WorldWideScience

Sample records for bivariate association tests

  1. Testing for bivariate spherical symmetry

    OpenAIRE

    Einmahl, J.H.J.; Gantner, M.

    2012-01-01

    An omnibus test for spherical symmetry in R2 is proposed, employing localized empirical likelihood. The thus obtained test statistic is distri- bution-free under the null hypothesis. The asymptotic null distribution is established and critical values for typical sample sizes, as well as the asymptotic ones, are presented. In a simulation study, the good perfor- mance of the test is demonstrated. Furthermore, a real data example is presented.

  2. Testing for Bivariate Spherical Symmetry

    NARCIS (Netherlands)

    Einmahl, J.H.J.; Gantner, M.

    2010-01-01

    An omnibus test for spherical symmetry in R2 is proposed, employing localized empirical likelihood. The thus obtained test statistic is distri- bution-free under the null hypothesis. The asymptotic null distribution is established and critical values for typical sample sizes, as well as the

  3. Testing for bivariate spherical symmetry

    NARCIS (Netherlands)

    Einmahl, J.H.J.; Gantner, M.

    2012-01-01

    An omnibus test for spherical symmetry in R2 is proposed, employing localized empirical likelihood. The thus obtained test statistic is distribution free under the null hypothesis. The asymptotic null distribution is established and critical values for typical sample sizes, as well as the asymptotic

  4. Joint association analysis of bivariate quantitative and qualitative traits.

    Science.gov (United States)

    Yuan, Mengdie; Diao, Guoqing

    2011-11-29

    Univariate genome-wide association analysis of quantitative and qualitative traits has been investigated extensively in the literature. In the presence of correlated phenotypes, it is more intuitive to analyze all phenotypes simultaneously. We describe an efficient likelihood-based approach for the joint association analysis of quantitative and qualitative traits in unrelated individuals. We assume a probit model for the qualitative trait, under which an unobserved latent variable and a prespecified threshold determine the value of the qualitative trait. To jointly model the quantitative and qualitative traits, we assume that the quantitative trait and the latent variable follow a bivariate normal distribution. The latent variable is allowed to be correlated with the quantitative phenotype. Simultaneous modeling of the quantitative and qualitative traits allows us to make more precise inference on the pleiotropic genetic effects. We derive likelihood ratio tests for the testing of genetic effects. An application to the Genetic Analysis Workshop 17 data is provided. The new method yields reasonable power and meaningful results for the joint association analysis of the quantitative trait Q1 and the qualitative trait disease status at SNPs with not too small MAF.

  5. On the matched pairs sign test using bivariate ranked set sampling ...

    African Journals Online (AJOL)

    BVRSS) is introduced and investigated. We show that this test is asymptotically more efficient than its counterpart sign test based on a bivariate simple random sample (BVSRS). The asymptotic null distribution and the efficiency of the test are derived.

  6. Parameter estimation and statistical test of geographically weighted bivariate Poisson inverse Gaussian regression models

    Science.gov (United States)

    Amalia, Junita; Purhadi, Otok, Bambang Widjanarko

    2017-11-01

    Poisson distribution is a discrete distribution with count data as the random variables and it has one parameter defines both mean and variance. Poisson regression assumes mean and variance should be same (equidispersion). Nonetheless, some case of the count data unsatisfied this assumption because variance exceeds mean (over-dispersion). The ignorance of over-dispersion causes underestimates in standard error. Furthermore, it causes incorrect decision in the statistical test. Previously, paired count data has a correlation and it has bivariate Poisson distribution. If there is over-dispersion, modeling paired count data is not sufficient with simple bivariate Poisson regression. Bivariate Poisson Inverse Gaussian Regression (BPIGR) model is mix Poisson regression for modeling paired count data within over-dispersion. BPIGR model produces a global model for all locations. In another hand, each location has different geographic conditions, social, cultural and economic so that Geographically Weighted Regression (GWR) is needed. The weighting function of each location in GWR generates a different local model. Geographically Weighted Bivariate Poisson Inverse Gaussian Regression (GWBPIGR) model is used to solve over-dispersion and to generate local models. Parameter estimation of GWBPIGR model obtained by Maximum Likelihood Estimation (MLE) method. Meanwhile, hypothesis testing of GWBPIGR model acquired by Maximum Likelihood Ratio Test (MLRT) method.

  7. Bivariate genome-wide association analyses identified genetic pleiotropic effects for bone mineral density and alcohol drinking in Caucasians.

    Science.gov (United States)

    Lu, Shan; Zhao, Lan-Juan; Chen, Xiang-Ding; Papasian, Christopher J; Wu, Ke-Hao; Tan, Li-Jun; Wang, Zhuo-Er; Pei, Yu-Fang; Tian, Qing; Deng, Hong-Wen

    2017-11-01

    Several studies indicated bone mineral density (BMD) and alcohol intake might share common genetic factors. The study aimed to explore potential SNPs/genes related to both phenotypes in US Caucasians at the genome-wide level. A bivariate genome-wide association study (GWAS) was performed in 2069 unrelated participants. Regular drinking was graded as 1, 2, 3, 4, 5, or 6, representing drinking alcohol never, less than once, once or twice, three to six times, seven to ten times, or more than ten times per week respectively. Hip, spine, and whole body BMDs were measured. The bivariate GWAS was conducted on the basis of a bivariate linear regression model. Sex-stratified association analyses were performed in the male and female subgroups. In males, the most significant association signal was detected in SNP rs685395 in DYNC2H1 with bivariate spine BMD and alcohol drinking (P = 1.94 × 10 -8 ). SNP rs685395 and five other SNPs, rs657752, rs614902, rs682851, rs626330, and rs689295, located in the same haplotype block in DYNC2H1 were the top ten most significant SNPs in the bivariate GWAS in males. Additionally, two SNPs in GRIK4 in males and three SNPs in OPRM1 in females were suggestively associated with BMDs (of the hip, spine, and whole body) and alcohol drinking. Nine SNPs in IL1RN were only suggestively associated with female whole body BMD and alcohol drinking. Our study indicated that DYNC2H1 may contribute to the genetic mechanisms of both spine BMD and alcohol drinking in male Caucasians. Moreover, our study suggested potential pleiotropic roles of OPRM1 and IL1RN in females and GRIK4 in males underlying variation of both BMD and alcohol drinking.

  8. Bayesian bivariate meta-analysis of diagnostic test studies using integrated nested Laplace approximations.

    Science.gov (United States)

    Paul, M; Riebler, A; Bachmann, L M; Rue, H; Held, L

    2010-05-30

    For bivariate meta-analysis of diagnostic studies, likelihood approaches are very popular. However, they often run into numerical problems with possible non-convergence. In addition, the construction of confidence intervals is controversial. Bayesian methods based on Markov chain Monte Carlo (MCMC) sampling could be used, but are often difficult to implement, and require long running times and diagnostic convergence checks. Recently, a new Bayesian deterministic inference approach for latent Gaussian models using integrated nested Laplace approximations (INLA) has been proposed. With this approach MCMC sampling becomes redundant as the posterior marginal distributions are directly and accurately approximated. By means of a real data set we investigate the influence of the prior information provided and compare the results obtained by INLA, MCMC, and the maximum likelihood procedure SAS PROC NLMIXED. Using a simulation study we further extend the comparison of INLA and SAS PROC NLMIXED by assessing their performance in terms of bias, mean-squared error, coverage probability, and convergence rate. The results indicate that INLA is more stable and gives generally better coverage probabilities for the pooled estimates and less biased estimates of variance parameters. The user-friendliness of INLA is demonstrated by documented R-code. Copyright (c) 2010 John Wiley & Sons, Ltd.

  9. Powerful bivariate genome-wide association analyses suggest the SOX6 gene influencing both obesity and osteoporosis phenotypes in males.

    Directory of Open Access Journals (Sweden)

    Yao-Zhong Liu

    2009-08-01

    Full Text Available Current genome-wide association studies (GWAS are normally implemented in a univariate framework and analyze different phenotypes in isolation. This univariate approach ignores the potential genetic correlation between important disease traits. Hence this approach is difficult to detect pleiotropic genes, which may exist for obesity and osteoporosis, two common diseases of major public health importance that are closely correlated genetically.To identify such pleiotropic genes and the key mechanistic links between the two diseases, we here performed the first bivariate GWAS of obesity and osteoporosis. We searched for genes underlying co-variation of the obesity phenotype, body mass index (BMI, with the osteoporosis risk phenotype, hip bone mineral density (BMD, scanning approximately 380,000 SNPs in 1,000 unrelated homogeneous Caucasians, including 499 males and 501 females. We identified in the male subjects two SNPs in intron 1 of the SOX6 (SRY-box 6 gene, rs297325 and rs4756846, which were bivariately associated with both BMI and hip BMD, achieving p values of 6.82x10(-7 and 1.47x10(-6, respectively. The two SNPs ranked at the top in significance for bivariate association with BMI and hip BMD in the male subjects among all the approximately 380,000 SNPs examined genome-wide. The two SNPs were replicated in a Framingham Heart Study (FHS cohort containing 3,355 Caucasians (1,370 males and 1,985 females from 975 families. In the FHS male subjects, the two SNPs achieved p values of 0.03 and 0.02, respectively, for bivariate association with BMI and femoral neck BMD. Interestingly, SOX6 was previously found to be essential to both cartilage formation/chondrogenesis and obesity-related insulin resistance, suggesting the gene's dual role in both bone and fat.Our findings, together with the prior biological evidence, suggest the SOX6 gene's importance in co-regulation of obesity and osteoporosis.

  10. Testing for a Common Volatility Process and Information Spillovers in Bivariate Financial Time Series Models

    NARCIS (Netherlands)

    J. Chen (Jinghui); M. Kobayashi (Masahito); M.J. McAleer (Michael)

    2016-01-01

    textabstractThe paper considers the problem as to whether financial returns have a common volatility process in the framework of stochastic volatility models that were suggested by Harvey et al. (1994). We propose a stochastic volatility version of the ARCH test proposed by Engle and Susmel (1993),

  11. Modeling Bivariate Change in Individual Differences: Prospective Associations Between Personality and Life Satisfaction.

    Science.gov (United States)

    Hounkpatin, Hilda Osafo; Boyce, Christopher J; Dunn, Graham; Wood, Alex M

    2017-09-18

    A number of structural equation models have been developed to examine change in 1 variable or the longitudinal association between 2 variables. The most common of these are the latent growth model, the autoregressive cross-lagged model, the autoregressive latent trajectory model, and the latent change score model. The authors first overview each of these models through evaluating their different assumptions surrounding the nature of change and how these assumptions may result in different data interpretations. They then, to elucidate these issues in an empirical example, examine the longitudinal association between personality traits and life satisfaction. In a representative Dutch sample (N = 8,320), with participants providing data on both personality and life satisfaction measures every 2 years over an 8-year period, the authors reproduce findings from previous research. However, some of the structural equation models overviewed have not previously been applied to the personality-life satisfaction relation. The extended empirical examination suggests intraindividual changes in life satisfaction predict subsequent intraindividual changes in personality traits. The availability of data sets with 3 or more assessment waves allows the application of more advanced structural equation models such as the autoregressive latent trajectory or the extended latent change score model, which accounts for the complex dynamic nature of change processes and allows stronger inferences on the nature of the association between variables. However, the choice of model should be determined by theories of change processes in the variables being studied. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  12. Bivariate genome-wide association meta-analysis of pediatric musculoskeletal traits reveals pleiotropic effects at the SREBF1/TOM1L2 locus.

    Science.gov (United States)

    Medina-Gomez, Carolina; Kemp, John P; Dimou, Niki L; Kreiner, Eskil; Chesi, Alessandra; Zemel, Babette S; Bønnelykke, Klaus; Boer, Cindy G; Ahluwalia, Tarunveer S; Bisgaard, Hans; Evangelou, Evangelos; Heppe, Denise H M; Bonewald, Lynda F; Gorski, Jeffrey P; Ghanbari, Mohsen; Demissie, Serkalem; Duque, Gustavo; Maurano, Matthew T; Kiel, Douglas P; Hsu, Yi-Hsiang; C J van der Eerden, Bram; Ackert-Bicknell, Cheryl; Reppe, Sjur; Gautvik, Kaare M; Raastad, Truls; Karasik, David; van de Peppel, Jeroen; Jaddoe, Vincent W V; Uitterlinden, André G; Tobias, Jonathan H; Grant, Struan F A; Bagos, Pantelis G; Evans, David M; Rivadeneira, Fernando

    2017-07-25

    Bone mineral density is known to be a heritable, polygenic trait whereas genetic variants contributing to lean mass variation remain largely unknown. We estimated the shared SNP heritability and performed a bivariate GWAS meta-analysis of total-body lean mass (TB-LM) and total-body less head bone mineral density (TBLH-BMD) regions in 10,414 children. The estimated SNP heritability is 43% (95% CI: 34-52%) for TBLH-BMD, and 39% (95% CI: 30-48%) for TB-LM, with a shared genetic component of 43% (95% CI: 29-56%). We identify variants with pleiotropic effects in eight loci, including seven established bone mineral density loci: WNT4, GALNT3, MEPE, CPED1/WNT16, TNFSF11, RIN3, and PPP6R3/LRP5. Variants in the TOM1L2/SREBF1 locus exert opposing effects TB-LM and TBLH-BMD, and have a stronger association with the former trait. We show that SREBF1 is expressed in murine and human osteoblasts, as well as in human muscle tissue. This is the first bivariate GWAS meta-analysis to demonstrate genetic factors with pleiotropic effects on bone mineral density and lean mass.Bone mineral density and lean skeletal mass are heritable traits. Here, Medina-Gomez and colleagues perform bivariate GWAS analyses of total body lean mass and bone mass density in children, and show genetic loci with pleiotropic effects on both traits.

  13. Effectiveness of enforcement levels of speed limit and drink driving laws and associated factors – Exploratory empirical analysis using a bivariate ordered probit model

    Directory of Open Access Journals (Sweden)

    Behram Wali

    2017-06-01

    Full Text Available The contemporary traffic safety research comprises little information on quantifying the simultaneous association between drink driving and speeding among fatally injured drivers. Potential correlation between driver's drink driving and speeding behavior poses a substantial methodological concern which needs investigation. This study therefore focused on investigating the simultaneous impact of socioeconomic factors, fatalities, vehicle ownership, health services and highway agency road safety policies on enforcement levels of speed limit and drink driving laws. The effectiveness of enforcement levels of speed limit and drink driving laws has been investigated through development of bivariate ordered probit model using data extricated from WHO's global status report on road safety in 2013. The consistent and intuitive parameter estimates along with statistically significant correlation between response outcomes validates the statistical supremacy of bivariate ordered probit model. The results revealed that fatalities per thousand registered vehicles, hospital beds per hundred thousand population and road safety policies are associated with a likely medium or high effectiveness of enforcement levels of speed limit and drink driving laws, respectively. Also, the model encapsulates the effect of several other agency related variables and socio-economic status on the response outcomes. Marginal effects are reported for analyzing the impact of such factors on intermediate categories of response outcomes. The results of this study are expected to provide necessary insights to elemental enforcement programs. Also, marginal effects of explanatory variables may provide useful directions for formulating effective policy countermeasures for overcoming driver's speeding and drink driving behavior.

  14. Ordinal Bivariate Inequality

    DEFF Research Database (Denmark)

    Sonne-Schmidt, Christoffer Scavenius; Tarp, Finn; Østerdal, Lars Peter Raahave

    2016-01-01

    This paper introduces a concept of inequality comparisons with ordinal bivariate categorical data. In our model, one population is more unequal than another when they have common arithmetic median outcomes and the first can be obtained from the second by correlation-increasing switches and....../or median-preserving spreads. For the canonical 2 × 2 case (with two binary indicators), we derive a simple operational procedure for checking ordinal inequality relations in practice. As an illustration, we apply the model to childhood deprivation in Mozambique....

  15. Ordinal bivariate inequality

    DEFF Research Database (Denmark)

    Sonne-Schmidt, Christoffer Scavenius; Tarp, Finn; Østerdal, Lars Peter Raahave

    This paper introduces a concept of inequality comparisons with ordinal bivariate categorical data. In our model, one population is more unequal than another when they have common arithmetic median outcomes and the first can be obtained from the second by correlationincreasing switches and/or median......-preserving spreads. For the canonical 2x2 case (with two binary indicators), we derive a simple operational procedure for checking ordinal inequality relations in practice. As an illustration, we apply the model to childhood deprivation in Mozambique....

  16. Monitoring bivariate process

    Directory of Open Access Journals (Sweden)

    Marcela A. G. Machado

    2009-12-01

    Full Text Available The T² chart and the generalized variance |S| chart are the usual tools for monitoring the mean vector and the covariance matrix of multivariate processes. The main drawback of these charts is the difficulty to obtain and to interpret the values of their monitoring statistics. In this paper, we study control charts for monitoring bivariate processes that only requires the computation of sample means (the ZMAX chart for monitoring the mean vector, sample variances (the VMAX chart for monitoring the covariance matrix, or both sample means and sample variances (the MCMAX chart in the case of the joint control of the mean vector and the covariance matrix.Os gráficos de T² e da variância amostral generalizada |S| são as ferramentas usualmente utilizadas no monitoramento do vetor de médias e da matriz de covariâncias de processos multivariados. A principal desvantagem desses gráficos é a dificuldade em obter e interpretar os valores de suas estatísticas de monitoramento. Neste artigo, estudam-se gráficos de controle para o monitoramento de processos bivariados que necessitam somente do cálculo de médias amostrais (gráfico ZMAX para o monitoramento do vetor de médias, ou das variâncias amostrais (gráfico VMAX para o monitoramento da matriz de covariâncias, ou então das médias e variâncias amostrais (gráfico MCMAX para o caso do monitoramento conjunto do vetor de médias e da matriz de covariâncias.

  17. Association of Supply Type with Fecal Contamination of Source Water and Household Stored Drinking Water in Developing Countries: A Bivariate Meta-analysis.

    Science.gov (United States)

    Shields, Katherine F; Bain, Robert E S; Cronk, Ryan; Wright, Jim A; Bartram, Jamie

    2015-12-01

    Access to safe drinking water is essential for health. Monitoring access to drinking water focuses on water supply type at the source, but there is limited evidence on whether quality differences at the source persist in water stored in the household. We assessed the extent of fecal contamination at the source and in household stored water (HSW) and explored the relationship between contamination at each sampling point and water supply type. We performed a bivariate random-effects meta-analysis of 45 studies, identified through a systematic review, that reported either the proportion of samples free of fecal indicator bacteria and/or individual sample bacteria counts for source and HSW, disaggregated by supply type. Water quality deteriorated substantially between source and stored water. The mean percentage of contaminated samples (noncompliance) at the source was 46% (95% CI: 33, 60%), whereas mean noncompliance in HSW was 75% (95% CI: 64, 84%). Water supply type was significantly associated with noncompliance at the source (p water (OR = 0.2; 95% CI: 0.1, 0.5) and HSW (OR = 0.3; 95% CI: 0.2, 0.8) from piped supplies had significantly lower odds of contamination compared with non-piped water, potentially due to residual chlorine. Piped water is less likely to be contaminated compared with other water supply types at both the source and in HSW. A focus on upgrading water services to piped supplies may help improve safety, including for those drinking stored water.

  18. Bivariate genome-wide association meta-analysis of pediatric musculoskeletal traits reveals pleiotropic effects at the SREBF1/TOM1L2 locus

    DEFF Research Database (Denmark)

    Medina-Gomez, Carolina; Kemp, John P; Dimou, Niki L

    2017-01-01

    Bone mineral density is known to be a heritable, polygenic trait whereas genetic variants contributing to lean mass variation remain largely unknown. We estimated the shared SNP heritability and performed a bivariate GWAS meta-analysis of total-body lean mass (TB-LM) and total-body less head bone...

  19. Bivariate genome-wide association meta-analysis of pediatric musculoskeletal traits reveals pleiotropic effects at the SREBF1/TOM1L2 locus

    NARCIS (Netherlands)

    M.C. Medina-Gomez (Carolina); J.P. Kemp (John); Dimou, N.L. (Niki L.); Kreiner, E. (Eskil); A. Chesi (Alessandra); B.S. Zemel (Babette S.); K. Bønnelykke (Klaus); Boer, C.G. (Cindy G.); T.S. Ahluwalia (Tarunveer Singh); H. Bisgaard; E. Evangelou (Evangelos); D.H.M. Heppe (Denise); Bonewald, L.F. (Lynda F.); Gorski, J.P. (Jeffrey P.); M. Ghanbari (Mohsen); S. Demissie (Serkalem); Duque, G. (Gustavo); M.T. Maurano (Matthew T.); D.P. Kiel (Douglas P.); Y.-H. Hsu (Yi-Hsiang); B.C.J. van der Eerden (Bram); Ackert-Bicknell, C. (Cheryl); S. Reppe (Sjur); K.M. Gautvik (Kaare); Raastad, T. (Truls); D. Karasik (David); J. van de Peppel (Jeroen); V.W.V. Jaddoe (Vincent); A.G. Uitterlinden (André); J.H. Tobias (Jon); S.F.A. Grant (Struan); Bagos, P.G. (Pantelis G.); D.M. Evans (David); F. Rivadeneira Ramirez (Fernando)

    2017-01-01

    markdownabstractBone mineral density is known to be a heritable, polygenic trait whereas genetic variants contributing to lean mass variation remain largely unknown. We estimated the shared SNP heritability and performed a bivariate GWAS meta-analysis of total-body lean mass (TB-LM) and total-body

  20. Association of Supply Type with Fecal Contamination of Source Water and Household Stored Drinking Water in Developing Countries: A Bivariate Meta-analysis

    OpenAIRE

    Shields, Katherine F.; Bain, Robert E.S.; Cronk, Ryan; Wright, Jim A.; Bartram, Jamie

    2015-01-01

    Background Access to safe drinking water is essential for health. Monitoring access to drinking water focuses on water supply type at the source, but there is limited evidence on whether quality differences at the source persist in water stored in the household. Objectives We assessed the extent of fecal contamination at the source and in household stored water (HSW) and explored the relationship between contamination at each sampling point and water supply type. Methods We performed a bivari...

  1. Bivariate genome-wide association meta-analysis of pediatric musculoskeletal traits reveals pleiotropic effects at the SREBF1/TOM1L2 locus

    DEFF Research Database (Denmark)

    Medina-Gomez, Carolina; Kemp, John P; Dimou, Niki L

    2017-01-01

    Bone mineral density is known to be a heritable, polygenic trait whereas genetic variants contributing to lean mass variation remain largely unknown. We estimated the shared SNP heritability and performed a bivariate GWAS meta-analysis of total-body lean mass (TB-LM) and total-body less head bone...... mineral density (TBLH-BMD) regions in 10,414 children. The estimated SNP heritability is 43% (95% CI: 34-52%) for TBLH-BMD, and 39% (95% CI: 30-48%) for TB-LM, with a shared genetic component of 43% (95% CI: 29-56%). We identify variants with pleiotropic effects in eight loci, including seven established...... as in human muscle tissue. This is the first bivariate GWAS meta-analysis to demonstrate genetic factors with pleiotropic effects on bone mineral density and lean mass.Bone mineral density and lean skeletal mass are heritable traits. Here, Medina-Gomez and colleagues perform bivariate GWAS analyses of total...

  2. Covariate analysis of bivariate survival data

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, L.E.

    1992-01-01

    The methods developed are used to analyze the effects of covariates on bivariate survival data when censoring and ties are present. The proposed method provides models for bivariate survival data that include differential covariate effects and censored observations. The proposed models are based on an extension of the univariate Buckley-James estimators which replace censored data points by their expected values, conditional on the censoring time and the covariates. For the bivariate situation, it is necessary to determine the expectation of the failure times for one component conditional on the failure or censoring time of the other component. Two different methods have been developed to estimate these expectations. In the semiparametric approach these expectations are determined from a modification of Burke's estimate of the bivariate empirical survival function. In the parametric approach censored data points are also replaced by their conditional expected values where the expected values are determined from a specified parametric distribution. The model estimation will be based on the revised data set, comprised of uncensored components and expected values for the censored components. The variance-covariance matrix for the estimated covariate parameters has also been derived for both the semiparametric and parametric methods. Data from the Demographic and Health Survey was analyzed by these methods. The two outcome variables are post-partum amenorrhea and breastfeeding; education and parity were used as the covariates. Both the covariate parameter estimates and the variance-covariance estimates for the semiparametric and parametric models will be compared. In addition, a multivariate test statistic was used in the semiparametric model to examine contrasts. The significance of the statistic was determined from a bootstrap distribution of the test statistic.

  3. Bivariate value-at-risk

    Directory of Open Access Journals (Sweden)

    Giuseppe Arbia

    2007-10-01

    Full Text Available In this paper we extend the concept of Value-at-risk (VaR to bivariate return distributions in order to obtain measures of the market risk of an asset taking into account additional features linked to downside risk exposure. We first present a general definition of risk as the probability of an adverse event over a random distribution and we then introduce a measure of market risk (b-VaR that admits the traditional b of an asset in portfolio management as a special case when asset returns are normally distributed. Empirical evidences are provided by using Italian stock market data.

  4. Bivariate hard thresholding in wavelet function estimation

    OpenAIRE

    Piotr Fryzlewicz

    2007-01-01

    We propose a generic bivariate hard thresholding estimator of the discrete wavelet coefficients of a function contaminated with i.i.d. Gaussian noise. We demonstrate its good risk properties in a motivating example, and derive upper bounds for its mean-square error. Motivated by the clustering of large wavelet coefficients in real-life signals, we propose two wavelet denoising algorithms, both of which use specific instances of our bivariate estimator. The BABTE algorithm uses basis averaging...

  5. Barriers and facilitators associated with HIV testing uptake in South ...

    African Journals Online (AJOL)

    Individuals (n ¼ 489) who had not tested for HIV on the day of the site visit were interviewed on awareness of HCT services, HIV testing history and barriers to HIV testing. Frequencies were run to describe the sample characteristics, barriers and facilitators to HIV testing. Bivariate and multivariate logistic regression was ...

  6. Reliability for some bivariate beta distributions

    Directory of Open Access Journals (Sweden)

    Nadarajah Saralees

    2005-01-01

    Full Text Available In the area of stress-strength models there has been a large amount of work as regards estimation of the reliability R=Pr( Xbivariate distribution with dependence between X and Y . In particular, we derive explicit expressions for R when the joint distribution is bivariate beta. The calculations involve the use of special functions.

  7. Reliability for some bivariate gamma distributions

    Directory of Open Access Journals (Sweden)

    Nadarajah Saralees

    2005-01-01

    Full Text Available In the area of stress-strength models, there has been a large amount of work as regards estimation of the reliability R=Pr( Xbivariate distribution with dependence between X and Y . In particular, we derive explicit expressions for R when the joint distribution is bivariate gamma. The calculations involve the use of special functions.

  8. Financial Applications of Bivariate Markov Processes

    OpenAIRE

    Ortobelli Lozza, Sergio; Angelelli, Enrico; Bianchi, Annamaria

    2011-01-01

    This paper describes a methodology to approximate a bivariate Markov process by means of a proper Markov chain and presents possible financial applications in portfolio theory, option pricing and risk management. In particular, we first show how to model the joint distribution between market stochastic bounds and future wealth and propose an application to large-scale portfolio problems. Secondly, we examine an application to VaR estimation. Finally, we propose a methodology...

  9. Spectral density regression for bivariate extremes

    KAUST Repository

    Castro Camilo, Daniela

    2016-05-11

    We introduce a density regression model for the spectral density of a bivariate extreme value distribution, that allows us to assess how extremal dependence can change over a covariate. Inference is performed through a double kernel estimator, which can be seen as an extension of the Nadaraya–Watson estimator where the usual scalar responses are replaced by mean constrained densities on the unit interval. Numerical experiments with the methods illustrate their resilience in a variety of contexts of practical interest. An extreme temperature dataset is used to illustrate our methods. © 2016 Springer-Verlag Berlin Heidelberg

  10. Bivariate Kumaraswamy Models via Modified FGM Copulas: Properties and Applications

    Directory of Open Access Journals (Sweden)

    Indranil Ghosh

    2017-11-01

    Full Text Available A copula is a useful tool for constructing bivariate and/or multivariate distributions. In this article, we consider a new modified class of FGM (Farlie–Gumbel–Morgenstern bivariate copula for constructing several different bivariate Kumaraswamy type copulas and discuss their structural properties, including dependence structures. It is established that construction of bivariate distributions by this method allows for greater flexibility in the values of Spearman’s correlation coefficient, ρ and Kendall’s τ .

  11. Solving Bivariate Polynomial Systems on a GPU

    International Nuclear Information System (INIS)

    Moreno Maza, Marc; Pan Wei

    2012-01-01

    We present a CUDA implementation of dense multivariate polynomial arithmetic based on Fast Fourier Transforms over finite fields. Our core routine computes on the device (GPU) the subresultant chain of two polynomials with respect to a given variable. This subresultant chain is encoded by values on a FFT grid and is manipulated from the host (CPU) in higher-level procedures. We have realized a bivariate polynomial system solver supported by our GPU code. Our experimental results (including detailed profiling information and benchmarks against a serial polynomial system solver implementing the same algorithm) demonstrate that our strategy is well suited for GPU implementation and provides large speedup factors with respect to pure CPU code.

  12. Bivariate Rayleigh Distribution and its Properties

    Directory of Open Access Journals (Sweden)

    Ahmad Saeed Akhter

    2007-01-01

    Full Text Available Rayleigh (1880 observed that the sea waves follow no law because of the complexities of the sea, but it has been seen that the probability distributions of wave heights, wave length, wave induce pitch, wave and heave motions of the ships follow the Rayleigh distribution. At present, several different quantities are in use for describing the state of the sea; for example, the mean height of the waves, the root mean square height, the height of the “significant waves” (the mean height of the highest one-third of all the waves the maximum height over a given interval of the time, and so on. At present, the ship building industry knows less than any other construction industry about the service conditions under which it must operate. Only small efforts have been made to establish the stresses and motions and to incorporate the result of such studies in to design. This is due to the complexity of the problem caused by the extensive variability of the sea and the corresponding response of the ships. Although the problem appears feasible, yet it is possible to predict service conditions for ships in an orderly and relatively simple manner Rayleigh (1980 derived it from the amplitude of sound resulting from many independent sources. This distribution is also connected with one or two dimensions and is sometimes referred to as “random walk” frequency distribution. The Rayleigh distribution can be derived from the bivariate normal distribution when the variate are independent and random with equal variances. We try to construct bivariate Rayleigh distribution with marginal Rayleigh distribution function and discuss its fundamental properties.

  13. Multiple imputation methods for bivariate outcomes in cluster randomised trials.

    Science.gov (United States)

    DiazOrdaz, K; Kenward, M G; Gomes, M; Grieve, R

    2016-09-10

    Missing observations are common in cluster randomised trials. The problem is exacerbated when modelling bivariate outcomes jointly, as the proportion of complete cases is often considerably smaller than the proportion having either of the outcomes fully observed. Approaches taken to handling such missing data include the following: complete case analysis, single-level multiple imputation that ignores the clustering, multiple imputation with a fixed effect for each cluster and multilevel multiple imputation. We contrasted the alternative approaches to handling missing data in a cost-effectiveness analysis that uses data from a cluster randomised trial to evaluate an exercise intervention for care home residents. We then conducted a simulation study to assess the performance of these approaches on bivariate continuous outcomes, in terms of confidence interval coverage and empirical bias in the estimated treatment effects. Missing-at-random clustered data scenarios were simulated following a full-factorial design. Across all the missing data mechanisms considered, the multiple imputation methods provided estimators with negligible bias, while complete case analysis resulted in biased treatment effect estimates in scenarios where the randomised treatment arm was associated with missingness. Confidence interval coverage was generally in excess of nominal levels (up to 99.8%) following fixed-effects multiple imputation and too low following single-level multiple imputation. Multilevel multiple imputation led to coverage levels of approximately 95% throughout. © 2016 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd. © 2016 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

  14. The Effects of Selection Strategies for Bivariate Loglinear Smoothing Models on NEAT Equating Functions

    Science.gov (United States)

    Moses, Tim; Holland, Paul W.

    2010-01-01

    In this study, eight statistical strategies were evaluated for selecting the parameterizations of loglinear models for smoothing the bivariate test score distributions used in nonequivalent groups with anchor test (NEAT) equating. Four of the strategies were based on significance tests of chi-square statistics (Likelihood Ratio, Pearson,…

  15. Bivariable analysis of ventricular late potentials in high resolution ECG records

    International Nuclear Information System (INIS)

    Orosco, L; Laciar, E

    2007-01-01

    In this study the bivariable analysis for ventricular late potentials detection in high-resolution electrocardiographic records is proposed. The standard time-domain analysis and the application of the time-frequency technique to high-resolution ECG records are briefly described as well as their corresponding results. In the proposed technique the time-domain parameter, QRSD and the most significant time-frequency index, EN QRS are used like variables. A bivariable index is defined, that combines the previous parameters. The propose technique allows evaluating the risk of ventricular tachycardia in post-myocardial infarct patients. The results show that the used bivariable index allows discriminating between the patient's population with ventricular tachycardia and the subjects of the control group. Also, it was found that the bivariable technique obtains a good valuation as diagnostic test. It is concluded that comparatively, the valuation of the bivariable technique as diagnostic test is superior to that of the time-domain method and the time-frequency technique evaluated individually

  16. Barriers and facilitators associated with HIV testing uptake in South African health facilities offering HIV Counselling and Testing

    Directory of Open Access Journals (Sweden)

    Neo Mohlabane

    2016-10-01

    Objective: An HCT survey was carried out to ascertain barriers and facilitators for HIV testing in South Africa. Methods: A cross-sectional survey of 67 HCT-offering health facilities in 8 South African provinces was undertaken. Individuals (n = 489 who had not tested for HIV on the day of the site visit were interviewed on awareness of HCT services, HIV testing history and barriers to HIV testing. Frequencies were run to describe the sample characteristics, barriers and facilitators to HIV testing. Bivariate and multivariate logistic regression was usedt o identify the association between never tested for HIV with socio-demographics, awareness of HCT services and type of HCT facilities. Results: In all 18.1% participants never had an HIV test. Major barriers to HCT uptake comprise being scared of finding out one's HIV test result or what people may say, shyness or embarrassment, avoidance of divulging personal information to health workers and fear of death. In multivariate analysis the age group 55 years and older, and not being recommended to have an HIV test were associated with never had an HIV test. Potential facilitators for HIV testing include community or household HIV testing, providing incentives for those who test for HIV, mandatory HIV testing and disclosure of HIV status by those who test HIV positive. Conclusion: The benefits of HCT which include the reduction of HIV transmission, the availability of HIV care and treatment needs to be emphasized to enhance HCT uptake.

  17. Stress-strength reliability for general bivariate distributions

    Directory of Open Access Journals (Sweden)

    Alaa H. Abdel-Hamid

    2016-10-01

    Full Text Available An expression for the stress-strength reliability R=P(X1bivariate distribution. Such distribution includes bivariate compound Weibull, bivariate compound Gompertz, bivariate compound Pareto, among others. In the parametric case, the maximum likelihood estimates of the parameters and reliability function R are obtained. In the non-parametric case, point and interval estimates of R are developed using Govindarajulu's asymptotic distribution-free method when X1 and X2 are dependent. An example is given when the population distribution is bivariate compound Weibull. Simulation is performed, based on different sample sizes to study the performance of estimates.

  18. STUDI PERBANDINGAN ANTARA ALGORITMA BIVARIATE MARGINAL DISTRIBUTION DENGAN ALGORITMA GENETIKA

    Directory of Open Access Journals (Sweden)

    Chastine Fatichah

    2006-01-01

    Full Text Available Bivariate Marginal Distribution Algorithm is extended from Estimation of Distribution Algorithm. This heuristic algorithm proposes the new approach for recombination of generate new individual that without crossover and mutation process such as genetic algorithm. Bivariate Marginal Distribution Algorithm uses connectivity variable the pair gene for recombination of generate new individual. Connectivity between variable is doing along optimization process. In this research, genetic algorithm performance with one point crossover is compared with Bivariate Marginal Distribution Algorithm performance in case Onemax, De Jong F2 function, and Traveling Salesman Problem. In this research, experimental results have shown performance the both algorithm is dependence of parameter respectively and also population size that used. For Onemax case with size small problem, Genetic Algorithm perform better with small number of iteration and more fast for get optimum result. However, Bivariate Marginal Distribution Algorithm perform better of result optimization for case Onemax with huge size problem. For De Jong F2 function, Genetic Algorithm perform better from Bivariate Marginal Distribution Algorithm of a number of iteration and time. For case Traveling Salesman Problem, Bivariate Marginal Distribution Algorithm have shown perform better from Genetic Algorithm of optimization result. Abstract in Bahasa Indonesia : Bivariate Marginal Distribution Algorithm merupakan perkembangan lebih lanjut dari Estimation of Distribution Algorithm. Algoritma heuristik ini mengenalkan pendekatan baru dalam melakukan rekombinasi untuk membentuk individu baru, yaitu tidak menggunakan proses crossover dan mutasi seperti pada Genetic Algorithm. Bivariate Marginal Distribution Algorithm menggunakan keterkaitan pasangan variabel dalam melakukan rekombinasi untuk membentuk individu baru. Keterkaitan antar variabel tersebut ditemukan selama proses optimasi berlangsung. Aplikasi yang

  19. Causal networks clarify productivity-richness interrelations, bivariate plots do not

    Science.gov (United States)

    Grace, James B.; Adler, Peter B.; Harpole, W. Stanley; Borer, Elizabeth T.; Seabloom, Eric W.

    2014-01-01

    Perhaps no other pair of variables in ecology has generated as much discussion as species richness and ecosystem productivity, as illustrated by the reactions by Pierce (2013) and others to Adler et al.'s (2011) report that empirical patterns are weak and inconsistent. Adler et al. (2011) argued we need to move beyond a focus on simplistic bivariate relationships and test mechanistic, multivariate causal hypotheses. We feel the continuing debate over productivity–richness relationships (PRRs) provides a focused context for illustrating the fundamental difficulties of using bivariate relationships to gain scientific understanding.

  20. Approximation of bivariate copulas by patched bivariate Fréchet copulas

    KAUST Repository

    Zheng, Yanting

    2011-03-01

    Bivariate Fréchet (BF) copulas characterize dependence as a mixture of three simple structures: comonotonicity, independence and countermonotonicity. They are easily interpretable but have limitations when used as approximations to general dependence structures. To improve the approximation property of the BF copulas and keep the advantage of easy interpretation, we develop a new copula approximation scheme by using BF copulas locally and patching the local pieces together. Error bounds and a probabilistic interpretation of this approximation scheme are developed. The new approximation scheme is compared with several existing copula approximations, including shuffle of min, checkmin, checkerboard and Bernstein approximations and exhibits better performance, especially in characterizing the local dependence. The utility of the new approximation scheme in insurance and finance is illustrated in the computation of the rainbow option prices and stop-loss premiums. © 2010 Elsevier B.V.

  1. OPATs: Omnibus P-value association tests.

    Science.gov (United States)

    Chen, Chia-Wei; Yang, Hsin-Chou

    2017-07-10

    Combining statistical significances (P-values) from a set of single-locus association tests in genome-wide association studies is a proof-of-principle method for identifying disease-associated genomic segments, functional genes and biological pathways. We review P-value combinations for genome-wide association studies and introduce an integrated analysis tool, Omnibus P-value Association Tests (OPATs), which provides popular analysis methods of P-value combinations. The software OPATs programmed in R and R graphical user interface features a user-friendly interface. In addition to analysis modules for data quality control and single-locus association tests, OPATs provides three types of set-based association test: window-, gene- and biopathway-based association tests. P-value combinations with or without threshold and rank truncation are provided. The significance of a set-based association test is evaluated by using resampling procedures. Performance of the set-based association tests in OPATs has been evaluated by simulation studies and real data analyses. These set-based association tests help boost the statistical power, alleviate the multiple-testing problem, reduce the impact of genetic heterogeneity, increase the replication efficiency of association tests and facilitate the interpretation of association signals by streamlining the testing procedures and integrating the genetic effects of multiple variants in genomic regions of biological relevance. In summary, P-value combinations facilitate the identification of marker sets associated with disease susceptibility and uncover missing heritability in association studies, thereby establishing a foundation for the genetic dissection of complex diseases and traits. OPATs provides an easy-to-use and statistically powerful analysis tool for P-value combinations. OPATs, examples, and user guide can be downloaded from http://www.stat.sinica.edu.tw/hsinchou/genetics/association/OPATs.htm. © The Author 2017

  2. A bivariate model for analyzing recurrent multi-type automobile failures

    Science.gov (United States)

    Sunethra, A. A.; Sooriyarachchi, M. R.

    2017-09-01

    The failure mechanism in an automobile can be defined as a system of multi-type recurrent failures where failures can occur due to various multi-type failure modes and these failures are repetitive such that more than one failure can occur from each failure mode. In analysing such automobile failures, both the time and type of the failure serve as response variables. However, these two response variables are highly correlated with each other since the timing of failures has an association with the mode of the failure. When there are more than one correlated response variables, the fitting of a multivariate model is more preferable than separate univariate models. Therefore, a bivariate model of time and type of failure becomes appealing for such automobile failure data. When there are multiple failure observations pertaining to a single automobile, such data cannot be treated as independent data because failure instances of a single automobile are correlated with each other while failures among different automobiles can be treated as independent. Therefore, this study proposes a bivariate model consisting time and type of failure as responses adjusted for correlated data. The proposed model was formulated following the approaches of shared parameter models and random effects models for joining the responses and for representing the correlated data respectively. The proposed model is applied to a sample of automobile failures with three types of failure modes and up to five failure recurrences. The parametric distributions that were suitable for the two responses of time to failure and type of failure were Weibull distribution and multinomial distribution respectively. The proposed bivariate model was programmed in SAS Procedure Proc NLMIXED by user programming appropriate likelihood functions. The performance of the bivariate model was compared with separate univariate models fitted for the two responses and it was identified that better performance is secured by

  3. mitants of Order Statistics from Bivariate Inverse Rayleigh Distribution

    Directory of Open Access Journals (Sweden)

    Muhammad Aleem

    2006-01-01

    Full Text Available The probability density function (pdf of the rth, 1 r n and joint pdf of the rth and sth, 1 rBivariate Inverse Rayleigh Distribution and their moments, product moments are obtained. Its percentiles are also obtained.

  4. GIS-based bivariate statistical techniques for groundwater potential ...

    Indian Academy of Sciences (India)

    Groundwater potential analysis prepares better comprehension of hydrological settings of different regions. This study shows the potency of two GIS-based data driven bivariate techniques namely statistical index (SI) and Dempster–Shafer theory (DST) to analyze groundwater potential in Broujerd region of Iran.

  5. Dissecting the correlation structure of a bivariate phenotype ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Genetics; Volume 84; Issue 2. Dissecting the correlation structure of a bivariate phenotype: common genes or shared environment? ... High correlations between two quantitative traits may be either due to common genetic factors or common environmental factors or a combination of both.

  6. Modelling of Uncertainty and Bi-Variable Maps

    Science.gov (United States)

    Nánásiová, Ol'ga; Pykacz, Jarosław

    2016-05-01

    The paper gives an overview and compares various bi-varilable maps from orthomodular lattices into unit interval. It focuses mainly on such bi-variable maps that may be used for constructing joint probability distributions for random variables which are not defined on the same Boolean algebra.

  7. An assessment on the use of bivariate, multivariate and soft ...

    Indian Academy of Sciences (India)

    Conditional probability (CP), logistic regression (LR) and artificial neural networks (ANN) models representing the bivariate, multivariate and soft computing techniques were used in GIS based collapse susceptibility mapping in an area from Sivas basin (Turkey). Collapse-related factors, directly or indirectly related to the ...

  8. An assessment on the use of bivariate, multivariate and soft ...

    Indian Academy of Sciences (India)

    The paper presented herein compares and discusses the use of bivariate, multivariate and soft computing techniques for ... map is a useful tool in urban planning. ..... 381. Table 1. Frequency ratio of geological factors to collapse occurrences and results of the P(A/Bi) obtained from the. Conditional Probability model. Class.

  9. Comparison between two bivariate Poisson distributions through the ...

    African Journals Online (AJOL)

    To remedy this problem, Berkhout and Plug proposed a bivariate Poisson distribution accepting the correlation as well negative, equal to zero, that positive. In this paper, we show that these models are nearly everywhere asymptotically equal. From this survey that the ø-divergence converges toward zero, both models are ...

  10. About some properties of bivariate splines with shape parameters

    Science.gov (United States)

    Caliò, F.; Marchetti, E.

    2017-07-01

    The paper presents and proves geometrical properties of a particular bivariate function spline, built and algorithmically implemented in previous papers. The properties typical of this family of splines impact the field of computer graphics in particular that of the reverse engineering.

  11. The approximation of bivariate Chlodowsky-Sz?sz-Kantorovich-Charlier-type operators

    OpenAIRE

    Agrawal, Purshottam Narain; Baxhaku, Behar; Chauhan, Ruchi

    2017-01-01

    Abstract In this paper, we introduce a bivariate Kantorovich variant of combination of Szász and Chlodowsky operators based on Charlier polynomials. Then, we study local approximation properties for these operators. Also, we estimate the approximation order in terms of Peetre’s K-functional and partial moduli of continuity. Furthermore, we introduce the associated GBS-case (Generalized Boolean Sum) of these operators and study the degree of approximation by means of the Lipschitz class of Bög...

  12. Bivariate extreme value with application to PM10 concentration analysis

    Science.gov (United States)

    Amin, Nor Azrita Mohd; Adam, Mohd Bakri; Ibrahim, Noor Akma; Aris, Ahmad Zaharin

    2015-05-01

    This study is focus on a bivariate extreme of renormalized componentwise maxima with generalized extreme value distribution as a marginal function. The limiting joint distribution of several parametric models are presented. Maximum likelihood estimation is employed for parameter estimations and the best model is selected based on the Akaike Information Criterion. The weekly and monthly componentwise maxima series are extracted from the original observations of daily maxima PM10 data for two air quality monitoring stations located in Pasir Gudang and Johor Bahru. The 10 years data are considered for both stations from year 2001 to 2010. The asymmetric negative logistic model is found as the best fit bivariate extreme model for both weekly and monthly maxima componentwise series. However the dependence parameters show that the variables for weekly maxima series is more dependence to each other compared to the monthly maxima.

  13. Univariate and Bivariate Empirical Mode Decomposition for Postural Stability Analysis

    Directory of Open Access Journals (Sweden)

    Jacques Duchêne

    2008-05-01

    Full Text Available The aim of this paper was to compare empirical mode decomposition (EMD and two new extended methods of  EMD named complex empirical mode decomposition (complex-EMD and bivariate empirical mode decomposition (bivariate-EMD. All methods were used to analyze stabilogram center of pressure (COP time series. The two new methods are suitable to be applied to complex time series to extract complex intrinsic mode functions (IMFs before the Hilbert transform is subsequently applied on the IMFs. The trace of the analytic IMF in the complex plane has a circular form, with each IMF having its own rotation frequency. The area of the circle and the average rotation frequency of IMFs represent efficient indicators of the postural stability status of subjects. Experimental results show the effectiveness of these indicators to identify differences in standing posture between groups.

  14. Probability distributions with truncated, log and bivariate extensions

    CERN Document Server

    Thomopoulos, Nick T

    2018-01-01

    This volume presents a concise and practical overview of statistical methods and tables not readily available in other publications. It begins with a review of the commonly used continuous and discrete probability distributions. Several useful distributions that are not so common and less understood are described with examples and applications in full detail: discrete normal, left-partial, right-partial, left-truncated normal, right-truncated normal, lognormal, bivariate normal, and bivariate lognormal. Table values are provided with examples that enable researchers to easily apply the distributions to real applications and sample data. The left- and right-truncated normal distributions offer a wide variety of shapes in contrast to the symmetrically shaped normal distribution, and a newly developed spread ratio enables analysts to determine which of the three distributions best fits a particular set of sample data. The book will be highly useful to anyone who does statistical and probability analysis. This in...

  15. Spectrum-based estimators of the bivariate Hurst exponent

    Czech Academy of Sciences Publication Activity Database

    Krištoufek, Ladislav

    2014-01-01

    Roč. 90, č. 6 (2014), art. 062802 ISSN 1539-3755 R&D Projects: GA ČR(CZ) GP14-11402P Institutional support: RVO:67985556 Keywords : bivariate Hurst exponent * power- law cross-correlations * estimation Subject RIV: AH - Economics Impact factor: 2.288, year: 2014 http://library.utia.cas.cz/separaty/2014/E/kristoufek-0436818.pdf

  16. Bivariate return periods of temperature and precipitation explain a large fraction of European crop yields

    Science.gov (United States)

    Zscheischler, Jakob; Orth, Rene; Seneviratne, Sonia I.

    2017-07-01

    Crops are vital for human society. Crop yields vary with climate and it is important to understand how climate and crop yields are linked to ensure future food security. Temperature and precipitation are among the key driving factors of crop yield variability. Previous studies have investigated mostly linear relationships between temperature and precipitation and crop yield variability. Other research has highlighted the adverse impacts of climate extremes, such as drought and heat waves, on crop yields. Impacts are, however, often non-linearly related to multivariate climate conditions. Here we derive bivariate return periods of climate conditions as indicators for climate variability along different temperature-precipitation gradients. We show that in Europe, linear models based on bivariate return periods of specific climate conditions explain on average significantly more crop yield variability (42 %) than models relying directly on temperature and precipitation as predictors (36 %). Our results demonstrate that most often crop yields increase along a gradient from hot and dry to cold and wet conditions, with lower yields associated with hot and dry periods. The majority of crops are most sensitive to climate conditions in summer and to maximum temperatures. The use of bivariate return periods allows the integration of non-linear impacts into climate-crop yield analysis. This offers new avenues to study the link between climate and crop yield variability and suggests that they are possibly more strongly related than what is inferred from conventional linear models.

  17. TREAT (TREe-based Association Test)

    Science.gov (United States)

    TREAT is an R package for detecting complex joint effects in case-control studies. The test statistic is derived from a tree-structure model by recursive partitioning the data. Ultra-fast algorithm is designed to evaluate the significance of association between candidate gene and disease outcome

  18. Sequence robust association test for familial data.

    Science.gov (United States)

    Dai, Wei; Yang, Ming; Wang, Chaolong; Cai, Tianxi

    2017-09-01

    Genome-wide association studies (GWAS) and next generation sequencing studies (NGSS) are often performed in family studies to improve power in identifying genetic variants that are associated with clinical phenotypes. Efficient analysis of genome-wide studies with familial data is challenging due to the difficulty in modeling shared but unmeasured genetic and/or environmental factors that cause dependencies among family members. Existing genetic association testing procedures for family studies largely rely on generalized estimating equations (GEE) or linear mixed-effects (LME) models. These procedures may fail to properly control for type I errors when the imposed model assumptions fail. In this article, we propose the Sequence Robust Association Test (SRAT), a fully rank-based, flexible approach that tests for association between a set of genetic variants and an outcome, while accounting for within-family correlation and adjusting for covariates. Comparing to existing methods, SRAT has the advantages of allowing for unknown correlation structures and weaker assumptions about the outcome distribution. We provide theoretical justifications for SRAT and show that SRAT includes the well-known Wilcoxon rank sum test as a special case. Extensive simulation studies suggest that SRAT provides better protection against type I error rate inflation, and could be much more powerful for settings with skewed outcome distribution than existing methods. For illustration, we also apply SRAT to the familial data from the Framingham Heart Study and Offspring Study to examine the association between an inflammatory marker and a few sets of genetic variants. © 2017, The International Biometric Society.

  19. Computational approach to Thornley's problem by bivariate operational calculus

    Science.gov (United States)

    Bazhlekova, E.; Dimovski, I.

    2012-10-01

    Thornley's problem is an initial-boundary value problem with a nonlocal boundary condition for linear onedimensional reaction-diffusion equation, used as a mathematical model of spiral phyllotaxis in botany. Applying a bivariate operational calculus we find explicit representation of the solution, containing two convolution products of special solutions and the arbitrary initial and boundary functions. We use a non-classical convolution with respect to the space variable, extending in this way the classical Duhamel principle. The special solutions involved are represented in the form of fast convergent series. Numerical examples are considered to show the application of the present technique and to analyze the character of the solution.

  20. On the construction of bivariate exponential distributions with an arbitrary correlation coefficient

    DEFF Research Database (Denmark)

    Bladt, Mogens; Nielsen, Bo Friis

    coefficient (also negative). Secondly, the class satisfies that any linear combination (projection) of the marginal random variables is a phase {type distributions, The latter property is potentially important for the development hypothesis testing in linear models. Thirdly, it is very easy to simulate......In this paper we use a concept of multivariate phase-type distributions to define a class of bivariate exponential distributions. This class has the following three appealing properties. Firstly, we may construct a pair of exponentially distributed random variables with any feasible correlation...

  1. A comparison between multivariate and bivariate analysis used in marketing research

    Directory of Open Access Journals (Sweden)

    Constantin, C.

    2012-01-01

    Full Text Available This paper is about an instrumental research conducted in order to compare the information given by two multivariate data analysis in comparison with the usual bivariate analysis. The outcomes of the research reveal that sometimes the multivariate methods use more information from a certain variable, but sometimes they use only a part of the information considered the most important for certain associations. For this reason, a researcher should use both categories of data analysis in order to obtain entirely useful information.

  2. The approximation of bivariate Chlodowsky-Szász-Kantorovich-Charlier-type operators

    Directory of Open Access Journals (Sweden)

    Purshottam Narain Agrawal

    2017-08-01

    Full Text Available Abstract In this paper, we introduce a bivariate Kantorovich variant of combination of Szász and Chlodowsky operators based on Charlier polynomials. Then, we study local approximation properties for these operators. Also, we estimate the approximation order in terms of Peetre’s K-functional and partial moduli of continuity. Furthermore, we introduce the associated GBS-case (Generalized Boolean Sum of these operators and study the degree of approximation by means of the Lipschitz class of Bögel continuous functions. Finally, we present some graphical examples to illustrate the rate of convergence of the operators under consideration.

  3. The approximation of bivariate Chlodowsky-Szász-Kantorovich-Charlier-type operators.

    Science.gov (United States)

    Agrawal, Purshottam Narain; Baxhaku, Behar; Chauhan, Ruchi

    2017-01-01

    In this paper, we introduce a bivariate Kantorovich variant of combination of Szász and Chlodowsky operators based on Charlier polynomials. Then, we study local approximation properties for these operators. Also, we estimate the approximation order in terms of Peetre's K-functional and partial moduli of continuity. Furthermore, we introduce the associated GBS-case (Generalized Boolean Sum) of these operators and study the degree of approximation by means of the Lipschitz class of Bögel continuous functions. Finally, we present some graphical examples to illustrate the rate of convergence of the operators under consideration.

  4. Bivariate generalized Pareto distribution for extreme atmospheric particulate matter

    Science.gov (United States)

    Amin, Nor Azrita Mohd; Adam, Mohd Bakri; Ibrahim, Noor Akma; Aris, Ahmad Zaharin

    2015-02-01

    The high particulate matter (PM10) level is the prominent issue causing various impacts to human health and seriously affecting the economics. The asymptotic theory of extreme value is apply for analyzing the relation of extreme PM10 data from two nearby air quality monitoring stations. The series of daily maxima PM10 for Johor Bahru and Pasir Gudang stations are consider for year 2001 to 2010 databases. The 85% and 95% marginal quantile apply to determine the threshold values and hence construct the series of exceedances over the chosen threshold. The logistic, asymmetric logistic, negative logistic and asymmetric negative logistic models areconsidered as the dependence function to the joint distribution of a bivariate observation. Maximum likelihood estimation is employed for parameter estimations. The best fitted model is chosen based on the Akaike Information Criterion and the quantile plots. It is found that the asymmetric logistic model gives the best fitted model for bivariate extreme PM10 data and shows the weak dependence between two stations.

  5. Efficient estimation of semiparametric copula models for bivariate survival data

    KAUST Repository

    Cheng, Guang

    2014-01-01

    A semiparametric copula model for bivariate survival data is characterized by a parametric copula model of dependence and nonparametric models of two marginal survival functions. Efficient estimation for the semiparametric copula model has been recently studied for the complete data case. When the survival data are censored, semiparametric efficient estimation has only been considered for some specific copula models such as the Gaussian copulas. In this paper, we obtain the semiparametric efficiency bound and efficient estimation for general semiparametric copula models for possibly censored data. We construct an approximate maximum likelihood estimator by approximating the log baseline hazard functions with spline functions. We show that our estimates of the copula dependence parameter and the survival functions are asymptotically normal and efficient. Simple consistent covariance estimators are also provided. Numerical results are used to illustrate the finite sample performance of the proposed estimators. © 2013 Elsevier Inc.

  6. Bell-Type Inequalities for Bivariate Maps on Orthomodular Lattices

    Science.gov (United States)

    Pykacz, Jarosław; Valášková, L'ubica; Nánásiová, Ol'ga

    2015-08-01

    Bell-type inequalities on orthomodular lattices, in which conjunctions of propositions are not modeled by meets but by maps for simultaneous measurements (-maps), are studied. It is shown, that the most simple of these inequalities, that involves only two propositions, is always satisfied, contrary to what happens in the case of traditional version of this inequality in which conjunctions of propositions are modeled by meets. Equivalence of various Bell-type inequalities formulated with the aid of bivariate maps on orthomodular lattices is studied. Our investigations shed new light on the interpretation of various multivariate maps defined on orthomodular lattices already studied in the literature. The paper is concluded by showing the possibility of using -maps and -maps to represent counterfactual conjunctions and disjunctions of non-compatible propositions about quantum systems.

  7. Selection effects in the bivariate brightness distribution for spiral galaxies

    International Nuclear Information System (INIS)

    Phillipps, S.; Disney, M.

    1986-01-01

    The joint distribution of total luminosity and characteristic surface brightness (the bivariate brightness distribution) is investigated for a complete sample of spiral galaxies in the Virgo cluster. The influence of selection and physical limits of various kinds on the apparent distribution are detailed. While the distribution of surface brightness for bright galaxies may be genuinely fairly narrow, faint galaxies exist right across the (quite small) range of accessible surface brightnesses so no statement can be made about the true extent of the distribution. The lack of high surface brightness bright galaxies in the Virgo sample relative to an overall RC2 sample (mostly field galaxies) supports the contention that the star-formation rate is reduced in the inner region of the cluster for environmental reasons. (author)

  8. An integrated user-friendly ArcMAP tool for bivariate statistical modeling in geoscience applications

    Science.gov (United States)

    Jebur, M. N.; Pradhan, B.; Shafri, H. Z. M.; Yusof, Z.; Tehrany, M. S.

    2014-10-01

    Modeling and classification difficulties are fundamental issues in natural hazard assessment. A geographic information system (GIS) is a domain that requires users to use various tools to perform different types of spatial modeling. Bivariate statistical analysis (BSA) assists in hazard modeling. To perform this analysis, several calculations are required and the user has to transfer data from one format to another. Most researchers perform these calculations manually by using Microsoft Excel or other programs. This process is time consuming and carries a degree of uncertainty. The lack of proper tools to implement BSA in a GIS environment prompted this study. In this paper, a user-friendly tool, BSM (bivariate statistical modeler), for BSA technique is proposed. Three popular BSA techniques such as frequency ratio, weights-of-evidence, and evidential belief function models are applied in the newly proposed ArcMAP tool. This tool is programmed in Python and is created by a simple graphical user interface, which facilitates the improvement of model performance. The proposed tool implements BSA automatically, thus allowing numerous variables to be examined. To validate the capability and accuracy of this program, a pilot test area in Malaysia is selected and all three models are tested by using the proposed program. Area under curve is used to measure the success rate and prediction rate. Results demonstrate that the proposed program executes BSA with reasonable accuracy. The proposed BSA tool can be used in numerous applications, such as natural hazard, mineral potential, hydrological, and other engineering and environmental applications.

  9. A bivariate space-time downscaler under space and time misalignment.

    Science.gov (United States)

    Berrocal, Veronica J; Gelfand, Alan E; Holland, David M

    2010-12-01

    Ozone and particulate matter PM(2.5) are co-pollutants that have long been associated with increased public health risks. Information on concentration levels for both pollutants come from two sources: monitoring sites and output from complex numerical models that produce concentration surfaces over large spatial regions. In this paper, we offer a fully-model based approach for fusing these two sources of information for the pair of co-pollutants which is computationally feasible over large spatial regions and long periods of time. Due to the association between concentration levels of the two environmental contaminants, it is expected that information regarding one will help to improve prediction of the other. Misalignment is an obvious issue since the monitoring networks for the two contaminants only partly intersect and because the collection rate for PM(2.5) is typically less frequent than that for ozone.Extending previous work in Berrocal et al. (2009), we introduce a bivariate downscaler that provides a flexible class of bivariate space-time assimilation models. We discuss computational issues for model fitting and analyze a dataset for ozone and PM(2.5) for the ozone season during year 2002. We show a modest improvement in predictive performance, not surprising in a setting where we can anticipate only a small gain.

  10. Factors associated with Mexican women's familiarity with the purpose of the Pap test.

    Science.gov (United States)

    Nájera Aguilar, P; Lazcano Ponce, E C; de Ruíz, P A; Ramírez Sánchez, T; Cantoral Uriza, L; Hernández Avila, M

    1996-12-01

    Use of health services is usually associated with a variety of factors, including the socioeconomic characteristics of the users, their familiarity with the usefulness of the services provided, and the acceptability and accessibility of those services. To study the factors associated with women's familiarity with the Pap test, a population-based study was carried out in Mexico City and two rural areas in the state of Oaxaca by means of household interviews. The sample consisted of 4208 women 15 to 49 years of age. Univariate, bivariate, and multivariate analyses were done using unconditional logistic regression; the independent variables were access to social security health services, age, education, housing quality, and place of residence (urban or rural); the dependent variable was the interview subject's familiarity with the purpose of the Pap test. The results were expressed as odds ratios with 95% confidence intervals. It was found that 41.5% of the women surveyed did not know the purpose of the Pap test, and that within this latter group, 97% had never had one. Factors found to be associated with not knowing the test's purpose were lack of access to the social security health services (OR = 1.9; 95% CI: 1.5-2.3); illiteracy (OR = 36.1; 95% CI: 17.9-72.7); and low socioeconomic level (OR = 2.9; 95% CI: 2.3-3.7). Also, rural dwellers had less familiarity with the Pap test than urban dwellers (OR = 0.5; 95% CI: 0.4-0.7). These results highlight the need to develop strategies for making the benefits of the Pap test known, bearing in mind the socioeconomic and cultural diversity of the populations involved.

  11. Factors Associated with HIV Testing History among Pregnant Women and Their Partners in Georgia: The ANRS 12127 Prenahtest Trial

    Directory of Open Access Journals (Sweden)

    Maia Butsashvili

    2014-01-01

    Full Text Available Despite the benefits of timely diagnosis of HIV infection and the wide availability of VCT services, the acceptance of HIV testing and counseling still remains a challenge in Georgia. The goal of our study was to assess the history of HIV testing and associated factors among pregnant women. The recruitment of study participants took place during routine antenatal care visits at one of the large Maternity Hospitals in Tbilisi, capital of Georgia. A total of 491 pregnant women were included in the sample. More than a third of women (38.5% reported that they were tested for HIV before the current pregnancy and almost all of them (91.5% were tested during previous pregnancies. Bivariate analysis revealed statistically significant association of women’s history of HIV testing with age, education level, remunerated activity, history of STI, and multiparity. In multivariate analysis, the only independent predictor of being HIV tested was ever being pregnant. In conclusion, HIV testing history among women at reproductive age was poor in Georgia. Women mostly received HIV testing at prenatal centers. Efforts should be made to promote HIV testing in primary care settings, which would increase its acceptability and overall testing rate in the population.

  12. Implicit Association Tests of Attitudes toward Persons with Disabilities

    Science.gov (United States)

    Thomas, Adrian; Vaughn, Edwin D.; Doyle, Andrea; Bubb, Robert

    2014-01-01

    The authors assessed 3 of the currently available implicit association tests designed to measure attitudes toward persons with disabilities. The Revised Multiple Disability Implicit Association Test, the Implicit Association Test for Attitudes Toward Athletes With Disabilities, and the Disability Attitude Implicit Association Test were related to…

  13. Probabilistic modeling using bivariate normal distributions for identification of flow and displacement intervals in longwall overburden

    Energy Technology Data Exchange (ETDEWEB)

    Karacan, C.O.; Goodman, G.V.R. [NIOSH, Pittsburgh, PA (United States). Off Mine Safety & Health Research

    2011-01-15

    Gob gas ventholes (GGV) are used to control methane emissions in longwall mines by capturing it within the overlying fractured strata before it enters the work environment. In order for GGVs to effectively capture more methane and less mine air, the length of the slotted sections and their proximity to top of the coal bed should be designed based on the potential gas sources and their locations, as well as the displacements in the overburden that will create potential flow paths for the gas. In this paper, an approach to determine the conditional probabilities of depth-displacement, depth-flow percentage, depth-formation and depth-gas content of the formations was developed using bivariate normal distributions. The flow percentage, displacement and formation data as a function of distance from coal bed used in this study were obtained from a series of borehole experiments contracted by the former US Bureau of Mines as part of a research project. Each of these parameters was tested for normality and was modeled using bivariate normal distributions to determine all tail probabilities. In addition, the probability of coal bed gas content as a function of depth was determined using the same techniques. The tail probabilities at various depths were used to calculate conditional probabilities for each of the parameters. The conditional probabilities predicted for various values of the critical parameters can be used with the measurements of flow and methane percentage at gob gas ventholes to optimize their performance.

  14. Bivariate Random Effects Meta-analysis of Diagnostic Studies Using Generalized Linear Mixed Models

    Science.gov (United States)

    GUO, HONGFEI; ZHOU, YIJIE

    2011-01-01

    Bivariate random effect models are currently one of the main methods recommended to synthesize diagnostic test accuracy studies. However, only the logit-transformation on sensitivity and specificity has been previously considered in the literature. In this paper, we consider a bivariate generalized linear mixed model to jointly model the sensitivities and specificities, and discuss the estimation of the summary receiver operating characteristic curve (ROC) and the area under the ROC curve (AUC). As the special cases of this model, we discuss the commonly used logit, probit and complementary log-log transformations. To evaluate the impact of misspecification of the link functions on the estimation, we present two case studies and a set of simulation studies. Our study suggests that point estimation of the median sensitivity and specificity, and AUC is relatively robust to the misspecification of the link functions. However, the misspecification of link functions has a noticeable impact on the standard error estimation and the 95% confidence interval coverage, which emphasizes the importance of choosing an appropriate link function to make statistical inference. PMID:19959794

  15. A bivariate optimal replacement policy for a multistate repairable system

    International Nuclear Information System (INIS)

    Zhang Yuanlin; Yam, Richard C.M.; Zuo, Ming J.

    2007-01-01

    In this paper, a deteriorating simple repairable system with k+1 states, including k failure states and one working state, is studied. It is assumed that the system after repair is not 'as good as new' and the deterioration of the system is stochastic. We consider a bivariate replacement policy, denoted by (T,N), in which the system is replaced when its working age has reached T or the number of failures it has experienced has reached N, whichever occurs first. The objective is to determine the optimal replacement policy (T,N)* such that the long-run expected profit per unit time is maximized. The explicit expression of the long-run expected profit per unit time is derived and the corresponding optimal replacement policy can be determined analytically or numerically. We prove that the optimal policy (T,N)* is better than the optimal policy N* for a multistate simple repairable system. We also show that a general monotone process model for a multistate simple repairable system is equivalent to a geometric process model for a two-state simple repairable system in the sense that they have the same structure for the long-run expected profit (or cost) per unit time and the same optimal policy. Finally, a numerical example is given to illustrate the theoretical results

  16. Epileptic seizure prediction based on a bivariate spectral power methodology.

    Science.gov (United States)

    Bandarabadi, Mojtaba; Teixeira, Cesar A; Direito, Bruno; Dourado, Antonio

    2012-01-01

    The spectral power of 5 frequently considered frequency bands (Alpha, Beta, Gamma, Theta and Delta) for 6 EEG channels is computed and then all the possible pairwise combinations among the 30 features set, are used to create a 435 dimensional feature space. Two new feature selection methods are introduced to choose the best candidate features among those and to reduce the dimensionality of this feature space. The selected features are then fed to Support Vector Machines (SVMs) that classify the cerebral state in preictal and non-preictal classes. The outputs of the SVM are regularized using a method that accounts for the classification dynamics of the preictal class, also known as "Firing Power" method. The results obtained using our feature selection approaches are compared with the ones obtained using minimum Redundancy Maximum Relevance (mRMR) feature selection method. The results in a group of 12 patients of the EPILEPSIAE database, containing 46 seizures and 787 hours multichannel recording for out-of-sample data, indicate the efficiency of the bivariate approach as well as the two new feature selection methods. The best results presented sensitivity of 76.09% (35 of 46 seizures predicted) and a false prediction rate of 0.15(-1).

  17. Preparation and bivariate analysis of suspensions of human chromosomes

    Energy Technology Data Exchange (ETDEWEB)

    van den Engh, G.J.; Trask, B.J.; Gray, J.W.; Langlois, R.G.; Yu, L.C.

    1985-01-01

    Chromosomes were isolated from a variety of human cell types using a HEPES-buffered hypotonic solution (pH 8.0) containing KCl, MgSO/sub 4/ dithioerythritol, and RNase. The chromosomes isolated by this procedure could be stained with a variety of fluorescent stains including propidium iodide, chromomycin A3, and Hoeschst 33258. Addition of sodium citrate to the stained chromosomes was found to improve the total fluorescence resolution. High-quality bivariate Hoeschst vs. chromomycin fluorescence distributions were obtained for chromosomes isolated from a human fibroblast cell strain, a human colon carcinoma cell line, and human peripheral blood lymphocyte cultures. Good flow karyotypes were also obtained from primary amniotic cell cultures. The Hoeschst vs. chromomycin flow karyotypes of a given cell line, made at different times and at dye concentrations varying over fourfold ranges, show little variation in the relative peak positions of the chromosomes. The size of the DNA in chromosomes isolated using this procedure ranges from 20 to 50 kilobases. The described isolation procedure is simple, it yields high-quality flow karyotypes, and it can be used to prepare chromosomes from clinical samples. 22 references, 7 figures, 1 table.

  18. A composite likelihood method for bivariate meta-analysis in diagnostic systematic reviews.

    Science.gov (United States)

    Chen, Yong; Liu, Yulun; Ning, Jing; Nie, Lei; Zhu, Hongjian; Chu, Haitao

    2017-04-01

    Diagnostic systematic review is a vital step in the evaluation of diagnostic technologies. In many applications, it involves pooling pairs of sensitivity and specificity of a dichotomized diagnostic test from multiple studies. We propose a composite likelihood (CL) method for bivariate meta-analysis in diagnostic systematic reviews. This method provides an alternative way to make inference on diagnostic measures such as sensitivity, specificity, likelihood ratios, and diagnostic odds ratio. Its main advantages over the standard likelihood method are the avoidance of the nonconvergence problem, which is nontrivial when the number of studies is relatively small, the computational simplicity, and some robustness to model misspecifications. Simulation studies show that the CL method maintains high relative efficiency compared to that of the standard likelihood method. We illustrate our method in a diagnostic review of the performance of contemporary diagnostic imaging technologies for detecting metastases in patients with melanoma.

  19. An integrated user-friendly ArcMAP tool for bivariate statistical modelling in geoscience applications

    Science.gov (United States)

    Jebur, M. N.; Pradhan, B.; Shafri, H. Z. M.; Yusoff, Z. M.; Tehrany, M. S.

    2015-03-01

    Modelling and classification difficulties are fundamental issues in natural hazard assessment. A geographic information system (GIS) is a domain that requires users to use various tools to perform different types of spatial modelling. Bivariate statistical analysis (BSA) assists in hazard modelling. To perform this analysis, several calculations are required and the user has to transfer data from one format to another. Most researchers perform these calculations manually by using Microsoft Excel or other programs. This process is time-consuming and carries a degree of uncertainty. The lack of proper tools to implement BSA in a GIS environment prompted this study. In this paper, a user-friendly tool, bivariate statistical modeler (BSM), for BSA technique is proposed. Three popular BSA techniques, such as frequency ratio, weight-of-evidence (WoE), and evidential belief function (EBF) models, are applied in the newly proposed ArcMAP tool. This tool is programmed in Python and created by a simple graphical user interface (GUI), which facilitates the improvement of model performance. The proposed tool implements BSA automatically, thus allowing numerous variables to be examined. To validate the capability and accuracy of this program, a pilot test area in Malaysia is selected and all three models are tested by using the proposed program. Area under curve (AUC) is used to measure the success rate and prediction rate. Results demonstrate that the proposed program executes BSA with reasonable accuracy. The proposed BSA tool can be used in numerous applications, such as natural hazard, mineral potential, hydrological, and other engineering and environmental applications.

  20. Comparison of Model Reliabilities from Single-Step and Bivariate Blending Methods

    DEFF Research Database (Denmark)

    Taskinen, Matti; Mäntysaari, Esa; Lidauer, Martin

    2013-01-01

    the production trait evaluation of Nordic Red dairy cattle. Genotyped bulls with daughters are used as training animals, and genotyped bulls and producing cows as candidate animals. For simplicity, size of the data is chosen so that the full inverses of the mixed model equation coefficient matrices can......Model based reliabilities in genetic evaluation are compared between three methods: animal model BLUP, single-step BLUP, and bivariate blending after genomic BLUP. The original bivariate blending is revised in this work to better account animal models. The study data is extracted from...... be calculated. Model reliabilities by the single-step and the bivariate blending methods were higher than by animal model due to genomic information. Compared to the single-step method, the bivariate blending method reliability estimates were, in general, lower. Computationally bivariate blending method was...

  1. Comparing Johnson’s SBB, Weibull and Logit-Logistic bivariate distributions for modeling tree diameters and heights using copulas

    Directory of Open Access Journals (Sweden)

    Jose Javier Gorgoso-Varela

    2016-04-01

    Full Text Available Aim of study: In this study we compare the accuracy of three bivariate distributions: Johnson’s SBB, Weibull-2P and LL-2P functions for characterizing the joint distribution of tree diameters and heights.Area of study: North-West of Spain.Material and methods: Diameter and height measurements of 128 plots of pure and even-aged Tasmanian blue gum (Eucalyptus globulus Labill. stands located in the North-west of Spain were considered in the present study. The SBB bivariate distribution was obtained from SB marginal distributions using a Normal Copula based on a four-parameter logistic transformation. The Plackett Copula was used to obtain the bivariate models from the Weibull and Logit-logistic univariate marginal distributions. The negative logarithm of the maximum likelihood function was used to compare the results and the Wilcoxon signed-rank test was used to compare the related samples of these logarithms calculated for each sample plot and each distribution.Main results: The best results were obtained by using the Plackett copula and the best marginal distribution was the Logit-logistic.Research highlights: The copulas used in this study have shown a good performance for modeling the joint distribution of tree diameters and heights. They could be easily extended for modelling multivariate distributions involving other tree variables, such as tree volume or biomass.

  2. Comparing Johnson’s SBB, Weibull and Logit-Logistic bivariate distributions for modeling tree diameters and heights using copulas

    Energy Technology Data Exchange (ETDEWEB)

    Cardil Forradellas, A.; Molina Terrén, D.M.; Oliveres, J.; Castellnou, M.

    2016-07-01

    Aim of study: In this study we compare the accuracy of three bivariate distributions: Johnson’s SBB, Weibull-2P and LL-2P functions for characterizing the joint distribution of tree diameters and heights. Area of study: North-West of Spain. Material and methods: Diameter and height measurements of 128 plots of pure and even-aged Tasmanian blue gum (Eucalyptus globulus Labill.) stands located in the North-west of Spain were considered in the present study. The SBB bivariate distribution was obtained from SB marginal distributions using a Normal Copula based on a four-parameter logistic transformation. The Plackett Copula was used to obtain the bivariate models from the Weibull and Logit-logistic univariate marginal distributions. The negative logarithm of the maximum likelihood function was used to compare the results and the Wilcoxon signed-rank test was used to compare the related samples of these logarithms calculated for each sample plot and each distribution. Main results: The best results were obtained by using the Plackett copula and the best marginal distribution was the Logit-logistic. Research highlights: The copulas used in this study have shown a good performance for modeling the joint distribution of tree diameters and heights. They could be easily extended for modelling multivariate distributions involving other tree variables, such as tree volume or biomass. (Author)

  3. Bivariate return periods of temperature and precipitation explain a large fraction of European crop yields

    Directory of Open Access Journals (Sweden)

    J. Zscheischler

    2017-07-01

    Full Text Available Crops are vital for human society. Crop yields vary with climate and it is important to understand how climate and crop yields are linked to ensure future food security. Temperature and precipitation are among the key driving factors of crop yield variability. Previous studies have investigated mostly linear relationships between temperature and precipitation and crop yield variability. Other research has highlighted the adverse impacts of climate extremes, such as drought and heat waves, on crop yields. Impacts are, however, often non-linearly related to multivariate climate conditions. Here we derive bivariate return periods of climate conditions as indicators for climate variability along different temperature–precipitation gradients. We show that in Europe, linear models based on bivariate return periods of specific climate conditions explain on average significantly more crop yield variability (42 % than models relying directly on temperature and precipitation as predictors (36 %. Our results demonstrate that most often crop yields increase along a gradient from hot and dry to cold and wet conditions, with lower yields associated with hot and dry periods. The majority of crops are most sensitive to climate conditions in summer and to maximum temperatures. The use of bivariate return periods allows the integration of non-linear impacts into climate–crop yield analysis. This offers new avenues to study the link between climate and crop yield variability and suggests that they are possibly more strongly related than what is inferred from conventional linear models.

  4. Covariance Association Test (CVAT) Identifies Genetic Markers Associated with Schizophrenia in Functionally Associated Biological Processes

    DEFF Research Database (Denmark)

    Rohde, Palle Duun; Demontis, Ditte; Castro Dias Cuyabano, Beatriz

    2016-01-01

    power to detect genetic markers with small effects. Instead, aggregating genetic markers based on biological information might increase the power to identify sets of genetic markers of etiological significance. Several set test methods have been proposed: Here we propose a new set test derived from......Schizophrenia is a psychiatric disorder with large personal and social costs, and understanding the genetic etiology is important. Such knowledge can be obtained by testing the association between a disease phenotype and individual genetic markers; however, such single-marker methods have limited...

  5. Using the noninformative families in family-based association tests : A powerful new testing strategy

    NARCIS (Netherlands)

    Lange, C; DeMeo, D; Silverman, EK; Weiss, ST; Laird, NM

    2003-01-01

    For genetic association studies with multiple phenotypes, we propose a new strategy for multiple testing with family-based association tests (FBATs). The strategy increases the power by both using all available family data and reducing the number of hypotheses tested while being robust against

  6. Dissecting the correlation structure of a bivariate phenotype ...

    Indian Academy of Sciences (India)

    Unknown

    We use Monte-Carlo simulations to evaluate the performance of the proposed test under different trait parameters and quantitative trait distributions. An application of the method is illustrated using data on two alcohol-related phenotypes from a project on the collaborative study on the genetics of alcoholism. [Ghosh S 2005 ...

  7. Bivariate empirical mode decomposition for ECG-based biometric identification with emotional data.

    Science.gov (United States)

    Ferdinando, Hany; Seppanen, Tapio; Alasaarela, Esko

    2017-07-01

    Emotions modulate ECG signals such that they might affect ECG-based biometric identification in real life application. It motivated in finding good feature extraction methods where the emotional state of the subjects has minimum impacts. This paper evaluates feature extraction based on bivariate empirical mode decomposition (BEMD) for biometric identification when emotion is considered. Using the ECG signal from the Mahnob-HCI database for affect recognition, the features were statistical distributions of dominant frequency after applying BEMD analysis to ECG signals. The achieved accuracy was 99.5% with high consistency using kNN classifier in 10-fold cross validation to identify 26 subjects when the emotional states of the subjects were ignored. When the emotional states of the subject were considered, the proposed method also delivered high accuracy, around 99.4%. We concluded that the proposed method offers emotion-independent features for ECG-based biometric identification. The proposed method needs more evaluation related to testing with other classifier and variation in ECG signals, e.g. normal ECG vs. ECG with arrhythmias, ECG from various ages, and ECG from other affective databases.

  8. Semiparametric bivariate zero-inflated Poisson models with application to studies of abundance for multiple species

    Science.gov (United States)

    Arab, Ali; Holan, Scott H.; Wikle, Christopher K.; Wildhaber, Mark L.

    2012-01-01

    Ecological studies involving counts of abundance, presence–absence or occupancy rates often produce data having a substantial proportion of zeros. Furthermore, these types of processes are typically multivariate and only adequately described by complex nonlinear relationships involving externally measured covariates. Ignoring these aspects of the data and implementing standard approaches can lead to models that fail to provide adequate scientific understanding of the underlying ecological processes, possibly resulting in a loss of inferential power. One method of dealing with data having excess zeros is to consider the class of univariate zero-inflated generalized linear models. However, this class of models fails to address the multivariate and nonlinear aspects associated with the data usually encountered in practice. Therefore, we propose a semiparametric bivariate zero-inflated Poisson model that takes into account both of these data attributes. The general modeling framework is hierarchical Bayes and is suitable for a broad range of applications. We demonstrate the effectiveness of our model through a motivating example on modeling catch per unit area for multiple species using data from the Missouri River Benthic Fishes Study, implemented by the United States Geological Survey.

  9. A Basic Bivariate Structure of Personality Attributes Evident Across Nine Languages.

    Science.gov (United States)

    Saucier, Gerard; Thalmayer, Amber Gayle; Payne, Doris L; Carlson, Robert; Sanogo, Lamine; Ole-Kotikash, Leonard; Church, A Timothy; Katigbak, Marcia S; Somer, Oya; Szarota, Piotr; Szirmák, Zsofia; Zhou, Xinyue

    2014-02-01

    Here, two studies seek to characterize a parsimonious common-denominator personality structure with optimal cross-cultural replicability. Personality differences are observed in all human populations and cultures, but lexicons for personality attributes contain so many distinctions that parsimony is lacking. Models stipulating the most important attributes have been formulated by experts or by empirical studies drawing on experience in a very limited range of cultures. Factor analyses of personality lexicons of nine languages of diverse provenance (Chinese, Korean, Filipino, Turkish, Greek, Polish, Hungarian, Maasai, and Senoufo) were examined, and their common structure was compared to that of several prominent models in psychology. A parsimonious bivariate model showed evidence of substantial convergence and ubiquity across cultures. Analyses involving key markers of these dimensions in English indicate that they are broad dimensions involving the overlapping content of the interpersonal circumplex, models of communion and agency, and morality/warmth and competence. These "Big Two" dimensions-Social Self-Regulation and Dynamism-provide a common-denominator model involving the two most crucial axes of personality variation, ubiquitous across cultures. The Big Two might serve as an umbrella model serving to link diverse theoretical models and associated research literatures. © 2013 Wiley Periodicals, Inc.

  10. Estimating twin concordance for bivariate competing risks twin data

    DEFF Research Database (Denmark)

    Scheike, Thomas; Holst, Klaus K.; Hjelmborg, Jacob B.

    2014-01-01

    For twin time-to-event data, we consider different concordance probabilities, such as the casewise concordance that are routinely computed as a measure of the lifetime dependence/correlation for specific diseases. The concordance probability here is the probability that both twins have experienced...... over time, and covariates may be further influential on the marginal risk and dependence structure. We establish the estimators large sample properties and suggest various tests, for example, for inferring familial influence. The method is demonstrated and motivated by specific twin data on cancer...

  11. Assessing factors associated with HIV testing among adolescents in Malawi.

    Science.gov (United States)

    Mkandawire, Paul

    2017-07-01

    Despite being at high risk of HIV/AIDS, most young people do not know their HIV status. Using survey data (n = 2428) and applying multilevel models, this paper assesses factors associated with HIV testing among adolescents in Northern Malawi. The results show that among both boys (OR = 0.39) and girls (OR = 0.47), orphan status is associated with low likelihood of HIV testing. Correct knowledge about HIV/AIDS (OR = 2.55) and having secondary education (OR = 3.24) are associated with HIV testing among boys and girls, respectively. At the household level, living in a household whose head has secondary or higher education is positively associated with testing for boys (OR = 2.63), while residing together with biological siblings predicts higher odds of testing (OR = 2.67) for girls. Notably, orphaned girls' disadvantage regarding HIV testing loses significance when residential arrangement is controlled. At the community level, having HIV testing facility (OR = 2.70) or post-test club (OR = 1.40) is positively associated with HIV testing for boys, while girls from areas where religious leaders hold judgmental views about HIV/AIDS are less likely (OR = 0.45) to test. These findings suggest that efforts to scale up HIV testing among youth could benefit greatly from an understanding of how individual and community factors operate to influence adolescents to know their sero-status.

  12. Patch testing for food-associated allergies in orofacial granulomatosis.

    LENUS (Irish Health Repository)

    Fitzpatrick, Laura

    2011-01-01

    Food-associated allergies, especially to benzoates and cinnamon-related compounds, have been associated with orofacial granulomatosis and both standard and urticarial patch testing have been used to detect such allergies. Elimination diets have also been shown to be effective in some patients.

  13. HIV Testing Rates and Factors Associated With Recent HIV Testing Among Male Couples

    OpenAIRE

    Mitchell, Jason W.; Petroll, Andrew E.

    2012-01-01

    Little data exists on HIV testing rates among male couples. By using dyadic data from 142 male couples, we found that less than a quarter of the men had gotten tested for HIV in the previous three months. Few factors also were associated with their most recent HIV test.

  14. Diagnostic performance of des-γ-carboxy prothrombin (DCP) for hepatocellular carcinoma: a bivariate meta-analysis.

    Science.gov (United States)

    Gao, P; Li, M; Tian, Q B; Liu, Dian-Wu

    2012-01-01

    Serum markers are needed to be developed to specifically diagnose Hepatocellular carcinoma (HCC). Des-γ-carboxy prothrombin (DCP) is a promising tool with limited expense and widely accessibility, but the reported results have been controversial. In order to review the performance of DCP for the diagnosis of HCC, the meta-analysis was performed. After a systematic review of relevant studies, the sensitivity, specificity, positive and negative likelihood ratios (PLR and NLR, respectively) were pooled using a bivariate meta-analysis. Potential between-study heterogeneity was explored by meta-regression model. The post-test probability and the likelihood ratio scattergram to evaluate clinical usefulness were calculated. Based on literature review of 20 publications, the overall sensitivity, specificity, PLR and NLR of DCP for the detection of HCC were 67% (95%CI, 58%-74%), 92% (95%CI, 88%-94%), 7.9 (95%CI, 5.6-11.2) and 0.36 (95%CI, 0.29-0.46), respectively. The area under the bivariate summary receiving operating characteristics curve was 0.89 (95%CI, 0.85-0.92). Significant heterogeneity was present. In conclusion, the major role of DCP is the moderate confirmation of HCC. More prospective studies of DCP are needed in future.

  15. A note on finding peakedness in bivariate normal distribution using Mathematica

    Directory of Open Access Journals (Sweden)

    Anwer Khurshid

    2007-07-01

    Full Text Available Peakedness measures the concentration around the central value. A classical standard measure of peakedness is kurtosis which is the degree of peakedness of a probability distribution. In view of inconsistency of kurtosis in measuring of the peakedness of a distribution, Horn (1983 proposed a measure of peakedness for symmetrically unimodal distributions. The objective of this paper is two-fold. First, Horn’s method has been extended for bivariate normal distribution. Secondly, to show that computer algebra system Mathematica can be extremely useful tool for all sorts of computation related to bivariate normal distribution. Mathematica programs are also provided.

  16. Effect of catchment properties and flood generation regime on copula selection for bivariate flood frequency analysis

    Science.gov (United States)

    Filipova, Valeriya; Lawrence, Deborah; Klempe, Harald

    2018-02-01

    Applying copula-based bivariate flood frequency analysis is advantageous because the results provide information on both the flood peak and volume. More data are, however, required for such an analysis, and it is often the case that only data series with a limited record length are available. To overcome this issue of limited record length, data regarding climatic and geomorphological properties can be used to complement statistical methods. In this paper, we present a study of 27 catchments located throughout Norway, in which we assess whether catchment properties, flood generation processes and flood regime have an effect on the correlation between flood peak and volume and, in turn, on the selection of copulas. To achieve this, the annual maximum flood events were first classified into events generated primarily by rainfall, snowmelt or a combination of these. The catchments were then classified into flood regime, depending on the predominant flood generation process producing the annual maximum flood events. A contingency table and Fisher's exact test were used to determine the factors that affect the selection of copulas in the study area. The results show that the two-parameter copulas BB1 and BB7 are more commonly selected in catchments with high steepness, high mean annual runoff and rainfall flood regime. These findings suggest that in these types of catchments, the dependence structure between flood peak and volume is more complex and cannot be modeled effectively using a one-parameter copula. The results illustrate that by relating copula types to flood regime and catchment properties, additional information can be supplied for selecting copulas in catchments with limited data.

  17. Association tests and software for copy number variant data

    Directory of Open Access Journals (Sweden)

    Plagnol Vincent

    2009-01-01

    Full Text Available Abstract Recent studies have suggested that copy number variation (CNV significantly contributes to genetic predisposition to several common disorders. These findings, combined with the imperfect tagging of CNVs by single nucleotide polymorphisms (SNPs, have motivated the development of association studies directly targeting CNVs. Several assays, including comparative genomic hybridisation arrays, SNP genotyping arrays, or DNA quantification through real-time polymerase chain reaction analysis, allow direct assessment of CNV status in cohorts sufficiently large to provide adequate statistical power for association studies. When analysing data provided by these assays, association tests for CNV data are not fundamentally different from SNP-based association tests. The main difference arises when the quality of the CNV assay is not sufficient to convert unequivocally the raw measurement into discrete calls -- a common issue, given the technological limitations of current CNV assays. When this is the case, association tests are more appropriately based on the raw continuous measurement provided by the CNV assay, instead of potentially inaccurate discrete calls, thus motivating the development of new statistical methods. Here, the programs available for CNV association testing for case control or family data are reviewed, using either discrete calls or raw continuous data.

  18. Neurotic nucleus and test anxiety.

    Science.gov (United States)

    de Man, A F; Hall, V; Stout, D

    1991-11-01

    Undergraduate university students (N = 103) participated in a study of the relationship between test anxiety and the variables of trait anxiety, self-esteem, locus of control, mental ability, and gender. Results indicated bivariate associations between total test anxiety and the other measures except for mental ability. Further analyses revealed independent relationships between the "worry" component of test anxiety and the variables of trait anxiety, internality, chance, and mental ability. We also found independent associations between the "emotionality" aspect of test anxiety and the measures of trait anxiety and chance.

  19. Accuracy of body mass index in predicting pre-eclampsia: bivariate meta-analysis

    NARCIS (Netherlands)

    Cnossen, J. S.; Leeflang, M. M. G.; de Haan, E. E. M.; Mol, B. W. J.; van der Post, J. A. M.; Khan, K. S.; ter Riet, G.

    2007-01-01

    OBJECTIVE: The objective of this study was to determine the accuracy of body mass index (BMI) (pre-pregnancy or at booking) in predicting pre-eclampsia and to explore its potential for clinical application. DESIGN: Systematic review and bivariate meta-analysis. SETTING: Medline, Embase, Cochrane

  20. Analysis of Blood Transfusion Data Using Bivariate Zero-Inflated Poisson Model: A Bayesian Approach.

    Science.gov (United States)

    Mohammadi, Tayeb; Kheiri, Soleiman; Sedehi, Morteza

    2016-01-01

    Recognizing the factors affecting the number of blood donation and blood deferral has a major impact on blood transfusion. There is a positive correlation between the variables "number of blood donation" and "number of blood deferral": as the number of return for donation increases, so does the number of blood deferral. On the other hand, due to the fact that many donors never return to donate, there is an extra zero frequency for both of the above-mentioned variables. In this study, in order to apply the correlation and to explain the frequency of the excessive zero, the bivariate zero-inflated Poisson regression model was used for joint modeling of the number of blood donation and number of blood deferral. The data was analyzed using the Bayesian approach applying noninformative priors at the presence and absence of covariates. Estimating the parameters of the model, that is, correlation, zero-inflation parameter, and regression coefficients, was done through MCMC simulation. Eventually double-Poisson model, bivariate Poisson model, and bivariate zero-inflated Poisson model were fitted on the data and were compared using the deviance information criteria (DIC). The results showed that the bivariate zero-inflated Poisson regression model fitted the data better than the other models.

  1. First-order dominance: stronger characterization and a bivariate checking algorithm

    DEFF Research Database (Denmark)

    Range, Troels Martin; Østerdal, Lars Peter Raahave

    2018-01-01

    distributions. Utilizing that this problem can be formulated as a transportation problem with a special structure, we provide a stronger characterization of multivariate first-order dominance and develop a linear time complexity checking algorithm for the bivariate case. We illustrate the use of the checking...

  2. On the Construction of Bivariate Exponential Distributions with an Arbitrary Correlation Coefficient

    DEFF Research Database (Denmark)

    Bladt, Mogens; Nielsen, Bo Friis

    2010-01-01

    In this article we use the concept of multivariate phase-type distributions to define a class of bivariate exponential distributions. This class has the following three appealing properties. Firstly, we may construct a pair of exponentially distributed random variables with any feasible correlation...

  3. Semi-automated detection of aberrant chromosomes in bivariate flow karyotypes

    NARCIS (Netherlands)

    Boschman, G. A.; Manders, E. M.; Rens, W.; Slater, R.; Aten, J. A.

    1992-01-01

    A method is described that is designed to compare, in a standardized procedure, bivariate flow karyotypes of Hoechst 33258 (HO)/Chromomycin A3 (CA) stained human chromosomes from cells with aberrations with a reference flow karyotype of normal chromosomes. In addition to uniform normalization of

  4. Bivariate analysis of sensitivity and specificity produces informative summary measures in diagnostic reviews

    NARCIS (Netherlands)

    Reitsma, Johannes B.; Glas, Afina S.; Rutjes, Anne W. S.; Scholten, Rob J. P. M.; Bossuyt, Patrick M.; Zwinderman, Aeilko H.

    2005-01-01

    Background and Objectives: Studies of diagnostic accuracy most often report pairs of sensitivity and specificity. We demonstrate the advantage of using bivariate meta-regression models to analyze such data. Methods: We discuss the methodology of both the summary Receiver Operating Characteristic

  5. A simple approximation to the bivariate normal distribution with large correlation coefficient

    NARCIS (Netherlands)

    Albers, Willem/Wim; Kallenberg, W.C.M.

    1994-01-01

    The bivariate normal distribution function is approximated with emphasis on situations where the correlation coefficient is large. The high accuracy of the approximation is illustrated by numerical examples. Moreover, exact upper and lower bounds are presented as well as asymptotic results on the

  6. A comparison of bivariate and univariate QTL mapping in livestock populations

    Directory of Open Access Journals (Sweden)

    Sorensen Daniel

    2003-11-01

    Full Text Available Abstract This study presents a multivariate, variance component-based QTL mapping model implemented via restricted maximum likelihood (REML. The method was applied to investigate bivariate and univariate QTL mapping analyses, using simulated data. Specifically, we report results on the statistical power to detect a QTL and on the precision of parameter estimates using univariate and bivariate approaches. The model and methodology were also applied to study the effectiveness of partitioning the overall genetic correlation between two traits into a component due to many genes of small effect, and one due to the QTL. It is shown that when the QTL has a pleiotropic effect on two traits, a bivariate analysis leads to a higher statistical power of detecting the QTL and to a more precise estimate of the QTL's map position, in particular in the case when the QTL has a small effect on the trait. The increase in power is most marked in cases where the contributions of the QTL and of the polygenic components to the genetic correlation have opposite signs. The bivariate REML analysis can successfully partition the two components contributing to the genetic correlation between traits.

  7. Evaluation of Factors Affecting E-Bike Involved Crash and E-Bike License Plate Use in China Using a Bivariate Probit Model

    OpenAIRE

    Guo, Yanyong; Zhou, Jibiao; Wu, Yao; Chen, Jingxu

    2017-01-01

    The primary objective of this study is to evaluate factors affecting e-bike involved crash and license plate use in China. E-bike crashes data were collected from police database and completed through a telephone interview. Noncrash samples were collected by a questionnaire survey. A bivariate probit (BP) model was developed to simultaneously examine the significant factors associated with e-bike involved crash and e-bike license plate and to account for the correlations between them. Margina...

  8. Functional imaging of implicit marijuana associations during performance on an Implicit Association Test (IAT)

    NARCIS (Netherlands)

    Ames, S.L.; Grenard, J.L.; Stacy, A.W.; Xiao, L.; He, Q.; Wong, S.W; Xue, G.; Wiers, R.W.; Bechara, A.

    2013-01-01

    This research evaluated the neural correlates of implicit associative memory processes (habit-based processes) through the imaging (fMRI) of a marijuana Implicit Association Test. Drug-related associative memory effects have been shown to consistently predict level of drug use. To observe

  9. Meta-analysis of studies with bivariate binary outcomes: a marginal beta-binomial model approach.

    Science.gov (United States)

    Chen, Yong; Hong, Chuan; Ning, Yang; Su, Xiao

    2016-01-15

    When conducting a meta-analysis of studies with bivariate binary outcomes, challenges arise when the within-study correlation and between-study heterogeneity should be taken into account. In this paper, we propose a marginal beta-binomial model for the meta-analysis of studies with binary outcomes. This model is based on the composite likelihood approach and has several attractive features compared with the existing models such as bivariate generalized linear mixed model (Chu and Cole, 2006) and Sarmanov beta-binomial model (Chen et al., 2012). The advantages of the proposed marginal model include modeling the probabilities in the original scale, not requiring any transformation of probabilities or any link function, having closed-form expression of likelihood function, and no constraints on the correlation parameter. More importantly, because the marginal beta-binomial model is only based on the marginal distributions, it does not suffer from potential misspecification of the joint distribution of bivariate study-specific probabilities. Such misspecification is difficult to detect and can lead to biased inference using currents methods. We compare the performance of the marginal beta-binomial model with the bivariate generalized linear mixed model and the Sarmanov beta-binomial model by simulation studies. Interestingly, the results show that the marginal beta-binomial model performs better than the Sarmanov beta-binomial model, whether or not the true model is Sarmanov beta-binomial, and the marginal beta-binomial model is more robust than the bivariate generalized linear mixed model under model misspecifications. Two meta-analyses of diagnostic accuracy studies and a meta-analysis of case-control studies are conducted for illustration. Copyright © 2015 John Wiley & Sons, Ltd.

  10. Test-Retest Reliability and Predictive Validity of the Implicit Association Test in Children

    Science.gov (United States)

    Rae, James R.; Olson, Kristina R.

    2018-01-01

    The Implicit Association Test (IAT) is increasingly used in developmental research despite minimal evidence of whether children's IAT scores are reliable across time or predictive of behavior. When test-retest reliability and predictive validity have been assessed, the results have been mixed, and because these studies have differed on many…

  11. Prevalence of positive tuberculin skin test and associated factors ...

    African Journals Online (AJOL)

    Abstract: Background: Tuberculosis infection among medical students is thought to be higher than that among comparable groups. Objectives: To determine the prevalence of positive Tuberculin Skin Test (TST) and associated factors among medical students at Makerere University. Methods: A-cross-sectional study among ...

  12. Association test with the principal component analysis in case ...

    Indian Academy of Sciences (India)

    PCA) to test association between multiple markers and the disease-susceptibility gene in case–parents data set. The proposed statistic is based on a difference vec- tor calculated by comparing the genotypes of affected off- spring with the ...

  13. HIV testing is associated with increased knowledge and reductions ...

    African Journals Online (AJOL)

    HIV testing is associated with increased knowledge and reductions in sexual risk behaviours among men in Cape Town, South Africa. Lori AJ Scott-Sheldon, Michael P Carey, Kate B Carey, Demetria Cain, Leickness C Simbayi, Vuyelwa Mehlomakhulu, Seth C Kalichman ...

  14. On the matched pairs sign test using bivariate ranked set sampling ...

    African Journals Online (AJOL)

    Administrator

    2008-01-15

    Jan 15, 2008 ... control confounding in the design stage of a study, matching is a strategy that must include elements of both design and analysis”. (Hennekens and Buring 1987). For example, a two-year .... used the RSS sampling method to improve parametric and non- parametric statistical inference. For non-parametric ...

  15. A Hybrid ANN-GA Model to Prediction of Bivariate Binary Responses: Application to Joint Prediction of Occurrence of Heart Block and Death in Patients with Myocardial Infarction.

    Science.gov (United States)

    Mirian, Negin-Sadat; Sedehi, Morteza; Kheiri, Soleiman; Ahmadi, Ali

    2016-01-01

    In medical studies, when the joint prediction about occurrence of two events should be anticipated, a statistical bivariate model is used. Due to the limitations of usual statistical models, other methods such as Artificial Neural Network (ANN) and hybrid models could be used. In this paper, we propose a hybrid Artificial Neural Network-Genetic Algorithm (ANN-GA) model to prediction the occurrence of heart block and death in myocardial infarction (MI) patients simultaneously. For fitting and comparing the models, 263 new patients with definite diagnosis of MI hospitalized in Cardiology Ward of Hajar Hospital, Shahrekord, Iran, from March, 2014 to March, 2016 were enrolled. Occurrence of heart block and death were employed as bivariate binary outcomes. Bivariate Logistic Regression (BLR), ANN and hybrid ANN-GA models were fitted to data. Prediction accuracy was used to compare the models. The codes were written in Matlab 2013a and Zelig package in R3.2.2. The prediction accuracy of BLR, ANN and hybrid ANN-GA models was obtained 77.7%, 83.69% and 93.85% for the training and 78.48%, 84.81% and 96.2% for the test data, respectively. In both training and test data set, hybrid ANN-GA model had better accuracy. ANN model could be a suitable alternative for modeling and predicting bivariate binary responses when the presuppositions of statistical models are not met in actual data. In addition, using optimization methods, such as hybrid ANN-GA model, could improve precision of ANN model.

  16. A geometric framework for evaluating rare variant tests of association.

    Science.gov (United States)

    Liu, Keli; Fast, Shannon; Zawistowski, Matthew; Tintle, Nathan L

    2013-05-01

    The wave of next-generation sequencing data has arrived. However, many questions still remain about how to best analyze sequence data, particularly the contribution of rare genetic variants to human disease. Numerous statistical methods have been proposed to aggregate association signals across multiple rare variant sites in an effort to increase statistical power; however, the precise relation between the tests is often not well understood. We present a geometric representation for rare variant data in which rare allele counts in case and control samples are treated as vectors in Euclidean space. The geometric framework facilitates a rigorous classification of existing rare variant tests into two broad categories: tests for a difference in the lengths of the case and control vectors, and joint tests for a difference in either the lengths or angles of the two vectors. We demonstrate that genetic architecture of a trait, including the number and frequency of risk alleles, directly relates to the behavior of the length and joint tests. Hence, the geometric framework allows prediction of which tests will perform best under different disease models. Furthermore, the structure of the geometric framework immediately suggests additional classes and types of rare variant tests. We consider two general classes of tests which show robustness to noncausal and protective variants. The geometric framework introduces a novel and unique method to assess current rare variant methodology and provides guidelines for both applied and theoretical researchers. © 2013 Wiley Periodicals, Inc.

  17. Genetic determinant of trabecular bone score (TBS) and bone mineral density: A bivariate analysis.

    Science.gov (United States)

    Ho-Pham, Lan T; Hans, Didier; Doan, Minh C; Mai, Linh D; Nguyen, Tuan V

    2016-11-01

    This study sought to estimate the extent of genetic influence on the variation in trabecular bone score (TBS). We found that genetic factors accounted for ~45% of variance in TBS, and that the co-variation between TBS and bone density is partially determined by genetic factors. Trabecular bone score has emerged as an important predictor of fragility fracture, but factors underlying the individual differences in TBS have not been explored. In this study, we sought to determine the genetic contribution to the variation of TBS in the general population. The study included 556 women and 189 men from 265 families. The individuals aged 53years (SD 11). We measured lumbar spine bone mineral density (BMD; Hologic Horizon) and then derived the TBS from the same Hologic scan where BMD was derived. A biometric model was applied to the data to partition the variance of TBS into two components: one due to additive genetic factors, and one due to environmental factors. The index of heritability was estimated as the ratio of genetic variance to total variance of a trait. Bivariate genetic analysis was conducted to estimate the genetic correlation between TBS and BMD measurements. TBS was strongly correlated with lumbar spine BMD (r=0.73; P<0.001). On average TBS in men was higher than women, after adjusting age and height which are significantly associated with both TBS and lumbar spine BMD. The age and height adjusted index of heritability of TBS was 0.46 (95% CI, 0.39-0.54), which was not much different from that of LSBMD (0.44; 95% CI, 0.31-0.55). Moreover, the genetic correlation between TBS and LSBMD was 0.35 (95% CI, 0.21-0.46), between TBS and femoral neck BMD was 0.21 (95% CI, 0.10-0.33). Approximately 45% of the variance in TBS is under genetic influence, and this effect magnitude is similar to that of lumbar spine BMD. This finding provides a scientific justification for the search for specific genetic variants that may be associated with TBS and fracture risk

  18. Bivariate functional data clustering: grouping streams based on a varying coefficient model of the stream water and air temperature relationship

    Science.gov (United States)

    H. Li; X. Deng; Andy Dolloff; E. P. Smith

    2015-01-01

    A novel clustering method for bivariate functional data is proposed to group streams based on their water–air temperature relationship. A distance measure is developed for bivariate curves by using a time-varying coefficient model and a weighting scheme. This distance is also adjusted by spatial correlation of streams via the variogram. Therefore, the proposed...

  19. Exact association test for small size sequencing data.

    Science.gov (United States)

    Lee, Joowon; Lee, Seungyeoun; Jang, Jin-Young; Park, Taesung

    2018-04-20

    Recent statistical methods for next generation sequencing (NGS) data have been successfully applied to identifying rare genetic variants associated with certain diseases. However, most commonly used methods (e.g., burden tests and variance-component tests) rely on large sample sizes. Notwithstanding, due to its-still high cost, NGS data is generally restricted to small sample sizes, that cannot be analyzed by most existing methods. In this work, we propose a new exact association test for sequencing data that does not require a large sample approximation, which is applicable to both common and rare variants. Our method, based on the Generalized Cochran-Mantel-Haenszel (GCMH) statistic, was applied to NGS datasets from intraductal papillary mucinous neoplasm (IPMN) patients. IPMN is a unique pancreatic cancer subtype that can turn into an invasive and hard-to-treat metastatic disease. Application of our method to IPMN data successfully identified susceptible genes associated with progression of IPMN to pancreatic cancer. Our method is expected to identify disease-associated genetic variants more successfully, and corresponding signal pathways, improving our understanding of specific disease's etiology and prognosis.

  20. Bivariate Developmental Relations between Calculations and Word Problems: A Latent Change Approach.

    Science.gov (United States)

    Gilbert, Jennifer K; Fuchs, Lynn S

    2017-10-01

    The relation between 2 forms of mathematical cognition, calculations and word problems, was examined. Across grades 2-3, performance of 328 children (mean starting age 7.63 [ SD =0.43]) was assessed 3 times. Comparison of a priori latent change score models indicated a dual change model, with consistently positive but slowing growth, described development in each domain better than a constant or proportional change model. The bivariate model including change models for both calculations and word problems indicated prior calculation performance and change were not predictors of subsequent word-problem change, and prior word-problem performance and change were not predictors of subsequent calculation change. Results were comparable for boys versus girls. The bivariate model, along with correlations among intercepts and slopes, suggest calculation and word-problem development are related, but through an external set of overlapping factors. Exploratory supplemental analyses corroborate findings and provide direction for future study.

  1. Global assessment of predictability of water availability: A bivariate probabilistic Budyko analysis

    Science.gov (United States)

    Wang, Weiguang; Fu, Jianyu

    2018-02-01

    Estimating continental water availability is of great importance for water resources management, in terms of maintaining ecosystem integrity and sustaining society development. To more accurately quantify the predictability of water availability, on the basis of univariate probabilistic Budyko framework, a bivariate probabilistic Budyko approach was developed using copula-based joint distribution model for considering the dependence between parameter ω of Wang-Tang's equation and the Normalized Difference Vegetation Index (NDVI), and was applied globally. The results indicate the predictive performance in global water availability is conditional on the climatic condition. In comparison with simple univariate distribution, the bivariate one produces the lower interquartile range under the same global dataset, especially in the regions with higher NDVI values, highlighting the importance of developing the joint distribution by taking into account the dependence structure of parameter ω and NDVI, which can provide more accurate probabilistic evaluation of water availability.

  2. Can the bivariate Hurst exponent be higher than an average of the separate Hurst exponents?

    Czech Academy of Sciences Publication Activity Database

    Krištoufek, Ladislav

    2015-01-01

    Roč. 431, č. 1 (2015), s. 124-127 ISSN 0378-4371 R&D Projects: GA ČR(CZ) GP14-11402P Institutional support: RVO:67985556 Keywords : Correlations * Power- law cross-correlations * Bivariate Hurst exponent * Spectrum coherence Subject RIV: AH - Economics Impact factor: 1.785, year: 2015 http://library.utia.cas.cz/separaty/2015/E/kristoufek-0452314.pdf

  3. On minimum divergence adaptation of discrete bivariate distributions to given marginals

    Czech Academy of Sciences Publication Activity Database

    Vajda, Igor; van der Meulen, E. C.

    2005-01-01

    Roč. 51, č. 1 (2005), s. 313-320 ISSN 0018-9448 R&D Projects: GA ČR GA201/02/1391; GA MŠk 1M0572 Institutional research plan: CEZ:AV0Z10750506 Keywords : approximation of contingency tables * bivariate discrete distributions * minimization of divergences Subject RIV: BD - Theory of Information Impact factor: 2.183, year: 2005

  4. Improving the modelling of redshift-space distortions - I. A bivariate Gaussian description for the galaxy pairwise velocity distributions

    Science.gov (United States)

    Bianchi, Davide; Chiesa, Matteo; Guzzo, Luigi

    2015-01-01

    As a step towards a more accurate modelling of redshift-space distortions (RSD) in galaxy surveys, we develop a general description of the probability distribution function of galaxy pairwise velocities within the framework of the so-called streaming model. For a given galaxy separation r, such function can be described as a superposition of virtually infinite local distributions. We characterize these in terms of their moments and then consider the specific case in which they are Gaussian functions, each with its own mean μ and dispersion σ. Based on physical considerations, we make the further crucial assumption that these two parameters are in turn distributed according to a bivariate Gaussian, with its own mean and covariance matrix. Tests using numerical simulations explicitly show that with this compact description one can correctly model redshift-space distortions on all scales, fully capturing the overall linear and non-linear dynamics of the galaxy flow at different separations. In particular, we naturally obtain Gaussian/exponential, skewed/unskewed distribution functions, depending on separation as observed in simulations and data. Also, the recently proposed single-Gaussian description of RSD is included in this model as a limiting case, when the bivariate Gaussian is collapsed to a two-dimensional Dirac delta function. We also show how this description naturally allows for the Taylor expansion of 1 + ξS(s) around 1 + ξR(r), which leads to the Kaiser linear formula when truncated to second order, explicating its connection with the moments of the velocity distribution functions. More work is needed, but these results indicate a very promising path to make definitive progress in our programme to improve RSD estimators.

  5. Robust bivariate error detection in skewed data with application to historical radiosonde winds

    KAUST Repository

    Sun, Ying

    2017-01-18

    The global historical radiosonde archives date back to the 1920s and contain the only directly observed measurements of temperature, wind, and moisture in the upper atmosphere, but they contain many random errors. Most of the focus on cleaning these large datasets has been on temperatures, but winds are important inputs to climate models and in studies of wind climatology. The bivariate distribution of the wind vector does not have elliptical contours but is skewed and heavy-tailed, so we develop two methods for outlier detection based on the bivariate skew-t (BST) distribution, using either distance-based or contour-based approaches to flag observations as potential outliers. We develop a framework to robustly estimate the parameters of the BST and then show how the tuning parameter to get these estimates is chosen. In simulation, we compare our methods with one based on a bivariate normal distribution and a nonparametric approach based on the bagplot. We then apply all four methods to the winds observed for over 35,000 radiosonde launches at a single station and demonstrate differences in the number of observations flagged across eight pressure levels and through time. In this pilot study, the method based on the BST contours performs very well.

  6. Multiresolution transmission of the correlation modes between bivariate time series based on complex network theory

    Science.gov (United States)

    Huang, Xuan; An, Haizhong; Gao, Xiangyun; Hao, Xiaoqing; Liu, Pengpeng

    2015-06-01

    This study introduces an approach to study the multiscale transmission characteristics of the correlation modes between bivariate time series. The correlation between the bivariate time series fluctuates over time. The transmission among the correlation modes exhibits a multiscale phenomenon, which provides richer information. To investigate the multiscale transmission of the correlation modes, this paper describes a hybrid model integrating wavelet analysis and complex network theory to decompose and reconstruct the original bivariate time series into sequences in a joint time-frequency domain and defined the correlation modes at each time-frequency domain. We chose the crude oil spot and futures prices as the sample data. The empirical results indicate that the main duration of volatility (32-64 days) for the strongly positive correlation between the crude oil spot price and the futures price provides more useful information for investors. Moreover, the weighted degree, weighted indegree and weighted outdegree of the correlation modes follow power-law distributions. The correlation fluctuation strengthens the extent of persistence over the long term, whereas persistence weakens over the short and medium term. The primary correlation modes dominating the transmission process and the major intermediary modes in the transmission process are clustered both in the short and long term.

  7. Definition study of a Variable Cycle Experimental Engine (VCEE) and associated test program and test plan

    Science.gov (United States)

    Allan, R. D.

    1978-01-01

    The Definition Study of a Variable Cycle Experimental Engine (VCEE) and Associated Test Program and Test Plan, was initiated to identify the most cost effective program for a follow-on to the AST Test Bed Program. The VCEE Study defined various subscale VCE's based on different available core engine components, and a full scale VCEE utilizing current technology. The cycles were selected, preliminary design accomplished and program plans and engineering costs developed for several program options. In addition to the VCEE program plans and options, a limited effort was applied to identifying programs that could logically be accomplished on the AST Test Bed Program VCE to extend the usefulness of this test hardware. Component programs were provided that could be accomplished prior to the start of a VCEE program.

  8. Associations Between Cancer Predisposition Testing Panel Genes and Breast Cancer.

    Science.gov (United States)

    Couch, Fergus J; Shimelis, Hermela; Hu, Chunling; Hart, Steven N; Polley, Eric C; Na, Jie; Hallberg, Emily; Moore, Raymond; Thomas, Abigail; Lilyquist, Jenna; Feng, Bingjian; McFarland, Rachel; Pesaran, Tina; Huether, Robert; LaDuca, Holly; Chao, Elizabeth C; Goldgar, David E; Dolinsky, Jill S

    2017-09-01

    Germline pathogenic variants in BRCA1 and BRCA2 predispose to an increased lifetime risk of breast cancer. However, the relevance of germline variants in other genes from multigene hereditary cancer testing panels is not well defined. To determine the risks of breast cancer associated with germline variants in cancer predisposition genes. A study population of 65 057 patients with breast cancer receiving germline genetic testing of cancer predisposition genes with hereditary cancer multigene panels. Associations between pathogenic variants in non-BRCA1 and non-BRCA2 predisposition genes and breast cancer risk were estimated in a case-control analysis of patients with breast cancer and Exome Aggregation Consortium reference controls. The women underwent testing between March 15, 2012, and June 30, 2016. Breast cancer risk conferred by pathogenic variants in non-BRCA1 and non-BRCA2 predisposition genes. The mean (SD) age at diagnosis for the 65 057 women included in the analysis was 48.5 (11.1) years. The frequency of pathogenic variants in 21 panel genes identified in 41 611 consecutively tested white women with breast cancer was estimated at 10.2%. After exclusion of BRCA1, BRCA2, and syndromic breast cancer genes (CDH1, PTEN, and TP53), observed pathogenic variants in 5 of 16 genes were associated with high or moderately increased risks of breast cancer: ATM (OR, 2.78; 95% CI, 2.22-3.62), BARD1 (OR, 2.16; 95% CI, 1.31-3.63), CHEK2 (OR, 1.48; 95% CI, 1.31-1.67), PALB2 (OR, 7.46; 95% CI, 5.12-11.19), and RAD51D (OR, 3.07; 95% CI, 1.21-7.88). Conversely, variants in the BRIP1 and RAD51C ovarian cancer risk genes; the MRE11A, RAD50, and NBN MRN complex genes; the MLH1 and PMS2 mismatch repair genes; and NF1 were not associated with increased risks of breast cancer. This study establishes several panel genes as high- and moderate-risk breast cancer genes and provides estimates of breast cancer risk associated with pathogenic variants in these genes among

  9. Cryogenic testing and analysis associated with Tevatron lower temperature operation

    International Nuclear Information System (INIS)

    Theilacker, J.C.

    1996-01-01

    An upgrade of the Tevatron cryogenic system was installed and commissioned in 1993 to allow lower temperature operation. As a result, higher energy operation of the Fermilab superconducting Tevatron accelerator is possible. Following the installation and initial commissioning, it was decided to continue the current colliding beam physics run at the previous energy of 900 GeV. This has allowed the author to perform parasitic lower temperature tests in the Tevatron over the last year and a half. This paper presents the results of operational experiences and thermal and hydraulic testing which have taken place. The primary goal of the testing is to better understand the operation of the cold compressor system, associated instrumentation, and the performance of the existing magnet system during lower temperature operation. This will lead to a tentatively scheduled higher energy test run in the fall of 1995. The test results have shown that more elaborate controlling methods are necessary in order to achieve reliable system operation. Fortunately, the new satellite refrigerator controls system is capable of the expansion necessary to reach this goal. New features are being added to the controls systems which will allow for more intelligent control and better diagnostics for component monitoring and trending

  10. Cryogenic testing and analysis associated with Tevatron lower temperature operation

    International Nuclear Information System (INIS)

    Theilacker, J.C.

    1996-09-01

    An upgrade of the Tevatron cryogenic system was installed and commissioned in 1993 to allow lower temperature operation. As a result, higher energy operation is possible. Following the installation and initial commissioning, it was decided to continue the current colliding beam physics at the previous energy of 900 GeV. This has allowed us to perform parasitic lower temperature tests in the Tevatron over the last year and a half. This paper presents the results of operational experiences and thermal and hydraulic testing which has taken place. The primary goal of the testing is to better understand the operation of the cold compressor system, associated instrumentation, and the performance of the existing magnet system during lower temperature operation. This will lead to a tentatively scheduled higher energy test run in the fall of 1995. The test results have shown that more elaborate controlling methods are necessary in order to achieve reliable system operation. Fortunately, our new satellite refrigerator controls system is capable of the expansion necessary to reach our goal. New features are being added to the control system which will allow for more intelligent control and better diagnostics for component monitoring and trending

  11. An evolutionary framework for association testing in resequencing studies.

    Directory of Open Access Journals (Sweden)

    C Ryan King

    2010-11-01

    Full Text Available Sequencing technologies are becoming cheap enough to apply to large numbers of study participants and promise to provide new insights into human phenotypes by bringing to light rare and previously unknown genetic variants. We develop a new framework for the analysis of sequence data that incorporates all of the major features of previously proposed approaches, including those focused on allele counts and allele burden, but is both more general and more powerful. We harness population genetic theory to provide prior information on effect sizes and to create a pooling strategy for information from rare variants. Our method, EMMPAT (Evolutionary Mixed Model for Pooled Association Testing, generates a single test per gene (substantially reducing multiple testing concerns, facilitates graphical summaries, and improves the interpretation of results by allowing calculation of attributable variance. Simulations show that, relative to previously used approaches, our method increases the power to detect genes that affect phenotype when natural selection has kept alleles with large effect sizes rare. We demonstrate our approach on a population-based re-sequencing study of association between serum triglycerides and variation in ANGPTL4.

  12. Test-retest reliability and predictive validity of the Implicit Association Test in children.

    Science.gov (United States)

    Rae, James R; Olson, Kristina R

    2018-02-01

    The Implicit Association Test (IAT) is increasingly used in developmental research despite minimal evidence of whether children's IAT scores are reliable across time or predictive of behavior. When test-retest reliability and predictive validity have been assessed, the results have been mixed, and because these studies have differed on many factors simultaneously (lag-time between testing administrations, domain, etc.), it is difficult to discern what factors may explain variability in existing test-retest reliability and predictive validity estimates. Across five studies (total N = 519; ages 6- to 11-years-old), we manipulated two factors that have varied in previous developmental research-lag-time and domain. An internal meta-analysis of these studies revealed that, across three different methods of analyzing the data, mean test-retest (rs of .48, .38, and .34) and predictive validity (rs of .46, .20, and .10) effect sizes were significantly greater than zero. While lag-time did not moderate the magnitude of test-retest coefficients, whether we observed domain differences in test-retest reliability and predictive validity estimates was contingent on other factors, such as how we scored the IAT or whether we included estimates from a unique sample (i.e., a sample containing gender typical and gender diverse children). Recommendations are made for developmental researchers that utilize the IAT in their research. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  13. ABACUS: an entropy-based cumulative bivariate statistic robust to rare variants and different direction of genotype effect.

    Science.gov (United States)

    Di Camillo, Barbara; Sambo, Francesco; Toffolo, Gianna; Cobelli, Claudio

    2014-02-01

    In the past years, both sequencing and microarray have been widely used to search for relations between genetic variations and predisposition to complex pathologies such as diabetes or neurological disorders. These studies, however, have been able to explain only a small fraction of disease heritability, possibly because complex pathologies cannot be referred to few dysfunctional genes, but are rather heterogeneous and multicausal, as a result of a combination of rare and common variants possibly impairing multiple regulatory pathways. Rare variants, though, are difficult to detect, especially when the effects of causal variants are in different directions, i.e. with protective and detrimental effects. Here, we propose ABACUS, an Algorithm based on a BivAriate CUmulative Statistic to identify single nucleotide polymorphisms (SNPs) significantly associated with a disease within predefined sets of SNPs such as pathways or genomic regions. ABACUS is robust to the concurrent presence of SNPs with protective and detrimental effects and of common and rare variants; moreover, it is powerful even when few SNPs in the SNP-set are associated with the phenotype. We assessed ABACUS performance on simulated and real data and compared it with three state-of-the-art methods. When ABACUS was applied to type 1 and 2 diabetes data, besides observing a wide overlap with already known associations, we found a number of biologically sound pathways, which might shed light on diabetes mechanism and etiology. ABACUS is available at http://www.dei.unipd.it/∼dicamill/pagine/Software.html.

  14. Bivariate spline solution of time dependent nonlinear PDE for a population density over irregular domains.

    Science.gov (United States)

    Gutierrez, Juan B; Lai, Ming-Jun; Slavov, George

    2015-12-01

    We study a time dependent partial differential equation (PDE) which arises from classic models in ecology involving logistic growth with Allee effect by introducing a discrete weak solution. Existence, uniqueness and stability of the discrete weak solutions are discussed. We use bivariate splines to approximate the discrete weak solution of the nonlinear PDE. A computational algorithm is designed to solve this PDE. A convergence analysis of the algorithm is presented. We present some simulations of population development over some irregular domains. Finally, we discuss applications in epidemiology and other ecological problems. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. A COMPARISON OF SOME ROBUST BIVARIATE CONTROL CHARTS FOR INDIVIDUAL OBSERVATIONS

    Directory of Open Access Journals (Sweden)

    Moustafa Omar Ahmed Abu - Shawiesh

    2014-06-01

    Full Text Available This paper proposed and considered some bivariate control charts to monitor individual observations from a statistical process control. Usual control charts which use mean and variance-covariance estimators are sensitive to outliers. We consider the following robust alternatives to the classical Hoteling's T2: T2MedMAD, T2MCD, T2MVE a simulation study has been conducted to compare the performance of these control charts. Two real life data are analyzed to illustrate the application of these robust alternatives.

  16. An efficient algorithm for generating random number pairs drawn from a bivariate normal distribution

    Science.gov (United States)

    Campbell, C. W.

    1983-01-01

    An efficient algorithm for generating random number pairs from a bivariate normal distribution was developed. Any desired value of the two means, two standard deviations, and correlation coefficient can be selected. Theoretically the technique is exact and in practice its accuracy is limited only by the quality of the uniform distribution random number generator, inaccuracies in computer function evaluation, and arithmetic. A FORTRAN routine was written to check the algorithm and good accuracy was obtained. Some small errors in the correlation coefficient were observed to vary in a surprisingly regular manner. A simple model was developed which explained the qualities aspects of the errors.

  17. Bivariate Drought Analysis Using Streamflow Reconstruction with Tree Ring Indices in the Sacramento Basin, California, USA

    Directory of Open Access Journals (Sweden)

    Jaewon Kwak

    2016-03-01

    Full Text Available Long-term streamflow data are vital for analysis of hydrological droughts. Using an artificial neural network (ANN model and nine tree-ring indices, this study reconstructed the annual streamflow of the Sacramento River for the period from 1560 to 1871. Using the reconstructed streamflow data, the copula method was used for bivariate drought analysis, deriving a hydrological drought return period plot for the Sacramento River basin. Results showed strong correlation among drought characteristics, and the drought with a 20-year return period (17.2 million acre-feet (MAF per year in the Sacramento River basin could be considered a critical level of drought for water shortages.

  18. Bivariate tensor product [Formula: see text]-analogue of Kantorovich-type Bernstein-Stancu-Schurer operators.

    Science.gov (United States)

    Cai, Qing-Bo; Xu, Xiao-Wei; Zhou, Guorong

    2017-01-01

    In this paper, we construct a bivariate tensor product generalization of Kantorovich-type Bernstein-Stancu-Schurer operators based on the concept of [Formula: see text]-integers. We obtain moments and central moments of these operators, give the rate of convergence by using the complete modulus of continuity for the bivariate case and estimate a convergence theorem for the Lipschitz continuous functions. We also give some graphs and numerical examples to illustrate the convergence properties of these operators to certain functions.

  19. Construct validity of the Big Five Implicit Association Test

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    Gaja Zager Kocjan

    2014-02-01

    Full Text Available Psychology has recently seen a noticeable increase in interest for implicit measures of attitudes and personality characteristics. The far most known implicit measure is the Implicit Association Test – IAT. We adapted this test in order to assess the Big Five personality dimensions (B5 IAT. We examined B5 IAT measurement characteristics on two samples. Based on the findings of the first sample (N = 62, improvements were made in the B5 IAT, to be tested again on another sample (N = 75. The two studies have shown similar results. The reliabilities of the personality dimensions measured with the B5 IAT failed to achieve a satisfactory level in most cases. The reason probably lies in a lower adequacy of certain stimuli and in the considerable length of the test procedure. The convergent validity of the B5 IAT with explicit measures of personality was low, which may be due to different structures underlying implicit and explicit measures. Results obtained on the first sample have shown that the correlations between IAT adjectives are adequately explained by five latent dimensions. However, these results should be interpreted with caution due to B5 IAT low reliabilities and small sample sizes. The second sample proved to be very unstable, thus the confirmatory factor analysis could not be conducted. Since this is the first attempt to adapt B5 IAT to Slovene language, it is hardly surprising that the results are not entirely consistent with the expectations. As implicit measures currently fail to meet relevant psychometric characteristics, they are not yet applicable in psychological practice. Nevertheless, they have great potential in exploring personality and individual differences, as they overcome many limitations of existing explicit measures.

  20. A bivariate measurement error model for semicontinuous and continuous variables: Application to nutritional epidemiology.

    Science.gov (United States)

    Kipnis, Victor; Freedman, Laurence S; Carroll, Raymond J; Midthune, Douglas

    2016-03-01

    Semicontinuous data in the form of a mixture of a large portion of zero values and continuously distributed positive values frequently arise in many areas of biostatistics. This article is motivated by the analysis of relationships between disease outcomes and intakes of episodically consumed dietary components. An important aspect of studies in nutritional epidemiology is that true diet is unobservable and commonly evaluated by food frequency questionnaires with substantial measurement error. Following the regression calibration approach for measurement error correction, unknown individual intakes in the risk model are replaced by their conditional expectations given mismeasured intakes and other model covariates. Those regression calibration predictors are estimated using short-term unbiased reference measurements in a calibration substudy. Since dietary intakes are often "energy-adjusted," e.g., by using ratios of the intake of interest to total energy intake, the correct estimation of the regression calibration predictor for each energy-adjusted episodically consumed dietary component requires modeling short-term reference measurements of the component (a semicontinuous variable), and energy (a continuous variable) simultaneously in a bivariate model. In this article, we develop such a bivariate model, together with its application to regression calibration. We illustrate the new methodology using data from the NIH-AARP Diet and Health Study (Schatzkin et al., 2001, American Journal of Epidemiology 154, 1119-1125), and also evaluate its performance in a simulation study. © 2015, The International Biometric Society.

  1. A non-stationary cost-benefit based bivariate extreme flood estimation approach

    Science.gov (United States)

    Qi, Wei; Liu, Junguo

    2018-02-01

    Cost-benefit analysis and flood frequency analysis have been integrated into a comprehensive framework to estimate cost effective design values. However, previous cost-benefit based extreme flood estimation is based on stationary assumptions and analyze dependent flood variables separately. A Non-Stationary Cost-Benefit based bivariate design flood estimation (NSCOBE) approach is developed in this study to investigate influence of non-stationarities in both the dependence of flood variables and the marginal distributions on extreme flood estimation. The dependence is modeled utilizing copula functions. Previous design flood selection criteria are not suitable for NSCOBE since they ignore time changing dependence of flood variables. Therefore, a risk calculation approach is proposed based on non-stationarities in both marginal probability distributions and copula functions. A case study with 54-year observed data is utilized to illustrate the application of NSCOBE. Results show NSCOBE can effectively integrate non-stationarities in both copula functions and marginal distributions into cost-benefit based design flood estimation. It is also found that there is a trade-off between maximum probability of exceedance calculated from copula functions and marginal distributions. This study for the first time provides a new approach towards a better understanding of influence of non-stationarities in both copula functions and marginal distributions on extreme flood estimation, and could be beneficial to cost-benefit based non-stationary bivariate design flood estimation across the world.

  2. Semiparametric probit models with univariate and bivariate current-status data.

    Science.gov (United States)

    Liu, Hao; Qin, Jing

    2018-03-01

    Multivariate current-status data are frequently encountered in biomedical and public health studies. Semiparametric regression models have been extensively studied for univariate current-status data, but most existing estimation procedures are computationally intensive, involving either penalization or smoothing techniques. It becomes more challenging for the analysis of multivariate current-status data. In this article, we study the maximum likelihood estimations for univariate and bivariate current-status data under the semiparametric probit regression models. We present a simple computational procedure combining the expectation-maximization algorithm with the pool-adjacent-violators algorithm for solving the monotone constraint on the baseline function. Asymptotic properties of the maximum likelihood estimators are investigated, including the calculation of the explicit information bound for univariate current-status data, as well as the asymptotic consistency and convergence rate for bivariate current-status data. Extensive simulation studies showed that the proposed computational procedures performed well under small or moderate sample sizes. We demonstrate the estimation procedure with two real data examples in the areas of diabetic and HIV research. © 2017, The International Biometric Society.

  3. Inheritance of dermatoglyphic traits in twins: univariate and bivariate variance decomposition analysis.

    Science.gov (United States)

    Karmakar, Bibha; Malkin, Ida; Kobyliansky, Eugene

    2012-01-01

    Dermatoglyphic traits in a sample of twins were analyzed to estimate the resemblance between MZ and DZ twins and to evaluate the mode of inheritance by using the maximum likelihood-based Variance decomposition analysis. The additive genetic variance component was significant in both sexes for four traits--PII, AB_RC, RC_HB, and ATD_L. AB RC and RC_HB had significant sex differences in means, whereas PII and ATD_L did not. The results of the Bivariate Variance decomposition analysis revealed that PII and RC_HB have a significant correlation in both genetic and residual components. Significant correlation in the additive genetic variance between AB_RC and ATD_L was observed. The same analysis only for the females sub-sample in the three traits RBL, RBR and AB_DIS shows that the additive genetic RBR component was significant and the AB_DIS sibling component was not significant while others cannot be constrained to zero. The additive variance for AB DIS sibling component was not significant. The three components additive, sibling and residual were significantly correlated between each pair of traits revealed by the Bivariate Variance decomposition analysis.

  4. Xp21 contiguous gene syndromes: Deletion quantitation with bivariate flow karyotyping allows mapping of patient breakpoints

    Energy Technology Data Exchange (ETDEWEB)

    McCabe, E.R.B.; Towbin, J.A. (Baylor College of Medicine, Houston, TX (United States)); Engh, G. van den; Trask, B.J. (Lawrence Livermore National Lab., CA (United States))

    1992-12-01

    Bivariate flow karyotyping was used to estimate the deletion sizes for a series of patients with Xp21 contiguous gene syndromes. The deletion estimates were used to develop an approximate scale for the genomic map in Xp21. The bivariate flow karyotype results were compared with clinical and molecular genetic information on the extent of the patients' deletions, and these various types of data were consistent. The resulting map spans >15 Mb, from the telomeric interval between DXS41 (99-6) and DXS68 (1-4) to a position centromeric to the ornithine transcarbamylase locus. The deletion sizing was considered to be accurate to [plus minus]1 Mb. The map provides information on the relative localization of genes and markers within this region. For example, the map suggests that the adrenal hypoplasia congenita and glycerol kinase genes are physically close to each other, are within 1-2 Mb of the telomeric end of the Duchenne muscular dystrophy (DMD) gene, and are nearer to the DMD locus than to the more distal marker DXS28 (C7). Information of this type is useful in developing genomic strategies for positional cloning in Xp21. These investigations demonstrate that the DNA from patients with Xp21 contiguous gene syndromes can be valuable reagents, not only for ordering loci and markers but also for providing an approximate scale to the map of the Xp21 region surrounding DMD. 44 refs., 3 figs.

  5. Bivariate pointing movements on large touch screens: investigating the validity of a refined Fitts' Law.

    Science.gov (United States)

    Bützler, Jennifer; Vetter, Sebastian; Jochems, Nicole; Schlick, Christopher M

    2012-01-01

    On the basis of three empirical studies Fitts' Law was refined for bivariate pointing tasks on large touch screens. In the first study different target width parameters were investigated. The second study considered the effect of the motion angle. Based on the results of the two studies a refined model for movement time in human-computer interaction was formulated. A third study, which is described here in detail, concerns the validation of the refined model. For the validation study 20 subjects had to execute a bivariate pointing task on a large touch screen. In the experimental task 250 rectangular target objects were displayed at a randomly chosen position on the screen covering a broad range of ID values (ID= [1.01; 4.88]). Compared to existing refinements of Fitts' Law, the new model shows highest predictive validity. A promising field of application of the model is the ergonomic design and evaluation of project management software. By using the refined model, software designers can calculate a priori the appropriate angular position and the size of buttons, menus or icons.

  6. A method of moments to estimate bivariate survival functions: the copula approach

    Directory of Open Access Journals (Sweden)

    Silvia Angela Osmetti

    2013-05-01

    Full Text Available In this paper we discuss the problem on parametric and non parametric estimation of the distributions generated by the Marshall-Olkin copula. This copula comes from the Marshall-Olkin bivariate exponential distribution used in reliability analysis. We generalize this model by the copula and different marginal distributions to construct several bivariate survival functions. The cumulative distribution functions are not absolutely continuous and they unknown parameters are often not be obtained in explicit form. In order to estimate the parameters we propose an easy procedure based on the moments. This method consist in two steps: in the first step we estimate only the parameters of marginal distributions and in the second step we estimate only the copula parameter. This procedure can be used to estimate the parameters of complex survival functions in which it is difficult to find an explicit expression of the mixed moments. Moreover it is preferred to the maximum likelihood one for its simplex mathematic form; in particular for distributions whose maximum likelihood parameters estimators can not be obtained in explicit form.

  7. [Using the Implicit Association Test (IAT) to measure implicit shyness].

    Science.gov (United States)

    Aikawa, Atsushi; Fujii, Tsutomu

    2011-04-01

    Previous research has shown that implicitly measured shyness predicted spontaneous shy behavior in social situations, while explicit self-ratings of shyness predicted controlled shy behavior (Asendorpf, Banse, & Mücke, 2002). The present study examined whether these same results would be replicated in Japan. In Study 1, college students (N=47) completed a shyness Implicit Association Test (IAT for shyness) and explicit self-ratings of shyness. In Study 2, friends (N=69) of the Study 1 participants rated those participants on various personality scales. Covariance structure analysis, revealed that only implicit self-concept measured by the shyness IAT predicted other-rated high interpersonal tension (spontaneous shy behavior). Also, only explicit self-concept predicted other-rated low praise seeking (controlled shy behavior). The results of this study are similar to the findings of the previous research.

  8. The association between conduct problems and maltreatment: testing genetic and environmental mediation.

    Science.gov (United States)

    Schulz-Heik, R Jay; Rhee, Soo Hyun; Silvern, Louise E; Haberstick, Brett C; Hopfer, Christian; Lessem, Jeffrey M; Hewitt, John K

    2010-05-01

    It is often assumed that childhood maltreatment causes conduct problems via an environmentally mediated process. However, the association may be due alternatively to either a nonpassive gene-environment correlation, in which parents react to children's genetically-influenced conduct problems by maltreating them, or a passive gene-environment correlation, in which parents' tendency to engage in maltreatment and children's conduct problems are both influenced by a hereditary vulnerability to antisocial behavior (i.e. genetic mediation). The present study estimated the contribution of these processes to the association between maltreatment and conduct problems. Bivariate behavior genetic analyses were conducted on approximately 1,650 twin and sibling pairs drawn from a large longitudinal study of adolescent health (Add Health). The correlation between maltreatment and conduct problems was small; much of the association between maltreatment and conduct problems was due to a nonpassive gene-environment correlation. Results were more consistent with the hypothesis that parents respond to children's genetically-influenced conduct problems by maltreating them than the hypothesis that maltreatment causes conduct problems.

  9. Applying the Implicit Association Test to Measure Intolerance of Uncertainty.

    Science.gov (United States)

    Mosca, Oriana; Dentale, Francesco; Lauriola, Marco; Leone, Luigi

    2016-08-01

    Intolerance of Uncertainty (IU) is a key trans-diagnostic personality construct strongly associated with anxiety symptoms. Traditionally, IU is measured through self-report measures that are prone to bias effects due to impression management concerns and introspective difficulties. Moreover, self-report scales are not able to intercept the automatic associations that are assumed to be main determinants of several spontaneous responses (e.g., emotional reactions). In order to overcome these limitations, the Implicit Association Test (IAT) was applied to measure IU, with a particular focus on reliability and criterion validity issues. The IU-IAT and the Intolerance of Uncertainty Inventory (IUI) were administered to an undergraduate student sample (54 females and 10 males) with a mean age of 23 years (SD = 1.7). Successively, participants were asked to provide an individually chosen uncertain event from their own lives that may occur in the future and were requested to identify a number of potential negative consequences of it. Participants' responses in terms of cognitive thoughts (i.e., cognitive appraisal) and worry reactions toward these events were assessed using the two subscales of the Worry and Intolerance of Uncertainty Beliefs Questionnaire. The IU-IAT showed an adequate level of internal consistency and a not significant correlation with the IUI. A path analysis model, accounting for 35% of event-related worry, revealed that IUI had a significant indirect effect on the dependent variable through event-related IU thoughts. By contrast, as expected, IU-IAT predicted event-related worry independently from IU thoughts. In accordance with dual models of social cognition, these findings suggest that IU can influence event-related worry through two different processing pathways (automatic vs. deliberative), supporting the criterion and construct validity of the IU-IAT. The potential role of the IU-IAT for clinical applications was discussed. © The Author

  10. Implicit associations in cybersex addiction: Adaption of an Implicit Association Test with pornographic pictures.

    Science.gov (United States)

    Snagowski, Jan; Wegmann, Elisa; Pekal, Jaro; Laier, Christian; Brand, Matthias

    2015-10-01

    Recent studies show similarities between cybersex addiction and substance dependencies and argue to classify cybersex addiction as a behavioral addiction. In substance dependency, implicit associations are known to play a crucial role, and such implicit associations have not been studied in cybersex addiction, so far. In this experimental study, 128 heterosexual male participants completed an Implicit Association Test (IAT; Greenwald, McGhee, & Schwartz, 1998) modified with pornographic pictures. Further, problematic sexual behavior, sensitivity towards sexual excitation, tendencies towards cybersex addiction, and subjective craving due to watching pornographic pictures were assessed. Results show positive relationships between implicit associations of pornographic pictures with positive emotions and tendencies towards cybersex addiction, problematic sexual behavior, sensitivity towards sexual excitation as well as subjective craving. Moreover, a moderated regression analysis revealed that individuals who reported high subjective craving and showed positive implicit associations of pornographic pictures with positive emotions, particularly tended towards cybersex addiction. The findings suggest a potential role of positive implicit associations with pornographic pictures in the development and maintenance of cybersex addiction. Moreover, the results of the current study are comparable to findings from substance dependency research and emphasize analogies between cybersex addiction and substance dependencies or other behavioral addictions. Copyright © 2015. Published by Elsevier Ltd.

  11. Obtaining DDF Curves of Extreme Rainfall Data Using Bivariate Copula and Frequency Analysis

    DEFF Research Database (Denmark)

    Sadri, Sara; Madsen, Henrik; Mikkelsen, Peter Steen

    2009-01-01

    , situated near Copenhagen in Denmark. For rainfall extracted using method 2, the marginal distribution of depth was found to fit the Generalized Pareto distribution while duration was found to fit the Gamma distribution, using the method of L-moments. The volume was fit with a generalized Pareto...... with duration for a given return period and name them DDF (depth-duration-frequency) curves. The copula approach does not assume the rainfall variables are independent or jointly normally distributed. Rainfall series are extracted in three ways: (1) by maximum mean intensity; (2) by depth and duration...... distribution and the duration was fit with a Pearson type III distribution for rainfall extracted using method 3. The Clayton copula was found to be appropriate for bivariate analysis of rainfall depth and duration for both methods 2 and 3. DDF curves derived using the Clayton copula for depth and duration...

  12. A Bivariate Chebyshev Spectral Collocation Quasilinearization Method for Nonlinear Evolution Parabolic Equations

    Directory of Open Access Journals (Sweden)

    S. S. Motsa

    2014-01-01

    Full Text Available This paper presents a new method for solving higher order nonlinear evolution partial differential equations (NPDEs. The method combines quasilinearisation, the Chebyshev spectral collocation method, and bivariate Lagrange interpolation. In this paper, we use the method to solve several nonlinear evolution equations, such as the modified KdV-Burgers equation, highly nonlinear modified KdV equation, Fisher's equation, Burgers-Fisher equation, Burgers-Huxley equation, and the Fitzhugh-Nagumo equation. The results are compared with known exact analytical solutions from literature to confirm accuracy, convergence, and effectiveness of the method. There is congruence between the numerical results and the exact solutions to a high order of accuracy. Tables were generated to present the order of accuracy of the method; convergence graphs to verify convergence of the method and error graphs are presented to show the excellent agreement between the results from this study and the known results from literature.

  13. Associations of an abnormal Pap test result with attitudes and beliefs relevant to cervical cancer: a study of rural Appalachian women.

    Science.gov (United States)

    Crosby, Richard A; Vanderpool, Robin; Jones, Cissi

    2016-07-01

    To compare women who recall being informed of an abnormal Pap to those not having this experience relative to attitudes and beliefs pertaining to screening for cervical cancer. Four hundred women were recruited from eight rural Appalachian counties, in 2013 and 2014. Women completed a paper-and-pencil survey after providing written informed consent. Bivariate associations and age-adjusted associations were calculated between the self-reported experience of being told of an abnormal Pap test result and eight attitudes/beliefs relative to the prevention of cervical cancer. Data analyses were performed in 2014. The mean age was 40.2 years (range 30-64 years). Eighteen women chose not to answer the question asking about ever having an abnormal Pap test result, leaving n = 382. Of the 382 women who did answer, 122 (30.6 %) indicated having an abnormal Pap test result and the remaining 260 (65.2 %) indicated never having this experience. With the exception of one item assessing knowledge that HPV is the cause of cervical cancer, between-group differences in attitudes, beliefs, and intent to have a Pap test the next time one is due were not observed. Although we hypothesized that women ever having an abnormal Pap test may have actively sought to learn more about cervical cancer and its prevention, findings suggest that this is not the case. Informing women of an abnormal result could be coupled with a high-intensity counseling designed to improve attitudes and beliefs relative to women's role in protecting themselves from cervical cancer.

  14. Association of speculum lubrication with pain and Papanicolaou test accuracy.

    Science.gov (United States)

    Uygur, Dilek; Guler, Tolga; Yayci, Eyup; Atacag, Tijen; Comunoglu, Cem; Kuzey, Gamze Mocan

    2012-01-01

    To determine the effects of lubrication of the vaginal speculum before insertion during a Papanicolaou test on perceived pain and quality of the cytology specimen. Four hundred eligible women participating in cervical cancer screening and an early detection program were randomized with respect to lubricant gel use before speculum insertion. Perceived pain during speculum insertion and cytology results were assessed in study groups. The mean age of the patients was 45.7 years (range, 23-77 years). Pain score of the NO GEL group was significantly higher than that of the GEL group (2.3 and 1.6, respectively; P lubricant gel use significantly reduced the pain scores of the participants (P lubrication of the vaginal speculum with a small amount of K-Y Jelly (a water-soluble lubricant gel) decreases the pain associated with insertion of the vaginal speculum among postmenopausal women without obscuring the cytological interpretation of conventional or liquid-based cytology. In women of reproductive age, lubrication of the speculum with K-Y Jelly does not cause a meaningful effect with respect to perceived pain.

  15. Historical and future drought in Bangladesh using copula-based bivariate regional frequency analysis

    Science.gov (United States)

    Mortuza, Md Rubayet; Moges, Edom; Demissie, Yonas; Li, Hong-Yi

    2018-02-01

    The study aims at regional and probabilistic evaluation of bivariate drought characteristics to assess both the past and future drought duration and severity in Bangladesh. The procedures involve applying (1) standardized precipitation index to identify drought duration and severity, (2) regional frequency analysis to determine the appropriate marginal distributions for both duration and severity, (3) copula model to estimate the joint probability distribution of drought duration and severity, and (4) precipitation projections from multiple climate models to assess future drought trends. Since drought duration and severity in Bangladesh are often strongly correlated and do not follow same marginal distributions, the joint and conditional return periods of droughts are characterized using the copula-based joint distribution. The country is divided into three homogeneous regions using Fuzzy clustering and multivariate discordancy and homogeneity measures. For given severity and duration values, the joint return periods for a drought to exceed both values are on average 45% larger, while to exceed either value are 40% less than the return periods from the univariate frequency analysis, which treats drought duration and severity independently. These suggest that compared to the bivariate drought frequency analysis, the standard univariate frequency analysis under/overestimate the frequency and severity of droughts depending on how their duration and severity are related. Overall, more frequent and severe droughts are observed in the west side of the country. Future drought trend based on four climate models and two scenarios showed the possibility of less frequent drought in the future (2020-2100) than in the past (1961-2010).

  16. Quasi-bivariate variational mode decomposition as a tool of scale analysis in wall-bounded turbulence

    Science.gov (United States)

    Wang, Wenkang; Pan, Chong; Wang, Jinjun

    2018-01-01

    The identification and separation of multi-scale coherent structures is a critical task for the study of scale interaction in wall-bounded turbulence. Here, we propose a quasi-bivariate variational mode decomposition (QB-VMD) method to extract structures with various scales from instantaneous two-dimensional (2D) velocity field which has only one primary dimension. This method is developed from the one-dimensional VMD algorithm proposed by Dragomiretskiy and Zosso (IEEE Trans Signal Process 62:531-544, 2014) to cope with a quasi-2D scenario. It poses the feature of length-scale bandwidth constraint along the decomposed dimension, together with the central frequency re-balancing along the non-decomposed dimension. The feasibility of this method is tested on both a synthetic flow field and a turbulent boundary layer at moderate Reynolds number (Re_{τ } = 3458) measured by 2D particle image velocimetry (PIV). Some other popular scale separation tools, including pseudo-bi-dimensional empirical mode decomposition (PB-EMD), bi-dimensional EMD (B-EMD) and proper orthogonal decomposition (POD), are also tested for comparison. Among all these methods, QB-VMD shows advantages in both scale characterization and energy recovery. More importantly, the mode mixing problem, which degrades the performance of EMD-based methods, is avoided or minimized in QB-VMD. Finally, QB-VMD analysis of the wall-parallel plane in the log layer (at y/δ = 0.12) of the studied turbulent boundary layer shows the coexistence of large- or very large-scale motions (LSMs or VLSMs) and inner-scaled structures, which can be fully decomposed in both physical and spectral domains.

  17. Body Mass Index and Depressive Symptoms: Testing for Adverse and Protective Associations in Two Twin Cohort Studies.

    Science.gov (United States)

    Jokela, Markus; Berg, Venla; Silventoinen, Karri; Batty, G David; Singh-Manoux, Archana; Kaprio, Jaakko; Davey Smith, George; Kivimäki, Mika

    2016-08-01

    Studies have suggested both adverse and protective associations of obesity with depressive symptoms. We examined the contribution of environmental and heritable factors in this association. Participants were same-sex twin pairs from two population-based twin cohort studies, the Older Finnish Twin Cohort (n = 8,215; mean age = 44.1) and the US Midlife Development in the United States (MIDUS; n = 1,105; mean age = 45.1). Body mass index (BMI) was calculated from self-reported height and weight. Depressive symptoms were assessed using Beck's Depression Inventory (BDI; Finnish Twin Cohort), and by negative and positive affect scales (MIDUS). In the Finnish Twin Cohort, higher BMI was associated with higher depressive symptoms in monozygotic (MZ) twins (B = 2.01, 95% CI = 1.0, 3.0) and dizygotic (DZ) twins (B = 1.17, 0.5, 1.9) with BMI >22. This association was observed in within-pair analysis in DZ twins (B = 1.47, CI = 0.4, 2.6) but not in within-pair analysis of MZ twins (B = 0.03, CI = -1.9, 2.0). Consistent with the latter result, a bivariate genetic model indicated that the association between higher BMI and higher depressive symptoms was largely mediated by genetic factors. The results of twin-pair analysis and bivariate genetic model were replicated in the MIDUS sample. These findings suggest an association between obesity and higher depressive symptoms, which is largely explained by shared heritable biological mechanisms.

  18. Bivariate tensor product ( p , q $(p, q$ -analogue of Kantorovich-type Bernstein-Stancu-Schurer operators

    Directory of Open Access Journals (Sweden)

    Qing-Bo Cai

    2017-11-01

    Full Text Available Abstract In this paper, we construct a bivariate tensor product generalization of Kantorovich-type Bernstein-Stancu-Schurer operators based on the concept of ( p , q $(p, q$ -integers. We obtain moments and central moments of these operators, give the rate of convergence by using the complete modulus of continuity for the bivariate case and estimate a convergence theorem for the Lipschitz continuous functions. We also give some graphs and numerical examples to illustrate the convergence properties of these operators to certain functions.

  19. Associated factors to urinary incontinence in women undergoing urodynamic testing.

    Science.gov (United States)

    Silva, Juliana Cristina Pereira da; Soler, Zaida Aurora Sperli Geraldes; DominguesWysocki, Anneliese

    2017-04-03

    Analyzing factors associated with urinary incontinence (UI) among women submitted to urodynamic testing. A cross-sectional study of 150 women attended at a urological center. Data were analyzed using univariate and multivariate statistics. White women (79.3%), overweight (45.3%), menopausal (53.3%), who drink coffee (82.7%), sedentary (65.3%), who had vaginal birth (51.4%), with episiotomy (80%), and who underwent the Kristeller maneuver (69%). 60.7% had Urethral Hypermobility (UH). A statistical association was found between: weight change and UH (p = 0.024); menopause, Intrinsic Sphincter Deficiency (ISD) and Detrusor Instability (DI) (p = 0.001); gynecological surgery, ISD and DI (p = 0.014); hysterectomy and all types of UI (p = 0.040); physical activity and mixed UI (p = 0.014). Interventions and guidance on preventing UI and strengthening pelvic muscles should be directed at women who present weight changes, who are sedentary menopausal women, and those who have undergone hysterectomy or other gynecological surgery. Studies on pelvic strengthening methods are needed in order to take into account the profile of the needs presented by women. Analisar os fatores associados à Incontinência Urinária (IU) entre mulheres submetidas a estudo urodinâmico. Estudo transversal realizado com 150 mulheres atendidas em um centro urológico. Os dados foram analisados por meio de estatística uni e multivariada. Mulheres brancas (79,3%), com sobrepeso (45,3%), na menopausa (53,3%), que ingeriam café (82,7%), sedentárias (65,3%), que fizeram parto normal (51,4%), com episiotomia (80%), que sofreram Manobra de Kristeller (69%). 60,7% apresentavam HipermobilidadeUretral (HU).Houve associação estatística entre: mudança de peso e HU (p=0,024); menopausa,Deficiência Esfincteriana Intrínseca (DEI) e Instabilidade Detrusora (ID) (p=0,001); cirurgia ginecológica, DEI e ID (p=0,014); histerectomia etodos os tipos de IU (p=0,040); realização de atividade física eIU mista

  20. Clinical utility of celiac disease associated HLA testing

    Science.gov (United States)

    Pallav, Kumar; Kabbani, Toufic; Tariq, Sohaib; Vanga, Rohini; Kelly, Ciaran P.; Leffler, Daniel A.

    2014-01-01

    Background Negative predictive value (NPV) of Celiac Disease (CD) related human leukocyte antigens (HLA) DQ2 and DQ8 approaches 100% in individual patients. However, studies evaluating its exclusionary utility in patient groups are lacking. Aim We aim to assess the performance of HLA testing when applied to patient groups with varying characteristics and propose evidence-based recommendations for its clinical use. Methods Demographic and clinical information was recorded in patients undergoing HLA testing. Using predetermined criteria, patients were classified as CD, Non CD or indeterminate. Diagnostic yield of HLA testing was defined as the percentage of patients in whom CD could be excluded based on negative HLA test. Results 256 patients underwent testing for CD related HLA DQ2 and DQ8. 102 (100 Non CD, 2 CD) patients tested HLA negative for a 98% NPV and 39% diagnostic yield. Diagnostic yield was highest (60%) in patients with intraepithelial lymphocytosis plus normal IgA tissue transglutaminase antibody (IgA-tTG) and lowest in patients with positive IgA-tTG plus villous atrophy (0%). CD was diagnosed in 2 HLA negative patients, who carried half of DQ2.5 trans genotype. Conclusions Diagnostic yield of CD related HLA testing varies widely depending on clinical indication. HLA testing is a practical and valuable test for most patients in whom initial evaluation for CD is inconclusive. A negative HLA result usually obviates the need for further celiac testing including endoscopy and gluten challenge. Rarely, in patients reported as HLA negative, half of HLA DQ2.5 (cis or trans) is sufficient for development of CD. PMID:24705698

  1. [Test anxiety: associations with personal and family variables].

    Science.gov (United States)

    Rosário, Pedro; Núñez, José Carlos; Salgado, Ana; González-Pienda, Julio A; Valle, Antonio; Joly, Cristina; Bernardo, Ana

    2008-11-01

    Test anxiety is a common behavior among students facing social pressure centered on mastery. Only a few studies have analyzed the relations between test anxiety, academic procrastination, personal and family variables and math grades. This work focus on the analysis of the impact of students' social-personal variables such as parents' education level, number of siblings and under-achievement by performing ANOVAs in two samples of 533 and 796 students from junior high-school. Corroborating the findings in other studies, the data stress that test anxiety is higher in girls and decreases when students' parents have higher educational levels, with the number of courses flunked, and when students' math grades were lower. Test anxiety and procrastination correlate positive and significantly. Findings are discussed and compared with those of previous researches. The implications for teaching practice are also analyzed.

  2. GIS-based bivariate statistical techniques for groundwater potential analysis (an example of Iran)

    Science.gov (United States)

    Haghizadeh, Ali; Moghaddam, Davoud Davoudi; Pourghasemi, Hamid Reza

    2017-12-01

    Groundwater potential analysis prepares better comprehension of hydrological settings of different regions. This study shows the potency of two GIS-based data driven bivariate techniques namely statistical index (SI) and Dempster-Shafer theory (DST) to analyze groundwater potential in Broujerd region of Iran. The research was done using 11 groundwater conditioning factors and 496 spring positions. Based on the ground water potential maps (GPMs) of SI and DST methods, 24.22% and 23.74% of the study area is covered by poor zone of groundwater potential, and 43.93% and 36.3% of Broujerd region is covered by good and very good potential zones, respectively. The validation of outcomes displayed that area under the curve (AUC) of SI and DST techniques are 81.23% and 79.41%, respectively, which shows SI method has slightly a better performance than the DST technique. Therefore, SI and DST methods are advantageous to analyze groundwater capacity and scrutinize the complicated relation between groundwater occurrence and groundwater conditioning factors, which permits investigation of both systemic and stochastic uncertainty. Finally, it can be realized that these techniques are very beneficial for groundwater potential analyzing and can be practical for water-resource management experts.

  3. Perceived social support and academic achievement: cross-lagged panel and bivariate growth curve analyses.

    Science.gov (United States)

    Mackinnon, Sean P

    2012-04-01

    As students transition to post-secondary education, they experience considerable stress and declines in academic performance. Perceived social support is thought to improve academic achievement by reducing stress. Longitudinal designs with three or more waves are needed in this area because they permit stronger causal inferences and help disentangle the direction of relationships. This study uses a cross-lagged panel and a bivariate growth curve analysis with a three-wave longitudinal design. Participants include 10,445 students (56% female; 12.6% born outside of Canada) transitioning to post-secondary education from ages 15-19. Self-report measures of academic achievement and a generalized measure of perceived social support were used. An increase in average relative standing in academic achievement predicted an increase in average relative standing on perceived social support 2 years later, but the reverse was not true. High levels of perceived social support at age 15 did not protect against declines in academic achievement over time. In sum, perceived social support appears to have no bearing on adolescents' future academic performance, despite commonly held assumptions of its importance.

  4. Modeling both of the number of pausibacillary and multibacillary leprosy patients by using bivariate poisson regression

    Science.gov (United States)

    Winahju, W. S.; Mukarromah, A.; Putri, S.

    2015-03-01

    Leprosy is a chronic infectious disease caused by bacteria of leprosy (Mycobacterium leprae). Leprosy has become an important thing in Indonesia because its morbidity is quite high. Based on WHO data in 2014, in 2012 Indonesia has the highest number of new leprosy patients after India and Brazil with a contribution of 18.994 people (8.7% of the world). This number makes Indonesia automatically placed as the country with the highest number of leprosy morbidity of ASEAN countries. The province that most contributes to the number of leprosy patients in Indonesia is East Java. There are two kind of leprosy. They consist of pausibacillary and multibacillary. The morbidity of multibacillary leprosy is higher than pausibacillary leprosy. This paper will discuss modeling both of the number of multibacillary and pausibacillary leprosy patients as responses variables. These responses are count variables, so modeling will be conducted by using bivariate poisson regression method. Unit experiment used is in East Java, and predictors involved are: environment, demography, and poverty. The model uses data in 2012, and the result indicates that all predictors influence significantly.

  5. Bivariate frequency analysis of rainfall intensity and duration for urban stormwater infrastructure design

    Science.gov (United States)

    Jun, Changhyun; Qin, Xiaosheng; Gan, Thian Yew; Tung, Yeou-Koung; De Michele, Carlo

    2017-10-01

    This study presents a storm-event based bivariate frequency analysis approach to determine design rainfalls in which, the number, intensity and duration of actual rainstorm events were considered. To derive more realistic design storms, the occurrence probability of an individual rainstorm event was determined from the joint distribution of storm intensity and duration through a copula model. Hourly rainfall data were used at three climate stations respectively located in Singapore, South Korea and Canada. It was found that the proposed approach could give a more realistic description of rainfall characteristics of rainstorm events and design rainfalls. As results, the design rainfall quantities from actual rainstorm events at the three studied sites are consistently lower than those obtained from the conventional rainfall depth-duration-frequency (DDF) method, especially for short-duration storms (such as 1-h). It results from occurrence probabilities of each rainstorm event and a different angle for rainfall frequency analysis, and could offer an alternative way of describing extreme rainfall properties and potentially help improve the hydrologic design of stormwater management facilities in urban areas.

  6. Bivariate spatial analysis of temperature and precipitation from general circulation models and observation proxies

    KAUST Repository

    Philbin, R.

    2015-05-22

    This study validates the near-surface temperature and precipitation output from decadal runs of eight atmospheric ocean general circulation models (AOGCMs) against observational proxy data from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis temperatures and Global Precipitation Climatology Project (GPCP) precipitation data. We model the joint distribution of these two fields with a parsimonious bivariate Matérn spatial covariance model, accounting for the two fields\\' spatial cross-correlation as well as their own smoothnesses. We fit output from each AOGCM (30-year seasonal averages from 1981 to 2010) to a statistical model on each of 21 land regions. Both variance and smoothness values agree for both fields over all latitude bands except southern mid-latitudes. Our results imply that temperature fields have smaller smoothness coefficients than precipitation fields, while both have decreasing smoothness coefficients with increasing latitude. Models predict fields with smaller smoothness coefficients than observational proxy data for the tropics. The estimated spatial cross-correlations of these two fields, however, are quite different for most GCMs in mid-latitudes. Model correlation estimates agree well with those for observational proxy data for Australia, at high northern latitudes across North America, Europe and Asia, as well as across the Sahara, India, and Southeast Asia, but elsewhere, little consistent agreement exists.

  7. Improved deadzone modeling for bivariate wavelet shrinkage-based image denoising

    Science.gov (United States)

    DelMarco, Stephen

    2016-05-01

    Modern image processing performed on-board low Size, Weight, and Power (SWaP) platforms, must provide high- performance while simultaneously reducing memory footprint, power consumption, and computational complexity. Image preprocessing, along with downstream image exploitation algorithms such as object detection and recognition, and georegistration, place a heavy burden on power and processing resources. Image preprocessing often includes image denoising to improve data quality for downstream exploitation algorithms. High-performance image denoising is typically performed in the wavelet domain, where noise generally spreads and the wavelet transform compactly captures high information-bearing image characteristics. In this paper, we improve modeling fidelity of a previously-developed, computationally-efficient wavelet-based denoising algorithm. The modeling improvements enhance denoising performance without significantly increasing computational cost, thus making the approach suitable for low-SWAP platforms. Specifically, this paper presents modeling improvements to the Sendur-Selesnick model (SSM) which implements a bivariate wavelet shrinkage denoising algorithm that exploits interscale dependency between wavelet coefficients. We formulate optimization problems for parameters controlling deadzone size which leads to improved denoising performance. Two formulations are provided; one with a simple, closed form solution which we use for numerical result generation, and the second as an integral equation formulation involving elliptic integrals. We generate image denoising performance results over different image sets drawn from public domain imagery, and investigate the effect of wavelet filter tap length on denoising performance. We demonstrate denoising performance improvement when using the enhanced modeling over performance obtained with the baseline SSM model.

  8. Multiscale Fluctuation Features of the Dynamic Correlation between Bivariate Time Series

    Directory of Open Access Journals (Sweden)

    Meihui Jiang

    2016-01-01

    Full Text Available The fluctuation of the dynamic correlation between bivariate time series has some special features on the time-frequency domain. In order to study these fluctuation features, this paper built the dynamic correlation network models using two kinds of time series as sample data. After studying the dynamic correlation networks at different time-scales, we found that the correlation between time series is a dynamic process. The correlation is strong and stable in the long term, but it is weak and unstable in the short and medium term. There are key correlation modes which can effectively indicate the trend of the correlation. The transmission characteristics of correlation modes show that it is easier to judge the trend of the fluctuation of the correlation between time series from the short term to long term. The evolution of media capability of the correlation modes shows that the transmission media in the long term have higher value to predict the trend of correlation. This work does not only propose a new perspective to analyze the correlation between time series but also provide important information for investors and decision makers.

  9. Bivariate Gaussian bridges: directional factorization of diffusion in Brownian bridge models.

    Science.gov (United States)

    Kranstauber, Bart; Safi, Kamran; Bartumeus, Frederic

    2014-01-01

    In recent years high resolution animal tracking data has become the standard in movement ecology. The Brownian Bridge Movement Model (BBMM) is a widely adopted approach to describe animal space use from such high resolution tracks. One of the underlying assumptions of the BBMM is isotropic diffusive motion between consecutive locations, i.e. invariant with respect to the direction. Here we propose to relax this often unrealistic assumption by separating the Brownian motion variance into two directional components, one parallel and one orthogonal to the direction of the motion. Our new model, the Bivariate Gaussian bridge (BGB), tracks movement heterogeneity across time. Using the BGB and identifying directed and non-directed movement within a trajectory resulted in more accurate utilisation distributions compared to dynamic Brownian bridges, especially for trajectories with a non-isotropic diffusion, such as directed movement or Lévy like movements. We evaluated our model with simulated trajectories and observed tracks, demonstrating that the improvement of our model scales with the directional correlation of a correlated random walk. We find that many of the animal trajectories do not adhere to the assumptions of the BBMM. The proposed model improves accuracy when describing the space use both in simulated correlated random walks as well as observed animal tracks. Our novel approach is implemented and available within the "move" package for R.

  10. Neural Systems with Numerically Matched Input-Output Statistic: Isotonic Bivariate Statistical Modeling

    Directory of Open Access Journals (Sweden)

    Simone Fiori

    2007-07-01

    Full Text Available Bivariate statistical modeling from incomplete data is a useful statistical tool that allows to discover the model underlying two data sets when the data in the two sets do not correspond in size nor in ordering. Such situation may occur when the sizes of the two data sets do not match (i.e., there are “holes” in the data or when the data sets have been acquired independently. Also, statistical modeling is useful when the amount of available data is enough to show relevant statistical features of the phenomenon underlying the data. We propose to tackle the problem of statistical modeling via a neural (nonlinear system that is able to match its input-output statistic to the statistic of the available data sets. A key point of the new implementation proposed here is that it is based on look-up-table (LUT neural systems, which guarantee a computationally advantageous way of implementing neural systems. A number of numerical experiments, performed on both synthetic and real-world data sets, illustrate the features of the proposed modeling procedure.

  11. Bivariate flow cytometric analysis and sorting of different types of maize starch grains.

    Science.gov (United States)

    Zhang, Xudong; Feng, Jiaojiao; Wang, Heng; Zhu, Jianchu; Zhong, Yuyue; Liu, Linsan; Xu, Shutu; Zhang, Renhe; Zhang, Xinghua; Xue, Jiquan; Guo, Dongwei

    2018-02-01

    Particle-size distribution, granular structure, and composition significantly affect the physicochemical properties, rheological properties, and nutritional function of starch. Flow cytometry and flow sorting are widely considered convenient and efficient ways of classifying and separating natural biological particles or other substances into subpopulations, respectively, based on the differential response of each component to stimulation by a light beam; the results allow for the correlation analysis of parameters. In this study, different types of starches isolated from waxy maize, sweet maize, high-amylose maize, pop maize, and normal maize were initially classified into various subgroups by flow cytometer and then collected through flow sorting to observe their morphology and particle-size distribution. The results showed that a 0.25% Gelzan solution served as an optimal reagent for keeping individual starch particles homogeneously dispersed in suspension for a relatively long time. The bivariate flow cytometric population distributions indicated that the starches of normal maize, sweet maize, and pop maize were divided into two subgroups, whereas high-amylose maize starch had only one subgroup. Waxy maize starch, conversely, showed three subpopulations. The subgroups sorted by flow cytometer were determined and verified in terms of morphology and granule size by scanning electron microscopy and laser particle distribution analyzer. Results showed that flow cytometry can be regarded as a novel method for classifying and sorting starch granules. © 2017 International Society for Advancement of Cytometry. © 2017 International Society for Advancement of Cytometry.

  12. The Role of Wealth and Health in Insurance Choice: Bivariate Probit Analysis in China

    Directory of Open Access Journals (Sweden)

    Yiding Yue

    2014-01-01

    Full Text Available This paper captures the correlation between the choices of health insurance and pension insurance using the bivariate probit model and then studies the effect of wealth and health on insurance choice. Our empirical evidence shows that people who participate in a health care program are more likely to participate in a pension plan at the same time, while wealth and health have different effects on the choices of the health care program and the pension program. Generally, the higher an individual’s wealth level is, the more likelihood he will participate in a health care program; but wealth has no effect on the participation of pension. Health status has opposite effects on choices of health care programs and pension plans; the poorer an individual’s health is, the more likely he is to participate in health care programs, while the better health he enjoys, the more likely he is to participate in pension plans. When the investigation scope narrows down to commercial insurance, there is only a significant effect of health status on commercial health insurance. The commercial insurance choice and the insurance choice of the agricultural population are more complicated.

  13. Problems Associated with Relating Normative and Skill Tests.

    Science.gov (United States)

    Temkin, Sanford

    How to describe the Individually Prescribed Instruction (IPI) Placement Tests to the non-IPI community; how to assess student performance over a period of time, and what information can be obtained relative to the IPI curriculum: such are the concerns of this study. A possible solution to the first problem is to describe the IPI Placement Test…

  14. Tests and Medical Conditions Associated with Dementia Diagnosis

    Science.gov (United States)

    Burt, Diana B.; Primeaux-Hart, Sharon; Loveland, Katherine A.; Cleveland, Lynne A.; Lewis, Kay R.; Lesser, Jary; Pearson, Pamela L.

    2005-01-01

    Diagnosis of dementia in adults with intellectual disabilities requires documentation of clinically significant declines in memory and other cognitive skills, as well as changes in everyday and emotional functioning. To improve diagnostic accuracy in adults with Down syndrome, the authors examined conditions often associated with dementia, as well…

  15. Errors Associated with Flexure Testing of Brittle Materials

    Science.gov (United States)

    1987-07-01

    Computer Analysis Worksheet. .. .... ................ . ........42 NOMENCLATURE E Young’s modulus of the test vmaterial E c Young’s modulus in compression of...lolden-Day Scrie in Mathenatical Physics. J. L. Brandstatter, ed.. 1963. p. 204. 4 is also an area in whigh further analysis will be required to assess...was used to compute the percent error because it would yield the largest error. Although the analysis was applied to a three-point loaded beam, the

  16. Assessing protein conformational sampling methods based on bivariate lag-distributions of backbone angles

    KAUST Repository

    Maadooliat, Mehdi

    2012-08-27

    Despite considerable progress in the past decades, protein structure prediction remains one of the major unsolved problems in computational biology. Angular-sampling-based methods have been extensively studied recently due to their ability to capture the continuous conformational space of protein structures. The literature has focused on using a variety of parametric models of the sequential dependencies between angle pairs along the protein chains. In this article, we present a thorough review of angular-sampling-based methods by assessing three main questions: What is the best distribution type to model the protein angles? What is a reasonable number of components in a mixture model that should be considered to accurately parameterize the joint distribution of the angles? and What is the order of the local sequence-structure dependency that should be considered by a prediction method? We assess the model fits for different methods using bivariate lag-distributions of the dihedral/planar angles. Moreover, the main information across the lags can be extracted using a technique called Lag singular value decomposition (LagSVD), which considers the joint distribution of the dihedral/planar angles over different lags using a nonparametric approach and monitors the behavior of the lag-distribution of the angles using singular value decomposition. As a result, we developed graphical tools and numerical measurements to compare and evaluate the performance of different model fits. Furthermore, we developed a web-tool (http://www.stat.tamu. edu/~madoliat/LagSVD) that can be used to produce informative animations. © The Author 2012. Published by Oxford University Press.

  17. New Colors for Histology: Optimized Bivariate Color Maps Increase Perceptual Contrast in Histological Images.

    Directory of Open Access Journals (Sweden)

    Jakob Nikolas Kather

    Full Text Available Accurate evaluation of immunostained histological images is required for reproducible research in many different areas and forms the basis of many clinical decisions. The quality and efficiency of histopathological evaluation is limited by the information content of a histological image, which is primarily encoded as perceivable contrast differences between objects in the image. However, the colors of chromogen and counterstain used for histological samples are not always optimally distinguishable, even under optimal conditions.In this study, we present a method to extract the bivariate color map inherent in a given histological image and to retrospectively optimize this color map. We use a novel, unsupervised approach based on color deconvolution and principal component analysis to show that the commonly used blue and brown color hues in Hematoxylin-3,3'-Diaminobenzidine (DAB images are poorly suited for human observers. We then demonstrate that it is possible to construct improved color maps according to objective criteria and that these color maps can be used to digitally re-stain histological images.To validate whether this procedure improves distinguishability of objects and background in histological images, we re-stain phantom images and N = 596 large histological images of immunostained samples of human solid tumors. We show that perceptual contrast is improved by a factor of 2.56 in phantom images and up to a factor of 2.17 in sets of histological tumor images.Thus, we provide an objective and reliable approach to measure object distinguishability in a given histological image and to maximize visual information available to a human observer. This method could easily be incorporated in digital pathology image viewing systems to improve accuracy and efficiency in research and diagnostics.

  18. New Colors for Histology: Optimized Bivariate Color Maps Increase Perceptual Contrast in Histological Images.

    Science.gov (United States)

    Kather, Jakob Nikolas; Weis, Cleo-Aron; Marx, Alexander; Schuster, Alexander K; Schad, Lothar R; Zöllner, Frank Gerrit

    2015-01-01

    Accurate evaluation of immunostained histological images is required for reproducible research in many different areas and forms the basis of many clinical decisions. The quality and efficiency of histopathological evaluation is limited by the information content of a histological image, which is primarily encoded as perceivable contrast differences between objects in the image. However, the colors of chromogen and counterstain used for histological samples are not always optimally distinguishable, even under optimal conditions. In this study, we present a method to extract the bivariate color map inherent in a given histological image and to retrospectively optimize this color map. We use a novel, unsupervised approach based on color deconvolution and principal component analysis to show that the commonly used blue and brown color hues in Hematoxylin-3,3'-Diaminobenzidine (DAB) images are poorly suited for human observers. We then demonstrate that it is possible to construct improved color maps according to objective criteria and that these color maps can be used to digitally re-stain histological images. To validate whether this procedure improves distinguishability of objects and background in histological images, we re-stain phantom images and N = 596 large histological images of immunostained samples of human solid tumors. We show that perceptual contrast is improved by a factor of 2.56 in phantom images and up to a factor of 2.17 in sets of histological tumor images. Thus, we provide an objective and reliable approach to measure object distinguishability in a given histological image and to maximize visual information available to a human observer. This method could easily be incorporated in digital pathology image viewing systems to improve accuracy and efficiency in research and diagnostics.

  19. Analysis of input variables of an artificial neural network using bivariate correlation and canonical correlation

    International Nuclear Information System (INIS)

    Costa, Valter Magalhaes; Pereira, Iraci Martinez

    2011-01-01

    The monitoring of variables and diagnosis of sensor fault in nuclear power plants or processes industries is very important because a previous diagnosis allows the correction of the fault and, like this, to prevent the production stopped, improving operator's security and it's not provoking economics losses. The objective of this work is to build a set, using bivariate correlation and canonical correlation, which will be the set of input variables of an artificial neural network to monitor the greater number of variables. This methodology was applied to the IEA-R1 Research Reactor at IPEN. Initially, for the input set of neural network we selected the variables: nuclear power, primary circuit flow rate, control/safety rod position and difference in pressure in the core of the reactor, because almost whole of monitoring variables have relation with the variables early described or its effect can be result of the interaction of two or more. The nuclear power is related to the increasing and decreasing of temperatures as well as the amount radiation due fission of the uranium; the rods are controls of power and influence in the amount of radiation and increasing and decreasing of temperatures; the primary circuit flow rate has the function of energy transport by removing the nucleus heat. An artificial neural network was trained and the results were satisfactory since the IEA-R1 Data Acquisition System reactor monitors 64 variables and, with a set of 9 input variables resulting from the correlation analysis, it was possible to monitor 51 variables. (author)

  20. Analysis of input variables of an artificial neural network using bivariate correlation and canonical correlation

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Valter Magalhaes; Pereira, Iraci Martinez, E-mail: valter.costa@usp.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    The monitoring of variables and diagnosis of sensor fault in nuclear power plants or processes industries is very important because a previous diagnosis allows the correction of the fault and, like this, to prevent the production stopped, improving operator's security and it's not provoking economics losses. The objective of this work is to build a set, using bivariate correlation and canonical correlation, which will be the set of input variables of an artificial neural network to monitor the greater number of variables. This methodology was applied to the IEA-R1 Research Reactor at IPEN. Initially, for the input set of neural network we selected the variables: nuclear power, primary circuit flow rate, control/safety rod position and difference in pressure in the core of the reactor, because almost whole of monitoring variables have relation with the variables early described or its effect can be result of the interaction of two or more. The nuclear power is related to the increasing and decreasing of temperatures as well as the amount radiation due fission of the uranium; the rods are controls of power and influence in the amount of radiation and increasing and decreasing of temperatures; the primary circuit flow rate has the function of energy transport by removing the nucleus heat. An artificial neural network was trained and the results were satisfactory since the IEA-R1 Data Acquisition System reactor monitors 64 variables and, with a set of 9 input variables resulting from the correlation analysis, it was possible to monitor 51 variables. (author)

  1. Utility of testing for apraxia and associated features in dementia.

    Science.gov (United States)

    Ahmed, Samrah; Baker, Ian; Thompson, Sian; Husain, Masud; Butler, Christopher R

    2016-11-01

    Existing literature suggests that the presence or absence of apraxia and associated parietal deficits may be clinically relevant in differential diagnosis of dementia syndromes. This study investigated the profile of these features in Alzheimer's disease (AD) and frontotemporal dementia (FTD) spectrum disorders, at first presentation. Retrospective case note analysis was undertaken in 111 patients who presented to the Oxford Cognitive Disorders Clinic, Oxford, UK, including 29 amnestic AD, 12 posterior cortical atrophy (PCA), 12 logopenic primary progressive aphasia (lvPPA), 20 behavioural variant FTD (bvFTD), 7 non-fluent variant PPA (nfvPPA), 6 semantic variant PPA (svPPA) and 25 patients with subjective cognitive impairment (SCI). The clinical features of interest were: limb apraxia, apraxia of speech (AOS), and left parietal symptoms of dyslexia, dysgraphia, and dyscalculia. The prevalence of limb apraxia was highest in PCA, amnestic AD, lvPPA and nfvPPA. AOS was only observed in nfvPPA. Associated parietal features were more prevalent in AD spectrum than FTD spectrum disorders. Group comparisons between key differential diagnostic challenges showed that lvPPA and nfvPPA could be significantly differentiated on the presence of left parietal features and AOS, and amnestic AD could be differentiated from bvFTD, svPPA and SCI by limb apraxia. Regression analysis showed that limb apraxia could successfully differentiate between AD and FTLD spectrum disorders with 83% accuracy. Disease-specific profiles of limb apraxia and associated deficits can be observed. FTD and AD spectrum disorders can be difficult to differentiate due to overlapping cognitive symptoms, and measures of apraxia, in particular, appear to be a promising discriminator. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  2. A Biochar Classification System and Associated Test Methods

    Energy Technology Data Exchange (ETDEWEB)

    Camps-Arbestain, Marta; Amonette, James E.; Singh, Balwant; Wang, Tao; Schmidt, Hans-Peter

    2015-02-18

    In this chapter, a biochar classification system related to its use as soil amendment is proposed. This document builds upon previous work and constrains its scope to materials with properties that satisfy the criteria for biochar as defined by either the International Biochar Initiative (IBI) Biochar Standards or the European Biochar Community (EBC) Standards, and it is intended to minimise the need for testing in addition to those required according to the above-mentioned standards. The classification system envisions enabling stakeholders and commercial entities to (i) identify the most suitable biochar to fulfil the requirements for a particular soil and/or land-use, and (ii) distinguish the application of biochar for specific niches (e.g., soilless agriculture). It is based on the best current knowledge and the intention is to periodically review and update the document based on new data and knowledge that become available in the scientific literature. The main thrust of this classification system is based on the direct or indirect beneficial effects that biochar provides from its application to soil. We have classified the potential beneficial effects of biochar application to soils into five categories with their corresponding classes, where applicable: (i) carbon (C) storage value, (ii) fertiliser value, (iii) liming value, (iv) particle-size, and (v) use in soil-less agriculture. A summary of recommended test methods is provided at the end of the chapter.

  3. [Testing doses? Environmental health stakes associated with nanotechnologies].

    Science.gov (United States)

    Jouzel, Jean-Noël

    2011-01-01

    In this contribution, we analyse how nanoscience and nanotechnology have given birth to an important environmental health controversy regarding the potential sanitary dangers of engineered nanomaterials. We show how this controversy is part of a larger picture, made of a series of social and scientific disputes about the effects of man made chemicals on the human body. We show how these disputes have contributed throughout the 20th century to the emergence and the transformation of toxicology as a scientific field, and to test the robustness of the dose paradigm that constitues the cornerstone of this discipline. We suggest that the contemporary emergence of a new scientific field known as "nanotoxicolgy" must be interpreted as a successful adaptation of this paradigm to the specific toxicological questions raised by engineered nanomaterials.

  4. Contributory fault and level of personal injury to drivers involved in head-on collisions: Application of copula-based bivariate ordinal models.

    Science.gov (United States)

    Wali, Behram; Khattak, Asad J; Xu, Jingjing

    2018-01-01

    The main objective of this study is to simultaneously investigate the degree of injury severity sustained by drivers involved in head-on collisions with respect to fault status designation. This is complicated to answer due to many issues, one of which is the potential presence of correlation between injury outcomes of drivers involved in the same head-on collision. To address this concern, we present seemingly unrelated bivariate ordered response models by analyzing the joint injury severity probability distribution of at-fault and not-at-fault drivers. Moreover, the assumption of bivariate normality of residuals and the linear form of stochastic dependence implied by such models may be unduly restrictive. To test this, Archimedean copula structures and normal mixture marginals are integrated into the joint estimation framework, which can characterize complex forms of stochastic dependencies and non-normality in residual terms. The models are estimated using 2013 Virginia police reported two-vehicle head-on collision data, where exactly one driver is at-fault. The results suggest that both at-fault and not-at-fault drivers sustained serious/fatal injuries in 8% of crashes, whereas, in 4% of the cases, the not-at-fault driver sustained a serious/fatal injury with no injury to the at-fault driver at all. Furthermore, if the at-fault driver is fatigued, apparently asleep, or has been drinking the not-at-fault driver is more likely to sustain a severe/fatal injury, controlling for other factors and potential correlations between the injury outcomes. While not-at-fault vehicle speed affects injury severity of at-fault driver, the effect is smaller than the effect of at-fault vehicle speed on at-fault injury outcome. Contrarily, and importantly, the effect of at-fault vehicle speed on injury severity of not-at-fault driver is almost equal to the effect of not-at-fault vehicle speed on injury outcome of not-at-fault driver. Compared to traditional ordered probability

  5. REVEALING STUDENTS' COGNITIVE STRUCTURE ABOUT PHYSICAL AND CHEMICAL CHANGE: USE OF A WORD ASSOCIATION TEST

    OpenAIRE

    Hasene Esra Yildirir; Hatice Demirkol

    2018-01-01

    The current study aimed at examining the utility of a word association test in revealing students’ cognitive structure in a specific chemistry topic through a word association test. The participants were 153 6th graders in a western Turkish city. The results revealed that the word association test serves a useful purpose in exploring the students’ cognitive structure with regard to physical and chemical change and identifying their misconceptions about this topic. Some students gave irrelevan...

  6. An improved method for bivariate meta-analysis when within-study correlations are unknown.

    Science.gov (United States)

    Hong, Chuan; D Riley, Richard; Chen, Yong

    2018-03-01

    Multivariate meta-analysis, which jointly analyzes multiple and possibly correlated outcomes in a single analysis, is becoming increasingly popular in recent years. An attractive feature of the multivariate meta-analysis is its ability to account for the dependence between multiple estimates from the same study. However, standard inference procedures for multivariate meta-analysis require the knowledge of within-study correlations, which are usually unavailable. This limits standard inference approaches in practice. Riley et al proposed a working model and an overall synthesis correlation parameter to account for the marginal correlation between outcomes, where the only data needed are those required for a separate univariate random-effects meta-analysis. As within-study correlations are not required, the Riley method is applicable to a wide variety of evidence synthesis situations. However, the standard variance estimator of the Riley method is not entirely correct under many important settings. As a consequence, the coverage of a function of pooled estimates may not reach the nominal level even when the number of studies in the multivariate meta-analysis is large. In this paper, we improve the Riley method by proposing a robust variance estimator, which is asymptotically correct even when the model is misspecified (ie, when the likelihood function is incorrect). Simulation studies of a bivariate meta-analysis, in a variety of settings, show a function of pooled estimates has improved performance when using the proposed robust variance estimator. In terms of individual pooled estimates themselves, the standard variance estimator and robust variance estimator give similar results to the original method, with appropriate coverage. The proposed robust variance estimator performs well when the number of studies is relatively large. Therefore, we recommend the use of the robust method for meta-analyses with a relatively large number of studies (eg, m≥50). When the

  7. Inland dissolved salt chemistry: statistical evaluation of bivariate and ternary diagram models for surface and subsurface waters

    Directory of Open Access Journals (Sweden)

    Stephen T. THRELKELD

    2000-08-01

    Full Text Available We compared the use of ternary and bivariate diagrams to distinguish the effects of atmospheric precipitation, rock weathering, and evaporation on inland surface and subsurface water chemistry. The three processes could not be statistically differentiated using bivariate models even if large water bodies were evaluated separate from small water bodies. Atmospheric precipitation effects were identified using ternary diagrams in water with total dissolved salts (TDS 1000 mg l-1. A principal components analysis showed that the variability in the relative proportions of the major ions was related to atmospheric precipitation, weathering, and evaporation. About half of the variation in the distribution of inorganic ions was related to rock weathering. By considering most of the important inorganic ions, ternary diagrams are able to distinguish the contributions of atmospheric precipitation, rock weathering, and evaporation to inland water chemistry.

  8. A non-parametric conditional bivariate reference region with an application to height/weight measurements on normal girls

    DEFF Research Database (Denmark)

    Petersen, Jørgen Holm

    2009-01-01

    A conceptually simple two-dimensional conditional reference curve is described. The curve gives a decision basis for determining whether a bivariate response from an individual is "normal" or "abnormal" when taking into account that a third (conditioning) variable may influence the bivariate...... response. The reference curve is not only characterized analytically but also by geometric properties that are easily communicated to medical doctors - the users of such curves. The reference curve estimator is completely non-parametric, so no distributional assumptions are needed about the two......-dimensional response. An example that will serve to motivate and illustrate the reference is the study of the height/weight distribution of 7-8-year-old Danish school girls born in 1930, 1950, or 1970....

  9. Bivariate Extension of the Quadrature Method of Moments for Modeling Simultaneous Coagulation and Sintering of Particle Populations.

    Science.gov (United States)

    Wright, Douglas L.; McGraw, Robert; Rosner, Daniel E.

    2001-04-15

    We extendthe application of moment methods to multivariate suspended particle population problems-those for which size alone is insufficient to specify the state of a particle in the population. Specifically, a bivariate extension of the quadrature method of moments (QMOM) (R. McGraw, Aerosol Sci. Technol. 27, 255 (1997)) is presented for efficiently modeling the dynamics of a population of inorganic nanoparticles undergoing simultaneous coagulation and particle sintering. Continuum regime calculations are presented for the Koch-Friedlander-Tandon-Rosner model, which includes coagulation by Brownian diffusion (evaluated for particle fractal dimensions, D(f), in the range 1.8-3) and simultaneous sintering of the resulting aggregates (P. Tandon and D. E. Rosner, J. Colloid Interface Sci. 213, 273 (1999)). For evaluation purposes, and to demonstrate the computational efficiency of the bivariate QMOM, benchmark calculations are carried out using a high-resolution discrete method to evolve the particle distribution function n(nu, a) for short to intermediate times (where nu and a are particle volume and surface area, respectively). Time evolution of a selected set of 36 low-order mixed moments is obtained by integration of the full bivariate distribution and compared with the corresponding moments obtained directly using two different extensions of the QMOM. With the more extensive treatment, errors of less than 1% are obtained over substantial aerosol evolution, while requiring only a few minutes (rather than days) of CPU time. Longer time QMOM simulations lend support to the earlier finding of a self-preserving limit for the dimensionless joint (nu, a) particle distribution function under simultaneous coagulation and sintering (Tandon and Rosner, 1999; D. E. Rosner and S. Yu, AIChE J., 47 (2001)). We demonstrate that, even in the bivariate case, it is possible to use the QMOM to rapidly model the approach to asymptotic behavior, allowing an immediate assessment of

  10. Long-lead station-scale prediction of hydrological droughts in South Korea based on bivariate pattern-based downscaling

    Science.gov (United States)

    Sohn, Soo-Jin; Tam, Chi-Yung

    2016-05-01

    Capturing climatic variations in boreal winter to spring (December-May) is essential for properly predicting droughts in South Korea. This study investigates the variability and predictability of the South Korean climate during this extended season, based on observations from 60 station locations and multi-model ensemble (MME) hindcast experiments (1983/1984-2005/2006) archived at the APEC Climate Center (APCC). Multivariate empirical orthogonal function (EOF) analysis results based on observations show that the first two leading modes of winter-to-spring precipitation and temperature variability, which together account for ~80 % of the total variance, are characterized by regional-scale anomalies covering the whole South Korean territory. These modes were also closely related to some of the recurrent large-scale circulation changes in the northern hemisphere during the same season. Consistent with the above, examination of the standardized precipitation evapotranspiration index (SPEI) indicates that drought conditions in South Korea tend to be accompanied by regional-to-continental-scale circulation anomalies over East Asia to the western north Pacific. Motivated by the aforementioned findings on the spatial-temporal coherence among station-scale precipitation and temperature anomalies, a new bivariate and pattern-based downscaling method was developed. The novelty of this method is that precipitation and temperature data were first filtered using multivariate EOFs to enhance their spatial-temporal coherence, before being linked to large-scale circulation variables using canonical correlation analysis (CCA). To test its applicability and to investigate its related potential predictability, a perfect empirical model was first constructed with observed datasets as predictors. Next, a model output statistics (MOS)-type hybrid dynamical-statistical model was developed, using products from nine one-tier climate models as inputs. It was found that, with model sea

  11. Meta-analysis for diagnostic accuracy studies: a new statistical model using beta-binomial distributions and bivariate copulas.

    Science.gov (United States)

    Kuss, Oliver; Hoyer, Annika; Solms, Alexander

    2014-01-15

    There are still challenges when meta-analyzing data from studies on diagnostic accuracy. This is mainly due to the bivariate nature of the response where information on sensitivity and specificity must be summarized while accounting for their correlation within a single trial. In this paper, we propose a new statistical model for the meta-analysis for diagnostic accuracy studies. This model uses beta-binomial distributions for the marginal numbers of true positives and true negatives and links these margins by a bivariate copula distribution. The new model comes with all the features of the current standard model, a bivariate logistic regression model with random effects, but has the additional advantages of a closed likelihood function and a larger flexibility for the correlation structure of sensitivity and specificity. In a simulation study, which compares three copula models and two implementations of the standard model, the Plackett and the Gauss copula do rarely perform worse but frequently better than the standard model. We use an example from a meta-analysis to judge the diagnostic accuracy of telomerase (a urinary tumor marker) for the diagnosis of primary bladder cancer for illustration. Copyright © 2013 John Wiley & Sons, Ltd.

  12. Testing genotypes-phenotype relationships using permutation tests on association rules.

    Science.gov (United States)

    Shaikh, Mateen; Beyene, Joseph

    2015-02-01

    Association rule mining is a knowledge discovery technique which informs researchers about relationships between variables in data. These relationships can be focused to a specific set of response variables. We propose an augmented version of this method to discover groups of genotypes which relate to specific outcomes. We derive the methodology to find these candidate groups of genotypes and illustrate how the method works on data regarding neuroinvasive complications of West Nile virus and through simulation.

  13. Testing for central symmetry

    NARCIS (Netherlands)

    Einmahl, John; Gan, Zhuojiong

    Omnibus tests for central symmetry of a bivariate probability distribution are proposed. The test statistics compare empirical measures of opposite regions. Under rather weak conditions, we establish the asymptotic distribution of the test statistics under the null hypothesis; it follows that they

  14. A powerful microbiome-based association test and a microbial taxa discovery framework for comprehensive association mapping.

    Science.gov (United States)

    Koh, Hyunwook; Blaser, Martin J; Li, Huilin

    2017-04-24

    The role of the microbiota in human health and disease has been increasingly studied, gathering momentum through the use of high-throughput technologies. Further identification of the roles of specific microbes is necessary to better understand the mechanisms involved in diseases related to microbiome perturbations. Here, we introduce a new microbiome-based group association testing method, optimal microbiome-based association test (OMiAT). OMiAT is a data-driven testing method which takes an optimal test throughout different tests from the sum of powered score tests (SPU) and microbiome regression-based kernel association test (MiRKAT). We illustrate that OMiAT efficiently discovers significant association signals arising from varying microbial abundances and different relative contributions from microbial abundance and phylogenetic information. We also propose a way to apply it to fine-mapping of diverse upper-level taxa at different taxonomic ranks (e.g., phylum, class, order, family, and genus), as well as the entire microbial community, within a newly introduced microbial taxa discovery framework, microbiome comprehensive association mapping (MiCAM). Our extensive simulations demonstrate that OMiAT is highly robust and powerful compared with other existing methods, while correctly controlling type I error rates. Our real data analyses also confirm that MiCAM is especially efficient for the assessment of upper-level taxa by integrating OMiAT as a group analytic method. OMiAT is attractive in practice due to the high complexity of microbiome data and the unknown true nature of the state. MiCAM also provides a hierarchical association map for numerous microbial taxa and can also be used as a guideline for further investigation on the roles of discovered taxa in human health and disease.

  15. [Test-retest reliability of the Implicit Association Test for measuring shyness: Inclusion of malleability of implicit shyness].

    Science.gov (United States)

    Fujii, Tsutomu; Sawaumi, Takafumi; Aikawa, Atsushi

    2015-10-01

    The Implicit Association Test of Shyness (Shyness IAT: Aikawa & Fujii, 2011) provides an indirect assessment of shyness by measuring associations of self (vs. other) with shyness-related (vs sociability-related) words. In this study we examined the test-retest reliability of the Shyness IAT. Thirty-five participants responded twice to the Shyness IAT with a time lag of one month. The correlation coefficient between the two time points was .54 (p = .001), confirming an adequate level of test-retest reliability. Indeed, changes in explicit and implicit shyness between the two time points were not related to sociable behavior during the one month period. Implications of the results for the assessment of personalities using IATs as well as relevant future directions are discussed.

  16. Association of sociodemographic factors and prostate-specific antigen (PSA) testing.

    Science.gov (United States)

    Gorday, William; Sadrzadeh, Hossein; de Koning, Lawrence; Naugler, Christopher

    2014-11-01

    There are conflicting recommendations regarding the use of prostate specific antigen (PSA) as a screening test. Integral to this debate is an understanding of who is currently being tested. The purpose of this study was to provide a detailed account of PSA testing practices in a major Canadian city (Calgary, Alberta) and to identify variables that may affect access to the PSA test. PSA test counts were retrieved from Calgary Laboratory Services' Laboratory Information System from January 1, 2011 to December 31, 2011. A total of 75,914 individual PSA tests were included in our analysis. The frequency of PSA testing was plotted onto a dissemination area map of Calgary using ArcGIS software. Associations with sociodemographic variables were tested using Poisson regression. The median PSA value was 0.93 μg/L and the median age at collection was 58 years. Forty-three percent of men aged 60-69 received a PSA test. Visible minority status 'Black' (P=0.0002) and Métis status (P=0.0075) were associated with lower PSA testing frequencies, while median household income (P=PSA testing frequencies. There are areas in Calgary which are significantly over or under tested relative to the mean. The amount of PSA testing in men PSA testing guidelines. Copyright © 2014 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  17. Predicting the Size of Sunspot Cycle 24 on the Basis of Single- and Bi-Variate Geomagnetic Precursor Methods

    Science.gov (United States)

    Wilson, Robert M.; Hathaway, David H.

    2009-01-01

    Examined are single- and bi-variate geomagnetic precursors for predicting the maximum amplitude (RM) of a sunspot cycle several years in advance. The best single-variate fit is one based on the average of the ap index 36 mo prior to cycle minimum occurrence (E(Rm)), having a coefficient of correlation (r) equal to 0.97 and a standard error of estimate (se) equal to 9.3. Presuming cycle 24 not to be a statistical outlier and its minimum in March 2008, the fit suggests cycle 24 s RM to be about 69 +/- 20 (the 90% prediction interval). The weighted mean prediction of 11 statistically important single-variate fits is 116 +/- 34. The best bi-variate fit is one based on the maximum and minimum values of the 12-mma of the ap index; i.e., APM# and APm*, where # means the value post-E(RM) for the preceding cycle and * means the value in the vicinity of cycle minimum, having r = 0.98 and se = 8.2. It predicts cycle 24 s RM to be about 92 +/- 27. The weighted mean prediction of 22 statistically important bi-variate fits is 112 32. Thus, cycle 24's RM is expected to lie somewhere within the range of about 82 to 144. Also examined are the late-cycle 23 behaviors of geomagnetic indices and solar wind velocity in comparison to the mean behaviors of cycles 2023 and the geomagnetic indices of cycle 14 (RM = 64.2), the weakest sunspot cycle of the modern era.

  18. Association between positive patch tests to epoxy resin and fragrance mix I ingredients.

    Science.gov (United States)

    Andersen, Klaus Ejner; Christensen, Lars Porskjaer; Vølund, Aage; Johansen, Jeanne Duus; Paulsen, Evy

    2009-03-01

    Both epoxy resin (diglycidyl ether of bisphenol A) and fragrance mix I are included in the European baseline series of contact allergens. A significant association between positive reactions to epoxy resin and fragrance mix has been reported by others. To investigate and possibly reproduce this association with the use of TRUE((R)) test data and supplementary tests with fragrance mix ingredients from the Department of Dermatology, Odense University Hospital. Six thousand one hundred and fifteen consecutive eczema patients tested from 1995 to 2007 were included, and test results from all patients tested with fragrance mix ingredients were analysed. One hundred and forty-five (2.4%) were positive to epoxy resin and 282 (4.6%) were positive to fragrance mix I. Nineteen were positive to both giving an odds ratio of 3.3, which is significant (95% CI 2.0-5.4). Analysis of association to individual fragrance mix ingredients showed a significant association to alpha-amyl cinnamal and isoeugenol. The significant association between positive reactions to epoxy resin and fragrance mix I was reproduced. However, the clinical implications are not clarified, and even though the association may be coincidental, the fact that it can be reproduced with a different patch test system and in a different population speaks against a random result. Further studies may help to interpret the association.

  19. Symptoms of common mental disorder and cognitive associations with seropositivity among a cohort of people coming for testing for HIV/AIDS in Goa, India: a cross-sectional survey.

    Science.gov (United States)

    Mayston, Rosie; Patel, Vikram; Abas, Melanie; Korgaonkar, Priya; Paranjape, Ramesh; Rodrigues, Savio; Prince, Martin

    2013-03-07

    The majority of research on HIV/AIDS and mental health has been carried out among clinical populations: the time of onset of comorbid depression and the mechanisms for this are therefore unclear. Although there is evidence to suggest that asymptomatic people living with HIV/AIDS exhibit some cognitive deficits, the prevalence of poor cognitive functioning among people in low income settings at an early, pre-clinical stage has not yet been investigated. We used a cross-sectional survey design to test the hypotheses that symptoms of Common Mental Disorder (CMD) and low scores on cognitive tests would be associated with seropositivity among participants coming for testing for HIV/AIDS. Participants were recruited at the time of coming for testing for HIV/AIDS; voluntary informed consent was sought for participation in research interviews and data linkage with HIV test results. Baseline questionnaires including sociodemographic variables and measures of mental health (PHQ-9, GAD-7, panic disorder questions, AUDIT and delayed word list learning and recall and animal naming test of verbal fluency) were administered by trained interviews. HIV status data was extracted from clinical records. CMD and scoring below the educational norm on the test of verbal fluency were associated with testing positive for HIV/AIDS in bivariate analysis (OR = 2.26, 1.31-3.93; OR = 1.77, 1.26-2.48, respectively). After controlling for the effects of confounders, the association between CMD and seropositivity was no longer statistically significant (AOR = 1.56, 0.86-2.85). After adjusting for the effects of confounders, the association between low scores on the test of verbal fluency and seropositivity was retained (AOR = 1.77, 1.27-2.48). Our findings provide tentative evidence to suggest that low cognitive test scores (and possibly depressive symptoms) may be associated with HIV status among people who have yet to receive their HIV test results. Impaired cognitive functioning and depression

  20. Powerful Tests for Multi-Marker Association Analysis Using Ensemble Learning.

    Directory of Open Access Journals (Sweden)

    Badri Padhukasahasram

    Full Text Available Multi-marker approaches have received a lot of attention recently in genome wide association studies and can enhance power to detect new associations under certain conditions. Gene-, gene-set- and pathway-based association tests are increasingly being viewed as useful supplements to the more widely used single marker association analysis which have successfully uncovered numerous disease variants. A major drawback of single-marker based methods is that they do not look at the joint effects of multiple genetic variants which individually may have weak or moderate signals. Here, we describe novel tests for multi-marker association analyses that are based on phenotype predictions obtained from machine learning algorithms. Instead of assuming a linear or logistic regression model, we propose the use of ensembles of diverse machine learning algorithms for prediction. We show that phenotype predictions obtained from ensemble learning algorithms provide a new framework for multi-marker association analysis. They can be used for constructing tests for the joint association of multiple variants, adjusting for covariates and testing for the presence of interactions. To demonstrate the power and utility of this new approach, we first apply our method to simulated SNP datasets. We show that the proposed method has the correct Type-1 error rates and can be considerably more powerful than alternative approaches in some situations. Then, we apply our method to previously studied asthma-related genes in 2 independent asthma cohorts to conduct association tests.

  1. Comparison of a commercial bovine pregnancy-associated glycoprotein ELISA test and a pregnancy-associated glycoprotein radiomimmunoassay test for early pregnancy diagnosis in dairy cattle.

    Science.gov (United States)

    Karen, Aly; Sousa, Noelita Melo De; Beckers, Jean-François; Bajcsy, Árpád Csaba; Tibold, János; Mádl, István; Szenci, Ottó

    2015-08-01

    The present study aimed to compare the accuracy of a commercial PAG-ELISA test (Bovine Preg Test 29) and bovine pregnancy-associated glycoprotein radioimmunoassay (PAG-RIA) for diagnosing pregnancy at Day 28 after insemination in dairy cows. Transrectal ultrasonography (TRUS) was performed in 100 Holstein-Friesian cows at Day 28 after artificial insemination (AI; Day 0) to diagnose pregnancy. After TRUS examination, blood sample was collected from the coccygeal vessels of each cow to measure the concentrations of bPAGs by PAG-RIA test and Bovine Preg Test 29. Milk samples were collected at Days 0, 21 and 28 for measurement of progesterone (P4) by ELISA test. The cows were re-examined by TRUS at Day 42 to confirm the pregnancy diagnoses. The actual gold standard was based on TRUS outcomes at Day 28 that agreed with the outcomes of PAG-RIA test or PAG-ELISA test. If the outcomes of TRUS at Day 28 and PAG-RIA test and PAG-ELISA test did not agree, the gold standard was based on the outcome of TRUS at Day 42. Out of 100 inseminated cows, 41 were confirmed pregnant at Day 28 after AI. Based on the actual gold standard, the sensitivity of TRUS, PAG-ELISA and PAG-RIA tests for diagnosing pregnant cows at Day 28 were 92.7%, 90.2% and 100%, while the specificity of the three tests for diagnosing non-pregnant cows were 91.5%, 98.3% and 94.4%, respectively. The overall accuracy of the three tests were 92%, 95% and 97%, respectively. The degree of agreement (Kappa±S.E.) between PAG-RIA and PAG-ELISA test was 0.90 ±0.04. The degrees of agreement between PAG-RIA and PAG-ELISA and TRUS at Day 28 were 0.80±0.05 and 0.76±0.06, respectively. In conclusion, the commercial PAG-ELISA test is a highly accurate method for diagnosing early pregnancy in dairy cows on Day 28 after AI and may be used as an alternative method to the TRUS and the PAG-RIA test. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Revision of the Word Association Test for assessing associations of patients reporting satanic ritual abuse in childhood.

    Science.gov (United States)

    Leavitt, F; Labott, S M

    1998-11-01

    A growing number of psychiatric patients report satanic ritual abuse, prompting research into this controversial area. In the current study, the Word Association Test (WAT) was modified to assess experience with satanic abuse. Pilot work resulted in norms for two domains: normative and satanic. Female psychiatric patients were compared on their associations in two studies. Based on a sexual history, they were grouped into those reporting sexual abuse, those reporting satanic ritual abuse (SRA), and those without a history of sexual abuse (controls). In both studies, SRA patients gave significantly more total associations, significantly fewer normative associations, and significantly more satanic associations than did the other two groups. These results suggest that an experience base is shared by individuals reporting SRA that is not found in individuals who do not report satanic abuse (even if they do report sexual abuse). The implications of these findings are discussed from the perspective of arguments advanced by advocates and critics of SRA.

  3. "Passageless" administration of the Nelson-Denny Reading Comprehension Test: associations with IQ and reading skills.

    Science.gov (United States)

    Ready, Rebecca E; Chaudhry, Maheen F; Schatz, Kelly C; Strazzullo, Sarah

    2013-01-01

    There are few tests that assess reading comprehension in adults, but these tests are needed for a comprehensive assessment of reading disorders (RD). The Nelson-Denny Reading Test (NDRT) has a long-passage reading comprehension component that can be used with adolescents and adults. A problem with the NDRT is that reading comprehension test items can be answered correctly without reading the associated passage. The current study determined how IQ, verbal comprehension, and reading skills were associated with scores on a passageless administration of the NDRT. Results indicated that IQ, verbal comprehension, and broad reading skills were significantly associated with greater NDRT passageless scores. Results raise questions about the validity of the reading comprehension component of the NDRT and suggest that the test may have differential validity based on individual differences in vocabulary, general fund of knowledge, and broad reading skills.

  4. Reliability Implications in Wood Systems of a Bivariate Gaussian-Weibull Distribution and the Associated Univariate Pseudo-truncated Weibull

    Science.gov (United States)

    Steve P. Verrill; James W. Evans; David E. Kretschmann; Cherilyn A. Hatfield

    2014-01-01

    Two important wood properties are the modulus of elasticity (MOE) and the modulus of rupture (MOR). In the past, the statistical distribution of the MOE has often been modeled as Gaussian, and that of the MOR as lognormal or as a two- or three-parameter Weibull distribution. It is well known that MOE and MOR are positively correlated. To model the simultaneous behavior...

  5. GYT: Get Yourself Tested Campaign Awareness: Associations With Sexually Transmitted Disease/HIV Testing and Communication Behaviors Among Youth.

    Science.gov (United States)

    McFarlane, Mary; Brookmeyer, Kathryn; Friedman, Allison; Habel, Melissa; Kachur, Rachel; Hogben, Matthew

    2015-11-01

    The GYT: Get Yourself Tested campaign promotes sexually transmitted disease (STD) and HIV testing and communication with partners and providers among youth. We evaluated these behaviors in relation to campaign awareness among youth through a national survey. We collected data from 4017 respondents aged 15 to 25 years through an online panel survey designed to be representative of the US population. The GYT campaign targeted 4 key behaviors: STD testing, HIV testing, talking to partners about testing, and talking to providers about testing. Respondents who were aware of the GYT campaign (24.4%) were more likely to report engaging in each of the 4 target behaviors. Associations remained significant when stratified by race and sex and when taking into account sexuality, sexual activity, age, insurance status, and use of campaign partner-provided services. Awareness of the GYT campaign is related to the 4 target behaviors promoted by the campaign, suggesting that health promotions campaigns oriented toward youth can be successful in increasing STD-related, health-seeking behavior, including among populations disproportionately affected by STD.

  6. Determining the Association between Language and Cognitive Tests in Poststroke Aphasia

    Directory of Open Access Journals (Sweden)

    Kylie J. Wall

    2017-05-01

    Full Text Available BackgroundIndividuals with aphasia are often excluded from studies exploring poststroke cognition because so many of the standard cognitive assessments rely on language ability. Our primary objective was to examine the association between performance on cognitive tests and performance on comprehension and naming tests in poststroke aphasia. Second, we aimed to determine the association between language performance and a real-life measure of cognition (Kettle Test. Third, we explored the feasibility of administering cognitive tests in aphasia.MethodsThirty-six participants with poststroke aphasia and 32 controls were assessed on a battery of pen-and-paper cognitive tests recommended in stroke. Auditory comprehension was measured using the Comprehensive Aphasia Test and naming was measured using the Boston Naming Test. Twenty-two community dwelling participants with aphasia and controls were also asked to complete the Kettle Test. Multiple linear regressions were used to explore the relationship between language performance and performance on the cognitive tests. Feasibility was determined by quantifying missing data.ResultsThe cognitive tests with the highest variance accounted for by auditory comprehension and naming were animal fluency (R2 = 0.67, R2 = 0.78 and the Hopkins Verbal Learning Test (recognition discrimination index (R2 = 0.65, R2 = 0.78. All cognitive tests were significantly associated with auditory comprehension and naming, except for the Star Cancellation Test and the Kettle Test. Thirty-three percent of participants with aphasia were unable to complete all the cognitive tests.ConclusionLanguage and non-linguistic cognitive processes are often interrelated. Most pen-and-paper cognitive tests were significantly associated with both auditory comprehension and naming, even in tests that do not require a verbal response. Language performance was not significantly associated with a real-life cognitive performance measure. Task

  7. Evaluation of Factors Affecting E-Bike Involved Crash and E-Bike License Plate Use in China Using a Bivariate Probit Model

    Directory of Open Access Journals (Sweden)

    Yanyong Guo

    2017-01-01

    Full Text Available The primary objective of this study is to evaluate factors affecting e-bike involved crash and license plate use in China. E-bike crashes data were collected from police database and completed through a telephone interview. Noncrash samples were collected by a questionnaire survey. A bivariate probit (BP model was developed to simultaneously examine the significant factors associated with e-bike involved crash and e-bike license plate and to account for the correlations between them. Marginal effects for contributory factors were calculated to quantify their impacts on the outcomes. The results show that several contributory factors, including gender, age, education level, driver license, car in household, experiences in using e-bike, law compliance, and aggressive driving behaviors, are found to have significant impacts on both e-bike involved crash and license plate use. Moreover, type of e-bike, frequency of using e-bike, impulse behavior, degree of riding experience, and risk perception scale are found to be associated with e-bike involved crash. It is also found that e-bike involved crash and e-bike license plate use are strongly correlated and are negative in direction. The result enhanced our comprehension of the factors related to e-bike involved crash and e-bike license plate use.

  8. A multivariate family-based association test using generalized estimating equations : FBAT-GEE

    NARCIS (Netherlands)

    Lange, C; Silverman, SK; Xu, [No Value; Weiss, ST; Laird, NM

    In this paper we propose a multivariate extension of family-based association tests based on generalized estimating equations. The test can be applied to multiple phenotypes and to phenotypic data obtained in longitudinal studies without making any distributional assumptions for the phenotypic

  9. Visual association test to detect early dementia of the Alzheimer type

    NARCIS (Netherlands)

    Lindeboom, J.; Schmand, B.; Tulner, L.; Walstra, G.; Jonker, C.

    2002-01-01

    Background: The visual association test (VAT) is a brief learning task based on imagery mnemonics. The test materials consist of six line drawings of pairs of interacting objects or animals-for example, an ape holding an umbrella. The person is asked to name each object and, later, is presented with

  10. Classification of Knee Joint Vibration Signals Using Bivariate Feature Distribution Estimation and Maximal Posterior Probability Decision Criterion

    Directory of Open Access Journals (Sweden)

    Fang Zheng

    2013-04-01

    Full Text Available Analysis of knee joint vibration or vibroarthrographic (VAG signals using signal processing and machine learning algorithms possesses high potential for the noninvasive detection of articular cartilage degeneration, which may reduce unnecessary exploratory surgery. Feature representation of knee joint VAG signals helps characterize the pathological condition of degenerative articular cartilages in the knee. This paper used the kernel-based probability density estimation method to model the distributions of the VAG signals recorded from healthy subjects and patients with knee joint disorders. The estimated densities of the VAG signals showed explicit distributions of the normal and abnormal signal groups, along with the corresponding contours in the bivariate feature space. The signal classifications were performed by using the Fisher’s linear discriminant analysis, support vector machine with polynomial kernels, and the maximal posterior probability decision criterion. The maximal posterior probability decision criterion was able to provide the total classification accuracy of 86.67% and the area (Az of 0.9096 under the receiver operating characteristics curve, which were superior to the results obtained by either the Fisher’s linear discriminant analysis (accuracy: 81.33%, Az: 0.8564 or the support vector machine with polynomial kernels (accuracy: 81.33%, Az: 0.8533. Such results demonstrated the merits of the bivariate feature distribution estimation and the superiority of the maximal posterior probability decision criterion for analysis of knee joint VAG signals.

  11. Collective estimation of multiple bivariate density functions with application to angular-sampling-based protein loop modeling

    KAUST Repository

    Maadooliat, Mehdi

    2015-10-21

    This paper develops a method for simultaneous estimation of density functions for a collection of populations of protein backbone angle pairs using a data-driven, shared basis that is constructed by bivariate spline functions defined on a triangulation of the bivariate domain. The circular nature of angular data is taken into account by imposing appropriate smoothness constraints across boundaries of the triangles. Maximum penalized likelihood is used to fit the model and an alternating blockwise Newton-type algorithm is developed for computation. A simulation study shows that the collective estimation approach is statistically more efficient than estimating the densities individually. The proposed method was used to estimate neighbor-dependent distributions of protein backbone dihedral angles (i.e., Ramachandran distributions). The estimated distributions were applied to protein loop modeling, one of the most challenging open problems in protein structure prediction, by feeding them into an angular-sampling-based loop structure prediction framework. Our estimated distributions compared favorably to the Ramachandran distributions estimated by fitting a hierarchical Dirichlet process model; and in particular, our distributions showed significant improvements on the hard cases where existing methods do not work well.

  12. 21 CFR 866.6010 - Tumor-associated antigen immunological test system.

    Science.gov (United States)

    2010-04-01

    .... Class II (special controls). Tumor markers must comply with the following special controls: (1) A... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Tumor-associated antigen immunological test system... SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Tumor Associated Antigen...

  13. Does the Name-Race Implicit Association Test measure racial prejudice?

    NARCIS (Netherlands)

    van Ravenzwaaij, D.; van der Maas, H.L.J.; Wagenmakers, E.-J.

    2011-01-01

    Research using the Implicit Association Test (IAT) has shown that names labeled as Caucasian elicit more positive associations than names labeled as non-Caucasian. One interpretation of this result is that the IAT measures latent racial prejudice. An alternative explanation is that the result is due

  14. Assessing autobiographical memory : The web-based autobiographical Implicit Association Test

    NARCIS (Netherlands)

    Verschuere, B.; Kleinberg, B.

    2016-01-01

    By assessing the association strength with TRUE and FALSE, the autobiographical Implicit Association Test (aIAT) [Sartori, G., Agosta, S., Zogmaister, C., Ferrara, S. D., & Castiello, U. (2008). How to accurately detect autobiographical events. Psychological Science, 19, 772–780.

  15. Is psychological distress in men recently diagnosed with testicular cancer associated with their neuropsychological test performance?

    Science.gov (United States)

    Skaali, Tone; Fosså, Sophie D; Andersson, Stein; Langberg, Carl W; Lehne, Gustav; Dahl, Alv A

    2011-04-01

    To study the level of cancer-related distress (CRD) and variables associated with CRD in recently diagnosed testicular cancer patients (TCPs), and to explore associations between distress levels and neuropsychological test performance at the same time-point. As part of a prospective study of their psychological and cognitive functioning, 135 TCPs completed the Impact of Event Scale (IES) as a measure of CRD at a median of 37 days after diagnosis. They also completed the Hospital Anxiety and Depression Scale (HADS) and the Positive and Negative Affect Schedule (PANAS). Among 135 TCPs, 131 were interviewed and 129 were also tested with a neuropsychological battery. All investigations were done after orchidectomy but before any additional treatment. The associations between neuropsychological test-scores and IES, HADS and PANAS were examined. Twenty-four percent (95%CI 17%-31%) of the TCPs reported clinically significant CRD (IES-total score>26). No demographic or cancer-related variables were associated with the CRD-level. In univariate analyses, previous mental problems, sleeping problems, a higher level of neuroticism, daily smoking and hazardous alcohol-use were significantly associated with the CRD-level. In multivariate analysis neuroticism, smoking and alcohol-use remained significantly associated with CRD. Four out of 18 neuropsychological test-scores were significantly associated with at least one distress-measure. Increasing distress-levels were associated with decreasing test performance on some measures of attention, working memory and executive functions. In newly diagnosed TCPs, the scores on neuropsychological tests should be considered in relation to co-existing mental distress. Future studies should consider adjustment for this on relevant tests. Copyright © 2010 John Wiley & Sons, Ltd.

  16. Gene-based testing of interactions in association studies of quantitative traits.

    Directory of Open Access Journals (Sweden)

    Li Ma

    Full Text Available Various methods have been developed for identifying gene-gene interactions in genome-wide association studies (GWAS. However, most methods focus on individual markers as the testing unit, and the large number of such tests drastically erodes statistical power. In this study, we propose novel interaction tests of quantitative traits that are gene-based and that confer advantage in both statistical power and biological interpretation. The framework of gene-based gene-gene interaction (GGG tests combine marker-based interaction tests between all pairs of markers in two genes to produce a gene-level test for interaction between the two. The tests are based on an analytical formula we derive for the correlation between marker-based interaction tests due to linkage disequilibrium. We propose four GGG tests that extend the following P value combining methods: minimum P value, extended Simes procedure, truncated tail strength, and truncated P value product. Extensive simulations point to correct type I error rates of all tests and show that the two truncated tests are more powerful than the other tests in cases of markers involved in the underlying interaction not being directly genotyped and in cases of multiple underlying interactions. We applied our tests to pairs of genes that exhibit a protein-protein interaction to test for gene-level interactions underlying lipid levels using genotype data from the Atherosclerosis Risk in Communities study. We identified five novel interactions that are not evident from marker-based interaction testing and successfully replicated one of these interactions, between SMAD3 and NEDD9, in an independent sample from the Multi-Ethnic Study of Atherosclerosis. We conclude that our GGG tests show improved power to identify gene-level interactions in existing, as well as emerging, association studies.

  17. Individual- and contextual-level factors associated with client-initiated HIV testing

    Directory of Open Access Journals (Sweden)

    Claudia Renata dos Santos Barros

    Full Text Available ABSTRACT: Background: Knowing the reasons for seeking HIV testing is central for HIV prevention. Despite the availability of free HIV counseling and testing in Brazil, coverage remains lacking. Methods: Survey of 4,760 respondents from urban areas was analyzed. Individual-level variables included sociodemographic characteristics; sexual and reproductive health; HIV/AIDS treatment knowledge and beliefs; being personally acquainted with a person with HIV/AIDS; and holding discriminatory ideas about people living with HIV. Contextual-level variables included the Human Development Index (HDI of the municipality; prevalence of HIV/AIDS; and availability of local HIV counseling and testing (CT services. The dependent variable was client-initiated testing. Multilevel Poisson regression models with random intercepts were used to assess associated factors. Results: Common individual-level variables among men and women included being personally acquainted with a person with HIV/AIDS and age; whereas discordant variables included those related to sexual and reproductive health and experiencing sexual violence. Among contextual-level factors, availability of CT services was variable associated with client-initiated testing among women only. The contextual-level variable “HDI of the municipality” was associated with client-initiated testing among women. Conclusion: Thus, marked gender differences in HIV testing were found, with a lack of HIV testing among married women and heterosexual men, groups that do not spontaneously seek testing.

  18. Testing for direct genetic effects using a screening step in family-based association studies

    Directory of Open Access Journals (Sweden)

    Sharon M Lutz

    2013-11-01

    Full Text Available In genome wide association studies (GWAS, families based studies tend to have less power to detect genetic associations than population based studies, such as case-control studies. This can be an issue when testing if genes in a family based GWAS have a direct effect on the phenotype of interest or if the genes act indirectly through a secondary phenotype. When multiple SNPs are tested for a direct effect in the family based study, a screening step can be used to minimize the burden of multiple comparisons in the causal analysis. We propose a 2-stage screening step that can be incorporated into the family based association test (FBAT approach similar to the conditional mean model approach in the VanSteen-algorithm [1]. Simulations demonstrate that the type 1 error is preserved and this method is advantageous when multiple markers are tested. This method is illustrated by an application to the Framingham Heart Study.

  19. The Effect of Supplemental Instruction on Retention: A Bivariate Probit Model

    Science.gov (United States)

    Bowles, Tyler J.; Jones, Jason

    2004-01-01

    Single equation regression models have been used to test the effect of Supplemental Instruction (SI) on student retention. These models, however, fail to account for the two salient features of SI attendance and retention: (1) both SI attendance and retention are categorical variables, and (2) are jointly determined endogenous variables. Adopting…

  20. Evaluation of internal validity using modern test theory: Application to word association.

    Science.gov (United States)

    Shono, Yusuke; Ames, Susan L; Stacy, Alan W

    2016-02-01

    Word association tests (WATs) have been widely used to examine associative/semantic memory structures and shown to be relevant to behavior and its underpinnings. Despite successful applications of WATs in diverse research areas, few studies have examined psychometric properties of these tests or other open-ended cognitive tests of common use. Modern test theory models, such as item response theory (IRT) models, are well suited to evaluate interpretations of this class of test. In this evaluation, unidimensional IRT models were fitted to the data on the WAT designed to capture associative memory relevant to an important applied issue: casual sex in a sample of 1,138 adult drug offenders. Using association instructions, participants were instructed to generate the first behavior or action that came to mind in response to cues (e.g., "hotel/motel") that might elicit casual sex-related responses. Results indicate a multitude of evidence for the internal validity of WAT score interpretations. All WAT items measured a single latent trait of casual sex-related associative memory, strongly related to the latent trait, and were invariant across gender, ethnicity, age groups, and sex partner profiles. The WAT was highly informative at average-to-high levels of the latent trait and also associated with risky sex behavior, demonstrating the usefulness of this class of test. The study illustrates the utility of the assessments in this at-risk population as well as the benefits of application of the modern test theory models in the evaluation of internal validity of open-ended cognitive test score interpretation. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  1. Mayo's Older Americans Normative Studies: Age- and IQ-Adjusted Norms for the Trail-Making Test, the Stroop Test, and MAE Controlled Oral Word Association Test.

    Science.gov (United States)

    Steinberg, Brett A; Bieliauskas, Linas A; Smith, Glenn E; Ivnik, Robert J

    2005-01-01

    Although normative data sets for standardized neuropsychometric instruments often include adjustments for subject variables, there are reasons to believe that improvements in interpretive accuracy that result from such adjustments are less than optimal. In particular, years of formal education may be less closely related to test performances than is general intellectual functioning. In this second of four reanalyses of results from the Mayo Clinic's Older Americans Normative Studies (MOANS) databases, age-adjusted scores for the Trail-Making Test, the Stroop Color-Word Test, and the MAE Controlled Oral Word Associations Test were found to be more strongly associated with Mayo age-adjusted WAIS-R Full Scale IQ scores (rs=.368 to .495) than with education (rs=.174 to .367) for healthy older examinees between 56 and 99 years of age. For the TMT and the COWAT, but not the Stroop, these associations became stronger as IQ increased (cf. Dodrill, 1997, 1999). Tables of age- and IQ-adjusted percentile equivalents of MOANS age-adjusted TMT, Stroop, and COWAT scores are presented for eleven age ranges and seven IQ ranges.

  2. Region-based association tests for sequencing data on survival traits.

    Science.gov (United States)

    Chien, Li-Chu; Bowden, Donald W; Chiu, Yen-Feng

    2017-09-01

    Family-based designs enriched with affected subjects and disease associated variants can increase statistical power for identifying functional rare variants. However, few rare variant analysis approaches are available for time-to-event traits in family designs and none of them applicable to the X chromosome. We developed novel pedigree-based burden and kernel association tests for time-to-event outcomes with right censoring for pedigree data, referred to FamRATS (family-based rare variant association tests for survival traits). Cox proportional hazard models were employed to relate a time-to-event trait with rare variants with flexibility to encompass all ranges and collapsing of multiple variants. In addition, the robustness of violating proportional hazard assumptions was investigated for the proposed and four current existing tests, including the conventional population-based Cox proportional model and the burden, kernel, and sum of squares statistic (SSQ) tests for family data. The proposed tests can be applied to large-scale whole-genome sequencing data. They are appropriate for the practical use under a wide range of misspecified Cox models, as well as for population-based, pedigree-based, or hybrid designs. In our extensive simulation study and data example, we showed that the proposed kernel test is the most powerful and robust choice among the proposed burden test and the existing four rare variant survival association tests. When applied to the Diabetes Heart Study, the proposed tests found exome variants of the JAK1 gene on chromosome 1 showed the most significant association with age at onset of type 2 diabetes from the exome-wide analysis. © 2017 WILEY PERIODICALS, INC.

  3. Bivariate flow karotyping in human philadelphia-positive chronic myelocytic leukemia

    NARCIS (Netherlands)

    Arkesteijn, G.J.A.; Martens, A.C.M.; Hagenbeek, A.

    1988-01-01

    Chromosome analysis on clinical leukemia material was done by means of flow cytometry (flow karyotyping) to investigate the applicability of this technique in the detection of leukemia-associated abnormalities. Flow karyotyping was performed on blood or bone marrow samples from eight patients with

  4. Association between positive patch tests to epoxy resin and fragrance mix I ingredients

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Christensen, Lars Porskjaer; Vølund, Aage

    2009-01-01

    BACKGROUND: Both epoxy resin (diglycidyl ether of bisphenol A) and fragrance mix I are included in the European baseline series of contact allergens. A significant association between positive reactions to epoxy resin and fragrance mix has been reported by others. OBJECTIVE: To investigate...... and possibly reproduce this association with the use of TRUE((R)) test data and supplementary tests with fragrance mix ingredients from the Department of Dermatology, Odense University Hospital. MATERIALS AND METHODS: Six thousand one hundred and fifteen consecutive eczema patients tested from 1995 to 2007...... were included, and test results from all patients tested with fragrance mix ingredients were analysed. RESULTS: One hundred and forty-five (2.4%) were positive to epoxy resin and 282 (4.6%) were positive to fragrance mix I. Nineteen were positive to both giving an odds ratio of 3.3, which...

  5. Bivariate modelling of the financial development-fossil fuel consumption nexus in Ghana

    OpenAIRE

    Yeboah Asuamah, Samuel

    2017-01-01

    The present paper modelled the relationship between financial developments and fossil fuel energy consumption in Ghana for the period 1970-2011 by applying Autoregressive Distributed Lad Model (ARDL). The findings of the paper on the cointegration test indicate significant evidence of cointegration between fossil fuel consumption and financial development. The findings seem to suggest that financial development is an explanatory variable in fossil fuel consumption management in achieving sust...

  6. A bivariate space–time downscaler under space and time misalignment

    OpenAIRE

    Berrocal, Veronica J.; Gelfand, Alan E.; Holland, David M.

    2010-01-01

    Ozone and particulate matter, PM2.5, are co-pollutants that have long been associated with increased public health risks. Information on concentration levels for both pollutants comes from two sources: monitoring sites and output from complex numerical models that produce concentration surfaces over large spatial regions. In this paper, we offer a fully-model-based approach for fusing these two sources of information for the pair of co-pollutants which is computationally ...

  7. A fast multilocus test with adaptive SNP selection for large-scale genetic-association studies

    KAUST Repository

    Zhang, Han

    2013-09-11

    As increasing evidence suggests that multiple correlated genetic variants could jointly influence the outcome, a multilocus test that aggregates association evidence across multiple genetic markers in a considered gene or a genomic region may be more powerful than a single-marker test for detecting susceptibility loci. We propose a multilocus test, AdaJoint, which adopts a variable selection procedure to identify a subset of genetic markers that jointly show the strongest association signal, and defines the test statistic based on the selected genetic markers. The P-value from the AdaJoint test is evaluated by a computationally efficient algorithm that effectively adjusts for multiple-comparison, and is hundreds of times faster than the standard permutation method. Simulation studies demonstrate that AdaJoint has the most robust performance among several commonly used multilocus tests. We perform multilocus analysis of over 26,000 genes/regions on two genome-wide association studies of pancreatic cancer. Compared with its competitors, AdaJoint identifies a much stronger association between the gene CLPTM1L and pancreatic cancer risk (6.0 × 10(-8)), with the signal optimally captured by two correlated single-nucleotide polymorphisms (SNPs). Finally, we show AdaJoint as a powerful tool for mapping cis-regulating methylation quantitative trait loci on normal breast tissues, and find many CpG sites whose methylation levels are jointly regulated by multiple SNPs nearby.

  8. Association between physiological falls risk and physical performance tests among community-dwelling older adults.

    Science.gov (United States)

    Singh, Devinder K A; Pillai, Sharmila G K; Tan, Sin Thien; Tai, Chu Chiau; Shahar, Suzana

    2015-01-01

    Physical performance and balance declines with aging and may lead to increased risk of falls. Physical performance tests may be useful for initial fall-risk screening test among community-dwelling older adults. Physiological profile assessment (PPA), a composite falls risk assessment tool is reported to have 75% accuracy to screen for physiological falls risk. PPA correlates with Timed Up and Go (TUG) test. However, the association between many other commonly used physical performance tests and PPA is not known. The aim of the present study was to examine the association between physiological falls risk measured using PPA and a battery of physical performance tests. One hundred and forty older adults from a senior citizens club in Kuala Lumpur, Malaysia (94 females, 46 males), aged 60 years and above (65.77±4.61), participated in this cross-sectional study. Participants were screened for falls risk using PPA. A battery of physical performance tests that include ten-step test (TST), short physical performance battery (SPPB), functional reach test (FRT), static balance test (SBT), TUG, dominant hand-grip strength (DHGS), and gait speed test (GST) were also performed. Spearman's rank correlation and binomial logistic regression were performed to examine the significantly associated independent variables (physical performance tests) with falls risk (dependent variable). Approximately 13% older adults were at high risk of falls categorized using PPA. Significant differences (Page, TST, SPPB, FRT, SBT, TUG between high and low falls risk group. A significant (Pphysiological falls risk (Pfalls screening to categorize high and low physiological falls risk among community-dwelling older adults. A more comprehensive assessment of falls risk can be performed thereafter for more specific intervention of underlying impairments.

  9. The association between methacholine challenge test and respiratory symptoms: a study on 146 patients

    Directory of Open Access Journals (Sweden)

    Paknejad O

    2011-02-01

    Full Text Available "nBackground: Asthma is a life-threatening disease that can cause death due to bronchospasm. In addition to clinical symptoms such as wheezing, acute paroxysmal dyspnea, chronic cough after exposure to cold air or cough after exercise, spirometry is also necessary for the diagnosis of asthma. The association between respiratory symptoms and a positive methacholine challenge test (MCT is still controversial. The aim of this study was to determine the association between methacholine test results and respiratory symptoms and allergy."n "nMethods: One hundred and forty-six patients with respiratory symptoms and normal baseline pulmonary function tests were enrolled in this cross-sectional study. The participants were divided into two groups according to their positive or negative response to MCT. The association between MCT and the clinical symptoms and allergy was later evaluated statistically."n "nResults: Out of 146 participants of the study 59 (40.4% were female and 87 (59.6% were male. The mean age of the participants was 33.8±13.8 years. Sixty-one patients (41.8% had positive results for the test. There was an association between a history of allergy, wheezing and age with positive MCT results. The other clinical signs had no association with the test."n "nConclusion: Methacholine challenge test is the best diagnostic test for ruling out asthma in patients with normal pulmonary function tests in whom we cannot definitely rule out asthma based solely on clinical symptoms. Nevertheless, in adults with a history of allergy, wheezing and also in patients below 30, the probability for a positive MCT is high.

  10. Subjective learning discounts test type: evidence from an associative learning and transfer task.

    Science.gov (United States)

    Touron, Dayna R; Hertzog, Christopher; Speagle, James Z

    2010-01-01

    We evaluated the extent to which memory test format and test transfer influence the dynamics of metacognitive judgments. Participants completed two study-test phases for paired-associates, with or without transferring test type, in one of four conditions: (1) recognition then recall, (2) recall then recognition, (3) recognition throughout, or (4) recall throughout. Global judgments were made prestudy, poststudy, and posttest for each phase; judgments of learning (JOLs) following item study were also collected. Results suggest that metacognitive judgment accuracy varies substantially by memory test type. Whereas underconfidence in JOLs and global predictions increases with recall practice (Koriat's underconfidence-with-practice effect), underconfidence decreases with recognition practice. Moreover, performance changes when transferring test type were not fully anticipated by pretest judgments.

  11. Testing for association with multiple traits in generalized estimation equations, with application to neuroimaging data.

    Science.gov (United States)

    Zhang, Yiwei; Xu, Zhiyuan; Shen, Xiaotong; Pan, Wei

    2014-08-01

    There is an increasing need to develop and apply powerful statistical tests to detect multiple traits-single locus associations, as arising from neuroimaging genetics and other studies. For example, in the Alzheimer's Disease Neuroimaging Initiative (ADNI), in addition to genome-wide single nucleotide polymorphisms (SNPs), thousands of neuroimaging and neuropsychological phenotypes as intermediate phenotypes for Alzheimer's disease, have been collected. Although some classic methods like MANOVA and newly proposed methods may be applied, they have their own limitations. For example, MANOVA cannot be applied to binary and other discrete traits. In addition, the relationships among these methods are not well understood. Importantly, since these tests are not data adaptive, depending on the unknown association patterns among multiple traits and between multiple traits and a locus, these tests may or may not be powerful. In this paper we propose a class of data-adaptive weights and the corresponding weighted tests in the general framework of generalized estimation equations (GEE). A highly adaptive test is proposed to select the most powerful one from this class of the weighted tests so that it can maintain high power across a wide range of situations. Our proposed tests are applicable to various types of traits with or without covariates. Importantly, we also analytically show relationships among some existing and our proposed tests, indicating that many existing tests are special cases of our proposed tests. Extensive simulation studies were conducted to compare and contrast the power properties of various existing and our new methods. Finally, we applied the methods to an ADNI dataset to illustrate the performance of the methods. We conclude with the recommendation for the use of the GEE-based Score test and our proposed adaptive test for their high and complementary performance. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Performance Test for Neutron Detector and Associated System using Research Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Seongwoo; Park, Sung Jae; Cho, Man Soon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Oh, Se Hyun [USERS, Daejeon (Korea, Republic of); Shin, Ho Cheol [KHNP CRI, Daejeon (Korea, Republic of)

    2016-10-15

    SPND (Self-Powered Neutron Detector) has been developed to extend its lifespan. ENFMS (Ex-Core Flux Monitoring System) of pressurized water reactor has been also improved. After the development and improvement, their performance must be verified under the neutron irradiation environment. We used a research reactor for the performance verification of neutron detector and associated system because the research reactor can meet the neutron flux level of commercial nuclear reactor. In this paper, we report the performance verification method and result for the SPND and ENFMS using the research reactor. The performance tests for the SPND and ENFMS were conducted using UCI TRIGA reactor. The test environment of commercial reactor’s neutron flux level must be required. However, it is difficult to perform the test in the commercial rector due to the constraint of time and space. The research reactor can be good alternative neutron source for the test of neutron detectors and associated system.

  13. Test Methods and Protocols for Environmental and Safety Hazards Associated with Home Energy Retrofits

    Energy Technology Data Exchange (ETDEWEB)

    Cautley, D.; Viner, J.; Lord, M.; Pearce, M.

    2012-12-01

    A number of health hazards and hazards to the durability of homes may be associated with energy retrofitting and home renovation projects. Among the hazards associated with energy retrofit work, exposure to radon is thought to cause more than 15,000 deaths per year in the U.S., while carbon monoxide poisoning results in about 20,000 injuries and 450 deaths per year. Testing procedures have been developed for identifying and quantifying hazards during retrofitting. These procedures commonly include a battery of tests to screen combustion appliances for safe operation, including worst case depressurization measurement, backdrafting (spillage) under depressurized or normal conditions, and carbon monoxide production.

  14. PedGenie: meta genetic association testing in mixed family and case-control designs

    Directory of Open Access Journals (Sweden)

    Allen-Brady Kristina

    2007-11-01

    Full Text Available Abstract Background- PedGenie software, introduced in 2006, includes genetic association testing of cases and controls that may be independent or related (nuclear families or extended pedigrees or mixtures thereof using Monte Carlo significance testing. Our aim is to demonstrate that PedGenie, a unique and flexible analysis tool freely available in Genie 2.4 software, is significantly enhanced by incorporating meta statistics for detecting genetic association with disease using data across multiple study groups. Methods- Meta statistics (chi-squared tests, odds ratios, and confidence intervals were calculated using formal Cochran-Mantel-Haenszel techniques. Simulated data from unrelated individuals and individuals in families were used to illustrate meta tests and their empirically-derived p-values and confidence intervals are accurate, precise, and for independent designs match those provided by standard statistical software. Results- PedGenie yields accurate Monte Carlo p-values for meta analysis of data across multiple studies, based on validation testing using pedigree, nuclear family, and case-control data simulated under both the null and alternative hypotheses of a genotype-phenotype association. Conclusion- PedGenie allows valid combined analysis of data from mixtures of pedigree-based and case-control resources. Added meta capabilities provide new avenues for association analysis, including pedigree resources from large consortia and multi-center studies.

  15. A bivariate approach to the widening of the frontal lobes in the genus Homo.

    Science.gov (United States)

    Bruner, Emiliano; Holloway, Ralph L

    2010-02-01

    Within the genus Homo, the most encephalized taxa (Neandertals and modern humans) show relatively wider frontal lobes than either Homo erectus or australopithecines. The present analysis considers whether these changes are associated with a single size-based or allometric pattern (positive allometry of the width of the anterior endocranial fossa) or with a more specific and non-allometric pattern. The relationship between hemispheric length, maximum endocranial width, and frontal width at Broca's area was investigated in extant and extinct humans. Our results do not support positive allometry for the frontal lobe's width in relation to the main endocranial diameters within modern humans (Homo sapiens). Also, the correlation between frontal width and hemispheric length is lower than the correlation between frontal width and parieto-temporal width. When compared with the australopithecines, the genus Homo could have experienced a non-allometric widening of the brain at the temporo-parietal areas, which is most evident in Neandertals. Modern humans and Neandertals also display a non-allometric widening of the anterior endocranial fossa at the Broca's cap when compared with early hominids, again more prominent in the latter group. Taking into account the contrast between the intra-specific patterns and the between-species differences, the relative widening of the anterior fossa can be interpreted as a definite evolutionary character instead of a passive consequence of brain size increase. This expansion is most likely associated with correspondent increments of the underlying neural mass, or at least with a geometrical reallocation of the frontal cortical volumes. Although different structural changes of the cranial architecture can be related to such variations, the widening of the frontal areas is nonetheless particularly interesting when some neural functions (like language or working memory, decision processing, etc.) and related fronto-parietal cortico

  16. Revealing Students' Cognitive Structure about Physical and Chemical Change: Use of a Word Association Test

    Science.gov (United States)

    Yildirir, Hasene Esra; Demirkol, Hatice

    2018-01-01

    The current study aimed at examining the utility of a word association test in revealing students' cognitive structure in a specific chemistry topic through a word association test. The participants were 153 6th graders in a western Turkish city. The results revealed that the word association test serves a useful purpose in exploring the students'…

  17. Comparison between different uncertainty propagation methods in multivariate analysis: An application in the bivariate case

    International Nuclear Information System (INIS)

    Mullor, R.; Sanchez, A.; Martorell, S.; Martinez-Alzamora, N.

    2011-01-01

    Safety related systems performance optimization is classically based on quantifying the effects that testing and maintenance activities have on reliability and cost (R+C). However, R+C quantification is often incomplete in the sense that important uncertainties may not be considered. An important number of studies have been published in the last decade in the field of R+C based optimization considering uncertainties. They have demonstrated that inclusion of uncertainties in the optimization brings the decision maker insights concerning how uncertain the R+C results are and how this uncertainty does matter as it can result in differences in the outcome of the decision making process. Several methods of uncertainty propagation based on the theory of tolerance regions have been proposed in the literature depending on the particular characteristics of the variables in the output and their relations. In this context, the objective of this paper focuses on the application of non-parametric and parametric methods to analyze uncertainty propagation, which will be implemented on a multi-objective optimization problem where reliability and cost act as decision criteria and maintenance intervals act as decision variables. Finally, a comparison of results of these applications and the conclusions obtained are presented.

  18. Comparison between different uncertainty propagation methods in multivariate analysis: An application in the bivariate case

    Energy Technology Data Exchange (ETDEWEB)

    Mullor, R. [Dpto. Estadistica e Investigacion Operativa, Universidad Alicante (Spain); Sanchez, A., E-mail: aisanche@eio.upv.e [Dpto. Estadistica e Investigacion Operativa Aplicadas y Calidad, Universidad Politecnica Valencia, Camino de Vera s/n 46022 (Spain); Martorell, S. [Dpto. Ingenieria Quimica y Nuclear, Universidad Politecnica Valencia (Spain); Martinez-Alzamora, N. [Dpto. Estadistica e Investigacion Operativa Aplicadas y Calidad, Universidad Politecnica Valencia, Camino de Vera s/n 46022 (Spain)

    2011-06-15

    Safety related systems performance optimization is classically based on quantifying the effects that testing and maintenance activities have on reliability and cost (R+C). However, R+C quantification is often incomplete in the sense that important uncertainties may not be considered. An important number of studies have been published in the last decade in the field of R+C based optimization considering uncertainties. They have demonstrated that inclusion of uncertainties in the optimization brings the decision maker insights concerning how uncertain the R+C results are and how this uncertainty does matter as it can result in differences in the outcome of the decision making process. Several methods of uncertainty propagation based on the theory of tolerance regions have been proposed in the literature depending on the particular characteristics of the variables in the output and their relations. In this context, the objective of this paper focuses on the application of non-parametric and parametric methods to analyze uncertainty propagation, which will be implemented on a multi-objective optimization problem where reliability and cost act as decision criteria and maintenance intervals act as decision variables. Finally, a comparison of results of these applications and the conclusions obtained are presented.

  19. Estimated of associated uncertainties of the linearity test of dose calibrators

    International Nuclear Information System (INIS)

    Sousa, Carlos H.S.; Peixoto, Jose G.P.

    2013-01-01

    Activimeters determine the activity of radioactive samples and them are validated by performance tests. This research determined the expanded uncertainties associated to the linearity test. Were used three dose calibrators and three sources of 99 Tc m for testing using recommended protocol by the IAEA, which considered the decay of radioactive samples. The expanded uncertainties evaluated were not correlated with each other and their analysis considered a rectangular probability distribution. The results are also presented in graphical form by the function of normalized activity measured in terms of conventional true value. (author)

  20. Fatigue testing of a carbon fibre composite wind turbine blade with associated material characterisation

    Energy Technology Data Exchange (ETDEWEB)

    Lowe, G.A.; Richardson, D.J. [Univ. of the West of England, Faculty of Engineering, Bristol (United Kingdom)

    1996-09-01

    Within the EC project JOULE 2, the University of the West of England (UWE) tested a carbon fibre reinforced epoxy (CFRE) full scale wind turbine blade together with an associated material test coupon programme. All the work was closely linked with the manufacturer Polymarine BV of the Netherlands, who designed and manufactured the blade and provided test specimens, the UWE carried out the research into the validation of the design calculations together with a check of the strength and fatigue life of the blade. (au)

  1. Factors associated with HIV testing and condom use in Mozambique: implications for programs.

    Science.gov (United States)

    Agha, Sohail

    2012-09-05

    To identify predictors of HIV testing and condom use in Mozambique. Nationally representative survey data collected in Mozambique in 2009 was analyzed. Logistic regression analysis was used for two outcomes: HIV testing and condom use. Women at a higher risk of HIV were less likely to be tested for HIV than women at a lower risk: compared to married women, HIV testing was lower among never married women (OR = 0.37, CI: 0.25-0.54); compared to women with one lifetime partner, HIV testing was lower among women with four or more lifetime partners (OR = 0.62, CI: 0.47-0.83). Large wealth differentials were observed: compared to the poorest women, HIV testing was higher among the wealthiest women (OR = 3.03, CI: 1.96-4.68). Perceived quality of health services was an important predictor of HIV testing: HIV testing was higher among women who rated health services as being of very good quality (OR = 2.12, CI: 1.49-3.00). Type of sexual partner was the strongest predictor of condom use: condom use was higher among men who reported last sex with a girlfriend (OR = 9.75, CI: 6.81-13.97) or a casual partner (OR = 11.05, CI: 7.21-16.94). Being tested for HIV during the last two years was the only programmatic variable that predicted condom use. Interestingly, being tested for HIV more than two years ago was not associated with condom use. Frequent mass media exposure was neither associated with HIV testing nor with condom use. The focus of HIV testing should shift from married women (routinely tested during antenatal care visits) to unmarried women and women with multiple sexual partners. Financial barriers to HIV testing appear to be substantial. Since HIV testing is done without a fee being charged, these barriers are presumably related to the cost of transportation to static health facilities. Mechanisms should be developed to cover the cost of transportation to health facilities. Substantially increasing community-based counseling is one way of reducing the cost of

  2. Factors associated with HIV testing and condom use in Mozambique: implications for programs

    Directory of Open Access Journals (Sweden)

    Agha Sohail

    2012-09-01

    Full Text Available Abstract Background To identify predictors of HIV testing and condom use in Mozambique. Methods Nationally representative survey data collected in Mozambique in 2009 was analyzed. Logistic regression analysis was used for two outcomes: HIV testing and condom use. Results Women at a higher risk of HIV were less likely to be tested for HIV than women at a lower risk: compared to married women, HIV testing was lower among never married women (OR = 0.37, CI: 0.25-0.54; compared to women with one lifetime partner, HIV testing was lower among women with four or more lifetime partners (OR = 0.62, CI: 0.47-0.83. Large wealth differentials were observed: compared to the poorest women, HIV testing was higher among the wealthiest women (OR = 3.03, CI: 1.96-4.68. Perceived quality of health services was an important predictor of HIV testing: HIV testing was higher among women who rated health services as being of very good quality (OR = 2.12, CI: 1.49-3.00. Type of sexual partner was the strongest predictor of condom use: condom use was higher among men who reported last sex with a girlfriend (OR = 9.75, CI: 6.81-13.97 or a casual partner (OR = 11.05, CI: 7.21-16.94. Being tested for HIV during the last two years was the only programmatic variable that predicted condom use. Interestingly, being tested for HIV more than two years ago was not associated with condom use. Frequent mass media exposure was neither associated with HIV testing nor with condom use. Conclusions The focus of HIV testing should shift from married women (routinely tested during antenatal care visits to unmarried women and women with multiple sexual partners. Financial barriers to HIV testing appear to be substantial. Since HIV testing is done without a fee being charged, these barriers are presumably related to the cost of transportation to static health facilities. Mechanisms should be developed to cover the cost of transportation to health facilities

  3. Information Decomposition in Bivariate Systems: Theory and Application to Cardiorespiratory Dynamics

    Directory of Open Access Journals (Sweden)

    Luca Faes

    2015-01-01

    Full Text Available In the framework of information dynamics, the temporal evolution of coupled systems can be studied by decomposing the predictive information about an assigned target system into amounts quantifying the information stored inside the system and the information transferred to it. While information storage and transfer are computed through the known self-entropy (SE and transfer entropy (TE, an alternative decomposition evidences the so-called cross entropy (CE and conditional SE (cSE, quantifying the cross information and internal information of the target system, respectively. This study presents a thorough evaluation of SE, TE, CE and cSE as quantities related to the causal statistical structure of coupled dynamic processes. First, we investigate the theoretical properties of these measures, providing the conditions for their existence and assessing the meaning of the information theoretic quantity that each of them reflects. Then, we present an approach for the exact computation of information dynamics based on the linear Gaussian approximation, and exploit this approach to characterize the behavior of SE, TE, CE and cSE in benchmark systems with known dynamics. Finally, we exploit these measures to study cardiorespiratory dynamics measured from healthy subjects during head-up tilt and paced breathing protocols. Our main result is that the combined evaluation of the measures of information dynamics allows to infer the causal effects associated with the observed dynamics and to interpret the alteration of these effects with changing experimental conditions.

  4. Techniques associated with thermal-vacuum testing of the OAO-C heat pipes

    Science.gov (United States)

    Marshburn, J. P.

    1972-01-01

    The mechanical problems associated with testing the two high-heat load pipes are discussed. One of these pipes was tested three times before being accepted. The first test resulted in the discovery of non-condensable hydrogen gas, which prevented the pipe from functioning properly. The second test was a repeat of the first, to see if all the gas had been removed. The third test was to see if any changes had occurred to the pipe as a result of saddle modifications. Saddle modifications were necessary because the epoxy binding agent between the saddles and the pipe had decomposed during the testing. The test problems discussed deal with the specially designed heat-removal devices, the mobile tilt table, the table position indicator, and the heat input mechanisms, all of which were necessary to conduct a high-heat load, thermal-vacuum test. The final results showed that the techniques used were adequate for thermal-vacuum testing of heat pipes.

  5. Clinical, social and ethical issues associated with non-invasive prenatal testing for aneuploidy.

    Science.gov (United States)

    Griffin, Blanche; Edwards, Samantha; Chitty, Lyn S; Lewis, Celine

    2018-03-01

    Non-invasive prenatal testing (NIPT), based on analysis of cell-free foetal DNA, is rapidly becoming a preferred method to screen for chromosomal aneuploidy with the technology now available in over 90 countries. This review provides an up-to-date discussion of the key clinical, social and ethical implications associated with this revolutionary technology. Stakeholders are positive about a test that is highly accurate, safe, can be perfomed early in pregnancy, identifies affected pregnancies that might otherwise have been missed and reduces the need for invasive testing. Nevertheless, professional societies currently recommend it as an advanced screening test due to the low false positive rate (FPR). Despite the practical and psychological benefits, a number of concerns have been raised which warrant attention. These include the potential for routinisation of testing and subsequent impact on informed decision-making, an "easy" blood test inadvertently contributing to women feeling pressured to take the test, fears NIPT will lead to less tolerance and support for those living with Down syndrome and the heightened expectation of having "perfect babies". These issues can be addressed to some extent through clinician education, patient information and establishing national and international consensus in the development of comprehensive and regularly updated guidelines. As the number of conditions we are able to test for non-invasively expands it will be increasingly important to ensure pre-test counselling can be delivered effectively supported by knowledgeable healthcare professionals.

  6. Testing key predictions of the associative account of mirror neurons in humans using multivariate pattern analysis.

    Science.gov (United States)

    Oosterhof, Nikolaas N; Wiggett, Alison J; Cross, Emily S

    2014-04-01

    Cook et al. overstate the evidence supporting their associative account of mirror neurons in humans: most studies do not address a key property, action-specificity that generalizes across the visual and motor domains. Multivariate pattern analysis (MVPA) of neuroimaging data can address this concern, and we illustrate how MVPA can be used to test key predictions of their account.

  7. Predicting alcohol use with a recoding-free variant of the Implicit Association Test

    NARCIS (Netherlands)

    Houben, K.; Rothermund, K.; Wiers, R.W.

    2009-01-01

    Recently, a modified version of the Implicit Association Test (IAT), the IAT-RF (IAT-Recoding Free) was developed which prevents recoding processes by switching response assignments randomly between trials rather than between blocks. In this study, the IAT-RF was used to measure and examine the

  8. Analysis of Secondary School Students' Perceptions about Information Technologies through a Word Association Test

    Science.gov (United States)

    Eren, Fetah; Sahin, Ismail; Celik, Ismail; Akturk, Ahmet Oguz

    2014-01-01

    The aim of this study is to discover secondary school students' perceptions related to information technologies and the connections between concepts in their cognitive structures. A word association test consisting of six concepts related to information technologies is used to collect data from 244 secondary school students. Concept maps that…

  9. Impairment of Self-control and its manifestations in Continuous Word Association Test

    Directory of Open Access Journals (Sweden)

    Gabriela Marhevská

    2013-01-01

    Full Text Available The aim of work is to find out how self–control influences word associations. The research presented herein provides new insight into manifestations of self–control. Experimental study is based on the Strength model (Baumeister, Bratslavsky, Muraven, & Tice, 1998, which assumes that self–control relies on limited resources of ego which become depleted with increased exercising of self–control (Ego depletion. The aim of this experiment was to verify in an empirical manner that the impairment of self–control can be manifested in word association tests. Continuous word association test (Kondáš, 1979 was used in this experiment. Distinct indicators of continuous word associations were divided into the following 4 categories; verbal dynamics, abnormalities in association, errors in the reproduction of association reactions and the overall number of mistakes. Parallel task and “e letter” crossing out exercises were used in order to impair ego resource.One–Way ANOVA was used in the analysis. The results of the study indicate that impaired self–control, induced by the “e letter” crossing out task, increased verbal dynamics. According to the obtained results, Continuous word association test provoke automatic processes. Further important indicators of impaired self–control were increased perseverations of potentially conflicting word ′control′, erroneous reproductions of potentially conflicting word ′explosions′ and the overall indicator of mistakes in conflict word‚ explosions and control‘. The experiment results show an increase in the number of mistakes of word association production when self–control is impaired.

  10. Association between pressure pain sensitivity and autonomic function as assessed by a tilt table test

    DEFF Research Database (Denmark)

    Ballegaard, Søren; Bergmann, Natasha; Karpatschof, Benny

    2015-01-01

    BACKGROUND: We tested the hypothesis that pressure sensitivity of the sternum (PPS) is associated with autonomic nervous system (ANS) function as assessed by tilt table test (TTT). in patients with stable ischemic heart disease. OBJECTIVES: (1) To evaluate an association between PPS and systolic...... blood pressure (SBP) and heart rate (HR) responses to TTT; and (2) to test the hypothesis that a reduction of resting PPS raises the PPS, SBP and HR responses to TTT response and lowers risk factors for ANS dysfunction (ANSD). METHODS: Cross-sectional study: In 361 patients with stable ischemic heart...... disease we measured PPS, SBP, and HR during TTT. Intervention study: We reassessed subjects with persistent stress who concluded a stress intervention trial by a second TTT. RESULTS: Cross-sectional study: Resting PPS and the PPS response to TTT were correlated (r = - 0.37). The PPS response to TTT...

  11. Association between physiological falls risk and physical performance tests among community-dwelling older adults

    Directory of Open Access Journals (Sweden)

    Singh DK

    2015-08-01

    Full Text Available Devinder KA Singh,1 Sharmila GK Pillai,1 Sin Thien Tan,1 Chu Chiau Tai,1 Suzana Shahar2 1Physiotherapy Programme, School of Rehabilitation Sciences, 2Nutrition and Dietetics Programme, School of Healthcare Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, Kuala Lumpur, Malaysia Background: Physical performance and balance declines with aging and may lead to increased risk of falls. Physical performance tests may be useful for initial fall-risk screening test among community-dwelling older adults. Physiological profile assessment (PPA, a composite falls risk assessment tool is reported to have 75% accuracy to screen for physiological falls risk. PPA correlates with Timed Up and Go (TUG test. However, the association between many other commonly used physical performance tests and PPA is not known. The aim of the present study was to examine the association between physiological falls risk measured using PPA and a battery of physical performance tests.Methods: One hundred and forty older adults from a senior citizens club in Kuala Lumpur, Malaysia (94 females, 46 males, aged 60 years and above (65.77±4.61, participated in this cross-sectional study. Participants were screened for falls risk using PPA. A battery of physical performance tests that include ten-step test (TST, short physical performance battery (SPPB, functional reach test (FRT, static balance test (SBT, TUG, dominant hand-grip strength (DHGS, and gait speed test (GST were also performed. Spearman’s rank correlation and binomial logistic regression were performed to examine the significantly associated independent variables (physical performance tests with falls risk (dependent variable.Results: Approximately 13% older adults were at high risk of falls categorized using PPA. Significant differences (P<0.05 were demonstrated for age, TST, SPPB, FRT, SBT, TUG between high and low falls risk group. A significant (P<0.01 weak correlation

  12. Efficient two-step testing of gene-gene interactions in genome-wide association studies.

    Science.gov (United States)

    Lewinger, Juan Pablo; Morrison, John L; Thomas, Duncan C; Murcray, Cassandra E; Conti, David V; Li, Dalin; Gauderman, W James

    2013-07-01

    Exhaustive testing of all possible SNP pairs in a genome-wide association study (GWAS) generally yields low power to detect gene-gene (G × G) interactions because of small effect sizes and stringent requirements for multiple-testing correction. We introduce a new two-step procedure for testing G × G interactions in case-control GWAS to detect interacting single nucleotide polymorphisms (SNPs) regardless of their marginal effects. In an initial screening step, all SNP pairs are tested for gene-gene association in the combined sample of cases and controls. In the second step, the pairs that pass the screening are followed up with a traditional test for G × G interaction. We show that the two-step method is substantially more powerful to detect G × G interactions than the exhaustive testing approach. For example, with 2,000 cases and 2,000 controls, the two-step method can have more than 90% power to detect an interaction odds ratio of 2.0 compared to less than 50% power for the exhaustive testing approach. Moreover, we show that a hybrid two-step approach that combines our newly proposed two-step test and the two-step test that screens for marginal effects retains the best power properties of both. The two-step procedures we introduce have the potential to uncover genetic signals that have not been previously identified in an initial single-SNP GWAS. We demonstrate the computational feasibility of the two-step G × G procedure by performing a G × G scan in the asthma GWAS of the University of Southern California Children's Health Study. © 2013 WILEY PERIODICALS, INC.

  13. Associations of maximal strength and muscular endurance test scores with cardiorespiratory fitness and body composition.

    Science.gov (United States)

    Vaara, Jani P; Kyröläinen, Heikki; Niemi, Jaakko; Ohrankämmen, Olli; Häkkinen, Arja; Kocay, Sheila; Häkkinen, Keijo

    2012-08-01

    The purpose of the present study was to assess the relationships between maximal strength and muscular endurance test scores additionally to previously widely studied measures of body composition and maximal aerobic capacity. 846 young men (25.5 ± 5.0 yrs) participated in the study. Maximal strength was measured using isometric bench press, leg extension and grip strength. Muscular endurance tests consisted of push-ups, sit-ups and repeated squats. An indirect graded cycle ergometer test was used to estimate maximal aerobic capacity (V(O2)max). Body composition was determined with bioelectrical impedance. Moreover, waist circumference (WC) and height were measured and body mass index (BMI) calculated. Maximal bench press was positively correlated with push-ups (r = 0.61, p strength (r = 0.34, p strength correlated positively (r = 0.36-0.44, p test scores were related to maximal aerobic capacity and body fat content, while fat free mass was associated with maximal strength test scores and thus is a major determinant for maximal strength. A contributive role of maximal strength to muscular endurance tests could be identified for the upper, but not the lower extremities. These findings suggest that push-up test is not only indicative of body fat content and maximal aerobic capacity but also maximal strength of upper body, whereas repeated squat test is mainly indicative of body fat content and maximal aerobic capacity, but not maximal strength of lower extremities.

  14. Factors associated with receiving Pap tests among married immigrant women of Vietnamese origin in southern Taiwan.

    Science.gov (United States)

    Lee, Fang-Hsin; Wang, Hsiu-Hung; Tsai, Hsiu-Min; Lin, Miao-Ling

    2016-01-01

    The purpose of this study was to explore the factors associated with Pap testing among married immigrant women of Vietnamese origin residing in Taiwan, including demographics, knowledge of cervical cancer, knowledge of Pap tests, fatalism, attitudes toward cervical cancer, and barriers to receiving Pap tests. A cross-sectional correlational design was used. Data were collected from July 2012 to January 2013. Participants were recruited through snowball sampling in two communities in Southern Taiwan. A total of 451 married immigrant women of Vietnamese origin aged 30 years and over were invited to participate in the study and 427 participated. Data analysis included descriptive statistics and multivariate logistic regression. Participants with no children were significantly less likely to have received a Pap test (odds ratio = 0.278, 95% confidence interval [CI] = 0.135-0.569); each additional point of knowledge about Pap tests increased the likelihood of having a Pap test by 19% (odds ratio = 1.190, 95% CI = 1.093-1.297), and each additional point in barriers to receiving Pap tests decreased the chances of having received a Pap test (odds ratio = 0.714, 95% CI = 0.637-0.800). The results can provide governments with a reference for developing policies for cervical cancer prevention among married immigrant Vietnamese women.

  15. Saline Infusion Test highly associated with the incidence of cardio- and cerebrovascular events in primary aldosteronism.

    Science.gov (United States)

    Hayashi, Reiko; Tamada, Daisuke; Murata, Masahiko; Mukai, Kosuke; Kitamura, Tetsuhiro; Otsuki, Michio; Shimomura, Iichiro

    2017-05-30

    Primary aldosteronism (PA) is caused by excess secretion of aldosterone and is an independent risk factor for cardio-cerebro-vascular (CCV) events. The goal of treatment of PA should include prevention of CCV events. A definitive diagnosis of PA is established by confirmatory tests [saline infusion test (SIT), furosemide upright test (FUT) and captopril challenge test (CCT)]. However, there is no information on whether the hormone levels measured by these confirmatory tests are associated with CCV events. The aim of this retrospective study was to elucidate the relationship between the results of the above confirmatory tests and prevalence of CCV disease in patients with PA. The study subjects were 292 PA patients who were assessed for past history of CCV events at the time of diagnosis of PA. CCV events were significantly higher in patients with positive than negative SIT (12.8% vs. 3.3%, p=0.04). There were no differences in the incidences of CCV events between patients with positive and negative CCT and FUT (CCT: 11.0% vs. 3.9%, p=0.13, FUT: 6.1% vs. 5.7%, p=0.93). Our results demonstrated a higher incidence of CCV disease in PA SIT-positive patients compared to those with negative test. SIT is a potentially useful test not only for the diagnosis of PA but also assessment of the risk of CCV events.

  16. Retrospective Binary-Trait Association Test Elucidates Genetic Architecture of Crohn Disease

    Science.gov (United States)

    Jiang, Duo; Zhong, Sheng; McPeek, Mary Sara

    2016-01-01

    In genetic association testing, failure to properly control for population structure can lead to severely inflated type 1 error and power loss. Meanwhile, adjustment for relevant covariates is often desirable and sometimes necessary to protect against spurious association and to improve power. Many recent methods to account for population structure and covariates are based on linear mixed models (LMMs), which are primarily designed for quantitative traits. For binary traits, however, LMM is a misspecified model and can lead to deteriorated performance. We propose CARAT, a binary-trait association testing approach based on a mixed-effects quasi-likelihood framework, which exploits the dichotomous nature of the trait and achieves computational efficiency through estimating equations. We show in simulation studies that CARAT consistently outperforms existing methods and maintains high power in a wide range of population structure settings and trait models. Furthermore, CARAT is based on a retrospective approach, which is robust to misspecification of the phenotype model. We apply our approach to a genome-wide analysis of Crohn disease, in which we replicate association with 17 previously identified regions. Moreover, our analysis on 5p13.1, an extensively reported region of association, shows evidence for the presence of multiple independent association signals in the region. This example shows how CARAT can leverage known disease risk factors to shed light on the genetic architecture of complex traits. PMID:26833331

  17. Cheating the lie detector: faking in the autobiographical Implicit Association Test.

    Science.gov (United States)

    Verschuere, Bruno; Prati, Valentina; Houwer, Jan De

    2009-04-01

    The autobiographical Implicit Association Test (aIAT) was recently introduced in this journal as a new and promising lie-detection tool. The initial report found 91% accuracy in determining which of two autobiographical events was true. It was suggested that the aIAT, unlike other lie-detection tests, is resistant to faking. We investigated whether participants can strategically alter their performance on the aIAT. Experiment 1 showed that participants guilty of a mock theft were able to obtain an innocent test outcome. Two additional experiments showed that guilty participants can fake the aIAT without prior experience with the aIAT and when a response deadline is imposed. The aIAT is subject to the same shortcomings as other lie-detection tests.

  18. Prevalence of condomless anal intercourse and recent HIV testing and their associated factors among men who have sex with men in Hangzhou, China: A respondent-driven sampling survey.

    Directory of Open Access Journals (Sweden)

    Runhua Li

    Full Text Available Men who have sex with men (MSM are a large high-risk population for HIV infection in recent years in China. A cross-sectional survey was conducted in Hangzhou, China, to determine rates of condomless anal intercourse (CAI, recent HIV testing (in the recent year and associated factors using respondent-driven sampling. Questionnaires using face-to-face interviews were employed to collect data on sexual risk behaviors and HIV testing. Five hundred eleven MSM were recruited, of which 459 (89.8% had anal intercourse in the past 6 months. Of these 459 participants, 457 (99.6% answered whether they had taken an HIV test in the recent year, so only their data were analyzed. Weighted data were analyzed using bivariate and multivariate logistic regression analysis. The CAI rate with male partners in the past 6 months was 43.7% (95% confidence interval [CI], 34.0-51.5%, while the rate of condomless vaginal intercourse (CVI was 21.6% (95% CI, 15.6-32.3%. The prevalence of recent HIV testing was 56.8% (95% CI, 48.7-66.5%, while the prevalence of HIV and syphilis were 8.8% and 6.5%, respectively. Multivariate analysis indicated that CAI was associated with earlier homosexual debut, suicidal inclinations, childhood sexual abuse, HIV testing in the recent year, and lower estimate of HIV prevalence. Recent HIV testing was associated with homosexual debut age, engaging in CAI with male partners in the past 6 months, having oral sex in the past 6 months, self-perceived higher likelihood of HIV infection, knowing about antiretroviral therapy for HIV/AIDS, receiving AIDS/sexually transmitted infection (STI interventions in the past year, and syphilis infection. Given high prevalence of HIV and syphilis, high levels of CAI and CVI, and low HIV testing rate, the results indicated high risk of HIV infection and transmission among MSM. HIV prevention interventions should target MSM with early homosexual debut and psychosocial health problems, while HIV/AIDS education

  19. An exponential combination procedure for set-based association tests in sequencing studies.

    Science.gov (United States)

    Chen, Lin S; Hsu, Li; Gamazon, Eric R; Cox, Nancy J; Nicolae, Dan L

    2012-12-07

    State-of-the-art next-generation-sequencing technologies can facilitate in-depth explorations of the human genome by investigating both common and rare variants. For the identification of genetic factors that are associated with disease risk or other complex phenotypes, methods have been proposed for jointly analyzing variants in a set (e.g., all coding SNPs in a gene). Variants in a properly defined set could be associated with risk or phenotype in a concerted fashion, and by accumulating information from them, one can improve power to detect genetic risk factors. Many set-based methods in the literature are based on statistics that can be written as the summation of variant statistics. Here, we propose taking the summation of the exponential of variant statistics as the set summary for association testing. From both Bayesian and frequentist perspectives, we provide theoretical justification for taking the sum of the exponential of variant statistics because it is particularly powerful for sparse alternatives-that is, compared with the large number of variants being tested in a set, only relatively few variants are associated with disease risk-a distinctive feature of genetic data. We applied the exponential combination gene-based test to a sequencing study in anticancer pharmacogenomics and uncovered mechanistic insights into genes and pathways related to chemotherapeutic susceptibility for an important class of oncologic drugs. Copyright © 2012 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  20. Identifying genetic marker sets associated with phenotypes via an efficient adaptive score test

    KAUST Repository

    Cai, T.

    2012-06-25

    In recent years, genome-wide association studies (GWAS) and gene-expression profiling have generated a large number of valuable datasets for assessing how genetic variations are related to disease outcomes. With such datasets, it is often of interest to assess the overall effect of a set of genetic markers, assembled based on biological knowledge. Genetic marker-set analyses have been advocated as more reliable and powerful approaches compared with the traditional marginal approaches (Curtis and others, 2005. Pathways to the analysis of microarray data. TRENDS in Biotechnology 23, 429-435; Efroni and others, 2007. Identification of key processes underlying cancer phenotypes using biologic pathway analysis. PLoS One 2, 425). Procedures for testing the overall effect of a marker-set have been actively studied in recent years. For example, score tests derived under an Empirical Bayes (EB) framework (Liu and others, 2007. Semiparametric regression of multidimensional genetic pathway data: least-squares kernel machines and linear mixed models. Biometrics 63, 1079-1088; Liu and others, 2008. Estimation and testing for the effect of a genetic pathway on a disease outcome using logistic kernel machine regression via logistic mixed models. BMC bioinformatics 9, 292-2; Wu and others, 2010. Powerful SNP-set analysis for case-control genome-wide association studies. American Journal of Human Genetics 86, 929) have been proposed as powerful alternatives to the standard Rao score test (Rao, 1948. Large sample tests of statistical hypotheses concerning several parameters with applications to problems of estimation. Mathematical Proceedings of the Cambridge Philosophical Society, 44, 50-57). The advantages of these EB-based tests are most apparent when the markers are correlated, due to the reduction in the degrees of freedom. In this paper, we propose an adaptive score test which up- or down-weights the contributions from each member of the marker-set based on the Z-scores of

  1. Radiocontrast media-associated exanthema: Identification of cross-reactivity and tolerability by allergologic testing

    Energy Technology Data Exchange (ETDEWEB)

    Seitz, Cornelia S.; Pfeuffer, Petra; Raith, Petra; Broecker, Eva-B. [Department of Dermatology, Venereology and Allergology, University of Wuerzburg, Josef Schneider Strasse 2, 97080 Wuerzburg (Germany); Trautmann, Axel [Department of Dermatology, Venereology and Allergology, University of Wuerzburg, Josef Schneider Strasse 2, 97080 Wuerzburg (Germany)], E-mail: trautmann_a@klinik.uni-wuerzburg.de

    2009-10-15

    Background: All iodinated radiocontrast media (RCM) may cause hypersensitivity reactions, either immediate-type within 5-10 min of RCM injection or delayed-type, which become apparent more than 1 h after RCM exposure. Delayed-type hypersensitivity to RCM may pose a problem for future radiologic investigations because due to possible immunological cross-reactivity all iodinated RCM are usually avoided. Objective: The aim of this study was not only to identify the causal RCM for the exanthema but also to demonstrate that patients may receive alternative iodinated RCM despite a history of RCM-induced allergic exanthema. Methods: We evaluated 32 patients with a history of exanthema after RCM application using standardized patch, prick and intradermal skin testing. In case of positive skin tests intravenous challenges with skin-test-negative RCM were performed to identify non-ionic monomer RCM which are tolerated. Results: In 6 out of 32 patients skin tests strongly suggested a delayed-type non-IgE-mediated allergic hypersensitivity to the RCM iomeprol (3 x), iopromide (2x), and iopamidol. In 4 patients alternative non-ionic monomer RCM (2x iosarcol, iopromide, and iomeprol) were identified by controlled challenge tests. Conclusions: The evaluation of patients with RCM-associated exanthema should always include appropriate skin tests ensuring that patients with a delayed-type allergic RCM-induced exanthema are not missed. Moreover, allergologic testing may identify alternative RCM of the group of non-ionic monomers, which are tolerated in future radiologic investigations.

  2. Association between preseason functional tests and injuries in youth football: a prospective follow-up.

    Science.gov (United States)

    Frisch, A; Urhausen, A; Seil, R; Croisier, J L; Windal, T; Theisen, D

    2011-12-01

    This prospective cohort study aimed at identifying player-related risk factors for injuries in youth football as determined by extensive preseasonal screening. All male U15-U19 players from a regional football school (season 2007-2008; n = 67) underwent preseason evaluations assessing physical fatigue, emotional stress and injury history (questionnaire), anthropometric variables, general joint laxity (Beighton score), lower limb coordination (functional hop tests), aerobic fitness (shuttle run test), strength of knee extensor and flexor muscles (isokinetic tests), static and dynamic balance (force plate tests), and explosive strength (jump tests on force plate). Football exposure and all football-related injuries (n = 163) were recorded during the entire subsequent season (44 weeks). Total injury incidence was 10.4 injuries/1000  h and was higher in competition than in training [relative risk = 3.3; CI(95%) (2.39; 4.54); P < 0.001]. Lower limb injuries were most frequent (87%). Acute contact injuries represented 37%, while intrinsic (noncontact and chronic) injuries amounted to 63%. Of all the variables tested, only physical fatigue was significantly associated with injury, as revealed by univariate and multivariate analyses. The same result was observed when considering only intrinsic injuries as outcome. A single preseason test session may be of limited interest in the framework of an injury prevention strategy. © 2011 John Wiley & Sons A/S.

  3. VIGOR TESTS ASSOCIATION AS AN ALTERNATIVE FOR PRECISE AND EFFICIENT ASSESSMENT OF MAIZE SEED QUALITY

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    MARCOS ALTOMANI NEVES DIAS

    2015-01-01

    Full Text Available This study aimed to associate two concepts of seed vigor testing, the aging and seedling growth using image analysis, providing a feasible and time-saving way to evaluate maize seed vigor in large scale. For this purpose, five seed lots with different vigor levels from two single hybrids were used. The seeds were characterized by moisture content, germination, seedling emergence, seedling emergence speed index, accelerated aging and cold tests. The treatments were composed by varying the accelerated aging periods (0, 24, 48, 72 and 96h and seedling growth periods (48 and 72h, before submitting the seedlings to image analysis for seedling root length measurement. Considering the results obtained, the adaptation of accelerated aging test by reducing the aging duration from 96h to 48h, and the replacement of the germination test by seedling root length measurement using image analysis could be considered a potential tool for maize seed vigor assessment. The treatments composed of 48h of seed aging followed by seedlings root length measurements using image analysis provided reliable data, compared to traditional vigor tests and it could be considered an efficient and timesaving approach, associating two different concepts of seed vigor analysis.

  4. A Simple Test of Class-Level Genetic Association Can Reveal Novel Cardiometabolic Trait Loci.

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    Jing Qian

    Full Text Available Characterizing the genetic determinants of complex diseases can be further augmented by incorporating knowledge of underlying structure or classifications of the genome, such as newly developed mappings of protein-coding genes, epigenetic marks, enhancer elements and non-coding RNAs.We apply a simple class-level testing framework, termed Genetic Class Association Testing (GenCAT, to identify protein-coding gene association with 14 cardiometabolic (CMD related traits across 6 publicly available genome wide association (GWA meta-analysis data resources. GenCAT uses SNP-level meta-analysis test statistics across all SNPs within a class of elements, as well as the size of the class and its unique correlation structure, to determine if the class is statistically meaningful. The novelty of findings is evaluated through investigation of regional signals. A subset of findings are validated using recently updated, larger meta-analysis resources. A simulation study is presented to characterize overall performance with respect to power, control of family-wise error and computational efficiency. All analysis is performed using the GenCAT package, R version 3.2.1.We demonstrate that class-level testing complements the common first stage minP approach that involves individual SNP-level testing followed by post-hoc ascribing of statistically significant SNPs to genes and loci. GenCAT suggests 54 protein-coding genes at 41 distinct loci for the 13 CMD traits investigated in the discovery analysis, that are beyond the discoveries of minP alone. An additional application to biological pathways demonstrates flexibility in defining genetic classes.We conclude that it would be prudent to include class-level testing as standard practice in GWA analysis. GenCAT, for example, can be used as a simple, complementary and efficient strategy for class-level testing that leverages existing data resources, requires only summary level data in the form of test statistics, and

  5. Brief implicit association test: Validity and utility in prediction of voting behavior

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    Pavlović Maša D.

    2013-01-01

    Full Text Available We employed the Brief Implicit Association Test (a recently developed short version of IAT to measure implicit political attitudes toward four political parties running for Serbian parliament. To test its criterion validity, we measured voting intention and actual voting behavior. In addition, we introduced political involvement as a potential moderator of the BIAT’s predictive and incremental validity. The BIAT demonstrated good internal and predictive validity, but lacked incremental validity over self-report measures. Predictive power of the BIAT was moderated by political involvement - the BIAT scores were stronger predictors of voting intention and behavior among voters highly involved in politics. [Projekat Ministarstva nauke Republike Srbije, br. 179018

  6. Can Implicit Associations Distinguish True and False Eyewitness Memory? Development and Preliminary Testing of the IATe.

    Science.gov (United States)

    Helm, Rebecca K; Ceci, Stephen J; Burd, Kayla A

    2016-11-01

    Eyewitness identification has been shown to be fallible and prone to false memory. In this study we develop and test a new method to probe the mechanisms involved in the formation of false memories in this area, and determine whether a particular memory is likely to be true or false. We created a seven-step procedure based on the Implicit Association Test to gauge implicit biases in eyewitness identification (the IATe). We show that identification errors may result from unconscious bias caused by implicit associations evoked by a given face. We also show that implicit associations between negative attributions such as guilt and eyewitnesses' final pick from a line-up can help to distinguish between true and false memory (especially where the witness has been subject to the suggestive nature of a prior blank line-up). Specifically, the more a witness implicitly associates an individual face with a particular crime, the more likely it is that a memory they have for that person committing the crime is false. These findings are consistent with existing findings in the memory and neuroscience literature showing that false memories can be caused by implicit associations that are outside conscious awareness. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  7. Early Bronchus-Associated Lymphoid Tissue Lymphoma Diagnosed with Immunoglobulin Heavy Chain Molecular Testing

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    Pen Li

    2016-01-01

    Full Text Available When extranodal marginal zone B-cell lymphoma of mucosa associated lymphoid tissue (MALT, a low grade B-cell lymphoma, arises in the lung it is referred to as bronchus-associated lymphoid tissue (BALT lymphoma. We describe a patient with a history of Sjögren’s syndrome and rheumatoid arthritis with dyspnea and imaging consistent with lymphoid interstitial pneumonia (LIP. However, while histology and immunohistochemistry lacked definitive features of a lymphoma, immunoglobulin heavy chain (IgH polymerase chain reaction testing demonstrated B-cell monoclonality, consistent with an early BALT lymphoma.

  8. Application of item response theory to tests of substance-related associative memory.

    Science.gov (United States)

    Shono, Yusuke; Grenard, Jerry L; Ames, Susan L; Stacy, Alan W

    2014-09-01

    A substance-related word-association test (WAT) is one of the commonly used indirect tests of substance-related implicit associative memory and has been shown to predict substance use. This study applied an item response theory (IRT) modeling approach to evaluate psychometric properties of the alcohol- and marijuana-related WATs and their items among 775 ethnically diverse at-risk adolescents. After examining the IRT assumptions, item fit, and differential item functioning (DIF) across gender and age groups, the original 18 WAT items were reduced to 14 and 15 items in the alcohol- and marijuana-related WAT, respectively. Thereafter, unidimensional one- and two-parameter logistic models (1PL and 2PL models) were fitted to the revised WAT items. The results demonstrated that both alcohol- and marijuana-related WATs have good psychometric properties. These results were discussed in light of the framework of a unified concept of construct validity (Messick, 1975, 1989, 1995).

  9. [The Visual Association Test to study episodic memory in clinical geriatric psychology].

    Science.gov (United States)

    Diesfeldt, Han; Prins, Marleen; Lauret, Gijs

    2018-04-01

    The Visual Association Test (VAT) is a brief learning task that consists of six line drawings of pairs of interacting objects (association cards). Subjects are asked to name or identify each object and later are presented with one object from the pair (the cue) and asked to name the other (the target). The VAT was administered in a consecutive sample of 174 psychogeriatric day care participants with mild to major neurocognitive disorder. Comparison of test performance with normative data from non-demented subjects revealed that 69% scored within the range of a major deficit (0-8 over two recall trials), 14% a minor, and 17% no deficit (9-10, and ≥10 respectively).VAT-scores correlated with another test of memory function, the Cognitive Screening Test (CST), based on the Short Portable Mental Status Questionnaire (r = 0.53). Tests of executive functioning (Expanded Mental Control Test, Category Fluency, Clock Drawing) did not add significantly to the explanation of variance in VAT-scores.Fifty-five participants (31.6%) were faced with initial problems in naming or identifying one or more objects on the cue cards or association cards. If necessary, naming was aided by the investigator. Initial difficulties in identifying cue objects were associated with lower VAT-scores, but this did not hold for difficulties in identifying target objects.A hierarchical multiple regression analysis was used to examine whether linear or quadratic trends best fitted VAT performance across the range of CST scores. The regression model revealed a linear but not a quadratic trend. The best fitting linear model implied that VAT scores differentiated between CST scores in the lower, as well as in the upper range, indicating the absence of floor and ceiling effects, respectively. Moreover, the VAT compares favourably to word list-learning tasks being more attractive in its presentation of interacting visual objects and cued recall based on incidental learning of the association

  10. Properties of global- and local-ancestry adjustments in genetic association tests in admixed populations.

    Science.gov (United States)

    Martin, Eden R; Tunc, Ilker; Liu, Zhi; Slifer, Susan H; Beecham, Ashley H; Beecham, Gary W

    2018-03-01

    Population substructure can lead to confounding in tests for genetic association, and failure to adjust properly can result in spurious findings. Here we address this issue of confounding by considering the impact of global ancestry (average ancestry across the genome) and local ancestry (ancestry at a specific chromosomal location) on regression parameters and relative power in ancestry-adjusted and -unadjusted models. We examine theoretical expectations under different scenarios for population substructure; applying different regression models, verifying and generalizing using simulations, and exploring the findings in real-world admixed populations. We show that admixture does not lead to confounding when the trait locus is tested directly in a single admixed population. However, if there is more complex population structure or a marker locus in linkage disequilibrium (LD) with the trait locus is tested, both global and local ancestry can be confounders. Additionally, we show the genotype parameters of adjusted and unadjusted models all provide tests for LD between the marker and trait locus, but in different contexts. The local ancestry adjusted model tests for LD in the ancestral populations, while tests using the unadjusted and the global ancestry adjusted models depend on LD in the admixed population(s), which may be enriched due to different ancestral allele frequencies. Practically, this implies that global-ancestry adjustment should be used for screening, but local-ancestry adjustment may better inform fine mapping and provide better effect estimates at trait loci. © 2017 WILEY PERIODICALS, INC.

  11. Bovine milk sampling efficiency for pregnancy-associated glycoproteins (PAG) detection test

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    Silva, H. K. da; Cassoli, L.D.; Pantoja, J.F.C.; Cerqueira, P.H.R.; Coitinho, T.B.; Machado, P.F.

    2016-07-01

    Two experiments were conducted to verify whether the time of day at which a milk sample is collected and the possible carryover in the milking system may affect pregnancy-associated glycoproteins (PAG) levels and, consequently, the pregnancy test results in dairy cows. In experiment one, we evaluated the effect of time of day at which the milk sample is collected from 51 cows. In experiment two, which evaluated the possible occurrence of carryover in the milk meter milking system, milk samples from 94 cows belonging to two different farms were used. The samples were subjected to pregnancy test using ELISA methodology to measure PAG concentrations and to classify the samples as positive (pregnant), negative (nonpregnant), or suspicious (recheck). We found that the time of milking did not affect the PAG levels. As to the occurrence of carryover in the milk meter, the PAG levels of the samples collected from Farm-2 were heavily influenced by a carryover effect compared with the samples from Farm-1. Thus, milk samples submitted to a pregnancy test can be collected during the morning or the evening milking. When the sample is collected from the milk meters, periodic equipment maintenance should be noted, including whether the milk meter is totally drained between different animals’ milking and equipment cleaning between milking is performed correctly to minimize the occurrence of carryover, thereby avoiding the effect on PAG levels and, consequently, the pregnancy test results. Therefore, a single milk sample can be used for both milk quality tests and pregnancy test.

  12. Direct testing of bronchoalveolar lavages from ventilator-associated pneumonia patients.

    Science.gov (United States)

    Boyer, Alexandre; Medrano, José; Mzali, Fatima; Balick-Weber, Claude-Charles; Bessède, Emilie; Picard, Walter; Clouzeau, Benjamin; Bébéar, Cécile M; Vargas, Frédéric; Hilbert, Gilles; Rogues, Anne Marie; Gruson, Didier

    2012-06-01

    In line with a rapid de-escalation of empirical antimicrobial therapy, this study assessed the validity of an E-test-based direct specimen testing method on bronchoalveolar lavage (BAL) samples from ventilator-associated pneumonia (VAP) patients. E-test strips were directly applied onto Mueller-Hinton agar plates seeded with BAL samples and read after 24 h of incubation. In parallel, the BAL samples were analyzed by the routine diagnostic laboratory. The microbroth dilution approach was used as a control method. In a cohort of 20 patients, 135 microorganism-antibiotic combinations were studied. Total agreement between the 2 methods was achieved for 88.9% combinations, with 1.5% very major errors (isolates susceptible by E-test and reported resistant by the diagnostic laboratory) and 9.6% major errors (isolates resistant by E-test and reported susceptible by the diagnostic laboratory). These results indicate that applying E-test directly on BAL samples is a promising method for obtaining susceptibility data after 24 h in critical patients with VAP. Copyright © 2012 Elsevier Inc. All rights reserved.

  13. Bovine milk sampling efficiency for pregnancy-associated glycoproteins (PAG) detection test

    International Nuclear Information System (INIS)

    Silva, H. K. da; Cassoli, L.D.; Pantoja, J.F.C.; Cerqueira, P.H.R.; Coitinho, T.B.; Machado, P.F.

    2016-01-01

    Two experiments were conducted to verify whether the time of day at which a milk sample is collected and the possible carryover in the milking system may affect pregnancy-associated glycoproteins (PAG) levels and, consequently, the pregnancy test results in dairy cows. In experiment one, we evaluated the effect of time of day at which the milk sample is collected from 51 cows. In experiment two, which evaluated the possible occurrence of carryover in the milk meter milking system, milk samples from 94 cows belonging to two different farms were used. The samples were subjected to pregnancy test using ELISA methodology to measure PAG concentrations and to classify the samples as positive (pregnant), negative (nonpregnant), or suspicious (recheck). We found that the time of milking did not affect the PAG levels. As to the occurrence of carryover in the milk meter, the PAG levels of the samples collected from Farm-2 were heavily influenced by a carryover effect compared with the samples from Farm-1. Thus, milk samples submitted to a pregnancy test can be collected during the morning or the evening milking. When the sample is collected from the milk meters, periodic equipment maintenance should be noted, including whether the milk meter is totally drained between different animals’ milking and equipment cleaning between milking is performed correctly to minimize the occurrence of carryover, thereby avoiding the effect on PAG levels and, consequently, the pregnancy test results. Therefore, a single milk sample can be used for both milk quality tests and pregnancy test.

  14. Factors associated with abnormalities of the cytopathological uterine cervix test in South of Brazil

    Directory of Open Access Journals (Sweden)

    Willian Augusto de Melo

    Full Text Available Abstract Objectives: to identify factors associated with abnormal cytopathological test uterine cervix. Methods: it is a analytical study with the participation of 390 women who presented abnormal cytopathological from a city in the state of Paraná in 2012. They were randomly selected through sampling plan. Sociodemographic information such as age, marital status, education level and ethnicity were considered independent variables while the high or low-grade cytological lesions as dependent variable. We analyzed the data statistically by Yates Corrected test, Fisher exact test and measures of association by odds ratio. For all analyzes was considered significance level of 5% and 95% confidence interval. Results: the mean age was 38.8 years, 72.9% were married or common-law marriage, 49.7% with low education level and 87.4% race/color white. HPV contamination was detected in 49.7% of women and high-grade cytological lesions in 18.2%. The low educa-tional level (95%OR=4.07 and non-white ethnicity (95%OR=2.22 were strongly associated with the development to cervical lesions (p<0.05. Conclusions: sociodemoghaphic characteristics were crucial to high-risk lesions and development of cervical cancer, especially in women with low educational level and race/color black or brown. These results confirm the persistence of diseases related to preventable and avoidable causes in the country.

  15. A comparison of the effect of 5-bromodeoxyuridine substitution on 33258 Hoechst- and DAPI-fluorescence of isolated chromosomes by bivariate flow karyotyping

    NARCIS (Netherlands)

    Buys, C. H.; Mesa, J.; van der Veen, A. Y.; Aten, J. A.

    1986-01-01

    Application of the fluorescent DNA-intercalator propidium iodide for stabilization of the mitotic chromosome structure during isolation of chromosomes from V79 Chinese hamster cells and subsequent staining with the fluorochromes 33258 Hoechst or DAPI allowed bivariate flow karyotyping of isolated

  16. Psychological coping in depressed outpatients: association with cortisol response to the combined dexamethasone/CRH test.

    Science.gov (United States)

    Hori, Hiroaki; Teraishi, Toshiya; Ota, Miho; Hattori, Kotaro; Matsuo, Junko; Kinoshita, Yukiko; Ishida, Ikki; Nagashima, Anna; Koga, Norie; Higuchi, Teruhiko; Kunugi, Hiroshi

    2014-01-01

    Depression is associated with dysfunctional coping styles and dysregulated hypothalamic-pituitary-adrenal (HPA) axis function. Studies have shown that maladaptive coping strategies relate to abnormal HPA axis function; however, such a relationship has been under-studied in patients with depression. We aimed to examine whether dysfunctional coping styles in depression would be associated with abnormal cortisol reactivity. Seventy-four outpatients with major depressive disorder and 133 age- and sex-matched healthy individuals were recruited. Coping was assessed by the Ways of Coping Checklist. Psychological distress was assessed by the Hopkins Symptom Checklist. Cortisol reactivity was measured by the combined dexamethasone/corticotropin-releasing hormone test. Compared to healthy individuals, depressed patients demonstrated significantly less use of problem-solving, positive reappraisal and social support coping styles and more use of self-blame and wishful thinking styles. Such a pattern of coping styles was significantly associated with patients' greater distress. Partial correlation analysis in patients, controlling for age and sex, revealed a significant correlation between more use of escape-avoidance coping and lower levels of reactive cortisol measures. A stepwise multiple regression analysis predicting cortisol reactivity from age, sex, distress, symptom severity and coping styles revealed that escape-avoidance coping was a significant predictor. The neuroendocrine challenge test was administered only once, based on a simple test protocol. More use of escape-avoidance coping in depressed patients was associated with less cortisol reactivity. Our findings shed light on the heterogeneity of depression in terms of low and high levels of avoidance associated with exaggerated and blunted HPA axis reactivity, respectively. © 2013 Elsevier B.V. All rights reserved.

  17. Factors associated with positive direct antiglobulin tests in pretransfusion patients: a case-control study.

    Science.gov (United States)

    Toy, P T; Chin, C A; Reid, M E; Burns, M A

    1985-01-01

    During routine pretransfusion testing, the presence of IgG on patient red cells is suggested by a positive autocontrol and confirmed by a positive direct antiglobulin test (DAT) using monospecific anti-IgG sera. Most IgG on patient red cells detected in this manner are of unknown etiology. We recently showed an association between elevated serum globulin levels and positive DAT with unreactive eluate in patients with acquired immunodeficiency syndrome (AIDS). In the present study, we wished to determine whether elevated serum globulin levels contribute to some of the positive DAT encountered in pretransfusion testing of patients without AIDS. 76 patients with positive DAT were compared with 90 controls without IgG detected on their red cells during pretransfusion testing. The rate of elevated serum globulin levels was 75% in positive DAT cases versus 29% in controls (p less than 0.001); the odds ratio was 7.6. Elevated blood urea nitrogen levels occurred in 42% of cases versus 19% of controls (p less than 0.025); the odds ratio was 3.1. Cases and controls were not significantly different with regard to age, sex, race, quinidine usage, or hyperalimentation. Elevated serum globulin and blood urea nitrogen levels are significantly associated with a positive DAT with unreactive eluate in pretransfusion patients.

  18. Community-acquired pneumonia and positive urinary antigen tests: Factors associated with targeted antibiotic therapy.

    Science.gov (United States)

    Mothes, A; Léotard, S; Nicolle, I; Smets, A; Chirio, D; Rotomondo, C; Tiger, F; Del Giudice, P; Perrin, C; Néri, D; Foucault, C; Della Guardia, M; Hyvernat, H; Roger, P-M

    2016-10-01

    The use of rapid microbiological tests is supported by antimicrobial stewardship policies. Targeted antibiotic therapy (TAT) for community-acquired pneumonia (CAP) with positive urinary antigen test (UAT) has been associated with a favorable impact on outcome. We aimed to determine the factors associated with TAT prescription. We conducted a retrospective multicenter study including all patients presenting with CAP and positive UAT for Streptococcus pneumoniae or Legionella pneumophila from January 2010 to December 2013. Patients presenting with aspiration pneumonia, coinfection, and neutropenia were excluded. CAP severity was assessed using the Pneumonia Severity Index (PSI). TAT was defined as the administration of amoxicillin for pneumococcal infection and either macrolides or fluoroquinolones (inactive against S. pneumoniae) for Legionella infection. A total of 861 patients were included, including 687 pneumococcal infections and 174 legionellosis from eight facilities and 37 medical departments. TAT was prescribed to 273 patients (32%). Four factors were found independently associated with a lower rate of TAT: a PSI score≥4 (OR 0.37), Hospital A (OR 0.41), hospitalization in the intensive care unit (OR 0.44), and cardiac comorbidities (OR 0.60). Four other factors were associated with a high rate of TAT: positive blood culture for S. pneumoniae (OR 2.32), Hospitals B (OR 2.34), E (OR 2.68), and H (OR 9.32). TAT in CAP with positive UAT was related to the hospitals as well as to patient characteristics. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  19. A multi-marker test based on family data in genome-wide association study

    Directory of Open Access Journals (Sweden)

    Zhang Shuanglin

    2007-09-01

    Full Text Available Abstract Background Complex diseases are believed to be the results of many genes and environmental factors. Hence, multi-marker methods that can use the information of markers from different genes are appropriate for mapping complex disease genes. There already have been several multi-marker methods proposed for case-control studies. In this article, we propose a multi-marker test called a Multi-marker Pedigree Disequilibrium Test (MPDT to analyze family data from genome-wide association studies. If the parental phenotypes are available, we also propose a two-stage test in which a genomic screening test is used to select SNPs, and then the MPDT is used to test the association of the selected SNPs. Results We use simulation studies to evaluate the performance of the MPDT and the two-stage approach. The results show that the MPDT constantly outperforms the single marker transmission/disequilibrium test (TDT 1. Comparing the power of the two-stage approach with that of the one-stage approach, which approach is more powerful depends on the value of the prevalence; when the prevalence is no less than 10%, the two-stage approach may be more powerful than the one-stage approach. Otherwise, the one-stage approach is more powerful. Conclusion The proposed MPDT, is more powerful than the single marker TDT. When the parental phenotypes are available and the prevalence is no less than 10%, the proposed two-stage approach is more powerful than the one-stage approach.

  20. Sleep quality and duration are associated with performance in maximal incremental test.

    Science.gov (United States)

    Antunes, B M; Campos, E Z; Parmezzani, S S; Santos, R V; Franchini, E; Lira, F S

    2017-08-01

    Inadequate sleep patterns may be considered a trigger to development of several metabolic diseases. Additionally, sleep deprivation and poor sleep quality can negatively impact performance in exercise training. However, the impact of sleep duration and sleep quality on performance during incremental maximal test performed by healthy men is unclear. Therefore, the purpose of the study was to analyze the association between sleep pattern (duration and quality) and performance during maximal incremental test in healthy male individuals. A total of 28 healthy males volunteered to take part in the study. Sleep quality, sleep duration and physical activity were subjectively assessed by questionnaires. Sleep pattern was classified by sleep duration (>7h or sleep per night) and sleep quality according to the sum of measured points and/or scores by the Pittsburgh Sleep Quality Index (PSQI). Incremental exercise test was performed at 35 watts for untrained subjects, 70 watts for physically active subjects and 105 watts for well-trained subjects. HR max was correlated with sleep quality (r=0.411, p=0.030) and sleep duration (r=-0.430, p=0.022). Participants reporting good sleep quality presented higher values of W max , VO 2max and lower values of HR max when compared to participants with altered sleep. Regarding sleep duration, only W max was influenced by the amount of sleeping hours per night and this association remained significant even after adjustment by VO 2max . Sleep duration and quality are associated, at least in part, with performance during maximal incremental test among healthy men, with losses in W max and HR max . In addition, our results suggest that the relationship between sleep patterns and performance, mainly in W max , is independent of fitness condition. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Opisthorchis felineus negatively associates with skin test reactivity in Russia-EuroPrevall-International Cooperation study.

    Science.gov (United States)

    Fedorova, O S; Janse, J J; Ogorodova, L M; Fedotova, M M; Achterberg, R A; Verweij, J J; Fernández-Rivas, M; Versteeg, S A; Potts, J; Minelli, C; van Ree, R; Burney, P; Yazdanbakhsh, M

    2017-07-01

    Most studies on the relationship between helminth infections and atopic disorders have been conducted in (sub)tropical developing countries where exposure to multiple parasites and lifestyle can confound the relationship. We aimed to study the relationship between infection with the fish-borne helminth Opishorchis felineus and specific IgE, skin prick testing, and atopic symptoms in Western Siberia, with lifestyle and hygiene standards of a developed country. Schoolchildren aged 7-11 years were sampled from one urban and two rural regions. Skin prick tests (SPT) and specific IgE (sIgE) against food and aeroallergens were measured, and data on allergic symptoms and on demographic and socioeconomic factors were collected by questionnaire. Diagnosis of opisthorchiasis was based on PCR performed on stool samples. Of the 732 children included, 34.9% had opisthorchiasis. The sensitization to any allergen when estimated by positive SPT was 12.8%, while much higher, 24.0%, when measured by sIgE. Atopic symptoms in the past year (flexural eczema and/or rhinoconjunctivitis) were reported in 12.4% of the children. SPT was positively related to flexural eczema and rhinoconjunctivitis, but not to wheezing. Opisthorchiasis showed association with lower SPT response, as well as borderline association with low IgE reactivity to any allergen. However, the effect of opisthorchiasis on SPT response was not mediated by IgE, suggesting that opisthorchiasis influences SPT response through another mechanism. Opisthorchiasis also showed borderline association with lower atopic symptoms. There is a negative association between a chronic helminth infection and skin prick test reactivity even in a developed country. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. Testing the ecological validity of the Trier Social Stress Test: Association with real-life exam stress.

    Science.gov (United States)

    Henze, Gina-Isabelle; Zänkert, Sandra; Urschler, David F; Hiltl, Tanja J; Kudielka, Brigitte M; Pruessner, Jens C; Wüst, Stefan

    2017-01-01

    The Trier Social Stress Test (TSST) is the most widely used laboratory stress protocol in psychoneuroendocrinology. Despite its popularity, surprisingly few attempts have been made to explore the ecological validity of the TSST. In the present study, 31 young healthy subjects (24 females) were exposed to the TSST about 4 weeks before completing an oral exam on a separate day. Salivary cortisol levels increased significantly in response to both stimuli (TSST: F(2.21, 66.33)=5.73, p=0.004; oral exam: F(1.98, 59.28)=4.38, p=0.017) with similar mean response curves and significant correlations between cortisol increases and areas under the response curves (increase: r=0.67; AUC: r=0.56; both p≤0.01). Correspondingly, changes in positive and negative affect did also show significant correlations between conditions (increase: positive affect: r=0.36; negative affect: r=0.50; both: p≤0.05; AUC: positive affect: r=0.81; negative affect: r=0.70; both p≤0.01) while mean time course dynamics were significantly different (positive affect: F(2.55, 76.60)=10.15, p=0.001; negative affect: F(1.56, 46.82)=23.32, p=0.001), indicating that the oral exam had a more pronounced impact on affect than the TSST. Our findings provide new evidence for the view that cortisol as well as subjective stress responses to the TSST are indeed significantly associated with acute stress responses in real life. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Identifying temporal and causal contributions of neural processes underlying the Implicit Association Test (IAT

    Directory of Open Access Journals (Sweden)

    Chad Edward Forbes

    2012-11-01

    Full Text Available The Implicit Association Test (IAT is a popular behavioral measure that assesses the associative strength between outgroup members and stereotypical and counterstereotypical traits. Less is known, however, about the degree to which the IAT reflects automatic processing. Two studies examined automatic processing contributions to a gender-IAT using a data driven, social neuroscience approach. Performance on congruent (e.g., categorizing male names with synonyms of strength and incongruent (e.g., categorizing female names with synonyms of strength IAT blocks were separately analyzed using EEG (event-related potentials, or ERPs, and coherence; Study 1 and lesion (Study 2 methodologies. Compared to incongruent blocks, performance on congruent IAT blocks was associated with more positive ERPs that manifested in frontal and occipital regions at automatic processing speeds, occipital regions at more controlled processing speeds and was compromised by volume loss in the anterior temporal lobe, insula and medial PFC. Performance on incongruent blocks was associated with volume loss in supplementary motor areas, cingulate gyrus and a region in medial PFC similar to that found for congruent blocks. Greater coherence was found between frontal and occipital regions to the extent individuals exhibited more bias. This suggests there are separable neural contributions to congruent and incongruent blocks of the IAT but there is also a surprising amount of overlap. Given the temporal and regional neural distinctions, these results provide converging evidence that stereotypic associative strength assessed by the IAT indexes automatic processing to a degree.

  4. Lactulose Hydrogen Breath Test Result Is Associated with Age and Gender

    Directory of Open Access Journals (Sweden)

    Carolyn Newberry

    2016-01-01

    Full Text Available Small intestinal bacterial overgrowth (SIBO is associated with chronic gastrointestinal diseases and structural/functional abnormalities of the gastrointestinal tract. SIBO’s association with clinical characteristics is unclear. This study investigates the association between clinical factors and SIBO according to lactulose hydrogen breath test (LHBT result. Methods. A cross-sectional study in a university-based gastroenterology practice was performed. Data was abstracted from the medical records of subjects undergoing LHBT from 6/1/2009 to 6/1/2013. Logistic regression analysis was performed to determine the association between predictor variables: age, sex, body mass index (BMI, and positive LHBT, the outcome of interest. Results. LHBT was performed in 791 subjects. Fifty-four percent had a positive LHBT. There was no statistically significant difference between the LHBT results according to age or BMI. In females, the likelihood of a positive LHBT increased with age (OR 1.02; 95% CI: 1.01–1.03. In males, the likelihood of a positive LHBT result decreased with age (OR 0.98; 95% CI: 0.97–1.00. Conclusion. There was an association between age, with respect to sex, and a positive LHBT. With increased age in females, the odds of a positive LHBT increased, while, in men, the odds of a positive LHBT decreased with age.

  5. Association between use of rapid antigen detection tests and adherence to antibiotics in suspected streptococcal pharyngitis.

    Science.gov (United States)

    Llor, Carl; Hernández, Silvia; Sierra, Nuria; Moragas, Ana; Hernández, Marta; Bayona, Carolina

    2010-03-01

    Few studies have analysed adherence to antibiotic treatment in pharyngitis. The aim of this study was to evaluate the association of rapid antigen detection tests (RADT) and treatment adherence among patients 18 years of age or over with pharyngitis treated with different antibiotic regimens. Prospective study from 2003 to 2008. Office-based physician practices. Intervention. The adherence of patients prior to the use of RADTs - no test was available until mid-2006 - was compared with the adherence associated with the use of RADTs. Patients with suspected streptococcal pharyngitis. Patient adherence was assessed by electronic monitoring. The adherence outcomes considered were antibiotic-taking adherence, correct dosing, and good timing adherence during at least 80% of the antibiotic course. A total of 196 patients were recruited. The percentage of container openings was 77.9%+/-17.7%, being significantly higher for patients in whom the RADTs were performed compared with those in whom this test was not undertaken (80.1% vs. 70.8% for thrice-daily antibiotic regimens and 88.1% vs. 76.5% for twice-daily regimens; p pills (71.3% vs. 42.2%; p dosing was always greater when the patient had undergone an RADT. Adherence to antibiotic treatment is higher when an RADT is carried out at the consultation prior to administration of antibiotic treatment.

  6. Association Between Allergic Diseases and Food Allergens Based on Skin Prick Test in Bushehr Province

    Directory of Open Access Journals (Sweden)

    Saman Keshvari

    2017-04-01

    Full Text Available Background: The Frequency of allergic diseases is growing in recent years. Identification of frequency of food allergens in different areas play an important role in diagnosis and treatment of these diseases. The aim of this study was to determine frequency and association of common food allergens in patients with allergic diseases based on Skin Prick Test in Bushehr province. Material and Methods: In this descriptive cross-sectional study, 1100 patients were enrolled with allergic diseases which had a sensitivity to at least one allergen.  This test was carried out with 21 common food allergens extract. Results: In all patients, association between the severity of the reaction prick allergy test and severity of allergic diseases with shrimp, cow's Milk and peanuts were (P= 0.01, (P= 0.02 and (P=0.04 respectively. In this study, the frequency of allergic rhinitis, asthma, chronic and acute urticaris and atopic eczema were 54.2%, 23%, 12.4%, 4.1% and 12%, respectively. While the the most common food allergens were peanuts (46.6%, egg yolk (43.1% and shrimp (42% respectively. Conclusion: This study indicated that food allergens such as shrimp, cow's Milk and peanuts have a greater role in severity of allergic diseases and this food allergens showed the highest frequency in patients.

  7. CDC'S Testing Makes Us Stronger (TMUS) Campaign: Was Campaign Exposure Associated With HIV Testing Behavior Among Black Gay and Bisexual Men?

    Science.gov (United States)

    Habarta, Nancy; Boudewyns, Vanessa; Badal, Hannah; Johnston, Jennie; Uhrig, Jennifer; Green, Donata; Ruddle, Paul; Rosenthal, Jacqueline; Stryker, Jo Ellen

    2017-06-01

    This study assessed exposure among Black gay, bisexual, and other men who have sex with men (BMSM) to a communication campaign, Testing Makes Us Stronger (TMUS), and its association with HIV testing to determine campaign effectiveness. Data from an online survey (N = 3,105) were analyzed using propensity score weight-adjusted logistic regression to examine the effect of exposure on HIV testing. Among BMSM aged 18-44 (n = 702), 43.2% reported TMUS exposure. The majority of those exposed were aged 25-34 (54%), HIV-negative (65%), and had some college education (87%). TMUS exposure was associated with reported increased HIV testing behaviors at 6- and 12-month frequencies. Communication campaigns with clear implementation strategies, focused objectives, and online and event presence can be associated with longer-term outcomes such as HIV testing.

  8. How allele frequency and study design affect association test statistics with misrepresentation errors.

    Science.gov (United States)

    Escott-Price, Valentina; Ghodsi, Mansoureh; Schmidt, Karl Michael

    2014-04-01

    We evaluate the effect of genotyping errors on the type-I error of a general association test based on genotypes, showing that, in the presence of errors in the case and control samples, the test statistic asymptotically follows a scaled non-central $\\chi ^2$ distribution. We give explicit formulae for the scaling factor and non-centrality parameter for the symmetric allele-based genotyping error model and for additive and recessive disease models. They show how genotyping errors can lead to a significantly higher false-positive rate, growing with sample size, compared with the nominal significance levels. The strength of this effect depends very strongly on the population distribution of the genotype, with a pronounced effect in the case of rare alleles, and a great robustness against error in the case of large minor allele frequency. We also show how these results can be used to correct $p$-values.

  9. 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....

  10. Measuring the bias against low-income country research: an Implicit Association Test.

    Science.gov (United States)

    Harris, Matthew; Macinko, James; Jimenez, Geronimo; Mullachery, Pricila

    2017-11-06

    With an increasing array of innovations and research emerging from low-income countries there is a growing recognition that even high-income countries could learn from these contexts. It is well known that the source of a product influences perception of that product, but little research has examined whether this applies also in evidence-based medicine and decision-making. In order to examine likely barriers to learning from low-income countries, this study uses established methods in cognitive psychology to explore whether healthcare professionals and researchers implicitly associate good research with rich countries more so than with poor countries. Computer-based Implicit Association Test (IAT) distributed to healthcare professionals and researchers. Stimuli representing Rich Countries were chosen from OECD members in the top ten (>$36,000 per capita) World Bank rankings and Poor Countries were chosen from the bottom thirty (based medicine and diffusion of innovations.

  11. Does the name-race implicit association test measure racial prejudice?

    Science.gov (United States)

    van Ravenzwaaij, Don; van der Maas, Han L J; Wagenmakers, Eric-Jan

    2011-01-01

    Research using the Implicit Association Test (IAT) has shown that names labeled as Caucasian elicit more positive associations than names labeled as non-Caucasian. One interpretation of this result is that the IAT measures latent racial prejudice. An alternative explanation is that the result is due to differences in in-group/out-group membership. In this study, we conducted three different IATs: one with same-race Dutch names versus racially charged Moroccan names; one with same-race Dutch names versus racially neutral Finnish names; and one with Moroccan names versus Finnish names. Results showed equivalent effects for the Dutch-Moroccan and Dutch-Finnish IATs, but no effect for the Finnish-Moroccan IAT. This suggests that the name-race IAT-effect is not due to racial prejudice. A diffusion model decomposition indicated that the IAT-effects were caused by changes in speed of information accumulation, response conservativeness, and non-decision time.

  12. Development of an implicit overall well-being measure using the Implicit Association Test.

    Science.gov (United States)

    Díaz, Darío; Horcajo, Javier; Blanco, Amalio

    2009-11-01

    Usually, well-being has been measured by means of questionnaires or scales. Although most of these methods have a high level of reliability and validity, they present some limitations. In order to try to improve well-being assessment, in the present work, the authors propose a new complementary instrument: The Implicit Overall Well-Being Measure (IOWBM). The Implicit Association Test (IAT) was adapted to measure wellbeing by assessing associations of the self with well-being-related words. In the first study, the IOWBM showed good internal consistency and adequate temporal reliability. In the second study, it presented weak correlations with explicit well-being measures. The third study examined the validity of the measure, analyzing the effect of traumatic memories on implicit well-being. The results showed that people who remember a traumatic event presented low levels of implicit well-being compared with people in the control condition.

  13. Association between routine laboratory tests and long-term mortality among acutely admitted older medical patients

    DEFF Research Database (Denmark)

    Klausen, Henrik Hedegaard; Petersen, Janne; Bandholm, Thomas

    2017-01-01

    BACKGROUND: Older people have the highest incidence of acute medical admissions. Old age and acute hospital admissions are associated with a high risk of adverse health outcomes after discharge, such as reduced physical performance, readmissions and mortality. Hospitalisations in this population...... are often by acute admission and through the emergency department. This, along with the rapidly increasing proportion of older people, warrants the need for clinically feasible tools that can systematically assess vulnerability in older medical patients upon acute hospital admission. These are essential...... for prioritising treatment during hospitalisation and after discharge. Here we explore whether an abbreviated form of the FI-Lab frailty index, calculated as the number of admission laboratory test results outside of the reference interval (FI-OutRef) was associated with long term mortality among acutely admitted...

  14. Estimate of uncertainties correlated and no correlated associated to performance tests of activity meters

    International Nuclear Information System (INIS)

    Sousa, C.H.S.; Teixeira, G.J.; Peixoto, J.G.P.

    2014-01-01

    Activimeters should undergo performance for verifying the functionality tests as technical recommendations. This study estimated the associated expanded uncertainties uncorrelated to the results conducted on three instruments, two detectors with ionization chamber and one with Geiger Mueller tubes. For this we used a standard reference source and screened certified by the National Institute of Technology and Standardization. The methodology of this research was based on the protocols listed in the technical document of the International Atomic Energy Agency. Later two quantities were correlated presenting real correlation and improving expanded uncertainty 3.7%. (author)

  15. Case of cytomegalovirus-associated direct anti-globulin test-negative autoimmune hemolytic anemia.

    Science.gov (United States)

    Kaneko, Saeko; Sato, Masanori; Sasaki, Goro; Eguchi, Hiroyuki; Oishi, Tsutomu; Kamesaki, Toyomi; Kawaguchi, Hiroyuki

    2013-12-01

    A 1-year-old boy developed autoimmune hemolytic anemia after a negative direct anti-globulin test. The concentration of erythrocyte membrane-associated immunoglobulin G, determined using an immunoradiometric assay, correlated with disease activity. He was positive for cytomegalovirus (CMV) both serologically and by quantitative real-time polymerase chain reaction, indicating that his autoimmune hemolytic anemia was directly caused by CMV infection. Since anti-CMV immunoglobulin G was not absorbed by the patient's erythrocytes, cross-reaction between erythrocyte antigens and CMV was not likely a causative factor for hemolysis. © 2013 The Authors. Pediatrics International © 2013 Japan Pediatric Society.

  16. Star Excursion Balance Test Anterior Asymmetry Is Associated With Injury Status in Division I Collegiate Athletes.

    Science.gov (United States)

    Stiffler, Mikel R; Bell, David R; Sanfilippo, Jennifer L; Hetzel, Scott J; Pickett, Kristen A; Heiderscheit, Bryan C

    2017-05-01

    Study Design Retrospective cohort. Background Star Excursion Balance Test (SEBT) performance differs by sport in healthy collegiate athletes, and lower extremity injury rates also vary by sport, sex, and athletic exposure. The relationship between SEBT performance and injury risk has not been evaluated with consideration of these additional variables, which may be necessary to fully describe the relationship between SEBT performance and injury risk. Objectives To assess the association between preseason SEBT performance and noncontact injury occurrence to the knee or ankle in Division I collegiate athletes when controlling for sport, sex, and athletic exposure. Methods Star Excursion Balance Test performance, starting status, and injury status were reviewed retrospectively in National Collegiate Athletic Association Division I collegiate athletes from a single institution. A total of 147 athletes were healthy at the time of preseason SEBT testing and either remained healthy (n = 118) or sustained a noncontact injury to the knee or ankle (n = 29) during their sport's subsequent competitive season. Side-to-side asymmetries were calculated in each direction as the absolute difference in reach distance between limbs. Star Excursion Balance Test reach distances and asymmetries were compared between groups using multivariable regression, controlling for sport, sex, and athletic exposure (starter, nonstarter). Receiver operating characteristic curves were used to determine optimal sensitivity and specificity for significant models. Results When controlling for sport, sex, and athletic exposure, SEBT side-to-side asymmetry in the anterior direction, expressed as an absolute or normalized to limb length, discriminated between injured and noninjured athletes (area under the curve greater than 0.82). Conclusion Assessing side-to-side reach asymmetry in the anterior direction of the SEBT may assist in identifying collegiate athletes who are at risk for sustaining noncontact

  17. Happy eating: the single target implicit association test predicts overeating after positive emotions.

    Science.gov (United States)

    Bongers, Peggy; Jansen, Anita; Houben, Katrijn; Roefs, Anne

    2013-08-01

    For many years, questionnaires have been considered the standard when examining emotional eating behavior. However, recently, some controversy has arisen about these questionnaires, and their usefulness in identifying emotional eaters has been questioned. The current study aimed to investigate the Single Target Implicit Association Test (ST-IAT) as a measure of emotional eating. Two ST-IATs (assessing food-positive and food-negative associations respectively) and the Dutch Eating Behaviour Questionnaire (DEBQ) were compared in undergraduate students. A positive, negative or neutral mood was induced by means of a film clip, and milkshake consumption was measured during and after the mood induction. It was hypothesized that participants with strong emotion-food associations on the ST-IATs (i.e., IAT-emotional eaters) would consume more food in the emotion induction condition corresponding to that emotion, as compared to those with weak emotion-food associations as well as to those in the neutral condition. Participants who scored high on both the positive and negative ST-IATs ate more during a positive mood induction than during a negative mood induction. This effect did not extend to milkshake consumption after the mood induction procedure. In addition, IAT-positive emotional eaters consumed more food than IAT-non-emotional eaters. No effects of the DEBQ on milkshake consumption were found. It is concluded that the ST-IAT has potential as a measure of emotional eating. © 2013 Elsevier Ltd. All rights reserved.

  18. Radioactive waste isolation in salt: Peer review of the Golder Associates draft test plan for in situ testing in an exploratory shaft in salt

    International Nuclear Information System (INIS)

    Hambley, D.F.; Mraz, D.Z.; Unterberter, R.R.

    1987-01-01

    This report documents the peer review conducted by Argonne National Laboratory of a document entitled ''Draft Test Plan for In Situ Testing in an Exploratory Shaft in Salt,'' prepared for Battelle Memorial Institute's Office of Nuclear Waste Isolation by Golder Associates, Inc. In general, the peer review panelists found the test plan to be technically sound, although some deficiencies were identified. Recommendations for improving the test plan are presented in this review report. A microfiche copy of the following unpublished report is attached to the inside back cover of this report: ''Draft Test Plan for In Situ Testing in an Exploratory Shaft in Salt,'' prepared by Golder Associates, Inc., for Office of Nuclear Waste Isolation, Battelle Memorial Institute, Columbus, Ohio (March 1985)

  19. Radioactive waste isolation in salt: Peer review of the Golder Associates draft test plan for in situ testing in an exploratory shaft in salt

    Energy Technology Data Exchange (ETDEWEB)

    Hambley, D.F.; Mraz, D.Z.; Unterberter, R.R.; Stormont, J.C.; Neuman, S.P.; Russell, J.E.; Jacoby, C.H.; Hull, A.B.; Brady, B.H.G.; Ditmars, J.D.

    1987-01-01

    This report documents the peer review conducted by Argonne National Laboratory of a document entitled ''Draft Test Plan for In Situ Testing in an Exploratory Shaft in Salt,'' prepared for Battelle Memorial Institute's Office of Nuclear Waste Isolation by Golder Associates, Inc. In general, the peer review panelists found the test plan to be technically sound, although some deficiencies were identified. Recommendations for improving the test plan are presented in this review report. A microfiche copy of the following unpublished report is attached to the inside back cover of this report: ''Draft Test Plan for In Situ Testing in an Exploratory Shaft in Salt,'' prepared by Golder Associates, Inc., for Office of Nuclear Waste Isolation, Battelle Memorial Institute, Columbus, Ohio (March 1985).

  20. Eat, sleep, work, play: associations of weight status and health-related behaviors among young adult college students.

    Science.gov (United States)

    Quick, Virginia; Byrd-Bredbenner, Carol; White, Adrienne A; Brown, Onikia; Colby, Sarah; Shoff, Suzanne; Lohse, Barbara; Horacek, Tanya; Kidd, Tanda; Greene, Geoffrey

    2014-01-01

    To examine relationships of sleep, eating, and exercise behaviors; work time pressures; and sociodemographic characteristics by weight status (healthy weight [body mass index or BMI college students (N = 1252; 18-24 years; 80% white; 59% female). Survey included the Pittsburgh Sleep Quality Index (PSQI), Three-Factor Eating Questionnaire (TFEQ), Satter Eating Competence Inventory (ecSI), National Cancer Institute Fruit/Vegetable Screener, International Physical Activity Questionnaire, Work Time Pressure items, and sociodemographic characteristics. Chi-square and t-tests determined significant bivariate associations of sociodemographics, sleep behaviors, eating behaviors, physical activity behavior, and work time pressures with weight status (i.e., healthy vs. overweight/obese). Statistically significant bivariate associations with weight status were then entered into a multivariate logistic regression model that estimated associations with being overweight/obese. Sex (female), race (nonwhite), older age, higher Global PSQI score, lower ecSI total score, and higher TFEQ Emotional Eating Scale score were significantly (p obesity in bivariate analyses. Multivariate logistic regression analysis showed that sex (female; odds ratio [OR] = 2.05, confidence interval [CI] = 1.54-2.74), older age (OR = 1.35, CI = 1.21-1.50), higher Global PSQI score (OR = 1.07, CI = 1.01-1.13), and lower ecSI score (OR = .96, CI = .94-.98), were significantly (p obesity. Findings suggest that obesity prevention interventions for college students should include an education component to emphasize the importance of overall sleep quality and improving eating competence.

  1. [Validation of a screening test for age associated cognitive impairment, in Chile].

    Science.gov (United States)

    Quiroga, Pilar; Albala, Cecilia; Klaasen, Gonzalo

    2004-04-01

    The real prevalence of dementia in a given population must be determined through prevalence studies, using validated screening tests. To validate and determine cutoff points for a cognitive impairment screening test composed by the Folstein Mini Mental State Examination (MMSE) and Pfeffer Functional Activities Questionnaire (PFAQ). Validation of the diagnostic test in a sample of 100 subjects over 65 years old (85 from the project "Age associated dementias" and 15 with a confirmed diagnosis of dementia). All were subjected to a complete neuropsychological test by a trained neurologist, that constituted the "gold standard" for the diagnosis of dementia. An independent interviewer applied the MMSE to the subjects and the PFAQ to a next of kin informer. Cutoff points were calculated using ROC curves. The points with the better equilibrium between sensitivity and specificity were selected, considering differences in results between groups with low and high educational level. The cutoff point for MMSE was 21/22, with a sensitivity of 93.6% (95% CI 70.6-99.7%) and a specificity of 46.1% (95% CI 34.7-57.8%). The figure for PFAQ was 5/6, with a sensitivity of 89.2% (95% CI 70.6-99.7%) and a specificity of 70.7% (95% CI 58.9-80.3%). The combination of both instruments gave a sensitivity of 94.4% (95% CI 58.9-80.3%) and a specificity of 83.3% (95% CI 72.3-90.7%). This screening test, using MMSE and PFAQ, has a good sensitivity and specificity for the diagnosis of dementia in Chile. Being simple and of low cost, it can be applied in primary health care.

  2. Water Associated Zero Maze: A novel rat test for long term traumatic re-experiencing

    Directory of Open Access Journals (Sweden)

    Gilad eRitov

    2014-01-01

    Full Text Available Often, freezing and startle behaviors in the context of a previously experienced stress are taken as an indication of posttraumatic stress disorder (PTSD-like symptoms in rats. However, PTSD is characterized by large individual variations of symptoms. In order to take into consideration the complex and long term distinctive variations in effects of trauma exposure additional behavioral measures are required.The current study used a novel behavioral test, the Water Associated Zero Maze (WAZM. This test was planned to enable a formation of an association between the context of the maze and an underwater trauma or swim stress in order to examine the impact of exposure to the context which immediately precedes a stressful or a traumatic experience on rat's complex behavior. Rats were exposed to the WAZM and immediately after to an underwater trauma or short swim. One month later rats were re-exposed to the context of the WAZM while their behavior was video recorded. Furthermore, c-Fos expression in the amygdala was measured 90 min after this exposure.The results of the current study indicate that the WAZM can be used to discern behavioral changes measured a long time after the actual traumatic or stressful events. Furthermore, the behavioral changes detected were accompanied by changes of c-Fos expression in the amygdala of exposed rats. We suggest that the WAZM can be used to model traumatic memories re-experiencing in rodent models of human stress-related pathologies such as PTSD.

  3. Associations of aerobic and strength exercise with clinical laboratory test values

    Science.gov (United States)

    Bi, Caixia; Chaump, Michael; Kaufman, Harvey W.; Kroll, Martin H.

    2017-01-01

    Objectives Physical exercise may affect levels of blood-based biomarkers. However, exercise status is seldom considered in the interpretation of laboratory results. This study reports the associations between habitual exercise participation and clinical laboratory test results. Methods The effects of days per week of aerobic and strength exercise participation on laboratory test results for 26 biomarkers in young adults aged 18 to 34 years (n = 80,111) were evaluated using percentile distribution analyses and multivariate regression. Results In both men and women, more days per week of either aerobic or strength exercise were significantly associated with lower levels of glucose, hemoglobin A1c, LDL cholesterol, total cholesterol, triglycerides, estimated glomerular filtration rate, globulin, and C-reactive protein, and significantly higher levels of HDL cholesterol, creatinine, iron, and percent saturation (all p exercise or gender influenced the observed relationships with exercise frequency for total cholesterol, aspartate aminotransferase, gamma-glutamyl transferase, alkaline phosphatase, uric acid, bilirubin, and iron binding capacity. Conclusions Physical exercise shifted the distribution of results into the direction suggestive of better health. Reported relationships may help clinicians and patients to better understand and interpret laboratory results in athletic populations and possibly re-evaluate interpretation of reference intervals for physically active populations. PMID:29059178

  4. Prevalence of abnormal patellofemoral congruence in elite American football players and association with quadriceps isokinetic testing.

    Science.gov (United States)

    Brown, Christopher A; Carragee, Cat; Sox-Harris, Alex; Merchant, Alan C; Mcadams, Timothy R

    2014-02-01

    Abnormal patellofemoral joint alignment has been discussed as a potential risk factor for patellofemoral disorders and can impact the longevity of any elite athlete's career. The prevalence of abnormal patellofemoral congruence in elite American football athletes is similar to the general population and does not have a relationship with quadriceps isokinetic testing. A total of 125 athletes (220 knees) from the 2011 National Football League (NFL) Combine database who had radiographic and isokinetic studies were reviewed. Congruence angles (CA) and lateral patellofemoral angles (LPA) were calculated on a Merchant radiographic view. Isokinetic testing was used to determine quadriceps-to-hamstring strength (Q/H) ratio and side-to-side deficits. The relationships between abnormal CA and LPA with Q/H ratios, side-to-side deficits, and body mass index (BMI) were examined in separate logistic regression models. A Chi-square test was used to examine the association between CA and player position. Of all, 26.8% of the knees (95% CI: 21.1-33.2%) had an abnormal CA. Knees with normal CA (n = 161) did not significantly differ from those with an abnormal CA (n  = 59) in Q/H ratios (mean: 0.699 vs. 0.728, p = 0.19) or side-to-side quadriceps deficits (mean: 4.0 vs. 1.24, p  = 0.45). For each point increase in BMI, the odds ratio (OR) of abnormal congruence increased by 11.4% (p = 0.002). Of all the knees, 4.1% (95% CI: 1.9-7.6%) had an abnormal LPA, and this was not associated with Q/H ratios (p  =  0.13). For each point increase in BMI, the odds of abnormal LPA increased by 16% (p  = 0.036). CA abnormality had much higher odds of having an abnormal LPA (OR: 5.96, p = 0.014). We found that abnormal patellofemoral radiographic alignment in elite American football players is relatively common and there was no association with isokinetic testing. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  5. Diagnosis of Lyme-associated uveitis: value of serological testing in a tertiary centre.

    Science.gov (United States)

    Bernard, Alexia; Kodjikian, Laurent; Abukhashabh, Amro; Roure-Sobas, Chantal; Boibieux, Andre; Denis, Philippe; Broussolle, Christiane; Seve, Pascal

    2018-03-01

    To determine the frequency and clinical presentation of Lyme disease in patients with uveitis and to assess the value of Borrelia burgdorferi serological testing. Retrospective study on all patients with uveitis who were referred to our tertiary hospital were serologically tested for Lyme in our laboratory between 2003 and 2016. Screening consisted of determining B. burgdorferi serum IgG and IgM by ELISA method. The patient's serology was considered as positive if the ELISA-positive result in IgM and/or IgG was confirmed by an immunoblot positive in IgM and/or IgG. Lyme-associated uveitis was diagnosed based on serological results as well as response to antibiotics and exclusion of other diagnosis. Of the 430 patients with uveitis (60% women, mean age 49 years) fulfilling inclusion criteria, 63 (14.7%) had an ELISA-positive serology, confirmed by immunoblot for 34 patients (7.9%). The diagnosis of Lyme-associated uveitis was finally retained in seven patients (1.6%). These patients reported either a previous exposure including tick bite or forest walks (n=5), symptoms suggestive of Lyme disease (n=5) and resistance to local and/or systemic steroids (n=7). Among the remaining 27 positive patients, 22 had other established aetiologies and 5 other were unclassified. The seroprevalence of B. burgdorferi among our patients with uveitis was 7.9% compared with 6 to 8.5% in the general French population which leads to a low predictive value of serological testing. Its use should be reserved for patients with unexplained uveitis, an exposure history, systemic findings suggestive of Lyme disease and steroids resistance. © 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.

  6. SU-C-BRC-04: Efficient Dose Calculation Algorithm for FFF IMRT with a Simplified Bivariate Gaussian Source Model

    Energy Technology Data Exchange (ETDEWEB)

    Li, F; Park, J; Barraclough, B; Lu, B; Li, J; Liu, C; Yan, G [University Florida, Gainesville, FL (United States)

    2016-06-15

    Purpose: To develop an efficient and accurate independent dose calculation algorithm with a simplified analytical source model for the quality assurance and safe delivery of Flattening Filter Free (FFF)-IMRT on an Elekta Versa HD. Methods: The source model consisted of a point source and a 2D bivariate Gaussian source, respectively modeling the primary photons and the combined effect of head scatter, monitor chamber backscatter and collimator exchange effect. The in-air fluence was firstly calculated by back-projecting the edges of beam defining devices onto the source plane and integrating the visible source distribution. The effect of the rounded MLC leaf end, tongue-and-groove and interleaf transmission was taken into account in the back-projection. The in-air fluence was then modified with a fourth degree polynomial modeling the cone-shaped dose distribution of FFF beams. Planar dose distribution was obtained by convolving the in-air fluence with a dose deposition kernel (DDK) consisting of the sum of three 2D Gaussian functions. The parameters of the source model and the DDK were commissioned using measured in-air output factors (Sc) and cross beam profiles, respectively. A novel method was used to eliminate the volume averaging effect of ion chambers in determining the DDK. Planar dose distributions of five head-and-neck FFF-IMRT plans were calculated and compared against measurements performed with a 2D diode array (MapCHECK™) to validate the accuracy of the algorithm. Results: The proposed source model predicted Sc for both 6MV and 10MV with an accuracy better than 0.1%. With a stringent gamma criterion (2%/2mm/local difference), the passing rate of the FFF-IMRT dose calculation was 97.2±2.6%. Conclusion: The removal of the flattening filter represents a simplification of the head structure which allows the use of a simpler source model for very accurate dose calculation. The proposed algorithm offers an effective way to ensure the safe delivery of FFF-IMRT.

  7. Crossmatch testing in kidney transplantation: Patterns of practice and associations with rejection and graft survival

    International Nuclear Information System (INIS)

    Salvalaggio, Paolo R; Graff, Ralph J; Pinsky, Brett; Schnitzler, Mark A; Takemoto, Steven K; Burroughs, Thomas E; Santos, Luiz S; Lentine Krista L

    2009-01-01

    Methods of crossmatch testing prior to kidney transplantation are not standardized and there are limited large-scale data on the use and outcomes implications of crossmatch modality. Data describing the most sensitive crossmatch modality for crossmatch-negative kidney transplants were drawn from the Organ Procurement and Transplant Network Registry. Within the cohort transplanted in 1999-2005, we identified patient and transplant characteristics predictive of each testing modality by multivariate logistic regression. We assessed associations of crossmatch modality with rejection risk by logistic regression and with graft survival by Cox's hazards analysis. Among 230,995 transplants, use of flow cytometry with T-and B-lymphocytes (T and B FC) increased progressively in 1987-2005. Among the recent transplants performed in 1999-2005 (n=64,320), negative T and B FC crossmatch was associated with 15% lower relative risk of first-year acute rejection (adjusted HR 0.85, 95% CI 0.80-0.89) compared to negative T-antihuman-globulin and B-National Institutes of Health/Wash (T AHG and B) crossmatch. Five-year graft survival after transplant with negative T and B FC (82.6%) was modestly better than after negative T AHG and B (81.4%, P0.008) or T AHG crossmatch (81.1%, P 60 years. Many subgroups for whom negative T and B FC crossmatch predicted lower rejection risk (Caucasians, deceased donor recipients, re-transplants) were not more likely to be crossmatched by this method. We conclude that current practice patterns have not aligned utilization of T and B FC crossmatch with associated benefits. Prospective evaluation of the relationship of crossmatch modality with outcomes is warranted. (author)

  8. Avian diversity and West Nile virus: testing associations between biodiversity and infectious disease risk.

    Science.gov (United States)

    Ezenwa, V.O.; Godsey, M.S.; King, R.J.; Guptill, S.C.

    2006-01-01

    The emergence of several high profile infectious diseases in recent years has focused attention on our need to understand the ecological factors contributing to the spread of infectious diseases. West Nile virus (WNV) is a mosquito-borne zoonotic disease that was first detected in the United States in 1999. The factors accounting for variation in the prevalence of WNV are poorly understood, but recentideas suggesting links between high biodiversity and reduced vector-borne disease risk may help account for distribution patterns of this disease. Since wild birds are the primary reservoir hosts for WNV, we tested associations between passerine (Passeriform) bird diversity, non-passerine (all other orders) bird diversity and virus infection rates in mosquitoes and humans to examine the extent to which bird diversity is associated with WNV infection risk. We found t h at non-passerine species richness (number of non-passerine species) was significantly negatively correlated with both mosquito and human infection rates, whereas there was no significant association between passerine species richness and any measure of infection risk. Our findings suggest that non-passerine diversity may play a role in dampening WNV amplification rates in mosquitoes, minimizing human disease risk.

  9. Regional admixture mapping and structured association testing: conceptual unification and an extensible general linear model.

    Directory of Open Access Journals (Sweden)

    David T Redden

    2006-08-01

    Full Text Available Individual genetic admixture estimates, determined both across the genome and at specific genomic regions, have been proposed for use in identifying specific genomic regions harboring loci influencing phenotypes in regional admixture mapping (RAM. Estimates of individual ancestry can be used in structured association tests (SAT to reduce confounding induced by various forms of population substructure. Although presented as two distinct approaches, we provide a conceptual framework in which both RAM and SAT are special cases of a more general linear model. We clarify which variables are sufficient to condition upon in order to prevent spurious associations and also provide a simple closed form "semiparametric" method of evaluating the reliability of individual admixture estimates. An estimate of the reliability of individual admixture estimates is required to make an inherent errors-in-variables problem tractable. Casting RAM and SAT methods as a general linear model offers enormous flexibility enabling application to a rich set of phenotypes, populations, covariates, and situations, including interaction terms and multilocus models. This approach should allow far wider use of RAM and SAT, often using standard software, in addressing admixture as either a confounder of association studies or a tool for finding loci influencing complex phenotypes in species as diverse as plants, humans, and nonhuman animals.

  10. Associations between psychological test results and failure to proceed with bariatric surgery.

    Science.gov (United States)

    Marek, Ryan J; Tarescavage, Anthony M; Ben-Porath, Yossef S; Ashton, Kathleen; Heinberg, Leslie J; Rish, Julie Merrell

    2017-03-01

    The reasons why some patients who begin the presurgical process for bariatric surgery fail to complete the procedure are understudied. Previous research implies that psychological factors play a role. To examine whether scores from baseline psychological testing incrementally predict failure to proceed with bariatric surgery beyond demographic information in patients' medical charts and data derived from a clinical interview. Cleveland Clinic Bariatric and Metabolic Institute. The sample (n = 1160) was mainly female (72.41%), middle aged (mean age = 46.07 yr, SD = 11.70) and of Caucasian descent (65.76%). Hierarchical logistic regressions were conducted to test the incremental validity of baseline Minnesota Multiphasic Personality Inventory-2 Restructured Form scores after controlling for information gathered from the psychological interview and medical charts. Relative risk ratios were calculated to reflect the clinical utility of the results. In total, 27.16% of patients failed to proceed with bariatric surgery after 1 year or more after a recommendation for surgery from their psychological evaluations. Psychological test scores were substantially associated with failure to proceed with surgery and significantly accounted for up to 6% of additional variance after controlling for psychological interview variables and medical chart data. Elevated scores on Minnesota Multiphasic Personality Inventory-2 Restructured Form scales, such as anxiety and substance use, identify patients at up to 2.5 times greater risk for failing to proceed with bariatric surgery. Objective psychological test data-notably, scale scores assessing for substance abuse, anxiety, and demoralization-add to information obtained from a clinical interview and medical records in identifying patients at risk for failing to proceed with bariatric surgery. Copyright © 2017 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

  11. Real-world injury patterns associated with Hybrid III sternal deflections in frontal crash tests.

    Science.gov (United States)

    Brumbelow, Matthew L; Farmer, Charles M

    2013-01-01

    This study investigated the relationship between the peak sternal deflection measurements recorded by the Hybrid III 50th percentile male anthropometric test device (ATD) in frontal crash tests and injury and fatality outcomes for drivers in field crashes. ATD sternal deflection data were obtained from the Insurance Institute for Highway Safety's 64 km/h, 40 percent overlap crashworthiness evaluation tests for vehicles with seat belt crash tensioners, load limiters, and good-rated structure. The National Automotive Sampling System Crashworthiness Data System (NASS-CDS) was queried for frontal crashes of these vehicles in which the driver was restrained by a seat belt and air bag. Injury probability curves were calculated by frontal crash type using the injuries coded in NASS-CDS and peak ATD sternal deflection data. Fatality Analysis Reporting System (FARS) front-to-front crashes with exactly one driver death were also studied to determine whether the difference in measured sternal deflections for the 2 vehicles was related to the odds of fatality. For center impacts, moderate overlaps, and large overlaps in NASS-CDS, the probability of the driver sustaining an Abbreviated Injury Scale (AIS) score ≥ 3 thoracic injury, or any nonextremity AIS ≥ 3 injury, increased with increasing ATD sternal deflection measured in crash tests. For small overlaps, however, these probabilities decreased with increasing deflection. For FARS crashes, the fatally injured driver more often was in the vehicle with the lower measured deflection in crash tests (55 vs. 45%). After controlling for other factors, a 5-mm difference in measured sternal deflections between the 2 vehicles was associated with a fatality odds ratio of 0.762 for the driver in the vehicle with the greater deflection (95% confidence interval = 0.373, 1.449). Restraint systems that reduce peak Hybrid III sternal deflection in a moderate overlap crash test are beneficial in real-world crashes with similar or greater

  12. Clarifying associations between psychopathy facets and personality disorders among offenders

    NARCIS (Netherlands)

    Klipfel, Kristen M.; Garofalo, C.; Kosson, D.S.

    2017-01-01

    Purpose This study examined bivariate, unique, and multivariate associations between psychopathy facets and other Personality Disorders (PDs). Method 76 incarcerated males were assessed with clinical interviews measuring psychopathy and DSM-5 PDs. Canonical Correlation Analysis (CCA) was used to

  13. If you provide the test, they will take it: factors associated with HIV/STI Testing in a representative sample of homeless youth in Los Angeles.

    Science.gov (United States)

    Ober, Allison J; Martino, Steven C; Ewing, Brett; Tucker, Joan S

    2012-08-01

    Homeless youth are at high risk for human immunodeficiency virus (HIV) and other sexually transmitted infections (STI), yet those at greatest risk may never have been tested for HIV or STI. In a probability sample of sexually active homeless youth in Los Angeles (n = 305), this study identifies factors associated with HIV/STI testing status. Most youth (85%) had ever been tested and 47% had been tested in the past 3 months. Recent testing was significantly more likely among youth who self-identified as gay, were Hispanic, injected drugs, and used drop-in centers, and marginally more likely among youth with more depressive symptoms. Drop-in center use mediated the association of injection drug use with HIV/STI testing. HIV/STI testing was unrelated to sexual risk behavior. Drop-in centers can play an important role in facilitating testing, including among injection drug users, but more outreach is needed to encourage testing in other at-risk subgroups.

  14. Measurement of psychological factors associated with genetic testing for hereditary breast, ovarian and colon cancers.

    Science.gov (United States)

    Vadaparampil, Susan T; Ropka, Mary; Stefanek, Michael E

    2005-01-01

    Despite numerous individual studies of psychological factors (depression, anxiety, distress) related to genetic testing for inherited cancer syndromes (CGT), there has been no systematic review of the psychological factors are measured among individuals at increased risk for hereditary breast, ovarian, or colon cancer. Our review provides an analysis of psychological factors in studies of CGT and discusses the instruments most commonly used to measure them. We performed a literature search using three major OVID databases from 1993 to January 2003. In the 19 studies that met our inclusion criteria, the most commonly assessed psychological factors were distress, anxiety, and depression. These factors were most often measured by the impact of event scale (IES), the state-trait anxiety inventory (STAI), and the Centers for Epidemiologic Studies and Depression scale (CES-D), respectively. Our results show deficits in the existing body of literature on psychological factors associated with CGT including limited documentation of psychometrics and variability in instrumentation.

  15. Association testing for next-generation sequencing data using score statistics

    DEFF Research Database (Denmark)

    Skotte, Line; Korneliussen, Thorfinn Sand; Albrechtsen, Anders

    2012-01-01

    computationally feasible due to the use of score statistics. As part of the joint likelihood, we model the distribution of the phenotypes using a generalized linear model framework, which works for both quantitative and discrete phenotypes. Thus, the method presented here is applicable to case-control studies...... of genotype calls into account have been proposed; most require numerical optimization which for large-scale data is not always computationally feasible. We show that using a score statistic for the joint likelihood of observed phenotypes and observed sequencing data provides an attractive approach...... to association testing for next-generation sequencing data. The joint model accounts for the genotype classification uncertainty via the posterior probabilities of the genotypes given the observed sequencing data, which gives the approach higher power than methods based on called genotypes. This strategy remains...

  16. Association of Health Sciences Reasoning Test scores with academic and experiential performance.

    Science.gov (United States)

    Cox, Wendy C; McLaughlin, Jacqueline E

    2014-05-15

    To assess the association of scores on the Health Sciences Reasoning Test (HSRT) with academic and experiential performance in a doctor of pharmacy (PharmD) curriculum. The HSRT was administered to 329 first-year (P1) PharmD students. Performance on the HSRT and its subscales was compared with academic performance in 29 courses throughout the curriculum and with performance in advanced pharmacy practice experiences (APPEs). Significant positive correlations were found between course grades in 8 courses and HSRT overall scores. All significant correlations were accounted for by pharmaceutical care laboratory courses, therapeutics courses, and a law and ethics course. There was a lack of moderate to strong correlation between HSRT scores and academic and experiential performance. The usefulness of the HSRT as a tool for predicting student success may be limited.

  17. Understanding and using the brief Implicit Association Test: recommended scoring procedures.

    Directory of Open Access Journals (Sweden)

    Brian A Nosek

    Full Text Available A brief version of the Implicit Association Test (BIAT has been introduced. The present research identified analytical best practices for overall psychometric performance of the BIAT. In 7 studies and multiple replications, we investigated analytic practices with several evaluation criteria: sensitivity to detecting known effects and group differences, internal consistency, relations with implicit measures of the same topic, relations with explicit measures of the same topic and other criterion variables, and resistance to an extraneous influence of average response time. The data transformation algorithms D outperformed other approaches. This replicates and extends the strong prior performance of D compared to conventional analytic techniques. We conclude with recommended analytic practices for standard use of the BIAT.

  18. Assessing bias against overweight individuals among nursing and psychology students: an implicit association test.

    Science.gov (United States)

    Waller, Tabitha; Lampman, Claudia; Lupfer-Johnson, Gwen

    2012-12-01

    To determine the implicit or unconscious attitudes of Nursing and Psychology majors towards overweight individuals in medical and non-medical contexts. Obesity is a leading health concern today, which impacts both physical and psychological health. Overweight individuals confront social biases in many aspects of their lives including health care. Examining the views of Nursing and Psychology students may reveal implicit attitudes towards overweight individuals that may lead to prejudiced behaviours. A mixed design experiment with one between-subjects variable (student major: Nursing or Psychology) and one within-subjects variable (condition: congruent or incongruent) was used to assess implicit attitudes in two convenience samples of Nursing and Psychology students. A computerised implicit association test was used to determine implicit attitudes towards overweight individuals in medical and non-medical contexts. A total of 90 students from Nursing (n= 45) and Psychology (n = 45) were recruited to complete an implicit association test. Reaction times in milliseconds between the congruent trials (stereotype consistent) and incongruent trials (stereotype inconsistent) were compared with determine adherence to social stereotypes or weight bias. A statistically significant implicit bias towards overweight individuals was detected in both subject groups and in both target settings (medical vs. non-medical). Stronger weight bias was found when the stimulus targets were female than male. Findings from this study expand understanding of the implicit attitudes and social biases of Nursing and Psychology students. The views held by these future healthcare professionals may negatively impact patient care. Providing education and support to overweight individuals is central to Nursing practice in a society struggling to manage obesity. Negative stereotypes or beliefs about these individuals may result in poor patient care. Therefore, nurses and other healthcare professionals

  19. Factors associated with suicidal ideation among university students 1

    Science.gov (United States)

    dos Santos, Hugo Gedeon Barros; Marcon, Samira Reschetti; Espinosa, Mariano Martínez; Baptista, Makilin Nunes; de Paulo, Paula Mirianh Cabral

    2017-01-01

    ABSTRACT Objective: to analyze the factors associated with suicidal ideation in a representative sample of university students. Methods: cross-sectional study, carried out with 637 students of the Federal University of Mato Grosso. The presence of suicidal ideation, demographic and socioeconomic variables, use of alcohol through the Alcohol, Smoking and Substance Involvement Screening Test, and depressive symptoms (Major Depression Inventory) were investigated. Bivariate analysis was performed with the Chi-square test and multivariate analysis using the Poisson regression model. Results: it was found that 9.9% of the students had suicidal thoughts in the previous 30 days and, in the bivariate analysis, the variables economic class, sexual orientation, religious practice, suicide attempts in the family and among friends, alcohol consumption and depressive symptoms were associated with suicidal ideation. In the multivariate analysis sexual orientation, suicide attempts in the family and the presence of depressive symptoms remained as associated factors. Conclusion: these findings constitute a situational diagnosis that enables the formulation of academic policies and preventive actions to confront this situation on the university campus. PMID:28513765

  20. Strategies for Solving Potential Problems Associated with Laboratory Diffusion and Batch Experiments - Part 1: An Overview of Conventional Test Methods

    International Nuclear Information System (INIS)

    Zhang, M.; Takeda, M.; Nakajima, H.

    2006-01-01

    Laboratory diffusion testing as well as batch experiments are well established and widely adopted techniques for characterizing the diffusive and adsorptive properties of geological, geotechnical, and synthetic materials in both scientific and applied fields, including geological disposal of radioactive waste. Although several types of diffusion test, such as the through- diffusion test, in-diffusion test, out-diffusion test, and column test, are currently available, different methods may have different advantages and disadvantages. In addition, traditional methods may have limitations, such as the need for relatively long test times, cumbersome test procedures, and the possibility of errors due to differences between analytical assumptions and actual test conditions. Furthermore, traditional batch experiments using mineral powders are known to overestimate the sorption coefficient. In part 1 of this report, we present a brief overview of laboratory diffusion and batch experiments. The advantages, disadvantages, limitations, and/or potential problems associated with individual tests were compared and summarized. This comprehensive report will provide practical references for reviewing the results obtained from relevant experiments, especially from the viewpoint of regulation. To solve and/or eliminate the potential problems associated with conventional methods, and to obtain the diffusion coefficient and rock capacity factor from a laboratory test both rapidly and accurately, part 2 of this study discusses possible strategies involving the development of rigorous solutions to some relevant test methods, and sensitivity analyses for the related tests that may be helpful to judge the accuracy of the two parameters to be determined from individual tests. (authors)

  1. Drilling and Production Testing the Methane Hydrate Resource Potential Associated with the Barrow Gas Fields

    Energy Technology Data Exchange (ETDEWEB)

    Steve McRae; Thomas Walsh; Michael Dunn; Michael Cook

    2010-02-22

    In November of 2008, the Department of Energy (DOE) and the North Slope Borough (NSB) committed funding to develop a drilling plan to test the presence of hydrates in the producing formation of at least one of the Barrow Gas Fields, and to develop a production surveillance plan to monitor the behavior of hydrates as dissociation occurs. This drilling and surveillance plan was supported by earlier studies in Phase 1 of the project, including hydrate stability zone modeling, material balance modeling, and full-field history-matched reservoir simulation, all of which support the presence of methane hydrate in association with the Barrow Gas Fields. This Phase 2 of the project, conducted over the past twelve months focused on selecting an optimal location for a hydrate test well; design of a logistics, drilling, completion and testing plan; and estimating costs for the activities. As originally proposed, the project was anticipated to benefit from industry activity in northwest Alaska, with opportunities to share equipment, personnel, services and mobilization and demobilization costs with one of the then-active exploration operators. The activity level dropped off, and this benefit evaporated, although plans for drilling of development wells in the BGF's matured, offering significant synergies and cost savings over a remote stand-alone drilling project. An optimal well location was chosen at the East Barrow No.18 well pad, and a vertical pilot/monitoring well and horizontal production test/surveillance well were engineered for drilling from this location. Both wells were designed with Distributed Temperature Survey (DTS) apparatus for monitoring of the hydrate-free gas interface. Once project scope was developed, a procurement process was implemented to engage the necessary service and equipment providers, and finalize project cost estimates. Based on cost proposals from vendors, total project estimated cost is $17.88 million dollars, inclusive of design work

  2. Association between cervical lesion grade and micronucleus frequency in the Papanicolaou test

    Directory of Open Access Journals (Sweden)

    Caroline Tanski Bueno

    2014-09-01

    Full Text Available The aim of this study was to evaluate the association between the frequency of micronuclei (MN and the cellular changes detected in the conventional Papanicolaou test. One hundred and seventy-four Papanicolaou test smears with cellular changes were examined. MN screening was done in cytopathological smears by counting 1,000 cervical cells in a light microscope. MN frequencies were significantly higher in the group with cellular changes compared to the control group (p < 0.001. The mean MN frequencies were 0.95 ± 1.12 (mean ± SD in the control group (n = 223, 2.98 ± 1.20 in individuals with atypical squamous cells of undetermined significance (ASC-US (n = 50, 4.04 ± 1.45 in cervical intraepithelial neoplasia (CIN I (n = 52, 5.97 ± 1.83 in CIN II (n = 30, 7.29 ± 1.55 in CIN III (n = 17 and 8.64 ± 1.55 in invasive cancer (n = 25. These findings suggest that MN monitoring should be included as an additional criterion for the early detection of cytogenetic damage in routine examinations. This monitoring should be done in the same smear as used for cytopathological examination. More specific and systematic studies are necessary to confirm this proposal.

  3. Personal influencing factors associated with pap smear testing and cervical cancer.

    Science.gov (United States)

    Ackerson, Kelly; Pohl, Joanne; Low, Lisa Kane

    2008-02-01

    Pap smear is a screening test that detects abnormal cells before they advance to cancer. Unfortunately, not all women obtain routine screening. The method used was a qualitative study exploring personal influences regarding Pap smears. Face-to-face interviews with 7 low-income African American women who do and do not obtain Pap smears (between 21 and 37 years of age) were conducted at a health department about their social influence, previous health care experience, and cognitive appraisal regarding Pap smears and cervical cancer. Women were found to be socially influenced by their family and their physician. Previous health care experience with the Pap and pelvic was perceived as negative. Cognitively, Pap smears were believed to test for sexually transmitted diseases, including HIV, and the women also felt that if one took good care of oneself it reduced the risk for cervical cancer. It was concluded that exploring beliefs associated with Pap smears and perceptions of vulnerability to cervical cancer and giving correct information and counseling may increase Pap smear screening in women.

  4. 'I'm happy to own my implicit biases': Public encounters with the implicit association test.

    Science.gov (United States)

    Yen, Jeffery; Durrheim, Kevin; Tafarodi, Romin W

    2018-02-16

    The implicit association test (IAT) and concept of implicit bias have significantly influenced the scientific, institutional, and public discourse on racial prejudice. In spite of this, there has been little investigation of how ordinary people make sense of the IAT and the bias it claims to measure. This article examines the public understanding of this research through a discourse analysis of reactions to the IAT and implicit bias in the news media. It demonstrates the ways in which readers interpreted, related to, and negotiated the claims of IAT science in relation to socially shared and historically embedded concerns and identities. IAT science was discredited in accounts that evoked discourses about the marginality of academic preoccupations, and helped to position test-takers as targets of an oppressive political correctness and psychologists as liberally biased. Alternatively, the IAT was understood to have revealed widely and deeply held biases towards racialized others, eliciting accounts that took the form of psychomoral confessionals. Such admissions of bias helped to constitute moral identities for readers that were firmly positioned against racial bias. Our findings are discussed in terms of their implications for using the IAT in prejudice reduction interventions, and communicating to the public about implicit bias. © 2018 The British Psychological Society.

  5. [Complex febrile seizures: study of the associated pathology and practical use of complementary tests].

    Science.gov (United States)

    Berzosa López, R; Ramos Fernández, J M; Martínez Antón, J; Espinosa Fernández, M G; Urda Cardona, A

    2014-06-01

    Although one third of febrile seizures are complex, a consensus has still not been reached on how to manage them, as is the case with simple febrile seizures. The objective of this study is to estimate the usefulness of complementary examinations and the risk of associated serious intracranial pathology. A retrospective review was conducted from 2003 until 2011 on patients from 6 months to 6 years presenting with a complex febrile seizure admitted to a tertiary care hospital, excluding the cases with previous neurological disease. Epidemiological and clinic variables were collected, as well as complementary tests and complications. We found 65 patients (31 females and 34 males), of whom 44 had repeated seizures in the first 24 hours, with 15 having focal seizures. The vast majority (90%) of the recurrences occurred before 15 hours. The mean age was 20.7 months and temperature was 39.1 ± 0.12°C. None of the patients had severe intracranial pathology. The electroencephalogram gave no helpful information for the diagnosis. Neuroimaging was normal in all studied cases. The incidence of complications in complex febrile seizure in our series did not justify the systematic admission or the systematic study with complementary tests when the neurological examination was normal. The routine electroencephalogram does not appear to be justified. Copyright © 2012 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

  6. Testing Students with Special Educational Needs in Large-Scale Assessments - Psychometric Properties of Test Scores and Associations with Test Taking Behavior.

    Science.gov (United States)

    Pohl, Steffi; Südkamp, Anna; Hardt, Katinka; Carstensen, Claus H; Weinert, Sabine

    2016-01-01

    Assessing competencies of students with special educational needs in learning (SEN-L) poses a challenge for large-scale assessments (LSAs). For students with SEN-L, the available competence tests may fail to yield test scores of high psychometric quality, which are-at the same time-measurement invariant to test scores of general education students. We investigated whether we can identify a subgroup of students with SEN-L, for which measurement invariant competence measures of adequate psychometric quality may be obtained with tests available in LSAs. We furthermore investigated whether differences in test-taking behavior may explain dissatisfying psychometric properties and measurement non-invariance of test scores within LSAs. We relied on person fit indices and mixture distribution models to identify students with SEN-L for whom test scores with satisfactory psychometric properties and measurement invariance may be obtained. We also captured differences in test-taking behavior related to guessing and missing responses. As a result we identified a subgroup of students with SEN-L for whom competence scores of adequate psychometric quality that are measurement invariant to those of general education students were obtained. Concerning test taking behavior, there was a small number of students who unsystematically picked response options. Removing these students from the sample slightly improved item fit. Furthermore, two different patterns of missing responses were identified that explain to some extent problems in the assessments of students with SEN-L.

  7. Pemphigus vulgaris of the cervix: diagnostic difficulties associated with the Pap test.

    Science.gov (United States)

    Munhoz de Paula Alves Coelho, Karina; Stall, Jaqueline; Henrique Condeixa de França, Paulo; Cristina de Carvalho Tavares, Lara; Stefanello Bublitz, Giuliano; Loos, Beliza; Carvalho Costa, Luciana; Fronza Júnior, Hercílio

    2015-08-01

    Pemphigus vulgaris (PV) is a rare mucocutaneous disease caused by the abnormal production of antibodies against epithelial cell surface glycoproteins, resulting in loss of cell adhesion and intraepithelial blister formation. Cervical involvement in PV has been poorly reported, and there is little information regarding the criteria about consequential cytological changes identified in a Papanicolaou-stained cervicovaginal smear (Pap smear). Here, we report a case of PV manifesting in the cervix as well as the difficulty associated with the cytomorphological identification and interpretation of acantholytic cells. This case involved a 40-year-old patient with no history of Pap test abnormalities and no prior diagnosis of PV. In the cytological assessment, cells were identified both in isolation and in clusters that exhibited round nuclei of increased volume, inconspicuous nucleoli, and perinuclear halos. The patient underwent a cervical biopsy that revealed vesiculobullous lesions and morphological pattern consistent with PV. A skin biopsy confirmed this diagnosis. We concluded that knowledge of PV cytomorphology is important because difficulties associated with the identification and interpretation of acantholytic cells might be responsible for false positive diagnoses of cervical neoplasia. However, a suspected diagnosis of PV is possible if the cytological findings are carefully correlated with the clinical data. © 2015 Wiley Periodicals, Inc.

  8. Genetic Testing for TMEM154 Mutations Associated with Lentivirus Susceptibility in Sheep

    Science.gov (United States)

    Petrik, Dustin T.; Simpson, Barry; Kijas, James W.; Clawson, Michael L.; Chitko-McKown, Carol G.; Harhay, Gregory P.; Leymaster, Kreg A.

    2013-01-01

    In sheep, small ruminant lentiviruses cause an incurable, progressive, lymphoproliferative disease that affects millions of animals worldwide. Known as ovine progressive pneumonia virus (OPPV) in the U.S., and Visna/Maedi virus (VMV) elsewhere, these viruses reduce an animal’s health, productivity, and lifespan. Genetic variation in the ovine transmembrane protein 154 gene (TMEM154) has been previously associated with OPPV infection in U.S. sheep. Sheep with the ancestral TMEM154 haplotype encoding glutamate (E) at position 35, and either form of an N70I variant, were highly-susceptible compared to sheep homozygous for the K35 missense mutation. Our current overall aim was to characterize TMEM154 in sheep from around the world to develop an efficient genetic test for reduced susceptibility. The average frequency of TMEM154 E35 among 74 breeds was 0.51 and indicated that highly-susceptible alleles were present in most breeds around the world. Analysis of whole genome sequences from an international panel of 75 sheep revealed more than 1,300 previously unreported polymorphisms in a 62 kb region containing TMEM154 and confirmed that the most susceptible haplotypes were distributed worldwide. Novel missense mutations were discovered in the signal peptide (A13V) and the extracellular domains (E31Q, I74F, and I102T) of TMEM154. A matrix-assisted laser desorption/ionization–time-of flight mass spectrometry (MALDI-TOF MS) assay was developed to detect these and six previously reported missense and two deletion mutations in TMEM154. In blinded trials, the call rate for the eight most common coding polymorphisms was 99.4% for 499 sheep tested and 96.0% of the animals were assigned paired TMEM154 haplotypes (i.e., diplotypes). The widespread distribution of highly-susceptible TMEM154 alleles suggests that genetic testing and selection may improve the health and productivity of infected flocks. PMID:23408992

  9. Genetic testing for TMEM154 mutations associated with lentivirus susceptibility in sheep.

    Directory of Open Access Journals (Sweden)

    Michael P Heaton

    Full Text Available In sheep, small ruminant lentiviruses cause an incurable, progressive, lymphoproliferative disease that affects millions of animals worldwide. Known as ovine progressive pneumonia virus (OPPV in the U.S., and Visna/Maedi virus (VMV elsewhere, these viruses reduce an animal's health, productivity, and lifespan. Genetic variation in the ovine transmembrane protein 154 gene (TMEM154 has been previously associated with OPPV infection in U.S. sheep. Sheep with the ancestral TMEM154 haplotype encoding glutamate (E at position 35, and either form of an N70I variant, were highly-susceptible compared to sheep homozygous for the K35 missense mutation. Our current overall aim was to characterize TMEM154 in sheep from around the world to develop an efficient genetic test for reduced susceptibility. The average frequency of TMEM154 E35 among 74 breeds was 0.51 and indicated that highly-susceptible alleles were present in most breeds around the world. Analysis of whole genome sequences from an international panel of 75 sheep revealed more than 1,300 previously unreported polymorphisms in a 62 kb region containing TMEM154 and confirmed that the most susceptible haplotypes were distributed worldwide. Novel missense mutations were discovered in the signal peptide (A13V and the extracellular domains (E31Q, I74F, and I102T of TMEM154. A matrix-assisted laser desorption/ionization-time-of flight mass spectrometry (MALDI-TOF MS assay was developed to detect these and six previously reported missense and two deletion mutations in TMEM154. In blinded trials, the call rate for the eight most common coding polymorphisms was 99.4% for 499 sheep tested and 96.0% of the animals were assigned paired TMEM154 haplotypes (i.e., diplotypes. The widespread distribution of highly-susceptible TMEM154 alleles suggests that genetic testing and selection may improve the health and productivity of infected flocks.

  10. Characterization of human organ donors testing positive for type 1 diabetes-associated autoantibodies

    Science.gov (United States)

    Wiberg, A; Granstam, A; Ingvast, S; Härkönen, T; Knip, M; Korsgren, O; Skog, O

    2015-01-01

    In this study we aim to describe the characteristics of non-diabetic organ donors with circulating diabetes-associated autoantibodies collected within the Nordic Network for Islet Transplantation. One thousand and thirty organ donors have been screened in Uppsala for antibodies against glutamic acid decarboxylase (GADA) and islet antigen-2 (IA-2A). The 32 non-diabetic donors that tested positive for GADA (3·3% of all non-diabetic donors) were studied in more detail, together with 32 matched controls. Mean age among the autoantibody-positive donors was 52·6 (range 21–74), family history of type 1 diabetes (T1D) was unknown, and no donor was genetically predisposed for T1D regarding the human leucocyte antigen (HLA) locus. Subjects were analysed for islet cell antibodies (ICA), insulin autoantibodies (IAA) and zinc transporter 8 antibodies (ZnT8A), and pancreas morphology and clinical data were examined. Eight non-diabetic donors tested positive for two antibodies and one donor tested positive for four antibodies. No insulitis or other signs of a diabetic process were found in any of the donors. While inflammatory cells were present in all donors, subjects with high GADA titres had significantly higher CD45 cell numbers in exocrine tissue than controls. The extent of fibrosis was more pronounced in autoantibody-positive donors, even in subjects with lower GADA titres. Notably, it is possible that events not related directly to T1D (e.g. subclinical pancreatitis) may induce autoantibodies in some cases. PMID:26313035

  11. A method to customize population-specific arrays for genome-wide association testing.

    Science.gov (United States)

    Ehli, Erik A; Abdellaoui, Abdel; Fedko, Iryna O; Grieser, Charlie; Nohzadeh-Malakshah, Sahar; Willemsen, Gonneke; de Geus, Eco Jc; Boomsma, Dorret I; Davies, Gareth E; Hottenga, Jouke J

    2017-02-01

    As an example of optimizing population-specific genotyping assays using a whole-genome sequence reference set, we detail the approach that followed to design the Axiom-NL array which is characterized by an improved imputation backbone based on the Genome of the Netherlands (GoNL) reference sequence and, compared with earlier arrays, a more comprehensive inclusion of SNPs on chromosomes X, Y, and the mitochondria. Common variants on the array were selected to be compatible with the Illumina Psych Array and the Affymetrix UK Biobank Axiom array. About 3.5% of the array (23 977 markers) represents SNPs from the GWAS catalog, including SNPs at FTO, APOE, Ion-channels, killer-cell immunoglobulin-like receptors, and HLA. Around 26 000 markers associated with common psychiatric disorders are included, as well as 6705 markers suggested to be associated with fertility and twinning. The platform can thus be used for risk profiling, detection of new variants, as well as ancestry determination. Results of coverage tests in 249 unrelated subjects with GoNL-based sequence data show that after imputation with 1000G as a reference, the median concordance between original and imputed genotypes is above 98%. The median imputation quality R 2 for MAF thresholds of 0.001, 0.01, 0.05, and >0.05 are 0.05, 0.28, 0.80, 0.99, respectively, for the 1000G imputed SNPs, with a similar quality for the autosomes and X chromosome, showing a good genome-wide coverage for association studies after imputation.

  12. Attitudes towards individuals with disabilities as measured by the implicit association test: a literature review.

    Science.gov (United States)

    Wilson, Michelle Clare; Scior, Katrina

    2014-02-01

    Research investigating attitudes towards individuals with disabilities has largely focused on self-reported explicit attitudes. Given that factors such as social desirability may influence explicit attitudes, researchers have developed tools which instead assess less consciously controllable implicit attitudes. Considering research on implicit attitudes thus seems pertinent. A review of studies measuring implicit attitudes towards individuals with physical disabilities (visual, motor or hearing) or intellectual disabilities via the Implicit Association Test (IAT; Greenwald, McGhee, & Schwartz, 1998) was carried out. Systematic searches of PsycINFO, CINAHL, EMBASE, ERIC, MEDLINE, PUBMED, Scopus and Web of Science databases identified relevant articles published between January 2000 and September 2012. Seventeen articles (reporting on 18 studies that employed the IAT) were identified. These investigated implicit attitudes towards individuals with; physical disabilities (N=13), intellectual disabilities (N=3), both physical and intellectual disabilities (N=1), and 'unspecified disabilities' (N=1). Across all studies, moderate to strong negative implicit attitudes were found and there was little to no association between explicit and implicit attitudes. Individuals' beliefs about the controllability of their future, sensitivity to the concept of disease, and contact with individuals with disabilities appear to be associated with implicit attitudes. A consistent pattern of moderate to strong negative implicit attitudes towards individuals with disabilities was evident. These studies provide a starting point, but methodological issues related to sampling and the employed IATs limit the generalizability of these results. Further research investigating implicit attitudes towards specific disability types, with a wider subject pool are necessary as well as further investigation of factors that contribute to these attitudes. Copyright © 2013 Elsevier Ltd. All rights

  13. Use of a radiorespirometric assay for testing the antibiotic sensitivity of catheter-associated bacteria

    International Nuclear Information System (INIS)

    Ladd, T.I.; Schmiel, D.; Nickel, J.C.; Costerton, J.W.

    1987-01-01

    A 14 C-radiorespirometric assay was used to show the sensitivity of fixed-film (sessile), catheter-associated and free-living (planktonic) cells of Pseudomonas aeruginosa to varying concentrations (100 micrograms/mL to 1000 micrograms/mL) tobramycin sulfate. This strain of P. aeruginosa has an MIC of 0.6 microgram/ml and an MBC of 50 micrograms/mL when tested by conventional methods. When 14 C-glutamic acid was used as a substrate in this radiorespirometric assay, it could be completed in less than one hour and planktonic samples showed a significant reduction in mineralization activity (evolution of 14 CO 2 ) within eight hours of the antibiotic challenge. These changes in respiratory activity appeared to be dose and time dependent. Within 18 hr. at 1000 micrograms/mL, there was no significant residual respiratory activity in planktonic samples. Some residual respiratory activity was detected, however, in samples exposed to 100 micrograms/mL for 36 hours. The mineralization activity of sessile catheter-associated bacteria was unaffected by four hr. and eight hr. exposures to 1000 micrograms/mL of the antibiotic. A significant reduction in respiratory activity was recorded in catheter samples exposed for 18 hr. or more at each concentration examined. Unlike the planktonic samples, however, the antibiotic challenge failed to eradicate the metabolic activity of the attached bacteria. Antibiotic stressed, catheter-associated bacteria transferred to a post-exposure enrichment broth showed a limited ability to re-establish respiratory activity. This apparent recovery was limited to antibiotic exposures less than 24 hr. and was not observed in planktonic samples. The radioisotopic assay is a non-culture method which can be used to assess the antibiotic sensitivity of both planktonic bacteria and in situ biofilm populations

  14. Longitudinal change of COPD assessment test (CAT in a telehealthcare cohort is associated with exacerbation risk

    Directory of Open Access Journals (Sweden)

    Rassouli F

    2017-10-01

    Full Text Available Frank Rassouli,1 Florent Baty,1 Daiana Stolz,2 Werner Christian Albrich,3 Michael Tamm,2 Sandra Widmer,1 Martin Hugo Brutsche1 1Department of Pulmonary and Sleep Medicine, Cantonal Hospital St Gallen, St Gallen, Switzerland; 2Department of Pulmonary and Sleep Medicine, University Hospital Basel, Basel, Switzerland; 3Division of Infectious Diseases and Hospital Epidemiology, Cantonal Hospital St Gallen, St Gallen, Switzerland Background: There are only scarce data regarding the evolution of the chronic obstructive pulmonary disease (COPD assessment test (CAT over time. Our aim was to investigate the evolution of the CAT in a telehealthcare (THC cohort and to evaluate its potential to predict exacerbations.Patients and methods: The CAT was measured weekly over up to 1 year in 40 COPD patients undergoing a THC intervention. The evolution of the CAT was analyzed using linear regression. The association between this evolution and the occurrence of exacerbations was evaluated using the Andersen–Gill formulation of the Cox proportional hazards model for the analysis of recurrent time-to-event data with time-varying predictors.Results: The median CAT at inclusion was 17 (interquartile range 13–22 points. During the study, 25% of patients had a significant negative slope (median –7 points per year [ppy], 38% were stable (median +0 ppy and 38% had a significant positive slope (median +6 ppy. The median slope of the CAT in the overall cohort was +1 (interquartile range –3 to +6 ppy. A significant positive association was found between the change in CAT scores and the risk of exacerbations (hazard ratio =1.08, 95% CI: 1.03–1.13; p<0.001. There was an 8% increase of the risk of exacerbation per unit increase in CAT. We detected a significant learning effect in filling out the CAT in 18.4% of patients with a median learning phase of five filled questionnaires.Conclusion: Sixty-three percent of the COPD patients monitored by THC experienced a stable

  15. Bias associated with delayed verification in test accuracy studies: accuracy of tests for endometrial hyperplasia may be much higher than we think!

    OpenAIRE

    Clark, T Justin; ter Riet, Gerben; Coomarasamy, Aravinthan; Khan, Khalid S

    2004-01-01

    Abstract Background To empirically evaluate bias in estimation of accuracy associated with delay in verification of diagnosis among studies evaluating tests for predicting endometrial hyperplasia. Methods Systematic reviews of all published research on accuracy of miniature endometrial biopsy and endometr ial ultrasonography for diagnosing endometrial hyperplasia identified 27 test accuracy studies (2,982 subjects). Of these, 16 had immediate histological verification of diagnosis while 11 ha...

  16. Perceived characteristics of the environment associated with active travel: development and testing of a new scale

    Directory of Open Access Journals (Sweden)

    Mutrie Nanette

    2008-05-01

    Full Text Available Abstract Background Environmental characteristics may be associated with patterns of physical activity. However, the development of instruments to measure perceived characteristics of the local environment is still at a comparatively early stage, and published instruments are not necessarily suitable for application in all settings. We therefore developed and established the test-retest reliability of a new scale for use in a study of the correlates of active travel and overall physical activity in deprived urban neighbourhoods in Glasgow, Scotland. Methods We developed and piloted a 14-item scale based on seven constructs identified from the literature (aesthetics, green space, access to amenities, convenience of routes, traffic, road safety and personal safety. We administered the scale to all participants in a random postal survey (n = 1322 and readministered the scale to a subset of original respondents (n = 125 six months later. We used principal components analysis and Varimax rotation to identify three principal components (factors and derived summary scores for subscales based on these factors. We examined the internal consistency of these subscales using Cronbach's alpha and examined the test-retest reliability of the individual items, the subscale summary scores and an overall summary neighbourhood score using a combination of correlation coefficients and Cohen's kappa with and without weighting. Results Public transport and proximity to shops were the items most likely to be rated positively, whereas traffic volume, traffic noise and road safety for cyclists were most likely to be rated negatively. Three principal components – 'safe and pleasant surroundings', 'low traffic' and 'convenience for walking' – together explained 45% of the total variance. The test-retest reliability of individual items was comparable with that of items in other published scales (intraclass correlation coefficients (ICCs 0.34–0.70; weighted Cohen

  17. Differential susceptibility or diathesis stress? Testing longitudinal associations among parenting, temperament and children’s problem behavior

    NARCIS (Netherlands)

    Stoltz, S.E.M.J.; Beijers, R.; Smeekens, Sanny; Dekovic, M.

    2017-01-01

    In this study we investigated longitudinal associations among parenting, children's temperamental negative affectivity, and internalizing and externalizing behavior. Second, we tested whether findings confirmed the diathesis-stress model or differential susceptibility theory when conducting

  18. Single test isolated lupus anticoagulant positivity is associated with increased plasma levels of inflammatory markers and dyslipidemia

    DEFF Research Database (Denmark)

    Just, S A; Nybo, M; Laustrup, H

    2016-01-01

    OBJECTIVE: To investigate whether a single positive test for lupus anticoagulant (LA) is associated with levels of inflammatory markers and traditional cardiovascular risk factors, independent of autoimmune disease, thrombophilia and occurrence of other antiphospholipid antibodies. METHODS: In a ...

  19. Analysis of CpG SNPs in 34 genes: association test with suicide attempt in schizophrenia.

    Science.gov (United States)

    Bani-Fatemi, Ali; Gonçalves, Vanessa F; Zai, Clement; de Souza, Renan; Le Foll, Bernard; Kennedy, James L; Wong, Albert H; De Luca, Vincenzo

    2013-07-01

    Suicide is the act of intentionally causing one's own death. The lifetime suicide risk in schizophrenia is 4.9% and 20% to 50% of patients with SCZ will attempt suicide during their life. The other risk factors for suicidal behavior in schizophrenia include prior history of suicide attempts, active psychosis, depression and substance abuse. To date, there are no robust genetic or epigenetic predictors of suicide or suicide attempt in this specific population. We collected detailed clinical information and DNA samples from 241 schizophrenia patients and performed the genetic analyses in suicide attempters and non-attempters, among these patients. Using the structured research interview, we determined the presence of suicide attempt lifetime and then we tested 384 DNA variants in candidate genes supposed to be involved in the neurobiology of schizophrenia. We applied a novel mapping analysis using a specific bioinformatic tool that analyzed only the polymorphic CpG sites in our SNP panel. This analysis looked at the presence or absence of methylation sites affected by the SNP allele. The SNPs in the candidate genes were studied under a different perspective considering their direct contribution to the availability of methylation sites within the gene of interest. The level of potential methylation was compared using a linear model in attempters and non-attempters. Among the 384 SNPs selected from the Illumina Bead Chip only the rs2661319 in the RGS4 gene was significantly associated with suicide attempt (p = 0.002). There were 119 CpG SNPs in the aforementioned panel. The gene-wise potential methylation level of RGS4 was 55% in the attempters and 65% in the non-attempters with a p-value of 0.005. The total level of potential metylation in the overall panel (119 SNPs combined) was not associated with suicide attempt. However, when considering the potential methylation at chromosome 1, we found that suicide attempt (p = 0.036) was associated with lower methylation. The

  20. Indirect measurement of motivation: Developing and testing a motivational recoding-free implicit association test (m-IAT-RF)

    DEFF Research Database (Denmark)

    Kraus, Alexandra Anita; Scholderer, Joachim

    2015-01-01

    For the indirect measurement of approach-avoidance tendencies, two procedures are introduced and compared. The procedures are modifications of the standard IAT and the Recoding-Free IAT (IAT-RF) and use a motivational attribute dimension (approach, avoidance) instead of an evaluative one. Study 1...... (N = 162) assesses their convergent and discriminant validity with respect to self-reported measures of motivation and evaluation, and their predictive validity with respect to actual behavior. Study 2 (N = 205) furthermore compares their validity to evaluative variants of the same test paradigms...

  1. Use of Test Facilities Associated with the 25MM M919 Cartridge Production Contract

    National Research Council Canada - National Science Library

    Brannin, Patricia

    1996-01-01

    The audit objective was to evaluate the justification for the use of contractor test facilities as opposed to Government test facilities for production lot acceptance testing of the 25mm M919 cartridges...

  2. Simplifying consent for HIV testing is associated with an increase in HIV testing and case detection in highest risk groups, San Francisco January 2003-June 2007.

    Directory of Open Access Journals (Sweden)

    Nicola M Zetola

    2008-07-01

    Full Text Available Populations at highest risk for HIV infection face multiple barriers to HIV testing. To facilitate HIV testing procedures, the San Francisco General Hospital Medical Center eliminated required written patient consent for HIV testing in its medical settings in May 2006. To describe the change in HIV testing rates in different hospital settings and populations after the change in HIV testing policy in the SFDH medical center, we performed an observational study using interrupted time series analysis.Data from all patients aged 18 years and older seen from January 2003 through June 2007 at the San Francisco Department of Public Health (SFDPH medical care system were included in the analysis. The monthly HIV testing rate per 1000 had patient-visits was calculated for the overall population and stratified by hospital setting, age, sex, race/ethnicity, homelessness status, insurance status and primary language.By June 2007, the average monthly rate of HIV tests per 1000 patient-visits increased 4.38 (CI, 2.17-6.60, p<0.001 over the number predicted if the policy change had not occurred (representing a 44% increase. The monthly average number of new positive HIV tests increased from 8.9 (CI, 6.3-11.5 to 14.9 (CI, 10.6-19.2, p<0.001, representing a 67% increase. Although increases in HIV testing were seen in all populations, populations at highest risk for HIV infection, particularly men, the homeless, and the uninsured experienced the highest increases in monthly HIV testing rates after the policy change.The elimination of the requirement for written consent in May 2006 was associated with a significant and sustained increase in HIV testing rates and HIV case detection in the SFDPH medical center. Populations facing the higher barriers to HIV testing had the highest increases in HIV testing rates and case detection in response to the policy change.

  3. King-Devick Test reference values and associations with balance measures in high school American football players.

    Science.gov (United States)

    Alsalaheen, B; Haines, J; Yorke, A; Diebold, J

    2016-02-01

    The King-Devick test appears to be a promising tool in screening for concussions. However, limited evidence exists on the baseline associations between the K-D test and age and baseline screening tools used after concussion. Additionally, there are no published reference values for the K-D test in high school football players. The K-D test, the Balance Error Scoring System, and the Limits of Stability (LOS) test were administered to 157 high school football players. Additionally, a subsample of 62 participants completed the test twice to examine the reliability of K-D test. There was no relationship between the K-D test and the BESS, or the reaction time and directional control of LOS test. Students aged between 16 and 18 years demonstrated faster K-D test performance compared to students between 13 and 15 years of age. However, there was no association between K-D test and history of concussion. The reliability of the K-D test was (ICC2,1 = 0.89), and the minimal detectable change was 6.10 s. Normative reference values for high school football players are presented in this study. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Prevalence of Orthorexia nervosa among college students based on Bratman's test and associated tendencies.

    Science.gov (United States)

    Bundros, Joanna; Clifford, Dawn; Silliman, Kathryn; Neyman Morris, Michelle

    2016-06-01

    Disordered eating is prevalent among college student populations, and Orthorexia nervosa (ON) is being explored as a new type of eating disorder. There is currently no standardized ON diagnostic tool, and the majority of ON research has been conducted among European populations. The present study explored the Bratman Orthorexia Test (BOT) for ON diagnosis, and its relationship to validated tools for assessing disordered eating, body dysmorphic, and obsessive-compulsive tendencies among college students attending a western university. A convenience sample of 448 college students with a mean age of 22 years was recruited to complete an online survey that included the BOT, Eating Attitudes Test-26 (EAT-26), Body Dysmorphic Disorder Questionnaire (BDDQ), Obsessive Compulsive Inventory, Revised (OCI-R) and demographics. Spearman correlation, Mann-Whitney U, Kruskal-Wallis, chi-square, and multiple linear regressions were used for analyses. The average BOT score was 4.71, near the "health fanatic" range, with Hispanic/Latino subjects and overweight/obese students having significantly higher median BOT scores. Gender, age, and college major were not significantly associated with BOT score. Significant positive correlations were observed between total BOT and EAT-26 scores (r = .47, p < 0.01), BOT and BDDQ scores (r = .25, p < 0.01), and BOT and OCI-R scores (r = .19, p < 0.01). ON tendencies may exist among college students and Hispanic/Latino and overweight/obese students may be at increased risk. Further research is needed to determine ON risk factors among diverse student populations in order to inform prevention and treatment approaches on college campuses. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Factors Associated with Recent HIV Testing among Heterosexuals at High-Risk for HIV Infection in New York City

    Directory of Open Access Journals (Sweden)

    Marya eGwadz

    2016-04-01

    Full Text Available Background. The CDC recommends persons at high-risk for HIV infection in the United States receive annual HIV testing to foster early HIV diagnosis and timely linkage to health care. Heterosexuals make up a significant proportion of incident HIV infections (>25%, but test for HIV less frequently than those in other risk categories. Yet factors that promote or impede annual HIV testing among heterosexuals are poorly understood. The present study examines individual/attitudinal-, social-, and structural-level factors associated with past-year HIV testing among heterosexuals at high-risk for HIV. Methods. Participants were African American/Black and Hispanic heterosexual adults (N=2307 residing in an urban area with both high poverty and HIV prevalence rates. Participants were recruited by respondent-driven sampling (RDS in 2012-2015 and completed a computerized structured assessment battery covering background factors, multi-level putative facilitators of HIV testing, and HIV testing history. Separate logistic regression analysis for males and females identified factors associated with past-year HIV testing.Results. Participants were mostly male (58%, African American/Black (75%, and 39 years old on average (SD = 12.06 years. Lifetime homelessness (54% and incarceration (62% were common. Half reported past-year HIV testing (50% and 37% engaged in regular, annual HIV testing. Facilitators of HIV testing common to both genders included sexually transmitted infection (STI testing or STI diagnosis, peer norms supporting HIV testing, and HIV testing access. Among women, access to general medical care and extreme poverty further predicted HIV testing, while recent drug use reduced the odds of past-year HIV testing. Among men, past-year HIV testing was also associated with lifetime incarceration and substance use treatment.Conclusions. The present study identified gaps in rates of HIV testing among heterosexuals at high-risk for HIV, and both common and

  6. Factors associated with Integrated Counselling and Testing Center (ICTC service satisfaction: experience from Chandigarh, India

    Directory of Open Access Journals (Sweden)

    Mahesh Devnani

    2017-03-01

    Full Text Available Background & Objectives: People while availing services at Integrated Counselling and Testing Centers (ICTC face a lot of administrative and procedural problems which affect their level of satisfaction. This study was conducted at ICTC, Post Graduate Institute of Medical Education and Research, Chandigarh; within the scope of a larger research evaluating the “Quality of Infrastructure and Services available to PLHA”; to analyze the user’s perception about quality of services and factors affecting satisfaction level. Materials & Methods: Exit interviews of 50 randomly selected ICTC clients were conducted with structured questionnaire containing five groups of questions and questions on waiting time and satisfaction level. A scoring system was devised. The satisfaction level was cross matched with group questionsResults:  The mean group scores of five groups of questions were: Information, access & guidance for services (42.5%, Behaviour of counsellors (94%, Quality of counselling (77.28%, Physical facilities (65.5%, Confidentiality, discrimination and grievance redressal (67%. All respondents said that counsellors were respectful and 91% found the behaviour of counsellor supportive & helpful, 80% reported that they understood everything that counsellor said. Eighty percent rated satisfaction level as satisfactory or above (6% very satisfactory, 74% satisfactory, 18% indifferent and 2% very dissatisfied. Factors found to be associated with client satisfaction level were counsellor’s response to the concerns and worries of clients up to their satisfaction (p=0.009, illumination in ICTC (p=0.04, knowledge of grievance redressal system (p=0.04 and total time spent in ICTC (p=0.03.Conclusion: This study provided user’s perspective about ICTC service and revealed the factors associated with ICTC service satisfaction level. Better quality ICTC Services can be provided by addressing these factors.

  7. Effects of computer-based immediate feedback on foreign language listening comprehension and test-associated anxiety.

    Science.gov (United States)

    Lee, Shu-Ping; Su, Hui-Kai; Lee, Shin-Da

    2012-06-01

    This study investigated the effects of immediate feedback on computer-based foreign language listening comprehension tests and on intrapersonal test-associated anxiety in 72 English major college students at a Taiwanese University. Foreign language listening comprehension of computer-based tests designed by MOODLE, a dynamic e-learning environment, with or without immediate feedback together with the state-trait anxiety inventory (STAI) were tested and repeated after one week. The analysis indicated that immediate feedback during testing caused significantly higher anxiety and resulted in significantly higher listening scores than in the control group, which had no feedback. However, repeated feedback did not affect the test anxiety and listening scores. Computer-based immediate feedback did not lower debilitating effects of anxiety but enhanced students' intrapersonal eustress-like anxiety and probably improved their attention during listening tests. Computer-based tests with immediate feedback might help foreign language learners to increase attention in foreign language listening comprehension.

  8. Are Child Abusers Sexually Attracted to Submissiveness? Assessment of Sex-Related Cognition With the Implicit Association Test

    NARCIS (Netherlands)

    Kanters, Thijs; Hornsveld, Ruud H J; Nunes, Kevin L.; Huijding, Jorg; Zwets, Almar J.; Snowden, Robert J.; Muris, Peter; van Marle, Hjalmar J C

    2016-01-01

    Child sexual abuse is associated with social anxiety, low self-esteem, and intimacy deficits. This, in combination with the core belief of a dangerous world, might suggest that child abusers are sexually attracted to submissiveness. The Implicit Association Test (IAT) was used to examine this

  9. Associations with HIV testing in Uganda: an analysis of the Lot Quality Assurance Sampling database 2003-2012.

    Science.gov (United States)

    Jeffery, Caroline; Beckworth, Colin; Hadden, Wilbur C; Ouma, Joseph; Lwanga, Stephen K; Valadez, Joseph J

    2016-01-01

    Beginning in 2003, Uganda used Lot Quality Assurance Sampling (LQAS) to assist district managers collect and use data to improve their human immunodeficiency virus (HIV)/AIDS program. Uganda's LQAS-database (2003-2012) covers up to 73 of 112 districts. Our multidistrict analysis of the LQAS data-set at 2003-2004 and 2012 examined gender variation among adults who ever tested for HIV over time, and attributes associated with testing. Conditional logistic regression matched men and women by community with seven model effect variables. HIV testing prevalence rose from 14% (men) and 12% (women) in 2003-2004 to 62% (men) and 80% (women) in 2012. In 2003-2004, knowing the benefits of testing (Odds Ratio [OR] = 6.09, 95% CI = 3.01-12.35), knowing where to get tested (OR = 2.83, 95% CI = 1.44-5.56), and secondary education (OR = 3.04, 95% CI = 1.19-7.77) were significantly associated with HIV testing. By 2012, knowing the benefits of testing (OR = 3.63, 95% CI = 2.25-5.83), where to get tested (OR = 5.15, 95% CI = 3.26-8.14), primary education (OR = 2.01, 95% CI = 1.39-2.91), being female (OR = 3.03, 95% CI = 2.53-3.62), and being married (OR = 1.81, 95% CI = 1.17-2.8) were significantly associated with HIV testing. HIV testing prevalence in Uganda has increased dramatically, more for women than men. Our results concurred with other authors that education, knowledge of HIV, and marriage (women only) are associated with testing for HIV and suggest that couples testing is more prevalent than other authors.

  10. Factors Associated With HIV Testing Among Men in Haiti: Results From the 2012 Demographic and Health Survey.

    Science.gov (United States)

    Conserve, Donaldson F; Iwelunmor, Juliet; Whembolua, Guy-Lucien; Sofolahan-Oladeinde, Yewande; Teti, Michelle; Surkan, Pamela J

    2017-09-01

    HIV testing serves as the gateway to HIV prevention and treatment. However, research examining men's HIV testing behaviors in the Caribbean remains limited. The Andersen Behavioral Model of Health Services Utilization was used to examine factors associated with HIV testing among 7,354 men who participated in the 2012 Demographic and Health Survey conducted in Haiti. Few men (35%) reported having ever been tested for HIV. Logistic regression analyses revealed that HIV testing increased with education and wealth. Marital status was associated with HIV testing, with married men more likely to have been tested (adjusted odds ratio: 2.57, 95% CI [2.07, 3.19]) than unmarried men. Positive attitudes toward people living with HIV, indicated by willing to care for a relative who has HIV/AIDS, was also correlated with higher odds of having been tested (adjusted odds ratio: 1.28, 95% CI [1.08, 1.51]). Men who reported condom use during last sex were more likely to have been tested (odds ratio: 1.58, 95% CI [1.33, 1.88). The findings indicate that HIV testing rates remain low among men in Haiti and more efforts are needed to increase HIV testing among men who are not married, have low level of education, and engage in unprotected sex.

  11. [Substance use, affective problems and personality traits: test of two association models].

    Science.gov (United States)

    Chakroun, N; Doron, J; Swendsen, J

    2004-01-01

    The International Consortium of Psychiatric Epidemiology has confirmed the high comorbidity in community-drawn samples between substance use disorders and anxiety or depression. In the same way, associations between substance use and specific personality traits (such as novelty seeking, harm avoidance or antisocial personality) have also been extensively documented. Self-medication and social deviance are among the most commonly evoked explanatory models for these forms of comorbidity, and are based on findings that affective disorders and specific personality traits often precede the onset of substance use disorders. The self-medication model postulates that an individual chooses a specific substance according to its psychopharmacologic action on the given psychological state of the person. By contrast, the social deviance model posits that this form of comorbidity is due to the fact that persons consuming certain substances may have affective or personality characteristics that are more severe or more deviant than non-consumers (or than consumers of socially well-accepted substances). In this way, the individual does not use a particular substance to assuage pre-existing disorders but, due to a more deviant personality, is less influenced by social norms and may more easily turn to using illicit substances or to polyconsumption. However, a major limitation of the current scientific literature concerning tests of these models is that previous investigations have been based in overwhelming majority on clinical populations. The examination only of clinical samples renders difficult the identification of causal (or primary) risk factors for the emergence of substance use disorders from the potential consequences of substance use itself. The goal of the current study was therefore to simultaneously compare both models of association using a non clinical population of substance users. In addition to selecting subjects based on use (rather than abuse or dependence

  12. Association between the Trail Making Test and physical performance in elderly Japanese.

    Science.gov (United States)

    Hirota, Chika; Watanabe, Misuzu; Sun, Wei; Tanimoto, Yoshimi; Kono, Rei; Takasaki, Kyosuke; Kono, Koichi

    2010-01-01

    The Trail Making Test (TMT) is used in Western countries as an indicator of executive function, but there is little information regarding its use in Japan. Our previous initial study showed that the TMT was significantly associated with mobility-related functions among elderly Japanese living in the community and in this study, we increased the number of participants to clarify that result. The TMT, comprised of two parts (part A and part B), was administered to 493 subjects aged 65 years or older (164 men, 329 women). Our assessment used the time difference (DeltaTMT) between parts B and A, and eight physical performance indicators: four of preventive care (usual walking speed, timed Up & Go [TUG], one-leg standing balance and handgrip strength) and four movement parameters (maximum walking speed, dual-task TUG, stair climbing and obstacle-negotiating gait). The median DeltaTMT score was 64.01 s for men and 65.56 s for women. The DeltaTMT score increased with age, and there was no difference between sexes. Multinomial logistic regression analysis showed that a poor DeltaTMT was related to low tertiles for all physical performances. It related to the intermediate tertile of TUG and maximum walking speed, dual-task TUG, stair climbing and obstacle-negotiating gait. The TMT reflects complex walking performance, so it can be a useful synthetic indicator for health programs promoting independence in elderly Japanese.

  13. [Verification of the double dissociation model of shyness using the implicit association test].

    Science.gov (United States)

    Fujii, Tsutomu; Aikawa, Atsushi

    2013-12-01

    The "double dissociation model" of shyness proposed by Asendorpf, Banse, and Mtücke (2002) was demonstrated in Japan by Aikawa and Fujii (2011). However, the generalizability of the double dissociation model of shyness was uncertain. The present study examined whether the results reported in Aikawa and Fujii (2011) would be replicated. In Study 1, college students (n = 91) completed explicit self-ratings of shyness and other personality scales. In Study 2, forty-eight participants completed IAT (Implicit Association Test) for shyness, and their friends (n = 141) rated those participants on various personality scales. The results revealed that only the explicit self-concept ratings predicted other-rated low praise-seeking behavior, sociable behavior and high rejection-avoidance behavior (controlled shy behavior). Only the implicit self-concept measured by the shyness IAT predicted other-rated high interpersonal tension (spontaneous shy behavior). The results of this study are similar to the findings of the previous research, which supports generalizability of the double dissociation model of shyness.

  14. Neutrophil gelatinase-associated lipocalin as a screening test in prostate cancer.

    Science.gov (United States)

    Muşlu, Necati; Ercan, Bahadır; Akbayır, Serin; Balcı, Şenay; Ovla, H Didem; Bozlu, Murat

    2017-03-01

    Prostate specific antigen (PSA) with digital rectal examination is used for diagnosis of prostate cancer (PCa), where definite diagnosis can only be made by prostate biopsy. Recently neutrophil gelatinase-associated lipocalin (NGAL), a lipocalin family member glycoprotein, come into prominence as a cancer biomarker. This study is aimed to test serum NGAL as a diagnostic biomarker for PCa and discriminate PCa from benign prostatic hyperplasia (BPH). In this prospective study, 90 patients who underwent transrectal ultrasound-guided 12-core prostate biopsy between May 2015 and September 2015, were evaluated. Histopathologically diagnosed 45 PCa and 45 BPH patients were enrolled in this study. Serum NGAL and PSA levels of all participants were measured, then these data were evaluated by statistical programs. When sensitivity fixed to 80% specificity of NGAL was better than PSA (49%, 31% respectively). Receiver operating characteristic (ROC) curve analysis showed that NGAL alone or its combined use with PSA have better area under curve (AUC) results than PSA alone (0.662, 0.693, and 0.623 respectively). In conclusion NGAL gave promising results such as increased sensitivity and a better AUC values in order to distinguish PCa from BPH. NGAL showed a potential to be a non-invasive biomarker which may decrease the number of unnecessary biopsies.

  15. Diagnosing Psychopathy through Emotional Regulation Tasks: Heart Rate Variability versus Implicit Association Test.

    Science.gov (United States)

    Flórez, Gerardo; Vila, Xosé A; Lado, María J; Cuesta, Pedro; Ferrer, Ventura; García, Luis S; Crespo, María R; Pérez, Manuel

    2017-01-01

    Nowadays, the assessment of psychopathy relies on semistructured interviews plus file reviews. In order to improve the predictive validity of psychopathy at the individual level, tools that are not based on the rating of signs and symptoms are in great need. The present study was conducted in a representative sample of 204 Spanish sentenced inmates. These inmates have served at least 6 months of their sentence at the Pereiro de Aguiar (Ourense, Spain) penitentiary. Psychopathy signs and symptoms were scored through interview and file review. The Implicit Association Test (IAT) and heart rate variability (HRV) experiments were also conducted. The Iowa Gambling Task (IGT) was performed as a control measure. Spectral HRV indices were able to detect psychopathic inmates at a significant level, while IAT experiments and the IGT could not discriminate them. HRV indices showed a more significant difference when assessing the affective-interpersonal dimensions of psychopathy. An HRV experiment is better than IAT in order to detect psychopathy in a representative sample of Spanish inmates. © 2017 S. Karger AG, Basel.

  16. The Association Between Low 50 g Glucose Challenge Test Values and Adverse Pregnancy Outcomes.

    Science.gov (United States)

    Kwon, Hayan; Lee, Joonho; Lee, Byung-Wan; Kwon, Ja-Young; Kim, Young-Han

    2018-01-11

    The implications of low values on the 50 g glucose challenge test (GCT) in pregnancy are not clearly defined. Few studies have evaluated the influence of maternal low GCT values on obstetrical outcomes. This study aimed to compare pregnancy outcomes between women with low 50 g GCT values and those with normal values. Women undergoing gestational diabetes mellitus screening at 24-28 weeks of gestational age between January 2010 and December 2016 were retrospectively evaluated. Women with multifetal pregnancies, prepregnancy type I or II diabetes, GCT performed before 24 or after 28 weeks of gestational age, and women undergoing multiple GCTs in the same pregnancy were excluded. Low GCT values and normal GCT values were defined as ≤85 mg/dL and 86-130 mg/dL, respectively. Of 3875 screened subjects, 519 (13.4%) women were included in the low GCT group and 3356 (86.6%) in the normal GCT group. Low GCT women had a significantly higher rate of small for gestational age (SGA) infants than normal GCT women (10.8% vs. 7.9%, p = 0.02). Cesarean section and postpartum hemorrhage (PPH) were less frequent in low GCT women than in normal women (32.6% vs. 42.8%, p values. Low GCT values were independently associated with an increased risk of SGA.

  17. Measuring automatic value orientations: The Achievement-Benevolence Implicit Association Test.

    Science.gov (United States)

    Dentale, Francesco; Vecchione, Michele; Gebauer, Jochen E; Barbaranelli, Claudio

    2018-01-01

    The construct and criterion validity of an Implicit Association Test designed to rate the importance ascribed to Achievement-Benevolence oriented goals (AB-IAT) according to Schwartz's model were investigated. In a first study (N = 113), the AB-IAT and three other value-IATs (Power-Universalism, Security-Self-direction, and Tradition-Stimulation) were administered along with the corresponding self-report scales. The AB-IAT showed the following: (1) an adequate internal consistency; (2) a small correlation and a different pattern of means with respect to the corresponding self-report scale; (3) a pattern of correlations with the other value-IATs that is consistent with Schwartz's model. In a second study (N = 99), results showed that (1) in contrast to self-report measures of values, the AB-IAT appeared unrelated to social desirability; (2) the AB-IAT was significantly correlated with an actual behaviour expressing Benevolence values; (3) in accordance with a double dissociation pattern of prediction, implicit and explicit values are best predictors of actual and self-rated behaviours, respectively. Overall, results of the studies support the construct and criterion validity of the AB-IAT. Moreover, they provide a first support for the generalizability of Schwartz's model in the realm of implicit social cognition, and for the applicability of dual-process models in value research. © 2017 The British Psychological Society.

  18. Are indirect genetic benefits associated with polyandry? Testing predictions in a natural population of lemon sharks.

    Science.gov (United States)

    DiBattista, Joseph D; Feldheim, Kevin A; Gruber, Samuel H; Hendry, Andrew P

    2008-02-01

    Multiple mating has clear fitness benefits for males, but uncertain benefits and costs for females. We tested for indirect genetic benefits of polyandry in a natural population, by using data from a long-term genetic and demographic study of lemon sharks (Negaprion brevirostris) at Bimini, Bahamas. To do so, we followed the fates of individuals from six cohorts (450 age-0 and 254 age-1 fish) in relation to their individual level of genetic variation, and whether they were from polyandrous or monoandrous litters. We find that offspring from polyandrous litters did not have a greater genetic diversity or greater survival than did the offspring of monoandrous litters. We also find no evidence of positive associations between individual offspring genetic diversity metrics and our surrogate measure of fitness (i.e. survival). In fact, age-1 individuals with fewer heterozygous microsatellite loci and more genetically similar parents were more likely to survive to age-2. Thus, polyandry in female lemon sharks does not appear to be adaptive from the perspective of indirect genetic benefits to offspring. It may instead be the result of convenience polyandry, whereby females mate multiply to avoid harassment by males. Our inability to find indirect genetic benefits of polyandry despite detailed pedigree and survival information suggests the need for similar assessments in other natural populations.

  19. The use of bivariate spatial modeling of questionnaire and parasitology data to predict the distribution of Schistosoma haematobium in Coastal Kenya.

    Directory of Open Access Journals (Sweden)

    Hugh J W Sturrock

    Full Text Available Questionnaires of reported blood in urine (BIU distributed through the existing school system provide a rapid and reliable method to classify schools according to the prevalence of Schistosoma haematobium, thereby helping in the targeting of schistosomiasis control. However, not all schools return questionnaires and it is unclear whether treatment is warranted in such schools. This study investigates the use of bivariate spatial modelling of available and multiple data sources to predict the prevalence of S. haematobium at every school along the Kenyan coast.Data from a questionnaire survey conducted by the Kenya Ministry of Education in Coast Province in 2009 were combined with available parasitological and environmental data in a Bayesian bivariate spatial model. This modeled the relationship between BIU data and environmental covariates, as well as the relationship between BIU and S. haematobium infection prevalence, to predict S. haematobium infection prevalence at all schools in the study region. Validation procedures were implemented to assess the predictive accuracy of endemicity classification.The prevalence of BIU was negatively correlated with distance to nearest river and there was considerable residual spatial correlation at small (~15 km spatial scales. There was a predictable relationship between the prevalence of reported BIU and S. haematobium infection. The final model exhibited excellent sensitivity (0.94 but moderate specificity (0.69 in identifying low (<10% prevalence schools, and had poor performance in differentiating between moderate and high prevalence schools (sensitivity 0.5, specificity 1.Schistosomiasis is highly focal and there is a need to target treatment on a school-by-school basis. The use of bivariate spatial modelling can supplement questionnaire data to identify schools requiring mass treatment, but is unable to distinguish between moderate and high prevalence schools.

  20. Utility of quantitative sensory testing and screening tools in identifying HIV-associated peripheral neuropathy in Western Kenya: pilot testing.

    Directory of Open Access Journals (Sweden)

    Deanna Cettomai

    2010-12-01

    Full Text Available Neuropathy is the most common neurologic complication of HIV but is widely under-diagnosed in resource-constrained settings. We aimed to identify tools that accurately distinguish individuals with moderate/severe peripheral neuropathy and can be administered by non-physician healthcare workers (HCW in resource-constrained settings.We enrolled a convenience sample of 30 HIV-infected outpatients from a Kenyan HIV-care clinic. A HCW administered the Neuropathy Severity Score (NSS, Single Question Neuropathy Screen (Single-QNS, Subjective Peripheral Neuropathy Screen (Subjective-PNS, and Brief Peripheral Neuropathy Screen (Brief-PNS. Monofilament, graduated tuning fork, and two-point discrimination examinations were performed. Tools were validated against a neurologist's clinical assessment of moderate/severe neuropathy.The sample was 57% male, mean age 38.6 years, and mean CD4 count 324 cells/µL. Neurologist's assessment identified 20% (6/30 with moderate/severe neuropathy. Diagnostic utilities for moderate/severe neuropathy were: Single-QNS--83% sensitivity, 71% specificity; Subjective-PNS-total--83% sensitivity, 83% specificity; Subjective-PNS-max and NSS--67% sensitivity, 92% specificity; Brief-PNS--0% sensitivity, 92% specificity; monofilament--100% sensitivity, 88% specificity; graduated tuning fork--83% sensitivity, 88% specificity; two-point discrimination--75% sensitivity, 58% specificity.Pilot testing suggests Single-QNS, Subjective-PNS, and monofilament examination accurately identify HIV-infected patients with moderate/severe neuropathy and may be useful diagnostic tools in resource-constrained settings.

  1. Proceedings of the International Test and Evaluation Association 1984 Symposium (Step Session). Supplement.

    Science.gov (United States)

    1985-04-01

    computer software for nission-critical applications. * The Software Test and Evaluation Guidebook is a two volume reference set that provides checklists ...Deputy Test Director for Software Evaluation ( DSE ) is a key AFOTEC position on the field test team. The DSE is supported by software evaluators from the

  2. Is Preoperative Fibrinogen Testing Associated With Total Blood Loss in Adolescent Idiopathic Scoliosis Correction?

    Science.gov (United States)

    Geck, Matthew J; Singh, Devender; Gunn, Holly; Stokes, John K; Truumees, Eeric

    2017-11-01

    Retrospective analysis. This study sought to investigate the potential association between preoperative fibrinogen, bleeding, and transfusion requirements in adolescent idiopathic scoliosis (AIS) corrections. Blood loss after major spinal reconstruction increases the risks and costs of surgery. Preoperative fibrinogen levels may predict intra- and postoperative blood loss. Data were collected from clinic charts and hospital medical records of all 110 of a single surgeon's consecutive AIS patients undergoing greater than three-level deformity correction surgeries from January 2011 to December 2013. Pearson test was used to investigate the correlation between bleeding and clinical variables, with level of significance set at α = 0.05. Mean total bleeding volume was 488 (±356) mL. Overall, mean preoperative fibrinogen concentration was 188.6 ± 32.8 mg/dL. Preoperative platelet counts, prothrombin time (PT), and activated partial thromboplastin time (aPTT) did not correlate significantly with preoperative fibrinogen concentration (p > .05). Both packed red cells (PRC) and packed red blood cells (PRBC) correlated significantly with preoperative fibrinogen (p preoperative fibrinogen was -0.042. There was a negative correlation between PRBC and preoperative fibrinogen (r = -0.46). Overall mean thromboelastography (TEG) values were within normal range in both males and females and both had comparable TEG parameter values. All the TEG variables (G, K, and Angle) correlated significantly with preoperative fibrinogen (p .05). The correlation coefficient between these TEG variables and preoperative fibrinogen were 0.51, 0.59, and 0.54, respectively. The total bleeding volume and % estimated blood volume correlated significantly with both PRC (r = 0.352, r = 0.376; p preoperative fibrinogen levels exhibited a significant negative logarithmic correlation with total blood loss. TEG variables also correlated significantly with preoperative fibrinogen levels. Efforts should be

  3. Sideways walk test: Reliability and association with lower limb motor function after stroke.

    Science.gov (United States)

    Ng, Shamay S M; Lau, Bobby K C; Law, Gilbert T C; Wom, Choco W K; Liu, Tai-Wa; Tam, Eric W C; Tse, Mimi M Y; Fong, Shirley S M

    2016-10-05

    To investigate (i) the intra-rater, inter-rater and test-retest reliability of sideways walk test times and counts in individuals with stroke; (ii) their correlations with stroke-specific measures of impairment; (iii) the cut-off sideways walk test times and counts between stroke survivors and healthy controls; and (iv) the minimum detectable changes in the sideways walk test times and counts. Cross-sectional study. University-based rehabilitation centre. Twenty-nine older adults with stroke and 32 healthy controls. The sideways walk test was conducted together with Fugl-Meyer motor assessments of the lower extremities, lower limb muscle strength tests, the Five-Times-Sit-To-Stand test, Berg Balance Scale, Timed Up-and-Go test, and Activity-based Confidence and Community Integration Measure questionnaires. The sideways walk test times and counts demonstrated good to excellent intra-rater, inter-rater, and test-retest reliabilities. The sideways walk test times and counts were significantly correlated with motor control and ankle dorsiflexor and plantarflexor strength of the affected leg, balance performance and functional mobility. The cut-off sideways walk test time and count that best discriminated between individuals with stroke and controls were 10.74 s and 8.83 steps, respectively. The minimal detectable change in the sideways walk test time in that situation was 1.85 s, and the count minimum detectable change was 1.12 steps. The sideways walk test is a reliable and easy-to-administer clinical test for assessing sideways walking ability of individuals with chronic stroke.

  4. C-reactive protein point-of-care testing and associated antibiotic prescribing.

    Science.gov (United States)

    Minnaard, Margaretha C; van de Pol, Alma C; Hopstaken, Rogier M; van Delft, Sanne; Broekhuizen, Berna D L; Verheij, Theo J M; de Wit, Niek J

    2016-08-01

    In clinical trials, the potential of point-of-care (POC) C-reactive protein (CRP) tests was demonstrated in decreasing antibiotic prescribing in adults with acute cough in general practice, but effects of implementation are unknown. To determine the overall effect of POC CRP testing on antibiotic prescribing rate in general practice. In an observational study, GPs were instructed to use POC CRP in adults with acute cough following current guidelines. After routine history taking and physical examination, they reported whether they intended to prescribe antibiotics ('pre-test decision'). They reported their revised decision after receiving the POC CRP test result ('post-test decision'). Primary outcome was the percentage of patients in whom the GP changed his or her decision to prescribe antibiotics. Secondary outcome was the difference between 'pre-test' and 'post-test' antibiotic prescribing % at group level. A total of 40 GPs enrolled 939 patients, 78% of whom were tested for CRP. GPs changed their decision after POC CRP testing in 200 patients (27%). Antibiotic prescribing before and after CRP testing did not differ ('pre-test' 31%, 'post-test' 28%; 95% confidence interval of difference -7 to 1). In 41% of the tested patients, the indication for testing was in accordance with the guidelines. POC CRP influenced GPs to change their decision about antibiotic prescribing in patients with acute cough. POC CRP testing does not reduce overall antibiotic prescribing by GPs who already have a low antibiotic prescribing rate. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  5. Histamine release positive test associates with disease remission in chronic spontaneous urticaria

    DEFF Research Database (Denmark)

    Berti, A; Yacoub, M R; Skov, Per Stahl

    2017-01-01

    Summary: Background. Histamine release (HR) test has previously been shown to predict the presence of endogenous histamine-releasing factors in chronic spontaneous urticaria (CSU). Objectives and methods. Twenty CSU patients unresponsive to antihistamine treatment were enrolled in order to evaluate...... with a positive HR test had a significant reduction of disease activity (p = 0.003) whereas patients with a negative HR test did not (p > 0.05), leading to disease remission and antihistamine treatment withdrawal in 67% (6/9) of positive HR test patients versus 18% (2/11) of negative HR test patients (p = 0...

  6. A Hybrid Forecasting Model Based on Bivariate Division and a Backpropagation Artificial Neural Network Optimized by Chaos Particle Swarm Optimization for Day-Ahead Electricity Price

    Directory of Open Access Journals (Sweden)

    Zhilong Wang

    2014-01-01

    Full Text Available In the electricity market, the electricity price plays an inevitable role. Nevertheless, accurate price forecasting, a vital factor affecting both government regulatory agencies and public power companies, remains a huge challenge and a critical problem. Determining how to address the accurate forecasting problem becomes an even more significant task in an era in which electricity is increasingly important. Based on the chaos particle swarm optimization (CPSO, the backpropagation artificial neural network (BPANN, and the idea of bivariate division, this paper proposes a bivariate division BPANN (BD-BPANN method and the CPSO-BD-BPANN method for forecasting electricity price. The former method creatively transforms the electricity demand and price to be a new variable, named DV, which is calculated using the division principle, to forecast the day-ahead electricity by multiplying the forecasted values of the DVs and forecasted values of the demand. Next, to improve the accuracy of BD-BPANN, chaos particle swarm optimization and BD-BPANN are synthesized to form a novel model, CPSO-BD-BPANN. In this study, CPSO is utilized to optimize the initial parameters of BD-BPANN to make its output more stable than the original model. Finally, two forecasting strategies are proposed regarding different situations.

  7. Examining word association networks: A cross-country comparison of women's perceptions of HPV testing and vaccination.

    Directory of Open Access Journals (Sweden)

    Bernd C Schmid

    Full Text Available In this study, we examined the perceptual associations women hold with regard to cervical cancer testing and vaccination across two countries, the U.S. and Australia. In a large-scale online survey, we presented participants with 'trigger' words, and asked them to state sequentially other words that came to mind. We used this data to construct detailed term co-occurrence network graphs, which we analyzed using basic topological ranking techniques. The results showed that women hold divergent perceptual associations regarding trigger words relating to cervical cancer screening tools, i.e. human papillomavirus (HPV testing and vaccination, which indicate health knowledge deficiencies with non-HPV related associations emerging from the data. This result was found to be consistent across the country groups studied. Our findings are critical in optimizing consumer education and public service announcements to minimize misperceptions relating to HPV testing and vaccination in order to maximize adoption of cervical cancer prevention tools.

  8. Examining word association networks: A cross-country comparison of women’s perceptions of HPV testing and vaccination

    Science.gov (United States)

    Schmid, Bernd C.; Carlson, Jamie; Rezniczek, Günther A.; Wyllie, Jessica; Jaaback, Kenneth; Vencovsky, Filip

    2017-01-01

    In this study, we examined the perceptual associations women hold with regard to cervical cancer testing and vaccination across two countries, the U.S. and Australia. In a large-scale online survey, we presented participants with ‘trigger’ words, and asked them to state sequentially other words that came to mind. We used this data to construct detailed term co-occurrence network graphs, which we analyzed using basic topological ranking techniques. The results showed that women hold divergent perceptual associations regarding trigger words relating to cervical cancer screening tools, i.e. human papillomavirus (HPV) testing and vaccination, which indicate health knowledge deficiencies with non-HPV related associations emerging from the data. This result was found to be consistent across the country groups studied. Our findings are critical in optimizing consumer education and public service announcements to minimize misperceptions relating to HPV testing and vaccination in order to maximize adoption of cervical cancer prevention tools. PMID:28982130

  9. Accuracy of serum uric acid as a predictive test for maternal complications in pre-eclampsia: Bivariate meta-analysis and decision analysis

    NARCIS (Netherlands)

    Koopmans, Corine M.; van Pampus, Maria G.; Groen, Henk; Aarnoudse, Jan G.; van den Berg, Paul P.; Mol, Ben W. J.

    2009-01-01

    The aim of this study is to determine the accuracy and clinical value of serum uric acid in predicting maternal complications in women with pre-eclampsia. An existing meta-analysis on the subject was updated. The accuracy of serum uric acid for the prediction of maternal complications was assessed

  10. Accuracy of serum uric acid as a predictive test for maternal complications in pre-eclampsia : Bivariate meta-analysis and decision analysis

    NARCIS (Netherlands)

    Koopmans, C.M.; van Pampus, Maria; Groen, H.; Aarnoudse, J.G.; van den Berg, P.P.; Mol, B.W.J.

    The aim of this study is to determine the accuracy and clinical value of serum uric acid in predicting maternal complications in women with pre-eclampsia. An existing meta-analysis on the subject was updated. The accuracy of serum uric acid for the prediction of maternal complications was assessed

  11. Artificial Differences in Clostridium difficile Infection Rates Associated with Disparity in Testing

    Science.gov (United States)

    Brite, Jennifer; Aslam, Anoshe; Kennington, Jessica; Babady, N. Esther; Calfee, David; Furuya, Yoko; Chen, Donald; Augenbraun, Michael; Ostrowsky, Belinda; Patel, Gopi; Mircescu, Monica; Kak, Vivek; Tuma, Roman; Karre, Teresa A.; Fry, Deborah A.; Duhaney, Yola P.; Moyer, Amber; Mitchell, Denise; Cantu, Sherry; Hsieh, Candace; Warren, Nancy; Martin, Stacy; Willson, Jill; Dickman, Jeanne; Knight, Julie; Delahanty, Kim; Flood, Annemarie; Harrington, Jennifer; Korenstein, Deborah; Eagan, Janet; Sepkowitz, Kent

    2018-01-01

    In 2015, Clostridium difficile testing rates among 30 US community, multispecialty, and cancer hospitals were 14.0, 16.3, and 33.9/1,000 patient-days, respectively. Pooled hospital onset rates were 0.56, 0.84, and 1.57/1,000 patient-days, respectively. Higher testing rates may artificially inflate reported rates of C. difficile infection. C. difficile surveillance should consider testing frequency. PMID:29460760

  12. Testing the associative-link hypothesis in immediate serial recall: Evidence from word frequency and word imageability effects.

    Science.gov (United States)

    Tse, Chi-Shing; Altarriba, Jeanette

    2007-08-01

    Two immediate serial recall experiments were conducted to test the associative-link hypothesis (Stuart & Hulme, 2000). We manipulated interitem association by varying the intralist latent semantic analysis (LSA) cosines in our 7-item study word lists, each of which consists of high- or low-frequency words in Experiment 1 and high- or low-imageability words in Experiment 2. Whether item recall performance was scored by a serial-recall or free-recall criterion, we found main effects of interitem association, word imageability, and word frequency. The effect of interitem association also interacted with the word frequency effect, but not with the word imageability effect. The LSA-cosinexword frequency interaction occurred in the recency, but not primacy, portion of the serial position curve. The present findings set explanatory boundaries for the associative-link hypothesis and we argue that both item- and associative-based mechanisms are necessary to account for the word frequency effect in immediate serial recall.

  13. Depressive Symptoms Are Negatively Associated with Glucose Testing and Eating Meals on Time among Individuals with Diabetes in Zambia

    DEFF Research Database (Denmark)

    Hapunda, Given; Abubakar, Amina; Pouwer, Frans

    2017-01-01

    and adult patients. Regression analysis indicated that there was no association between total diabetes self-care and the depression total score. However, depression was associated with poor glucose testing and not eating meals on time by patients with diabetes. CONCLUSION: Some variance on poor self......-care was explained by demographic characteristics, specifically age, body mass index, and to some extent, socioeconomic status. Recognition and successful treatment of depression in patients with diabetes might help to optimize self-care behaviors, especially glucose testing and eating meals on time. However...

  14. Simple Algorithms to Calculate Asymptotic Null Distributions of Robust Tests in Case-Control Genetic Association Studies in R

    Directory of Open Access Journals (Sweden)

    Wing Kam Fung

    2010-02-01

    Full Text Available The case-control study is an important design for testing association between genetic markers and a disease. The Cochran-Armitage trend test (CATT is one of the most commonly used statistics for the analysis of case-control genetic association studies. The asymptotically optimal CATT can be used when the underlying genetic model (mode of inheritance is known. However, for most complex diseases, the underlying genetic models are unknown. Thus, tests robust to genetic model misspecification are preferable to the model-dependant CATT. Two robust tests, MAX3 and the genetic model selection (GMS, were recently proposed. Their asymptotic null distributions are often obtained by Monte-Carlo simulations, because they either have not been fully studied or involve multiple integrations. In this article, we study how components of each robust statistic are correlated, and find a linear dependence among the components. Using this new finding, we propose simple algorithms to calculate asymptotic null distributions for MAX3 and GMS, which greatly reduce the computing intensity. Furthermore, we have developed the R package Rassoc implementing the proposed algorithms to calculate the empirical and asymptotic p values for MAX3 and GMS as well as other commonly used tests in case-control association studies. For illustration, Rassoc is applied to the analysis of case-control data of 17 most significant SNPs reported in four genome-wide association studies.

  15. A cross-sectional study of the association between mobility test performance and personality among older adults

    OpenAIRE

    Agmon, Maayan; Armon, Galit

    2016-01-01

    Background Falls among the elderly are a major public health challenge. The Timed-Up and Go (TUG) test is commonly used to identify older adults with mobility limitations. This study explored the association between TUG test results and personality among community-dwelling older adults. Methods This cross-sectional study included 85 older adults. Personality was evaluated with the Five Factor Model. Times to complete the TUG as a single task (TUGST) alone and also with an additional cognitive...

  16. Association between new indices in the locomotive syndrome risk test and decline in mobility: third survey of the ROAD study

    OpenAIRE

    Yoshimura, Noriko; Muraki, Shigeyuki; Oka, Hiroyuki; Tanaka, Sakae; Ogata, Toru; Kawaguchi, Hiroshi; Akune, Toru; Nakamura, Kozo

    2015-01-01

    Background We aimed to clarify the association between new indices in a locomotive syndrome risk test and decline in mobility. Methods In the third survey of the Research on Osteoarthritis/osteoporosis Against Disability (ROAD) study, data on the indices were obtained from 1575 subjects (513 men, 1062 women) of the 1721 participants in mountainous and coastal areas. As outcome measures for decline in mobility, we used the five-times-sit-to-stand test (FTSST) and walking speed with cutoff valu...

  17. A derived transformation of emotional functions using self-reports, implicit association tests, and frontal alpha asymmetries

    OpenAIRE

    Amd, Micah; Roche, Bryan

    2015-01-01

    Research on the derived transformation of stimulus functions (ToF) typically employs single dependent measures for assessing the stimulus functions after derived relations have been established. For the first time, we examined ToF using three dependent measures both prior to and after relational training and testing. Specifically, we employed self-reports, implicit association tests, and frontal alpha asymmetry as pre versus post measures for assessing ToF. First, we t...

  18. An Efficient Stepwise Statistical Test to Identify Multiple Linked Human Genetic Variants Associated with Specific Phenotypic Traits.

    Directory of Open Access Journals (Sweden)

    Iksoo Huh

    Full Text Available Recent advances in genotyping methodologies have allowed genome-wide association studies (GWAS to accurately identify genetic variants that associate with common or pathological complex traits. Although most GWAS have focused on associations with single genetic variants, joint identification of multiple genetic variants, and how they interact, is essential for understanding the genetic architecture of complex phenotypic traits. Here, we propose an efficient stepwise method based on the Cochran-Mantel-Haenszel test (for stratified categorical data to identify causal joint multiple genetic variants in GWAS. This method combines the CMH statistic with a stepwise procedure to detect multiple genetic variants associated with specific categorical traits, using a series of associated I × J contingency tables and a null hypothesis of no phenotype association. Through a new stratification scheme based on the sum of minor allele count criteria, we make the method more feasible for GWAS data having sample sizes of several thousands. We also examine the properties of the proposed stepwise method via simulation studies, and show that the stepwise CMH test performs better than other existing methods (e.g., logistic regression and detection of associations by Markov blanket for identifying multiple genetic variants. Finally, we apply the proposed approach to two genomic sequencing datasets to detect linked genetic variants associated with bipolar disorder and obesity, respectively.

  19. Instrumented static and dynamic balance assessment after stroke using Wii Balance Boards: reliability and association with clinical tests.

    Science.gov (United States)

    Bower, Kelly J; McGinley, Jennifer L; Miller, Kimberly J; Clark, Ross A

    2014-01-01

    The Wii Balance Board (WBB) is a globally accessible device that shows promise as a clinically useful balance assessment tool. Although the WBB has been found to be comparable to a laboratory-grade force platform for obtaining centre of pressure data, it has not been comprehensively studied in clinical populations. The aim of this study was to investigate the measurement properties of tests utilising the WBB in people after stroke. Thirty individuals who were more than three months post-stroke and able to stand unsupported were recruited from a single outpatient rehabilitation facility. Participants performed standardised assessments incorporating the WBB and customised software (static stance with eyes open and closed, static weight-bearing asymmetry, dynamic mediolateral weight shifting and dynamic sit-to-stand) in addition to commonly employed clinical tests (10 Metre Walk Test, Timed Up and Go, Step Test and Functional Reach) on two testing occasions one week apart. Test-retest reliability and construct validity of the WBB tests were investigated. All WBB-based outcomes were found to be highly reliable between testing occasions (ICC  = 0.82 to 0.98). Correlations were poor to moderate between WBB variables and clinical tests, with the strongest associations observed between task-related activities, such as WBB mediolateral weight shifting and the Step Test. The WBB, used with customised software, is a reliable and potentially useful tool for the assessment of balance and weight-bearing asymmetry following stroke. Future research is recommended to further investigate validity and responsiveness.

  20. Diagnostic value of 14C urea breath test for Hp-associated peptic ulcer

    International Nuclear Information System (INIS)

    Yuan Jimin; Xiang Zuqiong; Chen Ying; Xiao Shudong; Zhang Darong; Liu Wenzhong

    1998-01-01

    Purpose: To develop a method of 14 C urea breath test and to evaluate the accuracy of the method in clinical diagnosis. Methods: Helicobacter pylori(Hp)-positive patients were defined either by positive bacterial culture or by positive rapid urease test of endoscopic biopsy specimens. 1384 patients with suspected peptic disease were underwent 14 C urea breath test. Of them, 44 patients underwent dynamic test at various intervals to determine the optimal time for expiratory air collection. Results: Dynamic breath test showed that the highest point of 14 C counts was at 30 min after administration of 14 C urea. When a cut-off value of 3.5 was selected, the sensitivity and specificity was of the test for detecting Hp infection 96.7% and 96.5% respectively. Hp positive rate detected by 14 C urea breath test in 1092 adults and 292 children was 50.4% and 81.2%. Conclusions: This study suggests that 14 C urea breath test is a simple and reliable method for detection of Hp infection and is of high sensitivity and specificity

  1. Academic Performance in Predominantly Black Nursing Classes: Effects Associated with Intervention Designed for Standardized Test Preparation.

    Science.gov (United States)

    Frierson, Henry T., Jr.

    1987-01-01

    One hundred fifty-two senior nursing students at a traditionally Black college participated in a study to determine the effect on academic performance of: (1) test-taking instruction; (2) a combination of test-taking instruction with cooperative learning procedures; or (3) no intervention. Spring semester grades were used to represent academic…

  2. Factors associated with willingness to accept a routine offer of HIV test in a large referral hospital in Western Kenya.

    Science.gov (United States)

    Mangeni, J N; Ballidawa, J B; Ndege, S

    2012-03-01

    Although Voluntary Counseling and Testing (VCT) has existed for more than 10 years, majority of Kenyans still do not know their HIV status, thus necessitating the introduction of other testing strategies to increase the number of people taking the test. The routine offer of an HIV test to all patients in health-care settings has been proposed to increase access to care. The main objective of this study was to identify factors associated with willingness to accept a routine offer of an HIV test. This was a cross sectional study. The Setting was in the Outpatient department at a large Referral Hospital in Western Kenya. A total of 384 adult patients (both males and females) were recruited using systematic random sampling. Information was collected on basic socio demographic characteristics, knowledge about the routine offer of an HIV test, attitudes towards the testing and HIV testing practise. Of the 384 respondents, 64.3% were unaware about the routine offer of HIV testing in Health facilities. Multivariate analysis identified the main predictors of willingness to accept an HIV test offered in hospital as the age (OR 3.7, C.I 0.068-1.075), level of education (OR 3.4, C.I 0.186-62.602), Knowledge about the routine HIV testing (OR 4.6,C.I 2.118-9.847), self-perception of HIV risk (OR 8.4,C.I 3.424-20.496) and attitude towards routine offer of HIV testing (OR 9.2, C.I 0.042-0.284). There is a need to come up with tailored training on the routine offer of an HIV test and devising strategies to address the main factors that influence the decision for patients to test as identified above.

  3. Individual and family characteristics associated with BRCA1/2 genetic testing in high-risk families.

    Science.gov (United States)

    Katapodi, Maria C; Northouse, Laurel L; Milliron, Kara J; Liu, Guipeng; Merajver, Sofia D

    2013-06-01

    Little is known about family members' interrelated decisions to seek genetic testing for breast cancer susceptibility. The specific aims of this cross-sectional, descriptive, cohort study were (i) to examine whether individual and family characteristics have a direct effect on women's decisions to use genetic testing for hereditary susceptibility to breast cancer and (ii) to explore whether family characteristics moderate the relationships between individual characteristics and the decision to use genetic testing. Participants were women (>18 years old) who (i) received genetic testing for hereditary breast cancer and who agreed to invite one of their female relatives into the study and (ii) female relatives who had NOT obtained genetic testing and were identified by pedigree analysis as having >10% chances of hereditary susceptibility to breast cancer. The final sample consisted of 168 English-speaking, family dyads who completed self-administered, mailed surveys with validated instruments. Multivariate conditional logistic regression analyses showed that the proposed model explained 62% of the variance in genetic testing. The factors most significantly associated with genetic testing were having a personal history of cancer; perceiving genetic testing to have more benefits than barriers; having greater family hardiness; and perceiving fewer negative consequences associated with a breast cancer diagnosis. No significant interaction effects were observed. Findings suggest that both individual and family characteristics are associated with the decision to obtain genetic testing for hereditary breast cancer; hence, there is a need for interventions that foster a supportive family environment for patients and their high-risk relatives. Copyright © 2012 John Wiley & Sons, Ltd.

  4. Association between alcohol consumption and skin prick test reactivity to aeroallergens

    DEFF Research Database (Denmark)

    Assing, Kristian; Bodtger, Uffe; Linneberg, Allan

    2007-01-01

    A few studies have indicated a positive association between consumption of alcohol and allergic sensitization in age and socioeconomically heterogeneous populations.......A few studies have indicated a positive association between consumption of alcohol and allergic sensitization in age and socioeconomically heterogeneous populations....

  5. Association Between Direct-to-Consumer Advertising and Testosterone Testing and Initiation in the United States, 2009-2013.

    Science.gov (United States)

    Layton, J Bradley; Kim, Yoonsang; Alexander, G Caleb; Emery, Sherry L

    2017-03-21

    Testosterone initiation increased substantially in the United States from 2000 to 2013, especially among men without clear indications. Direct-to-consumer advertising (DTCA) also increased during this time. To investigate associations between televised DTCA and testosterone testing and initiation in the United States. Ecologic study conducted in designated market areas (DMAs) in the United States. Monthly testosterone advertising ratings were linked to DMA-level testosterone use data from 2009-2013 derived from commercial insurance claims. Associations between DTCA and testosterone testing, initiation, and initiation without recent baseline tests were estimated using Poisson generalized estimating equations. Monthly Nielsen ratings for testosterone DTCA in the 75 largest DMAs. (1) Rates of new serum testosterone testing; (2) rates of testosterone initiation (in-office injection, surgical implant, or pharmacy dispensing) for all testosterone products combined and for specific brands; and (3) rates of testosterone initiation without recent serum testosterone testing. Of 17 228 599 commercially insured men in the 75 DMAs, 1 007 990 (mean age, 49.6 [SD, 11.5] years) had new serum testosterone tests and 283 317 (mean age, 51.8 [SD, 11.3] years) initiated testosterone treatment. Advertising intensity varied by geographic region and time, with the highest intensity seen in the southeastern United States and with months ranging from no ad exposures to a mean of 13.6 exposures per household. Nonbranded advertisements were common prior to 2012, with branded advertisements becoming more common during and after 2012. Each household advertisement exposure was associated with a monthly increase in rates of new testosterone testing (rate ratio [RR], 1.006; 95% CI, 1.004-1.008), initiation (RR, 1.007; 95% CI, 1.004-1.010), and initiation without a recent test (RR, 1.008; 95% CI, 1.002-1.013). Mean absolute rate increases were 0.14 tests (95% CI, 0.09-0.19), 0.05 new

  6. Sperm toxicity testing: UK best practice guideline from the Association of Biomedical Andrologists.

    Science.gov (United States)

    Long, S; Woodward, B; Tomlinson, M

    2018-02-09

    In order to ensure the quality and integrity of diagnostic semen analysis results, materials used should be tested to ensure that they do not interfere with sperm function. As a toxicity test, complex sperm function testing may be considered controversial, since the fertilizing capacity of single sperm can never be assured. In preference, sperm motility offers a unique means of assessing the toxicity of reagents and materials before they are used in routine practice. Motility is the semen parameter most likely to be influenced by the external environment. Indeed, it is the main reason that laboratories insist on supplying their own approved specimen containers and ensuring that patients, as far as possible, adhere to strict conditions for sample collection and transport prior to testing. This differs to other indirect tests of toxicity such as the mouse embryo assay, whereby the rate of mouse pre-implantation embryo development to the blastocyst stage is compared. This guideline is aimed at health care scientists who deal with andrology in both general pathology and specialised fertility laboratories, and provides a model approach to sperm toxicity testing. For assisted reproduction clinics, the same methodology can be used to test any consumables that are used for sperm processing, and as an indirect guide for any consumables that come into direct contact with oocytes and pre-implantation embryos.

  7. Applicability of an Indirect VO2max Test: Its Association with the 400 Meters Freestyle Performance

    Directory of Open Access Journals (Sweden)

    Adalberto Veronese da Costa

    Full Text Available Abstract The aim of this study was to evaluate the VO2max using a previously validated indirect test for non-expert adult swimmers and to verify its connection with the 400 meters freestyle test. A total of 17 non-expert male swimmers (21.5 ± 3.12 years were evaluated. Body composition measurements included body weight (74 ± 9.41 kg, height (172.9 ± 5.21 cm and body fat percentage (15.2 ± 4.15 %. Two tests were conducted on different days; the 400 meters freestyle (400 MF and the Progressive Swim Test (PSwT, respectively. The participant's heart rate frequency before and after the test (BHR and AHR was analyzed, as well as the subjective perception of effort (RPE, the number of laps covered (NLP, and the time of test execution measured in minutes. Significant differences were identified in all variables (p - 0.60 was found between AHR and execution time (r > - 0.70, as well as between the VO2max estimated by the PSwT and the 400 MF performance test (r > - 0.70. The Bland-Altman Plot showed that the values discovered were within the established concordance limits of 95% (±1.96 SD. A negative correlation between a swimming test and a test that estimates the VO2max occurred, and the PSwT showed results of greater approximation of the aerobic power of non-expert swimmers. In conclusion, the PSwT is applicable for non-expert adult swimmers.

  8. A unifying framework for robust association testing, estimation, and genetic model selection using the generalized linear model.

    Science.gov (United States)

    Loley, Christina; König, Inke R; Hothorn, Ludwig; Ziegler, Andreas

    2013-12-01

    The analysis of genome-wide genetic association studies generally starts with univariate statistical tests of each single-nucleotide polymorphism. The standard approach is the Cochran-Armitage trend test or its logistic regression equivalent although this approach can lose considerable power if the underlying genetic model is not additive. An alternative is the MAX test, which is robust against the three basic modes of inheritance. Here, the asymptotic distribution of the MAX test is derived using the generalized linear model together with the Delta method and multiple contrasts. The approach is applicable to binary, quantitative, and survival traits. It may be used for unrelated individuals, family-based studies, and matched pairs. The approach provides point and interval effect estimates and allows selecting the most plausible genetic model using the minimum P-value. R code is provided. A Monte-Carlo simulation study shows that the asymptotic MAX test framework meets type I error levels well, has good power, and good model selection properties for minor allele frequencies ≥0.3. Pearson's χ(2)-test is superior for lower minor allele frequencies with low frequencies for the rare homozygous genotype. In these cases, the model selection procedure should be used with caution. The use of the MAX test is illustrated by reanalyzing findings from seven genome-wide association studies including case-control, matched pairs, and quantitative trait data.

  9. A qualitative study exploring factors associated with Pap test use among North Korean refugees.

    Science.gov (United States)

    Kim, Kyounghae; Kim, Soohyun; Chung, Yoonkyung

    2017-10-01

    Lack of medical care in North Korea and vulnerability to human trafficking during their migration increase risks of cervical cancer among North Korean refugees. To better understand factors influencing Pap test use, we conducted a qualitative study of eight North Korean refugees in South Korea. Individual barriers were limited knowledge, lack of perceived need for preventive services, and concerns about costs. Environmental facilitators included having female providers, receiving family support, and free screenings. Refugees' health outlook, including viewing cancers as fatal diseases, hindered seeking Pap tests. Multi-faceted approaches to address individual and environmental factors in promoting Pap tests are warranted.

  10. Design and testing of the first 2D Prototype Vertically Integrated Pattern Recognition Associative Memory

    Energy Technology Data Exchange (ETDEWEB)

    Liu, T.; Deptuch, G.; Hoff, J.; Jindariani, S.; Joshi, S.; Olsen, J.; Tran, N.; Trimpl, M.

    2015-02-01

    An associative memory-based track finding approach has been proposed for a Level 1 tracking trigger to cope with increasing luminosities at the LHC. The associative memory uses a massively parallel architecture to tackle the intrinsically complex combinatorics of track finding algorithms, thus avoiding the typical power law dependence of execution time on occupancy and solving the pattern recognition in times roughly proportional to the number of hits. This is of crucial importance given the large occupancies typical of hadronic collisions. The design of an associative memory system capable of dealing with the complexity of HL-LHC collisions and with the short latency required by Level 1 triggering poses significant, as yet unsolved, technical challenges. For this reason, an aggressive R&D program has been launched at Fermilab to advance state of-the-art associative memory technology, the so called VIPRAM (Vertically Integrated Pattern Recognition Associative Memory) project. The VIPRAM leverages emerging 3D vertical integration technology to build faster and denser Associative Memory devices. The first step is to implement in conventional VLSI the associative memory building blocks that can be used in 3D stacking, in other words, the building blocks are laid out as if it is a 3D design. In this paper, we report on the first successful implementation of a 2D VIPRAM demonstrator chip (protoVIPRAM00). The results show that these building blocks are ready for 3D stacking.

  11. Testing the association between social capital and health over time: a family-based design.

    Science.gov (United States)

    Giordano, Giuseppe N; Merlo, Juan; Ohlsson, Henrik; Rosvall, Maria; Lindström, Martin

    2013-07-17

    The past decade has seen a vast increase in empirical research investigating associations between social capital and health outcomes. Literature reviews reveal 'generalized trust' and 'social participation' to be the most robust of the commonly used social capital proxies, both showing positive association with health outcomes. However, this association could be confounded by unmeasured factors, such as the shared environment. Currently, there is a distinct lack of social capital research that takes into account such residual confounding. Using data from the United Kingdom's British Household Panel Survey (BHPS) (waves thirteen to eighteen, N = 6982), this longitudinal, multilevel study investigates the validity of the association between trust, social participation and self-rated health using a family-based design. As the BHPS samples on entire households, we employed 'mean' and 'difference from the mean' aggregate measures of social capital, the latter of which is considered a social capital measurement that is not biased by the shared environment of the household. We employed Generalized Estimating Equations for all analyses, our two-level model controlling for correlation at the household level. Results show that after adjusting for the shared environment of the household over a six year period, the association between social participation and self-rated health was fully attenuated (OR = 0.97 (95% confidence interval 0.89-1.06)), while the association with trust remained significant (OR = 1.11 (1.02-1.20)). Other health determinants, such as being a smoker, having no formal qualifications and being unemployed maintain their associations with poor self-rated health. The association between social capital (specifically trust and social participation) and self-rated health appear to be confounded by shared environmental factors not previously considered by researchers. However, the association with trust remains, adding to existing empirical evidence that

  12. Illegal performance enhancing drugs and doping in sport: a picture-based brief implicit association test for measuring athletes’ attitudes

    Science.gov (United States)

    2014-01-01

    Background Doping attitude is a key variable in predicting athletes’ intention to use forbidden performance enhancing drugs. Indirect reaction-time based attitude tests, such as the implicit association test, conceal the ultimate goal of measurement from the participant better than questionnaires. Indirect tests are especially useful when socially sensitive constructs such as attitudes towards doping need to be described. The present study serves the development and validation of a novel picture-based brief implicit association test (BIAT) for testing athletes’ attitudes towards doping in sport. It shall provide the basis for a transnationally compatible research instrument able to harmonize anti-doping research efforts. Method Following a known-group differences validation strategy, the doping attitudes of 43 athletes from bodybuilding (representative for a highly doping prone sport) and handball (as a contrast group) were compared using the picture-based doping-BIAT. The Performance Enhancement Attitude Scale (PEAS) was employed as a corresponding direct measure in order to additionally validate the results. Results As expected, in the group of bodybuilders, indirectly measured doping attitudes as tested with the picture-based doping-BIAT were significantly less negative (η2 = .11). The doping-BIAT and PEAS scores correlated significantly at r = .50 for bodybuilders, and not significantly at r = .36 for handball players. There was a low error rate (7%) and a satisfactory internal consistency (r tt  = .66) for the picture-based doping-BIAT. Conclusions The picture-based doping-BIAT constitutes a psychometrically tested method, ready to be adopted by the international research community. The test can be administered via the internet. All test material is available “open source”. The test might be implemented, for example, as a new effect-measure in the evaluation of prevention programs. PMID:24479865

  13. Risks associated with genetic testing: health insurance discrimination or simply business as usual?

    Science.gov (United States)

    Steinberg, K K

    2000-01-01

    Doctors can test patients for mutations that put them at high risk for hereditary forms of such diseases as breast and ovarian cancer. Even though the opportunities for disease prevention using genetic testing will increase with time, the risks of testing, which include insurance loss and employment discrimination, currently make testing problematic. Some have proposed making use of genetic information in health insurance underwriting illegal. But in the current system of risk-based underwriting, it is hard to imagine that insurance companies will willingly forego access to a growing body of information on risk. If the American public chooses to limit the use of genetic information, a reassessment of current laws or methods of paying for health care will be needed.

  14. Does knowledge make a difference? The association between knowledge about genes and attitudes toward gene tests

    DEFF Research Database (Denmark)

    Jallinoja, P; Aro, A R

    2000-01-01

    A survey was conducted (n = 1,216) to evaluate the level of knowledge about basic facts of genetics and attitudes toward gene tests among the Finnish population. Our results show that a majority of the Finnish population generally approved of gene tests. Well over half of the respondents believed...... for these enterprises could be the biology school curriculum, genetic counseling, media, as well as health education and health communication in general....

  15. Association between Education and Domestic Violence among Women Being Offered an HIV Test in Urban and Rural Areas in Kenya

    Science.gov (United States)

    Abuya, Benta A.; Onsomu, Elijah O.; Moore, DaKysha; Piper, Crystal N.

    2012-01-01

    The objective of this study was to examine the association between education and domestic violence among women being offered an HIV test in urban and rural areas in Kenya. A sample selection of women who experienced physical (n = 4,308), sexual (n = 4,309), and emotional violence (n = 4,312) aged 15 to 49 allowed for the estimation of the…

  16. Comparison of Culture, Cytotoxin Assay and Two Eia Tests with Clinical Diagnosis of Clostridium difficile-Associated Diarrhea

    Directory of Open Access Journals (Sweden)

    Marilyn Binning

    1994-01-01

    Full Text Available Objective: The most common etiology of infectious diarrhea in hospitalized patients is Clostridium difficile. No single laboratory test yields a definitive diagnosis. Four methods were evaluated for their sensitivity and specificity in patients who had clinically defined C difficile-associated diarrhea.

  17. Investigation 8th Grade Students Secondary School Cognitive Structure about Principles of Ataturk through Word Association Test

    Science.gov (United States)

    Akman, Ozkan; Koçoglu, Erol

    2016-01-01

    The purpose of this study is to present the connections between the concepts in perception and cognitive structures of secondary school 8th grade students for principles of Ataturk. Word association test is used in data collection. The number of the total participants in this research is 190. A frequency table is formed for the data obtained in…

  18. Mainstream Teachers' Implicit Beliefs about English Language Learners: An Implicit Association Test Study of Teacher Beliefs

    Science.gov (United States)

    Harrison, Jamie; Lakin, Joni

    2018-01-01

    Teacher attitudes toward inclusion of English Learners (ELs) in the mainstream classroom have primarily focused on explicit beliefs as accessed through observation, case studies, and self-report surveys. The authors explore implicit mainstream teacher beliefs about ELs using the newly created Implicit Association Test-EL, with correlations to…

  19. The effects of cognitive and emotional workload on physiological reactions in Word Association Test in healthy adults

    Czech Academy of Sciences Publication Activity Database

    Lukavský, Jiří

    2010-01-01

    Roč. 52, č. 1 (2010), s. 15-22 ISSN 0039-3320 Institutional research plan: CEZ:AV0Z70250504 Keywords : Word Association Test * electrodermal activity * pupillary activity Subject RIV: AN - Psychology Impact factor: 0.254, year: 2010

  20. Association between preoperative magnetic resonance imaging, pain intensity and quantitative sensory testing in patients awaiting lumbar diskectomy.

    LENUS (Irish Health Repository)

    Hegarty, Dominic

    2011-02-01

    Magnetic resonance imaging (MRI) offers important information regarding the morphology, location and size of a herniated disc, which influences the decision to offer lumbar diskectomy (LD). This study aims to examine the association between clinical neurophysiologic indices including pain intensity and quantitative sensory testing (QST), and the degree of lumbar nerve root compromise depicted on magnetic resonance (MR) in patients awaiting LD.

  1. Systematic reviews of diagnostic test accuracy

    DEFF Research Database (Denmark)

    Leeflang, Mariska M G; Deeks, Jonathan J; Gatsonis, Constantine

    2008-01-01

    More and more systematic reviews of diagnostic test accuracy studies are being published, but they can be methodologically challenging. In this paper, the authors present some of the recent developments in the methodology for conducting systematic reviews of diagnostic test accuracy studies......-operating characteristic or the bivariate model for the data analysis. Challenges that remain are the poor reporting of original diagnostic test accuracy studies and difficulties with the interpretation of the results of diagnostic test accuracy research....

  2. PyHLA: tests for the association between HLA alleles and diseases

    OpenAIRE

    Fan, Yanhui; Song, You-Qiang

    2017-01-01

    Background Recently, several tools have been designed for human leukocyte antigen (HLA) typing using single nucleotide polymorphism (SNP) array and next-generation sequencing (NGS) data. These tools provide high-throughput and cost-effective approaches for identifying HLA types. Therefore, tools for downstream association analysis are highly desirable. Although several tools have been designed for multi-allelic marker association analysis, they were designed only for microsatellite markers an...

  3. Cognitive capacity: no association with recovery of sensibility by Semmes Weinstein test score after peripheral nerve injury of the forearm.

    Science.gov (United States)

    Boender, Z J; Ultee, J; Hovius, S E R

    2010-02-01

    In the recovery process of sensibility after repair of a peripheral nerve injury of the forearm, not only age but also surgical repair techniques are of importance. If regenerating axons are misdirected, reorganisation or other adaptic processes are needed at the level of the somatosensory brain cortex. These processes are thought to be dependent on the patient's cognitive capacity. We conducted a prospective multicentre study to assess the association between cognitive capacity and recovery of sensibility after peripheral nerve damage of the forearm. Patients with a traumatic peripheral nerve lesion of the forearm and consecutive surgical repair were included. After 12 months, the patients were assessed with respect to recovery of sensibility (Semmes-Weinstein monofilaments) and cognitive capacity, with four tests assessing different aspects of cognitive functioning. Twenty-eight patients (25 male, three female; median age: 28.5 years; range: 15-79 years) with median and/or ulnar nerve injury of the forearm were included in the study. Younger age showed a positive association with sensory recovery (beta =-0.845, 95% CI: -1.456 to -0.233; p=0.01). No association was found between the cognitive-capacity tests used and sensory recovery. The present prospective study did not reveal any association between recovery of sensibility measured by Semmes-Weinstein test score and cognitive capacity. Further studies should be performed to confirm these results. 2008 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  4. [Application of association rule in mental health test for employees in a petrochemical enterprise].

    Science.gov (United States)

    Zhang, L F; Zhang, D N; Wang, Z P

    2017-10-20

    Objective: To investigate the occurrence ruleof common psychological abnormalities in petrochemical workers using association rule. Methods: From July to September,2014,the Symptom Checklist-90 (SCL-90)was used for the general survey of mental healthamong all employees in a petrochemical enterprise.The association rule Apriori algorithm was used to analyze the data of SCL-90 and investigate the occurrence rule of psychological abnormalities in petrochemical workers with different sexes,ages,or nationalities. Results: A total of 8 248 usable questionnaires were collected. The SCL-90 analysis showed that 1623 petrochemical workers(19.68%) had positive results,among whom 567(34.94%)had one positive factor and 1056 (65.06%)had two or more positive factors. A total of 7 strong association rules were identified and all of them included obsessive-compulsive symptom and depression. Male({obsessive-compulsive symptom,anxiety}=>{depression}) and female workers ({somatization,depression}=>{obsessive-compulsive symptom}) had their own special association rules. The workers aged 35-44 years had 17 special association rules,and ethnic minorities had 5 special association rules. Conclusion: Employeesin the petrochemical enterprise have multiple positive factors in SCL-90, and employees aged 35-44 years and ethnic minorities have a rich combination of psychological symptoms and need special attention during mental health intervention.

  5. Multiple regression methods show great potential for rare variant association tests.

    Directory of Open Access Journals (Sweden)

    ChangJiang Xu

    Full Text Available The investigation of associations between rare genetic variants and diseases or phenotypes has two goals. Firstly, the identification of which genes or genomic regions are associated, and secondly, discrimination of associated variants from background noise within each region. Over the last few years, many new methods have been developed which associate genomic regions with phenotypes. However, classical methods for high-dimensional data have received little attention. Here we investigate whether several classical statistical methods for high-dimensional data: ridge regression (RR, principal components regression (PCR, partial least squares regression (PLS, a sparse version of PLS (SPLS, and the LASSO are able to detect associations with rare genetic variants. These approaches have been extensively used in statistics to identify the true associations in data sets containing many predictor variables. Using genetic variants identified in three genes that were Sanger sequenced in 1998 individuals, we simulated continuous phenotypes under several different models, and we show that these feature selection and feature extraction methods can substantially outperform several popular methods for rare variant analysis. Furthermore, these approaches can identify which variants are contributing most to the model fit, and therefore both goals of rare variant analysis can be achieved simultaneously with the use of regression regularization methods. These methods are briefly illustrated with an analysis of adiponectin levels and variants in the ADIPOQ gene.

  6. Association with isokinetic ankle strength measurements and normal clinical muscle testing in sciatica patients.

    Science.gov (United States)

    Ustun, N; Erol, O; Ozcakar, L; Ceceli, E; Ciner, O Akar; Yorgancioglu, Z R

    2013-01-01

    Sensitive muscle strength tests are needed to measure muscle strength in the diagnosis and management of sciatica patients. The aim of this study was to assess the isokinetic muscle strength in sciatica patients' and control subjects' ankles that exhibited normal ankle muscle strength when measured clinically. Forty-six patients with L5 and/or S1 nerve compression, and whose age, sex, weight, and height matched 36 healthy volunteers, were recruited to the study. Heel-walking, toe-walking, and manual muscle testing were used to perform ankle dorsiflexion and plantar flexion strengths in clinical examination. Patients with normal ankle dorsiflexion and plantar flexion strengths assessed by manual muscle testing and heel-and toe-walking tests were included in the study. Bilateral isokinetic (concentric/concentric) ankle plantar-flexion-dorsiflexion measurements of the patients and controls were performed within the protocol of 30°/sec (5 repetitions). Peak torque and peak torque/body weight were obtained for each ankle motion of the involved limb at 30°/s speed. L5 and/or S1 nerve compression was evident in 46 patients (76 injured limbs). Mean disease duration was two years. The plantar flexion muscle strength of the patients was found to be lower than that of the controls (p=0.036). The dorsiflexion muscle strength of the patients was found to be the same as that of the controls (p=0.211). Isokinetic testing is superior to clinical muscle testing when evaluating ankle plantar flexion torque in sciatica patients. Therefore, isokinetic muscle testing may be helpful when deciding whether to place a patient into a focused rehabilitation program.

  7. Factors associated with willingness to accept oral fluid HIV rapid testing among most-at-risk populations in China.

    Directory of Open Access Journals (Sweden)

    Huanmiao Xun

    Full Text Available BACKGROUND: The availability of oral fluid HIV rapid testing provides an approach that may have the potential to expand HIV testing in China, especially among most-a-risk populations. There are few investigations about the acceptability of oral fluid HIV testing among most-at-risk populations in China. METHOD: A cross-sectional study with men who have sex with men (MSM, female sex workers (FSW and voluntary counseling and testing (VCT clients was conducted in three cities of Shandong province, China from 2011 to 2012. Data were collected by face-to-face questionnaire. RESULTS: About 71% of participants were willing to accept the oral fluid HIV rapid testing, and home HIV testing was independently associated with acceptability of the new testing method among MSM, FSW and VCT clients (AOR of 4.46, 3.19 and 5.74, respectively. Independent predictors of oral fluid HIV rapid testing acceptability among MSM were having ever taken an oral fluid HIV rapid test (AOR= 15.25, having ever taken an HIV test (AOR= 2.07, and education level (AOR= 1.74. Engagement in HIV-related risk behaviors (AOR= 1.68 was an independent predictor of acceptability for FSW. Having taken an HIV test (AOR= 2.85 was an independent predictor of acceptability for VCT clients. The primary concern about the oral fluid HIV testing was accuracy. The median price they would pay for the testing ranged from 4.8 to 8.1 U.S. dollars. CONCLUSION: High acceptability of oral fluid HIV rapid testing was shown among most-at-risk populations. Findings provide support for oral rapid HIV testing as another HIV prevention tool, and provide a backdrop for the implementation of HIV home testing in the near future. Appropriate pricing and increased public education through awareness campaigns that address concerns about the accuracy and safety of the oral fluid HIV rapid testing may help increase acceptability and use among most-at-risk populations in China.

  8. Prevalence of prior HIV testing and associated factors among MSM in Zhejiang Province, China: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Runhua Li

    2016-11-01

    Full Text Available Abstract Background Men who have sex with men (MSM have become one of high-risk population for human immunodeficiency virus (HIV infection, due to their multiple sex partners and unprotected anal intercourse. Promoting HIV testing is an effective strategy for the prevention and control of HIV infection. We assessed the factors associated with a prior HIV testing history, which could provide guidance for implementation of future HIV intervention programs. Methods A cross-sectional study was conducted in three cities of Zhejiang Province, namely, Hangzhou, Ningbo and Wenzhou, using respondent-driven sampling, between December 2013 and June 2014. A face-to-face questionnaire survey was employed to collect relevant information about HIV testing. Univariate and multivariate logistic regression analyses were used to identify the factors associated with a prior HIV testing history. Results The adjusted rate of prior HIV testing among MSM in Zhejiang Province was 55.9 %. The adjusted rates of HIV and syphilis infections among MSM in Zhejiang Province were 14.0 % and 11.4 %, respectively. A weighted multivariate analysis showed that MSM of older age were more likely to be tested, as were MSM with higher level of education, self-reported homosexuality and a higher frequency of receiving AIDS/sexually transmitted infections educational intervention in the past year. MSM with suicidal inclination and self-perceived lower possibility of HIV infection were less likely to report ever having undergone an HIV test. Conclusions The prevalence of prior HIV testing among MSM in Zhejiang Province, China is low. Effective and more frequent interventional measures should be adopted to improve risk awareness and psychosocial support for younger, less educated MSM, and to encourage more MSM to undergo HIV testing.

  9. Bias associated with delayed verification in test accuracy studies: accuracy of tests for endometrial hyperplasia may be much higher than we think!

    Directory of Open Access Journals (Sweden)

    Coomarasamy Aravinthan

    2004-05-01

    Full Text Available Abstract Background To empirically evaluate bias in estimation of accuracy associated with delay in verification of diagnosis among studies evaluating tests for predicting endometrial hyperplasia. Methods Systematic reviews of all published research on accuracy of miniature endometrial biopsy and endometr ial ultrasonography for diagnosing endometrial hyperplasia identified 27 test accuracy studies (2,982 subjects. Of these, 16 had immediate histological verification of diagnosis while 11 had verification delayed > 24 hrs after testing. The effect of delay in verification of diagnosis on estimates of accuracy was evaluated using meta-regression with diagnostic odds ratio (dOR as the accuracy measure. This analysis was adjusted for study quality and type of test (miniature endometrial biopsy or endometrial ultrasound. Results Compared to studies with immediate verification of diagnosis (dOR 67.2, 95% CI 21.7–208.8, those with delayed verification (dOR 16.2, 95% CI 8.6–30.5 underestimated the diagnostic accuracy by 74% (95% CI 7%–99%; P value = 0.048. Conclusion Among studies of miniature endometrial biopsy and endometrial ultrasound, diagnostic accuracy is considerably underestimated if there is a delay in histological verification of diagnosis.

  10. Association of serologic and hematologic test results in dengue infant patients in RSUP. Dr. Hasan Sadikin Bandung

    Science.gov (United States)

    Alam, A.; Handayani, I.; Indrati, A. R.

    2018-03-01

    The incidence of Dengue virus infection is increasing every year,and the progression of the disease is faster towards severe manifestations in infants than in children and adults.The clinical appearance is still challenging to make for the diagnosis of dengue fever, so routine blood examination becomes one of thefurther enforcement efforts. The gold standard isconfirmatory tests for dengue, but this examination would be difficult in remote areas and also cost more. Research on serological testing and its association with routine blood testing in infant dengue-infected patients is still less publicized. The purpose of this study was to describe theconnection between serological and routine blood test results of infant dengue infection patients in RSUP Dr. Hasan Sadikin. Observational design in dengue 56 infants with 2-12 months age range examined serologic test and routine blood examination. The results showed that serological testing tended to be on routine blood tests. It can be from differences in routine blood tests such as hemoglobin, hematocrit, and platelets. Also, there was also no difference in routine blood profile between reactive and non-reactive IgM groups. It suggests that routine blood examination results are still lacking for the diagnosis of dengue.

  11. Operational aspects, results and problems associated with R/B testing at Gentilly 2

    International Nuclear Information System (INIS)

    Garceau, N.; Beaudoin, R.

    1991-01-01

    There are many methods, some more complex or difficult to deal with than others, to verify the containment building integrity. At G-2, we chose the temperature compensation method. Our selection criteria were: 1) the greater precision of this method; 2) the possibility of executing the test with the plant running at full power; 3) short period required for the test; 4) after the technique is understood, its simplicity of execution; 5) can be easily inserted in the normal operating test program with a minimum of personnel; 6) this technique can be used at both low and high pressure. In this presentation we will succinctly discuss the different phases of the technique such as: the background, the prerequisite, the problems, the results and, finally, we will give some recommendations to facilitate the use of this method

  12. Routine blood tests are associated with short term mortality and can improve emergency department triage

    DEFF Research Database (Denmark)

    Kristensen, Michael; Iversen, Anne Kristine Servais; Gerds, Thomas Alexander

    2017-01-01

    BACKGROUND: Prioritization of acutely ill patients in the Emergency Department remains a challenge. We aimed to evaluate whether routine blood tests can predict mortality in unselected patients in an emergency department and to compare risk prediction with a formalized triage algorithm. METHODS...... registration. Multiple logistic regressions were used to predict 30-day mortality. Validation was performed by applying the regression models on the 2013 validation cohort. RESULTS: Thirty-day mortality was 5.3%. The routine blood tests had a significantly stronger discriminative value on 30-day mortality...... compared to the formalized triage (AUC 88.1 [85.7;90.5] vs. 63.4 [59.1;67.5], p blood tests was able to identify a larger number of low risk patients (n = 2100, 30-day mortality 0.1% [95% CI 0.0;0.3%]) compared to formalized triage (n = 1591, 2.8% [95% CI 2...

  13. Integrated experimental test program on waterhammer pressure pulses and associated structural responses within a feedwater sparger

    Energy Technology Data Exchange (ETDEWEB)

    Nurkkala, P.; Hoikkanen, J. [Imatran Voima Oy, Vantaa (Finland)

    1997-12-31

    This paper describes the methods and systems as utilized in an integrated experimental thermohydraulic/mechanics analysis test program on waterhammer pressure pulses within a revised feedwater sparger of a Loviisa generation VVER-440-type reactor. This program was carried out in two stages: (1) measurements with a strictly limited set of operating parameters at Loviisa NPP, and (2) measurements with the full set of operating parameters on a test article simulating the revised feedwater sparger. The experiments at Loviisa NPS served as an invaluable source of information on the nature of waterhammer pressure pulses and structural responses. These tests thus helped to set the objectives and formulate the concept for series of tests on a test article to study the water hammer phenomena. The heavily instrumented full size test article of a steam generator feedwater sparger was placed within a pressure vessel simulating the steam generator. The feedwater sparger was subjected to the full range of operating parameters which were to result in waterhammer pressure pulse trains of various magnitudes and duration. Two different designs of revised feedwater sparger were investigated (i.e. `grounded` and `with goose neck`). The following objects were to be met within this program: (1) establish the thermohydraulic parameters that facilitate the occurrence of water hammer pressure pulses, (2) provide a database for further analysis of the pressure pulse phenomena, (3) establish location and severity of these water hammer pressure pulses, (4) establish the structural response due to these pressure pulses, (5) provide input data for structural integrity analysis. (orig.). 3 refs.

  14. Electrophysiological correlates of the autobiographical Implicit Association Test (aIAT: response conflict and conflict resolution.

    Directory of Open Access Journals (Sweden)

    Maddalena Marini

    2016-08-01

    Full Text Available The autobiographical IAT (aIAT is an implicit behavioral instrument that can detect autobiographical memories encoded in an individual’s mind by measuring how quickly this person can categorize and associate sentences related to a specific event with the logical dimensions true and false. Faster categorization when an event (e.g., I went to Paris is associated with the dimension true than false indicates that that specific event is encoded as true in the individual’s mind. The aim of this study is to investigate the electrophysiological correlates of the aIAT, used as a memory-detection technique (i.e., to identify which of two events is true. To this end, we recorded ERPs while participants performed an aIAT assessing which of two playing cards they had previously selected. We found an increased N200 and a decreased LPC (or P300 at the fronto-central sites when participants associated the selected playing card with the dimension false than true. Notably, both components have been previously and consistently reported in studies investigating deception. These results suggest that associating a true autobiographical event with the concept of false may involve the same cognitive processes associated with deception.

  15. No trade-off between learning speed and associative flexibility in bumblebees: a reversal learning test with multiple colonies.

    Directory of Open Access Journals (Sweden)

    Nigel E Raine

    Full Text Available Potential trade-offs between learning speed and memory-related performance could be important factors in the evolution of learning. Here, we test whether rapid learning interferes with the acquisition of new information using a reversal learning paradigm. Bumblebees (Bombus terrestris were trained to associate yellow with a floral reward. Subsequently the association between colour and reward was reversed, meaning bees then had to learn to visit blue flowers. We demonstrate that individuals that were fast to learn yellow as a predictor of reward were also quick to reverse this association. Furthermore, overnight memory retention tests suggest that faster learning individuals are also better at retaining previously learned information. There is also an effect of relatedness: colonies whose workers were fast to learn the association between yellow and reward also reversed this association rapidly. These results are inconsistent with a trade-off between learning speed and the reversal of a previously made association. On the contrary, they suggest that differences in learning performance and cognitive (behavioural flexibility could reflect more general differences in colony learning ability. Hence, this study provides additional evidence to support the idea that rapid learning and behavioural flexibility have adaptive value.

  16. “Rosary of Testes”: Splenogonadal Fusion in Association with Bilateral Abdominal Testes Presenting as Polyorchidism

    Directory of Open Access Journals (Sweden)

    Pejman Shadpour

    2015-01-01

    Full Text Available Polyorchidism is a rare anomaly where early segmentation in the gonadal ridge can lead to the development of three or less commonly four testes in one individual. Just over 150 reports of this phenomenon exist in English medical literature. However, once confronted by the clinical finding of supernumerary gonads, one must remain mindful of other likely diagnoses involving nontesticular origin. We report on a male patient with bilaterally impalpable testes in whom splenogonadal fusion mimicked polyorchidism. By keeping such differential diagnoses in mind, surgeons are more liable to take the appropriate intraoperative course of action.

  17. Routine disc diffusion antimicrobial susceptibility testing of Clostridium difficile and association with PCR ribotype 027

    DEFF Research Database (Denmark)

    Holt, H M; Danielsen, T K; Justesen, U S

    2015-01-01

    Reduced susceptibility to metronidazole and vancomycin in Clostridium difficile has been reported, which emphasises the need for simple antimicrobial susceptibility testing methods. The aim of this study was to apply a published disc diffusion method and zone diameter breakpoint correlates...... to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) epidemiological minimum inhibitory concentration (MIC) cut-off values in a routine setting. Metronidazole and vancomycin zone diameters from 2702 isolates were recorded. Fifteen isolates had a metronidazole zone diameter below...... the published breakpoint (vancomycin zone diameter below the published breakpoint (

  18. Predicting the occurrence of mixed mode failure associated with hydraulic fracturing, part 2 water saturated tests

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, Stephen J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Broome, Scott Thomas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Choens, Charles [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Barrow, Perry Carl [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-09-14

    Seven water-saturated triaxial extension experiments were conducted on four sedimentary rocks. This experimental condition was hypothesized more representative of that existing for downhole hydrofracture and thus it may improve our understanding of the phenomena. In all tests the pore pressure was 10 MPa and confirming pressure was adjusted to achieve tensile and transitional failure mode conditions. Using previous work in this LDRD for comparison, the law of effective stress is demonstrated in extension using this sample geometry. In three of the four lithologies, no apparent chemo-mechanical effect of water is apparent, and in the fourth lithology test results indicate some chemo-mechanical effect of water.

  19. VolHOG: a volumetric object recognition approach based on bivariate histograms of oriented gradients for vertebra detection in cervical spine MRI.

    Science.gov (United States)

    Daenzer, Stefan; Freitag, Stefan; von Sachsen, Sandra; Steinke, Hanno; Groll, Mathias; Meixensberger, Jürgen; Leimert, Mario

    2014-08-01

    The automatic recognition of vertebrae in volumetric images is an important step toward automatic spinal diagnosis and therapy support systems. There are many applications such as the detection of pathologies and segmentation which would benefit from automatic initialization by the detection of vertebrae. One possible application is the initialization of local vertebral segmentation methods, eliminating the need for manual initialization by a human operator. Automating the initialization process would optimize the clinical workflow. However, automatic vertebra recognition in magnetic resonance (MR) images is a challenging task due to noise in images, pathological deformations of the spine, and image contrast variations. This work presents a fully automatic algorithm for 3D cervical vertebra detection in MR images. We propose a machine learning method for cervical vertebra detection based on new features combined with a linear support vector machine for classification. An algorithm for bivariate gradient orientation histogram generation from three-dimensional raster image data is introduced which allows us to describe three-dimensional objects using the authors' proposed bivariate histograms. A detailed performance evaluation on 21 T2-weighted MR images of the cervical vertebral region is given. A single model for cervical vertebrae C3-C7 is generated and evaluated. The results show that the generic model performs equally well for each of the cervical vertebrae C3-C7. The algorithm's performance is also evaluated on images containing various levels of artificial noise. The results indicate that the proposed algorithm achieves good results despite the presence of severe image noise. The proposed detection method delivers accurate locations of cervical vertebrae in MR images which can be used in diagnosis and therapy. In order to achieve absolute comparability with the results of future work, the authors are following an open data approach by making the image dataset

  20. A Test of the Bidirectional Association Between Sleep and Mood in Bipolar Disorder and Insomnia

    Science.gov (United States)

    Talbot, Lisa S.; Stone, Susan; Gruber, June; Hairston, Ilana S.; Eidelman, Polina; Harvey, Allison G.

    2012-01-01

    The present study investigates sleep, mood, and the proposed bidirectional relationship between the two in psychiatric disorders. Participants with interepisode bipolar disorder (n = 49), insomnia (n = 34), and no psychiatric history (n = 52) completed seven consecutive days of sleep diaries and mood measures. The interepisode bipolar and insomnia participants exhibited greater sleep disturbance than the healthy control individuals. Negative mood was equally heightened in both interepisode bipolar disorder and insomnia, and there were no differences between the three groups in positive mood. Total wake time was associated with next morning negative mood in bipolar disorder, whereas evening negative mood was associated with subsequent total wake time in both bipolar disorder and insomnia. Additionally, positive mood was associated with subsequent total wake time for the insomnia group. Results support the theory that disruptions in nighttime sleep and daytime mood may be mutually maintaining and suggest the potential importance of transdiagnostic or universal processes. PMID:21842957

  1. Testing the association between psychosocial job strain and adverse birth outcomes--design and methods

    DEFF Research Database (Denmark)

    Larsen, Ann D; Hannerz, Harald; Obel, Carsten

    2011-01-01

    A number of studies have examined the effects of prenatal exposure to stress on birth outcomes but few have specifically focused on psychosocial job strain. In the present protocol, we aim to examine if work characterised by high demands and low control, during pregnancy, is associated with the r......A number of studies have examined the effects of prenatal exposure to stress on birth outcomes but few have specifically focused on psychosocial job strain. In the present protocol, we aim to examine if work characterised by high demands and low control, during pregnancy, is associated...... with the risk of giving birth to a child born preterm or small for gestational age....

  2. An Exponential Combination Procedure for Set-Based Association Tests in Sequencing Studies

    OpenAIRE

    Chen, Lin S.; Hsu, Li; Gamazon, Eric R.; Cox, Nancy J.; Nicolae, Dan L.

    2012-01-01

    State-of-the-art next-generation-sequencing technologies can facilitate in-depth explorations of the human genome by investigating both common and rare variants. For the identification of genetic factors that are associated with disease risk or other complex phenotypes, methods have been proposed for jointly analyzing variants in a set (e.g., all coding SNPs in a gene). Variants in a properly defined set could be associated with risk or phenotype in a concerted fashion, and by accumulating in...

  3. The association of asthma, nasal allergies, and positive skin prick tests with obesity, leptin, and adiponectin

    DEFF Research Database (Denmark)

    Newson, R. B.; Jones, M.; Forsberg, B.

    2014-01-01

    measures of fatness including body mass index and waist/hip ratio, current asthma, and specific skin prick and IgE sensitisation. We used inverse sampling-probability-weighted rank and regression statistics to measure population associations of disease outcomes with adipokines in males and females......, adjusting for confounders (area, age, smoking history, and number of elder siblings) and also mutually adjusting associations with adipokines and fatness measures. ResultsOne thousand nine hundred and fifty-five subjects aged 16-77years had information on leptin or adiponectin levels. Leptin and leptin...

  4. An Exploratory Study Investigating How Adults with Intellectual Disabilities Perform on the Visual Association Test (VAT)

    Science.gov (United States)

    McPaul, Ann; Walker, Brigid; Law, Jim; McKenzie, Karen

    2017-01-01

    Background: Neuropsychological tests of memory are believed to offer the greatest sensitivity at identifying people at the risk of developing dementia. There is a paucity of standardized and appropriate neuropsychological assessments of memory for adults with an intellectual disability. This study examines how adults with an intellectual…

  5. ASSOCIATION BETWEEN NEUROMUSCULAR TESTS AND KUMITE PERFORMANCE ON THE BRAZILIAN KARATE NATIONAL TEAM

    Directory of Open Access Journals (Sweden)

    Emerson Franchini

    2009-11-01

    Full Text Available The aim of this study was to verify the relationship of strength and power with performance on an international level karate team during official kumite simulations. Fourteen male black belt karate athletes were submitted to anthropometric data collection and then performed the following tests on two different days: vertical jump test, bench press and squat maximum dynamic strength (1RM tests. We also tested power production for both exercises at 30 and 60%1RM and performed a kumite match simulation. Blood samples were obtained at rest and immediately after the kumite matches to measure blood lactate concentration. Karate players were separated by performance (winners vs. defeated on the kumite matches. We found no significant differences between winners and defeated for strength, vertical jump height, anthropometric data and blood lactate concentration. Interestingly, winners were more powerful in the bench press and squat exercises at 30% 1RM. Maximum strength was correlated with absolute (30% 1RM r = 0.92; 60% 1RM r = 0.63 and relative power (30% 1RM r = 0.74; 60% 1RM r = 0.11, p > 0.05 for the bench press exercise. We concluded that international level karate players' kumite match performance are influenced by higher levels of upper and lower limbs power production

  6. C-reactive protein point-of-care testing and associated antibiotic prescribing

    NARCIS (Netherlands)

    Minnaard, Margaretha C.; van de Pol, Alma C.; Hopstaken, Rogier M.; van Delft, Sanne; Broekhuizen, Berna D. L.; Verheij, Theo J. M.; de Wit, Niek J.

    Background. In clinical trials, the potential of point-of-care (POC) C-reactive protein (CRP) tests was demonstrated in decreasing antibiotic prescribing in adults with acute cough in general practice, but effects of implementation are unknown. Objective. To determine the overall effect of POC CRP

  7. American College Health Association Annual Pap Test and Sexually Transmitted Infection Survey: 2006

    Science.gov (United States)

    Smith, P. Davis; Roberts, Craig M.

    2009-01-01

    Objective: The authors describe the cervical cytology and sexually transmitted infection (STI) testing patterns of US college health centers. Participants and Methods: A total of 128 self-selected US college health centers--representing more than 2 million college students--completed an online survey during February and March 2007. Results: Almost…

  8. Using Association Rules to Study the Co-evolution of Production & Test Code

    NARCIS (Netherlands)

    Lubsen, Z.; Zaidman, A.; Pinzger, M.

    2009-01-01

    Paper accepted for publication in the proceedings of the 6th International Working Conference on Mining Software Repositories (MSR 2009). Unit tests are generally acknowledged as an important aid to produce high quality code, as they provide quick feedback to developers on the correctness of their

  9. Studying Co-evolution of Production and Test Code Using Association Rule Mining

    NARCIS (Netherlands)

    Lubsen, Z.; Zaidman, A.; Pinzger, M.

    2009-01-01

    Long version of the short paper accepted for publication in the proceedings of the 6th International Working Conference on Mining Software Repositories (MSR 2009). Unit tests are generally acknowledged as an important aid to produce high quality code, as they provide quick feedback to developers on

  10. I drink therefore I am: validating alcohol-related implicit association tests

    NARCIS (Netherlands)

    Lindgren, K.P.; Neighbors, C.; Teachman, B.A.; Wiers, R.W.; Westgate, E.; Greenwald, A.G.

    2013-01-01

    There is an imperative to predict hazardous drinking among college students. Implicit measures have been useful in predicting unique variance in drinking and alcohol-related problems. However, they have been developed to test different theories of drinking and have rarely been directly compared with

  11. A cross-sectional study of the association between mobility test performance and personality among older adults.

    Science.gov (United States)

    Agmon, Maayan; Armon, Galit

    2016-05-18

    Falls among the elderly are a major public health challenge. The Timed-Up and Go (TUG) test is commonly used to identify older adults with mobility limitations. This study explored the association between TUG test results and personality among community-dwelling older adults. This cross-sectional study included 85 older adults. Personality was evaluated with the Five Factor Model. Times to complete the TUG as a single task (TUGST) alone and also with an additional cognitive task i.e., dual-task (DT), were recorded. Ordinary least squares OLS regression models were used to examine the associations between personality factors and both single DT TUG. Extraversion was found to be inversely associated with time to complete the TUGST (β = -.26, p older adults with high Extraversion completed the TUGST test more quickly than those who had lower measures of this trait and, people with high Conscientiousness completed the TUGDT tests more quickly. These findings may contribute to early identification of older adults at higher risk from mobility limitations and falls, and to developing personality-tailored interventions for fall prevention.

  12. Rare-variant association tests in longitudinal studies, with an application to the Multi-Ethnic Study of Atherosclerosis (MESA).

    Science.gov (United States)

    He, Zihuai; Lee, Seunggeun; Zhang, Min; Smith, Jennifer A; Guo, Xiuqing; Palmas, Walter; Kardia, Sharon L R; Ionita-Laza, Iuliana; Mukherjee, Bhramar

    2017-12-01

    Over the past few years, an increasing number of studies have identified rare variants that contribute to trait heritability. Due to the extreme rarity of some individual variants, gene-based association tests have been proposed to aggregate the genetic variants within a gene, pathway, or specific genomic region as opposed to a one-at-a-time single variant analysis. In addition, in longitudinal studies, statistical power to detect disease susceptibility rare variants can be improved through jointly testing repeatedly measured outcomes, which better describes the temporal development of the trait of interest. However, usual sandwich/model-based inference for sequencing studies with longitudinal outcomes and rare variants can produce deflated/inflated type I error rate without further corrections. In this paper, we develop a group of tests for rare-variant association based on outcomes with repeated measures. We propose new perturbation methods such that the type I error rate of the new tests is not only robust to misspecification of within-subject correlation, but also significantly improved for variants with extreme rarity in a study with small or moderate sample size. Through extensive simulation studies, we illustrate that substantially higher power can be achieved by utilizing longitudinal outcomes and our proposed finite sample adjustment. We illustrate our methods using data from the Multi-Ethnic Study of Atherosclerosis for exploring association of repeated measures of blood pressure with rare and common variants based on exome sequencing data on 6,361 individuals. © 2017 WILEY PERIODICALS, INC.

  13. Regression-based approach for testing the association between multi-region haplotype configuration and complex trait

    Directory of Open Access Journals (Sweden)

    Zhao Hongbo

    2009-09-01

    Full Text Available Abstract Background It is quite common that the genetic architecture of complex traits involves many genes and their interactions. Therefore, dealing with multiple unlinked genomic regions simultaneously is desirable. Results In this paper we develop a regression-based approach to assess the interactions of haplotypes that belong to different unlinked regions, and we use score statistics to test the null hypothesis of non-genetic association. Additionally, multiple marker combinations at each unlinked region are considered. The multiple tests are settled via the minP approach. The P value of the "best" multi-region multi-marker configuration is corrected via Monte-Carlo simulations. Through simulation studies, we assess the performance of the proposed approach and demonstrate its validity and power in testing for haplotype interaction association. Conclusion Our simulations showed that, for binary trait without covariates, our proposed methods prove to be equal and even more powerful than htr and hapcc which are part of the FAMHAP program. Additionally, our model can be applied to a wider variety of traits and allow adjustment for other covariates. To test the validity, our methods are applied to analyze the association between four unlinked candidate genes and pig meat quality.

  14. Clinical trial tests drug for tumors associated with Krebs-cycle dysfunction | Center for Cancer Research

    Science.gov (United States)

    The Krebs cycle is part of the complex process where cells turn food into energy. One of the elements of the Krebs cycle is succinate dehydrogenase (SDH). Loss of SDH activity in cells has been linked to tumor formation. This new trial is studying guadecitabine for tumors associated with Krebs cycle dysfunction. Learn more...

  15. Characteristics Associated with Genital Herpes Testing among Young Adults: Assessing Factors from Two National Data Sets

    Science.gov (United States)

    Gilbert, Lisa K.; Levandowski, Brooke A.; Roberts, Craig M.

    2010-01-01

    Objectives and Participants: In the United States, genital herpes (GH) prevalence is 10.6% among 20- to 29-year-olds and about 90% of seropositive persons do not know their status. This study investigated individual characteristics associated with GH screening and diagnosis in sexually active young adults aged 18 to 24. Methods: Two data sets were…

  16. Testing key predictions of the associative account of mirror neurons in humans using multivariate pattern analysis

    NARCIS (Netherlands)

    Oosterhof, N.N.; Wiggett, AJ.; Cross, E.S.

    2014-01-01

    Cook et al. overstate the evidence supporting their associative account of mirror neurons in humans: most studies do not address a key property, action-specificity that generalizes across the visual and motor domains. Multivariate pattern analysis (MVPA) of neuroimaging data can address this

  17. The Association between Relational Aggression and Perceived Popularity in Early Adolescence: A Test of Competing Hypotheses

    Science.gov (United States)

    Gangel, Meghan J.; Keane, Susan P.; Calkins, Susan D.; Shanahan, Lilly; O'Brien, Marion

    2017-01-01

    This study examined two competing hypotheses regarding the moderators of the association between relational aggression and peer status in early adolescence. The "mitigation relational aggression" hypothesis examined whether positive social behaviors reduced the negative effects of relational aggression, thus amplifying the association…

  18. [Validity of self-perceived dental caries as a diagnostic test and associated factors in adults].

    Science.gov (United States)

    Haikal, Desirée Sant'Ana; Roberto, Luana Leal; Martins, Andréa Maria Eleutério de Barros Lima; Paula, Alfredo Maurício Batista de; Ferreira, Efigênia Ferreira E

    2017-08-21

    This study aimed to analyze the validity of self-perceived dental caries and associated factors in a sample of 795 adults (35-44 years). The dependent variable was self-perceived dental caries, and the independent variables were combined in blocks. Three logistic models were performed: (1) all adults; (2) adults with a formal diagnosis of caries; and (3) adults without such caries. Self-perceived dental caries showed 77.7% sensitivity, 58% specificity, 65% accuracy, 52% positive predictive value, and 81% negative predictive value. In Model 1, self-perceived dental caries was associated with time of use of dental services, access to information, flossing, formal diagnosis of caries, self-perceived need for treatment, toothache, and dissatisfaction with oral health and general health. In Model 2, self-perceived dental caries was associated with time of use of dental services, self-perceived need for treatment, and dissatisfaction with oral health and general health. In Model 3, self-perceived dental caries was associated with time of use of dental services, access to information, flossing, self-perceived need for treatment, and dissatisfaction with oral health. Self-perceived dental caries showed limited utility as a diagnostic method.

  19. A Sequence Kernel Association Test for Dichotomous Traits in Family Samples under a Generalized Linear Mixed Model.

    Science.gov (United States)

    Yan, Qi; Tiwari, Hemant K; Yi, Nengjun; Gao, Guimin; Zhang, Kui; Lin, Wan-Yu; Lou, Xiang-Yang; Cui, Xiangqin; Liu, Nianjun

    2015-01-01

    The existing methods for identifying multiple rare variants underlying complex diseases in family samples are underpowered. Therefore, we aim to develop a new set-based method for an association study of dichotomous traits in family samples. We introduce a framework for testing the association of genetic variants with diseases in family samples based on a generalized linear mixed model. Our proposed method is based on a kernel machine regression and can be viewed as an extension of the sequence kernel association test (SKAT and famSKAT) for application to family data with dichotomous traits (F-SKAT). Our simulation studies show that the original SKAT has inflated type I error rates when applied directly to family data. By contrast, our proposed F-SKAT has the correct type I error rate. Furthermore, in all of the considered scenarios, F-SKAT, which uses all family data, has higher power than both SKAT, which uses only unrelated individuals from the family data, and another method, which uses all family data. We propose a set-based association test that can be used to analyze family data with dichotomous phenotypes while handling genetic variants with the same or opposite directions of effects as well as any types of family relationships. © 2015 S. Karger AG, Basel.

  20. Behavioral Exchanges between Teachers and Children Over the Course of a Typical Preschool Day: Testing Bidirectional Associations.

    Science.gov (United States)

    Curby, Timothy W; Downer, Jason T; Booren, Leslie

    In the present study, 314 preschool classrooms and 606 children were observed to understand the behavioral exchanges between teachers and children. Teachers' emotionally and organizationally supportive behaviors and children's engagement were explored for longitudinal associations throughout a day. Observations were conducted in each classroom wherein emotional and organizational supports were assessed, followed by observations of two children's positive engagement with teachers, tasks, and peers as well as negative classroom engagement. Cross-lagged autoregressive models were used to test for time-lagged associations which could be unidirectional or bidirectional. Results indicated teachers' emotionally and organizationally supportive behaviors were related to later child engagement in seven of eight models. Furthermore, in two of those seven models, we found evidence of bidirectional associations whereby children's engagement was associated with later teacher emotional and organizational supports. Findings are discussed in terms of understanding classroom processes over the course of a day in preschool.

  1. A Pragmatic Test for Detecting Association between a Dichotomous Trait and the Genotypes of Affected Families, Controls and Independent Cases

    Directory of Open Access Journals (Sweden)

    Meng Wang

    2017-05-01

    Full Text Available The efficient analysis of hybrid designs [e.g., affected families, controls, and (optionally independent cases] is attractive because it should have increased power to detect associations between genetic variants and disease. However, the computational complexity of such an analysis is not trivial, especially when the data contain pedigrees of arbitrary size and structure. To address this concern, we developed a pragmatic test of association that summarizes all of the available evidence in certain hybrid designs, irrespective of pedigree size or structure. Under the null hypothesis of no association, our proposed test statistic (POPFAM+ is the quadratic form of two correlated tests: a population-based test (e.g., wQLS, and a family-based test (e.g., PDT. We use the parametric bootstrap in conjunction with an estimate of the correlation to compute p-values, and we illustrate the potential for increased power when (1 the heritability of the trait is high; and, (2 the marker-specific association is driven by the over-representation of risk alleles in cases, and by the preferential transmission of risk alleles from heterozygous parents to their affected offspring. Based on simulation, we show that type I error is controlled, and that POPFAM+ is more powerful than wQLS or PDT alone. In a real data application, we used POPFAM+ to analyze 43 genes of a hybrid epilepsy study containing 85 affected families, 80 independent cases, 234 controls, and 118 reference samples from the International HapMap Project. The results of our analysis identified a promising epilepsy candidate gene for follow-up sequencing: malic enzyme 2 (ME2; min p < 0.0084.

  2. Instrumented static and dynamic balance assessment after stroke using Wii Balance Boards: reliability and association with clinical tests.

    Directory of Open Access Journals (Sweden)

    Kelly J Bower

    Full Text Available The Wii Balance Board (WBB is a globally accessible device that shows promise as a clinically useful balance assessment tool. Although the WBB has been found to be comparable to a laboratory-grade force platform for obtaining centre of pressure data, it has not been comprehensively studied in clinical populations. The aim of this study was to investigate the measurement properties of tests utilising the WBB in people after stroke.Thirty individuals who were more than three months post-stroke and able to stand unsupported were recruited from a single outpatient rehabilitation facility. Participants performed standardised assessments incorporating the WBB and customised software (static stance with eyes open and closed, static weight-bearing asymmetry, dynamic mediolateral weight shifting and dynamic sit-to-stand in addition to commonly employed clinical tests (10 Metre Walk Test, Timed Up and Go, Step Test and Functional Reach on two testing occasions one week apart. Test-retest reliability and construct validity of the WBB tests were investigated.All WBB-based outcomes were found to be highly reliable between testing occasions (ICC  = 0.82 to 0.98. Correlations were poor to moderate between WBB variables and clinical tests, with the strongest associations observed between task-related activities, such as WBB mediolateral weight shifting and the Step Test.The WBB, used with customised software, is a reliable and potentially useful tool for the assessment of balance and weight-bearing asymmetry following stroke. Future research is recommended to further investigate validity and responsiveness.

  3. Association between HIV-related risk behaviors and HIV testing among high school students in the United States, 2009.

    Science.gov (United States)

    Balaji, Alexandra B; Eaton, Danice K; Voetsch, Andrew C; Wiegand, Ryan E; Miller, Kim S; Doshi, Sonal R

    2012-04-01

    To identify the human immunodeficiency virus (HIV)-related risk behaviors associated with HIV testing among US high school students who reported ever having sexual intercourse. Secondary analysis of a cross-sectional study. The 2009 national Youth Risk Behavior Survey. A total of 7591 US high school students who reported ever having sexual intercourse. Risk behaviors related to HIV. Having ever been tested for HIV. Among the 7591 students who reported ever having sexual intercourse, 22.6% had been tested for HIV. Testing for HIV was most likely to be done among students who had ever injected any illegal drug (41.3%; adjusted odds ratio, 1.70; 95% CI, 1.14-2.56), had ever been physically forced to have sexual intercourse (36.2%; adjusted odds ratio, 1.43; 95% CI, 1.19 -1.72), did not use a condom the last time they had sexual intercourse (28.7%; adjusted odds ratio, 1.28; 95% CI, 1.08-1.51), and had sexual intercourse with 4 or more persons during their life (34.7%; adjusted odds ratio, 2.32; 95% CI, 1.98-2.73). Most sexually active students, even among those who reported high-risk behaviors for HIV, have not been tested for HIV. New strategies for increasing HIV testing among the adolescent population, including encouraging routine voluntary HIV testing among those who are sexually active, are needed.

  4. Factors associated with the 6-minute walk test in nursing home residents and community-dwelling older adults

    Science.gov (United States)

    Caballer, Vicent-Benavent; Lisón, Juan Francisco; Rosado-Calatayud, Pedro; Amer-Cuenca, Juan José; Segura-Orti, Eva

    2015-01-01

    [Purpose] The main objective of this study was to determine the contributions and extent to which certain physical measurements explain performance in the 6-minute walk test in healthy older adults living in a geriatric nursing home and for older adults dwelling in the community. [Subjects] The subjects were 122 adults aged 65 and older with no cognitive impairment who were independent in their daily activities. [Methods] The 6-minute walk test, age, body mass index, walking speed, chair stand test, Berg Balance Scale, Timed Up-and-Go test, rectus femoris cross-sectional area, Short Physical Performance Battery, and hand-grip strength were examined. [Results] Strong significant associations were found between mobility, lower-limb function, balance, and the 6-minute walk test. A stepwise multiple regression on the entire sample showed that lower-limb function was a significant and independent predictor for the 6-minute walk test. Additionally, lower-limb function was a strong predictor for the 6-minute walk test in our nursing home group, whereas mobility was found to be the best predictor in our community-dwelling group. [Conclusion] Better lower-limb function, balance, and mobility result in a higher distance covered by healthy older adults. Lower-limb function and mobility appeared to best determine walking performance in the nursing home and community-dwelling groups, respectively. PMID:26696740

  5. Functional Performance and Associations between Performance Tests and Neurological Assessment Differ in Men and Women with Parkinson's Disease.

    Science.gov (United States)

    Medijainen, Kadri; Pääsuke, Mati; Lukmann, Aet; Taba, Pille

    2015-01-01

    Neurological assessment of a patient with Parkinson's disease (PD) is expected to reflect upon functional performance. As women are known to report more limitations even for same observed functional performance level, present study was designed to examine whether associations between neurological assessments and functional performance differ across genders. 14 men and 14 women with PD participated. Functional performance was assessed by measuring walking speeds on 10-meter walk test (10MWT) and by performing timed-up-and-go-test (TUG). Neurological assessment included Hoehn and Yahr Scale (HY), Movement Disorders Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS), Schwab and England Activities of Daily Living Scale (S-E), and Mini Mental State Examination (MMSE). In women with PD, Kendall's tau-b correlation analyses revealed significant correlations between functional performance tests and neurological assessment measures, with the exception in MMSE. No corresponding associations were found for men, although they demonstrated better functional performance, as expected. Men in similar clinical stage of the PD perform better on functional tests than women. Disease severity reflects upon functional performance differently in men and women with PD. Results indicate that when interpreting the assessment results of both functional performance and neurological assessment tests, the gender of the patient should be taken into consideration.

  6. Functional Performance and Associations between Performance Tests and Neurological Assessment Differ in Men and Women with Parkinson’s Disease

    Directory of Open Access Journals (Sweden)

    Kadri Medijainen

    2015-01-01

    Full Text Available Background. Neurological assessment of a patient with Parkinson’s disease (PD is expected to reflect upon functional performance. As women are known to report more limitations even for same observed functional performance level, present study was designed to examine whether associations between neurological assessments and functional performance differ across genders. Methods. 14 men and 14 women with PD participated. Functional performance was assessed by measuring walking speeds on 10-meter walk test (10MWT and by performing timed-up-and-go-test (TUG. Neurological assessment included Hoehn and Yahr Scale (HY, Movement Disorders Society Unified Parkinson’s Disease Rating Scale (MDS-UPDRS, Schwab and England Activities of Daily Living Scale (S-E, and Mini Mental State Examination (MMSE. Results. In women with PD, Kendall’s tau-b correlation analyses revealed significant correlations between functional performance tests and neurological assessment measures, with the exception in MMSE. No corresponding associations were found for men, although they demonstrated better functional performance, as expected. Conclusion. Men in similar clinical stage of the PD perform better on functional tests than women. Disease severity reflects upon functional performance differently in men and women with PD. Results indicate that when interpreting the assessment results of both functional performance and neurological assessment tests, the gender of the patient should be taken into consideration.

  7. Statistical testing of the association between annual turnover and marketing activities in SMEs using χ2

    Science.gov (United States)

    Pater, Liana; Miclea, Şerban; Izvercian, Monica

    2016-06-01

    This paper considers the impact of SMEs' annual turnover upon its marketing activities (in terms of marketing responsibility, strategic planning and budgeting). Empirical results and literature reviews unveil that SMEs managers incline to partake in planned and profitable marketing activities, depending on their turnover's level. Thus, using the collected data form 131 Romanian SMEs managers, we have applied the Chi-Square Test in order to validate or invalidate three research assumptions (hypotheses), created starting from the empirical and literature findings.

  8. A Test-Retest Reliability Study of the Whiplash Disability Questionnaire in Patients With Acute Whiplash-Associated Disorders

    DEFF Research Database (Denmark)

    Stupar, Maja; Côté, Pierre; Beaton, Dorcas E

    2015-01-01

    OBJECTIVE: The purpose of this study was to determine the test-retest reliability and the Minimal Detectable Change (MDC) of the Whiplash Disability Questionnaire (WDQ) in individuals with acute whiplash-associated disorders (WADs). METHODS: We performed a test-retest reliability study. We included...... insurance claimants from Ontario who were at least 18years of age, within 21days of their motor vehicle collision and diagnosed as having acute WAD grades I to III. The WDQ, a 13-item questionnaire scored from 0 (no disability) to 130 (complete disability), was administered to all participants at baseline...

  9. Evaluation of the drawer test and the tibial compression test for differentiating between cranial and caudal stifle subluxation associated with cruciate ligament instability.

    Science.gov (United States)

    Might, Kelly R; Bachelez, Andréas; Martinez, Steven A; Gay, John M

    2013-05-01

    To determine the sensitivity and specificity of the drawer test (DT) alone and in combination with the tibial compression test (TCT) to detect stifle subluxation after transection of the cranial cruciate (CrCL), caudal cruciate (CdCL) or both cruciate ligaments (total cruciate ligament or TCL). Experimental study. Cadaveric, skeletally mature canine pelvic limb pairs (n = 8). Pelvic limbs disarticulated at the coxofemoral joint were randomly assigned to the following 1 of 4 groups: (1) limbs had complete transection of the CrCL; (2) limbs had complete transection of the CdCL; (3) limbs had complete transection of both ligaments; and (4) both ligaments were left intact. Participants performed the DT and the TCT and a diagnosis was given based on the DT and on the combination of these tests. DT had a poor sensitivity for correctly identifying CrCL (69%), CdCL (45%), and TCL (26%) rupture, but had a high sensitivity when identifying intact limbs (97%). Specificity for DT was greatest when identifying limbs with CdCL (97%) and TCL (92%) rupture, and the lowest when palpating limbs with CrCL rupture (75%). Combining DT and TCT did not increase sensitivity or specificity values, nor did an increased level of evaluator training. Independent of evaluator training, the DT alone or combined with the TCT poorly differentiates the cause of stifle instability associated with CrCL, CdCL, and TCL rupture. © Copyright 2012 by The American College of Veterinary Surgeons.

  10. phenosim--A software to simulate phenotypes for testing in genome-wide association studies.

    Science.gov (United States)

    Günther, Torsten; Gawenda, Inka; Schmid, Karl J

    2011-06-29

    There is a great interest in understanding the genetic architecture of complex traits in natural populations. Genome-wide association studies (GWAS) are becoming routine in human, animal and plant genetics to understand the connection between naturally occurring genotypic and phenotypic variation. Coalescent simulations are commonly used in population genetics to simulate genotypes under different parameters and demographic models. Here, we present phenosim, a software to add a phenotype to genotypes generated in time-efficient coalescent simulations. Both qualitative and quantitative phenotypes can be generated and it is possible to partition phenotypic variation between additive effects and epistatic interactions between causal variants. The output formats of phenosim are directly usable as input for different GWAS tools. The applicability of phenosim is shown by simulating a genome-wide association study in Arabidopsis thaliana. By using the coalescent approach to generate genotypes and phenosim to add phenotypes, the data sets can be used to assess the influence of various factors such as demography, genetic architecture or selection on the statistical power of association methods to detect causal genetic variants under a wide variety of population genetic scenarios. phenosim is freely available from the authors' website http://evoplant.uni-hohenheim.de.

  11. Association Between Medication Use and Performance on Higher Education Entrance Tests in Individuals With Attention-Deficit/Hyperactivity Disorder.

    Science.gov (United States)

    Lu, Yi; Sjölander, Arvid; Cederlöf, Martin; D'Onofrio, Brian M; Almqvist, Catarina; Larsson, Henrik; Lichtenstein, Paul

    2017-08-01

    Individuals with attention-deficit/hyperactivity disorder (ADHD) are at greater risk for academic problems. Pharmacologic treatment is effective in reducing the core symptoms of ADHD, but it is unclear whether it helps to improve academic outcomes. To investigate the association between the use of ADHD medication and performance on higher education entrance tests in individuals with ADHD. This cohort study observed 61 640 individuals with a diagnosis of ADHD from January 1, 2006, to December 31, 2013. Records of their pharmacologic treatment were extracted from Swedish national registers along with data from the Swedish Scholastic Aptitude Test. Using a within-patient design, test scores when patients were taking medication for ADHD were compared with scores when they were not taking such medication. Data analysis was performed from November 24, 2015, to November 4, 2016. Periods with and without ADHD medication use. Scores from the higher education entrance examination (score range, 1-200 points). Among 930 individuals (493 males and 437 females; mean [SD] age, 22.2 [3.2] years) who had taken multiple entrance tests (n = 2524) and used ADHD medications intermittently, the test scores were a mean of 4.80 points higher (95% CI, 2.26-7.34; P < .001) during periods they were taking medication vs nonmedicated periods, after adjusting for age and practice effects. Similar associations between ADHD medication use and test scores were detected in sensitivity analyses. Individuals with ADHD had higher scores on the higher education entrance tests during periods they were taking ADHD medication vs nonmedicated periods. These findings suggest that ADHD medications may help ameliorate educationally relevant outcomes in individuals with ADHD.

  12. A robust and powerful two-step testing procedure for local ancestry adjusted allelic association analysis in admixed populations.

    Science.gov (United States)

    Duan, Qing; Xu, Zheng; Raffield, Laura M; Chang, Suhua; Wu, Di; Lange, Ethan M; Reiner, Alex P; Li, Yun

    2018-04-01

    Genetic association studies in admixed populations allow us to gain deeper understanding of the genetic architecture of human diseases and traits. However, population stratification, complicated linkage disequilibrium (LD) patterns, and the complex interplay of allelic and ancestry effects on phenotypic traits pose challenges in such analyses. These issues may lead to detecting spurious associations and/or result in reduced statistical power. Fortunately, if handled appropriately, these same challenges provide unique opportunities for gene mapping. To address these challenges and to take these opportunities, we propose a robust and powerful two-step testing procedure Local Ancestry Adjusted Allelic (LAAA) association. In the first step, LAAA robustly captures associations due to allelic effect, ancestry effect, and interaction effect, allowing detection of effect heterogeneity across ancestral populations. In the second step, LAAA identifies the source of association, namely allelic, ancestry, or the combination. By jointly modeling allele, local ancestry, and ancestry-specific allelic effects, LAAA is highly powerful in capturing the presence of interaction between ancestry and allele effect. We evaluated the validity and statistical power of LAAA through simulations over a broad spectrum of scenarios. We further illustrated its usefulness by application to the Candidate Gene Association Resource (CARe) African American participants for association with hemoglobin levels. We were able to replicate independent groups' previously identified loci that would have been missed in CARe without joint testing. Moreover, the loci, for which LAAA detected potential effect heterogeneity, were replicated among African Americans from the Women's Health Initiative study. LAAA is freely available at https://yunliweb.its.unc.edu/LAAA. © 2017 WILEY PERIODICALS, INC.

  13. Associations between cadmium exposure and neurocognitive test scores in a cross-sectional study of US adults

    Science.gov (United States)

    2013-01-01

    Background Low-level environmental cadmium exposure and neurotoxicity has not been well studied in adults. Our goal was to evaluate associations between neurocognitive exam scores and a biomarker of cumulative cadmium exposure among adults in the Third National Health and Nutrition Examination Survey (NHANES III). Methods NHANES III is a nationally representative cross-sectional survey of the U.S. population conducted between 1988 and 1994. We analyzed data from a subset of participants, age 20–59, who participated in a computer-based neurocognitive evaluation. There were four outcome measures: the Simple Reaction Time Test (SRTT: visual motor speed), the Symbol Digit Substitution Test (SDST: attention/perception), the Serial Digit Learning Test (SDLT) trials-to-criterion, and the SDLT total-error-score (SDLT-tests: learning recall/short-term memory). We fit multivariable-adjusted models to estimate associations between urinary cadmium concentrations and test scores. Results 5662 participants underwent neurocognitive screening, and 5572 (98%) of these had a urinary cadmium level available. Prior to multivariable-adjustment, higher urinary cadmium concentration was associated with worse performance in each of the 4 outcomes. After multivariable-adjustment most of these relationships were not significant, and age was the most influential variable in reducing the association magnitudes. However among never-smokers with no known occupational cadmium exposure the relationship between urinary cadmium and SDST score (attention/perception) was significant: a 1 μg/L increase in urinary cadmium corresponded to a 1.93% (95%CI: 0.05, 3.81) decrement in performance. Conclusions These results suggest that higher cumulative cadmium exposure in adults may be related to subtly decreased performance in tasks requiring attention and perception, particularly among those adults whose cadmium exposure is primarily though diet (no smoking or work based cadmium exposure). This

  14. The Total Work Measured During a High Intensity Isokinetic Fatigue Test Is Associated With Anaerobic Work Capacity

    Directory of Open Access Journals (Sweden)

    Laurent Bosquet, Kenan Gouadec, Nicolas Berryman, Cyril Duclos, Vincent Gremeaux, Jean Louis Croisier

    2016-03-01

    Full Text Available The purpose of the study was to determine whether total work measured during a high intensity isokinetic fatigue test (TWFAT could be considered as a valid measure of anaerobic work capacity (AWC, such as determined by total work measured during a Wingate Anaerobic Test (TWWAnT. Twenty well-trained cyclists performed 2 randomly ordered sessions involving a high intensity isokinetic fatigue test consisting in 30 reciprocal maximal concentric contractions of knee flexors and extensors at 180°·s-1, and a Wingate Anaerobic Test. We found that TWFAT of knee extensors was largely lower than TWWAnT (4151 ± 691 vs 22313 ± 2901 J, respectively, p < 0.05, Hedge’s g = 4.27. Both measures were highly associated (r = 0.83, and the 95% limits of agreement (LoA represented 24.5% of TWWAnT. TWFAT of knee flexors (2151 ± 540 J was largely lower than TWWAnT (p < 0.05, g = 9.52. By contrast, both measures were not associated (r = 0.09, and the 95% LoA represented 31.1% of TWWAnT. Combining TWFAT of knee flexors and knee extensors into a single measure (6302 ± 818 J did not changed neither improved these observations. We still found a large difference with TWWAnT (p < 0.05, g = 5.26, a moderate association (r = 0.65 and 95% LoA representing 25.5% of TWWAnT. We concluded that TWFAT of knee extensors could be considered as a valid measure of AWC, since both measure were highly associated. However, the mean difference between both measures and their 95% LoA were too large to warrant interchangeability.

  15. Asymmetry during preseason Functional Movement Screen testing is associated with injury during a junior Australian football season.

    Science.gov (United States)

    Chalmers, Samuel; Fuller, Joel T; Debenedictis, Thomas A; Townsley, Samuel; Lynagh, Matthew; Gleeson, Cara; Zacharia, Andrew; Thomson, Stuart; Magarey, Mary

    2017-07-01

    The Functional Movement Screen (FMS) is a popular screening tool, however, the postulated relationship between prospective injury and FMS scoring remains sparsely explored in adolescent athletes. The aim of the study was to examine the association between pre-season FMS scores and injuries sustained during one regular season competition in elite adolescent Australian football players. Prospective cohort study. 237 elite junior Australian football players completed FMS testing during the late pre-season phase and had their weekly playing status monitored during the regular season. The definition of an injury was 'a trauma which caused a player to miss a competitive match'. The median composite FMS score was 14 (mean=13.5±2.3). An apriori analysis revealed that the presence of ≥1 asymmetrical sub-test was associated with a moderate increase in the risk of injury (hazard ratio=2.2 [1.0-4.8]; relative risk=1.9; p=0.047; sensitivity=78.4%; specificity=41.0%). Notably, post-hoc analysis identified that the presence of ≥2 asymmetrical sub-tests was associated with an even greater increase in risk of prospective injury (hazard ratio=3.7 [1.6-8.6]; relative risk=2.8; p=0.003; sensitivity=66.7%; specificity=78.0%). Achieving a composite score of ≤14 did not substantially increase the risk of prospective injury (hazard ratio=1.1 [0.5-2.1]; p=0.834). Junior Australian football players demonstrating asymmetrical movement during pre-season FMS testing were more likely to sustain an injury during the regular season than players without asymmetry. Findings suggest that the commonly reported composite FMS threshold score of ≤14 was not associated with injury in elite junior AF players. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  16. Assessing sexual interest in children using the Go/No-Go Association Test

    OpenAIRE

    Bartels, Ross; Beech, Anthony; Harkins, Leigh; Thornton, David

    2018-01-01

    The present study investigated whether a latency-based Go/No-Go Association Task (GNAT) could be used as an indirect measure of sexual interest in children. A sample 29 individuals with a history of exclusive extrafamilial offenses against a child and 15 individuals with either a history of exclusive intrafamilial or mixed offenses (i.e., against both adults and children) were recruited from a treatment center in the US. Also, a sample of 26 nonoffenders was recruited from a university in the...

  17. Illustrating, Quantifying, and Correcting for Bias in Post-hoc Analysis of Gene-Based Rare Variant Tests of Association

    Directory of Open Access Journals (Sweden)

    Kelsey E. Grinde

    2017-09-01

    Full Text Available To date, gene-based rare variant testing approaches have focused on aggregating information across sets of variants to maximize statistical power in identifying genes showing significant association with diseases. Beyond identifying genes that are associated with diseases, the identification of causal variant(s in those genes and estimation of their effect is crucial for planning replication studies and characterizing the genetic architecture of the locus. However, we illustrate that straightforward single-marker association statistics can suffer from substantial bias introduced by conditioning on gene-based test significance, due to the phenomenon often referred to as “winner's curse.” We illustrate the ramifications of this bias on variant effect size estimation and variant prioritization/ranking approaches, outline parameters of genetic architecture that affect this bias, and propose a bootstrap resampling method to correct for this bias. We find that our correction method significantly reduces the bias due to winner's curse (average two-fold decrease in bias, p < 2.2 × 10−6 and, consequently, substantially improves mean squared error and variant prioritization/ranking. The method is particularly helpful in adjustment for winner's curse effects when the initial gene-based test has low power and for relatively more common, non-causal variants. Adjustment for winner's curse is recommended for all post-hoc estimation and ranking of variants after a gene-based test. Further work is necessary to continue seeking ways to reduce bias and improve inference in post-hoc analysis of gene-based tests under a wide variety of genetic architectures.

  18. Accuracy of cotinine serum test to detect the smoking habit and its association with periodontal disease in a multicenter study.

    Science.gov (United States)

    Duque, A; Martínez, P-J; Giraldo, A; Gualtero, D-F; Ardila, C-M; Contreras, A; Duarte, S; Lafaurie, G-I

    2017-07-01

    The validity of the surveys on self-reported smoking status is often questioned because smokers underestimate cigarette use and deny the habit. It has been suggested that self-report should be accompanied by cotinine test. This report evaluates the usefulness of serum cotinine test to assess the association between smoking and periodontal status in a study with a large sample population to be used in studies with other serum markers in epidemiologic and periodontal medicine researches. 578 patients who were part of a multicenter study on blood biomarkers were evaluated about smoking and its relation to periodontal disease. Severity of periodontal disease was determinate using clinical attachment loss (CAL). Smoking was assessed by a questionnaire and a blood sample drawn for serum cotinine determination. The optimal cut-off point for serum cotinine was 10 ng/ml. Serum cotinine showed greater association with severity of CAL than self-report for mild-moderate CAL [OR 2.03 (CI95% 1.16-3.53) vs. OR 1.08 (CI95% 0.62-1.87) ] advanced periodontitis [OR 2.36 (CI95% 1.30- 4.31) vs. OR 2.06 (CI95% 0.97-4.38) ] and extension of CAL > 3 mm [ OR 1.78 (CI95% 1.16-1.71) vs. 1.37 (CI95% 0.89-2.11)]. When the two tests were evaluated together were not shown to be better than serum cotinine test. Self-reported smoking and serum cotinine test ≥ 10ng/ml are accurate ,complementary and more reliable methods to assess the patient's smoking status and could be used in studies evaluating serum samples in large population and multicenter studies. The serum cotinine level is more reliable to make associations with the patient's periodontal status than self-report questionnaire and could be used in multicenter and periodontal medicine studies.

  19. Association between new indices in the locomotive syndrome risk test and decline in mobility: third survey of the ROAD study.

    Science.gov (United States)

    Yoshimura, Noriko; Muraki, Shigeyuki; Oka, Hiroyuki; Tanaka, Sakae; Ogata, Toru; Kawaguchi, Hiroshi; Akune, Toru; Nakamura, Kozo

    2015-09-01

    We aimed to clarify the association between new indices in a locomotive syndrome risk test and decline in mobility. In the third survey of the Research on Osteoarthritis/osteoporosis Against Disability (ROAD) study, data on the indices were obtained from 1575 subjects (513 men, 1062 women) of the 1721 participants in mountainous and coastal areas. As outcome measures for decline in mobility, we used the five-times-sit-to-stand test (FTSST) and walking speed with cutoff values of 12 s and 0.8 m/s, respectively. We first estimated the prevalence of the indices in locomotive syndrome risk test stage 1, including two-step test score syndrome risk test stage 2, including two-step test score immobility. Finally, we clarified the risk of immobility according to an increasing number of indices in both stages 1 and 2 and found that the odds ratio for both slow FTSST time and slow walking speed increased exponentially. We found that the three indices independently predicted immobility and that accumulation of indices increased the risk of immobility exponentially.

  20. HIV Prevention among Mexican Migrants at Different Migration Phases: Exposure to Prevention Messages and Association With Testing Behaviors

    Science.gov (United States)

    Martinez-Donate, Ana P.; Rangel, M. Gudelia; Zhang, Xiao; Simon, Norma-Jean; Rhoads, Natalie; Gonzalez-Fagoaga, J. Eduardo; Gonzalez, Ahmed Asadi

    2016-01-01

    Mobile populations are at increased risk for HIV infection. Exposure to HIV prevention messages at all phases of the migration process may help decrease im/migrants’ HIV risk. We investigated levels of exposure to HIV prevention messages, factors associated with message exposure, and the association between exposure to prevention messages and HIV testing behavior among Mexican im/migrants at different phases of the migration process. We conducted a cross-sectional, probability survey of Mexican im/migrants (N=3,149) traveling through the border city of Tijuana, Mexico. The results indicate limited exposure to prevention messages (57%–75%) and suboptimal last 12-month HIV testing rates (14%–25%) across five migration phases. Compared to pre-departure levels (75%), exposure to messages decreases at all post-departure migration phases (57%–63%, pprevention messages is positively associated with greater odds of HIV testing at the pre-departure, destination, and interception phases. Binational efforts need to be intensified to reach and deliver HIV prevention to Mexican im/migrants across the migration continuum. PMID:26595267

  1. Evaluation of association between exercise-induced bronchoconstriction and childhood asthma control test questionnaire scores in children.

    Science.gov (United States)

    Chinellato, Iolanda; Piazza, Michele; Sandri, Marco; Cardinale, Fabio; Peroni, Diego G; Boner, Attilio L; Piacentini, Giorgio L

    2012-03-01

    Asthma control represents a major challenge in the management of asthmatic children; however, correct perception of control is poor. The aim of the study was to evaluate the association between subjective answers given to the Childhood Asthma Control Test (C-ACT) and objective evaluation of exercise-induced bronchonstriction (EIB) by standardized treadmill exercise challenge. EIB was evaluated by standardized treadmill exercise challenge and related to C-ACT scores in 92 asthmatic children. Of the 92 studied children only six children had a concordance between a positive challenge test (ΔFEV1 ≥ 13%) and a positive response to the exercise-related issue of the C-ACT questionnaire (C-ACT total score ≤ 19). There was no significant association between the degree of EIB and the scores relative to the single question on exercise-related problems while a significant association was found when considering the whole questionnaire with C-ACT total score > 19 (r = -0.40, P asthma. The areas under the ROC curve (AUC) for the sum of the scores of these questions in relationship to a positive response to the exercise test was 0.74. The AUC of the C-ACT total score was 0.76 and 0.55 for the specific question on EIB related problems. The discrimination power of the C-ACT total score in relationship to EIB was moderately good, and C-ACT questionnaire was capable of correctly predicting the absence of EIB in children reporting a global score > 19. However, direct questions on EIB are associated with a high number of false positive and negative responses; better associations are found questioning on the presence on nocturnal symptoms. Copyright © 2011 Wiley Periodicals, Inc.

  2. Permutation-based variance component test in generalized linear mixed model with application to multilocus genetic association study.

    Science.gov (United States)

    Zeng, Ping; Zhao, Yang; Li, Hongliang; Wang, Ting; Chen, Feng

    2015-04-22

    In many medical studies the likelihood ratio test (LRT) has been widely applied to examine whether the random effects variance component is zero within the mixed effects models framework; whereas little work about likelihood-ratio based variance component test has been done in the generalized linear mixed models (GLMM), where the response is discrete and the log-likelihood cannot be computed exactly. Before applying the LRT for variance component in GLMM, several difficulties need to be overcome, including the computation of the log-likelihood, the parameter estimation and the derivation of the null distribution for the LRT statistic. To overcome these problems, in this paper we make use of the penalized quasi-likelihood algorithm and calculate the LRT statistic based on the resulting working response and the quasi-likelihood. The permutation procedure is used to obtain the null distribution of the LRT statistic. We evaluate the permutation-based LRT via simulations and compare it with the score-based variance component test and the tests based on the mixture of chi-square distributions. Finally we apply the permutation-based LRT to multilocus association analysis in the case-control study, where the problem can be investigated under the framework of logistic mixed effects model. The simulations show that the permutation-based LRT can effectively control the type I error rate, while the score test is sometimes slightly conservative and the tests based on mixtures cannot maintain the type I error rate. Our studies also show that the permutation-based LRT has higher power than these existing tests and still maintains a reasonably high power even when the random effects do not follow a normal distribution. The application to GAW17 data also demonstrates that the proposed LRT has a higher probability to identify the association signals than the score test and the tests based on mixtures. In the present paper the permutation-based LRT was developed for variance

  3. Genome-wide association study identifies polymorphisms associated with the analgesic effect of fentanyl in the preoperative cold pressor-induced pain test

    Directory of Open Access Journals (Sweden)

    Kaori Takahashi

    2018-03-01

    Full Text Available Opioid analgesics are widely used for the treatment of moderate to severe pain. The analgesic effects of opioids are well known to vary among individuals. The present study focused on the genetic factors that are associated with interindividual differences in pain and opioid sensitivity. We conducted a multistage genome-wide association study in subjects who were scheduled to undergo mandibular sagittal split ramus osteotomy and were not medicated until they received fentanyl for the induction of anesthesia. We preoperatively conducted the cold pressor-induced pain test before and after fentanyl administration. The rs13093031 and rs12633508 single-nucleotide polymorphisms (SNPs near the LOC728432 gene region and rs6961071 SNP in the tcag7.1213 gene region were significantly associated with the analgesic effect of fentanyl, based on differences in pain perception latency before and after fentanyl administration. The associations of these three SNPs that were identified in our exploratory study have not been previously reported. The two polymorphic loci (rs13093031 and rs12633508 were shown to be in strong linkage disequilibrium. Subjects with the G/G genotype of the rs13093031 and rs6961071 SNPs presented lower fentanyl-induced analgesia. Our findings provide a basis for investigating genetics-based analgesic sensitivity and personalized pain control. Keywords: Opioid sensitivity, Analgesia, Fentanyl, Polymorphism, GWAS

  4. Noninvasive Test for Mitochondrial DNA A1555G Mutation Associated with Deafness.

    Science.gov (United States)

    Fan, Wenlu; Zhu, Yi; Tang, Xiaowen; Xue, Ling

    2017-01-01

    The homoplasmic mitochondrial DNA (mtDNA) A1555G mutation in the highly conserved decoding site of 12S rRNA has been associated with aminoglycoside-induced and nonsyndromic hearing loss in many families worldwide. The A1555G mutation detection is an important part of hearing screening. At present, blood samples are the most common source of genomic DNA. However, drawing blood is invasive for individuals. The whole genomic DNA of samples carrying mitochondrial DNA A1555G mutation (LX010 and LX044) with aminoglycoside-induced and nonsyndromic deafness as well as wild type were used as templates. The PCR products were analyzed by DNA sequencing, PCR-RFLP, dot blot, and southern blot. The DNA sequencing, PCR-RFLP, dot blot, and southern blot demonstrate that buccal cell DNA can be used for the screening and identification of the A1555G mutation as well as peripheral blood DNA. This study established a convenient, noninvasive and suitable for clinical determination of mtDNA A1555G mutation associated with deafness.

  5. Parental monitoring and knowledge: Testing bidirectional associations with youths’ antisocial behavior

    Science.gov (United States)

    Wertz, Jasmin; Nottingham, Kate; Agnew-Blais, Jessica; Matthews, Timothy; Pariante, Carmine M.; Moffitt, Terrie E.; Arseneault, Louise

    2017-01-01

    In the present study, we used separate measures of parental monitoring and parental knowledge and compared their associations with youths’ antisocial behavior during preadolescence, between the ages of 10 and 12. Parental monitoring and knowledge were reported by mothers, fathers and youths taking part in the Environmental Risk (E-Risk) Longitudinal Twin Study which follows 1,116 families with twins. Information on youths’ antisocial behavior was obtained from mothers, as well as teachers. We report two main findings: First, longitudinal cross-lagged models revealed that greater parental monitoring did not predict less antisocial behavior later, once family characteristics were taken into account. Second, greater youth antisocial behavior predicted less parental knowledge later. This effect of youths’ behavior on parents’ knowledge was consistent across mothers’, fathers’, youths’, and teachers’ reports, and robust to controls for family confounders. The association was partially genetically-mediated according to a Cholesky decomposition twin model; youths’ genetically-influenced antisocial behavior led to a decrease in parents’ knowledge of youths’ activities. These two findings question the assumption that greater parental monitoring can reduce preadolescents’ antisocial behavior. They also indicate that parents’ knowledge of their children’s activities is influenced by youths’ behavior. PMID:27427796

  6. Parental monitoring and knowledge: Testing bidirectional associations with youths' antisocial behavior.

    Science.gov (United States)

    Wertz, Jasmin; Nottingham, Kate; Agnew-Blais, Jessica; Matthews, Timothy; Pariante, Carmine M; Moffitt, Terrie E; Arseneault, Louise

    2016-08-01

    In the present study, we used separate measures of parental monitoring and parental knowledge and compared their associations with youths' antisocial behavior during preadolescence, between the ages of 10 and 12. Parental monitoring and knowledge were reported by mothers, fathers, and youths taking part in the Environmental Risk (E-Risk) Longitudinal Twin Study that follows 1,116 families with twins. Information on youths' antisocial behavior was obtained from mothers as well as teachers. We report two main findings. First, longitudinal cross-lagged models revealed that greater parental monitoring did not predict less antisocial behavior later, once family characteristics were taken into account. Second, greater youth antisocial behavior predicted less parental knowledge later. This effect of youths' behavior on parents' knowledge was consistent across mothers', fathers', youths', and teachers' reports, and robust to controls for family confounders. The association was partially genetically mediated according to a Cholesky decomposition twin model; youths' genetically influenced antisocial behavior led to a decrease in parents' knowledge of youths' activities. These two findings question the assumption that greater parental monitoring can reduce preadolescents' antisocial behavior. They also indicate that parents' knowledge of their children's activities is influenced by youths' behavior.

  7. An efficient genome-wide association test for mixed binary and continuous phenotypes with applications to substance abuse research.

    Science.gov (United States)

    Buu, Anne; Williams, L Keoki; Yang, James J

    2018-03-01

    We propose a new genome-wide association test for mixed binary and continuous phenotypes that uses an efficient numerical method to estimate the empirical distribution of the Fisher's combination statistic under the null hypothesis. Our simulation study shows that the proposed method controls the type I error rate and also maintains its power at the level of the permutation method. More importantly, the computational efficiency of the proposed method is much higher than the one of the permutation method. The simulation results also indicate that the power of the test increases when the genetic effect increases, the minor allele frequency increases, and the correlation between responses decreases. The statistical analysis on the database of the Study of Addiction: Genetics and Environment demonstrates that the proposed method combining multiple phenotypes can increase the power of identifying markers that may not be, otherwise, chosen using marginal tests.

  8. Work-related stress is associated with impaired neuropsychological test performance: a clinical cross-sectional study.

    Science.gov (United States)

    Eskildsen, Anita; Andersen, Lars Peter; Pedersen, Anders Degn; Vandborg, Sanne Kjær; Andersen, Johan Hviid

    2015-01-01

    Patients on sick leave due to work-related stress often complain about impaired concentration and memory. However, it is undetermined how widespread these impairments are, and which cognitive domains are most long-term stress sensitive. Previous studies show inconsistent results and are difficult to synthesize. The primary aim of this study was to examine whether patients with work-related stress complaints have cognitive impairments compared to a matched control group without stress. Our secondary aim was to examine whether the level of self-reported perceived stress is associated with neuropsychological test performance. We used a broad neuropsychological test battery to assess 59 outpatients with work-related stress complaints (without major depression) and 59 healthy controls. We matched the patients and controls pairwise by sex, age and educational level. Compared to controls, patients generally showed mildly reduced performance across all the measured domains of the neuropsychological test battery. However, only three comparisons reached statistical significance (p working memory. There were no statistical significant associations between self-reported perceived stress level and neuropsychological test performance. In conclusion, we recommend that cognitive functions should be considered when evaluating patients with work-related stress complaints, especially when given advice regarding return to work. Since this study had a cross-sectional design, it is still uncertain whether the impairments are permanent. Further study is required to establish causal links between work-related stress and cognitive deficits.

  9. Nonparametric tests for data in randomised blocks with Ordered alternatives

    OpenAIRE

    Rayner, J. C. W.; Best, D. J.

    1999-01-01

    For randomized block designs, nonparametric treatment comparisons are usually made using the Friedman test for complete designs, and the Durbin test for incomplete designs; see, for example, Conover (1998). This permits assessment of only the mean rankings. Such comparisons are here extended to permit assessments of bivariate effects such as the linear by linear effect and the quadratic by linear, or umbrella effect.

  10. Conceptualising computerized adaptive testing for measurement of latent variables associated with physical objects

    Science.gov (United States)

    Camargo, F. R.; Henson, B.

    2015-02-01

    The notion of that more or less of a physical feature affects in different degrees the users' impression with regard to an underlying attribute of a product has frequently been applied in affective engineering. However, those attributes exist only as a premise that cannot directly be measured and, therefore, inferences based on their assessment are error-prone. To establish and improve measurement of latent attributes it is presented in this paper the concept of a stochastic framework using the Rasch model for a wide range of independent variables referred to as an item bank. Based on an item bank, computerized adaptive testing (CAT) can be developed. A CAT system can converge into a sequence of items bracketing to convey information at a user's particular endorsement level. It is through item banking and CAT that the financial benefits of using the Rasch model in affective engineering can be realised.

  11. Conceptualising computerized adaptive testing for measurement of latent variables associated with physical objects

    International Nuclear Information System (INIS)

    Camargo, F R; Henson, B

    2015-01-01

    The notion of that more or less of a physical feature affects in different degrees the users' impression with regard to an underlying attribute of a product has frequently been applied in affective engineering. However, those attributes exist only as a premise that cannot directly be measured and, therefore, inferences based on their assessment are error-prone. To establish and improve measurement of latent attributes it is presented in this paper the concept of a stochastic framework using the Rasch model for a wide range of independent variables referred to as an item bank. Based on an item bank, computerized adaptive testing (CAT) can be developed. A CAT system can converge into a sequence of items bracketing to convey information at a user's particular endorsement level. It is through item banking and CAT that the financial benefits of using the Rasch model in affective engineering can be realised

  12. Examination of the geology and seismology associated with area 410 at the Nevada test site

    International Nuclear Information System (INIS)

    Hannon, W.J.; McKague, H.L.

    1975-01-01

    This report summarizes regional and local geology at the Nevada Test Site and identifies major tectonic features and active faults. Sufficient information is given to perform seismic safety analyses of present and future critical construction at the Super Kukla Site and Sites A and B in Area 410. However, examination of local minor faults and joints and soil thickness studies should be undertaken at construction time. The Cane Spring Fault is identified as the most significant geologic feature from the viewpoint of the potential seismic risk. Predictions of the peak ground acceleration (0.9 g), the response spectra for the Safe Shutdown Earthquake, and the maximum displacement across the Cane Spring Fault are made. (U.S.)

  13. Observations on Faults and Associated Permeability Structures in Hydrogeologic Units at the Nevada Test Site

    Energy Technology Data Exchange (ETDEWEB)

    Prothro, Lance B.; Drellack, Sigmund L.; Haugstad, Dawn N.; Huckins-Gang, Heather E.; Townsend, Margaret J.

    2009-03-30

    Observational data on Nevada Test Site (NTS) faults were gathered from a variety of sources, including surface and tunnel exposures, core samples, geophysical logs, and down-hole cameras. These data show that NTS fault characteristics and fault zone permeability structures are similar to those of faults studied in other regions. Faults at the NTS form complex and heterogeneous fault zones with flow properties that vary in both space and time. Flow property variability within fault zones can be broken down into four major components that allow for the development of a simplified, first approximation model of NTS fault zones. This conceptual model can be used as a general guide during development and evaluation of groundwater flow and contaminate transport models at the NTS.

  14. The association between disease and profitability in individual finishing boars at a test station

    DEFF Research Database (Denmark)

    Jensen, Tina Birk; Baadsgaard, Niels Peter; Houe, Hans

    2008-01-01

    Endemic diseases in finisher herds are considered to be costly for the pig producer. We investigated the effect of diseases on the profit margin using data from a Danish boar test station (n = 5777) collected from July 2002 to December 2004. Boars reaching a target slaughter weight of at least 80...... a reduction in the range from 0.54 to 2.41 € (corresponding to a reduction in the profit margin ranging from 4 to 20%). The results were robust to changes in price of a 30 kilogram piglet and, relatively robust in regard to changes in the feed price. However, price per kilogram carcass weight appeared...... to influence the economic effect of oral and parenteral treatment and pathological findings on the profit margin. The effect of oral and parenteral treatments was also sensitive to changes in medicine prices....

  15. [Pap test used for detection of cellular changes associated with human papillomavirus].

    Science.gov (United States)

    Hernández-Valencia, Marcelino; Carrillo-Pacheco, Adia; Hernández-Quijano, Tomás; Zárate, Arturo

    2013-01-01

    Human papilloma virus can infect any mucous of the body and can cause cancer of the uterine cervix. This suggests recommending the Papanicolaou smear combined with a test for detection of human papillomavirus with a frequency interval of 3 years, since it grants greater information and fidelity to the result. The detection studies should begin at the age of 21 years and should stop at 65 years age. Until recently specific treatments did not exist to treat human papilloma virus, but recently some drugs that have demonstrated good effectiveness in curing the infection of human papilloma virus. One example is glycirrhicinic acid, which has demonstrated fewer adverse effects, as well as the possibility that its systemic employment allows treatment of lesions that are difficult to approach. The medical recommendations should be in constant revision, since a clinical trial can modify the interpretation of what is necessary to individualize each patient's treatment.

  16. High expression of testes-specific protease 50 is associated with poor prognosis in colorectal carcinoma.

    Directory of Open Access Journals (Sweden)

    Lei Zheng

    Full Text Available BACKGROUND: Testes-specific protease 50 (TSP50 is normally expressed in testes and abnormally expressed in breast cancer, but whether TSP50 is expressed in colorectal carcinoma (CRC and its clinical significance is unclear. We aimed to detect TSP50 expression in CRC, correlate it with clinicopathological factors, and assess its potential diagnostic and prognostic value. METHODOLOGY/PRINCIPAL FINDINGS: TSP50 mRNAs and proteins were detected in 7 CRC cell lines and 8 CRC specimens via RT-PCR and Western blot analysis. Immunohistochemical analysis of TSP50, p53 and carcinoembryonic antigen (CEA with tissue microarrays composed of 95 CRCs, 20 colorectal adenomas and 20 normal colorectal tissues were carried out and correlated with clinicopathological characteristics and disease-specific survival for CRC patients. There was no significant correlation between the expression levels of TSP50 and p53 (P = 0.751 or CEA (P = 0.663. Abundant expression of TSP50 protein was found in CRCs (68.4% while it was poorly expressed in colorectal adenomas and normal tissues (P<0.0001. Thus, CRCs can be distinguished from them with high specificity (92.5% and positive predictive value (PPV, 95.6%. The survival of CRC patients with high TSP50 expression was significantly shorter than that of the patients with low TSP50 expression (P = 0.010, specifically in patients who had early-stage tumors (stage I and II; P = 0.004. Multivariate Cox regression analysis indicated that high TSP50 expression was a statistically significant independent risk factor (hazard ratio  = 2.205, 95% CI = 1.214-4.004, P = 0.009. CONCLUSION: Our data demonstrate that TSP50 is a potential effective indicator of poor survival for CRC patients, especially for those with early-stage tumors.

  17. Independent quality assurance of refinery fugitives testing by western states petroleum association. Final audit report

    Energy Technology Data Exchange (ETDEWEB)

    1993-09-01

    Research Triangle Institute (RTI) undertook this task for the U.S. Environmental Protection Agency's (EPA's) Office of Air Quality Planning and Standards to provide third-party Quality Assurance (QA) support to a Western States' Petroleum Association (WSPA) program to measure fugitive emissions at petroleum refineries. The primary objectives of the WSPA study were to determine the correlation between screening values and true mass emission rates and to develop a relationship between liquid and gas composition. EPA's QA effort, however, focused only on the correlation objective because the number of leaking components in the California refineries cannot be expected to be representative of refineries in general. The number of components leaking at a given screening value is used in conjunction with the mass correlations to derive the average emission factors.

  18. Testing the Role of Dorsal Premotor Cortex in Auditory-Motor Association Learning Using Transcranical Magnetic Stimulation (TMS.

    Directory of Open Access Journals (Sweden)

    Carlotta Lega

    Full Text Available Interactions between the auditory and the motor systems are critical in music as well as in other domains, such as speech. The premotor cortex, specifically the dorsal premotor cortex (dPMC, seems to play a key role in auditory-motor integration, and in mapping the association between a sound and the movement used to produce it. In the present studies we tested the causal role of the dPMC in learning and applying auditory-motor associations using 1 Hz repetitive Transcranical Magnetic Stimulation (rTMS. In this paradigm, non-musicians learn a set of auditory-motor associations through melody training in two contexts: first when the sound to key-press mapping was in a conventional sequential order (low to high tones mapped onto keys from left to right, and then when it was in a novel scrambled order. Participant's ability to match the four pitches to four computer keys was tested before and after the training. In both experiments, the group that received 1 Hz rTMS over the dPMC showed no significant improvement on the pitch-matching task following training, whereas the control group (who received rTMS to visual cortex did. Moreover, in Experiment 2 where the pitch-key mapping was novel, rTMS over the dPMC also interfered with learning. These findings suggest that rTMS over dPMC disturbs the formation of auditory-motor associations, especially when the association is novel and must be learned rather explicitly. The present results contribute to a better understanding of the role of dPMC in auditory-motor integration, suggesting a critical role of dPMC in learning the link between an action and its associated sound.

  19. Factors associated with HIV testing among young men who have sex with men in Myanmar: a cross-sectional study.

    Science.gov (United States)

    Pham, Minh D; Aung, Poe Poe; Paing, Aye Kyawt; Pasricha, Naanki; Agius, Paul A; Tun, Waimar; Bajracharya, Ashish; Luchters, Stanley

    2017-11-01

    In Myanmar, men who have sex with men (MSM) experience high risk of HIV infection. However, access to HIV testing and prevention services remains a challenge among this marginalized population. The objective of this study was to estimate population prevalence and correlates of prior HIV testing among young MSM (YMSM) and informs the development of HIV testing and intervention programmes that respond to the specific needs of this population. Five hundred and eighty-five YMSM aged 18 to 24 years were recruited using respondent-driven sampling (RDS) in a cross-sectional survey conducted in six townships of Myanmar. RDS-adjusted population estimates were calculated to estimate prevalence of HIV testing; RDS-weighted logistic regression was used to examine correlates of HIV testing in the past 6 months and in a lifetime. There were 12 participants who reported receiving a HIV-positive test; of those, five were tested in the past 6 months. The RDS-weighted prevalence estimates of lifetime (any prior) HIV testing was 60.6% (95% CI: 53.3% to 66.4%) and of recent (≤ 6 months) HIV testing was 50.1% (95% CI: 44.1% to 55.5%). In multivariable analysis, sexual identity was associated with lifetime but not recent HIV testing. Lifetime and recent HIV testing were associated with having three or more male sexual partners in the past 12 months (adjusted ORs (aORs) = 2.28, 95% CIs: 1.21 to 4.32 and 2.69, 95% CI: 1.59 to 4.56), having good HIV-related knowledge (aORs = 1.96, 95% CIs: 1.11 to 3.44 and 1.77, 95% CI: 1.08 to 2.89), reporting high HIV testing self-efficacy (aORs = 13.5, 95% CIs: 6.0 to 30.1 and 9.81, 95% CI: 4.27 to 22.6) and having access to and use of non-HIV health-related services in the past 12 months (aORs = 13.2, 95% CIs: 6.85 to 25.6 and 7.15, 95% CI: 4.08 to 12.5) respectively. HIV testing coverage among YMSM aged 18 to 24 years old in Myanmar is still suboptimal. Integrated HIV testing and prevention services in existing health service

  20. Association of hip pain with radiographic evidence of hip osteoarthritis: diagnostic test study

    Science.gov (United States)

    Nevitt, Michael C; Niu, Jingbo; Clancy, Mary M; Lane, Nancy E; Link, Thomas M; Vlad, Steven; Tolstykh, Irina; Jungmann, Pia M.; Felson, David T; Guermazi, Ali

    2015-01-01

    Study question Is there concordance between hip pain and radiographic hip osteoarthritis? Methods In this diagnostic test study, pelvic radiographs were assessed for hip osteoarthritis in two cohorts: the Framingham Osteoarthritis Study (community of Framingham, Massachusetts) and the Osteoarthritis Initiative (a multicenter longitudinal cohort study of osteoarthritis in the United States). Using visual representation of the hip joint, participants reported whether they had hip pain on most days and the location of the pain: anterior, groin, lateral, buttocks, or low back. In the Framingham study, participants with hip pain were also examined for hip pain with internal rotation. The authors analysed the agreement between radiographic hip osteoarthritis and hip pain, and for those with hip pain suggestive of hip osteoarthritis they calculated the sensitivity, specificity, positive predictive value, and negative predictive value of radiographs as the diagnostic test. Study answer and limitations In the Framingham study (n=946), only 15.6% of hips in patients with frequent hip pain showed radiographic evidence of hip osteoarthritis, and 20.7% of hips with radiographic hip osteoarthritis were frequently painful. The sensitivity of radiographic hip osteoarthritis for hip pain localised to the groin was 36.7%, specificity 90.5%, positive predictive value 6.0%, and negative predictive value 98.9%. Results did not differ much for hip pain at other locations or for painful internal rotation. In the Osteoarthritis Initiative study (n=4366), only 9.1% of hips in patients with frequent pain showed radiographic hip osteoarthritis, and 23.8% of hips with radiographic hip osteoarthritis were frequently painful. The sensitivity of definite radiographic hip osteoarthritis for hip pain localised to the groin was 16.5%, specificity 94.0%, positive predictive value 7.1%, and negative predictive value 97.6%. Results also did not differ much for hip pain at other locations. What this

  1. The association between various visual function tests and low fragility hip fractures among the elderly: a Malaysian experience.

    Science.gov (United States)

    Chew, Fiona L M; Yong, Chee-Khuen; Mas Ayu, S; Tajunisah, I

    2010-03-01

    hip fractures are an increasing source of morbidity and mortality in older people. The role of visual function tests such as visual impairment, stereopsis, contrast sensitivity and visual field defects in low fragility hip fractures in Asian populations is not well understood. to determine the association between various visual function tests and low fragility hip fractures in an Asian population. case-control study. University Malaya Medical Centre, Kuala Lumpur, Malaysia. 108 cases aged > or = 55 years admitted with low fragility fractures and 108 controls (matched for age, gender and race). both cases and controls underwent a detailed ophthalmological examination, which included visual acuity, stereopsis, contrast sensitivity and visual field testing. poorer visual acuity (odds ratio, OR = 4.08; 95% confidence interval, CI: 1.44, 11.51), stereopsis (OR = 3.60, 95% CI: 1.55, 8.38), contrast sensitivity (OR = 3.34, 95% CI: 1.48, 7.57) and visual field defects (OR = 11.60, 95% CI: 5.21, 25.81) increased the risk of fracture. Increased falls were associated with poorer visual acuity (OR = 2.30, 95% CI: 1.04, 5.13), stereopsis (OR = 2.11, 95% CI: 1.03, 4.32), contrast sensitivity (OR = 2.12, 95% CI: 1.05, 4.30) and visual field defects (OR = 3.40, 95% CI: 1.69, 6.86). impaired visual acuity, stereopsis, contrast sensitivity and visual field defects are associated with an increased risk of low fragility hip fractures. We recommend that all patients aged > or = 55 should have an annual ophthalmological examination that includes visual acuity, contrast sensitivity, stereopsis and visual field testing to assess the risks for falls and low fragility fractures.

  2. Correlation between HRCT findings, pulmonary function tests and bronchoalveolar lavage cytology in interstitial lung disease associated with rheumatoid arthritis

    International Nuclear Information System (INIS)

    Biederer, J.; Muhle, C.; Heller, M.; Reuter, M.; Schnabel, A.; Gross, W.L.

    2004-01-01

    A prospective study correlating high-resolution computed tomography (HRCT), lung function tests (PFT) and bronchoalveolar lavage (BAL) cytology in patients with interstitial lung disease (ILD) associated with rheumatoid arthritis (RA). Fifty-three RA patients with suspected ILD (19 men, 34 women) underwent 71 HRCT (14 of 53 with sequential HRCT, mean follow-up 24.3 months). The HRCT evaluation by two observers on consensus included a semi-quantitative characterisation of lesion pattern and profusion on representative anatomical levels. Fifty-two HRCT were followed by PFT and BAL. Agreement or discordance of HRCT-, PFT- and BAL findings were analysed with Pearson's correlation, κ score and McNemar's test. Tobacco-fume exposure was estimated in pack years. Smoking/non-smoking groups were compared with Student's t test. In 49 of 53 patients, HRCT was suggestive of ILD associated with RA (66 of 71 HRCT). Reticular lesions were found in 40 of 53 patients, in 15 of 40 presenting as mixed pattern with ground-glass opacities (GGO). Pure reticular patterns predominated in patients with long duration of ILD (p>0.01). Pure GGO were not observed. Lesion profusion was highly variable and correlated moderately negative with diffusion capacity (mean 88.2% (SD±20.9%); r=-0.54; p 0.2), but not towards lymphocytosis (κ=0.10; p=0.23; McNemar test p>0.2). Differences in smoking history were not significant (p>0.1). The HRCT appears most appropriate for the detection and follow-up of ILD associated with RA. The PFT and BAL correlate only partially with lesion profusion or grading on HRCT, but they contribute valuable information about dynamic lung function and differential diagnoses (pneumonia, medication side effects). (orig.)

  3. Carbon-14 urea breath test for the diagnosis of Campylobacter pylori associated gastritis

    International Nuclear Information System (INIS)

    Marshall, B.J.; Surveyor, I.

    1988-01-01

    Urease in the human gastric mucosa is a marker for infection with Campylobacter pylori (CP), an organism suspected of causing chronic gastritis and peptic ulceration. To detect gastric urease, we examined 32 patients who were being evaluated for possible peptic ulcer disease. Fasting patients were given 10 microCi (370 kBq) of 14 C-labeled urea. Breath samples were collected in hyamine at intervals between 1 and 30 min. The amount of 14 C collected at these times was expressed as: body weight X (% of administered dose of 14 C in sample)/(mmol of CO 2 collected). The presence of C. pylori colonization was also determined by examination of multiple endoscopic gastric biopsy specimens. On average, patients who were proven to have C. pylori infection exhaled 20 times more labeled CO 2 than patients who were not infected. The difference between infected patients and C. pylori negative control patients was highly significant at all time points between 2 and 30 min after ingestion of the radionuclide (p less than 0.0001). The noninvasive urea breath is less expensive than endoscopic biopsy of the stomach and more accurate than serology as a means of detecting Campylobacter pylori infection. Because the test detects actual viable CP organisms, it can be used to confirm eradication of the bacterium after antibacterial therapy

  4. Carbon-14 urea breath test for the diagnosis of Campylobacter pylori associated gastritis

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, B.J.; Surveyor, I.

    1988-01-01

    Urease in the human gastric mucosa is a marker for infection with Campylobacter pylori (CP), an organism suspected of causing chronic gastritis and peptic ulceration. To detect gastric urease, we examined 32 patients who were being evaluated for possible peptic ulcer disease. Fasting patients were given 10 microCi (370 kBq) of /sup 14/C-labeled urea. Breath samples were collected in hyamine at intervals between 1 and 30 min. The amount of /sup 14/C collected at these times was expressed as: body weight X (% of administered dose of /sup 14/C in sample)/(mmol of CO/sub 2/ collected). The presence of C. pylori colonization was also determined by examination of multiple endoscopic gastric biopsy specimens. On average, patients who were proven to have C. pylori infection exhaled 20 times more labeled CO/sub 2/ than patients who were not infected. The difference between infected patients and C. pylori negative control patients was highly significant at all time points between 2 and 30 min after ingestion of the radionuclide (p less than 0.0001). The noninvasive urea breath is less expensive than endoscopic biopsy of the stomach and more accurate than serology as a means of detecting Campylobacter pylori infection. Because the test detects actual viable CP organisms, it can be used to confirm eradication of the bacterium after antibacterial therapy.

  5. American Thyroid Association guidelines for use of laboratory tests in thyroid disorders.

    Science.gov (United States)

    Surks, M I; Chopra, I J; Mariash, C N; Nicoloff, J T; Solomon, D H

    1990-03-16

    Selection of appropriate laboratory determinations will enable the clinician to diagnose thyroid dysfunction readily in the majority of patients. At the present time, estimation of free thyroxine and a "sensitive" thyrotropin assay are recommended as the principal laboratory tests for thyroid disease. A decrease in serum free thyroxine estimate and a raised level of serum thyrotropin confirm the diagnosis of hypothyroidism caused by thyroid gland failure. An increase in free thyroxine estimate combined with a serum sensitive thyrotropin level suppressed to less than 0.1 mU/L establishes the diagnosis of thyrotoxicosis. In sick patients, a normal or raised serum free thyroxine estimate together with a normal level of serum thyrotropin suggests that the patient has neither hypothyroidism nor thyrotoxicosis. Patients with severe illnesses, generally in the intensive care unit, and those treated with certain drugs, as well as individuals with unusual thyroid disorders, may present with confusing laboratory findings. An understanding of the regulation of the thyroid hormone system and/or judicious consultation with an endocrinologist should enable the clinician to diagnose thyroid disease, if present, in such patients.

  6. Symptom validity testing in memory clinics: Hippocampal-memory associations and relevance for diagnosing mild cognitive impairment.

    Science.gov (United States)

    Rienstra, Anne; Groot, Paul F C; Spaan, Pauline E J; Majoie, Charles B L M; Nederveen, Aart J; Walstra, Gerard J M; de Jonghe, Jos F M; van Gool, Willem A; Olabarriaga, Silvia D; Korkhov, Vladimir V; Schmand, Ben

    2013-01-01

    Patients with mild cognitive impairment (MCI) do not always convert to dementia. In such cases, abnormal neuropsychological test results may not validly reflect cognitive symptoms due to brain disease, and the usual brain-behavior relationships may be absent. This study examined symptom validity in a memory clinic sample and its effect on the associations between hippocampal volume and memory performance. Eleven of 170 consecutive patients (6.5%; 13% of patients younger than 65 years) referred to memory clinics showed noncredible performance on symptom validity tests (SVTs, viz. Word Memory Test and Test of Memory Malingering). They were compared to a demographically matched group (n = 57) selected from the remaining patients. Hippocampal volume, measured by an automated volumetric method (Freesurfer), was correlated with scores on six verbal memory tests. The median correlation was r = .49 in the matched group. However, the relation was absent (median r = -.11) in patients who failed SVTs. Memory clinic samples may include patients who show noncredible performance, which invalidates their MCI diagnosis. This underscores the importance of applying SVTs in evaluating patients with cognitive complaints that may signify a predementia stage, especially when these patients are relatively young.

  7. [Incidence and associated factors in ulcer bleeding recurrence post inyectotherapy with adrenaline].

    Science.gov (United States)

    Castillo-Elera, Christian; Montenegro-Idrogo, Juan J; Tagle, M; Montañez-Valverde, Raúl; Callupe-Huamán, Gabriel; Huayta-Córdova, Gisella; Rivera-Fernández, Gustavo; Whittembury-Vlásica, Alvaro; Montes-Teves, Pedro; Monge-Salgado, Eduardo

    2012-01-01

    To determine the incidence and associated factors with upper gastrointestinal bleeding after injection therapy with adrenaline in a general hospital. longitudinal and analytic. Clinical records of patients with upper gastrointestinal bleeding who received injection therapy with adrenalin during 2005 and 2011 in Daniel Alcides Carrion Hospital, Peru were reviewed. Rebleeding and pre-endoscopic and endoscopic associated factors were sought. A bivariate (Chi Square, Fisher Exact test and RR) and multivariate analysis were performed. A total of 111 patients were included. Rebleeding rate was 20.7%. Multivariate analysis showed active bleeding (p=0.002) and anticoagulant drugs (p=0.035) were associated with rebleeding. Rebleeding rate was 20.7% and active bleeding as well as anticoagulant drugs use were associated factors.

  8. Method performance and clinical workflow outcomes associated with meconium and umbilical cord toxicology testing.

    Science.gov (United States)

    Labardee, Ruth M; Swartzwelder, Jaime R; Gebhardt, Karen E; Pardi, Justine A; Dawsey, Anna C; Brent Dixon, R; Cotten, Steven W

    2017-12-01

    Neonatal abstinence syndrome (NAS) is a rising concern with unknown long-term effects. It is apparent that higher cost of care, impact on the community and reduced quality of life are associated with similar etiologies (e.g., fetal alcohol syndrome). Detection of drug exposure in utero allows for earlier intervention to potentially reduce undesired outcomes. Umbilical cord tissue (UCT) has been documented as a readily accessible specimen for detection of drug exposure and has emerged as an alternative specimen to meconium. The analytical and clinical impact of umbilical cord tissue relative to meconium was evaluated for assessment of in utero drug exposure. Quality metrics relating to turnaround-time and diagnosis of NAS were investigated after switching from meconium to UCT. Umbilical cord tissue showed higher clinical sensitivity but lower specificity for prediction of NAS diagnosis. Birth to result time decreased with adoption of UCT. Birth to result time decreased by the switching to UTC as well as the number of missed collections. The clinical sensitivity and negative predictive value for NAS increased with UCT; however both meconium and UTC samples were negative for opiates for a significant percentage of newborns with a diagnosis of NAS. Copyright © 2017 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  9. Association testing to detect gene-gene interactions on sex chromosomes in trio data

    Directory of Open Access Journals (Sweden)

    Yeonok eLee

    2013-11-01

    Full Text Available Autism Spectrum Disorder (ASD occurs more often among males than females in a 4:1 ratio. Among theories used to explain the causes of ASD, the X chromosome and the Y chromosome theories attribute ASD to X-linked mutation and the male-limited gene expressions on the Y chromosome, respectively. Despite the rationale of the theory, studies have failed to attribute the sex-biased ratio to the significant linkage or association on the regions of interest on X chromosome. We further study the gender biased ratio by examining the possible interaction effects between two genes in the sex chromosomes. We propose a logistic regression model with mixed effects to detect gene-gene interactions on sex chromosomes. We investigated the power and type I error rates of the approach for a range of minor allele frequencies and varying linkage disequilibrium between markers and QTLs. We also evaluated the robustness of the model to population stratification. We applied the model to a trio-family data set with an ASD affected male child to study gene-gene interactions on sex chromosomes.

  10. Uncertainties in coupled thermal-hydrological processes associated with the drift scale test at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Mukhopadhyay, Sumitra; Tsang, Y.W.

    2002-01-01

    Understanding thermally driven coupled hydrological, mechanical, and chemical processes in unsaturated fractured tuff is essential for evaluating the performance of the potential radioactive waste repository at Yucca Mountain, Nevada. The Drift Scale Test (DST), intended for acquiring such an understanding of these processes, has generated a huge volume of temperature and moisture redistribution data. Sophisticated thermal hydrological (TH) conceptual models have yielded a good fit between simulation results and those measured data. However, some uncertainties in understanding the TH processes associated with the DST still exist. This paper evaluates these uncertainties and provides quantitative estimates of the range of these uncertainties. Of particular interest for the DST are the uncertainties resulting from the unmonitored loss of vapor through an open bulkhead of the test. There was concern that the outcome from the test might have been significantly altered by these losses. Using alternative conceptual models, we illustrate that predicted mean temperatures from the DST are within 1 degree C of the measured mean temperatures through the first two years of heating. The simulated spatial and temporal evolution of drying and condensation fronts is found to be qualitatively consistent with measured saturation data. Energy and mass balance computation shows that no more than 13 percent of the input energy is lost because of vapor leaving the test domain through the bulkhead. The change in average saturation in fractures is also relatively small. For a hypothetical situation in which no vapor is allowed to exit through the bulkhead, the simulated average fracture saturation is not qualitatively different enough to be discerned by measured moisture redistribution data. This leads us to conclude that the DST, despite the uncertainties associated with open field testing, has provided an excellent understanding of the TH processes

  11. Asthma in pregnancy: association between the Asthma Control Test and the Global Initiative for Asthma classification and comparisons with spirometry.

    Science.gov (United States)

    de Araujo, Georgia Véras; Leite, Débora F B; Rizzo, José A; Sarinho, Emanuel S C

    2016-08-01

    The aim of this study was to identify a possible association between the assessment of clinical asthma control using the Asthma Control Test (ACT) and the Global Initiative for Asthma (GINA) classification and to perform comparisons with values of spirometry. Through this cross-sectional study, 103 pregnant women with asthma were assessed in the period from October 2010 to October 2013 in the asthma pregnancy clinic at the Clinical Hospital of the Federal University of Pernambuco. Questionnaires concerning the level of asthma control were administered using the Global Initiative for Asthma classification, the Asthma Control Test validated for asthmatic expectant mothers and spirometry; all three methods of assessing asthma control were performed during the same visit between the twenty-first and twenty-seventh weeks of pregnancy. There was a significant association between clinical asthma control assessment using the Asthma Control Test and the Global Initiative for Asthma classification (pspirometry. This study shows that both the Global Initiative for Asthma classification and the Asthma Control Test can be used for asthmatic expectant mothers to assess the clinical control of asthma, especially at the end of the second trimester, which is assumed to be the period of worsening asthma exacerbations during pregnancy. We highlight the importance of the Asthma Control Test as a subjective instrument with easy application, easy interpretation and good reproducibility that does not require spirometry to assess the level of asthma control and can be used in the primary care of asthmatic expectant mothers. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  12. From Ground Truth to Space: Surface, Subsurface and Remote Observations Associated with Nuclear Test Detection

    Science.gov (United States)

    Sussman, A. J.; Anderson, D.; Burt, C.; Craven, J.; Kimblin, C.; McKenna, I.; Schultz-Fellenz, E. S.; Miller, E.; Yocky, D. A.; Haas, D.

    2016-12-01

    Underground nuclear explosions (UNEs) result in numerous signatures that manifest on a wide range of temporal and spatial scales. Currently, prompt signals, such as the detection of seismic waves provide only generalized locations and the timing and amplitude of non-prompt signals are difficult to predict. As such, research into improving the detection, location, and identification of suspect events has been conducted, resulting in advancement of nuclear test detection science. In this presentation, we demonstrate the scalar variably of surface and subsurface observables, briefly discuss current capabilities to locate, detect and characterize potential nuclear explosion locations, and explain how emergent technologies and amalgamation of disparate data sets will facilitate improved monitoring and verification. At the smaller scales, material and fracture characterization efforts on rock collected from legacy UNE sites and from underground experiments using chemical explosions can be incorporated into predictive modeling efforts. Spatial analyses of digital elevation models and orthoimagery of both modern conventional and legacy nuclear sites show subtle surface topographic changes and damage at nearby outcrops. Additionally, at sites where such technology cannot penetrate vegetative cover, it is possible to use the vegetation itself as both a companion signature reflecting geologic conditions and showing subsurface impacts to water, nutrients, and chemicals. Aerial systems based on RGB imagery, light detection and ranging, and hyperspectral imaging can allow for combined remote sensing modalities to perform pattern recognition and classification tasks. Finally, more remote systems such as satellite based synthetic aperture radar and satellite imagery are other techniques in development for UNE site detection, location and characterization.

  13. Testing the association between anomalous microwave emission and PAHs in the diffuse ISM

    Science.gov (United States)

    Berkeley, Matthew R.; Chuss, David; Kogut, Al

    2018-01-01

    Testing cosmic inflation is currently a primary focus of the Cosmology community. In order to verify the theory and to determine the energy scale of inflation, it is necessary to identify the characteristic B-mode polarization signal in the CMB. This signal, predicted by inflation theory, is expected to be very faint. It is therefore important to accurately characterize and remove foreground polarization components such as thermal dust and synchrotron emission.Some of these components have already been accurately characterized, but there are others that are not so well understood. In 1996, a new galactic foreground emission component was discovered. Dubbed 'anomalous microwave emission' (AME), this new foreground has yet to be identified. Though its physical origin remains uncertain, the leading hypothesis for the origin of this foreground proposes that the emission comes from rapidly rotating small dust grains called Polycyclic Aromatic Hydrocarbons (PAHs), or 'spinning dust'. PAHs are a family of hydrocarbon molecules with characteristic bending and stretching modes that have identifiable emission spectra in the mid-infrared region. The Wide-field Infrared Survey Explorer (WISE) is a satellite that was launched in 2010 into a polar orbit, enabling it to take images of the entire sky at four different mid-infrared wavelengths. These wavelengths cover the spectral region with the aforementioned PAH emission features in the mid-infrared. WISE archival data therefore makes it possible to construct a full-sky map of PAH emission.We present full sky maps using WISE data as a preliminary result towards creating a full sky PAH map.

  14. Testing the association between psychosocial job strain and adverse birth outcomes - design and methods

    Directory of Open Access Journals (Sweden)

    Thulstrup Ane M

    2011-04-01

    Full Text Available Abstract Background A number of studies have examined the effects of prenatal exposure to stress on birth outcomes but few have specifically focused on psychosocial job strain. In the present protocol, we aim to examine if work characterised by high demands and low control, during pregnancy, is associated with the risk of giving birth to a child born preterm or small for gestational age. Methods and design We will use the Danish National Birth Cohort where 100.000 children are included at baseline. In the present study 49,340 pregnancies will be included. Multinomial logistic regression will be applied to estimate odds ratios for the outcomes: preterm; full term but small for gestational age; full term but large for gestational age, as a function of job-strain (high strain, active and passive versus low strain. In the analysis we control for maternal age, Body Mass Index, parity, exercise, smoking, alcohol use, coffee consumption, type of work (manual versus non-manual, maternal serious disease and parents' heights as well as gestational age at interview. Discussion The prospective nature of the design and the high number of participants strengthen the study. The large statistical power allows for interpretable results regardless of whether or not the hypotheses are confirmed. This is, however, not a controlled study since all kinds of 'natural' interventions takes place throughout pregnancy (e.g. work absence, medical treatment and job-redesign. The analysis will be performed from a public health perspective. From this perspective, we are not primarily interested in the effect of job strain per se but if there is residual effect of job strain after naturally occurring preventive measures have been taken.

  15. BIMOND3, Monotone Bivariate Interpolation

    International Nuclear Information System (INIS)

    Fritsch, F.N.; Carlson, R.E.

    2001-01-01

    1 - Description of program or function: BIMOND is a FORTRAN-77 subroutine for piecewise bi-cubic interpolation to data on a rectangular mesh, which reproduces the monotonousness of the data. A driver program, BIMOND1, is provided which reads data, computes the interpolating surface parameters, and evaluates the function on a mesh suitable for plotting. 2 - Method of solution: Monotonic piecewise bi-cubic Hermite interpolation is used. 3 - Restrictions on the complexity of the problem: The current version of the program can treat data which are monotone in only one of the independent variables, but cannot handle piecewise monotone data

  16. Statistical Modeling of Bivariate Data.

    Science.gov (United States)

    1982-08-01

    to one. Following Crain (1974), one may consider order m approximators m log f111(X) - k k (x) - c(e), asx ;b. (4.4.5) k,-r A m and attempt to find...literature. Consider the approximate model m log fn (x) = 7 ekk(x) + a G(x), aSx ;b, (44.8) " k=-Mn ’ where G(x) is a Gaussian process and n is a

  17. Combining Multiple Hypothesis Testing with Machine Learning Increases the Statistical Power of Genome-wide Association Studies

    Science.gov (United States)

    Mieth, Bettina; Kloft, Marius; Rodríguez, Juan Antonio; Sonnenburg, Sören; Vobruba, Robin; Morcillo-Suárez, Carlos; Farré, Xavier; Marigorta, Urko M.; Fehr, Ernst; Dickhaus, Thorsten; Blanchard, Gilles; Schunk, Daniel; Navarro, Arcadi; Müller, Klaus-Robert

    2016-01-01

    The standard approach to the analysis of genome-wide association studies (GWAS) is based on testing each position in the genome individually for statistical significance of its association with the phenotype under investigation. To improve the analysis of GWAS, we propose a combination of machine learning and statistical testing that takes correlation structures within the set of SNPs under investigation in a mathematically well-controlled manner into account. The novel two-step algorithm, COMBI, first trains a support vector machine to determine a subset of candidate SNPs and then performs hypothesis tests for these SNPs together with an adequate threshold correction. Applying COMBI to data from a WTCCC study (2007) and measuring performance as replication by independent GWAS published within the 2008–2015 period, we show that our method outperforms ordinary raw p-value thresholding as well as other state-of-the-art methods. COMBI presents higher power and precision than the examined alternatives while yielding fewer false (i.e. non-replicated) and more true (i.e. replicated) discoveries when its results are validated on later GWAS studies. More than 80% of the discoveries made by COMBI upon WTCCC data have been validated by independent studies. Implementations of the COMBI method are available as a part of the GWASpi toolbox 2.0. PMID:27892471

  18. Raising the stakes: How students’ motivation for mathematics associates with high- and low-stakes test achievement☆

    Science.gov (United States)

    Simzar, Rahila M.; Martinez, Marcela; Rutherford, Teomara; Domina, Thurston; Conley, AnneMarie M.

    2016-01-01

    This study uses data from an urban school district to examine the relation between students’ motivational beliefs about mathematics and high- versus low-stakes math test performance. We use ordinary least squares and quantile regression analyses and find that the association between students’ motivation and test performance differs based on the stakes of the exam. Students’ math self-efficacy and performance avoidance goal orientation were the strongest predictors for both exams; however, students’ math self-efficacy was more strongly related to achievement on the low-stakes exam. Students’ motivational beliefs had a stronger association at the low-stakes exam proficiency cutoff than they did at the high-stakes passing cutoff. Lastly, the negative association between performance avoidance goals and high-stakes performance showed a decreasing trend across the achievement distribution, suggesting that performance avoidance goals are more detrimental for lower achieving students. These findings help parse out the ways motivation influences achievement under different stakes. PMID:27840563

  19. A decade of studying implicit racial/ethnic bias in healthcare providers using the implicit association test.

    Science.gov (United States)

    Maina, Ivy W; Belton, Tanisha D; Ginzberg, Sara; Singh, Ajit; Johnson, Tiffani J

    2018-02-01

    Disparities in the care and outcomes of US racial/ethnic minorities are well documented. Research suggests that provider bias plays a role in these disparities. The implicit association test enables measurement of implicit bias via tests of automatic associations between concepts. Hundreds of studies have examined implicit bias in various settings, but relatively few have been conducted in healthcare. The aim of this systematic review is to synthesize the current knowledge on the role of implicit bias in healthcare disparities. A comprehensive literature search of several databases between May 2015 and September 2016 identified 37 qualifying studies. Of these, 31 found evidence of pro-White or light-skin/anti-Black, Hispanic, American Indian or dark-skin bias among a variety of HCPs across multiple levels of training and disciplines. Fourteen studies examined the association between implicit bias and healthcare outcomes using clinical vignettes or simulated patients. Eight found no statistically significant association between implicit bias and patient care while six studies found that higher implicit bias was associated with disparities in treatment recommendations, expectations of therapeutic bonds, pain management, and empathy. All seven studies that examined the impact of implicit provider bias on real-world patient-provider interaction found that providers with stronger implicit bias demonstrated poorer patient-provider communication. Two studies examined the effect of implicit bias on real-world clinical outcomes. One found an association and the other did not. Two studies tested interventions aimed at reducing bias, but only one found a post-intervention reduction in implicit bias. This review reveals a need for more research exploring implicit bias in real-world patient care, potential modifiers and confounders of the effect of implicit bias on care, and strategies aimed at reducing implicit bias and improving patient-provider communication. Future studies

  20. Modelling the vicious circle between obesity and physical activity in children and adolescents using a bivariate probit model with endogenous regressors.

    Science.gov (United States)

    Yeh, C-Y; Chen, L-J; Ku, P-W; Chen, C-M

    2015-01-01

    The increasing prevalence of obesity in children and adolescents has become one of the most important public health issues around the world. Lack of physical activity is a risk factor for obesity, while being obese could reduce the likelihood of participating in physical activity. Failing to account for the endogeneity between obesity and physical activity would result in biased estimation. This study investigates the relationship between overweight and physical activity by taking endogeneity into consideration. It develops an endogenous bivariate probit model estimated by the maximum likelihood method. The data included 4008 boys and 4197 girls in the 5th-9th grades in Taiwan in 2007-2008. The relationship between overweight and physical activity is significantly negative in the endogenous model, but insignificant in the comparative exogenous model. This endogenous relationship presents a vicious circle in which lower levels of physical activity lead to overweight, while those who are already overweight engage in less physical activity. The results not only reveal the importance of endogenous treatment, but also demonstrate the robust negative relationship between these two factors. An emphasis should be put on overweight and obese children and adolescents in order to break the vicious circle. Promotion of physical activity by appropriate counselling programmes and peer support could be effective in reducing the prevalence of obesity in children and adolescents.