Sample records for wald chi-square tests

  1. The chi-square test of independence.

    PubMed

    McHugh, Mary L

    2013-01-01

    The Chi-square statistic is a non-parametric (distribution free) tool designed to analyze group differences when the dependent variable is measured at a nominal level. Like all non-parametric statistics, the Chi-square is robust with respect to the distribution of the data. Specifically, it does not require equality of variances among the study groups or homoscedasticity in the data. It permits evaluation of both dichotomous independent variables, and of multiple group studies. Unlike many other non-parametric and some parametric statistics, the calculations needed to compute the Chi-square provide considerable information about how each of the groups performed in the study. This richness of detail allows the researcher to understand the results and thus to derive more detailed information from this statistic than from many others. The Chi-square is a significance statistic, and should be followed with a strength statistic. The Cramer's V is the most common strength test used to test the data when a significant Chi-square result has been obtained. Advantages of the Chi-square include its robustness with respect to distribution of the data, its ease of computation, the detailed information that can be derived from the test, its use in studies for which parametric assumptions cannot be met, and its flexibility in handling data from both two group and multiple group studies. Limitations include its sample size requirements, difficulty of interpretation when there are large numbers of categories (20 or more) in the independent or dependent variables, and tendency of the Cramer's V to produce relative low correlation measures, even for highly significant results.

  2. Your Chi-Square Test Is Statistically Significant: Now What?

    ERIC Educational Resources Information Center

    Sharpe, Donald

    2015-01-01

    Applied researchers have employed chi-square tests for more than one hundred years. This paper addresses the question of how one should follow a statistically significant chi-square test result in order to determine the source of that result. Four approaches were evaluated: calculating residuals, comparing cells, ransacking, and partitioning. Data…

  3. How-To-Do-It: Snails, Pill Bugs, Mealworms, and Chi-Square? Using Invertebrate Behavior to Illustrate Hypothesis Testing with Chi-Square.

    ERIC Educational Resources Information Center

    Biermann, Carol

    1988-01-01

    Described is a study designed to introduce students to the behavior of common invertebrate animals, and to use of the chi-square statistical technique. Discusses activities with snails, pill bugs, and mealworms. Provides an abbreviated chi-square table and instructions for performing the experiments and statistical tests. (CW)

  4. Reconnaissance On Chi-Square Test Procedure For Determining Two Species Association

    NASA Astrophysics Data System (ADS)

    Marisa, Hanifa

    2008-01-01

    Determining the assosiation of two species by using chi-square test has been published. Utility of this procedure to plants species at certain location, shows that the procedure could not find "ecologically" association. Tens sampling units have been made to record some weeds species in Indralaya, South Sumatera. Chi square test; Xt2 = N[|(ad)-(bc)|-(N/2)]2/mnrs (Eq:1) on two species (Cleome sp and Eleusine indica) of the weeds shows positive assosiation; while ecologically in nature, there is no relationship between them. Some alternatives are proposed to this problem; simplified chi-square test steps, make further study to find out ecologically association, or at last, ignore it.

  5. A Graphic Chi-Square Test For Two-Class Genetic Segregation Ratios

    Treesearch

    A.E. Squillace; D.J. Squillace

    1970-01-01

    A chart is presented for testing the goodness of fit of observed two-class genetic segregation ratios against hypothetical ratios, eliminating the need of computing chi-square. Although designed mainly for genetic studies, the chart can also be used for other types of studies involving two-class chi-square tests.

  6. Chi-Squared Test of Fit and Sample Size-A Comparison between a Random Sample Approach and a Chi-Square Value Adjustment Method.

    PubMed

    Bergh, Daniel

    2015-01-01

    Chi-square statistics are commonly used for tests of fit of measurement models. Chi-square is also sensitive to sample size, which is why several approaches to handle large samples in test of fit analysis have been developed. One strategy to handle the sample size problem may be to adjust the sample size in the analysis of fit. An alternative is to adopt a random sample approach. The purpose of this study was to analyze and to compare these two strategies using simulated data. Given an original sample size of 21,000, for reductions of sample sizes down to the order of 5,000 the adjusted sample size function works as good as the random sample approach. In contrast, when applying adjustments to sample sizes of lower order the adjustment function is less effective at approximating the chi-square value for an actual random sample of the relevant size. Hence, the fit is exaggerated and misfit under-estimated using the adjusted sample size function. Although there are big differences in chi-square values between the two approaches at lower sample sizes, the inferences based on the p-values may be the same.

  7. Principles and Practice of Scaled Difference Chi-Square Testing

    ERIC Educational Resources Information Center

    Bryant, Fred B.; Satorra, Albert

    2012-01-01

    We highlight critical conceptual and statistical issues and how to resolve them in conducting Satorra-Bentler (SB) scaled difference chi-square tests. Concerning the original (Satorra & Bentler, 2001) and new (Satorra & Bentler, 2010) scaled difference tests, a fundamental difference exists in how to compute properly a model's scaling correction…

  8. The Chi-Square Test: Often Used and More Often Misinterpreted

    ERIC Educational Resources Information Center

    Franke, Todd Michael; Ho, Timothy; Christie, Christina A.

    2012-01-01

    The examination of cross-classified category data is common in evaluation and research, with Karl Pearson's family of chi-square tests representing one of the most utilized statistical analyses for answering questions about the association or difference between categorical variables. Unfortunately, these tests are also among the more commonly…

  9. Measurement invariance via multigroup SEM: Issues and solutions with chi-square-difference tests.

    PubMed

    Yuan, Ke-Hai; Chan, Wai

    2016-09-01

    Multigroup structural equation modeling (SEM) plays a key role in studying measurement invariance and in group comparison. When population covariance matrices are deemed not equal across groups, the next step to substantiate measurement invariance is to see whether the sample covariance matrices in all the groups can be adequately fitted by the same factor model, called configural invariance. After configural invariance is established, cross-group equalities of factor loadings, error variances, and factor variances-covariances are then examined in sequence. With mean structures, cross-group equalities of intercepts and factor means are also examined. The established rule is that if the statistic at the current model is not significant at the level of .05, one then moves on to testing the next more restricted model using a chi-square-difference statistic. This article argues that such an established rule is unable to control either Type I or Type II errors. Analysis, an example, and Monte Carlo results show why and how chi-square-difference tests are easily misused. The fundamental issue is that chi-square-difference tests are developed under the assumption that the base model is sufficiently close to the population, and a nonsignificant chi-square statistic tells little about how good the model is. To overcome this issue, this article further proposes that null hypothesis testing in multigroup SEM be replaced by equivalence testing, which allows researchers to effectively control the size of misspecification before moving on to testing a more restricted model. R code is also provided to facilitate the applications of equivalence testing for multigroup SEM. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  10. A revisit to contingency table and tests of independence: bootstrap is preferred to Chi-square approximations as well as Fisher's exact test.

    PubMed

    Lin, Jyh-Jiuan; Chang, Ching-Hui; Pal, Nabendu

    2015-01-01

    To test the mutual independence of two qualitative variables (or attributes), it is a common practice to follow the Chi-square tests (Pearson's as well as likelihood ratio test) based on data in the form of a contingency table. However, it should be noted that these popular Chi-square tests are asymptotic in nature and are useful when the cell frequencies are "not too small." In this article, we explore the accuracy of the Chi-square tests through an extensive simulation study and then propose their bootstrap versions that appear to work better than the asymptotic Chi-square tests. The bootstrap tests are useful even for small-cell frequencies as they maintain the nominal level quite accurately. Also, the proposed bootstrap tests are more convenient than the Fisher's exact test which is often criticized for being too conservative. Finally, all test methods are applied to a few real-life datasets for demonstration purposes.

  11. False star detection and isolation during star tracking based on improved chi-square tests.

    PubMed

    Zhang, Hao; Niu, Yanxiong; Lu, Jiazhen; Yang, Yanqiang; Su, Guohua

    2017-08-01

    The star sensor is a precise attitude measurement device for a spacecraft. Star tracking is the main and key working mode for a star sensor. However, during star tracking, false stars become an inevitable interference for star sensor applications, which may result in declined measurement accuracy. A false star detection and isolation algorithm in star tracking based on improved chi-square tests is proposed in this paper. Two estimations are established based on a Kalman filter and a priori information, respectively. The false star detection is operated through adopting the global state chi-square test in a Kalman filter. The false star isolation is achieved using a local state chi-square test. Semi-physical experiments under different trajectories with various false stars are designed for verification. Experiment results show that various false stars can be detected and isolated from navigation stars during star tracking, and the attitude measurement accuracy is hardly influenced by false stars. The proposed algorithm is proved to have an excellent performance in terms of speed, stability, and robustness.

  12. Calibration of Self-Efficacy for Conducting a Chi-Squared Test of Independence

    ERIC Educational Resources Information Center

    Zimmerman, Whitney Alicia; Goins, Deborah D.

    2015-01-01

    Self-efficacy and knowledge, both concerning the chi-squared test of independence, were examined in education graduate students. Participants rated statements concerning self-efficacy and completed a related knowledge assessment. After completing a demographic survey, participants completed the self-efficacy and knowledge scales a second time.…

  13. Ensuring Positiveness of the Scaled Difference Chi-square Test Statistic.

    PubMed

    Satorra, Albert; Bentler, Peter M

    2010-06-01

    A scaled difference test statistic [Formula: see text] that can be computed from standard software of structural equation models (SEM) by hand calculations was proposed in Satorra and Bentler (2001). The statistic [Formula: see text] is asymptotically equivalent to the scaled difference test statistic T̄(d) introduced in Satorra (2000), which requires more involved computations beyond standard output of SEM software. The test statistic [Formula: see text] has been widely used in practice, but in some applications it is negative due to negativity of its associated scaling correction. Using the implicit function theorem, this note develops an improved scaling correction leading to a new scaled difference statistic T̄(d) that avoids negative chi-square values.

  14. Risk analysis in cohort studies with heterogeneous strata. A global chi2-test for dose-response relationship, generalizing the Mantel-Haenszel procedure.

    PubMed

    Ahlborn, W; Tuz, H J; Uberla, K

    1990-03-01

    In cohort studies the Mantel-Haenszel estimator ORMH is computed from sample data and is used as a point estimator of relative risk. Test-based confidence intervals are estimated with the help of the asymptotic chi-squared distributed MH-statistic chi 2MHS. The Mantel-extension-chi-squared is used as a test statistic for a dose-response relationship. Both test statistics--the Mantel-Haenszel-chi as well as the Mantel-extension-chi--assume homogeneity of risk across strata, which is rarely present. Also an extended nonparametric statistic, proposed by Terpstra, which is based on the Mann-Whitney-statistics assumes homogeneity of risk across strata. We have earlier defined four risk measures RRkj (k = 1,2,...,4) in the population and considered their estimates and the corresponding asymptotic distributions. In order to overcome the homogeneity assumption we use the delta-method to get "test-based" confidence intervals. Because the four risk measures RRkj are presented as functions of four weights gik we give, consequently, the asymptotic variances of these risk estimators also as functions of the weights gik in a closed form. Approximations to these variances are given. For testing a dose-response relationship we propose a new class of chi 2(1)-distributed global measures Gk and the corresponding global chi 2-test. In contrast to the Mantel-extension-chi homogeneity of risk across strata must not be assumed. These global test statistics are of the Wald type for composite hypotheses.(ABSTRACT TRUNCATED AT 250 WORDS)

  15. F-Test Alternatives to Fisher's Exact Test and to the Chi-Square Test of Homogeneity in 2x2 Tables.

    ERIC Educational Resources Information Center

    Overall, John E.; Starbuck, Robert R.

    1983-01-01

    An alternative to Fisher's exact test and the chi-square test for homogeneity in two-by-two tables is developed. The method provides for Type I error rates which are closer to the stated alpha level than either of the alternatives. (JKS)

  16. On Insensitivity of the Chi-Square Model Test to Nonlinear Misspecification in Structural Equation Models

    ERIC Educational Resources Information Center

    Mooijaart, Ab; Satorra, Albert

    2009-01-01

    In this paper, we show that for some structural equation models (SEM), the classical chi-square goodness-of-fit test is unable to detect the presence of nonlinear terms in the model. As an example, we consider a regression model with latent variables and interactions terms. Not only the model test has zero power against that type of…

  17. Filter Tuning Using the Chi-Squared Statistic

    NASA Technical Reports Server (NTRS)

    Lilly-Salkowski, Tyler B.

    2017-01-01

    This paper examines the use of the Chi-square statistic as a means of evaluating filter performance. The goal of the process is to characterize the filter performance in the metric of covariance realism. The Chi-squared statistic is the value calculated to determine the realism of a covariance based on the prediction accuracy and the covariance values at a given point in time. Once calculated, it is the distribution of this statistic that provides insight on the accuracy of the covariance. The process of tuning an Extended Kalman Filter (EKF) for Aqua and Aura support is described, including examination of the measurement errors of available observation types, and methods of dealing with potentially volatile atmospheric drag modeling. Predictive accuracy and the distribution of the Chi-squared statistic, calculated from EKF solutions, are assessed.

  18. Pearson's chi-square test and rank correlation inferences for clustered data.

    PubMed

    Shih, Joanna H; Fay, Michael P

    2017-09-01

    Pearson's chi-square test has been widely used in testing for association between two categorical responses. Spearman rank correlation and Kendall's tau are often used for measuring and testing association between two continuous or ordered categorical responses. However, the established statistical properties of these tests are only valid when each pair of responses are independent, where each sampling unit has only one pair of responses. When each sampling unit consists of a cluster of paired responses, the assumption of independent pairs is violated. In this article, we apply the within-cluster resampling technique to U-statistics to form new tests and rank-based correlation estimators for possibly tied clustered data. We develop large sample properties of the new proposed tests and estimators and evaluate their performance by simulations. The proposed methods are applied to a data set collected from a PET/CT imaging study for illustration. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

  19. In Defense of the Chi-Square Continuity Correction.

    ERIC Educational Resources Information Center

    Veldman, Donald J.; McNemar, Quinn

    Published studies of the sampling distribution of chi-square with and without Yates' correction for continuity have been interpreted as discrediting the correction. Yates' correction actually produces a biased chi-square value which in turn yields a better estimate of the exact probability of the discrete event concerned when used in conjunction…

  20. Normal versus Noncentral Chi-Square Asymptotics of Misspecified Models

    ERIC Educational Resources Information Center

    Chun, So Yeon; Shapiro, Alexander

    2009-01-01

    The noncentral chi-square approximation of the distribution of the likelihood ratio (LR) test statistic is a critical part of the methodology in structural equation modeling. Recently, it was argued by some authors that in certain situations normal distributions may give a better approximation of the distribution of the LR test statistic. The main…

  1. A Comparison of Lord's Chi Square and Raju's Area Measures in Detection of DIF.

    ERIC Educational Resources Information Center

    Cohen, Allan S.; Kim, Seock-Ho

    1993-01-01

    The effectiveness of two statistical tests of the area between item response functions (exact signed area and exact unsigned area) estimated in different samples, a measure of differential item functioning (DIF), was compared with Lord's chi square. Lord's chi square was found the most effective in determining DIF. (SLD)

  2. A Monte Carlo Study of an Iterative Wald Test Procedure for DIF Analysis

    ERIC Educational Resources Information Center

    Cao, Mengyang; Tay, Louis; Liu, Yaowu

    2017-01-01

    This study examined the performance of a proposed iterative Wald approach for detecting differential item functioning (DIF) between two groups when preknowledge of anchor items is absent. The iterative approach utilizes the Wald-2 approach to identify anchor items and then iteratively tests for DIF items with the Wald-1 approach. Monte Carlo…

  3. An Extension of the Chi-Square Procedure for Non-NORMAL Statistics, with Application to Solar Neutrino Data

    NASA Astrophysics Data System (ADS)

    Sturrock, P. A.

    2008-01-01

    Using the chi-square statistic, one may conveniently test whether a series of measurements of a variable are consistent with a constant value. However, that test is predicated on the assumption that the appropriate probability distribution function (pdf) is normal in form. This requirement is usually not satisfied by experimental measurements of the solar neutrino flux. This article presents an extension of the chi-square procedure that is valid for any form of the pdf. This procedure is applied to the GALLEX-GNO dataset, and it is shown that the results are in good agreement with the results of Monte Carlo simulations. Whereas application of the standard chi-square test to symmetrized data yields evidence significant at the 1% level for variability of the solar neutrino flux, application of the extended chi-square test to the unsymmetrized data yields only weak evidence (significant at the 4% level) of variability.

  4. Chi-square-based scoring function for categorization of MEDLINE citations.

    PubMed

    Kastrin, A; Peterlin, B; Hristovski, D

    2010-01-01

    Text categorization has been used in biomedical informatics for identifying documents containing relevant topics of interest. We developed a simple method that uses a chi-square-based scoring function to determine the likelihood of MEDLINE citations containing genetic relevant topic. Our procedure requires construction of a genetic and a nongenetic domain document corpus. We used MeSH descriptors assigned to MEDLINE citations for this categorization task. We compared frequencies of MeSH descriptors between two corpora applying chi-square test. A MeSH descriptor was considered to be a positive indicator if its relative observed frequency in the genetic domain corpus was greater than its relative observed frequency in the nongenetic domain corpus. The output of the proposed method is a list of scores for all the citations, with the highest score given to those citations containing MeSH descriptors typical for the genetic domain. Validation was done on a set of 734 manually annotated MEDLINE citations. It achieved predictive accuracy of 0.87 with 0.69 recall and 0.64 precision. We evaluated the method by comparing it to three machine-learning algorithms (support vector machines, decision trees, naïve Bayes). Although the differences were not statistically significantly different, results showed that our chi-square scoring performs as good as compared machine-learning algorithms. We suggest that the chi-square scoring is an effective solution to help categorize MEDLINE citations. The algorithm is implemented in the BITOLA literature-based discovery support system as a preprocessor for gene symbol disambiguation process.

  5. Wald Sequential Probability Ratio Test for Analysis of Orbital Conjunction Data

    NASA Technical Reports Server (NTRS)

    Carpenter, J. Russell; Markley, F. Landis; Gold, Dara

    2013-01-01

    We propose a Wald Sequential Probability Ratio Test for analysis of commonly available predictions associated with spacecraft conjunctions. Such predictions generally consist of a relative state and relative state error covariance at the time of closest approach, under the assumption that prediction errors are Gaussian. We show that under these circumstances, the likelihood ratio of the Wald test reduces to an especially simple form, involving the current best estimate of collision probability, and a similar estimate of collision probability that is based on prior assumptions about the likelihood of collision.

  6. Chi-square analysis of the reduction of ATP levels in L-02 hepatocytes by hexavalent chromium.

    PubMed

    Yuan, Yang; Peng, Li; Gong-Hua, Hu; Lu, Dai; Xia-Li, Zhong; Yu, Zhou; Cai-Gao, Zhong

    2012-06-01

    This study explored the reduction of adenosine triphosphate (ATP) levels in L-02 hepatocytes by hexavalent chromium (Cr(VI)) using chi-square analysis. Cells were treated with 2, 4, 8, 16, or 32 μM Cr(VI) for 12, 24, or 36 h. Methyl thiazolyl tetrazolium (MTT) experiments and measurements of intracellular ATP levels were performed by spectrophotometry or bioluminescence assays following Cr(VI) treatment. The chi-square test was used to determine the difference between cell survival rate and ATP levels. For the chi-square analysis, the results of the MTT or ATP experiments were transformed into a relative ratio with respect to the control (%). The relative ATP levels increased at 12 h, decreased at 24 h, and increased slightly again at 36 h following 4, 8, 16, 32 μM Cr(VI) treatment, corresponding to a "V-shaped" curve. Furthermore, the results of the chi-square analysis demonstrated a significant difference of the ATP level in the 32-μM Cr(VI) group (P < 0.05). The results suggest that the chi-square test can be applied to analyze the interference effects of Cr(VI) on ATP levels in L-02 hepatocytes. The decreased ATP levels at 24 h indicated disruption of mitochondrial energy metabolism and the slight increase of ATP levels at 36 h indicated partial recovery of mitochondrial function or activated glycolysis in L-02 hepatocytes.

  7. On the appropriateness of applying chi-square distribution based confidence intervals to spectral estimates of helicopter flyover data

    NASA Technical Reports Server (NTRS)

    Rutledge, Charles K.

    1988-01-01

    The validity of applying chi-square based confidence intervals to far-field acoustic flyover spectral estimates was investigated. Simulated data, using a Kendall series and experimental acoustic data from the NASA/McDonnell Douglas 500E acoustics test, were analyzed. Statistical significance tests to determine the equality of distributions of the simulated and experimental data relative to theoretical chi-square distributions were performed. Bias and uncertainty errors associated with the spectral estimates were easily identified from the data sets. A model relating the uncertainty and bias errors to the estimates resulted, which aided in determining the appropriateness of the chi-square distribution based confidence intervals. Such confidence intervals were appropriate for nontonally associated frequencies of the experimental data but were inappropriate for tonally associated estimate distributions. The appropriateness at the tonally associated frequencies was indicated by the presence of bias error and noncomformity of the distributions to the theoretical chi-square distribution. A technique for determining appropriate confidence intervals at the tonally associated frequencies was suggested.

  8. Use of Pearson's Chi-Square for Testing Equality of Percentile Profiles across Multiple Populations.

    PubMed

    Johnson, William D; Beyl, Robbie A; Burton, Jeffrey H; Johnson, Callie M; Romer, Jacob E; Zhang, Lei

    2015-08-01

    In large sample studies where distributions may be skewed and not readily transformed to symmetry, it may be of greater interest to compare different distributions in terms of percentiles rather than means. For example, it may be more informative to compare two or more populations with respect to their within population distributions by testing the hypothesis that their corresponding respective 10 th , 50 th , and 90 th percentiles are equal. As a generalization of the median test, the proposed test statistic is asymptotically distributed as Chi-square with degrees of freedom dependent upon the number of percentiles tested and constraints of the null hypothesis. Results from simulation studies are used to validate the nominal 0.05 significance level under the null hypothesis, and asymptotic power properties that are suitable for testing equality of percentile profiles against selected profile discrepancies for a variety of underlying distributions. A pragmatic example is provided to illustrate the comparison of the percentile profiles for four body mass index distributions.

  9. Double asymptotics for the chi-square statistic.

    PubMed

    Rempała, Grzegorz A; Wesołowski, Jacek

    2016-12-01

    Consider distributional limit of the Pearson chi-square statistic when the number of classes m n increases with the sample size n and [Formula: see text]. Under mild moment conditions, the limit is Gaussian for λ = ∞, Poisson for finite λ > 0, and degenerate for λ = 0.

  10. Performance of the S - [chi][squared] Statistic for Full-Information Bifactor Models

    ERIC Educational Resources Information Center

    Li, Ying; Rupp, Andre A.

    2011-01-01

    This study investigated the Type I error rate and power of the multivariate extension of the S - [chi][squared] statistic using unidimensional and multidimensional item response theory (UIRT and MIRT, respectively) models as well as full-information bifactor (FI-bifactor) models through simulation. Manipulated factors included test length, sample…

  11. Testing for independence in J×K contingency tables with complex sample survey data.

    PubMed

    Lipsitz, Stuart R; Fitzmaurice, Garrett M; Sinha, Debajyoti; Hevelone, Nathanael; Giovannucci, Edward; Hu, Jim C

    2015-09-01

    The test of independence of row and column variables in a (J×K) contingency table is a widely used statistical test in many areas of application. For complex survey samples, use of the standard Pearson chi-squared test is inappropriate due to correlation among units within the same cluster. Rao and Scott (1981, Journal of the American Statistical Association 76, 221-230) proposed an approach in which the standard Pearson chi-squared statistic is multiplied by a design effect to adjust for the complex survey design. Unfortunately, this test fails to exist when one of the observed cell counts equals zero. Even with the large samples typical of many complex surveys, zero cell counts can occur for rare events, small domains, or contingency tables with a large number of cells. Here, we propose Wald and score test statistics for independence based on weighted least squares estimating equations. In contrast to the Rao-Scott test statistic, the proposed Wald and score test statistics always exist. In simulations, the score test is found to perform best with respect to type I error. The proposed method is motivated by, and applied to, post surgical complications data from the United States' Nationwide Inpatient Sample (NIS) complex survey of hospitals in 2008. © 2015, The International Biometric Society.

  12. A Theorem on the Rank of a Product of Matrices with Illustration of Its Use in Goodness of Fit Testing.

    PubMed

    Satorra, Albert; Neudecker, Heinz

    2015-12-01

    This paper develops a theorem that facilitates computing the degrees of freedom of Wald-type chi-square tests for moment restrictions when there is rank deficiency of key matrices involved in the definition of the test. An if and only if (iff) condition is developed for a simple rule of difference of ranks to be used when computing the desired degrees of freedom of the test. The theorem is developed exploiting basics tools of matrix algebra. The theorem is shown to play a key role in proving the asymptotic chi-squaredness of a goodness of fit test in moment structure analysis, and in finding the degrees of freedom of this chi-square statistic.

  13. Evaluating the Wald Test for Item-Level Comparison of Saturated and Reduced Models in Cognitive Diagnosis

    ERIC Educational Resources Information Center

    de la Torre, Jimmy; Lee, Young-Sun

    2013-01-01

    This article used the Wald test to evaluate the item-level fit of a saturated cognitive diagnosis model (CDM) relative to the fits of the reduced models it subsumes. A simulation study was carried out to examine the Type I error and power of the Wald test in the context of the G-DINA model. Results show that when the sample size is small and a…

  14. Chi-squared and C statistic minimization for low count per bin data

    NASA Astrophysics Data System (ADS)

    Nousek, John A.; Shue, David R.

    1989-07-01

    Results are presented from a computer simulation comparing two statistical fitting techniques on data samples with large and small counts per bin; the results are then related specifically to X-ray astronomy. The Marquardt and Powell minimization techniques are compared by using both to minimize the chi-squared statistic. In addition, Cash's C statistic is applied, with Powell's method, and it is shown that the C statistic produces better fits in the low-count regime than chi-squared.

  15. Lord's Wald Test for Detecting Dif in Multidimensional Irt Models: A Comparison of Two Estimation Approaches

    ERIC Educational Resources Information Center

    Lee, Soo; Suh, Youngsuk

    2018-01-01

    Lord's Wald test for differential item functioning (DIF) has not been studied extensively in the context of the multidimensional item response theory (MIRT) framework. In this article, Lord's Wald test was implemented using two estimation approaches, marginal maximum likelihood estimation and Bayesian Markov chain Monte Carlo estimation, to detect…

  16. Pre-Deployment Stress, Mental Health, and Help-Seeking Behaviors Among Marines

    DTIC Science & Technology

    2014-01-01

    associations between two categori- cal variables, and Wald tests were conducted to compare mean scores on continuous variables across groups (e.g...Cluster- adjusted wald tests were conducted to determine whether there were significant differences by rank on the average number of potentially...deployed to Iraq or Afghanistan in 2010 or 2011 of rank O6 or lower. a Omnibus rao-Scott chi-square test or adjusted wald test is statistically

  17. Genome-Wide Analysis of Gene-Gene and Gene-Environment Interactions Using Closed-Form Wald Tests.

    PubMed

    Yu, Zhaoxia; Demetriou, Michael; Gillen, Daniel L

    2015-09-01

    Despite the successful discovery of hundreds of variants for complex human traits using genome-wide association studies, the degree to which genes and environmental risk factors jointly affect disease risk is largely unknown. One obstacle toward this goal is that the computational effort required for testing gene-gene and gene-environment interactions is enormous. As a result, numerous computationally efficient tests were recently proposed. However, the validity of these methods often relies on unrealistic assumptions such as additive main effects, main effects at only one variable, no linkage disequilibrium between the two single-nucleotide polymorphisms (SNPs) in a pair or gene-environment independence. Here, we derive closed-form and consistent estimates for interaction parameters and propose to use Wald tests for testing interactions. The Wald tests are asymptotically equivalent to the likelihood ratio tests (LRTs), largely considered to be the gold standard tests but generally too computationally demanding for genome-wide interaction analysis. Simulation studies show that the proposed Wald tests have very similar performances with the LRTs but are much more computationally efficient. Applying the proposed tests to a genome-wide study of multiple sclerosis, we identify interactions within the major histocompatibility complex region. In this application, we find that (1) focusing on pairs where both SNPs are marginally significant leads to more significant interactions when compared to focusing on pairs where at least one SNP is marginally significant; and (2) parsimonious parameterization of interaction effects might decrease, rather than increase, statistical power. © 2015 WILEY PERIODICALS, INC.

  18. Filter Tuning Using the Chi-Squared Statistic

    NASA Technical Reports Server (NTRS)

    Lilly-Salkowski, Tyler

    2017-01-01

    The Goddard Space Flight Center (GSFC) Flight Dynamics Facility (FDF) performs orbit determination (OD) for the Aqua and Aura satellites. Both satellites are located in low Earth orbit (LEO), and are part of what is considered the A-Train satellite constellation. Both spacecraft are currently in the science phase of their respective missions. The FDF has recently been tasked with delivering definitive covariance for each satellite.The main source of orbit determination used for these missions is the Orbit Determination Toolkit developed by Analytical Graphics Inc. (AGI). This software uses an Extended Kalman Filter (EKF) to estimate the states of both spacecraft. The filter incorporates force modelling, ground station and space network measurements to determine spacecraft states. It also generates a covariance at each measurement. This covariance can be useful for evaluating the overall performance of the tracking data measurements and the filter itself. An accurate covariance is also useful for covariance propagation which is utilized in collision avoidance operations. It is also valuable when attempting to determine if the current orbital solution will meet mission requirements in the future.This paper examines the use of the Chi-square statistic as a means of evaluating filter performance. The Chi-square statistic is calculated to determine the realism of a covariance based on the prediction accuracy and the covariance values at a given point in time. Once calculated, it is the distribution of this statistic that provides insight on the accuracy of the covariance.For the EKF to correctly calculate the covariance, error models associated with tracking data measurements must be accurately tuned. Over estimating or under estimating these error values can have detrimental effects on the overall filter performance. The filter incorporates ground station measurements, which can be tuned based on the accuracy of the individual ground stations. It also includes

  19. Measurement of sigma chi c2 B(chi c2-->J/psi gamma)/sigma chi c1 B(chi c1 -->J/psi gamma) in pp collisions at square root s=1.96 TeV.

    PubMed

    Abulencia, A; Adelman, J; Affolder, T; Akimoto, T; Albrow, M G; Ambrose, D; Amerio, S; Amidei, D; Anastassov, A; Anikeev, K; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Arguin, J-F; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Bedeschi, F; Behari, S; Belforte, S; Bellettini, G; Bellinger, J; Belloni, A; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bolshov, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Budroni, S; Burkett, K; Busetto, G; Bussey, P; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carillo, S; Carlsmith, D; Carosi, R; Carron, S; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, I; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Ciljak, M; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Coca, M; Compostella, G; Convery, M E; Conway, J; Cooper, B; Copic, K; Cordelli, M; Cortiana, G; Crescioli, F; Cuenca Almenar, C; Cuevas, J; Culbertson, R; Cully, J C; Cyr, D; DaRonco, S; Datta, M; D'Auria, S; Davies, T; D'Onofrio, M; Dagenhart, D; de Barbaro, P; De Cecco, S; Deisher, A; De Lentdecker, G; Dell'Orso, M; Delli Paoli, F; Demortier, L; Deng, J; Deninno, M; De Pedis, D; Derwent, P F; Di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; DiTuro, P; Dörr, C; Donati, S; Donega, M; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, I; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Field, R; Flanagan, G; Foland, A; Forrester, S; Foster, G W; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garcia, J E; Garberson, F; Garfinkel, A F; Gay, C; Gerberich, H; Gerdes, D; Giagu, S; Giannetti, P; Gibson, A; Gibson, K; Gimmell, J L; Ginsburg, C; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Goldstein, J; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Griffiths, M; Grinstein, S; Grosso-Pilcher, C; Group, R C; Grundler, U; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Hamilton, A; Han, B-Y; Han, J Y; Handler, R; Happacher, F; Hara, K; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hauser, J; Heijboer, A; Heinemann, B; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Holloway, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ishizawa, Y; Ivanov, A; Iyutin, B; James, E; Jang, D; Jayatilaka, B; Jeans, D; Jensen, H; Jeon, E J; Jindariani, S; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Karchin, P E; Kato, Y; Kemp, Y; Kephart, R; Kerzel, U; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kovalev, A; Kraan, A C; Kraus, J; Kravchenko, I; Kreps, M; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhlmann, S E; Kuhr, T; Kusakabe, Y; Kwang, S; Laasanen, A T; Lai, S; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; LeCompte, T; Lee, J; Lee, J; Lee, Y J; Lee, S W; Lefèvre, R; Leonardo, N; Leone, S; Levy, S; Lewis, J D; Lin, C; Lin, C S; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Loverre, P; Lu, R-S; Lucchesi, D; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Lytken, E; Mack, P; MacQueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Manca, G; Margaroli, F; Marginean, R; Marino, C; Marino, C P; Martin, A; Martin, M; Martin, V; Martínez, M; Maruyama, T; Mastrandrea, P; Masubuchi, T; Matsunaga, H; Mattson, M E; Mazini, R; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; Miao, T; Miladinovic, N; Miles, J; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyamoto, A; Moed, S; Moggi, N; Mohr, B; Moore, R; Morello, M; Movilla Fernandez, P; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Nachtman, J; Nagano, A; Naganoma, J; Nakano, I; Napier, A; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nigmanov, T; Nodulman, L; Norniella, O; Nurse, E; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Oldeman, R; Orava, R; Osterberg, K; Pagliarone, C; Palencia, E; Papadimitriou, V; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Piedra, J; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Portell, X; Poukhov, O; Pounder, N; Prakoshyn, F; Pronko, A; Proudfoot, J; Ptohos, F; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Ranjan, N; Rappoccio, S; Reisert, B; Rekovic, V; Renton, P; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Ruiz, A; Russ, J; Rusu, V; Saarikko, H; Sabik, S; Safonov, A; Sakumoto, W K; Salamanna, G; Saltó, O; Saltzberg, D; Sánchez, C; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savard, P; Savoy-Navarro, A; Scheidle, T; Schlabach, P; Schmidt, E E; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scott, A L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sfyrla, A; Shapiro, M D; Shears, T; Shepard, P F; Sherman, D; Shimojima, M; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakyan, A; Sjolin, J; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soderberg, M; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spinella, F; Spreitzer, T; Squillacioti, P; Stanitzki, M; Staveris-Polykalas, A; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Stuart, D; Suh, J S; Sukhanov, A; Sun, H; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Takikawa, K; Tanaka, M; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Thom, J; Thompson, A S; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Tourneur, S; Trischuk, W; Tsuchiya, R; Tsuno, S; Turini, N; Ukegawa, F; Unverhau, T; Uozumi, S; Usynin, D; Vallecorsa, S; van Remortel, N; Varganov, A; Vataga, E; Vázquez, F; Velev, G; Veramendi, G; Veszpremi, V; Vidal, R; Vila, I; Vilar, R; Vine, T; Vollrath, I; Volobouev, I; Volpi, G; Würthwein, F; Wagner, P; Wagner, R G; Wagner, R L; Wagner, J; Wagner, W; Wallny, R; Wang, S M; Warburton, A; Waschke, S; Waters, D; Weinberger, M; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Wynne, S M; Yagil, A; Yamamoto, K; Yamaoka, J; Yamashita, T; Yang, C; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zaw, I; Zhang, X; Zhou, J; Zucchelli, S

    2007-06-08

    We measure the ratio of cross section times branching fraction, Rp=sigma chi c2 B(chi c2-->J/psi gamma)/sigma chi c1 B(chi c1-->J/psi gamma), in 1.1 fb(-1) of pp collisions at square root s=1.96 TeV. This measurement covers the kinematic range pT(J/psi)>4.0 GeV/c, |eta(J/psi)<1.0, and pT(gamma)>1.0 GeV/c. For events due to prompt processes, we find Rp=0.395+/-0.016(stat)+/-0.015(syst). This result represents a significant improvement in precision over previous measurements of prompt chi c1,2 hadro production.

  20. Safeguarding a Lunar Rover with Wald's Sequential Probability Ratio Test

    NASA Technical Reports Server (NTRS)

    Furlong, Michael; Dille, Michael; Wong, Uland; Nefian, Ara

    2016-01-01

    The virtual bumper is a safeguarding mechanism for autonomous and remotely operated robots. In this paper we take a new approach to the virtual bumper system by using an old statistical test. By using a modified version of Wald's sequential probability ratio test we demonstrate that we can reduce the number of false positive reported by the virtual bumper, thereby saving valuable mission time. We use the concept of sequential probability ratio to control vehicle speed in the presence of possible obstacles in order to increase certainty about whether or not obstacles are present. Our new algorithm reduces the chances of collision by approximately 98 relative to traditional virtual bumper safeguarding without speed control.

  1. A chi-square goodness-of-fit test for non-identically distributed random variables: with application to empirical Bayes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Conover, W.J.; Cox, D.D.; Martz, H.F.

    1997-12-01

    When using parametric empirical Bayes estimation methods for estimating the binomial or Poisson parameter, the validity of the assumed beta or gamma conjugate prior distribution is an important diagnostic consideration. Chi-square goodness-of-fit tests of the beta or gamma prior hypothesis are developed for use when the binomial sample sizes or Poisson exposure times vary. Nine examples illustrate the application of the methods, using real data from such diverse applications as the loss of feedwater flow rates in nuclear power plants, the probability of failure to run on demand and the failure rates of the high pressure coolant injection systems atmore » US commercial boiling water reactors, the probability of failure to run on demand of emergency diesel generators in US commercial nuclear power plants, the rate of failure of aircraft air conditioners, baseball batting averages, the probability of testing positive for toxoplasmosis, and the probability of tumors in rats. The tests are easily applied in practice by means of corresponding Mathematica{reg_sign} computer programs which are provided.« less

  2. Chi-squared and C statistic minimization for low count per bin data. [sampling in X ray astronomy

    NASA Technical Reports Server (NTRS)

    Nousek, John A.; Shue, David R.

    1989-01-01

    Results are presented from a computer simulation comparing two statistical fitting techniques on data samples with large and small counts per bin; the results are then related specifically to X-ray astronomy. The Marquardt and Powell minimization techniques are compared by using both to minimize the chi-squared statistic. In addition, Cash's C statistic is applied, with Powell's method, and it is shown that the C statistic produces better fits in the low-count regime than chi-squared.

  3. Interactive application of quadratic expansion of chi-square statistic to nonlinear curve fitting

    NASA Technical Reports Server (NTRS)

    Badavi, F. F.; Everhart, Joel L.

    1987-01-01

    This report contains a detailed theoretical description of an all-purpose, interactive curve-fitting routine that is based on P. R. Bevington's description of the quadratic expansion of the Chi-Square statistic. The method is implemented in the associated interactive, graphics-based computer program. Taylor's expansion of Chi-Square is first introduced, and justifications for retaining only the first term are presented. From the expansion, a set of n simultaneous linear equations is derived, then solved by matrix algebra. A brief description of the code is presented along with a limited number of changes that are required to customize the program of a particular task. To evaluate the performance of the method and the goodness of nonlinear curve fitting, two typical engineering problems are examined and the graphical and tabular output of each is discussed. A complete listing of the entire package is included as an appendix.

  4. Application of the modified chi-square ratio statistic in a stepwise procedure for cascade impactor equivalence testing.

    PubMed

    Weber, Benjamin; Lee, Sau L; Delvadia, Renishkumar; Lionberger, Robert; Li, Bing V; Tsong, Yi; Hochhaus, Guenther

    2015-03-01

    Equivalence testing of aerodynamic particle size distribution (APSD) through multi-stage cascade impactors (CIs) is important for establishing bioequivalence of orally inhaled drug products. Recent work demonstrated that the median of the modified chi-square ratio statistic (MmCSRS) is a promising metric for APSD equivalence testing of test (T) and reference (R) products as it can be applied to a reduced number of CI sites that are more relevant for lung deposition. This metric is also less sensitive to the increased variability often observed for low-deposition sites. A method to establish critical values for the MmCSRS is described here. This method considers the variability of the R product by employing a reference variance scaling approach that allows definition of critical values as a function of the observed variability of the R product. A stepwise CI equivalence test is proposed that integrates the MmCSRS as a method for comparing the relative shapes of CI profiles and incorporates statistical tests for assessing equivalence of single actuation content and impactor sized mass. This stepwise CI equivalence test was applied to 55 published CI profile scenarios, which were classified as equivalent or inequivalent by members of the Product Quality Research Institute working group (PQRI WG). The results of the stepwise CI equivalence test using a 25% difference in MmCSRS as an acceptance criterion provided the best matching with those of the PQRI WG as decisions of both methods agreed in 75% of the 55 CI profile scenarios.

  5. Current-State Constrained Filter Bank for Wald Testing of Spacecraft Conjunctions

    NASA Technical Reports Server (NTRS)

    Carpenter, J. Russell; Markley, F. Landis

    2012-01-01

    We propose a filter bank consisting of an ordinary current-state extended Kalman filter, and two similar but constrained filters: one is constrained by a null hypothesis that the miss distance between two conjuncting spacecraft is inside their combined hard body radius at the predicted time of closest approach, and one is constrained by an alternative complementary hypothesis. The unconstrained filter is the basis of an initial screening for close approaches of interest. Once the initial screening detects a possibly risky conjunction, the unconstrained filter also governs measurement editing for all three filters, and predicts the time of closest approach. The constrained filters operate only when conjunctions of interest occur. The computed likelihoods of the innovations of the two constrained filters form a ratio for a Wald sequential probability ratio test. The Wald test guides risk mitigation maneuver decisions based on explicit false alarm and missed detection criteria. Since only current-state Kalman filtering is required to compute the innovations for the likelihood ratio, the present approach does not require the mapping of probability density forward to the time of closest approach. Instead, the hard-body constraint manifold is mapped to the filter update time by applying a sigma-point transformation to a projection function. Although many projectors are available, we choose one based on Lambert-style differential correction of the current-state velocity. We have tested our method using a scenario based on the Magnetospheric Multi-Scale mission, scheduled for launch in late 2014. This mission involves formation flight in highly elliptical orbits of four spinning spacecraft equipped with antennas extending 120 meters tip-to-tip. Eccentricities range from 0.82 to 0.91, and close approaches generally occur in the vicinity of perigee, where rapid changes in geometry may occur. Testing the method using two 12,000-case Monte Carlo simulations, we found the

  6. Multi-Sensor Fusion with Interaction Multiple Model and Chi-Square Test Tolerant Filter.

    PubMed

    Yang, Chun; Mohammadi, Arash; Chen, Qing-Wei

    2016-11-02

    Motivated by the key importance of multi-sensor information fusion algorithms in the state-of-the-art integrated navigation systems due to recent advancements in sensor technologies, telecommunication, and navigation systems, the paper proposes an improved and innovative fault-tolerant fusion framework. An integrated navigation system is considered consisting of four sensory sub-systems, i.e., Strap-down Inertial Navigation System (SINS), Global Navigation System (GPS), the Bei-Dou2 (BD2) and Celestial Navigation System (CNS) navigation sensors. In such multi-sensor applications, on the one hand, the design of an efficient fusion methodology is extremely constrained specially when no information regarding the system's error characteristics is available. On the other hand, the development of an accurate fault detection and integrity monitoring solution is both challenging and critical. The paper addresses the sensitivity issues of conventional fault detection solutions and the unavailability of a precisely known system model by jointly designing fault detection and information fusion algorithms. In particular, by using ideas from Interacting Multiple Model (IMM) filters, the uncertainty of the system will be adjusted adaptively by model probabilities and using the proposed fuzzy-based fusion framework. The paper also addresses the problem of using corrupted measurements for fault detection purposes by designing a two state propagator chi-square test jointly with the fusion algorithm. Two IMM predictors, running in parallel, are used and alternatively reactivated based on the received information form the fusion filter to increase the reliability and accuracy of the proposed detection solution. With the combination of the IMM and the proposed fusion method, we increase the failure sensitivity of the detection system and, thereby, significantly increase the overall reliability and accuracy of the integrated navigation system. Simulation results indicate that the

  7. Multi-Sensor Fusion with Interaction Multiple Model and Chi-Square Test Tolerant Filter

    PubMed Central

    Yang, Chun; Mohammadi, Arash; Chen, Qing-Wei

    2016-01-01

    Motivated by the key importance of multi-sensor information fusion algorithms in the state-of-the-art integrated navigation systems due to recent advancements in sensor technologies, telecommunication, and navigation systems, the paper proposes an improved and innovative fault-tolerant fusion framework. An integrated navigation system is considered consisting of four sensory sub-systems, i.e., Strap-down Inertial Navigation System (SINS), Global Navigation System (GPS), the Bei-Dou2 (BD2) and Celestial Navigation System (CNS) navigation sensors. In such multi-sensor applications, on the one hand, the design of an efficient fusion methodology is extremely constrained specially when no information regarding the system’s error characteristics is available. On the other hand, the development of an accurate fault detection and integrity monitoring solution is both challenging and critical. The paper addresses the sensitivity issues of conventional fault detection solutions and the unavailability of a precisely known system model by jointly designing fault detection and information fusion algorithms. In particular, by using ideas from Interacting Multiple Model (IMM) filters, the uncertainty of the system will be adjusted adaptively by model probabilities and using the proposed fuzzy-based fusion framework. The paper also addresses the problem of using corrupted measurements for fault detection purposes by designing a two state propagator chi-square test jointly with the fusion algorithm. Two IMM predictors, running in parallel, are used and alternatively reactivated based on the received information form the fusion filter to increase the reliability and accuracy of the proposed detection solution. With the combination of the IMM and the proposed fusion method, we increase the failure sensitivity of the detection system and, thereby, significantly increase the overall reliability and accuracy of the integrated navigation system. Simulation results indicate that the

  8. Landslide susceptibility mapping using decision-tree based CHi-squared automatic interaction detection (CHAID) and Logistic regression (LR) integration

    NASA Astrophysics Data System (ADS)

    Althuwaynee, Omar F.; Pradhan, Biswajeet; Ahmad, Noordin

    2014-06-01

    This article uses methodology based on chi-squared automatic interaction detection (CHAID), as a multivariate method that has an automatic classification capacity to analyse large numbers of landslide conditioning factors. This new algorithm was developed to overcome the subjectivity of the manual categorization of scale data of landslide conditioning factors, and to predict rainfall-induced susceptibility map in Kuala Lumpur city and surrounding areas using geographic information system (GIS). The main objective of this article is to use CHi-squared automatic interaction detection (CHAID) method to perform the best classification fit for each conditioning factor, then, combining it with logistic regression (LR). LR model was used to find the corresponding coefficients of best fitting function that assess the optimal terminal nodes. A cluster pattern of landslide locations was extracted in previous study using nearest neighbor index (NNI), which were then used to identify the clustered landslide locations range. Clustered locations were used as model training data with 14 landslide conditioning factors such as; topographic derived parameters, lithology, NDVI, land use and land cover maps. Pearson chi-squared value was used to find the best classification fit between the dependent variable and conditioning factors. Finally the relationship between conditioning factors were assessed and the landslide susceptibility map (LSM) was produced. An area under the curve (AUC) was used to test the model reliability and prediction capability with the training and validation landslide locations respectively. This study proved the efficiency and reliability of decision tree (DT) model in landslide susceptibility mapping. Also it provided a valuable scientific basis for spatial decision making in planning and urban management studies.

  9. Equivalence of binormal likelihood-ratio and bi-chi-squared ROC curve models

    PubMed Central

    Hillis, Stephen L.

    2015-01-01

    A basic assumption for a meaningful diagnostic decision variable is that there is a monotone relationship between it and its likelihood ratio. This relationship, however, generally does not hold for a decision variable that results in a binormal ROC curve. As a result, receiver operating characteristic (ROC) curve estimation based on the assumption of a binormal ROC-curve model produces improper ROC curves that have “hooks,” are not concave over the entire domain, and cross the chance line. Although in practice this “improperness” is usually not noticeable, sometimes it is evident and problematic. To avoid this problem, Metz and Pan proposed basing ROC-curve estimation on the assumption of a binormal likelihood-ratio (binormal-LR) model, which states that the decision variable is an increasing transformation of the likelihood-ratio function of a random variable having normal conditional diseased and nondiseased distributions. However, their development is not easy to follow. I show that the binormal-LR model is equivalent to a bi-chi-squared model in the sense that the families of corresponding ROC curves are the same. The bi-chi-squared formulation provides an easier-to-follow development of the binormal-LR ROC curve and its properties in terms of well-known distributions. PMID:26608405

  10. The Relation Among the Likelihood Ratio-, Wald-, and Lagrange Multiplier Tests and Their Applicability to Small Samples,

    DTIC Science & Technology

    1982-04-01

    S. (1979), "Conflict Among Criteria for Testing Hypothesis: Extension and Comments," Econometrica, 47, 203-207 Breusch , T. S. and Pagan , A. R. (1980...Savin, N. E. (1977), "Conflict Among Criteria for Testing Hypothesis in the Multivariate Linear Regression Model," Econometrica, 45, 1263-1278 Breusch , T...VNCLASSIFIED RAND//-6756NL U l~ I- THE RELATION AMONG THE LIKELIHOOD RATIO-, WALD-, AND LAGRANGE MULTIPLIER TESTS AND THEIR APPLICABILITY TO SMALL SAMPLES

  11. Using volcano plots and regularized-chi statistics in genetic association studies.

    PubMed

    Li, Wentian; Freudenberg, Jan; Suh, Young Ju; Yang, Yaning

    2014-02-01

    Labor intensive experiments are typically required to identify the causal disease variants from a list of disease associated variants in the genome. For designing such experiments, candidate variants are ranked by their strength of genetic association with the disease. However, the two commonly used measures of genetic association, the odds-ratio (OR) and p-value may rank variants in different order. To integrate these two measures into a single analysis, here we transfer the volcano plot methodology from gene expression analysis to genetic association studies. In its original setting, volcano plots are scatter plots of fold-change and t-test statistic (or -log of the p-value), with the latter being more sensitive to sample size. In genetic association studies, the OR and Pearson's chi-square statistic (or equivalently its square root, chi; or the standardized log(OR)) can be analogously used in a volcano plot, allowing for their visual inspection. Moreover, the geometric interpretation of these plots leads to an intuitive method for filtering results by a combination of both OR and chi-square statistic, which we term "regularized-chi". This method selects associated markers by a smooth curve in the volcano plot instead of the right-angled lines which corresponds to independent cutoffs for OR and chi-square statistic. The regularized-chi incorporates relatively more signals from variants with lower minor-allele-frequencies than chi-square test statistic. As rare variants tend to have stronger functional effects, regularized-chi is better suited to the task of prioritization of candidate genes. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. New Software for Market Segmentation Analysis: A Chi-Square Interaction Detector. AIR 1983 Annual Forum Paper.

    ERIC Educational Resources Information Center

    Lay, Robert S.

    The advantages and disadvantages of new software for market segmentation analysis are discussed, and the application of this new, chi-square based procedure (CHAID), is illustrated. A comparison is presented of an earlier, binary segmentation technique (THAID) and a multiple discriminant analysis. It is suggested that CHAID is superior to earlier…

  13. Differential Item Functioning Assessment in Cognitive Diagnostic Modeling: Application of the Wald Test to Investigate DIF in the DINA Model

    ERIC Educational Resources Information Center

    Hou, Likun; de la Torre, Jimmy; Nandakumar, Ratna

    2014-01-01

    Analyzing examinees' responses using cognitive diagnostic models (CDMs) has the advantage of providing diagnostic information. To ensure the validity of the results from these models, differential item functioning (DIF) in CDMs needs to be investigated. In this article, the Wald test is proposed to examine DIF in the context of CDMs. This study…

  14. Correcting Too Much or Too Little? The Performance of Three Chi-Square Corrections.

    PubMed

    Foldnes, Njål; Olsson, Ulf Henning

    2015-01-01

    This simulation study investigates the performance of three test statistics, T1, T2, and T3, used to evaluate structural equation model fit under non normal data conditions. T1 is the well-known mean-adjusted statistic of Satorra and Bentler. T2 is the mean-and-variance adjusted statistic of Sattertwaithe type where the degrees of freedom is manipulated. T3 is a recently proposed version of T2 that does not manipulate degrees of freedom. Discrepancies between these statistics and their nominal chi-square distribution in terms of errors of Type I and Type II are investigated. All statistics are shown to be sensitive to increasing kurtosis in the data, with Type I error rates often far off the nominal level. Under excess kurtosis true models are generally over-rejected by T1 and under-rejected by T2 and T3, which have similar performance in all conditions. Under misspecification there is a loss of power with increasing kurtosis, especially for T2 and T3. The coefficient of variation of the nonzero eigenvalues of a certain matrix is shown to be a reliable indicator for the adequacy of these statistics.

  15. Adjusted Wald Confidence Interval for a Difference of Binomial Proportions Based on Paired Data

    ERIC Educational Resources Information Center

    Bonett, Douglas G.; Price, Robert M.

    2012-01-01

    Adjusted Wald intervals for binomial proportions in one-sample and two-sample designs have been shown to perform about as well as the best available methods. The adjusted Wald intervals are easy to compute and have been incorporated into introductory statistics courses. An adjusted Wald interval for paired binomial proportions is proposed here and…

  16. Bringing care to the people: Lillian Wald's legacy to public health nursing.

    PubMed Central

    Buhler-Wilkerson, K

    1993-01-01

    Lillian Wald invented public health nursing in 1893, making this year the field's centennial. One of nursing's visionaries, Wald secured reforms in health, industry, education, recreation, and housing. This historical inquiry examines three of Wald's critical experiments, each of which illuminates the past of public health nursing and its contemporary dilemmas: invention of public health nursing itself, establishment of a nationwide system of insurance payments for home-based care, and creation of a national public health nursing service. Images p1779-a p1780-a p1781-a p1782-a PMID:7695663

  17. A modified Wald interval for the area under the ROC curve (AUC) in diagnostic case-control studies

    PubMed Central

    2014-01-01

    Background The area under the receiver operating characteristic (ROC) curve, referred to as the AUC, is an appropriate measure for describing the overall accuracy of a diagnostic test or a biomarker in early phase trials without having to choose a threshold. There are many approaches for estimating the confidence interval for the AUC. However, all are relatively complicated to implement. Furthermore, many approaches perform poorly for large AUC values or small sample sizes. Methods The AUC is actually a probability. So we propose a modified Wald interval for a single proportion, which can be calculated on a pocket calculator. We performed a simulation study to compare this modified Wald interval (without and with continuity correction) with other intervals regarding coverage probability and statistical power. Results The main result is that the proposed modified Wald intervals maintain and exploit the type I error much better than the intervals of Agresti-Coull, Wilson, and Clopper-Pearson. The interval suggested by Bamber, the Mann-Whitney interval without transformation and also the interval of the binormal AUC are very liberal. For small sample sizes the Wald interval with continuity has a comparable coverage probability as the LT interval and higher power. For large sample sizes the results of the LT interval and of the Wald interval without continuity correction are comparable. Conclusions If individual patient data is not available, but only the estimated AUC and the total sample size, the modified Wald intervals can be recommended as confidence intervals for the AUC. For small sample sizes the continuity correction should be used. PMID:24552686

  18. A modified Wald interval for the area under the ROC curve (AUC) in diagnostic case-control studies.

    PubMed

    Kottas, Martina; Kuss, Oliver; Zapf, Antonia

    2014-02-19

    The area under the receiver operating characteristic (ROC) curve, referred to as the AUC, is an appropriate measure for describing the overall accuracy of a diagnostic test or a biomarker in early phase trials without having to choose a threshold. There are many approaches for estimating the confidence interval for the AUC. However, all are relatively complicated to implement. Furthermore, many approaches perform poorly for large AUC values or small sample sizes. The AUC is actually a probability. So we propose a modified Wald interval for a single proportion, which can be calculated on a pocket calculator. We performed a simulation study to compare this modified Wald interval (without and with continuity correction) with other intervals regarding coverage probability and statistical power. The main result is that the proposed modified Wald intervals maintain and exploit the type I error much better than the intervals of Agresti-Coull, Wilson, and Clopper-Pearson. The interval suggested by Bamber, the Mann-Whitney interval without transformation and also the interval of the binormal AUC are very liberal. For small sample sizes the Wald interval with continuity has a comparable coverage probability as the LT interval and higher power. For large sample sizes the results of the LT interval and of the Wald interval without continuity correction are comparable. If individual patient data is not available, but only the estimated AUC and the total sample size, the modified Wald intervals can be recommended as confidence intervals for the AUC. For small sample sizes the continuity correction should be used.

  19. Noncentral Chi-Square versus Normal Distributions in Describing the Likelihood Ratio Statistic: The Univariate Case and Its Multivariate Implication

    ERIC Educational Resources Information Center

    Yuan, Ke-Hai

    2008-01-01

    In the literature of mean and covariance structure analysis, noncentral chi-square distribution is commonly used to describe the behavior of the likelihood ratio (LR) statistic under alternative hypothesis. Due to the inaccessibility of the rather technical literature for the distribution of the LR statistic, it is widely believed that the…

  20. Quantum chi-squared and goodness of fit testing

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Temme, Kristan; Verstraete, Frank

    2015-01-15

    A quantum mechanical hypothesis test is presented for the hypothesis that a certain setup produces a given quantum state. Although the classical and the quantum problems are very much related to each other, the quantum problem is much richer due to the additional optimization over the measurement basis. A goodness of fit test for i.i.d quantum states is developed and a max-min characterization for the optimal measurement is introduced. We find the quantum measurement which leads both to the maximal Pitman and Bahadur efficiencies, and determine the associated divergence rates. We discuss the relationship of the quantum goodness of fitmore » test to the problem of estimating multiple parameters from a density matrix. These problems are found to be closely related and we show that the largest error of an optimal strategy, determined by the smallest eigenvalue of the Fisher information matrix, is given by the divergence rate of the goodness of fit test.« less

  1. Dying with dignity in America: the transformational leadership of Florence Wald.

    PubMed

    Adams, Cynthia

    2010-03-01

    The aims of this study are to examine the constructs of transformational leadership as they played out for one nurse who steered significant change in the care of the dying in the United States and to provide deeper insights into how nursing leaders can design and direct meaningful changes in the delivery of health care in turbulent times. A significant problem was identified in how the terminally ill were treated in this country post World War II. The introduction of hospice care in the United States represented a paradigm shift in how the health care community viewed and treated dying patients. Critical to this transformation was the work of Florence Wald, who organized with community leaders, clergy, and other health care providers to create a vision and synergy around palliative care. She was instrumental in opening the first American hospice in 1971 in Connecticut. Within 15 years, there were more than 1,000 hospices in the United States. A single case study design was chosen for this qualitative research grounded in the theory of transformational leadership (J.M. Burns, 1978). The study used narrative inquiry to conduct an in-depth exploration of Florence Wald's transformational leadership and the perceptions of the group of founders she organized to conceptualize, build, and open the first hospice in the United States. The participants chosen for interview were involved directly in the designing, planning, and beginning of the first American hospice. In addition to the seven in-depth interviews conducted in 2007 in Connecticut, this research examined three groups of documents from The Florence and Henry Wald Archives in the Yale University Library. The findings from both interviews and the Yale Archives showed that Florence Wald based her leadership on the strong values of reverence for life and social justice for all. To direct meaningful change, Florence Wald elevated the consciousness of her hospice team by conducting a 2-year research study on the needs

  2. Improving the chi-squared approximation for bivariate normal tolerance regions

    NASA Technical Reports Server (NTRS)

    Feiveson, Alan H.

    1993-01-01

    Let X be a two-dimensional random variable distributed according to N2(mu,Sigma) and let bar-X and S be the respective sample mean and covariance matrix calculated from N observations of X. Given a containment probability beta and a level of confidence gamma, we seek a number c, depending only on N, beta, and gamma such that the ellipsoid R = (x: (x - bar-X)'S(exp -1) (x - bar-X) less than or = c) is a tolerance region of content beta and level gamma; i.e., R has probability gamma of containing at least 100 beta percent of the distribution of X. Various approximations for c exist in the literature, but one of the simplest to compute -- a multiple of the ratio of certain chi-squared percentage points -- is badly biased for small N. For the bivariate normal case, most of the bias can be removed by simple adjustment using a factor A which depends on beta and gamma. This paper provides values of A for various beta and gamma so that the simple approximation for c can be made viable for any reasonable sample size. The methodology provides an illustrative example of how a combination of Monte-Carlo simulation and simple regression modelling can be used to improve an existing approximation.

  3. Chi-Square Statistics, Tests of Hypothesis and Technology.

    ERIC Educational Resources Information Center

    Rochowicz, John A.

    The use of technology such as computers and programmable calculators enables students to find p-values and conduct tests of hypotheses in many different ways. Comprehension and interpretation of a research problem become the focus for statistical analysis. This paper describes how to calculate chisquare statistics and p-values for statistical…

  4. A novel chi-square statistic for detecting group differences between pathways in systems epidemiology.

    PubMed

    Yuan, Zhongshang; Ji, Jiadong; Zhang, Tao; Liu, Yi; Zhang, Xiaoshuai; Chen, Wei; Xue, Fuzhong

    2016-12-20

    Traditional epidemiology often pays more attention to the identification of a single factor rather than to the pathway that is related to a disease, and therefore, it is difficult to explore the disease mechanism. Systems epidemiology aims to integrate putative lifestyle exposures and biomarkers extracted from multiple omics platforms to offer new insights into the pathway mechanisms that underlie disease at the human population level. One key but inadequately addressed question is how to develop powerful statistics to identify whether one candidate pathway is associated with a disease. Bearing in mind that a pathway difference can result from not only changes in the nodes but also changes in the edges, we propose a novel statistic for detecting group differences between pathways, which in principle, captures the nodes changes and edge changes, as well as simultaneously accounting for the pathway structure simultaneously. The proposed test has been proven to follow the chi-square distribution, and various simulations have shown it has better performance than other existing methods. Integrating genome-wide DNA methylation data, we analyzed one real data set from the Bogalusa cohort study and significantly identified a potential pathway, Smoking → SOCS3 → PIK3R1, which was strongly associated with abdominal obesity. The proposed test was powerful and efficient at identifying pathway differences between two groups, and it can be extended to other disciplines that involve statistical comparisons between pathways. The source code in R is available on our website. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  5. Association between litterers' profile and littering behavior: A chi-square approach

    NASA Astrophysics Data System (ADS)

    Asmui, Mas'udah; Zaki, Suhanom Mohd; Wahid, Sharifah Norhuda Syed; Mokhtar, Noorsuraya Mohd; Harith, Siti Suhaila

    2017-05-01

    Littering is not a novelty, yet a prolonged issue. The solutions have been discussed for a long time; however this issue still remains unresolved. Littering is commonly associated with littering behavior and awareness. The littering behavior is normally influenced by the litter profile such as gender, family income, education level and age. Jengka Street market, which is located in Pahang, is popularly known as a trade market. It offers diversities of wet and dry goods and is awaited by local residents and tourists. This study analyzes association between litterers' profile and littering behavior. Littering behavior is measured based on factors of trash bin facilities, awareness campaign and public littering behavior. 114 respondents were involved in this study with 62 (54.39%) are female aged more than 18 years old and majority of these female respondents are diploma holders. In addition, 78.95% of the respondents have family income below than RM3,000.00 per month. Based on the data analysis, it was found that first-time visitors littered higher than frequent visitors, lack of providing trash bin facilities contributes to positive littering behavior and there is a significant association between litterers' age and littering behavior by using chi-square approach.

  6. The Impact of Micronutrient Supplementation in Alcohol-Exposed Pregnancies on Information Processing Skills in Ukrainian Infants

    PubMed Central

    Kable, J. A.; Coles, C. D.; Keen, C. L.; Uriu-Adams, J. Y.; Jones, K. L.; Yevtushok, L.; Kulikovsky, Y.; Wertelecki, W.; Pedersen, T. L.; Chambers, C. D.

    2015-01-01

    Objectives The potential of micronutrients to ameliorate the impact of prenatal alcohol exposure was explored in a clinical trial conducted in Ukraine. Cardiac orienting responses during a habituation/dishabituation learning paradigm were obtained from 6–12-month-olds to assess neurophysiological encoding and memory of environmental events. Materials and methods Women who differed in prenatal alcohol use were recruited during pregnancy and assigned to a group (no study-provided supplements, multivitamin/mineral supplement, or multivitamin/mineral supplement plus choline supplement). An infant habituation/dishabituation paradigm was used to assess outcomes in the offspring. Ten trials were used for the habituation and five for the dishabituation condition. Heart rate was collected for 30 sec prior to stimulus onset and then 12 sec post-stimulus onset. Difference values (ΔHR) were computed for the first three trials of each condition and aggregated for analysis. Gestational blood samples were collected to assess maternal nutritional status and changes as a function of the intervention. Results Choline supplementation resulted in a greater ΔHR on the visual habituation (Wald Chi-Square (1, 149) = 10.9, p < .001, eta-squared = .043) trials for all infants and for the infants with no prenatal alcohol exposure on the dishabituation (Wald Chi-Square (1, 139) = 6.1, p < .013, eta-squared = .065) trials. The latency of the response was reduced in both conditions (Habituation: Wald Chi-Square (1, 150) = 9.0, p < .003, eta-squared = .056; Dishabituation: Wald Chi-Square (1, 137) = 4.9, p < .027, eta-squared = .032) for all infants whose mothers received choline supplementation. Change in gestational choline level was positively related (r = .19) to ΔHR during habituation trials, and levels of one choline metabolite, dimethylglycine (DMG), predicted ΔHR during habituation trials (r = .23) and latency of responses (r = −.20). A trend was found between DMG and ΔHR on

  7. ATLAS particle detector CSC ROD software design and implementation, and, Addition of K physics to chi-squared analysis of FDQM

    NASA Astrophysics Data System (ADS)

    Hawkins, Donovan Lee

    In this thesis I present a software framework for use on the ATLAS muon CSC readout driver. This C++ framework uses plug-in Decoders incorporating hand-optimized assembly language routines to perform sparsification and data formatting. The software is designed with both flexibility and performance in mind, and runs on a custom 9U VME board using Texas Instruments TMS360C6203 digital signal processors. I describe the requirements of the software, the methods used in its design, and the results of testing the software with simulated data. I also present modifications to a chi-squared analysis of the Standard Model and Four Down Quark Model (FDQM) originally done by Dr. Dennis Silverman. The addition of four new experiments to the analysis has little effect on the Standard Model but provides important new restrictions on the FDQM. The method used to incorporate these new experiments is presented, and the consequences of their addition are reviewed.

  8. Ensuring Positiveness of the Scaled Difference Chi-Square Test Statistic

    ERIC Educational Resources Information Center

    Satorra, Albert; Bentler, Peter M.

    2010-01-01

    A scaled difference test statistic T[tilde][subscript d] that can be computed from standard software of structural equation models (SEM) by hand calculations was proposed in Satorra and Bentler (Psychometrika 66:507-514, 2001). The statistic T[tilde][subscript d] is asymptotically equivalent to the scaled difference test statistic T[bar][subscript…

  9. The applicability of ordinary least squares to consistently short distances between taxa in phylogenetic tree construction and the normal distribution test consequences.

    PubMed

    Roux, C Z

    2009-05-01

    Short phylogenetic distances between taxa occur, for example, in studies on ribosomal RNA-genes with slow substitution rates. For consistently short distances, it is proved that in the completely singular limit of the covariance matrix ordinary least squares (OLS) estimates are minimum variance or best linear unbiased (BLU) estimates of phylogenetic tree branch lengths. Although OLS estimates are in this situation equal to generalized least squares (GLS) estimates, the GLS chi-square likelihood ratio test will be inapplicable as it is associated with zero degrees of freedom. Consequently, an OLS normal distribution test or an analogous bootstrap approach will provide optimal branch length tests of significance for consistently short phylogenetic distances. As the asymptotic covariances between branch lengths will be equal to zero, it follows that the product rule can be used in tree evaluation to calculate an approximate simultaneous confidence probability that all interior branches are positive.

  10. A Search for WIMP Dark Matter Using an Optimized Chi-square Technique on the Final Data from the Cryogenic Dark Matter Search Experiment (CDMS II)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Manungu Kiveni, Joseph

    2012-12-01

    This dissertation describes the results of a WIMP search using CDMS II data sets accumulated at the Soudan Underground Laboratory in Minnesota. Results from the original analysis of these data were published in 2009; two events were observed in the signal region with an expected leakage of 0.9 events. Further investigation revealed an issue with the ionization-pulse reconstruction algorithm leading to a software upgrade and a subsequent reanalysis of the data. As part of the reanalysis, I performed an advanced discrimination technique to better distinguish (potential) signal events from backgrounds using a 5-dimensional chi-square method. This dataanalysis technique combines themore » event information recorded for each WIMP-search event to derive a backgrounddiscrimination parameter capable of reducing the expected background to less than one event, while maintaining high efficiency for signal events. Furthermore, optimizing the cut positions of this 5-dimensional chi-square parameter for the 14 viable germanium detectors yields an improved expected sensitivity to WIMP interactions relative to previous CDMS results. This dissertation describes my improved (and optimized) discrimination technique and the results obtained from a blind application to the reanalyzed CDMS II WIMP-search data.« less

  11. Does the adolescent patellar tendon respond to 5 days of cumulative load during a volleyball tournament?

    PubMed

    van Ark, M; Docking, S I; van den Akker-Scheek, I; Rudavsky, A; Rio, E; Zwerver, J; Cook, J L

    2016-02-01

    Patellar tendinopathy (jumper's knee) has a high prevalence in jumping athletes. Excessive load on the patellar tendon through high volumes of training and competition is an important risk factor. Structural changes in the tendon are related to a higher risk of developing patellar tendinopathy. The critical tendon load that affects tendon structure is unknown. The aim of this study was to investigate patellar tendon structure on each day of a 5-day volleyball tournament in an adolescent population (16-18 years). The right patellar tendon of 41 players in the Australian Volleyball Schools Cup was scanned with ultrasound tissue characterization (UTC) on every day of the tournament (Monday to Friday). UTC can quantify structure of a tendon into four echo types based on the stability of the echo pattern. Generalized estimating equations (GEE) were used to test for change of echo type I and II over the tournament days. Participants played between eight and nine matches during the tournament. GEE analysis showed no significant change of echo type percentages of echo type I (Wald chi-square = 4.603, d.f. = 4, P = 0.331) and echo type II (Wald chi-square = 6.070, d.f. = 4, P = 0.194) over time. This study shows that patellar tendon structure of 16-18-year-old volleyball players is not affected during 5 days of cumulative loading during a volleyball tournament. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Tai Chi for Essential Hypertension

    PubMed Central

    Wang, Jie; Feng, Bo; Yang, Xiaochen; Liu, Wei; Teng, Fei; Li, Shengjie; Xiong, Xingjiang

    2013-01-01

    Objectives. To assess the current clinical evidence of Tai Chi for essential hypertension (EH). Search Strategy. 7 electronic databases were searched until 20 April, 2013. Inclusion Criteria. We included randomized trials testing Tai Chi versus routine care or antihypertensive drugs. Trials testing Tai Chi combined with antihypertensive drugs versus antihypertensive drugs were also included. Data Extraction and Analyses. Study selection, data extraction, quality assessment, and data analyses were conducted according to the Cochrane standards. Results. 18 trials were included. Methodological quality of the trials was low. 14 trials compared Tai Chi with routine care. 1 trial compared Tai Chi with antihypertensive drugs. Meta-analysis all showed significant effect of TaiChi in lowering blood pressure (BP). 3 trials compared Tai Chi plus antihypertensive drugs with antihypertensive drugs. Positive results in BP were found in the other 2 combination groups. Most of the trials did not report adverse events, and the safety of Tai Chi is still uncertain. Conclusions. There is some encouraging evidence of Tai Chi for EH. However, due to poor methodological quality of included studies, the evidence remains weak. Rigorously designed trials are needed to confirm the evidence. PMID:23986780

  13. Pearson-type goodness-of-fit test with bootstrap maximum likelihood estimation.

    PubMed

    Yin, Guosheng; Ma, Yanyuan

    2013-01-01

    The Pearson test statistic is constructed by partitioning the data into bins and computing the difference between the observed and expected counts in these bins. If the maximum likelihood estimator (MLE) of the original data is used, the statistic generally does not follow a chi-squared distribution or any explicit distribution. We propose a bootstrap-based modification of the Pearson test statistic to recover the chi-squared distribution. We compute the observed and expected counts in the partitioned bins by using the MLE obtained from a bootstrap sample. This bootstrap-sample MLE adjusts exactly the right amount of randomness to the test statistic, and recovers the chi-squared distribution. The bootstrap chi-squared test is easy to implement, as it only requires fitting exactly the same model to the bootstrap data to obtain the corresponding MLE, and then constructs the bin counts based on the original data. We examine the test size and power of the new model diagnostic procedure using simulation studies and illustrate it with a real data set.

  14. Risk Factors Analysis and Death Prediction in Some Life-Threatening Ailments Using Chi-Square Case-Based Reasoning (χ2 CBR) Model.

    PubMed

    Adeniyi, D A; Wei, Z; Yang, Y

    2018-01-30

    A wealth of data are available within the health care system, however, effective analysis tools for exploring the hidden patterns in these datasets are lacking. To alleviate this limitation, this paper proposes a simple but promising hybrid predictive model by suitably combining the Chi-square distance measurement with case-based reasoning technique. The study presents the realization of an automated risk calculator and death prediction in some life-threatening ailments using Chi-square case-based reasoning (χ 2 CBR) model. The proposed predictive engine is capable of reducing runtime and speeds up execution process through the use of critical χ 2 distribution value. This work also showcases the development of a novel feature selection method referred to as frequent item based rule (FIBR) method. This FIBR method is used for selecting the best feature for the proposed χ 2 CBR model at the preprocessing stage of the predictive procedures. The implementation of the proposed risk calculator is achieved through the use of an in-house developed PHP program experimented with XAMP/Apache HTTP server as hosting server. The process of data acquisition and case-based development is implemented using the MySQL application. Performance comparison between our system, the NBY, the ED-KNN, the ANN, the SVM, the Random Forest and the traditional CBR techniques shows that the quality of predictions produced by our system outperformed the baseline methods studied. The result of our experiment shows that the precision rate and predictive quality of our system in most cases are equal to or greater than 70%. Our result also shows that the proposed system executes faster than the baseline methods studied. Therefore, the proposed risk calculator is capable of providing useful, consistent, faster, accurate and efficient risk level prediction to both the patients and the physicians at any time, online and on a real-time basis.

  15. Tests of Independence in Contingency Tables with Small Samples: A Comparison of Statistical Power.

    ERIC Educational Resources Information Center

    Parshall, Cynthia G.; Kromrey, Jeffrey D.

    1996-01-01

    Power and Type I error rates were estimated for contingency tables with small sample sizes for the following four types of tests: (1) Pearson's chi-square; (2) chi-square with Yates's continuity correction; (3) the likelihood ratio test; and (4) Fisher's Exact Test. Various marginal distributions, sample sizes, and effect sizes were examined. (SLD)

  16. Power of tests for comparing trend curves with application to national immunization survey (NIS).

    PubMed

    Zhao, Zhen

    2011-02-28

    To develop statistical tests for comparing trend curves of study outcomes between two socio-demographic strata across consecutive time points, and compare statistical power of the proposed tests under different trend curves data, three statistical tests were proposed. For large sample size with independent normal assumption among strata and across consecutive time points, the Z and Chi-square test statistics were developed, which are functions of outcome estimates and the standard errors at each of the study time points for the two strata. For small sample size with independent normal assumption, the F-test statistic was generated, which is a function of sample size of the two strata and estimated parameters across study period. If two trend curves are approximately parallel, the power of Z-test is consistently higher than that of both Chi-square and F-test. If two trend curves cross at low interaction, the power of Z-test is higher than or equal to the power of both Chi-square and F-test; however, at high interaction, the powers of Chi-square and F-test are higher than that of Z-test. The measurement of interaction of two trend curves was defined. These tests were applied to the comparison of trend curves of vaccination coverage estimates of standard vaccine series with National Immunization Survey (NIS) 2000-2007 data. Copyright © 2011 John Wiley & Sons, Ltd.

  17. Unsupervised change detection of multispectral images based on spatial constraint chi-squared transform and Markov random field model

    NASA Astrophysics Data System (ADS)

    Shi, Aiye; Wang, Chao; Shen, Shaohong; Huang, Fengchen; Ma, Zhenli

    2016-10-01

    Chi-squared transform (CST), as a statistical method, can describe the difference degree between vectors. The CST-based methods operate directly on information stored in the difference image and are simple and effective methods for detecting changes in remotely sensed images that have been registered and aligned. However, the technique does not take spatial information into consideration, which leads to much noise in the result of change detection. An improved unsupervised change detection method is proposed based on spatial constraint CST (SCCST) in combination with a Markov random field (MRF) model. First, the mean and variance matrix of the difference image of bitemporal images are estimated by an iterative trimming method. In each iteration, spatial information is injected to reduce scattered changed points (also known as "salt and pepper" noise). To determine the key parameter confidence level in the SCCST method, a pseudotraining dataset is constructed to estimate the optimal value. Then, the result of SCCST, as an initial solution of change detection, is further improved by the MRF model. The experiments on simulated and real multitemporal and multispectral images indicate that the proposed method performs well in comprehensive indices compared with other methods.

  18. Effects of T'ai Chi on Serotonin, Nicotine Dependency, Depression, and Anger in Hospitalized Alcohol-Dependent Patients.

    PubMed

    Oh, Chung-Uk; Kim, Nam-Cho

    2016-12-01

    The aim of this study was to investigate the effects of t'ai chi on blood serotonin levels, nicotine dependence, depression, and anger in hospitalized alcohol-dependent patients. This study followed an experimental and nonequivalent control group in a non-synchronized design. It was performed in a hospital located in Young Ju city, Korea, from April to August 2013. Thirty-eight patients who were hospitalized with alcohol dependence were included. They were randomly divided into an experimental and a control group, with 19 patients in each group. Patients in the experimental group practiced the 24-posture yang style t'ai chi for 50 min three times per week for 8 weeks as part of the routine hospital rehabilitation program, and those in the control group followed only the routine hospital rehabilitation program. The effect of treatment was measured using blood serotonin levels and a questionnaire on nicotine dependence, depression, and anger. Both measurements were performed before and after 8 weeks of intervention. Data were analyzed using the t-test, chi-square test, and paired t-tests. The experimental group showed a significantly increased blood serotonin level (p = 0.001) and significantly reduced nicotine dependence, depression, and anger (p = 0.001) than the control group did after 8 weeks of treatment. T'ai chi was shown to be an effective nursing intervention in hospitalized alcohol-dependent patients.

  19. Red square test for visual field screening. A sensitive and simple bedside test.

    PubMed

    Mandahl, A

    1994-12-01

    A reliable bedside test for screening of visual field defects is a valuable tool in the examination of patients with a putative disease affecting the sensory visual pathways. Conventional methods such as Donders' confrontation method, counting fingers in the visual field periphery, of two-hand confrontation are not sufficiently sensitive to detect minor but nevertheless serious visual field defects. More sensitive methods requiring only simple tools are also described. In this study, a test card with four red squares surrounding a fixation target, a black dot, with a total test area of about 11 x 12.5 degrees at a distance of 30 cm, was designed for testing experience of red colour saturation in four quadrants, red square test. The Goldmann visual field was used as reference. 125 consecutive patients with pituitary adenoma (159 eyes), craniopharyngeoma (9 eyes), meningeoma (21 eyes), vascular hemisphere lesion (40 eyes), hemisphere tumour (10 eyes) and hemisphere abscess (2 eyes) were examined. The Goldmann visual field and red square test were pathological in pituitary adenomas in 35%, in craniopharyngeomas in 44%, in meningeomas in 52% and in hemisphere tumours or abscess in 100% of the eyes. Among these, no false-normal or false-pathological tests were found. However, in vascular hemisphere disease the corresponding figures were Goldmann visual field 90% and red square test 85%. The 5% difference (4 eyes) was due to Goldmann visual field defects strictly peripheral to the central 15 degrees. These defects were easily diagnosed with two-hand confrontation and

  20. Statistical hypothesis tests of some micrometeorological observations

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    SethuRaman, S.; Tichler, J.

    Chi-square goodness-of-fit is used to test the hypothesis that the medium scale of turbulence in the atmospheric surface layer is normally distributed. Coefficients of skewness and excess are computed from the data. If the data are not normal, these coefficients are used in Edgeworth's asymptotic expansion of Gram-Charlier series to determine an altrnate probability density function. The observed data are then compared with the modified probability densities and the new chi-square values computed.Seventy percent of the data analyzed was either normal or approximatley normal. The coefficient of skewness g/sub 1/ has a good correlation with the chi-square values. Events withmore » vertical-barg/sub 1/vertical-bar<0.21 were normal to begin with and those with 0.21« less

  1. The Langer-Improved Wald Test for DIF Testing with Multiple Groups: Evaluation and Comparison to Two-Group IRT

    ERIC Educational Resources Information Center

    Woods, Carol M.; Cai, Li; Wang, Mian

    2013-01-01

    Differential item functioning (DIF) occurs when the probability of responding in a particular category to an item differs for members of different groups who are matched on the construct being measured. The identification of DIF is important for valid measurement. This research evaluates an improved version of Lord's chi [superscript 2]…

  2. Testing subleading multiple soft graviton theorem for CHY prescription

    NASA Astrophysics Data System (ADS)

    Chakrabarti, Subhroneel; Kashyap, Sitender Pratap; Sahoo, Biswajit; Sen, Ashoke; Verma, Mritunjay

    2018-01-01

    In arXiv:1707.06803 we derived the subleading multiple soft graviton theorem in a generic quantum theory of gravity for arbitrary number of soft external gravitons and arbitrary number of finite energy external states carrying arbitrary mass and spin. In this paper we verify this explicitly using the CHY formula for tree level scattering amplitudes of arbitrary number of gravitons in Einstein gravity. We pay special care to fix the signs of the amplitudes and resolve an apparent discrepancy between our general results in arXiv:1707.06803 and previous results on soft graviton theorem from CHY formula.

  3. Parameter Estimation in Astronomy with Poisson-Distributed Data. 1; The (CHI)2(gamma) Statistic

    NASA Technical Reports Server (NTRS)

    Mighell, Kenneth J.

    1999-01-01

    Applying the standard weighted mean formula, [Sigma (sub i)n(sub i)ssigma(sub i, sup -2)], to determine the weighted mean of data, n(sub i), drawn from a Poisson distribution, will, on average, underestimate the true mean by approx. 1 for all true mean values larger than approx.3 when the common assumption is made that the error of the i th observation is sigma(sub i) = max square root of n(sub i), 1).This small, but statistically significant offset, explains the long-known observation that chi-square minimization techniques which use the modified Neyman'chi(sub 2) statistic, chi(sup 2, sub N) equivalent Sigma(sub i)((n(sub i) - y(sub i)(exp 2)) / max(n(sub i), 1), to compare Poisson - distributed data with model values, y(sub i), will typically predict a total number of counts that underestimates the true total by about 1 count per bin. Based on my finding that weighted mean of data drawn from a Poisson distribution can be determined using the formula [Sigma(sub i)[n(sub i) + min(n(sub i), 1)](n(sub i) + 1)(exp -1)] / [Sigma(sub i)(n(sub i) + 1)(exp -1))], I propose that a new chi(sub 2) statistic, chi(sup 2, sub gamma) equivalent, should always be used to analyze Poisson- distributed data in preference to the modified Neyman's chi(exp 2) statistic. I demonstrated the power and usefulness of,chi(sub gamma, sup 2) minimization by using two statistical fitting techniques and five chi(exp 2) statistics to analyze simulated X-ray power - low 15 - channel spectra with large and small counts per bin. I show that chi(sub gamma, sup 2) minimization with the Levenberg - Marquardt or Powell's method can produce excellent results (mean slope errors approx. less than 3%) with spectra having as few as 25 total counts.

  4. An accurate test for homogeneity of odds ratios based on Cochran's Q-statistic.

    PubMed

    Kulinskaya, Elena; Dollinger, Michael B

    2015-06-10

    A frequently used statistic for testing homogeneity in a meta-analysis of K independent studies is Cochran's Q. For a standard test of homogeneity the Q statistic is referred to a chi-square distribution with K-1 degrees of freedom. For the situation in which the effects of the studies are logarithms of odds ratios, the chi-square distribution is much too conservative for moderate size studies, although it may be asymptotically correct as the individual studies become large. Using a mixture of theoretical results and simulations, we provide formulas to estimate the shape and scale parameters of a gamma distribution to fit the distribution of Q. Simulation studies show that the gamma distribution is a good approximation to the distribution for Q. Use of the gamma distribution instead of the chi-square distribution for Q should eliminate inaccurate inferences in assessing homogeneity in a meta-analysis. (A computer program for implementing this test is provided.) This hypothesis test is competitive with the Breslow-Day test both in accuracy of level and in power.

  5. Collisional super-Penrose process and Wald inequalities

    NASA Astrophysics Data System (ADS)

    Tanatarov, Igor V.; Zaslavskii, Oleg B.

    2017-09-01

    We consider collision of two massive particles in the equatorial plane of an axially symmetric stationary spacetime that produces two massless particles afterwards. It is implied that the horizon is absent but there is a naked singularity or another potential barrier that makes possible the head-on collision. The relationship between the energy in the center of mass frame E_{c.m.} and the Killing energy E measured at infinity is analyzed. It follows immediately from the Wald inequalities that unbounded E is possible for unbounded E_{c.m.} only. This can be realized if the spacetime is close to the threshold of the horizon formation. Different types of spacetimes (black holes, naked singularities, wormholes) correspond to different possible relations between E_{c.m.} and E. We develop a general approach that enables us to describe the collision process in the frames of the stationary observer and zero angular momentum observer. The escape cone and escape fraction are derived. A simple explanation of the existence of the bright spot is given. For the particular case of the Kerr metric, our results agree with the previous ones found in Patil et al. (Phys Rev D 93:104015, 2016).

  6. Conceptual Model on Application of Chi-Square Test in Education and Social Sciences

    ERIC Educational Resources Information Center

    Onchiri, Sureiman

    2013-01-01

    Whenever you think you have an idea of how something works, you have a mental model. That is, in effect, a layman's way of talking about having an hypothesis. The hypothesis needs to be tested for how closely it fits reality--and reality is the data collected from an experiment. So the data is collected on the few and compared with a few…

  7. Blockage Testing in the NASA Glenn 225 Square Centimeter Supersonic Wind Tunnel

    NASA Technical Reports Server (NTRS)

    Sevier, Abigail; Davis, David O.; Schoenenberger, Mark

    2017-01-01

    The starting characteristics for three different model geometries were tested in the Glenn Research Center 225 Square Centimeter Supersonic Wind Tunnel. The test models were tested at Mach 2, 2.5 and 3 in a square test section and at Mach 2.5 again in an asymmetric test section. The results gathered in this study will help size the test models and inform other design features for the eventual implementation of a magnetic suspension system.

  8. Correlates of HIV Testing Among Transgender Women in Ho Chi Minh, Vietnam.

    PubMed

    Bao, An; Colby, Donn J; Trang, Toan; Le, Bao Quoc; Dinh, Thien Duc; Nguyen, Quan Hoang; Hoang, Huyen Thi; Friedman, M Reuel; Stall, Ron

    2016-12-01

    HIV prevalence among transgender women (TW) in Ho Chi Minh City is estimated at 18 %. However, no evidence-based programs or surveillance data exist in Vietnam specific to HIV testing uptake. We examined prevalence and correlates of past-year HIV testing among TW (n = 204) recruited in 2015 via snowball sampling. 59.3 % reported HIV testing in the previous year. In adjusted models, factors positively associated with HIV testing included consistent condom use during sex work with male clients; STI testing in past year; sex with casual partners in the past month; and experiences of police harassment. Factors negatively associated with recent HIV testing included daily/weekly alcohol use and post-traumatic stress symptoms. This study found significant associations between greater safety in sexual behaviors and higher rates of HIV testing. Targeted and specific services are needed for TW in Vietnam in order to address sexual risk behaviors and provide appropriate access to regular HIV testing.

  9. Personalised news filtering and recommendation system using Chi-square statistics-based K-nearest neighbour (χ2SB-KNN) model

    NASA Astrophysics Data System (ADS)

    Adeniyi, D. A.; Wei, Z.; Yang, Y.

    2017-10-01

    Recommendation problem has been extensively studied by researchers in the field of data mining, database and information retrieval. This study presents the design and realisation of an automated, personalised news recommendations system based on Chi-square statistics-based K-nearest neighbour (χ2SB-KNN) model. The proposed χ2SB-KNN model has the potential to overcome computational complexity and information overloading problems, reduces runtime and speeds up execution process through the use of critical value of χ2 distribution. The proposed recommendation engine can alleviate scalability challenges through combined online pattern discovery and pattern matching for real-time recommendations. This work also showcases the development of a novel method of feature selection referred to as Data Discretisation-Based feature selection method. This is used for selecting the best features for the proposed χ2SB-KNN algorithm at the preprocessing stage of the classification procedures. The implementation of the proposed χ2SB-KNN model is achieved through the use of a developed in-house Java program on an experimental website called OUC newsreaders' website. Finally, we compared the performance of our system with two baseline methods which are traditional Euclidean distance K-nearest neighbour and Naive Bayesian techniques. The result shows a significant improvement of our method over the baseline methods studied.

  10. Antioxidant and anxiolytic activities of Crataegus nigra Wald. et Kit. berries.

    PubMed

    Popovic-Milenkovic, Marija T; Tomovic, Marina T; Brankovic, Snezana R; Ljujic, Biljana T; Jankovic, Slobodan M

    2014-01-01

    Hawthorn has been present for a long time in traditional medicine as antihypertensive, hypolipidemic, anti-inflammatory, gastroprotective, antimicrobial agent. Hawthorn can be used for the cure of stress, nervousness but there is no published paper about actions of Crataegus nigra Wald. et Kit. fruits. The present study was carried out to test free-radical-scavenging and anxiolytic activity of C. nigra fruits. DPPH (alpha,alpha-diphenyl-beta-picrylhydrazyl) assay was used to measure antioxidant activity. BHT, BHA, PG, quercetin and rutin were used as standards. The total amount of phenolic compounds, procyanidins, and flavonoids in the extracts, was determined spectrophotometrically. Results were expressed as equivalents of gallic acid, cyanidin chloride and quercetin equivalents, respectively. LC-MS/MS was used for identification and quantification of phenolic composition. The anxiety effect, expressed as the difference in time spent in the open and closed arms, was measured and compared between groups. Phenolic compound content of Crataegus nigra fruits was 72.7 mg/g. Yield of total flavonoid aglycones was 0.115 mg/g. Procyanidins were 5.6 mg/g. DPPH radical-scavenging capacity of the extracts showed linear concentration dependency, IC50 value were 27.33 microg/mL. Anxiolytic effect was observed. Species Crataegus nigra fruits hydroalcoholic extract showed antioxidant and anxiolytic activity.

  11. Partner HIV serostatus disclosure and determinants of serodiscordance among prevention of mother to child transmission clients in Nigeria.

    PubMed

    Onovo, Amobi Andrew; Nta, Iboro Ekpo; Onah, Aaron Anyebe; Okolo, Chukwuemeka Arinze; Aliyu, Ahmad; Dakum, Patrick; Atobatele, Akinyemi Olumuyiwa; Gado, Pamela

    2015-08-28

    Serodiscordance exists when the known HIV result of one member of a couple pair is positive while that of his/her partner is negative. In sub-Saharan Africa, in stable long-term couple partnerships (married or cohabiting), serodiscordance is a growing source of HIV-transmissions. This study aimed to ascertain across Nigeria, serodiscordance prevalence, partner HIV status disclosure and explore associations between suspected determinants and serodiscordance among PMTCT enrolled HIV positive pregnant women and their partners. A retrospective Quality of Care performance evaluation was conducted in July 2013 among 544 HIV positive pregnant enrolees of PMTCT services in 62 comprehensive facilities across 5 of Nigeria's 6 geo-political zones. Data of client-partner pairs were abstracted from pre-existing medical records and analysed using chi-square statistics and logistic regression. A total of 544 (22%) of 2499 clients with complete partner details were analysed. Clients' age ranged from 15 to 50 years with a mean of 30 years. Serodiscordant prevalence was 52% and chi-square test suggests no significant difference between serodiscordant and seroconcordant clients and their partners (p = 0.265). Serodiscordant rates were closely associated trend wise with national HIV sero-prevalence rates and the median CD4+ count was 425 ul/mm(3) (IQR: 290-606 ul/mm(3)). Similar proportion of clients (99%) received testing and agreed to disclose status to their partners. Yet, there was no association between clients agreement to disclose HIV status to their partners and these partners getting tested and receiving results (p = 0.919). Significantly, 87% of clients in concordant HIV positive relationships appeared to be symptomatic (WHO clinical stage 3 or 4) compared to 13% clients in HIV-discordant relationships (p < 0.003). Client's age and CD4+ count did not aptly predict serodiscordance (Wald = 0.011 and 0.436 respectively). However, the WHO clinical staging appeared to be a better

  12. Properties of the probability density function of the non-central chi-squared distribution

    NASA Astrophysics Data System (ADS)

    András, Szilárd; Baricz, Árpád

    2008-10-01

    In this paper we consider the probability density function (pdf) of a non-central [chi]2 distribution with arbitrary number of degrees of freedom. For this function we prove that can be represented as a finite sum and we deduce a partial derivative formula. Moreover, we show that the pdf is log-concave when the degrees of freedom is greater or equal than 2. At the end of this paper we present some Turán-type inequalities for this function and an elegant application of the monotone form of l'Hospital's rule in probability theory is given.

  13. A simple test of association for contingency tables with multiple column responses.

    PubMed

    Decady, Y J; Thomas, D R

    2000-09-01

    Loughin and Scherer (1998, Biometrics 54, 630-637) investigated tests of association in two-way tables when one of the categorical variables allows for multiple-category responses from individual respondents. Standard chi-squared tests are invalid in this case, and they developed a bootstrap test procedure that provides good control of test levels under the null hypothesis. This procedure and some others that have been proposed are computationally involved and are based on techniques that are relatively unfamiliar to many practitioners. In this paper, the methods introduced by Rao and Scott (1981, Journal of the American Statistical Association 76, 221-230) for analyzing complex survey data are used to develop a simple test based on a corrected chi-squared statistic.

  14. Distributional Tests for Gravitational Waves from Core-Collapse Supernovae

    NASA Astrophysics Data System (ADS)

    Szczepanczyk, Marek; LIGO Collaboration

    2017-01-01

    Core-Collapse Supernovae (CCSN) are spectacular and violent deaths of massive stars. CCSN are some of the most interesting candidates for producing gravitational-waves (GW) transients. Current published results focus on methodologies to detect single GW unmodelled transients. The advantages of these tests are that they do not require a background for which we have an analytical model. Examples of non-parametric tests that will be compared are Kolmogorov-Smirnov, Mann-Whitney, chi squared, and asymmetric chi squared. I will present methodological results using publicly released LIGO-S6 data recolored to the design sensitivity of Advanced LIGO and that will be time lagged between interferometers sites so that the resulting coincident events are not GW.

  15. Behavioral Health and Service Use Among Civilian Wives of Service Members and Veterans: Evidence from the National Survey of Drug Use and Health

    DTIC Science & Technology

    2015-01-01

    Prevalence Adjusted Odds Ratio* Disorder Category Comparison Group (%) Military Wives (%) OR 95% CI Wald Chi-Sq P-value Past-year major depression 5.93...Wives (%) OR 95% CI Wald Chi-Sq P-value Specialty treatment 6.8 7.4 1.15 (0.81, 1.62) 0.61 0.4368 Prescription drugs 12.6 18.1† 1.61 (1.23, 2.09) 12.29...Pfrommer, Lisa Miyashiro, Yashodhara Rana, and David M. Adamson, Access to Behavioral Health Care for Geographically Remote Service Members and Dependents

  16. Affected sib pair tests in inbred populations.

    PubMed

    Liu, W; Weir, B S

    2004-11-01

    The affected-sib-pair (ASP) method for detecting linkage between a disease locus and marker loci was first established 50 years ago, and since then numerous modifications have been made. We modify two identity-by-state (IBS) test statistics of Lange (Lange, 1986a, 1986b) to allow for inbreeding in the population. We evaluate the power and false positive rates of the modified tests under three disease models, using simulated data. Before estimating false positive rates, we demonstrate that IBS tests are tests of both linkage and linkage disequilibrium between marker and disease loci. Therefore, the null hypothesis of IBS tests should be no linkage and no LD. When the population inbreeding coefficient is large, the false positive rates of Lange's tests become much larger than the nominal value, while those of our modified tests remain close to the nominal value. To estimate power with a controlled false positive rate, we choose the cutoff values based on simulated datasets under the null hypothesis, so that both Lange's tests and the modified tests generate same false positive rate. The powers of Lange's z-test and our modified z-test are very close and do not change much with increasing inbreeding. The power of the modified chi-square test also stays stable when the inbreeding coefficient increases. However, the power of Lange's chi-square test increases with increasing inbreeding, and is larger than that of our modified chi-square test for large inbreeding coefficients. The power is high under a recessive disease model for both Lange's tests and the modified tests, though the power is low for additive and dominant disease models. Allowing for inbreeding is therefore appropriate, at least for diseases known to be recessive.

  17. A note on the SG( m) test

    NASA Astrophysics Data System (ADS)

    López, Fernando A.; Matilla-García, Mariano; Mur, Jesús; Páez, Antonio; Ruiz, Manuel

    2016-01-01

    López et al. (Reg Sci Urban Econ 40(2-3):106-115, 2010) introduce a nonparametric test of spatial dependence, called SG( m). The test is claimed to be consistent and asymptotically Chi-square distributed. Elsinger (Reg Sci Urban Econ 43(5):838-840, 2013) raises doubts about the two properties. Using a particular counterexample, he shows that the asymptotic distribution of the SG( m) test may be far from the Chi-square family; the property of consistency is also questioned. In this note, the authors want to clarify the properties of the SG( m) test. We argue that the cause of the conflict is in the specification of the symbolization map. The discrepancies can be solved by adjusting some of the definitions made in the original paper. Moreover, we introduce a permutational bootstrapped version of the SG( m) test, which is powerful and robust to the underlying statistical assumptions. This bootstrapped version may be very useful in an applied context.

  18. Journal of the Chinese Institute of Engineers. Special Issue: Commemoration of Chi-Chi Earthquake (II)

    NASA Astrophysics Data System (ADS)

    2002-09-01

    Contents include the following: Deep Electromagnetic Images of Seismogenic Zone of the Chi-Chi (Taiwan) Earthquake; New Techniques for Stress-Forecasting Earthquakes; Aspects of Characteristics of Near-Fault Ground Motions of the 1999 Chi-Chi (Taiwan) Earthquake; Liquefaction Damage and Related Remediation in Wufeng after the Chi-Chi Earthquake; Fines Content Effects on Liquefaction Potential Evaluation for Sites Liquefied during Chi-Chi Earthquake 1999; Damage Investigation and Liquefaction Potential Analysis of Gravelly Soil; Dynamic Characteristics of Soils in Yuan-Lin Liquefaction Area; A Preliminary Study of Earthquake Building Damage and Life Loss Due to the Chi-Chi Earthquake; Statistical Analyses of Relation between Mortality and Building Type in the 1999 Chi-Chi Earthquake; Development of an After Earthquake Disaster Shelter Evaluation Model; Posttraumatic Stress Reactions in Children and Adolescents One Year after the 1999 Taiwan Chi-Chi Earthquake; Changes or Not is the Question: the Meaning of Posttraumatic Stress Reactions One Year after the Taiwan Chi-Chi Earthquake.

  19. Effects of a 12-week program of Tai Chi exercise on the kidney disease quality of life and physical functioning of patients with end-stage renal disease on hemodialysis.

    PubMed

    Chang, Jo-Han; Koo, Malcolm; Wu, Sheng-Wen; Chen, Chiu-Yuan

    2017-02-01

    Previous studies have shown that exercise training in patients with end-stage renal disease could improve their physical functioning and quality of life. Nevertheless, few studies have evaluated the effects of Tai Chi exercise in patients on hemodialysis. To investigate the effects of a Tai Chi exercise intervention on the quality of life and physical functioning in end-stage renal disease patients on hemodialysis. A pre-post experimental design. Patients, aged 20 years or older, on hemodialysis recruited from the hemodialysis unit at a medical center in central Taiwan were assigned, based on their own preference, to either a control group (n=25) or an intervention group (n=21). A weekly one-hour short-form Yang style Tai Chi session for a total of 12 weeks. Physical functioning and Kidney Disease Quality of Life (KDQOL) at the baseline and at the end of the intervention. The least square means of repetition of sit-to-stand cycles in one minute (STS-60), 6-min walk test, and gait speed test were significantly improved in the intervention group. In addition, the least square means of the five different dimensions of the KDQOL were all significantly higher in the intervention group, except the SF-12 physical health score. Improvements in the kidney disease quality of life and physical functioning were observed in Taiwanese patients on hemodialysis with a 12-week Tai Chi exercise intervention. Copyright © 2016. Published by Elsevier Ltd.

  20. Effect of Box-Cox transformation on power of Haseman-Elston and maximum-likelihood variance components tests to detect quantitative trait Loci.

    PubMed

    Etzel, C J; Shete, S; Beasley, T M; Fernandez, J R; Allison, D B; Amos, C I

    2003-01-01

    Non-normality of the phenotypic distribution can affect power to detect quantitative trait loci in sib pair studies. Previously, we observed that Winsorizing the sib pair phenotypes increased the power of quantitative trait locus (QTL) detection for both Haseman-Elston (HE) least-squares tests [Hum Hered 2002;53:59-67] and maximum likelihood-based variance components (MLVC) analysis [Behav Genet (in press)]. Winsorizing the phenotypes led to a slight increase in type 1 error in H-E tests and a slight decrease in type I error for MLVC analysis. Herein, we considered transforming the sib pair phenotypes using the Box-Cox family of transformations. Data were simulated for normal and non-normal (skewed and kurtic) distributions. Phenotypic values were replaced by Box-Cox transformed values. Twenty thousand replications were performed for three H-E tests of linkage and the likelihood ratio test (LRT), the Wald test and other robust versions based on the MLVC method. We calculated the relative nominal inflation rate as the ratio of observed empirical type 1 error divided by the set alpha level (5, 1 and 0.1% alpha levels). MLVC tests applied to non-normal data had inflated type I errors (rate ratio greater than 1.0), which were controlled best by Box-Cox transformation and to a lesser degree by Winsorizing. For example, for non-transformed, skewed phenotypes (derived from a chi2 distribution with 2 degrees of freedom), the rates of empirical type 1 error with respect to set alpha level=0.01 were 0.80, 4.35 and 7.33 for the original H-E test, LRT and Wald test, respectively. For the same alpha level=0.01, these rates were 1.12, 3.095 and 4.088 after Winsorizing and 0.723, 1.195 and 1.905 after Box-Cox transformation. Winsorizing reduced inflated error rates for the leptokurtic distribution (derived from a Laplace distribution with mean 0 and variance 8). Further, power (adjusted for empirical type 1 error) at the 0.01 alpha level ranged from 4.7 to 17.3% across all tests

  1. From Wald to Savage: homo economicus becomes a Bayesian statistician.

    PubMed

    Giocoli, Nicola

    2013-01-01

    Bayesian rationality is the paradigm of rational behavior in neoclassical economics. An economic agent is deemed rational when she maximizes her subjective expected utility and consistently revises her beliefs according to Bayes's rule. The paper raises the question of how, when and why this characterization of rationality came to be endorsed by mainstream economists. Though no definitive answer is provided, it is argued that the question is of great historiographic importance. The story begins with Abraham Wald's behaviorist approach to statistics and culminates with Leonard J. Savage's elaboration of subjective expected utility theory in his 1954 classic The Foundations of Statistics. The latter's acknowledged fiasco to achieve a reinterpretation of traditional inference techniques along subjectivist and behaviorist lines raises the puzzle of how a failed project in statistics could turn into such a big success in economics. Possible answers call into play the emphasis on consistency requirements in neoclassical theory and the impact of the postwar transformation of U.S. business schools. © 2012 Wiley Periodicals, Inc.

  2. Simulation, Design, and Test of Square, Apodized Photon Sieves for High Contrast, Exoplanet Imaging

    DTIC Science & Technology

    reason, square apodized photon sieves were simulated, designed, and tested for high-contrast performance and use in an exoplanet imaging telescope...for apodizing sieves, measuring PSFs, and characterizing high-contrast performance. Tests indicated that square apodized sieves could detect

  3. Chi-squared Automatic Interaction Detection Decision Tree Analysis of Risk Factors for Infant Anemia in Beijing, China

    PubMed Central

    Ye, Fang; Chen, Zhi-Hua; Chen, Jie; Liu, Fang; Zhang, Yong; Fan, Qin-Ying; Wang, Lin

    2016-01-01

    Background: In the past decades, studies on infant anemia have mainly focused on rural areas of China. With the increasing heterogeneity of population in recent years, available information on infant anemia is inconclusive in large cities of China, especially with comparison between native residents and floating population. This population-based cross-sectional study was implemented to determine the anemic status of infants as well as the risk factors in a representative downtown area of Beijing. Methods: As useful methods to build a predictive model, Chi-squared automatic interaction detection (CHAID) decision tree analysis and logistic regression analysis were introduced to explore risk factors of infant anemia. A total of 1091 infants aged 6–12 months together with their parents/caregivers living at Heping Avenue Subdistrict of Beijing were surveyed from January 1, 2013 to December 31, 2014. Results: The prevalence of anemia was 12.60% with a range of 3.47%–40.00% in different subgroup characteristics. The CHAID decision tree model has demonstrated multilevel interaction among risk factors through stepwise pathways to detect anemia. Besides the three predictors identified by logistic regression model including maternal anemia during pregnancy, exclusive breastfeeding in the first 6 months, and floating population, CHAID decision tree analysis also identified the fourth risk factor, the maternal educational level, with higher overall classification accuracy and larger area below the receiver operating characteristic curve. Conclusions: The infant anemic status in metropolis is complex and should be carefully considered by the basic health care practitioners. CHAID decision tree analysis has demonstrated a better performance in hierarchical analysis of population with great heterogeneity. Risk factors identified by this study might be meaningful in the early detection and prompt treatment of infant anemia in large cities. PMID:27174328

  4. Chi-squared Automatic Interaction Detection Decision Tree Analysis of Risk Factors for Infant Anemia in Beijing, China.

    PubMed

    Ye, Fang; Chen, Zhi-Hua; Chen, Jie; Liu, Fang; Zhang, Yong; Fan, Qin-Ying; Wang, Lin

    2016-05-20

    In the past decades, studies on infant anemia have mainly focused on rural areas of China. With the increasing heterogeneity of population in recent years, available information on infant anemia is inconclusive in large cities of China, especially with comparison between native residents and floating population. This population-based cross-sectional study was implemented to determine the anemic status of infants as well as the risk factors in a representative downtown area of Beijing. As useful methods to build a predictive model, Chi-squared automatic interaction detection (CHAID) decision tree analysis and logistic regression analysis were introduced to explore risk factors of infant anemia. A total of 1091 infants aged 6-12 months together with their parents/caregivers living at Heping Avenue Subdistrict of Beijing were surveyed from January 1, 2013 to December 31, 2014. The prevalence of anemia was 12.60% with a range of 3.47%-40.00% in different subgroup characteristics. The CHAID decision tree model has demonstrated multilevel interaction among risk factors through stepwise pathways to detect anemia. Besides the three predictors identified by logistic regression model including maternal anemia during pregnancy, exclusive breastfeeding in the first 6 months, and floating population, CHAID decision tree analysis also identified the fourth risk factor, the maternal educational level, with higher overall classification accuracy and larger area below the receiver operating characteristic curve. The infant anemic status in metropolis is complex and should be carefully considered by the basic health care practitioners. CHAID decision tree analysis has demonstrated a better performance in hierarchical analysis of population with great heterogeneity. Risk factors identified by this study might be meaningful in the early detection and prompt treatment of infant anemia in large cities.

  5. An Ai Chi-based aquatic group improves balance and reduces falls in community-dwelling adults: A pilot observational cohort study.

    PubMed

    Skinner, Elizabeth H; Dinh, Tammy; Hewitt, Melissa; Piper, Ross; Thwaites, Claire

    2016-11-01

    Falls are associated with morbidity, loss of independence, and mortality. While land-based group exercise and Tai Chi programs reduce the risk of falls, aquatic therapy may allow patients to complete balance exercises with less pain and fear of falling; however, limited data exist. The objective of the study was to pilot the implementation of an aquatic group based on Ai Chi principles (Aquabalance) and to evaluate the safety, intervention acceptability, and intervention effect sizes. Pilot observational cohort study. Forty-two outpatients underwent a single 45-minute weekly group aquatic Ai Chi-based session for eight weeks (Aquabalance). Safety was monitored using organizational reporting systems. Patient attendance, satisfaction, and self-reported falls were also recorded. Balance measures included the Timed Up and Go (TUG) test, the Four Square Step Test (FSST), and the unilateral Step Tests. Forty-two patients completed the program. It was feasible to deliver Aquabalance, as evidenced by the median (IQR) attendance rate of 8.0 (7.8, 8.0) out of 8. No adverse events occurred and participants reported high satisfaction levels. Improvements were noted on the TUG, 10-meter walk test, the Functional Reach Test, the FSST, and the unilateral step tests (p < 0.05). The proportion of patients defined as high falls risk reduced from 38% to 21%. The study was limited by its small sample size, single-center nature, and the absence of a control group. Aquabalance was safe, well-attended, and acceptable to participants. A randomized controlled assessor-blinded trial is required.

  6. Comparative studies of differential expression of chitinolytic enzymes encoded by chiA, chiB, chiC and nagA genes in Aspergillus nidulans.

    PubMed

    Pusztahelyi, T; Molnár, Z; Emri, T; Klement, E; Miskei, M; Kerékgyárto, J; Balla, J; Pócsi, I

    2006-01-01

    N-Acetyl-D-glucosamine, chito-oligomers and carbon starvation regulated chiA, chiB, and nagA gene expressions in Aspergillus nidulans cultures. The gene expression patterns of the main extracellular endochitinase ChiB and the N-acetyl-beta-D-glucosaminidase NagA were similar, and the ChiB-NagA enzyme system may play a morphological and/or nutritional role during autolysis. Alterations in the levels of reactive oxygen species or in the glutathione-glutathione disulfide redox balance, characteristic physiological changes developing in ageing and autolyzing fungal cultures, did not affect the regulation of either the growth-related chiA or the autolysis-coupled chiB genes although both of them were down-regulated under diamide stress. The transcription of the chiC gene with unknown physiological function was repressed by increased intracellular superoxide concentration.

  7. An Extension of RSS-based Model Comparison Tests for Weighted Least Squares

    DTIC Science & Technology

    2012-08-22

    use the model comparison test statistic to analyze the null hypothesis. Under the null hypothesis, the weighted least squares cost functional is JWLS ...q̂WLSH ) = 10.3040×106. Under the alternative hypothesis, the weighted least squares cost functional is JWLS (q̂WLS) = 8.8394 × 106. Thus the model

  8. Spatial Autocorrelation Approaches to Testing Residuals from Least Squares Regression.

    PubMed

    Chen, Yanguang

    2016-01-01

    In geo-statistics, the Durbin-Watson test is frequently employed to detect the presence of residual serial correlation from least squares regression analyses. However, the Durbin-Watson statistic is only suitable for ordered time or spatial series. If the variables comprise cross-sectional data coming from spatial random sampling, the test will be ineffectual because the value of Durbin-Watson's statistic depends on the sequence of data points. This paper develops two new statistics for testing serial correlation of residuals from least squares regression based on spatial samples. By analogy with the new form of Moran's index, an autocorrelation coefficient is defined with a standardized residual vector and a normalized spatial weight matrix. Then by analogy with the Durbin-Watson statistic, two types of new serial correlation indices are constructed. As a case study, the two newly presented statistics are applied to a spatial sample of 29 China's regions. These results show that the new spatial autocorrelation models can be used to test the serial correlation of residuals from regression analysis. In practice, the new statistics can make up for the deficiencies of the Durbin-Watson test.

  9. Spatial Autocorrelation Approaches to Testing Residuals from Least Squares Regression

    PubMed Central

    Chen, Yanguang

    2016-01-01

    In geo-statistics, the Durbin-Watson test is frequently employed to detect the presence of residual serial correlation from least squares regression analyses. However, the Durbin-Watson statistic is only suitable for ordered time or spatial series. If the variables comprise cross-sectional data coming from spatial random sampling, the test will be ineffectual because the value of Durbin-Watson’s statistic depends on the sequence of data points. This paper develops two new statistics for testing serial correlation of residuals from least squares regression based on spatial samples. By analogy with the new form of Moran’s index, an autocorrelation coefficient is defined with a standardized residual vector and a normalized spatial weight matrix. Then by analogy with the Durbin-Watson statistic, two types of new serial correlation indices are constructed. As a case study, the two newly presented statistics are applied to a spatial sample of 29 China’s regions. These results show that the new spatial autocorrelation models can be used to test the serial correlation of residuals from regression analysis. In practice, the new statistics can make up for the deficiencies of the Durbin-Watson test. PMID:26800271

  10. PTSD's underlying symptom dimensions and relations with behavioral inhibition and activation.

    PubMed

    Contractor, Ateka A; Elhai, Jon D; Ractliffe, Kendra C; Forbes, David

    2013-10-01

    Reinforcement sensitivity theory (RST) stipulates that individuals have a behavioral activation system (BAS) guiding approach (rewarding) behaviors (Gray, 1971, 1981), and behavioral inhibition system (BIS) guiding conflict resolution between approach and avoidance (punishment) behaviors (Gray & McNaughton, 2000). Posttraumatic stress disorder (PTSD) severity overall relates to both BIS (e.g., Myers, VanMeenen, & Servatius, 2012; Pickett, Bardeen, & Orcutt, 2011) and BAS (Pickett et al., 2011). Using a more refined approach, we assessed specific relations between PTSD's latent factors (Simms, Watson, & Doebbeling, 2002) and observed variables measuring BIS and BAS using 308 adult, trauma-exposed primary care patients. Confirmatory factor analysis and Wald chi-square tests demonstrated a significantly greater association with BIS severity compared to BAS severity for PTSD's dysphoria, avoidance, and re-experiencing factors. Further, PTSD's avoidance factor significantly mediated relations between BIS/BAS severity and PTSD's dysphoria factor. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Obituary: Chi Yuan (1937-2008)

    NASA Astrophysics Data System (ADS)

    Ho, Paul

    2011-12-01

    Chi Yuan graduated from the National Taiwan University in1959, and received his Masters of Science degree from the University of Florida in 1962, and his Doctor of Philosophy from the University of Michigan in 1966. He was a postdoctoral fellow with Professor C.C. Lin at MIT for three years, before taking his faculty post at the City College of New York in 1969. He attained full professorship at CCNY in 1981. From 1994-1996, Chi returned to Taiwan as Director of the newly found Academia Sinica Institute of Astronomy and Astrophysics (ASIAA). From 1997-2002, he was the recipient of an Outstanding Scholar Award, reserved for the most distinguished scientists employed in Taiwan. Chi retired from ASIAA in 2007, but continued to be active in his research during his two-year fight with brain cancer. Chi Yuan made his greatest impact with his work on the density-wave theory for spiral arm structures in galaxies, with C.C. Lin and Frank Shu. His early work elucidated the observational tests of density-wave theory, and the effects of magnetic fields in galactic shocks. In the 1980s, Chi Yuan worked on spiral density waves in Saturn's rings. In the past two decades, Chi Yuan concentrated on the problem of barred and spiral structures in the nuclei of galaxies, with their implications for fueling the central supermassive black holes. He also worked on the problem of the migration of giant extrasolar planets in their solar disks. These studies were made possible by his establishment of a program on computational fluid dynamics, which became one of the key initiatives in theory at the ASIAA. Among his academic records, two contributions are particularly notable. First, with Typhoon Lee, Fred Lo, and Frank Shu, Chi Yuan founded the ASIAA in order to stimulate the growth of astronomy in Taiwan. Second, and perhaps his greatest influence, has been his training and mentoring of a great number of students in astrophysics, especially for the last 20 years in Taiwan. Today, astronomy

  12. Do older t'ai chi practitioners have better attention and memory function?

    PubMed

    Man, David W K; Tsang, William W N; Hui-Chan, Christina W Y

    2010-12-01

    Cognitive declines are common in older people and can be a major health issue in an aging world. One type of body-mind exercises, t'ai chi, can be a possible means to help maintaining older adults' cognitive abilities, in addition to beneficial effects of physical exercises. The purpose of this study was to investigate whether t'ai chi practitioners had better attention and memory functions than older people with or without regular exercises. A cross-sectional study examining the relationship between t'ai chi practice and age-, gender- and education-similar older peoples' attention and memory functions. Forty-two (42) community-dwelling elderly subjects, aged 60 or older, recruited from t'ai chi clubs in Hong Kong formed the t'ai chi group. Another 49 elderly having regular exercise habits were recruited from community centers for inclusion in the exercise group. A nonexercise group (normal healthy control) consisting of 44 subjects were also recruited by random selection and through contacting local elderly centers. They were also screened by the Modified Barthel Index, Chinese Mini-mental Status Examination, Geriatric Depression Scale, and evaluated by attention tests (Color Trail Form A-1 and 2) and memory tests (including Rivermead Behavioral Memory Test and The Hong Kong List Learning Test). The main finding was that the three groups differed in attention and memory functions, and the t'ai chi group had demonstrated better performance than the other two groups in most subtests. As a causal relationship cannot be assumed in the present cross-sectional study, future research is required to examine how t'ai chi can improve cognitive function using a randomized control trial as well as determining whether t'ai chi practice can lead to better health status among elderly people.

  13. A Monte Carlo Approach to Unidimensionality Testing in Polytomous Rasch Models

    ERIC Educational Resources Information Center

    Christensen, Karl Bang; Kreiner, Svend

    2007-01-01

    Many statistical tests are designed to test the different assumptions of the Rasch model, but only few are directed at detecting multidimensionality. The Martin-Lof test is an attractive approach, the disadvantage being that its null distribution deviates strongly from the asymptotic chi-square distribution for most realistic sample sizes. A Monte…

  14. Slip distribution and tectonic implication of the 1999 Chi-Chi, Taiwan, earthquake

    USGS Publications Warehouse

    Ji, C.; Helmberger, D.V.; Song, T.-R.A.; Ma, K.-F.; Wald, D.J.

    2001-01-01

    We report on the fault complexity of the large (Mw = 7.6) Chi-Chi earthquake obtained by inverting densely and well-distributed static measurements consisting of 119 GPS and 23 doubly integrated strong motion records. We show that the slip of the Chi-Chi earthquake was concentrated on the surface of a "wedge shaped" block. The inferred geometric complexity explains the difference between the strike of the fault plane determined by long period seismic data and surface break observations. When combined with other geophysical and geological observations, the result provides a unique snapshot of tectonic deformation taking place in the form of very large (>10m) displacements of a massive wedge-shaped crustal block which may relate to the changeover from over-thrusting to subducting motion between the Philippine Sea and the Eurasian plates.

  15. Observations of changes in waveform character induced by the 1999 Mw7.6 Chi-Chi earthquake

    USGS Publications Warehouse

    Chen, K.H.; Furumura, T.; Rubinstein, J.; Rau, R.-J.

    2011-01-01

    We observe changes in the waveforms of repeating earthquakes in eastern Taiwan following the 1999 Mw7.6 Chi-Chi earthquake, while their recurrence intervals appear to be unaffected. There is a clear reduction in waveform similarity and velocity changes indicated by delayed phases at the time of the Chi-Chi event. These changes are limited to stations in and paths that cross the 70 × 100 km region surrounding the Chi-Chi source area, the area where seismic intensity and co-seismic surface displacements were largest. This suggests that damage at the near-surface is responsible for the observed waveform changes. Delays are largest in the late S-wave coda, reaching approximately 120 ms. This corresponds to a path averaged Swave velocity reduction of approximately 1%. There is also evidence that damage in the fault-zone caused changes in waveform character at sites in the footwall, where source-receiver paths propagate either along or across the rupture. The reduction in waveform similarity persists through the most recent repeating event in our study (November 15, 2007), indicating that the subsurface damage induced by the Chi-Chi earthquake did not fully heal within the first 8 years following the Chi-Chi earthquake.

  16. Tai chi and chronic pain.

    PubMed

    Peng, Philip W H

    2012-01-01

    In the last 2 decades, a growing body of research aimed at investigating the health benefits of Tai Chi in various chronic health conditions has been recognized in the literature. This article reviewed the history, the philosophy, and the evidence for the role of Tai Chi in a few selected chronic pain conditions. The ancient health art of Tai Chi contributes to chronic pain management in 3 major areas: adaptive exercise, mind-body interaction, and meditation. Trials examining the health benefit of Tai Chi in chronic pain conditions are mostly low quality. Only 5 pain conditions were reviewed: osteoarthritis, fibromyalgia, rheumatoid arthritis, low back pain, and headache. Of these, Tai Chi seems to be an effective intervention in osteoarthritis, low back pain, and fibromyalgia. The limitations of the Tai Chi study design and suggestions for the direction of future research are also discussed.

  17. T'ai chi ch'uan.

    PubMed

    Lewis, D E

    2000-11-01

    The Chinese practice of t'ai chi seems to be receiving increased interest in the West. This article gives a brief overview of t'ai chi, including its origins, development, principles and potential health benefits. The function of the essential elements of t'ai chi, namely the Form and chi kung are described and their potential benefits for patients and nurses are discussed. Exponents of t'ai chi believe that it has health benefits on physical, psychological and spiritual levels, thus promoting a feeling of well-being. In addition, regular practitioners are empowered to be in greater control of themselves, their health, and situations in which they find themselves.

  18. Wald Sequential Probability Ratio Test for Space Object Conjunction Assessment

    NASA Technical Reports Server (NTRS)

    Carpenter, James R.; Markley, F Landis

    2014-01-01

    This paper shows how satellite owner/operators may use sequential estimates of collision probability, along with a prior assessment of the base risk of collision, in a compound hypothesis ratio test to inform decisions concerning collision risk mitigation maneuvers. The compound hypothesis test reduces to a simple probability ratio test, which appears to be a novel result. The test satisfies tolerances related to targeted false alarm and missed detection rates. This result is independent of the method one uses to compute the probability density that one integrates to compute collision probability. A well-established test case from the literature shows that this test yields acceptable results within the constraints of a typical operational conjunction assessment decision timeline. Another example illustrates the use of the test in a practical conjunction assessment scenario based on operations of the International Space Station.

  19. A Method for Assessing Change in Attitude: The McNemar Test.

    ERIC Educational Resources Information Center

    Ciechalski, Joseph C.; Pinkney, James W.; Weaver, Florence S.

    This paper illustrates the use of the McNemar Test, using a hypothetical problem. The McNemar Test is a nonparametric statistical test that is a type of chi square test using dependent, rather than independent, samples to assess before-after designs in which each subject is used as his or her own control. Results of the McNemar test make it…

  20. A Probability Based Framework for Testing the Missing Data Mechanism

    ERIC Educational Resources Information Center

    Lin, Johnny Cheng-Han

    2013-01-01

    Many methods exist for imputing missing data but fewer methods have been proposed to test the missing data mechanism. Little (1988) introduced a multivariate chi-square test for the missing completely at random data mechanism (MCAR) that compares observed means for each pattern with expectation-maximization (EM) estimated means. As an alternative,…

  1. A note on the misuses of the variance test in meteorological studies

    NASA Astrophysics Data System (ADS)

    Hazra, Arnab; Bhattacharya, Sourabh; Banik, Pabitra; Bhattacharya, Sabyasachi

    2017-12-01

    Stochastic modeling of rainfall data is an important area in meteorology. The gamma distribution is a widely used probability model for non-zero rainfall. Typically the choice of the distribution for such meteorological studies is based on two goodness-of-fit tests—the Pearson's Chi-square test and the Kolmogorov-Smirnov test. Inspired by the index of dispersion introduced by Fisher (Statistical methods for research workers. Hafner Publishing Company Inc., New York, 1925), Mooley (Mon Weather Rev 101:160-176, 1973) proposed the variance test as a goodness-of-fit measure in this context and a number of researchers have implemented it since then. We show that the asymptotic distribution of the test statistic for the variance test is generally not comparable to any central Chi-square distribution and hence the test is erroneous. We also describe a method for checking the validity of the asymptotic distribution for a class of distributions. We implement the erroneous test on some simulated, as well as real datasets and demonstrate how it leads to some wrong conclusions.

  2. Factor Structure of the PTSD Checklist for DSM-5: Relationships Among Symptom Clusters, Anger, and Impulsivity.

    PubMed

    Armour, Cherie; Contractor, Ateka; Shea, Tracie; Elhai, Jon D; Pietrzak, Robert H

    2016-02-01

    Scarce data are available regarding the dimensional structure of Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) posttraumatic stress disorder (PTSD) symptoms and how factors relate to external constructs. We evaluated six competing models of DSM-5 PTSD symptoms, including Anhedonia, Externalizing Behaviors, and Hybrid models, using confirmatory factor analyses in a sample of 412 trauma-exposed college students. We then examined whether PTSD symptom clusters were differentially related to measures of anger and impulsivity using Wald chi-square tests. The seven-factor Hybrid model was deemed optimal compared with the alternatives. All symptom clusters were associated with anger; the strongest association was between externalizing behaviors and anger (r = 0.54). All symptom clusters, except re-experiencing and avoidance, were associated with impulsivity, with the strongest association between externalizing behaviors and impulsivity (r = 0.49). A seven-factor Hybrid model provides superior fit to DSM-5 PTSD symptom data, with the externalizing behaviors factor being most strongly related to anger and impulsivity.

  3. Tai Chi for Posttraumatic Stress Disorder and Chronic Musculoskeletal Pain: A Pilot Study.

    PubMed

    Tsai, Pao-Feng; Kitch, Stephanie; Chang, Jason Y; James, G Andrew; Dubbert, Patricia; Roca, J Vincent; Powers, Cheralyn H

    2018-06-01

    Explore the feasibility of a Tai Chi intervention to improve musculoskeletal pain, emotion, cognition, and physical function in individuals with posttraumatic stress disorder. Two-phase, one-arm quasi-experimental design. Phase 1: 11 participants completed one Tai Chi session, feasibility questionnaire, and were offered participation in Phase 2, a 12-week Tai Chi intervention. Ten participants participated in Phase 2. Pain intensity, interference, physical function scales, an emotional battery, and cognition tests were used for pre- and postintervention outcome measures. Paired t tests and thematic analysis were used for analysis. In Phase 1, most felt Tai Chi would benefit health (90.9%) and expressed interest in continuing Tai Chi (6.73 out of 7). Phase 2 results showed improvement in fear-affect (raw t = -2.64, p = .03; age adjusted t = -2.90, p = .02), fear-somatic arousal (raw t = -2.53, p = .035), List Sorting Working Memory (raw t = 2.62, p = .031; age adjusted t = 2.96, p = .018), 6-Minute Walk Test ( t = 3.541, p = .008), and current level of Pain Intensity ( t = -4.00, p = .004). Tai Chi is an acceptable, holistic treatment to individuals with musculoskeletal pain and posttraumatic stress disorder. It may reduce pain, improve emotion, memory, and physical function.

  4. Stress Management: Tai Chi

    MedlinePlus

    ... in constant motion. Tai chi has many different styles. Each style may subtly emphasize various tai chi principles and methods. There are variations within each style. Some styles may focus on health maintenance, while ...

  5. Two-color holography concept (T-CHI)

    NASA Technical Reports Server (NTRS)

    Vikram, C. S.; Caulfield, H. J.; Workman, G. L.; Trolinger, J. D.; Wood, C. P.; Clark, R. L.; Kathman, A. D.; Ruggiero, R. M.

    1990-01-01

    The Material Processing in the Space Program of NASA-MSFC was active in developing numerous optical techniques for the characterization of fluids in the vicinity of various materials during crystallization and/or solidification. Two-color holographic interferometry demonstrates that temperature and concentration separation in transparent (T-CHI) model systems is possible. The experiments were performed for particular (succinonitrile) systems. Several solutions are possible in Microgravity Sciences and Applications (MSA) experiments on future Shuttle missions. The theory of the T-CHI concept is evaluated. Although particular cases are used for explanations, the concepts developed will be universal. A breadboard system design is also presented for ultimate fabrication and testing of theoretical findings. New developments in holography involving optical fibers and diode lasers are also incorporated.

  6. Observations of changes in waveform character induced by the 1999 M w7.6 Chi-Chi earthquake

    USGS Publications Warehouse

    Chen, K.H.; Furumura, T.; Rubinstein, J.; Rau, R.-J.

    2011-01-01

    We observe changes in the waveforms of repeating earthquakes in eastern Taiwan following the 1999 Mw7.6 Chi-Chi earthquake, while their recurrence intervals appear to be unaffected. There is a clear reduction in waveform similarity and velocity changes indicated by delayed phases at the time of the Chi-Chi event. These changes are limited to stations in and paths that cross the 70 ?? 100 km region surrounding the Chi-Chi source area, the area where seismic intensity and co-seismic surface displacements were largest. This suggests that damage at the near-surface is responsible for the observed waveform changes. Delays are largest in the late S-wave coda, reaching approximately 120 ms. This corresponds to a path averaged S wave velocity reduction of approximately 1%. There is also evidence that damage in the fault-zone caused changes in waveform character at sites in the footwall, where source-receiver paths propagate either along or across the rupture. The reduction in waveform similarity persists through the most recent repeating event in our study (November 15, 2007), indicating that the subsurface damage induced by the Chi-Chi earthquake did not fully heal within the first 8 years following the Chi-Chi earthquake. ?? 2011 by the American Geophysical Union.

  7. Empirical likelihood-based confidence intervals for the sensitivity of a continuous-scale diagnostic test at a fixed level of specificity.

    PubMed

    Gengsheng Qin; Davis, Angela E; Jing, Bing-Yi

    2011-06-01

    For a continuous-scale diagnostic test, it is often of interest to find the range of the sensitivity of the test at the cut-off that yields a desired specificity. In this article, we first define a profile empirical likelihood ratio for the sensitivity of a continuous-scale diagnostic test and show that its limiting distribution is a scaled chi-square distribution. We then propose two new empirical likelihood-based confidence intervals for the sensitivity of the test at a fixed level of specificity by using the scaled chi-square distribution. Simulation studies are conducted to compare the finite sample performance of the newly proposed intervals with the existing intervals for the sensitivity in terms of coverage probability. A real example is used to illustrate the application of the recommended methods.

  8. Some Exact Conditional Tests of Independence for R X C Cross-Classification Tables

    ERIC Educational Resources Information Center

    Agresti, Alan; Wackerly, Dennis

    1977-01-01

    Exact conditional tests of independence in cross-classification tables are formulated based on chi square and other statistics with stronger operational interpretations, such as some nominal and ordinal measures of association. Guidelines for table dimensions and sample sizes for which the tests are economically implemented on a computer are…

  9. The impact of prism adaptation test on surgical outcomes in patients with primary exotropia.

    PubMed

    Kiyak Yilmaz, Ayse; Kose, Suheyla; Guven Yilmaz, Suzan; Uretmen, Onder

    2015-05-01

    We aimed to determine the impact of the preoperative prism adaptation test (PAT) on surgical outcomes in patients with primary exotropia. Thirty-eight consecutive patients with primary exotropia were enrolled. Pre-operative PAT was performed in 18 randomly selected patients (Group 1). Surgery was based on the angle of deviation at distance measured after PAT. The remaining 20 patients in whom PAT was not performed comprised Group 2. Surgery was based on the angle of deviation at distance in these patients. Surgical success was defined as ocular alignment within eight prism dioptres (PD) of orthophoria. Satisfactory motor alignment (± 8 PD) was achieved in 16 Group 1 patients (88.9 per cent) and 16 Group 2 patients (80 per cent) one year after surgery (p = 0.6; chi-square test). There were no statistically significant differences in demographic parameters, pre-operative and post-operative angle of deviation between the two groups (p > 0.05; Mann-Whitney U and chi-square tests). Nine patients in Group 1 (50 per cent) and two patients in Group 2 (10 per cent) had increased binocular vision one year post-operatively. A statistically significant difference was determined in terms of change in binocular single vision between the two groups (p = 0.01; chi-square test). Although the prism adaptation test did not lead to a significant increment in motor success, it may be helpful in achieving a more favourable functional surgical outcome in patients with primary exotropia. © 2014 The Authors. Clinical and Experimental Optometry © 2014 Optometrists Association Australia.

  10. Biomedical wellness by tai chi and sports

    NASA Astrophysics Data System (ADS)

    Chin, Daniel C.; Chin, Amita G.

    2011-06-01

    Tai-chi chuan is popular worldwide especially in China. People practice tai-chi chuan daily with faith believing that they will be rewarded with health and varieties of other rewords. The Tai Chi Chuan Theory by Master Chang and the Tai Chi Chuan Theory by Master Wang are translated to be the baseline of the tai-chi chuan. The theory described in these two papers clearly shows that the tai-chi power source is the combination of the two antigravity forces distinction by each foot. The ying, yang and hollowed, solid discussed in the papers are the properties and body relationship of the two antigravity forces. The antigravity forces presented inside of body are as air to the balloon termed chi. However chi could be generated by any muscle pressing; only the antigravity forces from feet are called nature chi that has the maximum strength of the person. When a person is soft, as an infant the nature chi will fulfill entire body with no time and effort. The sequence forms were designed for deploying the nature chi in speed and power. The combination of chi and tai-chi form make tai chi chuan supreme than other kinds of martial art. In the training process chi massages whole body many time for a sequence form practice that stimulate all organs and could lead to cure body diseases, lose weight, postpone aging process, and remove the aging symptoms. For the people practicing in the park daily with proper guidance they will fulfill their wishes. Tai chi exercise could also apply to other sports as in dancing and golfing they are discussed at the end of the paper.

  11. Tai-Chi Chuan; Teacher's Handbook.

    ERIC Educational Resources Information Center

    Huang, Joe, Ed.

    The exercises and basic movements of Tai-chi Chuan, one form of the Chinese martial arts, are described and illustrated (through photographs) in this teaching guide. Chinese terms used in the text are defined, the benefits of Tai-chi Chuan are discussed, and background information concerning the history of Chinese martial arts and Tai-chi Chuan is…

  12. Analysis of static and dynamic balance in healthy elderly practitioners of Tai Chi Chuan versus ballroom dancing

    PubMed Central

    Rahal, Miguel Antônio; Alonso, Angélica Castilho; Andrusaitis, Felix Ricardo; Rodrigues, Thuam Silva; Speciali, Danielli Souza; Greve, Júlia Maria D′Andréa; Leme, Luiz Eugênio Garcez

    2015-01-01

    OBJECTIVE: To determine whether Tai Chi Chuan or ballroom dancing promotes better performance with respect to postural balance, gait, and postural transfer among elderly people. METHODS: We evaluated 76 elderly individuals who were divided into two groups: the Tai Chi Chuan Group and the Dance Group. The subjects were tested using the NeuroCom Balance Master® force platform system with the following protocols: static balance tests (the Modified Clinical Tests of Sensory Interaction on Balance and Unilateral Stance) and dynamic balance tests (the Walk Across Test and Sit-to-stand Transfer Test). RESULTS: In the Modified Clinical Test of Sensory Interaction on Balance, the Tai Chi Chuan Group presented a lower sway velocity on a firm surface with open and closed eyes, as well as on a foam surface with closed eyes. In the Modified Clinical Test of Sensory Interaction on Unilateral Stance, the Tai Chi Chuan Group presented a lower sway velocity with open eyes, whereas the Dance Group presented a lower sway velocity with closed eyes. In the Walk Across Test, the Tai Chi Chuan Group presented faster walking speeds than those of the Dance Group. In the Sit-to-stand Transfer Test, the Tai Chi Chuan Group presented shorter transfer times from the sitting to the standing position, with less sway in the final standing position. CONCLUSION: The elderly individuals who practiced Tai Chi Chuan had better bilateral balance with eyes open on both types of surfaces compared with the Dance Group. The Dance Group had better unilateral postural balance with eyes closed. The Tai Chi Chuan Group had faster walking speeds, shorter transfer times, and better postural balance in the final standing position during the Sit-to-stand Test. PMID:26017644

  13. Analysis of static and dynamic balance in healthy elderly practitioners of Tai Chi Chuan versus ballroom dancing.

    PubMed

    Rahal, Miguel Antônio; Alonso, Angélica Castilho; Andrusaitis, Felix Ricardo; Rodrigues, Thuam Silva; Speciali, Danielli Souza; Greve, Júlia Maria D Andréa; Leme, Luiz Eugênio Garcez

    2015-03-01

    To determine whether Tai Chi Chuan or ballroom dancing promotes better performance with respect to postural balance, gait, and postural transfer among elderly people. We evaluated 76 elderly individuals who were divided into two groups: the Tai Chi Chuan Group and the Dance Group. The subjects were tested using the NeuroCom Balance Master¯ force platform system with the following protocols: static balance tests (the Modified Clinical Tests of Sensory Interaction on Balance and Unilateral Stance) and dynamic balance tests (the Walk Across Test and Sit-to-stand Transfer Test). In the Modified Clinical Test of Sensory Interaction on Balance, the Tai Chi Chuan Group presented a lower sway velocity on a firm surface with open and closed eyes, as well as on a foam surface with closed eyes. In the Modified Clinical Test of Sensory Interaction on Unilateral Stance, the Tai Chi Chuan Group presented a lower sway velocity with open eyes, whereas the Dance Group presented a lower sway velocity with closed eyes. In the Walk Across Test, the Tai Chi Chuan Group presented faster walking speeds than those of the Dance Group. In the Sit-to-stand Transfer Test, the Tai Chi Chuan Group presented shorter transfer times from the sitting to the standing position, with less sway in the final standing position. The elderly individuals who practiced Tai Chi Chuan had better bilateral balance with eyes open on both types of surfaces compared with the Dance Group. The Dance Group had better unilateral postural balance with eyes closed. The Tai Chi Chuan Group had faster walking speeds, shorter transfer times, and better postural balance in the final standing position during the Sit-to-stand Test.

  14. Blockage Testing in the NASA Glenn 225 Square Centimeter Supersonic Wind Tunnel

    NASA Technical Reports Server (NTRS)

    Sevier, Abigail; Davis, David; Schoenenberger, Mark

    2017-01-01

    A feasibility study is in progress at NASA Glenn Research Center to implement a magnetic suspension and balance system in the 225 sq cm Supersonic Wind Tunnel for the purpose of testing the dynamic stability of blunt bodies. An important area of investigation in this study was determining the optimum size of the model and the iron spherical core inside of it. In order to minimize the required magnetic field and thus the size of the magnetic suspension system, it was determined that the test model should be as large as possible. Blockage tests were conducted to determine the largest possible model that would allow for tunnel start at Mach 2, 2.5, and 3. Three different forebody model geometries were tested at different Mach numbers, axial locations in the tunnel, and in both a square and axisymmetric test section. Experimental results showed that different model geometries produced more varied results at higher Mach Numbers. It was also shown that testing closer to the nozzle allowed larger models to start compared with testing near the end of the test section. Finally, allowable model blockage was larger in the axisymmetric test section compared with the square test section at the same Mach number. This testing answered key questions posed by the feasibility study and will be used in the future to dictate model size and performance required from the magnetic suspension system.

  15. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sen, Satyabrata; Rao, Nageswara S; Wu, Qishi

    There have been increasingly large deployments of radiation detection networks that require computationally fast algorithms to produce prompt results over ad-hoc sub-networks of mobile devices, such as smart-phones. These algorithms are in sharp contrast to complex network algorithms that necessitate all measurements to be sent to powerful central servers. In this work, at individual sensors, we employ Wald-statistic based detection algorithms which are computationally very fast, and are implemented as one of three Z-tests and four chi-square tests. At fusion center, we apply the K-out-of-N fusion to combine the sensors hard decisions. We characterize the performance of detection methods bymore » deriving analytical expressions for the distributions of underlying test statistics, and by analyzing the fusion performances in terms of K, N, and the false-alarm rates of individual detectors. We experimentally validate our methods using measurements from indoor and outdoor characterization tests of the Intelligence Radiation Sensors Systems (IRSS) program. In particular, utilizing the outdoor measurements, we construct two important real-life scenarios, boundary surveillance and portal monitoring, and present the results of our algorithms.« less

  16. New methods of testing nonlinear hypothesis using iterative NLLS estimator

    NASA Astrophysics Data System (ADS)

    Mahaboob, B.; Venkateswarlu, B.; Mokeshrayalu, G.; Balasiddamuni, P.

    2017-11-01

    This research paper discusses the method of testing nonlinear hypothesis using iterative Nonlinear Least Squares (NLLS) estimator. Takeshi Amemiya [1] explained this method. However in the present research paper, a modified Wald test statistic due to Engle, Robert [6] is proposed to test the nonlinear hypothesis using iterative NLLS estimator. An alternative method for testing nonlinear hypothesis using iterative NLLS estimator based on nonlinear hypothesis using iterative NLLS estimator based on nonlinear studentized residuals has been proposed. In this research article an innovative method of testing nonlinear hypothesis using iterative restricted NLLS estimator is derived. Pesaran and Deaton [10] explained the methods of testing nonlinear hypothesis. This paper uses asymptotic properties of nonlinear least squares estimator proposed by Jenrich [8]. The main purpose of this paper is to provide very innovative methods of testing nonlinear hypothesis using iterative NLLS estimator, iterative NLLS estimator based on nonlinear studentized residuals and iterative restricted NLLS estimator. Eakambaram et al. [12] discussed least absolute deviation estimations versus nonlinear regression model with heteroscedastic errors and also they studied the problem of heteroscedasticity with reference to nonlinear regression models with suitable illustration. William Grene [13] examined the interaction effect in nonlinear models disused by Ai and Norton [14] and suggested ways to examine the effects that do not involve statistical testing. Peter [15] provided guidelines for identifying composite hypothesis and addressing the probability of false rejection for multiple hypotheses.

  17. Tai chi and rheumatic diseases.

    PubMed

    Wang, Chenchen

    2011-02-01

    Tai chi is a complex multicomponent mind-body exercise. Many studies have provided evidence that tai chi benefits patients with a variety of chronic disorders. This form of mind-body exercise enhances cardiovascular fitness, muscular strength, balance, and physical function and seems to be associated with reduced stress, anxiety, and depression and improved quality of life. Thus, despite certain limitations in the evidence, tai chi can be recommended to patients with osteoarthritis, rheumatoid arthritis, and fibromyalgia as a complementary and alternative medical approach. This article overviews the current knowledge about tai chi to better inform clinical decision making for rheumatic patients. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. Computerized Classification Testing with the Rasch Model

    ERIC Educational Resources Information Center

    Eggen, Theo J. H. M.

    2011-01-01

    If classification in a limited number of categories is the purpose of testing, computerized adaptive tests (CATs) with algorithms based on sequential statistical testing perform better than estimation-based CATs (e.g., Eggen & Straetmans, 2000). In these computerized classification tests (CCTs), the Sequential Probability Ratio Test (SPRT) (Wald,…

  19. A randomized controlled trial of tai chi for long-term low back pain (TAI CHI): study rationale, design, and methods.

    PubMed

    Hall, Amanda M; Maher, Chris G; Latimer, Jane; Ferreira, Manuela L; Lam, Paul

    2009-05-28

    Low back pain persisting for longer than 3 months is a common and costly condition for which many current treatments have low-moderate success rates at best. Exercise is among the more successful treatments for this condition, however, the type and dosage of exercise that elicits the best results is not clearly defined. Tai chi is a gentle form of low intensity exercise that uses controlled movements in combination with relaxation techniques and is currently used as a safe form of exercise for people suffering from other chronic pain conditions such as arthritis. To date, there has been no scientific evaluation of tai chi as an intervention for people with back pain. Thus the aim of this study will be to examine the effects of a tai chi exercise program on pain and disability in people with long-term low back pain. The study will recruit 160 healthy individuals from the community setting to be randomised to either a tai chi intervention group or a wait-list control group. Individuals in the tai chi group will attend 2 tai chi sessions (40 minutes)/week for 8 weeks followed by 1 tai chi session/week for 2 weeks. The wait-list control will continue their usual health care practices and have the opportunity to participate in the tai chi program once they have completed the follow-up assessments. The primary outcome will be bothersomeness of back symptoms measured with a 0-10 numerical rating scale. Secondary outcomes include, self-reports of pain-related disability, health-related quality of life and global perceived effect of treatment. Statistical analysis of primary and secondary outcomes will be based on the intention to treat principle. Linear mixed models will be used to test for the effect of treatment on outcome at 10 weeks follow up. This trial has received ethics approval from The University of Sydney Human Research Ethics Committee. HREC Approval No.10452 This study will be the first trial in this area and the information on its effectiveness will allow

  20. {sigma}({chi}{sub c1})/{sigma}({chi}{sub c2}) ratio in the k{sub t}-factorization approach

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Baranov, S. P.

    2011-02-01

    We address the puzzle of {sigma}({chi}{sub c1})/{sigma}({chi}{sub c2}) ratio at the collider and fixed-target experiments. We consider several factors that can affect the predicted ratio of the production rates. In particular, we discuss the effect of {chi}{sub cJ} polarization, the effect of including next-to-leading order contributions, and the effect of probably different {chi}{sub c1} and {chi}{sub c2} wave functions.

  1. Generalizing Terwilliger's likelihood approach: a new score statistic to test for genetic association.

    PubMed

    el Galta, Rachid; Uitte de Willige, Shirley; de Visser, Marieke C H; Helmer, Quinta; Hsu, Li; Houwing-Duistermaat, Jeanine J

    2007-09-24

    In this paper, we propose a one degree of freedom test for association between a candidate gene and a binary trait. This method is a generalization of Terwilliger's likelihood ratio statistic and is especially powerful for the situation of one associated haplotype. As an alternative to the likelihood ratio statistic, we derive a score statistic, which has a tractable expression. For haplotype analysis, we assume that phase is known. By means of a simulation study, we compare the performance of the score statistic to Pearson's chi-square statistic and the likelihood ratio statistic proposed by Terwilliger. We illustrate the method on three candidate genes studied in the Leiden Thrombophilia Study. We conclude that the statistic follows a chi square distribution under the null hypothesis and that the score statistic is more powerful than Terwilliger's likelihood ratio statistic when the associated haplotype has frequency between 0.1 and 0.4 and has a small impact on the studied disorder. With regard to Pearson's chi-square statistic, the score statistic has more power when the associated haplotype has frequency above 0.2 and the number of variants is above five.

  2. Exact test-based approach for equivalence test with parameter margin.

    PubMed

    Cassie Dong, Xiaoyu; Bian, Yuanyuan; Tsong, Yi; Wang, Tianhua

    2017-01-01

    The equivalence test has a wide range of applications in pharmaceutical statistics which we need to test for the similarity between two groups. In recent years, the equivalence test has been used in assessing the analytical similarity between a proposed biosimilar product and a reference product. More specifically, the mean values of the two products for a given quality attribute are compared against an equivalence margin in the form of ±f × σ R , where ± f × σ R is a function of the reference variability. In practice, this margin is unknown and is estimated from the sample as ±f × S R . If we use this estimated margin with the classic t-test statistic on the equivalence test for the means, both Type I and Type II error rates may inflate. To resolve this issue, we develop an exact-based test method and compare this method with other proposed methods, such as the Wald test, the constrained Wald test, and the Generalized Pivotal Quantity (GPQ) in terms of Type I error rate and power. Application of those methods on data analysis is also provided in this paper. This work focuses on the development and discussion of the general statistical methodology and is not limited to the application of analytical similarity.

  3. Wrong Answers on Multiple-Choice Achievement Tests: Blind Guesses or Systematic Choices?.

    ERIC Educational Resources Information Center

    Powell, J. C.

    A multi-faceted model for the selection of answers for multiple-choice tests was developed from the findings of a series of exploratory studies. This model implies that answer selection should be curvilinear. A series of models were tested for fit using the chi square procedure. Data were collected from 359 elementary school students ages 9-12.…

  4. PSGL-1 is highly expressed on Ly-6Chi monocytes and a major determinant for Ly-6Chi monocyte recruitment to sites of atherosclerosis in mice

    PubMed Central

    An, Guangyu; Wang, Huan; Tang, Rong; Yago, Tadayuki; McDaniel, J. Michael; McGee, Samuel; Huo, Yuqing; Xia, Lijun

    2008-01-01

    Background Ly-6Chi monocytes are key contributors to atherosclerosis in mice. However, how Ly-6Chi monocytes selectively accumulate in atherosclerotic lesions is largely unknown. Monocyte homing to sites of atherosclerosis is primarily initiated by rolling on P- and E-selectin expressed on endothelium. We hypothesize that P-selectin glycoprotein ligand-1 (PSGL-1), the common ligand of P- and E-selectin on leukocytes, contributes to the preferential homing of Ly-6Chi monocytes to atherosclerotic lesions. Methods and Results To test this hypothesis, we examined the expression and function of PSGL-1 on Ly-6Chi and Ly-6Clo monocytes from wild-type mice, ApoE-/- mice, and mice lacking both ApoE and PSGL-1 genes (ApoE-/-/PSGL-1-/-). We found that Ly-6Chi monocytes expressed a higher level of PSGL-1, and had enhanced binding to fluid-phase P- and E-selectin, compared to Ly-6Clo monocytes. Under in vitro flow conditions, more Ly-6Chi monocytes rolled on P-, E-, and L-selectin at slower velocities than Ly-6Clo cells. In an ex vivo perfused carotid artery model, Ly-6Chi monocytes interacted preferentially with atherosclerotic endothelium compared with Ly-6Clo monocytes in a PSGL-1-dependent manner. In vivo, ApoE-/- mice lacking PSGL-1 had impaired Ly-6Chi monocyte recruitment to atherosclerotic lesions. Moreover, ApoE-/-/PSGL-1-/- mice exhibited significantly reduced monocyte infiltration in wire injury-induced neointima and in atherosclerotic lesions. ApoE-/-/PSGL-1-/- mice also developed smaller neointima and atherosclerotic plaques. Conclusions These data indicate that PSGL-1 is a new marker for Ly-6Chi monocytes and a major determinant for Ly-6Chi cell recruitment to sites of atherosclerosis in mice. PMID:18519846

  5. CHI Research on NSTX-U

    NASA Astrophysics Data System (ADS)

    Lay, W.-S.; Raman, R.; Jarboe, T. R.; Nelson, B. A.; Mueller, D.; Ebrahimi, F.; Ono, M.; Jardin, S. C.; Taylor, G.

    2017-10-01

    At present about 20% of the total plasma current required for sustained operation has been generated by transient CHI. The present understanding suggests that it may be possible to generate all of the needed current in a ST / tokamak using transient CHI. In such a scenario, one could transition directly from a CHI produced plasma to a non-inductively sustained plasma, without the difficult intermediate step that involves non-inductive current ramp-up. STs based on this new configuration would take advantage of evolving developments in high-temperature superconductor technology to develop a simpler design ST that relies primarily on CHI for plasma current generation. Motivated by the very good results from NSTX and HIT-II, we are examining the potential application of transient CHI for reactor configurations through these studies. (1) Study of the maximum levels of start-up currents that could be generated on NSTX-U, (2) application of a single biased electrode configuration on QUEST to protect the insulator from neutron damage in a CHI reactor installation, and (3) QUEST-like, but a double biased electrode configuration for PEGASUS and NSTX-U. Results from these on-going studies will be described. This work is supported by U.S. DOE Contracts: DE-AC02-09CH11466, DE-FG02-99ER54519 AM08, and DE-SC0006757.

  6. Appointment length, psychiatrists' communication behaviors, and medication management appointment adherence.

    PubMed

    Cruz, Mario; Roter, Debra L; Cruz, Robyn F; Wieland, Melissa; Larson, Susan; Cooper, Lisa A; Pincus, Harold Alan

    2013-09-01

    The authors explored the relationship between critical elements of medication management appointments (appointment length, patient-centered talk, and positive nonverbal affect among providers) and patient appointment adherence. The authors used an exploratory, cross-sectional design employing quantitative analysis of 83 unique audio recordings of split treatment medication management appointments for 46 African-American and 37 white patients with 24 psychiatrists at four ambulatory mental health clinics. All patients had a diagnosis of depression. Data collected included demographic information; Patient Health Questionnaire-9 scores for depression severity; psychiatrist verbal and nonverbal communication behaviors during medication management appointments, identified by the Roter Interaction Analysis System during analysis of audio recordings; and appointment adherence. Bivariate analyses were employed to identify covariates that might influence appointment adherence. Generalized estimating equations (GEEs) were employed to assess the relationship between appointment length, psychiatrist patient-centered talk, and positive voice tone ratings and patient appointment adherence, while adjusting for covariates and the clustering of observations within psychiatrists. Wald chi square analyses were used to test whether all or some variables significantly influenced appointment adherence. GEE revealed a significant relationship between positive voice tone ratings and appointment adherence (p=.03). Chi square analyses confirmed the hypothesis of a positive and significant relationship between appointment adherence and positive voice tone ratings (p=.03) but not longer visit length and more patient-centered communication. The nonverbal conveyance of positive affect was associated with greater adherence to medication management appointments by depressed patients. These findings potentially have important implications for communication skills training and adherence research.

  7. Sample Size Calculation for Estimating or Testing a Nonzero Squared Multiple Correlation Coefficient

    ERIC Educational Resources Information Center

    Krishnamoorthy, K.; Xia, Yanping

    2008-01-01

    The problems of hypothesis testing and interval estimation of the squared multiple correlation coefficient of a multivariate normal distribution are considered. It is shown that available one-sided tests are uniformly most powerful, and the one-sided confidence intervals are uniformly most accurate. An exact method of calculating sample size to…

  8. Tai Chi research review.

    PubMed

    Field, Tiffany

    2011-08-01

    This review briefly summarizes recent Tai Chi research on physical benefits including balance and muscle strength and psychological benefits including attentiveness, sleep and anxiety. Cardiovascular changes following Tai Chi include decreased heart rate and blood pressure, increased vagal activity and decreased cholesterol. Pain syndromes that have been affected include fibromyalgia, osteoarthritis and rheumatoid arthritis. Autoimmune and immune conditions recently researched and reviewed here include osteoporosis, diabetes and HIV. Methodological problems with this research include the variability in forms (series of postures) used across studies as well as the intensity of the Tai Chi schedule. Further, most of the studies are based on within group changes rather than attention control group comparisons. Nonetheless, significant clinical improvements have been noted. Copyright © 2010 Elsevier Ltd. All rights reserved.

  9. Tri-Squared Mean Cross Comparative Analysis: An Advanced Post Hoc Qualitative and Quantitative Metric for a More In-Depth Examination of the Initial Research Outcomes of the Tri-Square Test

    ERIC Educational Resources Information Center

    Osler, James Edward

    2013-01-01

    This monograph provides an epistemological rational for the design of an advanced novel analysis metric. The metric is designed to analyze the outcomes of the Tri-Squared Test. This methodology is referred to as: "Tri-Squared Mean Cross Comparative Analysis" (given the acronym TSMCCA). Tri-Squared Mean Cross Comparative Analysis involves…

  10. Permutation tests for goodness-of-fit testing of mathematical models to experimental data.

    PubMed

    Fişek, M Hamit; Barlas, Zeynep

    2013-03-01

    This paper presents statistical procedures for improving the goodness-of-fit testing of theoretical models to data obtained from laboratory experiments. We use an experimental study in the expectation states research tradition which has been carried out in the "standardized experimental situation" associated with the program to illustrate the application of our procedures. We briefly review the expectation states research program and the fundamentals of resampling statistics as we develop our procedures in the resampling context. The first procedure we develop is a modification of the chi-square test which has been the primary statistical tool for assessing goodness of fit in the EST research program, but has problems associated with its use. We discuss these problems and suggest a procedure to overcome them. The second procedure we present, the "Average Absolute Deviation" test, is a new test and is proposed as an alternative to the chi square test, as being simpler and more informative. The third and fourth procedures are permutation versions of Jonckheere's test for ordered alternatives, and Kendall's tau(b), a rank order correlation coefficient. The fifth procedure is a new rank order goodness-of-fit test, which we call the "Deviation from Ideal Ranking" index, which we believe may be more useful than other rank order tests for assessing goodness-of-fit of models to experimental data. The application of these procedures to the sample data is illustrated in detail. We then present another laboratory study from an experimental paradigm different from the expectation states paradigm - the "network exchange" paradigm, and describe how our procedures may be applied to this data set. Copyright © 2012 Elsevier Inc. All rights reserved.

  11. Effect of number of rooms and sibs on nutritional status among rural Bengalee preschool children from eastern India.

    PubMed

    Biswas, Sadaruddin; Bose, Kaushik

    2011-12-01

    In developing countries including rural India, undernutrition among preschool children is one of the main barriers of the national development. However, there exists scanty information on the prevalence of underweight and stunting and their socio-demographic predictors among preschool children in India and West Bengal. The aim of the present study was to investigate the prevalence of underweight and stunting and the impact of two socio-demographic indicators, namely number of living rooms (NLR) and number of sibs (NS), on them among 1-5 year old Bengalee rural preschool children of Integrated Child Development Services (ICDS) Centres. This cross sectional study was undertaken at 30 randomly selected ICDS centre of Chapra Block, Nadia District, West Bengal, India. A total of 673 children, aged 1-5 years were studied. The overall (age and sex combined) rates of underweight and stunting were 54.40% and 39.20%, respectively. NLR was significantly associated with the prevalence of underweight (chi2 = 4.34, df = 1, p < 0.05) and stunting (chi2 = 8.98, df = 1, p < 0.01) among girls. Similarly, NS had a significant association with prevalence of underweight (chi2 = 10.29, df = 1, p < 0.001) and stunting (chi2 = 5.42, df = 1, p < 0.05) among girls. Girls with < 2 NLR had significant higher risk of being underweight (OR = 1.64, C.I = 1.30-2.62) or stunted (OR=2.23, C.I = 1.31-3.80) than those with > or = 2 NLR. Moreover, girls with > or = 3 NS had significant higher rate of underweight (OR = 2.03, CI = 1.32-3.146) or stunting (OR = 1.69, C.I = 1.09-2.63) than those with < 3 sibs. Logistic regression analyses also revealed that both NLR as well as NS were strong predictors of underweight (NLR: Wald = 4.30, p < 0.05; NS: Wald = 8.74, p < 0.001) and stunting (NLR: Wald = 10.17, p < 0.001; NS: Wald = 5.38, p < 0.05) among girls. Gender discrimination could be a likely cause for this sex difference in the impact of NRL and NS. Moreover, logistic regression were also undertaken

  12. Prognostic value of cardiopulmonary exercise testing in heart failure with preserved ejection fraction. The Henry Ford HospITal CardioPulmonary EXercise Testing (FIT-CPX) project.

    PubMed

    Shafiq, Ali; Brawner, Clinton A; Aldred, Heather A; Lewis, Barry; Williams, Celeste T; Tita, Christina; Schairer, John R; Ehrman, Jonathan K; Velez, Mauricio; Selektor, Yelena; Lanfear, David E; Keteyian, Steven J

    2016-04-01

    Although cardiopulmonary exercise (CPX) testing in patients with heart failure and reduced ejection fraction is well established, there are limited data on the value of CPX variables in patients with HF and preserved ejection fraction (HFpEF). We sought to determine the prognostic value of select CPX measures in patients with HFpEF. This was a retrospective analysis of patients with HFpEF (ejection fraction ≥ 50%) who performed a CPX test between 1997 and 2010. Selected CPX variables included peak oxygen uptake (VO2), percent predicted maximum oxygen uptake (ppMVO2), minute ventilation to carbon dioxide production slope (VE/VCO2 slope) and exercise oscillatory ventilation (EOV). Separate Cox regression analyses were performed to assess the relationship between each CPX variable and a composite outcome of all-cause mortality or cardiac transplant. We identified 173 HFpEF patients (45% women, 58% non-white, age 54 ± 14 years) with complete CPX data. During a median follow-up of 5.2 years, there were 42 deaths and 5 cardiac transplants. The 1-, 3-, and 5-year cumulative event-free survival was 96%, 90%, and 82%, respectively. Based on the Wald statistic from the Cox regression analyses adjusted for age, sex, and β-blockade therapy, ppMVO2 was the strongest predictor of the end point (Wald χ(2) = 15.0, hazard ratio per 10%, P < .001), followed by peak VO2 (Wald χ(2) = 11.8, P = .001). VE/VCO2 slope (Wald χ(2)= 0.4, P = .54) and EOV (Wald χ(2) = 0.15, P = .70) had no significant association to the composite outcome. These data support the prognostic utility of peak VO2 and ppMVO2 in patients with HFpEF. Additional studies are needed to define optimal cut points to identify low- and high-risk patients. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Power and sensitivity of alternative fit indices in tests of measurement invariance.

    PubMed

    Meade, Adam W; Johnson, Emily C; Braddy, Phillip W

    2008-05-01

    Confirmatory factor analytic tests of measurement invariance (MI) based on the chi-square statistic are known to be highly sensitive to sample size. For this reason, G. W. Cheung and R. B. Rensvold (2002) recommended using alternative fit indices (AFIs) in MI investigations. In this article, the authors investigated the performance of AFIs with simulated data known to not be invariant. The results indicate that AFIs are much less sensitive to sample size and are more sensitive to a lack of invariance than chi-square-based tests of MI. The authors suggest reporting differences in comparative fit index (CFI) and R. P. McDonald's (1989) noncentrality index (NCI) to evaluate whether MI exists. Although a general value of change in CFI (.002) seemed to perform well in the analyses, condition specific change in McDonald's NCI values exhibited better performance than a single change in McDonald's NCI value. Tables of these values are provided as are recommendations for best practices in MI testing. PsycINFO Database Record (c) 2008 APA, all rights reserved.

  14. Tai Chi and Postural Stability in Patients with Parkinson's Disease

    PubMed Central

    Li, Fuzhong; Harmer, Peter; Fitzgerald, Kathleen; Eckstrom, Elizabeth; Stock, Ronald; Galver, Johnny; Maddalozzo, Gianni; Batya, Sara S.

    2012-01-01

    Background Patients with Parkinson's disease have substantially impaired balance, leading to diminished functional ability and an increased risk of falling. Although exercise is routinely encouraged by health care providers, few programs have been proven effective. Methods We conducted a randomized, controlled trial to determine whether a tailored tai chi program could improve postural control in patients with idiopathic Parkinson's disease. We randomly assigned 195 patients with stage 1 to 4 disease on the Hoehn and Yahr staging scale (which ranges from 1 to 5, with higher stages indicating more severe disease) to one of three groups: tai chi, resistance training, or stretching. The patients participated in 60-minute exercise sessions twice weekly for 24 weeks. The primary outcomes were changes from baseline in the limits-of-stability test (maximum excursion and directional control; range, 0 to 100%). Secondary outcomes included measures of gait and strength, scores on functional-reach and timed up-and-go tests, motor scores on the Unified Parkinson's Disease Rating Scale, and number of falls. Results The tai chi group performed consistently better than the resistance-training and stretching groups in maximum excursion (between-group difference in the change from baseline, 5.55 percentage points; 95% confidence interval [CI], 1.12 to 9.97; and 11.98 percentage points; 95% CI, 7.21 to 16.74, respectively) and in directional control (10.45 percentage points; 95% CI, 3.89 to 17.00; and 11.38 percentage points; 95% CI, 5.50 to 17.27, respectively). The tai chi group also performed better than the stretching group in all secondary outcomes and outperformed the resistance-training group in stride length and functional reach. Tai chi lowered the incidence of falls as compared with stretching but not as compared with resistance training. The effects of tai chi training were maintained at 3 months after the intervention. No serious adverse events were observed. Conclusions

  15. Systemic fat embolism and the patent foramen ovale--a prospective autopsy study.

    PubMed

    Nikolić, Slobodan; Zivković, Vladimir; Babić, Dragan; Djonić, Danijela; Djurić, Marija

    2012-05-01

    A fat embolism is a known and common complication of blunt force injuries, especially pelvic and long bones fractures. The aim of this study was to determine the importance of a patent foramen ovale (PFO) in developing systemic fat embolism (SFE) and eventually fat embolism syndrome (FES) in patients suffering from orthopaedic blunt injuries and consequent lung fat embolism. The sample was divided: 32 subjects with a sealed foramen ovale (SFO), and 20 subjects with a PFO. In our sample, there was no difference in either the incidence of renal fat embolism in subjects with PFO compared to those with SFO (Fisher's exact test 0.228, p=0.154) or in the grade of renal fat embolism (Pearson Chi-square 2.728, p=0.435). However, there was a statistically significant correlation between the grade of lung fat embolism and the number of fractured bones for the whole sample (Spearman's rho 0.271, p=0.052), but no correlation between the grade of lung fat embolism and the ISS or NISS (Pearson correlation 0.048, p=0.736, and 0.108, p=0.445, respectively). In our study, the presence of fat emboli in the kidney, i.e. SFE, could effectively be predicted by the grade of lung fat embolism (the moderate and slight grades of lung fat embolism were better predictors than the massive one: logistic regression - Wald. Coeff.=11.446, p=0.003, Wald. Coeff.=10.553, p=0.001, and Wald. Coeff.=4.128, p=0.042), and less effectively by presence of PFO (Wald. Coeff.=2.850, p=0.091). This study pointed out that lung and SFE are not pure biomechanical events, so the role of a PFO is not crucial in developing a lung fat embolism into a systemic embolism: the fat embolism is more of a biochemical and pathophsyiological event, than a biomechanical one. The appearance of a patent foramen ovale associated with a systemic fat embolism should be less emphasised: maybe arteriovenous shunts and anastomosis between the functional and nutritive, i.e. systemic circulation of lungs play a more important role in

  16. A Randomized Trial of Tai Chi for Fibromyalgia

    PubMed Central

    Wang, Chenchen; Schmid, Christopher H.; Rones, Ramel; Kalish, Robert; Yinh, Janeth; Goldenberg, Don L.; Lee, Yoojin; McAlindon, Timothy

    2010-01-01

    Background Previous research has suggested that tai chi offers a therapeutic benefit in patients with fibromyalgia. Methods We conducted a single-blind, randomized trial of classic Yang-style tai chi as compared with a control intervention consisting of wellness education and stretching for the treatment of fibromyalgia (defined by American College of Rheumatology 1990 criteria). Sessions lasted 60 minutes each and took place twice a week for 12 weeks for each of the study groups. The primary end point was a change in the Fibromyalgia Impact Questionnaire (FIQ) score (ranging from 0 to 100, with higher scores indicating more severe symptoms) at the end of 12 weeks. Secondary end points included summary scores on the physical and mental components of the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36). All assessments were repeated at 24 weeks to test the durability of the response. Results Of the 66 randomly assigned patients, the 33 in the tai chi group had clinically important improvements in the FIQ total score and quality of life. Mean (±SD) baseline and 12-week FIQ scores for the tai chi group were 62.9±15.5 and 35.1±18.8, respectively, versus 68.0±11 and 58.6±17.6, respectively, for the control group (change from baseline in the tai chi group vs. change from baseline in the control group, −18.4 points; P<0.001). The corresponding SF-36 physical-component scores were 28.5±8.4 and 37.0±10.5 for the tai chi group versus 28.0±7.8 and 29.4±7.4 for the control group (between-group difference, 7.1 points; P = 0.001), and the mental-component scores were 42.6±12.2 and 50.3±10.2 for the tai chi group versus 37.8±10.5 and 39.4±11.9 for the control group (between-group difference, 6.1 points; P = 0.03). Improvements were maintained at 24 weeks (between-group difference in the FIQ score, −18.3 points; P<0.001). No adverse events were observed. Conclusions Tai chi may be a useful treatment for fibromyalgia and merits long-term study in

  17. A randomized trial of tai chi for fibromyalgia.

    PubMed

    Wang, Chenchen; Schmid, Christopher H; Rones, Ramel; Kalish, Robert; Yinh, Janeth; Goldenberg, Don L; Lee, Yoojin; McAlindon, Timothy

    2010-08-19

    Previous research has suggested that tai chi offers a therapeutic benefit in patients with fibromyalgia. We conducted a single-blind, randomized trial of classic Yang-style tai chi as compared with a control intervention consisting of wellness education and stretching for the treatment of fibromyalgia (defined by American College of Rheumatology 1990 criteria). Sessions lasted 60 minutes each and took place twice a week for 12 weeks for each of the study groups. The primary end point was a change in the Fibromyalgia Impact Questionnaire (FIQ) score (ranging from 0 to 100, with higher scores indicating more severe symptoms) at the end of 12 weeks. Secondary end points included summary scores on the physical and mental components of the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36). All assessments were repeated at 24 weeks to test the durability of the response. Of the 66 randomly assigned patients, the 33 in the tai chi group had clinically important improvements in the FIQ total score and quality of life. Mean (+/-SD) baseline and 12-week FIQ scores for the tai chi group were 62.9+/-15.5 and 35.1+/-18.8, respectively, versus 68.0+/-11 and 58.6+/-17.6, respectively, for the control group (change from baseline in the tai chi group vs. change from baseline in the control group, -18.4 points; P<0.001). The corresponding SF-36 physical-component scores were 28.5+/-8.4 and 37.0+/-10.5 for the tai chi group versus 28.0+/-7.8 and 29.4+/-7.4 for the control group (between-group difference, 7.1 points; P=0.001), and the mental-component scores were 42.6+/-12.2 and 50.3+/-10.2 for the tai chi group versus 37.8+/-10.5 and 39.4+/-11.9 for the control group (between-group difference, 6.1 points; P=0.03). Improvements were maintained at 24 weeks (between-group difference in the FIQ score, -18.3 points; P<0.001). No adverse events were observed. Tai chi may be a useful treatment for fibromyalgia and merits long-term study in larger study populations. (Funded by

  18. Testing the non-unity of rate ratio under inverse sampling.

    PubMed

    Tang, Man-Lai; Liao, Yi Jie; Ng, Hong Keung Tony; Chan, Ping Shing

    2007-08-01

    Inverse sampling is considered to be a more appropriate sampling scheme than the usual binomial sampling scheme when subjects arrive sequentially, when the underlying response of interest is acute, and when maximum likelihood estimators of some epidemiologic indices are undefined. In this article, we study various statistics for testing non-unity rate ratios in case-control studies under inverse sampling. These include the Wald, unconditional score, likelihood ratio and conditional score statistics. Three methods (the asymptotic, conditional exact, and Mid-P methods) are adopted for P-value calculation. We evaluate the performance of different combinations of test statistics and P-value calculation methods in terms of their empirical sizes and powers via Monte Carlo simulation. In general, asymptotic score and conditional score tests are preferable for their actual type I error rates are well controlled around the pre-chosen nominal level, and their powers are comparatively the largest. The exact version of Wald test is recommended if one wants to control the actual type I error rate at or below the pre-chosen nominal level. If larger power is expected and fluctuation of sizes around the pre-chosen nominal level are allowed, then the Mid-P version of Wald test is a desirable alternative. We illustrate the methodologies with a real example from a heart disease study. (c) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

  19. [Comparison of thromboelastography and routine coagulation tests for evaluation of blood coagulation function in patients].

    PubMed

    Chen, Guan-Yi; Ou Yang, Xi-Lin; Wu, Jing-Hui; Wang, Li-Hua; Yang, Jin-Hua; Gu, Li-Nan; Lu, Zhu-Jie; Zhao, Xiao-Zi

    2015-04-01

    To investigate the correlation and consistency between thromboelastography(TEG) and routine coagulation tests, and to evaluate the value of the two methods in determining the blood coagulation of patients. The TEG, routine coagulation tests and platelet counts of 182 patients from the Intensive Care Unit(ICU) and Department of Gastroenterology in our hospital from January to September 2014 were performed and analyzed retrospectively for their correlation, Kappa identity test analysis and chi-square test, and the diagnostic sensitivity and specificity of both methods in the patients with bleeding were evaluated. The TEG R time and PT, R time and APTT showed a linear dependence (P<0.01). The relationship between the TEG K value, α-Angle, MA and Fibrinogen showed a linear dependence (P<0.001). And the relationship between the TEG K value, α-Angle, MA and the platelet count were in a linear dependent way (P<0.001). The Kappa values of the TEG R time with PT and APTT were 0.038 (P>0.05) and 0.061 (P>0.05), respectively. The chi-square test values of the TEG R time with PT and APTT were 35.309 (P<0.001) and 15.848 (P<0.001), respectively. The Fibrinogen and the TEG K value, α-Angle, MA value had statistical significance (P<0.001), with a Kappa value of 0.323, 0.288 and 0.427, respectively. The chi-square test values between Fibrinogen and the TEG K value, α-Angle, MA value were not statistically significant, with X2=1.091 (P=0.296), X2=1.361 (P=0.243), X2=0.108 (P=0.742). The Kappa values of the platelet count and the TEG K value, α-Angle, MA value were 0.379, 0.208 and 0.352, respectively, which were also statistically significant difference (P<0.001). The chi-square test values between the platelet count and the TEG K value, α-Angle, MA value showed a statistically significant difference (P<0.001), with X2=37.5, X2=37.23, X2=26.630. The diagnostic sensitivity of the two methods for the patients with bleeding was less than 50%. There was a significant correlation

  20. Simultaneous estimation of cross-validation errors in least squares collocation applied for statistical testing and evaluation of the noise variance components

    NASA Astrophysics Data System (ADS)

    Behnabian, Behzad; Mashhadi Hossainali, Masoud; Malekzadeh, Ahad

    2018-02-01

    The cross-validation technique is a popular method to assess and improve the quality of prediction by least squares collocation (LSC). We present a formula for direct estimation of the vector of cross-validation errors (CVEs) in LSC which is much faster than element-wise CVE computation. We show that a quadratic form of CVEs follows Chi-squared distribution. Furthermore, a posteriori noise variance factor is derived by the quadratic form of CVEs. In order to detect blunders in the observations, estimated standardized CVE is proposed as the test statistic which can be applied when noise variances are known or unknown. We use LSC together with the methods proposed in this research for interpolation of crustal subsidence in the northern coast of the Gulf of Mexico. The results show that after detection and removing outliers, the root mean square (RMS) of CVEs and estimated noise standard deviation are reduced about 51 and 59%, respectively. In addition, RMS of LSC prediction error at data points and RMS of estimated noise of observations are decreased by 39 and 67%, respectively. However, RMS of LSC prediction error on a regular grid of interpolation points covering the area is only reduced about 4% which is a consequence of sparse distribution of data points for this case study. The influence of gross errors on LSC prediction results is also investigated by lower cutoff CVEs. It is indicated that after elimination of outliers, RMS of this type of errors is also reduced by 19.5% for a 5 km radius of vicinity. We propose a method using standardized CVEs for classification of dataset into three groups with presumed different noise variances. The noise variance components for each of the groups are estimated using restricted maximum-likelihood method via Fisher scoring technique. Finally, LSC assessment measures were computed for the estimated heterogeneous noise variance model and compared with those of the homogeneous model. The advantage of the proposed method is the

  1. STUDIES IN RESEARCH METHODOLOGY. IV. A SAMPLING STUDY OF THE CENTRAL LIMIT THEOREM AND THE ROBUSTNESS OF ONE-SAMPLE PARAMETRIC TESTS,

    DTIC Science & Technology

    iconoclastic . Even at N=1024 these departures were quite appreciable at the testing tails, being greatest for chi-square and least for Z, and becoming worse in all cases at increasingly extreme tail areas. (Author)

  2. Near-surface versus fault zone damage following the 1999 Chi-Chi earthquake: Observation and simulation of repeating earthquakes

    USGS Publications Warehouse

    Chen, Kate Huihsuan; Furumura, Takashi; Rubinstein, Justin L.

    2015-01-01

    We observe crustal damage and its subsequent recovery caused by the 1999 M7.6 Chi-Chi earthquake in central Taiwan. Analysis of repeating earthquakes in Hualien region, ~70 km east of the Chi-Chi earthquake, shows a remarkable change in wave propagation beginning in the year 2000, revealing damage within the fault zone and distributed across the near surface. We use moving window cross correlation to identify a dramatic decrease in the waveform similarity and delays in the S wave coda. The maximum delay is up to 59 ms, corresponding to a 7.6% velocity decrease averaged over the wave propagation path. The waveform changes on either side of the fault are distinct. They occur in different parts of the waveforms, affect different frequencies, and the size of the velocity reductions is different. Using a finite difference method, we simulate the effect of postseismic changes in the wavefield by introducing S wave velocity anomaly in the fault zone and near the surface. The models that best fit the observations point to pervasive damage in the near surface and deep, along-fault damage at the time of the Chi-Chi earthquake. The footwall stations show the combined effect of near-surface and the fault zone damage, where the velocity reduction (2–7%) is twofold to threefold greater than the fault zone damage observed in the hanging wall stations. The physical models obtained here allow us to monitor the temporal evolution and recovering process of the Chi-Chi fault zone damage.

  3. Tai Chi and Rheumatic Diseases

    PubMed Central

    Wang, Chenchen

    2011-01-01

    SYNOPSIS Many patients with chronic rheumatic diseases such as osteoarthritis, rheumatoid arthritis and fibromyalgia experience high levels of pain, psychological distress and negative emotions and have limited therapeutic options. Tai Chi is a complex multi-component mind-body exercise that increasing numbers of Americans are practicing, particularly those with musculoskeletal conditions. Clinical trials and observational studies have provided encouraging evidence that Tai Chi, both short and long-term, has benefits for patients with a variety of chronic disorders. As a form of physical exercise, Tai Chi enhances cardiovascular fitness, muscular strength, balance, and physical function. It also appears to be associated with reduced stress, anxiety and depression as well as improved quality of life. Thus, despite the noted limitations in the evidence, and the need for further methodologically rigorous studies, Tai Chi can be safely recommended to patients with osteoarthritis, rheumatoid arthritis and fibromyalgia as a complementary and alternative medical approach to affect patient well-being. This overview synthesizes the current body of knowledge about this ancient Chinese mind-body medicine to better inform clinical decision-making for our rheumatic patients. PMID:21220083

  4. Tai Chi Chuan in Medicine and Health Promotion

    PubMed Central

    Lan, Ching; Chen, Ssu-Yuan; Lai, Jin-Shin; Wong, Alice May-Kuen

    2013-01-01

    Tai Chi Chuan (Tai Chi) is a Chinese traditional mind-body exercise and recently, it becomes popular worldwide. During the practice of Tai Chi, deep diaphragmatic breathing is integrated into body motions to achieve a harmonious balance between body and mind and to facilitate the flow of internal energy (Qi). Participants can choose to perform a complete set of Tai Chi or selected movements according to their needs. Previous research substantiates that Tai Chi has significant benefits to health promotion, and regularly practicing Tai Chi improves aerobic capacity, muscular strength, balance, health-related quality of life, and psychological well-being. Recent studies also prove that Tai Chi is safe and effective for patients with neurological diseases (e.g., stroke, Parkinson's disease, traumatic brain injury, multiple sclerosis, cognitive dysfunction), rheumatological disease (e.g., rheumatoid arthritis, ankylosing spondylitis, and fibromyalgia), orthopedic diseases (e.g., osteoarthritis, osteoporosis, low-back pain, and musculoskeletal disorder), cardiovascular diseases (e.g., acute myocardial infarction, coronary artery bypass grafting surgery, and heart failure), chronic obstructive pulmonary diseases, and breast cancers. Tai Chi is an aerobic exercise with mild-to-moderate intensity and is appropriate for implementation in the community. This paper reviews the existing literature on Tai Chi and introduces its health-promotion effect and the potential clinical applications. PMID:24159346

  5. Tai chi chuan in medicine and health promotion.

    PubMed

    Lan, Ching; Chen, Ssu-Yuan; Lai, Jin-Shin; Wong, Alice May-Kuen

    2013-01-01

    Tai Chi Chuan (Tai Chi) is a Chinese traditional mind-body exercise and recently, it becomes popular worldwide. During the practice of Tai Chi, deep diaphragmatic breathing is integrated into body motions to achieve a harmonious balance between body and mind and to facilitate the flow of internal energy (Qi). Participants can choose to perform a complete set of Tai Chi or selected movements according to their needs. Previous research substantiates that Tai Chi has significant benefits to health promotion, and regularly practicing Tai Chi improves aerobic capacity, muscular strength, balance, health-related quality of life, and psychological well-being. Recent studies also prove that Tai Chi is safe and effective for patients with neurological diseases (e.g., stroke, Parkinson's disease, traumatic brain injury, multiple sclerosis, cognitive dysfunction), rheumatological disease (e.g., rheumatoid arthritis, ankylosing spondylitis, and fibromyalgia), orthopedic diseases (e.g., osteoarthritis, osteoporosis, low-back pain, and musculoskeletal disorder), cardiovascular diseases (e.g., acute myocardial infarction, coronary artery bypass grafting surgery, and heart failure), chronic obstructive pulmonary diseases, and breast cancers. Tai Chi is an aerobic exercise with mild-to-moderate intensity and is appropriate for implementation in the community. This paper reviews the existing literature on Tai Chi and introduces its health-promotion effect and the potential clinical applications.

  6. Search for pair production of scalar bottom quarks in pp collisions at square root of s = 1.96 TeV.

    PubMed

    Abazov, V M; Abbott, B; Abolins, M; Acharya, B S; Adams, M; Adams, T; Agelou, M; Ahn, S H; Ahsan, M; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Anastasoaie, M; Andeen, T; Anderson, S; Andrieu, B; Anzelc, M S; Arnoud, Y; Arov, M; Askew, A; Asman, B; Jesus, A C S Assis; Atramentov, O; Autermann, C; Avila, C; Ay, C; Badaud, F; Baden, A; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, P; Banerjee, S; Barberis, E; Bargassa, P; Baringer, P; Barnes, C; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Bean, A; Begalli, M; Begel, M; Belanger-Champagne, C; Bellantoni, L; Bellavance, A; Benitez, J A; Beri, S B; Bernardi, G; Bernhard, R; Berntzon, L; Bertram, I; Besançon, M; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Binder, M; Biscarat, C; Black, K M; Blackler, I; Blazey, G; Blekman, F; Blessing, S; Bloch, D; Bloom, K; Blumenschein, U; Boehnlein, A; Boeriu, O; Bolton, T A; Borissov, G; Bos, K; Bose, T; Brandt, A; Brock, R; Brooijmans, G; Bross, A; Brown, D; Buchanan, N J; Buchholz, D; Buehler, M; Buescher, V; Burdin, S; Burke, S; Burnett, T H; Busato, E; Buszello, C P; Butler, J M; Calfayan, P; Calvet, S; Cammin, J; Caron, S; Carvalho, W; Casey, B C K; Cason, N M; Castilla-Valdez, H; Chakraborty, D; Chan, K M; Chandra, A; Charles, F; Cheu, E; Chevallier, F; Cho, D K; Choi, S; Choudhary, B; Christofek, L; Claes, D; Clément, B; Clément, C; Coadou, Y; Cooke, M; Cooper, W E; Coppage, D; Corcoran, M; Cousinou, M-C; Cox, B; Crépé-Renaudin, S; Cutts, D; Cwiok, M; da Motta, H; Das, A; Das, M; Davies, B; Davies, G; Davis, G A; De, K; de Jong, P; de Jong, S J; De La Cruz-Burelo, E; De Oliveira Martins, C; Degenhardt, J D; Déliot, F; Demarteau, M; Demina, R; Demine, P; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Doidge, M; Dominguez, A; Dong, H; Dudko, L V; Duflot, L; Dugad, S R; Duggan, D; Duperrin, A; Dyer, J; Dyshkant, A; Eads, M; Edmunds, D; Edwards, T; Ellison, J; Elmsheuser, J; Elvira, V D; Eno, S; Ermolov, P; Evans, H; Evdokimov, A; Evdokimov, V N; Fatakia, S N; Feligioni, L; Ferapontov, A V; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Fleck, I; Ford, M; Fortner, M; Fox, H; Fu, S; Fuess, S; Gadfort, T; Galea, C F; Gallas, E; Galyaev, E; Garcia, C; Garcia-Bellido, A; Gardner, J; Gavrilov, V; Gay, A; Gay, P; Gelé, D; Gelhaus, R; Gerber, C E; Gershtein, Y; Gillberg, D; Ginther, G; Gollub, N; Gómez, B; Goussiou, A; Grannis, P D; Greenlee, H; Greenwood, Z D; Gregores, E M; Grenier, G; Gris, Ph; Grivaz, J-F; Grünendahl, S; Grünewald, M W; Guo, F; Guo, J; Gutierrez, G; Gutierrez, P; Haas, A; Hadley, N J; Haefner, P; Hagopian, S; Haley, J; Hall, I; Hall, R E; Han, L; Hanagaki, K; Harder, K; Harel, A; Harrington, R; Hauptman, J M; Hauser, R; Hays, J; Hebbeker, T; Hedin, D; Hegeman, J G; Heinmiller, J M; Heinson, A P; Heintz, U; Hensel, C; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hobbs, J D; Hoeneisen, B; Hoeth, H; Hohlfeld, M; Hong, S J; Hooper, R; Houben, P; Hu, Y; Hubacek, Z; Hynek, V; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jain, S; Jakobs, K; Jarvis, C; Jenkins, A; Jesik, R; Johns, K; Johnson, C; Johnson, M; Jonckheere, A; Jonsson, P; Juste, A; Käfer, D; Kahn, S; Kajfasz, E; Kalinin, A M; Kalk, J M; Kalk, J R; Kappler, S; Karmanov, D; Kasper, J; Kasper, P; Katsanos, I; Kau, D; Kaur, R; Kehoe, R; Kermiche, S; Khalatyan, N; Khanov, A; Kharchilava, A; Kharzheev, Y M; Khatidze, D; Kim, H; Kim, T J; Kirby, M H; Klima, B; Kohli, J M; Konrath, J-P; Kopal, M; Korablev, V M; Kotcher, J; Kothari, B; Koubarovsky, A; Kozelov, A V; Kozminski, J; Krop, D; Kryemadhi, A; Kuhl, T; Kumar, A; Kunori, S; Kupco, A; Kurca, T; Kvita, J; Lammers, S; Landsberg, G; Lazoflores, J; Le Bihan, A-C; Lebrun, P; Lee, W M; Leflat, A; Lehner, F; Lesne, V; Leveque, J; Lewis, P; Li, J; Li, Q Z; Lima, J G R; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, Z; Lobo, L; Lobodenko, A; Lokajicek, M; Lounis, A; Love, P; Lubatti, H J; Lynker, M; Lyon, A L; Maciel, A K A; Madaras, R J; Mättig, P; Magass, C; Magerkurth, A; Magnan, A-M; Makovec, N; Mal, P K; Malbouisson, H B; Malik, S; Malyshev, V L; Mao, H S; Maravin, Y; Martens, M; McCarthy, R; Meder, D; Melnitchouk, A; Mendes, A; Mendoza, L; Merkin, M; Merritt, K W; Meyer, A; Meyer, J; Michaut, M; Miettinen, H; Millet, T; Mitrevski, J; Molina, J; Mondal, N K; Monk, J; Moore, R W; Moulik, T; Muanza, G S; Mulders, M; Mulhearn, M; Mundim, L; Mutaf, Y D; Nagy, E; Naimuddin, M; Narain, M; Naumann, N A; Neal, H A; Negret, J P; Neustroev, P; Noeding, C; Nomerotski, A; Novaes, S F; Nunnemann, T; O'Dell, V; O'Neil, D C; Obrant, G; Oguri, V; Oliveira, N; Oshima, N; Otec, R; Y Garzón, G J Otero; Owen, M; Padley, P; Parashar, N; Park, S-J; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Pawloski, G; Perea, P M; Perez, E; Peters, K; Pétroff, P; Petteni, M; Piegaia, R; Piper, J; Pleier, M-A; Podesta-Lerma, P L M; Podstavkov, V M; Pogorelov, Y; Pol, M-E; Pompos, A; Pope, B G; Popov, A V; Potter, C; Prado da Silva, W L; Prosper, H B; Protopopescu, S; Qian, J; Quadt, A; Quinn, B; Rangel, M S; Rani, K J; Ranjan, K; Ratoff, P N; Renkel, P; Reucroft, S; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F; Robinson, S; Rodrigues, R F; Royon, C; Rubinov, P; Ruchti, R; Rud, V I; Sajot, G; Sánchez-Hernández, A; Sanders, M P; Santoro, A; Savage, G; Sawyer, L; Scanlon, T; Schaile, D; Schamberger, R D; Scheglov, Y; Schellman, H; Schieferdecker, P; Schmitt, C; Schwanenberger, C; Schwartzman, A; Schwienhorst, R; Sekaric, J; Sengupta, S; Severini, H; Shabalina, E; Shamim, M; Shary, V; Shchukin, A A; Shephard, W D; Shivpuri, R K; Shpakov, D; Siccardi, V; Sidwell, R A; Simak, V; Sirotenko, V; Skubic, P; Slattery, P; Smith, R P; Snow, G R; Snow, J; Snyder, S; Söldner-Rembold, S; Song, X; Sonnenschein, L; Sopczak, A; Sosebee, M; Soustruznik, K; Souza, M; Spurlock, B; Stark, J; Steele, J; Stolin, V; Stone, A; Stoyanova, D A; Strandberg, J; Strandberg, S; Strang, M A; Strauss, M; Ströhmer, R; Strom, D; Strovink, M; Stutte, L; Sumowidagdo, S; Sznajder, A; Talby, M; Tamburello, P; Taylor, W; Telford, P; Temple, J; Tiller, B; Titov, M; Tokmenin, V V; Tomoto, M; Toole, T; Torchiani, I; Towers, S; Trefzger, T; Trincaz-Duvoid, S; Tsybychev, D; Tuchming, B; Tully, C; Turcot, A S; Tuts, P M; Unalan, R; Uvarov, L; Uvarov, S; Uzunyan, S; Vachon, B; van den Berg, P J; Van Kooten, R; van Leeuwen, W M; Varelas, N; Varnes, E W; Vartapetian, A; Vasilyev, I A; Vaupel, M; Verdier, P; Vertogradov, L S; Verzocchi, M; Villeneuve-Seguier, F; Vint, P; Vlimant, J-R; Von Toerne, E; Voutilainen, M; Vreeswijk, M; Wahl, H D; Wang, L; Wang, M H L S; Warchol, J; Watts, G; Wayne, M; Weber, M; Weerts, H; Wermes, N; Wetstein, M; White, A; Wicke, D; Wilson, G W; Wimpenny, S J; Wobisch, M; Womersley, J; Wood, D R; Wyatt, T R; Xie, Y; Xuan, N; Yacoob, S; Yamada, R; Yan, M; Yasuda, T; Yatsunenko, Y A; Yip, K; Yoo, H D; Youn, S W; Yu, C; Yu, J; Yurkewicz, A; Zatserklyaniy, A; Zeitnitz, C; Zhang, D; Zhao, T; Zhou, B; Zhu, J; Zielinski, M; Zieminska, D; Zieminski, A; Zutshi, V; Zverev, E G

    2006-10-27

    A search for direct production of scalar bottom quarks (b) is performed with 310 pb(-1) of data collected by the D0 experiment in pp collisions at square root s = 1.96 TeV at the Fermilab Tevatron Collider. The topology analyzed consists of two b jets and an imbalance in transverse momentum due to undetected neutralinos (chi(1)0), with chi(1)0 assumed to be the lightest supersymmetric particle. We find the data consistent with standard model expectations, and set a 95% C.L. exclusion domain in the (m(b), m(chi(1)0)) mass plane, improving significantly upon the results from run I of the Tevatron.

  7. Tests of Measurement Invariance without Subgroups: A Generalization of Classical Methods

    ERIC Educational Resources Information Center

    Merkle, Edgar C.; Zeileis, Achim

    2013-01-01

    The issue of measurement invariance commonly arises in factor-analytic contexts, with methods for assessment including likelihood ratio tests, Lagrange multiplier tests, and Wald tests. These tests all require advance definition of the number of groups, group membership, and offending model parameters. In this paper, we study tests of measurement…

  8. mRNA expression of EgCHI1, EgCHI2, and EgCHI3 in oil palm leaves (Elaeis guineesis Jacq.) after treatment with Ganoderma boninense pat. and Trichoderma harzianum Rifai.

    PubMed

    Naher, Laila; Tan, Soon Guan; Ho, Chai Ling; Yusuf, Umi Kalsom; Ahmad, Siti Hazar; Abdullah, Faridah

    2012-01-01

    Basal stem rot (BSR) disease caused by the fungus Ganoderma boninense is the most serious disease affecting the oil palm; this is because the disease escapes the early disease detection. The biocontrol agent Trichoderma harzianum can protect the disease only at the early stage of the disease. In the present study, the expression levels of three oil palm (Elaeis guineensis Jacq.) chitinases encoding EgCHI1, EgCHI2, and EgCHI3 at 2, 5, and 8 weeks inoculation were measured in oil palm leaves from plants treated with G. boninense or T. harzianum alone or both. The five-month-old oil palm seedlings were treated with Gano-wood blocks inoculum and trichomulch. Expression of EgCHI1, EgCHI2, and EgCHI3 in treated leaves tissue was determined by real-time PCR. Oil palm chitinases were not strongly expressed in oil palm leaves of plants treated with G. boninense alone compared to other treatments. Throughout the 8-week experiment, expression of EgCHI1 increased more than 3-fold in leaves of plants treated with T. harzianum and G. boninense when compared to those of control and other treated plants. The data illustrated that chitinase cDNA expression varied depending on tissue and the type of treatment.

  9. What Next After Ho Chi Minh?

    DTIC Science & Technology

    1966-04-08

    Propagands Department; Nguyen Chi Thanh, protege of Truong Chinh ; Nguyen Duy Trinh; and Le Duc Thoo The pro-Soviet faction consists of Pham Van Dong...Communist" "Pro-Soviet" Ho Chi Minh Le Duan Truong Chinh Pham Van Dong Pham Hung General Giap Le Duc Tho Nguyen Chi Thanh Nguyen Duy Trinh Le Thanh Nghi...0 o . 15 The contenders. 0 . . . .0.0 28 4a THE LINE-UP 0 * a 0 * * 0 0 31 The lessor three - Hoang Van Hoan, Le Duc Tho, Le Thanh Nghi o .* 0 * * 0

  10. Slip history and dynamic implications of the 1999 Chi-Chi, Taiwan, earthquake

    USGS Publications Warehouse

    Ji, C.; Helmberger, D.V.; Wald, D.J.; Ma, K.-F.

    2003-01-01

    We investigate the rupture process of the 1999 Chi-Chi, Taiwan, earthquake using extensive near-source observations, including three-component velocity waveforms at 36 strong motion stations and 119 GPS measurements. A three-plane fault geometry derived from our previous inversion using only static data [Ji et al., 2001] is applied. The slip amplitude, rake angle, rupture initiation time, and risetime function are inverted simultaneously with a recently developed finite fault inverse method that combines a wavelet transform approach with a simulated annealing algorithm [Ji et al., 2002b]. The inversion results are validated by the forward prediction of an independent data set, the teleseismic P and SH ground velocities, with notable agreement. The results show that the total seismic moment release of this earthquake is 2.7 ?? 1020 N m and that most of the slip occured in a triangular-shaped asperity involving two fault segments, which is consistent with our previous static inversion. The rupture front propagates with an average rupture velocity of ???2.0 km s-1, and the average slip duration (risetime) is 7.2 s. Several interesting observations related to the temporal evolution of the Chi-Chi earthquake are also investigated, including (1) the strong effect of the sinuous fault plane of the Chelungpu fault on spatial and temporal variations in slip history, (2) the intersection of fault 1 and fault 2 not being a strong impediment to the rupture propagation, and (3 the observation that the peak slip velocity near the surface is, in general, higher than on the deeper portion of the fault plane, as predicted by dynamic modeling.

  11. Therapeutic benefits of Tai Chi exercise: research review.

    PubMed

    Kuramoto, Alice M

    2006-10-01

    The majority of studies on Tai Chi conducted between 1996 and 2004 had focused on health and well being of Tai Chi exercise for senior adults. The results show that Tai Chi may lead to improved balance, reduced fear of falling, increased strength, increased functional mobility, greater flexibility, and increased psychological well-being, sleep enhancement for sleep disturbed elderly individuals, and increased cardio functioning. Wang, Collet, and Lau did a systematic review on Tai Chi research and found some limitations or biases existing in some of the studies, and it was difficult to draw firm conclusions about the benefits reported. Therefore, more well-designed studies are needed in the future. There need to be studies on the effects on younger and middle-aged people. More longitudinal studies are needed, since time is an important factor of physical and psychological interventions. Studies on the effects of Tai Chi on the immune system and bone loss reduction are still very exploratory and will be especially useful for arthritis patients and others with immune disorders. Future studies should investigate outcomes associated with Tai Chi training as a function of different instructional techniques, different Tai Chi styles, different diagnostic groups, and different age groups. It is not yet clear which of the components in Tai Chi makes the exercise form especially effective for seniors. Tai Chi exercise is a relatively "low tech" approach to preventing disability and maintaining physical performance in older adults. The positive effects of Tai Chi may be due solely to its relaxing, meditative aspects. The current data suggest that Tai Chi can influence older individuals' functioning and well being and provide some appreciation for why this exercise form has been practiced by older Chinese for more than 3 centuries.

  12. T'ai Chi

    MedlinePlus

    ... who practice it wear a martial arts training uniform. T'ai chi is usually practiced barefoot or ... health problem. Is your schedule jam-packed with school, work, and social activities? Here are a few ...

  13. On the Likelihood Ratio Test for the Number of Factors in Exploratory Factor Analysis

    ERIC Educational Resources Information Center

    Hayashi, Kentaro; Bentler, Peter M.; Yuan, Ke-Hai

    2007-01-01

    In the exploratory factor analysis, when the number of factors exceeds the true number of factors, the likelihood ratio test statistic no longer follows the chi-square distribution due to a problem of rank deficiency and nonidentifiability of model parameters. As a result, decisions regarding the number of factors may be incorrect. Several…

  14. A Journey to Wholeness Through Tai Chi

    NASA Astrophysics Data System (ADS)

    Al-Turki, Faiza

    Healing is a multifaceted venture. Whereas many traditional cultures see healing as a journey that, by necessity, combines body, mind, and spirit, today's Western society frequently divides healing, relegating its parts to various experts--body to physicians, mind to psychologists, spirit to religions. Employing heuristic and alchemical hermeneutic methodologies, this thesis explores tai chi as a healing tool that bridges that division, exploring the following question: is it possible that the connection of body, mind, and spirit offered by tai chi is the very mechanism by which it facilitates healing? The cultural and historical context of tai chi is introduced, as well as research showing various Western views. A heuristic approach offers personal examples of the use of tai chi as a process partner, while a depth psychological lens informs the use of tai chi principles to guide moments of self-exploration and transformation in a therapeutic way.

  15. A weighted generalized score statistic for comparison of predictive values of diagnostic tests.

    PubMed

    Kosinski, Andrzej S

    2013-03-15

    Positive and negative predictive values are important measures of a medical diagnostic test performance. We consider testing equality of two positive or two negative predictive values within a paired design in which all patients receive two diagnostic tests. The existing statistical tests for testing equality of predictive values are either Wald tests based on the multinomial distribution or the empirical Wald and generalized score tests within the generalized estimating equations (GEE) framework. As presented in the literature, these test statistics have considerably complex formulas without clear intuitive insight. We propose their re-formulations that are mathematically equivalent but algebraically simple and intuitive. As is clearly seen with a new re-formulation we presented, the generalized score statistic does not always reduce to the commonly used score statistic in the independent samples case. To alleviate this, we introduce a weighted generalized score (WGS) test statistic that incorporates empirical covariance matrix with newly proposed weights. This statistic is simple to compute, always reduces to the score statistic in the independent samples situation, and preserves type I error better than the other statistics as demonstrated by simulations. Thus, we believe that the proposed WGS statistic is the preferred statistic for testing equality of two predictive values and for corresponding sample size computations. The new formulas of the Wald statistics may be useful for easy computation of confidence intervals for difference of predictive values. The introduced concepts have potential to lead to development of the WGS test statistic in a general GEE setting. Copyright © 2012 John Wiley & Sons, Ltd.

  16. A weighted generalized score statistic for comparison of predictive values of diagnostic tests

    PubMed Central

    Kosinski, Andrzej S.

    2013-01-01

    Positive and negative predictive values are important measures of a medical diagnostic test performance. We consider testing equality of two positive or two negative predictive values within a paired design in which all patients receive two diagnostic tests. The existing statistical tests for testing equality of predictive values are either Wald tests based on the multinomial distribution or the empirical Wald and generalized score tests within the generalized estimating equations (GEE) framework. As presented in the literature, these test statistics have considerably complex formulas without clear intuitive insight. We propose their re-formulations which are mathematically equivalent but algebraically simple and intuitive. As is clearly seen with a new re-formulation we present, the generalized score statistic does not always reduce to the commonly used score statistic in the independent samples case. To alleviate this, we introduce a weighted generalized score (WGS) test statistic which incorporates empirical covariance matrix with newly proposed weights. This statistic is simple to compute, it always reduces to the score statistic in the independent samples situation, and it preserves type I error better than the other statistics as demonstrated by simulations. Thus, we believe the proposed WGS statistic is the preferred statistic for testing equality of two predictive values and for corresponding sample size computations. The new formulas of the Wald statistics may be useful for easy computation of confidence intervals for difference of predictive values. The introduced concepts have potential to lead to development of the weighted generalized score test statistic in a general GEE setting. PMID:22912343

  17. HIV-Related Risk Behaviors, Perceptions of Risk, HIV Testing, and Exposure to Prevention Messages and Methods among Urban American Indians and Alaska Natives

    ERIC Educational Resources Information Center

    Lapidus, Jodi A.; Bertolli, Jeanne; McGowan, Karen; Sullivan, Patrick

    2006-01-01

    The goal of this study was to describe HIV risk behaviors, perceptions, testing, and prevention exposure among urban American Indians and Alaska Natives (AI/AN). Interviewers administered a questionnaire to participants recruited through anonymous peer-referral sampling. Chi-square tests and multiple logistic regression were used to compare HIV…

  18. The effect of rare variants on inflation of the test statistics in case-control analyses.

    PubMed

    Pirie, Ailith; Wood, Angela; Lush, Michael; Tyrer, Jonathan; Pharoah, Paul D P

    2015-02-20

    The detection of bias due to cryptic population structure is an important step in the evaluation of findings of genetic association studies. The standard method of measuring this bias in a genetic association study is to compare the observed median association test statistic to the expected median test statistic. This ratio is inflated in the presence of cryptic population structure. However, inflation may also be caused by the properties of the association test itself particularly in the analysis of rare variants. We compared the properties of the three most commonly used association tests: the likelihood ratio test, the Wald test and the score test when testing rare variants for association using simulated data. We found evidence of inflation in the median test statistics of the likelihood ratio and score tests for tests of variants with less than 20 heterozygotes across the sample, regardless of the total sample size. The test statistics for the Wald test were under-inflated at the median for variants below the same minor allele frequency. In a genetic association study, if a substantial proportion of the genetic variants tested have rare minor allele frequencies, the properties of the association test may mask the presence or absence of bias due to population structure. The use of either the likelihood ratio test or the score test is likely to lead to inflation in the median test statistic in the absence of population structure. In contrast, the use of the Wald test is likely to result in under-inflation of the median test statistic which may mask the presence of population structure.

  19. mRNA Expression of EgCHI1, EgCHI2, and EgCHI3 in Oil Palm Leaves (Elaeis guineesis Jacq.) after Treatment with Ganoderma boninense Pat. and Trichoderma harzianum Rifai

    PubMed Central

    Naher, Laila; Tan, Soon Guan; Ho, Chai Ling; Yusuf, Umi Kalsom; Ahmad, Siti Hazar; Abdullah, Faridah

    2012-01-01

    Background. Basal stem rot (BSR) disease caused by the fungus Ganoderma boninense is the most serious disease affecting the oil palm; this is because the disease escapes the early disease detection. The biocontrol agent Trichoderma harzianum can protect the disease only at the early stage of the disease. In the present study, the expression levels of three oil palm (Elaeis guineensis Jacq.) chitinases encoding EgCHI1, EgCHI2, and EgCHI3 at 2, 5, and 8 weeks inoculation were measured in oil palm leaves from plants treated with G. boninense or T. harzianum alone or both. Methods. The five-month-old oil palm seedlings were treated with Gano-wood blocks inoculum and trichomulch. Expression of EgCHI1, EgCHI2, and EgCHI3 in treated leaves tissue was determined by real-time PCR. Results. Oil palm chitinases were not strongly expressed in oil palm leaves of plants treated with G. boninense alone compared to other treatments. Throughout the 8-week experiment, expression of EgCHI1 increased more than 3-fold in leaves of plants treated with T. harzianum and G. boninense when compared to those of control and other treated plants. Conclusion. The data illustrated that chitinase cDNA expression varied depending on tissue and the type of treatment. PMID:22919345

  20. Tai Chi for chronic obstructive pulmonary disease (COPD).

    PubMed

    Ngai, Shirley P C; Jones, Alice Y M; Tam, Wilson Wai San

    2016-06-07

    Tai Chi, a systematic callisthenic exercise first developed in ancient China, involves a series of slow and rhythmic circular motions. It emphasises use of 'mind' or concentration to control breathing and circular body motions to facilitate flow of internal energy (i.e. 'qi') within the body. Normal flow of 'qi' is believed to be essential to sustain body homeostasis, ultimately leading to longevity. The effect of Tai Chi on balance and muscle strength in the elderly population has been reported; however, the effect of Tai Chi on dyspnoea, exercise capacity, pulmonary function and psychosocial status among people with chronic obstructive pulmonary disease (COPD) remains unclear. • To explore the effectiveness of Tai Chi in reducing dyspnoea and improving exercise capacity in people with COPD.• To determine the influence of Tai Chi on physiological and psychosocial functions among people with COPD. We searched the Cochrane Airways Group Specialised Register of trials (which included the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), the Allied and Complementary Medicine Database (AMED) and PsycINFO); handsearched respiratory journals and meeting abstracts; and searched Chinese medical databases including Wanfang Data, Chinese Medical Current Contents (CMCC), Chinese Biomedical Database (CBM), China Journal Net (CJN) and China Medical Academic Conference (CMAC), from inception to September 2015. We checked the reference lists of all primary studies and review articles for relevant additional references. We included randomised controlled trials (RCTs) comparing Tai Chi (Tai Chi alone or Tai Chi in addition to another intervention) versus control (usual care or another intervention identical to that used in the Tai Chi group) in people with COPD. Two independent review authors screened and selected studies. Two independent review authors extracted data from included

  1. Response of seismicity to Coulomb stress triggers and shadows of the 1999 Mw=7.6 Chi-Chi, Taiwan, earthquake

    USGS Publications Warehouse

    Ma, K.-F.; Chan, C.-H.; Stein, R.S.

    2005-01-01

    The correlation between static Coulomb stress increases and aftershocks has thus far provided the strongest evidence that stress changes promote seismicity, a correlation that the Chi-Chi earthquake well exhibits. Several studies have deepened the argument by resolving stress changes on aftershock focal mechanisms, which removes the assumption that the aftershocks are optimally oriented for failure. Here one compares the percentage of planes on which failure is promoted after the main shock relative to the percentage beforehand. For Chi-Chi we find a 28% increase for thrust and an 18% increase for strike-slip mechanisms, commensurate with increases reported for other large main shocks. However, perhaps the chief criticism of static stress triggering is the difficulty in observing predicted seismicity rate decreases in the stress shadows, or sites of Coulomb stress decrease. Detection of sustained drops in seismicity rate demands a long catalog with a low magnitude of completeness and a high seismicity rate, conditions that are met at Chi-Chi. We find four lobes with statistically significant seismicity rate declines of 40-90% for 50 months, and they coincide with the stress shadows calculated for strike-slip faults, the dominant faulting mechanism. The rate drops are evident in uniform cell calculations, 100-month time series, and by visual inspection of the M ??? 3 seismicity. An additional reason why detection of such declines has proven so rare emerges from this study: there is a widespread increase in seismicity rate during the first 3 months after Chi-Chi, and perhaps many other main shocks, that might be associated with a different mechanism. Copyright 2005 by the American Geophysical Union.

  2. Tai Chi Improves Brain Metabolism and Muscle Energetics in Older Adults.

    PubMed

    Zhou, Min; Liao, Huijun; Sreepada, Lasya P; Ladner, Joshua R; Balschi, James A; Lin, Alexander P

    2018-04-17

    Tai Chi is a mind-body exercise that has been shown to improve both mental and physical health. As a result, recent literature suggests the use of Tai Chi to treat both physical and psychological disorders. However, the underlying physiological changes have not been characterized. The aim of this pilot study is to assess the changes in brain metabolites and muscle energetics after Tai Chi training in an aging population using a combined brain-muscle magnetic resonance spectroscopy (MRS) examination. Six healthy older adults were prospectively recruited and enrolled into a 12-week Tai Chi program. A brain 1 H MRS and a muscle 31 P MRS were scanned before and after the training, and postprocessed to measure N-acetylaspartate to creatine (NAA/Cr) ratios and phosphocreatine (PCr) recovery time. Wilcoxon-signed rank tests were utilized to assess the differences between pre- and post-Tai Chi training. A significant within-subject increase in both the NAA/Cr ratios (P = .046) and the PCr recovery time (P = .046) was observed between the baseline and the posttraining scans. The median percentage changes were 5.38% and 16.51% for NAA/Cr and PCr recovery time, respectively. Our pilot study demonstrates significant increase of NAA/Cr ratios in posterior cingulate gyrus and significantly improved PCr recovery time in leg muscles in older adults following short-term Tai Chi training, and thus provides insight into the beneficial mechanisms. Copyright © 2018 The Authors. Journal of Neuroimaging published by Wiley Periodicals, Inc. on behalf of American Society of Neuroimaging.

  3. Medical training fails to prepare providers to care for patients with chronic hepatitis B infection

    PubMed Central

    Chao, Stephanie D; Wang, Bing-Mei; Chang, Ellen T; Ma, Li; So, Samuel K

    2015-01-01

    AIM: To investigate physicians’ knowledge including chronic hepatitis B (CHB) diagnosis, screening, and management in various stages of their training. METHODS: A voluntary 20-question survey was administered in Santa Clara County, CA where Asian and Pacific Islanders (API) account for a third of the population. Among the 219 physician participants, there were 63 interns, 60 second-year residents, 26 chief residents and 70 attending physicians. The survey asked questions regarding respondents’ demographics, general hepatitis B virus knowledge questions (i.e., transmission, prevalence, diagnostic testing, prevention, and treatment options), as well as, self-reported practice behavior and confidence in knowledge. RESULTS: Knowledge about screening and managing patients with CHB was poor: only 24% identified the correct tests to screen for CHB, 13% knew the next steps for patients testing positive for CHB, 18% knew the high prevalence rate among API, and 31% knew how to screen for liver cancer. Wald chi-square analysis determined the effect of training level on knowledge; in all cases except for knowledge of liver cancer screening (P = 0.0032), knowledge did not significantly increase with length in residency training or completion of residency. CONCLUSION: Even in a high-risk region, both medical school and residency training have not adequately prepared physicians in the screening and management of CHB. PMID:26078568

  4. Branching fraction measurements of {chi}{sub c0} and {chi}{sub c2} to {pi}{sup 0{pi}0} and {eta}{eta}

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ablikim, M.; An, Z. H.; Bai, J. Z.

    2010-03-01

    Using a sample of 1.06x10{sup 8} {psi}{sup '} decays collected by the BESIII detector, {chi}{sub c0} and {chi}{sub c2} decays into {pi}{sup 0{pi}0} and {eta}{eta} are studied. The branching fraction results are Br({chi}{sub c0{yields}{pi}}{sup 0{pi}0})=(3.23{+-}0.03{+-}0.23{+-}0.14)x10{sup -3}, Br({chi}{sub c2{yields}{pi}}{sup 0{pi}0})=(8.8{+-}0.2{+-}0.6{+-}0.4)x10{sup -4}, Br({chi}{sub c0{yields}{eta}{eta}})=(3.44{+-}0.10{+-}0.24{+-}0.2)x10{sup -3}, and Br({chi}{sub c2{yields}{eta}{eta}})=(6.5{+-}0.4{+-}0.5{+-}0.3)x10{sup -4}, where the uncertainties are statistical, systematic due to this measurement, and systematic due to the branching fractions of {psi}{sup '{yields}{gamma}{chi}}{sub cJ}. The results provide information on the decay mechanism of {chi}{sub c} states into pseudoscalars.

  5. Tai Chi and balance control.

    PubMed

    Wong, Alice M K; Lan, Ching

    2008-01-01

    Balance function begins to decline from middle age on, and poor balance function increases the risk of fall and injury. Suitable exercise training may improve balance function and prevent accidental falls. The coordination of visual, proprioceptive, vestibular and musculoskeletal system is important to maintain balance. Balance function can be evaluated by functional balance testing and sensory organization testing. Tai Chi Chuan (TC) is a popular conditioning exercise in the Chinese community, and recent studies substantiate that TC is effective in balance function enhancement and falls prevention. In studies utilizing functional balance testing, TC may increase the duration of one-leg standing and the distance of functional reach. In studies utilizing sensory organization testing, TC improves static and dynamic balance, especially in more challenging sensory perturbed condition. Therefore, TC may be prescribed as an alternative exercise program for elderly subjects or balance-impaired patients. Participants can choose to perform a complete set of TC or selected movements according to their needs. In conclusion, TC may improve balance function and is appropriate for implementation in the community.

  6. Integrative set enrichment testing for multiple omics platforms

    PubMed Central

    2011-01-01

    Background Enrichment testing assesses the overall evidence of differential expression behavior of the elements within a defined set. When we have measured many molecular aspects, e.g. gene expression, metabolites, proteins, it is desirable to assess their differential tendencies jointly across platforms using an integrated set enrichment test. In this work we explore the properties of several methods for performing a combined enrichment test using gene expression and metabolomics as the motivating platforms. Results Using two simulation models we explored the properties of several enrichment methods including two novel methods: the logistic regression 2-degree of freedom Wald test and the 2-dimensional permutation p-value for the sum-of-squared statistics test. In relation to their univariate counterparts we find that the joint tests can improve our ability to detect results that are marginal univariately. We also find that joint tests improve the ranking of associated pathways compared to their univariate counterparts. However, there is a risk of Type I error inflation with some methods and self-contained methods lose specificity when the sets are not representative of underlying association. Conclusions In this work we show that consideration of data from multiple platforms, in conjunction with summarization via a priori pathway information, leads to increased power in detection of genomic associations with phenotypes. PMID:22118224

  7. Power of tests of normality for detecting contaminated normal samples

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Thode, H.C. Jr.; Smith, L.A.; Finch, S.J.

    1981-01-01

    Seventeen tests of normality or goodness of fit were evaluated for power at detecting a contaminated normal sample. This study used 1000 replications each of samples of size 12, 17, 25, 33, 50, and 100 from six different contaminated normal distributions. The kurtosis test was the most powerful over all sample sizes and contaminations. The Hogg and weighted Kolmogorov-Smirnov tests were second. The Kolmogorov-Smirnov, chi-squared, Anderson-Darling, and Cramer-von-Mises tests had very low power at detecting contaminated normal random variables. Tables of the power of the tests and the power curves of certain tests are given.

  8. Goodness-of-fit tests for open capture-recapture models

    USGS Publications Warehouse

    Pollock, K.H.; Hines, J.E.; Nichols, J.D.

    1985-01-01

    General goodness-of-fit tests for the Jolly-Seber model are proposed. These tests are based on conditional arguments using minimal sufficient statistics. The tests are shown to be of simple hypergeometric form so that a series of independent contingency table chi-square tests can be performed. The relationship of these tests to other proposed tests is discussed. This is followed by a simulation study of the power of the tests to detect departures from the assumptions of the Jolly-Seber model. Some meadow vole capture-recapture data are used to illustrate the testing procedure which has been implemented in a computer program available from the authors.

  9. Remission of depression following electroconvulsive therapy (ECT) is associated with higher levels of brain-derived neurotrophic factor (BDNF).

    PubMed

    Freire, Thiago Fernando Vasconcelos; Fleck, Marcelo Pio de Almeida; da Rocha, Neusa Sica

    2016-03-01

    Research on the association between electroconvulsive therapy (ECT) and increased brain derived neurotrophic factor (BDNF) levels has produced conflicting result. There have been few studies which have evaluated BDNF levels in clinical contexts where there was remission following treatment. The objective of this study was to investigate whether remission of depression following ECT is associated with changes in BDNF levels. Adult inpatients in a psychiatric unit were invited to participate in this naturalistic study. Diagnoses were made using the Mini-International Neuropsychiatric Interview (MINI) and symptoms were evaluated at admission and discharge using the Hamilton Rating Scale for Depression (HDRS-17). Thirty-one patients who received a diagnosis of depression and were subjected to ECT were included retrospectively. Clinical remission was defined as a score of less than eight on the HDRS-17 at discharge. Serum BDNF levels were measured in blood samples collected at admission and discharge with a commercial kit used in accordance with the manufacturer's instructions. Subjects HDRS-17 scores improved following ECT (t = 13.29; p = 0.00). A generalized estimating equation (GEE) model revealed a remission × time interaction with BDNF levels as a dependent variable in a Wald chi-square test [Wald χ(2) = 5.98; p = 0.01]. A post hoc Bonferroni test revealed that non-remitters had lower BDNF levels at admission than remitters (p = 0.03), but there was no difference at discharge (p = 0.16). ECT remitters had higher serum BDNF levels at admission and the level did not vary during treatment. ECT non-remitters had lower serum BDNF levels at admission, but levels increased during treatment and were similar to those of ECT remitters at discharge. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Grass height and transmission ecology of Echinococcus multilocularis in Tibetan communities, China.

    PubMed

    Wang, Qian; Raoul, Francis; Budke, Christine; Craig, Philip S; Xiao, Yong-fu; Vuitton, Dominique A; Campos-Ponce, Maiza; Qiu, Dong-chuan; Pleydell, David; Giraudoux, Patrick

    2010-01-05

    Alveolar echinococcosis is a major zoonosis of public health significance in western China. Overgrazing was recently assumed as a potential risk factor for transmission of alveolar echinococcosis. The research was designed to further test the overgrazing hypothesis by investigating how overgrazing influenced the burrow density of intermediate host small mammals and how the burrow density of small mammals was associated with dog Echinococcus multilocularis infection. The study sites were chosen by previous studies which found areas where the alveolar echinococcosis was prevalent. The data, including grass height, burrow density of intermediate host small mammals, dog and fox fecal samples as well as Global Positioning System (GPS) position, were collected from field investigations in Shiqu County, Sichuan Province, China. The fecal samples were analyzed using copro-PCR. The worms, teeth, bones and hairs in the fecal samples were visually examined. Single factor and multifactor analyses tools including chi square and generalized linear models were applied to these data. By using grass height as a proxy of grazing pressure in the homogenous pasture, this study found that taller grass in the pasture led to lower small mammals' burrow density (chi(2) = 4.670, P = 0.031, coefficient = -1.570). The Echinococcus multilocularis worm burden in dogs was statistically significantly related to the maximum density of the intermediate host Ochotona spp. (chi(2) = 5.250, P = 0.022, coefficient = 0.028). The prevalence in owned dogs was positively correlated to the number of stray dogs seen within a 200 meter radius (Wald chi(2) = 8.375, P = 0.004, odds ratio = 1.198). Our findings support the hypothesis that overgrazing promotes transmission of alveolar echinococcosis and confirm the role of stray dogs in the transmission of alveolar echinococcosis.

  11. CD11c(hi) Dendritic Cells Regulate Ly-6C(hi) Monocyte Differentiation to Preserve Immune-privileged CNS in Lethal Neuroinflammation.

    PubMed

    Kim, Jin Hyoung; Choi, Jin Young; Kim, Seong Bum; Uyangaa, Erdenebelig; Patil, Ajit Mahadev; Han, Young Woo; Park, Sang-Youel; Lee, John Hwa; Kim, Koanhoi; Eo, Seong Kug

    2015-12-02

    Although the roles of dendritic cells (DCs) in adaptive defense have been defined well, the contribution of DCs to T cell-independent innate defense and subsequent neuroimmunopathology in immune-privileged CNS upon infection with neurotropic viruses has not been completely defined. Notably, DC roles in regulating innate CD11b(+)Ly-6C(hi) monocyte functions during neuroinflammation have not yet been addressed. Using selective ablation of CD11c(hi)PDCA-1(int/lo) DCs without alteration in CD11c(int)PDCA-1(hi) plasmacytoid DC number, we found that CD11c(hi) DCs are essential to control neuroinflammation caused by infection with neurotropic Japanese encephalitis virus, through early and increased infiltration of CD11b(+)Ly-6C(hi) monocytes and higher expression of CC chemokines. More interestingly, selective CD11c(hi) DC ablation provided altered differentiation and function of infiltrated CD11b(+)Ly-6C(hi) monocytes in the CNS through Flt3-L and GM-CSF, which was closely associated with severely enhanced neuroinflammation. Furthermore, CD11b(+)Ly-6C(hi) monocytes generated in CD11c(hi) DC-ablated environment had a deleterious rather than protective role during neuroinflammation, and were more quickly recruited into inflamed CNS, depending on CCR2, thereby exacerbating neuroinflammation via enhanced supply of virus from the periphery. Therefore, our data demonstrate that CD11c(hi) DCs provide a critical and unexpected role to preserve the immune-privileged CNS in lethal neuroinflammation via regulating the differentiation, function, and trafficking of CD11b(+)Ly-6C(hi) monocytes.

  12. The Model-Size Effect on Traditional and Modified Tests of Covariance Structures

    ERIC Educational Resources Information Center

    Herzog, Walter; Boomsma, Anne; Reinecke, Sven

    2007-01-01

    According to Kenny and McCoach (2003), chi-square tests of structural equation models produce inflated Type I error rates when the degrees of freedom increase. So far, the amount of this bias in large models has not been quantified. In a Monte Carlo study of confirmatory factor models with a range of 48 to 960 degrees of freedom it was found that…

  13. Psi Chi/APA Edwin B. Newman Graduate Research Award.

    PubMed

    2016-11-01

    The Edwin B. Newman Graduate Research Award is sponsored jointly by Psi Chi, the national honor society in psychology, and the APA. The award is presented annually to the psychology graduate student who submits the best research paper that was published or presented at a national, regional, or state psychological association conference during the past calendar year. The Edwin B. Newman Graduate Research Award is given jointly by Psi Chi and APA. Members of the 2016 Edwin B. Newman Award Committee were Shawn Carlton, PhD, Psi Chi representative; Christina Frederick-Recascino, PhD; John Norcross, PhD, APA representative; Karenna Malavanti, PhD, Psi Chi representative; Steven Kohn, PhD, Psi Chi representative; Warren Fass, PhD, Psi Chi representative; Chris Lovelace, PhD, Psi Chi representative; and Cathy Epkins, PhD, APA representative. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  14. The effect of Ai Chi aquatic therapy on individuals with knee osteoarthritis: a pilot study.

    PubMed

    So, Billy C L; Kong, Iris S Y; Lee, Roy K L; Man, Ryan W F; Tse, William H K; Fong, Adalade K W; Tsang, William W N

    2017-05-01

    [Purpose] To examine the efficacy of Ai Chi in relieving the pain and stiffness of knee osteoarthritis and improving, physical functioning, proprioception and quality of life. [Subjects and Methods] Twenty-five persons with knee osteoarthritis completed 5 weeks Ai Chi practice (60 minutes per session, twice per week, 10 sessions in total). Knee pain and stiffness were measured before and after the intervention program. [Results] Significant improvements in pain, self-perceived physical functioning and self-perceived stiffness were observed after the Ai-Chi intervention. On average, no significant change in knee range of motion, 6-minute walk test distances or proprioception was observed. [Conclusion] A five-week Ai Chi intervention can improve the pain and stiffness of knee osteoarthritis and self-perceived physical functions and quality of life improvement. Ai Chi may be another treatment choice for people with knee OA to practice in the community.

  15. Statistical analysis of multivariate atmospheric variables. [cloud cover

    NASA Technical Reports Server (NTRS)

    Tubbs, J. D.

    1979-01-01

    Topics covered include: (1) estimation in discrete multivariate distributions; (2) a procedure to predict cloud cover frequencies in the bivariate case; (3) a program to compute conditional bivariate normal parameters; (4) the transformation of nonnormal multivariate to near-normal; (5) test of fit for the extreme value distribution based upon the generalized minimum chi-square; (6) test of fit for continuous distributions based upon the generalized minimum chi-square; (7) effect of correlated observations on confidence sets based upon chi-square statistics; and (8) generation of random variates from specified distributions.

  16. Recent results of {chi}{sub cJ} decays from BESIII

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yan Liang

    2011-05-23

    Using (106{+-}4)x10{sup 6} {psi}{sup '} events collected with BESIII/BEPCII in March and April 2009, some {chi}{sub cJ} decay modes are studied, such as {chi}{sub cJ}{yields}{pi}{sup 0}{pi}{sup 0}, {chi}{sub cJ}{yields}{eta}{eta}, {chi}{sub cJ}{yields}VV, {chi}{sub cJ}{yields}{gamma}V, and so on. The precisions of these branching fraction measurements are improved, which is helpful to understand {chi}{sub cJ} decay mechanism.

  17. CHI3L1 polymorphisms associate with asthma in a Taiwanese population

    PubMed Central

    2014-01-01

    Background A genome-wide association study uncovered Chitinase 3 like 1 (CHI3L1) as a candidate gene for asthma susceptibility. CHI3L1, which encodes the YKL-40 protein, is associated with asthma in Western European and American populations and with atopy in a Korean population. However, asthma-associated polymorphisms remain unknown for a Taiwanese population. Methods We enrolled 628 adult asthmatic patients and 1:1 age-sex matched community-based controls in southern Taiwan and performed a combined effect sizes analysis to test if CHI3L1 polymorphisms were related to genetic risks for asthma in the Asian population. Ten tagSNP polymorphisms for the CHI3L1 gene were selected from the HapMap database and genotyped using a TaqMan allelic discrimination assay. Results Adjusted odds ratios of the CHI3L1 rs1538372 CC genotype (aOR = 1.97, 95% CI: 1.23–3.14) and the rs10399931 GG genotype (aOR = 1.77, 95% CI: 1.13–2.77) were significantly associated with asthma in the Taiwanese populations. Predictive values of forced expiratory volume in the first second of the forced vital capacity (12.37%, P = 0.03) and of forced vital capacity (12.10%, P = 0.036) decreased in conjunction with an increase in YKL-40 levels among CHI3L1 rs1538372 CC carriers; these values were 16.1% (P = 0.004) and 14.5% (P = 0.011), respectively, among CHI3L1 rs10399931 GG carriers. Furthermore, steroid use by asthma patients did not affect serum YKL-40 levels, but both polymorphisms had significant effects on YKL-40 levels in asthma patients who used steroids. Conclusions Our findings suggest that the CHI3L1 polymorphisms rs1538372 and rs10399931 can be used as genetic markers for predicting asthma risk in the Taiwanese population. PMID:25056157

  18. Study of the hadronic decays of {chi}{sub c} states

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bai, J.Z.; Bian, J.G.; Chen, G.P.

    1999-10-01

    Hadronic decays of the {ital P}-wave spin-triplet charmonium states {chi}{sub cJ}(J=0,1,2) are studied using a sample of {psi}(2S) decays collected by the BES detector operating at the BEPC storage ring. Branching fractions for the decays {chi}{sub c1}{r_arrow}K{sub S}{sup 0}K{sup +}{pi}{sup {minus}}+c.c., {chi}{sub c0}{r_arrow}K{sub S}{sup 0}K{sub S}{sup 0}, {chi}{sub c2}{r_arrow}K{sub S}{sup 0}K{sub S}{sup 0}, {chi}{sub c0}{r_arrow}{phi}{phi}, {chi}{sub c2}{r_arrow}{phi}{phi} and {chi}{sub cJ}{r_arrow}K{sup +}K{sup {minus}}K{sup +}K{sup {minus}} are measured for the first time, and those for {chi}{sub cJ}{r_arrow}{pi}{sup +}{pi}{sup {minus}}{pi}{sup +}{pi}{sup {minus}}, {chi}{sub cJ}{r_arrow}{pi}{sup +}{pi}{sup {minus}}K{sup +}K{sup {minus}}, {chi}{sub cJ}{r_arrow}{pi}{sup +}{pi}{sup {minus}}p{bar p} and {chi}{sub cJ}{r_arrow}3({pi}{sup +}{pi}{sup {minus}}) are measured with improved precision.more » In addition, we determine the masses of the {chi}{sub c0} and {eta}{sub c} to be M{sub {chi}{sub c0}}=3414.1{plus_minus}0.6(stat){plus_minus}0.8(syst) MeV and M{sub {eta}{sub c}}=2975.8{plus_minus}3.9(stat){plus_minus}1.2(syst) MeV. {copyright} {ital 1999} {ital The American Physical Society}« less

  19. From least squares to multilevel modeling: A graphical introduction to Bayesian inference

    NASA Astrophysics Data System (ADS)

    Loredo, Thomas J.

    2016-01-01

    This tutorial presentation will introduce some of the key ideas and techniques involved in applying Bayesian methods to problems in astrostatistics. The focus will be on the big picture: understanding the foundations (interpreting probability, Bayes's theorem, the law of total probability and marginalization), making connections to traditional methods (propagation of errors, least squares, chi-squared, maximum likelihood, Monte Carlo simulation), and highlighting problems where a Bayesian approach can be particularly powerful (Poisson processes, density estimation and curve fitting with measurement error). The "graphical" component of the title reflects an emphasis on pictorial representations of some of the math, but also on the use of graphical models (multilevel or hierarchical models) for analyzing complex data. Code for some examples from the talk will be available to participants, in Python and in the Stan probabilistic programming language.

  20. Relating Trp-Glu dipeptide fluorescence to molecular conformation: the role of the discrete Chi 1 and Chi 2 angles.

    PubMed

    Eisenberg, Azaria Solomon; Juszczak, Laura J

    2013-07-05

    Molecular dynamics (MD), coupled with fluorescence data for charged dipeptides of tryptophanyl glutamic acid (Trp-Glu), reveal a detailed picture of how specific conformation affects fluorescence. Fluorescence emission spectra and time-resolved emission measurements have been collected for all four charged species. MD simulations 20 to 30 ns in length have also been carried out for the Trp-Glu species, as simulation provides aqueous phase conformational data that can be correlated with the fluorescence data. The calculations show that each dipeptide species is characterized by a similar set of six, discrete Chi 1, Chi 2 dihedral angle pairs. The preferred Chi 1 angles--60°, 180°, and 300°--play the significant role in positioning the terminal amine relative to the indole ring. A Chi 1 angle of 60° results in the arching of the backbone over the indole ring and no interaction of the ring with the terminal amine. Chi 1 values of 180° and 300° result in an extension of the backbone away from the indole ring and a NH3 cation-π interaction with indole. This interaction is believed responsible for charge transfer quenching. Two fluorescence lifetimes and their corresponding amplitudes correlate with the Chi 1 angle probability distribution for all four charged Trp-Glu dipeptides. Fluorescence emission band maxima are also consistent with the proposed pattern of terminal amine cation quenching of fluorescence. Copyright © 2013 Wiley Periodicals, Inc.

  1. Psi Chi/APA Edwin B. Newman Graduate Research Award.

    PubMed

    2017-12-01

    The Edwin B. Newman Graduate Research Award is sponsored jointly by Psi Chi, the national honor society in psychology, and the APA. The award is presented annually to the psychology graduate student who submits the best research paper that was published or presented at a national, regional, or state psychological association conference during the past calendar year. The Edwin B. Newman Graduate Research Award was established in 1979. The award was established to recognize young researchers at the beginning of their professional lives and to commemorate both the 50th anniversary of Psi Chi and the 100th anniversary of psychology as a science (dating from the founding of Wundt's laboratory). It was named for Dr. Edwin B. Newman, the first national president of Psi Chi (1929) and one of its founders. He was a prolific researcher and a long-time chair of the Department of Psychology at Harvard University. Newman was a member of APA's Board of Directors, served as recording secretary of the board from 1962 to 1967, and was parliamentarian for the APA Council of Representatives for many years. He served both Psi Chi and APA in a distinguished manner for half a century. The Edwin B. Newman Graduate Research Award is given jointly by Psi Chi and APA. Members of the 2017 Edwin B. Newman Award Committee were Shawn Carlton, PhD, Psi Chi representative; Christina Frederick-Recascino, PhD; John Norcross, PhD, APA representative; Karenna Malavanti, PhD, Psi Chi representative; Steven Kohn, PhD, Psi Chi representative; Warren Fass, PhD, Psi Chi representative; Chris Lovelace, PhD, Psi Chi representative; and Cathy Epkins, PhD, APA representative. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  2. Tai chi exercise in patients with chronic heart failure: a randomized clinical trial.

    PubMed

    Yeh, Gloria Y; McCarthy, Ellen P; Wayne, Peter M; Stevenson, Lynne W; Wood, Malissa J; Forman, Daniel; Davis, Roger B; Phillips, Russell S

    2011-04-25

    Preliminary evidence suggests that meditative exercise may have benefits for patients with chronic systolic heart failure (HF); this has not been rigorously tested in a large clinical sample. We sought to investigate whether tai chi, as an adjunct to standard care, improves functional capacity and quality of life in patients with HF. A single-blind, multisite, parallel-group, randomized controlled trial evaluated 100 outpatients with systolic HF (New York Heart Association class I-III, left ventricular ejection fraction ≤40%) who were recruited between May 1, 2005, and September 30, 2008. A group-based 12-week tai chi exercise program (n = 50) or time-matched education (n = 50, control group) was conducted. Outcome measures included exercise capacity (6- minute walk test and peak oxygen uptake) and disease-specific quality of life (Minnesota Living With Heart Failure Questionnaire). Mean (SD) age of patients was 67 (11) years; baseline values were left ventricular ejection fraction, 29% (8%) and peak oxygen uptake, 13.5 mL/kg/min; the median New York Heart Association class of HF was class II. At completion of the study, there were no significant differences in change in 6-minute walk distance and peak oxygen uptake (median change [first quartile, third quartile], 35 [-2, 51] vs 2 [-7, 54] meters, P = .95; and 1.1 [-1.1, 1.5] vs -0.5 [-1.2, 1.8] mL/kg/min, P = .81) when comparing tai chi and control groups; however, patients in the tai chi group had greater improvements in quality of life (Minnesota Living With Heart Failure Questionnaire, -19 [-23, -3] vs 1 [-16, 3], P = .02). Improvements with tai chi were also seen in exercise self-efficacy (Cardiac Exercise Self-efficacy Instrument, 0.1 [0.1, 0.6] vs -0.3 [-0.5, 0.2], P < .001) and mood (Profile of Mood States total mood disturbance, -6 [-17, 1] vs -1 [-13, 10], P = .01). Tai chi exercise may improve quality of life, mood, and exercise self-efficacy in patients with HF. Trial Registration clinicaltrials

  3. [T'ai chi in the elderly: practical aspects].

    PubMed

    Kressig, Reto W; Beauchet, Olivier; Tharicharu, Jai

    2003-11-01

    New approaches to health promotion for the growing geriatric population are needed. Low to moderately intense exercise programs, such as T'ai Chi seem particularly appropriate for older individuals because of many worthwhile physiological and psychological long-term benefits. T'ai Chi reduces falls and improves postural stability in older adults. It also has a positive impact on muscle strength and cardiovascular fitness and can improve mobility in patients with rheumatoid arthritis. It imparts a sense of well-being and confidence, and can reduce fear of falling in older adults. This article reviews the current medical literature regarding the multiple effects of T'ai Chi. Historical aspects of T'ai Chi and its current adaptation for practice by healthy older adults are presented. Finally, a set of modified exercises is proposed that is based on underlying principles of T'ai Chi and can be applied to patients with mild to moderate cognitive impairment.

  4. Testing second order cyclostationarity in the squared envelope spectrum of non-white vibration signals

    NASA Astrophysics Data System (ADS)

    Borghesani, P.; Pennacchi, P.; Ricci, R.; Chatterton, S.

    2013-10-01

    Cyclostationary models for the diagnostic signals measured on faulty rotating machineries have proved to be successful in many laboratory tests and industrial applications. The squared envelope spectrum has been pointed out as the most efficient indicator for the assessment of second order cyclostationary symptoms of damages, which are typical, for instance, of rolling element bearing faults. In an attempt to foster the spread of rotating machinery diagnostics, the current trend in the field is to reach higher levels of automation of the condition monitoring systems. For this purpose, statistical tests for the presence of cyclostationarity have been proposed during the last years. The statistical thresholds proposed in the past for the identification of cyclostationary components have been obtained under the hypothesis of having a white noise signal when the component is healthy. This need, coupled with the non-white nature of the real signals implies the necessity of pre-whitening or filtering the signal in optimal narrow-bands, increasing the complexity of the algorithm and the risk of losing diagnostic information or introducing biases on the result. In this paper, the authors introduce an original analytical derivation of the statistical tests for cyclostationarity in the squared envelope spectrum, dropping the hypothesis of white noise from the beginning. The effect of first order and second order cyclostationary components on the distribution of the squared envelope spectrum will be quantified and the effectiveness of the newly proposed threshold verified, providing a sound theoretical basis and a practical starting point for efficient automated diagnostics of machine components such as rolling element bearings. The analytical results will be verified by means of numerical simulations and by using experimental vibration data of rolling element bearings.

  5. An Evaluation of the Psychometric Properties of Three Different Forms of Daly and Miller's Writing Apprehension Test through Rasch Analysis

    ERIC Educational Resources Information Center

    Güler, Nese; Ilhan, Mustafa; Güneyli, Ahmet; Demir, Süleyman

    2017-01-01

    This study evaluates the psychometric properties of three different forms of the Writing Apprehension Test (WAT; Daly & Miller, 1975) through Rasch analysis. For this purpose, the fit statistics and correlation coefficients, and the reliability, separation ratio, and chi-square values for the facets of item and person calculated for the…

  6. An empirical test of Lanchester's square law: mortality during battles of the fire ant Solenopsis invicta

    PubMed Central

    Plowes, Nicola J.R; Adams, Eldridge S

    2005-01-01

    Lanchester's models of attrition describe casualty rates during battles between groups as functions of the numbers of individuals and their fighting abilities. Originally developed to describe human warfare, Lanchester's square law has been hypothesized to apply broadly to social animals as well, with important consequences for their aggressive behaviour and social structure. According to the square law, the fighting ability of a group is proportional to the square of the number of individuals, but rises only linearly with fighting ability of individuals within the group. By analyzing mortality rates of fire ants (Solenopsis invicta) fighting in different numerical ratios, we provide the first quantitative test of Lanchester's model for a non-human animal. Casualty rates of fire ants were not consistent with the square law; instead, group fighting ability was an approximately linear function of group size. This implies that the relative numbers of casualties incurred by two fighting groups are not strongly affected by relative group sizes and that battles do not disproportionately favour group size over individual prowess. PMID:16096093

  7. New measurement of exclusive decays of the {chi}{sub c0} and {chi}{sub c2} to two-meson final states

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Asner, D. M.; Edwards, K. W.; Reed, J.

    2009-04-01

    Using a sample of 2.59x10{sup 7} {psi}(2S) decays collected by the CLEO-c detector, we present results of a study of {chi}{sub c0} and {chi}{sub c2} decays into two-meson final states. We present the world's most precise measurements of the {chi}{sub cJ,(J=0,2)}{yields}{pi}{sup +}{pi}{sup -}, {pi}{sup 0}{pi}{sup 0}, K{sup +}K{sup -}, K{sub S}{sup 0}K{sub S}{sup 0}, {eta}{eta}, and {eta}{sup '}{eta}{sup '} branching fractions, and a search for {chi}{sub c} decays into {eta}{eta}{sup '}. These results shed light on the mechanism of charmonium decays into pseudoscalar mesons.

  8. The Tai Chi in Star Formation

    NASA Astrophysics Data System (ADS)

    Li, Hua-bai

    2017-10-01

    Tai Chi, a Chinese martial art developed based on the laws of nature, emphasises how 'to conquer the unyielding with the yielding'. The recent observation of star formation shows that stars result from the interaction between gravity, turbulence and magnetic fields. This interaction again follows the nature rules that inspired Tai Chi. For example, if self-gravity is the force that dominates, the molecular cloud will collapse isotropically, which compresses magnetic field lines. The density of the yielding field lines increases until magnetic pressure reaches the critical value to support the cloud against the gravitational force in directions perpendicular to the field lines (Lorentz force). Then gravity gives way to Lorentz force, accumulating gas only along the field lines till the gas density achieves the critical value to again compress the field lines. The Tai Chi goes on in a self-similar way.

  9. Effect of Tai Chi Training on Dual-Tasking Performance That Involves Stepping Down among Stroke Survivors: A Pilot Study.

    PubMed

    Chan, Wing-Nga; Tsang, William Wai-Nam

    2017-01-01

    Descending stairs demands attention and neuromuscular control, especially with dual-tasking. Studies have demonstrated that stroke often degrades a survivor's ability to descend stairs. Tai Chi has been shown to improve dual-tasking performance of healthy older adults, but no such study has been conducted in stroke survivors. This study investigated the effect of Tai Chi training on dual-tasking performance that involved stepping down and compared it with that of conventional exercise among stroke survivors. Subjects were randomized into Tai Chi ( n = 9), conventional exercise ( n = 8), and control ( n = 9) groups. Those in the former two groups received 12-week training. Assessments included auditory Stroop test, stepping down test, and dual-tasking test involving both simultaneously. They were evaluated before training (time-1), after training (time-2), and one month after training (time-3). Tai Chi group showed significant improvement in the auditory Stroop test from time-1 to time-3 and the performance was significantly better than that of the conventional exercise group in time-3. No significant effect was found in the stepping down task or dual-tasking in the control group. These results suggest a beneficial effect of Tai Chi training on cognition among stroke survivors without compromising physical task performance in dual-tasking. The effect was better than the conventional exercise group. Nevertheless, further research with a larger sample is warranted.

  10. Sitting Tai Chi Improves the Balance Control and Muscle Strength of Community-Dwelling Persons with Spinal Cord Injuries: A Pilot Study

    PubMed Central

    Tsang, William W. N.; Gao, Kelly L.; Chan, K. M.; Purves, Sheila; Macfarlane, Duncan J.; Fong, Shirley S. M.

    2015-01-01

    Objective. To investigate the effects of sitting Tai Chi on muscle strength, balance control, and quality of life (QOL) among survivors with spinal cord injuries (SCI). Methods. Eleven SCI survivors participated in the sitting Tai Chi training (90 minutes/session, 2 times/week for 12 weeks) and eight SCI survivors acted as controls. Dynamic sitting balance was evaluated using limits of stability test and a sequential weight shifting test in sitting. Handgrip strength was also tested using a hand-held dynamometer. QOL was measured using the World Health Organization's Quality of Life Scale. Results. Tai Chi practitioners achieved significant improvements in their reaction time (P = 0.042); maximum excursion (P = 0.016); and directional control (P = 0.025) in the limits of stability test after training. In the sequential weight shifting test, they significantly improved their total time to sequentially hit the 12 targets (P = 0.035). Significant improvement in handgrip strength was also found among the Tai Chi practitioners (P = 0.049). However, no significant within and between-group differences were found in the QOL outcomes (P > 0.05). Conclusions. Twelve weeks of sitting Tai Chi training could improve the dynamic sitting balance and handgrip strength, but not QOL, of the SCI survivors. PMID:25688276

  11. Study of {chi}{sub cj} Decays at BES III

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhong, J.

    2010-08-05

    In spring 2009 BES III has taken its first large data sample on the {psi}(2S) resonance. More than 1{center_dot}10{sup 8} {psi}(2S) decays have been recorded. First results on the analyses {chi}{sub cJ{yields}{pi}}{sup 0{pi}0}, {chi}{sub cj{yields}{eta}{eta}} and {chi}{sub cj{yields}{phi}{phi}} are presented. The decay mode {chi}{sub c1{yields}{phi}{phi}} has been observed for the first time. The results presented in this document are preliminary.

  12. A Note on Three Statistical Tests in the Logistic Regression DIF Procedure

    ERIC Educational Resources Information Center

    Paek, Insu

    2012-01-01

    Although logistic regression became one of the well-known methods in detecting differential item functioning (DIF), its three statistical tests, the Wald, likelihood ratio (LR), and score tests, which are readily available under the maximum likelihood, do not seem to be consistently distinguished in DIF literature. This paper provides a clarifying…

  13. Tai Chi and older people in the community: a preliminary study.

    PubMed

    Morris Docker, Sara

    2006-05-01

    This paper outlines a qualitative exploratory study of the individual experiences of older people who practise Tai Chi for health. The study aimed to identify factors that influence the attraction of Tai Chi for older people. Participants were recruited from a selection of Tai Chi clubs in the north of England. Participant and non-participant observation of a selection of Tai Chi practice sessions was undertaken along with interviews with 7 older people. Findings show that individuals who practice Tai Chi report a variety of immediate and lasting physical and mental benefits. Being part of a group that both learns and practises Tai Chi together appears to be important to the experience and awareness of the spiritual nature of Tai Chi was also reported. It is argued that older people who practise Tai Chi may have a particular view on ageing, health and well-being that the activity of Tai Chi allows them to express and future study intends to investigate this in more detail.

  14. Effects of Tai Chi on Cognition and Fall Risk in Older Adults with Mild Cognitive Impairment: A Randomized Controlled Trial.

    PubMed

    Sungkarat, Somporn; Boripuntakul, Sirinun; Chattipakorn, Nipon; Watcharasaksilp, Kanokwan; Lord, Stephen R

    2017-04-01

    To examine whether combined center- and home-based Tai Chi training can improve cognitive ability and reduce physiological fall risk in older adults with amnestic mild cognitive impairment (a-MCI). Randomized controlled trial. Chiang Mai, Thailand. Adults aged 60 and older who met Petersen's criteria for multiple-domain a-MCI (N = 66). Three weeks center-based and 12 weeks home-based Tai Chi (50 minutes per session, 3 times per week). Cognitive tests, including Logical Memory (LM) delayed recall, Block Design, Digit Span forward and backward, and Trail-Making Test Part B-A (TMT B-A), and fall risk index using the Physiological Profile Assessment (PPA). At the end of the trial, performance on LM, Block Design, and TMT B-A were significantly better for the Tai Chi group than the control group after adjusting for baseline test performance. The Tai Chi group also had significantly better composite PPA score and PPA parameter scores: knee extension strength, reaction time, postural sway, and lower limb proprioception. Combined center- and home-based Tai Chi training three times per week for 15 weeks significantly improved cognitive function and moderately reduced physiological fall risk in older adults with multiple-domain a-MCI. Tai Chi may be particularly beneficial to older adults with this condition. © 2016, Copyright the Authors Journal compilation © 2016, The American Geriatrics Society.

  15. Predicting falls in older adults using the four square step test.

    PubMed

    Cleary, Kimberly; Skornyakov, Elena

    2017-10-01

    The Four Square Step Test (FSST) is a performance-based balance tool involving stepping over four single-point canes placed on the floor in a cross configuration. The purpose of this study was to evaluate properties of the FSST in older adults who lived independently. Forty-five community dwelling older adults provided fall history and completed the FSST, Berg Balance Scale (BBS), Timed Up and Go (TUG), and Tinetti in random order. Future falls were recorded for 12 months following testing. The FSST accurately distinguished between non-fallers and multiple fallers, and the 15-second threshold score accurately distinguished multiple fallers from non-multiple fallers based on fall history. The FSST predicted future falls, and performance on the FSST was significantly correlated with performance on the BBS, TUG, and Tinetti. However, the test is not appropriate for older adults who use walkers. Overall, the FSST is a valid yet underutilized measure of balance performance and fall prediction tool that physical therapists should consider using in ambulatory community dwelling older adults.

  16. Item Performance Across Native Language Groups on the Test of English as a Foreign Language. TOEFL Research Reports, 9.

    ERIC Educational Resources Information Center

    Alderman, Donald L.; Holland, Paul W.

    The Test of English as a Foreign Language (TOEFL) was examined for instances in which the item performance of examinees with comparable scores differed according to their native languages. A chi-square procedure, sensitive to deviations of less than ten percent from the expected frequencies of correct item responses across several language groups,…

  17. Recommendation of LightSquared Subsidiary LLC

    DOT National Transportation Integrated Search

    2011-01-01

    After a five-month effort, LightSquared, in cooperation with interested federal agencies and the commercial GPS device industry, has issued a Report on the results of intensive testing of the interaction between LightSquareds planned terrestrial o...

  18. Statistical analysis of earthquakes after the 1999 MW 7.7 Chi-Chi, Taiwan, earthquake based on a modified Reasenberg-Jones model

    NASA Astrophysics Data System (ADS)

    Chen, Yuh-Ing; Huang, Chi-Shen; Liu, Jann-Yenq

    2015-12-01

    We investigated the temporal-spatial hazard of the earthquakes after the 1999 September 21 MW = 7.7 Chi-Chi shock in a continental region of Taiwan. The Reasenberg-Jones (RJ) model (Reasenberg and Jones, 1989, 1994) that combines the frequency-magnitude distribution (Gutenberg and Richter, 1944) and time-decaying occurrence rate (Utsu et al., 1995) is conventionally employed for assessing the earthquake hazard after a large shock. However, it is found that the b values in the frequency-magnitude distribution of the earthquakes in the study region dramatically decreased from background values after the Chi-Chi shock, and then gradually increased up. The observation of a time-dependent frequency-magnitude distribution motivated us to propose a modified RJ model (MRJ) to assess the earthquake hazard. To see how the models perform on assessing short-term earthquake hazard, the RJ and MRJ models were separately used to sequentially forecast earthquakes in the study region. To depict the potential rupture area for future earthquakes, we further constructed relative hazard (RH) maps based on the two models. The Receiver Operating Characteristics (ROC) curves (Swets, 1988) finally demonstrated that the RH map based on the MRJ model was, in general, superior to the one based on the original RJ model for exploring the spatial hazard of earthquakes in a short time after the Chi-Chi shock.

  19. In Defense of Chi's Ontological Incompatibility Hypothesis

    ERIC Educational Resources Information Center

    Slotta, James D.

    2011-01-01

    This article responds to an article by A. Gupta, D. Hammer, and E. F. Redish (2010) that asserts that M. T. H. Chi's (1992, 2005) hypothesis of an "ontological commitment" in conceptual development is fundamentally flawed. In this article, I argue that Chi's theoretical perspective is still very much intact and that the critique offered by Gupta…

  20. Investigation of Dynamic Force/Vibration Transmission Characteristics of Four-Square Type Gear Durability Test Machines

    NASA Technical Reports Server (NTRS)

    Kahraman, Ahmet

    2002-01-01

    In this study, design requirements for a dynamically viable, four-square type gear test machine are investigated. Variations of four-square type gear test machines have been in use for durability and dynamics testing of both parallel- and cross-axis gear set. The basic layout of these machines is illustrated. The test rig is formed by two gear pairs, of the same reduction ratio, a test gear pair and a reaction gear pair, connected to each other through shafts of certain torsional flexibility to form an efficient, closed-loop system. A desired level of constant torque is input to the circuit through mechanical (a split coupling with a torque arm) or hydraulic (a hydraulic actuator) means. The system is then driven at any desired speed by a small DC motor. The main task in hand is the isolation of the test gear pair from the reaction gear pair under dynamic conditions. Any disturbances originated at the reaction gear mesh might potentially travel to the test gearbox, altering the dynamic loading conditions of the test gear mesh, and hence, influencing the outcome of the durability or dynamics test. Therefore, a proper design of connecting structures becomes a major priority. Also, equally important is the issue of how close the operating speed of the machine is to the resonant frequencies of the gear meshes. This study focuses on a detailed analysis of the current NASA Glenn Research Center gear pitting test machine for evaluation of its resonance and vibration isolation characteristics. A number of these machines as the one illustrated has been used over last 30 years to establish an extensive database regarding the influence of the gear materials, processes surface treatments and lubricants on gear durability. This study is intended to guide an optimum design of next generation test machines for the most desirable dynamic characteristics.

  1. Power and Sample Size Calculations for Logistic Regression Tests for Differential Item Functioning

    ERIC Educational Resources Information Center

    Li, Zhushan

    2014-01-01

    Logistic regression is a popular method for detecting uniform and nonuniform differential item functioning (DIF) effects. Theoretical formulas for the power and sample size calculations are derived for likelihood ratio tests and Wald tests based on the asymptotic distribution of the maximum likelihood estimators for the logistic regression model.…

  2. Measurement of the resonance parameters of the chi(1)(1**3P(1)) and chi(2)(1**3P(2)) states of charmonium formed in antiproton-proton annihilations

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Andreotti, M.; Bagnasco, S.; Baldini, W.

    2005-03-01

    The authors have studied the {sup 3}P{sub J} ({chi}{sub e}) states of charmonium in formation by antiproton-proton annihilations in experiment E835 at the Fermilab Antiproton Source. The authors report new measurements of the mass, width, and B({chi}{sub cJ} {yields} {bar p}p) x {Lambda}({chi}{sub eJ} {yields} J/{psi} + anything) for the {chi}{sub c1} and {chi}{sub c2} by means of the inclusive reaction {bar p}p {yields} {chi}{sub cJ} {yields} J/{psi} + anything {yields} (e{sup +}e{sup -}) + anything. Using the subsample of events where {chi}{sub cJ} {yields} {gamma} + J/{psi} {yields} {gamma} + (e{sup +}e{sup -}) is fully reconstructed, we derive B({chi}{submore » cJ} {yields} {bar p}p) x {Lambda}({chi}{sub cJ} {yields} J/{psi} + {gamma}). They summarize the results of the E760 (updated) and E835 measurements of mass, width and B({chi}{sub cJ} {yields} {bar p}p){Lambda}({chi}{sub cJ} {yields} J/{psi} + {gamma}) (J = 0,1,2) and discuss the significance of these measurements.« less

  3. Tai chi and meditation: A conceptual (re)synthesis?

    PubMed

    Posadzki, Paul; Jacques, Samantha

    2009-06-01

    The aim of this article is to review the literature on Tai Chi and meditation. A coherent construct is developed that includes a comparative analysis and conceptual synthesis of existing theories. The authors discuss a set of assumptions that justify this synthesis; they also argue that this construct would facilitate greater understanding of Tai Chi from the perspective of meditation. Such synthesis may bring "additional" benefits to Tai Chi practitioners as they could recognize that this mind-body technique holds the essence of meditation. Within the scope of this article, the evidence shows a majority of common features when concerning Tai Chi and meditation. These mutual similarities should be taken into account when performing this type of mind-body medicine by patients and/or therapists. Finally, the authors suggest that this inspiring compilation of movements and mindfulness can be used for practical purposes.

  4. Two-photon widths of the {chi}{sub cJ} states of charmonium

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ecklund, K. M.; Love, W.; Savinov, V.

    2008-11-01

    Using a data sample of 24.5x10{sup 6} {psi}(2S) the reactions {psi}(2S){yields}{gamma}{chi}{sub cJ}, {chi}{sub cJ}{yields}{gamma}{gamma} have been studied for the first time to determine the two-photon widths of the {chi}{sub cJ} states of charmonium in their decay into two photons. The measured quantities are B({psi}(2S){yields}{gamma}{chi}{sub c0})xB({chi}{sub c0}{yields}{gamma}{gamma})=(2.17{+-}0.32{+-}0.10)x10{sup -5} and B({psi}(2S){yields}{gamma}{chi}{sub c2})xB({chi}{sub c2}{yields}{gamma}{gamma})=(2.68{+-}0.28{+-}0.15)x10{sup -5}. Using values for B({psi}(2S){yields}{gamma}{chi}{sub c0,c2}) and {gamma}({chi}{sub c0,c2}) from the literature the two-photon widths are derived to be {gamma}{sub {gamma}}{sub {gamma}}({chi}{sub c0})=(2.36{+-}0.35{+-}0.22) keV, {gamma}{sub {gamma}}{sub {gamma}}({chi}{sub c2})=(0.66{+-}0.07{+-}0.06) keV, and R{identical_to}{gamma}{sub {gamma}}{sub {gamma}}({chi}{sub c2})/{gamma}{sub {gamma}}{sub {gamma}}({chi}{sub c0})=0.278{+-}0.050{+-}0.036. The importance of the measurement of R is emphasized. For the forbiddenmore » transition, {chi}{sub c1}{yields}{gamma}{gamma}, an upper limit of {gamma}{sub {gamma}}{sub {gamma}}({chi}{sub c1})<0.03 keV is established.« less

  5. Flight Test of Orthogonal Square Wave Inputs for Hybrid-Wing-Body Parameter Estimation

    NASA Technical Reports Server (NTRS)

    Taylor, Brian R.; Ratnayake, Nalin A.

    2011-01-01

    As part of an effort to improve emissions, noise, and performance of next generation aircraft, it is expected that future aircraft will use distributed, multi-objective control effectors in a closed-loop flight control system. Correlation challenges associated with parameter estimation will arise with this expected aircraft configuration. The research presented in this paper focuses on addressing the correlation problem with an appropriate input design technique in order to determine individual control surface effectiveness. This technique was validated through flight-testing an 8.5-percent-scale hybrid-wing-body aircraft demonstrator at the NASA Dryden Flight Research Center (Edwards, California). An input design technique that uses mutually orthogonal square wave inputs for de-correlation of control surfaces is proposed. Flight-test results are compared with prior flight-test results for a different maneuver style.

  6. Testing of Lagrange multiplier damped least-squares control algorithm for woofer-tweeter adaptive optics

    PubMed Central

    Zou, Weiyao; Burns, Stephen A.

    2012-01-01

    A Lagrange multiplier-based damped least-squares control algorithm for woofer-tweeter (W-T) dual deformable-mirror (DM) adaptive optics (AO) is tested with a breadboard system. We show that the algorithm can complementarily command the two DMs to correct wavefront aberrations within a single optimization process: the woofer DM correcting the high-stroke, low-order aberrations, and the tweeter DM correcting the low-stroke, high-order aberrations. The optimal damping factor for a DM is found to be the median of the eigenvalue spectrum of the influence matrix of that DM. Wavefront control accuracy is maximized with the optimized control parameters. For the breadboard system, the residual wavefront error can be controlled to the precision of 0.03 μm in root mean square. The W-T dual-DM AO has applications in both ophthalmology and astronomy. PMID:22441462

  7. Ground reaction force characteristics of Tai Chi push hand.

    PubMed

    Chang, Yao-Ting; Chang, Jia-Hao; Huang, Chen-Fu

    2014-01-01

    Push Hand is an advanced training technique for the Yang-style old frame 108 forms Tai Chi Chuan. It is performed by two practitioners. To clarify how people use forces during Push Hand training, it is important to review the ground reaction force (GRF). Here, we quantify the characteristics of the GRF during Push Hand training. Kinematic data and GRF data from 10 Tai Chi Chuan practitioners (29.9 ± 7.87 years) were synchronously recorded using a three-dimensional motion analysis system (200 frames · s(-1)) and three-dimensional force plates (1000 Hz). The resultant GRF for both feet for the 0%, 50% and 100% phases of attack and defence were compared to body weight using a paired-samples t-test. The differences in the resultant GRF between the 0%, 50% and 100% phases of attack and defence were tested by one-way repeated-measures ANOVA. The significance level was set to 0.05. The total resultant GRF was almost equal to the participant's body weight in push hand. This result was consistent throughout the entire push hand process. Our results revealed that the GRF was comparable to the body weight, implying that practitioners do not push or resist their opponents during the push hand process.

  8. Absorber arc mitigation during CHI on NSTX

    NASA Astrophysics Data System (ADS)

    Mueller, D.; Bell, M. G.; Roquemore, A. L.; Raman, R.; Nelson, B. A.; Jarboe, T. R.

    2009-11-01

    A method of non-inductive startup, referred to as transient coaxial helicity injection (CHI), was successfully developed on the Helicity Injected Torus (HIT-II) experiment and employed on the National Spherical Torus Experiment (NSTX). This technique has produced 160 kA of plasma current on closed flux surfaces. Over 100 kA of the CHI current has been coupled to inductively driven current ramp-up. In transient CHI, a voltage is applied across the insulating gap separating the inner and outer vacuum vessel and gas is introduced at the lower gap (the injector). The resulting current in the injector follows the helical magnetic field connecting the electrodes, forms a toroidal current and expands into the vacuum vessel. At higher CHI current, the poloidal field due to the plasma can connect the inner and outer vessels at the insulating gap at the top (called the absorber) of NSTX and lower the impedance there. This results in arcs in the absorber which are a source of impurities and which reduce the desired current in the injector. Two coils installed in the absorber will be used to reduce the magnetic field across the absorber gap and mitigate the absorber arcs.

  9. Measuring Differential Delays With Sine-Squared Pulses

    NASA Technical Reports Server (NTRS)

    Hurst, Robert N.

    1994-01-01

    Technique for measuring differential delays among red, green, and blue components of video signal transmitted on different parallel channels exploits sine-squared pulses that are parts of standard test signals transmitted during vertical blanking interval of frame period. Technique does not entail expense of test-signal generator. Also applicable to nonvideo signals including sine-squared pulses.

  10. Analysis of the Latin Square Task with Linear Logistic Test Models

    ERIC Educational Resources Information Center

    Zeuch, Nina; Holling, Heinz; Kuhn, Jorg-Tobias

    2011-01-01

    The Latin Square Task (LST) was developed by Birney, Halford, and Andrews [Birney, D. P., Halford, G. S., & Andrews, G. (2006). Measuring the influence of cognitive complexity on relational reasoning: The development of the Latin Square Task. Educational and Psychological Measurement, 66, 146-171.] and represents a non-domain specific,…

  11. Tai Chi and Qi Gong

    MedlinePlus

    ... Iversen MD, McAlindon T, et al. Assessing the comparative effectiveness of tai chi versus physical therapy for knee osteoarthritis: design and rationale for a randomized trial. BMC Complementary ...

  12. Understanding the branching ratios of {chi}{sub c1{yields}{phi}{phi}}, {omega}{omega}, {omega}{phi} observed at BES-III

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chen Dianyong; He Jun; Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000

    In this work, we discuss the contribution of the mesonic loops to the decay rates of {chi}{sub c1{yields}{phi}{phi}}, {omega}{omega}, which are suppressed by the helicity selection rules and {chi}{sub c1{yields}{phi}{omega}}, which is a double-Okubo-Zweig-Iizuka forbidden process. We find that the mesonic loop effects naturally explain the clear signals of {chi}{sub c1{yields}{phi}{phi}}, {omega}{omega} decay modes observed by the BES Collaboration. Moreover, we investigate the effects of the {omega}-{phi} mixing, which may result in the order of magnitude of the branching ratio BR({chi}{sub c1{yields}{omega}{phi}}) being 10{sup -7}. Thus, we are waiting for the accurate measurements of the BR({chi}{sub c1{yields}{omega}{omega}}), BR({chi}{sub c1{yields}{phi}{phi}}), andmore » BR({chi}{sub c1{yields}{omega}{phi}}), which may be very helpful for testing the long-distant contribution and the {omega}-{phi} mixing in {chi}{sub c1{yields}{phi}{phi}}, {omega}{omega}, {omega}{phi} decays.« less

  13. From Tornadoes to Earthquakes: Forecast Verification for Binary Events Applied to the 1999 Chi-Chi, Taiwan, Earthquake

    NASA Astrophysics Data System (ADS)

    Chen, C.; Rundle, J. B.; Holliday, J. R.; Nanjo, K.; Turcotte, D. L.; Li, S.; Tiampo, K. F.

    2005-12-01

    Forecast verification procedures for statistical events with binary outcomes typically rely on the use of contingency tables and Relative Operating Characteristic (ROC) diagrams. Originally developed for the statistical evaluation of tornado forecasts on a county-by-county basis, these methods can be adapted to the evaluation of competing earthquake forecasts. Here we apply these methods retrospectively to two forecasts for the m = 7.3 1999 Chi-Chi, Taiwan, earthquake. These forecasts are based on a method, Pattern Informatics (PI), that locates likely sites for future large earthquakes based on large change in activity of the smallest earthquakes. A competing null hypothesis, Relative Intensity (RI), is based on the idea that future large earthquake locations are correlated with sites having the greatest frequency of small earthquakes. We show that for Taiwan, the PI forecast method is superior to the RI forecast null hypothesis. Inspection of the two maps indicates that their forecast locations are indeed quite different. Our results confirm an earlier result suggesting that the earthquake preparation process for events such as the Chi-Chi earthquake involves anomalous changes in activation or quiescence, and that signatures of these processes can be detected in precursory seismicity data. Furthermore, we find that our methods can accurately forecast the locations of aftershocks from precursory seismicity changes alone, implying that the main shock together with its aftershocks represent a single manifestation of the formation of a high-stress region nucleating prior to the main shock.

  14. Effects of Sun-style Tai Chi exercise on physical fitness and fall prevention in fall-prone older adults.

    PubMed

    Choi, Jung Hyun; Moon, Jung-Soon; Song, Rhayun

    2005-07-01

    This paper reports a study to determine changes in the physical fitness (knee and ankle muscle strength, balance, flexibility, and mobility), fall avoidance efficacy, and fall episodes of institutionalized older adults after participating in a 12-week Sun-style Tai Chi exercise programme. Fall prevention has a high priority in health promotion for older people because a fall is associated with serious morbidity in this population. Regular exercise is effective in fall prevention for older adults because of improvements in strength and balance. Tai Chi exercise is considered to offer great potential for health promotion and rehabilitation, particularly in the maintenance of good mental and physical condition in older people. A quasi-experimental design with a non-equivalent control group was used. Data were collected from September 2001 to January 2002. A total of 68 fall-prone older adults with a mean age of 77.8 years participated in the study, and 29 people in the Tai Chi group and 30 controls completed the post-test measures. The Tai Chi exercise programme was provided three times a week for 12 weeks in the experimental group. Data were analysed for group differences using t-tests. At post-test, the experimental group showed significantly improved muscle strength in knee and ankle flexors (P < 0.001) and extensors (P < 0.01), and improved flexibility (P < 0.01) and mobility (P < 0.001) compared with the control group. There was no significant group difference in fall episodes, but the relative risk ratio for the Tai Chi exercise group compared with the control group was 0.62. The experimental group reported significantly more confidence in fall avoidance than did the control group. The findings reveal that Tai Chi exercise programmes can safely improve physical strength and reduce fall risk for fall-prone older adults in residential care facilities.

  15. CHI during an ohmic discharge in HIT-II

    NASA Astrophysics Data System (ADS)

    Mueller, Dennis; Nelson, Brian A.; Redd, Aaron J.; Hamp, William T.

    2004-11-01

    Coaxial Helicity Injection (CHI) has been used on the National Spherical Torus Experiment (NSTX), the Helicity Injected Torus (HIT) and HIT-II to initiate plasma and to drive up to 400 kA of toroidal current. The primary goal of the CHI systems is to provide a start-up plasma with substantial toroidal current that can be heated and sustained with other methods. We have investigated the use of CHI systems to add current to an established, inductively driven plasma. This may be an attractive method to add edge current that may modify the stability characteristics of the discharge or modify the particle and energy transport in a spherical torus. For example, divertor biasing experiments have been successful in modifying particle and energy transport in the scrape-off layer of tokamaks. Use of IGBT power supplies to modulate the injector current makes analysis of current penetration feasible by comparisons of before and after CHI using EFIT analysis of the data.

  16. Testing of Lagrange multiplier damped least-squares control algorithm for woofer-tweeter adaptive optics.

    PubMed

    Zou, Weiyao; Burns, Stephen A

    2012-03-20

    A Lagrange multiplier-based damped least-squares control algorithm for woofer-tweeter (W-T) dual deformable-mirror (DM) adaptive optics (AO) is tested with a breadboard system. We show that the algorithm can complementarily command the two DMs to correct wavefront aberrations within a single optimization process: the woofer DM correcting the high-stroke, low-order aberrations, and the tweeter DM correcting the low-stroke, high-order aberrations. The optimal damping factor for a DM is found to be the median of the eigenvalue spectrum of the influence matrix of that DM. Wavefront control accuracy is maximized with the optimized control parameters. For the breadboard system, the residual wavefront error can be controlled to the precision of 0.03 μm in root mean square. The W-T dual-DM AO has applications in both ophthalmology and astronomy. © 2012 Optical Society of America

  17. Evaluation of unconfined-aquifer parameters from pumping test data by nonlinear least squares

    NASA Astrophysics Data System (ADS)

    Heidari, Manoutchehr; Wench, Allen

    1997-05-01

    Nonlinear least squares (NLS) with automatic differentiation was used to estimate aquifer parameters from drawdown data obtained from published pumping tests conducted in homogeneous, water-table aquifers. The method is based on a technique that seeks to minimize the squares of residuals between observed and calculated drawdown subject to bounds that are placed on the parameter of interest. The analytical model developed by Neuman for flow to a partially penetrating well of infinitesimal diameter situated in an infinite, homogeneous and anisotropic aquifer was used to obtain calculated drawdown. NLS was first applied to synthetic drawdown data from a hypothetical but realistic aquifer to demonstrate that the relevant hydraulic parameters (storativity, specific yield, and horizontal and vertical hydraulic conductivity) can be evaluated accurately. Next the method was used to estimate the parameters at three field sites with widely varying hydraulic properties. NLS produced unbiased estimates of the aquifer parameters that are close to the estimates obtained with the same data using a visual curve-matching approach. Small differences in the estimates are a consequence of subjective interpretation introduced in the visual approach.

  18. Evaluation of unconfined-aquifer parameters from pumping test data by nonlinear least squares

    USGS Publications Warehouse

    Heidari, M.; Moench, A.

    1997-01-01

    Nonlinear least squares (NLS) with automatic differentiation was used to estimate aquifer parameters from drawdown data obtained from published pumping tests conducted in homogeneous, water-table aquifers. The method is based on a technique that seeks to minimize the squares of residuals between observed and calculated drawdown subject to bounds that are placed on the parameter of interest. The analytical model developed by Neuman for flow to a partially penetrating well of infinitesimal diameter situated in an infinite, homogeneous and anisotropic aquifer was used to obtain calculated drawdown. NLS was first applied to synthetic drawdown data from a hypothetical but realistic aquifer to demonstrate that the relevant hydraulic parameters (storativity, specific yield, and horizontal and vertical hydraulic conductivity) can be evaluated accurately. Next the method was used to estimate the parameters at three field sites with widely varying hydraulic properties. NLS produced unbiased estimates of the aquifer parameters that are close to the estimates obtained with the same data using a visual curve-matching approach. Small differences in the estimates are a consequence of subjective interpretation introduced in the visual approach.

  19. Estimating gene function with least squares nonnegative matrix factorization.

    PubMed

    Wang, Guoli; Ochs, Michael F

    2007-01-01

    Nonnegative matrix factorization is a machine learning algorithm that has extracted information from data in a number of fields, including imaging and spectral analysis, text mining, and microarray data analysis. One limitation with the method for linking genes through microarray data in order to estimate gene function is the high variance observed in transcription levels between different genes. Least squares nonnegative matrix factorization uses estimates of the uncertainties on the mRNA levels for each gene in each condition, to guide the algorithm to a local minimum in normalized chi2, rather than a Euclidean distance or divergence between the reconstructed data and the data itself. Herein, application of this method to microarray data is demonstrated in order to predict gene function.

  20. Effects of Tai Chi intervention on dual-task ability in older adults: a pilot study.

    PubMed

    Hall, Courtney D; Miszko, Tanya; Wolf, Steven L

    2009-03-01

    To determine if a 12-week program of Tai Chi that has been shown to reduce falls incidence in older adults would improve the ability to allocate attention to balance under dual-task conditions. Pre-/posttest experimental research design. Movement studies research laboratory. Community dwelling older adults (N=15; range, 62-85y) participated in either Tai Chi training or health education classes (controls) for 12 weeks. Participants in the Tai Chi group attended a twice-weekly, 1.5-hour class taught by an experienced instructor. The control group attended a biweekly, 1-hour class for lectures on health-related topics. Two cognitive tasks (responding to auditory or visual stimulus as quickly as possible) were performed concurrently while maintaining static balance during the Sensory Organization Test (SOT) and while avoiding obstacles while walking. The percent change in performance relative to the single-task condition was calculated and defined as the dual-task cost. The dual-task cost was calculated for both the postural and cognitive measures. There was no improvement in the performance of postural stability or cognitive task under dual-task conditions for the SOT for Tai Chi versus controls. There was no improvement in avoiding obstacles under dual-task conditions for Tai Chi versus controls. Contrary to our hypothesis, the findings of this study did not support a benefit of Tai Chi on the ability to allocate attention to balance under dual-task conditions.

  1. Health benefits of tai chi: What is the evidence?

    PubMed

    Huston, Patricia; McFarlane, Bruce

    2016-11-01

    To summarize the evidence on the health benefits of tai chi. A literature review was conducted on the benefits of tai chi for 25 specific conditions, as well as for general health and fitness, to update a 2014 review of systematic reviews. Systematic reviews and recent clinical trials were assessed and organized into 5 different groups: evidence of benefit as excellent, good, fair, or preliminary, or evidence of no direct benefit. During the past 45 years more than 500 trials and 120 systematic reviews have been published on the health benefits of tai chi. Systematic reviews of tai chi for specific conditions indicate excellent evidence of benefit for preventing falls, osteoarthritis, Parkinson disease, rehabilitation for chronic obstructive pulmonary disease, and improving cognitive capacity in older adults. There is good evidence of benefit for depression, cardiac and stroke rehabilitation, and dementia. There is fair evidence of benefit for improving quality of life for cancer patients, fibromyalgia, hypertension, and osteoporosis. Current evidence indicates no direct benefit for diabetes, rheumatoid arthritis, or chronic heart failure. Systematic reviews of general health and fitness benefits show excellent evidence of benefit for improving balance and aerobic capacity in those with poor fitness. There is good evidence for increased strength in the lower limbs. There is fair evidence for increased well-being and improved sleep. There were no studies that found tai chi worsened a condition. A recent systematic review on the safety of tai chi found adverse events were typically minor and primarily musculoskeletal; no intervention-related serious adverse events have been reported. There is abundant evidence on the health and fitness effects of tai chi. Based on this, physicians can now offer evidence-based recommendations to their patients, noting that tai chi is still an area of active research, and patients should continue to receive medical follow-up for any

  2. Tai chi/yoga effects on anxiety, heartrate, EEG and math computations.

    PubMed

    Field, Tiffany; Diego, Miguel; Hernandez-Reif, Maria

    2010-11-01

    To determine the immediate effects of a combined form of Tai chi/yoga. 38 adults participated in a 20-min Tai chi/yoga class. The session was comprised of standing Tai chi movements, balancing poses and a short Tai chi form and 10 min of standing, sitting and lying down yoga poses. The pre- and post- Tai chi/yoga effects were assessed using the State Anxiety Inventory (STAI), EKG, EEG and math computations. Heartrate increased during the session, as would be expected for this moderate-intensity exercise. Changes from pre to post-session assessments suggested increased relaxation including decreased anxiety and a trend for increased EEG theta activity. The increased relaxation may have contributed to the increased speed and accuracy noted on math computations following the Tai chi/yoga class. Copyright © 2010 Elsevier Ltd. All rights reserved.

  3. Tai Chi/ Yoga Effects on Anxiety, Heartrate, EEG and Math Computations

    PubMed Central

    Field, Tiffany; Diego, Miguel; Hernandez-Reif, Maria

    2010-01-01

    Objective To determine the immediate effects of a combined form of tai chi/yoga. Design 38 adults participated in a 20-minute tai chi/yoga class. The session was comprised of standing tai chi movements, balancing poses and a short tai chi form and 10 minutes of standing, sitting and lying down yoga poses. Main outcome measures The pre- and post- tai chi/ yoga effects were assessed using the State Anxiety Inventory (STAI), EKG, EEG and math computations. Results Heartrate increased during the session, as would be expected for this moderate intensity exercise. Changes from pre to post session assessments suggested increased relaxation including decreased anxiety and a trend for increased EEG theta activity. Conclusions The increased relaxation may have contributed to the increased speed and accuracy noted on math computations following the tai chi/yoga class. PMID:20920810

  4. Precise measurement of spin-averaged {chi}{sub cJ}(1P) mass using photon conversions in {psi}(2S){yields}{gamma}{chi}{sub cJ}

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ablikim, M.; Bai, J.Z.; Bian, J.G.

    2005-05-01

    Using photon conversions to e{sup +}e{sup -} pairs, the energy spectrum of inclusive photons from {psi}(2S) radiative decays is measured with photon energy resolution ({sigma}{sub E{sub {gamma}}}) in the range from 2.3 to 3.8 MeV by BESII at the Beijing Electron-Positron Collider. The {chi}{sub cJ}(1P) states (J=0,1,2) are clearly observed, and their masses and the spin-averaged {chi}{sub cJ} mass are determined to be M{sub {chi}{sub c}{sub 0}}=3414.21{+-}0.39{+-}0.27, M{sub {chi}{sub c}{sub 1}}=3510.30{+-}0.14{+-}0.16, M{sub {chi}{sub c}{sub 2}}=3555.70{+-}0.59{+-}0.39, and M({sup 3}P{sub cog})=3524.85{+-}0.32{+-}0.30 MeV/c{sup 2}, respectively.

  5. Superconducting gravity gradiometer and a test of inverse square law

    NASA Technical Reports Server (NTRS)

    Moody, M. V.; Paik, Ho Jung

    1989-01-01

    The equivalence principle prohibits the distinction of gravity from acceleration by a local measurement. However, by making a differential measurement of acceleration over a baseline, platform accelerations can be cancelled and gravity gradients detected. In an in-line superconducting gravity gradiometer, this differencing is accomplished with two spring-mass accelerometers in which the proof masses are confined to motion in a single degree of freedom and are coupled together by superconducting circuits. Platform motions appear as common mode accelerations and are cancelled by adjusting the ratio of two persistent currents in the sensing circuit. The sensing circuit is connected to a commercial SQUID amplifier to sense changes in the persistent currents generated by differential accelerations, i.e., gravity gradients. A three-axis gravity gradiometer is formed by mounting six accelerometers on the faces of a precision cube, with the accelerometers on opposite faces of the cube forming one of three in-line gradiometers. A dedicated satellite mission for mapping the earth's gravity field is an important one. Additional scientific goals are a test of the inverse square law to a part in 10(exp 10) at 100 km, and a test of the Lense-Thirring effect by detecting the relativistic gravity magnetic terms in the gravity gradient tensor for the earth.

  6. Teaching Balance with Tai Chi: Strategies for College and Secondary School Instruction.

    ERIC Educational Resources Information Center

    Chen, David D.; Sherman, Clay P.

    2002-01-01

    Examines the benefits of incorporating Tai Chi into the secondary and college curriculum to teach balance, discussing: the history and philosophical underpinnings of Tai Chi, principles of Tai Chi movement, health benefits, and teaching Tai Chi in public schools. Tips for instructors include: follow the principles of progression, follow a…

  7. Observation of {chi}{sub cJ} Radiative Decays to Light Vector Mesons

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bennett, J. V.; Mitchell, R. E.; Shepherd, M. R.

    2008-10-10

    Using a total of 2.74x10{sup 7} decays of the {psi}(2S) collected with the CLEO-c detector, we present a study of {chi}{sub cJ}{yields}{gamma}V, where V={rho}{sup 0}, {omega}, {phi}. The transitions {chi}{sub c1}{yields}{gamma}{rho}{sup 0} and {chi}{sub c1}{yields}{gamma}{omega} are observed with B({chi}{sub c1}{yields}{gamma}{rho}{sup 0})=(2.43{+-}0.19{+-}0.22)x10{sup -4} and B({chi}{sub c1}{yields}{gamma}{omega})=(8.3{+-}1.5{+-}1.2)x10{sup -5}. In the {chi}{sub c1}{yields}{gamma}{rho}{sup 0} transition, the final state meson is dominantly longitudinally polarized. Upper limits on the branching fractions of other {chi}{sub cJ} states to light vector mesons are presented.

  8. Resilience of aging populations after devastating earthquake event and its determinants - A case study of the Chi-Chi earthquake in Taiwan

    NASA Astrophysics Data System (ADS)

    Hung, Chih-Hsuan; Hung, Hung-Chih

    2016-04-01

    1.Background Major portions of urban areas in Asia are highly exposed and vulnerable to devastating earthquakes. Many studies identify ways to reduce earthquake risk by concentrating more on building resilience for the particularly vulnerable populations. By 2020, as the United Nations' warning, many Asian countries would become 'super-aged societies', such as Taiwan. However, local authorities rarely use resilience approach to frame earthquake disaster risk management and land use strategies. The empirically-based research about the resilience of aging populations has also received relatively little attention. Thus, a challenge arisen for decision-makers is how to enhance resilience of aging populations within the context of risk reduction. This study aims to improve the understanding of the resilience of aging populations and its changes over time in the aftermath of a destructive earthquake at the local level. A novel methodology is proposed to assess the resilience of aging populations and to characterize their changes of spatial distribution patterns, as well as to examine their determinants. 2.Methods and data An indicator-based assessment framework is constructed with the goal of identifying composite indicators (including before, during and after a disaster) that could serve as proxies for attributes of the resilience of aging populations. Using the recovery process of the Chi-Chi earthquake struck central Taiwan in 1999 as a case study, we applied a method combined a geographical information system (GIS)-based spatial statistics technique and cluster analysis to test the extent of which the resilience of aging populations is spatially autocorrelated throughout the central Taiwan, and to explain why clustering of resilient areas occurs in specific locations. Furthermore, to scrutinize the affecting factors of resilience, we develop an aging population resilience model (APRM) based on existing resilience theory. Using the APRM, we applied a multivariate

  9. Effect of tai chi versus aerobic exercise for fibromyalgia: comparative effectiveness randomized controlled trial

    PubMed Central

    Schmid, Christopher H; Fielding, Roger A; Harvey, William F; Reid, Kieran F; Price, Lori Lyn; Driban, Jeffrey B; Kalish, Robert; Rones, Ramel; McAlindon, Timothy

    2018-01-01

    Abstract Objectives To determine the effectiveness of tai chi interventions compared with aerobic exercise, a current core standard treatment in patients with fibromyalgia, and to test whether the effectiveness of tai chi depends on its dosage or duration. Design Prospective, randomized, 52 week, single blind comparative effectiveness trial. Setting Urban tertiary care academic hospital in the United States between March 2012 and September 2016. Participants 226 adults with fibromyalgia (as defined by the American College of Rheumatology 1990 and 2010 criteria) were included in the intention to treat analyses: 151 were assigned to one of four tai chi groups and 75 to an aerobic exercise group. Interventions Participants were randomly assigned to either supervised aerobic exercise (24 weeks, twice weekly) or one of four classic Yang style supervised tai chi interventions (12 or 24 weeks, once or twice weekly). Participants were followed for 52 weeks. Adherence was rigorously encouraged in person and by telephone. Main outcome measures The primary outcome was change in the revised fibromyalgia impact questionnaire (FIQR) scores at 24 weeks compared with baseline. Secondary outcomes included changes of scores in patient’s global assessment, anxiety, depression, self efficacy, coping strategies, physical functional performance, functional limitation, sleep, and health related quality of life. Results FIQR scores improved in all five treatment groups, but the combined tai chi groups improved statistically significantly more than the aerobic exercise group in FIQR scores at 24 weeks (difference between groups=5.5 points, 95% confidence interval 0.6 to 10.4, P=0.03) and several secondary outcomes (patient’s global assessment=0.9 points, 0.3 to 1.4, P=0.005; anxiety=1.2 points, 0.3 to 2.1, P=0.006; self efficacy=1.0 points, 0.5 to 1.6, P=0.0004; and coping strategies, 2.6 points, 0.8 to 4.3, P=0.005). Tai chi treatment compared with aerobic exercise administered with

  10. Creating Magic Squares.

    ERIC Educational Resources Information Center

    Lyon, Betty Clayton

    1990-01-01

    One method of making magic squares using a prolongated square is illustrated. Discussed are third-order magic squares, fractional magic squares, fifth-order magic squares, decimal magic squares, and even magic squares. (CW)

  11. Tobacco-expressed Brassica juncea chitinase BjCHI1 shows antifungal activity in vitro.

    PubMed

    Fung, King-Leung; Zhao, Kai-Jun; He, Zhu-Mei; Chye, Mee-Len

    2002-09-01

    We have previously isolated a Brassica juncea cDNA encoding BjCHI1, a novel chitinase with two chitin-binding domains, and have shown that its mRNA is induced by wounding and methyl jasmonate treatment (K.-J. Zhao and M.-L. Chye, Plant Mol. Biol. 40 (1999) 1009-1018). By the presence of two chitin-binding domains, BjCHI1 resembles the precursor of UDA (Urtica dioica agglutinin) but, unlike UDA, BjCHI1 retains its chitinase catalytic domain after post-translational processing. Here, we indicate the role of BjCHI1 in plant defense by demonstrating its mRNA induction upon Aspergillus niger infection or caterpillar Pieris rapae (L.) feeding. To further investigate the biological properties of BjCHI1, we transformed tobacco with a construct expressing the BjCHI1 cDNA from the CaMV 35S promoter. Subsequently, we purified BjCHI1 from the resultant transgenic Ro plants using a regenerated chitin column followed by fast protein liquid chromatography (FPLC). Also, the significance of the second chitin-binding domain in BjCHI1 was investigated by raising transgenic tobacco plants expressing BjCHI2, a deletion derivative of BjCHI1 lacking one chitin-binding domain. Colorimetric chitinase assays at 25 degrees C, pH 5, showed no significant differences between the activities of BjCHI1 and BjCHI2, suggesting that chitinase activity, due to the catalytic domain, is not enhanced by the presence of a second chitin-binding domain. Both BjCHI1 and BjCHI2 show in vitro anti-fungal activity toward Trichoderma viride, causing reductions in hyphal diameter, hyphal branching and conidia size.

  12. Fall Risk-Relevant Functional Mobility Outcomes in Dementia Following Dyadic Tai Chi Exercise

    PubMed Central

    Yao, Lan; Giordani, Bruno J.; Algase, Donna L.; You, Mei; Alexander, Neil B.

    2012-01-01

    Whether persons with dementia benefit from fall prevention exercise is unclear. Applying the Positive Emotion-Motivated Tai Chi protocol, preliminary findings concerning adherence and effects of a dyadic Tai Chi exercise program on persons with Alzheimer’s disease (AD) are reported. Using pre/ posttest design, 22 community-dwelling AD-caregiver dyads participated in the program. Fall-risk-relevant functional mobility was measured using Unipedal Stance Time (UST) and Timed Up and Go (TUG) tests. Results showed that 19/22 (86.4%) AD patients completed the 16-week program and final assessment; 16/19 dyads (84.2%) completed the prescribed home program as reported by caregivers. UST adjusted mean improved from 4.0 to 5.1 (Week 4, p < .05) and 5.6 (Week 16, p < .05); TUG improved from 13.2 to 11.6 (Week 4, p < .05) and 11.6 (Week 16, p > .05) post intervention. Retaining dementia patients in an exercise intervention remains challenging. The dyadic Tai Chi approach appears to succeed in keeping AD-caregiver dyads exercising and safe. PMID:22517441

  13. Fall risk-relevant functional mobility outcomes in dementia following dyadic tai chi exercise.

    PubMed

    Yao, Lan; Giordani, Bruno J; Algase, Donna L; You, Mei; Alexander, Neil B

    2013-03-01

    Whether persons with dementia benefit from fall prevention exercise is unclear. Applying the Positive Emotion-Motivated Tai Chi protocol, preliminary findings concerning adherence and effects of a dyadic Tai Chi exercise program on persons with Alzheimer's disease (AD) are reported. Using pre/posttest design, 22 community-dwelling AD-caregiver dyads participated in the program. Fall-risk-relevant functional mobility was measured using Unipedal Stance Time (UST) and Timed Up and Go (TUG) tests. Results showed that 19/22 (86.4%) AD patients completed the 16-week program and final assessment; 16/19 dyads (84.2%) completed the prescribed home program as reported by caregivers. UST adjusted mean improved from 4.0 to 5.1 (Week 4, p < .05) and 5.6 (Week 16, p < .05); TUG improved from 13.2 to 11.6 (Week 4, p < .05) and 11.6 (Week 16, p > .05) post intervention. Retaining dementia patients in an exercise intervention remains challenging. The dyadic Tai Chi approach appears to succeed in keeping AD-caregiver dyads exercising and safe.

  14. Effectiveness of tai chi as a community-based falls prevention intervention: a randomized controlled trial.

    PubMed

    Taylor, Denise; Hale, Leigh; Schluter, Philip; Waters, Debra L; Binns, Elizabeth E; McCracken, Hamish; McPherson, Kathryn; Wolf, Steven L

    2012-05-01

    To compare the effectiveness of tai chi and low-level exercise in reducing falls in older adults; to determine whether mobility, balance, and lower limb strength improved and whether higher doses of tai chi resulted in greater effect. Randomized controlled trial. Eleven sites throughout New Zealand. Six hundred eighty-four community-residing older adults (mean age 74.5; 73% female) with at least one falls risk factor. Tai chi once a week (TC1) (n = 233); tai chi twice a week (TC2) (n = 220), or a low-level exercise program control group (LLE) (n = 231) for 20 wks. Number of falls was ascertained according to monthly falls calendars. Mobility (Timed-Up-and-Go Test), balance (step test), and lower limb strength (chair stand test) were assessed. The adjusted incident rate ratio (IRR) for falls was not significantly different between the TC1 and LLE groups (IRR = 1.05, 95% confidence interval (CI) = 0.83-1.33, P = .70) or between the TC2 and LLE groups (IRR = 0.88, 95% CI = 0.68-1.16, P = .37). Adjusted multilevel mixed-effects Poisson regression showed a significant reduction in logarithmic mean fall rate of -0.050 (95% CI = -0.064 to -0.037, P < .001) per month for all groups. Multilevel fixed-effects analyses indicated improvements in balance (P < .001 right and left leg) and lower limb strength (P < .001) but not mobility (P = .54) in all groups over time, with no differences between the groups (P = .37 (right leg), P = .66 (left leg), P = .21, and P = .44, respectively). There was no difference in falls rates between the groups, with falls reducing similarly (mean falls rate reduction of 58%) over the 17-month follow-up period. Strength and balance improved similarly in all groups over time. © 2012, Copyright the Authors Journal compilation © 2012, The American Geriatrics Society.

  15. The moderating role of parental smoking on their children's attitudes toward smoking among a predominantly minority sample: a cross-sectional analysis.

    PubMed

    Wilkinson, Anna V; Shete, Sanjay; Prokhorov, Alexander V

    2008-07-14

    In general having a parent who smokes or smoked is a strong and consistent predictor of smoking initiation among their children while authoritative parenting style, open communication that demonstrates mutual respect between child and parent, and parental expectations not to smoke are protective. It has been hypothesized that parental smoking affects their children's smoking initiation through both imitation of the behavior and effects on attitudes toward smoking. The goals of the current analysis were to examine these two potential mechanisms. In 2003, 1,417 high school students in Houston, Texas, completed a cross-sectional survey as part of the evaluation of an interactive smoking prevention and cessation program delivered via CD-ROM. To assess the relationship between number of parents who currently smoke and children's smoking status, we completed an unconditional logistic regression. To determine whether the attitudes that children of smokers hold toward smoking are significantly more positive than the attitudes of children of non-smokers we examined whether the parents smoking status moderated the relationship between children's attitudes toward smoking and their ever smoking using unconditional logistic regressions. Compared to participants whose parents did not currently smoke, participants who reported one or both parents currently smoke, had increased odds of ever smoking (OR = 1.31; 95% CI: 1.03-1.68; Wald chi2 = 4.78 (df = 1) p = 0.03 and OR = 2.16; 95% CI: 1.51-3.10; Wald chi2 = 17.80 (df = 1) p < 0.001, respectively). In addition, the relationship between attitudes and ever smoking was stronger among participants when at least one parent currently smokes (OR = 2.50; 95% CI: 1.96-3.19; Wald chi2 = 54.71 (df = 1) p < 0.001) than among participants whose parents did not smoke (OR = 1.72; 95% CI: 1.40-2.12; Wald chi2 = 26.45 (df = 1) p < 0.001). Children of smokers were more likely to smoke and reported more favorable attitudes toward smoking compared to

  16. Measurement of exclusive baryon-antibaryon decays of {chi}{sub cJ} mesons

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Naik, P.; Rademacker, J.; Asner, D. M.

    2008-08-01

    Using a sample of 2.59x10{sup 7} {psi}(2S) decays collected by the CLEO-c detector, we present results of a study of {chi}{sub cJ} (J=0, 1, 2) decays into baryon-antibaryon final states. We present the world's most precise measurements of the {chi}{sub cJ}{yields}pp and {chi}{sub cJ}{yields}{lambda}{lambda} branching fractions, and the first measurements of {chi}{sub c0} decays to other hyperons. These results illuminate the decay mechanism of the {chi}{sub c} states.

  17. How do we extract the three chi's that describe a compressible blend from SANS ?

    NASA Astrophysics Data System (ADS)

    Gujrati, P. D.; Rane, Sagar

    2000-03-01

    We demonstrate that a lattice model of a compressible blend is characterized by three bare chi parameters; chi-01 (between void and polymer1), chi-02 (between void and polymer2) and chi-12 (between polymer1 and polymer2). We propose a methodology to extract the corresponding three effective chi's from the scattering intensity and additional information on the compressibility and partial molar volumes. We have also defined and obtained a single effective chi for the blend (without RPA) and compared this single effective chi with the other three effective chi's. In all calculations, the athermal part was removed exactly resulting in an interaction part which remains finite over the entire composition regime. From thermodynamics, we know that this single chi is not the same as chi-12, and we shall determine when the two are close or similar. We have also obtained the values of the three chi's at the critical point for different systems to display their utility. We have carried out the calculations in different ensembles and find that the value of chi's depend on the ensemble chosen.

  18. Psychosocial effects of Tai Chi exercise on people with rheumatoid arthritis.

    PubMed

    Waite-Jones, Jennifer M; Hale, Claire A; Lee, Hea-Young

    2013-11-01

    To investigate the perceived psychosocial effects of participating in taught sessions of Tai Chi on people diagnosed with rheumatoid arthritis (RA). Tai Chi is thought to be psychologically as well as physically beneficial for people with arthritis. This study adopted a qualitative approach to follow-up participants who had previously demonstrated physical and psychological benefits from a specifically modified Tai Chi programme in an attempt to explore perceived psychosocial improvements. Nineteen semi-structured, audio-taped, interviews were carried out with participants who had taken part in, twice weekly, group-based Tai Chi sessions for 12 weeks. Data from transcripts were analysed using thematic analysis. Analysis suggests that participating in shared Tai Chi sessions provides increased awareness of the links between mind and body; reduces anxiety and depression; and improves self-esteem, self-efficacy and motivation. It was particularly striking to find that the highly structured nature of Tai Chi was felt to improve memory and seemed to offer aesthetic experiences through developing graceful, 'fluid' moves rather than the 'jarring' movements often imposed by having RA. Such group sessions were found to provide social support and help improve participants' sense of perspective. Although small scale, this study suggests that Tai Chi has the potential to offer psychosocial benefits for people with RA. Offering Tai Chi alongside traditional treatments for RA could promote psychological health and well-being, help inform clinical decision-making and prove cost-effective. © 2013 John Wiley & Sons Ltd.

  19. Using Squares to Sum Squares

    ERIC Educational Resources Information Center

    DeTemple, Duane

    2010-01-01

    Purely combinatorial proofs are given for the sum of squares formula, 1[superscript 2] + 2[superscript 2] + ... + n[superscript 2] = n(n + 1) (2n + 1) / 6, and the sum of sums of squares formula, 1[superscript 2] + (1[superscript 2] + 2[superscript 2]) + ... + (1[superscript 2] + 2[superscript 2] + ... + n[superscript 2]) = n(n + 1)[superscript 2]…

  20. A closure test for time-specific capture-recapture data

    USGS Publications Warehouse

    Stanley, T.R.; Burnham, K.P.

    1999-01-01

    The assumption of demographic closure in the analysis of capture-recapture data under closed-population models is of fundamental importance. Yet, little progress has been made in the development of omnibus tests of the closure assumption. We present a closure test for time-specific data that, in principle, tests the null hypothesis of closed-population model M(t) against the open-population Jolly-Seber model as a specific alternative. This test is chi-square, and can be decomposed into informative components that can be interpreted to determine the nature of closure violations. The test is most sensitive to permanent emigration and least sensitive to temporary emigration, and is of intermediate sensitivity to permanent or temporary immigration. This test is a versatile tool for testing the assumption of demographic closure in the analysis of capture-recapture data.

  1. Standardization and Prevalence of the Booster Phenomenon: Evaluation Using a Two-Step Skin Test with 43 kDa Glycoprotein in Individuals from an Endemic Region of Paracoccidioidomycosis.

    PubMed

    Marques, Ana Paula C; Oliveira, Sandra Maria V L; Rezende, Grazielli R; Melo, Dayane A; Fernandes-Fitts, Sonia M; Pontes, Elenir Rose J C; Bonecini-Almeida, Maria da Glória; Camargo, Zoilo P; Mendes, Rinaldo P; Paniago, Anamaria M M

    2017-10-01

    We estimated the occurrence rate of the booster phenomenon by using an intradermal test with 43 kDa glycoprotein in an endemic area of paracoccidioidomycosis in the central-west region of Brazil. Individuals who had a negative result on a survey performed by using an intradermal test with 43 kDa glycoprotein in an endemic area of paracoccidioidomycosis underwent a second intradermal test after 10-15 days to determine the presence or absence of the booster phenomenon. Statistical analyses were performed using the Chi-square test, Chi-square for linear trend test, Student's t test, and binomial test; p < 0.05 was considered significant. For the first time, we reported the occurrence of the booster phenomenon to an intradermal reaction caused by 43 kDa glycoprotein at a rate of 5.8-8.4%, depending on the test's cutoff point. This suggests that a cutoff point should be considered for the booster phenomenon in intradermal tests with 43 kDa glycoprotein: a difference of 6-7 mm between readings according to the first and second tests, depending on the purpose of the evaluation. The results indicate that the prevalence of paracoccidioidal infection in endemic areas is underestimated, as the booster phenomenon has not been considered in epidemiological surveys for this infection.

  2. Study of Factors Related to Army Delayed-Entry Program Attrition

    DTIC Science & Technology

    1985-11-01

    level, gender , and tenure in DEP. Military classification and assignment are determined almost solely on cognitive factors, physical examinations...Between Gender and Responses to Question 13 for Voluntary DEP Losses . . . . . , . . . , . . . . o , o . ° . 99 P-2. Chi-square Tests for Independence...Between Gender and Responses to Question 13 for DHP Aooession/ Voluntary Active Duty Losses . . 9 0 4 . 0 0 0 0 a a 0 106 B-9. Chi-square Tests for

  3. Prevalence of Smoking and Obesity Among U.S. Cancer Survivors: Estimates From the National Health Interview Survey, 2008-2012.

    PubMed

    Shoemaker, Meredith L; White, Mary C; Hawkins, Nikki A; Hayes, Nikki S

    2016-07-01

    To describe smoking and obesity prevalence among male and female cancer survivors in the United States.
. Cross-sectional survey.
. Household interviews.
. 9,753 survey respondents who reported ever having a malignancy, excluding nonmelanoma skin cancers. 
. Data from the National Health Interview Survey (2008-2012) were used to calculate weighted smoking status prevalence estimates. Cross-tabulations of smoking and weight status were produced, along with Wald chi-square tests and linear contrasts.
. Cancer history, smoking status, obesity status, gender, age, and age at diagnosis.
. Seventeen percent of cancer survivors reported current smoking. Female survivors had higher rates of current smoking than males, particularly in the youngest age category. Male survivors who currently smoked had lower obesity prevalence rates than males who previously smoked or never smoked. Among female survivors, 31% were obese and no significant differences were seen in obesity prevalence by smoking status for all ages combined. 
. The findings highlight the variation in smoking status and weight by age and gender. Smoking interventions may need to be targeted to address barriers specific to subgroups of cancer survivors.
. Nurses can be instrumental in ensuring that survivors receive comprehensive approaches to address both weight and tobacco use to avoid trading one risk for another.

  4. Has there been a change in the knowledge of GP registrars between 2011 and 2016 as measured by performance on common items in the Applied Knowledge Test?

    PubMed

    Neden, Catherine A; Parkin, Claire; Blow, Carol; Siriwardena, Aloysius Niroshan

    2018-05-08

    The aim of this study was to assess whether the absolute standard of candidates sitting the MRCGP Applied Knowledge Test (AKT) between 2011 and 2016 had changed. It is a descriptive study comparing the performance on marker questions of a reference group of UK graduates taking the AKT for the first time between 2011 and 2016. Using aggregated examination data, the performance of individual 'marker' questions was compared using Pearson's chi-squared tests and trend-line analysis. Binary logistic regression was used to analyse changes in performance over the study period. Changes in performance of individual marker questions using Pearson's chi-squared test showed statistically significant differences in 32 of the 49 questions included in the study. Trend line analysis showed a positive trend in 29 questions and a negative trend in the remaining 23. The magnitude of change was small. Logistic regression did not demonstrate any evidence for a change in the performance of the question set over the study period. However, candidates were more likely to get items on administration wrong compared with clinical medicine or research. There was no evidence of a change in performance of the question set as a whole.

  5. Improved line parameters for the Chi 2Pi-Chi 2Pi (1-0) bands of (35)ClO and (37)ClO

    NASA Technical Reports Server (NTRS)

    Goldman, Aaron; Gillis, James R.; Rinsland, Curtis P.; Burkholder, James B.

    1994-01-01

    Improved line parameters at 296 K for the Chi 2Pi-Chi 2Pi (1-0) bands of (35)ClO and (37)ClO have been calculated with J up to 43.5. The integrated intensity for the 2048 lines in the main and satellite bands has been normalized to 9.68-sq cm/atm at 296K.

  6. Effects of an Ai Chi fall prevention programme for patients with Parkinson's disease.

    PubMed

    Pérez-de la Cruz, S; García Luengo, A V; Lambeck, J

    2016-04-01

    One of the main symptoms of Parkinson's disease is the high incidence of falls occurring due to the decline of both static and dynamic balance. The aim of this study is to determine the effect of an Ai Chi programme designed to prevent falls in patients with Parkinson's disease by improving both functional independence and perception of physical pain. Fifteen patients diagnosed with Parkinson's disease (Hoehn and Yahr stages 1-3) participated in a 10-week Ai Chi programme consisting of 30 to 45-minute aquatic exercise sessions twice a week. The assessment measures used in this study were the pain visual analogue scale (VAS), the Tinetti gait and balance assessment tool, and the Timed Get up and Go test. The results were calculated by applying the Friedman test to 3 related measurements: patients at baseline, at post-treatment (at the end of the 10 week programme) and after one month of follow-up. The data obtained showed a significant improvement (p <.001) in scores for pain perception, balance, and gait function after the treatment programme. Furthermore, patients continued to show significant improvements and the benefits remained at the one-month follow-up visit. Ai Chi is a promising and feasible aquatic treatment for improving pain perception, balance, and functional capacity in patients diagnosed with mild or moderate Parkinson's disease. Copyright © 2015 Sociedad Española de Neurología. Published by Elsevier España, S.L.U. All rights reserved.

  7. Effect of tai chi versus aerobic exercise for fibromyalgia: comparative effectiveness randomized controlled trial.

    PubMed

    Wang, Chenchen; Schmid, Christopher H; Fielding, Roger A; Harvey, William F; Reid, Kieran F; Price, Lori Lyn; Driban, Jeffrey B; Kalish, Robert; Rones, Ramel; McAlindon, Timothy

    2018-03-21

    To determine the effectiveness of tai chi interventions compared with aerobic exercise, a current core standard treatment in patients with fibromyalgia, and to test whether the effectiveness of tai chi depends on its dosage or duration. Prospective, randomized, 52 week, single blind comparative effectiveness trial. Urban tertiary care academic hospital in the United States between March 2012 and September 2016. 226 adults with fibromyalgia (as defined by the American College of Rheumatology 1990 and 2010 criteria) were included in the intention to treat analyses: 151 were assigned to one of four tai chi groups and 75 to an aerobic exercise group. Participants were randomly assigned to either supervised aerobic exercise (24 weeks, twice weekly) or one of four classic Yang style supervised tai chi interventions (12 or 24 weeks, once or twice weekly). Participants were followed for 52 weeks. Adherence was rigorously encouraged in person and by telephone. The primary outcome was change in the revised fibromyalgia impact questionnaire (FIQR) scores at 24 weeks compared with baseline. Secondary outcomes included changes of scores in patient's global assessment, anxiety, depression, self efficacy, coping strategies, physical functional performance, functional limitation, sleep, and health related quality of life. FIQR scores improved in all five treatment groups, but the combined tai chi groups improved statistically significantly more than the aerobic exercise group in FIQR scores at 24 weeks (difference between groups=5.5 points, 95% confidence interval 0.6 to 10.4, P=0.03) and several secondary outcomes (patient's global assessment=0.9 points, 0.3 to 1.4, P=0.005; anxiety=1.2 points, 0.3 to 2.1, P=0.006; self efficacy=1.0 points, 0.5 to 1.6, P=0.0004; and coping strategies, 2.6 points, 0.8 to 4.3, P=0.005). Tai chi treatment compared with aerobic exercise administered with the same intensity and duration (24 weeks, twice weekly) had greater benefit (between group

  8. Conservativeness in Rejection of the Null Hypothesis when Using the Continuity Correction in the MH Chi-Square Test in DIF Applications

    ERIC Educational Resources Information Center

    Paek, Insu

    2010-01-01

    Conservative bias in rejection of a null hypothesis from using the continuity correction in the Mantel-Haenszel (MH) procedure was examined through simulation in a differential item functioning (DIF) investigation context in which statistical testing uses a prespecified level [alpha] for the decision on an item with respect to DIF. The standard MH…

  9. Water-based Tai Chi: theoretical benefits in musculoskeletal diseases. Current evidence

    PubMed Central

    Macías-Hernández, Salvador Israel; Vázquez-Torres, Lucio; Morones-Alba, Juan Daniel; Coronado-Zarco, Roberto; de los Angeles Soria-Bastida, María; Cruz-Medina, Eva; Nava-Bringas, Tania Inés

    2015-01-01

    Tai Chi is a low-impact and moderate intensity exercise that has shown positive effects in patients with musculoskeletal disorders. Recently have been developed clinical studies on the benefits of Tai Chi techniques combined with hydrotherapy. Both types of treatment include physical training of balance, mobility, strength, coordination and sensory input that could complement each other. This report aims to present the current evidence about the benefits of the combination of water based Tai Chi in musculoskeletal diseases in order to establish whether the combined intervention is better than Tai Chi or hydrotherapy alone. PMID:26171376

  10. Tai chi for upper limb rehabilitation in stroke patients: the patient's perspective.

    PubMed

    Desrochers, Pascal; Kairy, Dahlia; Pan, Shujuan; Corriveau, Hélène; Tousignant, Michel

    2017-06-01

    This study aimed at exploring the perceived benefits and drawbacks of practicing tai chi, an alternative therapy that can be implemented in the community, as part of upper-limb rehabilitation following stroke. Semistructured interviews were carried out with participants with chronic stroke (>6 months). The participants took part in 16 tai chi sessions over 8 weeks. Interviews were conducted in person using an interview guide based on the theory of planned behavior (TPB), and a thematic analysis was conducted. Eight interviews were carried out with participants at various stages of motor recovery. Participants perceived a number of physical, functional, and psychological benefits. They found tai chi to be a global exercise, including both physical and mental aspects, and suggested that it can be included as part of rehabilitation for stroke patients. Many participants expressed a desire to continue practicing tai chi after completion of the study because it exceeded their expectations, among other reasons. This study can serve to guide future tai chi interventions and research on tai chi for rehabilitation in terms of the characteristics of the intervention and the various areas to assess in order to measure the overall benefits. IMPLICATIONS FOR REHABILITATION Tai chi was perceived as a good way of integrating various skills learned during rehabilitation. Despite having different functional abilities, all the participants noted various physical, functional, and psychological benefits from participating in the tai chi sessions. Tai chi seems to be a form of exercise that stroke patients would perform more long-term since all the participants in this study expressed the desire to continue practicing tai chi.

  11. Instrumental intensity distribution for the Hector Mine, California, and the Chi-Chi, Taiwan, earthquakes: Comparison of two methods

    USGS Publications Warehouse

    Sokolov, V.; Wald, D.J.

    2002-01-01

    We compare two methods of seismic-intensity estimation from ground-motion records for the two recent strong earthquakes: the 1999 (M 7.1) Hector Mine, California, and the 1999 (M 7.6) Chi-Chi, Taiwan. The first technique utilizes the peak ground acceleration (PGA) and velocity (PGV), and it is used for rapid generation of the instrumental intensity map in California. The other method is based on the revised relationships between intensity and Fourier amplitude spectrum (FAS). The results of using the methods are compared with independently observed data and between the estimations from the records. For the case of the Hector Mine earthquake, the calculated intensities in general agree with the observed values. For the case of the Chi-Chi earthquake, the areas of maximum calculated intensity correspond to the areas of the greatest damage and highest number of fatalities. However, the FAS method producees higher-intensity values than those of the peak amplitude method. The specific features of ground-motion excitation during the large, shallow, thrust earthquake may be considered a reason for the discrepancy. The use of PGA and PGV is simple; however, the use of FAS provides a natural consideration of site amplification by means of generalized or site-specific spectral ratios. Because the calculation of seismic-intensity maps requires rapid processing of data from a large network, it is very practical to generate a "first-order" map from the recorded peak motions. Then, a "second-order" map may be compiled using an amplitude-spectra method on the basis of available records and numerical modeling of the site-dependent spectra for the regions of sparse station spacing.

  12. Clinical overlap between malaria and pneumonia: can malaria rapid diagnostic test play a role?

    PubMed

    Ukwaja, Kingsley Nnanna; Aina, Olufemi B; Talabi, Ademola A

    2011-03-21

    Malaria and pneumonia account for 40% of mortality among children under five years of age in sub-Saharan Africa. Due to lack of diagnostic facilities, their management is based on the integrated management of childhood illnesses (IMCI) strategy. Symptoms of malaria and pneumonia overlap in African children, necessitating dual IMCI classifications at health centres and treatment with both antibiotics and antimalarials. This study determined the prevalence of malaria-pneumonia symptom overlap and confirmed the diagnosis of malaria in these cases using a rapid diagnostic test. Consecutive consultations of 1,216 children (two months to five years old) were documented over a three-month period in a comprehensive health centre. Malaria rapid diagnostic tests were conducted only for children who had symptom overlap. Of the 1,216 children enrolled, 1,090 (90%) reported cough or fever. Among the children fulfilling the malaria case definition, 284 (30%) also met the pneumonia case definition. Twenty-three percent (284) of all children enrolled met the criteria for both malaria and pneumonia. However, only 130 (46%) of them had a positive result for malaria using a malaria rapid diagnostic test. During a malaria-pneumonia overlap, female children (chi-square 5.9, P = 0.01) and children ≥ one year (chi-square 4.8, P = 0.003) were more likely to seek care within two days of fever. Dual treatment with antimalarials and antibiotics in children with malaria-pneumonia overlap may result in unnecessary over-prescription of antimalarial medications. Use of rapid diagnostic tests in their management can potentially avoid over-prescribing of malaria medications.

  13. Tai Chi Exercise to Improve Non-Motor Symptoms of Parkinson's Disease.

    PubMed

    Nocera, Joe R; Amano, Shinichi; Vallabhajosula, Srikant; Hass, Chris J

    2013-08-20

    A substantial number of individuals with Parkinson's disease exhibit debilitating non-motor symptoms that decrease quality of life. To date, few treatment options exist for the non-motor symptomatology related to Parkinson's disease. The goal of this pilot investigation was to determine the effects of Tai Chi exercise on the non-motor symptomology in Parkinson's disease. Twenty-one individuals with Parkinson's disease were enrolled in a Tai Chi intervention (n=15) or a noncontact control group (n=6). Participants assigned to Tai Chi participated in 60-minute Tai Chi sessions three times per week, for 16 weeks. Pre and post measures included indices of cognitive-executive function including visuomotor tracking and attention, selective attention, working memory, inhibition, processing speed and task switching. Additionally, all participants were evaluated on the Parkinson's disease Questionnaire-39 and Tinetti's Falls Efficacy Scale. Results indicated that the Tai Chi training group had significantly better scores following the intervention than the control group on the Parkinson's disease Questionnaire-39 total score as well as the emotional well-being sub score. Trends for improvement were noted for the Tai Chi group on Digits Backwards, Tinetti's Falls Efficacy Scale, and the activities of daily living and communication sub scores of the Parkinson's disease Questionnaire-39. This research provides initial data that supports future studies to definitively establish efficacy of Tai Chi to improve non-motor features of Parkinson's disease.

  14. Product Quality Research Institute evaluation of cascade impactor profiles of pharmaceutical aerosols: part 2--evaluation of a method for determining equivalence.

    PubMed

    Christopher, David; Adams, Wallace P; Lee, Douglas S; Morgan, Beth; Pan, Ziqing; Singh, Gur Jai Pal; Tsong, Yi; Lyapustina, Svetlana

    2007-01-19

    The purpose of this article is to present the thought process, methods, and interim results of a PQRI Working Group, which was charged with evaluating the chi-square ratio test as a potential method for determining in vitro equivalence of aerodynamic particle size distribution (APSD) profiles obtained from cascade impactor measurements. Because this test was designed with the intention of being used as a tool in regulatory review of drug applications, the capability of the test to detect differences in APSD profiles correctly and consistently was evaluated in a systematic way across a designed space of possible profiles. To establish a "base line," properties of the test in the simplest case of pairs of identical profiles were studied. Next, the test's performance was studied with pairs of profiles, where some difference was simulated in a systematic way on a single deposition site using realistic product profiles. The results obtained in these studies, which are presented in detail here, suggest that the chi-square ratio test in itself is not sufficient to determine equivalence of particle size distributions. This article, therefore, introduces the proposal to combine the chi-square ratio test with a test for impactor-sized mass based on Population Bioequivalence and describes methods for evaluating discrimination capabilities of the combined test. The approaches and results described in this article elucidate some of the capabilities and limitations of the original chi-square ratio test and provide rationale for development of additional tests capable of comparing APSD profiles of pharmaceutical aerosols.

  15. Structure, Catalysis, and Inhibition of OfChi-h, the Lepidoptera-exclusive Insect Chitinase*

    PubMed Central

    Liu, Tian; Chen, Lei; Zhou, Yong; Jiang, Xi; Duan, Yanwei; Yang, Qing

    2017-01-01

    Chitinase-h (Chi-h) is of special interest among insect chitinases due to its exclusive distribution in lepidopteran insects and high sequence identity with bacterial and baculovirus homologs. Here OfChi-h, a Chi-h from Ostrinia furnacalis, was investigated. Crystal structures of both OfChi-h and its complex with chitoheptaose ((GlcN)7) reveal that OfChi-h possesses a long and asymmetric substrate binding cleft, which is a typical characteristics of a processive exo-chitinase. The structural comparison between OfChi-h and its bacterial homolog SmChiA uncovered two phenylalanine-to-tryptophan site variants in OfChi-h at subsites +2 and possibly −7. The F232W/F396W double mutant endowed SmChiA with higher hydrolytic activities toward insoluble substrates, such as insect cuticle, α-chitin, and chitin nanowhisker. An enzymatic assay demonstrated that OfChi-h outperformed OfChtI, an insect endo-chitinase, toward the insoluble substrates, but showed lower activity toward the soluble substrate ethylene glycol chitin. Furthermore, OfChi-h was found to be inhibited by N,N′,N″-trimethylglucosamine-N,N′,N″,N″′-tetraacetylchitotetraose (TMG-(GlcNAc)4), a substrate analog which can be degraded into TMG-(GlcNAc)1–2. Injection of TMG-(GlcNAc)4 into 5th-instar O. furnacalis larvae led to severe defects in pupation. This work provides insights into a molting-indispensable insect chitinase that is phylogenetically closer to bacterial chitinases than insect chitinases. PMID:28053084

  16. Effects of Ai Chi on balance, quality of life, functional mobility, and motor impairment in patients with Parkinson's disease.

    PubMed

    Kurt, Emine Eda; Büyükturan, Buket; Büyükturan, Öznur; Erdem, Hatice Rana; Tuncay, Figen

    2018-04-01

    In this study, we aimed to investigate effects of Ai Chi on balance, functional mobility, health-related quality of life, and motor impairment in patients with Parkinson's disease. This study was conducted as an open-label randomized controlled trial (ISRCTN26292510) with repeated measures. Forty patients with Parkinson's disease stages 2 to 3 according to the Hoehn and Yahr Scale were randomly allocated to either an Ai Chi exercise group or a land-based exercise control group for 5 weeks. Balance was measured using the Biodex-3,1 and the Berg Balance Scale. Functional mobility was evaluated using the Timed Up and Go Test. Additionally, health-related quality of life and motor activity were assessed with the Parkinson's Disease Questionnaire-39 and the Unified Parkinson's Disease Rating Scale-III. Although patients in both groups showed significant improvement in all outcome variables, improvement of dynamic balance was significantly greater in the Ai Chi group (p < 0.001), Berg Balance Scale (p < 0.001), Timed Up and Go Test (p = 0.002), Parkinson's Disease Questionnaire-39 (p < 0.001), Unified Parkinson's Disease Rating Scale-III (p < 0.001). Our results suggest that an Ai Chi exercise program improves balance, mobility, motor ability, and quality of life. In addition, Ai Chi exercise was more effective as an intervention than land-based exercise in patients with mild to moderate Parkinson's disease. Implications for rehabilitation Ai Chi exercises (aquatic exercises) may help improve balance, functional mobility, health-related quality of life, and motor ability in patients with mild to moderate Parkinson's disease more efficiently than similar land-based exercises. Ai Chi exercises should be considered as a rehabilitation option for treatment of patients with mild or moderate Parkinson's disease.

  17. Tai Chi training reduced coupling between respiration and postural control.

    PubMed

    Holmes, Matthew L; Manor, Brad; Hsieh, Wan-hsin; Hu, Kun; Lipsitz, Lewis A; Li, Li

    2016-01-01

    In order to maintain stable upright stance, the postural control system must account for the continuous perturbations to the body's center-of-mass including those caused by spontaneous respiration. Both aging and disease increase "posturo-respiratory synchronization;" which reflects the degree to which respiration affects postural sway fluctuations over time. Tai Chi training emphasizes the coordination of respiration and bodily movements and may therefore optimize the functional interaction between these two systems. The purpose of the project was to examine the effect of Tai Chi training on the interaction between respiration and postural control in older adults. We hypothesized that Tai Chi training would improve the ability of the postural control system to compensate for respiratory perturbations and thus, reduce posturo-respiratory synchronization. Participants were recruited from supportive housing facilities and randomized to a 12-week Tai Chi intervention (n=28; 86 ± 5 yrs) or educational-control program (n=34, 85 ± 6 yrs). Standing postural sway and respiration were simultaneously recorded with a force plate and respiratory belt under eyes-open and eyes-closed conditions. Posturo-respiratory synchronization was determined by quantifying the variation of the phase relationship between the dominant oscillatory mode of respiration and corresponding oscillations within postural sway. Groups were similar in age, gender distribution, height, body mass, and intervention compliance. Neither intervention altered average sway speed, sway magnitude or respiratory rate. As compared to the education-control group, however, Tai Chi training reduced posturo-respiratory synchronization when standing with eyes open or closed (p<0.001). Tai Chi training did not affect traditional parameters of standing postural control or respiration, yet reduced the coupling between respiration and postural control. The beneficial effects of Tai Chi training may therefore stem in part

  18. Tai Chi training reduced coupling between respiration and postural control

    PubMed Central

    Holmes, Matthew L; Manor, Brad; Hsieh, Wan-hsin; Hu, Kun; Lipsitz, Lewis A; Li, Li

    2015-01-01

    In order to maintain stable upright stance, the postural control system must account for the continuous perturbations to the body’s center-of-mass including those caused by spontaneous respiration. Both aging and disease increase “posturo-respiratory synchronization;” which reflects the degree to which respiration affects postural sway fluctuations over time. Tai Chi training emphasizes the coordination of respiration and bodily movements and may therefore optimize the functional interaction between these two systems. The purpose of the project was to examine the effect of Tai Chi training on the interaction between respiration and postural control in older adults. We hypothesized that Tai Chi training would improve the ability of the postural control system to compensate for respiratory perturbations and thus, reduce posturo-respiratory synchronization. Participants were recruited from supportive housing facilities and randomized to a 12-week Tai Chi intervention (n=28; 86±5yrs) or educational-control program (n=34, 85±6yrs). Standing postural sway and respiration were simultaneously recorded with a force plate and respiratory belt under eyes-open and eyes-closed conditions. Posturo-respiratory synchronization was determined by quantifying the variation of the phase relationship between the dominant oscillatory mode of respiration and corresponding oscillations within postural sway. Groups were similar in age, gender distribution, height, body mass, and intervention compliance. Neither intervention altered average sway speed, sway magnitude or respiratory rate. As compared to the education-control group, however, Tai Chi training reduced posturo-respiratory synchronization when standing with eyes open or closed (p<0.001). Tai Chi training did not affect traditional parameters of standing postural control or respiration, yet reduced the coupling between respiration and postural control. The beneficial effects of Tai Chi training may therefore stem in part

  19. The psychosocial effect of Tai Chi on nursing home residents.

    PubMed

    Lee, Linda Y K; Lee, Diana T F; Woo, Jean

    2010-04-01

    To determine the psychosocial effect of Tai Chi on nursing home residents. Moving into a nursing home usually imposes a certain degree of psychosocial challenge to older people. However, there is limited evidence suggesting a promising intervention that can promote the psychosocial health for this group. Although previous studies suggest that Tai Chi has the potential to enhance psychosocial well-being, existing evidence is deemed scarce and thus imposes a limitation on drawing out conclusions on this matter. Non-equivalent pretest-posttest control group design. A convenience sample of 139 residents from six nursing homes in Hong Kong was recruited for this study. The experimental group (n = 66) participated in a 26-week Tai Chi programme, while the control group (n = 73) continued its normal daily activities. The outcome measures included state self-esteem, the physical and mental component of health-related quality of life, social support network and social support satisfaction. Resident satisfaction was identified as a covariate because it demonstrated significant correlation with the outcome variables and, likewise, showed significant difference between the two study groups at baseline. Doubly multivariate analysis of covariance was performed to examine the effect of the intervention. Results indicate significant Group x Time interactions, with the experimental group experiencing significant improvement in the composite outcome of state self-esteem, the physical component of health-related quality of life and the mental component of health-related quality of life across the 26-week study period [F(6, 131) = 2.61, p = 0.02)]. No significant changes were detected regarding the effect of the Tai Chi programme on social support. Tai Chi practice is beneficial for nursing home residents. Tai Chi has unique characteristics that are particularly suitable in the practice of health exercise for nursing home residents. The inclusion of Tai Chi in residential care

  20. Sensitivity test of derivative matrix isopotential synchronous fluorimetry and least squares fitting methods.

    PubMed

    Makkai, Géza; Buzády, Andrea; Erostyák, János

    2010-01-01

    Determination of concentrations of spectrally overlapping compounds has special difficulties. Several methods are available to calculate the constituents' concentrations in moderately complex mixtures. A method which can provide information about spectrally hidden components in mixtures is very useful. Two methods powerful in resolving spectral components are compared in this paper. The first method tested is the Derivative Matrix Isopotential Synchronous Fluorimetry (DMISF). It is based on derivative analysis of MISF spectra, which are constructed using isopotential trajectories in the Excitation-Emission Matrix (EEM) of background solution. For DMISF method, a mathematical routine fitting the 3D data of EEMs was developed. The other method tested uses classical Least Squares Fitting (LSF) algorithm, wherein Rayleigh- and Raman-scattering bands may lead to complications. Both methods give excellent sensitivity and have advantages against each other. Detection limits of DMISF and LSF have been determined at very different concentration and noise levels.

  1. Streamflow Changes Induced by the 1999 MW 7.6 Chi-Chi Earthquake

    NASA Astrophysics Data System (ADS)

    Chia, Yeeping; Liu, Ching-Yi; Chuang, Po-Yu

    2016-04-01

    Anomalous streamflow changes have often been observed after strong earthquakes. These changes have been used to study crustal deformation induced by earthquakes. Previous studies indicated that co-seismic groundwater-level changes, ranging from a fall of 11.1 m to a rise of 7.42 m, were recorded in 152 monitoring wells near the seismogenic fault during the 1999 MW 7.6 Chi-Chi earthquake. Here we report anomalous streamflow changes due to the earthquake in central Taiwan. There are 32 stream gauges in the vicinity of the fault, mostly in the mountainous hanging wall area. Of those, 22 recorded anomalous streamflow increases, ranging from 60% to 732%, one to four days after the earthquake. Unlike a rapid decrease in discharge after heavy rainfall, the post-seismic increase is followed by a slow decline which may last for several months. Only one gauge recorded a sudden decrease in discharge immediately after the earthquake. Besides, the decrease was preceded by a large and abrupt streamflow increase over the four days before the earthquake. We attribute the post-seismic increase to fracturing in the mountainous area due to seismic shaking, while the decrease to co-seismic pore pressure drop induced by crustal extension. However, more evidence is needed to consider the pre-seismic streamflow changes as a potential precursory indicator of earthquakes.

  2. Comparisons of ground motions from five aftershocks of the 1999 Chi-Chi, Taiwan, earthquake with empirical predictions largely based on data from California

    USGS Publications Warehouse

    Wang, G.-Q.; Boore, D.M.; Igel, H.; Zhou, X.-Y.

    2004-01-01

    The observed ground motions from five large aftershocks of the 1999 Chi-Chi, Taiwan, earthquake are compared with predictions from four equations based primarily on data from California. The four equations for active tectonic regions are those developed by Abrahamson and Silva (1997), Boore et al. (1997), Campbell (1997, 2001), and Sadigh et al. (1997). Comparisons are made for horizontal-component peak ground accelerations and 5%-damped pseudoacceleration response spectra at periods between 0.02 sec and 5 sec. The observed motions are in reasonable agreement with the predictions, particularly for distances from 10 to 30 km. This is in marked contrast to the motions from the Chi-Chi mainshock, which are much lower than the predicted motions for periods less than about 1 sec. The results indicate that the low motions in the mainshock are not due to unusual, localized absorption of seismic energy, because waves from the mainshock and the aftershocks generally traverse the same section of the crust and are recorded at the same stations. The aftershock motions at distances of 30-60 km are somewhat lower than the predictions (but not nearly by as small a factor as those for the mainshock), suggesting that the ground motion attenuates more rapidly in this region of Taiwan than it does in the areas we compare with it. We provide equations for the regional attenuation of response spectra, which show increasing decay of motion with distance for decreasing oscillator periods. This observational study also demonstrates that ground motions have large earthquake-location-dependent variability for a specific site. This variability reduces the accuracy with which an earthquake-specific prediction of site response can be predicted. Online Material: PGAs and PSAs from the 1999 Chi-Chi earthquake and five aftershocks.

  3. A comprehensive review of health benefits of qigong and tai chi.

    PubMed

    Jahnke, Roger; Larkey, Linda; Rogers, Carol; Etnier, Jennifer; Lin, Fang

    2010-01-01

    Research examining psychological and physiological benefits of Qigong and Tai Chi is growing rapidly. The many practices described as Qigong or Tai Chi have similar theoretical roots, proposed mechanisms of action, and expected benefits. Research trials and reviews, however, treat them as separate targets of examination. This review examines the evidence for achieving outcomes from randomized controlled trials (RCTs) of both. The key words Tai Chi, Taiji, Tai Chi Chuan, and Qigong were entered into electronic search engines for the Cumulative Index for Allied Health and Nursing (CINAHL), psychological literature (PsycINFO), PubMed, Cochrane database, and Google Scholar. STUDY INCLUSION CRITERIA: RCTs reporting on the results of Qigong or Tai Chi interventions and published in peer-reviewed journals from 1993 to 2007. Country, type and duration of activity, number/type of subjects, control conditions, and reported outcomes were recorded for each study. Outcomes related to Qigong and Tai Chi practice were identified and evaluated. Seventy-seven articles met the inclusion criteria. The nine outcome category groupings that emerged were bone density (n = 4), cardiopulmonary effects (n = 19), physical function (n = 16), falls and related risk factors (n = 23), quality of life (n = 17), self-efficacy (n = 8), patient-reported outcomes (n = 13), psychological symptoms (n = 27), and immune function (n = 6). Research has demonstrated consistent, significant results for a number of health benefits in RCTs, evidencing progress toward recognizing the similarity and equivalence of Qigong and Tai Chi.

  4. A generalized Kruskal-Wallis test incorporating group uncertainty with application to genetic association studies.

    PubMed

    Acar, Elif F; Sun, Lei

    2013-06-01

    Motivated by genetic association studies of SNPs with genotype uncertainty, we propose a generalization of the Kruskal-Wallis test that incorporates group uncertainty when comparing k samples. The extended test statistic is based on probability-weighted rank-sums and follows an asymptotic chi-square distribution with k - 1 degrees of freedom under the null hypothesis. Simulation studies confirm the validity and robustness of the proposed test in finite samples. Application to a genome-wide association study of type 1 diabetic complications further demonstrates the utilities of this generalized Kruskal-Wallis test for studies with group uncertainty. The method has been implemented as an open-resource R program, GKW. © 2013, The International Biometric Society.

  5. Analytic Confusion Matrix Bounds for Fault Detection and Isolation Using a Sum-of-Squared- Residuals Approach

    NASA Technical Reports Server (NTRS)

    Simon, Dan; Simon, Donald L.

    2009-01-01

    Given a system which can fail in 1 or n different ways, a fault detection and isolation (FDI) algorithm uses sensor data in order to determine which fault is the most likely to have occurred. The effectiveness of an FDI algorithm can be quantified by a confusion matrix, which i ndicates the probability that each fault is isolated given that each fault has occurred. Confusion matrices are often generated with simulation data, particularly for complex systems. In this paper we perform FDI using sums of squares of sensor residuals (SSRs). We assume that the sensor residuals are Gaussian, which gives the SSRs a chi-squared distribution. We then generate analytic lower and upper bounds on the confusion matrix elements. This allows for the generation of optimal sensor sets without numerical simulations. The confusion matrix bound s are verified with simulated aircraft engine data.

  6. Comparative Effectiveness of Tai Chi Versus Physical Therapy for Knee Osteoarthritis

    PubMed Central

    Wang, Chenchen; Schmid, Christopher H.; Iversen, Maura D.; Harvey, William F.; Fielding, Roger A.; Driban, Jeffrey B.; Price, Lori Lyn; Wong, John B.; Reid, Kieran F.; Rones, Ramel; McAlindon, Timothy

    2016-01-01

    Background Few remedies effectively treat long-term pain and disability from knee osteoarthritis. Studies suggest that Tai Chi alleviates symptoms, but no trials have directly compared Tai Chi with standard therapies for osteoarthritis. Objective To compare Tai Chi with standard physical therapy for patients with knee osteoarthritis. Design Randomized, 52-week, single-blind comparative effectiveness trial. (ClinicalTrials.gov: NCT01258985) Setting An urban tertiary care academic hospital. Patients 204 participants with symptomatic knee osteoarthritis (mean age, 60 years; 70% women; 53% white). Intervention Tai Chi (2 times per week for 12 weeks) or standard physical therapy (2 times per week for 6 weeks, followed by 6 weeks of monitored home exercise). Measurements The primary outcome was Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score at 12 weeks. Secondary outcomes included physical function, depression, medication use, and quality of life. Results At 12 weeks, the WOMAC score was substantially reduced in both groups (Tai Chi, 167 points [95% CI, 145 to 190 points]; physical therapy, 143 points [CI, 119 to 167 points]). The between-group difference was not significant (24 points [CI, −10 to 58 points]). Both groups also showed similar clinically significant improvement in most secondary outcomes, and the benefits were maintained up to 52 weeks. Of note, the Tai Chi group had significantly greater improvements in depression and the physical component of quality of life. The benefit of Tai Chi was consistent across instructors. No serious adverse events occurred. Limitation Patients were aware of their treatment group assignment, and the generalizability of the findings to other settings remains undetermined. Conclusion Tai Chi produced beneficial effects similar to those of a standard course of physical therapy in the treatment of knee osteoarthritis. Primary Funding Source National Center for Complementary and Integrative Health of

  7. The effect of tai chi exercise on quality of life in hemodialysis patients

    PubMed Central

    Shahgholian, Nahid; Eshghinezhad, Ameneh; Mortazavi, Mojgan

    2014-01-01

    Background: Today, despite remarkable advances in the care of hemodialysis patients, the quality of life (QOL) for these patients is still unsatisfactory. Although previous reports confirmed the effect of exercise on the well-being of renal patients, less than 50% of end-stage kidney patients participate in a regular sports program. Tai chi is a slow and gentle exercise that is suitable for people with chronic illnesses and those with severe intolerance of exercise. Therefore, this study aimed to determine the effect of tai chi exercise on the QOL of hemodialysis patients. Materials and Methods: This was a quasi-experimental study conducted in a single group and in two steps. Twenty-five hemodialysis patients, admitted to hospitals in Isfahan, Iran, were selected, and their QOL was compared before and after intervention in two domains of satisfaction and importance. Convenience sampling was used. The sampling was convenience. The subjects were trained in the intervention through a single session of tai chi exercise class for one hour weekly, for 12 weeks, with a training compact disc (CD) that helped the patients to exercise at least twice a week at home. Data were collected by the completion of a demographic characteristics form and a researcher-made QOL questionnaire adopted from Ferrans and Powers Quality of Life Index Dialysis Version and the Kidney Disease Quality of Life-Short Form (KDQOL-SF) questionnaire by the researchers. The data were analyzed by a paired t-test through SPSS software version 18. Results: Data analysis showed that there was a statistically significant difference in health and functioning (P < 0.001), socioeconomic (P < 0.001), and psychospiritual (P < 0.001) dimensions, and the family dimension had P = 0.002 in the satisfaction domain and P = 0.008 in the importance domain; the total score of quality of life in both domains was P < 0.001. Conclusions: According to the research findings, tai chi exercise improves the QOL score

  8. Tri-Center Analysis: Determining Measures of Trichotomous Central Tendency for the Parametric Analysis of Tri-Squared Test Results

    ERIC Educational Resources Information Center

    Osler, James Edward

    2014-01-01

    This monograph provides an epistemological rational for the design of a novel post hoc statistical measure called "Tri-Center Analysis". This new statistic is designed to analyze the post hoc outcomes of the Tri-Squared Test. In Tri-Center Analysis trichotomous parametric inferential parametric statistical measures are calculated from…

  9. A unifying theoretical and algorithmic framework for least squares methods of estimation in diffusion tensor imaging.

    PubMed

    Koay, Cheng Guan; Chang, Lin-Ching; Carew, John D; Pierpaoli, Carlo; Basser, Peter J

    2006-09-01

    A unifying theoretical and algorithmic framework for diffusion tensor estimation is presented. Theoretical connections among the least squares (LS) methods, (linear least squares (LLS), weighted linear least squares (WLLS), nonlinear least squares (NLS) and their constrained counterparts), are established through their respective objective functions, and higher order derivatives of these objective functions, i.e., Hessian matrices. These theoretical connections provide new insights in designing efficient algorithms for NLS and constrained NLS (CNLS) estimation. Here, we propose novel algorithms of full Newton-type for the NLS and CNLS estimations, which are evaluated with Monte Carlo simulations and compared with the commonly used Levenberg-Marquardt method. The proposed methods have a lower percent of relative error in estimating the trace and lower reduced chi2 value than those of the Levenberg-Marquardt method. These results also demonstrate that the accuracy of an estimate, particularly in a nonlinear estimation problem, is greatly affected by the Hessian matrix. In other words, the accuracy of a nonlinear estimation is algorithm-dependent. Further, this study shows that the noise variance in diffusion weighted signals is orientation dependent when signal-to-noise ratio (SNR) is low (

  10. Comparisons of ground motions from the 1999 Chi-Chi, earthquake with empirical predictions largely based on data from California

    USGS Publications Warehouse

    Boore, D.M.

    2001-01-01

    This article has the modest goal of comparing the ground motions recorded during the 1999 Chi-Chi, Taiwan, mainshock with predictions from four empirical-based equations commonly used for western North America; these empirical predictions are largely based on data from California. Comparisons are made for peak acceleration and 5%-damped response spectra at periods between 0.1 and 4 sec. The general finding is that the Chi-Chi ground motions are smaller than those predicted from the empirically based equations for periods less than about 1 sec by factors averaging about 0.4 but as small as 0.26 (depending on period, on which equation is used, and on whether the sites are assumed to be rock or soil). There is a trend for the observed motions to approach or even exceed the predicted motions for longer periods. Motions at similar distances (30-60 km) to the east and to the west of the fault differ dramatically at periods between about 2 and 20 sec: Long-duration wave trains are present on the motions to the west, and when normalized to similar amplitudes at short periods, the response spectra of the motions at the western stations are as much as five times larger than those of motions from eastern stations. The explanation for the difference is probably related to site and propagation effects; the western stations are on the Coastal Plain, whereas the eastern stations are at the foot of young and steep mountains, either in the relatively narrow Longitudinal Valley or along the eastern coast-the sediments underlying the eastern stations are probably shallower and have higher velocity than those under the western stations.

  11. Overlap Areas of a Square Box on a Square Mesh

    DTIC Science & Technology

    2017-04-01

    ARL-TN-0818 ● APR 2017 US Army Research Laboratory Overlap Areas of a Square Box on a Square Mesh by James U Cazamias...originator. ARL-TN-0818 ● APR 2017 US Army Research Laboratory Overlap Areas of a Square Box on a Square Mesh by James U Cazamias...

  12. Feasibility and effectiveness of a Chen-style Tai Chi programme for stress reduction in junior secondary school students.

    PubMed

    Lee, Linda Y K; Chong, Yeuk Lan; Li, Ngai Yin; Li, Man Chung; Lin, Lai Na; Wong, Lee Yi; Wong, Brian Kit; Yip, Wing Ping; Hon, Cho Hang; Chung, Pui Kuen; Man, Shuk Yee

    2013-04-01

    Stress is common in junior secondary school students (JSSS). This study aimed to determine the feasibility and effectiveness of a Chen-style Tai Chi programme for stress reduction in JSSS. A non-equivalent pre-test/post-test control group design was adopted, and a convenience sample of 69 JSSS was recruited. The experimental group (n = 32) joined a Chen-style Tai Chi programme, which included 10 sessions of 80-minute Tai Chi training (one session per week). The control group (n = 37) proceeded with self-study. Participants' stress levels were assessed using the Perceived Stress Scale. Feasibility was determined as the percentage of participants completing and attending the programme. Effectiveness was measured as the significant difference in changes in stress levels before and after the intervention between the two groups. Results preliminarily supported that the programme was feasible for JSSS. Completion rate was 100%, and attendance rate was 90%. However, no significant difference was noted in changes in stress levels before and after the intervention between the two groups. The potential health benefits of Tai Chi could not be detected owing to the restrictions imposed by the research setting and study limitations. The present study represents initial efforts in this direction and serves as reference for future study. Copyright © 2012 John Wiley & Sons, Ltd.

  13. A Search for WIMP Dark Matter using an Optimized Chi-square Technique on the Final Data from the Cryogenic Dark Matter Search Experiment (CDMS II)

    NASA Astrophysics Data System (ADS)

    Manungu Kiveni, Joseph

    2012-06-01

    accumulated at the Soudan Underground Laboratory in Minnesota. Results from the original analysis of these data were published in 2009; two events were observed in the signal region with an expected leakage of 0.9 events. Further investigation revealed an issue with the ionization-pulse reconstruction algorithm leading to a software upgrade and a subsequent reanalysis of the data. As part of the reanalysis, I performed an advanced discrimination technique to better distinguish (potential) signal events from backgrounds using a 5-dimensional chi-square method. This data-analysis technique combines the event information recorded for each WIMP-search event to derive a background-discrimination parameter capable of reducing the expected background to less than one event, while maintaining high efficiency for signal events. Furthermore, optimizing the cut positions of this 5-dimensional chi-square parameter for the 14 viable germanium detectors yields an improved expected sensitivity to WIMP interactions relative to previous CDMS results. This dissertation describes my improved (and optimized) discrimination technique and the results obtained from a blind application to the reanalyzed CDMS II WIMP-search data. This analysis achieved the best expected sensitivity of the three techniques developed for the reanalysis and so was chosen as the primary timing analysis whose limit will be quoted in a on-going publication paper which is currently in preparation. For this analysis, a total raw exposure of 612.17 kg-days are analyzed for this work. No candidate events was observed, and a corresponding upper limit on the WIMP-nucleon scattering cross section as a function of WIMP mass is defined. These data set a 90% upper limit on spin-independent WIMP-nucleon elastic-scattering cross section of 3.19 × 10-44 cm2 for a WIMP mass of 60 GeV c 2. Combining this result with all previous CDMS II data gives an upper limit of 1.96 ×10-44 cm2 for a WIMP of mass 60 GeV/c2 (a factor of 2 better than

  14. Direct quantification of test bacteria in synthetic water-polluted samples by square wave voltammetry and chemometric methods.

    PubMed

    Carpani, Irene; Conti, Paolo; Lanteri, Silvia; Legnani, Pier Paolo; Leoni, Erica; Tonelli, Domenica

    2008-02-28

    A home-made microelectrode array, based on reticulated vitreous carbon, was used as working electrode in square wave voltammetry experiments to quantify the bacterial load of Escherichia coli ATCC 13706 and Pseudomonas aeruginosa ATCC 27853, chosen as test microorganisms, in synthetic samples similar to drinking water (phosphate buffer). Raw electrochemical signals were analysed with partial least squares regression coupled to variable selection in order to correlate these values with the bacterial load estimated by aerobic plate counting. The results demonstrated the ability of the method to detect even low loads of microorganisms in synthetic water samples. In particular, the model detects the bacterial load in the range 3-2,020 CFU ml(-1) for E. coli and in the range 76-155,556 CFU ml(-1) for P. aeruginosa.

  15. Test equality in binary data for a 4 × 4 crossover trial under a Latin-square design.

    PubMed

    Lui, Kung-Jong; Chang, Kuang-Chao

    2016-10-15

    When there are four or more treatments under comparison, the use of a crossover design with a complete set of treatment-receipt sequences in binary data is of limited use because of too many treatment-receipt sequences. Thus, we may consider use of a 4 × 4 Latin square to reduce the number of treatment-receipt sequences when comparing three experimental treatments with a control treatment. Under a distribution-free random effects logistic regression model, we develop simple procedures for testing non-equality between any of the three experimental treatments and the control treatment in a crossover trial with dichotomous responses. We further derive interval estimators in closed forms for the relative effect between treatments. To evaluate the performance of these test procedures and interval estimators, we employ Monte Carlo simulation. We use the data taken from a crossover trial using a 4 × 4 Latin-square design for studying four-treatments to illustrate the use of test procedures and interval estimators developed here. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  16. A Study on How to Breathe Properly When Practicing Tai Chi Chuan

    ERIC Educational Resources Information Center

    Yang, Hanchun

    2011-01-01

    When practicing Tai Chi Chuan, proper breath plays an important role in shaping Tai Chi Chuan's style and its fitness value. The paper aims to analyse the postures of Tai Chi Chuan and its breath characteristics. The paper also presents some new insights on how to co-ordinate breath with postures by case studies.

  17. Does Tai Chi relieve fatigue? A systematic review and meta-analysis of randomized controlled trials

    PubMed Central

    Xiang, Yu; Lu, Liming; Chen, Xiankun

    2017-01-01

    Background Fatigue is not only a familiar symptom in our daily lives, but also a common ailment that affects all of our bodily systems. Several randomized controlled trials (RCTs) have proven Tai Chi to be beneficial for patients suffering from fatigue, however conclusive evidence is still lacking. A systematic review and meta-analysis was performed on all RCTs reporting the effects of Tai Chi for fatigue. Methods In the end of April 2016, seven electronic databases were searched for RCTs involving Tai Chi for fatigue. The search terms mainly included Tai Chi, Tai-ji, Taiji, fatigue, tiredness, weary, weak, and the search was conducted without language restrictions. Methodological quality was assessed using the Cochrane Risk of Bias tool. RevMan 5.3 software was used for meta-analysis. Publication bias was estimated with a funnel plot and Egger’s test. We also assessed the quality of evidence with the GRADE system. Results Ten trials (n = 689) were included, and there was a high risk of bias in the blinding. Two trials were determined to have had low methodological quality. Tai Chi was found to have improved fatigue more than conventional therapy (standardized mean difference (SMD): -0.45, 95% confidence interval (CI): -0.70, -0.20) overall, and have positive effects in cancer-related fatigue (SMD:-0.38, 95% CI: -0.65, -0.11). Tai Chi was also more effective on vitality (SMD: 0.63, 95% CI: 0.20, 1.07), sleep (SMD: -0.32, 95% CI: -0.61, -0.04) and depression (SMD: -0.58, 95% CI: -1.04, -0.11). However, no significant difference was found in multiple sclerosis-related fatigue (SMD: -0.77, 95% CI: -1.76, 0.22) and age-related fatigue (SMD: -0.77, 95% CI: -1.78, 0.24). No adverse events were reported among the included studies. The quality of evidence was moderate in the GRADE system. Conclusions The results suggest that Tai Chi could be an effective alternative and /or complementary approach to existing therapies for people with fatigue. However, the quality of the

  18. Tai Chi and Kung-Fu practice maintains physical performance but not vascular health in young versus old participants.

    PubMed

    McAnulty, Steven; McAnulty, Lisa; Collier, Scott; Souza-Junior, Tacito P; McBride, Jeffrey

    2016-01-01

    Kung-Fu and Tai Chi along with other martial arts are gaining popularity but studies examining the benefits of martial arts on physical fitness, vascular health, nutrition, and psychological wellness are limited. Aging is associated with declines in these health components. The objectives of this study were to examine whether Tai Chi and Kung-Fu training would maintain physical fitness, vascular health, and psychological wellness components on older versus younger practitioners. Seventeen subjects were recruited and divided into Young (age <40 years, n=9) and Old (age 40 years and above, n=8). Participants reported twice for health screens, vascular and nutrition assessment, and fitness tests. Mean differences were compared between groups for all tests using Student's t-tests. Age, months of practice, systolic blood pressure, and cardiovascular augmentation index were significantly greater in Old versus Young (p=0.001, p=0.007, p=0.049, and p=0.011, respectively). Psychologically, old practitioners experienced greater sleep interference (p=0.035) and overall pain (p=0.036). No other differences existed for any variable. Our study indicates that the practice of Tai Chi and Kung-Fu maintains physical fitness in older compared to younger practitioners. However, age associated changes in cardiovascular stiffness, systolic blood pressure, and pain were not prevented.

  19. Improvements to CHI Plasma Start-up and Ramp-up in NSTX

    NASA Astrophysics Data System (ADS)

    Jarboe, T. R.; Raman, R.; Nelson, B. A.; Mueller, D.; Bell, M. G.; Roquemore, L.; Kugel, H. W.; Soukhanovskii, V.

    2009-11-01

    Experiments in NSTX have now demonstrated the savings of central solenoid inductive flux after coupling of toroidal plasmas produced by the technique of Coaxial Helicity Injection (CHI) to inductive sustainment and ramp-up of the toroidal plasma current. In these discharges, the central solenoid with zero pre-charge was used to apply an inductive loop voltage to the decaying CHI started discharges. The coupled discharges ramped up to 800kA without the benefit of auxiliary heating. Inductive flux savings was realized as a result of an effort to reduce the influx of low-Z impurities during the plasma start-up phase. This was achieved through the use of 400ms long CHI discharges produced using a DC rectifier power supply to ablate low-Z surface impurities from the lower divertor electrodes, followed by the use of Lithium evaporative coatings and an effort to reduce spurious arcs in the upper divertor region by controlling the extent of CHI plasma growth in the vessel. Previous work on NSTX has shown that CHI started discharges after coupling to neutral beam heated discharges can transition to an H-mode. These important new results from NSTX demonstrate that CHI is a viable solenoid-free plasma startup method for future STs and Tokamaks. This work supported by U.S. DOE Contracts # DE-AC02-09CH11466 and DE-FG02-99ER54519 AM08.

  20. Examining differences in HPV awareness and knowledge and HPV vaccine awareness and acceptability between U.S. Hispanic and island Puerto Rican women.

    PubMed

    Morales-Campos, Daisy Y; Vanderpool, Robin C

    2017-01-01

    In 2015, only 42% of Puerto Rican (PR) girls aged 13-17 and 44% of U.S. Hispanic girls aged 13-17 were vaccinated with all three Human Papillomavirus (HPV) vaccine doses; These percentages were far lower than the Healthy People 2020 goal of 80% of girls aged 13-15 the Healthy People 2020 goal of 80%. The purpose of this study was to examine potential differences in HPV awareness and knowledge and HPV vaccine awareness and acceptability between a population-based sample of U.S. Hispanic and island Puerto Rican women. We restricted our analyses to female respondents from the Health Information National Trends Survey (HINTS) 2007 (n=375; U.S. Hispanic) and HINTS Puerto Rico 2009 (n=417; PR). Using the Wald chi-square test, we assessed if there were significant differences in HPV awareness and knowledge and HPV vaccine awareness and acceptability between U.S. Hispanic and island PR women. We then utilized logistic or multinomial regression to control for covariates on significant outcomes. Both groups of Hispanic women were highly knowledgeable that HPV causes cancer (89.2% in both samples) and that HPV is a sexually transmitted infection (78.1% [U.S. Hispanics] and 84.7% [PR]). Less than 10% of both groups recognized that HPV can clear on its own without treatment. Island PR women had significantly higher HPV vaccine awareness (66.9% vs. 61.0%; Wald X 2 F(1, 97) = 16.03, p < .001) and were more accepting of the HPV vaccine for a real or hypothetical daughter, compared to U.S. Hispanic women (74.8% vs. 56.1%; Wald X 2 F(2, 96) = 7.18, p < .001). However, after controlling for sociodemographic variables and survey group, there was no longer a difference between the two groups of women and HPV vaccine awareness (AOR = .53; 95% CI = .23, 1.24). Moreover, after controlled analysis, island PR women were significantly less likely to have their hypothetical daughter get the HPV vaccine, compared to U.S. Hispanic women (AOR = 0.26; 95% CI = .08, .81). Future research focused

  1. Tai Chi exercise in improving cardiorespiratory capacity.

    PubMed

    Thornton, Everard W

    2008-01-01

    To evaluate evidence relating to effects of Tai Chi on cardiovascular outcomes, with emphasis on randomised control designs. Studies reviewed in 2004 were re-examined, together with more recent controlled trials of Tai Chi relating to cardiovascular outcome. The analysis provided comment on problems associated with randomised control design, including sources of bias in such trials. With a single exception, data support reduction of baseline systolic/diastolic blood pressure (BP). While there may be positive bias in these studies, data are from diverse ethnic groups, different gender, age, and level of functional ability. There are no data relating to BP reactive change to subsequent stressors. Few studies consider potential mediating mechanisms through which Tai Chi may provide these benefits. Caution is advocated in using randomised controlled trials as the only effective type of study. Such designs are difficult to conduct and effective trials are more likely given a better understanding of the mediating mechanism(s) through which benefits may be derived. It is currently unclear how changes in BP are derived. Some data indicate a shift to increased vagal relative to sympathetic dominance and there may be other potential physiological mediators. No study has examined relationships between potential psychological gains such as self-efficacy and BP change, or individual differences in outcomes.

  2. Developing and Testing a Model to Predict Outcomes of Organizational Change

    PubMed Central

    Gustafson, David H; Sainfort, François; Eichler, Mary; Adams, Laura; Bisognano, Maureen; Steudel, Harold

    2003-01-01

    Objective To test the effectiveness of a Bayesian model employing subjective probability estimates for predicting success and failure of health care improvement projects. Data Sources Experts' subjective assessment data for model development and independent retrospective data on 221 healthcare improvement projects in the United States, Canada, and the Netherlands collected between 1996 and 2000 for validation. Methods A panel of theoretical and practical experts and literature in organizational change were used to identify factors predicting the outcome of improvement efforts. A Bayesian model was developed to estimate probability of successful change using subjective estimates of likelihood ratios and prior odds elicited from the panel of experts. A subsequent retrospective empirical analysis of change efforts in 198 health care organizations was performed to validate the model. Logistic regression and ROC analysis were used to evaluate the model's performance using three alternative definitions of success. Data Collection For the model development, experts' subjective assessments were elicited using an integrative group process. For the validation study, a staff person intimately involved in each improvement project responded to a written survey asking questions about model factors and project outcomes. Results Logistic regression chi-square statistics and areas under the ROC curve demonstrated a high level of model performance in predicting success. Chi-square statistics were significant at the 0.001 level and areas under the ROC curve were greater than 0.84. Conclusions A subjective Bayesian model was effective in predicting the outcome of actual improvement projects. Additional prospective evaluations as well as testing the impact of this model as an intervention are warranted. PMID:12785571

  3. Effects of fault dip and slip rake angles on near-source ground motions: Why rupture directivity was minimal in the 1999 Chi-Chi, Taiwan, earthquake

    USGS Publications Warehouse

    Aagaard, Brad T.; Hall, J.F.; Heaton, T.H.

    2004-01-01

    We study how the fault dip and slip rake angles affect near-source ground velocities and displacements as faulting transitions from strike-slip motion on a vertical fault to thrust motion on a shallow-dipping fault. Ground motions are computed for five fault geometries with different combinations of fault dip and rake angles and common values for the fault area and the average slip. The nature of the shear-wave directivity is the key factor in determining the size and distribution of the peak velocities and displacements. Strong shear-wave directivity requires that (1) the observer is located in the direction of rupture propagation and (2) the rupture propagates parallel to the direction of the fault slip vector. We show that predominantly along-strike rupture of a thrust fault (geometry similar in the Chi-Chi earthquake) minimizes the area subjected to large-amplitude velocity pulses associated with rupture directivity, because the rupture propagates perpendicular to the slip vector; that is, the rupture propagates in the direction of a node in the shear-wave radiation pattern. In our simulations with a shallow hypocenter, the maximum peak-to-peak horizontal velocities exceed 1.5 m/sec over an area of only 200 km2 for the 30??-dipping fault (geometry similar to the Chi-Chi earthquake), whereas for the 60??- and 75??-dipping faults this velocity is exceeded over an area of 2700 km2 . These simulations indicate that the area subjected to large-amplitude long-period ground motions would be larger for events of the same size as Chi-Chi that have different styles of faulting or a deeper hypocenter.

  4. Structure of four executive functioning tests in healthy older adults.

    PubMed

    de Frias, Cindy M; Dixon, Roger A; Strauss, Esther

    2006-03-01

    The authors examined the factor structure of 4 indicators of executive functioning derived from 2 new (i.e., Hayling and Brixton) and 2 traditional (i.e., Stroop and Color Trails) tests. Data were from a cross-sectional sample of 55- to 85-year-old healthy adults (N=427) from the Victoria Longitudinal Study. Confirmatory factor analysis (LISREL 8.52) tested both a 2-factor model of Inhibition (Hayling, Stroop) and Shifting (Brixton, Color Trails) and a single-factor model. The 2-factor model did not fit the data because the covariance matrix of the factors was not positive definite. The single-factor model fit the data well, chi(2)(2, N=427)=0.32, p=.85, root-mean-square error of approximation (RMSEA)=.00, comparative fit index (CFI)=1.00, goodness-of-fit index (GFI)=1.00. Moreover, the single-factor structure of executive functioning was invariant (configural and metric) across gender, and invariant (configural with limited metric) across age. Structural relations showed that poorer executive functioning performance was related to older age and lower fluid intelligence, chi(2)(11, N=418)=23.04, p=.02, RMSEA=.05, CFI=.97, GFI=.98.

  5. Determination of suitable drying curve model for bread moisture loss during baking

    NASA Astrophysics Data System (ADS)

    Soleimani Pour-Damanab, A. R.; Jafary, A.; Rafiee, S.

    2013-03-01

    This study presents mathematical modelling of bread moisture loss or drying during baking in a conventional bread baking process. In order to estimate and select the appropriate moisture loss curve equation, 11 different models, semi-theoretical and empirical, were applied to the experimental data and compared according to their correlation coefficients, chi-squared test and root mean square error which were predicted by nonlinear regression analysis. Consequently, of all the drying models, a Page model was selected as the best one, according to the correlation coefficients, chi-squared test, and root mean square error values and its simplicity. Mean absolute estimation error of the proposed model by linear regression analysis for natural and forced convection modes was 2.43, 4.74%, respectively.

  6. Analysis of Square Cup Deep-Drawing Test of Pure Titanium

    NASA Astrophysics Data System (ADS)

    Ogawa, Takaki; Ma, Ninshu; Ueyama, Minoru; Harada, Yasunori

    2016-08-01

    The prediction of formability of titunium is more difficult than steels since its strong anisotropy. If computer simulation can estimate the formability of titanium, we can select the optimal forming conditions. The purpose of this study was to acquire knowledge for the formability prediction by the computer simulation of the square cup deep-drawing of pure titanium. In this paper, the results of FEM analsis of pure titanium were compared with the experimental results to examine the analysis validity. We analyzed the formability of deepdrawing square cup of titanium by the FEM using solid elements. Compared the analysis results with the experimental results such as the forming shape, the punch load, and the thickness, the validity was confirmed. Further, through analyzing the change of the thickness around the forming corner, it was confirmed that the thickness increased to its maximum value during forming process at the stroke of 35mm more than the maximum stroke.

  7. Square-lashing technique in segmental spinal instrumentation: a biomechanical study.

    PubMed

    Arlet, Vincent; Draxinger, Kevin; Beckman, Lorne; Steffen, Thomas

    2006-07-01

    Sublaminar wires have been used for many years for segmental spinal instrumentation in scoliosis surgery. More recently, stainless steel wires have been replaced by titanium cables. However, in rigid scoliotic curves, sublaminar wires or simple cables can either brake or pull out. The square-lashing technique was devised to avoid complications such as cable breakage or lamina cutout. The purpose of the study was therefore to test biomechanically the pull out and failure mode of simple sublaminar constructs versus the square-lashing technique. Individual vertebrae were subjected to pullout testing having one of two different constructs (single loop and square lashing) using either monofilament wire or multifilament cables. Four different methods of fixation were therefore tested: single wire construct, square-lashing wiring construct, single cable construct, and square-lashing cable construct. Ultimate failure load and failure mechanism were recorded. For the single wire the construct failed 12/16 times by wire breakage with an average ultimate failure load of 793 N. For the square-lashing wire the construct failed with pedicle fracture in 14/16, one bilateral lamina fracture, and one wire breakage. Ultimate failure load average was 1,239 N For the single cable the construct failed 12/16 times due to cable breakage (average force 1,162 N). 10/12 of these breakages were where the cable looped over the rod. For the square-lashing cable all of these constructs (16/16) failed by fracture of the pedicle with an average ultimate failure load of 1,388 N. The square-lashing construct had a higher pullout strength than the single loop and almost no cutting out from the lamina. The square-lashing technique with cables may therefore represent a new advance in segmental spinal instrumentation.

  8. A bicentric controlled study on the effects of aquatic Ai Chi in Parkinson disease.

    PubMed

    Pérez-de la Cruz, Sagrario

    2018-02-01

    Various exercise strategies have been suggested to address movement deficits in order to improve motor function and quality of life for individuals in the early or moderate stages of Parkinson disease. The purpose is to evaluate the effects of an aquatic Ai Chi intervention on balance, gait speed and quality of life of patients. Twenty-nine people with Parkinson disease participated in this pilot study. People were randomized into (1) aquatic Ai Chi program (experimental group) and (2) a dry land conventional Western physical therapy intervention (control group). Twenty-two twice-weekly sessions were performed with the 14 patients assigned to the experimental group, during the same period of time as the control group (same number of sessions), who received dry land therapy. Visual Analogue scale (VAS), The Timed Get up and Go test, Five Times Sit-to-Stand test, single leg standing, Yesavage test and Parkinson's Disease Questionnaire (PDQ-39). A descriptive analysis was performed on all study variables. The results showed a significant effect on time - of a high effect which indicates that the VAS scores (F 1.3; p < 0.001), Five time (F = 1.8; p = 0.001) and Get up and Go (F = 1.7; p < 0.001) significantly decreased in time, independent of the treatment group. In contrast, no significant differences were found in the results shown on the PDQ-39 scale, finding only changes in the section of social support (p < 0.001 F = 18.63). The results of this 11-week controlled pilot trial suggest that aquatic Ai Chi applied twice weekly may potentially reduce Parkinsonian symptoms as measured on different motor symptoms, bradykinesia and rigidity. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Unified Least Squares Methods for the Evaluation of Diagnostic Tests With the Gold Standard

    PubMed Central

    Tang, Liansheng Larry; Yuan, Ao; Collins, John; Che, Xuan; Chan, Leighton

    2017-01-01

    The article proposes a unified least squares method to estimate the receiver operating characteristic (ROC) parameters for continuous and ordinal diagnostic tests, such as cancer biomarkers. The method is based on a linear model framework using the empirically estimated sensitivities and specificities as input “data.” It gives consistent estimates for regression and accuracy parameters when the underlying continuous test results are normally distributed after some monotonic transformation. The key difference between the proposed method and the method of Tang and Zhou lies in the response variable. The response variable in the latter is transformed empirical ROC curves at different thresholds. It takes on many values for continuous test results, but few values for ordinal test results. The limited number of values for the response variable makes it impractical for ordinal data. However, the response variable in the proposed method takes on many more distinct values so that the method yields valid estimates for ordinal data. Extensive simulation studies are conducted to investigate and compare the finite sample performance of the proposed method with an existing method, and the method is then used to analyze 2 real cancer diagnostic example as an illustration. PMID:28469385

  10. Demonstration of Inductive Flux Saving by Transient CHI on NSTX

    NASA Astrophysics Data System (ADS)

    Raman, Roger

    2010-11-01

    Experiments in NSTX have now demonstrated the saving of central solenoid flux equivalent to 200kA of toroidal plasma current after coupling plasmas produced by Transient Coaxial Helicity Injection (CHI) to inductive sustainment and ramp-up of the toroidal plasma current [R. Raman, et al., PRL 104, 095003 (2010)]. This is a record for non-inductive plasma startup, and an important step for developing the spherical torus concept. With an injector current of only 4kA and total power supply energy of only 21 kJ, CHI initiated a toroidal current of 250 kA that when coupled to 0.11 Vs of induction ramped up to 525 kA without using any auxiliary heating, whereas an otherwise identical inductive-only discharge ramped to only 325 kA. This flux saving was realized by reducing the influx of low-Z impurities during the start-up phase through the use of electrode conditioning discharges, followed by lithium evaporative coating of the plasma-facing surfaces and reducing parasitic arcs in the upper divertor region through use of additional shaping-field coils. As a result of these improvements, and for the first time in NSTX, the electron temperature during the CHI phase continually increased with input energy, indicating that the additional injected energy was contributing to heating the plasma instead of being lost through impurity line radiation. Simulations with the Tokamak Simulation Code (TSC) show that the observed scaling of CHI start-up current with toroidal field in NSTX is consistent with theory, suggesting that use of CHI on larger machines is quite attractive. These exciting results from NSTX demonstrate that CHI is a viable solenoid-free plasma startup method for future STs and tokamaks. This work supported by U.S. DOE Contracts DE-AC02-09CH11466 and DE-FG02-99ER54519 AM08.

  11. The Effects of Tai Chi and Neck Exercises in the Treatment of Chronic Nonspecific Neck Pain: A Randomized Controlled Trial.

    PubMed

    Lauche, Romy; Stumpe, Christoph; Fehr, Johannes; Cramer, Holger; Cheng, Ying Wu; Wayne, Peter M; Rampp, Thomas; Langhorst, Jost; Dobos, Gustav

    2016-09-01

    This study aimed to test the efficacy of Tai Chi for treating chronic neck pain. Subjects with chronic nonspecific neck pain were randomly assigned to 12 weeks of group Tai Chi or conventional neck exercises with weekly sessions of 75 to 90 minutes, or a wait-list control. The primary outcome measure was pain intensity (visual analogue scale). Secondary outcomes included pain on movement, functional disability, quality of life, well-being and perceived stress, postural and interoceptive awareness, satisfaction, and safety. Altogether, 114 participants were included (91 women, 49.4 ± 11.7 years of age). After 12 weeks Tai Chi participants reported significantly less pain compared with the wait list group (average difference in mm on the visual analogue scale: -10.5; 95% confidence interval, -20.3 to -.9; P = .033). Group differences were also found for pain on movement, functional disability, and quality of life compared with the wait list group. No differences were found for Tai Chi compared with neck exercises. Patients' satisfaction with both exercise interventions was high, and only minor side effects were observed. Tai Chi was more effective than no treatment in improving pain in subjects with chronic nonspecific neck pain. Because Tai Chi is probably as effective as neck exercises it may be considered a suitable alternative to conventional exercises for those with a preference toward Tai Chi. This article presents results of a randomized controlled trial comparing Tai Chi, conventional neck exercises, and no treatment for chronic nonspecific neck pain. Results indicate that Tai Chi exercises and conventional neck exercises are equally effective in improving pain and quality of life therefore representing beneficial interventions for neck pain. Copyright © 2016 American Pain Society. Published by Elsevier Inc. All rights reserved.

  12. A Comprehensive Review of Health Benefits of Qigong and Tai Chi

    PubMed Central

    Jahnke, Roger; Larkey, Linda; Rogers, Carol; Etnier, Jennifer; Lin, Fang

    2011-01-01

    Objective Research examining psychological and physiological benefits of Qigong and Tai Chi is growing rapidly. The many practices described as Qigong or Tai Chi have similar theoretical roots, proposed mechanisms of action and expected benefits. Research trials and reviews, however, treat them as separate targets of examination. This review examines the evidence for achieving outcomes from randomized controlled trials (RCTs) of both. Data Sources The key words tai chi, taiji, and qigong were entered into electronic search engines for the Cumulative Index for Allied Health and Nursing (CINAHL), Psychological Literature (PsychInfo), PubMed, Cochrane database, and Google Scholar. Study Inclusion Criteria RCTs reporting on the results of Qigong or Tai Chi interventions and published in peer reviewed journals published from 1993–2007 Data Extraction Country, type and duration of activity, number/type of subjects, control conditions, and reported outcomes were recorded for each study. Synthesis Outcomes related to Qigong and Tai Chi practice were identified and evaluated. Results Seventy-seven articles met the inclusion criteria. The 9 outcome category groupings that emerged were: bone density (n=4), cardiopulmonary effects (n=19), physical function (n=16), falls and related risk factors (n=23), Quality of Life (n=17), self-efficacy (n=8), patient reported outcomes (n=13), psychological symptoms (n=27), and immune function (n=6). Conclusions Research has demonstrated consistent, significant results for a number of health benefits in RCTs, evidencing progress toward recognizing the similarity and equivalence of Qigong and Tai Chi. PMID:20594090

  13. Role of Tai Chi in the treatment of rheumatologic diseases.

    PubMed

    Wang, Chenchen

    2012-12-01

    Rheumatologic diseases (e.g., fibromyalgia, osteoarthritis, and rheumatoid arthritis) consist of a complex interplay between biologic and psychological aspects, resulting in therapeutically challenging chronic conditions to control. Encouraging evidence suggests that Tai Chi, a multi-component Chinese mind-body exercise, has multiple benefits for patients with a variety of chronic disorders, particularly those with musculoskeletal conditions. Thus, Tai Chi may modulate complex factors and improve health outcomes in patients with chronic rheumatologic conditions. As a form of physical exercise, Tai Chi enhances cardiovascular fitness, muscular strength, balance, and physical function. It also appears to be associated with reduced stress, anxiety, and depression, as well as improved quality of life. Thus, Tai Chi can be safely recommended to patients with fibromyalgia, osteoarthritis, and rheumatoid arthritis as a complementary and alternative medical approach to improve patient well-being. This review highlights the current body of knowledge about the role of this ancient Chinese mind-body medicine as an effective treatment of rheumatologic diseases to better inform clinical decision-making for our patients.

  14. Asymptotic formulae for likelihood-based tests of new physics

    NASA Astrophysics Data System (ADS)

    Cowan, Glen; Cranmer, Kyle; Gross, Eilam; Vitells, Ofer

    2011-02-01

    We describe likelihood-based statistical tests for use in high energy physics for the discovery of new phenomena and for construction of confidence intervals on model parameters. We focus on the properties of the test procedures that allow one to account for systematic uncertainties. Explicit formulae for the asymptotic distributions of test statistics are derived using results of Wilks and Wald. We motivate and justify the use of a representative data set, called the "Asimov data set", which provides a simple method to obtain the median experimental sensitivity of a search or measurement as well as fluctuations about this expectation.

  15. Spacecraft inertia estimation via constrained least squares

    NASA Technical Reports Server (NTRS)

    Keim, Jason A.; Acikmese, Behcet A.; Shields, Joel F.

    2006-01-01

    This paper presents a new formulation for spacecraft inertia estimation from test data. Specifically, the inertia estimation problem is formulated as a constrained least squares minimization problem with explicit bounds on the inertia matrix incorporated as LMIs [linear matrix inequalities). The resulting minimization problem is a semidefinite optimization that can be solved efficiently with guaranteed convergence to the global optimum by readily available algorithms. This method is applied to data collected from a robotic testbed consisting of a freely rotating body. The results show that the constrained least squares approach produces more accurate estimates of the inertia matrix than standard unconstrained least squares estimation methods.

  16. TECRA Unique test for rapid detection of Salmonella in food: collaborative study.

    PubMed

    Hughes, D; Dailianis, A E; Hill, L; McIntyre, D A; Anderson, A

    2001-01-01

    The TECRA Unique Salmonella test uses the principle of immunoenrichment to allow rapid detection of Salmonellae in food. A collaborative study was conducted to compare the TECRA Salmonella Unique test with the reference culture method given in the U.S. Food and Drug Administration's Bacteriological Analytical Manual. Three food types (milk powder, pepper, and soy flour) were analyzed in Australia and 2 food types (milk chocolate and dried egg) were analyzed in the United States. Forty-one collaborators participated in the study. For each of the 5 foods at each of the 3 levels, a comparison showed no significant differences (p > or = 0.05) in the proportion of positive test samples for Unique and that for the reference method using the Chi-square test for independence with continuity correction.

  17. Tai Chi for People with Visual Impairments: A Pilot Study

    ERIC Educational Resources Information Center

    Miszko, Tanya A.; Ramsey, Vincent K.; Blasch, Bruce B.

    2004-01-01

    This pilot study assessed the physical and psychological outcomes of a tai chi exercise program for eight adults with visual impairments. It found that after eight weeks of orientation and mobility training and tai chi practice, the participants' single leg-stance time and total knee flexion work and power improved, as did their frequency of,…

  18. [Effects of tai chi in postmenopausal women with osteoporosis: a systematic review].

    PubMed

    Chang, Ting-Jung; Ting, Yu-Ting; Sheu, Shei-Lan; Chang, Hsiao-Yun

    2014-10-01

    Tai chi has been increasingly applied in osteoporosis patients. However, systematic reviews of the efficacy of this practice have been few and of limited scope. This study reviews previous experimental research work using tai chi as an intervention in postmenopausal women with osteoporosis and to appraise the reported research designs used, tai chi methods used, and outcomes. A systematic review method was used to search 14 databases for articles published between January 1980 and July 2013. Searched keywords included: "tai chi," "osteoporosis," and "postmenopausal women". The 2,458 articles initially identified were reduced to 4 valid articles based on considerations of criteria and repeatability. The 4 valid articles used either a randomized clinical trial (RCT) or a controlled clinical trial (CCT). They were further analyzed and synthesized in terms of common variables such as balance, muscle strength, and quality of life. Three of the 4 studies identified significant pretest / posttest differences in physiological aspects of quality of life in participants but did not obtain consistent results in terms of the psychological aspects. While reports identified a significant and positive tai chi effect on balance, they all used different measurements to do so. Only one of the four studies identified significant improvement in muscle strength. Therefore, this review could not identify clear support for the effectiveness of tai chi on balance or muscle strength. This review did not definitively support the positive effects of tai chi on balance, muscle strength, and quality of life in postmenopausal women with osteoporosis. The designs used in the tai chi interventions may be referenced for future studies. We suggest that future studies use data triangulation rather than a single-item tool to validate the research in order to cross-verify the same information. This may strengthen the research and increase the credibility and the validity of related findings.

  19. Short and inflamed cervix predicts spontaneous preterm birth (COLIBRI study).

    PubMed

    Raiche, Evelyne; Ouellet, Annie; Berthiaume, Maryse; Rousseau, Éric; Pasquier, Jean-Charles

    2014-07-01

    To develop a new strategy of predicting spontaneous preterm birth (sPTB) by combination of transvaginal ultrasound (TVUS) assessment and inflammatory proteins detection in vaginal secretions. Prospective study of 87 women referred for cervical length assessment with a standardized TVUS combined to vaginal secretions sampling. Samples were analyzed for presence of 10 cytokines. Main outcome was sPTB (<37 weeks of gestation). Associations were assessed with the chi-square, Fisher's exact test (p < 0.05) and Wald's logistic regression. sPTB occurred in 25.3% of women at a median gestational age of 35.6 weeks of gestation. Short cervix (<25 mm) (n = 24) was associated with sPTB (p < 0.01) as interleukine (IL)-1β, IL-8 and IL-10 in vaginal secretions (p < 0.05). In multivariate analysis, short cervix and IL-8 in vaginal secretions were independently associated with sPTB (OR 3.58 (95%CI 1.02; 12.61) and 14.55 (95%CI 1.64; 128.83), respectively) as their combination (OR 4.33 (95%CI 1.25; 14.95)). By categorizing cervical length by presence of IL-8, sPTB occurred in 55.6% of women with a short inflamed cervix. COLIBRI study used a novel, single-step method of vaginal secretions sampling during TVUS and demonstrated that combination of short cervix and IL-8 in vaginal secretions is a promising sPTB predictive test.

  20. Quantal Response: Estimation and Inference

    DTIC Science & Technology

    2014-09-01

    considered. The CI-based test is just another way of looking at the Wald test. A small-sample simulation illustrates aberrant behavior of the Wald/CI...asymptotic power computation (Eq. 36) exhibits this behavior but not to such an extent as the simulated small-sample power. Sample size is n = 11 and...as |m1−m0| increases, but the power of the Wald test actually decreases for large |m1−m0| and eventually π → α . This type of behavior was reported as

  1. Tai Chi for Risk of Falls. A Meta-analysis.

    PubMed

    Lomas-Vega, Rafael; Obrero-Gaitán, Esteban; Molina-Ortega, Francisco J; Del-Pino-Casado, Rafael

    2017-09-01

    To analyze the effectiveness of tai chi for falls prevention. Systematic review and meta-analysis. Pubmed, Scopus, CINHAL, and Physiotherapy Evidence Database (PEDro) were searched to May 26, 2016. Older adult population and at-risk adults. Randomized controlled trials analyzing the effect of tai chi versus other treatments on risk of falls. The incidence rate ratio (IRR) for falls incidence and hazard ratio (HR) for time to first fall. The search strategy identified 891 potentially eligible studies, of which 10 met the inclusion criteria. There was high-quality evidence of a medium protective effect for fall incidence over the short term (IRR = 0.57; 95% CI = 0.46, 0.70) and a small protective effect over the long term (IRR = 0.87; 95% CI = 0.77, 0.98). Regarding injurious falls, we found very low-quality evidence of a medium protective effect over the short term (IRR = 0.50; 95% CI = 0.33, 0.74) and a small effect over the long term (IRR = 0.72; 95% CI = 0.54, 0.95). There was no effect on time to first fall, with moderate quality of evidence (HR = 0.98; 95% CI = 0.69, 1.37). In at-risk adults and older adults, tai chi practice may reduce the rate of falls and injury-related falls over the short term (<12 months) by approximately 43% and 50%, respectively. Tai chi practice may not influence time to first fall in these populations. Due to the low quality of evidence, more studies investigating the effects of tai chi on injurious falls and time to first fall are required. © 2017, Copyright the Authors Journal compilation © 2017, The American Geriatrics Society.

  2. Tai chi for health benefits in patients with multiple sclerosis: A systematic review

    PubMed Central

    Wang, Huiru; Xiao, ZhongJun; Fang, Qun; Zhang, Mark; Li, Ting; Du, Geng; Liu, Yang

    2017-01-01

    The aim of this systematic review was to evaluate the existing evidence on the effectiveness and safety of Tai chi, which is critical to provide guidelines for clinicians to improve symptomatic management in patients with multiple sclerosis (MS). After performing electronic and manual searches of many sources, ten relevant peer-reviewed studies that met the inclusion criteria were retrieved. The existing evidence supports the effectiveness of Tai chi on improving quality of life (QOL) and functional balance in MS patients. A small number of these studies also reported the positive effect of Tai chi on flexibility, leg strength, gait, and pain. The effect of Tai chi on fatigue is inconsistent across studies. Although the findings demonstrate beneficial effects on improving outcome measures, especially for functional balance and QOL improvements, a conclusive claim should be made carefully for reasons such as methodological flaws, small sample size, lack of specific-disease instruments, unclear description of Tai chi protocol, unreported safety of Tai chi, and insufficient follow-up as documented by the existing literature. Future research should recruit a larger number of participants and utilize the experimental design with a long-term follow-up to ascertain the benefits of Tai chi for MS patients. PMID:28182629

  3. [The effect of Ai Chi method in fibromyalgic patients].

    PubMed

    Santana, Jacqueline Soares de; Almeida, Ana Paula Gonçalves de; Brandão, Patrícia Martins Carvalho

    2010-06-01

    The objective of this article is to show the effect of the Ai Chi method, as an alternative form of hydrotherapeutic approach in fibromyalgia syndrome patients. Ten patients were studied, four were part of the experiment group and five of the control group, with one desistance. The patients were evaluated through the Fibromyalgia Impact Questionnaire (QIF) and Scale of Intensity and Index of pain in Sensible Points. Two evaluations were performed, before and after the treatment. The patients were submitted to ten sessions of the Ai Chi method during 40 minutes. The scale of intensity of pain in sensible points presented an improvement in the intensity of pain after the intervention, while quality of life remained without alteration. Regarding the quality of life, it was observed that the groups had similar results, because of the fact that patients had not presented improvement at depressive state. It was also verified a difference in the index of the sensible points between the groups; the explanation for this difference might be because of the benefits of the immersion in warm water and the effect of the Ai Chi method. There was no significant difference between the groups, which can be attributed to its limitations. In this way, new studies referring to the application of the Ai Chi method in patients carrying fibromyalgia syndrome become relevant.

  4. Managing cardiovascular risks with Tai Chi in people with coronary artery disease.

    PubMed

    Park, In Sook; Song, Rhayun; Oh, Kyong Ok; So, Hee Young; Kim, Dal Sook; Kim, Jong Im; Kim, Tae Sook; Kim, Hyun Li; Ahn, Suk Hee

    2010-02-01

    The paper is a report of the study to determine the effects of the cardiovascular risk management programme with Tai Chi on cardiovascular risks, health behaviours and quality of life in individuals with coronary artery disease. Many eligible patients with coronary artery disease do not participate in programmes for cardiovascular risk management, mainly because of lack of motivation, high cost or limited accessibility. Tai Chi has been introduced by health professionals to promote cardiovascular functioning and quality of life. A quasi-experimental design with a non-equivalent control group was used. Eighty-five people with a mean age of 66 years completed pretest and 6-month follow-up measures in the following three groups: Tai Chi with education (n = 33), Tai Chi only (n = 19) and control (n = 33). Analysis of covariance was used to compare outcome variables with pretest variables as covariates to adjust for baseline differences. The data were collected in 2005-2006. In the Tai-Chi-with-education group there were statistically significant reductions in modifiable cardiovascular risk factors (F = 3.49, P = 0.035) and improvements in health behaviours (F = 6.12, P = 0.003), mental scores (F = 3.96, P = 0.023), and in the role-emotional (F = 7.30, P = 0.001) and vitality (F = 3.81, P = 0.026) dimensions of quality of life. Tai Chi was safely implemented as an alternative form of exercise in a cardiovascular risk management programme. Whether the beneficial effects of Tai Chi in cardiovascular risk management are comparable with those induced by other types of aerobic exercise requires further investigation.

  5. [Qualitative research of the elderly real experience of long-term adherence to Tai Chi exercise].

    PubMed

    Qiao, Xue; Hao, Yu-fang

    2012-12-01

    To explore the experience of the process of Tai Chi exercise. The study was conducted in a local park in Beijing of China where varying numbers of community members gathered to practice Tai Chi every day. Volunteers meeting the inclusion and exclusion criteria were recruited after signed an informed consent form. In-depth interview and the participatory observation were used to know of the real feeling of practicing Tai Chi. The qualitative data obtained from the interviews were analyzed by using Colaizzi seven-step method to find the subjects. Six volunteers having a long-time Tai Chi exercise were recruited in this qualitative study, and their real experience was summarized in the physiological level, psychological level, social level and cultural level. In the physiological level, Tai Chi improves the health and exercise of Tai Chi assists the elderly to develop good living habits. In the psychological level, Tai Chi practice guides the person to inner peace, relieves tension, improves depressive mood state, and makes the elderly regain self worth. In the social level Tai Chi is a good form of community practice. In the cultural level, Tai Chi roots in yin and yang culture and integrates internal and external exercises. Tai Chi is good for body and mind health and the community of practice is very important for practitioners. Tai Chi gains popularity for its benefits to health and psychological adjustments, and its cultural connotation.

  6. Study of the hadronic decays of [chi][sub c] states

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bai, J.Z.; Bian, J.G.; Chen, G.P.

    1999-10-01

    Hadronic decays of the [ital P]-wave spin-triplet charmonium states [chi][sub cJ](J=0,1,2) are studied using a sample of [psi](2S) decays collected by the BES detector operating at the BEPC storage ring. Branching fractions for the decays [chi][sub c1][r arrow]K[sub S][sup 0]K[sup +][pi][sup [minus

  7. Reduced Cognitive-Motor Interference on Voluntary Balance Control in Older Tai Chi Practitioners.

    PubMed

    Varghese, Rini; Hui-Chan, Christina W Y; Bhatt, Tanvi

    2016-01-01

    Recent dual-task studies suggest that Tai Chi practitioners displayed better control of standing posture and maintained a quicker response time of postural muscle activation during a stepping down activity. Whether this effect extends to voluntary balance control, specifically the limits of excursion of the center of pressure, remains to be examined. The purpose of this study was to evaluate the cognitive-motor interference pattern by examining the effects of a concurrently performed cognitive task on attention of voluntary balance control in older adults who are long-term practitioners of Tai Chi. Ten older Tai Chi practitioners and 10 age-matched nonpractitioners performed a voluntary balance task that required them to shift their weight to reach a preset target in the forward and backward directions, with (single task, ST) and without (dual task, DT) a secondary cognitive task, which was the counting backward task. The counting backward task required the individual to compute and verbalize a series of arithmetic differences between a given pair of randomly generated numbers. The cognitive task was also performed independently (cognitive-ST). All trials were performed in a random order. Balance outcomes included reaction time, movement velocity, and maximal excursion of the center of pressure provided by the NeuroCom system. Cognitive outcome was the number of correct responses generated within the 8-second trial during the ST and DT conditions. Outcome variables were analyzed using a 2-factor, group by task, analysis of variance. DT costs for the variables were calculated as the relative difference between ST and DT conditions and were compared between the 2 groups using independent t tests. Tai Chi practitioners displayed shorter reaction times (P < .001) and faster movement velocities (P < .05) of their center of pressure than older nonpractitioners for both directions; however, no difference was found between the maximal excursions of the 2 groups. Cost

  8. Criterion Predictability: Identifying Differences Between [r-squares

    ERIC Educational Resources Information Center

    Malgady, Robert G.

    1976-01-01

    An analysis of variance procedure for testing differences in r-squared, the coefficient of determination, across independent samples is proposed and briefly discussed. The principal advantage of the procedure is to minimize Type I error for follow-up tests of pairwise differences. (Author/JKS)

  9. A goodness-of-fit test for capture-recapture model M(t) under closure

    USGS Publications Warehouse

    Stanley, T.R.; Burnham, K.P.

    1999-01-01

    A new, fully efficient goodness-of-fit test for the time-specific closed-population capture-recapture model M(t) is presented. This test is based on the residual distribution of the capture history data given the maximum likelihood parameter estimates under model M(t), is partitioned into informative components, and is based on chi-square statistics. Comparison of this test with Leslie's test (Leslie, 1958, Journal of Animal Ecology 27, 84- 86) for model M(t), using Monte Carlo simulations, shows the new test generally outperforms Leslie's test. The new test is frequently computable when Leslie's test is not, has Type I error rates that are closer to nominal error rates than Leslie's test, and is sensitive to behavioral variation and heterogeneity in capture probabilities. Leslie's test is not sensitive to behavioral variation in capture probabilities but, when computable, has greater power to detect heterogeneity than the new test.

  10. Factors affecting access to head and neck cancer care after a natural disaster: a post-Hurricane Katrina survey.

    PubMed

    Loehn, Bridget; Pou, Anna M; Nuss, Daniel W; Tenney, Justin; McWhorter, Andrew; DiLeo, Michael; Kakade, Anagha C; Walvekar, Rohan R

    2011-01-01

    Our aim was to survey the factors affecting access to cancer care in patients with head and neck cancer after Hurricane Katrina. In this cross-sectional survey, 207 patients with head and neck cancer were identified post-Hurricane Katrina, but only 83 patients completed the questionnaires and were analyzed. Clinical, demographic, and socioeconomic data were recorded. Chi-square test and t test were used for comparisons. Patients who felt that there was a lack of access to cancer care would have sought treatment earlier had they had better access to cancer care (chi-square[1] = 32; p < .0001). Patients who felt that there was a lack of access to cancer care also had difficulty receiving treatment (chi-square[1] = 48; p < .0001). Availability of transportation affected access to cancer care in patients with early-stage cancers (chi-square[1] = 4; p < .035). In the postdisaster environment, patients who felt the lack of access to cancer care post-Hurricane Katrina would have sought treatment earlier with better access to cancer care. These patients also reported difficulty obtaining cancer treatment. Availability of transportation affected access to cancer care in patients with early-stage cancers. Clinical, demographic, and socioeconomic factors did not influence access to cancer care. © 2010 Wiley Periodicals, Inc. Head Neck, 2011.

  11. Solenoid-free plasma startup in NSTX using transient CHI

    NASA Astrophysics Data System (ADS)

    Raman, R.; Jarboe, T. R.; Mueller, D.; Nelson, B. A.; Bell, M. G.; Bell, R.; Gates, D.; Gerhardt, S.; Hosea, J.; Kaita, R.; Kugel, H.; LeBlanc, B.; Maingi, R.; Maqueda, R.; Menard, J.; Nagata, M.; Ono, M.; Paul, S.; Roquemore, L.; Sabbagh, S.; Soukhanovskii, V.; Taylor, G.

    2009-06-01

    Experiments in NSTX have now demonstrated the coupling of toroidal plasmas produced by the technique of coaxial helicity injection (CHI) to inductive sustainment and ramp-up of the toroidal plasma current. In these discharges, the central Ohmic transformer was used to apply an inductive loop voltage to discharges with a toroidal current of about 100 kA created by CHI. The coupled discharges have ramped up to >700 kA and transitioned into an H-mode demonstrating compatibility of this startup method with conventional operation. The electron temperature in the coupled discharges reached over 800 eV and the resulting plasma had low inductance, which is preferred for long-pulse high-performance discharges. These results from NSTX in combination with the previously obtained record 160 kA non-inductively generated startup currents in an ST or tokamak in NSTX demonstrate that CHI is a viable solenoid-free plasma startup method for future STs and tokamaks.

  12. Progress with MGI and CHI Research on NSTX-U

    NASA Astrophysics Data System (ADS)

    Raman, R.; Lay, W.-S.; Jarboe, T. R.; Nelson, B. A.; Mueller, D.; Gerhardt, S. P.; Ebrahimi, F.; Jardin, S. C.; Taylor, G.

    2016-10-01

    NSTX-U experiments on Massive Gas Injection (MGI) will offer new insight to the MGI database by studying gas assimilation efficiencies for MGI gas injection from different poloidal locations. In support of this research, two ITER-type MGI valves have been successfully commissioned on NSTX-U. Results from the planned experiment `Comparison of Private Flux Region with Conventional Mid-plane MGI on NSTX-U', will be reported. In support of planned Coaxial Helicity Injection (CHI) research on NSTX-U, a new high-resolution grid has been generated for TSC simulations of CHI. This improves the resolution of the CHI injector region, and better models the closely-spaced divertor coils on NSTX-U. These new simulations support previous analysis that suggests a solenoid-free plasma current initiation capability of more than 400kA on NSTX-U. This work is supported by U.S. DOE Contracts: DE-AC02-09CH11466, DE-FG02-99ER54519 AM08, and DE-SC0006757.

  13. Stress evolution following the 1999 Chi-Chi, Taiwan, earthquake: Consequences for afterslip, relaxation, aftershocks and departures from Omori decay

    USGS Publications Warehouse

    Chan, C.-H.; Stein, R.S.

    2009-01-01

    We explore how Coulomb stress transfer and viscoelastic relaxation control afterslip and aftershocks in a continental thrust fault system. The 1999 September 21 Mw = 7.6 Chi-Chi shock is typical of continental ramp-d??collement systems throughout the world, and so inferences drawn from this uniquely well-recorded event may be widely applicable. First, we find that the spatial and depth distribution of aftershocks and their focal mechanisms are consistent with the calculated Coulomb stress changes imparted by the coseismic rupture. Some 61 per cent of the M ??? 2 aftershocks and 83 per cent of the M ??? 4 aftershocks lie in regions for which the Coulomb stress increased by ???0.1 bars, and there is a 11-12 per cent gain in the percentage of aftershocks nodal planes on which the shear stress increased over the pre-Chi Chi control period. Second, we find that afterslip occurred where the calculated coseismic stress increased on the fault ramp and d??collement, subject to the condition that friction is high on the ramp and low on the d??collement. Third, viscoelastic relaxation is evident from the fit of the post-seismic GPS data on the footwall. Fourth, we find that the rate of seismicity began to increase during the post-seismic period in an annulus extending east of the main rupture. The spatial extent of the seismicity annulus resembles the calculated ???0.05-bar Coulomb stress increase caused by viscoelastic relaxation and afterslip, and we find a 9-12 per cent gain in the percentage of focal mechanisms with >0.01-bar shear stress increases imparted by the post-seismic afterslip and relaxation in comparison to the control period. Thus, we argue that post-seismic stress changes can for the first time be shown to alter the production of aftershocks, as judged by their rate, spatial distribution, and focal mechanisms. ?? Journal compilation ?? 2009 RAS.

  14. Tai Chi practitioners have better postural control and selective attention in stepping down with and without a concurrent auditory response task.

    PubMed

    Lu, Xi; Siu, Ka-Chun; Fu, Siu N; Hui-Chan, Christina W Y; Tsang, William W N

    2013-08-01

    To compare the performance of older experienced Tai Chi practitioners and healthy controls in dual-task versus single-task paradigms, namely stepping down with and without performing an auditory response task, a cross-sectional study was conducted in the Center for East-meets-West in Rehabilitation Sciences at The Hong Kong Polytechnic University, Hong Kong. Twenty-eight Tai Chi practitioners (73.6 ± 4.2 years) and 30 healthy control subjects (72.4 ± 6.1 years) were recruited. Participants were asked to step down from a 19-cm-high platform and maintain a single-leg stance for 10 s with and without a concurrent cognitive task. The cognitive task was an auditory Stroop test in which the participants were required to respond to different tones of voices regardless of their word meanings. Postural stability after stepping down under single- and dual-task paradigms, in terms of excursion of the subject's center of pressure (COP) and cognitive performance, was measured for comparison between the two groups. Our findings demonstrated significant between-group differences in more outcome measures during dual-task than single-task performance. Thus, the auditory Stroop test showed that Tai Chi practitioners achieved not only significantly less error rate in single-task, but also significantly faster reaction time in dual-task, when compared with healthy controls similar in age and other relevant demographics. Similarly, the stepping-down task showed that Tai Chi practitioners not only displayed significantly less COP sway area in single-task, but also significantly less COP sway path than healthy controls in dual-task. These results showed that Tai Chi practitioners achieved better postural stability after stepping down as well as better performance in auditory response task than healthy controls. The improved performance that was magnified by dual motor-cognitive task performance may point to the benefits of Tai Chi being a mind-and-body exercise.

  15. Cross-Sectional Comparison of Executive Attention Function in Normally Aging Long-Term T'ai Chi, Meditation, and Aerobic Fitness Practitioners Versus Sedentary Adults

    PubMed Central

    Manselle, Wayne; Woollacott, Marjorie H.

    2014-01-01

    Abstract This cross-sectional field study documented the effect of long-term t'ai chi, meditation, or aerobic exercise training versus a sedentary lifestyle on executive function. It was predicted that long-term training in t'ai chi and meditation plus exercise would produce greater benefits to executive function than aerobic exercise. T'ai chi and meditation plus exercise include mental and physical training. Fifty-four volunteers were tested: t'ai chi (n=10); meditation+exercise (n=16); aerobic exercisers (n=16); and sedentary controls (n=12). A one-factor (group), one-covariate (age) multivariate analysis of covariance was performed. Significant main effects of group and age were found (group, 67.9%, p<0.001; age, 76.3%, p=0.001). T'ai chi and meditation practitioners but not aerobic exercisers outperformed sedentary controls on percent switch costs (p=0.001 and p=0.006, respectively), suggesting that there may be differential effects of training type on executive function. PMID:24286339

  16. Tai Chi and health-related quality of life in nursing home residents.

    PubMed

    Lee, Linda Y K; Lee, Diana T F; Woo, Jean

    2009-03-01

    Health-related quality of life (HRQOL) that is good is regarded as the goal of elderly residential care. However, limited evidence exists indicating a promising intervention that can achieve this goal. The aim of this study is to examine the effect of Tai Chi on HRQOL in nursing home residents. A nonequivalent pretest-posttest control-group design. A convenience sample of 139 residents from six nursing homes in Hong Kong was used. The experimental group (n=66) joined a 26-week Tai Chi program, while the control group (n=73) continued with usual daily activities. The physical and mental components of HRQOL were designated as the dependent variables. Resident satisfaction was considered as a covariate. Doubly multivariate repeated measures analysis of covariance was done to examine the intervention effect. After adjusting for the confounding effect of resident satisfaction, a statistically significant difference (p<0.05) in the physical and mental components of HRQOL between the experimental and control groups was found. Findings showed significant improvement in HRQOL after residents practiced Tai Chi. These investigators contribute additional knowledge about the health benefits of Tai Chi among nursing home residents and indicates support for its use in this population to improve HRQOL. Tai Chi has unique characteristics as a health exercise that is particularly suitable for nursing home residents. The inclusion of Tai Chi exercise in elderly residential care practice is recommended.

  17. Physical activity for osteoarthritis management: a randomized controlled clinical trial evaluating hydrotherapy or Tai Chi classes.

    PubMed

    Fransen, Marlene; Nairn, Lillias; Winstanley, Julie; Lam, Paul; Edmonds, John

    2007-04-15

    To determine whether Tai Chi or hydrotherapy classes for individuals with chronic symptomatic hip or knee osteoarthritis (OA) result in measurable clinical benefits. A randomized controlled trial was conducted among 152 older persons with chronic symptomatic hip or knee OA. Participants were randomly allocated for 12 weeks to hydrotherapy classes (n = 55), Tai Chi classes (n = 56), or a waiting list control group (n = 41). Outcomes were assessed 12 and 24 weeks after randomization and included pain and physical function (Western Ontario and McMaster Universities Osteoarthritis Index), general health status (Medical Outcomes Study Short Form 12 Health Survey [SF-12], version 2), psychological well-being, and physical performance (Up and Go test, 50-foot walk time, timed stair climb). At 12 weeks, compared with controls, participants allocated to hydrotherapy classes demonstrated mean improvements (95% confidence interval) of 6.5 (0.4, 12.7) and 10.5 (3.6, 14.5) for pain and physical function scores (range 0-100), respectively, whereas participants allocated to Tai Chi classes demonstrated improvements of 5.2 (-0.8, 11.1) and 9.7 (2.8, 16.7), respectively. Both class allocations achieved significant improvements in the SF-12 physical component summary score, but only allocation to hydrotherapy achieved significant improvements in the physical performance measures. All significant improvements were sustained at 24 weeks. In this almost exclusively white sample, class attendance was higher for hydrotherapy, with 81% attending at least half of the available 24 classes, compared with 61% for Tai Chi. Access to either hydrotherapy or Tai Chi classes can provide large and sustained improvements in physical function for many older, sedentary individuals with chronic hip or knee OA.

  18. Prevalence of Smoking and Obesity Among U.S. Cancer Survivors: Estimates From the National Health Interview Survey, 2008–2012

    PubMed Central

    Shoemaker, Meredith L.; White, Mary C.; Hawkins, Nikki A.; Hayes, Nikki S.

    2017-01-01

    Purpose/Objectives To describe smoking and obesity prevalence among male and female cancer survivors in the United States. Design Cross-sectional survey. Setting Household interviews. Sample 9,753 survey respondents who reported ever having a malignancy, excluding nonmelanoma skin cancers. Methods Data from the National Health Interview Survey (2008–2012) were used to calculate weighted smoking status prevalence estimates. Cross-tabulations of smoking and weight status were produced, along with Wald chi-square tests and linear contrasts. Main Research Variables Cancer history, smoking status, obesity status, gender, age, and age at diagnosis. Findings Seventeen percent of cancer survivors reported current smoking. Female survivors had higher rates of current smoking than males, particularly in the youngest age category. Male survivors who currently smoked had lower obesity prevalence rates than males who previously smoked or never smoked. Among female survivors, 31% were obese and no significant differences were seen in obesity prevalence by smoking status for all ages combined. Conclusions The findings highlight the variation in smoking status and weight by age and gender. Smoking interventions may need to be targeted to address barriers specific to subgroups of cancer survivors. Implications for Nursing Nurses can be instrumental in ensuring that survivors receive comprehensive approaches to address both weight and tobacco use to avoid trading one risk for another. PMID:27314186

  19. Changes in Consumer Attitudes toward Broad-Based and Environment-Specific Sodium Policies-SummerStyles 2012 and 2015.

    PubMed

    Odom, Erika C; Whittick, Corine; Tong, Xin; John, Katherine A; Cogswell, Mary E

    2017-08-04

    We examined temporal changes in consumer attitudes toward broad-based actions and environment-specific policies to limit sodium in restaurants, manufactured foods, and school and workplace cafeterias from the 2012 and 2015 SummerStyle surveys. We used two online, national research panel surveys to conduct a cross-sectional analysis of 7845 U.S. adults. Measures included self-reported agreement with broad-based actions and environment-specific policies to limit sodium in restaurants, manufactured foods, school cafeterias, workplace cafeterias, and quick-serve restaurants. Wald Chi-square tests were used to examine the difference between the two survey years and multivariate logistic regression was used to obtain odds ratios. Agreement with broad-based actions to limit sodium in restaurants (45.9% agreed in 2015) and manufactured foods (56.5% agreed in 2015) did not change between 2012 and 2015. From 2012 to 2015, there was a significant increase in respondents that supported environment-specific policies to lower sodium in school cafeterias (80.0% to 84.9%; p < 0.0001), workplace cafeterias (71.2% to 76.6%; p < 0.0001), and quick-serve restaurants (70.8% to 76.7%; p < 0.0001). Results suggest substantial agreement and support for actions to limit sodium in commercially-processed and prepared foods since 2012, with most consumers ready for actions to lower sodium in foods served in schools, workplaces, and quick-serve restaurants.

  20. Changes in Consumer Attitudes toward Broad-Based and Environment-Specific Sodium Policies—SummerStyles 2012 and 2015

    PubMed Central

    Odom, Erika C.; Whittick, Corine; Tong, Xin; Cogswell, Mary E.

    2017-01-01

    We examined temporal changes in consumer attitudes toward broad-based actions and environment-specific policies to limit sodium in restaurants, manufactured foods, and school and workplace cafeterias from the 2012 and 2015 SummerStyle surveys. We used two online, national research panel surveys to conduct a cross-sectional analysis of 7845 U.S. adults. Measures included self-reported agreement with broad-based actions and environment-specific policies to limit sodium in restaurants, manufactured foods, school cafeterias, workplace cafeterias, and quick-serve restaurants. Wald Chi-square tests were used to examine the difference between the two survey years and multivariate logistic regression was used to obtain odds ratios. Agreement with broad-based actions to limit sodium in restaurants (45.9% agreed in 2015) and manufactured foods (56.5% agreed in 2015) did not change between 2012 and 2015. From 2012 to 2015, there was a significant increase in respondents that supported environment-specific policies to lower sodium in school cafeterias (80.0% to 84.9%; p < 0.0001), workplace cafeterias (71.2% to 76.6%; p < 0.0001), and quick-serve restaurants (70.8% to 76.7%; p < 0.0001). Results suggest substantial agreement and support for actions to limit sodium in commercially-processed and prepared foods since 2012, with most consumers ready for actions to lower sodium in foods served in schools, workplaces, and quick-serve restaurants. PMID:28777339

  1. Comparative effectiveness of Tai Chi versus physical therapy for knee osteoarthritis: a randomized trial

    USDA-ARS?s Scientific Manuscript database

    Background: Few remedies effectively treat long-term pain and disability from knee osteoarthritis. Studies suggest that Tai Chi alleviates symptoms, but no trials have directly compared Tai Chi with standard therapies for osteoarthritis. Objective: To compare Tai Chi with standard physical therapy f...

  2. A retrospective clinical study of cervical restorations: longevity and failure-prognostic variables.

    PubMed

    Namgung, C; Rho, Y J; Jin, B H; Lim, B S; Cho, B H

    2013-01-01

    The aim of this retrospective clinical study was to compare the longevity of cervical restorations between resin composite (RC) and glass ionomer (GI) and to investigate variables predictive of their outcome. The clinical performance of the two restorative materials in function was compared using the ratings of the modified United States Public Health Service (USPHS) criteria. A total of 479 cervical restorations were included in the study. Ninety-one already-replaced restorations were reviewed from dental records. The other 388 restorations still in function were evaluated according to the modified USPHS criteria by two investigators. Longevity and prognostic variables were analyzed with the Kaplan-Meier survival analysis and multivariate Cox proportional hazard model. The clinical performances of the two materials were evaluated according to the ratings of the USPHS criteria and compared using the Pearson chi-square test and Fisher exact test. The longevity was not significantly different between RC and GI (median survival time, 10.4 ± 0.7 and 11.5 ± 1.1 years, respectively). The main reasons for failure were loss of retention (82.2%) and secondary caries (17.8%). The longevity of cervical restoration was significantly influenced by tooth group and operator group (Wald test, p<0.05), while material, gender, presence or absence of systemic diseases, arch, and reason for treatment did not affect the longevity. Contrary to the longevity, the clinical performance of RC was superior to GI in the criteria of retention, marginal discoloration, and marginal adaptation, but similar in secondary caries, wear, and postoperative sensitivity.

  3. Least Squares Metric, Unidimensional Scaling of Multivariate Linear Models.

    ERIC Educational Resources Information Center

    Poole, Keith T.

    1990-01-01

    A general approach to least-squares unidimensional scaling is presented. Ordering information contained in the parameters is used to transform the standard squared error loss function into a discrete rather than continuous form. Monte Carlo tests with 38,094 ratings of 261 senators, and 1,258 representatives demonstrate the procedure's…

  4. On the testing of Hardy-Weinberg proportions and equality of allele frequencies in males and females at biallelic genetic markers.

    PubMed

    Graffelman, Jan; Weir, Bruce S

    2018-02-01

    Standard statistical tests for equality of allele frequencies in males and females and tests for Hardy-Weinberg equilibrium are tightly linked by their assumptions. Tests for equality of allele frequencies assume Hardy-Weinberg equilibrium, whereas the usual chi-square or exact test for Hardy-Weinberg equilibrium assume equality of allele frequencies in the sexes. In this paper, we propose ways to break this interdependence in assumptions of the two tests by proposing an omnibus exact test that can test both hypotheses jointly, as well as a likelihood ratio approach that permits these phenomena to be tested both jointly and separately. The tests are illustrated with data from the 1000 Genomes project. © 2017 The Authors Genetic Epidemiology Published by Wiley Periodicals, Inc.

  5. Epigenetic Changes in Response to Tai Chi Practice: A Pilot Investigation of DNA Methylation Marks

    PubMed Central

    Ren, Hua; Collins, Veronica; Clarke, Sandy J.; Han, Jin-Song; Lam, Paul; Clay, Fiona; Williamson, Lara M.; Andy Choo, K. H.

    2012-01-01

    Tai chi exercise has been shown to improve physiological and psychosocial functions, well-being, quality of life, and disease conditions. The biological mechanisms by which tai chi exerts its holistic effects remain unknown. We investigated whether tai chi practice results in positive epigenetic changes at the molecular level. Design. The DNA methylation profiles of sixty CpG-dinucleotide marks in female tai chi practitioners (N = 237; 45–88 years old) who have been practising tai chi for three or more years were compared with those of age-matched control females (N = 263) who have never practised tai chi. Results. Six CpG marks originating from three different chromosomes reveal a significant difference (P < 0.05) between the two cohorts. Four marks show losses while two marks show gains in DNA methylation with age in the controls. In the tai chi cohort all six marks demonstrate significant slowing (by 5–70%) of the age-related methylation losses or gains observed in the controls, suggesting that tai chi practice may be associated with measurable beneficial epigenetic changes. Conclusions. The results implicate the potential use of DNA methylation as an epigenetic biomarker to better understand the biological mechanisms and the health and therapeutic efficacies of tai chi. PMID:22719790

  6. View of Corto Square Road from Corto Square. Buildings No. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of Corto Square Road from Corto Square. Buildings No. 27 at left, Building No. 25 at rear, and Building No. 26 at right. Parking areas on left and right, looking north - Easter Hill Village, Bordered by South Twenty-sixth Street, South Twenty-eighth Street, Hinkley Avenue, Foothill Avenue & Corto Square, Richmond, Contra Costa County, CA

  7. Change in perceived psychosocial status following a 12-week Tai Chi exercise programme.

    PubMed

    Taylor-Piliae, Ruth E; Haskell, William L; Waters, Catherine M; Froelicher, Erika Sivarajan

    2006-05-01

    This paper reports a study to examine change in psychosocial status following a 12-week Tai Chi exercise intervention among ethnic Chinese people with cardiovascular disease risk factors living in the United States of America. Regular participation in physical activity is associated with protection against cardioavascular disease, and improvements in physical and psychological health. Increasing amounts of scientific evidence suggests that mind-body exercise, such as Tai Chi, are related to improvements in mental health, emotional well-being, and stress reduction. No prior study has examined the effect of a Tai Chi exercise intervention on psychosocial status among people with cardiovascular disease risk factors. This was a quasi-experimental study. Participants attended a 60-minute Tai Chi exercise class three times per week for 12 weeks. Data were collected at baseline, 6 and 12 weeks following the intervention. Psychosocial status was assessed using Chinese versions of Cohen's Perceived Stress Scale, Profile of Mood States, Multidimensional Scale of Perceived Social Support, and Tai Chi exercise self-efficacy. A total of 39 participants, on average 66-year-old (+/-8.3), married (85%), Cantonese-speaking (97%), immigrants participated. The majority were women (69%), with < or =12 years education (87%). Statistically significant improvements in all measures of psychosocial status were found (P < or = 0.05) following the intervention. Improvement in mood state (eta2 = 0.12), and reduction in perceived stress (eta2 = 0.13) were found. In addition, Tai Chi exercise statistically significantly increased self-efficacy to overcome barriers to Tai Chi (eta2 = 0.19), confidence to perform Tai Chi (eta2 = 0.27), and perceived social support (eta2 = 0.12). Tai Chi was a culturally appropriate mind-body exercise for these older adults, with statistically significant psychosocial benefits observed over 12-weeks. Further research examining Tai Chi exercise using a randomized

  8. Comparative impacts of Tai Chi, balance training, and a specially-designed yoga program on balance in older fallers.

    PubMed

    Ni, Meng; Mooney, Kiersten; Richards, Luca; Balachandran, Anoop; Sun, Mingwei; Harriell, Kysha; Potiaumpai, Melanie; Signorile, Joseph F

    2014-09-01

    To compare the effect of a custom-designed yoga program with 2 other balance training programs. Randomized controlled trial. Research laboratory. A group of older adults (N=39; mean age, 74.15 ± 6.99 y) with a history of falling. Three different exercise interventions (Tai Chi, standard balance training, yoga) were given for 12 weeks. Balance performance was examined during pre- and posttest using field tests, including the 8-foot up-and-go test, 1-leg stance, functional reach, and usual and maximal walking speed. The static and dynamic balances were also assessed by postural sway and dynamic posturography, respectively. Training produced significant improvements in all field tests (P<.005), but group difference and time × group interaction were not detected. For postural sway, significant decreases in the area of the center of pressure with eyes open (P=.001) and eyes closed (P=.002) were detected after training. For eyes open, maximum medial-lateral velocity significantly decreased for the sample (P=.013). For eyes closed, medial-lateral displacement decreased for Tai Chi (P<.01). For dynamic posturography, significant improvements in overall score (P=.001), time on the test (P=.006), and 2 linear measures in lateral (P=.001) and anterior-posterior (P<.001) directions were seen for the sample. Yoga was as effective as Tai Chi and standard balance training for improving postural stability and may offer an alternative to more traditional programs. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  9. Simplified Estimation and Testing in Unbalanced Repeated Measures Designs.

    PubMed

    Spiess, Martin; Jordan, Pascal; Wendt, Mike

    2018-05-07

    In this paper we propose a simple estimator for unbalanced repeated measures design models where each unit is observed at least once in each cell of the experimental design. The estimator does not require a model of the error covariance structure. Thus, circularity of the error covariance matrix and estimation of correlation parameters and variances are not necessary. Together with a weak assumption about the reason for the varying number of observations, the proposed estimator and its variance estimator are unbiased. As an alternative to confidence intervals based on the normality assumption, a bias-corrected and accelerated bootstrap technique is considered. We also propose the naive percentile bootstrap for Wald-type tests where the standard Wald test may break down when the number of observations is small relative to the number of parameters to be estimated. In a simulation study we illustrate the properties of the estimator and the bootstrap techniques to calculate confidence intervals and conduct hypothesis tests in small and large samples under normality and non-normality of the errors. The results imply that the simple estimator is only slightly less efficient than an estimator that correctly assumes a block structure of the error correlation matrix, a special case of which is an equi-correlation matrix. Application of the estimator and the bootstrap technique is illustrated using data from a task switch experiment based on an experimental within design with 32 cells and 33 participants.

  10. All Square Chiliagonal Numbers

    ERIC Educational Resources Information Center

    A?iru, Muniru A.

    2016-01-01

    A square chiliagonal number is a number which is simultaneously a chiliagonal number and a perfect square (just as the well-known square triangular number is both triangular and square). In this work, we determine which of the chiliagonal numbers are perfect squares and provide the indices of the corresponding chiliagonal numbers and square…

  11. Kinematic and electromyographic analysis of the push movement in tai chi

    PubMed Central

    Chan, S; Luk, T; Hong, Y

    2003-01-01

    Background: Tai chi is a form of exercise derived from the martial art folk traditions of China. The force used in tai chi includes different principles of mechanical advantage. No studies on the kinematic features of tai chi exercise have been published. Objective: To analyse the kinematics and electromyographic characteristics of tai chi. Methods: An experienced tai chi master was asked to perform a sequence of basic movements: ward off, roll back, press, and push. The movements were videotaped and digitised using a motion analysis system. Electromyographic activities of the lumbar erector spinae, rectus femoris, medial hamstrings, and medial head of gastrocnemius were recorded by surface electrodes. The push movement data were analysed. Results: The medial hamstrings and medial head of gastrocnemius muscle groups maintained low activity, with higher electromyographic values in the lumbar erector spinae and substantially higher ones in the rectus femoris during the push movement. Both concentric and eccentric contractions occurred in muscles of the lower limbs, with eccentric contraction occurring mainly in the anti-gravity muscles such as the rectus femoris and the medial head of gastrocnemius. The forward and backward shifts in centre of gravity (CG) were mainly accomplished by increasing and decreasing respectively the joint angles of the bilateral lower limbs rather than by adopting a forward or backward postural lean. The path of the CG in the anteroposterior and mediolateral component was unique, and the sway or deviation from the path was small. The master maintained an upright posture and maintained a low CG (hips, knees, and ankles bent) while travelling slowly and steadily from one position to another. Conclusion: The eccentric muscle contraction of the lower limbs in the push movement of tai chi may help to strengthen the muscles. PMID:12893721

  12. Chi 3 dispersion in planar tantalum pentoxide waveguides in the telecommunications window.

    PubMed

    Chen, Ruiqi Y; Charlton, Martin D B; Lagoudakis, Pavlos G

    2009-04-01

    We report on the dispersion of the third-order nonlinear susceptibility (chi(3) or "Chi 3") in planar Ta2O5 waveguides in the telecommunications spectral window. We utilize the observation of third-harmonic generation under ultrashort pulsed excitation as a reference-free characterization method of chi(3) and obtain a large nonlinear coefficient, 2x10(-13) esu, at 1550 nm. Our observation of efficient third-harmonic generation in Ta2O5 waveguides in the telecoms window reveals the potential of this material system in high-speed integrated nonlinear optical switches.

  13. Preliminary findings of a 4-month Tai Chi intervention on tenderness, functional capacity, symptomatology, and quality of life in men with fibromyalgia.

    PubMed

    Carbonell-Baeza, Ana; Romero, Alejandro; Aparicio, Virginia A; Ortega, Francisco B; Tercedor, Pablo; Delgado-Fernández, Manuel; Ruiz, Jonatan R

    2011-09-01

    The study aimed to determine the effects of a 4-month Tai Chi intervention on tenderness, functional capacity, symptomatology, and quality of life in men with fibromyalgia. The effect of a 3-month detraining period was also analyzed. Six men with fibromyalgia (age 52.3 ± 9.3 years) followed a 4-month Tai Chi intervention. The outcome variables were tenderness, functional capacity (30-second chair stand, handgrip strength, chair sit and reach, back scratch, blind flamingo, 8 feet up and go, and 6-minute walk tests), and self-administered questionnaires. A significant improvement (p = .028) after the intervention period for the chair sit and reach test was found, such improvement was maintained after the detraining phase. Tenderness, symptomatology, and quality of life did not significantly change after the intervention period or the detraining phase. In summary, a 4-month Tai Chi intervention improved lower body flexibility in men with fibromyalgia. This improvement persisted after the detraining period.

  14. Least squares regression methods for clustered ROC data with discrete covariates.

    PubMed

    Tang, Liansheng Larry; Zhang, Wei; Li, Qizhai; Ye, Xuan; Chan, Leighton

    2016-07-01

    The receiver operating characteristic (ROC) curve is a popular tool to evaluate and compare the accuracy of diagnostic tests to distinguish the diseased group from the nondiseased group when test results from tests are continuous or ordinal. A complicated data setting occurs when multiple tests are measured on abnormal and normal locations from the same subject and the measurements are clustered within the subject. Although least squares regression methods can be used for the estimation of ROC curve from correlated data, how to develop the least squares methods to estimate the ROC curve from the clustered data has not been studied. Also, the statistical properties of the least squares methods under the clustering setting are unknown. In this article, we develop the least squares ROC methods to allow the baseline and link functions to differ, and more importantly, to accommodate clustered data with discrete covariates. The methods can generate smooth ROC curves that satisfy the inherent continuous property of the true underlying curve. The least squares methods are shown to be more efficient than the existing nonparametric ROC methods under appropriate model assumptions in simulation studies. We apply the methods to a real example in the detection of glaucomatous deterioration. We also derive the asymptotic properties of the proposed methods. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Tai Chi exercise and the improvement of health and well-being in older adults.

    PubMed

    Yau, Matthew Kwai-sang

    2008-01-01

    Activity participation has a positive impact on both quantity and quality of life (QOL). Regular participations in physical, social, and cultural activities are associated with successful aging. There is considerable evidence that Tai Chi has positive health benefits; physical, psychosocial and therapeutic. Furthermore, Tai Chi does not only consist of a physical component, but also sociocultural, meditative components that are believed to contribute to overall well-being. This chapter describes the benefits of Tai Chi exercise for the older adults, particularly in terms of the psychosocial aspect. The perceived meanings, associated values and well-being, as well as the impact on QOL, of Tai Chi practice among the older adults in Hong Kong are also discussed. Tai Chi exercise is chosen by the elderly participants for its gentle and soft movements. Besides the physical aspect, the benefits they describe include lifestyle issues, as well as psychological and social benefits. Evidence points out that the improvements in physical and mental health through the practice of Tai Chi among the older adults are related to their perceived level of QOL. Findings from numerous studies support the belief that the practice of Tai Chi has multiple benefits to practitioners that are not only physical in nature. It is recommended as a strategy to promote successful aging.

  16. Observation of the $$\\chi_\\mathrm{b1}$$(3P) and $$\\chi_\\mathrm{b2}$$(3P) and measurement of their masses

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sirunyan, Albert M; et al.

    Themore » $$\\chi_\\mathrm{b1}$$(3P) and $$\\chi_\\mathrm{b3}$$(3P) states are observed through their $$\\Upsilon$$(3S) $$\\gamma$$ decays, using an event sample of proton-proton collisions collected by the CMS experiment at the CERN LHC. data were collected at a center-of-mass energy of 13 TeV and correspond to an integrated luminosity of 80.0 fb$$^{-1}$$. $$\\Upsilon$$(3S) mesons are identified through their dimuon decay channel, while the low-energy photons are detected after converting to e$^+$e$^-$ pairs in the silicon tracker, leading to a $$\\chi_\\mathrm{b}$$(3P) mass resolution of 2.2 MeV. This is the first time that the $J =$ 1 and 2 states are well resolved and their masses individually measured: 10$$\\,$$513.42 $$\\pm$$ 0.41 (stat) $$\\pm$$ 0.18 (syst) MeV and 10$$\\,$$524.02 $$\\pm$$ 0.57 (stat) $$\\pm$$ 0.18 (syst) MeV; they are determined with respect to the world-average value of the $$\\Upsilon$$(3S) mass, which has an uncertainty of 0.5 MeV. mass splitting is measured to be 10.60 $$\\pm$$ 0.64 (stat) $$\\pm$$ 0.17 (syst) MeV.« less

  17. Foot forces induced through Tai Chi push-hand exercises.

    PubMed

    Wong, Shiu Hong; Ji, Tianjian; Hong, Youlian; Fok, Siu Lun; Wang, Lin

    2013-08-01

    The low impact forces of Tai Chi push-hand exercises may be particularly suited for older people and for those with arthritis; however, the biomechanics of push-hand exercises have not previously been reported. This paper examines the ground reaction forces (GRFs) and plantar force distributions during Tai Chi push-hand exercises in a stationary stance with and without an opponent. Ten male Tai Chi practitioners participated in the study. The GRFs of each foot were measured in three perpendicular directions using two force plates (Kistler). The plantar force distribution of each foot was measured concurrently using an insole sensor system (Novel). The results showed that the average maximum vertical GRF of each foot was not more than 88% ± 6.1% of the body weight and the sum of the vertical forces (103% ± 1.4%) generated by the two feet approximately equals the body weight at any one time. The horizontal GRFs generated by the two feet were in the opposite directions and the measured mean peak values were not more than 12% ± 2.8% and 17% ± 4.3% of the body weight in the medio-lateral and antero-posterior directions respectively. Among the nine plantar areas, the toes sustained the greatest plantar force. This study indicates that push-hand exercises generate lower vertical forces than those induced by walking, bouncing, jumping and Tai Chi gait, and that the greatest plantar force is located in the toe area, which may have an important application in balance training particularly for older adults.

  18. Effectiveness of Tai-Chi for decreasing acute pain in fibromyalgia patients.

    PubMed

    Segura-Jiménez, V; Romero-Zurita, A; Carbonell-Baeza, A; Aparicio, V A; Ruiz, J R; Delgado-Fernández, M

    2014-05-01

    Tai-Chi has shown benefits in physical and psychological outcomes in diverse populations. We aimed to determine the changes elicited by a Tai-Chi program (12 and 24 weeks) in acute pain (before vs. after session) in fibromyalgia patients. We also assessed the cumulative changes in pain brought about by a Tai-Chi program. Thirty-six patients (29 women) with fibromyalgia participated in a low-moderate intensity Tai-Chi program for 12 weeks (3 sessions/week). Twenty-eight patients (27 women) continued the program for an additional 12 weeks (i. e., 24 weeks). We assessed pain by means of a Visual Analogue Scale (VAS) before and after each single session (i. e., 72 sessions). We observed significant immediate changes (P-values from 0.037 to 0.0001) with an approximately 12% mean decrease of acute pain in the comparison of VAS-values before and after each session (72 sessions in total), with the exception of 4 sessions. We observed significant changes in cumulative pain pre-session (95% CI=-0.019; -0.014; P<0.001) and cumulative pain post-session (95% CI=-0.021; -0.015; P<0.001) along the 24-week intervention only. In conclusion, a low-moderate intensity Tai-Chi program for 12 weeks (3 times/week) decreased levels of acute pain in fibromyalgia patients. A longer period is necessary (e. g. 24 weeks) for observing cumulative changes in pain. © Georg Thieme Verlag KG Stuttgart · New York.

  19. The Listeria monocytogenes ChiA Chitinase Enhances Virulence through Suppression of Host Innate Immunity

    PubMed Central

    Chaudhuri, Swarnava; Gantner, Benjamin N.; Ye, Richard D.; Cianciotto, Nicholas P.; Freitag, Nancy E.

    2013-01-01

    ABSTRACT Environmental pathogens survive and replicate within the outside environment while maintaining the capacity to infect mammalian hosts. For some microorganisms, mammalian infection may be a relatively rare event. Understanding how environmental pathogens retain their ability to cause disease may provide insight into environmental reservoirs of disease and emerging infections. Listeria monocytogenes survives as a saprophyte in soil but is capable of causing serious invasive disease in susceptible individuals. The bacterium secretes virulence factors that promote cell invasion, bacterial replication, and cell-to-cell spread. Recently, an L. monocytogenes chitinase (ChiA) was shown to enhance bacterial infection in mice. Given that mammals do not synthesize chitin, the function of ChiA within infected animals was not clear. Here we have demonstrated that ChiA enhances L. monocytogenes survival in vivo through the suppression of host innate immunity. L. monocytogenes ΔchiA mutants were fully capable of establishing bacterial replication within target organs during the first 48 h of infection. By 72 to 96 h postinfection, however, numbers of ΔchiA bacteria diminished, indicative of an effective immune response to contain infection. The ΔchiA-associated virulence defect could be complemented in trans by wild-type L. monocytogenes, suggesting that secreted ChiA altered a target that resulted in a more permissive host environment for bacterial replication. ChiA secretion resulted in a dramatic decrease in inducible nitric oxide synthase (iNOS) expression, and ΔchiA mutant virulence was restored in NOS2−/− mice lacking iNOS. This work is the first to demonstrate modulation of a specific host innate immune response by a bacterial chitinase. PMID:23512964

  20. Efficacy and Safety of Tai Chi for Parkinson's Disease: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

    PubMed Central

    Ni, Xiaojia; Liu, Shaonan; Lu, Fuchang; Shi, Xiaogeng; Guo, Xinfeng

    2014-01-01

    Background and Objective In Parkinson's disease (PD), wearing off and side effects of long-term medication and complications pose challenges for neurologists. Although Tai Chi is beneficial for many illnesses, its efficacy for PD remains uncertain. The purpose of this review was to evaluate the efficacy and safety of Tai Chi for PD. Methods Randomized controlled trials (RCTs) of Tai Chi for PD were electronically searched by the end of December 2013 and identified by two independent reviewers. The tool from the Cochrane Handbook 5.1 was used to assess the risk of bias. A standard meta-analysis was performed using RevMan 5.2 software. Results Ten trials with PD of mild-to-moderate severity were included in the review, and nine trials (n = 409) were included in the meta-analysis. The risk of bias was generally high in the blinding of participants and personnel. Improvements in the Unified Parkinson's Disease Rating Scale Part III (mean difference (MD) −4.34, 95% confidence interval (CI) −6.67–−2.01), Berg Balance Scale (MD: 4.25, 95% CI: 2.83–5.66), functional reach test (MD: 3.89, 95% CI: 1.73–6.04), Timed Up and Go test (MD: −0.75, 95% CI: −1.30–−0.21), stride length (standardized MD: 0.56, 95% CI: 0.03–1.09), health-related quality of life (standardized MD: −1.10, 95% CI: −1.81–−0.39) and reduction of falls were greater after interventions with Tai Chi plus medication. Satisfaction and safety were high. Intervention with Tai Chi alone was more effective for only a few balance and mobility outcomes. Conclusions Tai Chi performed with medication resulted in promising gains in mobility and balance, and it was safe and popular among PD patients at an early stage of the disease. This provides a new evidence for PD management. More RCTs with larger sample size that carefully address blinding and prudently select outcomes are needed. PROSPERO registration number CRD42013004989. PMID:24927169

  1. Two-dimensional Co-Seismic Surface Displacements Field of the Chi-Chi Earthquake Inferred from SAR Image Matching.

    PubMed

    Hu, Jun; Li, Zhi-Wei; Ding, Xiao-Li; Zhu, Jian-Jun

    2008-10-21

    The M w =7.6 Chi-Chi earthquake in Taiwan occurred in 1999 over the Chelungpu fault and caused a great surface rupture and severe damage. Differential Synthetic Aperture Radar Interferometry (DInSAR) has been applied previously to study the co-seismic ground displacements. There have however been significant limitations in the studies. First, only one-dimensional displacements along the Line-of-Sight (LOS) direction have been measured. The large horizontal displacements along the Chelungpu fault are largely missing from the measurements as the fault is nearly perpendicular to the LOS direction. Second, due to severe signal decorrelation on the hangling wall of the fault, the displacements in that area are un-measurable by differential InSAR method. We estimate the co-seismic displacements in both the azimuth and range directions with the method of SAR amplitude image matching. GPS observations at the 10 GPS stations are used to correct for the orbital ramp in the amplitude matching and to create the two-dimensional (2D) co-seismic surface displacements field using the descending ERS-2 SAR image pair. The results show that the co-seismic displacements range from about -2.0 m to 0.7 m in the azimuth direction (with the positive direction pointing to the flight direction), with the footwall side of the fault moving mainly southwards and the hanging wall side northwards. The displacements in the LOS direction range from about -0.5 m to 1.0 m, with the largest displacement occuring in the northeastern part of the hanging wall (the positive direction points to the satellite from ground). Comparing the results from amplitude matching with those from DInSAR, we can see that while only a very small fraction of the LOS displacement has been recovered by the DInSAR mehtod, the azimuth displacements cannot be well detected with the DInSAR measurements as they are almost perpendicular to the LOS. Therefore, the amplitude matching method is obviously more advantageous than the

  2. Gain Shift Corrections at Chi-Nu

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Brown, Tristan Brooks; Devlin, Matthew James

    Ambient conditions have the potential to cause changes in liquid scintillator detector gain that vary with time and temperature. These gain shifts can lead to poor resolution in both energy as well as pulse shape discrimination. In order to correct for these shifts in the Chi-Nu high energy array, a laser system has been developed for calibration of the pulse height signals.

  3. Discrete square root smoothing.

    NASA Technical Reports Server (NTRS)

    Kaminski, P. G.; Bryson, A. E., Jr.

    1972-01-01

    The basic techniques applied in the square root least squares and square root filtering solutions are applied to the smoothing problem. Both conventional and square root solutions are obtained by computing the filtered solutions, then modifying the results to include the effect of all measurements. A comparison of computation requirements indicates that the square root information smoother (SRIS) is more efficient than conventional solutions in a large class of fixed interval smoothing problems.

  4. SQUARE WAVE AMPLIFIER

    DOEpatents

    Leavitt, M.A.; Lutz, I.C.

    1958-08-01

    An amplifier circuit is described for amplifying sigmals having an alternating current component superimposed upon a direct current component, without loss of any segnnent of the alternating current component. The general circuit arrangement includes a vibrator, two square wave amplifiers, and recombination means. The amplifier input is connected to the vibrating element of the vibrator and is thereby alternately applied to the input of each square wave amplifier. The detailed circuitry of the recombination means constitutes the novelty of the annplifier and consists of a separate, dual triode amplifier coupled to the output of each square wave amplifier with a recombination connection from the plate of one amplifier section to a grid of one section of the other amplifier. The recombination circuit has provisions for correcting distortion caused by overlapping of the two square wave voltages from the square wave amplifiers.

  5. Magic with Magic Squares.

    ERIC Educational Resources Information Center

    Wills, Herbert III

    1989-01-01

    Describes ways to make magic squares of 4 by 4 matrices. Presents two handouts: (1) Sets of 4 Numbers from 1 to 16 Whose Sum is 34; and (2) The Durer Square. Shows patterns which appeared in the magic squares, such as squares, chevrons, rhomboids, and trapezoids. (YP)

  6. Candidate SNP of CACNA2D1 Gene Associated with Clinical Mastitis and Production Traits in Sahiwal (Bos taurus indicus) and Karan Fries (Bos taurus taurus × Bos taurus indicus).

    PubMed

    Magotra, Ankit; Gupta, I D; Verma, Archana; Alex, Rani; Mr, Vineeth; Ahmad, Tavsief

    2018-02-20

    The present study was conducted to identify polymorphisms in CACNA2D1 gene and their association with clinical mastitis and production traits. Exon 18 and its flanking regions were screened for the presence of SNPs. Statistical analysis was performed to identify association of period of birth, breed, and genotype with mastitis incidence on randomly selected 103 Sahiwal and 102 Karan Fries cattle. PCR-RFLP analysis revealed that g.38819398G > A mutation in exon 18 (269 bp amplicon) of CACNA2D1 gene resolved into AA, AG, and GG genotypes in Sahiwal and Karan Fries cattle. Wald chi-square analysis revealed that the period of birth, breed, and genotype were significantly associated with mastitis incidence. GG genotyped cattle were found to be less susceptible to mastitis. Least square analysis revealed that GG and AG genotype animals of G38819398A SNP of CACNA2D1 gene in Sahiwal as well as in Karan Fries cattle were associated with higher average milk yields during 1st, 2nd, and 3rd lactations (P < 0.01). These observations and their differential association with the incidence of mastitis and production traits can be utilized as an aid to selection for simultaneous improvement of both antagonistic traits; however, validation of results on large number of animals is warranted.

  7. Weighted Least Squares Fitting Using Ordinary Least Squares Algorithms.

    ERIC Educational Resources Information Center

    Kiers, Henk A. L.

    1997-01-01

    A general approach for fitting a model to a data matrix by weighted least squares (WLS) is studied. The approach consists of iteratively performing steps of existing algorithms for ordinary least squares fitting of the same model and is based on maximizing a function that majorizes WLS loss function. (Author/SLD)

  8. Sex differences in the effect of birth order and parents' educational status on stunting: a study on Bengalee preschool children from eastern India.

    PubMed

    Biswas, Sadaruddin; Bose, Kaushik

    2010-08-01

    One of the greatest problems facing developing countries, including rural India, is undernutrition in terms of stunting among under 5-year-old children. However, there exists scanty information on the prevalence of stunting among preschool children in India and in particular in West Bengal. This study investigated prevalence of stunting and identified the predictor(s) of stunting among 1-5-year-old Bengalee rural preschool children of Integrated Child Development Services (ICDS) centres. This cross-sectional study was undertaken at different ICDS centres of Chapra Block, Nadia District, West Bengal, India. A total of 673 preschool children (323 boys and 350 girls), aged 1-5 years were selected from 30 randomly selected ICDS centres to study the impact of parents' educational status and child birth order on stunting. The overall (age and sex combined) rate of stunting was 39.2%. Child birth order (BO) (chi(2)=14.10, df=1, p<0.001), father educational status (FES) (chi(2)=21.11, p<0.001) and mother educational status (MES) (chi(2)=14.34, df=1, p>0.001) were significantly associated with the prevalence of stunting among girls. Logistic regression analyses revealed that both FES (Wald=19.97, p<0.001) as well as MES (Wald=13.95, p<0.001) were strong predictors of stunting among girls. Similarly BO (Wald=13.71, p<0.001) was a strong predictor of stunting among girls. Girls with >or=3rd BO had significantly higher risk (OR=2.49, CI=1.54-4.03) of stunting than those with or=secondary level. Similarly, girls with MESor=secondary level. In conclusion our study revealed that BO as well as parents' educational status were strong predictors of stunting among girls but not boys. Sex discrimination could be a likely cause for this

  9. Measurements of dynamo effect on double-CHI pulse ST plasmas on HIST

    NASA Astrophysics Data System (ADS)

    Ito, K.; Hanao, T.; Ishihara, M.; Matsumoto, K.; Higashi, T.; Kikuchi, Y.; Fukumoto, N.; Nagata, M.

    2011-10-01

    Coaxial Helicity injection (CHI) is an efficient current-drive method used in spheromak and spherical torus (ST) experiments. An anticipated issue for CHI is achieving good energy confinement, since it relies on the magnetic relaxation and dynamo. This is essentially because CHI cannot drive a dynamo directly inside a closed magnetic flux surface. Thus, it is an important issue to investigate dynamo effect to explore CHI current drive mechanisms in a new approach such as Multi-pulsing CHI method. To study the dynamo model with two-fluid Hall effects, we have started from the generalized Ohm law. We have measured each MHD dynamo term and Hall dynamo term separately by using Mach probe and Hall probe involving 3-axis magnetic pick-up coils. The result shows that the induced electric field due to MHD dynamo is large enough to sustain the mean toroidal current against resistive decay in the core region. In the other hand, the anti-dynamo effect in the MHD dynamo term is observed in the central open flux column (OFC) region. From the viewpoint of two-fluid theory, ion diamagnetic drift is opposite to the electron diamagnetic drift, maybe resulting in the anti-dynamo effect. Hall dynamo may arise from the fluctuating electron diamagnetic current due to high electron density gradient which is large in the OFC region.

  10. Ethnic Comparisons in HIV Testing Attitudes, HIV Testing, and Predictors of HIV Testing Among Black and White College Students.

    PubMed

    Moore, Melanie P; Javier, Sarah J; Abrams, Jasmine A; McGann, Amanda Wattenmaker; Belgrave, Faye Z

    2017-08-01

    This study's primary aim was to examine ethnic differences in predictors of HIV testing among Black and White college students. We also examined ethnic differences in sexual risk behaviors and attitudes toward the importance of HIV testing. An analytic sample of 126 Black and 617 White undergraduatestudents aged 18-24 were analyzed for a subset of responses on the American College Health Association-National College Health Assessment II (ACHA-NCHA II) (2012) pertaining to HIV testing, attitudes about the importance of HIV testing, and sexual risk behaviors. Predictors of HIV testing behavior were analyzed using logistic regression. t tests and chi-square tests were performed to access differences in HIV test history, testing attitudes, and sexual risk behaviors. Black students had more positive attitudes toward testing and were more likely to have been tested for HIV compared to White students. A greater number of sexual partners and more positive HIV testing attitudes were significant predictors of HIV testing among White students, whereas relationship status predicted testing among Black students. Older age and history of ever having sex were significant predictors of HIV testing for both groups. There were no significant differences between groups in number of sexual partners or self-reports in history of sexual experience (oral, vaginal, or anal). Factors that influence HIV testing may differ across racial/ethnic groups. Findings support the need to consider racial/ethnic differences in predictors of HIV testing during the development and tailoring of HIV testing prevention initiatives targeting college students.

  11. Variables Measured during Cardiopulmonary Exercise Testing as Predictors of Mortality in Chronic Systolic Heart Failure

    PubMed Central

    Keteyian, Steven J.; Patel, Mahesh; Kraus, William E.; Brawner, Clinton A.; McConnell, Timothy R.; Piña, Ileana L.; Leifer, Eric S.; Fleg, Jerome L.; Blackburn, Gordon; Fonarow, Gregg C.; Chase, Paul J.; Piner, Lucy; Vest, Marianne; O’Connor, Christopher M.; Ehrman, Jonathan K.; Walsh, Mary N.; Ewald, Gregory; Bensimhon, Dan; Russell, Stuart D.

    2015-01-01

    BACKGROUND Data from a cardiopulmonary exercise (CPX) test are used to determine prognosis in patients with chronic heart failure (HF). However, few published studies have simultaneously compared the relative prognostic strength of multiple CPX variables. OBJECTIVES We sought to describe the strength of the association among variables measured during a CPX test and all-cause mortality in patients with HF with reduced ejection fraction (HFrEF), including the influence of sex and patient effort, as measured by respiratory exchange ratio (RER). METHODS Among patients (n = 2,100, 29% women) enrolled in the HF-ACTION (HF-A Controlled Trial Investigating Outcomes of exercise traiNing) trial, 10 CPX test variables measured at baseline (e.g., peak oxygen uptake [VO2], exercise duration, percent predicted peak VO2 [%ppVO2], ventilatory efficiency) were examined. RESULTS Over a median follow-up of 32 months, there were 357 deaths. All CPX variables, except RER, were related to all-cause mortality (all p < 0.0001). Both %ppVO2 and exercise duration were equally able to predict (Wald χ2: ~141) and discriminate (c-index: 0.69) mortality. Peak VO2 (mL·kg−1·min−1) was the strongest predictor of mortality among men (Wald χ2: 129) and exercise duration among women (Wald χ2: 41). Multivariable analyses showed that %ppVO2, exercise duration, and peak VO2 (mL·kg−1·min−1) were similarly able to predict and discriminate mortality. In men, a 10% 1-year mortality rate corresponded to a peak VO2 of 10.9 mL·kg−1·min−1 versus 5.3 mlkg−1/min−1 in women. CONCLUSIONS Peak VO2, exercise duration, and % ppVO2 carried the strongest ability to predict and discriminate the likelihood of death in patients with HFrEF. The prognosis associated with a given peak V2 differed by sex. PMID:26892413

  12. The effects of Tai-Chi in conjunction with thera-band resistance exercise on functional fitness and muscle strength among community-based older people.

    PubMed

    Lin, Shu-Fen; Sung, Huei-Chuan; Li, Tzai-Li; Hsieh, Tsung-Cheng; Lan, Hsiao-Chin; Perng, Shoa-Jen; Smith, Graeme D

    2015-05-01

    The aim of this study was to investigate the effects of Tai-Chi in conjunction with thera-band resistance exercise on functional fitness and muscle strength in community-based older people. Tai-Chi is known to improve functional fitness in older people. Tai-Chi is usually performed with free hands without resistance training and usually focuses on training lower limbs. To date, no study has examined the use of Tai-Chi in conjunction with thera-band resistance exercise in this population. Cluster randomised trial design. Older people at six senior day care centres in Taiwan were assigned to thera-band resistance exercise or control group using a cluster randomisation. The thera-band resistance exercise group (n = 48) received sixty minute thera-band resistance exercise twice weekly for a period of 16 weeks. The control group (n = 47) underwent routine activities in the day care centre, receiving no Tai-Chi or resistance exercise. After receiving the thera-band resistance exercise, intervention participants displayed a significant increase in muscle strength of upper and lower extremities. Significant improvements were recorded on most measures of the Senior Fitness Test, with the exception of the chair-stand and back-scratch test. Thera-band resistance exercise has the potential to improve functional fitness and muscle strength in community-based older people. Thera-band resistance exercise potentially offers a safe and appropriate form of physical activity that nursing staff can easily incorporate into the daily routine of older people in day care centres, potentially improving functional performance and muscle strength. © 2015 John Wiley & Sons Ltd.

  13. Robust Satellite Techniques (RST) for monitoring earthquake prone areas by satellite TIR observations: The case of 1999 Chi-Chi earthquake (Taiwan)

    NASA Astrophysics Data System (ADS)

    Genzano, N.; Filizzola, C.; Paciello, R.; Pergola, N.; Tramutoli, V.

    2015-12-01

    different years (from 1995 to 2002). In this dataset the Chi-Chi earthquake (MW = 7.6) which occurred on September 20, 1999 represents the major, but not unique, event. The analysis shows that all identified SSTAs occur in the pre-fixed space-time window around (in terms of time and location) earthquakes with M > 4. The false positive rate remains zero even if only earthquakes with M > 4.5 are considered. In the case of the Chi-Chi earthquake, 3 SSTAs were identified (all within the established space-time correlation window), one of them appearing about 2 weeks before and very close to the epicentre of the earthquake just along the associated tectonic lineaments. The wide considered space-time window, together with the high seismicity of the considered area, surely positively conditioned the achieved results, so that further analyses should be carried out by using longer datasets and different geographic areas. However, also considering the coincidence with other (possible) precursor phenomena, independently reported (particularly within the iSTEP project) at the time of the Chi Chi earthquake, achieved results seem already sufficient (at least) to qualify TIR anomalies (identified by RST) among the parameters to be considered in the framework of a multi-parametric approach to a time-Dependent Assessment of Seismic Hazard (t-DASH).

  14. Comparative Effectiveness of Tai Chi Versus Physical Therapy for Knee Osteoarthritis: A Randomized Trial.

    PubMed

    Wang, Chenchen; Schmid, Christopher H; Iversen, Maura D; Harvey, William F; Fielding, Roger A; Driban, Jeffrey B; Price, Lori Lyn; Wong, John B; Reid, Kieran F; Rones, Ramel; McAlindon, Timothy

    2016-07-19

    Few remedies effectively treat long-term pain and disability from knee osteoarthritis. Studies suggest that Tai Chi alleviates symptoms, but no trials have directly compared Tai Chi with standard therapies for osteoarthritis. To compare Tai Chi with standard physical therapy for patients with knee osteoarthritis. Randomized, 52-week, single-blind comparative effectiveness trial. (ClinicalTrials.gov: NCT01258985). An urban tertiary care academic hospital. 204 participants with symptomatic knee osteoarthritis (mean age, 60 years; 70% women; 53% white). Tai Chi (2 times per week for 12 weeks) or standard physical therapy (2 times per week for 6 weeks, followed by 6 weeks of monitored home exercise). The primary outcome was Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score at 12 weeks. Secondary outcomes included physical function, depression, medication use, and quality of life. At 12 weeks, the WOMAC score was substantially reduced in both groups (Tai Chi, 167 points [95% CI, 145 to 190 points]; physical therapy, 143 points [CI, 119 to 167 points]). The between-group difference was not significant (24 points [CI, -10 to 58 points]). Both groups also showed similar clinically significant improvement in most secondary outcomes, and the benefits were maintained up to 52 weeks. Of note, the Tai Chi group had significantly greater improvements in depression and the physical component of quality of life. The benefit of Tai Chi was consistent across instructors. No serious adverse events occurred. Patients were aware of their treatment group assignment, and the generalizability of the findings to other settings remains undetermined. Tai Chi produced beneficial effects similar to those of a standard course of physical therapy in the treatment of knee osteoarthritis. National Center for Complementary and Integrative Health of the National Institutes of Health.

  15. Effectiveness of a tai-chi training and detraining on functional capacity, symptomatology and psychological outcomes in women with fibromyalgia.

    PubMed

    Romero-Zurita, Alejandro; Carbonell-Baeza, Ana; Aparicio, Virginia A; Ruiz, Jonatan R; Tercedor, Pablo; Delgado-Fernández, Manuel

    2012-01-01

    Background. The purpose was to analyze the effects of Tai-Chi training in women with fibromyalgia (FM). Methods. Thirty-two women with FM (mean age, 51.4 ± 6.8 years) attended to Tai-Chi intervention 3 sessions weekly for 28 weeks. The outcome measures were: tenderness, body composition, functional capacity and psychological outcomes (Fibromyalgia impact questionnaire (FIQ), Short Form Health Survey 36 (SF-36)). Results. Patients showed improvements on pain threshold, total number of tender points and algometer score (all P < 0.001). The intervention was effective on 6-min walk (P = 0.006), back scratch (P = 0.002), handgrip strength (P = 0.006), chair stand, chair sit & reach, 8 feet up & go and blind flamingo tests (all P < 0.001). Tai-Chi group improved the FIQ total score (P < 0.001) and six subscales: stiffness (P = 0.005), pain, fatigue, morning tiredness, anxiety, and depression (all P < 0.001). The intervention was also effective in six SF-36 subscales: bodily pain (P = 0.003), vitality (P = 0.018), physical functioning, physical role, general health, and mental health (all P < 0.001). Conclusions. A 28-week Tai-Chi intervention showed improvements on pain, functional capacity, symptomatology and psychological outcomes in female FM patients.

  16. Effectiveness of a Tai-Chi Training and Detraining on Functional Capacity, Symptomatology and Psychological Outcomes in Women with Fibromyalgia

    PubMed Central

    Romero-Zurita, Alejandro; Carbonell-Baeza, Ana; Aparicio, Virginia A.; Ruiz, Jonatan R.; Tercedor, Pablo; Delgado-Fernández, Manuel

    2012-01-01

    Background. The purpose was to analyze the effects of Tai-Chi training in women with fibromyalgia (FM). Methods. Thirty-two women with FM (mean age, 51.4 ± 6.8 years) attended to Tai-Chi intervention 3 sessions weekly for 28 weeks. The outcome measures were: tenderness, body composition, functional capacity and psychological outcomes (Fibromyalgia impact questionnaire (FIQ), Short Form Health Survey 36 (SF-36)). Results. Patients showed improvements on pain threshold, total number of tender points and algometer score (all P < 0.001). The intervention was effective on 6-min walk (P = 0.006), back scratch (P = 0.002), handgrip strength (P = 0.006), chair stand, chair sit & reach, 8 feet up & go and blind flamingo tests (all P < 0.001). Tai-Chi group improved the FIQ total score (P < 0.001) and six subscales: stiffness (P = 0.005), pain, fatigue, morning tiredness, anxiety, and depression (all P < 0.001). The intervention was also effective in six SF-36 subscales: bodily pain (P = 0.003), vitality (P = 0.018), physical functioning, physical role, general health, and mental health (all P < 0.001). Conclusions. A 28-week Tai-Chi intervention showed improvements on pain, functional capacity, symptomatology and psychological outcomes in female FM patients. PMID:22649476

  17. Squared Euclidean distance: a statistical test to evaluate plant community change

    Treesearch

    Raymond D. Ratliff; Sylvia R. Mori

    1993-01-01

    The concepts and a procedure for evaluating plant community change using the squared Euclidean distance (SED) resemblance function are described. Analyses are based on the concept that Euclidean distances constitute a sample from a population of distances between sampling units (SUs) for a specific number of times and SUs. With different times, the distances will be...

  18. Two-fluid equilibrium transition during multi-pulsing CHI in spherical torus

    NASA Astrophysics Data System (ADS)

    Kanki, T.; Nagata, M.

    2015-11-01

    Two-fluid dynamo current drive has been studied to achieve a quasi-steady sustainment and good confinement of spherical torus (ST) plasmas by multi-pulsing CHI (M-CHI) in the HIST device. The density gradient, poloidal flow shear, and radial electric shear enhanced by applying the second CHI pulse is observed around the separatrix in the high field side to cause not only the ExB drift but also the ion diamagnetic drift, leading the two-fluid dynamo. The two-fluid equilibrium transition during the M-CHI in the ST is investigated by modelling the M-CHI in the two-fluid equilibrium calculations. The toroidal magnetic field becomes from a diamagnetic to a paramagnetic profile in the closed flux region due to the increase of the poloidal electron flow velocity in the central open flux column (OFC) region, while the diamagnetic profile is kept in the OFC region. The toroidal ion flow velocity is increased from negative to positive values in the closed flux region due to the increase in the drift velocity and the Hall effect. As the ion diamagnetic drift velocity is changed in the same direction as the ExB drift velocity around the separatrix in the high field side through the negative ion pressure gradient there, the poloidal ion flow velocity is increased in the OFC region, enhancing the flow shear. The radial electric field shear around the separatrix is enhanced due to the strong dependence on the magnetic force through the interaction of toroidal ion flow velocity and axial magnetic field. The density is decreased in the closed flux region according to the generalized Bernoulli law and its negative gradient around the separatrix steepens.

  19. Classical Testing in Functional Linear Models.

    PubMed

    Kong, Dehan; Staicu, Ana-Maria; Maity, Arnab

    2016-01-01

    We extend four tests common in classical regression - Wald, score, likelihood ratio and F tests - to functional linear regression, for testing the null hypothesis, that there is no association between a scalar response and a functional covariate. Using functional principal component analysis, we re-express the functional linear model as a standard linear model, where the effect of the functional covariate can be approximated by a finite linear combination of the functional principal component scores. In this setting, we consider application of the four traditional tests. The proposed testing procedures are investigated theoretically for densely observed functional covariates when the number of principal components diverges. Using the theoretical distribution of the tests under the alternative hypothesis, we develop a procedure for sample size calculation in the context of functional linear regression. The four tests are further compared numerically for both densely and sparsely observed noisy functional data in simulation experiments and using two real data applications.

  20. Classical Testing in Functional Linear Models

    PubMed Central

    Kong, Dehan; Staicu, Ana-Maria; Maity, Arnab

    2016-01-01

    We extend four tests common in classical regression - Wald, score, likelihood ratio and F tests - to functional linear regression, for testing the null hypothesis, that there is no association between a scalar response and a functional covariate. Using functional principal component analysis, we re-express the functional linear model as a standard linear model, where the effect of the functional covariate can be approximated by a finite linear combination of the functional principal component scores. In this setting, we consider application of the four traditional tests. The proposed testing procedures are investigated theoretically for densely observed functional covariates when the number of principal components diverges. Using the theoretical distribution of the tests under the alternative hypothesis, we develop a procedure for sample size calculation in the context of functional linear regression. The four tests are further compared numerically for both densely and sparsely observed noisy functional data in simulation experiments and using two real data applications. PMID:28955155

  1. Chitin-induced T6SS in Vibrio cholerae is dependent on ChiS activation.

    PubMed

    Chourashi, Rhishita; Das, Suman; Dhar, Debarpan; Okamoto, Keinosuke; Mukhopadhyay, Asish K; Chatterjee, Nabendu Sekhar

    2018-05-01

    Vibrio cholerae regularly colonizes the chitinous exoskeleton of crustacean shells in the aquatic region. The type 6 secretion system (T6SS) in V. cholerae is an interbacterial killing device. This system is thought to provide a competitive advantage to V. cholerae in a polymicrobial community of the aquatic region under nutrient-poor conditions. V. cholerae chitin sensing is known to be initiated by the activation of a two-component sensor histidine kinase ChiS in the presence of GlcNAc2 (N,N'-diacetylchitobiose) residues generated by the action of chitinases on chitin. It is known that T6SS in V. cholerae is generally induced by chitin. However, the effect of ChiS activation on T6SS is unknown. Here, we found that ChiS inactivation resulted in impaired bacterial killing and reduced expression of T6SS genes. Active ChiS positively affected T6SS-mediated natural transformation in V. cholerae. ChiS depletion or inactivation also resulted in reduced colonization on insoluble chitin surfaces. Therefore, we have shown that V. cholerae colonization on chitinous surfaces activates ChiS, which promotes T6SS-dependent bacterial killing and horizontal gene transfer. We also highlight the importance of chitinases in T6SS upregulation.

  2. On squares of representations of compact Lie algebras

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zeier, Robert, E-mail: robert.zeier@ch.tum.de; Zimborás, Zoltán, E-mail: zimboras@gmail.com

    We study how tensor products of representations decompose when restricted from a compact Lie algebra to one of its subalgebras. In particular, we are interested in tensor squares which are tensor products of a representation with itself. We show in a classification-free manner that the sum of multiplicities and the sum of squares of multiplicities in the corresponding decomposition of a tensor square into irreducible representations has to strictly grow when restricted from a compact semisimple Lie algebra to a proper subalgebra. For this purpose, relevant details on tensor products of representations are compiled from the literature. Since the summore » of squares of multiplicities is equal to the dimension of the commutant of the tensor-square representation, it can be determined by linear-algebra computations in a scenario where an a priori unknown Lie algebra is given by a set of generators which might not be a linear basis. Hence, our results offer a test to decide if a subalgebra of a compact semisimple Lie algebra is a proper one without calculating the relevant Lie closures, which can be naturally applied in the field of controlled quantum systems.« less

  3. FORESEE: Fully Outsourced secuRe gEnome Study basEd on homomorphic Encryption

    PubMed Central

    2015-01-01

    Background The increasing availability of genome data motivates massive research studies in personalized treatment and precision medicine. Public cloud services provide a flexible way to mitigate the storage and computation burden in conducting genome-wide association studies (GWAS). However, data privacy has been widely concerned when sharing the sensitive information in a cloud environment. Methods We presented a novel framework (FORESEE: Fully Outsourced secuRe gEnome Study basEd on homomorphic Encryption) to fully outsource GWAS (i.e., chi-square statistic computation) using homomorphic encryption. The proposed framework enables secure divisions over encrypted data. We introduced two division protocols (i.e., secure errorless division and secure approximation division) with a trade-off between complexity and accuracy in computing chi-square statistics. Results The proposed framework was evaluated for the task of chi-square statistic computation with two case-control datasets from the 2015 iDASH genome privacy protection challenge. Experimental results show that the performance of FORESEE can be significantly improved through algorithmic optimization and parallel computation. Remarkably, the secure approximation division provides significant performance gain, but without missing any significance SNPs in the chi-square association test using the aforementioned datasets. Conclusions Unlike many existing HME based studies, in which final results need to be computed by the data owner due to the lack of the secure division operation, the proposed FORESEE framework support complete outsourcing to the cloud and output the final encrypted chi-square statistics. PMID:26733391

  4. FORESEE: Fully Outsourced secuRe gEnome Study basEd on homomorphic Encryption.

    PubMed

    Zhang, Yuchen; Dai, Wenrui; Jiang, Xiaoqian; Xiong, Hongkai; Wang, Shuang

    2015-01-01

    The increasing availability of genome data motivates massive research studies in personalized treatment and precision medicine. Public cloud services provide a flexible way to mitigate the storage and computation burden in conducting genome-wide association studies (GWAS). However, data privacy has been widely concerned when sharing the sensitive information in a cloud environment. We presented a novel framework (FORESEE: Fully Outsourced secuRe gEnome Study basEd on homomorphic Encryption) to fully outsource GWAS (i.e., chi-square statistic computation) using homomorphic encryption. The proposed framework enables secure divisions over encrypted data. We introduced two division protocols (i.e., secure errorless division and secure approximation division) with a trade-off between complexity and accuracy in computing chi-square statistics. The proposed framework was evaluated for the task of chi-square statistic computation with two case-control datasets from the 2015 iDASH genome privacy protection challenge. Experimental results show that the performance of FORESEE can be significantly improved through algorithmic optimization and parallel computation. Remarkably, the secure approximation division provides significant performance gain, but without missing any significance SNPs in the chi-square association test using the aforementioned datasets. Unlike many existing HME based studies, in which final results need to be computed by the data owner due to the lack of the secure division operation, the proposed FORESEE framework support complete outsourcing to the cloud and output the final encrypted chi-square statistics.

  5. Chitinase Chi1 from Myceliophthora thermophila C1, a Thermostable Enzyme for Chitin and Chitosan Depolymerization

    PubMed Central

    2018-01-01

    A thermostable Chitinase Chi1 from Myceliophthora thermophila C1 was homologously produced and characterized. Chitinase Chi1 shows high thermostability at 40 °C (>140 h 90% activity), 50 °C (>168 h 90% activity), and 55 °C (half-life 48 h). Chitinase Chi1 has broad substrate specificity and converts chitin, chitosan, modified chitosan, and chitin oligosaccharides. The activity of Chitinase Chi1 is strongly affected by the degree of deacetylation (DDA), molecular weight (Mw), and side chain modification of chitosan. Chitinase Chi1 releases mainly (GlcNAc)2 from insoluble chitin and chito-oligosaccharides with a polymerization degree (DP) ranging from 2 to 12 from chitosan, in a processive way. Chitinase Chi1 shows higher activity toward chitin oligosaccharides (GlcNAc)4–6 than toward (GlcNAc)3 and is inactive for (GlcNAc)2. During hydrolysis, oligosaccharides bind at subsites −2 to +2 in the enzyme’s active site. Chitinase Chi1 can be used for chitin valorisation and for production of chitin- and chito-oligosaccharides at industrial scale. PMID:29359934

  6. Chitinase Chi1 from Myceliophthora thermophila C1, a Thermostable Enzyme for Chitin and Chitosan Depolymerization.

    PubMed

    Krolicka, Malgorzata; Hinz, Sandra W A; Koetsier, Martijn J; Joosten, Rob; Eggink, Gerrit; van den Broek, Lambertus A M; Boeriu, Carmen G

    2018-02-21

    A thermostable Chitinase Chi1 from Myceliophthora thermophila C1 was homologously produced and characterized. Chitinase Chi1 shows high thermostability at 40 °C (>140 h 90% activity), 50 °C (>168 h 90% activity), and 55 °C (half-life 48 h). Chitinase Chi1 has broad substrate specificity and converts chitin, chitosan, modified chitosan, and chitin oligosaccharides. The activity of Chitinase Chi1 is strongly affected by the degree of deacetylation (DDA), molecular weight (Mw), and side chain modification of chitosan. Chitinase Chi1 releases mainly (GlcNAc) 2 from insoluble chitin and chito-oligosaccharides with a polymerization degree (DP) ranging from 2 to 12 from chitosan, in a processive way. Chitinase Chi1 shows higher activity toward chitin oligosaccharides (GlcNAc) 4-6 than toward (GlcNAc) 3 and is inactive for (GlcNAc) 2 . During hydrolysis, oligosaccharides bind at subsites -2 to +2 in the enzyme's active site. Chitinase Chi1 can be used for chitin valorisation and for production of chitin- and chito-oligosaccharides at industrial scale.

  7. Patterns of multi-drug resistant bacteria at first culture from patients admitted to a third level University hospital in Calabria from 2011 to 2014: implications for empirical therapy and infection control.

    PubMed

    Reale, Mariaconcetta; Strazzulla, Alessio; Quirino, Angela; Rizzo, Claudia; Marano, Vito; Postorino, Maria Concetta; Mazzitelli, Maria; Greco, Giuseppe; Pisani, Vincenzo; Costa, Chiara; Cesana, Bruno Mario; Liberto, Maria Carla; Torti, Carlo; Focà, Alfredo

    2017-06-01

    Surveillance of antimicrobial drug resistance is fundamental to guide empirical treatment. However, the European Antimicrobial Resistance Surveillance Network provides a general picture, which might not be applicable to clinical settings that are excluded from this survey. We evaluated resistance patterns of ESKAPE isolates over a four-year period in a third level University hospital in the province of Catanzaro (Southern Italy). In this retrospective study, we evaluated the frequency of ESKAPE isolates with different resistance patterns (group 1=low-resistant bacteria; group 2=multi-drug and extremely drug-resistant bacteria; group 3=pan-resistant bacteria), stratified by year (2011, 2012, 2013 and 2014), hospital units (intensive care units, medical and surgical units) and by sample type (urine, blood, wound swabs, respiratory samples, other samples). Chi square test was applied to find differences between isolates with different resistance patterns by hospital unit and by organs and systems. Cochran-Armitage trend test was applied to assess the trend in resistance patterns during the four years analyzed. Amongst 2385 isolates, Escherichia coli (38%) was the most frequent, followed by Pseudomonas aeruginosa (15%), Klebsiella pneumoniae (14%), Staphylococcus aureus (13%), Acinetobacter baumannii (9%), Enterococcus faecalis (8%) and Enterococcus faecium (3%). From 2011 to 2014, frequency of isolates in group 2 plus 3 decreased from 23% to 14% (chi square=55.093; p<0.0001), particularly for E. coli and K. pneumoniae, but the trend increased for S. aureus (from 5% in 2011 to 10% in 2014), and remained stable for the other species. Frequency of isolates in group 2 plus 3 was higher in intensive care units for K. pneumoniae (chi square =32.292; p<0.0001), A. baumannii (chi square =6.947; p<0.0001) and S. aureus (chi square =22.079; p<0.0001). It was also higher from blood than from different sources for most species.

  8. Can the Presence of Crystalluria Predict Stone Formation in Patients with Cystinuria?

    PubMed

    Wong, Kathie A; Pardy, Caroline; Pillay, Soma; Athanasiou, Thanos; Rottenberg, Giles; Bultitude, Matthew; Chandra, Ashish; Thomas, Kay

    2016-05-01

    To determine the feasibility of crystalluria as a biomarker for stone disease in patients with cystinuria. All patients attending a multidisciplinary cystinuria clinic provided early morning urine (EMU) and clinic urine (CU) samples for crystal measurement over a 2-year period (August 1, 2010, to July 31, 2012). Association between presence of crystals, presence of stone(s), and new stone growth (NSG) was determined using the chi-square test. Crystal numbers in EMU and CU were compared in patients with stones/NSG and no stones/stable disease using the Mann-Whitney U test. There was a statistically significant difference between the presence of crystalluria and presence of stones for CU (chi-square test = 5.86, df = 1, p = 0.02) but not EMU (chi-square test = 1.92, df = 1, p = 0.17) and between the presence of crystalluria and NSG for CU (chi-square test = 8.10, df = 1, p = 0.004) but not EMU (chi-square test = 1.32, df = 1, p = 0.25). Patients with stones and NSG have higher levels of crystalluria in CU than patients with no stones or stable disease (stones, median = 41, interquartile range [IQR] = 600 vs median = 0, IQR = 21, p = 0.01; NSG, median = 49, IQR = 525 vs median = 0, IQR = 40, p = 0.01). The presence of crystalluria in CU samples is associated with the presence of stones. Crystalluria is comparable to ultrasound and may serve as a useful adjunct to predict whether a patient with cystinuria has stones, which could guide the frequency of clinic review and imaging.

  9. Can indirect tests detect a known recombination event in human mtDNA?

    PubMed

    White, Daniel James; Gemmell, Neil John

    2009-07-01

    Whether human mitochondrial DNA (mtDNA) recombines sufficiently to influence its evolution, evolutionary analysis, and disease etiology, remains equivocal. Overall, evidence from indirect studies of population genetic data suggests that recombination is not occurring at detectable levels. This may be explained by no, or low, recombination or, alternatively, current indirect tests may be incapable of detecting recombination in human mtDNA. To investigate the latter, we have tested whether six well-established indirect tests of recombination could detect recombination in a human mtDNA data set, in which its occurrence had been empirically confirmed. Three showed statistical evidence for recombination (r(2) vs. distance, the Homoplasy test, Neighborhood Similarity Score), and three did not (D' vs. distance, Max Chi Squared, Pairwise Homoplasy Index). Possible reasons for detection failure are discussed. Further, evidence from earlier studies suggesting a lack of recombination in mtDNA in humans is reconsidered, taking into account the appropriateness of the tests used, based on our new findings.

  10. Usefulness of Leukocyte Esterase Test Versus Rapid Strep Test for Diagnosis of Acute Strep Pharyngitis.

    PubMed

    Nibhanipudi, Kumara V

    2015-01-01

    A study to compare the usage of throat swab testing for leukocyte esterase on a test strip(urine dip stick-multi stick) to rapid strep test for rapid diagnosis of Group A Beta hemolytic streptococci in cases of acute pharyngitis in children. The testing of throat swab for leukocyte esterase on test strip currently used for urine testing may be used to detect throat infection and might be as useful as rapid strep. All patients who come with a complaint of sore throat and fever were examined clinically for erythema of pharynx, tonsils and also for any exudates. Informed consent was obtained from the parents and assent from the subjects. 3 swabs were taken from pharyngo-tonsillar region, testing for culture, rapid strep & Leukocyte Esterase. Total number is 100. Cultures 9(+); for rapid strep== 84(-) and16 (+); For LE== 80(-) and 20(+) From data configuration Rapid Strep versus LE test don't seem to be a random (independent) assignment but extremely aligned. The Statistical results show rapid and LE show very agreeable results. Calculated Value of Chi Squared Exceeds Tabulated under 1 Degree Of Freedom (P<.0.0001) reject Null HYPOTHESIS and Conclude Alternative Conclusions: Leukocyte esterase on throat swab is as useful as rapid strep test for rapid diagnosis of strep pharyngitis on test strip currently used for urine dip stick causing acute pharyngitis in children.

  11. Association between composites of selected motion palpation and pain provocation tests for sacroiliac joint disorders.

    PubMed

    Soleimanifar, Manijeh; Karimi, Noureddin; Arab, Amir Massoud

    2017-04-01

    The sacroiliac joint (SIJ) has been implicated as a potential source of low back and buttock pain. Several types of motion palpation and pain provocation tests are used to evaluate SIJ dysfunction. The purpose of this study was to investigate the relationship between motion palpation and pain provocation tests in assessment of SIJ problems. This study is Descriptive Correlation. 50 patients between the ages of 20 and 65 participated. Four motion palpation tests (Sitting flexion, Standing flexion, Prone knee flexion, Gillet test) and three pain provocation tests (FABER, Posterior shear, Resisted abduction test) were examined. Chi-square analysis was used to assess the relationship between results of the individuals and composites of these two groups of tests. No significant relationship was found between these two groups of tests. It seems that motion palpation tests assess SIJ dysfunction and provocative tests assessed SIJ pain which do not appear to be related. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Modelling of the batch biosorption system: study on exchange of protons with cell wall-bound mineral ions.

    PubMed

    Mishra, Vishal

    2015-01-01

    The interchange of the protons with the cell wall-bound calcium and magnesium ions at the interface of solution/bacterial cell surface in the biosorption system at various concentrations of protons has been studied in the present work. A mathematical model for establishing the correlation between concentration of protons and active sites was developed and optimized. The sporadic limited residence time reactor was used to titrate the calcium and magnesium ions at the individual data point. The accuracy of the proposed mathematical model was estimated using error functions such as nonlinear regression, adjusted nonlinear regression coefficient, the chi-square test, P-test and F-test. The values of the chi-square test (0.042-0.017), P-test (<0.001-0.04), sum of square errors (0.061-0.016), root mean square error (0.01-0.04) and F-test (2.22-19.92) reported in the present research indicated the suitability of the model over a wide range of proton concentrations. The zeta potential of the bacterium surface at various concentrations of protons was observed to validate the denaturation of active sites.

  13. Real time groove characterization combining partial least squares and SVR strategies: application to eddy current testing

    NASA Astrophysics Data System (ADS)

    Ahmed, S.; Salucci, M.; Miorelli, R.; Anselmi, N.; Oliveri, G.; Calmon, P.; Reboud, C.; Massa, A.

    2017-10-01

    A quasi real-time inversion strategy is presented for groove characterization of a conductive non-ferromagnetic tube structure by exploiting eddy current testing (ECT) signal. Inversion problem has been formulated by non-iterative Learning-by-Examples (LBE) strategy. Within the framework of LBE, an efficient training strategy has been adopted with the combination of feature extraction and a customized version of output space filling (OSF) adaptive sampling in order to get optimal training set during offline phase. Partial Least Squares (PLS) and Support Vector Regression (SVR) have been exploited for feature extraction and prediction technique respectively to have robust and accurate real time inversion during online phase.

  14. {chi}{sub cJ} decays to h{sup +}h{sup -}h{sup 0}

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Athar, S. B.; Patel, R.; Potlia, V.

    2007-02-01

    Using a sample of 3x10{sup 6} {psi}(2S) decays recorded by the CLEO detector, we study three-body decays of the {chi}{sub c0}, {chi}{sub c1}, and {chi}{sub c2} produced in radiative decays of the {psi}(2S). We consider the final states {pi}{sup +}{pi}{sup -}{eta}, K{sup +}K{sup -}{eta}, pp{eta}, {pi}{sup +}{pi}{sup -}{eta}{sup '}, K{sup +}K{sup -}{pi}{sup 0}, pp{pi}{sup 0}, {pi}{sup +}K{sup -}K{sub S}{sup 0}, and K{sup +}p{lambda}, measuring branching fractions or placing upper limits. For {chi}{sub c1}{yields}{pi}{sup +}{pi}{sup -}{eta}, K{sup +}K{sup -}{pi}{sup 0}, and {pi}{sup +}K{sup -}K{sub S}{sup 0} our observed samples are large enough to indicate the largest contributions to the substructure.

  15. Comparison of delinquents and nondelinquents in ethnicity, ordinal position, and self-perception.

    PubMed

    Calhoun, G; Connley, S; Bolton, J A

    1984-01-01

    Compared three groups of black, white, and Mexican-American delinquent and nondelinquent males, aged 11 to 18, on measures of self-concept, self-esteem, and ordinal position by groups (N = 135). Data were analyzed with analysis of variance and Chi-square test. Significant main effects were found with respect to delinquency, self-concept, and self-esteem. A significant interaction was present for delinquency and ethnicity for both self-concept and self-esteem. Chi-square results found birth-order and ethnicity to be related significantly.

  16. Development of Chinese Version of Polycystic Ovary Syndrome Health-Related Quality of Life Questionnaire (Chi-PCOSQ)

    PubMed Central

    Ou, Huang-tz; Chen, Pei-Chi

    2015-01-01

    Objectives To develop the Chinese version of the Polycystic Ovary Syndrome Health-related Quality of Life Questionnaire (Chi-PCOSQ). Research Design and Method This cross-sectional study was conducted in a medical center in Taiwan. Eighty women who met the criteria were enrolled: female, age range of 18–45 years, competent in the Chinese language, had been diagnosed with polycystic ovary syndrome (PCOS), and were regularly followed at outpatient clinics (defined as at least two outpatient visits before enrollment). The PCOSQ was translated and culturally adapted according to standard procedures. A semi-structured interview was applied to assess face validity. Exploratory factor analysis (EFA) was applied to determine scale constructs. Measurements of internal consistency via Cronbach’s α, test-retest reliability via intraclass correlation coefficient (ICC), construct validity, and discriminative validity were performed. Results Five additional items, representing the issues of acne, hair loss, and fear of getting diabetes, were incorporated into the original scale. A six-factor structure emerged as a result of the EFA, explaining 71.9% of the variance observed. The reliability analyses demonstrated satisfactory results for Cronbach’s α ranging from 0.78–0.96, and for ICC ranging from 0.73–0.86. Construct validity was confirmed by significant correlation between the domains of the Chi-PCOSQ and generic health-related quality of life (HRQoL) measures (WHOQOL-BREF, EQ-5D) and clinical parameters (body mass index, waist-hip ratio, blood pressure). The known-group analysis indicated that the Chi-PCOSQ is a discriminative tool that differentiates patients according to their HRQoL. Conclusion The Chi-PCOSQ seems internally consistent, culturally acceptable, and our preliminary evidence suggests that it may be reliable and valid. The Chi-PCOSQ is a promising assessment tool to address the HRQoL of women affected by PCOS in Chinese-speaking countries and to

  17. Cost Growth in Weapons Systems: Re-examining Rubber Baselines and Economic Factors

    DTIC Science & Technology

    2007-03-01

    committee members for their support in this endeavor. They allowed me to test my econometric limits without performing the analysis for me. I...Bruesch-Pagan Het Test Ramsey Omitted Variable Test 6 The adjusted r-squared value indicates that this model explains nearly 16% of the factors...Observations 1150 Chi2(1) 69.01 P(Chi) 0.0000 F(3, 1139) 7.22 P(F) 0.0001 Bruesch-Pagan Het Test Ramsey Omitted Variable Test The results of these two

  18. Fast Algorithms for Structured Least Squares and Total Least Squares Problems

    PubMed Central

    Kalsi, Anoop; O’Leary, Dianne P.

    2006-01-01

    We consider the problem of solving least squares problems involving a matrix M of small displacement rank with respect to two matrices Z1 and Z2. We develop formulas for the generators of the matrix M HM in terms of the generators of M and show that the Cholesky factorization of the matrix M HM can be computed quickly if Z1 is close to unitary and Z2 is triangular and nilpotent. These conditions are satisfied for several classes of matrices, including Toeplitz, block Toeplitz, Hankel, and block Hankel, and for matrices whose blocks have such structure. Fast Cholesky factorization enables fast solution of least squares problems, total least squares problems, and regularized total least squares problems involving these classes of matrices. PMID:27274922

  19. Fast Algorithms for Structured Least Squares and Total Least Squares Problems.

    PubMed

    Kalsi, Anoop; O'Leary, Dianne P

    2006-01-01

    We consider the problem of solving least squares problems involving a matrix M of small displacement rank with respect to two matrices Z 1 and Z 2. We develop formulas for the generators of the matrix M (H) M in terms of the generators of M and show that the Cholesky factorization of the matrix M (H) M can be computed quickly if Z 1 is close to unitary and Z 2 is triangular and nilpotent. These conditions are satisfied for several classes of matrices, including Toeplitz, block Toeplitz, Hankel, and block Hankel, and for matrices whose blocks have such structure. Fast Cholesky factorization enables fast solution of least squares problems, total least squares problems, and regularized total least squares problems involving these classes of matrices.

  20. Efficacy of practising Tai Chi for older people with mild dementia: protocol for a randomised controlled study.

    PubMed

    Lyu, Jihui; Li, Wenjie; Rong, Xiangjiang; Wei, Lian; Huang, Nayan; Champ, Mei; Xiong, Qian; Chen, Xueli; Li, Mo; Li, Fangling

    2018-05-14

    Many studies suggest that Tai Chi exercise is a safe and appropriate mind-body exercise for older people and effectively slows down age-related cognitive decline. A set of bespoke Tai Chi exercise named 'Cognition Protecting Tai Chi' (CPT) has been created for older people with cognitive impairments by the research team of geriatricians, neurologists, rehabilitation specialists, experts of sports medicine and experienced practitioners of traditional Chinese medicine. This trial is designed to evaluate its effects on cognitive function, behaviour/moods, risk of falls and activities of daily living of the participants with mild dementia. A randomised controlled study will be conducted. Eighty participants with mild dementia will be recruited and randomly allocated to an intervention group and a control group. The intervention group will practice the CPT exercise three times a week for 20 min each time under the guidance of professional therapists. The control group will continue receiving their routine treatments. The duration of this study will be 10 months. All participants will be assessed with a battery of neuropsychological and functional evaluations, which include Mini Mental State Examination, Montreal Cognitive Assessment, the WHO-University of California Los Angeles-Auditory Verbal Learning test (WHO-UCLA-AVLT), Trail Making Test (TMT), Geriatric Depression Scale, Neuropsychological Inventory and Barthel Index, at the baseline, 5 and 10 months during the study period. Fall incident will also be recorded. The primary outcome will be the WHO-UCLA-AVLT delayed recall score. The secondary outcome will be the TMT score. This study has been approved by the ethical review committee of the Beijing Geriatric Hospital (protocol number: 2015-021). Informed consent will be obtained from all participants or their guardians. The authors intend to submit the findings of the study to peer-reviewed journals or academic conferences to be published. ChiCTR-INR-16009872; Pre

  1. Effect of baseline corrections on response spectra for two recordings of the 1999 Chi-Chi, Taiwan, earthquake

    USGS Publications Warehouse

    Boore, David M.

    1999-01-01

    Displacements derived from the accelerogram recordings of the 1999 Chi-Chi, Taiwan earthquake at stations TCU078 and TCU129 show drifts when only a simple baseline derived from the pre-event portion of the record is removed from the records. The appearance of the velocity and displacement records suggests that changes in the zero-level of the acceleration are responsible for these drifts. The source of the shifts in zero-level are unknown, but might include tilts in the instruments or the response of the instruments to strong shaking. This note illustrates the effect on the velocity, displacement, and response spectra of several schemes for accounting for these baseline shifts. The most important conclusion for earthquake engineering purposes is that the response spectra for periods less than about 20 sec are unaffected by the baseline correction. The results suggest, however, that staticdisplac ements estimated from the instruments should be used with caution. Although limited to the analysis of only two recordings, the results may have more general significance both for the many other recordings of this earthquake and for data that will be obtained in the future from similar high-quality accelerograph networks now being installed or soon to be installed in many parts of the world.

  2. BCL2 oncogene translocation is mediated by a chi-like consensus

    PubMed Central

    1992-01-01

    Examination of 64 translocations involving the major breakpoint region (mbr) of the BCL2 oncogene and the immunoglobulin heavy chain locus identified three short (14, 16, and 18 bp) segments within the mbr at which translocations occurred with very high frequency. Each of these clusters was associated with a 15-bp region of sequence homology, the principal one containing an octamer related to chi, the procaryotic activator of recombination. The presence of short deletions and N nucleotide additions at the breakpoints, as well as involvement of JH and DH coding regions, suggested that these sequences served as signals capable of interacting with the VDJ recombinase complex, even though no homology with the traditional heptamer/spacer/nonamer (IgRSS) existed. Furthermore, the BCL2 signal sequences were employed in a bidirectional fashion and could mediate recombination of one mbr region with another. Segments homologous to the BCL2 signal sequences flanked individual members of the XP family of diversity gene segments, which were themselves highly overrepresented in the reciprocal products (18q-) of BCL2 translocation. We propose that the chi-like signal sequences of BCL2 represent a distinct class of recognition sites for the recombinase complex, responsible for initiating interactions between regions of DNA separated by great distances, and that BCL2 translocation begins by a recombination event between mbr and DXP chi signals. Since recombinant joints containing chi, not IgRSS, occur in brain cells expressing RAG-1 (Matsuoka, M., F. Nagawa, K. Okazaki, L. Kingsbury, K. Yoshida, U. Muller, D. T. Larue, J. A. Winer, and H. Sakano. 1991. Science [Wash. DC]. 254:81; reference 1), we further suggest that the product of this gene could mediate both BCL2 translocation and the first step of normal DJ assembly through the creation of chi joints, rather than signal or coding joints. PMID:1588282

  3. Role of the C-terminal and chitin insertion domains on enzymatic activity of endochitinase ChiA74 of Bacillus thuringiensis.

    PubMed

    Juárez-Hernández, Estefania O; Casados-Vázquez, Luz E; Bideshi, Dennis K; Salcedo-Hernández, R; Barboza-Corona, José E

    2017-09-01

    ChiA74 has modular structure that includes a secretion signal peptide (sp) sequence, and catalytic (CD), chitin insertion (CID), fibronectin type-III (FnIII) and chitin binding (CBD) domains. We described for the first time the existence of a putative CID in ChiA74. Mature ChiA74 lacking its sp sequence (rChiA74Δsp, ∼70kDa) and two truncated versions, rChiA74Δsp-60, rChiA74Δsp-50 lacking, respectively, CBD and CDB-FnIII were produced. rChiA74Δsp and rChiA74Δsp-60 are unstable and were processed to generate stable proteins of ∼50kDa. With colloidal chitin, rChiA74Δsp and rChiA74Δsp-50 had higher activity than rChiA74Δsp-60. rChiA74Δsp showed similar ability to bind chitin than rChiA74Δsp-50. The catalytic efficiencies (kcat/Km) of rChiA74Δsp and rChiA74Δsp-50 were higher, ∼ 21-fold than rChiA74Δsp-60, using chitin as the substrate. Optimal activity was detected at pH 7 and 40°C. Data suggest that the CBD in ChiA74 is important for binding to chitin, but not necessary as the presence of a CID together with the CD in a stable truncated version (i.e. ChiA74Δsp-50) has similar affinity and hydrolytic activity as the mature enzyme. The CID of ChiA74 showed identities of ∼ 55% with CIDs of other chitinases such as those from B. circulans and B. licheniformis, respectively, and conserved residues important for interacting with chitin. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Observation of {psi}(3770){yields}{gamma}{chi}{sub c0}

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Briere, R. A.; Brock, I.; Chen, J.

    2006-08-01

    From e{sup +}e{sup -} collision data acquired with the CLEO-c detector at CESR, we search for the non-DD decays {psi}(3770){yields}{gamma}{chi}{sub cJ}, with {chi}{sub cJ} reconstructed in four exclusive decays modes containing charged pions and kaons. We report the first observation of such decays for J=0 with a branching ratio of (0.73{+-}0.07{+-}0.06)%. The rates for different J are consistent with the expectations assuming {psi}(3770) is predominantly a 1{sup 3}D{sub 1} state of charmonium, but only if relativistic corrections are applied.

  5. Differential Roles of the ChiB Chitinase in Autolysis and Cell Death of Aspergillus nidulans▿

    PubMed Central

    Shin, Kwang-Soo; Kwon, Nak-Jung; Kim, Young Hwan; Park, Hee-Soo; Kwon, Gi-Seok; Yu, Jae-Hyuk

    2009-01-01

    Autolysis is a natural event that occurs in most filamentous fungi. Such self-degradation of fungal cells becomes a predominant phenomenon in the absence of the regulator of G protein signaling FlbA in Aspergillus nidulans. Among a number of potential hydrolytic enzymes in the A. nidulans genome, the secreted endochitinase ChiB was shown to play a major role in autolysis. In this report, we investigate the roles of ChiB in fungal autolysis and cell death processes through genetic, biochemical, and cellular analyses using a set of critical mutants. Determination of mycelial mass revealed that, while the flbA deletion (ΔflbA) mutant autolyzed completely after a 3-day incubation, the ΔflbA ΔchiB double mutant escaped from hyphal disintegration. These results indicate that ChiB is necessary for the ΔflbA-induced autolysis. However, importantly, both ΔflbA and ΔflbA ΔchiB strains displayed dramatically reduced cell viability compared to the wild type. These imply that ChiB is dispensable for cell death and that autolysis and cell death are separate processes. Liquid chromatography-tandem mass spectrometry analyses of the proteins that accumulate at high levels in the ΔflbA and ΔflbA ΔchiB mutants identify chitinase (ChiB), dipeptidyl peptidase V (DppV), O-glycosyl compound hydrolase, β-N-acetylhexosaminidase (NagA), and myo-inositol-1-phosphate synthase (InoB). Functional characterization of these four genes reveals that the deletion of nagA results in reduced cell death. A working model bridging G protein signaling and players in autolysis/cell death is proposed. PMID:19286987

  6. 2 × 2 Tables: a note on Campbell's recommendation.

    PubMed

    Busing, F M T A; Weaver, B; Dubois, S

    2016-04-15

    For 2 × 2 tables, Egon Pearson's N - 1 chi-squared statistic is theoretically more sound than Karl Pearson's chi-squared statistic, and provides more accurate p values. Moreover, Egon Pearson's N - 1 chi-squared statistic is equal to the Mantel-Haenszel chi-squared statistic for a single 2 × 2 table, and as such, is often available in statistical software packages like SPSS, SAS, Stata, or R, which facilitates compliance with Ian Campbell's recommendations. Copyright © 2015 John Wiley & Sons, Ltd.

  7. Real time flaw detection and characterization in tube through partial least squares and SVR: Application to eddy current testing

    NASA Astrophysics Data System (ADS)

    Ahmed, Shamim; Miorelli, Roberto; Calmon, Pierre; Anselmi, Nicola; Salucci, Marco

    2018-04-01

    This paper describes Learning-By-Examples (LBE) technique for performing quasi real time flaw localization and characterization within a conductive tube based on Eddy Current Testing (ECT) signals. Within the framework of LBE, the combination of full-factorial (i.e., GRID) sampling and Partial Least Squares (PLS) feature extraction (i.e., GRID-PLS) techniques are applied for generating a suitable training set in offine phase. Support Vector Regression (SVR) is utilized for model development and inversion during offine and online phases, respectively. The performance and robustness of the proposed GIRD-PLS/SVR strategy on noisy test set is evaluated and compared with standard GRID/SVR approach.

  8. A recombinant Anticarsia gemmatalis MNPV harboring chiA and v-cath genes from Choristoneura fumiferana defective NPV induce host liquefaction and increased insecticidal activity.

    PubMed

    Lima, Anabele Azevedo; Aragão, Clara Wandenkolck Silva; de Castro, Maria Elita Batista; Oliveira, Juliana Velasco de Castro; Sosa Gómez, Daniel Ricardo; Ribeiro, Bergmann Morais

    2013-01-01

    One of the interesting features of Anticarsia gemmatalis multiple nucleopolyhedrovirus isolate 2D (AgMNPV-2D) genome is the absence of chitinase (chiA) and cathepsin (v-cath) genes. This characteristic may be responsible for the lack of liquefaction and melanization in A. gemmatalis larvae killed by AgMNPV-2D infection. This study aimed to test the hypothesis that CHIA and V-CATH proteins from Choristonera fumiferana DEF multiple nucleopolyhedrovirus (CfDEFNPV) are able to liquefy and melanize the cuticle of A. gemmatalis larvae infected by a recombinant AgMNPV containing chiA and v-cath genes inserted in its genome. A fragment from the CfDefNPV genome containing chiA and v-cath genes was inserted into the genome of AgMNPV-2D. The recombinant virus (vAgp2100Cf.chiA/v-cath) was purified and used to infect insect cells and larvae. Transcripts of v-cath and chiA genes were detected along the infection of insect cells by qRT-PCR, from early to late phases of infection. The analysis of A. gemmatalis larvae killed by vAgp2100Cf.chiA/v-cath infection confirmed the hypothesis proposed. The vAgp2100Cf.chiA/v-cath showed higher insecticidal activity against third instar A. gemmatalis larvae when compared to AgMNPV-2D. The mean time to death was also lower for the vAgp2100Cf.chiA/v-cath when compared to AgMNPV-2D at 10 days post infection. Occlusion body production was higher in A. gemmatalis larvae infected with vAgp2100Cf.chiA/v-cath when compared to AgMNPV-2D. Enzyme assays showed higher chitinase and cysteine protease activities in insect cells and insects infected with vAgp2100Cf.chiA/v-cath when compared to AgMNPV-2D. The introduction of chiA and v-cath genes into the genome of AgMNPV improves its insecticidal activity against A. gemmatalis larvae and this recombinant virus could be used as an alternative to the wild type virus to control this important insect pest.

  9. A Recombinant Anticarsia gemmatalis MNPV Harboring chiA and v-cath Genes from Choristoneura fumiferana Defective NPV Induce Host Liquefaction and Increased Insecticidal Activity

    PubMed Central

    Lima, Anabele Azevedo; Aragão, Clara Wandenkolck Silva; de Castro, Maria Elita Batista; Oliveira, Juliana Velasco de Castro; Sosa Gómez, Daniel Ricardo; Ribeiro, Bergmann Morais

    2013-01-01

    One of the interesting features of Anticarsia gemmatalis multiple nucleopolyhedrovirus isolate 2D (AgMNPV-2D) genome is the absence of chitinase (chiA) and cathepsin (v-cath) genes. This characteristic may be responsible for the lack of liquefaction and melanization in A. gemmatalis larvae killed by AgMNPV-2D infection. This study aimed to test the hypothesis that CHIA and V-CATH proteins from Choristonera fumiferana DEF multiple nucleopolyhedrovirus (CfDEFNPV) are able to liquefy and melanize the cuticle of A. gemmatalis larvae infected by a recombinant AgMNPV containing chiA and v-cath genes inserted in its genome. A fragment from the CfDefNPV genome containing chiA and v-cath genes was inserted into the genome of AgMNPV-2D. The recombinant virus (vAgp2100Cf.chiA/v-cath) was purified and used to infect insect cells and larvae. Transcripts of v-cath and chiA genes were detected along the infection of insect cells by qRT-PCR, from early to late phases of infection. The analysis of A. gemmatalis larvae killed by vAgp2100Cf.chiA/v-cath infection confirmed the hypothesis proposed. The vAgp2100Cf.chiA/v-cath showed higher insecticidal activity against third instar A. gemmatalis larvae when compared to AgMNPV-2D. The mean time to death was also lower for the vAgp2100Cf.chiA/v-cath when compared to AgMNPV-2D at 10 days post infection. Occlusion body production was higher in A. gemmatalis larvae infected with vAgp2100Cf.chiA/v-cath when compared to AgMNPV-2D. Enzyme assays showed higher chitinase and cysteine protease activities in insect cells and insects infected with vAgp2100Cf.chiA/v-cath when compared to AgMNPV-2D. The introduction of chiA and v-cath genes into the genome of AgMNPV improves its insecticidal activity against A. gemmatalis larvae and this recombinant virus could be used as an alternative to the wild type virus to control this important insect pest. PMID:24086357

  10. Surveillance of transmitted HIV drug resistance using matched plasma and dried blood spot specimens from voluntary counseling and testing sites in Ho Chi Minh City, Vietnam, 2007-2008.

    PubMed

    Duc, Nguyen Bui; Hien, Bui Thu; Wagar, Nick; Tram, Tran Hong; Giang, Le Truong; Yang, Chunfu; Wolfe, Mitchell I; Hien, Nguyen Tran; Tuan, Nguyen Anh

    2012-05-01

    During 2007-2008, surveillance of transmitted human immunodeficiency virus (HIV) drug resistance (TDR) was performed following World Health Organization guidance among clients with newly diagnosed HIV infection attending voluntary counseling and testing (VCT) sites in Ho Chi Minh City (HCMC), Vietnam. Moderate (5%-15%) TDR to nonnucleoside reverse-transcriptase inhibitors (NNRTIs) was observed among VCT clients aged 18-21 years. Follow-up surveillance of TDR in HCMC and other geographic regions of Vietnam is warranted. Data generated will guide the national HIV drug resistance surveillance strategy and support selection of current and future first-line antiretroviral therapy and HIV prevention programs.

  11. Herd-level risk factors for bovine viral diarrhea infection in cattle of Tamil Nadu.

    PubMed

    Kumar, Subbiah Krishna; Palanivel, K M; Sukumar, K; Ronald, B Samuel Masilamoni; Selvaraju, G; Ponnudurai, G

    2018-04-01

    A cross-sectional study was carried out to identify risk factors for bovine viral diarrhea virus (BVDV) infection in 62 randomly selected dairy herds which were tested for BVD serum antibodies by using an indirect ELISA kit (IDEXX). Results from the chi-square test analysis were interpreted by analyzing by chi-square test. A sum of 500 sera samples were screened and 66 animals (13.20%) showed positive for BVDV antibody. Within herd, BVD seroprevalence was 12-65%. This study concluded that epidemiological risk factors like location, herd size, housing patterns like, tail to tail system, roofing pattern, distance between the manure pit and farm, and distance between farms were significantly associated with BVDV serological status (P < 0.05).

  12. Discriminatory value of alanine aminotransferase for diabetes prediction: the Insulin Resistance Atherosclerosis Study.

    PubMed

    Lorenzo, C; Hanley, A J; Rewers, M J; Haffner, S M

    2016-03-01

    To examine the incremental usefulness of adding alanine aminotransferase to established risk factors for predicting future diabetes. The study population of the Insulin Resistance Atherosclerosis Study included 724 people aged 40-69 years. We excluded people who had excessive alcohol intake or were treated with lipid-lowering agents. Incident diabetes was assessed after a mean follow-up period of 5.2 years. Alanine aminotransferase had a non-linear relationship with incident diabetes (Wald chi-squared test, P < 0.001; P for linearity = 0.005) independent of demographic variables, family history of diabetes, BMI and fasting glucose; therefore, we used Youden's J statistic to dichotomize alanine aminotransferase [threshold ≥ 0.43 μkat/L ( ≥ 26 IU/l)]. Dichotomized alanine aminotransferase increased the area under the receiver-operating characteristic curve (0.805 vs. 0.823; P = 0.007) of a model that included demographic variables, family history of diabetes, BMI and fasting glucose as independent variables. The net reclassification improvement was 9.6% (95% CI 1.8-17.4; P = 0.016), and the integrated discrimination improvement was 0.031 (95% CI 0.011-0.050; P = 0.002). Dichotomized alanine aminotransferase reclassified a net of 9.6% of individuals more appropriately. Alanine aminotransferase may be useful for classifying individuals who are at risk of future diabetes after accounting for the effect of other risk factors, including family history, adiposity and plasma glucose. © 2015 The Authors. Diabetic Medicine © 2015 Diabetes UK.

  13. The Effect of Number of Ability Intervals on the Stability of Item Bias Detection.

    ERIC Educational Resources Information Center

    Loyd, Brenda

    The chi-square procedure has been suggested as a viable index of test bias because it provides the best agreement with the three parameter item characteristic curve without the large sample requirement, computer complexity, and cost. This study examines the effect of using different numbers of ability intervals on the reliability of chi-square…

  14. Is the ML Chi-Square Ever Robust to Nonnormality? A Cautionary Note with Missing Data

    ERIC Educational Resources Information Center

    Savalei, Victoria

    2008-01-01

    Normal theory maximum likelihood (ML) is by far the most popular estimation and testing method used in structural equation modeling (SEM), and it is the default in most SEM programs. Even though this approach assumes multivariate normality of the data, its use can be justified on the grounds that it is fairly robust to the violations of the…

  15. Latin and Magic Squares

    ERIC Educational Resources Information Center

    Emanouilidis, Emanuel

    2005-01-01

    Latin squares have existed for hundreds of years but it wasn't until rather recently that Latin squares were used in other areas such as statistics, graph theory, coding theory and the generation of random numbers as well as in the design and analysis of experiments. This note describes Latin and diagonal Latin squares, a method of constructing…

  16. Eta Squared, Partial Eta Squared, and Misreporting of Effect Size in Communication Research.

    ERIC Educational Resources Information Center

    Levine, Timothy R.; Hullett, Craig R.

    2002-01-01

    Alerts communication researchers to potential errors stemming from the use of SPSS (Statistical Package for the Social Sciences) to obtain estimates of eta squared in analysis of variance (ANOVA). Strives to clarify issues concerning the development and appropriate use of eta squared and partial eta squared in ANOVA. Discusses the reporting of…

  17. Tai Chi for Chronic Pain Conditions: A Systematic Review and Meta-analysis of Randomized Controlled Trials

    PubMed Central

    Kong, Ling Jun; Lauche, Romy; Klose, Petra; Bu, Jiang Hui; Yang, Xiao Cun; Guo, Chao Qing; Dobos, Gustav; Cheng, Ying Wu

    2016-01-01

    Several studies reported that Tai Chi showed potential effects for chronic pain, but its role remains controversial. This review assessed the evidence regarding the effects of Tai Chi for chronic pain conditions. 18 randomized controlled trials were included in our review. The aggregated results have indicated that Tai Chi showed positive evidence on immediate relief of chronic pain from osteoarthritis (standardized mean difference [SMD], −0.54; 95% confidence intervals [CI], −0.77 to −0.30; P < 0.05). The valid duration of Tai Chi practice for osteoarthritis may be more than 5 weeks. And there were some beneficial evidences regarding the effects of Tai Chi on immediate relief of chronic pain from low back pain (SMD, −0.81; 95% CI, −1.11 to −0.52; P < 0.05) and osteoporosis (SMD, −0.83; 95% CI, −1.37 to −0.28; P = 0.003). Therefore, clinicians may consider Tai Chi as a viable complementary and alternative medicine for chronic pain conditions. PMID:27125299

  18. Least Squares Procedures.

    ERIC Educational Resources Information Center

    Hester, Yvette

    Least squares methods are sophisticated mathematical curve fitting procedures used in all classical parametric methods. The linear least squares approximation is most often associated with finding the "line of best fit" or the regression line. Since all statistical analyses are correlational and all classical parametric methods are least…

  19. An evidence map of the effect of Tai Chi on health outcomes.

    PubMed

    Solloway, Michele R; Taylor, Stephanie L; Shekelle, Paul G; Miake-Lye, Isomi M; Beroes, Jessica M; Shanman, Roberta M; Hempel, Susanne

    2016-07-27

    This evidence map describes the volume and focus of Tai Chi research reporting health outcomes. Originally developed as a martial art, Tai Chi is typically taught as a series of slow, low-impact movements that integrate the breath, mind, and physical activity to achieve greater awareness and a sense of well-being. The evidence map is based on a systematic review of systematic reviews. We searched 11 electronic databases from inception to February 2014, screened reviews of reviews, and consulted with topic experts. We used a bubble plot to graphically display clinical topics, literature size, number of reviews, and a broad estimate of effectiveness. The map is based on 107 systematic reviews. Two thirds of the reviews were published in the last five years. The topics with the largest number of published randomized controlled trials (RCTs) were general health benefits (51 RCTs), psychological well-being (37 RCTs), interventions for older adults (31 RCTs), balance (27 RCTs), hypertension (18 RCTs), fall prevention (15 RCTs), and cognitive performance (11 RCTs). The map identified a number of areas with evidence of a potentially positive treatment effect on patient outcomes, including Tai Chi for hypertension, fall prevention outside of institutions, cognitive performance, osteoarthritis, depression, chronic obstructive pulmonary disease, pain, balance confidence, and muscle strength. However, identified reviews cautioned that firm conclusions cannot be drawn due to methodological limitations in the original studies and/or an insufficient number of existing research studies. Tai Chi has been applied in diverse clinical areas, and for a number of these, systematic reviews have indicated promising results. The evidence map provides a visual overview of Tai Chi research volume and content. PROSPERO CRD42014009907.

  20. Plasmoid formation in the elongated current sheet during transient CHI on HIST

    NASA Astrophysics Data System (ADS)

    Nagata, Masayoshi; Fujita, Akihiro; Matsui, Takahiro; Kikuchi, Yusuke; Fukumoto, Naoyuki; Kanki, Takashi

    2016-10-01

    The Transient-Coaxial Helicity Injection (T-CHI) is a promising candidate for the non-inductive plasma start-up on Spherical Torus (ST). The problem of the flux closure in the T-CHI is important and related to understand the physics of fast magnetic reconnection. The recent MHD simulation (F. Ebrahimi and R. Raman, Phys. Rev. Lett. 114, 205003 (2015)) on T-CHI for NSTX predicts the formation and breakup of an elongated Sweet-Parker (S-P) current sheet and a transient to plasmoid instability. According to this simulation, the reconnection rate based on the plasmoid instability is faster than that by S-P model and becomes nearly independent of the Lundquist number S. In this meeting, we will present that the formation of multiple X-points and plasmoids has been observed in T-CHI start-up plasmas on HIST. The stronger external guide (toroidal) magnetic field makes plasma less compressible, leading to slower reconnection time and longer current sheet. The experimental observation shows that 2/3 plasmoids are generated in the elongated current sheet with the narrow width comparable to the ion skin depth or the ion sound gyro-radius. The small plasmoids develop to a large-scale flux structure due to a current inward diffusion during the decay phase.

  1. Sound field simulation and acoustic animation in urban squares

    NASA Astrophysics Data System (ADS)

    Kang, Jian; Meng, Yan

    2005-04-01

    Urban squares are important components of cities, and the acoustic environment is important for their usability. While models and formulae for predicting the sound field in urban squares are important for their soundscape design and improvement, acoustic animation tools would be of great importance for designers as well as for public participation process, given that below a certain sound level, the soundscape evaluation depends mainly on the type of sounds rather than the loudness. This paper first briefly introduces acoustic simulation models developed for urban squares, as well as empirical formulae derived from a series of simulation. It then presents an acoustic animation tool currently being developed. In urban squares there are multiple dynamic sound sources, so that the computation time becomes a main concern. Nevertheless, the requirements for acoustic animation in urban squares are relatively low compared to auditoria. As a result, it is important to simplify the simulation process and algorithms. Based on a series of subjective tests in a virtual reality environment with various simulation parameters, a fast simulation method with acceptable accuracy has been explored. [Work supported by the European Commission.

  2. Influence of surface-normal ground acceleration on the initiation of the Jih-Feng-Erh-Shan landslide during the 1999 Chi-Chi, Taiwan, earthquake

    USGS Publications Warehouse

    Huang, C.-C.; Lee, Y.-H.; Liu, Huaibao P.; Keefer, D.K.; Jibson, R.W.

    2001-01-01

    The 1999 Chi-Chi, Taiwan, earthquake triggered numerous landslides throughout a large area in the Central Range, to the east, southeast, and south of the fault rupture. Among them are two large rock avalanches, at Tsaoling and at Jih-Feng-Erh-Shan. At Jih-Feng-Erh-Shan, the entire thickness (30-50 m) of the Miocene Changhukeng Shale over an area of 1 km2 slid down its bedding plane for a distance of about 1 km. Initial movement of the landslide was nearly purely translational. We investigate the effect of surface-normal acceleration on the initiation of the Jih-Feng-Erh-Shan landslide using a block slide model. We show that this acceleration, currently not considered by dynamic slope-stability analysis methods, significantly influences the initiation of the landslide.

  3. Irrational Square Roots

    ERIC Educational Resources Information Center

    Misiurewicz, Michal

    2013-01-01

    If students are presented the standard proof of irrationality of [square root]2, can they generalize it to a proof of the irrationality of "[square root]p", "p" a prime if, instead of considering divisibility by "p", they cling to the notions of even and odd used in the standard proof?

  4. Testing non-inferiority of a new treatment in three-arm clinical trials with binary endpoints.

    PubMed

    Tang, Nian-Sheng; Yu, Bin; Tang, Man-Lai

    2014-12-18

    A two-arm non-inferiority trial without a placebo is usually adopted to demonstrate that an experimental treatment is not worse than a reference treatment by a small pre-specified non-inferiority margin due to ethical concerns. Selection of the non-inferiority margin and establishment of assay sensitivity are two major issues in the design, analysis and interpretation for two-arm non-inferiority trials. Alternatively, a three-arm non-inferiority clinical trial including a placebo is usually conducted to assess the assay sensitivity and internal validity of a trial. Recently, some large-sample approaches have been developed to assess the non-inferiority of a new treatment based on the three-arm trial design. However, these methods behave badly with small sample sizes in the three arms. This manuscript aims to develop some reliable small-sample methods to test three-arm non-inferiority. Saddlepoint approximation, exact and approximate unconditional, and bootstrap-resampling methods are developed to calculate p-values of the Wald-type, score and likelihood ratio tests. Simulation studies are conducted to evaluate their performance in terms of type I error rate and power. Our empirical results show that the saddlepoint approximation method generally behaves better than the asymptotic method based on the Wald-type test statistic. For small sample sizes, approximate unconditional and bootstrap-resampling methods based on the score test statistic perform better in the sense that their corresponding type I error rates are generally closer to the prespecified nominal level than those of other test procedures. Both approximate unconditional and bootstrap-resampling test procedures based on the score test statistic are generally recommended for three-arm non-inferiority trials with binary outcomes.

  5. Study of ChiR function in Serratia marcescens and its application for improving 2,3-butanediol from crystal chitin.

    PubMed

    Yan, Qiang; Hong, Eunsoo; Fong, Stephen S

    2017-10-01

    Microbial utilization of chitin, a potential renewable biomass feedstock, is being pursued as a means of developing novel consolidated bioprocessing for the production of chemicals. Serratia marcescens is a gram-negative bacterium that is known for its chitinolytic capability and as a native 2,3-butanediol producer. In S. marcescens, ChiR has been suggested to be a positive regulator of chitinase production. In this study, we aim to understand the effect of ChiR in regulating nine chitinase-related genes in S. marcescens Db11 and demonstrate manipulation of chiR as a useful and efficient genetic target to enhance chitin utilization. First, a chiR overexpression (chiROE) strain and a chiR deletion (ΔchiR) strain were generated and characterized in terms of cellular growth, chitinase activity, and total secreted protein. Compared to the wild-type Db11 strain, the S. marcescens chiROE strain showed an increase in chitinase activity (2.14- to 6.31-fold increase). Increased transcriptional expression of chitinase-related genes was measured using real-time PCR, showing 2.12- to 10.93-fold increases. The S. marcescens ΔchiR strain showed decreases in chitinase activity (4.5- to 25-fold decrease), confirming ChiR's role as a positive regulator of chitinase expression. Finally, chiR overexpression was investigated as a means of increasing biochemical production (2,3-butanediol) from crystal chitin. The chiROE strain produced 1.13 ± 0.08 g/L 2,3-butanediol from 2% crystal chitin, a 2.83-fold improvement from the wild-type strain, indicating ChiR is an important and useful genetic engineering target for enhancing chitin utilization in S. marcescens.

  6. 9 Square in the Air: Not Your Parents' Traditional Four Square Game

    ERIC Educational Resources Information Center

    Hanson, Amber Hall; Barney, David

    2018-01-01

    Physical educators are constantly looking for new ideas and activities that will quickly grab the interest of their students. 9 Square in the Air is a game that does just this. The game was developed as a way to integrate students who enjoy volleyball and those who like Four Square. 9 Square in the Air provides the opportunity for students to use…

  7. A Least-Squares Transport Equation Compatible with Voids

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hansen, Jon; Peterson, Jacob; Morel, Jim

    Standard second-order self-adjoint forms of the transport equation, such as the even-parity, odd-parity, and self-adjoint angular flux equation, cannot be used in voids. Perhaps more important, they experience numerical convergence difficulties in near-voids. Here we present a new form of a second-order self-adjoint transport equation that has an advantage relative to standard forms in that it can be used in voids or near-voids. Our equation is closely related to the standard least-squares form of the transport equation with both equations being applicable in a void and having a nonconservative analytic form. However, unlike the standard least-squares form of the transportmore » equation, our least-squares equation is compatible with source iteration. It has been found that the standard least-squares form of the transport equation with a linear-continuous finite-element spatial discretization has difficulty in the thick diffusion limit. Here we extensively test the 1D slab-geometry version of our scheme with respect to void solutions, spatial convergence rate, and the intermediate and thick diffusion limits. We also define an effective diffusion synthetic acceleration scheme for our discretization. Our conclusion is that our least-squares S n formulation represents an excellent alternative to existing second-order S n transport formulations« less

  8. Road to Victory: Building the Ho Chi Minh Trail.

    ERIC Educational Resources Information Center

    Kenney, Marianne

    1993-01-01

    Presents a secondary school lesson on the building of the Ho Chi Minh Trail during the Vietnam War. Helps students link history and geographical skills through cooperative group learning. Includes maps, diagrams, and three student readings. (CFR)

  9. Study on community Tai Chi Chuan participants' leisure benefits and well-being: Using Taoyuan City as an example.

    PubMed

    Lee, Cheng-Jong; Tseng, Chun-Chi; Liu, Mei-Yu

    2015-01-01

    The aim of this study was to discuss the Research of Community Tai Chi Chuan Participants' Leisure Benefits and Well-being. A questionnaire survey was conducted on the community Tai Chi Chuan participants in Taoyuan city. A total of 500 valid questionnaires were retrieved, and the data were analyzed with SPSS 12.0 and AMOS 7.0 structural equation model analysis (SEM). The findings were as followed: 1) The background variables of the community Tai Chi Chuan participants in Taoyuan City: Gender had no difference in the factor of ``psychological benefit'' of leisure benefits. Occupation, age, education, the number of times a week to participate community Tai Chi Chuan and participation in seniority reached significant difference in leisure benefits. 2) The background variables of the community Tai Chi Chuan participants in Taoyuan City: gender, occupation, age, education, the number of times a week to participate community Tai Chi Chuan, participation in seniority reached significant difference in well-being. 3) The study showed community Tai Chi Chuan participants' leisure benefits had a significant positive correlation in well-being. Based on the findings, suggestions were proposed to related Taiwan Tai Chi Chuan promotion for reference.

  10. Usefulness of Leukocyte Esterase Test Versus Rapid Strep Test for Diagnosis of Acute Strep Pharyngitis

    PubMed Central

    2015-01-01

    Objective: A study to compare the usage of throat swab testing for leukocyte esterase on a test strip(urine dip stick-multi stick) to rapid strep test for rapid diagnosis of Group A Beta hemolytic streptococci in cases of acute pharyngitis in children. Hypothesis: The testing of throat swab for leukocyte esterase on test strip currently used for urine testing may be used to detect throat infection and might be as useful as rapid strep. Methods: All patients who come with a complaint of sore throat and fever were examined clinically for erythema of pharynx, tonsils and also for any exudates. Informed consent was obtained from the parents and assent from the subjects. 3 swabs were taken from pharyngo-tonsillar region, testing for culture, rapid strep & Leukocyte Esterase. Results: Total number is 100. Cultures 9(+); for rapid strep== 84(-) and16 (+); For LE== 80(-) and 20(+) Statistics: From data configuration Rapid Strep versus LE test don’t seem to be a random (independent) assignment but extremely aligned. The Statistical results show rapid and LE show very agreeable results. Calculated Value of Chi Squared Exceeds Tabulated under 1 Degree Of Freedom (P<.0.0001) reject Null Hypothesis and Conclude Alternative Conclusions: Leukocyte esterase on throat swab is as useful as rapid strep test for rapid diagnosis of strep pharyngitis on test strip currently used for urine dip stick causing acute pharyngitis in children. PMID:27335975

  11. Observation of K*(892){sup 0}K*(892){sup 0} in {chi}{sub cJ} decays

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ablikim, M.; Bai, J.Z.; Bian, J.G.

    2004-11-01

    K*(892){sup 0}K*(892){sup 0} signals from {chi}{sub cJ}(J=0,1,2) decays are observed for the first time using a data sample of 14 million {psi}(2S) events accumulated in the BES II detector. The branching fractions B[{chi}{sub cJ}{yields}K*(892){sup 0}K*(892){sup 0}] (J=0,1,2) are determined to be (1.78{+-}0.34{+-}0.34)x10{sup -3} (1.67{+-}0.32{+-}0.31)x10{sup -3}, and (4.86{+-}0.56{+-}0.88)x10{sup -3} for the {chi}{sub c0}, {chi}{sub c1}, and {chi}{sub c2} decays, respectively, where the first errors are statistical and the second are systematic. The significances of these signals are about 4.7{sigma}, 4.5{sigma}, and 7.6{sigma}, respectively.

  12. An index of effluent aquatic toxicity designed by partial least squares regression, using acute and chronic tests and expert judgements.

    PubMed

    Vindimian, Éric; Garric, Jeanne; Flammarion, Patrick; Thybaud, Éric; Babut, Marc

    1999-10-01

    The evaluation of the ecotoxicity of effluents requires a battery of biological tests on several species. In order to derive a summary parameter from such a battery, a single endpoint was calculated for all the tests: the EC10, obtained by nonlinear regression, with bootstrap evaluation of the confidence intervals. Principal component analysis was used to characterize and visualize the correlation between the tests. The table of the toxicity of the effluents was then submitted to a panel of experts, who classified the effluents according to the test results. Partial least squares (PLS) regression was used to fit the average value of the experts' judgements to the toxicity data, using a simple equation. Furthermore, PLS regression on partial data sets and other considerations resulted in an optimum battery, with two chronic tests and one acute test. The index is intended to be used for the classification of effluents based on their toxicity to aquatic species. Copyright © 1999 SETAC.

  13. An index of effluent aquatic toxicity designed by partial least squares regression, using acute and chronic tests and expert judgments

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Vindimian, E.; Garric, J.; Flammarion, P.

    1999-10-01

    The evaluation of the ecotoxicity of effluents requires a battery of biological tests on several species. In order to derive a summary parameter from such a battery, a single endpoint was calculated for all the tests: the EC10, obtained by nonlinear regression, with bootstrap evaluation of the confidence intervals. Principal component analysis was used to characterize and visualize the correlation between the tests. The table of the toxicity of the effluents was then submitted to a panel of experts, who classified the effluents according to the test results. Partial least squares (PLS) regression was used to fit the average valuemore » of the experts' judgments to the toxicity data, using a simple equation. Furthermore, PLS regression on partial data sets and other considerations resulted in an optimum battery, with two chronic tests and one acute test. The index is intended to be used for the classification of effluents based on their toxicity to aquatic species.« less

  14. Short-range inverse-square law experiment in space

    NASA Technical Reports Server (NTRS)

    Strayer, D.; Paik, H. J.; Moody, M. V.

    2002-01-01

    The objective of ISLES (Inverse-Square Law Experiment in Space) is to perform a null test ofNewton's law on the ISS with a resolution of one part in lo5 at ranges from 100 pm to 1 mm. ISLES will be sensitive enough to detect axions with the strongest allowed coupling and to test the string-theory prediction with R z 5 pm.

  15. 40 CFR 761.306 - Sampling 1 meter square surfaces by random selection of halves.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Sampling 1 meter square surfaces by...(b)(3) § 761.306 Sampling 1 meter square surfaces by random selection of halves. (a) Divide each 1 meter square portion where it is necessary to collect a surface wipe test sample into two equal (or as...

  16. 40 CFR 761.306 - Sampling 1 meter square surfaces by random selection of halves.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Sampling 1 meter square surfaces by...(b)(3) § 761.306 Sampling 1 meter square surfaces by random selection of halves. (a) Divide each 1 meter square portion where it is necessary to collect a surface wipe test sample into two equal (or as...

  17. 40 CFR 761.306 - Sampling 1 meter square surfaces by random selection of halves.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Sampling 1 meter square surfaces by...(b)(3) § 761.306 Sampling 1 meter square surfaces by random selection of halves. (a) Divide each 1 meter square portion where it is necessary to collect a surface wipe test sample into two equal (or as...

  18. 40 CFR 761.306 - Sampling 1 meter square surfaces by random selection of halves.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Sampling 1 meter square surfaces by...(b)(3) § 761.306 Sampling 1 meter square surfaces by random selection of halves. (a) Divide each 1 meter square portion where it is necessary to collect a surface wipe test sample into two equal (or as...

  19. 40 CFR 761.306 - Sampling 1 meter square surfaces by random selection of halves.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Sampling 1 meter square surfaces by...(b)(3) § 761.306 Sampling 1 meter square surfaces by random selection of halves. (a) Divide each 1 meter square portion where it is necessary to collect a surface wipe test sample into two equal (or as...

  20. Effects of Tai Chi exercise on physical and psychological health of older people.

    PubMed

    Blake, Holly; Hawley, Helen

    2012-02-01

    Tai Chi is a traditional Chinese form of conditioning exercise derived from martial arts and rooted in eastern philosophy and Chinese Medicine. Based on the inter-relatedness of mind, body and spirit this form of exercise focuses on producing an inner calmness which is thought to have both physical and psychological therapeutic value. This article provides a brief overview of selected current evidence examining the relationship between Tai Chi and physical, neurocognitive and psychosocial outcomes in older people. This is an emerging and growing area of research and improvements have often been reported in health functioning, physical and emotional health, reducing falls, fear of falling and risk of falls, and possibly enhancing cardiovascular functioning in older adults although the effects on bone density, cognitive and immunological functioning are less clear. Results overall are inconsistent and health improvements have not been evident in all studies. Tai Chi is becoming increasingly popular in practice, and more recent evidence is emerging which is based on experimental and longitudinal designs, although many of the proposed benefits of Tai Chi are yet to be validated in large, randomised controlled trials.

  1. Raman-noise-induced noise-figure limit for chi (3) parametric amplifiers

    NASA Astrophysics Data System (ADS)

    Voss, Paul L.; Kumar, Prem

    2004-03-01

    The nonzero response time of the Kerr [chi (3)] nonlinearity determines the quantum-limited noise figure of c3 parametric amplifiers. This nonzero response time of the nonlinearity requires coupling of the parametric amplification process to a molecular-vibration phonon bath, causing the addition of excess noise through Raman gain or loss at temperatures above 0 K. The effect of this excess noise on the noise figure can be surprisingly significant. We derive analytical expressions for this quantum-limited noise figure for phase-insensitive operation of a chi (3) amplifier and show good agreement with published noise-figure measurements.

  2. Observation of {chi}{sub c1} Decays into Vector Meson Pairs {phi}{phi}, {omega}{omega}, and {omega}{phi}

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ablikim, M.; An, Z. H.; Bai, J. Z.

    Using (106{+-}4)x10{sup 6} {psi}(3686) events accumulated with the BESIII detector at the BEPCII e{sup +}e{sup -} collider, we present the first measurement of decays of {chi}{sub c1} to vector meson pairs {phi}{phi}, {omega}{omega}, and {omega}{phi}. The branching fractions are measured to be (4.4{+-}0.3{+-}0.5)x10{sup -4}, (6.0{+-}0.3{+-}0.7)x10{sup -4}, and (2.2{+-}0.6{+-}0.2)x10{sup -5}, for {chi}{sub c1}{yields}{phi}{phi}, {omega}{omega}, and {omega}{phi}, respectively, which indicates that the hadron helicity selection rule is significantly violated in {chi}{sub cJ} decays. In addition, the measurement of {chi}{sub cJ}{yields}{omega}{phi} provides the first indication of the rate of doubly OZI-suppressed {chi}{sub cJ} decay. Finally, we present improved measurements for the branching fractionsmore » of {chi}{sub c0} and {chi}{sub c2} to vector meson pairs.« less

  3. Tai Chi: moving for better balance -- development of a community-based falls prevention program.

    PubMed

    Li, Fuzhong; Harmer, Peter; Mack, Karin A; Sleet, David; Fisher, K John; Kohn, Melvin A; Millet, Lisa M; Xu, Junheng; Yang, Tingzhong; Sutton, Beth; Tompkins, Yvaughn

    2008-05-01

    This study was designed to develop an evidence- and community based falls prevention program -- Tai Chi: Moving for Better Balance. A mixed qualitative and quantitative approach was used to develop a package of materials for program implementation and evaluation. The developmental work was conducted in 2 communities in the Pacific Northwest. Participants included a panel of experts, senior service program managers or activity coordinators, and older adults. Outcome measures involved program feasibility and satisfaction. Through an iterative process, a program package was developed. The package contained an implementation plan and class training materials (ie, instructor's manual, videotape, and user's guidebook). Pilot testing of program materials showed that the content was appropriate for the targeted users (community-living older adults) and providers (local senior service organizations). A feasibility survey indicated interest and support from users and providers for program implementation. A 2-week pilot evaluation showed that the program implementation was feasible and evidenced good class attendance, high participant satisfaction, and interest in continuing Tai Chi. The package of materials developed in this study provides a solid foundation for larger scale implementation and evaluation of the program in community settings.

  4. Least-Squares Curve-Fitting Program

    NASA Technical Reports Server (NTRS)

    Kantak, Anil V.

    1990-01-01

    Least Squares Curve Fitting program, AKLSQF, easily and efficiently computes polynomial providing least-squares best fit to uniformly spaced data. Enables user to specify tolerable least-squares error in fit or degree of polynomial. AKLSQF returns polynomial and actual least-squares-fit error incurred in operation. Data supplied to routine either by direct keyboard entry or via file. Written for an IBM PC X/AT or compatible using Microsoft's Quick Basic compiler.

  5. Is there an association between astrological data and personality?

    PubMed

    Hume, N

    1977-07-01

    A test was made of the hypothesis that personality characteristics can be predicted on the basis of various features of the individual's astrological chart. Astrological charts were prepared for 196 college-age Ss who also were administered the MMPI and the Leary Interpersonal Check List. Ss were divided into those who had extreme scores on any of the 13 personality variables studied and those who did not. For each personality variable, comparisons were made on a large number of astrological dimensions between distributions of Ss with and without extreme test scores. Six hundred thirty-two such comparisons were made and evaluated with chi-square tests. In that the obtained number of statistically significnat chi-squares was less than what would be expected on a chance basis, the hypothesis was rejected.

  6. Mechanical Circle-Squaring

    ERIC Educational Resources Information Center

    Wagon, Stan; Cox, Barry

    2009-01-01

    A technique discovered in 1939 can be used to build a device that is driven by standard circular motion (as in a drill press) and drills exact square holes. This device is quite different from the classic design by Watts, which uses a Reuleaux triangle and drills a hole that is almost, but not exactly, square. We describe the device in detail,…

  7. Comparison of hypertabastic survival model with other unimodal hazard rate functions using a goodness-of-fit test.

    PubMed

    Tahir, M Ramzan; Tran, Quang X; Nikulin, Mikhail S

    2017-05-30

    We studied the problem of testing a hypothesized distribution in survival regression models when the data is right censored and survival times are influenced by covariates. A modified chi-squared type test, known as Nikulin-Rao-Robson statistic, is applied for the comparison of accelerated failure time models. This statistic is used to test the goodness-of-fit for hypertabastic survival model and four other unimodal hazard rate functions. The results of simulation study showed that the hypertabastic distribution can be used as an alternative to log-logistic and log-normal distribution. In statistical modeling, because of its flexible shape of hazard functions, this distribution can also be used as a competitor of Birnbaum-Saunders and inverse Gaussian distributions. The results for the real data application are shown. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  8. Magnetic propulsion of a magnetic device using three square-Helmholtz coils and a square-Maxwell coil.

    PubMed

    Ha, Yong H; Han, Byung H; Lee, Soo Y

    2010-02-01

    We introduce a square coil system for remote magnetic navigation of a magnetic device without any physical movements of the coils. We used three square-Helmholtz coils and a square-Maxwell coil for magnetic propulsion of a small magnet along the desired path. All the square coils are mountable on a cubic frame that has an opening to accommodate a living subject. The square-Helmholtz coils control the magnetic propulsion direction by generating uniform magnetic field along the desired direction while the square-Maxwell coil controls the propulsion force by generating magnetic gradient field. We performed magnetic propulsion experiments with a down-scaled coil set and a three-channel coil driver. Experimental results demonstrate that we can use the square coil set for magnetic navigation of a magnetic device without any physical movements of the coils.

  9. Branching fractions for {chi}{sub cJ{yields}}pp{pi}{sup 0}, pp{eta}, and pp{omega}

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Onyisi, P. U. E.; Rosner, J. L.; Alexander, J. P.

    2010-07-01

    Using a sample of 25.9x10{sup 6} {psi}(2S) decays acquired with the CLEO-c detector at the CESR e{sup +}e{sup -} collider, we report branching fractions for the decays {chi}{sub cJ{yields}}pp{pi}{sup 0}, pp{eta}, and pp{omega}, with J=0, 1, 2. Our results for B({chi}{sub cJ{yields}}pp{pi}{sup 0}) and B({chi}{sub cJ{yields}}pp{eta}) are consistent with, but more precise than, previous measurements. Furthermore, we include the first measurement of B({chi}{sub cJ{yields}}pp{omega}).

  10. Heterologous Expression and Characterization of a Novel Chitinase (ChiEn1) from Coprinopsis cinerea and its Synergism in the Degradation of Chitin.

    PubMed

    Niu, Xin; Zhou, Jiang-Sheng; Wang, Yan-Xin; Liu, Cui-Cui; Liu, Zhong-Hua; Yuan, Sheng

    2017-08-16

    Chitinase ChiEn1 did not hydrolyze insoluble chitin but showed hydrolysis and transglycosylation activities toward chitin-oligosaccharides. Interestingly, the addition of ChiEn1 increased the amount of reducing sugars released from chitin powder by endochitinase ChiIII by 105.0%, and among the released reducing sugars the amount of (GlcNAc) 2 was increased by 149.5%, whereas the amount of GlcNAc was decreased by 10.3%. The percentage of GlcNAc in the products of chitin powder with the combined ChiIII and ChiEn1 was close to that in the products of chitin-oligosaccharides with ChiEn1, rather than that with ChiIII. These results indicate that chitin polymers are first degraded into chitin oligosaccharides by ChiIII and the latter are further degraded to monomers and dimers by ChiEn1, and the synergistic action of ChiEn1 and ChiIII is involved in the efficient degradation of chitin in cell walls during pileus autolysis. The structure modeling explores the molecular base of ChiEn1 action.

  11. Computation of the Percentage Points of the Chi-Square Distribution

    DTIC Science & Technology

    1977-04-01

    0D.4 ’ 2th cW%(F. ffA ’*. .0 Dp 46 v Ne #% N’ c %c 0% rmsn",0a0r fWN ..an W% *SA%0 0 9. M do Q at Ge .4.4 ~N P) ) AIII0 t- t.. 40 so(PO cC3.4..4 W N...0V %0, n:U ( bbP P xv 0-.V~ Pa bONP . CY R. .4 1 6 6 6. 6 6 6 6 6S * 6 6 6 6 6 6 6 6 6 6 6 6 6 . 6 . . 6 6 6 6 6 WS- mom4 .0f 0 M4SA on a~ 4tq .4~b M

  12. Prevalence of antibodies against avian influenza A (H5N1) virus among Cullers and poultry workers in Ho Chi Minh City, 2005.

    PubMed

    Schultsz, Constance; Nguyen, Van Dung; Hai, Le Thanh; Do, Quang Ha; Peiris, J S Malik; Lim, Wilina; Garcia, Jean-Michel; Nguyen, Dac Tho; Nguyen, Thi Hoang Lan; Huynh, Huu Tho; Phan, Xuan Thao; van Doorn, H Rogier; Nguyen, Van Vinh Chau; Farrar, Jeremy; de Jong, Menno D

    2009-11-23

    Between 2003 and 2005, highly pathogenic avian influenza A (H5N1) viruses caused large scale outbreaks in poultry in the Ho Chi Minh City area in Vietnam. We studied the prevalence of antibodies against H5N1 in poultry workers and cullers who were active in the program in Ho Chi Minh City in 2004 and 2005. Single sera from 500 poultry workers and poultry cullers exposed to infected birds were tested for antibodies to avian influenza H5N1, using microneutralization assays and hemagglutination inhibition assay with horse blood. All sera tested negative using microneutralization tests. Three samples showed a 1ratio80 titer in the hemagglutination inhibition assay. This study provides additional support for the low transmissibility of clade 1 H5N1 to humans, but limited transmission to highly exposed persons cannot be excluded given the presence of low antibody titers in some individuals.

  13. Comparison of the tuberculin skin test and the QuantiFERON-TB Gold test in detecting latent tuberculosis in health care workers in Iran

    PubMed Central

    2016-01-01

    OBJECTIVES: The tuberculin skin test (TST) and the QuantiFERON-TB Gold test (QFT) are used to identify latent tuberculosis infections (LTBIs). The aim of this study was to determine the agreement between these two tests among health care workers in Iran. METHODS: This cross-sectional study included 177 tuberculosis (TB) laboratory staff and 67 non-TB staff. TST indurations of 10 mm or more were considered positive. The Student’s t-test and the chi-square test were used to compare the mean score and proportion of variables between the TB laboratory staff and the non-TB laboratory staff. Kappa statistics were used to evaluate the agreement between these tests, and logistic regression was used to assess the risk factors associated with positive results for each test. RESULTS: The prevalence of LTBIs according to both the QFT and the TST was 17% (95% confidence interval [CI], 12% to 21%) and 16% (95% CI, 11% to 21%), respectively. The agreement between the QFT and the TST was 77.46%, with a kappa of 0.19 (95% CI, 0.04 to 0.34). CONCLUSIONS: Although the prevalence of LTBI based on the QFT and the TST was not significantly different, the kappa statistic was low between these two tests for the detection of LTBIs. PMID:27457062

  14. Characteristics of Muti-pulsing CHI driven ST plasmas on HIST

    NASA Astrophysics Data System (ADS)

    Ishihara, M.; Hanao, T.; Ito, K.; Matsumoto, K.; Higashi, T.; Kikuchi, Y.; Fukumoto, N.; Nagata, M.

    2011-10-01

    The flux amplification and sustainment of the ST configurations by operating in Multi-pulsing Coaxial Helicity Injection (M-CHI) method have been demonstrated on HIST. The multi-pulsing experiment was demonstrated in the SSPX spheromak device at LLNL. In the double pulsing discharges, we have observed that the plasma current has been sustained much longer against the resistive decay as compared to the single CHI. We have measured the radial profiles of the flow velocities by using Ion Doppler Spectrometer and Mach probes. The result shows that poloidal shear flow exists between the open flux column and the most outer closed flux surface. The poloidal velocity shear at the interface may be caused by the ion diamagnetic drift, because of a steep density gradient there. The radial electric field is determined by the flow velocities and the ion pressure gradient through the radial momentum balance equation. We have investigated the contribution of ExB or the ion pressure gradient on the poloidal velocity shear by comparing the impurity ion flow obtained from the IDS with the bulk ion flow from the Mach probe. It should be noted that the diamagnetic drift velocity of the impurity is much smaller than ExB drift velocity. We will discuss characteristics of M-CHI-driven ST plasmas by varying TF coil current and the line averaged electron density.

  15. The Versatile Magic Square.

    ERIC Educational Resources Information Center

    Watson, Gale A.

    2003-01-01

    Demonstrates the transformations that are possible to construct a variety of magic squares, including modifications to challenge students from elementary grades through algebra. Presents an example of using magic squares with students who have special needs. (YDS)

  16. The influence of tai chi and yoga on balance and falls in a residential care setting: A randomised controlled trial.

    PubMed

    Saravanakumar, Padmapriya; Higgins, Isabel Johanna; van der Riet, Pamela Jane; Marquez, Jodie; Sibbritt, David

    2014-01-01

    Abstract Falls amongst older people is a global public health concern. Whilst falling is not a typical feature of ageing, older people are more likely to fall. Fall injuries amongst older people are a leading cause of death and disability. Many older people do not do regular exercise so that they lose muscle tone, strength, and flexibility which affect balance and predispose them to falls. The management of falls in residential care settings is a major concern with strategies for prevention and monitoring a focus in this setting. Yoga and tai chi have shown potential to improve balance and prevent falls in older adults. They also have potential to improve pain and quality of life. The aim of this study was to determine the feasibility of conducting a three-arm randomised controlled trial (RCT) with frail older people in a residential care setting to test the hypothesis that a 14-week modified tai chi or yoga programme is more effective than usual care activity in improving balance function, quality of life, pain experience and in reducing number of falls. There were no statistically significant differences between the three groups in the occurrence of falls. Yoga demonstrated a slight decrease in fall incidence; quality of life improved for the tai chi group. Only the yoga group experienced a reduction in average pain scores though not statistically significant. The findings of the study suggest it is possible to safely implement modified yoga and tai chi in a residential care setting and evaluate this using RCT design. They show positive changes to balance, pain and quality of life and a high level of interest through attendance amongst the older participants. The results support offering tai chi and yoga to older people who are frail and dependent with physical and cognitive limitations.

  17. Evidence of CCR2-independent transmigration of Ly6C(hi) monocytes into the brain after permanent cerebral ischemia in mice.

    PubMed

    Chu, Hannah X; Kim, Hyun Ah; Lee, Seyoung; Broughton, Brad R S; Drummond, Grant R; Sobey, Christopher G

    2016-04-15

    Previously we showed that INCB3344, a CCR2 antagonist, inhibits transmigration of Ly6C(hi) monocytes into the brain after ischemia-reperfusion. Here we tested the effect of CCR2 inhibition during permanent cerebral ischemia. Mice were administered either vehicle (dimethyl sulfoxide/carboxymethylcellulose) or INCB3344 (30 or 100mg/kg IP) 1h before middle cerebral artery occlusion and at 2 and 6h after the initiation of ischemia. After 24h, we assessed functional outcome, infarct volume and quantified immune cells in blood and brain. The increase in circulating bone marrow-derived Ly6C(hi) monocytes, but not the infiltration of those cells into the brain, was blocked by the CCR2 antagonist. INCB3344 had no effect on either neurological deficit or infarct volume. Our data confirm that cerebral ischemia triggers a CCR2-dependent increase in circulating Ly6C(hi) monocytes, but suggest that in the absence of reperfusion these cells may transmigrate into the ischemic brain in a CCR2-independent manner. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. An Evaluation of Statistical Strategies for Making Equating Function Selections. Research Report. ETS RR-08-60

    ERIC Educational Resources Information Center

    Moses, Tim

    2008-01-01

    Nine statistical strategies for selecting equating functions in an equivalent groups design were evaluated. The strategies of interest were likelihood ratio chi-square tests, regression tests, Kolmogorov-Smirnov tests, and significance tests for equated score differences. The most accurate strategies in the study were the likelihood ratio tests…

  19. Modeling and control of non-square MIMO system using relay feedback.

    PubMed

    Kalpana, D; Thyagarajan, T; Gokulraj, N

    2015-11-01

    This paper proposes a systematic approach for the modeling and control of non-square MIMO systems in time domain using relay feedback. Conventionally, modeling, selection of the control configuration and controller design of non-square MIMO systems are performed using input/output information of direct loop, while the output of undesired responses that bears valuable information on interaction among the loops are not considered. However, in this paper, the undesired response obtained from relay feedback test is also taken into consideration to extract the information about the interaction between the loops. The studies are performed on an Air Path Scheme of Turbocharged Diesel Engine (APSTDE) model, which is a typical non-square MIMO system, with input and output variables being 3 and 2 respectively. From the relay test response, the generalized analytical expressions are derived and these analytical expressions are used to estimate unknown system parameters and also to evaluate interaction measures. The interaction is analyzed by using Block Relative Gain (BRG) method. The model thus identified is later used to design appropriate controller to carry out closed loop studies. Closed loop simulation studies were performed for both servo and regulatory operations. Integral of Squared Error (ISE) performance criterion is employed to quantitatively evaluate performance of the proposed scheme. The usefulness of the proposed method is demonstrated on a lab-scale Two-Tank Cylindrical Interacting System (TTCIS), which is configured as a non-square system. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  20. [Hospitalization period and nutritional status in hospitalized patients].

    PubMed

    Merhi, V A Leandro; de Oliveira, Ma R Marques; Caran, A L; Tristão, T Menuzzo Graupner; Ambo, R Miante; Tanner, M A; Vergna, C Marton

    2007-01-01

    With the objective of studying the nutritional status and its relationship with hospitalization period, a cross-sectional study was done with patients from a private hospital representing a population with a better socioeconomic condition. The anthropometric data of 267 patients, 46% males and 54% females ranging from 20 to 80 years of age, were assessed on the second day of hospitalization. Hospitalization period associated with nutritional status. The data were analyzed by the software Excel and Sigma Stat, using Fisher's exact test and the chi-square test. The studied population presented a body mass index of 25.9 +/- 5.3 and most patients lost weight during hospitalization. The longest hospitalization periods were found among patients with lung diseases (13 days), some being pre-obese (40%) with a small prevalence of undernutrition (4%). The percentage distribution of nutritional status among the groups according to diagnosis was different (P < 0.01) when assessed by the Fisher's exact test and the percentage distribution in weight variation between men and women was different (P < 0.02) when assessed by the chi-square test. When the population was segmented according to age, the percentage distribution of the nutritional status between > 60 and < or = 60 did not present a difference when assessed by the chi-square test. The results of this study show that the nutritional status in some diseases deserves special attention given the greater risk found in these situations, contributing to a longer hospitalization period.

  1. Tai Chi Chuan and Baduanjin Increase Grey Matter Volume in Older Adults: A Brain Imaging Study.

    PubMed

    Tao, Jing; Liu, Jiao; Liu, Weilin; Huang, Jia; Xue, Xiehua; Chen, Xiangli; Wu, Jinsong; Zheng, Guohua; Chen, Bai; Li, Ming; Sun, Sharon; Jorgenson, Kristen; Lang, Courtney; Hu, Kun; Chen, Shanjia; Chen, Lidian; Kong, Jian

    2017-01-01

    The aim of this study is to investigate and compare how 12-weeks of Tai Chi Chuan and Baduanjin exercise can modulate brain structure and memory function in older adults. Magnetic resonance imaging and memory function measurements (Wechsler Memory Scale-Chinese revised, WMS-CR) were applied at both the beginning and end of the study. Results showed that both Tai Chi Chuan and Baduanjin could significantly increase grey matter volume (GMV) in the insula, medial temporal lobe, and putamen after 12-weeks of exercise. No significant differences were observed in GMV between the Tai Chi Chuan and Baduanjin groups. We also found that compared to healthy controls, Tai Chi Chuan and Baduanjin significantly improved visual reproduction subscores on the WMS-CR. Baduanjin also improved mental control, recognition, touch, and comprehension memory subscores of the WMS-CR compared to the control group. Memory quotient and visual reproduction subscores were both associated with GMV increases in the putamen and hippocampus. Our results demonstrate the potential of Tai Chi Chuan and Baduanjin exercise for the prevention of memory deficits in older adults.

  2. On estimating gravity anomalies: A comparison of least squares collocation with least squares techniques

    NASA Technical Reports Server (NTRS)

    Argentiero, P.; Lowrey, B.

    1976-01-01

    The least squares collocation algorithm for estimating gravity anomalies from geodetic data is shown to be an application of the well known regression equations which provide the mean and covariance of a random vector (gravity anomalies) given a realization of a correlated random vector (geodetic data). It is also shown that the collocation solution for gravity anomalies is equivalent to the conventional least-squares-Stokes' function solution when the conventional solution utilizes properly weighted zero a priori estimates. The mathematical and physical assumptions underlying the least squares collocation estimator are described, and its numerical properties are compared with the numerical properties of the conventional least squares estimator.

  3. Seated Tai Chi to alleviate pain and improve quality of life in individuals with spinal cord disorder

    PubMed Central

    Karasik, Darlene; Carufel, Paul; Kao, Ming-Chih; Zheng, Patricia

    2016-01-01

    Context Previous research studies have confirmed therapeutic physical and psychological benefits of Tai Chi for both the able-bodied and disabled populations. However, given the limited availability of seated Tai Chi, there have not been any studies to date that have examined the effectiveness of seated Tai Chi in individuals with spinal cord disorder (SCD). We designed a customized seated Tai Chi program to meet the need for improved exercise options for individuals with SCD. Findings Twenty-six participants were enrolled in a 12-week seated Tai Chi course consisting of weekly sessions. After each Tai Chi session, patients reported improved visual analog scale (VAS) monitoring pain (P) (3.18 v 2.93; P 1.63E-03), emotional sense of well-being (EWB) (2.61 vs 2.04; P 2.86E-07), mental distraction (MD) (3.13 v 2.29; P 9.36E-08), physical sense of well-being (PWB) (2.84 v 2.25; p 7.38E-08), and sense of spiritual connection (SC) (3.28 v 2.50; P 6.46E-08). In our limited follow-up of 9 participants who completed half of the sessions and the long term surveys after the 12-week course, there were no detectable differences in weekly P, EWB, MD, PWB, and SC before each session. Conclusion and Clinical Relevance Individuals with SCD demonstrated benefits in pain, emotional sense of well-being, mental distraction, physical sense of well-being, and sense of spiritual connection immediately after seated Tai Chi exercise sessions in our pilot study. More research in a larger population would be needed to study the long-term impact of seated Tai Chi. PMID:26914968

  4. China's Chemical Information Online Service: ChI2Net.

    ERIC Educational Resources Information Center

    Naiyan, Yu; And Others

    1997-01-01

    Describes the Chemical Integrated Information Service Network (ChI2Net), a comprehensive online information service system which includes chemical, technical, economic, market, news, and management information based on computer and modern communication technology that was built by the China National Chemical Information Centre. (Author/LRW)

  5. To Your Health: NLM update transcript - Fibromyalgia and tai chi

    MedlinePlus

    ... for 24 weeks - or six months, reported more comparative benefits than peers who left the exercise program ... and fitness. While some previous studies suggested a comparative benefit of tai chi for fibromyalgia patients, the ...

  6. Changes of heart rate variability and prefrontal oxygenation during Tai Chi practice versus arm ergometer cycling.

    PubMed

    Lu, Xi; Hui-Chan, Christina Wan-Ying; Tsang, William Wai-Nam

    2016-11-01

    [Purpose] Exercise has been shown to improve cardiovascular fitness and cognitive function. Whether the inclusion of mind over exercise would increase parasympathetic control of the heart and brain activities more than general exercise at a similar intensity is not known. The aim of this study was to compare the effects of Tai Chi (mind-body exercise) versus arm ergometer cycling (body-focused exercise) on the heart rate variability and prefrontal oxygenation level. [Subjects and Methods] A Tai Chi master was invited to perform Tai Chi and arm ergometer cycling with similar exercise intensity on two separate days. Heart rate variability and prefrontal oxyhemoglobin levels were measured continuously by a RR recorder and near-infrared spectroscopy, respectively. [Results] During Tai Chi exercise, spectral analysis of heart rate variability demonstrated a higher high-frequency power as well as a lower low-frequency/high-frequency ratio than during ergometer cycling, suggesting increased parasympathetic and decreased sympathetic control of the heart. Also, prefrontal oxyhemoglobin and total hemoglobin levels were higher than those during arm ergometer exercise. [Conclusion] These findings suggest that increased parasympathetic control of the heart and prefrontal activities may be associated with Tai Chi practice. Having a "mind" component in Tai Chi could be more beneficial for older adults' cardiac health and cognitive function than body-focused ergometer cycling.

  7. Hadronic decays of the X(3872) to {chi}{sub cJ} in effective field theory

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Fleming, Sean; Mehen, Thomas

    2008-11-01

    The decays of the X(3872) to P-wave quarkonia are calculated under the assumption that it is a shallow bound state of neutral charmed mesons. The X(3872) is described using an effective theory of nonrelativistic D mesons and pions (X-EFT). We calculate X(3872) decays by first matching heavy hadron chiral perturbation theory (HH{chi}PT) amplitudes for D{sup 0}D*{sup 0}{yields}{chi}{sub cJ}({pi}{sup 0},{pi}{pi}) onto local operators in X-EFT, and then using these operators to calculate the X(3872) decays. This procedure reproduces the factorization theorems for X(3872) decays to conventional quarkonia previously derived using the operator product expansion. For single pion decays, we find nontrivialmore » dependence on the pion energy from HH{chi}PT diagrams with virtual D mesons. This nontrivial energy dependence can potentially modify heavy-quark symmetry predictions for the relative sizes of decay rates. At leading order, decays to final states with two pions are dominated by the final state {chi}{sub c1}{pi}{sup 0}{pi}{sup 0}, with a branching fraction just below that for the decay to {chi}{sub c1}{pi}{sup 0}. Decays to all other final states with two pions are highly suppressed.« less

  8. Measurements of Doppler-ion temperature and flow in the multi-pulsing CHI experiment on HIST

    NASA Astrophysics Data System (ADS)

    Hanao, T.; Ishihara, M.; Hirono, H.; Hyobu, T.; Ito, K.; Matsumoto, K.; Nakayama, T.; Kikuchi, Y.; Fukumoto, N.; Nagata, M.

    2012-10-01

    The steady-state current sustainment of spherical torus (ST) configurations is expected to be achieved by Multi-pulsing Coaxial Helicity Injection (M-CHI) method. In the double-pulsing discharges, the plasma current can be sustained much longer against the resistive decay compared to the single CHI. The M-CHI has capabilities as a static ion heating method. Ion Doppler Spectrometer (IDS) measurements confirmed a significant increase in the ion temperature after the second CHI pulse. The ion heating mechanism is an important issue to be explored in the M-CHI experiments. It is considered due to the magnetic reconnection process of plasmoids and/or the damping of the Alfven wave. The ion heating becomes suppressed around the separatrix layer in the high field side where the amplitude of the magnetic fluctuations is minimized due to the poloidal flow shear. The shear flow generation is caused by ExB drift and ion diamagnetic drift. The contribution from the diamagnetic drift on the shear flow can be evaluated by measuring the flow velocity of hydrogen and impurity ions by using Mach probe and IDS. We will discuss the dependence of the ion heating characteristics on the variation of the density gradient by varying TF coil current.

  9. Tai Chi for osteopenic women: design and rationale of a pragmatic randomized controlled trial

    PubMed Central

    2010-01-01

    Background Post-menopausal osteopenic women are at increased risk for skeletal fractures. Current osteopenia treatment guidelines include exercise, however, optimal exercise regimens for attenuating bone mineral density (BMD) loss, or for addressing other fracture-related risk factors (e.g. poor balance, decreased muscle strength) are not well-defined. Tai Chi is an increasingly popular weight bearing mind-body exercise that has been reported to positively impact BMD dynamics and improve postural control, however, current evidence is inconclusive. This study will determine the effectiveness of Tai Chi in reducing rates of bone turnover in post-menopausal osteopenic women, compared with standard care, and will preliminarily explore biomechanical processes that might inform how Tai Chi impacts BMD and associated fracture risks. Methods/Design A total of 86 post-menopausal women, aged 45-70y, T-score of the hip and/or spine -1.0 and -2.5, have been recruited from primary care clinics of a large healthcare system based in Boston. They have been randomized to a group-based 9-month Tai Chi program plus standard care or to standard care only. A unique aspect of this trial is its pragmatic design, which allows participants randomized to Tai Chi to choose from a pre-screened list of community-based Tai Chi programs. Interviewers masked to participants' treatment group assess outcomes at baseline and 3 and 9 months after randomization. Primary outcomes are serum markers of bone resorption (C-terminal cross linking telopeptide of type I collagen), bone formation (osteocalcin), and BMD of the lumbar spine and proximal femur (dual-energy X-ray absorptiometry). Secondary outcomes include health-related quality-of-life, exercise behavior, and psychological well-being. In addition, kinetic and kinematic characterization of gait, standing, and rising from a chair are assessed in subset of participants (n = 16) to explore the feasibility of modeling skeletal mechanical loads and

  10. Covariance Structure Model Fit Testing under Missing Data: An Application of the Supplemented EM Algorithm

    ERIC Educational Resources Information Center

    Cai, Li; Lee, Taehun

    2009-01-01

    We apply the Supplemented EM algorithm (Meng & Rubin, 1991) to address a chronic problem with the "two-stage" fitting of covariance structure models in the presence of ignorable missing data: the lack of an asymptotically chi-square distributed goodness-of-fit statistic. We show that the Supplemented EM algorithm provides a…

  11. Residuals and the Residual-Based Statistic for Testing Goodness of Fit of Structural Equation Models

    ERIC Educational Resources Information Center

    Foldnes, Njal; Foss, Tron; Olsson, Ulf Henning

    2012-01-01

    The residuals obtained from fitting a structural equation model are crucial ingredients in obtaining chi-square goodness-of-fit statistics for the model. The authors present a didactic discussion of the residuals, obtaining a geometrical interpretation by recognizing the residuals as the result of oblique projections. This sheds light on the…

  12. A SIGNIFICANCE TEST FOR THE LASSO1

    PubMed Central

    Lockhart, Richard; Taylor, Jonathan; Tibshirani, Ryan J.; Tibshirani, Robert

    2014-01-01

    In the sparse linear regression setting, we consider testing the significance of the predictor variable that enters the current lasso model, in the sequence of models visited along the lasso solution path. We propose a simple test statistic based on lasso fitted values, called the covariance test statistic, and show that when the true model is linear, this statistic has an Exp(1) asymptotic distribution under the null hypothesis (the null being that all truly active variables are contained in the current lasso model). Our proof of this result for the special case of the first predictor to enter the model (i.e., testing for a single significant predictor variable against the global null) requires only weak assumptions on the predictor matrix X. On the other hand, our proof for a general step in the lasso path places further technical assumptions on X and the generative model, but still allows for the important high-dimensional case p > n, and does not necessarily require that the current lasso model achieves perfect recovery of the truly active variables. Of course, for testing the significance of an additional variable between two nested linear models, one typically uses the chi-squared test, comparing the drop in residual sum of squares (RSS) to a χ12 distribution. But when this additional variable is not fixed, and has been chosen adaptively or greedily, this test is no longer appropriate: adaptivity makes the drop in RSS stochastically much larger than χ12 under the null hypothesis. Our analysis explicitly accounts for adaptivity, as it must, since the lasso builds an adaptive sequence of linear models as the tuning parameter λ decreases. In this analysis, shrinkage plays a key role: though additional variables are chosen adaptively, the coefficients of lasso active variables are shrunken due to the l1 penalty. Therefore, the test statistic (which is based on lasso fitted values) is in a sense balanced by these two opposing properties—adaptivity and

  13. Perceptions of acceptable conducts by university students.

    PubMed

    Marques, Dora Nazaré; Macedo, António Filipe

    2016-01-01

    To determine perceptions of acceptable conducts amongst under and postgraduate optometry students and to compare them with students from other disciplines. Students (under/postgraduate) of optometry (n=156) and other courses (n=54) from University of Minho participated in a voluntary online questionnaire about perception of conducts, classifying as acceptable or unacceptable 15 academic or professional scenarios. 210 questionnaires were analyzed. Differences in perceptions were found between optometry under and postgraduates in scenario 5, Chi-square(2,156)=4.3, p=0.038, and scenario 7, Chi-square(2,156)=7.0, p=0.008 (both with cheating more acceptable for postgrads). Differences between under and postgraduates from other courses were found in scenario 9 (taking supplies from classroom more acceptable for undergrads), Chi-square(1,54)=5.0, p=0.025, and scenario 14 (forging a signature more acceptable for postgrads), Chi-square(1,54)=3.9, p=0.046. Differences between optometry and other courses undergraduates were observed in scenario 2 (plagiarism more acceptable for optometry undergrads), Chi-square(1,154)=8.3, p=0.004 and scenario 9 (taking supplies from classroom more acceptable for other undergrads), chi-square(1,54)=7.8, p=0.005. Differences between optometry and other courses postgraduates were observed in scenario 7, Chi-square(1,56)=5.8, p=0.016, scenario 10 (both with cheating more acceptable for optometry postgrads), chi-square(1,54)=8.1, p=0.004 and scenario 14 (forging a signature more acceptable for other postgrads), Chi-square(1,54)=6.1, p=0.026. Academic misconducts were mainly considered more acceptable than professional misconducts. Our results show that perceptions of acceptable conducts amongst optometry students are not very different from other students, and, against our initial prediction, do not show a general change in misconduct perception when students become more mature. Universities should pay more attention to this problem and take

  14. AKLSQF - LEAST SQUARES CURVE FITTING

    NASA Technical Reports Server (NTRS)

    Kantak, A. V.

    1994-01-01

    The Least Squares Curve Fitting program, AKLSQF, computes the polynomial which will least square fit uniformly spaced data easily and efficiently. The program allows the user to specify the tolerable least squares error in the fitting or allows the user to specify the polynomial degree. In both cases AKLSQF returns the polynomial and the actual least squares fit error incurred in the operation. The data may be supplied to the routine either by direct keyboard entry or via a file. AKLSQF produces the least squares polynomial in two steps. First, the data points are least squares fitted using the orthogonal factorial polynomials. The result is then reduced to a regular polynomial using Sterling numbers of the first kind. If an error tolerance is specified, the program starts with a polynomial of degree 1 and computes the least squares fit error. The degree of the polynomial used for fitting is then increased successively until the error criterion specified by the user is met. At every step the polynomial as well as the least squares fitting error is printed to the screen. In general, the program can produce a curve fitting up to a 100 degree polynomial. All computations in the program are carried out under Double Precision format for real numbers and under long integer format for integers to provide the maximum accuracy possible. AKLSQF was written for an IBM PC X/AT or compatible using Microsoft's Quick Basic compiler. It has been implemented under DOS 3.2.1 using 23K of RAM. AKLSQF was developed in 1989.

  15. Applications of square-related theorems

    NASA Astrophysics Data System (ADS)

    Srinivasan, V. K.

    2014-04-01

    The square centre of a given square is the point of intersection of its two diagonals. When two squares of different side lengths share the same square centre, there are in general four diagonals that go through the same square centre. The Two Squares Theorem developed in this paper summarizes some nice theoretical conclusions that can be obtained when two squares of different side lengths share the same square centre. These results provide the theoretical basis for two of the constructions given in the book of H.S. Hall and F.H. Stevens , 'A Shorter School Geometry, Part 1, Metric Edition'. In page 134 of this book, the authors present, in exercise 4, a practical construction which leads to a verification of the Pythagorean theorem. Subsequently in Theorems 29 and 30, the authors present the standard proofs of the Pythagorean theorem and its converse. In page 140, the authors present, in exercise 15, what amounts to a geometric construction, whose verification involves a simple algebraic identity. Both the constructions are of great importance and can be replicated by using the standard equipment provided in a 'geometry toolbox' carried by students in high schools. The author hopes that the results proved in this paper, in conjunction with the two constructions from the above-mentioned book, would provide high school students an appreciation of the celebrated theorem of Pythagoras. The diagrams that accompany this document are based on the free software GeoGebra. The author formally acknowledges his indebtedness to the creators of this free software at the end of this document.

  16. Feasibility, stability and validity of the four square step test in typically developed children and children with brain damage.

    PubMed

    Leizerowitz, Gil; Katz-Leurer, Michal

    2017-01-01

    To assess feasibility, test-retest reliability and validity of the Four Square Step Test (FSST) in typically developed children (TD), and children with cerebral palsy (CP) and acquired brain injury (ABI). 30 TD children, 20 with CP and 12 with ABI participated in the study. The FSST while sitting and standing, the Timed Up and Go (TUG) and the balance subtest of the Bruininks-Oseretsky Test (BOT-2) were assessed. Each child attempted the FSST twice within 1 week. The scores for the FSST were assigned according to the original test: two successes in four trials, and according to a more lenient test, one success in four trials. The original form of the FSST is not feasible for children with CP or ABI. In TD children the lenient version is feasible (93%) and has moderate stability (Interclass correlation, ICC = 0.723), with a significant, positive correlation with the TUG (r s = 0.56). In children with CP the lenient test is feasible (80%), stable (r s = 0.83) and negatively correlates with the BOT-2 (r s =-0.69). In children with ABI the test is less feasible (67%) and neither stable nor valid. The lenient form of the FSST is feasible, reliable and valid in TD children and children with CP.

  17. Is Pregnancy Associated with Severe Dengue? A Review of Data from the Rio de Janeiro Surveillance Information System

    PubMed Central

    Machado, Carolina Romero; Machado, Elizabeth Stankiewicz; Rohloff, Roger Denis; Azevedo, Marina; Campos, Dayse Pereira; de Oliveira, Robson Bruniera; Brasil, Patrícia

    2013-01-01

    Background Dengue is a reportable disease in Brazil; however, pregnancy has been included in the application form of the Brazilian notification information system only after 2006. To estimate the severity of maternal dengue infection, the available data that were compiled from January 2007 to December 2008 by the official surveillance information system of the city of Rio de Janeiro were reviewed. Methods and Principal Findings During the study period, 151,604 cases of suspected dengue infection were reported. Five hundred sixty-one women in their reproductive age (15–49 years) presented with dengue infection; 99 (18.1%) pregnant and 447 (81.9%) non-pregnant women were analyzed. Dengue cases were categorized using the 1997 WHO classification system, and DHF/DSS were considered severe disease. The Mann-Whitney test was used to compare maternal age, according to gestational period, and severity of disease. A chi-square test was utilized to evaluate the differences in the proportion of dengue severity between pregnant and non-pregnant women. Univariate analysis was performed to compare outcome variables (severe dengue and non-severe dengue) and explanatory variables (pregnancy, gestational age and trimester) using the Wald test. A multivariate analysis was performed to assess the independence of statistically significant variables in the univariate analysis. A p-value<0.05 was considered statistically significant. A higher percentage of severe dengue infection among pregnant women was found, p = 0.0001. Final analysis demonstrated that pregnant women are 3.4 times more prone to developing severe dengue (OR: 3.38; CI: 2.10–5.42). Mortality among pregnant women was superior to non-pregnant women. Conclusion Pregnant women have an increased risk of developing severe dengue infection and dying of dengue. PMID:23675548

  18. Experimental Study on 3D Chi - Hap Scaffolds for Thyroid Cartilage Repairing

    NASA Astrophysics Data System (ADS)

    Sun, Nannan; Shi, Tingchun; Fan, Yuan; Hu, Binbin

    2018-01-01

    Due to the limitation of self-repairing capability for cartilage injury, the construction of tissue engineering in vitro has been an ideal treatment to repair tissue injury. In this paper, hydroxyapatite (Hap) and chitosan (Chi) were selected to fabricate the scaffold through low temperature deposition manufacturing (LDM) technique. The scaffold was characterized with interconnected structure and high porosity, as well as lower toxicity to cells (TDC-5-EGPE). Animal experiment was performed, Twelve white New Zealand rabbits were randomly divided into two groups, the side of the thyroid cartilage was removed, Chi-HAP composite scaffold was implanted into the cartilage defect as the experimental group A. Group B was treated for thyroid cartilage defects without any treatment. After 10 weeks, hematoxylin-eosin (HE) staining and S-O staining were carried out on the injured tissues. The result showed that newborn chondrocytes were found in repaired areas for group A, and there are no new cells found for group B. Therefore, Chi-HAP composite scaffolds formed by LDM possess biological activity for repairing injury cartilage.

  19. Anomalous Streamflow and Groundwater-Level Changes Before the 1999 M7.6 Chi-Chi Earthquake in Taiwan: Possible Mechanisms

    NASA Astrophysics Data System (ADS)

    King, Chi-Yu; Chia, Yeeping

    2017-12-01

    Streamflow recorded by a stream gauge located 4 km from the epicenter of the 1999 M7.6 Chi-Chi earthquake in central Taiwan showed a large and rapid anomalous increase of 124 m3/s starting 4 days before the earthquake. This increase was followed by a comparable co-seismic drop to below the background level for 8 months. In addition, groundwater-levels recorded at a well 1.5 km east of the seismogenic fault showed an anomalous rise 2 days before the earthquake, and then a unique 4-cm drop beginning 3 h before the earthquake. The anomalous streamflow increase is attributed to gravity-driven groundwater discharge into the creek through the openings of existing fractures in the steep creek banks crossed by the upstream Shueilikun fault zone, as a result of pre-earthquake crustal buckling. The continued tectonic movement and buckling, together with the downward flow of water in the crust, may have triggered the occurrence of some shallow slow-slip events in the Shueilikun and other nearby fault zones. When these events propagate down-dip to decollement, where the faults merges with the seismogenic Chelungpu fault, they may have triggered other slow-slip events propagating toward the asperity at the hypocenter and the Chelungpu fault. These events may then have caused the observed groundwater-level anomaly and helped to trigger the earthquake.

  20. Magnetism of toroidal field in two-fluid equilibrium of CHI driven spherical torus

    NASA Astrophysics Data System (ADS)

    Kanki, T.; Nagata, M.

    2016-10-01

    Double-pulsing CHI (D-CHI) experiment has been conducted in the HIST device to achieve a quasi-steady sustainment and good confinement of spherical torus (ST) plasmas. The feature of CHI driven ST such as diamagnetic toroidal field in the central open flux column (OFC) region and strong poloidal flow shear around the separatrix in the high field side suggests the two-fluid effect. The relationship between the magnetism of the toroidal field and the poloidal flow velocity is investigated by modelling the D-CHI (mainly driving the poloidal electron flow along the open flux) in the two-fluid equilibrium calculations. The poloidal component of Ampere's law leads that the toroidal field is related to the difference between the stream functions of ion ψi and electron ψe for the poloidal flow, indicating that the toroidal field with ψe >ψi results in a diamagnetic profile, while that with ψe <ψi results in a paramagnetic one. The gradient of the stream function determines the polarity and the strength of the poloidal flow velocity. It is found that the two-fluid equilibrium of CHI driven ST satisfies ψe > 0 and ψi < 0 in the OFC region, and ψe < 0 and ψi < 0 in the closed flux region. The toroidal field is a diamagnetic profile in the OFC region due to ψe >ψi and |uez | > |uiz | , where uez and uiz denote the poloidal electron and ion flow velocities, respectively. It becomes from a diamagnetic to a paramagnetic profile in the closed flux region, because ψe (uez) approaches ψi (uiz) around the magnetic axis. The poloidal ion flow shear is enhanced in the OFC region due to the ion inertial effect through the toroidal ion flow velocity.

  1. Patient Engagement in Randomized Controlled Tai Chi Clinical Trials among the Chronically Ill.

    PubMed

    Jiang, Dongsheng; Kong, Weihong; Jiang, Joanna J

    2017-01-01

    Physicians encounter various symptom-based complaints each day. While physicians strive to support patients with chronic illnesses, evidence indicates that patients who are actively involved in their health care have better health outcomes and sometimes lowers costs. This article is to analyze how patient engagement is described when complex interventions such as Tai Chi were delivered in Randomized Controlled clinical Trials (RCTs). It reviews the dynamic patient- physician relationship in chronic illness management and to illustrate the patient engagement process, using Tai Chi as an example intervention. RCTs are considered the gold standard in clinical research. This study is a qualitative analysis of RCTs using Tai Chi as an intervention. A systematic literature search was performed to identify quality randomized controlled clinical trials that investigated the effects of Tai Chi. Selected clinical trials were classified according to research design, intervention style, patient engagement, and outcomes. Patient engagement was classified based on levels of patient participation, compliance, and selfmanagement. The chronic health conditions included in this paper are Parkinson's disease, polyneuropathy, hypertension, stroke, chronic insomnia, chronic heart failure, fibromyalgia, osteoarthritis, central obesity, depression, deconditioning in the elderly, or being pre-clinically disabled. We found that patient engagement, as a concept, was not well defined in literature. It covers a wide range of related terms, such as patient involvement, participation, shared decision- making, patient activation, adherence, compliance, and self-management. Tai Chi, as a very complex practice system, is to balance all aspects of a patient's life; however, the level of patient engagement is difficult to describe using conventional clinical trial design. To accurately illustrate the effect of a complex intervention, novel research design must explore ways to measure patient

  2. A New Class of Pandiagonal Squares

    ERIC Educational Resources Information Center

    Loly, P. D.; Steeds, M. J.

    2005-01-01

    An interesting class of purely pandiagonal, i.e. non-magic, whole number (integer) squares of orders (row/column dimension) of the powers of two which are related to Gray codes and square Karnaugh maps has been identified. Treated as matrices these squares possess just two non-zero eigenvalues. The construction of these squares has been automated…

  3. Contrasting Ohlsson's Resubsumption Theory with Chi's Categorical Shift Theory

    ERIC Educational Resources Information Center

    Chi, Michelene T. H.; Brem, Sarah K.

    2009-01-01

    Ohlsson's proposal of resubsumption as the dominant process in conceptual, or nonmonotonic, change presents a worthy challenge to more established theories, such as Chi's theory of ontological shift. The two approaches differ primarily in that Ohlsson's theory emphasizes a process of learning in which narrower, more specific concepts are subsumed…

  4. Tai Chi Chuan and Baduanjin increase grey matter volume in older adults: a brain imaging study

    PubMed Central

    Tao, Jing; Liu, Jiao; Liu, Weilin; Huang, Jia; Xue, Xiehua; Chen, Xiangli; Wu, Jinsong; Zheng, Guohua; Chen, Bai; Li, Ming; Sun, Sharon; Jorgenson, Kristen; Lang, Courtney; Hu, Kun; Chen, Shanjia; Chen, Lidian; Kong, Jian

    2017-01-01

    The aim of this study is to investigate and compare how 12-weeks of Tai Chi Chuan and Baduanjin exercise can modulate brain structure and memory function in older adults. Magnetic Resonance Imaging(MRI) and memory function measurements (Wechsler Memory Scale-Chinese revised, WMS-CR)were applied at both the beginning and end of the study. Results showed that both Tai Chi Chuan and Baduanjin could significantly increase grey matter volume (GMV) in the insula, medial temporal lobe (MTL), and putamen after 12-weeks of exercise. No significant differences were observed in grey matter volume (GMV) between the Tai Chi Chuan and Baduanjin groups. We also found that compared to healthy controls, Tai Chi Chuan and Baduanjin significantly improved visual reproduction subscores on the WMS-CR. Baduanjin also improved mental control, recognition, touch and comprehension memory subscores of the WMS-CR compared to the control group. Memory quotient (MQ)and visual reproduction subscores were both associated with GMV increases in the putamen and hippocampus. Our results demonstrate the potential of Tai Chi Chuan and Baduanjin exercise for the prevention of memory deficits in older adults. PMID:28869478

  5. The Square Kilometre Array

    NASA Technical Reports Server (NTRS)

    Huynh, Minh; Lazio, Joseph

    2011-01-01

    The Square Kilometre Array (SKA) will be the premier instrument to study radiation at centimetre and metre wavelengths from the cosmos, and in particular neutral hydrogen, the most abundant element in the universe. The SKA will probe the dawn of galaxy formation as well as allow advances in many other areas of astronomy, such as fundamental physics, astro-biology and cosmology. The SKA will have a collecting area of up to one million square metres spread over at least 3000 km, providing a collecting area more than twenty times greater than the current largest radio telescope. Its field of view on the sky will be several tens of square degrees with potentially several large (100 square degrees) independent beams at the lower frequencies, providing a survey speed many thousands of times greater than current facilities. This paper summarises the key science drivers of the SKA and provides an update on the international project.

  6. Green Space and Deaths Attributable to the Urban Heat Island Effect in Ho Chi Minh City.

    PubMed

    Dang, Tran Ngoc; Van, Doan Quang; Kusaka, Hiroyuki; Seposo, Xerxes T; Honda, Yasushi

    2018-04-01

    To quantify heat-related deaths in Ho Chi Minh City, Vietnam, caused by the urban heat island (UHI) and explore factors that may alleviate the impact of UHIs. We estimated district-specific meteorological conditions from 2010 to 2013 using the dynamic downscaling model and calculated the attributable fraction and number of mortalities resulting from the total, extreme, and mild heat in each district. The difference in attributable fraction of total heat between the central and outer districts was classified as the attributable fraction resulting from the UHI. The association among attributable fraction, attributable number with a green space, population density, and budget revenue of each district was then explored. The temperature-mortality relationship between the central and outer areas was almost identical. The attributable fraction resulting from the UHI was 0.42%, which was contributed by the difference in temperature distribution between the 2 areas. Every 1-square-kilometer increase in green space per 1000 people can prevent 7.4 deaths caused by heat. Green space can alleviate the impacts of UHIs, although future studies conducting a heath economic evaluation of tree planting are warranted.

  7. Green Space and Deaths Attributable to the Urban Heat Island Effect in Ho Chi Minh City

    PubMed Central

    Van, Doan Quang; Kusaka, Hiroyuki; Seposo, Xerxes T.; Honda, Yasushi

    2018-01-01

    Objectives. To quantify heat-related deaths in Ho Chi Minh City, Vietnam, caused by the urban heat island (UHI) and explore factors that may alleviate the impact of UHIs. Methods. We estimated district-specific meteorological conditions from 2010 to 2013 using the dynamic downscaling model and calculated the attributable fraction and number of mortalities resulting from the total, extreme, and mild heat in each district. The difference in attributable fraction of total heat between the central and outer districts was classified as the attributable fraction resulting from the UHI. The association among attributable fraction, attributable number with a green space, population density, and budget revenue of each district was then explored. Results. The temperature–mortality relationship between the central and outer areas was almost identical. The attributable fraction resulting from the UHI was 0.42%, which was contributed by the difference in temperature distribution between the 2 areas. Every 1-square-kilometer increase in green space per 1000 people can prevent 7.4 deaths caused by heat. Conclusions. Green space can alleviate the impacts of UHIs, although future studies conducting a heath economic evaluation of tree planting are warranted. PMID:29072938

  8. Development of the Modified Four Square Step Test and its reliability and validity in people with stroke.

    PubMed

    Roos, Margaret A; Reisman, Darcy S; Hicks, Gregory; Rose, William; Rudolph, Katherine S

    2016-01-01

    Adults with stroke have difficulty avoiding obstacles when walking, especially when a time constraint is imposed. The Four Square Step Test (FSST) evaluates dynamic balance by requiring individuals to step over canes in multiple directions while being timed, but many people with stroke are unable to complete it. The purposes of this study were to (1) modify the FSST by replacing the canes with tape so that more persons with stroke could successfully complete the test and (2) examine the reliability and validity of the modified version. Fifty-five subjects completed the Modified FSST (mFSST) by stepping over tape in all four directions while being timed. The mFSST resulted in significantly greater numbers of subjects completing the test than the FSST (39/55 [71%] and 33/55 [60%], respectively) (p < 0.04). The test-retest, intrarater, and interrater reliability of the mFSST were excellent (intraclass correlation coefficient ranges: 0.81-0.99). Construct and concurrent validity of the mFSST were also established. The minimal detectable change was 6.73 s. The mFSST, an ideal measure of dynamic balance, can identify progress in people with stroke in varied settings and can be completed by a wide range of people with stroke in approximately 5 min with the use of minimal equipment (tape, stop watch).

  9. Transformation of a metaphor: semantic shift in a Cantonese term 'Chi Sin' denoting insanity.

    PubMed

    Ng, J Y W; Chen, E Y H

    2015-03-01

    The historical evolution of the existing terms used to describe insanity may be able to shed light on the formation of stigma towards psychosis patients. In Hong Kong, a widely used Cantonese term for insanity 'Chi Sin' provides a unique example because of its neutral original sense, as it literally means misconnection in a network circuit. We attempt to trace the origin and subsequent evolution of the term 'Chi Sin' from its early use to the present day to understand how local Hong Kong people have attached increasingly negative connotations to this scientific term since the mid-20th century. We sampled as many newspapers and magazines published in Hong Kong from 1939 to June 2014 as possible, and sampled 7 popular local movies from the 1950s and 1960s. We also searched all the newspapers published in Hong Kong, Macau, Taiwan, and Mainland China from January 1998 to June 2014, and searched several other local historical resources. In one early use of 'Chi Sin' in 1939, the term was only used in a technical sense to describe 'short circuiting'. We found that the development of the telephone system, the Strowger system, in Hong Kong is closely related to the evolution of the semantics of the term 'Chi Sin'. The original meaning of short circuitry of the term 'Chi Sin' is no longer used, and it has become a dead metaphor through repeated use with negative emotional connotations. This illustrates some of the factors facilitating the emergence of a metaphor with subsequent semantic drift.

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

    ERIC Educational Resources Information Center

    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,…

  11. The effect of Tai Chi exercises on postural stability and control in older patients with knee osteoarthritis.

    PubMed

    Ghandali, Elham; Moghadam, Saeed Talebian; Hadian, Mohammad Reza; Olyaei, Gholamreza; Jalaie, Shohreh; Sajjadi, Elaheh

    2017-07-01

    A few studies have examined the effect of Tai Chi on balance in elder patients with knee osteoarthritis (OA). The aim of this study was to determine the balance measures in elder patients with knee OA after Tai Chi exercises. For this purpose 14 females and 6 males with knee OA were chosen. Area and mean velocity of the center of pressure movements (CoP) were measured by force plate in standing positions (on foam and rigid surfaces). The measurements of area and mean velocity of CoP were performed before and after 60 min of Tai Chi sessions (twice a week for 8 weeks). The results showed that the area of CoP in standing position on rigid surface was significantly decreased (P < 0.01) after Tai Chi exercises. Furthermore, the mean velocity of CoP was significantly decreased after Tai Chi exercises on both rigid and foam surfaces (P < 0.001). Our study also indicated that changes in surfaces (rigid and foam) would cause significant differences regarding the area of CoP in standing positions. However, similar findings were not found regarding the mean velocity of CoP. Considering the effects of Tai Chi on mean velocity of CoP, it might be concluded that motor control and postural stability improvements have occurred. Therefore, based on these results, Tai Chi exercises could be recommended for elder patients with knee OA as part of their rehabilitation and physical therapy protocols. Copyright © 2016. Published by Elsevier Ltd.

  12. Environmental justice assessment for transportation : risk analysis

    DOT National Transportation Integrated Search

    1999-04-01

    This paper presents methods of comparing populations and their racial/ethnic compositions using tabulations, histograms, and Chi Squared tests for statistical significance of differences found. Two examples of these methods are presented: comparison ...

  13. Effectiveness of the U.S. National HIV Testing Day Campaigns in Promoting HIV Testing: Evidence from CDC-Funded HIV Testing Sites, 2010

    PubMed Central

    Mulatu, Mesfin S.

    2014-01-01

    Objectives We assessed if HIV testing and diagnoses increased during the week of National HIV Testing Day (NHTD) and if characteristics of people who were tested varied compared with control weeks. Methods We analyzed HIV testing data from the 2010 National HIV Prevention Program Monitoring and Evaluation system to compare NHTD week (June 24–30, 2010) with two control weeks (January 7–13, 2010, and August 12–18, 2010) for the number of HIV testing events and new HIV-positive diagnoses, by demographics and other HIV-related variables. Characteristics associated with testing during NHTD week compared with control weeks were identified using Chi-square analyses. Results In 2010, an average of 15,000 more testing events were conducted and 100 more new HIV-positive diagnoses were identified during NHTD week than during the control weeks (p<0.001). Compared with control weeks, people tested during NHTD week were significantly less likely to be aged 20–29 years and non-Hispanic white and significantly more likely to be (1) aged ≥50 years, (2) non-Hispanic black or African American, (3) men who have sex with men, (4) low-risk heterosexuals, (5) tested with a rapid HIV test, or (6) tested in a non-health-care setting. Conclusion In 2010, CDC-funded HIV testing events and new HIV-positive diagnoses increased during NHTD week compared with control weeks. HIV testing programs increased the use of rapid tests and returned a high percentage of test results. NHTD campaigns reached populations disproportionately affected by HIV and further expanded testing to people traditionally less likely to be tested. Incorporating strategies used during NHTD in programs conducted throughout the year may assist in increasing HIV testing and the number of HIV-positive diagnoses. PMID:25177056

  14. Relationships between flow experience, IKIGAI, and sense of coherence in Tai chi practitioners.

    PubMed

    Iida, Kenji; Oguma, Yuko

    2013-01-01

    The purpose of this study was to examine the mental health effects of Tai chi on regular practitioners by investigating the relationships between flow experience, IKIGAI (Japanese: "Life worth living"), and sense of coherence. The results indicated that flow experience may influence IKIGAI and IKIGAI may influence sense of coherence; this suggests that IKIGAI may act as an intermediary between flow experience and sense of coherence. The results also indicated that the longer the Tai chi experience, the higher was the flow experience.

  15. JPRS Report, East Asia, Vietnam: TAP CHI CONG SAN, No. 10, October 1987

    DTIC Science & Technology

    1988-02-09

    Followers in the Countries of Latin America [ Tran Anh] 48 JPRS-ATC-88-002 9 February 1988 VIETNAM: TAP CHI CONG SAN No 10, October 1987 [Except...character is not simply an ideological-political category applied in literature. Our party, as Truong Chinh said at the Third National Literature and Art...Hanoi TAP CHI CONG SAN in Vietnamese No 10, Oct 87pp 39-42 [Article by Nguyen Dang Quang, assistant editor-in-chief of GIAO DUC LY LUAN Journal

  16. Multivariate normality

    NASA Technical Reports Server (NTRS)

    Crutcher, H. L.; Falls, L. W.

    1976-01-01

    Sets of experimentally determined or routinely observed data provide information about the past, present and, hopefully, future sets of similarly produced data. An infinite set of statistical models exists which may be used to describe the data sets. The normal distribution is one model. If it serves at all, it serves well. If a data set, or a transformation of the set, representative of a larger population can be described by the normal distribution, then valid statistical inferences can be drawn. There are several tests which may be applied to a data set to determine whether the univariate normal model adequately describes the set. The chi-square test based on Pearson's work in the late nineteenth and early twentieth centuries is often used. Like all tests, it has some weaknesses which are discussed in elementary texts. Extension of the chi-square test to the multivariate normal model is provided. Tables and graphs permit easier application of the test in the higher dimensions. Several examples, using recorded data, illustrate the procedures. Tests of maximum absolute differences, mean sum of squares of residuals, runs and changes of sign are included in these tests. Dimensions one through five with selected sample sizes 11 to 101 are used to illustrate the statistical tests developed.

  17. The Cannabis Withdrawal Scale development: patterns and predictors of cannabis withdrawal and distress.

    PubMed

    Allsop, David J; Norberg, Melissa M; Copeland, Jan; Fu, Shanlin; Budney, Alan J

    2011-12-01

    Rates of treatment seeking for cannabis are increasing, and relapse is common. Management of cannabis withdrawal is an important intervention point. No psychometrically sound measure for cannabis withdrawal exists, and as a result treatment developments cannot be optimally targeted. The aim is to develop and test the psychometrics of the Cannabis Withdrawal Scale and use it to explore predictors of cannabis withdrawal. A volunteer sample of 49 dependent cannabis users provided daily scores on the Cannabis Withdrawal Scale during a baseline week and 2 weeks of abstinence. Internal reliability (Cronbach's alpha=0.91), test-retest stability (average intra-class correlation=0.95) and content validity analysis show that the Cannabis Withdrawal Scale has excellent psychometric properties. Nightmares and/or strange dreams was the most valid item (Wald χ²=105.6, P<0.0001), but caused relatively little associated distress (Wald χ²=25.11, P=0.03). Angry outbursts were considered intense (Wald χ²=73.69, P<0.0001) and caused much associated distress (Wald χ²=45.54, P<0.0001). Trouble getting to sleep was also an intense withdrawal symptom (Wald χ²=42.31, P<0.0001) and caused significant associated distress (Wald χ²=47.76, P<0.0001). Scores on the Severity of Dependence Scale predicted cannabis withdrawal. The Cannabis Withdrawal Scale can be used as a diagnostic instrument in clinical and research settings where regular monitoring of withdrawal symptoms is required. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  18. XAFS study of copper(II) complexes with square planar and square pyramidal coordination geometries

    NASA Astrophysics Data System (ADS)

    Gaur, A.; Klysubun, W.; Nitin Nair, N.; Shrivastava, B. D.; Prasad, J.; Srivastava, K.

    2016-08-01

    X-ray absorption fine structure of six Cu(II) complexes, Cu2(Clna)4 2H2O (1), Cu2(ac)4 2H2O (2), Cu2(phac)4 (pyz) (3), Cu2(bpy)2(na)2 H2O (ClO4) (4), Cu2(teen)4(OH)2(ClO4)2 (5) and Cu2(tmen)4(OH)2(ClO4)2 (6) (where ac, phac, pyz, bpy, na, teen, tmen = acetate, phenyl acetate, pyrazole, bipyridine, nicotinic acid, tetraethyethylenediamine, tetramethylethylenediamine, respectively), which were supposed to have square pyramidal and square planar coordination geometries have been investigated. The differences observed in the X-ray absorption near edge structure (XANES) features of the standard compounds having four, five and six coordination geometry points towards presence of square planar and square pyramidal geometry around Cu centre in the studied complexes. The presence of intense pre-edge feature in the spectra of four complexes, 1-4, indicates square pyramidal coordination. Another important XANES feature, present in complexes 5 and 6, is prominent shoulder in the rising part of edge whose intensity decreases in the presence of axial ligands and thus indicates four coordination in these complexes. Ab initio calculations were carried out for square planar and square pyramidal Cu centres to observe the variation of 4p density of states in the presence and absence of axial ligands. To determine the number and distance of scattering atoms around Cu centre in the complexes, EXAFS analysis has been done using the paths obtained from Cu(II) oxide model and an axial Cu-O path from model of a square pyramidal complex. The results obtained from EXAFS analysis have been reported which confirmed the inference drawn from XANES features. Thus, it has been shown that these paths from model of a standard compound can be used to determine the structural parameters for complexes having unknown structure.

  19. First-Order System Least-Squares for Second-Order Elliptic Problems with Discontinuous Coefficients

    NASA Technical Reports Server (NTRS)

    Manteuffel, Thomas A.; McCormick, Stephen F.; Starke, Gerhard

    1996-01-01

    The first-order system least-squares methodology represents an alternative to standard mixed finite element methods. Among its advantages is the fact that the finite element spaces approximating the pressure and flux variables are not restricted by the inf-sup condition and that the least-squares functional itself serves as an appropriate error measure. This paper studies the first-order system least-squares approach for scalar second-order elliptic boundary value problems with discontinuous coefficients. Ellipticity of an appropriately scaled least-squares bilinear form of the size of the jumps in the coefficients leading to adequate finite element approximation results. The occurrence of singularities at interface corners and cross-points is discussed. and a weighted least-squares functional is introduced to handle such cases. Numerical experiments are presented for two test problems to illustrate the performance of this approach.

  20. Square tracking sensor for autonomous helicopter hover stabilization

    NASA Astrophysics Data System (ADS)

    Oertel, Carl-Henrik

    1995-06-01

    Sensors for synthetic vision are needed to extend the mission profiles of helicopters. A special task for various applications is the autonomous position hold of a helicopter above a ground fixed or moving target. As a proof of concept for a general synthetic vision solution a restricted machine vision system, which is capable of locating and tracking a special target, was developed by the Institute of Flight Mechanics of Deutsche Forschungsanstalt fur Luft- und Raumfahrt e.V. (i.e., German Aerospace Research Establishment). This sensor, which is specialized to detect and track a square, was integrated in the fly-by-wire helicopter ATTHeS (i.e., Advanced Technology Testing Helicopter System). An existing model following controller for the forward flight condition was adapted for the hover and low speed requirements of the flight vehicle. The special target, a black square with a length of one meter, was mounted on top of a car. Flight tests demonstrated the automatic stabilization of the helicopter above the moving car by synthetic vision.