the scientific method: inputs, processes, outputs. The contents of this paper examines the similarities and test characteristics as science.

  16. Turbine Engine Testing.

    Science.gov (United States)

    1981-01-01

    English climate. (c) Functional Testing Functional testing is a ’catch all’ title for the multitude of tests required to examine and confirm or correct the...rage I I I , I ’s slot envs Atar ONK propulsent les Miraiges IV de la levce A~rientic Strat~giqiie l-vanlaisc, tanilis tilit leg mcters Atar 91K50 sent...moignent. Irtuwi Atar 9 ~K50 est tine version MANv~ du motenr Atar 9K proptilsant le hirdaceur vi1 *c ~Ik (lttur 11 et dest in 5 6qtiiper I ’avion polyvalent

  17. Instant testing with QUnit

    CERN Document Server

    Sheiko, Dmitry

    2013-01-01

    Filled with practical, step-by-step instructions and clear explanations for the most important and useful tasks. A concise guide full of step-by-step recipes to teach you how to perform automated testing using QUnit.""Instant Testing with QUnit"" is for anyone working with JavaScript who is looking for a powerful and easy-to-use testing framework. The reader does not need to know any particular framework, only the basic principles of JavaScript and HTML.

  18. Accelerated cyclic corrosion tests

    Directory of Open Access Journals (Sweden)

    Prošek T.

    2016-06-01

    Full Text Available Accelerated corrosion testing is indispensable for material selection, quality control and both initial and residual life time prediction for bare and painted metallic, polymeric, adhesive and other materials in atmospheric exposure conditions. The best known Neutral Salt Spray (NSS test provides unrealistic conditions and poor correlation to exposures in atmosphere. Modern cyclic accelerated corrosion tests include intermittent salt spray, wet and dry phases and eventually other technical phases. They are able to predict the material performance in service more correctly as documented on several examples. The use of NSS should thus be restricted for quality control.

  19. Progress test utopia.

    Science.gov (United States)

    van der Vleuten, Cees; Freeman, Adrian; Collares, Carlos Fernando

    2018-04-01

    This paper discusses the advantages of progress testing. A utopia is described where medical schools would work together to develop and administer progress testing. This would lead to a significant reduction of cost, an increase in the quality of measurement and phenomenal feedback to learner and school. Progress testing would also provide more freedom and resources for more creative in-school assessment. It would be an educationally attractive alternative for the creation of cognitive licensing exams. A utopia is always far away in the future, but by formulating a vision for that future we may engage in discussions on how to get there.

  20. Application testing with Capybara

    CERN Document Server

    Robbins, Matthew

    2013-01-01

    Start performing integration testing with Capybara immediately. This book will get you up and running quickly and assumes no knowledge or experience of the technology.This book is for developers and testers who have had some exposure to Ruby but who want to know how to test their applications using Capybara and its compatible drivers, such as Selenium-Webdriver and Rack-Test. The examples are deliberately kept simple and example HTML mark-up is always included so that you can copy the examples to practice and experiment on your own machine.

  1. Laboratory testing in hyperthyroidism.

    Science.gov (United States)

    Grebe, Stefan K G; Kahaly, George J

    2012-09-01

    The clinical diagnosis of hypo- or hyperthyroidism is difficult (full text available online: http://education.amjmed.com/pp1/272). Clinical symptoms and signs are often non-specific, and there is incomplete correlation between structural and functional thyroid gland changes. Laboratory testing is therefore indispensible in establishing the diagnosis of thyrotoxicosis. Similar considerations apply to treatment monitoring. Laboratory testing also plays a crucial role in establishing the most likely cause for a patient's hyperthyroidism. Finally, during pregnancy, when isotopic scanning is relatively contraindicated and ultrasound is more difficult to interpret, laboratory testing becomes even more important. Copyright © 2012. Published by Elsevier Inc.

  2. Thermal test options

    International Nuclear Information System (INIS)

    Koski, J.A.; Keltner, N.R.; Sobolik, K.B.

    1993-02-01

    Shipping containers for radioactive materials must be qualified to meet a thermal accident environment specified in regulations, such at Title 10, Code of Federal Regulations, Part 71. Aimed primarily at the shipping container design, this report discusses the thermal testing options available for meeting the regulatory requirements, and states the advantages and disadvantages of each approach. The principal options considered are testing with radiant heat, furnaces, and open pool fires. The report also identifies some of the facilities available and current contacts. Finally, the report makes some recommendations on the appropriate use of these different testing methods

  3. Reduction in language testing

    DEFF Research Database (Denmark)

    Dimova, Slobodanka; Jensen, Christian

    2013-01-01

    /video recorded speech samples and written reports produced by two experienced raters after testing. Our findings suggest that reduction or reduction-like pronunciation features are found in tested L2 speech, but whenever raters identify and comment on such reductions, they tend to assess reductions negatively......This study represents an initial exploration of raters' comments and actual realisations of form reductions in L2 test speech performances. Performances of three L2 speakers were selected as case studies and illustrations of how reductions are evaluated by the raters. The analysis is based on audio...

  4. GRE math tests

    CERN Document Server

    Kolby, Jeff

    2014-01-01

    Twenty-three GRE Math Tests! The GRE math section is not easy. There is no quick fix that will allow you to ""beat"" the section. But GRE math is very learnable. If you study hard and master the techniques in this book, your math score will improve--significantly! The GRE cannot be ""beaten."" But it can be mastered--through hard work, analytical thought, and by training yourself to think like a test writer. Many of the problems in this book are designed to prompt you to think like a test writer. For example, you will find ""Duals."" These are pairs of similar problems in which only one prop

  5. GTK beam test 2017

    CERN Document Server

    Vostinic, Snezana

    2017-01-01

    The GTK is in operation at NA62 since 2014 and is among the few silicon pixel detectors performing 4D tracking. This summer, a beam test was conducted to study the phenomena determining the detector time resolution. The project described here contributed to the beam test preparation, data taking and data analyses. One of the main goals of the test was to understand the weight field contribution to the detector time resolution. This field is distorting the signal pulse shape at the edge of the pixel. Hence, to study this effect, the position of the hits inside the pixel has to be determined. An external telescope was therefore used for this purpose.

  6. TestComplete cookbook

    CERN Document Server

    Alpaev, Gennadiy

    2013-01-01

    A practical cookbook, with a perfect package of simple, medium, and advanced recipes targeted at basic programmers as well as expert software testers, who will learn to create, manage, and run automated tests. It is packed with problem-solving recipes that are supported by simple examples.If you are a software tester or a programmer who is involved with testing automation using TestComplete, this book is ideal for you! You will be introduced to the very basics of using the tool, as well as polish any previously gained knowledge in using the tool. If you are already aware of programming basics,

  7. Inspection and test planning

    International Nuclear Information System (INIS)

    Miller, T.

    1980-01-01

    Purpose of Quality Plan - arrangement of all necessary tests or inspections as far as possible filted to certain components or systems. Subject of Quality Plan - precise determination of tests or inspections and - according to the actual safety significance - the certificates to be done. Disposition of Quality Plan - accommodation of tests to the actual state of fabrication. Application of Quality Plan - to any component or system that is regarded. Supervision of Employment - by authorized personnel of manufacturer, customer or authority providing exact employment of quality plan. Overservance of Instructions - certificates given by authorized personnel. (orig./RW)

  8. Allergy Skin Tests

    Science.gov (United States)

    ... and symptoms. Medications can interfere with results Before scheduling a skin test, bring your doctor a list ... of Privacy Practices Notice of Nondiscrimination Manage Cookies Advertising Mayo Clinic is a not-for-profit organization ...

  9. Creatinine urine test

    Science.gov (United States)

    Urine creatinine test ... Creatinine is a chemical waste product of creatine. Creatine is a chemical the body makes to supply ... done to see how well your kidneys work. Creatinine is removed by the body entirely by the ...

  10. Nitroblue tetrazolium test

    Science.gov (United States)

    ... infections. Normal value ranges may vary slightly from one lab to another. Talk to your doctor about the meaning of your test results. What Abnormal Results Mean If the sample does not change color when NBT is added, ...

  11. FTA-ABS test

    Science.gov (United States)

    ... Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures . 6th ed. St Louis, MO: Elsevier Saunders; 2013:533-534. Radolf JD, Tramont EC, Salazar JC. Syphilis ( Treponema pallidum ). In: Bennett JE, Dolin R, Blaser ...

  12. Test Your Sodium Smarts

    Science.gov (United States)

    ... You may be surprised to learn how much sodium is in many foods. Sodium, including sodium chloride ... foods with little or no salt. Test your sodium smarts by answering these 10 questions about which ...

  13. Penetration testing with Perl

    CERN Document Server

    Berdeaux, Douglas

    2014-01-01

    If you are an expert Perl programmer interested in penetration testing or information security, this guide is designed for you. However, it will also be helpful for you even if you have little or no Linux shell experience.

  14. CPK isoenzymes test

    Science.gov (United States)

    ... such as dexamethasone This list is not all-inclusive. How the Test will Feel You may feel ... Cardiology, Harborview Medical Center, University of Washington Medical School, Seattle, WA. Also reviewed by David Zieve, MD, ...

  15. Histoplasma skin test

    Science.gov (United States)

    Histoplasmosis skin test ... health care provider cleans an area of your skin, usually the forearm. An allergen is injected just below the cleaned skin surface. An allergen is a substance that causes ...

  16. Climatic Environmental Test Facilities

    Data.gov (United States)

    Federal Laboratory Consortium — RTTC has an extensive suite of facilities for supporting MIL-STD-810 testing, toinclude: Temperature/Altitude, Rapid Decompression, Low/High Temperature,Temperature...

  17. Testing strong interaction theories

    International Nuclear Information System (INIS)

    Ellis, J.

    1979-01-01

    The author discusses possible tests of the current theories of the strong interaction, in particular, quantum chromodynamics. High energy e + e - interactions should provide an excellent means of studying the strong force. (W.D.L.)

  18. Materials Test Station

    Data.gov (United States)

    Federal Laboratory Consortium — When completed, the Materials Test Station at the Los Alamos Neutron Science Center will meet mission need. MTS will provide the only fast-reactor-like irradiation...

  19. C-Peptide Test

    Science.gov (United States)

    ... insulin injections or an insulin pump; when your health practitioner suspects that you have insulin resistance ; when you have documented ... Preparation Needed? Fasting for 8 to 10 hours before blood testing ...

  20. Coagulation Factors Test

    Science.gov (United States)

    ... Blood Testing Alpha-1 Antitrypsin Alpha-fetoprotein (AFP) Tumor Marker AMAS Aminoglycoside Antibiotics Ammonia Amniocentesis Amylase ANCA/MPO/ ... Beta-2 Microglobulin Kidney Disease Beta-2 Microglobulin Tumor Marker Bicarbonate (Total CO2) Bilirubin Blood Culture Blood Gases ...

  1. ROSE MIU Testing

    Science.gov (United States)

    Austin, Rebekah

    2015-01-01

    Overview of work done by Rebekah Austin during Pathways Internship work tour. Describes ROSE MIU (Reconfigurable Operational Spacecraft for Science and Exploration Module Interface Unit) features and test plan.

  2. Creatine phosphokinase test

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003503.htm Creatine phosphokinase test To use the sharing features on this page, please enable JavaScript. Creatine phosphokinase (CPK) is an enzyme in the body. ...

  3. Final focus test beam

    International Nuclear Information System (INIS)

    1991-03-01

    This report discusses the following: the Final Focus Test Beam Project; optical design; magnets; instrumentation; magnetic measurement and BPM calibration; mechanical alignment and stabilization; vacuum system; power supplies; control system; radiation shielding and personnel protection; infrastructure; and administration

  4. Practical acoustic emission testing

    CERN Document Server

    2016-01-01

    This book is intended for non-destructive testing (NDT) technicians who want to learn practical acoustic emission testing based on level 1 of ISO 9712 (Non-destructive testing – Qualification and certification of personnel) criteria. The essential aspects of ISO/DIS 18436-6 (Condition monitoring and diagnostics of machines – Requirements for training and certification of personnel, Part 6: Acoustic Emission) are explained, and readers can deepen their understanding with the help of practice exercises. This work presents the guiding principles of acoustic emission measurement, signal processing, algorithms for source location, measurement devices, applicability of testing methods, and measurement cases to support not only researchers in this field but also and especially NDT technicians.

  5. Prenatal Genetic Diagnostic Tests

    Science.gov (United States)

    ... are available for many inherited disorders. The main disadvantage is that diagnostic testing carries a very small ... chromosomes, arranged in order of size. Microarray: A technology that examines all of a person’s genes to ...

  6. Newborn Screening Tests

    Science.gov (United States)

    ... don't have enough biotinidase, an enzyme that recycles biotin (a B vitamin) in the body. Biotinidase ... about additional tests: Do you have a family history of an inherited disorder? Have you previously given ...

  7. Dynamics test on structures

    International Nuclear Information System (INIS)

    De Canio, G.; Ranieri, N.

    2009-01-01

    Shake table tests allow to assess the effectiveness of technologies for structures protection from natural events such as earthquakes. The article summarizes the remarkable results of the most significant projects. [it

  8. AC Test Chambers

    Data.gov (United States)

    Federal Laboratory Consortium — The Psychrometric Test Chamber’s primary purpose is to evaluate the performance of split type central air conditioners and heat pumps in the cooling capacity range...

  9. Liver Function Tests

    Science.gov (United States)

    ... Liver Function Tests Clinical Trials Liver Transplant FAQs Medical Terminology Diseases of the Liver Alagille Syndrome Alcohol-Related ... the Liver The Progression of Liver Disease FAQs Medical Terminology HOW YOU CAN HELP Sponsorship Ways to Give ...

  10. Potassium Blood Test

    Science.gov (United States)

    ... K. Brunner & Suddarth's Handbook of Laboratory and Diagnostic Tests. 2 nd Ed, Kindle. Philadelphia: Wolters Kluwer Health, Lippincott Williams & Wilkins; c2014. Potassium, Serum; 426–27 p. Lab ...

  11. SP-100 Test Site

    International Nuclear Information System (INIS)

    Cox, C.M.; Mahaffey, M.K.; Miller, W.C.

    1988-01-01

    Preparatory activities are well under way at Hanford to convert the 309 Containment Building and its associated service wing to a 2.5 MWt nuclear test facility for the SP-100 Ground Engineering System (GES) test. Preliminary design is complete, encompassing facility modifications, a secondary heat transport system, a large vacuum system to enclose the high temperature reactor, a test assembly cell and handling system, control and data processing systems, and safety and auxiliary systems. The design makes extensive use of existing equipment to minimize technical risk and cost. Refurbishment of this equipment is 75% complete. The facility has been cleared of obstructing equipment from its earlier reactor test. Current activities are focusing on definitive design and preparation of the Preliminary Safety Analysis Report (PSAR) aimed at procurement and construction approvals and schedules to achieve reactor criticality by January 1992. 6 refs

  12. Tuberculin Skin Testing

    Science.gov (United States)

    ... Appendix 1 Appendix 2 Appendix 3 Interim Laboratory Biosafety Guidance for XDR Mycobacterium tuberculosis strains Data & Statistics ... The Mantoux tuberculin skin test (TST) is the standard method of determining whether a person is infected ...

  13. Concrete decontamination scoping tests

    International Nuclear Information System (INIS)

    Archibald, K.E.

    1995-01-01

    This report details the research efforts and scoping tests performed at the Idaho Chemical Process Plant using scabbling, chemical, and electro-osmotic decontamination techniques on radiologically contaminated concrete

  14. Methylmalonic Acid Test

    Science.gov (United States)

    ... Factor Antibody Iron Iron Tests JAK2 Mutation Kidney Stone Analysis Kidney Stone Risk Panel KRAS Mutation Lactate Lactate Dehydrogenase (LD) ... in Previous Reviews Clarke, W. and Dufour, D. R., Editors (2006). Contemporary Practice in Clinical Chemistry, AACC ...

  15. Lyme Disease Tests

    Science.gov (United States)

    ... Wu, A. (© 2006). Tietz Clinical Guide to Laboratory Tests, 4th Edition: Saunders Elsevier, St. Louis, MO. Pp 1538. Forbes, B. et. al. (© 2007). Bailey & Scott's Diagnostic Microbiology, 12th Edition: Mosby Elsevier Press, St. Louis, MO. ...

  16. Chickenpox and Shingles Tests

    Science.gov (United States)

    ... Wu, A. (© 2006). Tietz Clinical Guide to Laboratory Tests , Fourth Edition: Saunders Elsevier, St. Louis, MO. Pp 1623. Forbes, B. et. al. (© 2007). Bailey & Scott's Diagnostic Microbiology , Twelfth Edition: Mosby Elsevier Press, St. Louis, MO. ...

  17. ELECTROFORCE 3330 TEST SYSTEM

    Data.gov (United States)

    Federal Laboratory Consortium — The Bose Electroforce 3330 is a test system with an axial electromagnetic linear motor, a torsional motor, and an environmental chamber for high and low temperature...

  18. Manipulator comparative testing program

    International Nuclear Information System (INIS)

    Draper, J.V.; Handel, S.J.; Sundstrom, E.; Herndon, J.N.; Fujita, Y.; Maeda, M.

    1986-01-01

    The Manipulator Comparative Testing Program examined differences among manipulator systems from the United States and Japan. The manipulator systems included the Meidensha BILARM 83A, the Model M-2 of Central Research Laboratories Division of Sargent Industries (CRL), and the GCA Corporation PaR Systems Model 6000. The site of testing was the Remote Operations Maintenance Demonstration (ROMD) facility, operated by the Fuel Recycle Division in the Consolidated Fuel Reprocessing Program at the Oak Ridge National Laboratory (ORNL). In all stages of testing, operators using the CRL Model M-2 manipulator had consistently lower times to completion and error rates than they did using other machines. Performance was second best with the Meidensha BILARM 83A in master-slave mode. Performance with the BILARM in switchbox mode and the PaR 6000 manipulator was approximately equivalent in terms of criteria recorded in testing. These data show no impact of force reflection on task performance

  19. IPv6 Testing

    National Research Council Canada - National Science Library

    Landis, Christopher B

    2006-01-01

    .... The DoD is also forming working relationships to conduct testing and share information. IPv6 was developed to resolve the issues of IPv4, mainly the limited amount of addresses and lack of security...

  20. Five Common Glaucoma Tests

    Science.gov (United States)

    ... About Us Donate In This Section Five Common Glaucoma Tests en Español email Send this article to ... year or two after age 35. A Comprehensive Glaucoma Exam To be safe and accurate, five factors ...